Abstract

Los Alamos National Laboratory is pursuing a research and development program leading to eventual establishment of a free-electron laser (FEL) facility, based upon a single rf linear accelerator, for production of coherent radiation extending from the visible spectrum to the extreme untraviolet (XUV) and soft X-ray wavelengths as short as 10 nm. (Figure 1 illustrates such a multi-oscillator configuration.) Several key areas have been identified for concentrated attention over the next two years, particularly to assure feasibility at the short-wavelength end of this range. First, theoretical studies are directed toward maximizing the single-pass gain and output power from FEL oscillators using realistic electron beams produced by rf linacs. Since electron beam emittance is the primary concern for ultraviolet wavelengths, a unique three-dimensional code (FELEX) has been developed for numerical simulation of FEL parameter variations. Accelerator calculations of the influence of single-bunch beam loading on longitudinal energy spread are being performed with an advanced version of PARMELA. Also, to project further into the XUV and soft X-ray regions, methods to maximize the conversion efficiency to coherent optical harmonics of the fundamental lasing wavelength are being evaluated.

© 1986 Optical Society of America