A Charged-Particle Scintillation Spectrometer with Large Geometric Factor

A charged particle scintillation spectrometer with a geometric factor of 350 cm2 sr has been built and flown in polar orbit aboard the Air Force STP 72-1(1972-076B) Satellite. The primary purpose of the sensor is to measure low-intensity solar proton fluxes over the polar caps, in the energy range of 1-15 MeV. Incorporated in the circuitry is a pulse-shape discrimination scheme enabling the instrument to differentiate between protons and electrons. A second pulse shape discriminator prevents analysis of signals produced by particles which penetrate the primary (CsI (T1) Scintillator and produce light in a backing layer of fast scintillating plastic.