Semiconductor Detector with an Anticoincidence System for the Suppression of Backscattered Beta Rays

Abstract

A lithium-drifted silicon semiconductor detector (LIDS) and a plastic scintillator are operated in anticoincidence in a measuring arrangement with small energy distortion. With this measuring arrangement the whole energy distortion in the semiconductor β-spectrum cannot be eliminated, but the part of the distortion that depends on backscattering is strongly suppressed. This gives an improvement of the energy resolution. Fermi-Curie plots become more linear and the maximum energies, determined by them, more correct. The spectrometer was tested by measuring the β-spectra from 207Bi, 137Cs and 59Fe. The measurements show that the method is applicable even to β-sources giving γ-radiation, and when the lifetime of the daughter nucleus is short. As by-results some measuring data are obtained, upon which the distortion effect has a negligible influence.