Editing Collider (section)

== History ==
The first serious proposal for a collider originated with a group at the [[Midwestern Universities Research Association]] (MURA).  This group proposed building two tangent radial-sector [[FFAG accelerator]] rings.<ref>{{cite journal | last1 = Kerst | first1 = D. W. | author-link1 = Donald William Kerst | last2 = Cole | first2 = F. T. | last3 = Crane | first3 = H. R. | last4 = Jones | first4 = L. W. | year = 1956 | title = Attainment of Very High Energy by Means of Intersecting Beams of Particles | journal = [[Physical Review]] | volume = 102 | issue = 2 | pages = 590–591 | doi = 10.1103/PhysRev.102.590 |display-authors=etal|bibcode = 1956PhRv..102..590K }}</ref> [[Tihiro Ohkawa]], one of the authors of the first paper, went on to develop a radial-sector FFAG accelerator design that could accelerate two counterrotating particle beams within a single ring of magnets.<ref>{{US patent reference
 | number = 2890348
 | y = 1959
 | m = 06
 | d = 09
 | inventor = Tihiro Ohkawa
 | title = [https://patents.google.com/patent/US2890348 Particle Accelerator]
}}</ref><ref>Science: Physics & Fantasy, [https://web.archive.org/web/20121106173215/http://www.time.com/time/magazine/article/0,9171,809067-1,00.html Time], Monday, Feb. 11, 1957.</ref>  The third FFAG prototype built by the MURA group was a 50&nbsp;MeV electron machine built in 1961 to demonstrate the feasibility of this concept.

[[Gerard K. O'Neill]] proposed using a single accelerator to inject particles into a pair of tangent [[storage ring]]s.  As in the original MURA proposal, collisions would occur in the tangent section.  The benefit of storage rings is that the storage ring can accumulate a high beam flux from an injection accelerator that achieves a much lower flux.<ref>{{Cite journal | last1 = O'Neill | first1 = G. | author-link1 = Gerard K. O'Neill | title = Storage-Ring Synchrotron: Device for High-Energy Physics Research | doi = 10.1103/PhysRev.102.1418 | journal = [[Physical Review]] | volume = 102 | issue = 5 | pages = 1418–1419 | year = 1956 | bibcode = 1956PhRv..102.1418O | url = http://www.feynman.princeton.edu/mumu/physics/oneill_pr_102_1418_56.pdf | url-status = dead | archive-url = https://web.archive.org/web/20120306163409/http://www.feynman.princeton.edu/mumu/physics/oneill_pr_102_1418_56.pdf | archive-date = 2012-03-06 }}</ref>

The first [[electron]]-[[positron]] colliders were built in late 1950s-early 1960s in Italy, at the [[Istituto Nazionale di Fisica Nucleare]] in [[Frascati]] near Rome, by the Austrian-Italian physicist [[Bruno Touschek]] and in the US, by the Stanford-Princeton team that included William C.Barber, Bernard Gittelman, Gerry O’Neill, and [[Burton Richter]]. Around the same time, the ''VEP-1'' electron-electron collider was independently developed and built under supervision of [[Gersh Budker]] in the [[Budker Institute of Nuclear Physics|Institute of Nuclear Physics]] in [[Novosibirsk]], [[USSR]]. The first observations of particle reactions in the colliding beams were reported almost simultaneously by the three teams in mid-1964 - early 1965. <ref>{{cite arXiv | last1 = Shiltsev | first1 = V. | title = The first colliders: AdA, VEP-1 and Princeton-Stanford | eprint = 1307.3116 | class = physics.hist-ph | year = 2013 }}</ref>

In 1966, work began on the [[Intersecting Storage Rings]] at [[CERN]], and in 1971, this collider was operational.<ref>Kjell Johnsen, The ISR in the time of Jentschke, [http://cerncourier.com/cws/article/cern/28876 CERN Courier], June 1, 2003.</ref>  The ISR was a pair of storage rings that accumulated and collided protons injected by the CERN [[Proton Synchrotron]].  This was the first [[hadron]] collider, as all of the earlier efforts had worked with [[electrons]] or with electrons and [[positrons]].

In 1968 construction began on the highest energy proton accelerator complex at [[Fermilab]]. It was eventually upgraded to become the [[Tevatron]] collider and in October 1985 the first [[proton]]-[[antiproton]] collisions were recorded at a center of mass energy of 1.6 TeV, making it the highest energy collider in the world, at the time. The energy had later reached 1.96 TeV and at the end of the operation in 2011 the collider luminosity exceeded 430 times its original design goal. <ref>{{cite journal | last1 = Holmes | first1 = Stephen D. | last2 = Shiltsev | first2 = Vladimir D. | year = 2013 | title = The Legacy of the Tevatron in the Area of Accelerator Science | journal = [[Annual Review of Nuclear and Particle Science]] | volume = 63 | pages = 435–465 | doi = 10.1146/annurev-nucl-102212-170615 | arxiv = 1302.2587 | bibcode = 2013ARNPS..63..435H | s2cid = 118385635 }}</ref>

Since 2009, the most high-energetic collider in the world is the [[Large Hadron Collider]] (LHC) at CERN. It currently operates at 13 TeV center of mass energy in proton-proton collisions. More than a dozen future particle collider projects of various types - circular and linear, colliding hadrons (proton-proton or ion-ion), leptons (electron-positron or muon-muon), or electrons and ions/protons - are currently under consideration for detail exploration of the Higgs/electroweak physics and discoveries at the post-LHC energy frontier. <ref>{{cite journal | last1 = Shiltsev | first1 = Vladimir | last2 = Zimmermann | first2 = Frank | year = 2021 | title = Modern and future colliders | journal = [[Reviews of Modern Physics]] | volume = 93 | issue = 1 | pages = 015006  | doi = 10.1103/RevModPhys.93.015006| arxiv = 2003.09084 | bibcode = 2021RvMP...93a5006S | s2cid = 214605600 }}</ref>