Centers & Labs

Initiative Research Units / Special Research Units

Atomic Physics Research Unit

Unit Leader: Yasunori Yamazaki (D.Eng.)
Yasunori  Yamazaki(D.Eng.)

Developments of a new powerful scheme to synthesize spin-polarized cold antihydrogen beam to test the CPT symmetry of nature. For this purpose, a superconducting double cusp magnet (a combined double anti-Helmholtz coils) has been invented, and a high precision 3D antiproton annihilation detector as well as a high s/n antihydrogen beam detector consisting of a BGO plate surrounded by double-layered hodoscope have been developed.
In parallel, a new scheme to prepare a micro-beam of MeV ions which can be injected in an arbitrary point in liquid has been developed, and applied to make partial irradiation on living cells.

Main Research Field


Related Research Fields


Research Subjects

  • Synthesis of spin-polarized antihydrogen beam and the CPT symmetry test
  • Production of microbeam of MeV ions, and partical irradiation of living cell nucleus
  • Interaction of slow highly charged ions with insulator, and the study of the guiding effects

Selected Publications

  1. S. Ulmer, C. Smorra, A. Mooser, K. Franke, H. Nagahama, G. Schneider, T. Higuchi, S. Van Gorp, K. Blaum, Y. Matsuda, W. Quint, J. Walz & Y. Yamazaki.:
    "High precision comparison of the antiproton-to-proton charge-to-mass ratio"
    Nature 524, 196 (2015).
  2. V. Mäckel, N. Puttaraksa, T. Kobayashi, and Y. Yamazaki.:
    "Single proton counting at the RIKEN cell irradiation facility"
    Rev. Sci. Instrum. 86, 085103 (2015).
  3. N. Kuroda, S. Ulmer, Simon Van Gorp, Y. Yamazaki et al.:
    "A source of antihydrogen for in-flight hyperfine spectroscopy"
    Nature Communications 4089 (2014).
  4. Y. Yamazaki and S. Ulmer.:
    "CPT symmetry tests with cold p and antihydrogen"
    Ann. d Physik 525 (2013) 493-504.
  5. M. Kato, W. Meissl, K. Umezawa, T. Ikeda and Y. Yamazaki.:
    "Real-time observation of Escherichia coli cells under irradiation with a 2-MeV H+ microbeam"
    Appl. Phys. Lett. 100 (12)193792(May 10)
  6. Y. Enomoto, N. Kuroda, K. Michishio, C. H. Kim, H. Higaki, Y. Nagata, Y. Kanai, H. A. Torii, M. Corradini, M. Leali, E. Lodi-Rizzini, V. Mascagna, L. Venturelli, N. Zurlo, K. Fujii, M. Ohtsuka, K. Tanaka, H. Imao, Y. Nagashima, Y. Matsuda, B. Juhász, A. M.:
    "Synthesis of Cold Antihydrogen in a Cusp Trap"
    Phys. Rev. Lett. 105 (2010) 243401
  7. G. B. Andresen, M. D. Ashkezari, M. Baquero-Ruiz, W. Bertsche, P. D. Bowe, E. Butler, C. L. Cesar, S. Chapman, M. Charlton, A. Deller, S. Eriksson, J. Fajans, T. Friesen, M. C. Fujiwara, D. R. Gill, A. Gutierrez, J. S. Hangst, W. N. Hardy, M. E. Hayden, A.:
    "Trapped antihydrogen"
    Nature 468(2010)673-676
  8. Kuroda, N., Torii, H.A., Shibata, M., Nagata, Y., Barna, D., Hori, M., Horvath, D., Mohri, A., Eades, J., Komaki, K., and Yamazaki, Y.:
    "Radial compression of antiproton cloud for production of intense antiproton beams."
    Phys.Rev.Lett. 100, 203402 (2008)
  9. Kuroda, N., Torii, H.A., Franzen, K. Y., Wang, Z., Yoneda, S., Inoue, N., Hori, M., Juhasz, B., Horvath, D., Higaki, H., Mohri, A., Komaki, K., and Yamazaki, Y.:
    "Confinement of a large number of antiprotons and production of an ultra-slow antiproton beam."
    Phys. Rev. Lett. 94 (2005) 023401
  10. S. Ninomiya, Y. Yamazaki, F. Koike, H. Masuda, T. Azuma, K. Komaki, K. Kuroki, and M. Sekiguchi i.:
    "Stabilized hollow ions extracted in vacuum."
    Phys.Rev.Lett. 78 (1997) 4557-4560

Lab Members

Principal Investigator

Yasunori Yamazaki
Unit Leader

Core Members

Yasuyuki Kanai
Senior Research Scientist
Pierre Dupre
Postdoctoral Researcher
Minori Tajima
Junior Research Associate
Kanetada Nagamine
Visiting Scientist
Hiroyuki Higaki
Visiting Scientist
Yugo Nagata
Visiting Scientist
Isao Shimamura
Research Consultant
Ken-ichirou Komaki
Research Consultant
Hitomi Wada
Megumi Morita
Part-time Worker

Contact information

2-1 Hirosawa, Wako, Saitama 351-0198, Japan

Email: yasunori [at]

Related links

Recent research results


Annual research report