Search found 794 matches
- Thu Jul 03, 2008 7:50 pm
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
The latest picture from Carter is wierd. I don't understand it at all, especially since he seems to be using square coils, where I would expect such effects to be smaller. Is there a significant difference between the electron trajectories and the field lines? Can you give us a picture of the whole ...
- Thu Jul 03, 2008 2:10 pm
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
I did this plot several months back of individual electron trajectories. As you can see the line cusps receive nearly zero flux. Only one path actually penetrated the line cusp from all the trials, it myst hit the cusp directly or the internal structure of the magnetic field funnels any electrons h...
- Wed Jul 02, 2008 7:10 pm
- Forum: Theory
- Topic: Carlson and Nebel
- Replies: 108
- Views: 80188
impression that Bussard erroneously thought he could turn a bi-conical cusp into a configuration with only point cusps by adding more coils That seems like a good summary of the concept. So I gather your main contention (at the moment) is that this won't actually produce all point cusps: it will le...
- Wed Jul 02, 2008 3:49 pm
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
Re: Why is polywell supposed to be better than cusp confinem
Of course, compared to a cusp machine, the polywell may also get some credit for density peaking and recirculation (although I will question both of these effects), but it seems certain that line cusps will be a killer, and it seems pretty sure to me that line cusps are unavoidable." To me, from a ...
- Wed Jul 02, 2008 2:05 pm
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
I'm sorry I don't have time to respond immediately to all the responses. In particular I would like to talk in numbers concerning the consequences of a super thin current layer. But I'll make a couple quick comments right away. Since Mike Holmes thinks hanelyp raised some interesting points, I will ...
- Wed Jul 02, 2008 6:03 am
- Forum: Theory
- Topic: Carlson and Nebel
- Replies: 108
- Views: 80188
Art - the answer to the first salvo was homework: # Bussard, Robert W., King, Katherine E., "Electron Recirculation in Electrostatic Multicusp Systems: I-Confinement and Losses in Simple Power Law Wells," 1991, EMC2-0491-03 Yeah. I got the assignment and finished it before writing my latest tirade....
- Tue Jul 01, 2008 8:41 pm
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
Re: Why is polywell supposed to be better than cusp confinem
More basically, it looks like the polywell should be classed as high beta cusp confinement. I'm not familiar with the details, but I know that this idea is as old as the hills and was rejected very early. Why is the polywell supposed to be better? Possibly it is the idea of using point cusps instea...
- Tue Jul 01, 2008 7:47 pm
- Forum: Theory
- Topic: Carlson and Nebel
- Replies: 108
- Views: 80188
The man in charge of this spectacle claims they have achieved high power and have clearly not rejected the idea. That, if mr. Carlson cannot fire a little more convincing salvos at it, ought to be enough to justify some polywell daydreaming. Me? I've been holding back to give somebody a chance to a...
- Fri Jun 27, 2008 8:54 am
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
Re: Why is polywell supposed to be better than cusp confinem
There used to be a Polywell wiki but it never saw much traffic and now it is gone. Too bad. I've been thinking that this BB format is sometimes hard to follow, and it's easy for content to get lost (and therefore at best rehashed). A wiki format with the Wikipedia rules against original research re...
- Fri Jun 27, 2008 8:39 am
- Forum: Theory
- Topic: Carlson and Nebel
- Replies: 108
- Views: 80188
Pardon me if I have it wrong, but I thought the "twisting" motion was produced by currents internal to the plasma, and not a product of the external magnets. If so what then keeps the internal current stable and in the "center". Yes, the twisting in a tokamak comes from internal currents. (In a ste...
- Thu Jun 26, 2008 4:42 pm
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
Then you would be Rick. Seems appropriate to use first names among scientists and also for an internet forum. Call me Ishmael. My thesis advisor was George Vlases. The LANL folks are more likely to know Fred Ribe. My actual thesis experiment was done at Mathematical Sciences Northwest, whatever it m...
- Thu Jun 26, 2008 1:30 pm
- Forum: Theory
- Topic: Carlson and Nebel
- Replies: 108
- Views: 80188
Concerning questions from several authors about tokamak physics: The radial electric field in a tokamak is a very important parameter that is thought to influence the confinement by up to a factor of two. What's important is actually the gradient in the field (the curvature in the potential). The pi...
- Thu Jun 26, 2008 1:19 pm
- Forum: Theory
- Topic: Carlson and Nebel
- Replies: 108
- Views: 80188
- Thu Jun 26, 2008 8:31 am
- Forum: Theory
- Topic: Why is polywell supposed to be better than cusp confinement?
- Replies: 74
- Views: 52800
Why is polywell supposed to be better than cusp confinement?
Greetings! After some interesting though inconclusive exchanges with some of you on cosmiclog.msnbc.msn.com, I thought it would be fun to drop by here. Allow me to introduce myself. I have a Ph.D. in plasma physics from the University of Washington, where I worked on Field-Reversed Configurations. A...