  This article describes the crystal selection and quality control utilized to
develop and calibrate a high resolution array of CsI(TI) 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 240 MeV alpha beam reveal that local light output
variations within each of the tested CsI(TI) 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.

Nuclear Experiment