RE: GM Response (formerly Respect)

["Jim F. Herrold" <Herrold@UWYO.EDU>]

> ----------
> From: 	LIPTONW@dteenergy.com[SMTP:LIPTONW@dteenergy.com]
> Sent: 	Friday, September 04, 1998 9:46 AM
> To: 	Multiple recipients of list
> Subject: 	Re: GM Response (formerly Respect)
> 
>  
> You should correct for "backscatter" if you use a metal backed, beta 
> calibration source, especially if you will be using the instrument for a 
> sample which may have a different backscatter factor, such as a smear or
> air sample. 
> 
Bill:

One quick question: I'm a fan of Knoll, but don't suppliers of NIST sources
take the backing material into account when they give the 4 pi dpm values?
If your detector and source have the same area, should it matter? Having
said that, I've seen mysteriously different efficiencies when using a 12 cm2
source to calibrate large-faced (126 cm2) detectors on different surface
types.

Jim Herrold
Radiation Safety Officer
University of Wyoming

herrold@uwyo.edu
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