Design and commissioning of a windowless gas-target system for high-current beams at JUNA

@misc{wang2026design,
  title = {{Design and commissioning of a windowless gas-target system for high-current beams at JUNA}},
  author = {Xuyang Wang and Fuqiang Cao and Weike Nan and Gang Lian and Wei Nan and Hongwei Huang and Yuchen Jiang and Jingyu Dong and Minghao Zhu and Yuwen Chen and Yihui Liu and Jinlong Ma and Yueran Wang and Jie Chen and Yunju Li and Shengquan Yan and Youbao Wang and Xiao Fang and Luohuan Wang and Yangping Shen and Bing Guo and Weiping Liu and JUNA collaboration},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.08782},
  eprint = {2609.08782},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.08782},
  note = {CC BY-NC-ND 4.0},
}

TY  - UNPB
TI  - Design and commissioning of a windowless gas-target system for high-current beams at JUNA
AU  - Xuyang Wang
AU  - Fuqiang Cao
AU  - Weike Nan
AU  - Gang Lian
AU  - Wei Nan
AU  - Hongwei Huang
AU  - Yuchen Jiang
AU  - Jingyu Dong
AU  - Minghao Zhu
AU  - Yuwen Chen
AU  - Yihui Liu
AU  - Jinlong Ma
AU  - Yueran Wang
AU  - Jie Chen
AU  - Yunju Li
AU  - Shengquan Yan
AU  - Youbao Wang
AU  - Xiao Fang
AU  - Luohuan Wang
AU  - Yangping Shen
AU  - Bing Guo
AU  - Weiping Liu
AU  - JUNA collaboration
PY  - 2026
DA  - 2026/09/09
PB  - arXiv
DO  - 10.48550/arxiv.2609.08782
UR  - https://arxiv.org/abs/2609.08782
AB  - Windowless gas targets avoid the beam-energy loss and straggling introduced by entrance foils and are therefore well suited for direct measurements of low-energy nuclear reactions. A windowless gas-target system designed for operation with milliampere beams has been developed for the Jinping Underground Nuclear Astrophysics facility (JUNA). The system combines three-stage differential pumping, closed-loop gas recovery and purification, a constant-temperature power-compensation calorimeter, and a position-resolved target-thickness monitor based on secondary elastic scattering. Stable operation was achieved over a target-pressure range of 1-3 mbar, with pressure fluctuations below 1% during 8 h of continuous circulation, while the accelerator-side pressure was maintained at approximately 10^−4 Pa. The closed-loop gas-circulation system maintained stable target conditions, while gas-transport calculations indicated that the axial pressure nonuniformity remained within approximately 1.6% under representative operating conditions. Calorimeter measurements were consistent with the thermal calculations, supporting the sensitivity correction used for beam-power determination. Beam commissioning with ^14N(p,γ)^15O and ^12C(p,γ)^13N at the 600 kV Cockcroft-Walton accelerator of the China Institute of Atomic Energy (CIAE) demonstrated stable operation of the gas-target and γ-ray detection systems and provided information on the influences of reaction position and beam heating. These results demonstrate the operating stability and diagnostic capability of the system for future high-current, low-energy nuclear-reaction measurements at JUNA.
ER  -