高中低能电子联合辐照电介质薄膜充放电效应

高能(350KeV)-中能(18—30KeV可调)-低能(4—5KeV可调)电子联合辐照聚酯薄膜和特氟隆薄膜,得到与中能电子辐照、高-中能电子联合辐照以及中-低能电子联合辐照不同的结果。实验结果表明,高能电子能诱发电介质薄膜充放电。特氟隆薄膜的三能电子联合辐照实验结果与Coakley和Treadaway的1-100keVdN/dE∝E~(-2)谱电子辐照实验结果以及NASCAP计算机模拟结果符合。得出结论,三能电子联合辐照可较为完善地模拟静止卫星电介质的充放电效应。论证了选用三种能量电子的充分性和必要性。推断出,如果在星食期遇到象1979年4月24日磁层亚暴事件,则静止卫星表面某些电介质局部电位有可能超过SCATHA卫星近期数据给出的和NASCAP计算的-2—-4KV,而且会出现大的放电。

CHARGING AND DISCHARGING OF DIELECTRIC FILMS IRRADIATED BY COMBINED HIGH-/MEDIUM-/LOW-ENERGY ELECTRONS

Exposure of Mylar and Teflon films to combine dhigh-/medium-/low-energy electrons has been performed whose results differ from that of exposure to medium-energy electron environment alone, combined high-/medium-energy electron environment, and combined medium-/low-energy electron environment. The experimental results have shown that dielectric discharge can be initiated by highenergy electron exposure. The results of exposure of Teflon films to combined high-/medium-/low-energy electron environment agree with that of exposure to 1—100keV dN/dE∝E~(-2) spectral energy electron environment and that of NASCAP computer simulation. It is concluded that combined high-/mediumow-energy electron exposure can perfectly simulate charging and subsequent discharging effects of dielectrics aboard geosynchronous satellites. Necessity and sufficiency of using electrons with the three different energies have been demonstrated. It is inferred that the surface potential of dielectrics on spacecraft surface will be raised and discharges will be initiated if high-and/or mediumenergy electron fluxes increase to an adequate value in geosynchronous orbit during geomagnetic storm or substorm.