Compton Suppression Using Pulse-Shape Discrimination and Anticoincidence Techniques

The suppression of the background continuum in solid-state detectors by anticoincidence and/or pulse-shape discrimination aids in the interpretation of spectra and enhances the peak to Compton ratio. Studies were performed with both 137Cs and 59Fe sources. For the 59Fe source, an average reduction of 85% in the continuum resulted using a planar diode 110 mm2 by 2.4 mm deep in an anticoincidence annulus of NaI(Tl). Both the distribution and number of events rejected varies with the amplifier shaping time constants. Results are compared with those obtained by other investigators.