Looking East down the LCLS Undulator Array
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.
“This milestone establishes proof-of-concept for this incredible machine, the first of its kind,” said SLAC Director Persis Drell. “The LCLS team overcame unprecedented technical challenges to make this happen, and their work will enable frontier research in a host of fields. For some disciplines, this tool will be as important to the future as the microscope has been to the past.”
Even in these initial stages of operation, the LCLS X-ray beam is brighter than any other human-made source of short-pulse, hard X-rays. Initial tests produced laser light with a wavelength of 1.5 Angstroms, or 0.15 nanometers—the shortest-wavelength, highest-energy X-rays ever created by any laser. To generate that light, the team had to align the electron beam with extreme precision. The beam cannot deviate from a straight line by more than about 5 micrometers per 5 meters—an astounding feat of engineering.
“This is the most difficult lightsource that has ever been turned on,” said LCLS Construction Project Director John Galayda. “It’s on the boundary between the impossible and possible, and within two hours of start-up these guys had it right on.”
Good luck – and science the world over will be watching and waiting for information. I was around in early days when X-ray metallography just began to reach into commercial use. I can only imagine what a tool like this will be capable of producing.