[ RadSafe ] GammaVision gamma spectroscopy software

[Michael McNaughton]

Dear Radsafers

I would appreciate some help on how to interpret the detailed "Gamma 
Spectroscopy" pages printed by the GammaVision Report Writer.

For example, in the "Summary of Library Peak Usage," when several 
peaks are listed for a particular radionuclide, I expect to see the 
activity listed for each peak, and then I expect the "Average 
Activity" to be an average of some or all of the activities for 
individual peaks. Also, I would expect to see the peaks that 
contribute to the final activity to be marked to indicate: "This peak 
is used in the nuclide activity average." In some cases, I do indeed 
see what I expect. In other cases, I see several peaks listed with an 
activity identical to the average, including peaks that are marked: 
"Peak fails sensitivity test" or "Peak activity lower than counting 
uncertainty range".

I am also puzzled by the "Identified peak summary", for example for 
Ra-226. Many of the peaks used by Ra-226 are from Bi-214 or Pb-214. 
However, the "Net Area Counts" for Ra-226 are very different from 
those for Bi-214 or Pb-214. For example, I have a case for which the 
area of the 1408-keV peak is listed as 0.00 counts for Pb-214 and 
1206.11 counts for Ra-226. Also, the 609-keV peak is listed as 0.00 
counts for Bi-214 and 983.77 counts for Ra-226.

mike


Mike McNaughton
Los Alamos National Lab.
email: mcnaught at LANL.gov or mcnaughton at LANL.gov
phone: 505-667-6130; page: 505-664-7733