Study On The Radiation Damage Effect Of High-voltage Power Source Encapsulating Materials

Silicone rubber and epoxy resin have excellent dimensional stability,thermodynamic properties,electrical insulation properties,ozone and radiation resistance,and low surface activity.In recent years,such polymer materials have been encapsulated in electronic components in spacecraft.A wide range of applications.Spacecraft operate in a space environment filled with radiation bands within high-energy particles.Polymer materials may be exposed to high-energy radiation and have a high cumulative fluence after several years of use.Irradiation can cause chemical structural changes in the polymer material,such as cross-linking or degradation of the material,thereby causing relatively large damage to its dielectric properties.Therefore,it is important to study the anti-irradiation properties of polymers for their applications in space environments.In this paper,the computer software CASINO simulates the incident path,backscattered electron depth distribution,electron energy deposition distribution and electron depth distribution in the high voltage power potting material.Taking the simulation results as a reference,the beam density is 1.33×1012cm-2·s-1 the irradiation energy is 50keV,70keV and 100keV,the irradiation fluence range is 5×1014?1×1016cm-2,the vacuum degree is 10-5Pa,and the ambient temperature is 300K.The surface morphology,microstructure change,thermodynamic properties and dielectric properties of RTV560 silicone rubber and bisphenol A epoxy resin under space electron irradiation were investigated and studied in various sets of ground simulated electron irradiation experiments.The results show that the surface morphology of RTV560 silicone rubber and bisphenol A epoxy resin is gradually increased with the increase of electron irradiation fluence,and the increase of mass loss rate,surface gassing,cracking and color change occur.After RTV560 silicone rubber and bisphenol A epoxy resin are irradiated by electron energy of 70keV,the dielectric constant becomes larger,the electrical conductivity increases,and the insulation performance deteriorates.Among them,the dielectric properties of RTV560 silicone rubber decrease.XPS and FT-IR analysis showed that the ratio of C element in RTV560 silicone rubber and bisphenol A epoxy resin increased to some extent after electron irradiation,namely"carbon enrichment" phenomenon.Electron irradiation At low fluence,RTV560 silicone rubber and bisphenol A epoxy resin mainly undergo radiation crosslinking,and radiation degradation mainly occurs at high fluence,and the two processes often have mutual constraints.