The Channel Electron Multiplier as an Alpha Detector

The response of Bendix CEM 401 channel electron multipliers to a hot filament electron source and a 244Cm alpha source has been investigated. This investigation shows that a CEM operated in the saturated mode produces output pulses for alpha particles which are, on the average, about twice the height of those for single electrons. A series of pulse height distribution curves obtained with various alpha absorbers and electric field potentials between the source and CEM are presented to substantiate this conclusion.