Researcher Information

BAJO Ken-ichi

Assistant Professor

Noble gas cosmochemistry

Department of Earth and Planetary Sciences, Earth and Planetary System Science

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Theme

Cosmochemistry reveled by using noble gas isotopes in extra-terrestrial matters

FieldGeochemistry, Mass spectrometry
KeywordNoble gas, Mass spectrometry, In-situ isotope analysis, Solar wind, Sample return mission

Introduction of Research

My research interests lie in the origin and evolution of the solar system. The present study utilizes extraterrestrial materials to investigate the evolution of the solar system through the application of scanning electron microscopy, X-ray spectroscopy, and mass spectrometry. In order to obtain new information (elemental and isotopic compositions) from extraterrestrial materials, new analytical methods and instruments are being designed and developed. We employ a Secondary Neutral Mass Spectrometer (SNMS), a device developed by our research group, to analyze the in situ isotope distribution of extraterrestrial materials. The implementation of these novel techniques promises to unveil novel phenomena in the solar system.

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Secondary Neutral Mass Spectrometer: LIMAS

Representative Achievements

Y. Otsuki, K. Bajo, T. Obase, H. Yurimoto (2025) Depth profiling of noble gases in ilmenite and olivine substrates. Journal of Analytical Atomic Spectrometry, In press.
K. Bajo, N. Kawasaki, I. Sakaguchi, T. T. Suzuki, S. Itose, M. Matsuya, M. Ishihara, K. Uchino, H. Yurimoto (2024) In situ helium isotope micro-imaging of meteorites, Analytical Chemistry, 96, 13, 5143–5149.
R. Okazaki, B. Marty, H. Busemann, K. Hashizume, J.D. Gilmour, A. Meshik, T. Yada, F. Kitajima, M.W. Broadley. D. Byrne, E. Furi, M.E.I. Riebe, D. Krietsch, C. Maden, A. Ishida, P. Clay, S.A Crowther, L. Fawcett, T. Lawton, O. Pravdivseva, Y.N. Miura, J. Park, K. Bajo, Y. Takano, K. Yamada, S. Kawagucci, Y. Matsui, Y. Yamamoto, K. Righter, S. Sakai, N. Iwata, N. Shirai, S. Sekimoto, M. Inagaki, M. Ebihara, R. Yokochi, K. Nishiizumi, K. Nagao, J.I. Lee, A. Kano, M.W. Caffee, R. Uemura et al. (2023) Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution. Science, 379, eabo0431.
K. Bajo, J. Aoki, M. Ishihara, S. Furuya, M. Nishimura, M. Yoshitake, and H. Yurimoto (2022) Development of electrostatic‐induced charge detector for multiturn time‐of‐flight mass spectrometer. Journal of Mass Spectrometry, 57, 11, e4892. (Cover Art)
K. Bajo, C.T. Olinger, A.J.G. Jurewicz, D.S. Burnett, I. Sakaguchi, T.T. Suzuki, S. Itose, M. Ishihara, K. Uchino, R. Wieler and H. Yurimoto (2015) Depth profiling analysis of solar wind helium collected in diamond-like carbon film from Genesis. Geochemical Journal, 49, 559-566.
Academic degreePh. D
Academic background2006 Bachelor Degree of Science at Tokyo University of Science
2008 Master Degree of Science at the University of Tokyo
2011 Doctor Degree of Science at the University of Tokyo
2011 Project researcher, Department of Natural History Sciences, Graduate School of Science, Hokkaido University
2013 Research Assistant Professor, Creative Research Institution, Hokkaido University
2014- Assistant Professor, Earth and Planetary System Sciences, Department of Earth and Planetary Sciences, Graduate School of Science, Hokkaido University
Room addressInstitute for Integrated Innovations 02-321

Department of Earth and Planetary Sciences, Earth and Planetary System Science

BAJO Ken-ichi

Assistant Professor

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What is the research theme that you are currently focusing on?

I am developing analytical methods to study the distribution of noble gases derived from the solar wind and trapped in lunar samples and meteorites. My scientific goal is to use noble gas cosmochemistry to reveal the history of celestial impacts and the surface environments of planetary bodies.

Mass spectrometer for measuring noble gases derived from the solar wind
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What made you decide to become a researcher?

In my fourth year of university, I joined Professor Keisuke Nagao’s laboratory and was given a graduation assignment to develop a mass spectrometer. I was fascinated by the opportunity to freely explore and use the lab’s various instruments, and that experience completely drew me into research.

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What do you usually do when your research work gets stuck?

Whenever I hit a wall in my research, I like to take a break from studying. I often go cycling in the countryside, riding along quiet roads until my head feels clear again.