Using pulse shape discrimination to sort individual energy deposition events in a germanium crystal

Abstract: A fast digital oscilloscope based pulse shape discrimination (PSD) system has been tested with intrinsic germanium detectors large enough to allow ionizing events which generate localized electron-hole pairs at a single site to be segregated from those depositing energy at several different sites in the crystal. Drift velocities of the electrons and holes result in pulses several hundred nanoseconds long. Since the electric field varies by almost a factor of 10 between the outer and inner surfaces, collection of electrons and holes can frequently be dinstinguished, and pulses due to multi-site events can be distinguished from single site events.