The Stanford Synchrotron Radiation Lightsource (formerly Stanford Synchrotron Radiation Laboratory), a division of

SLAC National Accelerator Laboratory SLAC National Accelerator Laboratory, originally named the Stanford Linear Accelerator Center, is a Federally funded research and development centers, federally funded research and development center in Menlo Park, California, Menlo Park, Ca ...

, is operated by

Stanford University Leland Stanford Junior University, commonly referred to as Stanford University, is a Private university, private research university in Stanford, California, United States. It was founded in 1885 by railroad magnate Leland Stanford (the eighth ...

for the Department of Energy. SSRL is a National User Facility which provides

synchrotron radiation Synchrotron radiation (also known as magnetobremsstrahlung) is the electromagnetic radiation emitted when relativistic charged particles are subject to an acceleration perpendicular to their velocity (). It is produced artificially in some types ...

, a name given to electromagnetic radiation in the x-ray, ultraviolet, visible and infrared realms produced by electrons circulating in a

storage ring A storage ring is a type of circular particle accelerator in which a continuous or pulsed particle beam may be kept circulating, typically for many hours. Storage of a particular particle depends upon the mass, momentum, and usually the charge o ...

(Stanford Positron Electron Asymmetric Ring -

SPEAR A spear is a polearm consisting of a shaft, usually of wood, with a pointed head. The head may be simply the sharpened end of the shaft itself, as is the case with Fire hardening, fire hardened spears, or it may be made of a more durable materia ...

) 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, biology, basic research, and education. 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 Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiog ...

. It is located in

San Mateo County San Mateo County ( ), officially the County of San Mateo, is a county (United States), county located in the U.S. state of California. As of the 2020 United States census, the population was 764,442. Redwood City, California, Redwood City is th ...

, in the city of Menlo Park, California, close to the Stanford University main campus.

History

In 1972, the first

x-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

beamline In accelerator physics, a beamline refers to the trajectory of the beam of particles, including the overall construction of the path segment (guide tubes, diagnostic devices) along a specific path of an accelerator facility. This part is either ...

was constructed by Ingolf Lindau and Piero Pianetta as literally a "hole in the wall" extending off of the SPEAR storage ring. SPEAR had been built in an era of particle

collider A collider is a type of particle accelerator that brings two opposing particle beams together such that the particles collide. Compared to other particle accelerators in which the moving particles collide with a stationary matter target, collid ...

s, where physicists were more interested in smashing particles together in hope of discovering

antimatter In modern physics, antimatter is defined as matter composed of the antiparticles (or "partners") of the corresponding subatomic particle, particles in "ordinary" matter, and can be thought of as matter with reversed charge and parity, or go ...

than in using x-ray radiation for solid state physics and chemistry. From those meager beginnings the Stanford

Synchrotron A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The strength of the magnetic field which bends the particle beam i ...

Radiation Project (SSRP) began. Within a short time SSRP had five experimental hutches that each used the radiation originating from only one of the large SPEAR dipole (bending) magnets. Each one of those stations was equipped with a

monochromator A monochromator is an optics, optical device that transmits a mechanically selectable narrow band of wavelengths of light or other radiation chosen from a wider range of wavelengths available at the input. The name is . Uses A device that can ...

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

. The SLAC 2-mile linear accelerator was the original source for 3GeV electrons, but by 1991 SPEAR had its own 3-section linac and energy-ramping booster ring. Today, the SPEAR storage ring is dedicated completely to the Stanford Synchrotron Radiation Lightsource as part of the

facility. SSRL currently operates 24/7 for about nine months each year; the remaining time is used for major maintenance and upgrades where direct access to the storage ring is needed. There are currently 17 beamlines and over 30 unique experimental stations which are made available to users from universities, government labs, and industry from all over the world.

Directors

# Sebastian Doniach 1973-1977 # Arthur Bienenstock 1978-1998 # Keith Hodgson 1998-2005 # Joachim Stöhr 2005-2009 # Piero Pianetta 2009 # Chi-Chang Kao 2010-2012 # Piero Pianetta 2012-2014 # Kelly Gaffney 2014-2019 # Paul McIntyre 2019-present

Facilities

''listed by

Beamline In accelerator physics, a beamline refers to the trajectory of the beam of particles, including the overall construction of the path segment (guide tubes, diagnostic devices) along a specific path of an accelerator facility. This part is either ...

and Station'' *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 (2.4-6 keV) 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 (resonant and non-resonant x-ray emission spectroscopy), XRS (non-resonant x-ray Raman scattering and

RIXS Resonant inelastic X-ray scattering (RIXS) is an advanced X-ray spectroscopy technique. In the last two decades RIXS has been widely exploited to study the electronic, magnetic and structural properties of quantum materials and molecules. It is ...

( resonant inelastic X-ray scattering). *BL 8-2, 10-1, 13-2 These three beamlines are specialized for soft x-ray absorption spectroscopy, including NEXAFS ( Near edge X-ray absorption fine structure), some light atom Ligand K-edge (

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

), PES ( Photoemission spectroscopy), and L-edge measurements. All experiments on these beamlines require special handling and advanced

ultra high vacuum Ultra-high vacuum (often spelled ultrahigh in American English, UHV) is the vacuum regime characterised by pressures lower than about . UHV conditions are created by pumping the gas out of a UHV chamber. At these low pressures the mean free path of ...

experience and techniques. *BL 11-3

Materials Science Materials science is an interdisciplinary field of researching and discovering materials. Materials engineering is an engineering field of finding uses for materials in other fields and industries. The intellectual origins of materials sci ...

Scattering, Reflectivity and

Single Crystal In materials science, a single crystal (or single-crystal solid or monocrystalline solid) is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no Grain boundary, grain bound ...

Diffraction Diffraction is the deviation of waves from straight-line propagation without any change in their energy due to an obstacle or through an aperture. The diffracting object or aperture effectively becomes a secondary source of the Wave propagation ...

Experiments. Uses to date include: study of structure in organic, metal, and

semiconductor A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. Its conductivity can be modified by adding impurities (" doping") to its crystal structure. When two regions with different doping level ...

thin films and multilayers; study of charge-density waves in rare earth tri-tellurides; study of ''in-situ'' growth of

biogenic A biogenic substance is a product made by or of life forms. While the term originally was specific to metabolite compounds that had toxic effects on other organisms, it has developed to encompass any constituents, secretions, and metabolites of p ...

minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): M ...

; partial determination of texture in recrystallized

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of extremely vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicula ...

; quick determination of single crystal orientation. *BL 1-5, 7-1, 9-1, 9-2, 11-1, 11-3, 12-2 These beamlines are used for

macromolecular A macromolecule is a "molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass." Polymers are physi ...

x-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...

. All of the beamlines are for general use, except for beamline 12-2, which was funded in part by

Caltech The California Institute of Technology (branded as Caltech) is a private university, private research university in Pasadena, California, United States. The university is responsible for many modern scientific advancements and is among a small g ...

via a gift from the Gordon and Betty Moore Foundation. As a result, 40% of beamtime on 12-2 is reserved for Caltech researchers. *BL 4-2 Biological small-angle X-ray scattering beamline.

External links

SSRL Headline News
A Monthly Digital Publication
Lightsources.orgArchives and History Office - Stanford Synchrotron Radiation Project (SSRP)

References

SSRL Home page
# #: {{authority control Synchrotron Radiation Lightsource Synchrotron radiation facilities Laboratories in California United States Department of Energy national laboratories Buildings and structures in San Mateo County, California Particle physics facilities University and college laboratories in the United States Research institutes in the San Francisco Bay Area