Validity of various semi-empirical formulae and analytical functions for the efficiency of Ge(Li) detectors

The validity of various semi-empirical formulae, proposed for representing the full energy peak efficiency, has been tested for 3.0 cm3 and 4.2 cm3 Ge(Li) planar detectors in the gamma ray energy range from 59.54 to 1836.13 keV. For a 38 cm3 coaxial detector the existing analytical functions and a semi-empirical formula have been examined from 319.80 to 2598.80 keV. For planar detectors the semi-empirical formulae of Freeman and Jenkin, and Mowatt give excellent representation of the efficiency in the entire energy range. The eight-parameter function of McNelles and Campbell gives the best results for the 38 cm3 coaxial detector. (Auth.)