ion-assisted electron injection

Discuss the technical details of an "open source" community-driven design of a polywell reactor.

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happyjack27
Posts: 1431
Joined: Wed Jul 14, 2010 5:27 pm

ion-assisted electron injection

Postby happyjack27 » Fri May 20, 2016 9:14 pm

okay, we have two methods of injection ions and electrons:

* gas puff
* ion guns and electron guns.

it occurred to me that gas puffs may be a good way of getting high precision, if you have a long thin nozzle, a very cold gas, and a continuous very slow injection.

then i thought, well it would also be nice to inject the ions and electrons co-linear, just with a gun, and then they can de-ionize and the heavy ion can help straighten out the electron's course.

then it occured to me that since the ion is so much heavier, you could just put the ion gun in back, perfectly on-axis, and then in front of that put an electron source, maybe in a tight circle around the axis. as the ion passes through, it'll grab the electron and give it a nice straight course, before they ionize again. (alternatively you could shoot the ions off in a circle around a linear or pointwise electron source.)

so it's kind of a hybrid between gas puff and electron/ion injection.

ion-assisted electron injection.

in addition to providing a straight course for the electron until it reaches a point where it ionizes, it provides a quasi-neutral environment for both the ions and the electrons, thus helping mitigate mutual electric repulsion, resulting in a more focused beam.

happyjack27
Posts: 1431
Joined: Wed Jul 14, 2010 5:27 pm

Re: ion-assisted electron injection

Postby happyjack27 » Fri May 20, 2016 10:56 pm

Ah, it occurs to me that amounts a wormhole and nothing more. When deionized, the electron will be at best at zero point energy.

When it re-ionizes that ZPE will turn into KE in an effectively random direction. And then the Velocity -- which is the _square root_ of the KE, divided by the mass -- of the ion it left will add to linear velocity component, so the z-velocity to radial velocity ratio after de-ionization will almost completely depend on the ratio of the ion's (_square root_ of KE divided by about 8,000), squared, to the ZPE of the atom.

Comparing this to an electron gun with very high angular precision, there's be a cutoff where one method results in better injection efficiency than the other.

And the max ion Velocity is very limited (cause it has to lose a large fraction of that KE in one orbit) and ZPE is more than limited - it's quantized. So really this threshold is determined completely by the magnetic field strength and the angular precision of an electron gun. And possibly only the latter since the former also effects the average z-coordinate of ionization.
Last edited by happyjack27 on Sat May 21, 2016 4:34 pm, edited 2 times in total.

KitemanSA
Posts: 6101
Joined: Sun Sep 28, 2008 3:05 pm
Location: OlyPen WA

Re: ion-assisted electron injection

Postby KitemanSA » Tue Jun 28, 2016 1:09 pm

With a Polywell, build an X-Cusp machine and you have "your wormhole".


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