how weird are the electronics actually used in nuclear weapons?

[jmelson]

I wonder if there is something that can be hit with a neutron to get you to one of the Astatine isotopes, that would get you 3 alphas in the decay chain within a few minutes.

Astatine is the rarest element in the universe.  Supposedly, there's no more than 5 g in the whole earth!  There must be good reasons related to neutron capture cross sections or something that prevents much of it from ever being created.

Jon

[dmills]

It is the tiny half life and the fact that it is mostly a decay product of things having **very** much longer half lives.

There is a route via Bismuth capturing an alpha particle which is interesting, but I don't think the cross section works to get that to go directly as a chain reaction which is a pity.

If the cross sections were better, you could build a pile of bismuth, hit it with a few alphas and watch as the thing gradually ramped up a mixture of Alphas (that would actually be driving the reaction) and betas plus heat, longest half life in the main line of the resulting decay series would be ~30 minutes which would make it a cool play toy for the shed, but with a delayed alpha gain of 3 it does not work.

Back to the drawing board on that one....

Regards, Dan.