Search found 794 matches

by Art Carlson
Tue Jul 08, 2008 4:49 pm
Forum: Theory
Topic: Carlson and Nebel
Replies: 108
Views: 48272

and the fact that Bussard was confused about the dramatic difference between electron density and neutral density Nah, I think that was just a typo. In one place he talks about neutral density and ionization, in another he has an incomplete sentence about electron density ratios and arcing. He prob...
by Art Carlson
Tue Jul 08, 2008 3:55 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

drmike wrote:Simon is right - "recirculation" is a bad term because it conjures up "circles".
"Bouncing" or "oscillation" makes a lot more sense.
Why not call it "cusp confinement", then?
by Art Carlson
Tue Jul 08, 2008 3:46 pm
Forum: Theory
Topic: Carlson and Nebel
Replies: 108
Views: 48272

Bussard felt that the addition of electrostatics made the polywell sufficiently different from the other cusp confinement systems. I think you need 4 coils in a tetrahedron as a minimum rather than a biconical form because you won't get the pseudo spherical E field portion. By "electrostatics" do y...
by Art Carlson
Tue Jul 08, 2008 2:07 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

Re: Excuse my ignorance

Let me make a stab at this, myself. The easy way to do fusion would be with a magic wall that totally reflects ions. The second best thing would be a magic wall that totally reflects electrons, because the ions won't dare to go much at all beyond the outskirts of the electron cage. The closest we c...
by Art Carlson
Tue Jul 08, 2008 1:53 pm
Forum: Theory
Topic: Carlson and Nebel
Replies: 108
Views: 48272

Art - your question was "what is the difference between regular cusp devices and polywell." If you'd have read Bussard's paper, you would have seen this: Thus much, if not all, of the historical work on "cusp confinement" is simply not of relevance to the problem in Polywell systems. Conclusion, pe...
by Art Carlson
Tue Jul 08, 2008 1:02 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

I am just pointing out that the picture on the table (pure electron plasma outside the cusps with a significant density) is not consistent. A polywell machine will certainly do something , and that something will certainly be consistent with the laws of physics. I don't think we understand yet what...
by Art Carlson
Tue Jul 08, 2008 7:59 am
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

Well, as I see it there are only two possibilities for keeping the potential in the outer region within the boundaries of the machine. Either there are ions there to balance the electron's charge, as you say, or the electron density is just not very high outside to begin with. And, like I already s...
by Art Carlson
Tue Jul 08, 2008 7:54 am
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

The cusps plugging with low-energy electrons was my interpretation of the behavior of PXL-1 (a closed-box machine) in one particular configuration. Dr. Bussard did not think that was correct, although he was certain some "two-color electron" effects would be important. Whatever was happening, PXL-1...
by Art Carlson
Tue Jul 08, 2008 7:42 am
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

Hmmmm? Bussard addresses that here: As previously noted, no Polywell can operate at all if arcing occurs outside the machine, between the walls and the machine, because this destroys the ability of the driving power supplies to produce deep potential wells. Thus the mean free path for ionization ou...
by Art Carlson
Tue Jul 08, 2008 7:12 am
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

If there are no ions, then the Poisson equation says the electrons will produce a potential of about nqd^2/epsilon_0 = 2.5e17*1.6e-19*0.1^2/8.85e-12 = 450 MV. (Check my math!) I think we can agree that we don't want that kind of voltage running around our little reactor, so we had better rather neu...
by Art Carlson
Mon Jul 07, 2008 8:54 pm
Forum: Theory
Topic: Where's the beef?
Replies: 132
Views: 39276

MSimon wrote:The power density of the sun is pitiful. Microwatts per cc of volume.
That was my point. Stars are a lousy example to follow.
by Art Carlson
Mon Jul 07, 2008 8:48 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

If you can't manage to hold them back electrostaticly That is the whole game. Have you been paying attention? Maybe you need to reread my original post, that also deals with this part of the game. The cusps may be small, but directly along the field line through the middle of a cusp, there is no co...
by Art Carlson
Mon Jul 07, 2008 8:41 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

Even outside the coils you will have a quasineutral plasma. Huh? That's not my understanding. I was under the impression the ions generally don't make it outside the device. Remember when Nebel said the Larmor radius was essentially infinite for the ions because they almost never see the B field? S...
by Art Carlson
Mon Jul 07, 2008 8:15 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 33890

Thanks, Indrek. That should give us a useful reference point. If we say that the outer limits of your diagram are the sort of dimensions we are thinking of for the outer box of a reactor, then we can say a field line in the cusp that is off-axis by about 1/30 of the coil radius will just reach the o...
by Art Carlson
Mon Jul 07, 2008 7:50 pm
Forum: Theory
Topic: Where's the beef?
Replies: 132
Views: 39276

My personal favorite longshot for fusion energy is the Field-Reversed Configuration. Field Reversed Configuration - you mean something like these guys are working with - A High Density Field Reversed Configuration Plasma for Magnetized Target Fusion - Intrator, Park and co - http://fusionenergy.lan...