Numerical Study on RFV Model of Conductivity Induced by Steady X-Ray Radiation of Polyimide Materials

As the main component of intense ionizing radiation, X-ray irradiation will cause surface and deep charging of dielectric materials, leading to surface flashover or body breakdown of materials. Polyimide is an insulating dielectric material with excellent performance, and radiation-induced conductivity is directly related to the charging of materials. It is one of the important parameters for studying radiation effects. This article improves the classic RFV model from two perspectives: quantitative calculation of carrier excitation rate and quantitative calculation of mobility. It calculates and analyzes the effects of pulse X-ray dose rate and electric field intensity on the radiation-induced conductivity of dielectric materials. Numerical calculations indicate that under low-intensity X-ray radiation, the steady-state increment of radiation-induced conductivity of the dielectric material increases linearly with dose rate, radiation-induced conductivity increment in the order of 10-15Ω-1·cm-1; At 0.8×1064×106V/m electric field intensity, the radiation-induced conductivity increases with the increase of electric field intensity.