magrid configuration brainstorming

Discuss how polywell fusion works; share theoretical questions and answers.

Moderators: tonybarry, MSimon

Solo
Posts: 261
Joined: Fri Jun 29, 2007 12:12 pm
Location: Wisconsin
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

magrid configuration brainstorming

Postby Solo » Fri Nov 09, 2007 2:56 am

What other variations of magrids might work besides a polyhedron? How about two coils parallel, with either same or opposite direction of B-field, or a single coil?

The single coil would be like the Levitated Dipole Experiment, except that electron transport outward should be minimized by the charge of the coil.

The north-north or south-south configuration with two coils would be kinda like a polywell, but with one big line cusp and then the normal coil-center cusps. It might be able to create a wiffle-ball.

The north-on-south config would be a magnetic bottle or magnetic mirror. This has demonstrated confinement ability; a problem might be that the ions might be confined as well. This and the above set-up both resemble the U. of Wisc. beam-bunching operation with the coil position.

These would all have to rely heavily on recirculation; the single-coil is the ultimate recirculator. They might not have sufficient confinement to achieve a high electron density in the center and low density outside (although they might have better B-shielding of the magrid). How do you think the transparence of the grids to alphas in these configs would stack up against polyhedrons?

pstudier
Posts: 79
Joined: Thu Jun 28, 2007 11:37 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby pstudier » Fri Nov 09, 2007 4:45 am

The levitated dipole would have most of the electrons on the outside, like the Van Allen belts of the earth. With the Van Allen belts, there is zero density in the center, because the earth is there. See http://en.wikipedia.org/wiki/Van_Allen_radiation_belt.
Fusion is easy, but break even is horrendous.

drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:

Postby drmike » Fri Nov 09, 2007 4:47 am

Good questions!! I spent a lot of time looking at how to place an arbitrary number of coils around a sphere. For 4, 6 or 12 you can get them all equal and uniformly distributed, but no other combination will work (1 and 2 can be "equally distributed, but my other rule was they touched).

That led me to ask "why uniformly distributed?" and then the question "why on a sphere?"
and the answer is "it's easier!" This is why I like the virtual polywell - we can ask lots of questions and try all kinds of different experiments in theory. If it doesn't work in theory, there's no point in trying it for real.

One of the main questions I'd like to answer even for the 6 coil setup is "what radius is optimal for circulation?" If the coils actually touch, it makes it hard for the electron current to flow past the coil. If the coils are too small, they don't create any well to speak of. So there has to be an optimal radius of the coil. How do we find it? Lots and lots of simulations. It will be a lot easier to run 50 simulations than to build 50 real experiments.

However - we have to build at least 2 or 3 experiments to verify the simulations. Simulations help point the way, but they can't possibly tell you everything.

The more ideas we come up with to try in theory, the better chance we have of finding a great way to build something real. I think it'd be fun to try to model your questions and see what happens!

Keegan
Posts: 206
Joined: Fri Aug 17, 2007 6:29 am
Location: Brisbane, Australia
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby Keegan » Fri Nov 09, 2007 5:20 am

Dr Bussard is quoted as saying that he patented the polyhedral configuration because it was the only one that could ever work. I firmly believe he was correct. People have been trying for years to design magnetic fields for colliding particle reactors, as evident in these patents







Some work was done in the 70's trying to use penning traps for fusion confinement, but it all comes down to the losses. Yes you can trap some electrons, but when it comes to what we are trying to do anything other than the polyhedral cusp just has too many losses. But i dont want to discourage you solo, keep thinking, you could stumble upon something we missed.

It a good thing you bought up coil geometry Dr Mike. I was thinking about it a few days ago.

WB6's minor torus diameter = 1/5 of major torus diameter.

It seems to closely follow the ideal geometry of a Its geometry is minor diameter = 1/4 of Major diameter. Its obvious this gets tweaked to the 1/5th rule to allow for the circular conformal coil geometry to minimise electron losses.
Purity is Power

Solo
Posts: 261
Joined: Fri Jun 29, 2007 12:12 pm
Location: Wisconsin
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby Solo » Fri Nov 09, 2007 6:59 am


scareduck
Posts: 552
Joined: Wed Oct 17, 2007 5:03 am
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby scareduck » Fri Nov 09, 2007 5:42 pm


drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:

Postby drmike » Fri Nov 09, 2007 6:33 pm


Solo
Posts: 261
Joined: Fri Jun 29, 2007 12:12 pm
Location: Wisconsin
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby Solo » Fri Nov 09, 2007 7:32 pm


JohnP
Posts: 296
Joined: Mon Jul 09, 2007 3:29 am
Location: Chicago
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby JohnP » Fri Nov 09, 2007 11:17 pm


Solo
Posts: 261
Joined: Fri Jun 29, 2007 12:12 pm
Location: Wisconsin
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby Solo » Sat Nov 10, 2007 3:44 am


drmike
Posts: 825
Joined: Sat Jul 14, 2007 11:54 pm
Contact:

Postby drmike » Sat Nov 10, 2007 3:17 pm


hanelyp
Posts: 2255
Joined: Fri Oct 26, 2007 8:50 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby hanelyp » Mon Nov 12, 2007 3:27 am

On the topic of alternate coil configurations, I thought I'd illustrate an idea I've been kicking around. The wiffleball would be in the center. This was inspired by a proposed permanent magnet configuration.
Image

jlumartinez
Posts: 143
Joined: Thu Jun 28, 2007 7:29 pm
Location: Spain
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby jlumartinez » Mon Nov 12, 2007 12:54 pm

It seem quite interesting!!!. Congratulations!! I am not an expert but maybe it could reduce even more the electron loosses because the recirculated electrons will go always around the inner part of each magnet. If the electron lifetime is increased it would be a perfect candidate to get net power. What about the Magrid and the WB in the cusps? Is it maintained fine? Opinions?

Bussard metions, I think in Google video, that a good confinement is reached if in all the border regions of each magnet the polarity is alternated with the one in front ( North-South-North-South ) to help creating the WB. Have you check it for your device? The opinion of some expert is needed.

hanelyp
Posts: 2255
Joined: Fri Oct 26, 2007 8:50 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

toriodal well

Postby hanelyp » Thu Nov 15, 2007 9:23 pm

Another configuration to chew on:
The core principle of the polywell is that electrons, with their high charge to mass ratio, are much easier to contain. The resultant charge well can then be used to contain ions. What if the electrons were contained in some other magnetic configuration, like the tokomak? Having no cusps, this toroid might contain the electrons better, unless there's some instability I'm not familiar with. The secondary ion containment still works. But I expect the electrons will thermalize. Then again, I'm not sure they wouldn't in a polywell.

93143
Posts: 1131
Joined: Fri Oct 19, 2007 7:51 pm
[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Postby 93143 » Thu Nov 15, 2007 10:11 pm

The trouble with a tokamak configuration is that the centre of charge for the electron distribution is outside the confinement area (ie: in the hole in the middle of the donut).

There could be some sort of equilibrium with ions in a generally tighter ring than the electrons but with the distribution overlapping, but something feels off about that idea (and I'm apparently too tired to figure out what). It would be fine for attracting ions perpendicular to the plane of the torus, but I'm not so sure it would be a good idea for radial confinement...


[phpBB Debug] PHP Warning: in file [ROOT]/vendor/twig/twig/lib/Twig/Extension/Core.php on line 1236: count(): Parameter must be an array or an object that implements Countable

Return to “Theory”

Who is online

Users browsing this forum: No registered users and 3 guests