Factors affecting the spectral resolution of scintillation detectors

Two sets of experiments were conducted to investigate the impact on energy resolution of non-uniformity in the distribution of optical photons in scintillation detector systems. The uniformity of light output from radiation interactions in CsI(T1) scintillation crystals was determined independently from the optical response of photomultiplier tubes. The results indicate that the energy resolution intrinsic to the scintillator itself is degraded by passing these photons from the crystal and into the photomultiplier tube readout.