面向空间天文探测的液氦温区脉冲管制冷机理研究

在我国大力推动天体物理及宇宙学前沿研究的背景下，空间天文探测项目对制冷机的需求日益增多。然而目前国内空间制冷机工作温度都高于20K，更低温区制冷技术发展滞后，成为我国极低温天文探测发展的一大瓶颈。本项目探索使用脉冲管制冷机直接获得液氦温区温度。围绕空间天文探测的“更低温度”、“多温区供冷（冷却探测器、多个辐射屏和引线热沉）”和“重量轻”等实际需求，开展气耦合脉冲管制冷机理与流程研究。在揭示高频回热损失机制和探明非理想气体效应抑制与利用途径的基础上，研制出原理样机。相对国外“多级预冷+节流”方案，高效工作区间从2-5K提高至2-20K，运动部件压缩机数量从4-5个减少至1-2个。研究成果可直接满足“宇宙热重子探寻计划”、“觅音计划”，以及量子超导干涉器件、超导纳米线单光子探测器和不同波段探测器对2-20K制冷技术的迫切需求，其紧凑的结构和固有的低振动属性也为发展轻量化mK制冷系统奠定基础。

Under the background that China vigorously promotes the research of the frontier of astrophysics and cosmology, the demand for the refrigerator for space astronomy exploration projects increasing rapidly. The working temperature of the space refrigerator that has been successfully applied in China is higher than 20 K, and the development of the refrigeration technology in the lower temperature zone is lagging behind, which is a major bottleneck restricting the exploration of ultra-low-temperature astronomy in China. This project explores the use of a pulse tube refrigerator to obtain the liquid helium temperature directly. Based on the actual requirements of "lower temperature", "cooling at multiple temperatures (In addition to the detector, it is necessary to cool the radiation shields and heat sinks outside the detector.)" and "lightweight" for space astronomical exploration, the gas-coupled pulse tube refrigerator mechanism and refrigeration process will be studied. A prototype will be developed based on revealing the mechanism of high-frequency regenerator loss and identify ways to suppress and utilize non-ideal gas effects. Compared with the foreign "multi-stage pre-cooling + JT" scheme, the efficient working range is increased from 2-5 K to 2-20 K, and the number of moving part compressors is reduced from 4-5 to 1-2. The research results can directly meet the urgent demand of 2-20 K refrigeration technology for satellite programs such as "Hot University Baryon Surveyor" and "Mi Yin", as well as quantum superconducting interference devices, superconducting nanowires single-photon detectors and detectors of different wavebands. Its compact structure and inherent low vibration properties also laid the foundation for the development of a lightweight mK refrigeration system.