magrid configuration brainstorming

[Randy]

But they aren't going in the same direction, wrt a radial sight looking into the coils. Isn't it necessary to have all currents going around clockwise, or ac, when looking towards the centre? Else the mag fields will simply curl around the edges and there would be no 'cusp-containment'? What you'd be generating then is a set of inductively coupled plasmas around each edge?

Maybe I got it wrong, but there it is as I thought it was meant to be?

If you look at the relative directions of the separate coil currents with respect to their closest line segment (edge) of the octahedron you will see that these separate currents always run in the SAME direction with respect to that line segment (edge) of the octahedron. This is a critical concept. Do not proceed until you clearly understand this.
~Randy

[Randy]

But they aren't going in the same direction, wrt a radial sight looking into the coils. Isn't it necessary to have all currents going around clockwise, or ac, when looking towards the centre? Else the mag fields will simply curl around the edges and there would be no 'cusp-containment'? What you'd be generating then is a set of inductively coupled plasmas around each edge?

Maybe I got it wrong, but there it is as I thought it was meant to be?

Maybe I should ask what do you think a line cusp is, how is one formed and how does your definition compare to the definition of a line cusp as defined in the Theory section F.A.Q?
~Randy

[Randy]

Been up all night and all day... Will be back early next a.m.
~Randy

[KitemanSA]

From the patent definition it’s clear that the optimum magrid configuration is an octahedron not a cube. Another member in this same thread (I believe it was ‘tombo’) recognized this back in 2008.

Actually, Dr. B never proposed a "cube" polywell and never actually built one either.

What he tried to approximate was a RECTIFIED cube, also known as a cuboctohedron. Many folks think it is better than an pure octohedron because is has more faces and better approximates a sphere (has more sphericity). For similar reasons, some folks believe that an icosidodecahedron (a rectified dodecahedron) would be more spherical and thus better still.

Dr. B. in his Valencia paper stated that he wanted to build two more small scale MaGrids, a cuboctohedron with square plan-form magnets rather the the round plan-form used in WB6, and also a "higher order" polyhedron which almost certainly would have been the icos...

You accurately depicted the main problem with the WB6 MaGrid design, the existance of "line-like" cusps instead of the "funny cusps" that were part of the patented design. The square plan form magnets would have solved that design flaw.

Please note that many on this forum think the flaws are more easily overcome by a slight increase in size rather than an increase in complexity. They may be right for plants where size/mass is not an issue.

[KitemanSA]

But they aren't going in the same direction, wrt a radial sight looking into the coils. Isn't it necessary to have all currents going around clockwise, or ac, when looking towards the centre?

Absolutely NOT! I am surprised at you. The only time that is the case is when you are relying on REAL magnets to provide one polarity and virtual magnets to provide the other. Such is the case for the WB6/7/8 series but is NOT a requirement. If you look at the real in and the virtual out you will see the current in the same direction in the conductor between them... because they are the SAME conductor.

Else the mag fields will simply curl around the edges and there would be no 'cusp-containment'? What you'd be generating then is a set of inductively coupled plasmas around each edge?

Maybe I got it wrong, but there it is as I thought it was meant to be?

You got it wrong, which may explain a lot. Could it be that your constant harping against Polywell is because you just don't get it? Hmmm. As I said, I'm surprised!

[WizWom]

You accurately depicted the main problem with the WB6 MaGrid design, the existance of "line-like" cusps instead of the "funny cusps" that were part of the patented design. The square plan form magnets would have solved that design flaw.

Um... you're not getting it. The "flaw" they fixed was having conductor in the line cusps. The polywell will never be free of line cusps.

[KitemanSA]

You accurately depicted the main problem with the WB6 MaGrid design, the existance of "line-like" cusps instead of the "funny cusps" that were part of the patented design. The square plan form magnets would have solved that design flaw.

Um... you're not getting it. The "flaw" they fixed was having conductor in the line cusps. The polywell will never be free of line cusps.

You and I are talking totally different issues.

The WB7 had nubs (cross-connects) in the middle of the line-like cusps that by inference were a problem. WB7.1 was supposed to investigate potential solutions to THAT problem.

Dr. B proposed to build a square plan-form version of a cuboctohedral MaGrid in order to eliminate the line-like cusps that show up in lieu of the anticipated "funny cusps" when round plan-form magnets are use.

Different subjects. I do get it. Good morning.

Just to point out the obvious, "line cusps" are on edges between surfaces of same polarity. Funny cusps are at vertices where an even number (at least 4) fields of alternating polarity meet. The square plan form magnet would approximate the "Funny Cusp" better. In effect, it would shrink the line cusp to APPROXIMATELY zero length. When you do that you get a funny cusp.
Got it?

[chrismb]

Could it be that your constant harping against Polywell is because you just don't get it?

I harp, but I don't think it is against Polywell. It's just my usual level of harping about stuff. Nothing special. I do not believe I have ever suggested I am either for or against. I wish you people would stop presuming that, just cos I haven't got my cheer-leaders pants on and I'm not jumping up and down screaming for it irrationally!

The harping is because I don't get it!! Still don't. Suspect I never will. I just wanna see it operating, with some real honest-to-goodness data explaining its operation. That is all.

[TallDave]

Dr. B proposed to build a square plan-form version of a cuboctohedral MaGrid in order to eliminate the line-like cusps that show up in lieu of the anticipated "funny cusps" when round plan-form magnets are use.

I wish we knew how much of the expected 3-5x improvement was from the higher-order polygon overall anode grid shape and how much was from the "square or polygonal" plan-form coils. Maybe there's a way we can figure this out.

Just to review -- a true "funny cusp" is zero field over zero radius, which requires zero-radius coils. Since zero-radius coils are impossible, you get a radius of some value. The hope is that different ("square or polygonal") coil plan-form shapes might make that value smaller and improve performance.

Is there a pic of a PW with "square or polygonal" plan-form coils? I'll have to dig around. I seem to recall the ones I've seen had round ones like on WB-6/7.

[Randy]

From the patent definition it’s clear that the optimum magrid configuration is an octahedron not a cube. Another member in this same thread (I believe it was ‘tombo’) recognized this back in 2008.

Actually, Dr. B never proposed a "cube" polywell and never actually built one either.

What he tried to approximate was a RECTIFIED cube, also known as a cuboctohedron. Many folks think it is better than an pure octohedron because is has more faces and better approximates a sphere (has more sphericity). For similar reasons, some folks believe that an icosidodecahedron (a rectified dodecahedron) would be more spherical and thus better still.

Dr. B. in his Valencia paper stated that he wanted to build two more small scale MaGrids, a cuboctohedron with square plan-form magnets rather the the round plan-form used in WB6, and also a "higher order" polyhedron which almost certainly would have been the icos...

You accurately depicted the main problem with the WB6 MaGrid design, the existance of "line-like" cusps instead of the "funny cusps" that were part of the patented design. The square plan form magnets would have solved that design flaw.

Please note that many on this forum think the flaws are more easily overcome by a slight increase in size rather than an increase in complexity. They may be right for plants where size/mass is not an issue.

Oh… I see what you’re saying now. If I have it right then the square faces of the cuboctahedron would represent pole faces of the six real magnet coils and the triangular faces would be the virtual pole faces. In this case you would want all six real coils to have the same polarity pointing toward the core. Am I right about this?
~Randy

[ladajo]

Can you guess which?

[KitemanSA]

Is there a pic of a PW with "square or polygonal" plan-form coils? I'll have to dig around. I seem to recall the ones I've seen had round ones like on WB-6/7.

Not a great image, but it gets the idea across I hope.

[Randy]

Can you guess which?

This, of course, is the next logical question. At first thought I would think that it wouldn’t matter which polarity of the six square plan-form coils was observed as viewed from the core (as long as they were all the same). Is there a preferred polarity (N/S) of the six square plan-form coil faces as viewed from the core? If so, what is it and why is this so?

[Randy]

Just to make sure, am I correct by saying that from the core viewpoint I should observe clockwise currents flowing around all the square surfaces of the cuboctahedron and counter-clockwise currents flowing around all the triangle faces?

[Randy]

Just did a calculation on a rectified unit cube. The area of a square face on the cuboctahedron produced is 0.5 square units. The area of a triangle face on the cuboctahedron produced is 0.2165 square units. There are six square faces on a cuboctahedron and eight triangle faces on a cuboctahedron. So the total surface area of the square faces on the cuboctahedron is 0.5 * 6 = 3 square units, and the total surface area of the triangle faces on the cuboctahedron is 0.2165 * 8 = 1.732 square units. So this means that the magnetic flux density (the B field) going through the triangular faces will be almost double that of the B field going through the square faces. Is this an issue?