A compact energy recovered FEL for biomedical and material science applications

In this paper the authors describe how, with present day technology, it is possible to build a modest size infrared-to-visible free electron laser (FEL) machine that offers tremendous flexibility in operating parameters, while producing a time average output laser power of l kw. Different FEL applications have different requirements, both in terms of wavelength and pulse durations. The machine outlined below would have an operating wavelength range of 0.5 microns on 10 microns. The output radiation is in the form of a continuous train of micropulses 40 ns apart, with pulse widths ranging from 2 ps (corresponding to a peak pulse power of 20 MW) to 200 ps. The size of such a machine would be about 10 meters long: larger than the average room, but not by much. In this paper the authors discuss the salient features of the accelerator and the design choices that have been made. This is followed by a discussion of the FEL wiggler and the operation of the system over its parameter space