空间太阳望远镜中的轻量化铍镜研究

Study on lightweight beryllium mirror of space solar telescope

为提高空间太阳望远镜相关跟踪系统的动态性能,验证金属铍作为可见光波段反射镜材料的可行性与可靠性,对空间太阳望远镜相关跟踪器中的摆镜进行了研究,设计与研制了Φ84 mm轻量化铍镜。利用冲击研磨工艺得到铍粉,再通过热等静压工艺和机械加工得到铍镜镜坯。使用化学镀镍工艺在镜坯基体上镀覆镍磷合金过渡层,再经过光学加工完成铍镜研制。镜面干涉检测后得到面形精度为RMS:0.012λ,PV:0.114λ,铍镜轻量化率为43.68%。检测结果满足空间太阳望远镜的技术要求。

In order to improve the dynamic performance of the correlation tracker in a Space Solar Tel escope, and to verify the feasibility and reliability of a beryllium mirror working in visible band, the tip-tilt mirror of the correlation tracker in the space solar telescope was studied. A φ84 mm light weight beryllium mirror was designed and fabricated. Beryllium powder was obtained by impact attrition technique, and the beryllium mirror blank was fabricated by hot isostatic pressing technique and mechanical processing. The nickel-phosphorus alloy layer was plated onto the substrate of beryllium mirror by electroless nickel plating, and the beryllium mirror was completed by optical processing. Surface testing results indicate that the surface figure errors of beryllium mirror are PV value of 0.114λ and RMSof0.012λ（λ=f32.8nm）, and the lightweight ratio is 43.68%. The results of surface figure error satisfy the technical requirements for the space solar telescope, which shows that be ryllium can be used as mirror substrate materials of space astronomical instruments.