Peak/total-ratios for NaI(Tl)-crystals

Abstract

The fraction of γ-quanta totally absorbed in NaI(Tl)-crytals was determined for eight scintillation assemblies having dimensions from 1″ dia.× 1″ hgt through 8″ dia.× 8″ hgt. The γ-energies varied from 122 keV to 2.62 MeV and the γ-sources were placed at distances of 10 cm and 50 cm from crystal face. For the crystals up to 5″ dia.× 5″ hgt we also used collimated γ-beams. The measured ratios are about 10% to 30% lower than the ratios calculated by Miller et al.