• The world's brightest X-ray source sprang to life last week at the U.S. Department of Energy's SLAC National Accelerator Laboratory. The Linac Coherent Light Source (LCLS) offers researchers the first-ever glimpse of high-energy or "hard" X-ray laser light produced in a laboratory. When fine tuning is complete, the LCLS will provide the world's brightest, shortest pulses of laser X-rays for scientific study. It will give scientists an unprecedented tool for studying and understanding the arrangement of atoms in materials such as metals, semiconductors, ceramics, polymers, catalysts, plastics, and biological molecules, with wide-ranging impact on advanced energy research and other fields.