Evaluation of Deep Charging Phenomenon of 3-D Solar Array Driving Assembly under Space Radiation Environment

Solar Array Driving Assembly(SADA) is an important high-power device on spacecraft, which is easily affected by electron radiation due to its direct exposure to space. To ensure the safe operation of spacecraft, we perform simulated evaluate on SADA and found that the insulation material of SADA structure should be fully optimized to reduce the discharge risk of sensitive parts. First, a three-dimensional SADA structure made of polyimide and copper electrode was established in this paper, and the electron radiation was simulated using Geant4 software. The interpolation function was used to introduce the charge deposition rate and radiation dose rate into COMSOL, and the visualization analysis was performed. The potential and electric field distribution in polyimide were obtained by solving the CCL (charge conservation law) equation and compared with previous studies. Second, the effects of different width, height, and grounding area of polyimide ring structure on electric potential and electric field intensity were investigated under the FLUMIC3 energy spectrum. The results show that the electric field intensity increases as the width and height of the polyimide increase, and the electric field intensity of inner wall is slightly greater than outer wall, which is explained by the competition between charge deposition and release. The combined simulation of Geant4 and COMSOL provides an evaluation method for the dielectric charging problem in space environment, and provides a certain reference for the design of SADA structure.