| European Organization for Nuclear Research Organisation européenne pour la recherche nucléaire |
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Member states |
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| Formation | 29 September 1954[1] |
| Headquarters | Geneva, Switzerland |
| Membership | 21 member states and 7 observers |
| Director General | Rolf-Dieter Heuer |
| Website | cern.ch |
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 (). 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, as well as some 7931 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 an international facility, are officially under neither Swiss nor French jurisdiction. Member states' contributions to CERN for the year 2008 totaled CHF 1 billion (approximately € 664 million).
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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]".
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.
Several important achievements in particle physics have been made during experiments at CERN. They include:
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."
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.
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.
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]
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:
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[14] 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.[15] The first attempt to circulate a beam through the entire LHC was at 8:28 GMT on 10 September 2008,[16] 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 a long 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. At the end of the 7 TeV experimental period, the LHC will be shut down for maintenance for up to a year, with the main purpose of this shut down being to strengthen the huge magnets inside the accelerator. When it re-opens, it will attempt to create 14 TeV events.
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:
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.
| 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)
The original twelve CERN signatories from 1954 were:
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:
There are currently twenty member countries, eighteen of which are also European Union member states.
Four countries applying for membership have all formally confirmed their wish to become members.[22]
Five countries have observer status:[23]
Also observers are the following international organizations:
Non-Member States (with dates of Co-operation Agreements) currently involved in CERN programmes are:
| Maps of the history of CERN membership |
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Facilities at CERN open to the public include:
| Book: Large Hadron Collider | |
| Wikipedia books are collections of articles that can be downloaded or ordered in print. | |
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