Was that back around the SCIF days? I'm a little fuzzy on the early 90s research.
FWIW, here was one of Rick's last posts regarding results:
3. Energy confinement on the WB-7 exceeds the classical predictions (wiffleball based on the electron gyro-radius) by a large factor.
Our conclusion is that both the wiffleball and the cusp recycle are working at a reasonable level.
He also says they don't trust any small-machine results in terms of loss scaling, which WB-8 should tell us something about.
I wouldn't be surprised either if it takes a few iterations at the WB-8 size to get something with confinement good enough to go to reactor sizes. Results may be more nuanced than "This tech is a dead end" or "This tech is about to change the world."
And on the aforementioned stimulus worries:
We have to be very careful about dealing with Congress on this. Money that gets appropriated through Congressional pressure looks like an earmark and gets labeled as pork. That kind of money can go away in a big hurry. That wouldn't serve anyone very well. Consequently, we are going through the peer review process. That's the right way to do things.
Looks like they ended up doing both, for better or worse.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
For my above comment, I was thinking of PSR, but got it wrong. PSR = Pacific Sierra Research, EMC was a sub for them. This occured in the 1987-88 timeframe I believe. It was not PCR. Sorry.
There was also the MPG series. Magnetic Polyhedral Grid device. 2000-01 timeframe.
Last edited by ladajo on Thu Jul 01, 2010 4:06 pm, edited 1 time in total.
TallDave wrote: Hmm? Which one would that be? AFAIK, Bussard never built a machine anywhere near as expensive as WB-8. MPG-1,2, WB1-6, the PXLs... they're all fairly small and cheap from I can gather from Valencia. Maybe we're talking machine vs. contract. Bussard did build some things in parallel.
In the 99-05 time frame there was a $12.7M contract which culminated in WB5 which was 40cm radius. a decade earlier there was a $10M contract that culminated in an un-named machine (though I've seen it called HEPS) that was similar to the WB5 but 93cm radius.
This is the largest contract since "the lesson" was learned.
Hmm, hard to tell much about the level of funding or the machine costs without knowing contract lengths. The WB-8 contract is $8M and it's, what, 18 months, plus the option? Gotta dig that contract up again.
Here's an interesting page with a letter from Bussard. It mentions HEPS, among other things.
AND we will convene a review panel of very high-level and internationally distinguished people to spend about 6 weeks going over this to recommend for or against proceeding sith a full scale demo.
This may or may not happen. If it does, I have little doubt as to the panel recommendation, as the data and insight from WB-5/6 is just too clear. We really have solved the last engineering physics problem that has plagued our work for 12 year s or so. Yes, there is much left to do, iespecially in controls and diagnostics, but these are predictable things not dependent on beating the Paschen curve.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
I didn't realize there had once been a $30M contract (even if it was reduced to $10M). It's still hard to tell how much HEPS cost. That thing is a monster! It looks like we're getting much better diagnostics on WB-8, in addition to the obvious design improvements.
I love this part:
When I turned to our contract monitor, and asked
should we accept this invitation. He said, “No, now that
you got this thing working, no more talks, don’t go to
any more physics conferences, don’t write any papers,
just lay quiet. Do your work and don’t publish.”
Heh, why do I get the feeling that guy still works there?
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
HEPS was a closed cubical box, large device, Radius = 93
cm, 25 ms pulsed, E = 15 kV, Ie = 5��10 Amps, water��
cooled, truncated��cube coil magnets, B = 3.5 Kgauss.
So .35T for HEPS versus .8T for WB-8. I don't think WB-8 has cooling, though, so maybe they're comparable.
I wonder if Rick's team is getting fusion yet?
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
Can someone generate a definitive list of each of the Bussard-Polywell projects done, with their costs and time lines, to date?
This should [surely?] be an important thing on such a forum, or is it likely to look too much like the time/cost line for токамаки in their first 25 years [at which point, Bussard declared them to be demonstrably a wate of money, by virtue of the time and money sucked up with nothing to demonstrate].
bennmann wrote:To state the obvious, the "lesson" kite is referring to is cusp loses on WB-6.
The the slight modification to magnet spacing changed everything.
Just putting it out there in case random internet people read and do not understand.
Actually, I would say the lessons learned on WB4 and WB5 cusp losses , lead to the spaced WB6 open recirculating design, which confirmed the evolving understanding of the Polywell concept.
TallDave wrote:It looks like in WB-7.1 they tried some things with the coil joints, and ultimately decided to do away with them in WB-8.
There is no evidence for that is there?
Nebel commented that they found that the nubs was a major, perhaps dominate(?) source of electron loss- hot spots. Changing their geometry and/ or magnetically shielding them would be possible partial solutions that they may or may not have tried. The drawings of a WB 8 like model showed the separate standoffs for each coil. Whether this outsider(?) approach matches EMC2's plans or not is speculation. But, the drawing on EMC2's website of the WB 8 vacuum vessel would accommodate such a design, with each separate magnet being attached to a different removable face plate. Contrast this to the WB7 vacuum vessel which had a swinging door on one side for access to large structures.*
* Note- WB8 chamber is mislabeled as WB7. The picture of the WB7 vacuum chamber is no longer on the website.
