Free-electron lasers driven by RF linacs

Using an electron beam in a magnetic field as the gain medium, free-electron lasers offer a powerful new source of tunable, coherent radiation. Results are just becoming available from several new experiments, but they confirm the theoretical promise of these devices. Backed up by a strong base of accelerator technology, free-electron lasers using RF linacs are expected to become important in applications requiring wavelengths from the infrared part of the spectrum to the vacuum ultraviolet.