错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Stepped-up development of accelerator mass spectrometry method for the detection of 60Fe with the HI-13 tandem accelerator

  • Yang Zhang,
  • Sheng-Quan Yan,
  • Ming He,
  • Qing-Zhang Zhao,
  • Wen-Hui Zhang,
  • Chao-Xin Kan,
  • Jian-Ming Zhou,
  • Kang-Ning Li,
  • Xiao-Fei Wang,
  • Jian-Cheng Liu,
  • Zhao-Hua Peng,
  • Zhuo Liang,
  • Ai-Ling Li,
  • Jian Zheng,
  • Qi-Wen Fan,
  • Yun-Ju Li,
  • You-Bao Wang,
  • Zhi-Hong Li,
  • Yang-Ping Shen,
  • Ding Nan,
  • Wei Nan,
  • Yu-Qiang Zhang,
  • Jia-Ying-Hao Li,
  • Jun-Wen Tian,
  • Jiang-Lin Hou,
  • Chang-Xin Guo,
  • Zhi-Cheng Zhang,
  • Ming-Hao Zhu,
  • Yu-Wen Chen,
  • Yu-Chen Jiang,
  • Tao Tian,
  • Jin-Long Ma,
  • Yi-Hui Liu,
  • Jing-Yu Dong,
  • Run-Long Liu,
  • Mei-Yue-Nan Ma,
  • Yong-Shou Chen,
  • Wei-Ping Liu,
  • Bing Guo

摘要

The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae. Lunar samples retain valuable information from these events, via detectable long-lived “fingerprint” radionuclides such as \({}^{60} \hbox{Fe}\) 60 Fe . In this work, we stepped up the development of an accelerator mass spectrometry (AMS) method for detecting \({}^{60} \hbox{Fe}\) 60 Fe using the HI-13 tandem accelerator at the China Institute of Atomic Energy (CIAE). Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph, a Wien filter with a maximum voltage of \(\pm\,60\,\text {kV}\) ± 60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide \({}^{60} \hbox{Fe}\) 60 Fe . A \(1\,\upmu \text {m}\) 1 μ m thick Si \(_{3}\) 3 N \(_{4}\) 4 foil was installed in front of the Q3D as an energy degrader. For particle detection, a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph. Finally, an \({}^{60} \hbox{Fe}\) 60 Fe sample with an abundance of \(1.125 \times 10^{-10}\) 1.125 × 10 - 10 was used to test the new AMS system. These results indicate that \({}^{60} \hbox{Fe}\) 60 Fe can be clearly distinguished from the isobar \({}^{60} \hbox{Ni}\) 60 Ni . The sensitivity was assessed to be better than \(4.3 \times 10^{-14}\) 4.3 × 10 - 14 based on blank sample measurements lasting \(5.8\) 5.8 h, and the sensitivity could, in principle, be expected to be approximately \(2.5 \times 10^{-15}\) 2.5 × 10 - 15 when the data were accumulated for 100 h, which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.