Search found 3161 matches

by chrismb
Tue Dec 16, 2008 9:14 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

Let me say it again. There is a qualitative difference between a toroidal plasma and a polywell, related to the fact that the confining fields of a polywell are all convex to the plasma, while for a toroidal plasma some field lines are concave. hmm... the posts and papers I have read suggest that a...
by chrismb
Tue Dec 16, 2008 8:31 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

I'd curious why you don't believe there will be an excess of electrons in the centre. Because of the first page of this thread, and particularly Art Carlson's post of Mon Dec 15, 2008 4:28 pm, which no-one seemed to correct otherwise. I have been arguing in this thread that if there were a bunch of...
by chrismb
Tue Dec 16, 2008 7:22 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

Yep. That's how I saw it, but my misunderstanding has been corrected now. It does not appear that there is a ball of electrons, in excess of the ions around it, at the centre.
by chrismb
Tue Dec 16, 2008 6:51 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

I'm very familiar with the fusor, thanks. I just don't see how it relates to the Polywell [anymore - I thought I did, but no longer]. For DD, the fusor works by colliding fast ions with background neutrals along the beam paths. This is evidentially demonstrated now. For D3He, most fusion tends to go...
by chrismb
Tue Dec 16, 2008 6:04 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

Re: Bussard's perspective

The entire philosophy behind the polywell design was to make a grid-less fusor so you could scale up without burning out the grid That's what I thought originally when I started posting a few days ago. But, no, this does not seem to be the case. Some sort of potential gradient is formed by means I ...
by chrismb
Tue Dec 16, 2008 5:59 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

There's a big difference. The polywell plasma stays put but loses particles through the cusps. The toroidal plasma moves as a whole across the magnetic field. It's like the difference between putting a leaky balloon in a cage and putting a balloon in a bucket of water. If you estimate the time scal...
by chrismb
Tue Dec 16, 2008 2:22 pm
Forum: Theory
Topic: Total ion flux in a Polywell - disruption to magnetic field?
Replies: 38
Views: 22383

Chris, In a fusor the beams pass through the holes. Not all the holes have beams. It's a good and interesting point and I do not pretend to have a known answer other than the electric fields are not uniform and also that once a beam starts up it will, specifically, ionise more material along ITS pa...
by chrismb
Tue Dec 16, 2008 1:18 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

But we already know what happens when you put a plasma in a toroidal field without a rotational transform. It accelerates to the outside in short order As it would in a Polywell. What is the difference? This is a discussion of the mechanism of the process of charge transport. I see no difference wh...
by chrismb
Tue Dec 16, 2008 1:15 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

Also if a zero B field region is important there is no way to get that with a toroid. Why not? If the idea is that a core of electrons will push back cusped magnetic surfaces until they are smooth, why would they not also push back already smooth surfaces?? The argument was about taking up a surfac...
by chrismb
Tue Dec 16, 2008 1:13 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

What's to stop the plasma flowing around the toroidal axis and flopping and banging around like a tokomak again? Do you know something about stabilising turbulent flows that the legions of tokomak researches have missed? Why would it? It is a symmetrical system without directional bias (again, quit...
by chrismb
Tue Dec 16, 2008 1:08 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

Exactly. I am talking about a fast-aimed sphere versus a fast-aimed toroid. I am NOT talking about Polywell versus tokamak. The 'wiffleball' seems to be regarded as ideal - why? - because it is a continuous magnetic surface. So why not exploit the best magnetic surface possible for the fast-aimed id...
by chrismb
Tue Dec 16, 2008 12:45 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

It is possible you misunderstand my point. The issue is not 'the tokamak'. The tokamak is a device which exploits toroidal magnetic fields. It isn't *just* a toroidal field - you have to monkey around with other sutff aswell, like generate a toroidal current. I'm saying that the Polywell can also ex...
by chrismb
Tue Dec 16, 2008 12:30 pm
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

So.... I'm very sorry, but I don't get this at all. It is my improved understanding now, following the helpful replies to my earlier emails, that the principle means for accelerating ions in the Polywell is that you feed a mass of electrons and ions with more electrons so that it is off-neutrality a...
by chrismb
Tue Dec 16, 2008 11:34 am
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

"Held together"? Equilibrium is not a problem. Well, OK, my phrase was a little vague - 'held in place' was the intent. Bremsstrahlung power, if you can keep the plasma clean, is only a couple percent of the fusion power. (Of course, that's for the D-T fuel cycle. For the fairy tale fuel cycle of p...
by chrismb
Tue Dec 16, 2008 7:37 am
Forum: Theory
Topic: A few questions on Polywell facts and figures.
Replies: 63
Views: 33699

You seem rather knowledgeable. I'm surprised you missed that. I did miss it. Quite right! End of a long day.. I do keep making that silly mistake because I tend to think mostly about fast ions into lab-stationary ones, the collision energy for which is a half of the fast ion's energy (because there...