Effects of temporal dimensional instability on the Advanced X-ray Astrophysics Facility (AXAF-I) high-resolution mirror assembly (HRMA)
Effects of temporal dimensional instability on the Advanced X-ray Astrophysics Facility (AXAF-I) high-resolution mirror assembly (HRMA)
复制标题
时间维度不稳定性对先进 X 射线天体物理设施 (AXAF-I) 高分辨率反射镜组件 (HRMA) 的影响
DOI：
10.1117/12.212603
复制
发表时间：
1995
影响因子：
2.8
通讯作者：
L. Cohen
中科院分区：
文献类型：
--
作者：
L. Cohen
美国航天局高级X射线天体物理学设施-成像（AXAF-I）是美国航天局的大型观测台之一，将于1998年发射。AXAF-I高分辨率反射镜组件（HRMA）将在五年的预期使命寿命内提供亚弧秒成像分辨率。在望远镜的组装和使用寿命期间，结构支撑系统的小尺寸变化会通过引入不必要的力而降低望远镜的分辨能力。引入的力部分取决于望远镜中使用的材料的长期时间尺寸稳定性。亚利桑那大学尺寸稳定性实验室进行的一项为期一年的稳定性研究最近得出结论。研究了氰酸酯基复合材料，7050-T7451铝，LR-35因瓦，6Al-4V钛，6061-T6铝和Zerodur。发现Zerodur材料的稳定性优于0.03 ppm/年。发现钛的稳定性优于0.5 ppm/年。发现7050- T7451铝和氰酸酯基复合材料相对不稳定，但其不稳定性随时间显著改善。蒙特-卡罗和确定性技术被用来预测不稳定性对望远镜性能的影响。时间不稳定性效应在系统最高要求范围内。
The NASA Advanced X-ray Astrophysics Facility-Imaging (AXAF-I), one of NASA's Great Observatories, will be launched in 1998. The AXAF-I High Resolution Mirror Assembly (HRMA) will provide sub-arc second imaging resolution over the expected mission life of five years. During assembly and operational life of the telescope, small dimensional changes of the structural support system can degrade the telescopes resolving power by introducing unwanted forces. The forces that are introduced depend, in part, on the long term temporal dimensional stability of the materials that are used in the telescope. A year-long stability study carried out at the university of Arizona Dimensional Stability Laboratory recently concluded. Cyanate ester-based composites, 7050-T7451 aluminum, LR-35 invar, 6Al-4V titanium, 6061-T6 aluminum and Zerodur were studied. The Zerodur material was found to be stable to better than 0.03 ppm/yr. The titanium was found to be stable to better than 0.5 ppm/yr. The 7050- T7451 aluminum and cyanate ester-based composites were found relatively unstable but their instability improved significantly with time. Monte-Carlo and deterministic techniques were used to predict the effects of the instability on the telescopes' performance. Temporal instability effects were within the systems top level requirements.