• M. A. Bakr, K. Higashimura, T. Kii, R. Kinjo, K. Masuda, H. Ohgaki, T. Sonobe, K. Yoshida
  Kyoto IAE, Kyoto
• Y.U. Jeong
  KAERI, Daejon
• H. Zen
  UVSOR, Okazaki

The first laser amplification at a 12 micrometre mid-infrared free-electron laser (MIR-FEL) was observed at the Institute of Advanced Energy (IAE), Kyoto University in March 2008. A 25 MeV electron beam of 17 A peak current was used for the lasing experiment. FEL gain was estimated to be 16% from the exponential growth of the laser output signal. A beam loading compensation method with an RF amplitude control both in the thermionic RF gun and in the accelerator tube was used to extend the macropulse duration against the back bombardment effect in the gun. We also developed a feedforward RF phase control to stabilize the RF phase shifts which were originated with RF amplitude control. As a result FEL saturation was observed in May 2008. The estimated FEL gain was 33% with the electron beam of 5.5 microsecond macropulse duration by use of peak current of 33 A which was deduced from GENESIS simulation. A user beamline was designed and constructed. The laser characterization at the user station will be reported in the conference. Applications of the MIR-FEL at Kyoto University in the chemistry energy research will be presented as well.

• T. Kii, M. A. Bakr, K. Higashimura, R. Kinjo, K. Masuda, H. Ohgaki, T. Sonobe, K. Yoshida
  Kyoto IAE, Kyoto
• H. Zen
  UVSOR, Okazaki

A short period undulator with strong magnetic field will play an important role in future light source. We proposed a new type of staggered array undulator by use of bulk high-Tc superconductor*. We have constructed a prototype of the undulator using DyBaCuO bulk superconductors and a normal conducting solenoid. In the conference, we will present results of the magnetic field measurement and discuss on the feasibility of the new type bulk high-Tc staggered array undulator.

*R. Kinjo et al., Proceedings of the FEL2008, in press.