AI 中文总结
该研究设计了一款1.4米长的圆柱形低温恒温器，用于微波望远镜光学元件的全息测试，通过优化结构与工艺大幅降低泄漏率，可容纳宇宙微波背景相关的全尺寸光学组件。
AI 中文摘要
我们描述了一款长度为1.4米的圆柱形低温恒温器的设计、制造、组装及室温真空合格性验证，该恒温器专为低温微波望远镜光学元件的全息测试而开发。该系统包含一个焊接成型的6061铝真空容器，内部嵌套45K和4K两层铝制辐射屏蔽层，通过商用无氧高导铜（OFHC）柔性热链接由两级脉冲管制冷机冷却。中间的45K级拦截来自室温的辐射、传导及布线热负载，而4K级则限定了用于光学测试的体积。该低温恒温器设有一个直径38厘米的微波透明真空窗口，尺寸可容纳与宇宙微波背景仪器相关的全尺寸光学组件。我们总结了该低温恒温器的架构、轻量化辐射屏蔽层、G-10支撑挠性件、焊接真空容器制造及室温泄漏检测工作。反复进行氦泄漏检测及焊接修复后，低温恒温器的观测泄漏率降低了三个数量级以上。
英文摘要
We describe the design, fabrication, assembly, and room-temperature vacuum qualification of a 1.4-m long cylindrical cryostat developed for holographic testing of cryogenic microwave telescope optics. The system consists of a welded 6061-aluminum vacuum vessel containing nested 45- and 4-K aluminum radiation shields, cooled by a two-stage pulse-tube cryocooler through commercial OFHC copper flexible thermal straps. The intermediate 45-K stage intercepts radiative, conductive, and wiring heat loads from room temperature, while the 4-K stage defines the volume used for optical testing. The cryostat includes a 38-cm aperture for a microwave-transparent vacuum window and is sized to accommodate full-scale optical assemblies relevant to cosmic microwave background instrumentation. We summarize the cryostat architecture, lightweighted radiation shields, G-10 support flexures, welded vacuum-vessel fabrication, and room-temperature leak-checking campaign. Iterative helium leak checking and weld repair reduced the observed leak rate in the cryostat by over three orders of magnitude.
CommentsSPIE Astronomical Telescopes + Instrumentation 2026, paper 14156-89, 8 pages, 5 figures
