真空环境温度对聚酰亚胺表面充电特性的影响

Impact of vacuum environmental temperature on surface charging characteristics of polyimide

摘要:

空间环境温度的变化会对航天器表面介质材料的带电程度造成不同的影响，为此，本文基于电流平衡方程建立了温度对聚酰亚胺表面充电影响的数值模型。在此基础上，利用航天器材料表面充电模拟实验系统，研究电子辐照下温度变化对聚酰亚胺表面充电特性的影响。仿真结果表明，当温度一定，束流密度分别为0.5 nA/cm²、1 nA/cm²、2 nA/cm²时，聚酰亚胺表面充电平衡电位随着束流密度的增大而增大；当束流密度一定时，在243~363 K范围内，聚酰亚胺表面充电平衡电位随着温度的升高而减小。束流密度越大，温度变化对平衡电位的影响越小，这一研究结论可为航天器介质材料面对温度变化时带电防护提供参考。

Abstract:

Variations in space environment temperatures can have distinct effects on the level of charging on dielectric materials surfaces of spacecraft. To address this, a numerical model has been established in this paper based on the current balance equation to study the impact of temperature on the surface charging of polyimide. Subsequently, utilizing a spacecraft material surface charging simulation experiment system, the influence of temperature changes on the surface charging characteristics of polyimide under electron irradiation is investigated. The simulation results indicate that when the temperature is fixed, the surface charging equilibrium potential of polyimide increases as the beam current density increases at levels of 0.5 nA/cm², 1 nA/cm², and 2 nA/cm². Conversely, when the beam current density is held constant, the surface charging equilibrium potential of polyimide decreases with the rise in temperature within the range of 243 K to 363 K. The larger the beam current density, the less significant the effect of temperature changes on the equilibrium potential. This research finding can serve as a reference for the charging protection of dielectric materials on spacecraft in response to temperature variations.