Temperature dependence of radiation hardness of lead tungstate (PWO) scintillation crystals

Influence of irradiation on the light yield of PWO (lead tungstate, PbWO4) scintillation crystals was studied in the temperature range from −25 °C to +60 °C. Light output and optical transmittance were simultaneously measured as a function of time under irradiation in PWO single crystals grown in first and second recrystallization cycle of raw material, doped with different lanthanides and annealed in different conditions. Increased sensitivity to irradiation and slower recovery of the initial light yield were observed at decreased temperatures. The model of tungsten oxide clusters in a regular PWO lattice is used to interpret the experimental results, and dynamics of the light yield under irradiation at different temperatures are qualitatively explained using rate equations describing composition changes in the clusters.