不同能量电子辐照下星用瑞侃导线性能退化研究

目的研究卫星上外露导线在空间辐射环境下的耐受能力。方法通过分析GEO轨道下在轨10年航天器外露瑞侃导线的辐照环境,研究低能和高能电子对导线性能的影响,地面模拟试验参数选择能量分别为45 keV和1 MeV,注量率均为8.3×10^10 e/(cm^2·s),总注量均为2×10^16 e/cm^2。考察瑞侃导线力学性能(断裂伸长率、拉伸强度)和电性能(击穿电压)的退化情况,并用XPS和SEM测试分析手段,对其电子辐照损伤机理进行研究。结果在不同能量电子辐照下,瑞侃导线的力学性能均略有下降,没有显著区别,而电学性能严重退化,且低能电子较高能电子对其电学性能影响更为严重,其击穿电压分别下降了100%和50%。结论通过剂量-深度分布计算,45 keV入射电子能量全部沉积在样品表层下数微米的深度范围内,完全被导线外皮吸收,对样品的损伤较大;而1 MeV入射电子能量绝大部分穿透表皮沉积在样品铜芯中,因而其性能退化情况相对低能电子较小。进一步的,通过SEM和XPS测试和分析发现,电子辐照造成瑞侃导线分子链降解,形成自由基以及气体,自由基的再交联是造成瑞侃导线损伤的重要机理。

Degradation of Satellite Rykan Wires Irradiated by Electrons of Different Energies

The paper aims to study the tolerance ability of exposed wires on satellite in the space radiation environment.In this paper, the influence of low energy and high energy electrons on the conductor performance was studied by analyzing the radiation environment of the Rykan wire exposed in orbit for 10 years under GEO orbit. In the ground simulation test, the selected energy was 45 keV and 1 MeV; the fluence rate was 8.3×1010 e/(cm2.s); and the total dose was 2×1016 e/cm2. The degradation of mechanical properties (elongation at break, tensile strength) and electrical properties (breakdown voltage) of the Rykan wire were investigated during the test. The mechanism of electron irradiation damage was studied by means of XPS and SEM. The experimental results showed that the mechanical properties of Rykan wire were slightly reduced after irradiation under different energy electron irradiation. But the electrical properties were seriously degraded, and the influence of low-energy electrons was more serious than that of high-energy electrons. The breakdown voltage was reduced by 100% and 50% respectively.According to the calculation of dose-depth distribution, all the incoming electron energy of 45 keV is deposited in the depth range of a few microns below the surface of the sample, which is completely absorbed by the skin of the wire, causing great damage to the sample. However, most of 1MeV incident electron energy penetrates the skin and is deposited in the sample copper core, so its performance degradation is relatively small. Further, through SEM and XPS test and analysis, it is concluded that electron irradiation degrades the molecular chain of the Rykan wire, forms free radicals and gases, and the recrosslinking of free radicals is an important mechanism for the damage of the Rykan wire.