WEP119 　加速器技術／レーザー　 8月5日 小ホール 13:00 - 15:00

卓上マイクロビーム源のためのファイバーレーザーおよび電子源の研究

Study on Fiber Laser and Electron Beam Source for Table-top Micro Beam Source

○岡元 勇人（東大），吉田 光宏（高エネルギー加速器研究機構），上坂 充，大槻 祥平（東大），佐藤 大輔（東工大）

○Hayato Okamoto (UTokyo), Mitsuhiro Yoshida (KEK), Mitsuru Uesaka, Shohei Otsuki (UTokyo), Daisuke Sato (Tokyo Tech)

Most of radiobiology experiments are done in the limited conditions, such that machine time is limited and the area is treated as radiation controlled area. Our laboratory is aiming for developing a table-top electron micro beam source, whose beam size is micrometer order so that we can irradiate just the nuclei of cells (~1μm) and observe the behavior in real time. This beam source will be realized by dielectric laser accelerators (DLAs), which is expected to produce acceleration gradients of ~GV/m. To drive these accelerators, femtosecond pulse laser (~GW) has to be incident to the structure. For this laser, we chose Ytterbium(Yb) laser, which has high quantum efficiency and high thermal conductivity, and is proper to produce ultra short pulse because it has wide range spectrum of oscillation band. We succeeded in getting ultra short pulse (central wavelength: 1030nm, average output: 10W, pulse width: 100fs, reputation rate: 84MHz) from Yb fiber laser system. Also in order to make electron beam source by make ultraviolet laser incident into photocathode, we then converted the obtained infrared laser (1030nm) to 258nm (4ω) using BBO and LBO non-linear crystals.