Abstract
A Compton suppression spectrometer used for gamma-ray spectroscopy in high level radioenvironmental studies is described. A 113 cm 3 intrinsic germanium detector is inserted into a 22.9×25.4 cm annular NaI(Tl) detector and coupled to an anticoincidence gating system. The performance of suppression of the Compton continuum is studied as a function of various source-to-detector distances, incident gamma-ray energies, as well as the intensity of activities. The optimum suppression factor is 5.2 at a photon energy of 662 keV. Examples are given for use at medium and high level radioenvironmental measurements on the nuclear reactor experimental floor before and during reactor operation. Characteristics of this spectrometer are compared with other representative systems and special features are discussed. © 1986.