Re: Unknown Sealed Sources

[mikeg@SLAC.Stanford.EDU (Michael P. Grissom)]

Just a point of clarification on my earlier posting below.  Ron,
Al, et al., are certainly correct as to what Ra-D and Rad-E would
NORMALLY be.  However, I seem to recall having a Collin's disk
set that had one (I don't recall if it was a "D" or "E" source)
that gamma spec'd as Cs-137 and did not demonstrate Bi-210, Po-210,
or Pb-210 (above our relatively low backgrounds on the counting
systems used--10" NaI(Tl) flat face crystal in a heavy safe and 
Beckman proportional counter)!  I believe this was a mislabeled, 
that is, not contaminated, source that would now be well over
twenty years old (if still in the system).

>Based on my past experience with Collin's sources, I believe Dave
>is right.  However, you should go for a positive radionuclidic
>ID just to be sure!

>>We have two sealed sources that are labeled Ra-DE. Does anyone know 
>>what the DE stands for. ...
>>
>Just a guess, but it might be Ra D (Pb-210) and Ra E (Bi-210).  The parent
>half-life is about 20 y.  The other members of the decay chain would add to
>an alpha, but not much to the beta spectrum.
>
>Dave Scherer
>scherer@uiuc.edu
-----------------------
Michael P. Grissom
mikeg@slac.stanford.edu
Phone:  (415) 926-2346
Fax:    (415) 926-3030