Detection of Low Energy Particles

Abstract

<p>The channel electron multiplier is a radiation detector suitable for the detection of 0.1-100 keV electrons and atomic particles. Studies were made to determine channeltron absolute efficiency as a function of input particle rate, time, and incident energy. The efficiency for electrons was found to vary from 90% for 1 keV electrons to 50% for 4 keV electrons. The channeltron efficiency was found to depend strongly on input rate below 50 counts per second. Although the cause of this discrepency is unclear, a possible explanation was developed involving the secondary emission coefficient of the detector multiplying surface. The channeltron was subsequently used to detect secondary electrons from gold foil bombarded with both electrons and protons. By scattering the incident. particles from a gold foil, the number of secondary electrons generated was found to vary linearly with energy from 2 to 11 keV. The possibility exists for use of the foil-channeltron detector to count neutral atomic particles with known efficiency. This has been a difficult problem in the past. </p>