Coordinates: 46°14′03″N 6°03′10″E / 46.23417°N 6.05278°E / 46.23417; 6.05278

European Organization for Nuclear Research Organisation européenne pour la recherche nucléaire
Member states
Formation	29 September 1954[1]
Headquarters	Geneva, Switzerland
Membership	21 member states and 7 observers
Director General	Rolf-Dieter Heuer
Website	cern.ch

The 12 founding member states of CERN in 1954 ^a[›] (map borders from 1989)

54 years after its foundation, membership to CERN increased to 20 states, 18 of which are also EU members as of 2010

The European Organization for Nuclear Research (French: Organisation européenne pour la recherche nucléaire), known as CERN ( /ˈsɜrn/; French pronunciation: [sɛʁn]; see History), is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border (46°14′3″N 6°3′19″E / 46.23417°N 6.05528°E / 46.23417; 6.05528). Established in 1954, the organization has twenty European member states.

The term CERN is also used to refer to the laboratory itself, which employs just under 2400 full-time employees and hosts some 10000 visiting scientists and engineers representing 608 universities and research facilities and 113 nationalities.

CERN's main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research. Numerous experiments have been constructed at CERN by international collaborations to make use of them. It is also the birthplace of the World Wide Web. The main site at Meyrin also has a large computer centre containing very powerful data-processing facilities primarily for experimental data analysis and, because of the need to make them available to researchers elsewhere, has historically been a major wide area networking hub.

The CERN sites, as international facilities, are officially under neither Swiss nor French jurisdiction. Member states' contributions to CERN for the year 2008 totaled CHF 1 billion (approximately € 664 million).^{[citation needed]}

History[link]

The convention establishing CERN was ratified on 29 September 1954 by 12 countries in Western Europe.^a[›][1] The acronym CERN originally stood, in French, for Conseil Européen pour la Recherche Nucléaire (European Council for Nuclear Research), which was a provisional council for setting up the laboratory, established by 12 European governments in 1952. The acronym was retained for the new laboratory after the provisional council was dissolved, even though the name changed to the current Organisation Européenne pour la Recherche Nucléaire (European Organization for Nuclear Research) in 1954.^[2] According to Lew Kowarski, a former director of CERN, when the name was changed the acronym could have become the awkward OERN, and Heisenberg said that the acronym could "still be CERN even if the name is [not]".^{[citation needed]}

Soon after its establishment the work at the laboratory went beyond the study of the atomic nucleus into higher-energy physics, which is mainly concerned with the study of interactions between particles. Therefore the laboratory operated by CERN is commonly referred to as the European laboratory for particle physics (Laboratoire européen pour la physique des particules) which better describes the research being performed at CERN.

Scientific achievements[link]

Several important achievements in particle physics have been made during experiments at CERN. They include:

• 1973: The discovery of neutral currents in the Gargamelle bubble chamber.^[3]
• 1983: The discovery of W and Z bosons in the UA1 and UA2 experiments.^[4]
• 1989: The determination of the number of light neutrino families at the Large Electron–Positron Collider (LEP) operating on the Z boson peak.
• 1995: The first creation of antihydrogen atoms in the PS210 experiment.^[5]
• 1999: The discovery of direct CP violation in the NA48 experiment.^[6]
• 2010: The isolation of 38 atoms of antihydrogen^[7]
• 2011: Maintaining antihydrogen for over 15 minutes^[8]

The 1984 Nobel Prize in physics was awarded to Carlo Rubbia and Simon van der Meer for the developments that led to the discoveries of the W and Z bosons. The 1992 Nobel Prize in physics was awarded to CERN staff researcher Georges Charpak "for his invention and development of particle detectors, in particular the multiwire proportional chamber."

Computer science[link]

This NeXT Computer used by British scientist Sir Tim Berners-Lee at CERN became the first Web server.

The World Wide Web began as a CERN project called ENQUIRE, initiated by Tim Berners-Lee in 1989 and Robert Cailliau in 1990.^[9] Berners-Lee and Cailliau were jointly honored by the Association for Computing Machinery in 1995 for their contributions to the development of the World Wide Web.

Based on the concept of hypertext, the project was aimed at facilitating sharing information among researchers. The first website went on-line in 1991. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone. A copy^[10] of the original first webpage, created by Berners-Lee, is still published on the World Wide Web Consortium's website as a historical document.

This Cisco Systems router at CERN was probably one of the first IP routers deployed in Europe.

Prior to the Web's development, CERN had been a pioneer in the introduction of Internet technology, beginning in the early 1980s. A short history of this period can be found at CERN.ch.^[11]

More recently, CERN has become a centre for the development of grid computing, hosting among others the Enabling Grids for E-sciencE (EGEE) and LHC Computing Grid projects. It also hosts the CERN Internet Exchange Point (CIXP), one of the two main Internet Exchange Points in Switzerland.

Faster-than-light neutrino anomaly[link]

On September 22, 2011, the OPERA Collaboration reported detection of 17-GeV and 28-GeV muon neutrinos, sent 730 kilometers (454 miles) from CERN near Geneva, Switzerland to the Gran Sasso National Laboratory in Italy, traveling apparently faster than light by a factor of 2.48×10⁻⁵ (approximately 1 in 40,000), a statistic with 6.0-sigma significance.^[12] Recently, it was reported by a new team of scientists for CERN, Icarus, that the previous experiment was most likely flawed and will be retested by scientists of both the Opera and Icarus teams;^[13] on 16 March, CERN came up with press release, saying the results were flawed due to incorrectly connected GPS-synchronization cable.^[14]

Particle accelerators[link]

Current complex[link]

Map of the CERN accelerator complex

Map of the Large Hadron Collider together with the Super Proton Synchrotron at CERN

CERN operates a network of six accelerators and a decelerator. Each machine in the chain increases the energy of particle beams before delivering them to experiments or to the next more powerful accelerator. Currently active machines are:

• Two linear accelerators generate low energy particles. Linac2 accelerates protons to 50 MeV for injection into the Proton Synchrotron Booster (PSB), and Linac3 provides heavy ions at 4.2 MeV/u for injection into the Low Energy Ion Ring (LEIR).^[15]
• The Proton Synchrotron Booster increases the energy of particles generated by the proton linear accelerator before they are transferred to the other accelerators.
• The Low Energy Ion Ring (LEIR) accelerates the ions from the ion linear accelerator, before transferring them to the Proton Synchrotron (PS). This accelerator was commissioned in 2005, after having been reconfigured from the previous Low Energy Antiproton Ring (LEAR).
• The 28 GeV Proton Synchrotron (PS), built in 1959 and still operating as a feeder to the more powerful SPS.
• The Super Proton Synchrotron (SPS), a circular accelerator with a diameter of 2 kilometres built in a tunnel, which started operation in 1976. It was designed to deliver an energy of 300 GeV and was gradually upgraded to 450 GeV. As well as having its own beamlines for fixed-target experiments (currently COMPASS and NA62), it has been operated as a proton–antiproton collider (the SppS collider), and for accelerating high energy electrons and positrons which were injected into the Large Electron–Positron Collider (LEP). Since 2008, it has been used to inject protons and heavy ions into the Large Hadron Collider (LHC).
• The On-Line Isotope Mass Separator (ISOLDE), which is used to study unstable nuclei. The radioactive ions are produced by the impact of protons at an energy of 1.0–1.4 GeV from the Proton Synchrotron Booster. It was first commissioned in 1967 and was rebuilt with major upgrades in 1974 and 1992.
• REX-ISOLDE increases the charge states of ions coming from the ISOLDE targets, and accelerates them to a maximum energy of 3 MeV/u.
• The Antiproton Decelerator (AD), which reduces the velocity of antiprotons to about 10% of the speed of light for research into antimatter.
• The Compact Linear Collider Test Facility, which studies feasibility issues for the future normal conducting linear collider project.

The Large Hadron Collider[link]

Construction of the CMS detector for LHC at CERN

Most of the activities at CERN are currently directed towards operating the new Large Hadron Collider (LHC), and the experiments for it. The LHC represents a large-scale, worldwide scientific cooperation project.

The LHC tunnel is located 100 metres underground, in the region between the Geneva airport and the nearby Jura mountains. It uses the 27 km circumference circular tunnel previously occupied by LEP which was closed down in November 2000. CERN's existing PS/SPS accelerator complexes will be used to pre-accelerate protons which will then be injected into the LHC.

Seven experiments (CMS, ATLAS, LHCb, MoEDAL^[16] TOTEM, LHC-forward and ALICE) will run on the collider; each of them will study particle collisions from a different point of view, and with different technologies. Construction for these experiments required an extraordinary engineering effort. Just as an example, a special crane had to be rented from Belgium in order to lower pieces of the CMS detector into its underground cavern, since each piece weighed nearly 2,000 tons. The first of the approximately 5,000 magnets necessary for construction was lowered down a special shaft at 13:00 GMT on 7 March 2005.

This accelerator has begun to generate vast quantities of data, which CERN streams to laboratories around the world for distributed processing (making use of a specialised grid infrastructure, the LHC Computing Grid). In April 2005, a trial successfully streamed 600 MB/s to seven different sites across the world. If all the data generated by the LHC is to be analysed, then scientists must achieve 1,800 MB/s before 2008.

The initial particle beams were injected into the LHC August 2008.^[17] The first attempt to circulate a beam through the entire LHC was at 8:28 GMT on 10 September 2008,^[18] but the system failed because of a faulty magnet connection, and it was stopped for repairs on 19 September 2008.

The LHC resumed its operation on Friday the 20 November 2009 by successfully circulating two beams, each with an energy of 3.5 trillion electron volts. The challenge that the engineers then faced was to try to line up the two beams so that they smashed into each other. This is like "firing two needles across the Atlantic and getting them to hit each other" according to the LHC's main engineer Steve Myers, director for accelerators and technology at the Swiss laboratory.

At 1200 BST on Tuesday 30 March 2010 the LHC successfully smashed two proton particle beams travelling with 3.5 TeV (trillion electron volts) of energy, resulting in a 7 TeV event. However, this is just the start of the road toward the expected discovery of the Higgs boson. This is mainly because the amount of data produced is so huge it could take up to 24 months to completely analyse it all. When the 7 TeV experimental period ended, the LHC revved up to 8 TeV (4 TeV acceleration in both directions) in March 2012, and will begin particle collisions at that rate in early April, 2012. At the end of 2012 the LHC will be shut down for maintenance for up to a year, to strengthen the huge magnets inside the accelerator. It will then attempt to create 14 TeV events.

Decommissioned accelerators[link]

• The original linear accelerator (LINAC 1).
• The 600 MeV Synchrocyclotron (SC) which started operation in 1957 and was shut down in 1991.
• The Intersecting Storage Rings (ISR), an early collider built from 1966 to 1971 and operated until 1984.
• The Large Electron–Positron Collider (LEP), which operated from 1989 to 2000 and was the largest machine of its kind, housed in a 27 km-long circular tunnel which now houses the Large Hadron Collider.
• The Low Energy Antiproton Ring (LEAR), commissioned in 1982, which assembled the first pieces of true antimatter, in 1995, consisting of nine atoms of antihydrogen. It was closed in 1996, and superseded by the Antiproton Decelerator.

Sites[link]

CERN's main site, as seen from Switzerland looking towards France.

Interior of office building 40 at the Meyrin site. Building 40 hosts many offices for scientists working for CMS and Atlas.

John Ellis in his office at CERN in January 2012.

The smaller accelerators are located on the main Meyrin site (also known as the West Area), which was originally built in Switzerland alongside the French border, but has been extended to span the border since 1965. The French side is under Swiss jurisdiction and so there is no obvious border within the site, apart from a line of marker stones. There are six entrances to the Meyrin site:

• A, in Switzerland. Open for all CERN personnel at specific times.
• B, in Switzerland. Open for all CERN personnel at all times. Often referred to as the main entrance.
• C, in Switzerland. Open for all CERN personnel at specific times.
• D, in Switzerland. Open for goods reception at specific times.
• E, in France. Open for French-resident CERN personnel at specific times. Controlled by customs personnel. Named "Porte Charles de Gaulle" in recognition of his role in the creation of the CERN.^[19]
• Tunnel entrance, in France. Open for equipment transfer to and from CERN sites in France by personnel with a specific permit. This is the only permitted route for such transfers. Under the CERN treaty, no taxes are payable when such transfers are made. Controlled by customs personnel.

The SPS and LEP/LHC tunnels are located underground almost entirely outside the main site, and are mostly buried under French farmland and invisible from the surface. However they have surface sites at various points around them, either as the location of buildings associated with experiments or other facilities needed to operate the colliders such as cryogenic plants and access shafts. The experiments themselves are located at the same underground level as the tunnels at these sites.

Three of these experimental sites are in France, with ATLAS in Switzerland, although some of the ancillary cryogenic and access sites are in Switzerland. The largest of the experimental sites is the Prévessin site, also known as the North Area, which is the target station for non-collider experiments on the SPS accelerator. Other sites are the ones which were used for the UA1, UA2 and the LEP experiments (the latter which will be used for LHC experiments).

Outside of the LEP and LHC experiments, most are officially named and numbered after the site where they were located. For example, NA32 was an experiment looking at the production of charmed particles and located at the Prévessin (North Area) site while WA22 used the Big European Bubble Chamber (BEBC) at the Meyrin (West Area) site to examine neutrino interactions. The UA1 and UA2 experiments were considered to be in the Underground Area, i.e. situated underground at sites on the SPS accelerator.

[edit] Financing (Budget 2009)^[20]

Member state	Contribution	Mil. CHF	Mil. EUR
Germany	19.88 %	218.6	144.0
France	15.34 %	168.7	111.2
United Kingdom	14.70 %	161.6	106.5
Italy	11.51 %	156.5	93.4
Spain	8.52 %	93.7	61.8
Netherlands	4.79 %	52.7	34.7
Switzerland	3.01 %	33.1	21.8
Poland	2.85 %	31.4	20.7
Belgium	2.77 %	30.4	20.1
Sweden	2.76 %	30.4	20.0
Norway	2.53 %	27.8	18.3
Austria	2.24 %	24.7	16.3
Greece	1.96 %	20.5	13.5
Denmark	1.76 %	19.4	12.8
Finland	1.55 %	17.0	11.2
Czech Republic	1.15 %	12.7	8.4
Portugal	1.14 %	12.5	8.2
Hungary	0.78 %	8.6	5.6
Slovakia	0.54 %	5.9	3.9
Bulgaria	0.22 %	2.4	1.6
Total	100 %	1098.6	724.0

Exchange rates: 1 CHF = 0,829 EUR (19 Sep 2011)

Member states[link]

Member states of CERN as of 2008

  CERN members

  Membership candidates

  Declared intent to join

Animated map showing changes in CERN membership from 1954 until 1999 (borders as of 1989 and 2008)

CERN members (in blue) and observers (in red: USA, Israel, Turkey, Japan, India, and Russia) as of 2008^[update]

CERN: where the Web was born^[21]

The original twelve CERN signatories from 1954 were:

•  Belgium
•  Denmark
•  France
•  Germany (at first only West Germany)
•  Greece
•  Italy
•  Netherlands
•  Norway
•  Sweden
•  Switzerland
•  United Kingdom
•  Yugoslavia (later withdrawn).

All founding members have so far (as of 2008^[update]) remained in the CERN organisation, except Yugoslavia which left in 1961 and never re-joined.

Since its foundation, CERN regularly accepted new members. All new members have remained in the organisation continuously since their acceptance, except Spain which joined in 1961, withdrew eight years later, and joined anew in 1983. CERN's membership history is as follows:

•  Austria joined in 1959, bringing the total number of members to thirteen.
•  Yugoslavia left in 1961 (twelve members)
•  Spain joined in 1961 (thus increasing the number of member states to 13 again), left in 1969 (twelve members), rejoined in 1983 (thirteen members)
•  Portugal joined in 1985 (fourteen member states)
•  Finland joined in 1991
•  Poland joined in 1991 (together with Finland bringing the number of participating member states to sixteen)
•  Hungary joined in 1992 (seventeen members)
•  Czech Republic joined in 1993
•  Slovakia joined in 1993 (together with Czech Republic increasing the total members to nineteen)
•  Bulgaria joined in 1999 (twenty member states)

There are currently twenty member countries, eighteen of which are also European Union member states.

•  Romania became a candidate for accession to CERN in 2010 and will become a member country in 2015.^[22]
•  Serbia became a candidate for accession to CERN on December 19, 2011. Associate member on January 10, 2012.^[23]
•  Israel became an associate member in 2011, with a decision to be made on its full membership in 2013.^[24]

Four countries applying for membership have all formally confirmed their wish to become members.^[25]

•  Cyprus since 14 February 2006 Non-Member State status
•  Slovenia since 7 January 1991 Non-Member State status
•  Turkey since 1961 Observer State status

Five countries have observer status:^[26]

•  Turkey – since 1961
•  Russia – since 1993
•  Japan – since 1995
•  United States – since 1997
•  India – since 2002

Also observers are the following international organizations:

•  UNESCO – since 1954
• European Commission – since 1985

Non-Member States (with dates of Co-operation Agreements) currently involved in CERN programmes are:

•  Algeria
•  Argentina – 11 March 1992
•  Armenia – 25 March 1994
•  Australia – 1 November 1991
•  Azerbaijan – 3 December 1997
•  Belarus – 28 June 1994
•  Brazil – 19 February 1990 & October 2006
•  Canada – 11 October 1996
•  Chile – 10 October 1991
•  China – 12 July 1991, 14 August 1997 & 17 February 2004
•  Colombia – 15 May 1993
•  Croatia – 18 July 1991
•  Cuba
•  Cyprus – 14 February 2006
•  Egypt – 16 January 2006
•  Estonia – 23 April 1996
•  Georgia – 11 October 1996
•  Iceland – 11 September 1996
•  Iran – 5 July 2001
•  Ireland
•  Jordan - 12 June 2003.^[27] MoU with Jordan and SESAME, in preparation of a cooperation agreement signed in 2004.^[28]
•  Lithuania – 9 November 2004
•  Macedonia – 27 April 2009^[29]
•  Mexico – 20 February 1998
•  Montenegro – 12 October 1990
•  Morocco – 14 April 1997
•  New Zealand – 4 December 2003
•  Pakistan – 1 November 1994.
•  Peru – 23 February 1993
•  Romania – 1 October 1991. Since 12 December 2008 it has the Status of Candidate for Accession to Membership.
•  Saudi Arabia – 21 January 2006
•  Slovenia – 7 January 1991
•  South Africa – 4 July 1992
•  South Korea – 25 October 2006.
•  Republic of China (Taiwan)
•  Thailand
•  United Arab Emirates – 18 January 2006
•  Ukraine – 2 April 1993
•  Vietnam

Public exhibits[link]

The Globe of Science and Innovation at CERN

Facilities at CERN open to the public include:

• The Globe of Science and Innovation, which opened in late 2005 and is used four times a week for special exhibits.
• The Microcosm museum on particle physics and CERN history.
• The Hindu deity, Shiva engaging in the Nataraja dance, parallelling the movements or “dance” of subatomic particles.^[30]

In popular culture[link]

• CERN's Large Hadron Collider is the subject of a (scientifically accurate) rap video starring Katherine McAlpine with some of the facility's staff.^[31][32]
• CERN's is depicted in an episode of South Park (Season 13, Episode 6) called "Pinewood Derby". Randy Marsh, the father of one of the main characters, breaks into the "Hadron Particle Super Collider in Switzerland" and steals a "superconducting bending magnet created for use in tests with particle acceleration" to use in his son Stan's Pinewood Derby racer. Randy breaks into CERN dressed in disguise as Princess Leia from the Star Wars saga. The break-in is captured on surveillance tape which is then broadcast on the news.^[33]
• CERN is depicted in the visual novel (later adapted into an anime series) Steins;Gate under the name SERN. In the video game, SERN is a shadowy organization that has been researching time travel and attempts to use it to restructure and control the world in the near future.
• In Dan Brown's mystery-thriller novel Angels & Demons, a canister of antimatter is stolen from CERN.^[34]
• In the popular children's series The 39 Clues, CERN is said to be an Ekaterina stronghold hiding the clue hydrogen.

See also[link]

	Geneva portal
	Science portal

• Fermilab
• Large Hadron Collider
• List of Directors General of CERN
• Nederlandse Organisatie voor Wetenschappelijk Onderzoek
• Science and technology in Switzerland
• SLAC National Accelerator Laboratory

References[link]

External links[link]

Wikimedia Commons has media related to: CERN

	Book: Large Hadron Collider
Wikipedia books are collections of articles that can be downloaded or ordered in print.

• Official website (public)
• Official website (users)
• CERN at 50
• CERN Courier – International journal of high-energy physics