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Research and Development of Ground Simulation Methods for Spacecraft Environment, and Degradation Experiments of Spacecraft Materials

航天器环境地面模拟方法研究与进展及航天器材料降解实验

基本信息

批准号：
09555301
负责人：
TAHARA Hirokazu
金额：
$ 5.57万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

A ground facility was developed for simulation of material and space plasma interaction and for study of spacecraft charging and discharge phenomena. The plasma simulator consisted of a vacuum tank, two turbo-molecular pumps and an electron cyclotron resonance plasma source of a magnetic-field-expansion plasma accelerator. Oxygen, nitrogen and argon plasma properties were measured. The simulator was found to have a high potential for ground tests. Using the simulator, the structure of an ion sheath created around a high voltage solar array and the degradation of surface materials near the array due to high energy ion bombardment were investigated. A negatively biased plate was exposed to oxygen plasma flow. The ion current and the plasma potential distribution were found to be intensively changed by the biased voltage and the attack angle, particularly a scaling parameter derived from the one-dimensional ion sheath theory. Furthermore, in order to examine the influences of ion bombardment on chemical structures of spacecraft surface materials, polymer films of polyimide BPDA-PDA Kapton, located on the biased plate, were exposed to oxygen plasma flow. The XPS analysis showed that an addition reaction of oxygen atoms or ions at wake condition was negligible compared with that at ram condition because of a smaller ion flux. Consequently, the addition reaction and a desorption of structural components were found to occur by ion bombardment. They are expected to cause the decrease in performance of spacecraft thermal control. Furthermore, in order to understand the relaxation of spacecraft charging by plasma flow, i.e., plasma contactor operation, Kapton and Teflon FEP films negatively charged by exposure to high energy electron beams and metal plates in series with negatively charged condensers were exposed to argon plasma flow. Negative charging was rapidly relaxed, and the attack angle influenced the time variation of the neutralization current.

为模拟物质与空间等离子体的相互作用以及研究航天器充电和放电现象开发了一个地面设施。等离子体模拟器由一个真空罐，两个涡轮分子泵和一个磁场膨胀等离子体加速器的电子回旋共振等离子体源组成。测量了氧、氮和氩等离子体的特性。该模拟器被认为具有很高的地面测试潜力。利用该模拟器，研究了高压太阳能电池阵周围产生的离子鞘的结构以及高能离子轰击引起的电池阵附近表面材料的退化。将负偏压板暴露于氧等离子体流。离子电流和等离子体电位分布被发现强烈改变的偏置电压和攻角，特别是一个标度参数来自一维离子鞘理论。此外，为了研究离子轰击对航天器表面材料的化学结构的影响，聚酰亚胺BPDA-PDA Kapton的聚合物膜，位于偏置板上，暴露于氧等离子体流。XPS分析表明，尾流条件下的氧原子或氧原子离子的加成反应比冲压条件下的小，可以忽略不计。因此，发现通过离子轰击发生加成反应和结构组分的解吸。它们将导致航天器热控性能的下降。此外，为了理解等离子体流对航天器充电的弛豫，即，在等离子体接触器操作中，Kapton和Teflon FEP膜通过暴露于高能电子束而带负电荷，并且将与带负电荷的冷凝器串联的金属板暴露于氩等离子体流。负电荷迅速弛豫，攻角影响中和电流的时间变化。