1995.04.18 / Rich Hawryluk /  TFTR Update April 18, 1995
     
Originally-From: rhawryluk@pppl.gov (Rich Hawryluk)
Newsgroups: pppl.tftr.news,sci.physics.fusion
Subject: TFTR Update April 18, 1995
Date: 18 Apr 1995 23:00:16 -0400
Organization: Princeton Plasma Physics Laboratory

Status (April 18, 1995):

The week of March 6th was a maintenance week.

Diagnostic system calibrations (Rayleigh scattering) the week of March 6th
required the venting of the torus to 20 torr with nitrogen and then pumping
the vessel back down via the neutral beam roughing system.  This was the
first demonstration of the pumping and purging scenarios that would be used
during TFTR decommissioning or in the vent of required internal TFTR
maintenance.

While the vacuum vessel was vented to 20 torr for the Rayleigh scattering
calibration, attempts were made to observe the effects of beta decay of the
tritium in the vessel by using the vessel as an ionization chamber with a
fixed glow discharge probe as the electrode.  The glow probe was biased
from 0-30 volts with respect the vessel, and the I-V curve determined.
This was repeated at several pressures during vessel pumpdown.

During the period of March 13th to April 7th, a series of D-T and D
experiments were performed.

Measurement of the slowing down of the alpha particle distribution using
the alpha CHERS diagnostic (University of Wisconsin) and the pellet
charge-exchange system (GA and Ioffe Institute) in sawtoothing and
non-sawtoothing discharges were performed.

The portion of the Pellet Charge-Exchange (PCX) experimental proposal had 3
goals; a) Develop pellet penetration strategies, b) Study sawtooth mixing
of alphas, and c) Obtain the full alpha spectra up to the birth energy.
The results obtained are as follows:

a)      Good pellet penetration was obtained in D-D at Pb ~ 22 MW for
pellet injection times of 200-500 ms after beam turn off.  At earlier
times, it was found that the electron temperature had to be reduced below 8
keV (by reducing beam power) in order to get adequate pellet penetration.

b)      Good data was obtained for pellets injected just before the first
sawtooth crash after beam turn off (~ 200 ms), just after the first crash
and after two sawtooth crashes.  The data showed fast ion mixing as
anticipated from earlier results.

c)      The attempt to obtain a classical alpha spectrum out to 3.5 MeV was
not completed.  On one shot (84609), an alpha spectrum was obtained from
1.0 - 3.0 MeV, but the signal to noise was marginal.  This part of the
experiment will require more run time.

The Alpha-CHERS confined, fast alpha particle diagnostic performed a
spatial scan in 2.0 MA, R=2.52 m, D-T supershots at 22 MW neutral beam
power.  Following extensive conditioning and D-D discharge development,
four D-T shots and four companion D-D shots required for analysis of the
data were performed.  The D-T shots had a 1.3 sec. D-T beam phase followed
by a 0.7 sec. D-D beam phase for observation of the alphas by Alpha-CHERS.
The neutral source strength in these shots was 1.5e18 n/s.  These
discharges were very reproducible and had no sawteeth.  We expect that this
data set should allow the spatial profile of the alpha density and energy
distribution in the 0-0.7 MeV range to be measured in a typical
non-sawtoothing TFTR supershot.  Analysis of this data set is in progress.

A series of experiments with tritium gas puffs of different size were
puffed into a deuterium supershot plasma (Pb = 20 MW, Ip = 2.0 MA).  Gas
puff flow rates of 6, 12, and 18 torr-liters/s and 16 ms duration were
introduced into the deuterium neutral beam phase of the discharge.  The
long term decay of the neutrons = 0.19 s which is on the order of the
energy confinement time.  These different gas puff sizes will be carefully
examined for non-linear transport behavior.

High betap experiments using the current rampdown techniques were performed
in collaboration with Columbia University.  Excellent machine conditions
were established for the target discharge for the high beta experiments,
and operation to a maximum power level of 28 MW in a D plasma was achieved.
The plan was to re-establish this condition, and perform a similar shot in
D-T.  However, when the D-T shot was taken a major disruption was observed.
This disruption was at a  BetaN ~ 2.8 well below the normal beta limit for
the current rampdown scenario.  The problem may be associated with the
presence of "fishbone MHD activity:" and edge ELM's which are larger in DT
shots.  This plasma is being studied in detail at present.

Deuterium set-up work was performed to develop the reverse magnetic-shear
scenario..  MHD  and disruptions were observed when q-min crossed 3.
Presuming that the problem was too much pressure at the q-min=3 crossing, a
notch was programmed in the NB prelude power, starting ~ 0.2 sec. before
the normal MHD spike time at 2.0 sec.  This proved to be very effective in
getting rid of these MHD bursts, spikes, and disruptions; and they were not
an issue for the rest of the campaign.  The reverse shear group is now
studying a similar (smaller) MHD burst that occurs at ~ 1 sec. which
correlates with past MSE measurements of when q-min goes though 4.

After getting rid of the 2 sec. MHD distress, we successfully reproduced
one of our best reverse shear discharges (shot number 84011).  A power scan
was performed with 22 and 25 MW of NBI.  The 22 MW case got density peaking
of 3.5 without disruption.  The 25 MW case got a peakedness of 4. and
central density of ~ 1e14cm-3, but then disrupted with a 5/2 and ballooning
mode sequence similar to 84011 which was an excellent shot achieved during
the previous experimental campaign.  The recent shot disrupted even though
the BetaN feedback system was turning down the beam power and limiting
BetaN to ~ 1.5 (instead of 84011's 1.7) for the last ~ 0.13 sec.   The next
real challenge is to figure out how to evade these kinds of disruptions.
Theoretical analysis is in progress for these shots.

High density helium plasmas were investigated with charge exchange
recombination spectroscopy.  The helium ion density was inferred from
measurements of the absolute charge exchange line brightness observed
during short neutral beam pulses in these otherwise ohmic plasmas.  The
helium concentration was determined to be nearly 50%, in accord with
expectations from visible bremsstrahlung measurements.  These measurements
confirm that observed increases in the absolute helium line brightness in
high power D-T plasmas are in good agreement with predictions based on
expected helium ash densities.

Last week, April 10th was another maintenance week.

Future Plans
The next four weeks will continue the deuterium-tritium experiments.  This
week we have begun a series of experiments to study the effects of BAE
modes.  This experiment is in collaboration with W. Heidbrink (U. of C. at
Irvine),  and T. Strait and R. James (GA).

Announcement
A compendium of 21 TFTR D-T papers  which were published and presented in
1994 is available.  If you wish a copy,  send a message to
pshangle@pppl.gov requesting a copy.

R. J. Hawryluk
609-243-3306
e-mail rhawryluk@pppl.gov


P.S.  If you do not wish to receive notices of TFTR status, please contact
me or send a message to postmaster@pppl.gov.  If you are aware of others
who wish to receive notices, please send a message to postmaster@pppl.gov
and do not send a message to tftr_news_info.



_________________________________________________________________________
R. J. Hawryluk
rhawryluk@pppl.gov
PPPL - LOB 325
Phone:  (609) 243-3306
Fax:    (609) 243-3248


cudkeys:
cuddy18 cudenrhawryluk cudfnRich cudlnHawryluk cudmo4 cudqt2 cudszL cudyr1995 
------------------------------
1995.04.19 / Paul Koloc /  Re: Fusion Digest 3576
     
Originally-From: pmk@prometheus.UUCP (Paul M. Koloc)
Newsgroups: sci.physics.fusion
Subject: Re: Fusion Digest 3576
Date: Wed, 19 Apr 1995 04:25:14 GMT
Organization: Prometheus II, Ltd.

In article <199504130803.SAA05828@oznet02.ozemail.com.au> rvanspaa@ozema
l.com.au (Robin van Spaandonk) writes:
>>>Originally-From: barry@starfire.ucsd.edu (Barry Merriman)

>>Newsgroups: sci.physics.fusion
>>Subject: Re:       Re:  Fusion timetable
>>Date: 12 Apr 1995 02:02:04 GMT
>>Organization: UCSD SOE
>>
>>In article <199504101239.WAA10213@oznet02.ozemail.com.au>
>>rvanspaa@ozemail.com.au (Robin van Spaandonk) writes:
>>>
>>> How about the following suggestion:
>>>
>>> Take only $50.- million / annum off the Tokamak program, for a period

>>Well, they took 15 million of last week---can you say budget recision---and
>>you didn't even get a single AC funded by that :-)

Good chopping practice for the bigger chops left to come.  

>>Still, it doesn't really work like you suggest---thats akin to saying:
>>ok, Robin, why don't you have 6 kids, and to feed them you get by
>>on 1000 calories a day for the next 5 years.

>>Two obvious problems: (1) you will shrivel away on 1000 cal/day, and
>>(2) as your kids grow, they will want increased food---where does
>>that come from.

The problem is this family is on the come from the outset.  The country
should be put in chapter 11.  I guess if the tokamak can't live on 
50 megabucks then it will die from starvation and some academic and
AC (combined likely) work might get done, but perhaps funded by states
from block grants.  Yep! Seems to be going that way, and who would 
have believed the tumbling wall.   

>>Those realities are on top of the turf wars that always result from shifting
>>funding around within one community.
There should be enough left for a crocket match, turf war is a bit strong.  

>This is a poor analogy.  To start with I would have to go without
>more than 1 part in 7 of my food in order to feed six children. In
>other words I'm only suggesting a 1/7 reduction in the work on the
>tok. This would take the form of certain experiments not being
>carried out, or delayed for a few years, and the associated
>researchers transferring to work on ACs, on a voluntary basis.
>(I suspect that at least 1 in 7 of the current researchers wouldn't 
>mind working on at least 1 of the ACs of their choice - especially if 
>the pay remained the same, and they had the option of returning to 
>the tok. programme if the AC didn't pan out.)

The pay has come down, down, down;just buy something from the Japanese.   
The taxes will go up (the deficit you know).  

>Your second point is also barely applicable, as I would be morally
>bound to support all of my children, come what may, where the
>same is not true of the AC programmes. 

And include the tokamak as not morally important.  In times like 
these it is morally questionable that we should consider funding the 
tokamak.  So maybe for the future of the children an AC or two should 
be considered.   That should leave two or three funded since PLASMAK(tm)
Development can be funded privately and possibly through other government 
agencies with interests other than grid electric power.  

>non-viable you can simply stop funding them. If on the other hand
>they prove promising, then they have demonstrated their worth, and
>should continue to be funded. Perhaps in conjunction with the tok.
>programme, perhaps instead of it (if they prove very good).

As I say, at times like these, tokamak research is a bit of an 
extravagance.   

>Where turf wars are concerned, I think that given the commitment of
>the nation to the fusion programme, it behoves researchers in the
>field to put aside petty emotional squabbles, and get on with a
>reasonable and well balanced approach to the problem of harnessing
>nuclear fusion, which I am sure in the long run, is everyone's goal.

Why not short run?      :-)    What are you pessimistic?

>It is natural for someone working on a large project like the tok. to feel 
>a certain pride in their work. I would not wish to decry this, but rather 
>redirect it. Instead of saying "I work on the tokamak programme", one 
>could say "I work on the fusion programme". And this would be 
>acknowledged as valuable work, irrespective of the particular device. 

Now that makes sense.  Perhaps this will happen when the program is 
de-centralized.  But for the time, DoE Germantown rules that scenario 
out as if they were threatened tyrrants.  On the other hand, the nation
can ill afford their choice, so... . something will break, if this
perception is true.   If not then there will be no end until government
financial collapse occurs or deep global depression takes place-- if ever.    

>>Barry,
>Robin van Spaandonk <rvanspaa@ozemail.com.au>
+-------------------------------------------------------------------------+
| Paul M. Koloc, Bx 1037 Prometheus II Ltd, College Park MD 20741-1037    |
| mimsy!promethe!pmk; pmk%prometheus@mimsy.umd.edu   FAX (301) 434-6737   |
| VOICE (301) 445-1075   *****  Commercial FUSION in the Nineties *****   |
+-------------------------------------------------------------------------+

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------------------------------
1995.04.19 /  Dougatlake /  Re: POLL: How long till power plants?
     
Originally-From: dougatlake@aol.com (Dougatlake)
Newsgroups: sci.physics.fusion
Subject: Re: POLL: How long till power plants?
Date: 19 Apr 1995 02:00:12 -0400
Organization: America Online, Inc. (1-800-827-6364)

Any ideas what I should do with original space shuttle flight technology
designs left to me by my father, one of the Space Shuttle designers. I
have eight notebooks filled with nearly 400 designs from his 35 years at
North American Aviation which became Rockwell International contracting
with NASA to build the space hardware. The Smithsonian has requested I
forward the notebooks thataway...but if I do, no one will ever see them
again. Any advice is appreciated, Douglas J. Mahr
cudkeys:
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------------------------------
1995.04.19 / Dieter Britz /  Peroxide: nail in the coffin
     
Originally-From: britz@kemi.aau.dk (Dieter Britz)
Newsgroups: sci.physics.fusion
Subject: Peroxide: nail in the coffin
Date: Wed, 19 Apr 1995 08:45:12 GMT
Organization: Sci.physics.fusion/Mail Gateway

There have been some interruptions here in our News service, so I can't
quote Tom, who asked whether it is not possible that a gunky cathode is
not able to catalyse the decomposition of peroxide. My point was that, if
peroxide should perchance be generated at the anode (which I doubt, and now
have experimental evidence for doubting), then it would, after being carried
over to the cathode, be reduced again.

OK, Tom, could a gunked-up cathode fail to do this re-reduction job? No, it
couldn't, because no matter how gunky it is, there is still current flowing
at it - otherwise there would not be any water electrolysis, and the people
would notice. Gunk has holes in it, through which current can flow.

It has been pointed out to me that there has in fact been an attempt to
measure peroxide formation in a cold fusion electrolysis cell. Steve Jones
has the reference, and kindly sent me a copy. It is by Guruswamy, Rajamani,
Li and Wadsworth, in the Report of the National Cold Fusion Institute, April
1991, p. 1-185 "Calorimetric measurements during electrochemical loading of
deuterium in palladium and palladium alloys". They were aware of the peroxide
argument for energy storage, and analysed the electrolyte after electrolysis.
They found "less than 10^-4 moles/cm^3", i.e. < 10^-7 M peroxide. If you are
a peroxide TB, you can now say, ah, but with Certain Additives, you might
still get a peroxide sirup, and that's what P&F use... but for us normal
people, this reinforces what I keep saying:

FORGET PEROXIDE.

-- Dieter Britz  alias  britz@kemi.aau.dk

cudkeys:
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------------------------------
1995.04.19 / Paul Koloc /  Re: POLL: How long till power plants? 2062  Tell me you joking? Help
     
Originally-From: pmk@prometheus.UUCP (Paul M. Koloc)
Newsgroups: sci.physics.fusion
Subject: Re: POLL: How long till power plants? 2062  Tell me you joking? Help
Date: Wed, 19 Apr 1995 06:00:58 GMT
Organization: Prometheus II, Ltd.

In article <3mjkog$46a@curly.cc.utexas.edu> johncobb@uts.cc.utexas.edu
(John W. Cobb) writes:
>In article <D6r5ts.AxJ@prometheus.UUCP>,
>Paul M. Koloc <pmk@promethe.UUCP> wrote:
>>In article <3lpc6n$9i6@curly.cc.utexas.edu> johncobb@uts.cc.utexas.edu
(John W. Cobb) writes:
>>>In article <D6EHuv.1zq@prometheus.UUCP>,
>>>Paul M. Koloc <pmk@promethe.UUCP> wrote:
>>>>In article <3lc6tj$qpd@curly.cc.utexas.edu> johncobb@uts.cc.utexas.e
u (John W. Cobb) writes:
>
>>In the case of a Spherical compression, which has ANY net inward 
>>additional volume confining surface tension other than the bounding
>>atmosphere, it is a different situation, since the internal energy 
>>(pressure) is higher and perturbations are met with increasing 
>>(restorative) force. ...

>Interesting, I'll have to cogitate on this a bit
Let me know. 

>I'm still a bit skeptical, because you know, the plasma is always
>out to screw us. :>

Yes, we have considered using them to remove hemoroids.    :-)

>Whew, I did and I feel much better.

>It could be because the flame is fairly cool, much less than fusion
>ignition temperatures and moreover, much of the energy of the flame is
>leaving in the form of visible of infrared radiation because it hasn't
>"burned through the ioniztion barrier. The really hot plasmas don't glow, 
>they are dark. Radiation == cooling.

Right, but we aren't talking about the Kernel plasma, that is bounded 
by a vacuum and dense strongly insulating field.  It gets very much
hotter than the Mantle plasma.   

Here we are talking about the Mantle plasma which is bounded on its
out surface by the blanket atmosphere at whatever compression induced 
density.  So at its inner vacuum surface it intercepts whatever 
Bremsstrahlung (cooling) radiation emminates from the Kernel plasma 
(compression heated hot and dense).   

>>If you think about this John, you will see that the Mantle is an onion 
>>of layers upon layers of plasmas and gas mixtures and radiation 
>>environments that filters the radiated energy from the Kernel plasma 
>>on its way out to freedom,  absorbing and reemitting it at lower energy 
>>over and over again producing a avalance of gradient regimes, which ease 
>>the energy out of there hoarding it as if they were Scottish bankers 
>>at a gold minting festival.  

>The devil's in the details here. Ionization/recombination fronts are
>notoriously unstable. 

Why is that?  Once they achieve equilibrium, these boundaries don't seem 
to be unstable in our PMKs. 

>                    Transport across them also means a lot of energy
>loss. 

Only if the respective bounding region beyond (outbound side) is not 
insulating.  

>I don't see how this arrangement sets up some sort of heavy
>duty transport barrier, although this seems like what you are describing.
>Is this what you are trying to communicate? 

Yep.  Actually composed of a lamination of said barriers which combine
to act as a "heavy duty " fellow.   But read on, I think we will hit this
again below. 

>                            .. . .    If so, why is there a
>transport barrier. Remember, dense gas is NOT a better insulator than
>vacuum. 

Let's not rush to judgement here.    Two points to consider.  

1. 
First place dense gas that doesn't CONVECT IS an excellent insulator. 
Call it "dead dense gas" or ddg.   Think of your home in Minnesota
*oops wrong John*.  and all that 8 cm Pink Panther fiberglas insulation.
That's pretty much what we use here, except it's the weak field that 
diffused into the Mantle during formation that replaces the pussy cat. 
This magnetic far field stuff got in there before the PMK  became
hyperconducting (runaways ran above _Vcrit_).   This field clamps radial
electron diffusion by about 3 orders, which is just fine.  The poles
are an exception, but the divergence layer collects all the excess 
plasma produced over the whole surface and (acting like a natural 
divertor) ejects it from the poles.  (you saw the blue phophorescence 
from the metastables of the Copper seed in the color photos I sent to 
Logajan's site.) 

2.  A vacuum is a terrible insulator for radiation.  Look at the sweat
that rolls off Tokers when Lidsky walks by.  Naw, even with a Mag
field, all that might happen to that radiation is it may experience
a bit of Faraday rotation.    :-) 
So for insulating a fueled and burning plasma, a vacuum  SUCKS.  A 
Mantle at 20 kbars + is GREAT!  p-^11B only burns for a few milliseconds.  

>  And in terms of radiation, it doesn't make any difference because
>all media are optically thin, or are you saying you are going to be
>optically thick? That presents its own problems.

No it's not.  Not at that pressure.  The Mantle is thick, and we
can use inert noble gases for closed cycle operation which is added
for the final fast compression.  Of course, it will be contaminated 
with that uncoronated stuff (^4He), but who's to notice among all 
that royalty.   

>I'll grant that a liquid first wall has engineering advantages over a
>solid wall. For example, its really easy to install a new liquid wall.
>However, the catch is it has got to work. It is like I keep cautioning
>about FRC's. I really like them and they have a lot of reactor advantages,
>but its no use if they don't work. So until we know transport better,
>we can't commit.

Think in generic terms...  Think   "FLUID" wall.  
As for your comment about FRC's, that's why I moved the evolution this
far.  It was to find something that works.  Now, it certainly does have
characteristics more similar to stars.  It can be compression heated
efficiently, and well ... we shall see.   Should burn on the first 
attempted run with full compression and fuel loaded Kernel plasma.  

>>You remember we have made these things in air? 

>Yea, I know, I keep hearing that, and I know you gave me a set of
>refs. htat I haven't been able to lay hands on yet (mea culpa). But in
>spite of my laziness, would you care to describe a little about your 
>experiments? What size discharges? Do you have diagnostics about things
>like the internal peak temperature or transport information?

Let me know if you get the paper I sent.  That was the first work, the
next stuff will look inside, and then we will make some big buggers
and with strange gases and finally give them a thump.  

>I'm not being silly. If its glowing, it must be giving off energy (how
>else could you see it?) So given the same internal core temperature,
>I'll take the dark plasma over the glowing one anyday because it means
>it is probably better at confining energy. 

Your missing the point.  If you were inside the sun you couldn't see me 
if I was standing next to you.  But far enough out, the temperature has 
abated tremendously.  Here due to the density and Z differences (we are
speaking of the fusion case here)?  As long as the Kernel plasma doesn't
conduct like tokamaks due or radiate due to high Z impurities, then
we can cook it through compression to burn.  The Mantle will survive, 
since it will survive from birth, and things only get better for it,
due to the increase of cooling radiation from heating Kernel.  Let's
take a size for  a compressed Kernel plasma that is burning.  100cc
Okay!  It puts out about 10 megawatts/cc  or 100 megawatts for a 
few milliseconds.  Then we replace it 60 times and we run 3 of these
things for 3/phase.  Well,  it comes out to something that can get
you to MARS  in 2 weeks or replace most any large power complex.  Say 
order 10*10^9 watts electric out.   Guess what? That surrounding blanket
sees this fusion rad stuff coming and it says ... HEY youse guys!  can 
we join your state of matter???  .. .   Why Shure little crowded fellas 
Then we can blast outa here together and push some mag flux around
BIGTIME.  

Think about it. When the
>house energy guys come and take a picture of my house in infrared, they
>point to the BRIGHT spots in the photo as indications of where I am
>losing heat. They same is true with plasmas.

Yep and where you are NOT losing heat is where that nice thick "ddg" is
doing its job.  With the help of the pink Pussy cat.    

>This is correct. If the core temperature is very different, then it is an
>apples and oranges comparison, but if the core is the same temp., then
>dark means better confinement. Now any glowing we are seeing here is NOT
>from p^11B burning, because it hasn't happened yet. It is from radiative
>losses of external energy input (in PMK's case, from compressive heating,
>I believe).

Of course the temperatures differences are very large and significant.  
So? that's an initial state.  But notice that initially, the Mantle 
plasma is optically thick along absorption bands for the air like BL 
case.  This is comparable to the fusion formation case, but before as 
much ohmic heating has set in.  The p-11B heats to about 1.2KeV
before compression.  That's ohmic heating with a difference. Then 
an ATC is down with a compression ratio of 10 or so.  

>How about the obligatory steak dinner that PMK's will not produce electric
>power delivered to the grid by year XXXX, or a bet that the first 
>commercial fusion power will be something other than Plasmak's?
>Although I fear neither of us will have teeth enough to chew on a cow
>when that happens :>

I had a similiar bet with Furth for just the formation of the plasmoids
in air, but since his heart surgery went bad, he couldn't remember, so
I was out of luck.   There is another chap that owes me. His name is
Schluter, a German, that was quit arrogant about it at the time. It was
when I was with both of them, although my bet with Harold was from an
earlier time.   Anyway, I'm out of the steak thingy, since my MD ordered
me to lose 30 pounds, and that stuff can keep me alive for three days.. .
at least the amount I would consume to get my money .. John's money's
worth.   How about you running numbers, or do some high pulsed power 
development (need really fast rise times and energy delivery).   

>>content to just leave things open to question?   

>Ouch, it hurts when the aim is true. In all honesty, I have not had time
>to trace all citations to PMK-type devices, although I am familiar with
>spheromaks. And no, I really haven't committed to "follow through" with
>my negative speculations. As you have noticed, my reply is already a bit 
>tardy, times are busy here. So there is a mea culpa here. I wish I could
>have, but I haven't and realistically, I don't think I will be able to
>curl up with a set of papers and work out the details in the near future.
>Thinking about these things is not my vocation, but my avocation. Having
>said that, let me add that I am not content to leave thing open to question.
>My point is that I don't want others to get the impression that there is
>a closed consensus opinion that is actually counter to the conclusions one
>would draw from a "counting noses" opinion survey. Now just because most 
>people don't think highly of PMK's, or more accurately, are not aware of 
>the idea, doesn't make that opinion correct. So lacking universal awareness
>and agreement and given my reluctance to speed dozens of hours in 
>"recreational research" at this time, maybe you could facillitate and
>deeper Q&A here on this newsgroup? I know I would be interested.

As I say let me know if you get the paper.  If you don't it's because
the old APS address is not current, or a screwed up somehow.  

>>can come to agreement on numbers?

>That would be nice.

>>>Speaking of confinement times, what is the energy loss time in a plasmak and
>>>how does it scale with device size?  

>>Better than inductance or size. 

>Now wait a minute. What is the energy confinement time? This is a very
>well defined concept. Has it been measured?

It has been estimated at 30 seconds, but the stuff we have done for
diags shorten the confinement time significantly. That's due to the Copper. 
Also, you may have noticed that confinement time is related to size or
inductance, so pick a value so that we can reference our times to your
times.  We can burn up fuel in 3 to 7 milliseconds.  Our tiny fellows
we have reported on which must be scaled to compare to ITER or whatever,
lasted for only 250 milliseconds.  However, they collided with a plastic
wall, and were seeded with copper, so until we move out of that mode, our
"record lifetimes" (mag field loss times) are going to be uninteresting. 
I think the longest Spheromak lifetime at LANL on CTX was around 2.2 to
to 2.5 milliseconds, and that was achieved by converging a significant
number of spheromak rings which merged from a repeatably fired Marshall
Gun.  

>> For p-11^B, we want to get the energy into the blanket fast, 
>>and recover self compression heating. The loss times should be okay, BUT
>>it does depend on the behavior and exact nature of super sharp boundaries. 
>>These occur because of the hyperconductivity.  What the nature of 
>>the current density at the boundary is will have to be investigated 
>>experimentally.  

>>Loss times before compression are "forever".  Notice
>>that they ran energetics in TFTR and ATC at PPPL and TK Chu analysed
>>the data.  He discovered that losses were clamped also, and was the
>>first one I heard use the expression "forever" for the current trapping.  
>>These currents were induced in shakedown during gas fill/drive EMF profile
>>studies on those tokamak devices.  

>you lost me here. How can a particle decay time, or current decay time
>be forever?

Compared to the thermal discharge in a tokamak, you could go out and get
lunch and come back and currents were still running a significant levels.  
Of course that's not the days that particle accelerators achieve. 

>>Electricity?.. H..l,  Propulsion my good man.  propulsion.  
>>                              Or was that  "Plastic" 

>Okay fine, but let's walk before we high jump 27 feet. Some people
>suggest that we should crawl before we walk, but I am not that patient.
>Apparently Paul is even less so.

It's easier to do propulsion than closed cycle electric power.  

>>>for years to come. 
>>I just calls it the way I sees it.  One must first have a "workable idea".
>>That just could be the difference.  What do you have to sweat, it's
>>not costing you a dime.  

>It could cost people their careers. It has in the past.

Well you said a mouthful there, friend. Let's hope all you chaps are 
quickly employed just in case the funders think that tokamak thing 
appears to be everything I think it is, and not the 5x more to keep 
on funding it.  

>John W. Cobb	Quietly Making Noise, Pissing off the old Kill-Joys
>		-Jimmy Buffett
+-------------------------------------------------------------------------+
| Paul M. Koloc, Bx 1037 Prometheus II Ltd, College Park MD 20741-1037    |
| mimsy!promethe!pmk; pmk%prometheus@mimsy.umd.edu   FAX (301) 434-6737   |
| VOICE (301) 445-1075   *****  Commercial FUSION in the Nineties *****   |
+-------------------------------------------------------------------------+


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