*Riko Yagihashi¹, Kazuho Horiuchi¹, Hideaki Motoyama², Takeyasu Yamagata³, Hiroyuki Matsuzaki³ (1.Graduate School of Science and Technology, Hirosaki University, 2.National Institute of Polar Research, 3.Micro Analysis Laboratory, Tandem accelerator (MALT), The University of Tokyo)

*Riko Yagihashi¹, Kazuho Horiuchi¹, Kohsei Yoshioka², Iizuka Yoshinori³, Sumito Matoba³, Kaoru Kawakami^3,4, Sakiko Ishino⁵, Mahiro Sasage^3,4, Mai Matsumoto^3,4, Takeyasu Yamagata⁶, Hiroyuki Matsuzaki⁶ (1.Graduate School of Science and Technology, Hirosaki University, 2.Faculty of Science and Technology, Hirosaki University, 3.Institute of Low Temperature Science, Hokkaido University, 4.Graduate School of Environmental Science, Hokkaido University, 5.Institute of Nature and Environmental Technology, Kanazawa University, 6.Micro Analysis Laboratory, Tandem accelerator (MALT), The University of Tokyo)

*Kazuho Horiuchi¹, Kento Sato², Riko Yagihashi¹, Kimikazu Sasa³, Masumi Matsumura³, Tsutomu Takahashi³, Hideaki Motoyama⁴ (1.Graduate School of Science and Technology, Hirosaki University, 2.Faculty of Science and Technology, Hirosaki University, 3.Accelerator Mass Spectrometry Group, Tandem Accelerator Complex, University of Tsukuba, 4.National Institute of Polar Research)