How LCLS X-ray pulses can be used to determine the atomic
structure of a complicated molecule. A New Kind of Laser SLAC's
two-mile-long linear accelerator (or linac) has begun a new
phase of its career, with the creation of the Linac Coherent
Light Source (LCLS). For nearly 50 years, SLAC's linac has
produced high-energy electrons for cutting-edge physics
experiments. Now, scientists continue this tradition of
discovery by using the linac to drive a new kind of laser,
creating X-ray pulses of unprecedented brilliance. LCLS produces
pulses of X-rays more than a billion times brighter than the
most powerful existing sources, the so-called synchrotron
sources which are also based on large electron accelerators. The
ultrafast X-ray pulses are used much like flashes from a high-
speed strobe light, enabling scientists to take stop-motion
pictures of atoms and molecules in motion, shedding light on the
fundamental processes of chemistry, technology, and life itself.
Probing the Ultrasmall The diameter of a human hai