by Doug Coulter » Thu Feb 24, 2011 4:41 pm
OK, I get it now. Cool! I was thinking more of selecting between easier things -- like D+ vs D2+ for example (2::1 c/m ratio), where those limits aren't so difficult as real isotope separation. Comes from thinking more about my own problems here than yours, I guess, oops! And yup, at mA currents and those voltages, there's going to be a bit of target melting going on unless "heroic" measures are taken indeed, and maybe even then. I'd guess using an implant beam as an annealing heater is not very smart?
In fact, that cooling problem is probably the driver for an "inside out" fusor design I've seen as a neutron generator. Not really a fusor, but a beam on target device. Cylindrical ion source in the center of a big pipe, and the pipe is the target, all spread out for low watts/sq cm -- and all the heat shows up conveniently outside the thing through the thin pipe walls for easy cooling. I've thought of making one to play with activations as a side project, since we now have those cheap ebay turbos and I have a handy cave to put it in. But I'll walk first, then run -- MarkB has made me some nice quartz beamline parts for a more conventional borehole type design I'll use to learn a bit more first.
Posting as just me, not as the forum owner. Everything I say is "in my opinion" and YMMV -- which should go for everyone without saying.