Stanford Linear Accelerator Center:
This article is about the particle physics research facility. For other uses of SLAC, see SLAC (disambiguation).
SLAC at Stanford University
The SLAC National Accelerator Laboratory, originally named Stanford Linear Accelerator Center,[1] is a United States Department of Energy National Laboratory operated by Stanford University under the programmatic direction of the U.S. Department of Energy Office of Science. The SLAC research program centers on experimental and theoretical research in elementary particle physics using electron beams and a broad program of research in atomic and solid-state physics, chemistry, biology, and medicine using synchrotron radiation.[2] The 2.0 mile (3.2 kilometer) long underground accelerator is the longest linear accelerator in the world, and is claimed to be "the world's straightest object."[3] SLAC's meeting facilities also provided a venue for the homebrew computer club and other pioneers of the 1980s home computer revolution, and later SLAC hosted the first webpage in the U.S. The above-ground klystron gallery atop the beamline is the longest building in the United States.
[edit] History
Aerial photo of the Stanford Linear Accelerator
Founded in 1962 as the Stanford Linear Accelerator Center, the facility is located on 426 acres (1.72 square kilometers) of Stanford University-owned land on Sand Hill Road in Menlo Park, California—just west from the University's main campus. The main accelerator, a 2.0 mile-long RF linear accelerator, which can accelerate electrons and positrons up to 50 GeV, has been operational since 1966. It is buried 30 feet (10 meters) below ground and passes underneath Interstate 280. As of 2005, SLAC employs over 1,000 people, some 150 of which are physicists with doctorate degrees, and serves over 3,000 visiting researchers yearly, operating particle accelerators for high-energy physics and the Stanford Synchrotron Radiation Laboratory (SSRL) for synchrotron light radiation research.[2]
Research at SLAC has produced three Nobel Prizes in Physics:
SLAC 1.9 mile (3 kilometer) long Klystron Gallery above the beam line Accelerator
Also, SSRL was "indispensable" in the research leading to the 2006 Nobel Prize in Chemistry.[7]
In the early-to-mid 90s, the Stanford Linear Collider or SLC, investigated the properties of the Z boson using the Stanford Large Detector.
In October 2008, the Department of Energy announced that the Center's name would be changed to SLAC National Accelerator Laboratory. The reasons given include better representing the new direction of the lab and being able to trademark the laboratory's name. Stanford University had legally opposed the Department of Energy's attempt to trademark "Stanford Linear Accelerator Center".[1][8]
[edit] Stanford Linear Collider
The Stanford Linear Collider was a linear accelerator that collided electrons and positrons at SLAC. The center of mass energy was about 90 GeV, equal to the mass of the Z boson, which the accelerator was designed to study. The first Z event was recorded on April 12, 1989 by the Mark II detector [1]. The bulk of the data was collected by the Stanford Large Detector, which came online in 1991. Although largely overshadowed by the Large Electron-Positron Collider collider at CERN, which began running in 1989, the highly polarized electron beam at SLC (close to 80%) made certain unique measurements possible.
Presently no beam enters the south and north arcs in the machine, which leads to the Final Focus, therefore this section is mothballed to run beam into the PEP2 section from the beam switchyard.
[edit] Stanford Large Detector
The Stanford Large Detector (SLD) was the main detector for the Stanford Linear Collider. It was designed primarily to detect Z bosons produced by the accelerator's electron-positron collisions. The SLD operated from 1992 to 1998.
[edit] PEP-II
Since 1999 the main purpose of the linear accelerator has been to inject electrons and positrons into the PEP-II accelerator, an electron-positron collider with a pair of storage rings 1.4 miles (2.2 km) in circumference. PEP-II was host to the BaBar experiment, one of the so-called B-Factory experiments studying charge-parity symmetry. The experiment was ended prematurely due to 2008 budget cuts.[9]
SSRL is a synchrotron light user facility located on the SLAC campus. Originally built for particle physics, it was used in experiments where the J/Ψ particle particle was discovered. It is now used exclusively for materials science and biology experiments which take advantage of the high-intensity, monochromatic synchrotron radiation emitted by the stored electron beam to study the structure of molecules. In the 1980s, an independent electron injector was built for this storage ring, allowing it to operate independently of the main linear accelerator.
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SLAC plays host to part of the GLAST project, a collaborative international project also known as The Gamma Ray Large Area Space Telescope, the principle objectives of which are:
- To understand the mechanisms of particle acceleration in AGNs, pulsars, and SNRs.
- Resolve the gamma-ray sky: unidentified sources and diffuse emission.
- Determine the high-energy behavior of gamma-ray bursts and transients.
- Probe dark matter and early Universe.
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The Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) is located on the grounds of SLAC.
[edit] Other discoveries
- SLAC has also been instrumental in the development of the klystron, a high-power microwave amplification tube.
- There is active research on plasma acceleration with recent successes such as the doubling of the energy of 42GeV electrons in a meter-scale accelerator.
- There was a Paleoparadoxia found at the SLAC site, and its skeleton can be seen at a small museum there in the Breezeway.[10]
- SLAC developed and hosted the first WWW server outside of Europe in December 1991 [11].
[edit] Pictures
[edit] See also
[edit] References
- ^ a b "SLAC renamed to SLAC Natl. Accelerator Laboratory", The Stanford Daily, The Stanford Daily Publishing Corporation (2008-10-16). Retrieved on 16 October 2008.
- ^ a b U.S. Department of Energy Office of Science. Review of the Stanford Linear Accelerator Center Integrated Safety Management System: Final Report. Washington: GPO, October 2005. p. 1.
- ^ Saracevic, Alan T. "Silicon Valley: It's where brains meet bucks." San Francisco Chronicle 23-October-2005. p J2. Accessed 2005-10-24.
- ^ Nobel Prize in Physics 1976. Half prize awarded to Burton Richter.
- ^ Nobel Prize in Physics 1990 Award split between Jerome I. Friedman, Henry W. Kendall, and Richard E. Taylor.
- ^ Nobel Prize in Physics 1995 Half prize awarded to Martin L. Perl.
- ^ 2006 Nobel Prize in Chemistry : Synchrotron Radiation Laboratory at SLAC Contributes
- ^ A New Name for SLAC
- ^ http://www.sciam.com/article.cfm?id=future-of-top-us-particle
- ^ Stanford's SLAC Paleoparadoxia much thanks to Adele Panofsky, Dr. Panofsky's wife, for her reassembly of the bones of the Paleoparadoxia uncovered at SLAC.
- ^ The Early World Wide Web at SLAC: Early Chronology and Documents
[edit] External links
Coordinates: 37°24′53″N 122°13′18″W / 37.41472, -122.22167
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