Influence of color centers on the luminescent response of radiation-damaged CsI:Tl crystal

Abstract

Luminescence properties of Tl0va+ and Tl+vc- color centers induced by irradiation in CsI:Tl crystal are studied within a temperature range of 80-300 K. It is found, that electron Tl0va+ and hole Tl+vc- color centers arising due to radiation damage do not reduce conversion efficiency of CsI:Tl crystal, but participate in scintillation process to get energy from Tl+ centers by resonance. Degradation of the light yield of the irradiated CsI:Tl crystal is caused by the radiative energy transfer from Tl+ to Tl0va+ centers, whose emission is quenched at temperature above 210 K. Non-radiative energy transfer from Tl+ to Tl+vc- centers results in long-wave spectral shift and the duration increase of the scintillation pulse.