Re: consumer products that make nice sources

At 5:46 PM 11/3/95, Brad Dolan wrote:

>The tag on my Montana Sunshine Radon Mine radon pillow is a little blurred.
>I think the following is the right phone number.
>
>Sunshine Mine is an amusing concept.  People pay money to go breathe radon
>there, while others are spending much money avoiding radon.
>
>Anyway, the pillows make nice sources and good conversation pieces.

I'd say they make poor sources. Far too large. A smaller source has better
access to the detector without adding much to the overall background the
user is exposed to. (I'm not saying low-level uranium or thorium sources
are much of a hazard, but the fluence presented at the detector is very low
for such an extended source.)

It depends on the detector type (alpha, beta, gamma, neutrino?), but high
count rates can be obtained in a variety of ways. (Don't get too high a
count rate, or the dead time characteristics of the pulse-height analyzers
will introduce spurious correlations that decrease entropy--I mention this
to show that even radiation detector sources of entropy have non-random
issues to take into account.)

--Tim May

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On Fri, 3 Nov 1995, Timothy C. May wrote:


> 
> I'd say they make poor sources. Far too large. A smaller source has better
> access to the detector without adding much to the overall background the
> user is exposed to. (I'm not saying low-level uranium or thorium sources
> are much of a hazard, but the fluence presented at the detector is very low
> for such an extended source.)
> 
> It depends on the detector type (alpha, beta, gamma, neutrino?), but high
> count rates can be obtained in a variety of ways. (Don't get too high a
> count rate, or the dead time characteristics of the pulse-height analyzers
> will introduce spurious correlations that decrease entropy--I mention this
> to show that even radiation detector sources of entropy have non-random
> issues to take into account.)


Gotta watch yourself around the physicist....

Most of the sources I mentioned are fairly anemic, however the Coleman 
lantern mantles are pretty good beta emitters.  I can get count rates 
approaching 1000 cpm on a tired GM tube detector with a beta window of 
unknown thickness.

Brad D.