Wavelet analysis of scintillation discharge current on DC tracking resistance of gamma-ray irradiated polyethylene and modified polycarbonate

The use of organic insulating materials in environments such as space and nuclear power stations is spreading rapidly. There is increasing concern about the reliability of electrical insulation in these environments due to radiation effects on the surface characteristics of polymeric materials. Irradiation effects on tracking resistance should be investigated due to the increasing usage of organic materials in radiation-prone environments. This paper presents a study on the DC tracking resistance of gamma-ray irradiated polyethylene and modified-polycarbonate materials by use of the International Electrotechnical Commission (IEC) Publication (Publ.) 112 method. Polyethylene and modified-polycarbonate materials were irradiated in air up to 1/spl times/10/sup 7/ R and 1/spl times/10/sup 8/ R with dosage rates of 10/sup 6/ R/hr using a /sup 60/Co gamma source as the test samples. The total radiation effects on erosion depth and scintillation discharge energy levels were studied. A gaussian wavelet analysis was applied to show these scintillation discharge energy levels.