Without annealing, upscattered ions in a polywell escape the electrostatic primary confinement, and are prevented from prompt escape only by the much lossier cusp magnetic confinement.
Annealing is largely explained by the greater collision cross section at low energy.
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I take that as a compliment. Call me Peter.D Tibbets wrote:Arguing with chrismb is like arguing with a rock.
Dan, you have the evangelistic zeal of a Jehovah's Witness on my door-step. You are as persistent, yet courteous, as any of those I have met. I am also quite sure you have about the same level of justification for your claims.
The way I see it is that either Dan, who has done the ferreting out of multiple lines of data, is correct, and the fact that EMC2 is still working on Polywell with a significant pot of money is EVIDENCE that there is somethng worth investigating;
OR
Chris, who has sat around and whined a lot and shown some calcs that Polywell can't work as a Tokamak, is correct and the fact that EMC2 is still working on Polywell with a significant pot of money is EVIDENCE that the entire group of individuals involved are venal lying scumbags.
I choose Dan.
OR
Chris, who has sat around and whined a lot and shown some calcs that Polywell can't work as a Tokamak, is correct and the fact that EMC2 is still working on Polywell with a significant pot of money is EVIDENCE that the entire group of individuals involved are venal lying scumbags.
I choose Dan.
Well, some might regard the Pope as a venal lying scumbag. But on the whole even if you don't believe in God and therefore think the Catholic Church is extracting billions in subscriptions from its followers , who have been persuaded that the Pope is truly God's representative, without any good reason I don't think an atheist would call him such. And I don't call EMC2 such either. That is a total misrepresentation of what I have said. It might even be libelous.KitemanSA wrote:The way I see it is that either Dan, who has done the ferreting out of multiple lines of data, is correct, and the fact that EMC2 is still working on Polywell with a significant pot of money is EVIDENCE that there is somethng worth investigating;
OR
Chris, who has sat around and whined a lot and shown some calcs that Polywell can't work as a Tokamak, is correct and the fact that EMC2 is still working on Polywell with a significant pot of money is EVIDENCE that the entire group of individuals involved are venal lying scumbags.
I choose Dan.
If I believe someone is deluded and others have also joined in the delusion sufficiently that they hand over other people's money [who might not be so easily deluded, if only they actually had direct control over their money], well, you can say my belief is wrong if you like, but saying I have called them venal scumbags is absurd - in the same way that saying "all atheists call the Pope a venal scumbag" is absurd just because they don't believe he is God's representative.
Fine. Just remember we were talking about evidence here. Being able to get funding for an idea have never been evidence that the idea is working, and/or true. As per example, people have been funding the Catholic Church since its inception. That proves nothing - unless you want to believe it proves something. This is why Dan's script reads to me like that of a religious convert.
I do feel more and more out of place here. I guess it's what it must feel like if an atheist goes visit a church, Mosque, Synagogue, whatever.
I tell you what, I'll leave you and Estragon to carry on with your sacraments. I hope Godot turns up for you.
I do feel more and more out of place here. I guess it's what it must feel like if an atheist goes visit a church, Mosque, Synagogue, whatever.
I tell you what, I'll leave you and Estragon to carry on with your sacraments. I hope Godot turns up for you.
Just to continue this topic drift. I will reemphasize my perspective. Chrismb is correct in being a sceptic as he has not been shown the data on the various processes that all have to work for the Polywell to be a success. My objection, though is that he is actively pessimistic, and presents arguments that support his pessimism. In subsequent debate (at least from my perspective) these criticisms are shown to not apply or at least are open to several interpretations.
It is basically a matter of perspective, is the glass half empty or half full. The same applies to the Tokamak approach, except the argument is whether the glass is 3/4th full or 1/4th empty. The costs and time necessary to determine the proper perspective of both approaches is what separates them and leads to lots of entertaining, and occasionally educational debates.
hanelyp's brief and concise description of annealing is good. But I cannot resist confusing the issue some. Many arguments against the Polywell seem to be based on absolutes and static viewpoints. As Bussard complained, the dynamics of the machine have to be in the forefront to understand the machine and how it overcomes the individual challenges.
Annealing of course is not absolute, it decreases the energy spread to a small degree. The saving grace is the short times involved . Annealing would not help if the ions had to dwell in the machine for hundreds of seconds, or probably even tenths of a second before fusing. But it is good enough to limit the thermalization (at least full thermalization) for a few millliseconds and perhaps a few thousand ion passes. Note this all depends on the Wiffleball effect and resultant density gains. Bussard was satisfied with this since experiments in the 1990's. Nebel was a little more vague concerning his impression with WB7. What was frustrating Bussard till WB6 was the electron losses through cusps and associated exposed surfaces- ie: the confinement portion of the triple product. Whether that is solved is what I see as the major physics challenge for the Polywell. Issues of output scaling, and thermalization issues will determine how much smaller than a Tokamak the machine might be. There are all sorts of other issues like cooling, magnetic field strength considerations, direct conversion, etc. But the physics of the fusion process has been solved. This was Bussard's conclusions and I have not seem seen any non contested arguments that disproves it. As Chrismb has repeatedly stressed, it also has not been proved with hard data that is available to a wide audience.
The Pollywell is indeed dismal at ion confinement compared to a Tokamak, or probably any other cuspless confinement scheme. But, talking of the Triple Product again; the Polywell (through the Wiffleball effect) is claimed to be much better at concentrating the ions to much higher densities. It is intermediate between Tokamaks and implosion schemes like DPF, or hydrogen bombs. In them, the confinement times are extremely short, but this is compensated by even greater densities.
The Tokamak schemes seem to concentrate on confinement, whole DPF , Laser confinement fusion, and bombs concentrate on density. The Polywell is a compromise between the two.
It occurs to me that that an analogy between a Tokamak and a Polywell may be helium balloons and hot air balloons. One holds onto buoyant helium within a closed bag for long periods of time. The hot air balloon has a large hole in it, but it feeds hot air in through this hole faster than the 'contained' air can cool and leak out. Both balloons can maintain a buoyant state long enough for useful purposes, though the mechanism for maintaining the buoyant state is different. In a sense the helium balloon is an ignition machine, while the hot air balloon is not an ignition machine, but more like a Polywell.
Dan Tibbets
It is basically a matter of perspective, is the glass half empty or half full. The same applies to the Tokamak approach, except the argument is whether the glass is 3/4th full or 1/4th empty. The costs and time necessary to determine the proper perspective of both approaches is what separates them and leads to lots of entertaining, and occasionally educational debates.
hanelyp's brief and concise description of annealing is good. But I cannot resist confusing the issue some. Many arguments against the Polywell seem to be based on absolutes and static viewpoints. As Bussard complained, the dynamics of the machine have to be in the forefront to understand the machine and how it overcomes the individual challenges.
Annealing of course is not absolute, it decreases the energy spread to a small degree. The saving grace is the short times involved . Annealing would not help if the ions had to dwell in the machine for hundreds of seconds, or probably even tenths of a second before fusing. But it is good enough to limit the thermalization (at least full thermalization) for a few millliseconds and perhaps a few thousand ion passes. Note this all depends on the Wiffleball effect and resultant density gains. Bussard was satisfied with this since experiments in the 1990's. Nebel was a little more vague concerning his impression with WB7. What was frustrating Bussard till WB6 was the electron losses through cusps and associated exposed surfaces- ie: the confinement portion of the triple product. Whether that is solved is what I see as the major physics challenge for the Polywell. Issues of output scaling, and thermalization issues will determine how much smaller than a Tokamak the machine might be. There are all sorts of other issues like cooling, magnetic field strength considerations, direct conversion, etc. But the physics of the fusion process has been solved. This was Bussard's conclusions and I have not seem seen any non contested arguments that disproves it. As Chrismb has repeatedly stressed, it also has not been proved with hard data that is available to a wide audience.
The Pollywell is indeed dismal at ion confinement compared to a Tokamak, or probably any other cuspless confinement scheme. But, talking of the Triple Product again; the Polywell (through the Wiffleball effect) is claimed to be much better at concentrating the ions to much higher densities. It is intermediate between Tokamaks and implosion schemes like DPF, or hydrogen bombs. In them, the confinement times are extremely short, but this is compensated by even greater densities.
The Tokamak schemes seem to concentrate on confinement, whole DPF , Laser confinement fusion, and bombs concentrate on density. The Polywell is a compromise between the two.
It occurs to me that that an analogy between a Tokamak and a Polywell may be helium balloons and hot air balloons. One holds onto buoyant helium within a closed bag for long periods of time. The hot air balloon has a large hole in it, but it feeds hot air in through this hole faster than the 'contained' air can cool and leak out. Both balloons can maintain a buoyant state long enough for useful purposes, though the mechanism for maintaining the buoyant state is different. In a sense the helium balloon is an ignition machine, while the hot air balloon is not an ignition machine, but more like a Polywell.
Dan Tibbets
To error is human... and I'm very human.
Thats right, and those were the only three neutrons ever and they just HAPPENED to hit the quite small and widely scattered detectors. Its a miracle! We have seen to ONLY three neutrons EVER produced by WB machines in the HISTORY of the world.
No, wait. Didn't they do several tests in that week in November? I guess none of them produced neutrons. Only one of the tests produced neutrons and there were only the three and the detectors caught them all.
And obviously, despite being told that the WB7 was consistent with WB6 there were no neutrons then either so the Navy threw money at them for no results.
Yup, obviously three and only three neutrons.
Idiots.
No, wait. Didn't they do several tests in that week in November? I guess none of them produced neutrons. Only one of the tests produced neutrons and there were only the three and the detectors caught them all.
And obviously, despite being told that the WB7 was consistent with WB6 there were no neutrons then either so the Navy threw money at them for no results.
Yup, obviously three and only three neutrons.
Idiots.
Once again, three neutrons detected in WB6 (per test) is derided . How many times does it need to be pointed out that WB6 was only one of a series of machines that produced data, and that neutron counts were only one of a fist full of different measurements that were used to characterize the physics within the Polywell. As Bussard pointed out , the significance of WB6 was the changes that improved electron confinement and recirculation. This eased the input power necessary to maintain deep potential wells, and (I think) the power to maintain a Wiffleball. Though I cannot present conclusive evidence, I believe the output side of the problem was not the issue. It had been characterized in earlier machines. It was the energy input requirements that was resolved by WB6.
I again point out the several B field strength tests that addressed (at least at small scales) the magnetic scaling. The solid copper block machine that produced over a million neutrons per second in a small volume, B field of ~ 3 T and at a ridiculously low potential well of ~ 300 Volts is what impresses me from a fusion output perspective.
Dan Tibbets
I again point out the several B field strength tests that addressed (at least at small scales) the magnetic scaling. The solid copper block machine that produced over a million neutrons per second in a small volume, B field of ~ 3 T and at a ridiculously low potential well of ~ 300 Volts is what impresses me from a fusion output perspective.
Dan Tibbets
To error is human... and I'm very human.