Hmmm... Here's a Thought
Linear particle accelerators may be a little too complicated, but what about a cyclotron? I found someone's thesis on "The Design of a Small Cyclotron." It seems relatively straightforward. Plus, Milton Stanley Livingston built a successful 4 inch cyclotron in 1931 that he used for experiments for his doctoral thesis. That's almost pocket sized, and that was in the '30s.
But here's my theory. It turns out that there are a fair number of useful applications of neutron generators, but all of the neutron generators I know of use nuclear fusion (the Farnsworth reactor, for instance). It's relatively easy to isolate protons to be accelerated in this cyclotron, so if you could accelerate a proton into an electron beam, I think you might be able to create sort of a reverse beta decay process. This would create neutrons. It's what happens in neutron stars, but I'm guessing that the energy requirements are too high to be practical. There's also this crazy physicist who is probably full of misshapen bologna, and he theorizes that absorpsion of thermal neutrons is essential to the production of excess power in electrolytic cells by the P-F effect. So I was talking about this with Dr. Dash one day, and I brought up the idea of bombarding our cathodes with neutrons. I think he chuckled a little bit. In any case, that's why I've been thinking about neutrons a lot lately. I've got to think about this cyclotron some more.
And for the record, I've heard of two high school students who have built nuclear reactors now. Someone from OES had some connections with Reed and got a bunch of parts from their reactor. Another person from southern Utah scrounged up parts in junk yards for a year (he just "happened" to find a neutron detector in Idaho junk yard) and built a reactor with the same design.

For the sake of all that is good and true, LEARN TO SPEELL CORRECTLY!!!
Also, I know the individual who worked with the reactor at Reed.
Um, Ted? What exactly are you complaining about?
You know Michael Li? He's an interesting character from what I've heard.