聚丙烯薄膜辐射后生成电子陷阱的实验研究

EXPERIMENTAL INVESTIGATION OF ELECTRON TRAPS INDUCED BY IRRADIATION IN POLYPROPYLENE FILMS

本文详细地研究了聚丙烯薄膜受到高能电子束辐照以后介质电性能的变化,利用不同吸收剂量下相应的热刺激电流直接地表征了介质中的陷阱密度随吸收剂量的变化.实验结果表明,在本文所研究的吸收剂量范围(1×10~3Gy～1×10~5Gy)内,辐照在薄膜中引起的电子陷阱密度随吸收剂量的增加迅速增大,介电常数与吸收剂量无关,介质损耗角正切随吸收剂量增加而升高.进一步分析表明,薄膜性能的这些变化主要是由氧化作用、辐射交联、辐射裂解所引起的.根据实验结果,本文提出了聚丙烯薄膜应用的吸收剂量宜限制在<1×10~4Gy的范围内.

The variation of electrical properties of polypropylene(PP)films irradiated by high energy elec- tron beam is studied in detail in this papre.The relation between trap densities and difernt absorbed doses is expressed directly with thermally stimulated currents.It is found that new electron trap densities induced by irradiation increase rapidly when the absorbed dose is raised within the range from 1×10~3 Gy to 1×10~5 Gy.Permittivity keeps constant while dissipation factor increases with the dose. Further analysis reveals that these changes are caused by oxidation,irradiation crosslinking and irradia- tion degradation.Finally, it is suggested that PP films be used within the aborbed dose of 1×1X^4 Gy.