Thermally stimulated optical scintillations in preheated plastic scintillators


PVT-based plastic scintillators, irrespective of their radiation history, are found to exhibit thermally stimulated optical scintillations in the temperature interval 40-80°C following a preheat to 200°C or above and cooling to RT. Maximum scintillation activity occurs near 65°C, which is the glass transition temperature Tg of the scintillators. Comparing our results with the literature data of similar work it is suggested that pyroelectricity is the mechanism producing these scintillations. They occur due to electrical breakdown of air caused by depolarization of polarized dipoles in the crystalline moiety and detrapping of the trapped charges in the crystal-amorphous interfaces of the material, which were formed by preheating. © 1992.

Publication Title

Nuclear Inst. and Methods in Physics Research, A