Leading lights

摘要

China is not the only country brightening up its X-ray sources. Two other new light-source facilities, the Linac Coherent Light Source (LCLS) in Stanford, California, and the Positron-Electron Tandem Ring Accelerator (PETRA) III, in Hamburg, Germany, have opened in the past month. And more than a dozen are under way elsewhere (see map). rnThis 'fourth generation' of new facilities improves on older synchrotrons by making photon beams that are many orders of magnitude brighter, and delivering much shorter-duration light pulses.