At 06:17 PM 12/8/2012, Axil Axil wrote:
"The problem is that I have an Am-241 source which is a sheet of
metal (steel?) with a circular ridge welded onto it. The Am-241 is
in the well formed by the ridge. So if I place the beryllium on top
of the ridge, it will be elevated from the source by ... okay, damn
it! I'll go find the durn thing and measure it."
Use a Americium 241 button to get around the spacing issue.
<http://www.youtube.com/watch?v=6J_KqY81EmA>http://www.youtube.com/watch?v=6J_KqY81EmA
A closer look at the Americium 241 button from a smoke detector.
I have two buttons, but don't know what happened to the first, so
another smoke detector had to die.
The buttons looked a bit different.
The Americium 241 button seems to be a standard product found in a
large verity of smoke detectors.
My guess is that someone sells these. But a major smoke detector
manufacturer may well make their own.
The design of the smoke detector must be radiation failsafe
The button is small but powerful. Use more than one button to
increase alpha intensity by stacking them on each other.
Well, think about it, Axil. The button is a circular piece of metal,
probably steel. It has a well in it, shallow, as I described. At the
bottom of the well, there is what looks like, under magnification,
some kind of "smear" of something. It would be americium oxide, which
is insoluble. You can swallow this stuff, apparently without harm,
because it does not dissolve with stomach acides. This would be 0.9
microcurie of Am-241, which is really tiny. That amount should
produce about 2.2 million disintegrations per minute. But half of
those would have a trajectory not out of the button, but into the
well. These will be absorbed.
There is no way to "increase alpha intensity" by stacking them,
except maybe to stack *two*, well to well, in which case there would
be double the intensity, but it would be rather useless. Half would
have a track one way and half the other. Alphas will not penetrate a
piece of paper, and I'm surprised that the penetration for air is as
much as 4 cm for 5.5 MeV alphas, i.e., from Am-241. I have not
attempted to separate the button from the small piece of sheet metal
that it is mounted on. I suppose that if I did, I could arrange some
well so that the "beams" intersected, but the alpha intensity would
be reduced from distance, I'm not at all sure I'd gain anything. I'd
rather have a strongly anisotropic source.
I imagine that the neutrons will remain anisotropic, more likely to
exit the other side of the piece of beryllium, which is what I want.
Only trying to help: axil
Of course, Axil, thanks.
