Experimental study on infrared free-electron laser at University of Tokyo

The UT-FEL project has been carried out to constitute a compact infrared free-electron laser (FEL) utilizing an existing rf-linac. Since the linac is 15 years old one originally designed to generate ultra short pulses for radio-chemistry experiments, the early stage of the project was devoted to develop an electron beam of high-brightness satisfying requirements for FEL lasing. After improving the accelerator and constructing a wiggler magnet and optical systems, we started a lasing experiment. First laser oscillation was achieved at a wavelength of 42.8μm on 25 June 1993. In this paper, we summarize the experimental studies on FEL: development of high-brightness electron beam, design and construction of a wiggler magnet and optical systems, results of the lasing experiment. (author)