发表机构
Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology（佐治亚理工学院丹尼尔·古根海姆航空航天工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究提出两阶段方法优化Halbach阵列，以最小化毛细驱动轨道液体镜望远镜的界面误差，经536磁体演示阵列验证，可显著降低表面误差，为未来阵列设计提供方向。
AI 中文摘要
磁控铁磁流体液体镜望远镜在自适应光学和大型天基望远镜等应用中，是传统固体镜的有前景替代方案。然而，该概念的关键在于能否精确配置驱动铁磁流体的磁场。对于Halbach阵列驱动的镜面，表面光滑度要求对应于开尔文体积力场的均匀性要求。由于永磁体之间的剩磁、磁化轴对齐和偶极位置存在个体差异，可实现的场均匀性取决于有限磁体库存如何分配到阵列中。本研究提出了一种两阶段方法，用于最小化由单独表征的磁体库存组装而成的球冠Halbach阵列的界面误差。第一阶段，将分析静磁模型与铁磁流体等势模型耦合，嵌入遗传算法中，为每个磁体分配位置、方向和安装高度，以最小化径向加权均方根（RMS）表面残差。第二阶段，使用磁测绘仪对组装后的阵列进行表征，并通过迭代高度微调校正剩余误差。将该方法应用于536个磁体、0.1米孔径的演示阵列，优化后的放置方法与未优化分配相比，可将建模的加权RMS残差降低38.6%。然而，由于制造误差，组装后的阵列测得的RMS表面误差仍高达107.4微米，迭代磁体高度调整可将该误差降低28.3%，至77.0微米。对建模和实测残差的比较表明，磁体间作用力导致的磁体机械倾斜是主要剩余误差源，这为未来阵列设计提供了方向，即采用更坚固的固定硬件和更高分辨率的磁体支架设计。
英文摘要
Space-based liquid mirror telescopes (LMTs) have been recently proposed to overcome the scaling limits of traditional rigid mirrors. In these new space architectures, capillary forces would shape a reflective liquid into a spherical optical surface in microgravity. However, the equilibrium, stability, and dynamic behavior of such liquid interfaces under orbital perturbations remain largely uncharacterized. This study investigates the feasibility of space LMTs by combining axisymmetric capillary with thin-film models. Solar radiation pressure and self-gravitation are found to be the dominant perturbations in Sun--Earth L2 orbits, causing equilibrium deformations that exceed the $λ/20$ optical threshold at apertures above 0.86 m for visible ($λ= 380$ nm) and 1.58 m for near-infrared observatories ($λ= 2.5$ $μ$m). Micrometeoroid impacts self-heal within seconds to minutes, settling after filling requires years to decades at large apertures, and propulsive maneuvers breach optical limits within seconds to hours. These results highlight the need for interface control in large-scale systems such as NASA's 50 m Fluidic Telescope (FLUTE). Thermocapillary actuation supports apertures of 2.3/8.0 m (VIS/NIR) at 100 $μ$K and 10.6/37.7 m at 10 $μ$K. Simultaneously, parasitic Marangoni flows impose sub-mK uniformity for NIR and 1--100 $μ$K for visible operation on any capillary LMT. Departing the capillary regime by imposing a surface-normal settling acceleration, ranging from 39 mm s$^{-2}$ (NIR,5 m) to 17 m s$^{-2}$ (VIS,50 m), is the most promising route to tens of meters in aperture. This approach enables a passive implementation effectively suppressing perturbation induced interface distortions and thermal Marangoni flows. Keywords: Liquid mirror telescope, Optics, Space
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