The LCLS: A fourth generation light source using the SLAC linac

Recent technological developments make it possible to consider use of the Stanford linear accelerator to drive a linac coherent light source (LCLS)—a laser operating at hard x-ray wavelengths. In the LCLS, stimulated emission of radiation would be achieved in a single pass of a high-energy, extremely bright electron beam through an undulator, without the optical cavity resonator normally used in storage ring-based free-electron lasers. The x-ray laser beam would be nearly diffraction limited with very high transverse coherence, and would exhibit unprecedented peak intensity and peak brightness, and sub-picosecond pulse length. Such an x-ray source offers unique capabilities for a large number of scientific applications.