Author: Nishimura, Y.
Paper Title Page
WEPFI023 Study on Two-cell RF-deflector Cavity for Ultra-short Electron Bunch Measurement 2753
  • Y. Nishimura, K. Sakaue, T. Takahashi, M. Washio
    Waseda University, Tokyo, Japan
  • T. Takatomi, J. Urakawa
    KEK, Ibaraki, Japan
  Funding: Work supported by JSPS Grant-in-Aid for Scientific Research (A) 10001690 and the Quantum Beam Technology Program of MEXT.
We have been developing an S-band Cs-Te photocathode rf electron gun system for pulse radiolysis and laser Compton scattering experiment at Waseda University. These researches demand for high quality and well controlled electron beam. In order to measure the ultra-short electron bunch, we decided to use rf-deflector cavity, which can convert the longitudinal distribution to that of transverse. With this technique, the longitudinal bunch profile can be obtained as the transverse profile. We used the 3D electromagnetic simulation codes HFSS for designing rf deflector cavity and GPT for beam tracking. The cavity has 2 cell structures operating on π mode, standing wave, dipole (TM120) mode at 2856MHz. We have confirmed on HFSS that 2 cell rf-deflector cavity can produce 660G magnetic field per cell on beam line with 750kW input rf power. This field strength is enough for our target, which is 100fs bunch length measurement at 4.3MeV. In this conference, we will present the cavity structure design, the present progresses and future plan.