Comment on the low energy efficiency calibration of NaI MCA

[LAM HOI CHING <lamhc@hkusua.hku.hk>]

I have a whole body counter from Canberra, model ACCUSCAN 2280, in using a
mixed gamma source for the efficiency calibration in the energy range from
Cd109(88keV) to Y88(1836keV), in between there are gamma peaks of
Co57(122keV), since NaI has quite wide FWHM wrt. Ge, the gamma peaks
interferences may be quite significant, which may result in very large
uncertainty in calculating the net area of peaks during efficiency
calculation. The efficiency error can be a few tens of percent. Can any
body give advice on this issue. If the mixed gamma source is really
suitable for efficiency calibration of NaI detector anymore.


************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html