the problem of pumping electrons into the Polywell

[CharlesKramer]

The most current FY 2012 update states, "The Navy is funding EMC2 an additional $5.3 million over next 2 years to work on the problem of pumping electrons into the Polywell. Big new pulsed power supply to support the electron guns (100+A, 10kV)...." https://www.facebook.com/groups/10194280667/

I'm not a physicist, but the reference to the "problem of pumping electrons into the Polywell" is not encouraging. This has been the sad history of fusion to date -- attempting to correct a failed (not positive energy) system by boosting temperature and/or boosting particle density as though supercharging a car.

What happened to Bussard's claim in his speech on Google Talks that he *already* licked the problem of energy loss -- something he determined just as his funding ran out when reviewing data after the fact from the run that burned out his last device?

[GIThruster]

I don't understand your complaint. In order to have a viable commercial device, the numbers of fusion events needs to be far higher. If what they need to begin exploring this is a better source of electrons, then that's what they need. This has nothing to do with Bussard's claim to have licked energy loss. It has to do with modeling what a commercial grade reactor ought to perform like. It seems to me in order to begin to get a real handle on future systems, it makes sense to dump LOTS of electrons into the well and see how they perform at densities much closer to what will be required for commercial activity. This is a very cheap and easy step compared to building a new poly with heat recovery.

Baby steps are called for here.

Why would you think this has anything to do with the energy loss issue?

[KitemanSA]

The issue with the electrons is that anything that is really really good at keeping them in would also tend to be really good at keeping them out.

Sounds like what is needed is a set of very small holes in the magnetic field which, as it happens, is exactly what the X-Cusps would provide.

Hmmm. Dr. Park, are you listening?

[choff]

I think a good analogy would be blowing up a balloon, the more air inside, the harder it gets to pump more in, that doesn't mean it's leaking air though.

[MSimon]

CharlesKramer,

Losses go down as size goes up. So I take it you are arguing in favor of building a full size machine instead of wasting money on electron guns? If so - I agree.

[KitemanSA]

Using your analogy, their problem is that they keep trying to blow the air in THROUGH the rubber. What they SHOULD do is blow the air in through the hole in the stem (X-Cusp).

Of course they would need to make a balloon with stems.

[CharlesKramer]

Baby steps are called for here

Harrumph!

Bussard in his Googletalk is quite smug -- all those successful fusion devices out there (meaning stars) "and not one of them is torroidal."

Very funny, but Bussard gave the impression he'd DONE it -- figured out how to make a practical fusion machine, jumping the last real barrier -- and prevented from immediately showing that to the world only because funding ended and his equipment burned out. Consistent with that, EMC2's website depicts a drawing (complete with human figure to illustrate size) of its idea of a Polywell scaled up -- the Demo version of a practical energy source.

Princeton's Spitzer in the 1950s also planned a demo version of his stellator; the forth in a series of prototypes -- but he never got there.

Ditto Tokamak which produced results that were lousy, but still vastly better than Spitzer's stellarators. A lot of baby steps followed: neutral beam injection, and radio frequency heating.... and more baby steps to ITER, just the latest in 50 years of iterations.

Forgive me for tossing those terms around -- I'm the first to acknowledge my understanding of them is extremely limited. But what I take away from all this is:

-- EMC2 should not be depicting a demo device on its website. It may be making progress, but it's still mucking around in a very speculative experiment.

-- I'm all in favor of continued funding for Polywell and other speculative fusion devices, but fusion history teaches "that last step is a doozy."

With all these fusion devices the added energy -- so far -- has not achieved its expected result. Energy density may improve, but the losses increase nearly as fast.

CK

[CharlesKramer]

I'm very pro-fusion, and very pro-spending in speculative science. I wish NASA would bring back (and more seriously fund) it's Breakthrough Propulsion Physics project http://www.grc.nasa.gov/WWW/bpp/

Losses go down as size goes up. So I take it you are arguing in favor of building a full size machine instead of wasting money on electron guns? If so - I agree.

I don't have the chops to evaluate that -- but the statement sounds like Bullwinkle's sincere promise to pull a rabbit out of his hat -- and each time being suprised by something else.

Why is no one listening to you (the Navy, or private funding)? The $50m or whatever it would cost seems worthwhile measured against the potential benefit.

Isn't your statement as speculative as every fusion researcher who for 50+ years planned a demo model, but got roadblocked by unexpected realities? The Farnsworth Fusion makes Polywell even older than Spitzer's stellarator -- 60 years of believing the technology is "close."

CK

[GIThruster]

The $50m or whatever it would cost seems worthwhile measured against the potential benefit.

It always seems worthwhile when its someone else's money.

Private investors need to see not only a sure thing, but one they can expect will give them a huge ROI ins 5 years or less. The Poly is not going to be a commercial item in less than 5 years so private investors are not going to be interested.

At least its got DoD funding. If M-E research had 1/10 the funding the Poly receives we'd have plans for deep space exploration vehicles that don't use propellant.

[CharlesKramer]

The Poly is not going to be a commercial item in less than 5 years so private investors are not going to be interested.

That's probably true.

But didn't you have different expectations 4 years ago? Rightly or wrongly I did.

- Charles

[GIThruster]

I have never had expectations that entailed a timeline. I expect there to be snags and I have never seen anyone keep to their predictions. I would say I did expect more open science and better distribution of data. The new EMC2 seems to be much more conservative and much less open science. I guess now that they seem to have secure funding they can afford to be that way, but Bussard would roll over in his grave if he knew how the data has been managed since his demise.

Lawrenceville Plasma Physics is much more like what Bussard had in mind.

[ladajo]

I would say it is not EMC2 that is driving visibility control. I would say it is the navy, specifically ONR. The oft stated sponsor controls.

[rcain]

@CharlesKramer - really imnteresting/timely thread you've started here - so thanks for that. Also excellent link:: from which (as well as some half decent discussion), this link ::

http://newenergyandfuel.com/http:/newen ... n-thought/

- detailing work which i'd read about elsewhere (FocusFusion site iirc), and which i'm pretty certain is cited in another thread here also - but, i don't recall reading this exact article before. of note to me::

...Its worth noting that part of the funding for this research came from a US Department of Energy grant number DEFG02-97ER41033 and Tri Alpha Energy Incorporated itself who has strong motivations to get accurate numbers...

also, that Duke University (amongst others) was responsible for the work.
notably, it was 'theoretical' confirmation/detailing, rather than experimental - from what i understand.

its certainly good to see pB11 pushed up the agenda/into the scientific eye a bit. if only greater political will and resources would follow.

as to 'getting electrons in' - as Kiteman says already - back to the old 'discussions' about ambipolar cusp flows (or not) - for a start - see the old threads featuring Art Carlson in particular - has a view that something of this nature might defeat us. (but he was pretty 'pessimistic' imvho).

then there's the whole (possibly related) 'cusp-plugging' phenomenon - which also works both ways - then on top of that the scaling factors - noting what MSimon has suggested already, being (in general) true - there are other 'engineering' difficulties that also come with scaling up - one of them being maintaining precision and reliability with power, budget and available time and technology.

Personally, I still have 'high' confidence that they will bust the 'injection issue' - though to maintain the overall %Q, i suspect they will need to crack the problem with stealth and smart thinking/innovation rather than 'brute force' (keV's?). Again, as Kite has suggested, using corner X-cusps by preference (maybe they are already?), else more injectors, (hence cusps, hence higher order polyhedron, (eg: the favoured dodecahedron) 'trickling' in rather than blasting.

Maybe 'phase' the magfields (magrid coils) and provide some (non-reflexive) 'chirality' to the cusps - maybe - some other 'asymmetry', (convection, pressure...?)... just thinking aloud.

i also think a lot more 'detailed' research needs to be carried out concerning 'cusps' and what happens in them, at them, around them - it was always known to be a 'debatable' topic - here's one reason why.

btw: @Ladajo - quoted on that Facebook page CharlesKrammer links - is quoted:

...
The most current FY 2012 update states, "The Navy is funding EMC2 an additional $5.3 million over next 2 years to work on the problem of pumping electrons into the Polywell. Big new pulsed power supply to support the electron guns (100+A, 10kV)...."
...

am i getting confused here, or is Stan Komperda? - I thought that 5.3mil$ was last years bung (and sure, injectors were (a late) part of it) - or did i miss something...?! (there was 'coincidentally' i recollect, announcements from EMC2.Navy that injection was (still) a current/heightened issue - but i dont recall any new funding off the back of that). am i going completely mad?

(shome mishtake surely)

[ladajo]

The plus up was to cover the additional work. Of the 5.3 they have so far invoiced 1.2.
As for the timeline, that is up for some debate. But I do not think 2 years is correct.

[hanelyp]

Possible means of getting electrons in:

- inject along the right magnetic field line to pass through the cusp. A matter of position and velocity of injection.

- neutral gas stripping. Requires supplemental heating, and is more dependent on annealing.

- negative ions. Pass through cusps about as well as positive ions, then stripped by collisions.