Investigation of photoradiation resistance of polystyrene scintillators in vacuum

Maximum permissible absorbed doses of ⁶⁰Co ionizing radiation were first measured in thin (1 mm) polystyrene scintillator samples at simultaneous irradiation by 0.01–1 Gy s^-1 gamma radiation and ∼10¹⁶ cm² s^-1 light in vacuum. It was shown that photoradiation resistance (unlike radiation resistance) is not increased if samples are placed into vacuum and all other conditions are preserved the same. The process of formation in the polymer of unsaturated conjugated structures, whose fraction is independent of oxygen content and supply, is probably responsible for the loss of light yield.