CERN logo
The 'European Organization for Nuclear Research' (), commonly known as 'CERN'
(see
''Naming''), pronounced (or in
French), is the world's largest
particle physics laboratory, situated just northwest of
Geneva on the border between
France and
Switzerland. The convention establishing CERN was signed on
29 September 1954. From the original 12 signatories of the CERN convention, membership has grown to the present 20
member states.
Its 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.
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 (and continues to be) a major
wide area networking hub.
CERN currently has approximately 2600 full-time employees. Some 7931
scientists and
engineers (representing 500 universities and 80 nationalities), about half of the world's particle physics community, work on experiments conducted at CERN.
As an international facility, the CERN sites are not officially under Swiss or French jurisdiction, and some company vehicles have diplomatic number plates.
Naming
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 11
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.
[1] 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 "But the acronym can still be CERN even if the name is [...]"
Soon after its establishment, the work at the laboratory went beyond the study of the
atomic nucleus, into higher-energy physics, an activity 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 current research being performed at CERN.
Scientific achievements
Several important achievements in particle physics have been made during experiments at CERN. These include, but are not limited to:
★ 1973: The discovery of
neutral currents in the
Gargamelle bubble chamber.
★ 1983: The discovery of
W and Z bosons in the
UA1 and
UA2 experiments.
★ 1995: The first creation of
antihydrogen atoms in the
PS210 experiment.
★ 2001: The discovery of direct
CP-violation in the
NA48 experiments.
The
1984 Nobel Prize in physics was awarded to
Carlo Rubbia and
Simon van der Meer for the developments that lead to the discoveries of
the W and Z bosons.
The
1992 Nobel Prize in physics was awarded to
Georges Charpak "for his invention and development of particle detectors, in particular the
multiwire proportional chamber."
Current accelerator complex
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 for injection into the Proton Synchrotron. The 50 MeV Linac2 is for protons, and the 4.2 MeV/
u Linac3 is for heavy ions.
[1]
★ 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 Anti-proton 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, it has been operated as a
proton-
antiproton collider, and for accelerating high energy
electrons and
positrons which were injected into the
Large Electron-Positron Collider (LEP). From 2008 onwards, it will 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. Particles are initially accelerated in the PS Booster before entering ISOLDE. It was first commissioned in
1967 and was rebuilt with major upgrades in
1974 and
1992.
★ The
Antiproton Decelerator (AD), which reduces the velocity of antiprotons to about 10% the speed of light for research into
antimatter.
The accelerator of the future: the Large Hadron Collider
Main articles: Large Hadron Collider
Construction of the
CMS detector for
LHC at CERN
Most of the activities at CERN are currently directed towards building a new collider, the
Large Hadron Collider (LHC) and the experiments for it. The LHC represents a large-scale, worldwide scientific cooperation project. Physics experiments are expected to start May
2008, delayed due to a inner triplet magnet assembly failing a pressure test in March
2007[2][3].
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.
Six experiments (
CMS,
ATLAS,
LHCb,
TOTEM,
LHC-forward and
ALICE) are currently being built, and will be running on the collider; each of them will study particle collisions under a different point of view, and with different technologies. Construction for these experiments needed an extraordinary engineering effort. Just as an example, to lower the pieces for the CMS experiment into the underground cavern which will host it, a special
crane will have to be rented from Belgium, which will be able to lift the almost 2000 tons for each piece. 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 will generate vast quantities of computer data, which CERN will stream to laboratories around the world for distributed processing (the
GRID technology). In April 2005, a trial successfully streamed 600 MB per second to seven different sites across the world. If all the data generated by the LHC is to be analyzed, then scientists must achieve 1,800 MB per second before 2008.
Decommissioned accelerators
★ The original linear accelerator (Linac1).
★ The 600 MeV
Synchro-Cyclotron (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 is now being used to build 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.
CERN sites
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 . 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 "Port Charles de Gaulle" at the request of President Chirac
[4] it is known colloquially as "Checkpoint Charlie"
★ ''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
BEBC bubble chamber 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.
Computer Science and CERN
This
NeXTcube used by Berners-Lee(UK)at CERN became the first Web server.
The
World Wide Web began as a CERN project called
ENQUIRE, initiated by
Tim Berners-Lee and
Robert Cailliau in 1990. Berners-Lee and Cailliau were jointly honored by the
ACM 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 of the original first webpage, created by Berners-Lee, is kept
here.
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 in Europe, beginning in the early 1980s. A short history of this period can be found
here.
More recently, CERN has become a centre for the development of
Grid computing, hosting among others the
Enabling Grids for E-sciencE and
LHC Computing Grid projects. It also hosts the
CERN Internet Exchange Point (CIXP), one of the two main
Internet Exchange Points in
Switzerland.
Member States
Member States of CERN
The original CERN signatories were:
★
★
★ (then
West Germany)
★
★
★
★
★
★
★
★
★
Since then:
★ joined in 1959
★ left in 1961
★ joined in 1961, left in 1969, rejoined in 1983
★ joined in 1985
★ joined in 1991
★ joined in 1991
★ joined in 1992
★ joined in 1993
★ joined in 1993
★ joined in 1999
There are currently twenty member countries.
Eight additional international organizations or countries have "observer status":
★
European Commission
★
★
★
★
★
★
UNESCO
★
Public exhibits
The Globe of Science and Innovation at CERN
Facilities at CERN open to the public include:
★ The ''Globe of Science and Innovation'', which recently opened and is used four times a week for special exhibits.
★ The
Microcosm museum on
particle physics and CERN history.
In fiction
★ CERN played an important part in
Dan Brown's novel ''
Angels and Demons''.
★ CERN played a prominent role in
Stel Pavlou's novel ''
Decipher''.
★ CERN was a prominent location in
Robert J. Sawyer's novel ''
Flashforward''.
★ CERN was mentioned in asides in
Cliff Stoll's novel ''
The Cuckoo's Egg'' (a non-fiction piece).
★ CERN was mentioned in
Michael Crichton's novel ''
State of Fear''.
★ CERN was mentioned in
John G. Cramer's novel ''
Einstein's Bridge''.
★ CERN was mentioned in
Anne McCaffrey's novel ''
Pegasus in Space''.
★ CERN was referred to by
Maddox in one of his older satire articles.
★ CERN played a critical role in the final season of the TV series
Lexx. Although not mentioned by
name, the particle accelerator was described as doing all the same research that CERN actually does.
Notes
1. The CERN Name, on the CERN website. Last accessed on 25 October 2006.
2. BBC article on revised LHC schedule
3. CERN report on LHC inner triplet incident
4. Red Carpet for CERN's 50th, , , , , 2004
See also
★
List of Directors General of CERN
★
Fermilab
★
ROOT
★
Léon Van Hove
★
SLAC
External links
★
Official site
★
''CERN at 50''
★
CERN chronology
★
CERN Visits
★
Hands-On-CERN (Educational Site about CERN and Particle Physics)
★
Globe of Science and Innovation info
★
Microcosm Museum Info
★
CERN Courier - International Journal of High-Energy Physics
★
NYT's A Giant Takes On Physics’ Biggest Questions
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