Talk-Polywell.org

From http://forums.randi.org/showthread.php?t=58665#27 we find that the electron confinement time is 0.1 microsecond, but we also find that the electrons recirculate 100,000 times. Which is correct? If the life is 0.1 microsecond, then one needs to fuse the fuel in about 85 microseconds to break even. (D-T fusion yields about 17 mev, the electrons are accelerated with about 10kev, and there are two electrons present per fusion.) If the lifetime is 100,000 recirculations, then the electrons have plenty of time to thermalize with themselves and the ions.

Hi, I was attracted to this site from the Randi forums. I should start by stating that I'm not a professional physicist; but I kind of know my way around a lot of physics. And I think I know the answer to your question.

The lifetime specified is the lifetime of an electron in the confinement zone. If I understand things correctly, the electrons spend only some of their time providing the charge to create the "virtual cathode" and the rest of it being recirculated. Only a percentage of the electrons that are recirculating are actually providing the charge; the rest are going around the rest of the loop. I believe the 60cm figure you quote is correct; and this is on the close order of the size of the device.

Bussard, I think, claims that getting the number of recirculations high enough is a key to break-even operation. It makes sense, because if you lose electrons you'll have to add some current to replace them, and that will cost energy.

Hello,
I'm not a physicist either, but anyway here's my take on this:

The 0.1 microsecond refers to the electron lifetime in WB6, whereas 100'000 recirculation are required for net power.
I don't know about thermalization. I think Dr. Bussard mentioned in the IAC paper that it could become a problem if electron confinement gets to good, but he doesn't seem to think it would be a problem at the proposed reactor size.