Radiation damage and recovery in the light emittance efficiency and the attenuation length of barium fluoride scintillator

Radiation damage and its recovery in the light emittance efficiency and the attenuation length of barium fluoride (BaF2) scintillator have been investigated. The light yield and transmittance of small samples of BaF2 scintillator were measured after γ-irradiation from 0.5x104 to 1.1x105 Gy for deterioration, and after sunlight exposure for recovery. Suspension of deterioration was observed both in light yield and in attenuation length at an integrated dose of γ-rays of about 104 Gy. Fairly good and quick recovery of the deteriorated BaF2 scintillator was obtained by sunlight exposure. Using a Monte Carlo simulation method, the dependence of the light emittance efficiency on γ-irradiation and sunlight exposure was studied. It has been found that the light emittance efficiency, as well as the attenuation length, is influenced by γ-irradiation and sunlight exposure. (orig.)