His research fields are accelerator physics and free electron laser (FEL). He is interested in particle accelerators and generation of light with high-energy electron beams. He conducts researches on development of the L-band electron linear accelerator (linac), which is distinctive because of its RF frequency 1.3 GHz compared with the most common RF frequency 2.856 GHz adopted in the majority of electron linacs, for producing the highly brilliant and stable electron beam and related beam dynamics. The electron beam accelerated with the linac is used for development of FEL and Self-Amplified Spontaneous Emission (SASE) in the far-infrared wavelength region or in the Tera-Hertz frequency region.

40 MeV L-band electron linac viewed from the electron gun in the gray tank.

FEL system on a beam line from the L-band linac. The red apparatus is the undulator and the L-band linac is behind it.

Schematic drawing of free electron laser.

Selected Publications:

Rigorous evaluation of the edge-focusing wiggler based on the magnetic field measurement, S. Kashiwagi, R. Kato, A. Mihara, Ta. Noda, G. Isoyama, K. Tsuchiya, T. Shioya, and S. Yamamoto, Phys. Rev. ST Accel. Beam 12 (2009) 120703 (1-14).

Development of FEL and SASE in the Far-Infrared Region at ISIR, Osaka University, G. Isoyama, R. Kato, S. Kashiwagi, T. Igo and Y. Morio, Infrared Phys. Technol. 51 (2008) 371-374.

Proposal for the edge-focusing wiggler for SASE, G. Isoyama, M. Fujimoto, R. Kato, S. Yamamoto, K. Tsuchiya, Nucl. Instr. Meth. A507 (2003) 234-237.

Characteristic measurements of higher harmonics generated in the SASE-FEL process, R. Kato, M. Fujimoto, T. Igo, S. Isaka, T. Onishi, S. Furukawa, S. Okuda, S. Suemine, G. Isoyama, Nucl. Instr. Meth. A507 (2003) 409-412.

Lasing at 150 μm wavelength and measurement of characteristics of the free-electron laser at ISIR, Osaka University, R. Kato, S. Kondo, T. Igo, T. Okita, T. Konishi, S. Suemine, S. Okuda and G. Isoyama, Nucl. Instr. Meth. A445 (2000) 169-172.

Goro Isoyama received a doctor of science degree from Tohoku University, Japan, in 1978. He worked as a post-doctoral fellow at the Japan Atomic Energy Research Institute in 1978-1979, approximately for a year. He then moved to the Synchrotron Radiation Laboratory, the Institute for Solid State Physics, University of Tokyo and worked as a research associate in 1979-1989. He worked as an associate professor at the Ultraviolet Synchrotron Radiation Facility, Institute for Molecular Science in 1989-1994. He has been working as a professor at the Institute of Scientific and Industrial Research, Osaka University since 1994.