Weak Conductive Channel Effect of Glass Fabric on Deep Charging of Polyimide in GEO

Spacecraft operating in the geosynchronous orbital (GEO) environment often experience deep dielectric charging effects in their internal insulation materials, while researchers have attempted to optimize the internal electric field through material modification and internal grounding techniques. Therefore, this article combined the advantages of material modification and structural optimization to establish a glass fabric-modified polyimide structure. We employed a Geant4-COMSOL joint simulation method to obtain the electric field strength distribution under the flux model for internal charging (FLUMIC) electron radiation environment for both single-layer glass fabric modifications at different positions and multilayer glass fabric modifications at varying layer counts. The results indicate that under a single-layer glass fabric-modified structure, the modified glass fabric at Position 3 exhibits the lowest maximum electric field strength. Additionally, according to the glass fabric position, the charge transport behavior in the single-layer glass fabric-modified structure was analyzed through three typical cases by a charge transport model. Finally, the engineering value of the multilayer glass fabric-modified structure was assessed from three dimensions: process design, maximum electric field strength, and electric field distortion rate. For multilayer glass fabric structures, as the number of layers increases, the maximum electric field strength is progressively suppressed, but the mass and manufacturing complexity also increase, imposing an additional burden on the spacecraft. The comprehensive analysis suggests that for practical engineering applications, a three-layer glass fabric modification at Positions 1, 3, and 5 should be adopted to suppress the occurrence of charging phenomena in 1.6-mm polyimide under the GEO environment.