Study on the Influence of Degradation on the Electrical Performance of Polyetherimide under High-Energy Electron Irradiation

摘要

Under the extreme environment of space, the insulation performance of spacecraft is liable to decline under the action of high-energy electron radiation, which greatly threatens the operation safety of spacecraft. Aiming at the polyetherimide (PEI) materials commonly used in spacecraft, two kinds of low earth orbit radiation doses were simulated by high energy electron radiation device to carry out radiation experiments on PEI samples. The electrical properties of PEI such as volume resistivity, breakdown strength, surface trap distribution and pulse flashover voltage under high vacuum were measured before and after irradiation. The mechanism of PEI material degradation on its electrical properties, especially pulse flashover characteristics, is studied and analyzed. The results show that the volume resistivity of PEI increases after high-energy electron radiation, and the shallow traps deepen, while the deep traps become shallow. In addition, under the condition of high dose radiation, the pulse surface flashover voltage decreases obviously. It is considered that the degradation of materials under high energy electron radiation is the main reason for the change of electrical properties, which provides theoretical and experimental basis for the application of spacecraft medium in extreme environment.