|European Organization for Nuclear Research
|English name||European Organization for Nuclear Research|
|French name||Organization of européenne pour la recherche nucléaire|
|Seat of the organs||Meyrin , Switzerland|
|Member States||23 (sorted by contribution) :|
|Official and working languages|
September 29, 1954
The CERN , the European Organization for Nuclear Research , is a major research facility near Geneva , partly in France and partly in Switzerland is. Basic physical research is carried out at CERN , in particular the structure of matter is researched with the help of large particle accelerators . The currently (2019) most important is the Large Hadron Collider , which was put into operation in 2008.
The acronym CERN is derived from the French name of the council that was in charge of founding the organization, the C onseil e uropéen pour la r echerche n ucléaire . The official names of CERN are European Organization for Nuclear Research in English and Organization européenne pour la recherche nucléaire in French .
CERN currently has 23 member states. With around 3,400 employees (as of December 31, 2017), CERN is the world's largest research center in the field of particle physics . Over 14,000 guest scientists from 85 nations are working on CERN experiments. The annual budget of CERN in 2014 was approximately 1.11 billion Swiss francs (approx. 1 billion euros).
CERN is also the birthplace of the World Wide Web .
After two UNESCO conferences in Florence and Paris, eleven European governments signed the agreement on a provisional CERN. In May 1952 the Provisional Council met for the first time in Paris. On June 29, 1953, at the 6th conference of the provisional CERN in Paris, representatives of the twelve European countries signed the founding charter. In October 1953, at a conference in Amsterdam, the seat of CERN and its laboratory near Geneva was determined. On February 24, 1954, the first conference of the CERN Council after its foundation took place in Geneva. On September 29, 1954, seven of the twelve member states ratified the State Treaty establishing it. On June 10, 1955, the foundation stone of the CERN laboratory was laid by Felix Bloch , the first regular general director of CERN.
Originally, CERN was primarily intended for research in the field of nuclear energy , but the first particle accelerators were soon built. In 1957 the synchro-cyclotron (SC), which accelerated protons up to 600 MeV , was put into operation, which was only to be switched off in 1990 after 33 years of operation. The proton synchrotron (PS) followed on November 24, 1959, with a proton energy of 28 GeV (the highest in the world at the time) ; it still works today as a pre-accelerator. In 1965 an agreement was reached with France to expand the planned proton storage rings , called Intersecting Storage Rings (ISR), on French soil. In 1968 Georges Charpak invented a particle detector that contained a large number of parallel wires in a gas-filled chamber for better spatial and energy resolution. With this wire chamber, he revolutionized particle detection and received the Nobel Prize in Physics in 1992 . In 1970 the budget of CERN was 370 million Swiss francs . In 1970, 23 percent of the costs were borne by the Federal Republic of Germany, 22 percent by the United Kingdom and 20 percent by France.
In 1970/71, the large Gargamelle and BEBC bubble chambers went into operation to investigate neutrino reactions. In 1971 the ISR was also completed. 1973 was achieved with the discovery Gargamelle the neutral currents of the Z0 particles by André Lagarrigue . In 1976 the super proton synchrotron (SPS) followed as a new accelerator, which delivers protons at 400 GeV on a 7 km orbit. In 1981 it was expanded to become a proton-antiproton collider ; the technique of stochastic cooling by Simon van der Meer was used. In May 1983 the W and Z bosons were discovered at CERN , Carlo Rubbia and Simon van der Meer received the 1984 Nobel Prize for them.
The accelerators that have been used over the course of more than 60 years of history and have since been dismantled or decommissioned are:
- Large Electron-Positron Collider (LEP, the predecessor of the LHC, out of service)
- Synchro-Cyclotron (synchro cyclotron , TT)
- Intersecting Storage Rings ( storage rings , ISR, TT)
- Low Energy Antiproton Ring (LEAR, converted to LEIR)
Large electron-positron collider
In August 1989 the Large Electron-Positron Collider (LEP) went into operation, one of the largest accelerators ever built. In a tunnel 27 km long, electrons and their antiparticles, the positrons , collided with energies of 100 GeV at selected locations . In 1996, anti-hydrogen atoms were produced for the first time at the LEAR storage ring (Low Energy Antiproton Ring) ; there were first indications of slight differences between matter and antimatter ( CP violation ), which was confirmed in another experiment in 2001.
The four detectors at the LEP were developed for testing the standard model. After successful operation, they were dismantled to make room for the LHC detectors. These were the following LEP detectors:
- ALEPH (Apparatus for LEp PHysics) is used to detect particles that arise when electrons and positrons collide
- DELPHI (DEtector with Lepton PHoton and Hadron Identification): Particle identification and three-dimensional particle traces
- OPAL (Omni Purpose Apparatus for Lep) is a large, onion-shaped, multi-purpose detector for measuring reaction products
- L3 detector: The largest LEP detector contains more than 10,000 bismuth germanate crystals for the detection of electrons and photons. L3 got this name because it was the third submitted proposal for a LEP detector.
In 1999, construction work began on the LHC in the tunnel of the Large Electron-Positron Collider. In 2000 the LEP was finally switched off.
Experiments and facilities
At CERN, the structure of matter and the fundamental interactions between the elementary particles are researched, i.e. the fundamental question of what the universe is made of and how it works. With large particle accelerators, particles are accelerated to almost the speed of light and made to collide. The trajectories of the particles created during the collisions are then reconstructed using a large number of different particle detectors, which in turn allows conclusions to be drawn about the properties of the collided and newly created particles. This is associated with an enormous technical effort for the production and operation of the systems as well as with extreme demands on the computer performance for the purpose of data evaluation. For this reason, too, CERN is operated and financed internationally.
|CERN's accelerator complex|
|List of the current
particle accelerators at CERN
|Linac 2||Accelerates protons|
|Linac 3||Accelerates ions|
|Linac 4||Accelerates negative hydrogen ions|
|LHC||Collides protons or heavy ions|
|LEIR||Accelerates lead ions|
|PSB||Accelerates protons or ions|
|PS||Mainly accelerates protons|
|PLC||Accelerates protons, among other things|
At the beginning of the experiments there are accelerators, which give the particles the kinetic energy necessary for the investigations. The Super Proton Synchrotron (SPS) for pre-acceleration and the Large Hadron Collider (LHC), the large hadron storage ring, by far the largest and most complex accelerator at the start of many experiments, deserve special mention . Other systems are the CERN Hadron Linacs :
- Proton linear accelerator (Linac2; 50 MeV)
- Heavy ion linear accelerator (Linac3)
- Proton linear accelerator (Linac4; 160 MeV)
- Proton Synchrotron Booster (PSB)
- Proton Synchrotron (PS)
- Low Energy Ion Ring (LEIR)
- Antiproton Decelerator (AD)
- Isotope Separator On Line DEvice (ISOLDE)
Large Hadron Collider
The Large Hadron Collider (LHC) is the largest particle accelerator in the world. The accelerator ring has a circumference of 26,659 m and contains 9,300 magnets. To carry out the experiments, the storage ring must be cooled down to operating temperature in two steps. In the first step the magnets are cooled down to 80 K (−193.2 ° C) with the help of liquid nitrogen, in a second step to 1.9 K (−271.25 ° C) with liquid helium. The system is then started up in a controlled manner. The particles are accelerated in several revolutions to almost the speed of light and collided with extremely high kinetic energy.
The first protons were shot into the LHC on August 8, 2008, followed by the first round trip of protons on September 10, 2008. The first proton collisions should take place before October 21, 2008; However, this deadline could not be kept due to the forced shutdown after a problem. On October 23, 2009, protons were again injected into the tunnel. On March 30, 2010 it was possible for the first time to collide protons with a record energy of 3.5 TeV each (a total of 7 TeV). Lead ions have also been successfully brought to collision, as well as collisions of lead ions with protons.
In 2012 the total energy was increased to 8 TeV. Since then, the LHC has operated in a series of runs in which experiments are in progress, interrupted by scheduled breaks used for repairs and improvements. After the long shutdown LS1, the LHC has been running with a total energy of 13 TeV since April 5, 2015. Since the end of 2018, the LHC has been upgraded as part of the second scheduled long shutdown (LS2) to the operation planned from 2021 with a design energy of 14 TeV and a higher collision rate.
The particles produced during the collisions are registered with the help of detectors in various experiments and then analyzed by international teams of scientists using special computer programs. The experiments or detectors at the LHC are:
- ALICE ( A Large Ion Collider Experiment ) is a multi-purpose detector, optimized for collisions of heavy ions , for example lead, in which extreme energy densities occur.
- ATLAS ( A Toroidal Lhc ApparatuS ) with an onion-shaped structure primarily investigates high-energy proton - proton collisions. In particular, the Higgs boson should be detected. In July 2012, ATLAS in conjunction with CMS succeeded in detecting (5σ) the Higgs boson, which has been suspected since 1964. After the discovery, the Nobel Prize in Physics was awarded for the publications on the prediction of this particle. We also looked for supersymmetric particles.
- CMS ( Compact Muon Solenoid ) also investigates proton-proton collisions; Special features are a calorimeter made of lead tungstate crystals for high-energy photons , additional semiconductor track detectors and a muon detection system. CMS and ATLAS are designed in such a way that they guarantee a mutual review of scientific results.
- LHCb ( Large Hadron Collider beauty experiment ) measures CP violation in B and D mesons , and searches for rare decays of hadrons containing the heavy bottom quark .
- TOTEM ( TOTal Elastic and diffractive cross section Measurement ) to determine the size of the proton with unprecedented accuracy.
- LHCf ( Large Hadron Collider forward ) examines collision products that fly almost exactly in the direction of the particle beams. The results are used, among other things, to simulate cosmic rays .
- MoEDAL ( Monopole and Exotics Detector at the LHC ) searches for magnetic monopoles and possible relics of microscopic black holes and supersymmetric particles .
More physical experiments
In addition to the experiments at the LHC, further experiments are carried out with the other accelerators and detectors to investigate hadron structure and production, neutrino oscillation and dark matter:
- COMPASS experiment ( Co mmon M uon P roton A pparatus for S tructure and S pectroscopy): COMPASS is an experiment in the field of high energy physics at the Super Proton Synchrotron (SPS). The aim of the experiment is, on the one hand, to research the hadron structure and, on the other hand, to conduct hadron spectroscopy with high-intensity muon and hadron beams. The COMPASS spectrometer was built between 1999 and 2000 and put into operation in 2001 as part of a technical run. Data collection began in summer 2001 and has been continued since 2005 after a one-year break. 240 scientists from 12 countries and 28 institutes are involved in COMPASS.
- NA61 / SHINE Experiment ( S PS H eavy I on and N eutrino E xperiment): NA61 / SHINE researches hadron production in collisions of different hadron and ion beams with various nuclear targets at SPS energies. The aims of the experiment include the investigation of the properties of the onset of deconfinement , the search for the critical point of the strongly interacting matter, as well as reference measurements for experiments with neutrinos ( T2K ) and cosmic rays ( Pierre Auger Observatory ).
- CNGS ( C ERN N eutrinos to G ran S asso (Italy) ): The aim of the experiment is to investigate the neutrino oscillation . For this purpose, a neutrino beam is generated with the help of the SPS accelerator , which is to be detected and examined with the OPERA in the Italian Gran Sasso National Laboratory (LNGS) . Construction began in September 2000. On August 18, 2006, OPERA detected the first neutrino beam, and on October 2, 2007, the first beam from CERN
- ISEULT ( I sotope S eparator O n L ine DE vice ): Is may be an on-line isotope mass separator, produced with a plurality of radioactive ion beams and biomedical in experiments, the atomic, nuclear, astro and solid state physics studies Find use. More than 700 isotopes of 70 different elements with lifetimes down to the millisecond range have been investigated so far.
- CAST experiment ( C ERN A xion S olar T elescope): In this experiment, an attempt is made by means of a very strong magnetic field so-called solar Axions demonstrated. These are hypothetical, subatomic particles that interact only very weakly with ordinary matter, which are considered to be the main candidates for the existence of dark matter (see also: Primakoff effect ).
In addition, a large number of smaller experiments are carried out, including:
- CLOUD experiment ( C osmics L eaving Ou tdoor D roplets): Is one since 2006 ongoing international project on Proton Synchrotron (PS) to evaluate the impact of cosmic rays on the formation of condensation nuclei (aerosols) in the atmosphere and thus on the formation of clouds .
The LHC Computing Grid , a system for distributed computing , was developed in order to be able to process the enormous amounts of data that have been accumulating since November 2009 in the four large experiments ALICE, ATLAS, CMS and LHCb of the LHC .
The World Wide Web also has its origins at CERN. In order to be able to exchange research results between scientists in a simple way, the concept was developed in 1989 as a by-product of the actual research work by Tim Berners-Lee .
Many fundamental insights into the structure of matter and the basic forces of physics were gained at CERN. The discovery of the W and Z bosons was made in 1983 by Carlo Rubbia and Simon van der Meer , for which they received the Nobel Prize in 1984. The first indication of the formation of a quark-gluon plasma at extremely high temperatures was also found in 1999 at the Relativistic Heavy Ion Collider (RHIC). Follow-up experiments are running at the LHC with the ALICE detector. In 2002 the ATHENA collaboration succeeded in producing and storing several thousand “cold” anti-hydrogen atoms , and data recording in the COMPASS experiment also began .
Another field of research is the study of the Higgs boson , an important part of the Standard Model . After a search lasting for decades, a particle was found in 2012 that corresponds to the Higgs boson in all of its measured properties. The increase in energy at the Large Hadron Collider from 7 to 13 TeV enables its properties to be measured more precisely. This is also necessary for the search for heavy particles and for a more detailed investigation of the quark-gluon plasma.
Location and legal status
CERN has two main campuses, which are located near Geneva . One of them, the Site de Meyrin , is located on the border between France and Switzerland and is spread over the municipality of Meyrin in Switzerland and the municipalities of Prévessin-Moëns and Saint-Genis-Pouilly in France. The Site de Prévessin is located about three kilometers further north and is exclusively on French territory. It is distributed roughly equally between Prévessin-Moëns and Saint-Genis-Pouilly.
Like the European Molecular Biology Laboratory, CERN has a special position as an international research center. The highest decision-making body of the organization is the Council of CERN , to which all member states send two delegates each: a representative of the government and a scientist. The official working languages of CERN are English and French .
Since December 2012, CERN has had observer status at the General Assembly of the United Nations . This special status gives CERN the right to speak at General Assembly conferences, to vote in formal votes, and to support and sign UN resolutions, but not vote on them. The status was awarded after Switzerland and France had submitted a corresponding application with the approval of all other 18 member states and various other non-member states. The decision was justified with the important role of CERN in science and development and the aspect of extraordinary international cooperation.
The legal status of CERN is based on an agreement between Switzerland and the European Organization for Nuclear Physics Research of June 11, 1955. The agreement defines the international legal personality and the legal capacity of the organization. Accordingly, CERN enjoys the immunities and privileges customary in international organizations, insofar as they are necessary for the performance of its tasks. The natural persons who represent CERN externally also enjoy immunity in Switzerland. CERN is not subject to Swiss jurisdiction or the Swiss tax regime.
The founding members in 1954 were Switzerland , Belgium , Denmark , the Federal Republic of Germany , France , Greece , the United Kingdom , Italy , Yugoslavia (until 1961), the Netherlands , Norway and Sweden .
Other countries followed: Austria (1959), Spain (1961–1968 and from 1983), Portugal (1986), Finland (1991), Poland (1991), Hungary (1992), Czech Republic (1993), Slovakia (1993), Bulgaria (1999), Israel (2013), Romania (2016) and Serbia (2018).
Financing (2020 budget)
|Member State||Proportion of (%)||Million CHF||approximately million EUR *|
The proportions of the financing have little or no influence on the representation of the individual nationalities. This is reflected both in the official working languages English and French , as well as in the origin of the employees ( staff members ) and guest researchers ( users ). With 1,194 visiting scholars (as of 2015), Germany is clearly underrepresented compared to its share of funding. The shares in the financing also have no influence on the number of representatives sent to the Council of CERN .
Associate members, observer status and collaborations
|image||Surname||Term of office||Office||origin||Life dates|
|Edoardo Amaldi||September 1952 – September 1954||General Director of the Provisional CERN||Italy||1908-1989|
|Felix Bloch||October 1954 – August 1955||General Director of CERN||Switzerland / United States||1905-1983|
|Cornelis Jan Bakker||September 1955 – April 1960||Netherlands||1904–1960
was killed in a plane crash
|John Bertram Adams||May 1960 – July 1961||Great Britain||1920-1984|
|Victor Frederick Weisskopf||August 1961 – December 1965||General Director||Austria / United States||1908-2002|
|Bernard Paul Gregory||January 1966 – December 1970||France||1919-1977|
|Willibald Karl Jentschke||January 1971 – December 1975||General Director for the CERN Laboratory I in Meyrin (Switzerland)||Austria||1911-2002|
|John Bertram Adams||General Director for the CERN Laboratory II||Great Britain||1920-1984|
|John Bertram Adams||January 1976 – December 1980||managing director general||Great Britain||1920-1984|
|Léon Van Hove||Director of the theory department at CERN||Belgium||1924-1990|
|Herwig Schopper||January 1981-December 1988||General Director||Germany||* 1924|
|Carlo Rubbia||January 1989 – December 1993||General Director||Italy||* 1934|
|Christopher Llewellyn Smith||January 1994-December 1998||General Director||Great Britain||* 1942|
|Luciano Maiani||January 1999-December 2003||General Director||Italy||* 1941|
|Robert Aymar||January 2004 – December 2008||General Director||France||* 1936|
|Rolf-Dieter Heuer||January 2009 – December 2015||General Director||Germany||* 1948|
|Fabiola Gianotti||since January 2016||General Director||Italy||* 1960|
- (15332) CERN , an asteroid named after CERN
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- Martin Beglinger: The state of physicists . In: Das Magazin , N ° 43, November 1st, 2013, Loud particle accelerators: People at Cern . Tamedia AG , Zurich. Retrieved December 6, 2014 (online) .
- Hannelore Dittmar-Ilgen: 50 years of CERN - Europe's contribution to the future . In: Naturwissenschaftliche Rundschau. 57, 12, Stuttgart 2004, , pp. 653-660.
- Jürgen Drees, Hans Jürgen Hilke: 50 Years of CERN , Physik Journal, Volume 3, 2004, No. 10, pp. 47–53
- Rolf Landua: On the edge of dimensions. Conversations about physics at CERN. Suhrkamp, Frankfurt am Main 2008, ISBN 3-518-26003-0 .
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History of CERN , 3 volumes, North Holland
- Volume 1: Armin Hermann , Lanfranco Belloni, Gerhard John Krige, Ulrike Mersits, Dominique Pestre: Launching the European Organization for Nuclear Research
- Volume 2: Armin Hermann, Gerhard John Krige, Ulrike Mersits, Dominique Pestre, Laura Weiss: Building and Running the Laboratory, 1990
- Volume 3: Editor J. Krige, 1996
- Homepage (English, French)
- Detailed page about the LHC particle accelerator with many individual articles
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- What is CERN? - Interview with a CERN physicist about CERN, the LHC and the search for HIGGS from March 6, 2008
- Le CERN en bref
- CERN - Human Resources Department: CERN Personnel Statistics 2017 - July 2017 ( at CDS , English)
- Member States' Contributions - 2014 ( Memento from May 14, 2014 in the Internet Archive ), CERN Resources planning, Processes and Controlling Group (accessed on May 13, 2014)
- Quittner, Joshua: Network Designer Tim Berners-Lee , published March 29, 1999 in Time Magazine (in English)
- CERN Bulletin ( fr / en )
- Big Bang Experiment succeeds without the end of the world in Die Welt from March 30, 2010
- Article at weltmaschine.de ( memento of November 23, 2015 in the Internet Archive ), accessed on November 22, 2015
- LHC long term schedule. CERN, January 2016, accessed April 25, 2019 .
- Long shutdown 1: Exciting times ahead. CERN, February 8, 2013, accessed April 25, 2019 .
- Proton beams are back in the LHC. CERN, April 5, 2015, accessed April 25, 2019 .
- Restarting the LHC: Why 13 TeV? CERN, 2015, accessed April 25, 2019 .
- LHC prepares for new achievements. CERN, December 3, 2018, accessed April 25, 2019 .
- Neutrinos sent from CERN in Geneva “photographed” at the Gran Sasso Laboratory after a travel of 730 km under the Earth crust. (Interactions News Wire # 59-07), accessed November 20, 2013
- ISOLDE - History. ISOLDE - The Radioactive Ion Beam Facility, accessed August 14, 2013.
- First collisions in the big bang machine. Retrieved March 31, 2010 .
- Christian Speicher: Particle Physics at Cern: Greetings from a bugbear In: Neue Zürcher Zeitung of August 26, 2016
- CERN organization
- The Official and Working Languages of the Organization (eng., Frz.)
- CERN becomes first pure physics voice in UN chorus , newscientist.com of December 14, 2012
- European nuclear research body CERN gets observer status at UN Assembly , Times of India article of December 15, 2012
- Agreement with Switzerland (1955)
- Agreement with France (version 1965) ( Memento of November 5, 2011 in the Internet Archive )
- Member States' Contributions - 2020 (Retrieved July 7, 2020)
- CERN: Participation in CERN , accessed on January 8, 2018.