Measurements of electron detection efficiencies in solid state detectors.

Abstract

Detailed laboratory measurement 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 and 1000 microns to the beam from a magnetic beta-ray spectrometer. The data were extended to 5000 microns 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.