高能电子辐照下介质材料内沉积电荷分布试验研究

Experimental study on dielectric materials deposited charge distribution under high-energy electron irradiation

深层带电是影响航天器在轨安全和正常运行的重要空间环境效应,而高能电子在介质材料内部的沉积电荷分布特性是深层带电效应的重要考量因素。文章采用脉冲电声(pulsed electro-acoustic,PEA)法测试了0.3~1.0 MeV电子辐照下聚酰亚胺(PI)材料内部的沉积电荷分布特性,研究了电子能量和入射电子数对材料内部沉积电荷分布的影响规律。结果表明:高能电子主要沉积在辐照区的后端,随着入射电子数的增加,材料内部沉积的电荷量将不断增加,最终达到稳定状态;能量越高的电子穿透能力越强,并在材料内部形成分布范围更广的电荷沉积峰。

Internal charge is an important space environmental effect affecting the safety and normal operation of spacecraft in orbit.The deposited charge distributions in dielectric materials under high-energy electron irradiation is an important factor of internal charge effect.In this paper,the deposited charge distributions in polyimide(PI)materials irradiated by 0.3 MeV to 1.0 MeV electrons was tested by pulsed electro-acoustic(PEA)method.The effects of electron energy and number of incident electrons on the internal deposited charge distributions were studied.The results show that high-energy electrons are mainly deposited at the back end of the irradiation region.With the increase of the number of incident electrons,the amount of charge deposited inside the materials would continue to increase and eventually reach a stable state.The electrons with higher energy have greater penetration ability,resulting in charge deposition peaks with a wider range inside the materials.