One day as I was thinking about all of these fancy, thousand dollar counters, I started to wonder if there was a better way to do it. By "better", of course, I mean cheaper. It occurred to me that you could probably find a way to emulate the scintillation counters with ordinary metal.
As you all know, when metal is hit by high energy particles, it produces several lower energy particles, which then each create several even lower energy particles. Soon you have a pulse of ionized particles. My idea was, if you took ordinary lead plates and placed them in a stack, you could produce an electric signal similar to what is seen with the photoelectric effect. Surround it with some sheilding and cool it down, and you could reduce the noise quite a bit.
I suspected there was some reason this was never done, then today I ran across this web page.
http://www2.slac.stanford.edu/vvc/detec ... eters.html
SLAC uses this very kind of detector for capturing neutral particles. It is obviously much larger, complicated, and expensive than what an amateur needs, but it seems the idea is sound. I intend to try it out on a small scale when I have a working, neutron producing fusor.
A thought on counters
Re: A thought on counters
Are you thinking about secondary emission from impact ionization at the surface? If so, then I believe you might consider the configuration of what are called Channeltrons. These function like an electron multiplier, but have a continuous surface, rather than discrete electrodes or dynodes.
the general construction resembles a cornucopia or horn... with the narrow end at a couple kV positive potential. A particle enters the large end, impacts the surface which is often a lead oxide on glass and then creates what grows into an avanlanche of electrons toward the narrow positive end of the horn. When new these can achieve current gains of over 10 ^ 8, with very fast response time.. But they are not rebuildable or so it is claimed.
Your lead plates would probably work in a similar way if you arranged for a steadily increasing positive potential to drive the avalanche.
Dave Cooper
the general construction resembles a cornucopia or horn... with the narrow end at a couple kV positive potential. A particle enters the large end, impacts the surface which is often a lead oxide on glass and then creates what grows into an avanlanche of electrons toward the narrow positive end of the horn. When new these can achieve current gains of over 10 ^ 8, with very fast response time.. But they are not rebuildable or so it is claimed.
Your lead plates would probably work in a similar way if you arranged for a steadily increasing positive potential to drive the avalanche.
Dave Cooper