High-Power, cw, Efficient, Tunable (uv through ir) Free-Electron Laser Using Low-Energy Electron Beams

Using beams of low-energy electrons ($E<\mathrm{}5\mathrm{}$ MeV), a free-electron laser can be operated as a continuously tunable ($1000 \AA <\lambda <50\mathrm{} \mu$m), high-power ($P>\mathrm{}10\mathrm{}$ kW, cw) source of laser radiation. With electrostatic accelerators the electron beam can be recycled to increase the overall efficiency of the laser. Wall power to laser power efficiencies greater than 10% are possible.