TY - CPAPER
AU - Zen, H.
AU - Kii, T.
AU - Kuroda, R.
AU - Masuda, K.
AU - Ohgaki, H.
AU - Suphakul, S.
AU - Taira, Y.
TI - MIR-FEL Oscillator Lasing by Photocathode Operation of LaB6 Thermionic Cathode in KU-FEL
J2 - Proc. of FEL2015
AB - Kyoto University Free Electron Laser (KU-FEL) is an oscillator type mid-infrared FEL having the tunable wavelength range from 5 to 22 micro-m [1]. The first lasing and power saturation of the facility using a 4.5-cell RF gun with a LaB6 thermionic cathode has been achieved in 2008 by overcoming the severe back-bombardment effect in the RF gun [2,3]. For upgrading the FEL performance, a multi-bunch picosecond mode-locked laser has been developed for driving a photocathode in the RF gun [4]. In February 2015, we have achieved first lasing of KU-FEL with photocathode operation of the LaB6 cathode in the 4.5-cell RF gun. The micro-pulse energy of the FEL at the wavelength of 11.7 micro-m with the photocathode operation was around 6.5 times as high as that with the thermionic cathode operation without any other modification of the FEL system. The performance of KU-FEL in the photocathode operation mode and comparison with the thermionic cathode operation will be presented in the conference.
PB - JACoW
CY - Geneva, Switzerland
ER -