Yoshishige Yamazaki

Professor of Physics, FRIB Accelerator Systems
Division Deputy Director


Education and training

  • BE, Applied Physics, University of Tokyo, 1969
  • ME, Applied Physics, University of Tokyo, 1971
  • PhD, Physics, University of Tokyo, 1974


Particle accelerators, which were at first invented and developed mainly for studying atomic nuclei and fundamental particles, are nowadays applied to a wide variety of fields, including materials science, life science, cancer therapy, and so forth. Future possible applications may include the transmutation of nuclear waste, which arises from nuclear energy plants. In other words, the development of particle accelerator technology is required not only for studying fundamental particle physics and nuclear physics, but also for other sciences and industrial technology.

In order to build a world-class particle accelerator, we have to make use of a wide variety of state-of-art technologies.Not only that, in many cases, we have to newly invent and develop some key components, which are themselves applied to other industrial use. In other words, not only accelerators themselves, but also technologies developed for accelerators contribute a lot to the progress in science and technology.

Here, the key word is “world-class.” The linear accelerator in the Facility for Rare Isotope Beams (FRIB) is truly a world-class accelerator. Many species of heavy ions up to uranium are accelerated to 400-MeV/u, generating a beam power of 400 kW (the world-highest uranium beam power). With that amount of power, many rare isotopes will be discovered and studied, opening up a new era for nuclear physics, astrophysics and others. 

For that purpose, superconducting cavities are entirely used to accelerate the beams from a very front end. The FRIB accelerator, thus innovative, presents many chances for new inventions and developments.

I developed, built, and commissioned the RF cavity systems of KEK-PF (Photon Factory, world-highest power synchrotron radiation source, when built) and TRISTAN (world-highest energy electron/positron ring collider, when built) and the RF system of KEKB (B Factory, worldhighest luminosity electron/positron ring collider). Before joining FRIB, I was an accelerator team leader for J-PARC, which generates a world-highest pulse power of neutrons, muons, Kaons and neutrinos. I measured the threshold currents of the coupled-bunch instabilities for the first time and cured the instability for KEK-PF, developed the on-axis coupled accelerating structure for rings for TRISTAN, invented the ARES cavity, for KEKB, invented π-mode stabilizing loops for J-PARC RFQ, and developed the annular-ring coupled structure (ACS) for J-PARC linac. As can be seen from above, I have covered both the beam instability study and the RF technology.

The technology/engineering is nothing but applied science. In other words, deep understanding of physics is really necessary for accelerator physics. On the other hand, accelerator development is a good playground to enjoy physics. I would like to invite many graduate students to enjoy physics by developing, building and commissioning the FRIB accelerator. Here are many chances for invention and innovation, and I can guide you for those.

Scientific publications