Radiation-Induced Conductivity of Polyimide Under Monochromatic X-Ray Irradiation: Calculation, Numerical Simulation, and Measurement

X-ray irradiation on dielectric materials will affect their electrical properties, reducing the service life of the equipment. Therefore, calculating and measuring the radiation-induced conductivity is of tremendous significance in studying the radiation effects of dielectric materials. For the research requirements of detector calibration and numerical calculation of radiation-induced conductivity, the generation method of quasi-monochromatic X-ray is studied. The geometric model is established, and the Monte Carlo numerical simulations of the emitted energy spectrum and the photon numbers are carried out. A steady-state quasi-monochromatic X-ray conductivity measurement system was built to test polyimide materials. Experiments show that under a strong electric field and quasi-monochromatic X-ray, the volume conductivity of the sample can rise to 10 ^-16 ~10 ^-15 Ω ^-1 ·cm ^-1 . The radiation-induced conductivity is in the order of 10 ^-16 Ω ^-1 ·cm ^-1 and increases with the X-ray intensity. The Rose-Fowler-Vaisberg (RFV) model is discretized for MATLAB numerical calculation. The radiation-induced conductivity of polyimide material is calculated based on the model under specified X-ray energy and X-ray tube current. The calculated results are consistent with the experimental results using the given parameters. The radiation-induced conductivity increases linearly with the increase of X-ray intensity.