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Photo-Molecular Science Katoh(M) Group

Katoh(M) Group-main_image
Location: Myoudaiji, UVSOR Synchrotron Facility, 2F Room202
Annual Review : Link

Accelerator, Beam Physics, Astrobiology

Light Source Developments by Using Relativistic Electron Beams

UVSOR is a synchrotron light source providing low energy synchrotron light ranging from terahertz wave to soft X-rays. Although it was constructed about 30 years ago, its performance is still in the world top level. This is the result of the continuous effort on improving the machine. Our research group has been developing accelerator technologies toward producing bright and stable synchrotron light, such as high brightness electron beam optics, novel insertion devices or state-of-the-art beam injection technique. We have been also developing novel light source technologies toward producing photons with excellent properties, such as free electron laser, coherent synchrotron radiation and laser Compton gamma-rays. We are also investigating beam physics which would be the basis of the novel light source technologies. We have revealed that an electron in circular motion radiates strange photons called optical vortices, which possesses spiral phase structure and carrying orbital angular momentum. We have started exploring their applications as novel probes for material sciences and their possible roles in nature.

Radiation from relativistic electrons and its interaction with matters are also interesting as subjects of basic physics, astrophysics, plasma physics, materials science, life science including astrobiology. In cooperation with researchers in a wide range of fields, we are exploring new research areas.


UVSOR-III Electron Storage Ring and Synchrotron Radiation Beam-lines.
The circumference is 53m. The electron energy is 750 MeV. Electrons are circulating in the storage ring at almost the speed of light and radiate intense vacuum ultraviolet light.  

Selected Publications

  1. M. Katoh, M. Fujimoto, H. Kawaguchi, K. Tsuchiya, K. Ohmi, T. Kaneyasu, Y. Taira, M. Hosaka, A. Mochihashi, Y. Takashima, “Angular Momentum of Twisted Radiation from an Electron in Spiral Motion”, Phys. Rev. Lett. 118, 094801 (2017)
  2. M. Katoh, M. Fujimoto, N. S. Mirian, T. Konomi, Y. Taira, T. Kaneyasu, M. Hosaka, N. Yamamoto, A. Mochihashi, Y. Takashima, K. Kuroda, A. Miyamoto, K. Miyamoto, S. Sasaki, “Helical Phase Structure of Radiation from an Electron in Circular Motion”, Scientific Reports 7, 6130 (2017)