Validation of a method for computer calculation of germanium detector efficiencies

Abstract

This project was organized under the auspices of the International Committee for Radionuclide Metrology (ICRM) to demonstrate the validity of a method for computer calculations of germanium detector efficiencies. This computer method subject to validation is a simple semi-empirical method where the detector peak efficiency for any geometry can be calculated on the basis of one experimentally determined efficiency for the same detector. Seventeen laboratories participated with 26 different detectors and 25 volume sources, altogether 38 detector-beaker combinations. For most detectors, good agreement between experimental and calculated efficiencies was achieved in the energy interval 60–1800 keV. This project has proved that a major limitation for using this computer method is the insufficiency or inaccuracy in detector and detector housing dimensions. With accurate data available, the method should offer a simple and accurate way of calculating peak efficiencies for germanium detectors. The data collected for this project would also be useful for validating other efficiency calibration techniques.