Thanks Horace,
And thanks too to the couple of vortexians who gave
some suggestions off list. Got a neat little protocol
for some final electrolyte selection, and then the
matter of boron for neutron detection. Boric acid is
easy enough to pick up, but I also have some serious
quantities of boron nitride ceramic powder, as well as
plates or coatings of same.
Now I am not sure, though that the window on my old GM
counter is thin enough to admit the alpha particles.
I thought the emission from manganese was a couple of
gamma peaks.
The silver dollar trick makes sense. I saw an article
that may have been linked here a while back about how
Oak Ridge used to have a souvenir silver dime gimmick
whereupon the bombardment from Ra or Pu would kick up
some short life emission from one particular silver
isotope. The tourist could then take the dime with
him or her, - by the time it rolled away from the
Geiger counter it was already cooled off!
Will keep all advised...
Best,
NR
--- Horace Heffner <[EMAIL PROTECTED]> wrote:
> At 4:28 AM 10/2/4, Nick Reiter wrote:
>
> >2. Any last thoughts on a better homebrew neutron
> >detection scheme? Someone hinted to me recently
> that
> >old style D cell batteries with manganese sulphate
> in
> >them made a good neutron detector for use with a GM
> >counter.
>
> As you probably know, tubes having boron compounds
> on their inner walls
> and/or BF3 gas are typically used for neutron
> detection. They work due to
> the reaction:
>
> 5B10 + 0n1 --> 3Li7 + 2He4
>
> Thus there is one alpha generated per reaction. The
> cross section of Boron
> is large, but unfortunately is inversely
> proportional to neutron velocity.
> BF3 tubes are thus only good for low energy
> neutrons. They can be used for
> high energy neutron counters by placing high density
> hydrogen materials
> (e.g. plastic) in front of the tube to slow down the
> neutrons (moderate
> them) via collision with the protons, which are
> effective at moderating
> because they have roughly the same mass. If you are
> looking for high
> energy neutrons then you might get some results by
> placing a plastic
> moderator, say about 1/4" thick, in front of the
> tube and counting recoil
> protons, but this would not be any good for low flux
>
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