The Effect of Dislocation Density on the Energy Resolution of Sodium Iodide Scintillators

Sodium Iodide activated with thallium was used as the detector in a scititillation counter. The scintillating crystals were stressed with the intention of introducing oislocations and observing whether or not there was any measurable effect on the scintillation enercy resolution intrinsic to the crystal. The photopeak was fitted to a gaussian curve to determine accurately the full width at half maximum. The results suggest that dislocations have a significant and detectable effect on the resolution.