Comparative Analysis of Deep Dielectric Charging Models of Spacecraft Slip Ring Assembly

Numerical simulation is widely used as an important means for the design, evaluation, and qualitative analysis of deep dielectric charging in spacecraft. In this paper, for the commonly used radiation-induced conductivity (RIC) model and the charge conservation law (CCL) model, a comparative analysis is conducted from the perspective of control equations and physical meanings. The RIC model is a microscopic expression considering free charge and trapped charge, and the CCL model is a further simplification of the RIC model. Based on the RIC model, a typical back-grounded plate example is calculated to explore the internal charging of the medium under different particle energies. Based on the CCL model, utilizing a combination of Monte-Carlo particle transport simulation and finite element calculation, the 3-D distribution of the electric field intensity inside the solar array drive assembly (SADA) slip ring is accurately described. It can be seen from the calculation results that the two results are basically consistent, but the three-dimensional calculation can more accurately describe the internal electric field intensity distribution of the medium. The maximum internal electric field intensity is about - 1.81 × 10⁷ V/m, which is close to the internal breakdown threshold of the dielectric.