R. Nagai, M. Sawamura, R. Hajima, N. Kikuzawa, N. Nishimori, T. Shizuma and E. Minehara
Free-Electron Laser Laboratory, Advanced Photon Research Center, JAERI
The performance of optical resonator with scraper output coupler is studied for the JAERI far-infrared free electron laser using a Fox-Li procedure. Total efficiency of the scraper coupler and center hole coupler FEL system are evaluated by calculating the amount of useful power output coupled through the coupler and the diffraction loss. It is found that the scraper output coupler is more efficient than the center-hole one.
