The Stanford Synchrotron Radiation Lightsource, a division of SLAC National Accelerator Laboratory, is operated byStanford University for the Department of Energy. SSRL is a National User Facility which provides synchrotron radiation, a name given to electromagnetic radiation in the x-ray, ultraviolet, visible and infrared realms produced by electrons circulating in a storage ring at nearly the speed of light. The extremely bright light that is produced can be used to investigate various forms of matter ranging from objects of atomic and molecular size to man-made materials with unusual properties. The obtained information and knowledge is of great value to society, with impact in areas such as the environment, future technologies, health, and education. The SSRL provides experimental facilities to some 2,000 academic and industrial scientists working in such varied fields as drug design, environmental cleanup, electronics, and x-ray imaging. It is located in southern San Mateo County, just outside the city ofMenlo Park.
History
In 1972 the first x-ray beamline was constructed by Ingolf Lindau and Piero Pianetta as literally a "hole in the wall" extending off of the SPEAR storage ring. At that time, the SPEAR had been built in an era of particle colliders, where physicists were more interested in smashing particles together in hope of discovering antimatter than in using x-ray radiation for solid state physics and chemistry. From those meager beginnings the Stanford Synchrotron Radiation Project began. Within a short time SSRP had five experimental hutches sharing the radiation of only a few inches of the curved SPEAR dipole magnets. Each one of those stations was equipped with a monochromator to select the radiation of interest, and experimenters would bring their samples and end stations from all over the world to study the unique effects only achieved through synchrotron radiation. Today the SPEAR storage ring is dedicated completely to the Stanford Synchrotron Radiation Lightsource as part of the SLACNational Accelerator Laboratory facility. SSRL currently operates 24/7 for about nine solid months out of the year; the remaining time is used for major maintenance and upgrades where direct access to the storage ring is needed. There are over 30 unique experimental stations which are made available to users from universities, government labs, and industry from all over the world.
BL 7-3, 9-3, 4-3 These three beamlines are dedicated to biological x-ray absorption spectroscopy. Beamline 7-3 is an unfocused beamline and thus is best suited for XAS on dilute protein samples. Beamline 9-3 has an additional upstream focusing mirror, over 7-3, making it the preferred choice for photo reducing samples or ones where multiple different spots are needed. Beamline 4-3 was newly reopened as of 4/6/2009 bringing special capabilities for soft-energy studies in addition to hard x-rays. Beamline 4-3 now replaces 6-2 as the preferred location for Sulfur K-edge experiments at SSRL.
BL 6-2 With three upstream mirrors, two for focusing and a third for harmonic rejection, this beamline has become dedicated to transmission x-ray microscopy in the 4-12 keV range, soft x-ray absorption spectroscopy including Rapid-scanning xRF imaging, and advanced spectroscopy such as XES, XRS.
BL 8-2, 10-1, 13-2 These three beamlines are specialized for soft x-ray absorption spectroscopy, including NEXAFS, some light atom Ligand K-edge, PES, and L-edge measurements. All experiments on these beamlines require special handling and advanced ultra high vacuum experience and techniques.
