NIST beta cal

[Les Slaback <lester.slaback@nist.gov>]

>From: "Jim F. Herrold" <Herrold@UWYO.EDU>
>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?

To the best of my knowledge NIST does not sell beta sources based on beta
emission.  They sell standards certified for the content, i.e., the
activity of the beta emitting nuclide.  Hence backing is not relevant.  I
believe the Radioactivity group will calibrate sources of a specific kind
(i.e., compatible with NIST instrumentation) for beta emission on a special
request basis but this is not routine (and it is relatively expensive).
And of course any such special calibration would specify the conditions and
corrections made.

Contact Lisa.Karam@NIST.GOV (Head of the Radioactivity Group) or check the
NIST web site (www.nist.gov) for more specifics.

Disclaimer:  the above are the personal musings of the author, and do not
represent any past, present, or future position of NIST, the U.S. government,
or anyone else who might think that they are in a position of authority. 
Lester Slaback, Jr.  [Lester.Slaback@NIST.GOV] 
NBSR Health Physics 
Center for Neutron Research 
NIST 
Gaithersburg, MD  20899 
301 975-5810
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