Author: Zen, H.
Paper Title Page
TUPO013 Development of Pulse Width Measurement Techniques in a Picosecond Range of Ultra-short Gamma Ray Pulses 1473
 
  • Y. Taira, M. Hosaka, K. Soda, N. Yamamoto
    Nagoya University, Nagoya, Japan
  • M. Adachi, M. Katoh, H. Zen
    Sokendai - Okazaki, Okazaki, Aichi, Japan
  • T. Tanikawa
    UVSOR, Okazaki, Japan
 
  Funding: This work was supported by Grants-in-Aid for Scientific Research from Japan Society for the Promotion of Science (JSPS).
We are developing the ultra-short gamma ray pulse source with the energy of MeV region based on laser Compton scattering at the 750 MeV electron storage ring, UVSOR-II. Gamma rays with pulse width of sub-picosecond range can be generated by injecting femtosecond laser pulses into the electron beam from the vertical 90-degree direction* because the electron beam circulating in the storage ring is focused more tightly in the vertical direction than in the longitudinal direction. The energy, intensity, and pulse width of the gamma rays can be tuned by changing the collision angle between the electron beam and the laser. We are developing pulse width measurement techniques of ultra-short gamma ray pulses at present. As the first step of the pulse width measurement, we used a fast response photodetector, Geiger-mode APD, the time resolution of which is few hundreds picoseconds. Although we cannot measure the pulse width of the gamma rays with sub-picosecond range using this detector, we could measure the pulse width of the gamma rays as 430 ps or less by measuring the timing of Cherenkov radiations generated from the gamma rays.
* Y. Taira et al., Nucl. Instrum. Meth. A, in press, 2010.
 
 
THPC087 Saturation Effect on VUV Coherent Harmonic Generation at UVSOR-II 3098
 
  • T. Tanikawa, M. Adachi, M. Katoh, J. Yamazaki, H. Zen
    UVSOR, Okazaki, Japan
  • M. Hosaka, Y. Taira, N. Yamamoto
    Nagoya University, Nagoya, Japan
 
  Light source technologies based on laser seeding are under development at the UVSOR-II electron storage ring. In the past experiments, we have succeeded in generating coherent harmonics (CHs) in deep ultraviolet (UV) and vacuum UV (VUV) region and also in generating CH with variable polarizations in deep UV*. In previous conference, we reported an introduction of new-constructed spectrometer for VUV and results of spectra measurement, undulator gap dependence, and injection laser power dependence on VUV CHs**. This time we have successfully observed saturation on CHs intensities and have found some interesting phenomena in different harmonic orders. In this conference, we will discuss the results of some systematic measurements and those analytical and particle tracking simulations***.
*M. Labat et al., Phys. Rev. Lett. 101 (2008) 164803.
**T. Tanikawa et al., Proc. IPAC'10, TUPE029, p. 2206 (2010).
***T. Tanikawa et al., Appl. Phys. Express 3 (2010) 122702.