The General Antiparticle Spectrometer (GAPS) is an Antarctic balloon experiment designed for low-energy (0.1–0.3 GeV/$n$) cosmic antinuclei as signatures of dark matter annihilation or decay. GAPS is optimized to detect low-energy antideuterons, as well as to provide unprecedented sensitivity to low-energy antiprotons and antihelium nuclei. The novel GAPS antiparticle detection technique, based on the formation, decay, and annihilation of exotic atoms, provides greater identification power for these low-energy antinuclei than previous magnetic spectrometer experiments. This work reports the sensitivity of GAPS to detect antihelium-3 nuclei, based on full instrument simulation, event reconstruction, and realistic atmospheric influence simulations. The report of antihelium nuclei candidate events by AMS-02 has generated considerable interest in antihelium nuclei as probes of dark matter and other beyond the Standard Model theories. GAPS is in a unique position to detect or set upper limits on the cosmic antihelium nuclei flux in an energy range that is essentially free of astrophysical background. In three 35-day long-duration balloon flights, GAPS will be sensitive to an antihelium flux on the level of $1.3_{-1.2}^{+4.5}·{10}^{-6}$ m^-2sr^-1s^-1(GeV/$n$)^-1 (95% confidence level) in the energy range of 0.11–0.3 GeV/$n,$ opening a new window on rare cosmic physics.

通用反粒子光谱仪（GAPS）是为低能（0.1–0.3 GeV /$ñ$）宇宙反核是暗物质matter灭或衰变的标志。GAPS经过优化，可检测低能抗氘核，并为低能抗质子和抗氦核提供前所未有的灵敏度。基于异质原子的形成，衰变和an灭的新颖GAPS反粒子检测技术比以前的电磁光谱仪实验为这些低能反核提供了更大的识别能力。这项工作报告了GAPS检测抗氦3核的敏感性，这是基于完整的仪器模拟，事件重建和现实的大气影响模拟。AMS-02关于抗氦核候选事件的报告引起了人们对抗氦核作为暗物质和其他超出标准模型理论的探究的兴趣。GAPS在检测或设置宇宙抗氦原子核通量的上限（其能量范围基本上没有天文学背景）的唯一位置。在三个35天的长时间热气球飞行中，GAPS将对抗氦气通量的水平敏感$\mathrm{1个}。3_{-1.2}^{+4.5}·{10}^{-6}$ m ^-2 sr ^-1 s ^-1（GeV /$ñ$）^-1（95％置信水平）在0.11-0.3 GeV /的能量范围内$ñ，$ 打开了一个罕见的宇宙物理学的新窗口。