Energy resolution and energy–light response of CsI(Tl) scintillators for charged particle detection

Abstract

This article describes the crystal selection and quality control utilized to develop and calibrate a high-resolution array of CsI(Tl) scintillator crystals for the detection of energetic charged particles. Alpha sources are used to test the light output variation due to thallium doping gradients. Selection of crystals with better than 1% non-uniformity in light output is accomplished using this method. Tests with a 240 MeV alpha beam reveal that local light output variations within each of the tested CsI(Tl) crystals limit the resolution to about 0.5%. Charge and mass dependences in the energy–light output relationship are determined by calibrating with energetic projectile fragmentation beams.