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Re: [Phys-L] Half-Life measurement



On 10/15/21 7:31 PM, Paul Nord wrote:

Also: I like the idea of a cylindrical copper sample around the detector.
However the primary decay is a beta. This is best observed through the end
window on the tube.

A) They make thin-walled Geiger tubes that are sensitive to
half-MeV betas along their entire length. No end window.
See e.g. the GMT-02 here:
https://www.imagesco.com/geiger/geiger-counter-tubes.html

I imagine that the annoying background is mostly gammas.
Any tube will be sensitive to gammas along its entire
length.

So ... using a thin-walled GMT surrounded by a tubular
copper sample seems like a good way to level the playing
field. I imagine this could improve the signal-to-noise
ratio by a factor of 10.

I could imagine setting up some guide rails or a sturdy
transparent outer tube so that the students don't break
the GMT by pulling the sample tube at an angle... but
could still see what's going on.

========

B) It would still help to split the experiment:
-- One part optimized for the fast component.
-- One part optimized for the slow component.


C) Combining (A) and (B) could make quite a difference.

OTOH probably there would still be enough remaining nonidealities
that students would still benefit from being smart and careful
during the analysis phase.