A Quantitative Detector for Neutral Particles

Abstract

A neutral particle detector has been constructed and calibrated for H, He, and N atoms in the energy range 0.5–50 keV. These neutral particles were incident on a Cu or AgMg surface that emitted secondary electrons which were accelerated to 20 keV. These energetic electrons were collected by a silicon barrier detector from which the pulse height spectrum was shown to obey Poisson statistics. From the statistical distribution the detector efficiency was determined. The efficiency of the detector increases from 77% at 0.5 keV to 100% at 2 keV and remains constant at approximately 100% up to 50 keV. Measurements and results are presented for secondary electron and reflection coefficients for electrons and H incident on various surfaces.