Measurements of Electron Detection Efficiencies in Solid State Detectors

Abstract

Detailed laboratory measurements have been made of the electron response of solid state detectors as a function of incident electron energy, detector depletion depth, and energy-loss discriminator threshold. These response functions were determined by exposing totally-depleted silicon surface barrier detectors with depletion depths between 50 μm and 1000 μm to the beam from a magnetic β-ray spectrometer. The data were extended to 5000 μm depletion depth using the results of previously published Monte Carlo electron calculations. When the electron counting efficiency of a given detector is plotted as a function of energy-loss threshold for various incident energies, the efficiency curves are bounded by a smooth envelope which represents the upper limit to the detection efficiency. These upper limit curves, which scale in a simple way, make it possible to easily estimate the electron sensitivity of solid state detector systems.