Experimental Study on The Flashover Characteristics of Typical Medium Materials of Spacecraft Along the Surface

Abstract

Along the surface flashover is one of the main forms of electrostatic discharge on the surface of the aircraft, the construction of low-pressure electrostatic discharge simulation test system, taking the typical dielectric material commonly used in spacecraft as the research object, simulating the typical structure of the spacecraft surface with the metal-medium structure, simulating the charging process of the spacecraft surface in the operating environment by injecting electrons with an electron gun, starting from the formation process of the electrostatic discharge channel and the theory of the discharge, the change law of the characteristics of the dielectric material along the surface flash discharge is studied. Studies have shown that under vacuum conditions, when the dielectric material is charged with an electron gun, the surface potential of the material is gradually increased, and finally reaches a limit value of dynamic equilibrium (surface charging balance potential); And with the increase of the energy of the electron gun, the balance potential of the surface will also increase; The thicker the dielectric material, the lower the discharge frequency, and the higher the surface dynamic balance potential. The change of material electrical parameters and surface roughness caused by chemical changes in the dielectric material during discharge is an important reason for the influence of the flashover voltage along the surface; Increasing the conductivity and surface roughness of the material, introducing transition substances with a small dielectric constant, and increasing the hydrophobicity of the material can effectively reduce the flashover voltage, which is an effective means of flash network protection for dielectric materials.