A 3-stage adiabatic demagnetization refrigerator (ADR)[1] is used on the Soft X-ray Spectrometer instrument[2] on Astro-H[3] to cool a 6×6 array of x-ray microcalorimeters to 50 mK. The ADR is supported by a cryogenic system[4] consisting of a superfluid helium tank, a 4.5 K Joule-Thomson (JT) cryocooler, and additional 2-stage Stirling cryocoolers that pre-cool the JT cooler and cool radiation shields within the cryostat. The ADR is configured so that it can use either the liquid helium or the JT cryocooler as its heat sink, giving the instrument an unusual degree of tolerance for component failures or degradation in the cryogenic system. The flight detector assembly, ADR and dewar were integrated into the flight dewar in early 2014, and have since been extensively characterized and calibrated. This paper summarizes the operation and performance of the ADR in all of its operating modes.

中文翻译：

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为 Astro-H 上的软 X 射线光谱仪仪器开发的 3 级 ADR 的操作模式和冷却能力

Astro-H[3] 上的软 X 射线光谱仪 [2] 使用 3 级绝热退磁制冷机 (ADR)[1] 将 6×6 的 X 射线微量热计阵列冷却至 50 mK。ADR 由一个低温系统 [4] 支持，该系统由一个超流氦气罐、一个 4.5 K 焦耳-汤姆逊 (JT) 低温冷却器和额外的 2 级斯特林低温冷却器组成，这些低温冷却器预冷却 JT 冷却器和冷却低温恒温器内的辐射屏蔽. ADR 的配置使其可以使用液氦或 JT 低温冷却器作为其散热器，从而使仪器对低温系统中的组件故障或退化具有不同寻常的容忍度。飞行探测器组件、ADR 和杜瓦瓶于 2014 年初集成到飞行杜瓦瓶中，此后进行了广泛的表征和校准。