【摘要】 利用放射性同位素（RI）束流开展逆运动学直接核反应，研究短寿命弱束缚原子核结构，是当今核物理前沿之一。由于放射性束流强相对较低，需采用高纯度、高密度气体靶以提高亮度。通常使用的高纯度轻核靶包括H₂、D₂、^3,4He气体，常温常压下密度小。为了克服这些局限性，中国科学院近代物理研究所与合作团队研制了一套液氮冷却低温气体靶系统，通过降温和加压显著增加靶气体密度。本工作介绍该系统的设计、工作原理及离线测试结果。0.2 MPa下的⁴He气体经液氮冷却后，靶面密度达到3.3 mg/cm²，为常温常压的8倍。系统运行稳定，满足放射性束流实验要求，为利用各类气体靶开展放射性束实验提供了坚实的技术平台。更多还原

【Abstract】 Experiments with radioactive isotope（RI） beams using direct nuclear reactions in inverse kinematics are at the forefront of nuclear physics research to study the structure of short-lived, weakly bound nuclei. Due to the relatively low intensity of RI beams, it is essential to use pure and dense targets to increase luminosity. Commonly used high-purity light nuclear targets include H₂, D₂, and ^3,4He gases, which have low densities at room temperature and pressure. To overcome this limitation, the Institute of Modern Physics, Chinese Academy of Sciences, in collaboration with partner teams, has developed a liquid-nitrogen-cooled, low-temperature gas target system that significantly increases gas density by lowering temperature and increasing pressure. This paper describes its design, operating principle, and offline measurement results. After cooling by liquid nitrogen, the areal density of the target reaches 3.3 mg/cm² with ⁴He gas at 0.2 MPa, eight times higher than at room temperature and pressure. The system operates stably and meets the requirements of RI beam experiments, providing a robust technical platform for RI-beam experiments with gas targets.更多还原