A STUDY OF THE OPTICAL AND RADIATION-DAMAGE PROPERTIES OF LEAD TUNGSTATE CRYSTALS

A study has been made of the optical and radiation damage properties o f undoped and niobium doped lead tungstate crystals. Data were obtaine d on the optical absorbance, the intensity and decay time of the scint illation light output, and the radioluminescence and photoluminescence emission spectra. Radiation damage was studied in several undoped and niobium doped samples using Co-60 gamma ray irradiation. The change i n optical absorption and observed scintillation light output was measu red as a function of dose up to total cumulative doses on the order of 800 krad. The radiation induced phosphorescence and thermoluminescenc e was also measured, as well as recovery from damage by optical bleach ing and thermal annealing. An investigation was also made to determine trace element impurities in several samples.