A study on the radiation hardness of lead tungstate crystals

This report presents recent progress of a study on the radiation damage in lead tungstate (PbWO/sub 4/) crystals. The dose rate dependence of radiation damage in PbWO/sub 4/ has been observed. An optimization of the oxygen compensation through post-growth thermal annealing has led to PbWO/sub 4/ samples with significantly improved radiation hardness. Front irradiation is found to cause a factor of 2 to 6 times less severe damage than uniform irradiation. Lanthanum doping was found not to be a determining factor for PbWO/sub 4/ radiation hardness improvement. Finally, a TEM/EDS analysis revealed that the radiation damage in PbWO/sub 4/ crystals is caused by oxygen vacancies.