Re: Eff. & En. Calibrations

[steven t hand <hand@wam.umd.edu>]

In reference to this subject, we purchased a "multinuclide" source from	
Isotope Products in California, energy range is from Cd-109 at .088 to	
Y-88 at 1.836 Mev.  This was for our HpGe detector.  We requested that	
they configure to our geometry for our air sampler and they had no
problem	complying with our request.  It has worked out nicely, and after initial	
calibration we use is as a check source for peak location each time we
count, unless we need to recalibrate.   There are 9 nuclides in the mix.

steve at UMCP

Hope this helps.

On Wed, 16 Oct 1996 FRAMEP@ORAU.GOV wrote:

> A few additional thoughts:
> 
> Even with an energy calibration (versus an efficiency calibration) the
> relationship can't be expected to be linear at high energies. As such, it
> would be desirable to have a calibration point every 200 kev if possible.
> Certainly, that would also be true for an efficiency calibration. 
> 
> Assuming we are doing quantitative work and need an efficiency
> calibration, the source should be relatively long lived and NIST traceable
> (I understand that there is now an ANSI standard that defines NIST
> traceable).
> 
> ANSI N42.14-1991 is almost indispensible in this regard "Calibration and
> Use of Germanium Spectrometers for the Measurement of Gamma Ray
> Emission Rates of Radionuclides"  It includes guidance for efficiency
> calibrations above 2Mev.
>  
> If we are trying to do good work here, something like the Bi-214 I
> mentioned in my previous post is a potential problem because of cascade
> summing counting losses at small source-detector distances.
> 
> Paul Frame
> Professional Training Programs
> ORISE
> framep@orau.gov
>