1995.05.27 / Conrad / Re: The Farce of Physics Originally-From: conrad@skid.ps.uci.edu (Conrad) Newsgroups: alt.sci.physics.new-theories,sci.astro,sci.energy,sci.misc,s i.physics,sci.physics.electromag,sci.physics.fusion,sci.physics.particle sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 27 May 95 23:27:06 GMT Organization: University of California, Irvine wallaceb@news.IntNet.net (Bryan Wallace) writes: >General relativity has a good Newtonian limit for a single body! JPL >must use Newtonian Mechanics to calculate *real* orbits in the solar system! Neither statment is true. The Newtonian limit of GR has a much wider range of validity, see Frittelli & Reula, Commun. Math. Phys. 166:221 (1994); Misner, Thorne, and Wheeler; Weinberg; etc. In the "Explanatory Supplement to the Astronomical Almanac" edited by P. K. Seidelmann, chapter 5 is entitled "Orbital Ephemerides of the Sun, Moon, and Planets". The authors, E. M. Standish, X. X. Newhall, J. G. Williams, and D. K Yeomans, are from JPL. The first paragraph includes the following sentence. "The fundamental planetary and lunar ephemerides of `The Astronomical Almanac' are DE200/LE200, constructed at the Jet Propulsion Laboratory in 1980." Paragraph 2 of section 5.11 states, "Included in the equations of motion were the following (1) point-mass interactions among the Moon, planets, and Sun; (2) GENERAL RELATIVITY (isotropic, parametrized post-Newtonian), complete to order 1/c^2; (...)" -- //===============================\\ || Conrad, conrad@hepxvt.uci.edu || || You have to decide to live. || \\===============================// cudkeys: cuddy27 cudenconrad cudlnConrad cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.27 / jedrothwell@de / Re: Cravens pump power Originally-From: jedrothwell@delphi.com Newsgroups: sci.physics.fusion Subject: Re: Cravens pump power Date: Sat, 27 May 95 20:11:00 -0500 Organization: Delphi (info@delphi.com email, 800-695-4005 voice) Arnie Frisch writes: >Everything about this stuff seems to be "a little tricky". So there is >a built-in excuse for why I can't do what he does. > >Does astrology have anything to do with it? > >How about the phase of the moon? > >Arnold Frisch >Tektronix Laboratories So tell us, Arnold Frisch, does Tektronix make any complicated products? Do you people ever research or manufacture any product or machine that gives you trouble, or that does not work exactly the way you expect? Is it possible that every single project at Tektronix always goes exactly as planned, and you never experience any difficulty whatsoever in research, manufacturing, installation or customer support? If your job is so easy that nothing ever goes wrong, and nothing is ever "a little tricky" then I think I will get into your business. It must be so easy that a trained monkey could do it. For my part, I have never done anything that did not require hard work and hard thinking. Everything I have ever done has always called for learning tricks, for practice, for experience. Cold fusion is, of course, no different in that regard than anything else. It is a form of surface chemistry and it causes nuclear reactions. Anyone with any knowledge of physics or chemistry would know that something like that is bound to be complicated, with a long learning curve requiring a lot of knowledge and hard work to master. I don't what makes you and Dick Blue think it should be easy. Nothing else is. Nothing made by Tektronix is either. Heck, I have had one or two of your products screw up royally, for reasons nobody could figure out. (Although in general your products are excellent.) - Jed cudkeys: cuddy27 cudenjedrothwell cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Bill Snyder / Re: More insanity from Richard Blue Originally-From: bsnyder@iadfw.net (Bill Snyder) Newsgroups: sci.physics.fusion Subject: Re: More insanity from Richard Blue Date: 28 May 1995 01:01:02 GMT Organization: Internet America In article , Bill Rowe (browe@netcom.com) says... > >Jed Rothwell seems to agree with Dick Blues comments as follows. > >1) Craven's experiment is supposed to be a robust demo of CF >2) It requires an expert to get good results >3) There are unpublished details which are needed to get good results >4) No info is available re scaling or otherwise controling the output > This is pretty typical Rothwellspeak. The demo is robust -- *if* nobody is permitted to examine it too closely, for fear they should learn some of its deep, dark secrets. It is robust -- *if* any skeptic who reproduces it and gets different results can simply be written off as having insufficient expertise. Translating into standard English, the demo is robust enough to survive any challenge -- so long as nobody is permitted to challenge it. Sounds logical to me... -- Bill Snyder [ This space unintentionally left blank. ] cudkeys: cuddy28 cudenbsnyder cudfnBill cudlnSnyder cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.27 / BILLC / Richard Schultz does not Originally-From: billc@execnet.com (BILLC) Newsgroups: sci.physics.fusion Subject: Richard Schultz does not Date: Sat, 27 May 95 08:05:00 -0500 Organization: Execnet Information System - 914-667-4567 - 198.232.143.136 JE>of predicting the future. So far, events have proved my point many times ove JE>Pd systems do not work. They are a technological dead end, like the Tokamak JE>reactor. Things like thin film Pd, Ni, proton conductors, or the Griggs JE>machine show *far more promise* for commercial applications. The palladium JE>stuff may have scientific value but I do not care about that. I'm out of date on CF and trying to put myself in the current picture. Can anyone point me to a good primer/refresher; eg what is the "Griggs" machine? --- þ SLMR 2.1a þ Old Chemists never die! They just reach Equilibrium. cudkeys: cuddy27 cudenbillc cudlnBILLC cudmo5 cudqt2 cudszS cudyr1995 ------------------------------ 1995.05.27 / BILLC / Re: What's wrong with H2O Originally-From: billc@execnet.com (BILLC) Newsgroups: sci.physics.fusion Subject: Re: What's wrong with H2O Date: Sat, 27 May 95 08:05:00 -0500 Organization: Execnet Information System - 914-667-4567 - 198.232.143.136 JE>Answers: Yes, it does work. It will be dirt cheap. I don't know when JE>electrical generators will be available but thousands of room heaters have JE>already been sold, primarily in Russian and Eastern Europe. They are a JE>heck of a lot better than heat pumps, gas, oil or coal. This is a fascinating statement! Can you pls give some detail? --- þ SLMR 2.1a þ Old Chemists never die! They just reach Equilibrium. cudkeys: cuddy27 cudenbillc cudlnBILLC cudmo5 cudqt2 cudszS cudyr1995 ------------------------------ 1995.05.27 / David Tyler / Re: The Farce of Physics Originally-From: tyler@ug1.plk.af.mil (David Tyler) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 27 May 1995 20:32:01 -0600 Organization: Air Force Phillips Lab. Ed Matthews writes: >On 27 May 1995, Bryan Wallace wrote: >> The very *fact* that JPL refuses to publish an objective >> comparison of the wave and particle models for light in space is >> *overwhelming* evidence that modern physics is a *farce*! >I don't understand your point here. Are you suggesting that JPL is >suppressing information? If that is based on some particular incident, >are the other options ruled out (such as the idea that there may have >been some fundamental flaw in a report which would have invalidated the >data, and not publishing the report because of that)? you've hit on the most ridiculous facet of wallace's jpl diatribe: in this day and age of nasa budget slashing, is it likely that not just one jpl employee, but many, would keep secret a discovery that would shake the world of physics (that gr is wrong) and thereby *ensure* funding for jpl to continue research in this area? i think not... dave cudkeys: cuddy27 cudentyler cudfnDavid cudlnTyler cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Vertner Vergon / Re: The Farce of Physics Originally-From: vergon@netcom.com (Vertner Vergon) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: Sun, 28 May 1995 05:46:40 GMT Organization: NETCOM On-line Communication Services (408 261-4700 guest) In article <3q7fi8$4b6@xcalibur.intnet.net>, Bryan Wallace wrote: >KAnko (kanko@aol.com) wrote: >: Mr. Wallace, > >: Before I take exception to your work, I would like to agree with you on >: something. I agree that scientists who are unwilling to test their >: hypothesis are not good scientists. I agree that modern physics is theory >: driven today, which is wrong. Someone who derives a theory and then heads >: out to prove it are doomed to prove whatever they want. Science should be >: about observing-theorizing-testing-retheorizing-and so on. However, much >: like Rush Limbaugh, you have started with sound footing and have left the >: path. > >: Since I studied particle physics, that is where I will start. For what I >: could get out of your book you do not believe in quarks?? If this is >: true, how do you explain away the results from both electron-positron >: colliders and proton-antiproton colliders?? If you collide an electron >: and a positron above a certain energy, jets of hadrons emerge. Where are >: these coming from?? Also as you increase the energy of the C.O.M. system, >: new jets emerge. The ratio of e+e- >> jets / e+e- >> mu+mu- jumps in >: steps as each new qaurk can be made. The coupling is consistant with 1/3 >: or 2/3 electric charges being involved. And this is QED, maybe the most >: tested theory in nature. > >: In proton collisions, how do you explain large tranverse momentum events >: without quarks. If protons have no underlying structure, then p+p- >: collisions would yeild a mush of stuff down the collider pipe. However, >: both UA1 and CDF have seen events where jets of particles are thrown >: almost perpendicular to the collider pipe. This certainly seems like >: quarks colliding. > >: I will stp here to allow you a chance to reply, but there is much more. >: Again, I agree with you when you sopeak out against a theory driven >: science. Science must make observations first and then attempt to explain >: them. >: Dr. Kevin Ankoviak >Kevin, I think you said above that whoever heads out to prove a thory will prove whatever they want -- so be it with quarks. > I agree with Hiesenberg's arguments in Chapter 2 of my free book "The >Farce of Physics." Particles are not "elementary" but are the "spectrum >of matter" I offer my hypothesis (ON THE QUANTUM AS A PHYSICAL ENTITY) in which the universe is composed of *one* and only one particle. I call it THE quantum. It has very few characteristics, energy of expansion/contraction, spin, mass and co-spatiality. These charateristics blend together in a fractal-like manner to form electromagnetic radiation, electrons, protons, neutrons and neutrinos. These are the only stable particles in the universe (except neutrinos and neutrons which are semi-stable. The entire subatomic zoo consists of unstable shards that break off or are formed when the stable particles are smashed together. If anyone is interested, I suggest they read my thesis. ... "the quark hypothesis is not really taken seriously today >by its proponents" ... "Everthing outside of the dynamics is just a >verbal description of the table of data." Also the arguments of Glashow >and Lederman: > > True, the standard Model does explain a very great deal. Nevertheless >it is not yet a proper theory, principally because it does not satisfy >the physicists naive faith in elegance and simplicity. How simple can you get with ONE basic particle? V.V. The Ugly Duckling >Bryan > > cudkeys: cuddy28 cudenvergon cudfnVertner cudlnVergon cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Sven Geier / Re: The Farce of Physics Originally-From: sgeier@bootes.astro.umd.edu (Sven Geier) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 28 May 1995 06:55:30 GMT Organization: U. of Maryland @ College Park, Astronomy wallaceb@news.IntNet.net (Bryan Wallace) writes: | Also the arguments of Glashow | and Lederman: | | True, the standard Model does explain a very great deal. Nevertheless | it is not yet a proper theory, principally because it does not satisfy | the physicists naive faith in elegance and simplicity. It involves some | 17 allegedly fundamental particles and the same number of arbitrary and | tunable parameters, ... Do you happen to know, which "17 allegedly fundamental particles" they meant? If I count six quarks, three leptons and the associated three leptonic neutrinos, I have 12 fermions. Add to these the photon, two W-particles and the Z and you have 16 actually observed particles. That leaves 1 for the graviton, gluons, the Higgs, ... S (mad scientist) -- -------------------------------------------------------------------------- /''' Sven Geier (http://www.astro.umd.edu/~sgeier/private.html) c-OO \ > I'm a lover, not a fighter, but then im a physicist, not a poet. \_v -- Jake Mannix on a.s.p.n-t cudkeys: cuddy28 cudensgeier cudfnSven cudlnGeier cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 6/26 (F) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 6/26 (F) Date: 28 May 1995 13:04:17 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/f Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 6: Terms beginning with "F" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF # F: Variable typically used for force; sometimes flux. & F: Chemical symbol for the element fluorine. * FLiBe or flibe or FLIBE: Fluorine-LIthium-BEryllium; see entry "Flibe" below. @ FEDC: Fusion Engineering Design Center; see entry @ FLR: Finite Larmor Radius; see entry @ FPD: Fusion Power Demonstration facility; see DEMO. @ FRC: Field-Reversed Configuration; see entry @ FY: Fiscal Year; see entry & Fabry-Perot Interferometer: A type of interferometer with two parallel mirrors (with a variable separation of a few centimeters) arranged so that incoming light is reflected between them multiple times before ultimately being transmitted. Useful in spectroscopy because it gives very good frequency resolution without losing too much of the incident signal. * Faraday Rotator: A device which rotates the plane of polarization of an optical-light pulse, typically by using a glass disc suitably doped with a magnetic ion and placed in a magnetic field. These devices are used to isolate (protect) a laser amplifier chain against back-reflection from the laser target; the Faraday rotator in this case gives a 90-degree phase change on the round trip, so that the returning light is rejected by a polarizer which transmits the outgoing light. * Fast neutron: Neutron with energy greater than roughly 100,000 electron volts (100 keV). Distinguished from slow or thermal neutrons. (See appropriation entries.) * Fertile Material: In nuclear physics, this refers to a nuclide which converts to fissile material (see entry) upon neutron capture and subsequent radioactive decay. Examples include Uranium-238 and Thorium-232. & Field: In physics, any macroscopic quantity which exists (and typically varies) througout a region of space. Standard examples include Electric and Magnetic fields, velocity flow fields, gravitational fields, etc. & Field Lines: Lines in space along which a field is either changing or not changing (depends on the field) but which help to create diagrams which characterize the behavior and effects of the field. For instance, electric field lines run in the direction that the electric field will push charged particles; the strength of the field is proportional to the density of the field lines. On the other hand, the magnetic force pushes particles in a direction perpendicular to both the particle's velocity and the direction of the magnetic field line. > Field-Reversed Configuration: A compact torus produced in a theta pinch and having (in principle) no toroidal field. The potential advantages for a fusion reactor include a simple (linear) machine geometry, an average plasma pressure close to the confining field pressure, and physical separation of formation and burn chambers. The are predicted to be violently unstable to tilting, but this is rarely observed. See also: compact torus, theta pinch. (Arthur Carlson, awc@ipp-garching.mpg.de) * Field Shaping Coils: Type of poloidal field coils (in a tokamak) which create magnetic fields which shape and control the plasma. Used to constrain horizontal and vertical displacements of the plasma, as well as (in some configurations) produce non-circular plasma cross sections (poloidal cross-section) and/or create one or more divertor separatrices. (See relevant entries.) * Finite Larmor Radius: In many plasma theories the size of the Larmor radius (or gyroradius - see entries) is assumed to be negligibly small, or infinitesimal. Different effects occur when the size of the Larmor radius is finite and needs to be considered. (Anyone out there with a succint, but more detailed explanation?) * First Wall: The first physical boundary that surrounds a plasma. * Fiscal Year (FY): Year used to open and close accounting records; not necessarily the same as the calendar year. (For instance, the U.S. government's Fiscal Year begins Oct 1 and ends Sept 30.) * Fishbones: Oscillations in soft x-ray emissions which occur during intense neutral-beam heating; associated with a recurring m=1 internal kink mode. Mode was given its name from its characteristic signal (looked like the bones of a fish, of course). Fishbones are associated with loss of fast ions from the plasma and are triggered by exceeding the upper limit on plasma beta. (see relevant entries) * Fissile Material: Material containing a large number of easily fissionable nuclei which give off multiple neutrons in the fission process. Usual meaning is that if a sufficiently large amount of fissile material is put together, a fission chain reaction can occur. Sometimes used synonymously with "fissionable material," i.e., material that *can* be fissioned (though often under restricted circumstances, such as only with thermal (slow) neutrons). A more restricted meaning use of fissile material limits the concept to those materials which can be fissioned by neutrons of all energies (fast & slow). Examples include Uranium-235 and Plutonium-239. & Fission (Nuclear): Nuclear decay process whereby a large nucleus splits into two smaller (typically comparably-sized) nuclei (which are thus nuclei of lighter elements), with or without emission of other particles such as neutrons. When it occurs, fission typically results in a large energy release. Fission can occur spontaneously in some nuclei, but is usually caused by nuclear absorption of gamma rays, neutrons, or other particles. See also spallation, radioactivity. * Fission Bomb: see atomic bomb, A-bomb. * Fission Reactor: (from Herman) A device that can initiate and control a self-sustaining series of nuclear fissions. * Flat-top: Stable period in the middle of a tokamak discharge, characterized by a flat, stable peak in a plot of plasma (current, temperature) vs. time. * Flibe: Molten salt of Fluorine, Lithium, and Beryllium; candidate blanket/coolant/breeder material for fusion reactors. * Flute Instability: Term used to describe an interchange instability in which the perturbation is uniform parallel to the magnetic field. In cyclindrical geometry, the structure resembles a fluted column (as in classical architecture). Occurs in some mirror machines. & Flux: The total amount of a quantity passing through a given surface per unit time. Typical "quantities" include field lines, particles, heat, energy, mass of fluid, etc. Common usage in plasma physics is for "flux" by itself to mean "magnetic field flux." & Flux Density: Total amount of a quantity passing through a unit surface area in unit time. See also flux, above. * Flux freezing: See frozen-in law. * Flux surfaces: See magnetic flux surfaces. * Flux trapping: See frozen-in law. & F-number: In optics, denotes the ratio of the equivalent focal length of an objective lens to the diameter of its entrance pupil. * Fokker-Planck Equation: An equation that describes the time rate of change of a particle's velocity as a result of small-angle collisional deflections. Applicable when the cumulative effect of many small-angle collisions is greater than the effect of rarer large-angle deflections. & Force: Rate of change of momentum with time. Forces are said to cause accelerations via F = ma (Newton's law). There are four primary forces known presently: the gravitational, electromagnetic, weak nuclear, and strong nuclear forces. The gravitational and electromagnetic forces are long-range (dropping as 1/distance^2), while the nuclear forces are short range (effective only within nuclei; distances on the order of 10^-15 meters). The electromagnetic force is much stronger than the gravitational force, but is generally cancelled over large distances because of the balance of positive and negative charges. Refer to entries for each force for more information. See also momentum. * Free Electron: An electron not bound to an atom, molecule, or other particle via electric forces. * Free Wave: A wave (e.g., electromagnetic) travelling in a homogeneous infinite medium (no boundary conditions). * Frozen-in Flow Law: In a perfect conductor, the total magnetic flux through any surface is a constant. In a plasma which is nearly perfectly conducting, the relevant surfaces move with the plasma; the result is that the plasma is tied to the magnetic field, and the field is tied to the plasma. Motion of the plasma thus deforms the magnetic field, and vice versa. * Fusion (Nuclear): a nuclear reaction in which light atomic nuclei combine to form heavier nuclei, typically accompanied by the release of energy. (See also Controlled Thermonuclear Fusion) % Fusion Engineering Design Center: Facility managed by ORNL and staffed mainly by industrial personnel; undertakes detailed engineering design of planned fusion facilities. (Is it still in operation? The reference I have is out of date.) * Fusion Reactor: Device which creates energy in a controlled manner through fusion reactions. > Fusion-Fission Hybrid: Proposed nuclear reactor relying on both fusion and fission reactions. A central fusion chamber would produce neutrons to provoke fission in a surrounding blanket of fissionable material. The neutron source could also be used to convert other materials into additional fissile fuels (breeder hybrid). Safer than a plain fission reactor because the fission fuel relies on the fusion neutrons, and therefore won't spontaneously melt down. On the other hand, hybrids are more complex because of the fusion power core, and still generate fission's radioactive byproducts. But could be more economical and have easier technical requirements than a straight fusion reactor. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 7/26 (G) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 7/26 (G) Date: 28 May 1995 13:04:18 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/g Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 7: Terms beginning with "G" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG $ G: abbreviation for Gauss; see entry @ GA: General Atomic; see entry. @ GDC: Glow Discharge Cleaning; see entry. @ GN2: Gaseous diatomic Nitrogen (N2) @ GNP: Gross National Product; see entry. @ GW: Gigawatt; see entry @ GWe: Gigawatt - electrical energy; see gigawatt @ GWt: Gigawatt - thermal energy; see gigawatt & Gain: (Amplification) Increase in a signal transmitted from one point to another through an amplifier. # gamma: Third letter in the Greek alphabet; variable used for a number of things in phyics; in plasma physics gamma is often used as the variable for growth rates of instabilities. * Gamma Emission: Nuclear decay process whereby the nucleus goes from an excited state to a more stable state by emitting a gamma ray. (See entry for gamma ray.) * Gamma Rays: Electromagnetic radiation (photons) with energies greater than (roughly) 100 keV (that is, 100,000 electron volts). Gamma radiation frequently accompanies alpha and beta decays, and always accompanies fission. Gamma rays are highly penetrating and are best shielded against using dense materials, such as lead or depleted uranium. (Gamma rays are similar to X-rays, but are generally higher in energy and nuclear in origin.) See relevant entries for more info. % Garching: A town in Germany just north of Munich, where the Max Planck Institute for Plasma Physics (see entry) is located. "Garching" in plasma physics frequently refers to the Max Planck Institute. * Gas Blanket: A cold, dense volume of gas surrounding a hot plasma and used to protect a material wall from bombardment by hot ions (with subsequent sputtering and impurity production). ! Gauss, Carl Friedrich: (1777-1855) German mathmetician, astronomer and physicist. $ Gauss - unit of magnetic field strength (CGS units) 10,000 gauss = 1 tesla (see also Tesla) & Gaussian Units - See CGS Units % General Atomic: U.S. corporation involved in fusion research; operates the DIII-D device in San Diego; see also Doublet III-D. (Officially known as GA Technologies, I believe; or is that the name of the parent company???) & Getters: Materials which absorb ("get") atoms and can be used in purifying near-vacuum atmospheres. $ Gigawatt: Unit of power equal to 10^9 watts, 1000 megawatts, or 1 million kilowatts. See entry for watt. 1 gigawatt is a typical size for a nuclear fission reactor, and is expected to be the typical size of a fusion reactor. * Glow Discharge: Low-density, low-temperature plasma discharge (such as in a fluorescent light) which, well, glows. Sputtering in glow discharges is useful in plasma processing of materials. The voltage applied to the plasma must be greater than the ionization potential of the gas used; most of the plasma voltage drop is near the cathode, where the majority of ionization occurs. Discharge is sustained by secondary electrons emitted when ions or recombination radiation impact on the cathode; electrons are accelerated away from the cathode and ionize neutral gas in the discharge. * Glow Discharge Cleaning: Cleaning in which impurities are removed by sputtering in a glow discharge. (?) * Grad-Shafranov Equation: Reduced MHD-equilibrium equation for an axisymmetric, toroidal plasma. (Similar reduced equations can be derived for the cases of helical symmetry and for the straight cylinder.) Analytic and numerical studies of these equations are important in exploring potential plasma configurations. -> Additional info Contributed by James Crotinger, with minor revisions: The lowest order force balance in the plasma is simply that the Lorentz force must be balanced by the pressure force. This balance, combined with Maxwell's equations, determines the equilibrium configuration of the magnetic field. When the toroidal configuration is axisymmetric, and the equilibrium plasma flow is zero, the magnetic field may be written in terms of a stream function \psi that satisfies the Grad-Shafranov equation \Delta*\psi = - \mu_0 R^2 p'(\psi) - FF'(\psi). Here p is the plasma pressure and F = R B_\phi. (R is the radial distance from the axis of the machine) (Alternatively, leaving out the equation): In an axisymmetric torus, in the absence of equilibrium plasma fluid flows, the magnetic field may be written in terms of a scalar potential. When the plasma is in equilibrium (forces balance and the plasma is stationary), this scalar potential obeys a non-linear elliptic equation known as the Grad-Shafranov equation. & Gradient: Mathematical term for the operator which determines the magnitude and direction of the greatest rate-of-change of a given function with position. Similarly used to describe such a rate-of-change. For instance, at a given point on a hill, the slope of the hill in the steepest uphill direction is the gradient of the altitude funtion for the hill. & Gravitational Force: Force which attracts two bodies together based on the product of their masses and the reciprocal of the square of their distances. "Gravity" is the force field created by one massive body (like the earth) which another body (like you) will experience. * Gross National Product: Total value of goods and services produced in a country; measure of economic strength of a nation. $ Gray: A unit of absorbed dose of radiation, equal to one joule of energy per kilogram of mass. 1 Gray = 100 rads. Defined relative to the material into which such radiation passed, which should therefore be specified. & Group Velocity: This is derived from the dispersion relation (see entry) as Vgroup = dw/dk; the group velocity is the rate at which modulations or information within a wave travel through a given medium. * Guiding Center: Particles placed in a magnetic field will gyrate in circles around the magnetic field lines, and drift in various directions. The guiding center represents the instantaneous center of the circular motion. The idea is that you can think of the guiding center as drifting, and the particle as orbiting the guiding center. * Gyrofrequency: See cyclotron frequency. * Gyromagnetic Ratio: Ratio of the magnetic moment to the angular momentum of a particle. (see magnetic moment, angular momentum) * Gyroradius: radius of charged particle in magnetic field. Same thing as cyclotron radius, Larmor radius. * Gyrotron: A device for producing microwave energy that utilizes a strong axial magnetic field in a cavity resonator to produce azimuthal bunching of an electron beam. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 0/26 (intro) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 0/26 (intro) Date: 28 May 1995 13:04:11 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/intro Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-monthly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). ***************************************************************** Glossary of Frequently Used Terms in Plasma Physics and Fusion Energy Research Edited by Robert F. Heeter, rfheeter@pppl.gov ### This file introduces the Conventional Fusion Glossary ### # Editorial Note: Like any discipline, fusion research has evolved terminology used to facilitate discussion. This includes the scientific vocabulary of the discipline, the names of various research machines and devices used, the names of various researchers in the field, the names of the various research labs and funding authorities, the mathematical symbols used, and the acronyms frequently used as shorthand for some of the above. In the case of conventional (magnetic confinement, inertial confinement, thermonuclear, muon-catalyzed, etc - but not Cold) fusion, this terminology has grown to the point where newcomers (including the author of the glossary!) may be intimidated by the apparent obscurity of the discussions. This file is an attempt to provide a comprehensive and detailed listing and explanation of terms frequently used, so that those new to the group/field will be able to understand what is being said, and to contribute with a minimum of confusion and frustration. Many terms are still missing, and some terms may have less-than-fully-correct entries, so if you would like to see something added or changed, let me know. # Yes, it's a big glossary! The last time I counted, there were roughly 1000 entries, occupying something like 300 kilobytes. But everything is organized alphabetically, and to make things even better, each entry is coded by type (names, acronyms, types of machines, basic physics terms, advanced plasma terms, etc). Hopefully this will make the glossary easier to use. # What's in the FUT: We started with an initial list supplied by Jim Day (Jim.Day@support.com). To this were added some comments from various responses I received to the first draft. I then incorporated terms from PPPL and other glossaries. Then acronyms, machine names, and names of important scientists were added as they came. I added categories for research and funding/political agencies, tried to broaden the base of basic science terms, and wrote up a few more preliminary definitions based upon explanations that have appeared in the newsgroup and in my studies. Many of the terms listed still do not have explanations given. Recent drafts have been mostly incremental improvements to the previous versions. New categories of terms have been made, the organization has been improved, and of course definitions have been added and improved. The most recent project has been to incorporate terms from the "Glossary of Fusion Energy" published in 1985 by the Office of Scientific and Technical Information (OSTI) of the U.S. Department of Energy. This has been a fairly major effort, which has roughly doubled the size of the glossary. My current plan for the Glossary is to write entries for terms used in my classes. This will be useful to me, as part of studying for my upcoming PhD qualifying exam, and hopefully will also help incoming graduate students, both here and around the world. # What's Needed to Improve the FUT: I am looking for additional contributions (and improvements) to the list. It would be nice if people posting to the group could occasionally take a few moments to include definitions of a few terms used when you use them; in browsing through the group I can then snip out the terms and definitions and simply paste them into the evolving Glossary files. It also would be nice if references to the FAQ and the Reading List / Bibliography could be given to supplement the Glossary descriptions, at least for some of the more complicated terms. # Comment on Sources: The terms and definitions occurring here represent a collection of contributions from numerous sources. Rather than include acknowledgements for each individual definition, I have made blanket acknowledgements below. I have tried to include citations in most cases where only a single textual source was used. # Acknowledgements for the Glossary: ! = someone I believe is a scientist * = people who are not scientists so far as I know, organizations, etc. ! Jake Blanchard, blanchard@engr.wisc.edu - suggested we have a list of acronyms too. ! Arthur Carlson, awc@ipp-garching.mpg.de - supplied additional definitions, made corrections / amplifications / revisions to earlier definitions. ! Edward Chao, ehchao@theory.pppl.gov - info on LANL fusion research, additions and corrections to various definitions. ! Albert Chou, albert@seas.ucla.edu - supplied additional definitions, made corrections / amplifications / revisions to earlier definitions. ! John Cobb, johncobb@uts.cc.utexas.edu - lots o' definitions. ! James Crotinger, jac@gandalf.llnl.gov - additional definitions, quality control, and comments on the usefulness of the FUT. * Jim Day, jim.day@support.com - initial list of terms, additional definitions, modifications to earlier definitions. ! Steve Fairfax, Fairfax@cmod.pfc.mit.edu - additional definitions from the Alcator weekly reports. * Robin Herman, _Fusion: Search for Endless Energy_; I borrowed a few terms from her glossary. Cited as (from Herman). (Many of these terms derived from the PPPL glossary I also used.) ! Paul M. Koloc, pmk@prometheus.UUCP - quality control, some entries ! Emilio Martines, martines@pdigi3.igi.pd.cnr.it - quality control, reversed-field entries & information. ! Robert Nachtrieb, nachtrieb@pfc.mit.edu - numerous acronyms * Princeton Plasma Physics Lab, Glossary of Fusion Terms - list of terms prepared by PPPL staff at some point. Consulted in many cases, blatantly paraphrased in some, quoted and cited in others. * Vicki Rosenzweig, vr%acmcr.uucp@murphy.com - Proofreading entries * Mike Ross, mikeross@almaden.ibm.com - additional Livermore info and corrections to some entries. * Richard Schroeppel, rcs@cs.arizona.edu - suggestions/corrections to many definitions. ! Philip Snyder, pbsnyder@theory.pppl.gov - corrections to definitions. ! Paul Stek, Stek@cmod.pfc.mit.edu - additional definitions !? Mitchell Swarz, mica@world.std.com - supplied additional definitions / corrections and revisions to existing definitions. * United States Department of Energy, Office of Fusion Energy - for funding fusion research and making everything possible * United States Department of Energy, Office of Scientific and Technical Information - for the 1985 Glossary of Fusion Energy, which I have utilized extensively and incorporated into this Glossary. # This file may be freely distributed; I recommend you retain the revision date, and in any case I'd like to be cited as the editor. # # Any and all errors are solely my responsibility. # ##################### Robert F. Heeter rfheeter@pppl.gov Graduate Student, Princeton Plasma Physics Lab (Usual disclaimers apply.) cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 8/26 (H) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 8/26 (H) Date: 28 May 1995 13:04:19 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/h Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 8: Terms beginning with "H" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== HHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH # H: chemical symbol for the element hydrogen; see entry # He: chemical symbol for the element helium; see entry. @ HIREX: High-REsolution X-ray spectroscopy @ H-mode: see high-mode @ HTO: (Hydrogen-Tritium-Oxygen) Water with a tritium atom replacing a hydrogen. See entry for tritium. * Half-life: For a given quantity of a radioactive isotope, there is a time period in which half the nuclei will decay to a different state; this period is called the half-life. Measured half-lives range from less than millionths of a second (for very short-lived isotopes) to billions of years (for isotopes which are almost stable, but not quite). The time in which half the atoms of a particular radioactive isotope disintegrate to another nuclear form. By analogy, "half-life" can also be used to describe similar time-periods for other sorts of exponential decay phenomena. * Hall Effect: Transverse electric field which develops in a conductor (as a result of the Lorentz Force acting on the charge carriers) when current is driven across a magnetic field. * Halo: The cold, dense plasma formed outside the last closed flux surface during a vertical displacement event. The large currents which flow through this plasma stop the displacement and transfer the force to the vacuum vessel. If care is not taken in design, the halo currents can be large enough to threaten the structural integrity of the vacuum vessel or in-vessel components. Whereas the center of a tokamak plasma is too hot for material probes to survive, probes (such as magnetic-field coils) can sometimes be placed in the halo, and can measure things such as the halo current (see below). See also entry for vertical instability. * Halo Current: Currents in the halo region of a plasma discharge. See entry for halo above. * Hamada coordinates: A particular magnetic-flux coordinate system useful for MHD calculations. In this system the current density and magnetic field lines are straight and the Jacobian of the coordinate transformation equals one. & Hamiltonian Function: Function arising from the Hamiltonian approach to mechanics which characterizes the total energy of a system as a function of generalized coordinates and momenta and can be used to obtain the dynamical equations of motion of the system. (Consult an intermediate or advanced mechanics text for more info.) > Hard-core pinch device: plasma pinch-discharge device using a solid central conductor ("hard-core"). The discharge then occurs in an annular region about the central conductor. & Hartree-Fock approximation: a refinement of the Hartree method (see entry) in which one uses determinants of single-particle wave functions rather than products, thereby introducing exchange terms into the Hamiltonian. & Hartree method: An iterative, variational method of finding an approximate quantum-mechanical wavefunction for a system of many electrons, in which one attempts to find a product of single-particle wave functions, each of which is a solution of the Schrodinger equation with the field deduced from the charge density distribution due to all the other electrons; also known as the self-consistent field method. & Heat exchanger: device that transfers heat from one fluid (liquid or gas) to another (or to an external environment). * Heavy Hydrogen: somewhat informal alternative name for deuterium. (see entry for deuterium). * Heavy Water: (D2O) Water with enriched content of deuterium relative to hydrogen (greater than the natural abundance of 1 D per 6500 H). Heavy water is used as a moderator in some fission reactors (see CANDU entry) because it slows down neutrons effectively but also has a low collision cross-section for absorption of neutrons. > Heliac: A confinement configuration which superimposes an l=1 stellarator-type field upon a tokamak-like poloidal field. The resulting plasma configuration is a helix bent around into a loop. * Helicity: (from John Cobb) A measurement of the topological "tangledness" of magnetic field lines. It is formally defined as the scalar product of the magnetic vector potential with the magnetic field, K = A dot B. If the plasma is perfectly conducting, then helicity is a conserved quantity. (Without resistance, field lines cannot reconnect, and magnetic topology is conserved, so helicity is conserved). (See frozen-in flow). If the plasma has a small amount of resistivity, then Helicity is not exactly conserved. However, the total helicity inside of a given flux surface is often conserved to a good approximation. In that case, the dynamics of a plasma can be analyzed as an evolution toward a minimum energy state subject to the constraint of a conserved total helicity (See Taylor State, J.B. Taylor). This is often used in analyzing the equilibrium and relaxation of RFP's and other toroidal devices. > Helios Facility: Los Alamos laser inertial fusion facility. & Helium: Element whose nuclei all contain two protons. Stable isotopes are 3He and 4He. 3He is rare on earth (only 1.3 ppm of naturally-occuring He), can be generated from decaying tritium (half life of about 12 years), and is relatively abundant in the crust of the moon. Helium is the second most abundant element in the universe and in the sun, and occurs at about (I believe) 1 part per million in earth's atmosphere. Helium is also found in significant quantities in natural gas deposits. The nucleus of the He atom is also known as an alpha particle. Helium is chemically inert, behaves nearly as an ideal gas under a wide range of pressures and temperatures, and can only be liquefied at 4 Kelvin (at atmospheric pressures). One mole of He weighs 4 grams. ! Hertz, Heinrich: 19th-century German physicist; first (?) observed low-frequency electromagnetic waves. $ Hertz: Unit of frequency equal to one complete oscillation (cycle) per second. Common abbreviation is Hz. * High-beta plasma: A plasma in which the beta value (see entry) is typically 0.1 to 1. * High-mode or H-mode: A regime of operation most easily attained during auxiliary heating of diverted tokamak plasmas when the injected power is sufficiently high. A sudden improvement in particle confinement time leads to increased density and temperature, distinguishing this mode from the normal "low mode." However, H-mode has been achieved without divertors, auxiliary heating, or a tokamak. (H-modes have been observed in stellarators.) & Holography: A technique for recording and later reconstructing the amplitude and phase distribution of a wave disturbance. & Homopolar generator: A direct-current generator in which the poles presented to the armature are all of the same polarity, so that the voltage generated in the active conductors has the same polarity at all times. A pure direct current is thus produced without commutation. * Hot cells: Heavily radiation-shielded enclosure in which radioactive materials can be handled by persons using remote manipulators and viewing the materials through shielded windows or periscopes. * Hybrid diode: An ion diode that uses a field coil in series with the ion diode's accelerating gap to generate sufficient magnetic flux in the diode for electron control. The diode is a combination of the Applied-B diode's ion source and the Ampfion diode's field coil. * Hybrid reactor: see fusion-fission hybrid. * Hybrid resonance: A resonance in a magnetized plasma which involves aspects of both bunching of lighter species parallel to the magnetic field, characterized by the plasma frequency; and perpendicular particle motions (heavier species) characterized by the cyclotron frequency. & Hydrogen: (H) Element whose nuclei all contain only one proton. Isotopes are protium (p, no neutrons) deuterium (D or d, one neutron), and tritium (T or t, two neutrons). Hydrogen is the lightest and the single most abundant element in the universe, and in the sun. Hydrogen is a major element in organic compounds, water (H2O), and many other substances. Hydrogen is ordinarily a gas, but can be liquefied at low temperatures, and even solidified at low temperature and high pressure. Hydrogen gas can burn explosively in the presence of oxygen. * Hydrogen bomb or H-bomb: (from Herman) An extremely powerful type of atomic bomb based on nuclear fusion. The atoms of heavy isotopes of hydrogen (deuterium and tritium) undergo fusion when subjected to the immense heat and pressure generated by the explosion of a nuclear fission unit in the bomb. * Hydrogen embrittlement: A decrease in the fracture strength of metals (embrittlement) due to the incorporation of hydrogen within the metal lattice. * Hydromagnetic Instability: See MHD Instability * Hydromagnetics: see magnetohydrodynamics (MHD) cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 1/26 (A) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 1/26 (A) Date: 28 May 1995 13:04:12 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/a Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-monthly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 1: Terms beginning with "A" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = vocabulary specific to plasma/fusion/energy research & = basic/general physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA # A: symbol used to indicate either area or magnetic vector potential. $ A: abbreviation for Amperes; see entry. @ AAPT: American Assocation of Physics Teachers; see entry @ AC: Alternating Current; see entry. @ ACT-I: Advanced Concepts Torus I; see entry. @ AEC: (US) Atomic Energy Commission; see entry @ AIC: Alfven Ion Cyclotron Instability; see entry @ AIP: American Institute of Physics; see entry @ AJP: American Journal of Physics; see entry @ ALEX: (see entry "ALEX" below) @ AMBAL: (see entry "AMBAL" below) @ ANL: Argonne National Laboratory; see entry @ ANS: American Nuclear Society; see entry @ APS: American Physical Society; see entry @ APS-DPP: American Physical Society - Division of Plasma Physics; see entry. # Ar: Chemical symbol for the element Argon @ ARIES: Advanced Reactor Innovative Engineering Study (?) See Entry under ARIES @ ASDEX: Axially Symmetric Divertor EXperiment; see entry @ ASDEX-U: ASDEX-Upgrade; see entry for ASDEX. @ ASME: American Society of Mechanical Engineers @ ATF: Advanced Toroidal Facility; see entry. * Absolute Instabilities: A class of plasma instabilities growing exponentially with time at a point in space, in contrast to convective instabilities (see entry). * Absorption: In plasma physics, the loss of (electromagnetic) energy to a medium. For instance, an electromagnetic wave which propagates through a plasma will set the electrons into motion. If the electrons make collisions with other particles, they will absorb net energy from the wave. * Absorption Coefficient: Measures the degree of wave absorption (see Absorption above); defined as the fraction of wave energy lost as the wave travels a unit distance. & Activation: Activation occurs when a particle interacts with an atomic nucleus, shifting the nucleus into an unstable state, and causing it to become radioactive. In fusion research, where deuterium-tritium is a common fuel mixture, the neutron released when (D + T) combine to form (4He + n) can activate the reactor structure. Sometimes called "radioactivation." See also activation product, activation analysis. & Activation Analysis: Method for identifying and measuring chemical elements in a sample of material. Sample is first made radioactive by bombardment with neutrons, charged particles, or gamma rays. Newly formed radioactive atoms in the sample then give off characteristic radiations (such as gamma rays) that tell what kinds of atoms are present, and how many. * Activation Product: The unstable nucleus formed when activation occurs. (See activation above.) & Adiabatic: Not involving an exchange of heat between the system said to be adiabatic and the rest of the universe. & Adiabatic Compression: Compression (of a gas, plasma, etc.) not accompanied by gain or loss of heat from outside the system. For a plasma in a magnetic field, a compression slow enough that the magnetic moment (and other adiabatic invariants - see entry) of the plasma particles may be taken as constant. * Adiabatic Invariant: Characteristic parameters which do not change as a physical system slowly evolves; the most commonly used one in plasma physics is the magnetic moment of a charged particle spiraling around a magnetic field line. * Aftercooling: Cooling of a reactor after it has been shut down. * Afterglow: Recombination radiation emitted from a cooling plasma when the source of ionization (heating, etc) is removed. (See entry for recombination radiation.) * Advanced Fuels: There are several elements/isotopes which could be fused together, besides the DT fuel mixture. Many such fuel combinations would have various advantages over DT, but it is generally more difficult to achieve fusion with these advanced fuels than with the DT mix. See fuels section of FAQ for discussion. > Advanced Concepts Torus I: (ACT-I) A steady-state toroidal device built primarily for studies of RF heating (see entry) and RF current drive (see entry). Operated at PPPL but shut down several years ago. > Advanced Toroidal Facility: (ATF) A large stellarator device developed at Oak Ridge National Lab (ORNL), but recently mothballed. See Section 5 for more information. > Alcator: Name given to a set of tokamaks designed and built at MIT; these machines are distinguished by high magnetic fields with relatively small diameters. The high magnetic field helps create plasmas with relatively high current and particle densities. The current incarnation is Alcator C-mod, and is described further in Section 5. Alcator C was donated to LLNL for use as the Microwave Tokamak eXperiment (MTX), now shut down. > Alcator A: First of the Alcator series of tokamaks at MIT; was operational from 1969 to 1982. > Alcator C: Commissioned in 1978; used extensively to study plasma confinement under strong ohmic heating (see entries). Also studied high-density plasmas and used frozen fuel pellet injection. Set record values of Lawson product (density times confinement time; see entries) of 8 x 10^19 m^3-seconds. Was donated to Livermore (LLNL; see entry) for use as the Microwave Tokamak eXperiment (MTX: see entry), now shut down. > Alcator C-mod: Successor to Alcator C; actually a completely new device. Currently operational; described in more detail in Section 5. > Alcator DCT: Proposed fully-superconducting extension of the Alcator series; never built. * Alcator Scaling: A proposed empirical law in which the energy confinement time is proportional to the product of the average density and the square of the plasma radius (see relevant entries). > ALEX: A single-cell, minimum-B magnetic mirror system (see entries) in which the magnetic field was generated by a baseball coil (see entry) wound on a 60 cm sphere. Formerly operated at the Rensselaer Polytechnic Institute, Troy, New York. * Alfven Ion Cyclotron instability: (AIC) An electromagnetic microinstability near the ion cyclotron frequency; driven by the ion loss cone in a mirror device. (See relevant entries.) * Alfven velocity: Phase velocity of the Alfven wave; equal to the speed of light divided by the square root of (1 plus the ratio of the plasma frequency to the cyclotron frequency for a given species). i.e., Va = c / SQRT(1 + plasma freq. / cyclotron freq.) (As defined in Stix, _Waves in Plasmas_, 2nd ed. 1992, p. 31) * Alfven waves: Transverse electromagnetic waves that are propagated along lines of magnetic force in a plasma. The waves have frequency significantly less than the ion cyclotron frequency, and are characterized by the fact that the field lines oscillate (wiggle) with the plasma. The propagation velocity depends on the particle density and the strength of the magnetic field. "[Relatively] Low frequency ion oscillation in the presence of an equilibrium magnetic field. Also called the transverse hydromagnetic wave along Bo. The torsional Alfven wave in cylindrical geometry was first measured in liquid mercury by B. Lehnert. Alfven waves were first generated and detected in plasma by Allen, Baker, Pyle, and Wilcox in Berkeley and by Jephcott in England in 1959." (quoting from Chen's book; see bibliography) - Albert Chou ! Alfven, Hannes Olof: Nobel Prize-Winning Plasma Physicist and Astronomer who first suggested the possibility of MHD waves in 1942. * Alpha Channeling: Term for an idea (so far theoretical) in magnetic confinement fusion; the idea is that plasma waves can be used to control the alpha particles produced in a fusion reactor, to transfer their energy directly to fuel ions, and to help push them out of the plasma. This could potentially help to substantially improve the power output capabilities of fusion plasmas. * Alpha emission: Form of nuclear decay where the nucleus emits an alpha particle (see entry below). * Alpha particle: The nucleus of a Helium-4 atom; is a typical product of fusion reactions; also released in various nuclear decay processes. Alpha particles readily grab electrons from other sources, becoming neutral helium; even energetic alpha particles are easily stopped by thin barriers (sheets of paper, dead layers of skin, etc.), so that as a radiological hazard alpha particles are only dangerous if they are generated inside one's body (where the skin cannot protect tissue from damage). Alpha particles are common products in fusion reactions between light elements. & Alternating Current: (AC) Electrical Current (see entry) which alternates in direction with time. (For instance, household electric current is AC alternating at 60 oscillations/sec (60 Hertz) in the United States, and 50 Hertz in many other countries.) > AMBAL: An ambipolar trap (tandem mirror) located at Novosibirsk in Russia. (Any additional information would be welcome.) * Ambipolar Diffusion: Diffusion process in which buildup of spatial charge creates electric fields which cause electrons and ions to leave the plasma at the same rate. (Such electric fields are self-generated by the plasma and act to preserve charge neutrality.) % American Association for the Advancement of Science: (AAAS) Organization dedicated to promoting science research and education in the United States. Publishers of _Science_. % American Association of Physics Teachers: (AAPT) Professional society of physics teachers in the United States. Organizes conferences on physics education. Publishers of _American Journal of Physics_ (AJP) % American Institute of Physics: (AIP) Organization dedicated to promoting physics research and the dissemination of physics knowledge; publishers of many physics books. % American Nuclear Society: (ANS) Professional society of nuclear scientists in the United States. % American Physical Society: (APS) Professional society of physicists in the United States. Organizes major conferences and publishes many peer-reviewed journals. % American Physical Society - Division of Plasma Physics: (APS-DPP) Branch of the APS for plasma physicists, including fusion scientists. The Annual Meeting of the APS-DPP is the largest plasma physics conference in the United States. $ Ampere, kiloampere, megampere: (from Herman) The standard unit for measuring the strength of an electric current representing a flow of one coulomb of electricity per second. 1 kiloampere = 1000 amperes; 1 megampere = 1,000,000 amperes. Common abbreviations: A, amps, kiloamps, megamps, kA, MA ! Ampere, Andre-Marie (1775-1836): French physicist responsible for much of what is known about the fundamentals of electromagnetism. & Ampere's Law: General equation in electromagnetism relating the magnetic field and the currents generating it. * Aneutronic Fuels: Advanced fusion fuels which would not produce fusion neutrons. See fuels section of FAQ for discussion. $ Angstrom: A unit of distance equal to 10^-10 meters or 10^-8 cm. & Angular Momentum: Momentum involved in the rotation of a body about an axis; conserved like ordinary momentum (see momentum). Angular momentum is defined as the cross product of ordinary momentum with the position vector running from the axis of rotation to the body whose angular momentum is being determined. Torque is the rate of change of angular momentum with time. (see also torque) & Anisotropy: Term used to describe a medium whose characteristic properties vary in with direction of travel through the medium. (e.g., velocity of light transmission, conductivity of heat or electric current, compressibility, etc.) * Anomalous Diffusion: Diffusion in most plasma devices, particularly tokamaks, is higher than what one would predict from understood causes. The observed, "typical" diffusion is referred to as "anomalous" because it has not yet been explained. Anomalous diffusion includes all diffusion which is not due to collisions and geometric effects. While such effects were not understood when the term was coined, and most still aren't, diffusion due to well-understood wave phenomena is still 'anomalous'. "Classical" diffusion and "Neo-classical" diffusion are the two well-understood diffusion theories, neither is adequate to fully explain the observed "anomalous" diffusion. See also: entries for classical and neoclassical diffusion. (Acknowledgements to Philip Snyder) * Antares: Laser-target irradiation system (i.e., laser fusion research device) at Los Alamos National Lab; was operational in 1982. (The author would welcome current information.) & Aperture: The opening in an optical system which restricts the size of the bundle of rays incident on a given surface. (Usually circular and specified by diameter.) * Applied-B Diode: An ion diode with an applied magnetic field to prevent electrons flowing from cathode to anode. The applied magnetic field also regularizes the electron swarm to reduce beam divergence. * Arc: A type of electrical discharge between two electrodes; characterized by high current density. Similar in meaning to "spark" in common language. % Argonne National Laboratory: One of the U.S. Department of Energy basic-research Laboratories, located in Illinois... (need more info!) > Argus: Two-beam, 5-terawatt Nd-glass laser system used at Livermore (LLNL) for inertial-confinement fusion research from 1976 to 1981. * ARIES: Set of four fusion reactor design studies which investigated the safety, economic, and environmental implications of various advances in fusion reactor science and technology. * Ash: Fusion reaction products trapped in a plasma. Ash is bad because (a) it generally radiates more strongly than the fuel ions, and thus reduces energy confinement, and (b) it creates additional plasma pressure and/or reduces pressure available for fuel ions. (due to beta limits, see beta) Controlling ash is a major area of fusion research. Ideally one would be able to extract the ash ions after diverting an appropriate fraction of their energy to heating the fuel ions, and then convert the remaining ash energy to electricity. Current research involves using RF waves to transfer energy from ash ions to fuel ions, and to push the ash into the scrape-off layer, where it can be collected via divertors. (See also scrape-off layer, divertors) * Ash control - see ash, divertors. * Ash removal - see ash, divertors. * Aspect Ratio: In toroidal geometry, the ratio of the major diameter (total width of the torus) to the minor diameter (width of a slice taken through one side of the ring). (This would be much better with a picture!) In inertial-confinement fusion, aspect ratio refers to the ratio of a fuel pellet's radius to its wall thickness. & Atom: (from Herman) The smallest unit of an element that retains the characteristics of that element. At the center of the atom is the nucleus, made up of neutrons and protons, around which the electrons orbit. Atoms of ordinary hydrogen, the lightest element, consists of a nucleus of one proton orbited by one electron. (Note: distinct from a molecule, which is the smallest unit of a substance which retains the characteristics of that substance. It takes far less energy to break apart a stable molecule into its constituent atoms than to divide a stable atom into two smaller atoms.) Note that in solids, atoms are typically two angstroms (2 x 10^-10 meters) apart; in air the gas molecules are about 30 angstroms apart. A drop of water has on the order of 10^21 atoms in it. Atoms are generally electrical neutral; when an atom acquires an electrical charge (by gaining or losing electrons) it is usually called an ion. & Atomic Bomb, A-Bomb: (from Herman) A weapon with a large explosive power due to the sudden release of energy when the nuclei of heavy atoms such as plutonium-239 or uranium-235 are split. This fission is brought about by the bombardment of the fuel with neutrons, setting off a chain reaction. The bomb releases shock, blast, heat, light, and lethal radiation. The world's first atomic bomb was successfully tested by the United States on July 16, 1945. % Atomic Energy Commission: United States governmental authority for atomic energy; split into ERDA and NRC in 1975. (may not be 100% correct) & Atomic Mass: Mass of an atom relative to 1/12th the mass of a carbon atom. Approximately equal to the sum of the number of protons and neutrons in the nucleus of the atom. & Atomic Number (Z): The number of protons in a nucleus; same as the number of electrons in a neutral atom; determines the position of an element in the periodic table, and hence its chemical properties (see also isotope). * Atomic Temperature: The temperature corresponding to the mean kinetic energy of the neutral atoms in a plasma. (If there were no ions or electrons, the atomic temperature would be what we normally think of as the temperature of a gas, such as the air.) * Auger effect: Transition of an electron in an atom from a discrete electronic level to an ionized continuous level with the same energy; also known as autoionization. & Avogadro's number: N = 6.02497 x 10^23. Number of particles in a mole of a substance. Coefficient relating Boltzmann's constant to the ideal gas constant. This is the number of atoms per gram-atom. See also: mole > Axially Symmetric Divertor EXperiment (from Herman) (ASDEX, Asdex: Garching, Germany) A large tokamak designed for the study of impurities and their control by a magnetic divertor. The H mode or high mode of operation with neutral beam injection was first observed on ASDEX. > Axially Symmetric Divertor EXperiment (ASDEX, Asdex): "The original ASDEX, located in Garching, Germany and decommisioned in 1990(?), would qualify today as a medium-sized tokamak. It was designed for the study of impurities and their control by a magnetic divertor. The H mode or high mode of operation with neutral beam injection was first observed on ASDEX. Its successor ASDEX-Upgrade (a completely new machine, not really an "upgrade") is larger and more flexible. It is the first tokamak whose toroidal and poloidal field coils are not linked, which will be a necessary design factor in a reactor. It will achieve parameters at the edge which are very similar to those needed for a power reactor." - Arthur Carlson * Azimuth: An angle measured clockwise relative to some reference point on a circle (e.g., "south" or "north"). * Azimuthal: Generally an angle, measured "around" an object. In spherical geometries, the angle which is *not* the "polar angle". On the earth, one incarnation of the azimuthal angle is the longitude of a location relative to the prime meridian through Greenwich, England. In toroidal geometries, the longitude idea still applies, but the other angle is the "poloidal" angle, not the "polar" angle. The azimuthal direction is the "long way" around a torus. See also: poloidal. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 2/26 (B) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 2/26 (B) Date: 28 May 1995 13:04:13 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/b Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 2: Terms beginning with "B" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = vocabulary specific to plasma/fusion/energy research & = basic/general physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement Citations and Acknowledgements appear in Section 11 of the FAQ. ================================================================== BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB # B: variable used for Magnetic Field # B: chemical symbol for the element boron; see entry # Be: chemical symbol for the element beryllium; see entry @ BCSS: Blanket Comparison and Selection Study (no entry) @ BHP: Biological Hazard Potential; see entry @ BPX: Burning Plasma eXperiment; see entry @ BTU: British Thermal Unit; see entry @ BWR: Boiling Water Reactor (fission); see entry * Background Radiation: Level of environmental radation due to "background" sources. Background sources can be natural, such as cosmic rays and natural radioactive elements (principally radon, but including other elements such as isotopes of potassium (which people get substantial amounts of in foods like bananas)). They can also be man-made, such as from fossil-fuel combustion, everyday leakage from nuclear activities, and leftover from atmospheric nuclear weapons tests. Background radiation is usually distinguished from acute radiation, such as from medical x-rays, nuclear accidents, radioisotope therapy, or other short-term doses. The man-made contribution to background radiation is quite small compared to the natural contribution; medical uses dominate human exposure to acute radiation. & Backscattering: Deflection of incident particle / radiation through an angle greater than 90 degrees relative to the original direction of motion/propagation. * Ballooning Instability: See Ballooning Mode * Ballooning Mode: A mode which is localized in regions of unfavorable magnetic field curvature ("bad curvature") and which becomes unstable when the force due to pressure gradients (grad p) is greater than the mean magnetic pressure force (grad B^2)/(8*pi). * Banana Orbit: The fast spiraling of an charged particle around a magnetic field line is accompanied by a slow movement ("drift") of the center of the sprial. Projected onto a poloidal plane, the drift orbit has the shape of a banana. These orbits are responsible for neo-classical diffusion (see entry). $ Barn: Unit of area equal to 1x10^-24 square centimeters (or 1x10^-28 square meters). Commonly used in describing cross sections of atomic, nuclear, and particle interactions. (see cross section). * Baseball Coils: Used in magnetic-mirror geometries to produce a minimum-B configuration; so-called because of their resemblance to the characteristic shape of lacing on a baseball. * Beam: stream of particles or electromagnetic radiation travelling in a single direction. * Beam-Beam Reaction: Fusion reaction which occurs from the collision of two fast ions originating in injected neutral beams. * Beam Dump: A mass of shielding material which absorbs the energy of a beam of particles or electromagnetic radiation. * Beam-Plasma Reaction: Fusion reaction which occurs from the collision of a fast beam ion with a thermal plasma ion. * Beam Splitter: Optical device for dividing a beam of electromagnetic radiation into two or more separate beams. * Beam-Wall Reaction: Fusion reaction which occurs from the collision of a fast beam ion with an ion embedded in or adsorbed onto the reactor wall. * Bean-Shaped Plasma: A toroidal plasma indented on the inboard side (that is, on the side with the "donut hole"); results in additional stability to ballooning modes (see entry). Moderate indentation (does, can, may?) provide access to the second-stability region (high beta). (see relevant entries) ! Becquerel, Antoine-Henri: French scientist and discoverer of radioactivity; co-winner of Nobel Prize. (See Curie) $ Becquerel: Unit of radioactivity equal to 1 disintegration per second. (see Curie) * Bellows: Flexible mechanical structure with walls like those of an accordion. * Bernstein Mode: Type of mode which propagates perpendicular to the equilibrium magnetic field in a hot plasma. The waves have their electric field nearly parallel to the wave propagation vector (nearly longitudinal). The modes propagate in frequency ranges lying between integer harmonics of the electron cyclotron frequency. Named after Ira Bernstein. & Beryllium: (Be) Element with atomic number 4 (four protons). May be useful in multiplying fusion neutrons to enhance tritium production in a lithium blanket; rather hazardous to handle. (See relevant terms mentioned.) * Beta, or beta-value: Ratio between plasma kinetic pressure and magnetic-field pressure; proportional to the ratio between plasma kinetic energy density and magnetic field energy density. Beta is usually measured relative to the total, local field (loosely called beta toroidal), but sometimes the plasma pressure relative to only the poloidal component of the field (beta poloidal) or relative to some external field (like the maximum field at the magnetic coils) is more useful. There is also a normalized beta (beta_N) of interest when discussing the beta limit (see entry). (lots of help from Art Carlson with the above.) "Because the cost of a reactor is strongly influenced by the strength of the magnetic field that must be provided, beta values are directly related to the economics of fusion power production. Beta is usually expressed as a percentage, with 5% generally believed to be the minimum value required for an economical fusion reactor." - from the PPPL WWW page on PBX-M. See also: pressure, kinetic pressure, magnetic pressure, second stability. * Beta-Normal: Beta-N, the normalized beta, is beta relative to the beta limit (see below). * Beta-Poloidal: Beta-P is the same as the ordinary beta, except only the poloidal field is used in calculating the magnetic field pressure. Beta-P is > 1 in many modern tokamaks. * Beta Emission: Form of nuclear decay where a neutron splits into a proton plus electron plus neutrino set. The proton stays in the nucleus but the electron ("beta ray") is ejected. * Beta Limit, also called Troyon Limit: If the plasma pressure in a tokamak becomes too high, the so-called ballooning modes become unstable and lead to a loss of confinement (sometimes catastophic, sometimes not). The exact value at which this occurs depends strongly on the magnetic field B, the plasma minor radius a, and the toroidal plasma current I, such that maximum value of the normalized beta, beta_N=beta*B*a/I, is around 4% (with B in Teslas, a in meters, and I in Mega-amperes). The exact value depends on details of the plasma shape, the plasma profiles, and the safety factor. (Beta entries provided by Art Carlson.) * Beta Particle / Beta Ray: Original term used for electrons (and positrons) ejected from decaying nuclei via beta emission. (Label derives from the old days when we had various kinds of radiation emission, and they were labeled alpha, beta, and gamma (the first letters of the Greek Alphabet) because no one really knew what any of them were.) * Beta value: See "beta" just above. * Biasing: [from Art Carlson] The vacuum vessel of a tokamak (or other device) has a variety of structures--limiters, divertor plates, the wall itself. These are usually mechanically and electrically connected, but it is possible to bias (charge) them to different voltages relative to each other. This allows some control over the electric fields and currents around the plasma, which can influence, for example, the thickness of the scrape-off-layer, the transition between L- and H-mode, and the equilibrium configuration. Biasing experiments are being done on DIII-D, TEXTOR, and TdeV. * Binary Collisions: Collisions involving only two particles; multiparticle collisions (eg, three-body collisions) are usually neglected/approximated... * Binding Energy: Energy required to separate two objects; conversely, energy released when two objects are allow to bind together. Equivalent to the mass defect (see entry) via E=mc^2. * Biological Hazard Potential (BHP): Measure of the hazard posed by a given quantity of radioactive material in which the variation in biological effects of the various elements are accounted for. (See also integrated biological hazard potential, IBHP) & Biot-Savart Law: General formula for determining the magnetic field due to a steady line (not space) current. Related to Ampere's Law. * Blanket: a region surrounding a fusion reactor core within which the fusion neutrons (if any) are slowed down, heat is transferred to a primary coolant, and tritium is bred from lithium (if tritium is used as fuel). In hybrid applications, fertile materials (U-238 or Th-232) are located in the blanket for conversion into fissile fuels. * Bohm diffusion: A rapid loss of plasma across magnetic field lines caused by microinstabilities. Theory formulated by the physicist David Bohm. From Chen's book (see bibliography): "Semiempirical formula for the diffusion coefficient given by Bohm in 1946 (noted by Bohm, Burhop, and Massey, who were developing a magnetic arc for use in uranium isotope separation)." Bohm diffusion was proposed (not derived from first principles) to scale as 1/B rather than the 1/B^2 scaling predicted by classical diffusion. A 1/B scaling results from assuming that particles diffuse across field lines at an optimum rate (effective collision frequency=cyclotron frequency). The 1/B scaling is observed (approximately) in most reactors. (Acknowledgements to Philip Snyder) See also: diffusion, microinstabilities, field lines... * Boiling Water Reactor (BWR): Class of fission reactor where water is used as a coolant and allowed to boil into steam. (I don't remember much more about it - any help out there?) & Boltzmann constant: k = 1.38 x 10^-16 erg/degree. This is the ratio of the universal gas constant to Avogadro's number. It is also used to relate temperatures (Kelvin) to energies (ergs or Joules) via E = (constant of order unity) * kT. & Boltzmann Distribution: See Maxwell-Boltzmann distribution; distribution function. * Boltzmann Equation: Fundamental equation in kinetic theory which describes the evolution of the distribution function. (See also Vlasov equation.) * Bootstrap Current: Currents driven in toroidal devices by neo-classical diffusion (see entry). They may amount to a substantial fraction of the net current in a tokamak reactor, thus lengthening the pulse time or decreasing the power needed for current drive. & Boron: (B) Fifth element (Z=5) in the periodic table; has 5 protons; potential use as an aneutronic fuel. (See FAQ section 1, part on reactions.) Also useful as a neutron-absorber. * Boronization: Energy confinement in a fusion plasma depends strongly on the average atomic number (Z) of the elements in the plasma. Boronization refers to a process whereby boron (atomic number 5) is injected into a plasma and used to coat the walls of the reactor; the effect is that impurities from the reactor walls which enter the fusion plasma are primarily boron (which has a fairly low Z) rather than the higher-atomic-number metals typically used in reactor structures. Boronization has been associated with improved fusion plasma performance. Boronization is an example of Wall Conditioning. See also Boron, atomic number, wall conditioning, impurities. * Bounce Frequency: The average frequency of oscillation of a particle trapped in a magnetic mirror as it bounces back and forth between its "turning points" in regions of high magnetic field. (See also trapped particle, turning points, banana orbit). * Boundary Layer: In fluid flow, a narrow region next to a fixed boundary or surface where the fluid velocity rapidly changes from zero to some finite value. The term has been generalized to situations with similar mathematics. * Branching Ratio: In a fusion reaction involving two nuclei, there are typically a variety of possible sets of products which can form. The branching ratio for a particular set of products is the probability that that set of products will be produced. * Breakeven: there are several types: Commercial: When fusion power can be converted into enough electric power to power the reactor and generate enough electricity to cover the costs of the plant at economically competitive rates. (?) Engineering: When enough energy can be generated from the fusion power output to supply power for the reactor and generate a surplus; sort of commercial breakeven without the economic considerations. (?) Scientific: When fusion power = input power; Q=1. (See also Lawson Criterion) Extrapolated - projected for actual reactor fuel using an alternative fuel. Actual - determined using the actual fusion fuel to be used in the reactor (typically DT). * Breeder Material: In D-T fusion, refers to lithium or lithium-containing substances which are placed in the blanket to convert the fusion neutrons back into tritium, using nuclear transmutation of lithium isotopes. * Breeder Reactor: Class of nuclear reactor (could be fission or fusion) which uses some of the nuclear byproducts (generally neutrons) to transmute non-fuel materials to new materials which can be used for fuel in other reactors, in such a way that the reactor creates more fuel than it consumes (breeding). Term usually refers to reactors which breed fission fuel. Use of breeder reactors would greatly extend the fuel supply for nuclear fission energy, but also creates additional opportunities for diversion of fissile materials to weapons production and could exacerbate proliferation of nuclear weapons. & Bremsstrahlung: (German for "Braking Radiation") Electromagnetic radiation from a charged particle as it slows down (decelerates), or as it changes direction due to near collisions with other particles. Similar to synchrotron radiation (see also). In a plasma bremsstrahlung occurs when electrons (which are lighter and generally move faster) collide with ions (which are heavier and generally move slower); the acceleration/deceleration of the electrons causes them to radiate bremsstrahlung. & Brewster's Angle: The angle of incidence at which electromagnetic waves reflected from a dielectric medium are completely polarized perpendicular to the plane of incidence; the component polarized parallel to the plane of incidence is completely transmitted. * British Thermal Unit: Unit of energy needed to raise a pound of water by one degree fahrenheit; equal to 252 calories or 1055 Joules. (See also calorie, joule). Not part of the metric system. > Bumpy Torus: I believe this concept tries to combine mirror concepts with toroidal ones. My understanding is that it is essentially a series of mirrors stuck end to end and bent into a ring. - Albert Chou (corrections / enhancements welcome!) * Bunching: A technique for spatial compression of a pulse in a beam of charged particles. * Bundle Divertor: Divertor concept where a toroidal field coil extracts a "bundle" of toroidal field lines (flux) and forms a separatrix in the toroidal field. (Hard to do and tends to mess up axisymmetry of the torus; not used much.) > Burning Plasma eXperiment (BPX): Proposed U.S. successor to TFTR; never funded. See also: CIT, TPX. * Burnout: Rapid reduction in the neutral particle density in a plasma discharge; occurs when the ionization rate (which converts neutrals to ions and electrons) exceeds the rate of recombination (which converts ions to neutrals) and the rate of influx of neutral particles. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 3/26 (C) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 3/26 (C) Date: 28 May 1995 13:04:14 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/c Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 3: Terms beginning with "C" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC # c: Speed of light; 3.0x10E+8 meters/second or 3.0x10E+10 cm/sec @ CAMAC: Computer Automated Measurement and Control @ CANDU: CAnadian Deuterium-Uranium class of fission reactor; see entry > CASCADE: See entry (not an acronym as far as I know). @ CCD: Charge Coupled Device @ CGS: Centimeters, Grams, Seconds; see CGS Units @ CGS Units: see entry below; see also CGS above. @ CFFTP: Canadian Fusion Fuels Technology Project; see entry. @ CIT: Compact Ignition Tokamak; see entry @ COE: Cost of Electricity @ CT: Compact Torus; see entry @ CTX Facility: Compact Toroid Experimental facility; see entry. @ cw: Continuous Wave (distinct from pulsed). @ CY: Calendar Year (as opposed to Fiscal Year, FY) $ cm: centimeters; unit of distance. See also centi- * C-Coil: C-shaped magnet coil * Calorimeter: In conventional fusion research, this name refers to any device used to measure power or energy in a laser or particle beam. (e.g., for ICF or neutral beam heating or a magnetically-confined plasma.) * Canadian Deuterium-Uranium Fission Reactor: Nuclear fission reactor type developed in, and prominent in, Canada; characterized by use of heavy water (deuterium instead of hydrogen, D2O) as moderator and coolant. Neutrons absorbed by the deuterium create a source of marketable tritium. * Canadian Fusion Fuels Technology Project: Fusion power development project, jointly funded by the National Research Council of Canada, the Province of Ontario, and Ontario Hydro (energy company and project manager), to develop and internationally apply technologies related to management of fusion fuels. (Any current info, anyone?) & Carbon: (C) Sixth element (Z=5) in the periodic table; has 6 protons; often described as the basis of life on earth because of its chemical properties; has potential for use with silicon as a low-activation structural material for fusion reactors, in the form silicon carbide. (See relevant parts of FAQ section 2.) Also useful as a neutron moderator. See also low-activation materials. & Carnot Efficiency: maximum possible efficiency for conversion of thermal energy to useful work (such as electrical energy), as determined by the laws of thermodynamics. The Carnot efficiency (eta) for conversion of thermal to electric energy (e.g., the upper limit on efficiency of a steam turbine) is given by (eta) = [ (T-hot) - (T-cold) ] / (T-hot). That is, one gets the efficiency from the values of the input and output temperatures (measured in Kelvin). & Capacitor: device used to store electrical energy by accumulating charges on nearby conductors. Energy may be stored and withdrawn at varying rates. Used in short-pulse plasma devices where only a moderate amount of energy is needed. * Capacity Factor: Index (typically in percent) indicating the average power supplied by an energy plant, relative to its maximum rated capacity. * Capital: Economic term for wealth of a permanent nature, rather than that which is consumed; includes money and other financial goods, plant & equipment, etc. (I'm not an economist - anyone know any better?) > CASCADE: An inertial-fusion energy conversion concept where a flowing, replenished layer of ceramic granules (in a rotating chamber) protects the chamber wall from the fusion environment while absorbing neutrons, breeding tritium fuel, and serving as the high-temperature heat exchange fluid. & Celsius: Temperature scale where zero degrees corresponds to the freezing point of water (32 Fahrenheit) and 100 degrees corresponds to the boiling point (212 Fahrenheit). Zero celsius = 273.16 Kelvin. * Centering Force: Term for the mutual attraction between the parallel currents in the inboard leg of the toroidal field coils in a toroidal magnetic fusion system (e.g., a tokamak). The portion of the coil running "through the doughnut hole" is attracted towards the center of the hole. & Centi-: metric prefix indicating 1/100th of a given unit. e.g., one centimeter is 1/100th of a meter. & Centigrade: see Celsius & CGS Units: System of measurement where the fundamental units are centimeters, grams, and seconds. & Chain Reaction: (from Herman) A self-sustaining series of chemical or nuclear reactions in which the products of the reaction contribute directly to the propagation of the process. * Channel Transport: In inertial fusion research using light ion drivers, describes the use of current-carrying plasma channels (which are magnetically confined to the channel) to transport electron or ion beams between the ion diode and the fusion target. This allows the ion source to stand back from the target. & Charge Density: See density, and apply to electrical charge. & Charge, Electrical: As a noun: A fundamental physical attribute of a particle, which characterizes the particle's electromagnetic interaction with other particles and with electric and magnetic fields. (See also particle, field) As a verb: Storing energy in a battery or electric capacitor by running a current through it; opposite of discharge. (It is possible to charge most capacitors in either direction, but batteries charge one way, and discharge the other.) * Charge Exchange: Phenomenon in which an ion colliding with a molecule (or an atom) neutralizes itself by capturing an electron from the molecule/atom, and transforming the molecule/atom into a positive radical/ion. * Charge Transfer: see charge exchange * Charged Particle: a particle which carries a positive or negative electrical charge. In plasma physics, this typically means an ionized atom or molecule, or an electron. * China Syndrome: American jargon/slang for a nuclear fission meltdown accident (see meltdown) in which the molten nuclear core heats and melts the ground beneath it, thus sinking into the earth, and heading towards China (which is roughly on the opposite side of the globe). * Classical Confinement: Plasma confinement in which energy transfer is via classical diffusion; best possible case for magnetically confined plasmas. See entry for classical diffusion below. * Classical Diffusion: In plasma physics, diffusion due solely to scattering (collisions) of charged particles (with unlike charges) via electrical ("Coulomb") interactions. (See also diffusion.) * Coherent Radiation: Any form of radiation in which the phase relationship between sections of the wave at different locations is not random (or incoherent!). Typical example is a laser beam, in which the phase is more or less uniform across the beam, and changes along the beam in accordance with the wavelength. Radiation in which the photons tend to "agree" with one another, rather than being randomly distributed. * Cold Plasma Model: Model of a plasma in which the temperature is neglected with respect to the effects of interest. * Collision: Refers to the close approach of two or more particles, photons, atoms, nuclei, etc, during which such quantities as energy, momentum, and charge may be altered. More-or-less synonymous with "scattering," except in scattering one generally thinks of one of the particles as being at rest, and the other colliding particles "scatter" from their initial direction of motion due to the collision. & Collision Cross-Section: Effective surface area of a particle when it collides with another; describes probability of collisions between the two particles. * Collisionless Plasma Model: Model of a plasma in which the density is so low, or the temperature so high, that close binary (two-body) collisions have practically no significance (on certain timescales) because the time scales of interest are smaller than the collision time. Yields valid physical results for timescales much shorter than the average collision time in a real plasma. & Collision Time: Typical time which passes between the time a particle collides, and when it collides again. Inverse of the collision frequency; equal to the mean free path divided by the particle's velocity. The collision time decreases with increasing density, and increases with increasing temperature. > Compact Ignition Tokamak (CIT): Proposed U.S. successor to TFTR; never funded. See also, BPX, TPX. > Compact Torus: Any of a series of axially symmetric fusion configurations having closed flux surfaces (like a tokamak, not like a mirror machine), but having no material objects piercing the core (as do the toroidal field coils of a tokamak). These devices have an inherently low aspect ratio, approximately unity. The most successful variants are the spheromak and the Field Reversed Configuration. See also: low aspect ratio, spheromak, field-reversed configuration. (Arthur Carlson, awc@ipp-garching.mpg.de) > CTX Facility (Compact Toroid Experimental facility): Los Alamos facility to investigate plasma physics of compact toroids. (No longer in operation?) * Compression Waves: Also known as density waves (I think!); waves where the quantity which oscillates is the density of the medium, that is the medium at a given point alternately compresses and expands. Low-amplitude compression waves in air or water are commonly known as sound waves; shock waves are a high-amplitude form. See also waves. & Conductivity: Degree to which a substance transmits (conducts) a given physical property, such as heat or electricity. See electrical conductivity, thermal conductivity. * Confinement, Classical: See classical confinement. * Confinement, Electrostatic: See electrostatic confinement. * Confinement, Inertial: See inertial confinement. * Confinement, Magnetic: See magnetic confinement. * Confinement Time: There are several types. The general definition is that tau = [total]/[loss per unit time]; hence Tau_E = [total energy]/[energy loss per unit time]. Tau_[E, N, ...] is the amount of time the plasma is contained by magnetic fields before its [energy (E), particles (N or P)] leak / dissipate away. The different types are, in general, similar but not equal. (Note note note: Tau_E is NOT electron confinement time!) > Constance: Small mirror devices; formerly operated at MIT. * Containment Vessel: Gas-tight shell or other enclosure around a fusion (or fission) reactor, to prevent accidental leakage of radioactive contents. * Controlled Thermonuclear Fusion: The process in which light nuclei, heated to a high temperature in a confined region, undergo fusion reactions under controlled conditions, with associated release of energy which may be harnessed for useful purposes. * Coolant: Substance circulated through a device (including fusion reactors, fusion reactor magnets, etc.) to remove or transfer heat. Common types include water, helium, and liquid-metals such as sodium (Na). * Cooperative Phenomena: The motion of interacting particles acting collectively, rather than individually. Includes plasma oscillations, turbulence, and instabilities. (Plasmas are distinguished from collections of individual particles in that they exhibit cooperative phenomena, whereby the plasma particles "cooperate" with one another. Early fusion researchers who devised fusion schemes based upon theories where plasmas acted as merely a collection of individual particles (and therefore sought to confine only individual particles) often found themselves frustrated at the ability of plasma cooperative phenomena (such as MHD instabilities) to thwart their efforts. * Core plasma: Hot plasma at the center of a fusion reactor; distinguished from edge plasma. The core plasma does not directly feel the effects of the divertor or limiter in the way the edge plasma does. (More info anyone?) * Corona: The outermost (?) part of a star's atmosphere; characterized by high temperatures and low densities; home to many plasma phenomena. * Corrosion: Chemical interactions between a fluid, (such as lithium or water coolant) and the containing material (such as stainless steel), which results in wall material dissolving into the fluid, and possibly degradation of the mechanical properties of the containing structure $ Coulomb: standard unit of electric charge. A single electron or proton has a charge of (+/-) 1.6022E-19 coulombs. Hence there are 6.2414E+18 electrons in a coulomb of electrons. * Coulomb Collision: An interparticle collision where Coulomb's Law (electrical attraction and repulsion) is the governing force. (See Coulomb's Law) Coulomb collisions have a number of interesting properties, but these are better described in textbooks. The interaction of the charged particles with each other's electric fields results in deflections of the particles away from their initial paths. & Coulomb Force: See Coulomb's Law. Also called "electrostatic force." * Coulomb Ionization: Ionization produced by Coulomb forces between a moving particle ("projectile") and another particle it interacts/collides with ("target"). & Coulomb's Law: Force law governing the electrical interaction between charged particles. Force is proportional to (charge of first particle) * (charge of second particle) / (square of separation between particles). Constant of proportionality depends on system of units used. (In SI units, it is 1/(4*pi*epsilon-0), where epsilon-0 is the permittivity of free space = 8.854 x 10^-12 ) & Cross Section: (usually symbolized with a lower-case Greek sigma) In physics this usually refers to the (apparent) area presented by a target particle to an oncoming particle (or electromagnetic wave). This measures the probability of an interaction occuring. For typical interactions between ions and electrons, or between two nuclei, these cross sections are generally measured in barns. (See relevant entries.) & Cryogenic: Loosely, "very cold". Used to describe systems which operate at very low temperatures. Superconducting magnetic field coils currently need to operate at cryogenic temperatures (e.g., liquid helium at 4 Kelvin). * Curie: Unit of radioactivity roughly equal to the rate of radioactive decay of a gram of radium; named after Marie Curie (see below). Corresponds to 3.7 x 10^10 disintegrations/second (37 billion). (See Becquerel) ! Curie: Marie and Pierre; husband-wife pair of French scientists. Pierre's name is attatched to the "Curie point" in magnetism, which is not discussed here. He and his wife shared with Antoine-Henri Becquerel the Nobel Prize for physics in 1903. Marie Curie, a.k.a. Madame Curie, received the Nobel Prize for chemistry in 1911, becoming the first person to receive more than one Nobel Prize. She remains the only person to receive Nobel Prizes in different fields. (I believe - RFH) & Current Density: Amount of current flowing through a substance, per unit area perpendicular to the direction of current flow. (See also density) * Current Drive: Any of a variety of techniques used to cause current flow in a plasma. See inductive current drive, RF current drive, non-inductive current drive. Usually applied to schemes used to generate current in tokamaks and other toroidal devices which require internal plasma currents. See also: bootstrap current. * Cusped Geometry: I can't figure out how to explain this one in words; suffice it to say that this is a description of a magnetic field configuration where the magnetic field lines, rather than closing in on themselves, tend to squirt out and form cusps at certain points; I recommend you look this up in a plasma physics text (e.g., Chen - see bibliography entry) to really understand it. The magnetic field lines are everywhere convex towards the center. Such a geometry is interesting because it is theoretically stable against a variety of MHD instabilities. > Cyclops: Single-chain, 0.6 terawatt Nd-glass laser system at Lawrence Livermore National Laboratory that was used for laser studies and inertial-confinement fusion experiments in 1975-1976. * Cyclotron: Particle accelerator in which a magnetic field causes particles to orbit in circles, and an oscillating electric field accelerates the particles. * Cyclotron Frequency: Number of times per second that a particle orbits in a magnetic field. (Often, and incorrectly, called the Larmor frequency. The cyclotron or gyrofrequency is twice the Larmor frequency of precession.) * Cyclotron Radius: Radius of orbit of charged particle about a magnetic field line. Also called gyroradius, Larmor radius. * Cyclotron Radiation: See synchrotron radiation * Cyclotron Resonance: Charged particles in a magnetic field resonate with (and absorb energy from) an electric field (perpendicular to the magnetic field) which oscillates at the particles' cyclotron frequency, or at a harmonic (multiple) of that frequency. * Cyclotron Resonance Heating: see Electron Cyclotron Resonance Heating, Ion Cyclotron Resonance Heating. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 4/26 (D) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 4/26 (D) Date: 28 May 1995 13:04:15 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/d Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 4: Terms beginning with "D" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = vocabulary specific to plasma/fusion/energy research & = basic/general physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD @ D: nuclear/chemical symbol for deuterium/deuteron @ DC, dc: Direct Current; see entry @ DCLC: Drift Cyclotron Loss Cone instabilities; see entry. @ DT: Deuterium-Tritium; see entry labeled DT Fuel @ DIII-D: not an acronym (anymore); see entry @ DOE: Department of Energy (United States); see entry @ dpa: Displacements per atom; see entry @ DPP: Division of Plasma Physics; see APS-DPP * D-shaped plasma: A toroidal plasma whose cross section (poloidal plane) is a D (instead of a circle). A D-shape has a higher beta limit (see entry) than a circular shape. * Debye Length: The characteristic distance over which charges are shielded in a plasma. See also: Debye shielding. lambda_D = ( epsilon_0 k_B T_e / (n_e e^2) )^(1/2) lambda_D[m] = (7.434*10^3)*(_e[eV])^(1/2)*n[m^(-3)]^(-1/2) (Arthur Carlson, awc@ipp-garching.mpg.de) ! Debye, Peter Joseph: Physical chemist, studied behavior of conductive solutions (plasmas have some similar behaviors). * Debye Radius: See Debye Length. * Debye Sheath: The region of strong electric field in front of a material surface in contact with a plasma. Its characteristic thickness is the Debye length, and it is caused by Debye shielding of the negative surface charge resulting from electrons flowing to the surface much faster (initially) than the ions. The lost electrons leave behind a region of net positive charge which gradually diminishes the strength of the electric field over the debye length. See also: Debye Length, Debye Shielding. (Arthur Carlson, awc@ipp-garching.mpg.de, with modifications by John Cobb, johncobb@uts.cc.utexas.edu) * Debye Shielding: If a positive (or negative) charge is inserted into a plasma, it will change the local charge distribution by attracting (repelling) electrons. The net result is an additional negative (positive) charge density which cancels the effect of the initial charge at distances large compared to the Debye length. (There is a corresponding effect of shielding by the ions, which, for various and subtle reasons, usually is less important.) See also: Debye Length. (Arthur Carlson, awc@ipp-garching.mpg.de) * Debye Sphere: Sphere around a charged test particle whose radius is equal to the Debye length. & Decay, Radioactive: See radioactive decay. * Decay Modes: Different pathways for decay of radioactive nuclei. The decay modes for a given unstable state can include beta emission (negative = electron, positive = positron), electron capture, alpha emission, fission, and gamma emission. (Did I miss any?) See entries for each mode for more information. * Dee-Shaped: see D-shaped plasma above. * Degenerate Configuration: Magnetic field configuration in which the magnetic lines of force close exactly on themselves after passing around the configuration a finite number of times. * Dense Plasma Focus: See Plasma Focus. (Densities of up to 10^26 particles/m^3 have been reported.) & Density: amount per unit of volume, or per unit surface area, or per unit length. (Usually specified or clear from context which of these is meant). Several types: Charge density - amount of charge per unit (volume, area, length) Current density - current flow per unit transverse surface area. Energy density - amount of energy per unit volume. Flux density - flux per unit of transverse surface area. Mass density - mass per unit volume. Number density - number of particles per unit volume. Particle density - same as number density. % Department of Energy: (DOE) Department within the executive branch of the U.S. government (at the cabinet level) which has managed and overseen federally-sponsored energy research. The DOE was formed in 1977 from ERDA, the Energy Research and Development Administration, and (I think) the Atomic Enegy Commission (AEC). & Deuterium: A heavy isotope of hydrogen whose nucleus contains both a neutron and a proton. * Deuteron: A deuterium ion; nucleus consisting of a proton and a neutron. * Diagnostics: (from Herman) Procedures for determining (diagnosing) the state of a plasma during an experiment; also refers to the instruments used for diagnosing. * Diamagnetic Effects: Application of a magnetic field to a plasma will tend to create circulating current within the plasma that will reduce the strength of the magnetic field. * Diffusion: The interpenetration of one substance into another as a result of thermal / random motion of the individual particles. (e.g., the diffusion of a plasma across a magnetic field as a result of collisions which cause particles to move along new field lines.) See also classical diffusion, neoclassical diffusion, anomalous diffusion, transport. * Direct Conversion: The generation of electricity by direct recovery of the kinetic energy of the charged fusion reaction products. & Direct Current: Electric current which is unchanging in time, or at least not oscillating. Opposite of Alternating Current. * Direct Drive: An approach to inertial-confinement fusion in which the energy of the driver (laser or particle beam) is directly incident on the (usually spherical) target, causing compression heating via ablation of the target surface. * Dispersion Relation: For a given wave, the dispersion relation relates the temporal frequency of a wave (w, or omega) to its wavenumber k and other physical quantities characteristic of the system. Dispersion relations can be quite simple (e.g., w = k * c for light; c being the speed of light), and they can also be quite complex, with interesting mathematical structure. The dispersion relation and its mathematical structure provide important information about the wave, including the phase and group velocities. (See relevant entries.) Note that the meaning of "dispersion relation" is different in plasma physics than in other fields. * Displacements Per Atom: (dpa) This is a measure of the amount of radiation damage in neutron-irradiated materials; e.g., 10 dpa means each atom in the material has been displaced from its structural lattice site and average of 10 times (due to interactions between the atoms and the energetic neutrons irradiating the material.) * Disruption: Plasma instabilities (usually oscillatory modes) sometimes grow and cause disruptions of the carefully-engineered plasma conditions in the reactor. Major disruptions can cause an abrupt temperature drop and the termination of the plasma. Stored energy in the plasma is rapidly dumped into the rest of the plasma system (vacuum vessel walls, magnet coils, etc.) and can cause significant damage if precautions are not taken. * Disruptive Instability: Instability which causes a disruption; see entry for disruption. * Dissociative Recombination: The combination of an electron with a positive molecular ion, followed by dissociation of the molecule in which the resulting atoms/molecules carry off the excess energy released in the recombination. & Distribution Function: Function characterizing the density of particles located at a given point in phase space (a combination of either velocity or position coordinates) at a given time. The velocity-space distribution function gives the number of particles with a particular velocity; the position-space distribution function is synonymous with the particle density in position-space. Different combinations of position and spatial coordinates are useful in different problems. * Divertor: Component of a toroidal fusion device that diverts charged particles on the outer edge of the plasma into a separate chamber where they strike a barrier and become neutralized. In a reactor, the divertor would incorporate a system for pumping out the neutralized particles as exhaust from the machine. A divertor, like a limiter, prevents the particles from striking and degrading the chamber walls and dislodging secondary particles that would cool and contaminate the plasma. Whereas a limiter is a material object used to limit the shape of the plasma, a divertor is a magnetic-field construction. The advantage of the divertor is that it allows the neutralization region to be removed from the main plasma. See also: limiter. * Doppler Broadening: Frequency spreading which causes broadening of single-frequency radiation (e.g., spectral lines) when the radiating bodies (atoms, molecules, etc.) have different velocities. Radiation from each individual radiating body has a different Doppler shift, and the collection of radiations at different frequencies broadens the peak of the line in an intensity-vs-frequency plot. & Doppler Effect: Variation in the frequency of a wave (as measured by an observer) due to relative motion between the observer and the source of the wave. (The observed frequency increases if the source is moving towards the observer.) & Doppler Shift: The amount of change in the observed frequency of a wave due to the Doppler effect; sometimes called the Doppler frequency. > DIII-D: Latest in a series of tokamaks designed by General Atomics (formerly GA Technologies) in San Diego making plasmas with noncircular cross sections, including kidney shapes and D-shapes. * Doublet Device / Doublet Plasma: Tokamak-type devices where the plasma cross-section is kidney-shaped, with a deep indentation in the middle so that the plasma has two major rings of current (on top and bottom). * Drift Cyclotron Loss Cone Instabilities: (DCLC) This is an electrostatic microinstability (frequencies at harmonics of the ion cyclotron frequency) which is of major concern in small mirror devices. Mode is driven by radial gradients in the electron density, and causes loss of ions due to non-conservation of magnetic moment (see adiabatic invariant) as they interact with the mode, and are dispersed in velocity space into the loss cone. Stabilization is accomplished by increasing the plasma size and by partially filling the loss cone with a continuous extermal warm plasma stream. * Drift Motion: Ordinarily particles placed in a magnetic field will simply orbit in circles, but if the magnetic field is not uniform, or curves, or there is an electrical field perpendicular to the magnetic field, or another force is applied perpendicular to the magnetic field, then the "guiding centers" of the particle orbits will drift (generally perpendicular to the magnetic field and to the applied force). There are several sorts of drifts; refer to a plasma physics text for more information (see Section 11: Bibliography). For a good introduction at the undergraduate physics level, see Chen. * Drift Pumping: A process that removes ions trapped in a thermal barrier using radial transport induced by an exterally-applied radiofrequency field tuned to resonate with the azimuthal drift frequency. * Drift Surface: Surface on which the guiding center of a particle is constrained to move, due to the effects of the laws of adiabatic invariance on its drift motion. * Drift Velocity: Characteristic velocity at which the center of a particle's orbit ("guiding center") drifts when drift motion (see above) occurs. * Drift Waves: Oscillations in a magnetically-confined plasma arising in the presence of density gradients (such as at the plasma's surface). These resemble the waves that propagate at the interface of two fluids with different density in a gravitational field. * DT Fuel: (Deuterium-Tritium) Easiest fuel mixture to use in achieving fusion; unless otherwise specified, probably refers to a 50-50 (by numbers or by moles) mix of deuterium and tritium. * Duty Factor: Ratio of the duration of time when a system is actually operating to the total time for a complete cycle of the system. e.g., if a tokamak experiment runs for 5 seconds and then sits for 500 seconds while the power supplies are recharged, then the duty factor is 1%. Similar to capacity factor for powerplants. * Dye laser: A type laser in which the active material (the material which emits the laser light) is a dye. These lasers are tunable when the dye has very large molecules (such as acridine red or esculin) and the laser action takes place between the first excited and ground electronic states, because each of these states contains a broad continuum band of vibrational-rotational levels. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 9/26 (I) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 9/26 (I) Date: 28 May 1995 13:04:19 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/i Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 9: Terms beginning with "I" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII # I: variable used to indicate total current through a conductor. @ IAEA: International Atomic Energy Agency; see entry @ IBHP: Integrated Biological Hazard Potential; see entry @ ICE: Ion Cyclotron Emission; see entry @ ICF: Inertial Confinement Fusion; see entry @ ICH: Ion Cyclotron Heating - see ICRH @ ICRF: Ion Cyclotron Range of Frequencies @ ICRH: Ion Cyclotron Resonance Heating; see entry @ IEEE: Institute of Electrical and Electronic Engineers; see entry @ INEL: Idaho National Engineering Laboratory; see entry @ IPP: Max Planck Institute for Plasma Physics; see entry @ IR: Infrared (region of the electromagnetic spectrum) @ ITER: International Thermonuclear Experimental Reactor; see entry % Idaho National Engineering Laboratory: U.S. Department of energy laboratory involved in engineering studies for fusion and fission reactors, among other things. Not surprisingly, located in Idaho. * Ignition: In fusion, as in an ordinary (chemical) fire, ignition is the point where the temperature and confinement of heat in the fuel (plasma in the case of fusion) are such that energy released from ongoing reactions is sufficient to maintain the temperature of the system, and no external heating is needed. An ignited fusion plasma produces so much energy from fusion reactions that the plasma is fully heated by fusion reaction products (alpha particles in the case of D-T fusion), and the plasma no longer needs any external source of power to maintain its temperature. (The plasma may, however, still need something to maintain its confinement; this gives us control over the fusion reaction and helps prevent fusion reactors from having "meltdown" problems like fission reactors.) * Ignition Temperature: For given values of density and energy confinement, the temperature at which ignition occurs. (see ignition above) > Impact Fusion: Fusion approach where a "fuel" projectile is acclerated and impacted into either a stationary target or another projectile. (Valuable for scientific purposes but not a candidate for a fusion energy source because the likelihood of fusion occurring in a single collision is too low. Multiple accelerated pellets colliding with spherical symmetry might be a viable inertial confinement approach, though.) * Impact fusion drivers: macroparticle/projectile accelerator which could be used in inertial confinement fusion. * Impurities: atoms of unwanted elements in the plasma, which tend to degrade plasma performance, and in the case of fusion plasmas tends to inhibit fusion ("poisoning the reactor"). See also poisoning. * Impurity Control: Processes which reduce or control the level of impurities in a plasma, and thereby improve its quality; see also wall conditioning. * Inboard side: portion of a tokamak (or other toroidal device) closest to the central axis. (As distinguished from "outboard side.") * Incoherent scattering: Type of scattering in which the scattering elements act independently, so that no definite phase relationships exist among the different parts of the scattered beam (particles or photons). & Index of Refraction: For a given wavelength, this is the ratio of the velocity of light in vacuum (c) to the velocity of light in a refractive material (e.g., glass, plasma, etc.). & Inductance: Characteristic relating the magnetic flux generated through a loop of wires to the current in the wires; Phi=LI. & Induction: A changing magnetic flux through a current loop will induce an electric field which will drive a current through the loop. This is the principle behind an AC transformer, where an oscillating electric voltage in one loop of the transformer creates a current which generates an oscillating magnetic field, which then induces a different voltage and current in a second loop. * Inductive Current Drive: Method to drive current in a toroidal plasma by using the torus of conducting plasma as the second coil in a transformer. The primary coil usually runs down the center of the torus; changes in the current driven through the primary coil create changing magnetic fields which drive current in the plasma. The current thus driven can be used to heat the plasma as well (see also ohmic heating; induction). * Inertial Confinement Fusion: Approach to fusion where the plasma is imploded so quickly that the inertia of the converging particles is so high that many fuse before they disperse. This is the method used in a hydrogen bomb; ICF schemes for power production usually use small pellets of fuel in an attempt to make "miniature" h-bomb type explosions. Methods for imploding the pellet include bombardment from all sides with high-powered laser and particle beams, and of course implosion in a fission bomb. Parts of ICF fusion research remain classified due to their military implications and applications, though much ICF research was recently declassified. * Instability: A state of a plasma (or any other physical system) in which a small perturbation amplifies itself to a considerable alteration of the state of the system. In plasmas instabilities sometimes leads to disruptions (see entry). Most instabilities are associated with waves and other natural modes of oscillation in the plasma, which can sometimes grow. There are (unfortunately!) many kinds. See also: Flute instability, MHD instability, Interchange instability, microinstability, kink instability, resistive instability, trapped particle instability, two-stream instability, universal instability, and velocity-space instability. % Institute of Electrical and Electronic Engineers: Professional society for this branch of engineering. * Integrated Biological Hazard Potential (IBHP): Total biological hazard potential of a collection of radioactive materials summed over their decay lifetimes. See also BHP. One measure of the IBHP is the amount of water one would need to use to dilute the materials to the point where the water would be safe to drink. * Integrated neutron flux: Sum (integral) of the neutron flux (neutrons per unit time per unit area, see flux) over all time; total number of neutrons which passed through a unit area. Important figure-of-merit in testing effects of neutron radiation on materials, and in assessing how long such materials can survive exposure to neutron sources (such as fission reactor cores and D-T fusion plasmas). * Intensity: This term has different meanings in different contexts. Can refer to the amount of power (energy per unit time) incident on a unit surface area, or flowing through a unit volume. Can refer to the number of particles or photons incident, per unit time, on a unit area, or flowing through a unit volume. Also, for an amount of a radioactive material, intensity can refer to the number of radioactive disintegrations per unit time. * Interchange Instability: In the simplest form, if you place a high-density fluid on top of a low density fluid, gravity will pull the high density fluid downwards so that the low-density fluid ends up on top. The two fluids therefore interchange places. More generally, an interchange instability occurs when two types of fluid are situated with an external force such that the potential energy is not a minimum; the two fluids will then interchange locations to bring the potential energy to a minimum. In plasmas with magnetic fields, the plasma may interchange position with the magnetic field. A prime example is the flute instability in mirror machines. (See MHD, instability, flute, mirror.) * Interference: When two waves propagate through the same region of space, they interfere with each other. Neither wave is altered, but the amplitudes of the waves add (or cancel, if they're of opposite sign) to give the total effect to the medium at that point. * Interferometer: Device which measures changes in a medium by looking at effects on the interference of two waves which are passed through that medium. See interferometry, laser interferometer, optical inteferometer, Fabry-Perot interferometer, microwave interferometer. * Interferometry: Method of gathering information about a medium by using an interferometer or similar technique. Optical - Uses light as the wave to be interfered. Microwave - Uses microwaves instead. Microwave interferometry is especially useful in plasma physics for measuring plasma densities. > Internal ring devices: Toroidal configurations in which current-carrying rings are suspended (either mechanically or magnetically) inside the plasma chamber. % International Atomic Energy Agency: (from Herman) An autonomous intergovernmental organization established in 1956 with the purpose of advancing peaceful uses of atomic energy, with headquarters in Vienna. > International Thermonuclear Experimental Reactor (ITER): Huge fusion reactor being planned by the EC, US, Japan, and Russia (former USSR?). Should generate far more energy than it consumes. Research goals include engineering studies of reactor materials, component designs for steady-state devices, and testing/proving commercial feasibility. Discussed in sections 5 and 9. * Ioffe Bars: Special configuration of conductors which, when added to a conventional magnetic mirror, generate a "magnetic well" which stabilizes the mirror against MHD instabilities. & Ion: An atom (or molecule) which has become charged as a result of gaining or losing one or more orbiting electrons. A completely ionized atom is one stripped of all its electrons. * Ion acoustic wave: a longitudinal compression wave in the ion density of a plasma, which can occur at high electron temperatures and low frequencies, caused by a * Ion Cyclotron Emission (ICE): As ions gyrate around in a magnetic field (see also larmor radius or cyclotron radius), they radiate radio-frequency electromagnetic waves. This is known as ion cyclotron emission, and can be measured to help diagnose a plasma. * Ion Cyclotron Resonance Heating: Like Electron Cyclotron Heating, but heats ions using waves near the ion cyclotron frequency. See Electron Cyclotron Heating. * Ion diode: Device for producing and accelerating ion beams for light ion drivers for inertial confinement fusion. Ions are produced in an anode plasma, extracted as space-charge-limited ion flow, and accelerated to the cathode, composed of a confined electron swarm, by an applied electric field. Millions of amperes of current at millions of volts have been produced this way. * Ion Temperature: the temperature corresponding to the mean kinetic energy of the ions in a plasma. & Ionization: Process by which a neutral atom is converted to an ion (or one ion is converted to another of a different type), by removal or addition of electrons. & Ionization Energy: Generally refers to the amount of energy required to strip a particular electron from an atom. The first-ionization-energy is a commonly used quantity in many fields of physics and chemistry. Typically measured in electron-volts. Equivalent to the atomic binding energy of the electron. & Ionization Potential: See ionization energy. * Ionizing radiation: Any high-energy radiation which can displace electrons from atoms or molecules, thereby producing ions. Examples: alpha-particle radiation; beta radiation; x-rays, gamma, and hard ultraviolet light; and accelerated ions. Ionizing radiation in large quantities may cause severe skin and tissue damage and adverse effects. (On the other hand, but not to belittle the hazards of radiation, we are continuously exposed to a "natural background" of ionizing radiation too.) * Ionosphere: Ionized region of the upper earth atmosphere, which behaves like a plasma, including reflection of AM radio waves and generation of auroral glows. * Irradiation: Process of exposure to radiation. * Isomer, Nuclear: two nuclei with the same nuclear mass (total number of protons and neutrons) but different nuclear compostions. (e.g.: T & 3He are isomers: T has 1p, 2n; 3He has 2p, 1n) & Isotope: One of several species of the same element, possessing different numbers of neutrons but the same number of protons in their nuclei. Most elements have several stable isotopes, and also several possible unstable and semi-stable isotopes. The chemical and physical properties of the different isotopes are generally the same (except for the slight mass difference and the possibility of radioactivity). Examples include the hydrogen isotopes protium (ordinary hydrogen), deuterium, and tritium (two neutrons, one proton); also uranium 238, 233, and 235. The chemistry of an element depends only on the number of protons (nuclear charge) and is therefore the same for all isotopes of an element, but the nuclear properties of different isotopes will be different. There are roughly 300 known stable isotopes, and over 1000 unstable ones. & Isotropic: adjective which describes a medium whose physical properties are independent of the direction in which they are measured. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 5/26 (E) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 5/26 (E) Date: 28 May 1995 13:04:16 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/e Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 5: Terms beginning with "E" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE # e: symbol for the electron, for the unit electric charge (e = 1.6x10^-19 coulombs), and for a Euler's fundamental mathematical constant e = 2.71828... # E: Variable typically used for Energy or Electric Field (usually in vector notation in the latter case; which is meant is usually clear from context; when both are used in the same place the energy is usually represented as U instead of E.) @ EBT: Elmo Bumpy Torus; see entry @ EC: European Community; see entry @ ECDC: Electron Cyclotron Discharge Cleaning; see entry @ ECE: Electron Cyclotron Emission; see entry @ ECH: Electron Cyclotron Heating; see entry @ ECRH: Electron Cyclotron Resonance Heating - same as ECH. @ EF: Equilibrium (vertical) Field Electromagnet Coil; see vertical field $ ECU: European Currency Unit @ ELM: Edge-Localized Mode; see entry @ EM: Electromagnetic @ EM Wave: Electromagnetic Wave; see entry @ EPA: Environmental Protection Agency (U.S.); see entry @ ERDA: Energy Research and Development Agency; see entry @ ESECOM: Reactor design study done in the mid 1980s to evaluate the Environmental, Safety, and ECOnoMic potential of different types of fusion and advanced fission reactors. @ ESNET: Energy Sciences NETwork; no entry yet @ ETF: Engineering Test Facility @ EU: European Union; see entry @ eV: Electron-volt; see entry $ Exa: metric prefix for 10^18 or 1,000,000,000,000,000,000 $ Exajoule: unit of energy, 10^18 joules; often used as unit of measure for world annual energy use. Comparable in size to a Quad (1 EJ = 0.948 Quads); see entry for Quad. * E-Coil: The plasma current driving (Ohmic Heating) coil in a Doublet device (see entry for doublet). Ideally the E-coil makes no magnetic field in the confinement system. (?) * E-Layer: Cylinder of relativistic electrons gyrating in a magnetic field, which produce a self-field strong enough to dominate the externally applied field and produce a field-reversal (where the B field changes sign) in the system. See Field-Reversed Configuration, Field-Reversed Pinch. * Echoes: Wave packets (pulses) which have been reflected or otherwise returned to the detector, which are sufficiently delayed and retain sufficient magnitude so that they are perceived as a signal distinct from the one transmitted directly. (In other words, just like sound echoes, only for analogous phenomena with other waves.) * Eddy Current: Electric current induced inside a conductor when the conductor (a) moves through a nonuniform magnetic field, or (b) experiences a change in the magnetic flux through its surface. * Eddy-Current Loss: Energy loss due to eddy currents circulating in a resistive material. * Edge Localized Mode: (ELM) Mode found often in H-mode plasmas. This is a temporary relaxation of the very high edge gradients found in H-modes. It may be a relaxation back to the L-mode. (Borrowed from a posting by Paul Stek) * Edge Plasma: Cooler, less dense plasma away from the center of a reactor; affected by limiter or divertor, includes scrape-off layer. Distinguished from core plasma. See entries for relevant terms used. * Edge-Localized Mode: (info from Paul Stek) Found often in H-mode plasmas, this is a temporary relaxation of the very high edge gradients found in H-modes. It may be a relaxation back to the L-mode. * Effective Collision Cross-section: (See collision cross section) * Effective Collision Radius: Effective size of a particle equal to the square root of (cross section/pi). Determines the effective range of interaction of the particle. * Effective Half-Life: Time required for a radioactive substance contained in a biological system (such as a person or an animal) to reduce its radioactivity by half, as a combination result of radioactive decay and biological elimination from the system. & Eigenfrequency: One of the characteristic frequencies at which an oscillatory system can vibrate. & Eigenfunction: Function describing an eigenstate of a system. & Eigenstate: One of the characteristic states of an oscillatory system, such that the system does not leave the state unless disturbed. (?) & Eigenvector: Same thing as an eigenfunction, only from the perspective that the eigenfunction is a "vector" in an appropriate mathematical vectorspace. * Eikonal Equation: An equation for propagation of electromagnetic or acoustic waves in an inhomogenous medium; valid only when the scale length for variation in the properties of the medium is small compared to a wavelength. (Similar in character to WKB?) & Elastic: Term used to describe a process in which kinetic energy is conserved; usually refers to (elastic) collisions or (elastic) scattering. & Electric Charge: See charge, electrical. & Electric Field: A property of a patch of space which causes the acceleration of electric charges located at that patch of space. The acceleration is given by a = qE/m, where q is the charge, E the electric field vector, and m the mass of the particle. % Electric Power Research Institute: (EPRI) Research organization funded by the electric power utilities to study, well, electric power. * Electric Probe: See Langmuir Probe. & Electrical Conductivity: Degree to which a substance conducts electric current. Can be defined by: (current density) = (conductivity) * (applied electric field) Electrons and ions both contribute to current in proportion to their mobility in the system. In a plasma with a magnetic field, there is no longer a one-to-one correspondence between current and electric field. Instead, the current in each direction can be due to combinations of the electric fields in all the other directions. In this case, the current density and the electric field are vectors, and the conductivity becomes a tensor (matrix) which relates them. * Electromagnetic Coupling: A means of extracting energy from a magnetically confined plasma, where the plasma expands and pushes on the confining magnetic field, causing electrical energy to be generated in the external field-generating circuits. & Electromagnetic Force: * Electromagnetic Radiation: Radiation (such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays) which consists of associated, interacting electric and magnetic field waves which travel at the speed of light (because electromagnetic radiation *is* light, except for the variation in frequencies!). All forms of electromagnetic radiation can be transmitted through vacuum. Electromagnetic waves in plasmas are generally more complex in their behavior, depending on their frequency. & Electromagnetic Wave: Wave characterized by combined oscillations of both electric and magnetic fields. The particle equivalent is the photon. There is a whole spectrum of electromagnetic waves where the classes are distinguished by energy (or, equivalently, wavelength or frequency); the spectrum of electromagnetic waves includes radio waves, microwaves, infrared light, visible light, ultraviolet light, x-rays, and gamma rays. & Electron: Elementary particle with a negative electric charge. Electrons orbit around the positively charged nucleus in an atom. The charge on an electron is -1.6x10^-19 coulombs; the electron has a mass of 9.11 x 10^-31 kg (about 1/1837 times that of a proton.) The configuration of electrons around an atom determines its chemical properties. The positron is the antiparticle to the electron, and is identical except for having a positive charge. > Electron Beam Fusion Accelerator: See PBFA (Particle Beam Fusion Accelerator) * Electron Capture: Nuclear decay process whereby a proton in the nucleus absorbs an orbiting electron and converts to a neutron. * Electron Cyclotron Discharge Cleaning: (ECDC) Using relatively low power microwaves (at the electron cyclotron frequency) to create a weakly ionized, essentially unconfined hydrogen plasma in the vacuum chamber. The ions react with impurities on the walls of the tokamak and help remove them from the chamber. For instance, Alcator C-mod typically applies ECDC for a few days prior to beginning a campaign, and a few hours before each day's run. * Electron Cyclotron Emission: (ECE) As electrons gyrate around in a magnetic field (see also larmor radius or cyclotron radius), they radiate radio-frequency electromagnetic waves. This is known as electron cyclotron emission, and can be measured to help diagnose a plasma. * Electron Cyclotron Heating: (ECH or ECRH) Radiofrequency (RF) heating scheme that works by injecting electromagnetic (EM) wave energy at the electron cyclotron gyration frequency. The electric field of the EM wave at this frequency looks to a gyrating electron like a static electric field, and it causes acceleration of the electron. The accelerated electron gains energy, which is then shared with other particles through collisions, resulting in heating. * Electron Cyclotron Wave: Radiofrequency waves at the electron cyclotron frequency. See also Whistler. * Electron Density: Number of electrons in a unit volume. See density for more info. * Electron Temperature: The temperature corresponding to the mean kinetic energy of the free electrons in a plasma. $ Electron-volt: 1 eV = 1.6 x 10^-12 erg, or 1.6 x 10^-19 Joules. This is a unit of kinetic energy equal to that of an electron having a velocity of 5.93 x 10^5 m/sec. This is the energy an electron (or other particle of charge=1 such as a proton), gains as it is accelerated through a potential difference of 1 volt. In plasma physics the eV is used as a unit of temperature; when the mean particle energy is 1eV, the temperature of the plasma is roughly 11,700 Kelvin. * Electrostatic Analyzer: A device which filters an electrn beam (band-pass), permitting only electrons within a narrow energy (velocity) range to pass. > Electrostatic Confinement: An approach to fusion based on confining charged particles by means of electric fields, rather than the magnetic fields used in magnetic confinement. See discussion in Section 4 for more information. * Electrostatic Waves: Longitudinal oscillations appearing in a plasma due to a perturbation of electric neutrality. For a cold unmagnetized plasma, or at large wavelengths, the frequency of these waves is by definition the plasma frequency. & Element: One of the fundamental chemical substances which cannot be divided into simpler substances by chemical means. Atoms with the same atomic number (# of protons) all belong to the same element. (e.g., hydrogen, helium, oxygen, lead) (list and perhaps periodic table in appendix? isotope table with half-lives and decay modes might also be useful.) & Elementary Particles worth knowing about: (at the nuclear-energy level) electron & positron - seem to be stable proton - thought to be stable, life > 10^30 sec neutron - decays in ?10 min unless it's in a nucleus, which often extends its life. other particles important for nuclear energy: muon, neutrino (m,e,tau), photon muonic atoms pi-meson antiparticles this part is new - maybe separate entries with listing here?? > Elmo Bumpy Torus: Bumpy Torus at ORNL; no longer operating. See Bumpy Torus, ORNL. * Elongation: parameter indicating the degree to which the cross section of a toroidal plasma is non-circular. kappa=b/a, where "b" and "a" are the vertical and horizontal minor radii. As kappa is increased, the confinement in relation to the total current improves, but the plasma also becomes more and more unstable to vertical displacements. A circular plasma has kappa of 1, a common value for elongated plasmas is 1.7, and the absolute limit is probably around 2. & Energy: Typically defined as "the ability to do work". Power is the rate at which work is done, or the rate at which energy is changed. "Work" characterizes the degree to which the properties of a substance are transformed. Energy exists in many forms, which can be converted from one to another in various ways. Examples include: gravitational energy, electrical energy, magnetic and electric field energy, atomic binding energy (a form of electrical energy really), nuclear binding energy, chemical energy (another form of electrical energy), kinetic energy (energy due to motion), thermal energy ("heat"; a form of kinetic energy where the motion is due to thermal vibrations/motions), and so on. * Energy Balance: Comparison of energy put into a plasma with the energy dissipated by the system; related to energy confinement. * Energy Confinement Time: See energy loss time. * Energy Loss Time: Characteristic time in which 1/e (or sometimes 1/2) of a system's energy is lost to its surroundings. In a plasma device, the energy loss time (or the energy confinement time) is one of three critical parameters determining whether enough fusion will occur. (See Lawson criterion) * Energy Replacement Time: Time required for a plasma to lose (via radiation or other loss mechanisms) an amount of energy equal to its average kinetic energy. % Energy Research and Development Agency (ERDA): US Agency created by splitting of the AEC into ERDA and NRC in about 1975, charged with managing US energy R&D (???). Merged with ??? to become the Department of Energy in about 1977. (???? correct? help??) * Entropy Trapping: The process of trapping an ordered beam of particles in a magnetic field configuration (e.g., cusp geometry) by randomizing the ordered motion of the particles, with corresponding increase in the entropy of the system. % Environmental Protection Agency: Agency within the executive branch of the U.S. government (under the Department of the Interior? Independent?) charged with, well, protection of the environment. Activities include research, regulatory, and cleanup functions. (Any government people reading this who could help me out?) * Equations of Motion: Set of equations describing the time evolution of the variables which describe the state of a physical system. * Equilibrium: [ acknowledgements to John Cobb ] An equilibrium is a state of a system where the critical parameters do not change significantly, within a given time frame. In the case when this time frame is infinite, It is called a Thermodynamic equilibrium. There are many cases where a plasma equilibrium is constant on some fast time scale, but changes over some slower time scale. For example, an IDEAL MHD equilibrium is constant over fluid time scales (microseconds to milliseconds), but it will evolve on the slower resistive or viscous time scales (milliseconds to seconds). All terrestial plasmas are NOT in thermodynamic equilibrium, but they may be constant over very long time periods. An equilibrium is unstable when a small change in a critical parameter leads the state of the system to diverge from the equilibrium. An equilibrium is stable when a small change in a critical parameter leads to a "restoring force" which tends to return the system to equilibrium. * Equilibrium Field: See Vertical Field $ Erg / ergs: CGS unit for energy. 1E7 ergs = 1 joule. * Ergodic: A mathematical term meaning "space-filling". If a magnetic field is ergodic, any field line will eventually pass arbitrarily close to any point in space. Closely related to "chaotic". * Ergodic Regime: In this regime, a given magnetic field line will cover every single point on a magnetic surface (see magnetic surface or flux surface) if the rotational transform (or q) is not rational. * ESECOM: Reactor design study done in the mid 1980s to evaluate the Environmental, Safety, and ECOnoMic potential of different types of fusion and advanced fission reactors. * Eulerian Coordinates: Coordinates which are fixed in an inertial reference frame. % European Community: see European Union % European Union: (from Herman) Organization of European countries (formerly European Community, EC, formerly European Economic Community, EEC) established in 1967 to coordinate policies on the economy, energy, agriculture, and other matters. The original member countries were France, Belgium, West Germany, Italy, Luxembourg, and the Netherlands. Joining later were Denmark, Ireland, the United Kingdom, Greece, Spain, and Portugal. Other countries are in the process of joining now. % Euratom: European Atomic Energy Community. International organization established in 1958 by members of the European Economic Community for the purpose of providing joint funding and management of the scientific research of the member countries - initially Belgium, France, Italy, Holland, and West Germany. * Excitation Radiation: Line radiation (at characteristic frequencies / wavelengths) as a result of the excitation of excited states, and the subsequent de-excitation of these states by radiative transitions. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 10/26 (J) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 10/26 (J) Date: 28 May 1995 13:04:20 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/j Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 10: Terms beginning with "J" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== JJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJJ # J: variable used to indicate current density $ J: abbreviation for Joule; see entry @ JET: Joint European Torus; see entry @ JT-60, JT-60U: Japan Torus - 60 (Upgrade); see entry > Janus: Early Inertial Confinement laser system at Livermore; used for one- and two-beam laser-target irradiation experiments in 1974 and 1975. > Joint European Torus: Large tokamak next to the Culham Laboratory in Oxfordshire, England, commonly owned by the European Community. First reactor to achieve > 1 MW of fusion power, in 1991. Largest tokamak currently in operation (to the best of the editor's knowledge). > JT-60: A large Japanese tokamak, located north of Tokyo. JT-60U is an "upgrade" to JT-60 now in operation. See also entry in Section 5. $ Joule: SI unit of energy. 1 Joule = 1E7 ergs = 1 Watt of power occurring for one second. 1 Joule is roughly 0.001 BTU and 1 calorie is roughly 4 joules. There are 3.6 million joules in a kilowatt hour. & Joule Heating: See ohmic heating cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 11/26 (K) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 11/26 (K) Date: 28 May 1995 13:04:21 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/k Last-modified: 4-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 11: Terms beginning with "K" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK # k: Mathematical symbol usually used for Boltzmann's Constant. Value is 1.4 x 10^-23 Joules/Kelvin (in SI units), or 1.4 x 10^-16 ergs/Kelvin (in cgs units). $ kA: KiloAmpere; see kilo, Ampere @ KDP: Potassium Dihydrogen Phosphate; crystal used in frequency conversion of Nd:glass laser light. $ kW: KiloWatt (1000 watts); see also kilo, Watt $ kWh: kilowatt-hour; see entry & Kelvin: (K) temperature scale where zero degrees corresponds to absolute zero (no thermal energy); degrees have same size as in Celsius/centigrade scale. 273.16 K = zero C; 373.16 = 100 C. ! (Lord) Kelvin: honorary name given to William Thompson; 19th century British physicist (many contributions in many subfields). * Kerma: Kinetic Energy (of charged particles) produced by ionizing Radiation per unit MAss of irradiated material. (ergs/gm) & kilo: metric prefix used to indicate 1000 times the following unit. e.g., a kiloampere is 1000 amperes. $ kilowatt-hour: standard unit of electrical energy; equals one kilowatt of power delivered for one hour. Equivalent to 3.6 million joules. * Kinetic Pressure: Density of kinetic energy (energy in the thermal motions of the plasma particles). For an ideal plasma, pressure is given by p = nkT, that is: pressure = (density) * (Boltzmann's constant)* (temperature), * Kinetic Temperature: A measure of the energy of random motion (kinetic energy) of an assembly of particles in thermodynamic equilibrium. * Kinetic Theory: A theory which attempts to explain the behavior of physical systems using the assumptions that the systems are composed of large numbers of atoms/molecules/particles in vigorous motion, that energy and momentum are conserved in collisions of these particles, and that statistical methods can be applied to deduce the behavior of such systems. * Kink Instability: Instability resulting from excessive growth of a kink mode; see kink mode. * Kink Mode: Class of MHD instabilities which sometimes develop in a thin plasma column carrying a strong axial current. If a kink begins to develop in such a column the magnetic forces on the inside of the kink become larger than those on the outside, so that in general it tends to grow in magnitude. The column then becomes unstable and can be displaced into the walls of the discharge chamber, causing a disruption. & Klystron: An evacuated electron-beam tube in which electrons are given initial velocities such that the beam's charge density is modulated; the passage of a modulated current generates microwave radiation, some of which is then fed back to modulate the electrons' velocities. The result is a microwave amplifier. * Kruskal Limit: In tokamaks, a theoretical limiting value for plasma current beyond which MHD instabilities are predicted. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 12/26 (L) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 12/26 (L) Date: 28 May 1995 13:04:22 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/l Last-modified: 20-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 12: Terms beginning with "L" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL # L: variable typically used to indicate self-inductance; see inductance. # Li: chemical symbol for the element lithium; see entry. @ L-mode: see low mode. @ LAMPF: Los Alamos Meson Physics Facility; see entry @ LANL: Los Alamos National Laboratory; see entry @ Laser: Light Amplification by Stimulated Emission of Radiation. see entry. @ LBL: Lawrence Berkeley Laboratory; see entry @ LCFS: Last Closed Flux Surface; see entry @ LLE: Laboratory for Laser Energetics; see entry @ LLNL: Lawrence Livermore National Laboratory; see entry @ LMFBR: Liquid-Metal Fast-Breeder Reactor; see entry @ LMR: Liquid-Metal Reactor; see entry @ LN2: Liquid (diatomic) Nitrogen (N2) @ LOCA: Loss-of-Coolant Accident; see entry @ LWR: Light-Water Reactor; see entry % Laboratory for Laser Energetics: Second-largest (?) inertial confinement research facility in the United States; located at the University of Rochester in New York state. Home of Omega; future home of Improved-Omega. & Lagrangian: The difference between the kinetic energy and the potential energy of a system of particles, expressed as a function of generalized coordinates and velocities. Equations of motion can be derived from the Lagrangian. (see an intermediate or advanced mechanics text for more information.) * Lagrangian coordinates: coordinates which follow fluid motion. (As distinct from Eulerian coordinates; see entry). * Landau Damping: Damping of a wave propagating in a hot plasma, due to the interaction of the wave with particles whose velocity is close to the phase velocity of the wave. Depends on the shape of the velocity-space distribution function at the phase velocity of the wave. More info from John Cobb, with modifications: The phenomenon is very similar to surfing on water waves at the beach. If a particle's speed is just slightly lower than the wave, then the particle can "catch the wave" and surf along at the wave speed. In so doing, the particle will gain some energy, which will be at the expense of the wave. This is called Landau Damping, since the loss of energy tends to damp the wave. At the same time, if a particle moves just slightly faster than the wave, then it will also be caught on the wave. However, in this case, it will slow down, giving the wave some extra energy. In this case particles transfer energy to the wave; this is called inverse Landau damping. Which effect dominates depends on whether there are more particles moving faster than the wave or more particles moving slower. Thus it depends on the derivative of the distribution function with respect to velocity, evaluated at the wave's phase velocity. Landau dmaping can lead to the decay of waves. Inverse Landau damping can be a mechanism for some kinetic instabilities. ! Langmuir, Irving (1881-1957): American chemist, won Nobel Prize in chemistry in 1932, developed the theory of Langmuir probes (see entry). Numerous inventions for General Electric (lighting). * Langmuir frequency: See plasma frequency. * Langmuir oscillation: See electrostatic waves. * Langmuir probe: a small conductive electrode used to measure the density, temperature, and electric potential (voltage) of a plasma. Plasma parameters are deduced from the probe's "Characteristic" current-drawn vs. voltage-applied curve. & Larmor radius: the radius of the path of a charged particle moving in a magnetic field (and transverse to the field lines). Also known as gyroradius and cyclotron radius. & Laser: An optical device that amplifies and concentrates light waves, emitting them in a narrow, intense beam. Laser light radiation is notable for its brightness and to some extent for its monochromaticity and spatial and temporal coherence. > Laser Fusion: Form of inertial confinement fusion where laser beams are used to compress and heat the fuel pellet. * Laser interferometer: an interferometer which uses a laser as a light source (see entries). Because of the monochromatic nature and high brightness of laser light, laser interferometers can operate with much longer beam paths and path differences than conventional interferometers. * Laser scattering device: See Thomson scattering device. * Last Closed Flux Surface (LCFS): [from Art Carlson] The boundary between the interior region of a tokamak (or other device), where the field lines close back on themselves, and the scrape-off layer (see entry), where the run into a material wall. (See also separatrix.) % Lawrence Berkeley Laboratory: Located in Berkeley, CA; Another large U.S. science laboratory; minor (?) U.S. fusion research center. % Lawrence Livermore National Laboratory: Located in Livermore, CA, about an hour east of SF in the Bay Area. Home of the Nova laser inertial confinement fusion program; Nova is the largest laser in the world. Home of the former mirror projects MFTF (Mirror Fusion Test Facility, shut down on the day it became operational, or thereabouts, due to budget cutting), TMX-U (Tandem Mirror eXperiment Upgrade), and the recently shut down Microwave Tokamak eXperiment (MTX). Some notable older fusion experiments at Livermore included Table Top, Toy Top, Baseball (and Baseball-II) and TMX (predecessor to TMX-U). Livermore is also the site of the Rotating Target Neutron Sources (I and II) for testing materials samples in high-intensity 14 MeV neutron fluxes and the High Field Test Stand for testing neutral beams. Workplace of Albert Chou and several other sci.physics.fusion participants. :) * Lawson Criterion: Scientific breakeven criterion based on the product of energy confinement time and particle density. Together with plasma temperature, the Lawson value of a plasma indicates how close it is to self-sustained (ignited) fusion; see also ignition. & Lenz's Law: Electromagnetism law which states that whenever there is an induced electromotive force (emf) in a conductor, it is always in such a direction that the current it would induce would act in opposition to the change which caused the induced emf. > Levitron: Single-ring multipole device with an additional current-carrying rod perpendicular to the ring axis. * Light-ion fusion: Light-Ion-Beam-Driven Inertial Confinement fusion, using beams of light ions driven at implosion targets. Pulsed-power driven accelerators are relatively efficient and cost-effective, but beam-focusing is a technical hurdle for this approach. > Light-Water Reactor: Class of fission reactors using ordinary "light" water as a coolant, rather than liquid metal or heavy water (water with deuterium instead of hydrogen). * Limiters: Structures placed in contact with the edge of a confined plasma which are used to define the shape of the outermost magnetic surface. See also: divertor. * Line-tying: Connection of field lines from the end of an open-ended device (such as a mirror system) to a conducting plate. The rigidity of field lines trapped in the plate can be transferred to the high-field region of the mirror by using a cold, moderately-dense plasma in between. Line-tying helps to stabilize against interchange instabilities (see entry). * Liquid Metal: Metal which has been heated past its melting point and can be used as a working fluid for pumping heat out from a powerplant. Liquid metal used as coolant in a system where significant magnetic fields exist, it behaves differently due to MHD effects; these cause pressure which resists fluid circulation, suppression of turbulence, and altered flow patterns compared to non-magnetic liquid metal systems. > Liquid-Metal Reactor: (Fission) reactor which uses liquid metal as the reactor coolant. > Liquid-Metal Fast-Breeder Reactor: (LMFBR) Fission breeder reactor concept (see entry for breeder reactor) using liquid-metal coolant and breeding additional fuel off fast neutrons. & Lithium: (Li) Third element in the periodic table, so all isotopes contain 3 protons. Pure lithium at room temperature is a soft silver-white material, the lightest of all metals. It is chemically very reactive, making it hazardous. Lithium liquefies at 355 degrees Fahrenheit, making it viable as a liquid-metal coolant. Lithium nuclei have two stable isotopes: Li-6 (7.5% abundance) and Li-7 (92.5%). Lithium is a candidate for breeding tritium (for D-T fusion) from neutrons, via the reactions: n + 6Li -> 4He + T + 4.8 MeV n + 7Li -> 4He + T + n - 2.5 MeV. * Longitudinal Waves: (by John Cobb, with editing) Waves where the variation of the field is partially or totally in the direction of propagation (parallel to wavennumber, k [a vector]). Examples include sound waves and Langmuir waves. Contrasted with transverse waves, where the variation is perpendicular to the direction of propagation, such as light waves. * Lorentz dissociation: dissociation of molecular ions by Lorentz ionization (see entry). & Lorentz Force: Total electromagnetic force on a charged particle moving in electric & magnetic fields. F = q(E + (v/c)xB). See also force, cross product, charge, velocity, and relevant variable symbols. * Lorentz Gas: Plasma model in which the electrons are assumed not to interact with each other, but only with ions (Z -> infinity) and where the ions are assumed to remain at rest/fixed (M-i -> infinity). Also known as "electron gas." * Lorentz ionization: Ionization of neutral atoms (taken generally at a highly-excited state) obtained by launching them at high velocity across a strong magnetic field. The neutral atoms feel an electric field proportional to their perpendicular velocity times the magnetic field strength, and if this electric field is strong enough ionization can occur. * Lorentz Model - see Lorentz Gas % Los Alamos Meson Physics Facility (LAMPF): Physics research facility at Los Alamos National Lab; major site for U.S. muon-catalyzed fusion research in the 1980s. May be shut down soon. % Los Alamos National Laboratory (LANL): Major DOE research facility, located in Los Alamos, New Mexico, about an hour west of Santa Fe. Former home of a frozen-deuterium-fiber Z-pinch device, which was dismantled. Home to an active theory division, including the Numerical Tokamak Grand Challenge (being performed on the CM-5 massively-parallel supercomputer). Also home to former alternative-concepts experimental devices like Scyllac, FRX-A, FRX-B, FRX-C/LSM, ZT40, and the aborted CPRF which was killed in 1991 when it was almost complete (budget cuts). Currently there are some small in-house experiments, including one on electrostatic confinement as a possible fusion device, and/or a compact neutron source. They also do theory and experimental collaboration with other labs worldwide. (Information provided by John Cobb and Ed Chao) * Loss Cone: (from John Cobb, with modifications and additions) In a magnetic mirror machine, particles with a large velocity parallel to the magneitc field and a small velocity perpendicular to the field will be able to escape past the magnetic mirror (see magnetic mirror). In that case the velocity distribution function (see distribution function) will be almost zero in the region of velocity space that allows particles to escape. The shape of that region (in a velocity space diagram with parallel velocity and perpendicular velocity as the axes) is a cone. When a particle undergoes a collision, its velocity gets somewhat randomized. Particles that are scattered into that cone are lost very quickly (in one mirror bounce time). Thus it is called a loss cone. Because of the loss cone, the theoretical maximum particle confinement time of a magnetic mirror machine can be only a few times the particle collision time; this is generally seen as a showstopper for mirror-based fusion research. * Loss of Coolant Accident (LOCA): Powerplant accident where the supply of coolant to the hot power-producing core is interrupted, or where the coolant drains out for some reason. Can lead to meldown of a fission reactor core in extreme cases, or to small nuclear explosions (e.g., Chernobyl). Fusion reactors are expected to be less vulnerable to LOCAs, but these must still be designed for. * Low-activation materials: In fission reactors, one is forced to deal with the radioactive byproducts of the fission process, but in fusion reactors one generally has a choice of what materials to expose to neutrons produced by the fusion process. A major problem for fusion reactors is developing materials (such as for the reactor vacuum vessel structure) which can be exposed to high levels of neutron bombardment without becoming permanently radioactive. Candidate structural materials which have relatively low induced radiactivation (generally relative to stainless steel) are known as low-activation materials; these include titanium, vanadium, and silicon-carbide. * Low Aspect Ratio: (entry from John Cobb, slightly edited) An aspect ratio for a torus that is small (minor radius is almost as big as major radius). There are many fusion devices which are designed to have a low aspect ratio. Such devices look more like tractor tires than bicycle tires, as toruses go. There are reasons to believe that low aspect ratio devices will offer some advantages for a fusion reactor. Usually, ease of theoretical and/or numerical analysis is not one of these advantages :>. * Low-beta plasma: a plasma in which the beta value (see entry) is typically 0 to 0.01. * Low mode or L-Mode: (from Herman) The "normal" behavior of a tokamak plasma, characterized by poor confinement and a particular scaling of decreasing confinement with increasing temperature. * Lower hybrid frequency: * Lower Hybrid Heating: form of RF heating using Lower Hybrid Waves. * Lower Hybrid Waves: "Electrostatic ion oscillations at a frequency intermediate to the electron extraordinary wave (high frequency) and the magnetosonic wave (low frequency). Not waves, strictly speaking, because they do not propagate (I think)." - Albert Chou, albert@seas.ucla.edu * Luminescence: Light emission that cannot be attributed merely to the temperature of the emitting body, but results from such causes as chemical reactions at ordinary temperatures, electron bombardment, electromagnetic radiation, and electric fields. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 13/26 (M) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 13/26 (M) Date: 28 May 1995 13:04:24 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/m Last-modified: 18-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 13: Terms beginning with "M" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM # m, M: variable typically used for mass. $ MA: MegaAmpere or MegAmpere; see Mega, Ampere $ m: meters; SI unit of distance $ M: metric prefix "mega", meaning million @ MARS: Mirror Advanced Reactor Study; see entry $ MeV: Millions of electron volts; see mega, electron-volt. @ MFE: Magnetic Fusion Energy @ MFTF-B: Mirror Fusion Test Facility; see entry @ MHD: Magnetohydrodynamics; see entry @ MHD Instability: see Magnetohydrodynamic instability. @ MHTGR: Modular High-Temperature Gas-Cooled Reactor; see entry. @ MIT: Massachusetts Institute of Technology; see entry @ MITL: Magnetically Insulated Transmission Line; see entry @ MIX 1: see entry under "MIX 1" @ MKS: Meters, Kilometers, Seconds - see SI Units @ MKSA: Meters, Kilometers, Seconds, Amperes - See SI Units. @ MMX: Multiple Mirror eXperiment; see entry @ MS: Maryland Spheromak; see entry @ MTX: Microwave Tokamak eXperiment; see entry $ MW: Megawatt; one million watts; see entry for watts. * Mach-Zender Interferometer: This is a variation of the Michelson interferometer which is used mainly in measuring the spatial variation in the refractive index of a gas (or plasma). A Mach-Zender interferometer uses two semi-transparent mirrors and two fully reflective mirrors located at the corners of a rectangle. The incoming beam is split in two at the first semi-transparent mirror, and the two halves of the beam travel along separate paths around the edge of the rectangle, meeting at the opposite corner. Typically one beam is a control, and the other travels through the system under study. The two beams meet at the second semi-transparent mirror, after which they are mixed together and interfere. % Madison: See University of Wisconsin-Madison * Magnetic Axis: This typically refers to the location of the innermost flux "surface" in a toroidal device, the one which encloses no volume and has therefore degenerated from a flux surface into a single field line. Roughly, the circle through the middle of the dough of the donut. Additionally, in systems with magnetic islands (see entry below), each island has a local magnetic axis, distinct from the overall magnetic axis of the torus. * Magnetic Bottle: Colorful term used to describe a magnetic field structure which confines a plasma "like in a bottle". * Magnetic Confinement: Use of magnetic fields to confine a plasma. (Confinement involves restricting the volume of the plasma and/or restricting particle or energy transport from the center of the plasma to the edge.) * Magnetic Confinement Fusion: Method of fusion which uses magnetic fields / magnetic bottles to confine a hot plasma until fusion occurs. * Magnetic Diffusion: * Magnetic Field: * Magnetic Field Coil: Coiled current-carrying wires used to generate magnetic fields. * Magnetic Flux Surfaces: * Magnetic Force Parameter: A dimensionless number equal to [(magnetic permeability squared) * (magnetic field strength squared) * electrical conductivity * characteristic length of system in question] / [(mass density) * (fluid velocity)]. This measures the strength of magnetic forces relative to the plasma's inertia. * Magnetic Island: A magnetic topology near a "rational surface" (see entry) where the flux surface is broken up into tubes which are not connected with each other poloidally. Islands may develop in non-ideal magnetohydrodynamic fluids, where electrical resistance becomes important and magnetic field lines are no longer "frozen-in" to the fluid. Then magnetic tearing and reconnection may allow field lines to link up and form "islands" with a local magnetic axis (see entry) in a narrow region near a rational surface (see entry). (See also MHD, frozen-in law). The development of islands may be caused by a small perturbation, whether internal or external, whether deliberate or accidental, and is usually associated with enhanced transport (i.e., reduced confinement). The centers of the islands are magnetic O-points, while the boundaries between islands are marked by X-points (see entries). * Magnetic Limiter: See divertor. * Magnetic Mach Number: A dimensionless number equal to the ratio of the velocity of a fluid to the velocity of Alfven waves in that fluid. (See also entry for Alfen waves.) > Magnetic Mirror: See mirror effect, mirror device * Magnetic Moment: (a) A vector associated with a magnet, current loop, or particle; the cross product of this vector with the magnetic field is equal to the torque which the field exerts on the system. (b) The adiabatic invariant associated with the rapid gyromotion of a charged particle in a slowly varying magnetic field. (The value of the magnetic moment in sense (b) is the magnitude of the vector in sense (a).) * Magnetic Number: A dimensionless number equal to the square root of the magnetic force parameter. * Magnetic Pressure: Pressure which a magnetic field is capable of exerting on a plasma; equal to the magnetic energy density; proportional to B^2. (The proportionality constant is 1/(2*mu-o) in SI units, 1/8pi in CGS units). * Magnetic Probe: A conducting coil (sometimes insulated and inserted into the plasma) will have an induced voltage due to changes in the magnetic flux through the coil, and can therefore be used to measure changes in magnetic field strength. Small coils used to measure the local field strength are known as probes. (Other plasma diagnostics using this effect are the Rogowski coil, the voltage loop, and the diamagnetic loop.) Magnetic probes placed outside a toroidal plasma which are used to measure the poloidal magnetic field are also called Mirnov coils. * Magnetic Pumping: Form of plasma heating where the plasma is successively compressed and expanded by means of a fluctuating external magnetic field. (See also adiabatic compression, frozen-in law.) * Magnetic Reconnection: (entry by John Cobb, with some modifications) When a plasma has some resistivity, then the frozen-in flow requirement is relaxed (see frozen-in flow). In that case, the magnetic field can move through the plasma fluid on the resistive (magnetic diffusion) time scale. (Typically slow compared to MHD timescales.) This allows field lines to reconnect with each other to change their topology in response to magnetic and other forces in the plasma. (see also Helicity, which is not conserved when reconnection is significant.) The predominant theory for solar flares is based on the transfer of energy from magnetic fields to plasma particles which can occur in reconnection. Reconnection can also be studied in the laboratory. * Magnetic Stress Tensor: A second-rank tensor, proportional to the dyadic product of the magnetic field (B) with itself. The divergence of the magnetic stress tensor gives that part of the force which a magnetic field exerts on a unit volume of conducting fluid due to the curvature of the magnetic field lines. * Magnetic Switching: The use as switches of saturable inductors for producing high power pulses without electrical arcs. This is a principal technology for extending single-shot accelerators in light-ion-beam-driven inertial confinement fusion to repetitively pulsed devices for possible reactors. Three terawatt, 200 KJ magnetic switches have been developed for fusion drivers at Sandia National Laboratories. (Info from the 1985 OSTI Glossary of Fusion Energy; may be out of date.) * Magnetic Viscosity: A magnetic field in a conducting fluid will damp fluid motions perpendicular to the field lines, similar to ordinary viscosity, even in the absence of sizeable mechanical forces or electric fields. * Magnetic Well: see Minimum-B Configuration. * Magnetically Insulated Transmission Line (MITL): Used to transport power efficiently in vacuum lines at very high power densities. Although the cathode is a space-charge limited electron emitter, the electron flow is confined by self-generated or applied magnetic fields. MITL's are used extensively in light-ion-driven inertial confinement fusion. * Magnetohydrodynamics (MHD): Physical model describing the properties of electrically conducting fluids interacting with magnetic and electric fields. MHD theory is relevant at relatively low frequencies and for distance scales larger than the Larmor radius. Also known as hydromagnetics. * Magnetohydrodynamic Generator: A device that extracts kinetic energy from a jet of plasma and generates electricity. * Magnetohydrodynamic Instability (MHD instability): Class of unstable (growing, not damped) waves and other modes of oscillation which are described by MHD theory. * Magnetohydrodynamic Turbulence: Motion of a plasma in which velocities and pressures fluctuate irregularly. * Magnetohydrodynamic Waves: Material waves in an electrically conducting fluid in the presence of a magnetic field, which are described by magnetohydrodynamics. * Marx Generator: A pulsed-power device invented by Erwin Marx. Capacitors are charged in parallel and then quickly discharged in series to produce high voltage, high current (and thus high power) pulses. Used in light-ion-driven and some laser-driven inertial confinement fusion systems. > Maryland Spheromak: A University of Maryland spheromak facility, used to investigate the production, equilibrium, stability, and confinement properties of spheromaks. (What happened to it?) * Mass Defect: The energy from fusion reactions comes from the difference in mass between the reactants and the products. In an energy-releasing reaction, some mass is converted to energy via Einsteins famous equation E (energy) = m (mass) * c^2 (speed of light squared). The energy released is the difference between the binding energies of the reactants and the products (see entry on binding energy). % Massachusetts Institute of Technology (MIT): Located in Cambridge, MA (just outside Boston). Home of the Plasma Fusion Center and the Alcator series of compact tokmaks. % Max Planck Institute for Plasma Physics (IPP): In Garching (near Munich). The largest plasma physics institute in Germany. Presently home of ASDEX-Upgrade and Wendelstein-7AS. (See entries) ! Maxwell, James Clerk: 19th-century British physicist, responsible for the synthesis of the equations of electromagnetism and the prediction of electromagnetic waves, among other things. & Maxwell-Boltzmann Distribution: Distribution function of particle velocities (or energies) corresponding to a system in thermal equilibrium with a temperature value of T. See also: distribution functions, temperature. & Maxwellian Distribution: see Maxwell-Boltzmann Distribution & Maxwell ('s) Equations: The key equations governing electrical and magnetic phenomena. These are a set of four vector partial differential equations relating electric and magnetic fields to each other and to electric charges and currents. & Mean Free Path (for a given event, e.g., collisons): Average distance a particle travels between occurrences of the given event; e.g., between collisions. For collisions, the mean free path is roughly equal to unity divided by the product of the collision cross section times the particle density. & Mega-: Metric prefix indicating 1,000,000 times a given quantity. e.g., a megawatt is 1,000,000 watts. * Meltdown: In a fission reactor, if there is insufficient coolant or the fission chain reaction proceeds too rapidly, heat can build up in the reactor fuel, causing it to melt. In extreme cases the whole fission core can melt down to (or even through) the reactor floor. Fusion reactors are not vulnerable to this. & Metastable state: several types Electronic Nuclear & Micro-: Metric prefix indicating 1/1,000,000th of a given quantity. e.g., a microampere is 1/1,000,000th of an ampere. * Microinstability: Instabilities due to particle / kinetic- theoretical effects, typically occuring on small scales, as opposed to those derivable from fluid models valid on larger scales. As with other instabilities, these are driven by various types of available free energy. (See also kinetic theory.) * Microwave Interferometer: See interferometer, interferometry. A microwave interferometer uses radio waves in the microwave frequency (or wavelength) range as the electromagnetic signal. Microwave interferometers are used to measure the line-averaged density of a plasma along the path through which the microwave beam is passed, through phase shifts in the propagated beam. * Microwave Tokamak eXperiment (MTX): a reincarnation of Alcator C at LLNL, now shut down. > Migma devices: Non-thermal, non-pulsed devices in which fusion occurs among the ions of a self-colliding particle beam. $ mill: financial unit equal to 0.1 cents or 0.001 dollars; standard unit which electrical utilities use in charging for electricity (e.g., 50 mills/kwh = $0.05/kwh). > Minimum-B Configuration: Confinement configuration where the magnetic field strength is a minimum where the plasma is to be confined, and increases in all directions away from the confinement region. Stability is favorable in such a configuration because the magnetic pressure increases in all directions away from the plasma. * Mirnov Oscillations: Fluctuations in the poloidal magnetic field (of a toroidal magnetic confinement system) which rotate in the electron diamagnetic drift direction at a speed comparable to the electron diagmagnetic drift velocity and with frequencies due to 5-20 kHz. Mirnov oscillations arise from tearing modes. Poloidal magnetic probes used to measure the poloidal field in order to diagnose Mirnov oscillations (and other MHD phenomena) are often called Mirnov coils or Mirnov loops. See relevant entries... > Mirror Advanced Reactor Study (MARS): This was a collaborative effort between government, academia, and industry to design a commercial-scale tandem mirror fusion power plant. Participants included the Department of Energy (LLNL); University of Wisconsin; TRW, Inc.; General Dynamics; EBASCO Services; Science Applications, Inc.; and Grumman Aerospace Corp. System was never actually built. > Mirror device, mirror machine: Generally, linear fusion machines which confine the plasma using the mirror effect. Basically there is a weak field in the center, and strong fields at the ends. Particles are then reflected at the ends by the strong fields, and are confined in the center of the device. (Some particles will have enough velocity along the axis of the device to escape from the mirror, however.) * Mirror effect: A charged particle travelling into an increasing magnetic field will (if the field becomes strong enough) reverse direction and be reflected back. This is a direct result of the adiabatic invariance (see entry) of the magnetic moment (see entry). Plasmas can be confined by devices which utilize this effect; see entry above for mirror device. The effect also occurs in some toroidal plasmas, since the toroidal magnetic field is stronger on the inboard side than on the outboard side; in this case it gives rise to so-called "neoclassical" effects. The strength of the mirror is determined by the mirror ratio. (See relevant entries. Consult an introductory plasma physics text for a more technical explanation.) > Mirror Fusion Test Facility (MFTF): A large mirror device built at LLNL from the late 1970s to the mid-1980s, but mothballed for political reasons (decrease in magnetic fusion funding) just before it was to begin operation. * Mirror Ratio: In a magnetic mirror, the mirror ratio is the ratio between the strongest value of the magnetic field on the mirror's axis, and the value at some other point on the axis. In a mirror confinement device, the "other point" is taken to be the location of weakest field strength between two confining mirrors. The mirror ratio is a key factor in determining confinement properties of the system. > MIX-1: A small, gun-injected mirror machine at the University of Maryland; was used to study the drift-cyclotron loss cone instability (see entries for DCLC, DCLC instability). * Mobility: The ease with which a charge in a medium (e.g. a plasma) moves in response to an electric field. Related to diffusivity and to resistivity. Measured by the average equilibrium drift velocity attained by the charged particle when subjected to acceleration by a unit electric field and the opposing frictional force of collisions with other particles. * Mode Rational Surface: A magnetic surface on which field lines resonate with the helicity of a particular perturbation or instability; see also rational surface. * Moderator: Substance used in a fission reactor to slow down ("moderate") energetic fission neutrons so that they are more easily captured within the reactor and therefore maintain the fission chain-reaction. > Modular High-Temperature Gas-Cooled Reactor: Class of fission reactors under study in the U.S.; designed to run at higher temperatures and use gas cooling to achieve greater efficiency of conversion from thermal to electric energy. & Mole: The amount of given substance such that the mass in grams is equal to its [atomic weight, molecular weight, mass number]. The number of particles in a mole of a substance is Avogadro's Number N = 6.02497 x 10^23 (see entry). For instance, one mole of water weighs 18 grams, since water is H2O, the H's weigh one apiece, and the O weighs 16. Heavy water, or D2O, weighs 20 grams/mole, because each D weighs 2 instead of 1. * Molecular ion injection: Heating concept for magnetic confinement fusion in which energetic (accelerated) molecular ions are injected into the plasma, dissociate, and heat the plasma while building up the population of trapped high-energy ions. Not widely used (see neutral beam injection). & Momentum: Basic physical quantity measuring motion; generally defined as momentum = mass * velocity. The total momentum of all bodies in a system is conserved in all physical processes known so far, I believe. Momentum is related to force in that force = rate of change of momentum with time. See also force. * Motor-Generator: Device used to store energy by accelerating a rotating flywheel to high speeds; energy may be rapidly discharged and converted to shorter-pulse energy. (Used to power TFTR; the electric utility would be a little unhappy if TFTR were to suddenly draw its 30 MW+ of power at random intervals. :) > Multiple Mirror eXperiment (MMX): A 10-meter long simple mirror facility which was located at the University of California, Berkeley. > Muon-Catalyzed Fusion: Alternative approach to fusion where muons are introduced to D-T fluid. The muon is heavy enough that it binds more strongly to the D or T than an electron would, and the result is that the D and T nuclei in the molecule are drawn more tightly together, and fusion results. More detailed discussion is given in section 4B. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 15/26 (O) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 15/26 (O) Date: 28 May 1995 13:04:26 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/o Last-modified: 20-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 15: Terms beginning with "O" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO @ OFE: Office of Fusion Energy; see entry @ OH: Ohmic Heating; see entry @ OH1, OH2L, OH2U: Ohmic Heating Coils (1,2, upper, lower) on Alcator C-Mod @ OPEC: Organization of Petroleum Exporting Countries; see entry @ ORNL: Oak Ridge National Laboratory; see entry % Oak Ridge National Laboratory: Located in Oak Ridge, TN. Home of a series of various fusion devices. Recent machines have included the Elmo Bumpy Torus and the Advanced Toroidal Facility (stellarator). (Could use more info!) % Office of Fusion Energy: This is the office (within the Office of Energy Research in the U.S. Department of Energy) which administers the fusion energy research program. Web users can visit http://wwwofe.er.doe.gov/ for more info. ! Ohm, Georg Simon (1789-1854): Physicist who discovered the relationship between electric current, potential and resistance. (Yes, it is Georg. Swedish, I believe.) $ Ohm: Unit of electrical resistance. & Ohmic heating: Heating that results from the flow of current through a medium with electrical resistance. In plasmas subjected to ohmic heating, ions are heated almost entirely by transfer of energy from the hotter, more mobile electrons. * Ohmic heating coil: On a tokamak, this is the coil (generally a set of coils; part of the poloidal field system) used to induce an electric field in the plasma via a transformer effect. The electric field generates of a toroidal plasma current, with resultant ohmic heating. * Ohmic heating solenoid: See ohmic heating coil, solenoid. & Ohm's Law: The relationship between the net current and the electric field in a conducting medium. For simple resistors, the voltage equals current times resistance, V = I*R. In plasmas the "generalized Ohm's Law" is a more complex tensor relationship involving the vector current density, the vector for the electric field, and a generalized resistance tensor that relates the two. > OMEGA: Inertial confinement fusion facility at the Laboratory for Laser Energetics, University of Rochester (NY). OMEGA uses a 24-beam Nd:glass laser at wavelengths of 1.054 or .351 microns. # Omega: Variable frequently used to denote frequencies. * O-Point: Place where the poloidal magnetic field vanishes in such a way that the nearby flux surfaces are elliptical, e.g. on the magnetic axis (see entry) or at the center of a magnetic island (see entry). (See also X-Point.) & Optical Axis: The line passing through both the centers of curvature of the optical surfaces of a lens; the optical centerline for all the centers of a lens system. & Optical Interferometer: This is an interferometer (see entry) which uses the interference of optical-frequency light waves. These are useful in measuring distances precisely, and can be used to test optical system elements (lenses, mirrors, etc.) during manufacture. * Optical Pumping: In laser physics, this denotes the process in which absorbed light is stored in the laser medium. If the absorption & storage process creates a population inversion, laser action can occur (and extract the energy stored by optical pumping in the form of laser emission). * Oscillator: In laser physics, this refers to a device to generate coherent optical energy. (i.e., it's another term for the laser-light creating device itself, minus the source of power which pumps the oscillator.) The oscillator generally consists of a laser medium placed within an optical resonant cavity (pair of mirrors). Optical energy will be trapped between the mirrors and the optical (laser) oscillations will grow so long as the gain of the laser medium exceeds the losses at the mirrors. * Outboard Side: portion of a tokamak / toroidal device on the outer side, opposite the central axis. * Overturning Moment: Torque ("moment") on a toroidal field coil in a tokamak, about the device's radial direction, that results from out-of-plane forces on the coil due to the interactions between the coil current and the poloidal (vertical) magnetic field. This torque tends to "overturn" the vertical toroidal field coil, and must be engineered against. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 14/26 (N) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 14/26 (N) Date: 28 May 1995 13:04:25 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/n Last-modified: 20-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 14: Terms beginning with "N" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN # n: variable used for number density of particles. # n: also used as the symbol for a neutron. # n: also sometimes used for the index of refraction @ NAS: National Academy of Sciences; see entry @ NASA: National Aeronautics and Space Administration $ nano: metric prefix indicating 10^-9 * the base unit @ NBETF: Neutral Beam Engineering Test Facility @ NBI: Neutral Beam Injection; see entry @ NBS: National Bureau of Standards @ ND-YAG: Neodymium yttrium Aluminum Garnet # ne: (n subscript e) - usually electron density # Ne: chemical symbol for Neon. @ NERSC: National Energy Research Supercomputer Center; see entry @ NIF: National Ignition Facility; see entry @ NIKE: Naval? Inertial Confinement Experiment????; see entry @ NINJA: Neutral gas INJection Array (on Alcator C-Mod) @ NIST: National Institute for Science & Technology? @ NRC: National Research Council *OR* Nuclear Regulatory Commission; see entries. @ NRL: Naval Research Laboratory; see entry @ NSTX: National Spherical Tokamak eXperiment; see entry % National Academy of Sciences: Elite, honorary, independent, self-perpetuating organization of highly-successful scientists; chartered by the U.S. Congress to provide technical advice to the federal government upon request. % National Energy Research Supercomputer Center (NERSC): Formerly the National Magnetic Fusion Energy Computer Center, or NMFECC, NERSC is a supercomputer facility located at Livermore, CA. Originally developed to provide high-performance computing facilities for the needs of the magnetic fusion energy program, the facility now benefits all energy research programs. NERSC is a part of the Energy Sciences Network, ESNET, run by the Department of Energy, which links several of the national laboratories. > National Ignition Facility (NIF): Inertial-Confinement Fusion Facility proposed to be built at Livermore and operational around the year 2000. See Section 9 on Future Plans for more information. % National Research Council: Research arm of the National Academy of Sciences. > National Spherical Tokamak eXperiment (NSTX): Mid-sized low aspect-ratio tokamak / spheromak experiment proposal; still in design phase / not funded. See Section 9 on Future Plans for more information. % Naval Research Laboratory: Basic-science research laboratory operated by the U.S. Navy. * Neoclassical Diffusion: In a magnetized plasma, _classical_ diffusion refers to transport of particles due to Coulomb collisions, taking the spiral orbits in the magnetic field into account. In a toroidal magnetic field, the actual rate of diffusive transport is much higher due to slow changes in the positions of the centers of the spirals, known as banana orbits (see entry). This faster transport is called _neo-classical_. With very few exceptions the transport in toroidal devices is observed to be 10-100 times larger still, presumably due to small-scale turbulence. The observed transport is called _anomalous_ (although it actually is the "normal" state). * Neoclassical transport: See neo-classical diffusion. > Neutral Beam Engineering Test Facility: Facility located at LBL which tested neutral beam injection systems that were designed for use in magnetic fusion reactors. * Neutral Beam Injection: This is one of the fundamental plasma heating methods. A particle accelerator is used to create fast ion beams (the particle energies are on the order of 100 keV); the ion beam is then passed through a neutral gas region, where the ions neutralize via charge-exchange reactions with the neutral gas. The neutralized beam is then injected into a magnetically confined plasma. The neutral atoms are unaffected (not confined) by the magnetic field, but ionize as they penetrate into the plasma. The high-energy ions then transfer some of their energy to the plasma particles in repeated collisions, and heat the plasma. * Neutral Injection Concept: See Neutral Beam Injection, above. * Neutralized Plasma: Plasma with no net electrical charge. & Neutron: [Symbol: n] Fundamental atomic particle with zero electrical charge (therefore not confined by a magnetic field) and a mass roughly equal to a proton's mass. Neutrons are found in all nuclei except for ordinary hydrogen; they are also products of many nuclear reactions. Neutrons will react with nuclei, and can induce radioactivity or fission. Free neutrons which do not collide and react with a nucleus decay into an electron, a proton, and an neutrino, with a half life of about 13 minutes. * Neutron Wall Loading: Energy flux carried by fusion neutrons into the first physical boundary that surrounds the plasma (the first wall). (see also First Wall, Flux, Neutrons) > NIKE: Medium-scale(?) inertial-confinement fusion facility at the Naval Research Lab; see discussion in Section 5. * Non-Inductive Current Drive: Current drives schemes that do not rely upon the "transformer" effect in tokamaks. The attainment of non-inductive current drive is crucial to the success of tokamaks as truly steady-state devices. See also inductive current drive. > Nova: The United States' largest laser (ICF) fusion facility, and the world's most powerful laser; located at LLNL. This is a 10-beam, 100 terawatt, Nd-glass laser system, which can operate at the infrared/visible wavelengths of 1.05, 0.53, or 0.35 microns. It was completed in 1984 and is the successor to the Shiva system. (The next flagship laser-fusion facility currently planned in the U.S. is the National Ignition Facility.) * Nuclear Binding Energy: The difference between the total energy ( = mc^2) of the bound nucleus, and the energies of the individual constituent particles ( = sum of masses * c^2). The nuclear binding energy *per nucleon* is a maximum for iron. Fusion releases energy because light nuclei are less tightly bound than medium-weight nuclei, and thus energy is liberated when they become more tightly bound after fusing. Fission releases energy for the same reason - heavy nuclei are also less tightly bound than medium-weight nuclei, and energy is liberated when heavy nuclei split into lighter nuclei. & Nuclear Force: See Weak (Nuclear) Force, Strong (Nuclear) Force. % Nuclear Regulatory Commission: U.S. organization in charge of overseeing safety of nuclear facilities, including fission (and presumably fusion) reactors. * Nucleon: Generic term for a component particle of a nucleus, i.e., either a proton or a neutron. & Nucleus: The tiny core of an atom, positively charged, containing protons and neutrons (except for simple hydrogen, which has only a single proton). In an atom, electrons "orbit" the nucleus, forming a cloud around it. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 16/26 (P) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 16/26 (P) Date: 28 May 1995 13:04:27 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/p Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 16: Terms beginning with "P" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== PPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPP # p, P: Variables used for plasma (kinetic) pressure. # p: also used as symbol for the proton $ p: also the metric prefix for pico (10^-12 * base unit) @ PBFA-II: Particle Beam Fusion Accelerator-II; see entry @ PBX-M: Princeton Beta eXperiment-Modified; see entry @ PCS: Plasma Control System (Alcator C-Mod) @ PCX: Neutral Particle Analyzer @ PDX: Poloidal Divertor eXperiment; see entry @ PEOS: Plasma Erosion Opening Switch; see entry for Plasma Opening Switch (POS) @ PEP: Pellet Enhanced Performance; see entry on pellet injection @ PEST: Plasma Equilibrium and STability code; see entry @ PF: Poloidal Field; Poloidal Field Magnet Coil @ PLT: Princeton Large Torus; see entry @ PNL: Pacific National (Northwest?) Laboratory; no entry yet. @ POS: Plasma Opening Switch; see entry @ PPPL: Princeton Plasma Physics Lab; see entry @ PV: Photo-Voltaic; see entry @ PWR: Pressurized Water Reactor (fission); see entry * Parametric Instability: Instability which occurs in a system whose equilibrium is weakly modulated in time or space. The modulation produces a coupling of the linear eigenmodes of the system and can lead to destabilization. & Particle: > Particle Beam Fusion Accelerator II: Light ion accelerator inertial confinement fusion research system at Sandia National Laboratories. & Particle Density: number of particles present per unit volume (typically a cubic centimeter). See also density; typically represented by the variable "n". * Pellet Injection / Pellet Injector: This is a device which accelerates (shoots) small (less than 4 mm diameter) frozen pellets of hydrogen (or other) isotopes; these are then launched at high speed (ca. 1000 m/sec) into the inner regions of hot plasmas. Use of lithium and boron pellets allows coating of the vacuum vessel walls, and is useful for impurity control. Pellet injection can also be used to fuel the plasma, and the light emitted by the pellet's ablation cloud is useful for diagnostic purposes. * Pfirsch-Schluter Regime, P-S Transport: One of the neoclassical transport parameter regimes in a tokamak plasma; characterized by the collisional mean free path being shorter than the connection length. (This is the high-collisionality end of the spectrum; plateau transport is in the middle, and the banana regime is on the low-collisionality end.) In this regime the diffusion coefficient is q^2 times greater than the classical value (q being the safety factor, q > 1). See also classical transport, neoclassical transport, plateau transport, banana transport, safety factor. & Phase Velocity: Defined as w/k, this describes the rate of propagation of a wave through space. & Photoionization: The ionization of an atom or molecule by the collision of a high-energy photon (i.e., electromagnetic radiation) with the particle. & Photo-voltaic: Adjective used to describe devices which convert light, particularly solar energy, into electricity. $ pico-: Metric prefix indicating 10^-12 times the base unit. * Pinch effect: General term for a class of phenomena whereby the plasma is compressed or restricted ("pinched"). There are a variety of types of pinches. The Z-pinch is a constriction of a plasma carrying a large current, caused by the interaction of that current with its own encircling magnetic field. The Theta pinch is a constriction of a plasma by an increase in the axial magnetic field generated by an external solenoidal current. The Ware pinch arises in tokamaks due to neoclassical effects. And there are others. > Pinch Device or Pinch Machine: Device which confines plasma using a pinch effect. (Typically the Z or Theta pinch.) * Pinch Reflex Diode: A self-insulated ion diode in which the magnetic field from the ion and electron flow alone provide electron control, and the ion source is an anode plasma formed by relexing the electrons through a thin plastic foil. * Pitch Angle: For a charged particle moving in a magnetic field, this is the angle arctan (v-perp/v-parallel), where v-parallel is the component of the particle's velocity parallel to the magnetic field, and v-perp is the perpendicular component. The pitch angle is zero when the particle moves purely parallel to the field, and 90-degrees when the particle has no parallel velocity at all. * Pitch Angle Scattering: Scattering (collisional, or due to wave-particle effects) of particles in velocity space, in which the pitch angle (see entry above) is changed. * Plant Factor: Another term for Capacity Factor; see entry. * Plasma: A "Fourth State of Matter" in which many of the atoms or molecules are ionized. Plasmas have unique physics compared to solids, liquids, and gases. (Most plasmas can be thought of at first as extremely hot gases, but their properties are generally quite different.) Some (but not all!) Examples: the sun, fluorescent light bulbs and other gas-discharge tubes, very hot flames, much of interplanetary, interstellar, and intergalactice space, the earth's ionosphere, parts of the atmosphere around lightning discharges, and of course fusion plasmas. * Plasma Beta: see Beta * Plasma, Cold: See Cold Plasma Model * Plasma Containment: (quoting from the PPPL Glossary of Fusion Terms) "In plasma physics experiments or nuclear fusion experiments, operation is intended to prevent, in an effective and sufficiently prolonged manner, the particles of a plasma from striking the walls of the container in which this plasma is produced. Plasma confinement is a fundamental requirement for obtaining net energy from a fusion plasma. The reason is that scattering (hence diffusion) is at least an order of magnitude more probable than fusion reactions. Hence, without confinement, the plasma fuel would disperse before enough fusion reactions could take place." * Plasma Equilibrium and STability Code: (PEST) This is a widely-used, well-developed computer simulation ("code") used to calculate MHD equilibrium and stability in various fusion devices. > Plasma Focus: The Plasma Focus is another device which depends on the pinch effect. Possible applications include both fusion and plasma propulsion, as well as other plasma research. In essence the plasma focus is generated by discharge of a current across the ends of two coaxial insulated conducting pipes. The Plasma Focus caused a huge stir when they generated copious neutrons, until it was discovered that the source of the neutrons was knockoffs from deuterium due to pinch accelerated electrons or ions. Plasma focus is sort of a point version of the "Z"pinch. For more information on the plasma focus, see the entry in the section on confinement approaches (4B). * Plasma Frequency: The natural collective oscillation frequency of a charge species (electrons, ions, etc.) in a plasma, in the absence of (or at least parallel to) a magnetic field. Also known as Langmuir or Langmuir-Tonks frequency; see also electrostatic waves, plasma oscillations. * Plasma Oscillations: Class of electrostatic oscillations which occur at/near the plasma frequency (see entry) and involve oscillations in the plasma charge density. Also known as Langmuir Oscillations; In Stix's _Waves in Plasmas_ these are called Langmuir-Tonks Plasma Oscillations. * Plasma-Plasma Reaction: Fusion reaction which occurs from the collision of two thermal plasma ions. (See also beam-wall, beam-beam, and beam-plasma reaction entries.) * Plasma Wave: A disturbance of a plasma away from equilibrium, involving oscillations of the plasma's constituent particles and of an electromagnetic field. Plasma waves can propagate from one point in the plasma to another without net motion of the plasma. > Plasmak: Controversial advanced spheromak-type concept using a fluid rather than solid conducting shell and a plasma with purely internal magnetic fields, whose pressure is supported by a surrounding gas; for more information see entry in section 4. * Plasmoid: An isolated plasma which holds together for a duration much longer than the collison times for the consituent particles. * Plateau Region, Plateau Transport: The collision frequency (and transport) regime characterized by an effective coulomb scattering rate equal to or greater than the poloidal transit ("bounce") frequency, but where collisional mean free path is less than the connection length (2qR*PI). In this regime, the transport coefficients are independent of the collision frequency. (Thus a plot of transport coefficients vs. frequency becomes horizontal line in this regime, forming a "plateau" in the graph; hence the name.) & Plutonium: Radioactive metallic element (Pu). The primary isotope, plutonium-239, is a product of neutron absorption by U-238, esp. in fission reactors. Pu is used in nuclear weapons and as a fission reactor fuel. * Poisoning: Buildup of ash and impurities in a fusion plasma tends to reduce the quality of the plasma and reduce the fusion output; this sort of process is sometimes called "poisioning" the reactor or the plasma. See also ash, impurities. & Polarization: * Polarization of Reacting Particles: See Spin-Polarized Fusion. * Poloidal: In toroidal geometries, the direction along the circumference of a slice through one side of the torus. "The short way around a torus". - Albert Chou, albert@seas.ucla.edu * Poloidal Divertor: A divertor (see entry) which takes a bundle of poloidal field lines, forming a separatrix in the poloidal magnetic field which creates separate plasma regions (which can then have different physical parameters, since transport is reduced across the separatrix where q => infinity). > Poloidal Divertor Experiment: (PDX) A medium-size, high-current divertor tokamak which was operated at Princeton, whose primary research objective was to determine the effectiveness of poloidal magnetic divertors in controlling impurities in reactorlike fusion plasmas. PDX was modified and became PBX, which was modified again and is now PBX-M (see entry for Princeton Beta Experiment). * Poloidal Field: In toroidal devices, the magnetic field that encircles the plasma axis. (i.e., loops around the torus "the short way".) * Poloidal Field Coils: In toroidal devices (eg, tokamaks), the sets of windings which are (typically) aligned along the plasma axis and produce poloidal fields. These include ohmic heating, shaping, vertical, equilibrium, and divertor windings. * Poloidal Field Windings: See Poloidal Field Coils above. * Positive Column: The luminous glow, often striated, which occurs between the Faraday dark space and the anode in a glow discharge plasma tube. & Positron: Antiparticle to the electron; this particle has the mass of the electron but the opposite charge. * Positron Emission: Form of nuclear decay where a proton disintegrates into a neutron, positron, and some sort of neutrino. (?) & Power: Defined as amount of work per unit time, or change in energy per unit time. * Power Density: In fusion, the rate at which energy is generated per unit volume in the reactor core. (See also entries for power, density.) & Pressure: Defined as force per unit area. * Pressure Tensor: A generalized pressure (can be anisotropic) which plays a role in MHD (see entry) analogous to that of pressure in ordinary fluid mechanics. > Pressurized-Water Reactor (fission): Type of nuclear reactor where the coolant is water kept under pressure to prevent it from turning to steam inside the plant. (I think!) * Price-Anderson Act: U.S. Federal law passed in the 1950s (?) which limits utility liability for nuclear fission plant accident damages. U.S. Government effectively insures the utilities against external costs associated with nuclear accidents. * Primary Energy: Energy before conversion. For instance, the United States uses about 30,000 megajoules of electricity per capita per year, but electricity is generally obtained by converting other forms of energy (primarily chemical/heat) at an efficiency of around 30%, so the U.S. consumes 90,000 megajoules of primary energy per capita for electrical use. (Total U.S. primary energy consumption is 300,000 megajoules per capita.) % Princeton - See Princeton University and/or Princeton Plasma Physics Lab > Princeton Beta Experiment-Modified (PBX-M): mid-sized tokamak research device at Princeton, which evolved from the Poloidal Divertor Experiment (PDX) machine. Research on PBX is aimed at investigating advanced tokamak regimes, such as indented plasmas (kidney-bean cross sections) with high-beta, providing access to the second-stability regirme. > Princeton Large Torus (PLT): Large tokamak formerly operated at the Princeton Plasma Physics Laboratory (PPPL). Was operated in the 1970s and 80s and studied RF heating and current drive, as well as neutral beam injection heating and other aspects of tokamak physics. Roughly a predecessor to TFTR. % Princeton Plasma Physics Lab (PPPL): Located in Princeton, New Jersey. Single largest fusion research facility in the United States; sole U.S. single-purpose plasma physics laboratory; operated by Princeton University for the Department of Energy. Site of PLT, PBX-M, TFTR, several other past and present experiments, and future site of TPX. (Refer to entries for relevant machines, both here and in FAQ.) % Princeton University: Among other research activities, the University operates the Princeton Plasma Physics Laboratory for the Department of Energy (see above entry for PPPL). * Process Heat: Heat produced by a powerplant (could be a nuclear reactor, or a fusion reactor someday) and used directly for industrial processes, such as metals manufacturing or chemical production. * Project Matterhorn: Code name of the United States' first secret controlled fusion project, started by Lyman Spitzer at Princeton University in 1951. Became a subprogram within Project Sherwood (see entry below.) * Project Sherwood: Name often used to describe the U.S. controlled fusion program in the 1950s and '60s. * Proliferation (nuclear): Proliferation generally describes the way something spreads (rapidly) from one area to another; in the case of nuclear weapons, nuclear proliferation refers to the spread of nuclear bomb-building technology from one state to another. > Proto II: A high-power (10 TW) pulsed (24 ns) electron accelerator which was (is?) used for inertial-confinement research. & Proton: (from Herman) An elementary particle found in the nucleus of all atoms. It carries a single positive electrical charge. & Pulse Height Analyzer: Instrument which records and stores pulses and indicates ("Analyzes") the number of pulse occurrences falling within each of a set of amplitude ("height") ranges. * Pulsed Power: The technology of using electrical energy stores for producing multi-terawatt (10^12 Watts or higher) pulses of electrical power for inertial confinement fusion, nuclear weapon effects simulation, and directed energy weapons. High efficiency and cost effectiveness make it desirable technology for large energy experiments. * Pumpout: Name given to the anomalously high loss of particles to the walls in (some) stellarator discharges; the loss rate when pumpout occurs is substantially greater than that expected from normal classical diffusion processes. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 17/26 (Q) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 17/26 (Q) Date: 28 May 1995 13:04:28 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/q Last-modified: 21-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 17: Terms beginning with "Q" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== QQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQQ # q - Variable used to indicate electric charge; also used for the "safety factor" (see charge, safety factor). Usually clear from context which is meant. # Q: See Q-factor * Q-enhancement: Refers to methods for improving the power balance in mirror-based magnetic confinement fusion reactors. * Q-factor: Ratio of power produced by fusion to power put into the reactor to heat the plasma and drive the magnetic fields. Q = 1 is the definition of scientific breakeven, where power out = power in. Economical fusion will require Q significantly greater than 1. Fortunately Q increases dramatically as the plasma parameters approach the Lawson criterion for ignition. Power to drive the magnetic fields is frequently ignored in discussions of Q, with the justification that a steady-state, continuous-output fusion reactor will have superconducting magnet coils. * Q-machine: Plasma device studied in the 1960s; noted for its natural quiescence, which made it attractive for plasma wave phyics experimentation. * Q-switch: Optical switch used to rapidly change the Q of an optical resonator (see entry for oscillator); utilized in the optical resonator of a laser to prevent lasing action until a high level of gain and energy storage are achieved in the laser medium. When the switch is triggered and rapidly increases the Q of the cavity, a stronger laser pulse is generated. $ Quad: Unit of energy equal to a Quadrillion BTUs (10^15) or roughly one exajoule (see entry for joule, exajoule, BTU). * Quasi-linear Theory: A weakly nonlinear theory of plasma oscillations which uses perturbation theory and the random phase approximation to find the time-evolution of the plasma state. * Quasi-neutral plasma: an ionized gas in which positive and negative charges are present in approximately equal numbers. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 20/26 (T) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 20/26 (T) Date: 28 May 1995 13:04:31 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/t Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 20: Terms beginning with "T" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT # t: variable generally used to represent time # tau: label generally used to represent confinement time # T: variable generally used to represent temperature # T: nuclear/chemical symbol for tritium/triton; see entry $ T: abbreviation for Tesla, SI unit of magnetic field; see entry > TARA: See entry under TARA below. @ TCI: Two-Color Interferometry @ TCV: Variable Configuration Tokamak - from French; see Section 5. @ TCX: Tangential Charge Exchange # Te: (subscript e) Electron Temperature $ Tera: Metric prefix indicating one trillion (10^12) times base unit. $ Terawatt: One trillion (10^12) watts. @ TEXT-U: TEXas Tokamak-Upgrade; see entry under TEXT below. @ TEXTOR: Tokamak EXperiment for Technology Oriented Research; see entry for TEXTOR below. @ TF: Toroidal Field (or Toroidal Field Coil) @ TFR: FRench Tokamak, see entry under TFR below @ TFTR: Tokamak Fusion Test Reactor; see entry # Ti: Chemical Symbol for Titanium; if subscript i, Ion Temperature @ TMX: Tandem Mirror eXperiment; see entry. @ TMX-U: Tandem Mirror eXperiment-Upgrade; see entry. @ TORMAC: TORoidal MAgnetic Cusps; see entry @ TPX: Tokamak Physics Experiment; see entry @ TRANSP: Princeton's TRANSPort Simulation Code (Tokamak) @ TW: terawatt; 10^12 watts; see watt. @ TWyr: terawatt-year; Unit of energy equal to 3.15 x10^19 joules or 30 Quads (see entries) > T-3: A Soviet tokamak located at the Kurchatov Institute in Moscow which first proved concept viability, by producing a plasma temperature of 10 million degrees centigrage/Kelvin. (Result was disbelieved in the West until a British team confirmed the results using Thomson scattering.) > T-10: A later, larger Soviet tokamak, located at the Kurchatov Institute (Moscow). (PLT was largely a copy of T-10, only PLT had neutral beams, whereas T-10 was (I believe) purely ohmic-heated. > T-11: Another Soviet tokamak (rather small) located at the Kurchatov Institute (Moscow); studied neutral-beam heating. > T-15: (formerly T-10M) Another, much larger Soviet tokamak (somewhat smaller than TFTR, but similar size) with superconducting magnets, currently (?) under construction. (Was it completed? Is it operational?) > T-20: A huge Soviet tokamak that was designed to operate under reactor conditions (net energy production) but which was abandoned for budgetary reasons. > Tandem Mirror Experiment: (TMX) Located at LLNL, this was one of the first devices to experiment with placing magnetic mirror devices at either end of a (relatively) long cylindrical central region. In TMX the plasma was supplied by neutral beams. > Tandem Mirror Experiment-Upgrade: (TMX-U) Upgrade of TMX which was brought on line in 1983. Incorporated rf heating systems and improved neutral beam systems. Predecessor to MFTF-B (see entry) as a flagship magnetic mirror in the U.S. > TARA: Medium scale tandem mirror device commissioned at MIT in 1984 to develop greater understanding of basic tandem mirror physics, with emphasis on microstability properties, thermal barrier formation, and RF heating. * Target Plasma: Plasma used to trap a neutral atom beam. A background plasma of sufficiently high density and temperature can ionize neutral atoms more effectively than the Lorentz process (where v cross B creates effective electric field?). * Tau: See # tau above. ! Taylor, J.B.: Renowned plasma physicist; noted for helicity work?? * Taylor State: (John Cobb?) * Tearing Mode, Tearing Instability: A resistive MHD instability which is spatially localized near a rational surface and which grows at a rate slower than the MHD Alfven rate, but faster than the resistive skin diffusion rate. The instability "tears" magnetic field lines and reconnects them into a new state of lower magnetic energy. (see other entries for more information about the terms used above.) & Temperature, Kinetic: See Temperature, Plasma, and Kinetic Temperature. * Temperature, Plasma: A measure of the random (thermal) kinetic energy of the ions or electrons in the plasma. The temperature of each component of a plasma depends on the mean kinetic energy of that component. An example of this is the fluorescent light bulb, which is an example of a weakly-ionized plasma where the electrons are at temperatures of tens of thousands of degrees, whereas the ions and neutrals are much cooler (so that you can touch the bulb without being burned). See atomic temperature, electron temperature, and ion temperature. $ Tesla - SI unit of magnetic field strength; 1 tesla = 10,000 gauss. > TEXT-U Device: A medium-size research tokamak at the University of Texas, Austin; upgraded version of the TEXT device, with divertor. > TEXTOR: (Tokamak EXperiment for Technology Oriented Research. Medium-sized European tokamak located in Julich, Germany. Research objectives involve things like developing plasma-facing components and studying effects of plasma-wall interactions. > TFR: An iron-cored French Tokamak, now retired (I believe). Pioneered a number of important tokamak ideas and innovations. * Thermal Barrier: In magnetic mirror devices, this is a depression of electrostatic potential formed by enhancing ion loss in the region between the central cell and the positive potential plug. The thermal barrier significantly reduces the density requirements in the plug and lowers the overall power required to sustain the solenoidal plugging by thermally decoupling central cell electrons from the end plugs. & Thermal Conductivity: degree to which a substance transmits heat. (basic definition, I believe, is: (heat flow) = (thermal conductivity) * (temperature gradient) ) & Thermal Conversion Cycle: Process of generating electrical power with a fusion reactor by means of a steam / other gas turbine. This is distinct from "direct conversion" cycles. & Thermal Efficiency: Ratio of the electric power produced by a power plant to the original amount of heat produced. This measures the efficiency with which the thermal energy is converted to electricity. * Thermal (Slow) Neutron: A neutron in thermal equilibrium with its surrounding environment. Thermal neutrons are those that have been slowed down by a moderator to speeds characteristic of the local temperature. (Compare with fast neutron.) & Thermodynamic Equilibrium: There is a very general result from statistical mechanics which states that, if a system is in thermodynamic equilibrium with another (or several other) system(s), all processes by which the systems can exchange energy must be exactly balanced by their reverse processes, so that there is no net exchange of energy. For plasma systems in thermodynamic equilibrium, ionization must be balanced by recombination, Bremsstrahlung by absorption, and so on. When thermodynamic equilibrium exists, the distribution function of particle energies and excited energy levels of the atoms can be obtained from the Maxwell-Boltzmann distribution (which is a function only of the temperature). The Saha equation is a special application of this. * Thermonuclear Conditions: Achievement of an adequately confined plasma, having temperature and density sufficiently high to yield significant release of energy from fusion reactions. * Thermonuclear Fusion: fusion achieved by heating up the fuel into the plasma state to the point where ions have sufficient energy to fuse. > Theta Pinch: A fast-pulsed pinch device in which the external current imposed goes in the azimuthal/circumferential direction (generally in a solenoid) around a cylindrical plasma. Use of a fast-rising solenoidal current causes a rapidly increasing axial magnetic field, which compresses and heats the plasma. * Thomson Scattering: Scattering of photons by electrons, in the classical (low photon energy) limit. Laser light passed through a plasma will experience Thomson scattering; the spread of the scattered light in energy provides a very good measurement of the electron temperature of the plasma. > Tokamak: (Acronym created from the Russian words, "TOroidalnaya KAmera MAgnitnaya," or "Toroidal Chamber-Magnetic".) Because the tokamak is the primary research machine for magnetic confinement fusion today, we provide several descriptions from various sources: -> One of several types of toroidal discharge chamber in which a longitudinal magnetic field is used to confine a plasma. The tokamak is distinguished by a plasma current running around the torus, which generates a stabilizing poloidal magnetic field. An externally-applied vertical magnetic field is also used to achieve plasma equilibrium. -> (Contributed by James Crotinger, jac@gandalf.llnl.gov) An axisymmetric toroidal confinement device characterized by a strong toroidal magnetic field (1-10 Tesla) and a toroidal plasma current (several mega-Amps) that leads to a modest poloidal magnetic field. The plasma current is usually induced by ramping a current in a large solonoid along the symmetry axis of the tokamak. This is an inherently pulsed mode of operation, and other mechanisms of current drive are under investigation. -> TOKAMAK (tokomak) (contributed by Paul M. Koloc) "A three component magnetoplasma toroidal construct in which the poloidal magnetic component is provided by a toroidal plasma current. The other two components are coil driven, namely, the vertical field (which opposes the major radial expansion) and the toroidal field (which acts to provide a "stiff guide" field for the plasma to gain more MHD stability. Note: It is better to think that the toroidal or longitudinal field "stiffens" the plasma as against flopping or kinking, while the plasma current driven poloidal (locally azimuthal) field provides "confinement" pressure. Actually, the toroidal field interacting with plasma diamagnetism may also contribute to a "magnetic bouyancy", which is a sort of UN-confinement -- (it actually gives the plasma a tendency to expand radially outward in the equatorial plane)." -> (from Herman:) "Based on an original Soviet design, a device for containing plasma inside a torus chamber by using the combination of two magnetic fields - one created by electric coils around the torus, the other created by intense electric current in the plasma itself, which also servers to heat the plasma [partially]. TFTR and JET are tokamaks." > Tokamak Fusion Test Reactor: Large tokamak at Princeton, first machine to use 50-50 mix of D-T fuel, current world's record holder in fusion energy production. Largest tokamak in the United States. > Tokamak Physics Experiment: Smaller successor to TFTR at Princeton. Engineering design underway; construction scheduled to begin in FY 1995. > Tore Supra: Large tokamak in Cadarache (southern France). The second largest tokamak in Europe; largest tokamak using superconducting toroidal field magnets. Tore Supra has a circular cross-section (like TFTR), which limits the achievable confinement time and experimental flexibility. In addition to developing superconducting technology, it concentrates on the physics of long pulses and ergodic magnetic limiters. See also: ergodic; magnetic limiter; superconductor; tokamak. * Toroidal: in the shape of a torus, or doughnut. Or: Coordinate indicating which part of the torus a particle is in. (Azimuthal coordinate) Or: General term referring to toruses as opposed to other geometries. (e.g., tokamaks and stellarators are examples of toroidal devices.) * Toroidal Field Coils: Coils in a toroidal system, typically wound around the torus in a solenoid-like arrangement, used to generate the toroidal magnetic field. Each turn completely surrounds the plasma. > TORMAC: (TORoidal MAgnetic Cusps) Hybrid confinement scheme operating at high beta. A region of closed toroidal magnetic flux with high-beta plasma is separated by a narrow sheath from the surrounding field, which contains externally produced poloidal components arranged in a toroidal line-cusp configuration. Plasma migrating to the outer sheath is temporarily mirror-confined before being removed in a divertor system. > Toroidal Pinch: & Torque: > Torsatron: A modification of the stellarator concept, the torsatron has a toroidal non-axisymmetric configuration, and rotational transform is provided by external coils. Unlike a stellarator, however, both toroidal and poloidal fields are generated by helical fields alone, with half the number of helical conductors required for a stellarator. & Transformer, Transformer Effect: See entry for Induction. & Transmittance: Ratio of the radiant power transmitted by an object to the incident radiant power. See also reflectivity. & Transmutation: Transformation of atoms of one element into atoms of another element via nuclear reactions. (e.g., the transmutation of uranium-238 into plutonium-239 via the absorption of a neutron and subsequent beta emission.) * Transport: Refers to processes which cause heat energy, or particles, or something else, to flow out of the plasma and cease being confined. Diffusion partly determines the rate of transport. See also: diffusion, classical diffusion, neoclassical diffusion, anomalous diffusion. * Transverse Waves: Waves in which the direction of the oscillation is perpendicular ("transverse") to the direction of the wave propagation. Examples include plucked strings and electromagnetic waves in free space/air. * Trapped-Particle Instability: Slowly-growing class of instabilities driven by particles which cannot circulate freely in a toroidal system. See also banana orbit. * Trapped-Particle Modes: See trapped-particle instability * Triangularity: Geometric factor measuring an aspect of the shape (how "triangular" it is) of the cross-section of a non-circular plasma in a toroidal device. See also elongation. & Tritium: A radioactive isotope of hydrogen with one proton and two neutrons in its nucleus and one orbiting electron. A more efficient fuel than ordinary hydrogen (protium) because of the extra neutrons. Tritium decays to helium-3 by emission of an electron ("beta emission") with a half-life of 12.3 years. Tritium can be synthesized from deuterium via neutron bombardment, or by fissioning lithium (see lithium). * Tritium-Breeding Ratio: The amount of tritium generated by the breeding blanket of a D-T fusion reactor, divided by the amount of tritium burned in the reactor. A tritium breeding ration greater than unity is necessary for self-sufficient fueling. * Triton: nucleus of a tritium atom; tritium ion. * Troyon Limit: see beta limit * Turbulence: "Violent macroscopic fluctuations which can develop under certain conditions in fluids and plasmas and which usually result in the rapid transfer of energy through the medium." (PPPL & OSTI Glossaries have same entry) * Turbulent Heating: Technique of using turbulence induced by large electric fields to rapidly heat a plasma. * Two-Stream Instability: Instability which can develop when a stream of particles of one type has a velocity distribution with its peak well separated from that of another type of particle through which it is flowing. A stream of energetic electrons passing through a cold plasma can, for example, excite ion waves which will grow rapidly in magnitude at the expense of the kinetic energy of the electrons. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 18/26 (R) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 18/26 (R) Date: 28 May 1995 13:04:28 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/r Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 18: Terms beginning with "R" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR @ Rad: Radiation Absorbed Dose; see entry "rad" @ Rem: Raditation (or Roentgen) Equivalent for Man; see entry "rem" @ R&D: Research and Development. @ RD&D: Research, Development, and Demonstration. @ RF: Radio Frequency; see entry @ RF Current Drive: Radio Frequency Current Drive; see entry @ RF Heating: Radio Frequency Heating; see entry ! R.F. Heeter: Plasma physics graduate student at PPPL; the editor of the sci.physics.fusion FAQ, bibliography, and glossary. :) (note similarity to RF Heating.) @ RF Plugging: See entry for radiofrequency plugging @ RF Trapping: See entry for radiofrequency trapping @ RFC: Reversed-Field Configuration: see Field-Reversed Configuration. @ RFP: Reversed-Field Pinch; see entry @ RFX: Reversed-Field eXperiment; see entry @ RGA: Residual Gas Analyzer $ Rad: radiation absorbed dose. A unit used to measure the amount of radiation energy absorbed per gram of a given substance, that is the dose. One rad means absorption of 100 ergs of energy per gram. See also gray, rem, sievert. * Radial Ponderomotive Force Stabilization: In magnetic mirror devices, use of rf waves in the neighborhood of the ion cyclotron frequency to stabilize interchange modes. The radial ponderomotive force produced by a radial gradient in the applied rf electric field opposes the destabilizing centrifugal force resulting from bad magnetic field curvature. The net particle current is in the direction that would result from field lines with good curvature, eliminating the drive for the interchange instability. & Radiation: (Sense 1) Process of emission of energy from a body in the form of light or heat waves, or energetic particles such as alpha particles, electrons, or neutrons. (Sense 2) Radiation also refers to *what is emitted* when an object radiates (but not *what does the emitting*). A nucleus which does the emitting is said to be radioactive. Electrons in atoms can also emit radiation in the form of ordinary visible light; such atoms are not said to be radioactive. * Radiation Damage, Bulk: General term describing changes in chemical and/or metallurgical properties of structure components of fusion reactor caused by atomic displacement and nuclear transmutation events occuring as a result of exposure to a radiation environment (such as the neutrons emitted from a fission or D-T fusion reactor). * Radiation Damage, Surface: General term describing damage to the surface of the containment structure which directly interfaces with the thermonuclear plasma; includes such phenomena as radiation blistering, charged-particle (or neutron) sputtering, and spallation or exfoliation of layers of the surface. & Radioactive Decay: Spontaneous transformation of one nuclide into a different nuclide or into a different energy state of the same nuclide. This process results in a decrease, with time, in the number of originally radioactive atoms in a sample. See Decay Modes for a listing of the different mechanisms by which radioactive decay can occur. & Radioactive waste: Equipment and materials from nuclear operations which are radioactive and for which there is no further anticipated use. Wastes are generally classified as high-level (having radioactivity concentrations of hundreds to thousands of curies per gallon or cubic foot), low-level (in the range of 1 microcurie per gallon or cubic foot), or intermediate (between high and low). See also curie. & Radioactivity: Characteristic property of unstable nuclei which decay to other nuclei by emission of radiation. A list of common decay / transmutation modes is given under "decay modes". * Radio Frequency or radiofrequency: Term used to describe electromagnetic radiation with frequencies less than infrared, but greater than "audio frequencies," i.e., greater than about 15,000 Hz. Wavelengths are therefore less than about 20,000 km and greater than about 0.01 mm. (These numbers are not precise.) * Radio Frequency Current Drive: Plasma waves in the radio-frequency range can be used to push plasma particles in such a way that current forms in the plasma; this is a method of non-inductive current drive (see entry) which would allow for steady-state fusion reactors to operate. * Radio Frequency Heating: Process for heating the plasma by transferring energy to ions or electrons using waves generated by an external oscillator at an appropriate frequency. (This is similar to how a microwave oven heats food.) There are various types: see also ECRH, ICRH, and Lower Hybrid... * Radiofrequency Plugging: Use of axial ponderomotive force to plug an open-ended device. First demonstrated on RFC-XX, Institute of Plasma Physics, Nagoya University, Nagoya, Japan, and later demonstrated in the Phaedrus device at the University of Wisconsin. * Radiofrequency Trapping: Use of RF waves to pitch angle scatter particles flowing axially into a magnetic mirror cell. The particles are scattered out of the loss cone and are trapped. (See entries for pitch angle scattering, magnetic mirror, loss cone.) * Railgun Accelerator: Projectile accelerator which accelerates the particle using electromagnetic forces which arise when the particle completes an electrical circuit between two conducting rails connected to a source of high current. * Raman Effect: A phenomenon observed in the scattering of light as it passes through a transparent medium; the light undergoes a change in frequency and a random alteration in phase due to a change in rotational or vibrational energy of the scattering molecules. * Ramsauer Effect: Term for a quantum-mechanical effect allowing free electrons within a narrow range of energies to pass through a noble gas with very little elastic scattering. * Rational Surface: (related to q-factor, see entry) Magnetic flux surface (see entry for this too) where the ratio of toroidal to poloidal field strengths is a rational number; this means that a particle travelling along this surface makes an integer number of turns in each direction and then its orbit closes in on itself. The result is that the particle doesn't sample the entire flux surface in its motion, which is important for various technical reasons (which mostly result in reduced confinement); see also magnetic island. * Reactor: See fission reactor, fusion reactor. & Recombination Coefficient: The rate of recombination of positive ions with electrons (or negative ions) in a gas, per unit volume, divided by the product of the particle densities of the two species (positive ions and electrons/negative ions) involved. * Recombination Radiation: radiation produced when a free electron in a plasma is captured by an ion. & Reflectivity: Fraction of incident radiant energy which is reflected by a given surface. (The power which is not reflected is either absorbed or transmitted.) & Refraction: Bending of waves as they pass from a medium having one refractive index to a medium (or region within a medium) having a different refractive index. $ Rem: Radiation (or Roentgen) Equivalent for Man. Unit of absorbed radiation dose based on the definition rem = rad * quality. The quality factor depends on the type of radiation involved and is used to scale the radiation dose based on the relative harmfulness of different sorts of radiation, compared to ordinary X-rays. Annual US average dose is about 300 millirem (0.3 rem), of which more than 2/3 is natural (primarily radon and cosmic rays), and the majority of the human-generated dose is due to medical uses (primarily X-rays). See also radiation dose, roentgen, sievert, rad, gray. * Reserves: Amount of a substance which can be extracted from the earth with current technology at current prices. Typically much smaller than resources (see entry for resources). & Resistance (electrical): Ability of a given object to resist the flow of electrical current. To drive a given current a voltage must be applied to overcome the resistance according to V = I * R (V = voltage, I = current, R = resistance). Resistance is determined by resistivity and geometrical factors. * Resistive Instability: Instability resulting from macroscopic equations used to model a plasma of finite conductivity / nonzero resistivity. & Resistivity: Tendency for a material/substance to resist the flow of electrical current and to dissipate its energy. Resistivity, when combined with certain geometry factors (generally length and cross-sectional area for wires) determines resistance. * Resource: Total amount of a substance which exists in the earth and could conceivably be extracted someday at some price with some technology. Typically much larger than reserves. (See also reserve.) > Reversed-Field Pinch (RFP): A toroidal magnetic confinement scheme which could constitute an alternative to the Tokamak for building a fusion reactor. It is characterized by a magnetic field mostly generated by the plasma itself, with toroidal and poloidal components of comparable intensities, in contrast with the Tokamak where most of the field is toroidal and externally applied. The name of the configuration is given by the fact that the toroidal component of the magnetic field changes sign in the outer region of the plasma. The main attractivness of the Reversed Field Pinch is that, according to presently established scalings, it could reach ignition without the need of auxiliary heating. (Emilio Martines, martines%pdigi3.igi.pd.cnr.it) > Reversed-Field eXperiment (RFX): It is the largest Reversed Field Pinch device presently in operation. Located in Padova (Italy) it is planned to reach a plasma current of 2 MA. (Emilio Martines, martines%pdigi3.igi.pd.cnr.it) * Roentgen: Unit of exposure to ionizing radiation. The Roentgen is that amount of gamma or X-rays (electromagnetic radiation) required to produce ions carrying one electrostatic unit of electrical charge (either positive or negative) in 1 cubic centimeter of dry air under standard conditions. Named after Wilhelm Roentgen. (Compare with curie, rad, gray, sievert.) ! Roentgen, Wilhelm: German scientist who discovered X rays in 1895. * Rogowski Loop or Coil: A coiled wire loop which encircles a current-carrying plasma. Changes in total plasma current induce a voltage in the loop; integrating (adding up) the voltage over time gives the plasma current. * Rotational Transform: (labels: \iota = 2*PI/q) Due to the combination of applied toroidal field and induced poloidal field, the magnetic field lines wind helically around the torus (and on most flux surfaces they fill the surface ergodically). The rotational transform is a measure of this helicity, and is defined as the average angle the field line shifts in the poloidal direction per complete circuit in the toroidal direction. The quantity q = 2*\pi / \iota is known as the ``safety factor'' because of its role in stability theory. (Contributed by James Crotinger) Entry from 1985 OSTI Glossary: A magnetic field configuration is said to posses rotational transform if the lines of force, after one complete circuit around the configuration (e.g., a torus) do not simply close exactly on themselves, but are instead rotated through some angle about the magnetic axies. (See entries for flux surface, magnetic axis, toroidal and poloidal field, helicity, safety factor.) * Runaway Electrons: Those electrons in a plasma that gain energy from an applied electrical field at a faster rate than they lose it through collisions with other particles. These electrons tend to "run away" in *energy* (not position) from the cooler remainder of the background plasma, because the collision cross-section decreases as the particle's velocity increases, so that the faster the particle goes, the less likely it is to be stopped. See also: collision cross-section. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 19/26 (S) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 19/26 (S) Date: 28 May 1995 13:04:29 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/s Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 19: Terms beginning with "S" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS @ (?) SHIVA: see entry under Shiva, below. @ SI: Systeme Internationale; see SI Units @ SM: Symmetric Mirror @ SN: Single Null; see entry for Divertor @ SNL: Sandia National Laboratories; see entry @ SOL: Scrape-Off Layer; see entry @ STM: Symmetric Tandem Mirror experiment. $ Sv: Sievert; see entry * Safety Factor: (q) The number of times a field line goes around a torus "the long way" for each time around "the short way". In a tokamak, this number is typically near unity in the center of the plasma and between two and 6 or 8 at the edge. So-called because it helps to determine the degree of stability the plasma has against certain instabilities. The safety factor is the inverse of the rotational transform, and can be expressed mathematically as q = (r * Bt )/(R * Bp), where r and R are the minor and major radii of the torus, and Bt and Bp are the toroidal and poloidal magnetic fields. ! Sakharov, Andrei: Russian physicist; among other achievements, he is credited with the initial design of the tokamak. % Sandia National Laboratories: Located in Albuquerque, New Mexico. Another large DOE laboratory; has PBFA-II (Particle Beam Fusion Accelerator, an ICF device) and some pinch devices. Some divisions located in Livermore (Sandia-Livermore). * Sawtooth: When a tokamak runs with enough current to achieve q < 1 on the magnetic axis, the plasma parameters (n, T, B) oscillate with a "sawtooth" waveform. The oscillation is localized to a region roughly within the q=1 surface, and arises from internal MHD effects. Confinement is degraded within the sawtooth region. * Scaling Laws: These are mathematical rules explaining how variation in one quantity affects variations in other quantities. For instance, in a tokamak reactor it's generally believed that energy confinement depends on the size of the device and the strength of the magnetic field, but the precise nature of the dependence is not fully understood, so empirical "scaling laws" are tested to see what the dependence is. Scaling laws are useful for extrapolating from parameter regimes where the mathematical relationships between the various quantities are known, into unexplored regimes. & Scattering: The deflection of one particle as a result of collisions with other particles or with waves. See also Elastic. * Schlieren Method: An optical technique that detects density gradients occuring in a fluid flow. In its simplest form, light from a slit is collimated by a lens and focused onto a knife edge by a second lens; the flow pattern is placed between the two lenses, and the resulting diffraction pattern is observed on a screen or photographic film placed behind the knife edge. * Scientific Feasibility: Fusion will be considered scientifically feasible when (a) experiments are done which reach scientific breakeven-type plasma conditions (see entry on breakeven), and (b) the experimental results suggest that the approach can be "scaled up" into a power-producing system. Tokamak fusion reactors are closing in on (a), and tokamak researchers think (b) holds as well, so they are designing a power-producing machine (ITER) to demonstrate net energy production from tokamak fusion. Inertial confinement is also approaching this point. * Scrape-Off Layer (SOL): [from Art Carlson] Outer layer of a plasma which is affected ("scraped off") by a divertor or limiter. That is, the outer layer of a magnetically confined plasma (ca. 2 cm thick) where the field lines penetrate a material surface (limiter or divertor plate) rather than close upon themselves. This region defines the outer limit of the plasma because any plasma crossing into the SOL is rapidly lost since transport along the field is much faster than that across the field. That is, particles follow these field lines into the material surface and are lost from the plasma. * Screw Pinch: A variant on the theta pinch, in which axial currents (as in a z pinch, but less intense) produce a poloidal magnetic field (in addition to the usual longitudinal field), thus making a corkscrew field configuration. See also theta pinch, z pinch, pinch device. * Second-stability Region: A high pressure region where the plasma becomes stable to the pressure-gradient-driven ballooning ballooning instability. The plasma is stable in the limit of small pressure gradients, becomes unstable at some intermediate pressure, and then becomes stable again at still higher pressures. Tokamaks operating in the second-stability region would be more attractive because the higher pressures (beta) would provide more fusion reactivity per unit volume of plasma, allowing smaller reactors to be built. * Separatrix: [from Art Carlson] In a divertor tokamak (and some other configurations), the last closed flux surface (see entry) is formed not by inserting an object (limiter) but by manipulating the magnetic field, so that some field lines take a topologically different route (through the divertor, rather than simply around the central plasma). The boundary between the two types of field lines is called the separatrix. * Sheared Flow: Fluid flow where the magnitude of the fluid velocity changes along a direction perpedicular to the direction of the fluid flow. (Freeway traffic often exhibits sheared flow in that traffic in the "fast lane" moves more rapidly than traffic in the slow lane with the exits...) Sheared flow typically correlates with reduced transport and enhanced confinement. (This definition is rather informal and may not be fully technically correct - R.F. Heeter) * Shear Fields: As used in plasma physics, this refers to magnetic fields having a rotational transform (or, alternatively, safety factor) that changes with radius (e.g., in the stellarator concept, magnetic fields that increase in pitch with distance from the magnetic axis.) * Sheath: See Debye Sheath > Shiva: 20-beam Nd-glass fusion laser facility at LLNL. Was completed in 1977 and used for target irradiation experiments until mid-1981. Succeeded by Nova. * Shock Heating: Heating produced by the impact of a shock wave. * Shock Tube: A gas-filled tube used in plasma physics to quickly ionize a gas. A capacitor bank charged to a high voltage is discharged into the gas at one tube end to ionize and heat the gas, producing a shock wave that may be studied as it travels down the tube. * Shock Wave: Wave produced (e.g., in a gas or plasma) as a result of a sudden violent disturbance. To produce a shock wave in a given region, the disturbance must take place in a shorter time than the time required for sound waves to traverse the region. $ Sievert: International unit for radiation dose. One Sievert equals 100 rem (see entry for rem); average per-capita exposure is about 0.3 Sv, primarily from natural background (see entry) and medical x-rays. * Shock Heating: The heating produced by the impact of a shock wave. * Shock Wave: Wave produced as a result of a sudden, violent disturbance which occurs in a particular region faster than sound waves can traverse the region. * Shot: Fusion jargon for the production of a (short-lived) plasma. In the early days, plasmas were produced by the "discharge" of capacitor banks, which (frequently) made a BANG. A modern tokamak produces a few dozen "shots" per day, each lasting a few seconds and, if nothing goes wrong, inaudible. See also: capacitor, tokamak (Arthur Carlson, awc@ipp-garching.mpg.de) $ SI Units: (also known as MKS, MKSA Units) System of measurement in which the fundamental units are meters, kilometers, seconds, and the ampere. $ Sievert: Unit of absorbed radiation dose equivalent to 100 rem. (see also rem, rad, Gray) The sievert is based on the Gray in the same way that the rem is based on the rad, I believe. & Solenoid: Cylindrical coil of wire which, when current flows through it, acts as an electromagnet. For long solenoids with many turns, the magnetic field inside the center is nearly uniform. * Solid Breeder: Solid lithium-bearing compounds, usually ceramics such as Li2O and LiAlO2, which might be used in the blanket of a D-T fusion reactor to produce ("breed") additional tritium fuel from the n + Li => He + T (+n) reactions. * Solid State Laser: A laser using a transparent substance (crystalline or glass) as the active medium, doped to provide the energy states necessary for lasing. The pumping mechanism is the radiation from a powerful light source, such as a flashlamp. The ruby, Nd-YAG, and Nd:glass lasers are solid-state lasers. * Solitons: Stable, shape-preserving and localized solutions of nonlinear classical field equations. Of recent interest as possible models of extended elementary particles. * Sound Waves: See entries on compression waves, waves. * Space Frame or Spaceframe: Three-dimensional "optical bench" that holds laser components stable from vibrational and thermal excursions. * Spallation: See radiation damage, surface. * Spatial Filter: Device consisting of a lens pair and a pinhole aperture stop. Intensity fluctuations over the spatial extent of a laser beam are removed by passing the focused beam through the aperture stop. The pinhole must be placed in a vacuum to prevent air breakdown by the focused beam. These filters are used to counter the effects caused by self-focusing. > Spherator: Single-ring multipole device with an additional current-carrying rod perpendicular to the ring axis. > Spheromak: [from Art Carlson] A compact torus with comparable toroidal and poloidal magnetic fields. The plasma is roughly spherical and is usually surrounded by a close-fitting conducting shell or cage. Both the poloidal and toroidal magnetic fields are generated by plasma currents. There are no toroidal field coils "linking" the plasma through the central plasma axis. External force is supplied by poloidal field coils outside the plasma separatrix. The resulting configuration is approximately a force-free magnetic field. The spheromak machine geometry can be simpler than a tokamak, but the close-fitting wall is a source of impurities and the current cannot be inductively driven. After early experiments failed to achieve a reasonable beta, interest has ebbed. The spheromak can also be considered as the low-aspect-ratio limit of the tokamak. See also: compact torus. * Spin-Polarized Fusion: A method to enhance nuclear fusion reaction rates in some fusion fuels by polarizing the nuclear spins. ! Spitzer, Lyman: Early Princeton Fusion Scientist; astrophysicist who first proposed orbiting space telescope; inventor of the stellarator. & Spontaneous Emission: Radiation randomly emitted by excited atoms or ions. Contrast with stimulated emission. * Sputtering: Process by which atoms are ejected from a solid surface by bombardment with plasma particles. See entry for "Radiation Damage, Surface." * Stability: characteristic of some types of equilibrium states; see equilibrium. > Starfire Tokamak: A conceptual design study of a modular tokamak reactor that operates in a steady-state condition while using conventional power-generating systems. & Stark Effect: The effect an electric field has on the spectral lines emitted from excited atoms. The effect may arise from externally-applied electric fields, from internal fields due to the presence of neighboring ions or atoms (pressure), or from the electric field associated with the Lorentz (v cross B) force (motional stark effect). Spectroscopic measurements of plasmas using the pressure-based and motional Stark effects are useful for diagnostic purposes. > Stellarator: (adapted from Herman) Device invented by Lyman Spitzer for the containment of a plasma inside a racetrack-shaped (sometimes a figure-8) tube. The plasma is contained by a magnetic field created by helical windings around the tube. More generally, a toroidal sort of device that attempts to average out particle drifts that would otherwise take plasma to the walls of the vacuum vessel by imposing a given amount of helicity to the toroidal field lines. "A toroidal plasma configuration, which, unlike a tokamak, is not axially symmetric. The poloidal fields necessary for confinement are produced by external coils (rather than a current in the plasma), either helical coils in addition to plane toroidal field coils, or out-of-plane toroidal field coils (pioneered in Germany on Wendelstein 7-AS). The stellarator is generally considered to be the most serious alternative to the tokamak. Since the concept is inherently steady state, it would not have the tokamak's problems with thermal and mechanical cycling, current drive, and disruptions." -- Arthur Carlson, awc@ipp-garching.mpg.de & Stimulated Emission: Radiation coherently emitted by excited ions when driven by a passing light wave and the appropriate transition wavelength. "Laser" means Light Amplification by Stimulated Emission of Radiation; it occurs when there is a population inversion between the upper and lower energy states of the transition, such that stimulated emission can dominate excitation. Stimulated emission is coherent and codirectional with the stimulating wave, and the rate of stimulated emission is proportional to the intensity of the stimulating wave. * Strong (Nuclear) Force: * Sturm-Liouville Problem: The general problem of solving a linear differential equation of order 2n, together with 2n boundary conditions; also known as the eigenvalue problem. * Superconductor: A type of electrical conductor that permits a current to flow with zero resistance. Without superconducting coils, a toroidal magnetic-confinement fusion reactor would not be possible, because too much energy would be required to maintain the magnetic fields against resistive energy losses in the coil conductors. * Suydam Stability Criterion: A criterion for the stability of modes localized arbitrarily close to a mode-rational surface (see rational surface) in a circular cylindrical geometry. & Synchrotron Radiation: (Also known as cyclotron radiation.) Electromagnetic energy radiated from a charged particle moving in a curved orbit (typically in a magnetic field), due to the acceleration required to change the direction of the particle's velocity. See also bremsstrahlung. * Symmetry axis: [from Art Carlson] The straight line (usually vertical) through the center of a configuration, when the configuration is symmetric to all (axisymmetric, like the tokamak) or some (periodic, like the stellarator) rotations about this line. Usually the z-axis. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 21/26 (U) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 21/26 (U) Date: 28 May 1995 13:04:31 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/u Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 21: Terms beginning with "U" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== UUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU # u: variable commonly used for energy density of electric or magnetic fields; also sometimes used for velocity. @ UT, UTA: University of Texas at Austin; see entry @ UV: Ultraviolet (range of the electromagnetic spectrum) @ UW, UWM: University of Wisconsin at Madsion; see entry & Ultraviolet: Region of the electromagnetic spectrum intermediate between the visible and the x-ray portions. UV photons have energies greater than a few eV, but less than (roughly) 100 ev to 1 keV. * Unipolar Arc: Arc between a metal surface and a plasma in contact with it. Such an arc requires only one electrode and is maintained by the thermal energy of the electrons. & Universal gas constant: R = 8.314 x 10^7 ergs per degree C per mole. * Universal Instability: Low-frequency instability resulting from the presence of density gradients perpendicular to the magnetic field lines. An instability of this type is generally localized and usually has a small rate of growth. % University of Texas at Austin (UT): Among other things, UT has a large theoretical plasma physcs research center. (info, anyone?) The TEXT experimental tokamak is also located here. % University of Wisconsin at Madison: Among other facilities, "Wisconsin" has a large research program in both plasma physics and fusion engineering. * Upper Hybrid Waves: Similar to lower hybrid waves, but at a higher frequency. (more description?) Not truly propagating waves, but plasma oscillations. (?) & Uranium: (from Herman) A radioactive metallic element whose isotope, uranium-235, is a nuclear fission fuel. Plutonium, another fission fuel, can be produced from the more plentiful isotope uranium-238. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 22/26 (V) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 22/26 (V) Date: 28 May 1995 13:04:32 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/v Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 22: Terms beginning with "V" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV # v: variable typically used for velocity # V: variable typically used for electrical potential (Voltage) $ V: abbreviation for Volts; see entry @ VDE: Vertical Displacement Event & Vector: & Vector Notation: & Velocity: The rate of change of position with time for a given object. & Velocity Space: Mathematical space where each point corresponds not to a certain location in reality, but to a certain velocity. Distribution functions typically involve mixes of both position and velocity spaces. (See distribution function.) Contrast with "position space" where each point corresponds to a given location. & Velocity Space Instability: A class of instabilities driven by particle distributions (in velocity space) which are not in thermal equilibrium. * Vertical Field, Vertical Field Coils: See Poloidal Field / Coils. * Vertical Instability: [mostly by James Crotinger] A type of MHD (n=0) instability where the plasma drifts vertically upward. Nearly all tokamaks are vertically unstable (all highly shaped ones are). Controlling this instability is possible in many cases, and is an important facet of machine design. Vertical instabilities give rise to halo effects (see entry for halo). & Viscosity: * Vlasov Equation: * Voltage Loop: A wire which encircles the main axis of a tokamak in the vicinity of the vacuum vessel. The voltage induced in this loop during the shot is a measure of the ohmic heating voltage induced by transformer action and applied to the plasma. $ Volt: Unit of electrical potential. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 23/26 (W) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 23/26 (W) Date: 28 May 1995 13:04:33 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/w Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 23: Terms beginning with "W" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW # W: Chemical symbol for Tungsten @ W-7AS, W-7X: See Wendelstein entry * Wall Conditioning: Describes a class of procedures used to control the composition of materials adsorbed onto the walls of a plasma device. Conditioning is important because material from the walls can create impurities in the plasma, and these impurities typically degrade plasma performance. See also boronization, impurity control, electron cyclotron discharge cleaning. * Wall Loading: Fusion reactor thermal output power divided by the area of the wall facing the plasma. (Neutron wall loading is 4/5 of the total for D-T fusion.) & Waste, Radioactive: See Radioactive Waste. & Wavelength: The length of a single cycle of a wave; usually measured from crest-to-crest. For electromagnetic waves, the wavelength determines the type (radio, infrared, visible, ultraviolet, X-Ray, gamma-ray) of radiation; in the case of visible light, wavelength determines the color of the light. & Waves: & Weak (Nuclear) Force: > Wendelstein: A family of stellarators built in Garching, Germany. The machine currently in operation is Wendelstein-7AS (aka W-7AS). Wendelstein ("spiral rock") is a craggy Bavarian mountain; some of W-1 through W-6 were built, some were just paper studies; AS stands for "advanced stellarator" and refers on the physical side to an attempt to minimize neoclassical effects (see entry for Neo-classical Diffusion) such as the bootstrap current (see entry), and on the technical side to the use of out-of-plane coils as an alternative to linked coils. W-7X, a much larger, superconducting stellarator based on the same concepts has been proposed to be built by the European Union in Greifswald, on the north coast of Germany. * Whistler: A wave in a plasma which propagates parallel to the magnetic field produced by currents outside the plasma at a frequency less than that of the electron cyclotron frequency, and which is circularly polarized, rotating in the same sense as the electrons in the plasma (about the magnetic field); also known as the electron cyclotron wave. Whistlers are so-named because of their characteristic descending audio-frequency tone, which is a result of the dispersion relation for the wave (higher frequencies travel somewhat faster). This tone was frequently picked up during World War I by large ground-loop antennas (which were actually being used to spy on enemy field telephone signals). % Wisconsin - See University of Wisconsin-Madison cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 24/26 (X) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 24/26 (X) Date: 28 May 1995 13:04:34 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/x Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 24: Terms beginning with "X" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX # Xe: Chemical symbol for the element Xenon. * X-Point: Place where the poloidal magnetic field vanishes in such a way that two flux surfaces appear to cross, e.g. where the main plasma joins the divertor (see entry) or between magnetic islands. Location where magnetic reconnection takes place. (See magnetic reconnection; see also divertors and O-point.) & X Ray: A penetrating form of electromagnetic radiation emitted either when the inner orbital electrons of an excited atom return to their normal state (characteristic x-rays), or when a high speed electron collides sharply with an ion or atomic target (bremsstrahlung). X-rays have energies from roughly 100 eV to roughly 100 keV. (Below X-rays are ultraviolet rays, and above X-rays in energy are gamma rays.) X-rays are (basically by definition) non-nuclear in origin. (Nuclear electromagnetic radiation termed gamma radiation.) See also ultraviolet, gamma rays, bremsstrahlung. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 25/26 (Y) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 25/26 (Y) Date: 28 May 1995 13:04:35 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/y Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 25: Terms beginning with "Y" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY * Yin-Yang Coil: See baseball coil. * Yucca Mountain: Proposed U.S. site for permanent storage of high-level nuclear waste; feasibility currently being explored by U.S. Dept. of Energy. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Robert Heeter / Conventional Fusion FAQ Glossary Part 26/26 (Z) Originally-From: Robert F. Heeter Newsgroups: sci.physics.fusion,sci.answers,news.answers Subject: Conventional Fusion FAQ Glossary Part 26/26 (Z) Date: 28 May 1995 13:04:36 GMT Organization: Princeton University Archive-name: fusion-faq/glossary/z Last-modified: 25-Feb-1995 Posting-frequency: More-or-less-quarterly Disclaimer: While this section is still evolving, it should be useful to many people, and I encourage you to distribute it to anyone who might be interested (and willing to help!!!). =============================================================== Glossary Part 26: Terms beginning with "Z" FREQUENTLY USED TERMS IN CONVENTIONAL FUSION RESEARCH AND PLASMA PHYSICS Edited by Robert F. Heeter, rfheeter@pppl.gov Guide to Categories: * = plasma/fusion/energy vocabulary & = basic physics vocabulary > = device type or machine name # = name of a constant or variable ! = scientists @ = acronym % = labs & political organizations $ = unit of measurement The list of Acknowledgements is in Part 0 (intro). ================================================================== ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ # Z: see atomic number @ ZETA: Zero Energy Thermonuclear Assembly; see entry > Zero Energy Thermonuclear Assembly: A British fusion device in which scientists observed fusion neutrons in 1958. They were erroneously considered to be thermonuclear (coming from particles with a Maxwellian velocity distribution) and were a cause for the initial optimism that fusion energy would be easy. They were actually due to electromagnetic acceleration during a plasma instability, an effect which cannot be scaled up to produce useful energy. > Z-Pinch: Pinch device in which the externally-driven pinching current goes in the z direction (parallel to / through the cylindrical plasma). See discussion in Section 4B. cudkeys: cuddy28 cudenrfheeter cudfnRobert cudlnHeeter cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Junkyard Dodge / Re: The Farce of Physics Originally-From: wreck@falcon.ic.net (Junkyard Dodge) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 28 May 1995 14:00:55 GMT Organization: ICNET... Your Link To The Internet... +1.313.998.0090 Bryan Wallace (wallaceb@news.IntNet.net) wrote: : If you read my book you will find my references to the published : literature. The very *fact* that JPL refuses to publish an objective : comparison of the wave and particle models for light in space is : *overwhelming* evidence that modern physics is a *farce*! -- Let me do a translation from Bryan's dialect to English: Jet Propulsion Laboratory, an organization which depends on its ability to apply physical theory and construct accurate models of reality from it, refuses to publish my crackpot theory. Therefore, JPL and the theories it uses are all a farce. The conclusion I would draw is the opposite: that Bryan has written a farce, albeit unwittingly if we are to take him seriously. -- That which does not bore me makes me stranger wreck@ic.net cudkeys: cuddy28 cudenwreck cudfnJunkyard cudlnDodge cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Bryan Wallace / Re: The Farce of Physics Originally-From: wallaceb@news.IntNet.net (Bryan Wallace) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 28 May 1995 09:41:23 -0400 Organization: Intelligence Network Online, Inc. David M. Cook (dcook@linux5.ph.utexas.edu) wrote: : In article <3q7kik$4ub@xcalibur.intnet.net>, : Bryan Wallace wrote: : >I have also shown the overwhelming evidence against his two basic postulates : >[...] : And I was quite underwhelmed by it. : Dave Cook In Chapter 2 of my book "The Farce of Physics" I state: In an evaluation of modern physics based on Langmuir's arguments, we find that many of the dominant theories should be classed as pathological science. For example, starting with his first characteristic rule "The maximum effect that is observed is produced by a causative agent of barely detectable intensity."; we find that Einstein's special relativity theory which is generally acknowledged as the foundation of the rest of the dominant theories of 20th century physics, is based on the fact that the Michelson-Morley experiment could not detect the motion of the earth through the ether! As I have shown in Chapter 3 "Mathematical Magic", Einstein believed that the ether sea exists but that it is invisible and can't be detected by experiments. In Chapter 3 I present the following: My main insight into Einstein and his work came from a book by Dr. Abraham Pais titled 'Subtle is the Lord...' The Science and the Life of Albert Einstein.[37] Pais is an award-winning physicist who knew Einstein personally during the last nine years of his life. On page 13 we find that in Einstein's own words he had been an "unscrupulous opportunist." On page 44 we learn that Einstein did not attend lectures or study, but instead used Marcel Grossman's lecture notes to pass his college examinations. With regard to the mathematics of relativity, page 152 states: Initially, Einstein was not impressed and regarded the transcriptions of his theory into tensor form as 'uberglussige Gelehrsamkeit,' (superfluous learnedness). However, in 1912 he adopted tensor methods and in 1916 acknowledged his indebtedness to Minkowski for having greatly facilitated the transition from special to general relativity. Since most scientists do not use or are conversant in tensor mathematics, its use has tended to obscure the intimate meaning behind the relativity theoretical arguments. On page 164 Pais asks: Why, on the whole, was Einstein so reticent to acknowledge the influence of the Michelson-Morley experiment on his thinking? On page 168 we find the answer to this question in the second volume of Sir Edmund Whittaker's masterpiece book entitled "History of the Theories of Aether and Electricity", where: Whittaker's opinion on this point is best conveyed by the title of his chapter on this subject: 'The Relativity Theory of Poincare' and Lorentz.' In effect Whittaker showed that Einstein's special relativity theory was not original work, but just a clever restatement of the theoretical work of Poincare' and Lorentz. The translation of Lorentz's 1904 relativity paper[57 p.12] states: ...Poincare' has objected to the existing theory of electric and optical phenomena in moving bodies that, in order to explain Michelson's negative result, the introduction of a new hypothesis has been required, and that the same necessity may occur each time new facts will be brought to light. Surely this course of inventing special hypotheses for each new experimental result is somewhat artificial. It would be more satisfactory if it were possible to show by means of certain fundamental assumptions and without neglecting terms of one order of magnitude or another, that many electromagnetic actions are entirely independent of the motion of the system. The translation of Einstein's 1905 special relativity paper[57 p.37] presented the argument that one could explain many electromagnetic actions by fundamental assumptions based on two postulates and that the "introduction of a "luminiferous ether" will prove to be superfluous", and his paper made no direct reference to the Michelson-Morley experiment or the work of Poincare' and Lorentz. On page 313 of Pais' book we learn that in 1920, after Einstein had become famous, he made an inaugural address on aether and relativity theory for his special chair in Leiden. In the address he states: The aether of the general theory of relativity is a medium without mechanical and kinematic properties, but which codetermines mechanical and electromagnetic events. So we finally find that relativity is an ether theory after all, and that this ether has arbitrary abstract contradictory physical characteristics! This illustrates the arbitrary nature of relativity, most physicists, and for that matter, most physics text books, present the argument that relativity is not an ether theory. On page 467 we find that near the end of his life, Einstein wrote to his dear friend M. Besso in 1954: I consider it quite possible that physics cannot be based on the field concept,i.e., on continuous structures. In that case, nothing remains of my entire castle in the air, gravitation theory included, [and of] the rest of modern physics. With regard to the problem of the average physicist not understanding relativity theory, Dr. S. Chandrasekhar, a Nobel laureate physicist, writes in an article[46] titled "Einstein and general relativity: Historical perspectives": The meeting of November 6, 1919 of the Royal Society also originated a myth that persists even today (though in a very much diluted version):"Only three persons in the world understand relativity." Eddington explained the origin of this myth during the Christmas-recess conversation with which I began this account. Thomson, as President of the Royal Society at that time, concluded the meeting with the statement:"I have to confess that no one has yet succeeded in stating in clear language what the theory of Einstein really is." And Eddington recalled that as the meeting was dispersing, Ludwig Silberstein (the author of one of the early books on relativity) came up to him and said: "Professor Eddington, you must be one of three persons in the world who understands general relativity." On Eddington demurring to this statement, Silberstein responded, "Don't be modest Eddington." And the Eddington's reply was, "On the contrary, I am trying to think who the third person is!" This lack of comprehension of Relativity theory, is not uncommon among physicists and astronomers. Over the years, in many intimate conversations and correspondence with them, I've found few scientists willing to admit to an indepth understanding of the theory, yet most of them will argue of their belief in it. I have also discovered that even the scientists that are willing to admit to full comprehension of the theory, have serious gaps in their knowledge of it. For example, Prof. William H. McCrea of England wrote the counter argument to Prof. Herbert Dingle's controversial attack on the inconsistent logic in the theory, which was published in the prestigious journal NATURE.[47] Dingle was an interesting fellow, at one time he was a leading proponent of the relativity theory, and even was a member of several British solar eclipse expeditions. He was a professor at University College in London, and the author of many books and papers on astrophysics, relativity, and the history of science. I was introduced to McCrea by Prof. Thornton Page, at the 1968 Fourth Texas Symposium on Relativistic Astrophysics. McCrea who is considered to be an authority on relativity theory, was surprised to find that Einstein considered relativity to be an ether theory. With regard to the argument that I showed McCrea that represented relativity as an ether theory, Einstein and Infeld state: ...On the other hand, the problem of devising the mechanical model of ether seemed to become less and less interesting and the result, in view of the forced and artificial character of the assumptions, more and more discouraging. Our only way out seems to be to take for granted the fact that space has the physical property of transmitting electromagnetic waves, and not to bother too much about the meaning of this statement. We may still use the word ether, but only to express some physical property of space. This word ether has changed its meaning many times in the development of science. At the moment it no longer stands for a medium built up of particles. Its story, by no means finished, is continued by the relativity theory.[20 p.153] There is a very interesting article on this question published in the August 1982 issue of Physics Today by Prof. Yoshimasa A. Ono. The article begins: It is known that when Albert Einstein was awarded the Nobel Prize for Physics in 1922, he was unable to attend the ceremonies in Stockholm in December of that year because of an earlier commitment to visit Japan at the same time. In Japan, Einstein gave a speech entitled "How I Created the Theory of Relativity" at Kyoto University on 14 December 1922. This was an impromptu speech to students and faculty members, made in response to a request by K. Nishida, professor of philosophy at Kyoto University. Einstein himself made no written notes. The talk was delivered in German and a running translation was given to the audience on the spot by J. Isiwara, who had studied under Arnold Sommerfeld and Einstein from 1912 to 1914 and was a professor of physics at Tohoku University. Isiwara kept careful notes of the lecture, and published his detailed notes (in Japanese) in the monthly Japanese periodical Kaizo in 1923; Ishiwara's notes are the only existing notes of Einstein's talk.... Ono ends his introduction to his translation with the statement: It is clear that this account of Einstein's throws some light on the current controversy as to whether or not he was aware of the Michelson- Morley experiment when he proposed the special theory of relativity in 1905; the account also offers insight into many other aspects of Einstein's work on relativity. With regard to the ether, Einstein states: Light propagates through the sea of ether, in which the Earth is moving. In other words, the ether is moving with respect to the Earth.... With regard to the experiment he argues: Soon I came to the conclusion that our idea about the motion of the Earth with respect to the ether is incorrect, if we admit Michelson's null result as a fact. This was the first path which led me to the special theory of relativity. Since then I have come to believe that the motion of the Earth cannot be detected by any optical experiment, though the Earth is revolving around the Sun.[48] The above information gives us insight into the nature of Einstein's relativity theory. He believes that the sea of ether exists, but he also believes that it cannot be detected by experiments, in other words, he believes it is invisible. The situation in modern physics is very much like the Hans Christian Andersen tale of "The Emperor's New Clothes", with Einstein playing the part of the Emperor. The tale goes that the Emperor, who was obsessed with fine clothing to the point that he cared about nothing else, let two swindlers sell him a suit of cloth that would be invisible to anyone who was "unfit for his office or unforgivably stupid." It turned out that no one could see the suit--not the emperor, not his courtiers, not the citizens of the town who lined the street to see him show off his new finery. Yet no one dared admit it until a little child cried out, "But he doesn't have anything on!" In regard to Einstein's reluctance to acknowledge the influence of the Michelson-Morley experiment on his thinking, and Whittaker's argument that his special relativity theory was a clever restatement of the work of Poincar‚ and Lorentz, I report the following published[56] statements which Einstein made to Prof. R. S. Shankland on this matter: The several statements which Einstein made to me in Princeton concerning the Michelson-Morley experiment are not entirely consistent, as mentioned above and in my earlier publication. His statements and attitudes towards the Michelson-Morley experiment underwent a progressive change during the course of our several conversations. I wrote down within a few minutes after each meeting exactly what I recalled that he had said. On 4 February 1950 he said,"...that he had become aware of it through the writings of H. A. Lorentz, but only after 1905 had it come to his attention." But at a later meeting on 24 October, 1952 he said, "I am not sure when I first heard of the Michelson experiment. I was not conscious that it had influenced me directly during the seven years that relativity had been my life. I guess I just took it for granted that it was true." However, in the years 1905-1909 (he told me) he thought a great deal about Michelson's result in his discussions with Lorentz and others, and then he realized (so he told me) that he "had been conscious of Michelson's result before 1905 partly through his reading of the papers of Lorentz and more because he had simply assumed this result of Michelson to be true."... With regard to the politics that led to Einstein's fame Dr. S. Chandrasekhar's article[46] states: In 1917, after more than two years of war, England enacted conscription for all able-bodied men. Eddington, who was 34, was eligible for draft. But as a devout Quaker, he was a conscientious objector; and it was generally known and expected that he would claim deferment from military service on that ground. Now the climate of opinion in England during the war was very adverse with respect to conscientious objectors: it was, in fact, a social disgrace to be even associated with one. And the stalwarts of Cambridge of those days--Larmor (of the Larmor precession), Newall, and others--felt that Cambridge University would be disgraced by having one of its distinguished members a declared conscientious objector. They therefore tried through the Home Office to have Eddington deferred on the grounds that he was a most distinguished scientist and that it was not in the long-range interests of Britain to have him serve in the army.... In any event, at Dyson's intervention--as the Astronomer Royal, he had close connections with the Admiralty--Eddington was deferred with the express stipulation that if the war should have ended by 1919, he should lead one of two expeditions that were being planned for the express purpose of verifying Einstein's prediction with regard to the gravitational deflection of light.... The Times of London for November 7, 1919, carried two headlines: "The Glorious Dead, Armistice Observance. All Trains in the Country to Stop," and "Revolution in Science. Newtonian Ideas Overthrown." Dr. F. Schmeidler of the Munich University Observatory has published a paper[49] titled "The Einstein Shift -- An Unsettled Problem," and a plot of shifts for 92 stars for the 1922 eclipse shows shifts going in all directions, many of them going the wrong way by as large a deflection as those shifted in the predicted direction! Further examination of the 1919 and 1922 data originally interpreted as confirming relativity, tended to favor a larger shift, the results depended very strongly on the manner for reducing the measurements and the effect of omitting individual stars. So now we find that the legend of Albert Einstein as the world's greatest scientist was based on the Mathematical Magic of Trimming and Cooking of the eclipse data to present the illusion that Einstein's general relativity theory was correct in order to prevent Cambridge University from being disgraced because one of its distinguished members was close to being declared a "conscientious objector"! Bryan cudkeys: cuddy28 cudenwallaceb cudfnBryan cudlnWallace cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Bryan Wallace / Re: The Farce of Physics Originally-From: wallaceb@news.IntNet.net (Bryan Wallace) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 28 May 1995 09:49:14 -0400 Organization: Intelligence Network Online, Inc. KAnko (kanko@aol.com) wrote: : Bryan Wallace responded: : ------------------------------forwarded message------------------- : Kevin, : I agree with Hiesenberg's arguments in Chapter 2 of my free book "The : Farce of Physics." Particles are not "elementary" but are the "spectrum : of matter" ... "the quark hypothesis is not really taken seriously today : by its proponents" ... "Everthing outside of the dynamics is just a : verbal description of the table of data." Also the arguments of Glashow : and Lederman: : True, the standard Model does explain a very great deal. Nevertheless : it is not yet a proper theory, principally because it does not satisfy : the physicists naive faith in elegance and simplicity. It involves some : 17 allegedly fundamental particles and the same number of arbitrary and : tunable parameters, ... : Bryan : -------------------------------------------------------------------------- : - : Sir, : I understand this, I have read your book. Now I have some results you : haven't discussed which I want you to justify. : If the particles are just exited states of each other, then the kind of : collisions one would get in proton-antiproton colliders would be very : different. You would not have the proportion of high transverse momentum : collisions that are seen. Probability calculations are not the : mathematics mumbo-jumbo you attack. Anyone can make a probability : calculation. So once again, how do you explain away the kinematics of : high transverse momentum particles in the aftermath of a proton-antiproton : collision??? : Also, how do you explain away the electron-proton scattering results from : Stanford in the 60's?? If you send pointlike particles (the electrons) at : the protons, they don't scatter off the protons. They seem to be : scattering off of smaller objects inside the protons, the quarks or : partons. If you are invalidating this result, then you are invalidating : Rutherford's famous scattering of alpha particles off of gold experiments. : Do you also believe that the atom is not made up of a nucleus and an : electron cloud around it?? : I am always interested in alternative theories Mr. Wallace, however : Heisenberg was never able to explain these two results. Can you, : Thank you in advance, : Dr. Kevin Ankoviak : "Now that we've found truth, will it become beauty" Kevin, Instead of changing the subject, how about you giving your answers to the arguments of Heisenberg, Glashow, and Lederman. Over the years I've heard the particle experimentalists claim that for every experiment the theorists come up with 1000 theories! What are yours and have you published them? Bryan cudkeys: cuddy28 cudenwallaceb cudfnBryan cudlnWallace cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / BILLC / Re: Good news: PPPL fundi Originally-From: billc@execnet.com (BILLC) Newsgroups: sci.physics.fusion Subject: Re: Good news: PPPL fundi Date: Sun, 28 May 95 09:58:00 -0500 Organization: Execnet Information System - 914-667-4567 - 198.232.143.136 TD>Businesses might be quite willing to work together if not for the Sherman TD>anti-trust law that makes it very difficult. But it is a tough problem. TD>If we let them work together they will get together and raise prices and TD>divide up the market. So we gain a fiercely competative market that TD>lowers prices for most of us. We loose the ability of businesses to get TD>together and take on something big and long range. So it is one of the TD>few areas that I can see a mission for government. Anti-trust is a real problem to industry. There are legal exceptions. One that comes to mind is the casuality insurance business which is allowed to pool rate info. Years ago the big three auto mfgs were given the right to pool R&D resulte through a patent pool. Super big can come to mean fat, self-satisfied and loosing market share. Just ask Toyota! TD>But it is not very efficient. I have spent 40 years in government labs. TD>It is hard to turn off something once it is started, even though many TD>recognize it is folly. But on the whole a net plus. This is also a problem in industry. I spent 25 yrs in R&D in the chemical industry and I know that it can be tough to kill a project if it has support from on high. --- þ SLMR 2.1a þ Old Chemists never die! They just reach Equilibrium. cudkeys: cuddy28 cudenbillc cudlnBILLC cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Mike H / Re: The Farce of Physics Originally-From: "Mike H." Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skepti Subject: Re: The Farce of Physics Date: 28 May 1995 18:48:20 +0100 Date: 28 May 1995 16:55 GMT Organization: Demon Internet News Service Date: 28 May 1995 16:55 GMT Message-ID: <05281995165522umw@avon.demon.co.uk> References: <3q7fi8$4b6@xcalibur.intnet.net> X-mailer: Umail 1.50g On Sun, 28 May 1995 05:46:40 GMT, in vergon@netcom.com (Vertner Vergon) wrote..... > I offer my hypothesis (ON THE QUANTUM AS A PHYSICAL ENTITY) in which the > universe is composed of *one* and only one particle. I call it THE quantum. > > It has very few characteristics, energy of expansion/contraction, spin, > mass and co-spatiality. > > These charateristics blend together in a fractal-like manner to form > electromagnetic radiation, electrons, protons, neutrons and neutrinos. > > These are the only stable particles in the universe (except neutrinos > and neutrons which are semi-stable. > > The entire subatomic zoo consists of unstable shards that break off > or are formed when the stable particles are smashed together. > Surely this breaks with the idea of a particle. If you can take two particles and smash them together to make three particles then this either emplies that the two particles are not the smallest unit or that there is something remiss. I find it hard to accept that if a particle can shatter into fragments that those fragments are in fact not made up of smaller units of matter. If these particles are stable, why is it easy to break them ? How do you account for different apparent particle densities and masses and charges? What about anti-particles? > If anyone is interested, I suggest they read my thesis. > ftp site.... ? > > True, the standard Model does explain a very great deal. Nevertheless > >it is not yet a proper theory, principally because it does not satisfy > >the physicists naive faith in elegance and simplicity. > > How simple can you get with ONE basic particle? A proper theory is one that allows you to make predictions which can be experimentally proven. QM is a proper theory because it allows you to make predictions about energy levels, alpha decay and particle interactions. The absence of special cases and fudge factors is also an important aspect. --------------------------------------------------------------------------- Mike H. (Software Sans Frontieres) PGP:818C97EB75366540 8A27D2AB8E7482CB Umail 1.50 from ftp.demon.co.uk:/pub/ibmpc/umail,/pub/ibmpc/windows/umail --------------------------------------------------------------------------- cudkeys: cuddy28 cudenmike cudfnMike cudlnH cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / Mike H / Re: The Farce of Physics Originally-From: "Mike H." Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skepti Subject: Re: The Farce of Physics Date: 28 May 1995 18:48:27 +0100 Date: 28 May 1995 17:11 GMT Organization: Demon Internet News Service Date: 28 May 1995 17:11 GMT Message-ID: <05281995171136umw@avon.demon.co.uk> References: <3q9ui3$t0d@xcalibur.IntNet.net> Distribution: world X-mailer: Umail 1.50g On 28 May 1995 09:41:23 -0400, in <3q9ui3$t0d@xcalibur.IntNet.net> wallaceb@news.IntNet.net (Bryan Wallace) wrote..... > which is generally acknowledged as the foundation of the rest of the > dominant theories of 20th century physics, is based on the fact that the > Michelson-Morley experiment could not detect the motion of the earth > through the ether! As I have shown in Chapter 3 "Mathematical Magic", > Einstein believed that the ether sea exists but that it is invisible and > can't be detected by experiments. At the time the MM experiment was conducted, space was thought of as absolute - something that the earth moved through. The MM experiment was designed to detect this motion to a high degree of accuracy. At the time that the experiment was conducted it was assumed that light had a finite speed of propogation which was not bounded but was subject to the normal rules of velocity addition. The premise behind the MM experiment was that if the earth is moving in one direction, light moving in the direction of the earth will appear to move at a different speed to that moving at right-angles to the direction of the earth. Therefore you should be able to detect motion relative to absolute space. MM found a null-result. They were told to redo the experiment properly. This they did and came up with a second more accurate null result. The conclusion reached was that if the aether exists it is not possible to detect movement through it. All directions in space are equivalent. > > Why, on the whole, was Einstein so reticent to acknowledge the influence of > the Michelson-Morley experiment on his thinking? > > On page 168 we find the answer to this question in the second volume of Sir > Edmund Whittaker's masterpiece book entitled "History of the Theories of > Aether and Electricity", where: Probably because the MM result went against what was commonly believed. Scientists are really quite conservative. > The aether of the general theory of relativity is a medium without > mechanical and kinematic properties, but which codetermines mechanical and > electromagnetic events. > > So we finally find that relativity is an ether theory after all, and that this > ether has arbitrary abstract contradictory physical characteristics! This > illustrates the arbitrary nature of relativity, most physicists, and for that > matter, most physics text books, present the argument that relativity is not > an ether theory. On page 467 we find that near the end of his life, Einstein GR does not need an aether. The victorian idea of aether was something which has substance. > The above information gives us insight into the nature of Einstein's > relativity theory. He believes that the sea of ether exists, but he also > believes that it cannot be detected by experiments, in other words, he > believes it is invisible. The situation in modern physics is very much Not at all. If something cannot be detected by any experiment is it not reasonable to say that the something is not there. GR and SR are both excellent theories that allow us to model the world as we find it. > the predicted direction! Further examination of the 1919 and 1922 data > originally interpreted as confirming relativity, tended to favor a larger > shift, the results depended very strongly on the manner for reducing the > measurements and the effect of omitting individual stars. What about red-shitft, blue-shift caused by the prescence of a gravitational field? What about the effect of acceleration on local time? > So now we find that the legend of Albert Einstein as the world's greatest > scientist was based on the Mathematical Magic of Trimming and Cooking of the > eclipse data to present the illusion that Einstein's general relativity theory Guess you never read the mathematics then ? --------------------------------------------------------------------------- Mike H. (Software Sans Frontieres) PGP:818C97EB75366540 8A27D2AB8E7482CB Umail 1.50 from ftp.demon.co.uk:/pub/ibmpc/umail,/pub/ibmpc/windows/umail --------------------------------------------------------------------------- cudkeys: cuddy28 cudenmike cudfnMike cudlnH cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ 1995.05.28 / Bill Rowe / Re: Richard Schultz does not Originally-From: browe@netcom.com (Bill Rowe) Newsgroups: sci.physics.fusion Subject: Re: Richard Schultz does not Date: Sun, 28 May 1995 17:43:33 GMT Organization: NETCOM On-line Communication Services (408 261-4700 guest) In article <8AA21E5.063F003483.uuout@execnet.com>, billc@execnet.com (BILLC) wrote: >JE>of predicting the future. So far, events have proved my point many times ove >JE>Pd systems do not work. They are a technological dead end, like the Tokamak >JE>reactor. Things like thin film Pd, Ni, proton conductors, or the Griggs >JE>machine show *far more promise* for commercial applications. The palladium >JE>stuff may have scientific value but I do not care about that. > >I'm out of date on CF and trying to put myself in the current picture. >Can anyone point me to a good primer/refresher; eg what is the "Griggs" >machine? The Griggs device seems to be a high speed pump. Input water is pumped via a high speed rotor and converted to steam. It appears to be highly efficient at steam generation. As far as being over unity or an energy source, the jury's still out on the Griggs device. Discussion of this device seems to have fallen off after Tom Droege's report. Tom didn't show the Griggs device was not over unity. However, he did find a lack of calibration curves, log books etc. Based on this, it sounds like the over unity effects are not likely to be real. As to the rest of Jed's comments about "thin film Pd, Ni" etc showing more promise than Tokamak reactors I'd bet on the Tokamak. At least there is a pretty good understanding of Tokamak physics. As for the CF devices Jed mentions, noone seems to have any understanding of why they seem to generate more heat than can easily be explained. Until this happens, I very much doubt you will see these devices generating commercial power. -- William Rowe browe@netcom.com MD5OfPublicKey: F29A99C805B41838D9240AEE28EBF383 cudkeys: cuddy28 cudenbrowe cudfnBill cudlnRowe cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / John Archer / Re: The Farce of Physics Originally-From: ivo@rbdc.rbdc.com (John Archer) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic Subject: Re: The Farce of Physics Date: 28 May 1995 16:08:06 -0400 Organization: Trionic Research Institue Bryan Wallace wrote: As I have shown in Chapter 3 "Mathematical Magic", Einstein believed that the ether sea exists but that it is invisible and can't be detected by experiments. This seems to be the basis of an argument designed to show that Special Relativity should be classified as an 'ether theory' rather than a 'non-ether theory'. Well, if we do perform this linguistic operation, what difference would it make? Would SR suddenly make different predictions? If no differences can be detected by this linguistic reclassification, then we must conclude, with William James, that 'a difference that makes no difference is no difference'. John Archer Trionic Research Institute Duke of URLs = http://www.rbdc.com/~ivo/Trionic.html ___ /\ \ / \ \ / /\ \ \ / / /\ \ \ / / / \ \ \ / / / \ \ \ / / / \ \ \ / / / \ \ \ / / / \ \ \ / / /____________\_\ \ / / /___________________\ \/______________________/ No Truth Higher Than Love cudkeys: cuddy28 cudenivo cudfnJohn cudlnArcher cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / jedrothwell@de / Re: Good news: PPPL funding will be gutted Originally-From: jedrothwell@delphi.com Newsgroups: sci.physics.fusion Subject: Re: Good news: PPPL funding will be gutted Date: Sun, 28 May 95 21:55:40 -0500 Organization: Delphi (info@delphi.com email, 800-695-4005 voice) Bob Arthur writes: > But these facilities and personnel exist, and they already do great >work. My goal would be to strenghten them, so that they may _help_ in our >free-market economy. I see no reason why, for example, the Dept. of >Science could not hire itself out to industry to do contract research. >Maybe a government department could actually _make_ money... I would go along with that, but with one condition: if nobody the Dept. of Science, it should then go out of business. It is real simple: offer the services, if nobody buys them, you are bankrupt, everyone is fired, and your people find some other way to make a living that contributes to society. Let me just make a prediction here. If you did that, the entire Dept. of Science would close down in a year or two. The DoE projects that I have seen are a gigantic waste of money; especially the hot fusion program, but the others are too. No sane corporation would pay any money at all for that kind of crap. A few years ago, a Congressman asked me if I could suggest a change to the hot fusion funding bill. I suggested they add just one paragraph to it. It was innocuous as could be. In any business contract, a paragraph like this would never cause any problem at all. I suggested that they find some paying customers for the tokamak reactors and ask them to put down some earnest money for the product. If private industry agrees to pay for 51% of the hot fusion program, because private industry intends to buy the product, that is fine with me. Everyone knows that you could not get industry to pay even 5% or even 1% of the hot fusion program, because everyone knows it is a bill of goods -- a gigantic kludge that will never work. - Jed cudkeys: cuddy28 cudenjedrothwell cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.28 / M Kagalenko / Re: The Farce of Physics Originally-From: mkagalen@lynx.dac.neu.edu (Michael Kagalenko) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skeptic,alt.religion.kibology Subject: Re: The Farce of Physics Date: 28 May 1995 23:15:46 -0400 Organization: Division of Academic Computing, Northeastern University, Boston, MA. USA Vertner Vergon wrote: ]I offer my hypothesis (ON THE QUANTUM AS A PHYSICAL ENTITY) in which the ]universe is composed of *one* and only one particle. I call it THE quantum. And I call it THE Wednesday ]It has very few characteristics, energy of expansion/contraction, spin, ]mass and co-spatiality. And cleavage ! You forgot that, oh Ugly one. ]How simple can you get with ONE basic particle? As simple as VV, comprenes-vois ?? ]V.V. The Ugly Duckling -- Save the Earth - kill a lawyer cudkeys: cuddy28 cudenmkagalen cudfnMichael cudlnKagalenko cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.29 / C Harrison / Periodic Post: Cold Fusion online at sunsite.unc.edu Originally-From: harr@netcom.com (Charles (Chuck) Harrison) Newsgroups: sci.physics.fusion Subject: Periodic Post: Cold Fusion online at sunsite.unc.edu Date: Mon, 29 May 1995 03:49:05 GMT Organization: Fitful This message is posted periodically to inform readers about on-line data sources related to "cold fusion" which are located at the University of North Carolina SunSITE server. Two public WAIS (Wide Area Information Server) sources are online: (1) Dieter Britz's Bibliography (periodically updated), and (2) A sci.physics.fusion archive (1989 to present). WAIS provides for multiple keyword searches in these databases. It does _not_ support boolean logic in the searching :-(. 1. If you are directly connected to Internet, you can log onto a public WAIS server at the University of North Carolina: %telnet sunsite.unc.edu ... login: swais ... TERM = (unknown) vt100 It takes a minute to load ... < or use /fusion to locate the fusion-digest source> 2. If you have a "gopher" client, you can use it for WAIS access. Many university campuses provide gopher as a public information service. 2a. On most systems, you first select an option labeled "Other Systems", then from that menu select "WAIS based information". Since each gopher site creates its own menus, I can't tell you exactly where to go from there. 2b. If you can gopher to SunSITE, at UNC, navigate the menus down thru SunSITE archives..All archives..Academic..Physics..Cold-fusion. You will find the searchable databases (typically marked ), as well as the primary-literature files discussed below. 2c. If you can 'telnet' but not 'gopher', you may telnet to sunsite.unc.edu and login as 'gopher'. Then follow 2a or 2b above. 3. If you have World Wide Web (WWW) browser, such as Mosaic, Cello, or Lynx, you may use the following URL's: wais://sunsite.unc.edu/cold-fusion Britz bibliography wais://sunsite.unc.edu/fusion-digest newsgroup archive gopher://sunsite.unc.edu/11/../.pub/academic/physics/Cold-fusion 4. If you have a WAIS client on your system (the most common ones are "swais" -- character-based, and "xwais" -- for X-Windows), use it. The Britz source is called "cold-fusion" and it is listed in the directory-of-servers. If you _want_ a WAIS client program to run on your system, several are available in the public domain. Try ftp-ing to one of these sites: sunsite.unc.edu think.com There are several additional files archived at sunsite (e.g. Bollinger's Twist of Ribbon, preprints of the Fleischmann&Pons 1989 paper), which are accessible by anonymous ftp. %ftp sunsite.unc.edu . . . >cd pub/academic/physics/Cold-fusion >dir The collection (mostly primary papers) maintained by vince cate has been copied over to pub/academic/physics/Cold-fusion/vince-cate. Additional contributions are welcome; e-mail cfh@sunsite.unc.edu. cudkeys: cuddy29 cudenharr cudfnCharles cudlnHarrison cudmo5 cudqt2 cudszM cudyr1995 ------------------------------ 1995.05.29 / Tstolper@aol.c / Why Does Traffic on Moderated Groups Drop? Originally-From: Tstolper@aol.com Newsgroups: sci.physics.fusion Subject: Why Does Traffic on Moderated Groups Drop? Date: Mon, 29 May 1995 04:33:09 GMT Organization: Sci.physics.fusion/Mail Gateway Bill Page, In your post dated May 18, 1995, carried in Scott Hazen Mueller's Fusion Digest No. 3712 of the same date, you said that you had been told that it is typical of moderated groups to experience a drop in traffic. Did your informants suggest any reasons why moderated groups tend to wilt on the vine? Tom Stolper cudkeys: cuddy29 cudenTstolper cudmo5 cudqt2 cudszS cudyr1995 ------------------------------ 1995.05.29 / Vertner Vergon / Re: The Farce of Physics Originally-From: vergon@netcom.com (Vertner Vergon) Newsgroups: alt.alien.visitors,alt.paranet.ufo,alt.philosophy.objectivis ,alt.sci.physics.new-theories,misc.books.technical,sci.astro,sci.energy, ci.misc,sci.physics,sci.physics.electromag,sci.physics.fusion,sci.physic .particle,sci.research,sci.skepti Subject: Re: The Farce of Physics Date: Mon, 29 May 1995 05:22:49 GMT Organization: NETCOM On-line Communication Services (408 261-4700 guest) Organization: NETCOM On-line Communication Services (408 261-4700 guest) Organization: NETCOM On-line Communication Services (408 261-4700 guest) Keywords: Cc: In article <9505281841.aa00925@post.demon.co.uk>, Mike H. wrote: >Date: 28 May 1995 16:55 GMT >Message-ID: <05281995165522umw@avon.demon.co.uk> >References: <3q7fi8$4b6@xcalibur.intnet.net> >X-mailer: Umail 1.50g > > >On Sun, 28 May 1995 05:46:40 GMT, in > vergon@netcom.com (Vertner Vergon) wrote..... > > >> I offer my hypothesis (ON THE QUANTUM AS A PHYSICAL ENTITY) in which the >> universe is composed of *one* and only one particle. I call it THE >quantum. >> >> It has very few characteristics, energy of expansion/contraction, spin, >> mass and co-spatiality. >> >> These charateristics blend together in a fractal-like manner to form >> electromagnetic radiation, electrons, protons, neutrons and neutrinos. >> >> These are the only stable particles in the universe (except neutrinos >> and neutrons which are semi-stable. >> >> The entire subatomic zoo consists of unstable shards that break off >> or are formed when the stable particles are smashed together. >> > >Surely this breaks with the idea of a particle. If you can take two >particles and smash them together to make three particles then this either >implies that the two particles are not the smallest unit or that there is >something remiss. See, I'm having the same problem. How much QED can you explain in 50 lines or less? I ask people to read my work (posted here on the newsgroup) and they refuse. Then they criticize by reiterating the present model. The quanta, in particle formation, are spherical and *concentric*. They constantly expand and contract because there is no internal friction. Thus they form a concentric standing group wave. The only stable groups are electrons, protons, nucleus neutrons, and photons (which are group waves *nearly* concentric but not quite). When accelerated in a LINAC these particles (except photons) gain in mass due to the absorption of e.m.r. . When collisions occur they break up into various shards ("elementary particles") which, being unstable, *immediately* reduce to the next lowest stable configuration. THESE SHARDS ARE NOT CONSTITUENT PARTICLES. >I find it hard to accept that if a particle can shatter into fragments that >those fragments are in fact not made up of smaller units of matter. > >If these particles are stable, why is it easy to break them ? Its not easy. Take a look at a LINAC. >How do you account for different apparent particle densities and masses and >charges? > A neutron is composed of 2.27 x 10^23 concentric quanta. It's density varies as the fourth power of the distance from the center. Its "effective" radius is LS/2.27 x 10^23 (2) = 6.59 x 10^-14 cm. ((where LS = light second)) The calculated density is 1.39 x 10^15 gr/cc The density is a function of the number of quanta in the particle -- as is the mass. Some interesting relationships between Angular momentum, modular momentum, electric moment and magnetic moment are explored. They are all related. >What about anti-particles? That, too is analyzed and categorized. >> If anyone is interested, I suggest they read my thesis. ON THE QUANTUM AS A PHYSICAL ENTITY It is currently posted on this newsgroup. >ftp site.... ? I understand it is also on http://www.fys.ruu.nl/~stein/vergon.html I haven't yet found out the protocol to place it there so Jasper Stein was kind enough to do it for me. V.V. The Ugly Duckling >> > True, the standard Model does explain a very great deal. Nevertheless >> >it is not yet a proper theory, principally because it does not satisfy >> >the physicists naive faith in elegance and simplicity. >> >> How simple can you get with ONE basic particle? > >A proper theory is one that allows you to make predictions which can be >experimentally proven. QM is a proper theory because it allows you to make >predictions about energy levels, alpha decay and particle interactions. The >absence of special cases and fudge factors is also an important aspect. > > >---------------------------------------------------------------------------- > > Mike H. (Software Sans Frontieres) PGP:818C97EB75366540 8A27D2AB8E7482CB > > Umail 1.50 from ftp.demon.co.uk:/pub/ibmpc/umail,/pub/ibmpc/windows/umail > >---------------------------------------------------------------------------- > cudkeys: cuddy29 cudenvergon cudfnVertner cudlnVergon cudmo5 cudqt2 cudszL cudyr1995 ------------------------------ processed by cud.pl ver. 0.5 Mon May 29 04:37:07 EDT 1995 ------------------------------