Editing Tevatron (section)

==History==
December 1, 1968, saw the breaking of ground for the linear accelerator (linac). The construction of the Main Accelerator Enclosure began on October 3, 1969, when the first shovel of earth was turned by [[Robert R. Wilson]], NAL's director. This would become the 6.3&nbsp;km circumference Fermilab's Main Ring.<ref name="Fermilab History"/>

The linac first 200&nbsp;MeV beam started on December 1, 1970. The booster first 8&nbsp;GeV beam was produced on May 20, 1971. On June 30, 1971, a proton beam was guided for the first time through the entire National Accelerator Laboratory accelerator system including the Main Ring. The beam was accelerated to only 7&nbsp;GeV. Back then, the Booster Accelerator took 200&nbsp;MeV protons from the Linac and "boosted" their energy to 8&nbsp;billion electron volts. They were then injected into the Main Accelerator.<ref name="Fermilab History"/>

On the same year before the completion of the Main Ring, Wilson testified to the Joint Committee on Atomic Energy on March 9, 1971, that it was feasible to achieve a higher energy by using [[superconducting magnet]]s. He also suggested that it could be done by using the same tunnel as the main ring and the new magnets would be installed in the same locations to be operated in parallel to the existing magnets of the Main Ring. That was the starting point of the Tevatron project.<ref name="Fermilab Transition"/> The Tevatron was in research and development phase between 1973 and 1979 while the acceleration at the Main Ring continued to be enhanced.<ref name="TevCryo"/>

A series of milestones saw acceleration rise to 20&nbsp;GeV on January 22, 1972, to 53&nbsp;GeV on February 4 and to 100&nbsp;GeV on February 11. On March 1, 1972, the then NAL accelerator system accelerated for the first time a beam of protons to its design energy of 200&nbsp;GeV. By the end of 1973, NAL's accelerator system operated routinely at 300&nbsp;GeV.<ref name="Fermilab History"/>

On 14 May 1976 Fermilab took its protons all the way to 500&nbsp;GeV. This achievement provided the opportunity to introduce a new energy scale, the teraelectronvolt (TeV), equal to 1000&nbsp;GeV. On 17 June of that year, the European [[Super Proton Synchrotron]] accelerator (SPS) had achieved an initial circulating proton beam (with no accelerating radio-frequency power) of only 400 GeV.<ref>{{cite news|url=http://cerncourier.com/cws/article/cern/28470|title=Super Proton Synchrotron marks its 25th birthday|work=CERN courier|date=2 July 2011|access-date=7 October 2012}}</ref>

The conventional magnet Main Ring was shut down in 1981 for installation of superconducting magnets underneath it. The Main Ring continued to serve as an injector for the Tevatron until the Main Injector was completed west of the Main Ring in 2000.<ref name="Fermilab Transition">{{cite web|url=http://history.fnal.gov/transition.html|title=Accelerator History—Main Ring transition to Energy Doubler/Saver|access-date=7 October 2012|publisher=Fermilab History and Archives Project|archive-date=18 December 2012|archive-url=https://web.archive.org/web/20121218092249/http://history.fnal.gov/transition.html|url-status=dead}}</ref> The 'Energy Doubler', as it was known then, produced its first accelerated beam—512 GeV—on July 3, 1983.<ref>{{cite journal|url=http://www.fnal.gov/pub/ferminews/ferminews03-11-01/p4.html|journal=Fermi News|title=1983—The Year the Tevatron Came to Life|volume=26|year=2003|issue=15}}</ref>

Its initial energy of 800&nbsp;GeV was achieved on February 16, 1984. On October 21, 1986, acceleration at the Tevatron was pushed to 900&nbsp;GeV, providing a first proton–antiproton collision at 1.8&nbsp;TeV on November 30, 1986.<ref name=timeline>{{cite web|url=http://www.fnal.gov/pub/tevatron/milestones/interactive-timeline.html|title=Interactive timeline|access-date=7 October 2012|publisher=Fermilab}}</ref>

The ''Main Injector'', which replaced the Main Ring,<ref name=cern2001/> was the most substantial addition, built over six years from 1993 at a cost of $290 million.<ref name="Fermilab Main injector">{{cite web|url=http://www-fmi.fnal.gov/History/history.html|title=Main Injector and Recycler Ring History and Public Information|access-date=7 October 2012|publisher=Fermilab Main Injector department|url-status=dead|archive-url=https://web.archive.org/web/20111015015038/http://www-fmi.fnal.gov/History/history.html|archive-date=15 October 2011}}</ref> Tevatron collider Run II begun on March 1, 2001, after successful completion of that facility upgrade. From then, the beam had been capable of delivering an energy of 980&nbsp;GeV.<ref name=cern2001>{{cite news|url=http://cerncourier.com/cws/article/cern/28420|title=Run II begins at the Tevatron|work=CERN courier|date=30 April 2001|access-date=7 October 2012}}</ref>

On July 16, 2004, the Tevatron achieved a new peak [[Luminosity_(scattering_theory)|luminosity]], breaking the record previously held by the old European [[Intersecting Storage Rings]] (ISR) at CERN. That very Fermilab record was doubled on September 9, 2006, then a bit more than tripled on March 17, 2008, and ultimately multiplied by a factor of 4 over the previous 2004 record on April 16, 2010 (up to 4{{e|32}}&nbsp;cm<sup>−2</sup> s<sup>−1</sup>).<ref name=timeline/>

The Tevatron ceased operations on 30 September 2011. By the end of 2011, the Large Hadron Collider (LHC) at CERN had achieved a luminosity almost ten times higher than Tevatron's (at 3.65{{e|33}}&nbsp;cm<sup>−2</sup> s<sup>−1</sup>) and a beam energy of 3.5&nbsp;TeV each (doing so since March 18, 2010), already ~3.6 times the capabilities of the Tevatron (at 0.98&nbsp;TeV).