Evaluation of dielectric relaxation parameters from TSDC analysis of pristine and ion irradiated kapton-H polyimide

The TSD currents of pristine and 75 MeV oxygen ion irradiated kapton-H polyimide were obtained in the temperature region 20–250 °C. The samples were polarized under different temperature windows (temperature regions in the absence of electric field) termed as window-I (75–55 °C) and window-II (90–75 and 55–20 °C). The TSDC characteristics consist of two current maxima termed as β′-peak and β-peak around 30 and 120 °C, respectively. The peak magnitude significantly depends on temperature windows. The strength of the β′-peak and β-peak is being affected in opposite modes in the pristine and ion irradiated samples, as pristine samples show an enhancement in the β′-peak while there appears a suppression in the β′-peak in case of ion irradiated samples. The precise determination of the dielectric relaxation parameters has been made by elementary Debye processes.