Influence of temperature treatment on radiation stability of plastic scintillator and wave-length shifter

The influence of temperature treatment before or after irradiation on the radiation damage of plastic scintillators and wave - length shifters has been measured. The PMMA based wave - length shifters show in argon strong recovery for heating after irradiation wheras the polystyrene based scintillator SCSN-38 in air suffers not only of heating before but also after irradiation. UV absorbants added to wave - length shifter material Y-7 in PMMA are responsible for additional radiation damage in the scintillator/wave - length shifter system SCSN-38/7- 7 if their cut-off wave-lengths are higher than 360 nm.