Point charge

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

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tpo939
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Joined: Sun Nov 16, 2008 1:27 pm

Point charge

Post by tpo939 »

I am new to this forum and this subject, so keep that in mind when responding.

From what I have read, the wiffleball idea works because positive ions are attracted to the confined electrons. What about the + ions that enter the well? Don't they get trapped by the magnetic field also. Doesn't that negate the point charge concept? Over operation of the device, it seems to me that the net charge in the center will approach zero.
Can somebody explain how to get over that problem?

Thanks

drmike
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Post by drmike »

Think of the ions as bowling balls and the electrons and ping-pong balls. In the same force field, the ping-pong balls change direction quickly, but the bowling balls don't change much.

So when the ions fall into the center of the polywell, they don't stop, they keep on going until they reach the coil on the other side. And then they fall back into the center and repeat the cycle.

It is the electric field which contains the ions. The magnetic field helps contain the electrons, without affecting the ion motion that much.

But it's a lot more complicated because the electric field generated by the plasma particles affects all the particles in the plasma. But the mass ratio holds in any case, so if you can contain the ions, the electrons will stay fairly contained.

TallDave
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Post by TallDave »

The ions are confined by their attraction to the electrons rather than by the magnetic field. I got the impression they rarely ever see the magnetic field at all due to the electron pushback.

As to the charges cancelling each other out, that confused me a bit as well at first, especially as the ratio is very nearly even; iirc Bussard says it varies by something like 1/million. I think it has to do with the spatial distribution: the ions see a "bottom" to the well at the center and race toward it, then arc back up toward the edge where they are much slower again, with the result they spend most of their time near the edge rather than sitting in the middle cancelling the well.

As drmike says, though, it's a dynamic process.

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