Count rate effect on the response of a low-cost PIN diode for electron spectrometry

Abstract

The response of a low-cost Si photodiode model BPX 65 for low-energy electron spectrometry is investigated envisaging its use in measurements of electron multiple elastic scattering. The electron beam with energy between 10-100 keV is delivered by the gun of the Racetrack Microtron at Instituto de Física, Universidade de São Paulo, with an energy dispersion less than 0.5 keV. The energy resolution achieved was less than 3.5 keV, limited mainly by noise from the electronic acquisition chain. For count rates between 20 and 5500 counts/s, the variation on the centroid of electron peak was smaller than 0.4% throughout the energy range. Therefore, the BPX 65 is suitable for electron spectrometry.