中文摘要：

中国科学院等离子体物理研究所ITERCC导体测试装置背景超导磁体，由4．2K液氦浸泡冷却，能够提供7T背景场，为了满足超导导体测试需要更大背景场（10T）的要求，将采用1．8K超流氦浸泡冷却。针对该测试装置的低温系统设计了一种1．8K常压超流氦低温系统，给出了该系统的关键组成部分并对获取1．8K常压超流氦的流程进行了分析。针对预冷与节流相结合获取1．75K超流氦方案进行了分析和计算，同时针对此方案给出了其物理过程的T—S图，计算了1．75K超流氦液体得率。

英文摘要：

The superconducting magnet of the testing facility in Institute of Plasma Physics, Chinese Academy of Sciences（ASIPP）for ITER CC conductor was immersed by the 4.2 K liquid helium cooling to provide a 7 T background magnetic field. In order to meet the demands of superconducting conductor test requi- ring a larger background field （10 T） ,the superconducting was immersed by a 1.8 K super fluid helium. A 1.8 K-atmospheric super fluid helium cryogenic system was designed for the testing facility, the system＇s key components were given and how to obtain the 1.8 K-atmospheric super fluid helium was analyzed. Calculation and analysis of the throttling process according to pre-cooling and the temperature-entropy diagram of the process were put forward. The liquid ratios of super fluid helium of the method was computed and given.