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We are developing an FEL (Free-Electron Laser) facility “KU-FEL” (Kyoto University FEL) as a key facility for the R&D of the future energy systems. The KU-FEL is to be realize a compact, economical, and easy-to-operate FEL system which provides coherent and tunable laser in IR region.
The FEL system has been almost completed in the Laboratory for Photon and Charged Particle Reserch.
For the first step, the KU-FEL is designed to achieve FEL lasing from 4 to 13 μm. The tunable IR laser will be used for basic study of high-efficiency solar cells, generation of sustainable energy source, separation of DNA and/or RNA, etc.
Left figure shows estimated laser power in KU-FEL. Estimated power from the present configuration, from the future upgrade of the undulator, photocathode rf gun, and from a commercially available OPO device are shown.
A 4.5 cell S-band thermionic rf gun has been developed as an electron injector. This device can generate high-brightness electron beam of 9 MeV energy with long macro-pulse (up to 5 μsec) from its compact body of 236 mm.
The S-band accelerator tube ( 2.9-m effective length) accelerates electron beam up to 40 MeV by using 20 MW RF power.
The undulator length is 1.6 m, the period is 40 mm, the number of period is 40, and undulator parameter, K-value, is 0.95～0.17. The FEL wavelength from 4 to 13 μm is expected with the present system with electron-beam energy from 20 to 40 MeV.