• D. Li, K. Imasaki
  ILT, Suita, Osaka
• M.R. Asakawa
  Kansai University, Osaka

The interest on the terahertz radiation sources keeps growing in recent years because this frequency provides widely applications in medical, industrial and material science The Cherenkov free-electron lasers have an advantage over the usual undulator free-electron lasers, and they can generate terahertz radiation with low energy electron beam. We plan to construct a compact terahertz Cherenkov free-electron laser with moderate (~10 mW) average power. To achieve this goal, a compact electron beam source is in developing, and a double-slab Cherenkov free-electron laser resonator is studied. To perform a preliminary lasing experiment, this resonator is designed to generate the millimeter wave. In this paper, we aim at the analysis of the gain for the double-slab Cherenkov device. The dispersion equation is derived and solved numerically, as well as the single-pass gain is worked out for the parameters of our experiment.

• D. Li, K. Imasaki
  ILT, Suita, Osaka
• S. Amano, K. Horikawa, S. Miyamoto, T. Mochizuki
  NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo

Transmutation is considered as an approach by reducing the radioactive life of the nuclear waste through converting the nuclei of long-lived activity to its corresponding isotope of short-lived activity. High-energy photons can induce nuclear reaction, which is regarded as an approach to make transmutation. Laser Compton scattering (LCS) gamma ray seems a good photons source. The LCS gamma ray is generated from the collision of a laser light to a high-energy electron beam, and it holds a peak in the energy spectrum, which can well overlap the peak of nuclear giant resonance and hence realize a good coupling. I¹²⁹ has a very long life of more than 16 million years and a high chemical activity. Besides these, Iodine is hard to include in the normal reposing container due to their low temperature boiling point. So Iodine is recognized as discrete waste for transmutation. The reaction rate of transmutation plays an important role in this proposal of deposing nuclear waste; therefore, the aim of this paper is to experimentally investigate the reaction rate of Iodine.