[8a-Z25-1~12] 【CS.1】 Code-sharing Session of 2.4 & 7.5

[8a-Z25-3] Study on Removal Method of Isobaric ³⁶S Interference for ³⁶Cl AMS

〇Kimikazu Sasa¹, Tsutomu Takahashi¹, Masumi Matsumura¹ (1.UTTAC, Univ. Tsukuba)

Keywords:Accelerator Mass Spectrometry, Cl-36, Isobar suppression technique

A 6 MV tandem accelerator at the University of Tsukuba has been working on multi-nuclide accelerator mass spectrometry (AMS). This paper reports improvement of isobar suppression techniques for ³⁶Cl AMS. A Cu sample holder with AgBr backing is the most suitable for ³⁶Cl AMS to decrease isobaric ³⁶S interference. We found that preparation under acidic conditions was most appropriate to reduce ³⁶S in ³⁶Cl AMS. Cl charge states and their analysis method were considered to improve peak separation. ³⁶Cl⁷⁺ and ³⁶Cl⁸⁺ were chosen for detection because it allows clear separation of ³⁶S from the ³⁶Cl spectrum. As a result, a ³⁶Cl/Cl background of < 3×10^-15 was achieved.