Author: Kii, T.
Paper Title Page
MOPFI020 Cold Test of the Coaxial Cavity for Thermionic Triode Type RF Gun 324
  • T. Konstantin, Y.W. Choi, T. Kii, R. Kinjo, K. Masuda, M. Mishima, K. Nagasaki, H. Negm, H. Ohgaki, K. Okumura, M. Omer, S. Shibata, K. Shimahashi, K. Yoshida, H. Zen
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  A thermionic rf gun has several advantages as compared to photocathode gun. Such as low cost, high averaged current and simple operation. However a thermionic rf gun has a significant disadvantage in form of back bombardment effect. The KU-FEL facility is an oscillator type FEL, which uses a thermionic 4.5 cell S-band RF gun for electron beam generation. The back bombardment effect causes increasing current in macropulse, which limits the gain of the FEL. In order to mitigate the current increase we plan to modify thermionic rf gun to triode type rf gun. Therefore an additional rf cavity has been designed. This cavity has separate rf power supply with amplitude and phase control. By this means we can properly adjust the injection of electrons into the main gun body. According to simulations the triode type gun can reduce 80% of back streaming electron energy*. The cold tests of the first prototype have revealed deviation from designed values**. Based on the tests of the first prototype new prototype with integrated mechanism for resonance tuning has been designed and fabricated. In this work we report the cold test of the redesigned prototype of the coaxial rf cavity.
* K. Masuda et al. Proceedings of FEL 2006, BESSY Berlin.
** M. Takasaki et al. Proceedings of FEL 2010, Malbö
TUPEA013 Present Status of Mid-infrared Free Electron Laser Facility in Kyoto University 1190
  • H. Zen, Y.W. Choi, H. Imon, M. Inukai, T. Kii, R. Kinjo, T. Konstantin, K. Masuda, K. Mishima, H. Negm, H. Ohgaki, K. Okumura, M. Omer, S. Shibata, K. Shimahashi, K. Yoshida
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  A Mid-Infrared Free Electron Laser (MIR-FEL) facility named as KU-FEL has been constructed for energy science in Institute of Advanced Energy, Kyoto University*. The accelerator of KU-FEL consists of an S-band 4.5-cell thermionic RF gun, a Dog-leg section for energy filtering, a 3-m traveling-wave type accelerator tube, 180-degree arc section for bunch compression and a hybrid undulator. We have already succeeded in lasing of the FEL from 5.5 to 14.5 micro-meter. Present status and recent activity for the FEL development will be presented in the conference.
*H. Zen, et al., Infrared Physics & Technology, vol.51, 382-385.
WEPME019 Development of Beam Position Feedback Control System in KU-FEL 2968
  • H. Ohgaki, Y.W. Choi, H. Imon, T. Kii, R. Kinjo, T. Konstantin, K. Masuda, H. Negm, K. Okumura, M. Omer, S. Shibata, K. Shimahashi, K. Yoshida, H. Zen
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  The stability of electron beam parameters such as position, energy etc. is very crucial for stable FEL operation. In Kyoto University MIR-FEL facility (KU-FEL), fluctuation of beam position and energy is caused by external fluctuations, such as the fluctuation in the cathode temperature of the thermionic RF-gun due to the back-streaming electrons, fluctuation of RF phase and amplitude, fluctuations of room and water temperatures, electric noises and so on. To monitor electron beam movement, we have already developed BPM system consisting of a 4-button electrode type BPM, a heterodyne detector, and CAMAC ADC in KU-FEL. By using this BPM system we have observed some correlations between external fluctuations and the beam position movements. In this conference, we will present the developed BPM system as well as the beam feedback system for stable KU-FEL operation.  
THPWA011 Concepts of 220 MeV Racetrack Microtron for Non-destructive Nuclear Material Detection System 3651
  • T. Hori, T. Kii, R. Kinjo, H. Ohgaki, M. Omer, H. Zen
    Kyoto University, Institute for Advanced Energy, Kyoto, Japan
  • I. Daito, R. Hajima, T. Hayakawa, M. Kando, H. Kotaki
    JAEA, Kyoto, Japan
  • F. Sakai
    SHI, Tokyo, Japan
  Funding: Japan Science and Technology Agency Special Coordination Funds for Promoting Science and Technology (Grant No. 066)
A nuclear material detection system (NMDS) using the quasi-monochromatic gamma-ray beam from a laser Compton scattering (LCS) source is proposed for the container inspection, where nuclear resonance fluorescence method is to be employed for the specific isotope identification such as U-235. In the system an electron beam of good quality at about 220-MeV must be provided for LCS. One of the most promising electron source is a compact electron accelerator named racetrack microtron (RTM). Some concepts of RTM suitable for NMDS and expected beam qualities will be presented.