SYSTEMATIC STUDY OF THE SHORT-TERM INSTABILITY OF PBWO4 SCINTILLATOR PARAMETERS UNDER IRRADIATION

The effect of irradiation on lead tungstate PbWO4 (PWO) scintillator p roperties has been studied at different irradiation facilities. Lead t ungstate crystals, grown with the oxide content in the melt tuned to t he stoichiometry of pure sheelite or sheelite-like crystal types and d oped with heterovalent, trivalent and pentavalent impurities, have bee n studied in order to optimize their resistance to irradiation. A comb ination of a selective cleaning of raw materials, a tuning of the melt from crystallization to crystallization and a destruction or compensa tion of the point-structure defects has to be used to minimize the sho rt-term instability of PWO parameters under irradiation. (C) 1998 Else vier Science Ltd. All rights reserved.