Citation: | Fang S J, Li B H, He B, et al. Design and thermal stability analysis of primary mirror assembly for space-borne gravitational wave telescope[J]. Opto-Electron Eng, 2024, 51(2): 230157. doi: 10.12086/oee.2024.230157 |
[1] | Einstein A. Approximative integration of the field equations of gravitation[J]. Sitzungsber Preuss Akad Wiss Berlin (Math Phys), 1916, 1916: 688−696. |
[2] | Abbott B P, Abbott R, Abbott T D, et al. Observation of gravitational waves from a binary black hole merger[J]. Phys Rev Lett, 2016, 116(6): 061102. doi: 10.1103/PhysRevLett.116.061102 |
[3] | Danzmann K, The LISA Study Team. LISA: laser interferometer space antenna for gravitational wave measurements[J]. Class Quantum Grav, 1996, 13(11A): A247−A250. doi: 10.1088/0264-9381/13/11A/033 |
[4] | Luo J, Chen L S, Duan H Z, et al. TianQin: a space-borne gravitational wave detector[J]. Class Quantum Grav, 2016, 33(3): 035010. doi: 10.1088/0264-9381/33/3/035010 |
[5] | Ruan W H, Guo Z K, Cai R G, et al. Taiji program: gravitational-wave sources[J]. Int J Mod Phys A, 2020, 35(17): 2050075. doi: 10.1142/S0217751X2050075X |
[6] | 范纹彤, 赵宏超, 范磊, 等. 空间引力波探测望远镜系统技术初步分析[J]. 中山大学学报(自然科学版), 2021, 60(1-2): 178−185. doi: 10.13471/j.cnki.acta.snus.2020.11.02.2020b111 Fan W T, Zhao H C, Fan L, et al. Preliminary analysis of space gravitational wave detection telescope system technology[J]. Acta Sci Nat Univ Sunyatseni, 2021, 60(1-2): 178−185. doi: 10.13471/j.cnki.acta.snus.2020.11.02.2020b111 |
[7] | 王小勇,白绍竣,张倩,等. 空间引力波探测望远镜研究进展[J]. 光电工程, 2023, 50(11): 230219. doi: 10.12086/oee.2023.230219 Wang X Y, Bai S J, Zhang Q, et al. Research progress of telescopes for space-based gravitational wave missions[J]. Opto-Electron Eng, 2023, 50(11): 230219. doi: 10.12086/oee.2023.230219 |
[8] | 李博宏,罗健,丘敏艳,等. 引力波探测望远镜超低热变形桁架支撑结构设计技术[J]. 光电工程, 2023, 50(11): 230155. doi: 10.12086/oee.2023.230155 Li B H, Luo J, Qiu M Y, et al. Design technology of the truss support structure of the ultra-low thermal deformation gravitational wave detection telescope[J]. Opto-Electron Eng, 2023, 50(11): 230155. doi: 10.12086/oee.2023.230155 |
[9] | Livas J, Arsenovic P, Castelluci K, et al. LISA telescope spacer design issues[R]. Washington: NASA Goddard Space Flight Center, 2010. |
[10] | Sanjuán J, Korytov D, Mueller G, et al. Note: silicon carbide telescope dimensional stability for space-based gravitational wave detectors[J]. Rev Sci Instrum, 2012, 83(11): 116107. doi: 10.1063/1.4767247 |
[11] | Livas J, Blake S, Davis A, et al. Proposed LISA telescope design[R]. Washington: NASA Goddard Space Flight Center, 2019. |
[12] | Livas J, Derosa R, Keski-Kuha R, et al. Technology development for LISA: the telescope[EB/OL]. Bull Am Phys Soc, 2020, 65. https://absuploads.aps.org/presentation.cfm?pid=18123 |
[13] | 李钰鹏, 王智, 沙巍, 等. Bipod反射镜支撑结构的柔度计算及分析[J]. 光学 精密工程, 2018, 26(7): 1691−1697. doi: 10.3788/OPE.20182607.1691 Li Y P, Wang Z, Sha W, et al. Flexibility calculation and analysis of Bipod reflector support structure[J]. Opt Precis Eng, 2018, 26(7): 1691−1697. doi: 10.3788/OPE.20182607.1691 |
[14] | 李钰鹏, 王智, 沙巍, 等. 空间引力波望远镜主镜组件的结构设计[J]. 红外与激光工程, 2018, 47(8): 0818004. doi: 10.3788/IRLA201847.0818004 Li Y P, Wang Z, Sha W, et al. Structural design of primary mirror subassembly for spatial gravitational wave telescope[J]. Infrared Laser Eng, 2018, 47(8): 0818004. doi: 10.3788/IRLA201847.0818004 |
[15] | 王辰忠, 胡中文, 陈忆, 等. 空间引力波望远镜主反射镜系统的结构设计优化[J]. 红外与激光工程, 2020, 49(7): 20190469. doi: 10.3788/IRLA20190469 Wang C Z, Hu Z W, Chen Y, et al. Structural design optimization of space gravitational wave telescope primary mirror system[J]. Infrared Laser Eng, 2020, 49(7): 20190469. doi: 10.3788/IRLA20190469 |
[16] | Dai J S, Ding X L. Compliance analysis of a three-legged rigidly-connected platform device[J]. J Mech Des, 2006, 128(4): 755−764. doi: 10.1115/1.2202141 |
[17] | Selig J M, Ding X L. A screw theory of Timoshenko beams[J]. J Appl Mech, 2009, 76(3): 031003. doi: 10.1115/1.3063630 |
[18] | 张丽敏, 王富国, 安其昌, 等. Bipod柔性结构在小型反射镜支撑中的应用[J]. 光学 精密工程, 2015, 23(2): 438−443. doi: 10.3788/OPE.20152302.0438 Zhang L M, Wang F G, An Q C, et al. Application of Bipod to supporting structure of minitype reflector[J]. Opt Precis Eng, 2015, 23(2): 438−443. doi: 10.3788/OPE.20152302.0438 |
[19] | Kihm H, Yang H S, Lee Y W. Bipod flexure for 1-m primary mirror system[J]. Rev Sci Instrum, 2014, 85(12): 125101. doi: 10.1063/1.4902151 |
Space gravitational wave detection missions typically consist of three identical satellites, with two laser links between the satellites at an angle of sixty degrees forming a Michelson interferometer. The arm length changes are measured using high-precision inter-satellite laser interferometry. As a key component of the inter-satellite laser interferometry system, the telescope system needs to have picometer-level optical path stability, a wavefront error of λ/30, and stray light less than 10−10 of the transmitted power. To meet the requirements of space gravitational wave detection for the telescope system, an optical and mechanical integrated analysis and optimization method is proposed to design and optimize the primary mirror and its supporting structure. The off-axis parabolic primary mirror adopts the side three-point support method, and the influence of the support point position on the mirror surface shape and the rigid body displacement under gravity conditions has been studied. Optimization of the size of the triangular lightweighting holes on the primary mirror has been performed, and density-based topology optimization has been used to optimize the support backplate while ensuring that the first-order mode of the primary mirror component remains essentially unchanged. The flexural matrix of the primary mirror component supported by a parallel bipod linkage structure was derived based on spinor theory, and an evaluation function for the support structure was established. The size parameter range of flexible support was preliminarily determined by Matlab analysis. A optical-mechanical integrated simulation platform is set up to optimize the parameters of the support structure using a weighted sum method to convert the multi-objective optimization problem into a single-objective optimization problem. The results showed that the first-order frequency of the primary mirror component system was 392.43 Hz. Under gravity and temperature loads, the deformation of the primary mirror surface was better than λ/60, the translational rigid body displacement was better than 2.5 μm, and the rotational rigid body displacement was better than 0.5 μrad, all of which met the design specifications. Under space thermal disturbance of 10 μK/Hz1/2, the size stability of the primary mirror component, represented by the displacement of the central point of the mirror, was at a level of 10 pm/Hz1/2.
Schematic diagram of the telescope system. (a) Telescope optical system; (b) Primary mirror assembly
Primary mirror lightweight model. (a) Support point layout; (b) Rib plate parameters; (c) Mirror thickness
Relation between top angle of support and surface shape and rigid body displacement under different gravity directions. (a) Gravity force in the X-direction; (b) Gravity force in the Y-direction
Topology optimization results of the backplane. (a) Initial backplane; (b) Topological result; (c) Optimized backplane
Stress-strain diagram of the beam element
Parameters of the flexible legs
Schematic diagram of a single Bipod flexible support
Schematic diagram of primary mirror’s flexible support
Influence of structural parameters on the evaluation function
The structure of the primary mirror assembly is deformed. (a) Finite element model; (b) Gravity condition; (c) Temperature condition; (d) Superposition condition
Surface error of the primary mirror. (a) Gravity condition; (b) Temperature condition; (c) Superposition condition
Structural stability of primary mirror assembly. (a) Temperature stability of the environment; (b) Dimensional stability of structure