Polywell Question

[swebster]

I am quite confused on how polywell fusion works. The part that I am most unsure about is the cathode. Where is it. Is it the coils? I would really appreciate any help here.

[Mike Beauford]

Here's an animation http://www.youtube.com/watch?v=XiHsSAS_SQw regarding a Polywell device.

[swebster]

Thanks for the link, but my filter blocks youtube. Could someone explain to me what it was about?

[tonybarry]

For discussion on the electrical disposition of the polywell, you may wish to
visit the talk-polywell forum:-
http://www.talk-polywell.org/bb/viewtopic.php?p=237
Regards,
TB

[johnp]

The coils create a quasi-spherical magnetic confinement area. Electrons injected into this tend to stay trapped. So you end up with a fuzzy ball of trapped electrons. The cathode isn't a physical grid, it's this fuzzy ball of electrons. So they call it a virtual cathode. They attract the incoming fusion fuel (which is positively charged).

[swebster]

How does the fuel get a positive charge?

[nathematics]

Seth Webster wrote:
> How does the fuel get a positive charge?

The fuel gets a positive charge by whatever means are employed to remove any electrons bound to the fuel nuclei. Positively charged elements are called positive ions. Creating ideal sources for positive ions would be part of the next phase of the polywell effort. The means Bussard's company was using may not have been ideal.

[swebster]

What are some of the ways used to ionize the particles? Which of them are the most common?

[tonybarry]

To make electrons, a filament will provide a small number of electrons; but
it's easy to break. A magnetron will provide a larger number, though I am
not clear on whether the magnetron provides predominantly photons or
electrons (or both). Corona discharge will also provide electrons.
Ions (positively charged species) are made by heating the species atoms
to gas, and stripping the gas particles of electrons by high positive
voltage. There are sure to be other ways (this is all I know of).

[Zixinus]

I recall that there was something about ion guns.

[Larry Upjohn]

For proton creation using the cyclotron the accelerated beam of hydrogen or deuterium is passed through a graphite or carbon film. I can't quote the physics right now but afterwards the beam is focused on the specimen to be activated and afterward the desired radioactive isotope is extracted for intended use.

[Zixinus]

That sounds promising... what about helium-3 or even boron?