Radiation Damage in Scintillating Crystals1)

Crystal Calorimetry in future high energy physics experiments faces a new challenge to maintain its precision in a hostile radiation environment. This paper discusses the effects of radiation damage in scintillating crystals, and concludes that the predominant radiation damage effect in crystal scintillators is the radiation induced absorption, or color center formation, not the loss of scintillation light yield. The importance of maintaining crystal’s light response uniformity and the feasibility to build a precision crystal calorimeter under radiation are elaborated. The mechanism of radiation damage in scintillating crystals is also discussed. While the damage in alkali halides is found to be caused by the oxygen/hydroxyl contamination, it is the structure defects, such as oxygen vacancies, cause damage in oxides. Material analysis methods used to reach these conclusions are presented in details. 1) Invited talks presented in “International Conference on Inorganic Scintillators and Their Applications”, Shanghai, Sept. 1997 and “VII International Conference on Calorimetry in High Energy Physics”, Tucson, Nov. 1997.