How to power an RF Linear Accelerator?

[Strat-O]

I want to build a small linear accelerator with an energy level around 2-2.5 MeV and as much beam current as I can get without getting too exotic (but I'll be happy with whatever I can get initially). I will need a means of generating microwave RF with the power requirements, I'm guessing, to be around 1000-1200 watts. I'm not sure what frequency to go with. I've seen variations on frequency for various linacs running from 100 - 800 Mhz.

What I'd like to know is what are some good and relatively inexpensive ways of powering an RF linac?

I'll list what I've discovered so far:

Self contained signal generators
Klystron, Reflex
Magnetron
TWT (?)

Amplifiers (Require external signal generation)
Klystron
TWTA
Solid state microwave amplifier

OK, so obviously, the cheapest of the cheap would be a Magnetron liberated from a microwave oven. But the problem with those is their frequency is fixed but it also is subject to operational variability. For a practical accelerator I think you'd need to have a reliable frequency that doesn't change during operation and also the ability to vary the frequency as needed to tune the linac operation.

I've been looking at ebay and see tube collectors buying and selling Klystrons (mostly reflex). One possibility would be to buy several smaller amplifying klystrons and ganging them together as required to get the requisite power level.

Any input would be appreciated.
(BTW would there be a more appropriate forum for this?)

Strat-O

 

[Bob S]

OK, so obviously, the cheapest of the cheap would be a Magnetron liberated from a microwave oven. But the problem with those is their frequency is fixed but it also is subject to operational variability. For a practical accelerator I think you'd need to have a reliable frequency that doesn't change during operation and also the ability to vary the frequency as needed to tune the linac operation.

MIT Lab for Nuclear Science had a phase-locked multi-magnetron (S-band I think) standing wave ~20 MeV electron linac in Bldg. 20, that was still there (mothballed) in 1966. Peter Demos was the group leader. Experiments included measuring nuclear (gamma,n) cross sections.

See this paper on phase locking magnetrons

http://epaper.kek.jp/p87/PDF/PAC1987_1464.PDF

Bob S

 

[Strat-O]

Thanks Bob. I guess magnetrons are a possibility. (Plus I'm seeing some hits when I Google search linac and magnetron)

I'm not going for big energy so I don't imagine I'll have to try to synch up several magnetrons but that is interesting that that's a possibility!

Strat-O