Ground-based observatories across a wide range of wavelengths implement cryogenic cooling techniques to increase the sensitivity of instruments and enable low temperature detector technologies. Commercial pulse tube cryocoolers (PTCs) are frequently used to provide 40 K and 4 K stages as thermal shells in scientific instruments. However, PTC operation is dependent on gravity, giving rise to changes in cooling capacity over the operational tilt range of pointed telescopes. We present a study of the performance of a two stage PTC with a cooling capacity of 1.8 W at 4.2 K and 50 W at 45 K (Cryomech PT420-RM) from $0-55°$ away from vertical to probe capacity as a function of angle over a set of realistic thermal loading conditions. Our study provides a method to extract temperature estimates given predicted thermal loading conditions across the angular range sampled. We then discuss the design implications for current and future tilted cryogenic systems.

各种波长的地面天文台采用低温冷却技术，以提高仪器的灵敏度并启用低温探测器技术。商业脉冲管低温冷却器 (PTC) 经常用于提供 40  K 和 4  K 级作为科学仪器中的热壳。然而，PTC 操作依赖于重力，导致在尖头望远镜的操作倾斜范围内冷却能力发生变化。我们研究了两级 PTC 的性能，其冷却能力为 4.2  K 时为 1.8  W，45  K 时为50 W （Cryomech PT420-RM）$0——55°$在一组真实的热负载条件下，从垂直到探头容量作为角度的函数。我们的研究提供了一种方法，可以在给定的采样角度范围内的预测热负载条件下提取温度估计值。然后我们讨论了对当前和未来倾斜低温系统的设计影响。