View source for SPEAR

{{About|the particle accelerator|other uses|spear (disambiguation)}}
{{No footnotes|date=December 2013}}

'''SPEAR''' (originally '''Stanford Positron Electron Accelerating Ring''', now simply a name)<ref name=":0">{{Cite web |title=S {{!}} SLAC Archives, History & Records Office |url=https://ahro.slac.stanford.edu/slacspeak/s |access-date=2024-04-24 |website=ahro.slac.stanford.edu}}</ref>{{ref label |notea|a}} was a [[collider]] at the [[Stanford Linear Accelerator Center|SLAC National Accelerator Laboratory]].<ref>{{cite web |last1=Williams |first1=Shawna |title=The Ring on the Parking Lot |url=https://cerncourier.com/a/the-ring-on-the-parking-lot/ |website=CERN Courier |date=31 May 2003 |access-date=29 March 2022}}</ref>  It began running in 1972, colliding [[electron]]s and [[positron]]s with an energy of {{val|3|ul=GeV}}.  During the 1970s, experiments at the accelerator played a key role in [[particle physics]] research, including the discovery of the {{SubatomicParticle|link=yes|J/Psi}} [[meson]] (awarded the 1976 [[Nobel Prize in Physics]]), many [[charmonium]] states, and the discovery of the [[tau (particle)|tau]] (awarded the 1995 [[Nobel Prize in Physics]]).

Today, SPEAR is used as a [[synchrotron radiation]] source for the [[Stanford Synchrotron Radiation Lightsource]] (SSRL). The latest major upgrade of the ring in that finished in 2004 rendered it the current name SPEAR3.<!--What was SPEAR2?-->

== Notes ==
a:{{note|notea}} The original design consists of a single ring, an upgraded proposal for a pair of asymmetric rings did not receive enough funding and finally the acronym was kept as a simple name.<ref name=":0" /> Though the name '''Stanford Positron Electron Asymmetric Ring''' is also used in official sources.

== References ==
{{reflist}}

== External links ==
* {{Official website}}
* [http://www.slac.stanford.edu/spires/find/slacspeak/www?PH=spear&EXP= Brief explanation of the acronym in SLACspeak]
* [https://web.archive.org/web/20051223105553/http://www.slac.stanford.edu/gen/pubinfo/SPEAR25.html 25th Anniversary Info from SLAC]
* [http://www-ssrl.slac.stanford.edu/talk_display.html SPEAR3 status]

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[[Category:Buildings and structures in San Mateo County, California]]
[[Category:Particle physics facilities]]
[[Category:Stanford University]]
[[Category:Particle accelerators]]

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