## Search found 113 matches

Sat Aug 09, 2008 11:25 pm
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
Indrek can you give the exact parameters of the coils and sphere and magnitudes of field values at the surface from image coils? For specific parameters: A=0.150000 R=0.150000, S=0.080000, I=200000.000000 iR=0.051787, iS=0.027620, iI=-340380.343468 http://www.mare.ee/indrek/ephi/invwb/ball_scale.pn...
Tue Jul 29, 2008 7:36 pm
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
I finally got around to putting all the equations, images and code into a single fancy PDF:

http://www.mare.ee/indrek/ephi/images.pdf

Btw Art what would be your response to Icarus' objections?

- Indrek
Mon Jul 28, 2008 5:13 pm
Forum: Theory
Topic: MatLab ...
Replies: 9
Views: 4350
Maxima is more useful for symbolic math (mainly working with equations instead of evaluating them) and probably not that fast for numeric calculations. Octave is more for the numeric calculations and mimics Matlab directly so should be your first look. As pointed out packaged for both linux and wind...
Wed Jul 23, 2008 4:27 pm
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
For 1 here's a picture: http://www.mare.ee/indrek/ephi/invwb/cross.jpg For the second item on your shopping list there are a few ambiguities that should be hashed out: Current in the coils and coil sizes, spacings, etc? What I've used so far is 200K amps, 15cm radius coils, 8cm spacing. Electron ran...
Tue Jul 22, 2008 1:26 pm
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565

- Indrek
Mon Jul 21, 2008 10:19 am
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
The render of them is square because matlab does not have a "draw circle" function, at least that I found, and I was lazy so I just drew squares. In math they are circles. I don't have the visual skills you do, hehe. Oh, here you are: function [x, y, z] = circle3d(center, normal, radius) p = cross(...
Mon Jul 21, 2008 5:49 am
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
I decided to attempt this as well just guess the value should solve for the sphere radius. I had it crop the fields inside the sphere since, well, there aren't supposed to be any there due to the electrons. In the pic some of the field lines actually terminate on the very surface of the sphere. Tha...
Sat Jul 19, 2008 1:35 pm
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
And here's a plot of the field intensity on the sphere (done with octave):

- Indrek
Sat Jul 19, 2008 11:05 am
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
Here's the first visualization of the field lines on the ball. Unfortunately I didn't find any way in the gnuplot to hide the lines on the other side of the sphere so looking at it takes a bit of getting used to. For bearings: two fixed faces up and down, 4 rotating on the center line. http://www.ma...
Sat Jul 19, 2008 3:49 am
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
I decided to attempt this as well just guess the value should solve for the sphere radius. ... I think you have to tune the spacing between the inner coils so that the field lines don't terminate inside. I tried this manually here: http://www.mare.ee/indrek/ephi/tmp/lines.jpg The blue line starts a...
Fri Jul 18, 2008 11:30 am
Forum: Theory
Topic: Possible wiffle-ball analytical solution
Replies: 88
Views: 40565
Last night I wrote some Octave/Matlab code for a loop of current and the cube polywell: http://www.mare.ee/indrek/ephi/octave/ The code is there so feel free to use it. I'd love to get some feedback as I'm a complete beginner at octave/matlab. Here's a plot of the opposed coils: http://www.mare.ee/i...
Tue Jul 08, 2008 5:15 pm
Forum: Theory
Topic: Vlasov Solver [work in progress]
Replies: 86
Views: 27749
drmike, or anyone having experience with this, I am having an issue with QNAN apearing in my data. I'm not quite sure why and I have't been able to find any information on what operations actually produce this. Which makes it hard to trace the code producing it. Everything I have tried to reproduce...
Mon Jul 07, 2008 9:07 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 35263
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...
Mon Jul 07, 2008 4:26 pm
Forum: Theory
Topic: All that can go wrong with recirculation
Replies: 112
Views: 35263
The field lines would direct the electrons way away from the machine. Recirculation as in making circles out one cusp and in another would not work. Have a look at this image of the field lines: http://www.mare.ee/indrek/ephi/tmp/bfield_wide.png The blue lines are the b-field lines (should be correc...
Fri Jul 04, 2008 6:10 pm
Forum: Theory
Topic: Why is polywell supposed to be better than cusp confinement?
Replies: 74
Views: 33578
1) I think I need some numbers, though. If I understand Bussard (and if he is right), the confinement is much worse at low beta, so it is possible that the line cusps are spewing out their R*rho worth, but the corner cusps are for some reason much much worse in this regime. Can you count up the par...