Research Theme

Development and utilization of novel quantum beam sources using a high energy electron beam

Keywords

Electron beams, synchrotron radiation, gamma-rays, positrons

Our group develop new electromagnetic wave sources using a high energy electron beam. In the UVSOR-III electron storage ring at the Institute for Molecular Science, a 750-MeV electron beam can be generated. Electromagnetic waves in a wide frequency range from ultraviolet waves to gamma-rays are generated by interacting the electron beam with magnetic fileds and lasers.

Laser Thomson (Compton) scattering is a method to generate a high energy gamma-ray by the interaction between a high energy electron and a laser. We have developed ultra-short pulsed gamma-rays with the pulse width of sub-ps to ps range by using 90-degree laser Thomson scattering. We applied this ultra-short pulsed gamma-rays to gamma induced positron annihilation lifetime spectroscopy (GiPALS). A positron is an excellent probe of lattice defects in solids and of free volumes in polymers at the sub-nm to nm scale. GiPALS enables defect analysis of a thick material in a few cm because positrons are generated throughout a bulk material via pair production. Our group is conducting research on improving the properties of the material by using GiPALS.

Figure 1: Schematic illustration of 90-degree laser Thomson scattering.

Figure 2: Positron annihilation lifetime spectrum of pure iron measured using ultra-short pulsed gamma rays.

Selected Publications

1. Y. Taira, M. Adachi, H. Zen, T. Tanikawa, N. Yamamoto, M. Hosaka, Y. Takashima, K. Soda, M. Katoh, “Generation of energy-tunable and ultra-short-pulse gamma ray via inverse Compton scattering in an electron storage ring”, Nucl. Instr. Meth. A, 652 (2011) 696.
2. Y. Taira, T. Hayakawa, M. Katoh, “Gamma-ray vortices from nonlinear inverse Thomson scattering of circularly polarized light”, Scientific Reports, 7 (2017) 5018.
3. Y. Taira, M. Katoh, “Gamma-ray vortices emitted from nonlinear inverse Thomson scattering of a two-wavelength laser beam”, Phys. Rev. A, 98 (2018) 052130.
4. Y. Taira, M. Katoh, “Generation of optical vortices by nonlinear inverse Thomson scattering at arbitrary angle interactions”, The Astrophysical Journal, 860 (2018) 45.
5. Y. Taira, M. Fujimoto, S. Ri, M. Hosaka, M. Katoh, "Measurement of the phase structure of elliptically polarized undulator radiation", New Journal of Physics, 22 (2020) 093061.
6. Y. Taira, R. Yamamoto, K. Sugita, Y. Okano, T. Hirade, S. Namizaki, T. Ogawa, Y. Adachi, "Development of gamma-ray-induced positron age-momentum correlation measurement", Rev. of Sci. Instr., 93 (2022) 113304.
7. Y. Taira, S. Endo, S. Kawamura, T. Nambu, M. Okuizumi, T. Shizuma, M. Omer, H. Zen, Y. Okano, M. Kitaguchi, "Measurement of the spatial polarization distribution of circularly polarized gamma rays produced by inverse Compton scattering", Phys. Rev. A, 107 (2023) 063503.
8. Y. Taira, "Spatial distribution of gamma rays produced by axially symmetric polarized and optical vortex lasers", Phys. Rev. A, 110 (2024) 043525.