Talk-Polywell.org

crowberry wrote:

Skipjack wrote:

crowberry wrote:
Here is the abstract of Victoria Suponitskys presentation at the ISSW30 conference:
https://events.eventact.com/ProgramView ... de=1666701

Another interesting ISSW30 abstract is A review of the Richtmyer-Meshkov Instability from an Experimental Perspective by Riccardo Bonazza:
https://events.eventact.com/ProgramView ... de=1661287

Strange, but these URLs are not working for me.

Thanks Skipjack for this observation. It is true that the links don't work if you have not visited the conference pages in the same session.The website is using Javascript and seems to be a little bit buggy. Anyway from this page you can find Victoria Suponitskys presentation: https://events.eventact.com/programview ... sion=28671

Riccardo Bonazzas abstract can be found from this page: https://events.eventact.com/programview ... sion=28676

These work, thanks!

Looks like GF has gotten a solution for their anvil seal:

http://www.generalfusion.com/blog/categ ... challenge/

GENERAL FUSION ANNOUNCES WINNER OF CROWDSOURCED ENGINEERING CHALLENGE
the winning “Metallic Pressure-Balanced Anvil Seal” design and claimed the $20,000 winner’s prize. Running for 30 days this spring, the challenge attracted over 60 submissions originating from 17 different countries.

“As a mechanical engineer and inventor with a long interest in fusion power, working on a hard mechanical problem that could advance fusion technology was irresistible,” he said. “I was able to draw from my knowledge of high temperature seal technology gained by recent work on reduced friction piston rings for internal combustion engines.

Now GF only has the true hurdle, stable plasma compression.

Michel Laberge will talk at the 2015 Fortune Brainstorm: E conference during September 28–29, 2015 in Austin, Texas.
He has been given 10 min to discuss:

HARNESSING THE POWER OF THE UNIVERSE

A plasma physicist and entrepreneur argues that fusion is finally real.
Michel Laberge, Founder and Chief Scientist, General Fusion
Interviewer: Katie Fehrenbacher, Fortune

I guess we should not expect much new insight in General Fusions progress from this talk. The event is by invitation only and the tickets for the whole thing are $3000, so it seems similar to TED.
http://www.fortuneconferences.com/brain ... 15/agenda/

"Argues" means it is in dispute and therefore is in doubt. Hence, it hasn't been achieved. What's new there? Looks like the Washington, DC crony lineup for 'free' money. $3000 per is to keep the unwashed out.

The main goal of that event is probably for General Fusion to attract more investors with deep enough pockets.

GF is again hiring new people:

Manager Research Partnerships Jobs,
Marketing Coordinator Jobs

http://ca.jobscenter.info/job-29707d194 ... rnaby.html

http://ca.jobscenter.info/job-251b2ff0f ... rnaby.html

A GF staff member presented at the UW-Madison plasma physics colloquium yesterday. From memory:

*He was focused on plasma injector development. They were getting adiabatic compression up to a point, but as the plasma was focused down at the end of the gun, it did not heat up as much as expected. They are trying to determine why.

*They are confident that the blast produced by the fusion reaction will not cause enough of a shock wave to damage the outer wall. However, they need to make sure the coolant flow is fast enough to transport the hot lead away from the center of the tank so that the vapor pressure isn't too high.

*He played a video showing the lead implosion, and it looked as though the inner surface was being sprayed out into the vortex, rather than collapsing in a smooth fashion. Evidently cavitation takes place several cm outside the vortex, which is what allows the cylindrical shell of lead to become a liner that implodes on the plasma. After the collapse, a jet of lead squirts out along the vortex axis.

*In the explosive compression tests, they have been using a central conductor to increase the plasma lifetime by adding toroidal flux, or at least using it to suppress tilt instability. He said it might be possible to use a cylindrical jet of liquid lead in the piston version. Also, it might be possible to sustain the spheromak by DC current drive from the gun.

*The montage of the explosive compression tests was awesome

Any chance that someone took a video of the event and will post it online?

*He played a video showing the lead implosion, and it looked as though the inner surface was being sprayed out into the vortex, rather than collapsing in a smooth fashion. Evidently cavitation takes place several cm outside the vortex, which is what allows the cylindrical shell of lead to become a liner that implodes on the plasma. After the collapse, a jet of lead squirts out along the vortex axis.

Thank you for giving a nice summary, very kind.

I think it should be mentioned on the cavitation issue that the 14 piston test setup that GF has acknowledged that there just aren't enough pistons to avoid the surface instability. However, GF is confident in the ability of the hydraulic models to provide design information for the full size machine. Hydraulic computer models stand in sharp contrast to modeling plasma compression and so experimental results are required. Plasma is the devil's spawn.

Solo wrote:A GF staff member presented at the UW-Madison plasma physics colloquium yesterday. From memory:
...
*The montage of the explosive compression tests was awesome

Thanks Solo for the summary of the GF presentation! Is there a web page with an abstract for this colloquium?

Last year in December when GF had a talk at PPPL Michel Laberge said they had made about eight explosive tests so far. Do you remember how many explosive tests they mentioned in this talk?

It sounds as GF is struggling with roughly the same issues concerning plasma compression as were mentioned in December last year. But they are in a good position with the new funding allowing them to hire more people. There is an interview with Michael Delage on the recent success with acquiring new funding. No technical details are given, there is only general discussion about GF in the article. http://www.ept.ca/features/bcs-general- ... rgy-needs/

Michael Delage from General Fusion will speak at the Pecha Kucha Vol. 37 “Our Green Future” event in Vancouver, Canada on September 23, 2015.
http://voguetheatre.com/events/pecha-ku ... en-future/

Michele Laberge will give a talk in November at the University of British Columbia, Canada.

Event Date and Time: Thu, 2015-11-05 16:00 - 17:00
Title: Fusion
Speaker: Michel Laberge, General Fusion
Location: Hennings 201

http://www.phas.ubc.ca/events_dept_upcoming

It seems that GF is rather active currently on giving talks on various forums.

University of California Berkeley
ANS General Meeting: General Fusion Speaker

American Nuclear Society
Event Time and Date
Thursday, October 15 2015, 6:30 PM to 7:30 PM

We will be hosting the CEO from General Fusion as our speaker (a Cal Grad!).

https://callink.berkeley.edu/organizati ... ils/719432

Reports from events like these are of course highly welcomed on TP.

Crowberry, mvanwink5: you're quite welcome! Unfortunately the presentation was arranged at the last minute, so there was no abstract or videotaping. I think there were nine explosive tests.
mvanwink: you jogged my memory, I think the speaker did claim that they were optimistic that with a larger number of pistons, the implosion would be more uniform. It seems to me though that the likelihood of cavitation events to happen uniformly without causing spallation is quite low. This is reminiscent of the difficulties that NIF et al have with fuel mix due to nonuniform implosions & Rayleigh-Taylor instability.

Yup. You can't gloss over the creation of instabilities in any medium using dynamic compression. They will be there, the question is "Do they matter?"
Unfortunately in plasma world, tiny instabilities have a nasty habit of quickly becoming out of control instabilities. It is one of those things that is just natural to a chaotic system. If you can't find a way to bound the instabilities in the system, the system will find its own new bound. Sometimes (especially in plasmas) that new bounds allows the system to fail. The bounds of a chaotic system are a function of the sum total of its instabilities.

Michel Laberge is giving a talk on the 18th of December at MIT: Acoustically-Driven Magnetized Target Fusion at General Fusion

Magnetized Target Fusion (MTF) involves forming a magnetically confined plasma of about 1e23 m-3, 100 eV, 7 Tesla, 20 cm radius, 100 ms energy confinement time and compressing the plasma by 1000X in volume in 100 ms within a conductive liner. If the compression is close to adiabatic, the final plasma of ~1e26 m-3, 10 keV, 700 Tesla, 2 cm radius, and confined for 10 ms would produce interesting fusion energy gain. General Fusion is developing an acoustic compression system involving pneumatic pistons focusing a shock wave on the plasma in the center of a 3 m diameter sphere filled with liquid lead-lithium. The combination of a low cost driver, good breeding ratio and excellent neutron protection could lead to a practical power plant. We will review the plasma formation and compression results achieved so far and our plans moving forwards. Work on the compression system will also be described.

http://www.psfc.mit.edu/events/2015/aco ... ral-fusion

We will review the plasma formation and compression results achieved so far and our plans moving forwards.

This makes it interesting to me. It also seems to imply that they are not there yet, but have a path forward that has promise. My memory of where they are is that they can compress, but are having unexpected thermal losses during compression (non adiabatic). Perhaps they now have some understanding of the loss paths.