Re: [Phys-L] re Bayesian Inference in Half-Life measurement

[Paul Nord <Paul.Nord@valpo.edu>]

I've not used the Cs-137 "cow".  Frankly, it seem best to stay away from
so-called "smearable" sources.

We also do neutron activation with thin indium foils to determine the
absolute neutron flux.  This even includes a thin Cadmium shield to block
the thermal neutrons and get the flux from the fast neutrons.  And we
correct for the neutron depletion inside the thin sample.  Maybe the lesson
goal is, "absolute measurements are hard."

Paul


On Thu, Sep 23, 2021 at 6:41 PM bernard cleyet <bernard@cleyet.org> wrote:

> > On 2021/Sep/23, at 07:54, Brian Whatcott <betwys1@sbcglobal.net> wrote:
> >
> > Basically, the "old school" method is wrong and is not used in modern
> > analysis of half-life measurements.
> >
> > Paul
>
>
> If one is only instructing simple measurement of half life to determine
> its time,  suppose old school does.  I’ve never heard of old school and
> having a neutron activator, it a horrible waste of not using the
> opportunity of separating two half lives.  Furthermore, old school is much
> less expensive and dangerous using a Cs-137/Ba-m137 “cow”.
>
> Back in the previous century, I (as lab mgr.) used a 2Ci Pu/Be source to
> “activate” silver.
>
> Much more convenient!   v. ~ 25s" and 2.4’  W/an MCS.   I suppose the Cu
> is better if one want to instruct in the Bayesian analysis.
>
>
>
>
> bc
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