The race is on, Polywell vs Focus Fusion

[Helius]

Otherwise why not go back to his Los Alamos job of extending POPS?

To clearly define the impasse so that no one falls for it? Not that that's my hunch either.

Right on.
Success/failure of the experiments is not the same as success/failure of the device as it's conceived here. Our interest in this regimen is not misdirected in terms of the science. What are the details? If Q<1 then so what? What is the internal dynamics of this machine? This is great stuff. If waiting means further depth in this research, then we will wait, and learn more later.

[TallDave]

Ha, no. Focus fusion has very basic scaling and continuous operation problems.

Ha, yes. Are you really suggesting that if fusion experiment A produces fusion neutrons and fusion experiment B does not that experiment A is not ahead of B??

Not sure what you're talking about. IEC has been producing fusion neutrons since the mid-twentieth. Polywell was producing fusion neutrons in the early to mid-1990s.

But no, that is not a good measure of how far a fusion tech is from commercial applications. Fusion neutrons are trivially easy to produce as compared to the manifold challenges of designing an economic fusion reactor.

Either it's a fusor or it's not: If it is a fusor, then remember that the fusor has been discarded as anything but an experimental tool.

Lots of things have gone from experimental tools to extremely useful technology.

But maybe not after it has been discarded as an experimental tool. Name an experimental tool that has been studied and experimented on for 50 years to improve it, without any practically demonstrated improvement whatsoever, but that then goes on to be useful. Name it.

Fusors have not been discarded; they are used commercially and have seen improvements over the decades. And of course Polywell is a huge improvement.

http://en.wikipedia.org/wiki/Fusor

I think your conclusions here are based on some basic misinformation.

But yes, discarded ideas and tools have come back and turned out to be incredibly useful many, many times in the history of scientific advance. The most obvious example is that of a moving Earth, which was proposed and dismissed by the ancients then abandoned for thousands of years, but turned out to be very useful.

People generally don't appreciate just how messy the process has been. Boltzmann was driven to suicide by attacks on his atomic theory of matter from proponents of phenomenological thermodynamics.

[chrismb]

Fusors have not been discarded

I was just quoting MSimon. Besides, I think you've missed the point I was trying to raise; that DPFs are 'known commodities' and Polywells are not. I have not said DPFs are better or otherwise, just that they are more advanced as a point of fact. That other experiments will overtake the current fare of tokamaks, z-pinches, ICF experiments is something I guess we're all keen to see - not for dislike of any of these but just that they've been blocking the front of the race-course for several decades and we'd like to see the dwarf get a fair crack at the straight-ahead - though DPF is, nonetheless, just nosing ahead of Polywell at this particular moment in that race.

[TallDave]

I don't see where MSimon said fusors were discarded as a tool. In any case, it's not true.

though DPF is, nonetheless, just nosing ahead of Polywell at this particular moment in that race.

I don't see any basis for this statement.

Perhaps it was this?

Plus the material capacity to tolerate the enormous total amount of energy output, charge flux and enormous demands on a vacuum system that would occur in the net-power output scaled version. In fact, in many analogous ways to the problems raised for DPF?

The alpha sputtering problem was addressed. The vacuum problem does not appear to be serious. I haven't seen any evidence from FF that the electrode erosion is addressed.

DPFs are 'known commodities' and Polywells are not.

Not an advantage, as the things we know about DPFs suggest they won't work as a reactor, and there are some unknowns that may not fall out favorably. They are talking about a thousand pulses a second for a year. They are depending on gigagauss plasmoid fields to suppress x-ray cooling.

WB-8 will tell us a lot about whether the unknowns follow Polywell theory. If loss scaling is favorable, as predicted, then Polywell is easily the best shot at economic fusion power.

Maybe Lerner has answers for FF's problems. I doubt it, though, since he was kicked off Wikipedia for repeatedly deleting the issues Art raised there rather than addressing them. If they start scaling to something approaching a reactor, I'll be interested.

The market seems skeptical.

https://www.intrade.com/index.jsp?reque ... nID=684780

At best, based on their research plan, I think we can say FF is a few years behind Polywell.

http://focusfusion.org/index.php/site/a ... arch_plan/

[Carl White]

Maybe Lerner has answers for FF's problems. I doubt it, though, since he was kicked off Wikipedia for repeatedly deleting the issues Art raised there rather than addressing them.

Not that I'm offering an opinion on the prospects for FF's success, but being kicked off of Wikipedia doesn't indicate much of anything, given the level of politics that is happening at the editorial level there.

[chrismb]

I don't see any basis for this statement.

Watch lerner's talk to Google. In it, you will see him drawing on many actual measured experiments and trying to get a handle on data pulled out of actual experiemental results. By his own admission, focus fusion has many unknowns (and though he says there is theoretical progress I am not well convinced by that).

His future designs are based on many current, contiguous, 'self-consistent' [viz - not 'nuanced'] pratical measurements.

Do I suck up all of that as some form of ready truth and proof of design? No, of course not, but the 'basis' of his claims are empirical extrapolations, not an esoteric combination of theory of unproven scaling laws.

Lerner concludes focus fusion is fit for net-energy by extrapolation of actual measurements. Polywell's claim to net energy is theoretical extrapolation of theory. This is my basis for saying it is nosing ahead (though I am not claiming either will work or fail, I simply hold experimental material with higher weighting).

DPFs can measurably kick out 100's of billions of neutrons per pulse in DD experiments (and not just Lerner's). How about we rate it just on pure numbers of neutrons? That's still a gnat's fart worth of stuff and doesn't prove the dwarf can't overtake, but it holds water right now, at this particular moment. 18 months hence, we may or may not know different.

Claiming erosion of the electrode doesn't really cut it either, as a critique over and above Polywell's own problems. The claim is that the fusion product will all 'beam' out of the device, axially to the hollow electrode. This would require sufficiently elevated magnetic fields that current test devices do not manage, so a comparison with those is unequal. This is no bigger a claim than some of Polywell's 'beaming' claims that will assist in the evacuation of helium ash.

I simply say; may there be many winners in this race, all could win a podium place for there is no limit on how many can fit on that podium. But right now it's not an argument you can 'win' on behalf of Polywell, however much bickering there is to try to talk it up.

[MSimon]

Do I suck up all of that as some form of ready truth and proof of design? No, of course not, but the 'basis' of his claims are empirical extrapolations, not an esoteric combination of theory of unproven scaling laws.

And the solution to the erosion problem when pumping 1 GJ through electrodes is?

The power scaling laws for Polywell are standard physics. The unknown is the laws of loss scaling. So far the guys funding the experiments are satisfied with the progress in defining the laws of loss scaling. So much so that they are adding funds to extend the project. Not as good as real data. But not "no data" either.

The question for Polywell is: how do losses scale.

For FF the question is: where will we find materials that can function in the desired regime.

The FF guys have a harder problem.

[chrismb]

And the solution to the erosion problem when pumping 1 GJ through electrodes is?

..presumably [I'm not arguing Lerner's case, I'm just devil's advocate here] there is no erosion problem. Why do you say there is? Because lower mag-field variants show erosion? Why would higher field variants be the same, if the ion emissions are more tightly bound?

The power scaling laws for Polywell are standard physics.

...if Polywell works as it is claimed, but may not scale as expected if the presumption of mechamisms are not as expected.

The FF guys have a harder problem.

...to reach net fusion output, maybe that's true, maybe not, but right now they have more neutrons to show for their troubles than Polywell.

If it were a football game and neutrons were footballs, it'd be "Polywell, 26 thousand; DPF, several hundred billion". Seems a one-sided game at the moment, despite your protestations of a superior speculated future for Polywell. That's not addressing the present-tense of the subject line, is it?

Why not start a new thread "The race is going to be on one day, Polywell vs Focus Fusion"

[chrismb]

And the solution to the erosion problem when pumping 1 GJ through electrodes is?

I just took a quick 'slide' through Lerner's google talk. He's claiming 13kJ would be required to achieve each net energy pulse, and he's talking 300/sec, so that makes an input of some 4MW, I guess. Still a large amount, question is; how much energy is coupled into the plasmoid. Again, answered. He seems to be thinking in the 80% range, so could a cooled electrode cope with 800kW input energy? Still sounds a tall order to me, but more 'engineering challenge' than outright impossible.

He seemingly [already] has answers to such questions as you pose, and claims DPF actually exploits instability so there are fewer 'unknowns' in that regard that he is relying on 'coming good', unlike Polywell. My rating purely based on quantity of unanswered questions: DPF plausibility, 30%; Polywell 10%.

[MSimon]

chris,

FF has not even addressed the erosion problem. The only mention is a picture.

You assume making FF bigger will fix the erosion problem while doing the same for Polywell will make things worse. Real world evidence with real electrodes is the opposite. So far nothing definite (experimental) can be said about Polywell.

I will grant that FF MAY be ahead in neutrons if you don't count Farnsworth.

Polywell has the advantage re: scalability (higher B fields make everything better).

[MSimon]

And the solution to the erosion problem when pumping 1 GJ through electrodes is?

I just took a quick 'slide' through Lerner's google talk. He's claiming 13kJ would be required to achieve each net energy pulse, and he's talking 300/sec, so that makes an input of some 4MW, I guess. Still a large amount, question is; how much energy is coupled into the plasmoid. Again, answered. He seems to be thinking in the 80% range, so could a cooled electrode cope with 800kW input energy? Still sounds a tall order to me, but more 'engineering challenge' than outright impossible.

He seemingly [already] has answers to such questions as you pose, and claims DPF actually exploits instability so there are fewer 'unknowns' in that regard that he is relying on 'coming good', unlike Polywell. My rating purely based on quantity of unanswered questions: DPF plausibility, 30%; Polywell 10%.

All well and good. And yet Polywell is turning away money and FF is begging. So maybe your valuation is at variance with the market.

BTW what he says at Google Talk and what he presents on his graphs are at variance - at least if he was talking pB11 in both places.

[Betruger]

[...]

Begging for a wager.

[chrismb]

I will grant that FF MAY be ahead in neutrons if you don't count Farnsworth.

Ah! Some concession breaking through!!!

Farnsworth also tried to confine electrons centrally (electrostatically). As far as I am aware, he did achieve electron confinement. But you do know he never made any neutrons that way, I presume you know this? Neutrons only flowed when the grid was a fixed wire structure, so, no, I don't count Farnsworth's work as demonstrating Polywell - quite the reverse, in fact.

Plus a) no-one has reproduced Farnsworth's 10E12/sec claims, though you could just buy enough NSD neutron generators and call it a fusion experiment(!), and b) focus fusion hasn't been the biggest DPF experiment. I don't know what the biggest was, but didn't Los Alamos get 10E12/pulse from DD (which would be 10E14 if they ran DT like Farnsworth) with DPF-6 for a 400kJ input? Makes 26,000 look like chicken sh*t, doesn't it??

[chrismb]

[...]

Begging for a wager.

...on a race between a dwarf on a penny farthing and a small kid on a pogo stick that's too big for him to compress the spring? Nah! I'll keep my money, for now!!....

[MSimon]

I will grant that FF MAY be ahead in neutrons if you don't count Farnsworth.

Ah! Some concession breaking through!!! :wink:

Farnsworth also tried to confine electrons centrally (electrostatically). As far as I am aware, he did achieve electron confinement. But you do know he never made any neutrons that way, I presume you know this? Neutrons only flowed when the grid was a fixed wire structure, so, no, I don't count Farnsworth's work as demonstrating Polywell - quite the reverse, in fact.

Plus a) no-one has reproduced Farnsworth's 10E12/sec claims, though you could just buy enough NSD neutron generators and call it a fusion experiment(!), and b) focus fusion hasn't been the biggest DPF experiment. I don't know what the biggest was, but didn't Los Alamos get 10E12/pulse from DD (which would be 10E14 if they ran DT like Farnsworth) with DPF-6 for a 400kJ input? Makes 26,000 look like chicken sh*t, doesn't it??

And yet Polywell is getting funds and FF is begging.

Evidently people with real money to spend have evaluated the chances differently.