Abstract In space science missions that uses cryogen-free mechanical cooler systems to cool the low temperature telescope and detectors, a cooling time from room temperature to low temperature should be considered in the required mission life time, because of a limited cooling power of mechanical cooler. For instance, in the Space Infrared Telescope for Cosmology and Astrophysics (SPICA), the 4K-class Joule Thomson cooler (4K-JT) and the 1K-class Joule Thomson cooler (1K-JT) are being considered to cool a 2.5 m telescope and provide a 1–4 K environment for scientific instruments. The cooling capability of these JT coolers, below 20 K and even lower than 5 K, is critical for initial cooling. The 4K-JT cooling from precooling to operating temperatures under the heat input was measured and confirmed that the 4K-JT has enough cooling power to cool with these heat load. The 1K-JT cool down measurement with heater was also performed. These results enabled us to estimate the cool down time for the heat capacity provided by the telescope and scientific instruments assumed in SPICA, LiteBIRD and the ESA X-ray mission ATHENA.

中文翻译：

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JT 冷却器在空间科学任务冷却阶段的冷却能力

摘要 在使用无制冷剂机械冷却系统冷却低温望远镜和探测器的空间科学任务中，由于机械冷却器的冷却能力有限，在所需的任务寿命中应考虑从室温到低温的冷却时间。 . 例如，在宇宙学和天体物理学空间红外望远镜 (SPICA) 中，正在考虑使用 4K 级焦耳汤姆逊冷却器 (4K-JT) 和 1K 级焦耳汤姆逊冷却器 (1K-JT) 来冷却 2.5 m 望远镜并为科学仪器提供 1–4 K 环境。这些 JT 冷却器的冷却能力低于 20 K 甚至低于 5 K，对于初始冷却至关重要。在热输入下测量了从预冷到工作温度的 4K-JT 冷却，并确认 4K-JT 具有足够的冷却能力来冷却这些热负荷。还进行了带加热器的 1K-JT 冷却测量。这些结果使我们能够估计 SPICA、LiteBIRD 和 ESA X 射线任务 ATHENA 中假设的望远镜和科学仪器提供的热容量的冷却时间。