Pulse height and transient response of semiconductor radiation detectors to fission fragments.

Abstract

The pulse height response of silicon surface barrier detectors was measured as a function of energy for median light and heavy fission fragments of Cf ^ over an energy range of 100 > E > 7MeV. The results demonstrated that the calibration procedure proposed by Schmltt, e_t al for undegraded fission fragments is actually valid over an energy range of 100 > E > 25 MeV. Comparison of the pulse height response to fission fragments with the response to alpha particles yielded the pulse height defect as a function of energy. The magnitude and shape of the curve were found to be in disagreement with a calculation by Haines and Whitehead based on the unified range theory of Lindhard and co-workers. The transient response of silicon surface barrier detectors was measured as a function of the energy of incident Cf2^2 fission fragments. The effect of the plasma formed by the incident fission fragment on the collection time was determined. The time to disperse the plasma was found to be proportional to E ' m where 2 S m < 3 and E is the incident particle energy. A simple model was proposed for the plasma effect and found to give agreement with experiment.