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CERN

The European Organization for Nuclear Research, known as CERN (Conseil européen pour la Recherche nucléaire), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in Meyrin, western suburb of Geneva, on the France–Switzerland border. It comprises 23 member states. Israel, admitted in 2013, is the only non-European full member. CERN is an official United Nations General Assembly observer.

The acronym CERN is also used to refer to the laboratory; in 2019, it had 2,660 scientific, technical, and administrative staff members, and hosted about 12,400 users from institutions in more than 70 countries. In 2016, CERN generated 49 petabytes of data.

CERN's main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research – consequently, numerous experiments have been constructed at CERN through international collaborations. CERN is the site of the Large Hadron Collider (LHC), the world's largest and highest-energy particle collider. The main site at Meyrin hosts a large computing facility, which is primarily used to store and analyze data from experiments, as well as simulate events. As researchers require remote access to these facilities, the lab has historically been a major wide area network hub. CERN is also the birthplace of the World Wide Web.

History
The convention establishing CERN was ratified on 29 September 1954 by 12 countries in Western Europe. The acronym CERN originally represented the French words for Conseil Européen pour la Recherche Nucléaire ('European Council for Nuclear Research'), which was a provisional council for building the laboratory, established by 12 European governments in 1952. During these early years, the council worked at the University of Copenhagen under the direction of Niels Bohr before moving to its present site near Geneva. 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. According to Lew Kowarski, a former director of CERN, when the name was changed, the abbreviation could have become the awkward OERN, and Werner Heisenberg said that this could "still be CERN even if the name is [not]".

CERN's first president was Sir Benjamin Lockspeiser. Edoardo Amaldi was the general secretary of CERN at its early stages when operations were still provisional, while the first Director-General (1954) was Felix Bloch.

The laboratory was originally devoted to the study of atomic nuclei, but was soon applied to higher-energy physics, concerned mainly with the study of interactions between subatomic 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 there.

Founding members
At the sixth session of the CERN Council, which took place in Paris from 29 June to 1 July 1953, the convention establishing the organization was signed, subject to ratification, by 12 states. The convention was gradually ratified by the 12 founding Member States: Belgium, Denmark, France, the Federal Republic of Germany, Greece, Italy, the Netherlands, Norway, Sweden, Switzerland, the United Kingdom, and Yugoslavia.

Scientific achievements
Several important achievements in particle physics have been made through experiments at CERN. They include:
 * 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;
 * 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;
 * 1995–2005: Precision measurement of the Z lineshape, based predominantly on LEP data collected on the Z resonance from 1990 to 1995;
 * 1999: The discovery of direct CP violation in the NA48 experiment;
 * 2000: The Heavy Ion Programme discovered a new state of matter, the Quark Gluon Plasma.
 * 2010: The isolation of 38 atoms of antihydrogen;
 * 2011: Maintaining antihydrogen for over 15 minutes;
 * 2012: A boson with mass around 125 GeV/c2 consistent with the long-sought Higgs boson.

In September 2011, CERN attracted media attention when the OPERA Collaboration reported the detection of possibly faster-than-light neutrinos. Further tests showed that the results were flawed due to an incorrectly connected GPS synchronization cable.

The 1984 Nobel Prize for Physics was awarded to Carlo Rubbia and Simon van der Meer for the developments that resulted in the discoveries of the W and Z bosons. The 1992 Nobel Prize for Physics was awarded to CERN staff researcher Georges Charpak "for his invention and development of particle detectors, in particular the multiwire proportional chamber". The 2013 Nobel Prize for Physics was awarded to François Englert and Peter Higgs for the theoretical description of the Higgs mechanism in the year after the Higgs boson was found by CERN experiments.

Computer science
CERN pioneered the introduction of TCP/IP for its intranet, beginning in 1984. This played an influential role in the adoption of the TCP/IP in Europe (see History of the Internet and Protocol Wars).

The World Wide Web was invented at CERN by Tim Berners-Lee in 1989. Based on the concept of hypertext, the idea was designed to facilitate the information sharing between researchers. This stemmed from Berners-Lee's earlier work at CERN on a database named ENQUIRE. A colleague, Robert Cailliau, became involved in 1990. Berners-Lee and Cailliau were jointly honoured by the Association for Computing Machinery in 1995 for their contributions to the development of the World Wide Web. A copy of the first webpage, created by Berners-Lee, is still published on the World Wide Web Consortium's website as a historical document. The first website was activated in 1991. On 30 April 1993, CERN announced that the World Wide Web would be free to anyone. It became the dominant way through which most users interact with the Internet.

More recently, CERN has become a facility for the development of grid computing, hosting projects including the Enabling Grids for E-sciencE (EGEE) and LHC Computing Grid. It also hosts the CERN Internet Exchange Point (CIXP), one of the two main internet exchange points in Switzerland. , CERN employs ten times more engineers and technicians than research physicists.

Current complex

CERN operates a network of seven accelerators and two decelerators, and some additional small accelerators. Each machine in the chain increases the energy of particle beams before delivering them to experiments or to the next more powerful accelerator (the decelerators naturally decrease the energy of particle beams before delivering them to experiments or further accelerators/decelerators). Before an experiment is able to use the network of accelerators, it must be approved by the various Scientific Committees of CERN. Currently (as of 2022) active machines are the LHC accelerator and:
 * The LINAC 3 linear accelerator generating low energy particles. It provides heavy ions at 4.2 MeV/u for injection into the Low Energy Ion Ring (LEIR).
 * The Low Energy Ion Ring (LEIR) accelerates the ions from the ion linear accelerator LINAC 3, 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 Linac4 linear accelerator accelerates negative hydrogen ions to an energy of 160 MeV. The ions are then injected to the Proton Synchrotron Booster (PSB) where both electrons are then stripped from each of the hydrogen ions and thus only the nucleus containing one proton remains. The protons are then used in experiments or accelerated further in other CERN accelerators. Linac4 serves as the source of all proton beams for CERN experiments.
 * The Proton Synchrotron Booster increases the energy of particles generated by the proton linear accelerator before they are transferred to the other accelerators.
 * The 28 GeV Proton Synchrotron (PS), built during 1954–1959 and still operating as a feeder to the more powerful SPS and to many of CERN's experiments.
 * 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 Sp$\overline{p}$S 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.
 * The Antiproton Decelerator (AD), which reduces the velocity of antiprotons to about 10% of the speed of light for research of antimatter. The AD machine was reconfigured from the previous Antiproton Collector (AC) machine.
 * The Extra Low Energy Antiproton ring (ELENA), which takes antiprotons from AD and decelerates them into low energies (speeds) for use in antimatter experiments.
 * The AWAKE experiment, which is a proof-of-principle plasma wakefield accelerator.
 * The CERN Linear Electron Accelerator for Research (CLEAR) accelerator research and development facility.

Large Hadron Collider
Many activities at CERN currently involve operating the 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 Geneva International Airport and the nearby Jura mountains. The majority of its length is on the French side of the border. It uses the 27 km circumference circular tunnel previously occupied by the Large Electron–Positron Collider (LEP), which was shut down in November 2000. CERN's existing PS/SPS accelerator complexes are used to pre-accelerate protons and lead ions which are then injected into the LHC.

Eight experiments (CMS, ATLAS, LHCb, MoEDAL, TOTEM, LHCf, FASER and ALICE ) are located along the collider; each of them studies particle collisions from a different aspect, and with different technologies. Construction for these experiments required an extraordinary engineering effort. For example, a special crane was rented from Belgium to lower pieces of the CMS detector into its 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.

The LHC has begun to generate vast quantities of data, which CERN streams to laboratories around the world for distributed processing (making use of a specialized grid infrastructure, the LHC Computing Grid). During April 2005, a trial successfully streamed 600 MB/s to seven different sites across the world.

The initial particle beams were injected into the LHC August 2008. The first beam was circulated through the entire LHC on 10 September 2008, but the system failed 10 days later because of a faulty magnet connection, and it was stopped for repairs on 19 September 2008.

The LHC resumed operation on 20 November 2009 by successfully circulating two beams, each with an energy of 3.5 teraelectronvolts (TeV). The challenge for the engineers was then 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 Steve Myers, director for accelerators and technology.

On 30 March 2010, the LHC successfully collided two proton beams with 3.5 TeV of energy per proton, resulting in a 7 TeV collision energy. However, this was just the start of what was needed for the expected discovery of the Higgs boson. When the 7 TeV experimental period ended, the LHC revved to 8 TeV (4 TeV per proton) starting March 2012, and soon began particle collisions at that energy. In July 2012, CERN scientists announced the discovery of a new sub-atomic particle that was later confirmed to be the Higgs boson.

In March 2013, CERN announced that the measurements performed on the newly found particle allowed it to conclude that it was a Higgs boson. In early 2013, the LHC was deactivated for a two-year maintenance period, to strengthen the electrical connections between magnets inside the accelerator and for other upgrades.

On 5 April 2015, after two years of maintenance and consolidation, the LHC restarted for a second run. The first ramp to the record-breaking energy of 6.5 TeV was performed on 10 April 2015. In 2016, the design collision rate was exceeded for the first time. A second two-year period of shutdown begun at the end of 2018.

Accelerators under construction
As of October 2019, the construction is on-going to upgrade the LHC's luminosity in a project called High Luminosity LHC (HL–LHC). This project should see the LHC accelerator upgraded by 2026 to an order of magnitude higher luminosity.

As part of the HL–LHC upgrade project, also other CERN accelerators and their subsystems are receiving upgrades. Among other work, the LINAC 2 linear accelerator injector was decommissioned and replaced by a new injector accelerator, the LINAC4.

Decommissioned accelerators

 * The original linear accelerator LINAC 1. Operated 1959–1992.
 * The LINAC 2 linear accelerator injector. Accelerated protons to 50 MeV for injection into the Proton Synchrotron Booster (PSB). Operated 1978–2018.
 * The 600 MeV Synchro-Cyclotron (SC) which started operation in 1957 and was shut down in 1991. Was made into a public exhibition in 2012–2013.
 * The Intersecting Storage Rings (ISR), an early collider built from 1966 to 1971 and operated until 1984.
 * The Super Proton–Antiproton Synchrotron (Sp$\overline{p}$S), operated 1981–1991. A modification of Super Proton Synchrotron (SPS) to operate as a proton-antiproton collider.
 * The Large Electron–Positron Collider (LEP), which operated 1989–2000 and was the largest machine of its kind, housed in a 27 km-long circular tunnel which now houses the Large Hadron Collider.
 * The LEP Pre-Injector (LPI) accelerator complex, consisting of two accelerators, a linear accelerator called LEP Injector Linac (LIL; itself consisting of two back-to-back linear accelerators called LIL V and LIL W) and a circular accelerator called Electron Positron Accumulator (EPA). The purpose of these accelerators was to inject positron and electron beams into the CERN accelerator complex (more precisely, to the Proton Synchrotron), to be delivered to LEP after many stages of acceleration. Operational 1987–2001; after the shutdown of LEP and the completion of experiments that were directly fed by the LPI, the LPI facility was adapted to be used for the CLIC Test Facility 3 (CTF3).
 * The Low Energy Antiproton Ring (LEAR) was commissioned in 1982. LEAR 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. The LEAR apparatus itself was reconfigured into the Low Energy Ion Ring (LEIR) ion booster.
 * The Antiproton Accumulator (AA), built 1979–1980, operations ended in 1997 and the machine was dismantled. Stored antiprotons produced by the Proton Synchrotron (PS) for use in other experiments and accelerators (for example the ISR, Sp$\overline{p}$S and LEAR). For later half of its working life operated in tandem with Antiproton Collector (AC), to form the Antiproton Accumulation Complex (AAC).
 * The Antiproton Collector (AC), built 1986–1987, operations ended in 1997 and the machine was converted into the Antiproton Decelerator (AD), which is the successor machine for Low Energy Antiproton Ring (LEAR). Operated in tandem with Antiproton Accumulator (AA) and the pair formed the Antiproton Accumulation Complex (AAC), whose purpose was to store antiprotons produced by the Proton Synchrotron (PS) for use in other experiments and accelerators, like the Low Energy Antiproton Ring (LEAR) and Super Proton–Antiproton Synchrotron (Sp$\overline{p}$S).
 * The Compact Linear Collider Test Facility 3 (CTF3), which studied feasibility for the future normal conducting linear collider project (the CLIC collider). In operation 2001–2016. One of its beamlines has been converted, from 2017 on, into the new CERN Linear Electron Accelerator for Research (CLEAR) facility.

Possible future accelerators
CERN, in collaboration with groups worldwide, is investigating two main concepts for future accelerators: A linear electron-positron collider with a new acceleration concept to increase the energy (CLIC) and a larger version of the LHC, a project currently named Future Circular Collider.

Sites

The smaller accelerators are 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 there is no obvious border within the site, apart from a line of marker stones.

The SPS and LEP/LHC tunnels are 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 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 are used by 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 so-called "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.

Most of the roads on the CERN Meyrin and Prévessin sites are named after famous physicists, such as Wolfgang Pauli, who pushed for CERN's creation. Other notable names are Richard Feynman, Albert Einstein, and Bohr.

Member states and budget
Since its foundation by 12 members in 1954, CERN regularly accepted new members. All new members have remained in the organization continuously since their accession, except Spain and Yugoslavia. Spain first joined CERN in 1961, withdrew in 1969, and rejoined in 1983. Yugoslavia was a founding member of CERN but quit in 1961. Of the 23 members, Israel joined CERN as a full member on 6 January 2014, becoming the first (and currently only) non-European full member.

The budget contributions of member states are computed based on their GDP.

Enlargement
Associate Members, Candidates:
 * Turkey signed an association agreement on 12 May 2014 and became an associate member on 6 May 2015.
 * Pakistan signed an association agreement on 19 December 2014 and became an associate member on 31 July 2015.
 * Cyprus signed an association agreement on 5 October 2012 and became an associate member in the pre-stage to membership on 1 April 2016.
 * Ukraine signed an association agreement on 3 October 2013. The agreement was ratified on 5 October 2016.
 * India signed an association agreement on 21 November 2016. The agreement was ratified on 16 January 2017.
 * Slovenia was approved for admission as an Associate Member state in the pre-stage to membership on 16 December 2016. The agreement was ratified on 4 July 2017.
 * Lithuania was approved for admission as an Associate Member state on 16 June 2017. The association agreement was signed on 27 June 2017 and ratified on 8 January 2018.
 * Croatia was approved for admission as an Associate Member state on 28 February 2019. The agreement was ratified on 10 October 2019.
 * Estonia was approved for admission as an Associate Member in the pre-stage to membership state on 19 June 2020. The agreement was ratified on 1 February 2021.
 * Latvia and CERN signed an associate membership agreement on 14 April 2021. Latvia was formally admitted as an Associate Member on 2 August 2021.
 * Brazil became the first associate member of the Americas on 13 March 2024, after signing the associate membership agreement in March 2022.

International relations
Three countries have observer status:
 * Japan – since 1995
 * Russia – since 1993 (suspended as of March 2022)
 * United States – since 1997

Also observers are the following international organizations:
 * UNESCO – since 1954
 * European Commission – since 1985
 * JINR – since 2014 (suspended as of March 2022)

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

• Albania – October 2014

• Algeria – 2008

• Argentina – 11 March 1992

• Armenia – 25 March 1994

• Australia – 1 November 1991

• Azerbaijan – 3 December 1997

• Bangladesh – 2014

• Belarus – 28 June 1994 (suspended as of March 2022 )

• Bolivia – 2007

• Bosnia & Herzegovina – 16 February 2021

• Canada – 11 October 1996

• Chile – 10 October 1991

• China – 12 July 1991, 14 August 1997 & 17 February 2004

• Colombia – 15 May 1993

• Costa Rica – February 2014

• Ecuador – 1999

• Egypt – 16 January 2006

• Georgia – 11 October 1996

• Iceland – 11 September 1996

• Iran – 5 July 2001

• Jordan – 12 June 2003 MoU with Jordan and SESAME, in preparation of a cooperation agreement signed in 2004.

• Kazakhstan – June 2018

• Lebanon – 2015

• Malta – 10 January 2008

• Mexico – 20 February 1998

• Mongolia – 2014

• Montenegro – 12 October 1990

• Morocco – 14 April 1997

• Nepal – 19 September 2017

• New Zealand – 4 December 2003

• North Macedonia – 27 April 2009

• Palestine – December 2015

• Paraguay – January 2019

• Peru – 23 February 1993

• Philippines – 2018

• Qatar – 2016

• Republic of Korea (South Korea) – 25 October 2006

• Saudi Arabia – 2006

• South Africa – 4 July 1992

• Sri Lanka – February 2017

• Thailand – 2018

• Tunisia – May 2014

• United Arab Emirates – 2006

• Vietnam – 2008

CERN also has scientific contacts with the following other countries:

• Bahrain

• Cuba

• Ghana

• Honduras

• Hong Kong

• Indonesia

• Ireland

• Kuwait

• Luxemburg

• Madagascar

• Malaysia

• Mauritius

• Morocco

• Mozambique

• Oman

• Rwanda

• Singapore

• Sudan

• Taiwan

• Tanzania

• Uzbekistan

• Zambia

International research institutions, such as CERN, can aid in science diplomacy.

Associated institutions
A large number of institutes around the world are associated to CERN through current collaboration agreements and/or historical links. The list below contains organizations represented as observers to the CERN Council, organizations to which CERN is an observer and organizations based on the CERN model:
 * European Molecular Biology Laboratory, organization based on the CERN model
 * European Space Research Organisation (since 1975 ESA), organization based on the CERN model
 * European Southern Observatory, organization based on the CERN model
 * JINR, observer to CERN Council, CERN is represented in the JINR Council. JINR is currently suspended, due to the CERN Council Resolution of 25 March 2022.
 * SESAME, CERN is an observer to the SESAME Council
 * UNESCO, observer to CERN Council

.cern
.cern is a top-level domain for CERN. It was registered on 13 August 2014. On 20 October 2015, CERN moved its main Website to https://home.cern.

Open science
The Open Science movement focuses on making scientific research openly accessible and on creating knowledge through open tools and processes. Open access, open data, open source software and hardware, open licenses, digital preservation and reproducible research are primary components of open science and areas in which CERN has been working towards since its formation.

CERN has developed a number of policies and official documents that enable and promote open science, starting with CERN's founding convention in 1953 which indicated that all its results are to be published or made generally available. Since then, CERN published its open access policy in 2014, which ensures that all publications by CERN authors will be published with gold open access and most recently an open data policy that was endorsed by the four main LHC collaborations (ALICE, ATLAS, CMS and LHCb). The open data policy complements the open access policy, addressing the public release of scientific data collected by LHC experiments after a suitable embargo period. Prior to this open data policy, guidelines for data preservation, access and reuse were implemented by each collaboration individually through their own policies which are updated when necessary. The European Strategy for Particle Physics, a document mandated by the CERN Council that forms the cornerstone of Europe's decision-making for the future of particle physics, was last updated in 2020 and affirmed the organisation's role within the open science landscape by stating: "The particle physics community should work with the relevant authorities to help shape the emerging consensus on open science to be adopted for publicly-funded research, and should then implement a policy of open science for the field".

Beyond the policy level, CERN has established a variety of services and tools to enable and guide open science at CERN, and in particle physics more generally. On the publishing side, CERN has initiated and operates a global cooperative project, the Sponsoring Consortium for Open Access Publishing in Particle Physics, SCOAP3, to convert scientific articles in high-energy physics to open access. Currently, the SCOAP3 partnership represents 3000+ libraries from 44 countries and 3 intergovernmental organizations who have worked collectively to convert research articles in high-energy physics across 11 leading journals in the discipline to open access.

Public-facing results can be served by various CERN-based services depending on their use case: the CERN Open Data portal, Zenodo, the CERN Document Server, INSPIRE and HEPData are the core services used by the researchers and community at CERN, as well as the wider high-energy physics community for the publication of their documents, data, software, multimedia, etc. CERN's efforts towards preservation and reproducible research are best represented by a suite of services addressing the entire physics analysis lifecycle (such as data, software and computing environment). CERN Analysis Preservation helps researchers to preserve and document the various components of their physics analyses; REANA (Reusable Analyses) enables the instantiating of preserved research data analyses on the cloud.

All of the abovementioned services are built using open source software and strive towards compliance with best effort principles where appropriate and where possible, such as the FAIR principles, the FORCE11 guidelines and Plan S, while at the same time taking into account relevant activities carried out by the European Commission.

Public exhibits

The CERN Science Gateway, opened in October 2023, is CERN's latest facility for science outreach and education. It is home to a range of immersive exhibits, workshops, and shows.

The Globe of Science and Innovation, which opened in late 2005, is open to the public. It is used four times a week for special exhibits.

The Microcosm museum previously hosted another on-site exhibition on particle physics and CERN history. It closed permanently on 18 September 2022, in preparation for the installation of the exhibitions in Science Gateway.

CERN also provides daily tours to certain facilities such as the Synchro-cyclotron (CERNs first particle accelerator) and the superconducting magnet workshop.

In 2004, a two-meter statue of the Nataraja, the dancing form of the Hindu god Shiva, was unveiled at CERN. The statue, symbolizing Shiva's cosmic dance of creation and destruction, was presented by the Indian government to celebrate the research center's long association with India. A special plaque next to the statue explains the metaphor of Shiva's cosmic dance with quotations from physicist Fritjof Capra:

"Hundreds of years ago, Indian artists created visual images of dancing Shivas in a beautiful series of bronzes. In our time, physicists have used the most advanced technology to portray the patterns of the cosmic dance. The metaphor of the cosmic dance thus unifies ancient mythology, religious art and modern physics."

Arts at CERN
CERN launched its Cultural Policy for engaging with the arts in 2011. The initiative provided the essential framework and foundations for establishing Arts at CERN, the arts programme of the Laboratory.

Since 2012, Arts at CERN has fostered creative dialogue between art and physics through residencies, art commissions, exhibitions and events. Artists across all creative disciplines have been invited to CERN to experience how fundamental science pursues the big questions about our universe.

Even before the arts programme officially started, several highly regarded artists visited the Laboratory, drawn to physics and fundamental science. As early as 1972, James Lee Byars was the first artist to visit the Laboratory and the only one, so far, to feature on the cover of the CERN Courier. Mariko Mori, Gianni Motti, Cerith Wyn Evans, John Berger and Anselm Kiefer are among the artists who came to CERN in the years that followed.

The programmes of Arts at CERN are structured according to their values and vision to create bridges between cultures. Each programme is designed and formed in collaboration with cultural institutions, other partner laboratories, countries, cities and artistic communities eager to connect with CERN's research, support their activities, and contribute to a global network of art and science.

They comprise research-led artistic residencies that take place on-site or remotely. More than 200 artists from 80 countries have participated in the residencies to expand their creative practices at the Laboratory, benefiting from the involvement of 400 physicists, engineers and CERN staff. Between 500 and 800 applications are received every year. The programmes comprise Collide, the international residency programme organised in partnership with a city; Connect, a programme of residencies to foster experimentation in art and science at CERN and in scientific organisations worldwide in collaboration with Pro Helvetia, and Guest Artists, a short stay for artists to stay to engage with CERN's research and community.

In popular culture

 * The band Les Horribles Cernettes was founded by women from CERN. The name was chosen so to have the same initials as the LHC.
 * The science journalist Katherine McAlpine made a rap video called "Large Hadron Rap" about CERN's Large Hadron Collider with some of the facility's staff.
 * Particle Fever, a 2013 documentary, explores CERN throughout the inside and depicts the events surrounding the 2012 discovery of the Higgs Boson.
 * John Titor, a self-proclaimed time traveler, alleged that CERN would invent time travel in 2001.
 * CERN is depicted in the visual novel/anime series Steins;Gate as SERN, a shadowy organization that has been researching time travel in order to restructure and control the world.
 * In Robert J. Sawyer's 1999 science fiction novel Flashforward, as CERN's Large Hadron Collider accelerator is performing a run to search for the Higgs boson the entire human race sees themselves twenty-one years and six months in the future.
 * A number of conspiracy theories feature CERN, accusing the organization of partaking in occult rituals and secret experiments involving opening portals into Hell or other dimensions, shifting the world into an alternative timeline and causing earthquakes.
 * In Dan Brown's 2000 mystery-thriller novel Angels & Demons and 2009 film of the same name, a canister of antimatter is stolen from CERN.
 * CERN is depicted in a 2009 episode of South Park (Season 13, Episode 6), "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.
 * In the 2010 season 3 episode 15 of the TV situation comedy The Big Bang Theory, "The Large Hadron Collision", Leonard and Raj travel to CERN to attend a conference and see the LHC.
 * The 2012 student film Decay, which centers on the idea of the Large Hadron Collider transforming people into zombies, was filmed on location in CERN's maintenance tunnels.
 * The Compact Muon Solenoid at CERN was used as the basis for the Megadeth's Super Collider album cover.
 * CERN forms part of the back story of the massively multiplayer augmented reality game Ingress, and in the 2018 Japanese anime television series Ingress: The Animation, based on Niantic's augmented reality mobile game of the same name.
 * In 2015, Sarah Charley, US communications manager for LHC experiments at CERN with graduate students Jesse Heilman of the University of California, Riverside, and Tom Perry and Laser Seymour Kaplan of the University of Wisconsin, Madison created a parody video based on "Collide", a song by American artist Howie Day. The lyrics were changed to be from the perspective of a proton in the Large Hadron Collider. After seeing the parody, Day re-recorded the song with the new lyrics, and released a new version of "Collide" in February 2017 with a video created during his visit to CERN.
 * In 2015, Ryoji Ikeda created an art installation called "Supersymmetry" based on his experience as a resident artist at CERN.
 * The television series Mr. Robot features a secretive, underground project apparatus that resembles the ATLAS experiment.
 * Parallels, a Disney+ television series released in March 2022, includes a particle-physics laboratory at the French-Swiss border called "ERN". Various accelerators and facilities at CERN are referenced during the show, including ATLAS, CMS, the Antiproton Decelerator, and the FCC.

Archival collections

 * CERN reports, 1952–1993, Niels Bohr Library & Archives

title: CERN


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Claymore mine

The Claymore mine is a directional anti-personnel mine developed for the United States Armed Forces. Its inventor, Norman MacLeod, named the mine after a large medieval Scottish sword. Unlike a conventional land mine, the Claymore may be command-detonated (fired by remote-control), and is directional, shooting a wide pattern of metal balls into a kill zone. The Claymore can also be activated by a booby-trap tripwire firing system for use in area denial operations.

The Claymore fires steel balls out to about 100 m within a 60° arc in front of the device. It is used primarily in ambushes and as an anti-infiltration device against enemy infantry. It is also used against unarmored vehicles.

Many countries have developed and used mines like the Claymore. Examples include models MON-50, MON-90, MON-100, and MON-200 introduced by the Soviet Union and used by its successor Russia, as well as MRUD (Serbia), MAPED F1 (France), and Mini MS-803 (South Africa).

Description
The M18A1 Claymore mine has a horizontally convex gray-green plastic case (inert training versions are light blue or green with a light blue band). The shape was developed through experimentation to deliver the optimum distribution of fragments at 50 m range. The case has the words "FRONT TOWARD ENEMY" embossed on the front of the mine. A simple open sight on the top surface allows for aiming the mine. Two pairs of scissor legs attached to the bottom support the mine and allow it to be aimed vertically. On both sides of the sight are fuse wells set at 45 degrees.

Internally the mine contains a layer of C-4 explosive behind a matrix of about seven hundred 1/8 in steel balls set into an epoxy resin.

When the M18A1 is detonated, the explosion drives the matrix forward, out of the mine at a velocity of 1200 m/s, at the same time breaking it into individual fragments. The steel balls are projected in a 60° fan-shaped pattern that is 2.0 m high and 50 m wide at a range of 50 m. The force of the explosion deforms the relatively soft steel balls into a shape similar to a .22 rimfire projectile. These fragments are moderately effective up to a range of 100 m, with a hit probability of around 10% on a prone man-sized 1.3 sqft target. The fragments can travel up to 250 m. The optimum effective range is 50 m, at which the optimal balance is achieved between lethality and area coverage, with a hit probability of 30% on a man-sized target.

The weapon and all its accessories are carried in an M7 bandolier ("Claymore bag"). The mine is detonated as the enemy personnel approaches the killing zone. Controlled detonation may be accomplished by use of either an electrical or non-electrical firing system. When mines are employed in the controlled role, they are treated as individual weapons and are reported in the unit fire plan. They are not reported as mines; however, the emplacing unit must ensure that the mines are removed, detonated, or turned over to a relieving unit. The 100 ft M4 electric firing wire on a green plastic spool is provided in each bandolier. The M57 firing device (colloquially referred to as the "clacker") is included with each mine. An M40 circuit test set is packed in each case of six mines. When the mines are daisy-chained together, one firing device can detonate several mines.

The mine can be detonated by any mechanism that activates the blasting cap. There are field-expedient methods of detonating the mine by tripwire, or by a timer, but these are rarely used.

Development
The development of the M18A1 mine dates back to work done during World War II. The Misnay–Schardin effect was independently discovered during that war by József Misnay, a Hungarian, and Hubert Schardin, a German. When a sheet of explosive detonates in contact with a heavy backing surface (for example, a metal plate), the resulting blast is primarily directed away from the surface in a single direction. Schardin spent some time developing the discovery as a side-attack anti-tank weapon, but development was incomplete at the end of the war. Schardin also spent time researching a "trench mine" that used a directional fragmentation effect.

Norman MacLeod and Calord Corporation
Following the massed Chinese attacks during the Korean War, Canada and the United States began to develop projects to counter them. Canada fielded a weapon called the "Phoenix" landmine, which used the Misnay–Schardin effect to project a spray of 0.25 in steel cubes towards the enemy. The cubes were embedded in 5 lb of Composition B explosive. It was too large to be a practical infantry weapon and was relatively ineffective, with a maximum effective range of only 20 to 30 yards (about 20 to 30 meters).

Around 1952 Norman MacLeod, at his company the Calord Corporation, began working on a small directional mine for use by infantry. It is not clear if the United States Picatinny Arsenal took the concept from the Canadian weapon and asked Norman MacLeod to develop it, or if he developed the design independently and presented it to them. MacLeod designed a weapon called the T-48; broadly similar to the final M18A1, it lacked a number of the design details that made the M18A1 effective.

Through Picatinny, the United States Army accepted the weapon into service as the M18 Claymore and approximately 10,000 were produced. It was used in small numbers in Vietnam from around 1961. It was not until the improved M18A1 was developed that the Claymore became a widely used weapon.

The M18 was 9.25 in long and 3.27 in high, held in a plastic case with three folding spike legs on the bottom. An electrical blasting cap for triggering the mine was inserted through a small hole in the side. Internally the mine consisted of a layer of 12 oz of C-3 explosive (the forerunner of C-4 explosive) in front of which was laid an array of 0.25 in steel cubes. In total the mine weighed about 2.43 lb, and could be fitted with an optional peep sight for aiming. It lacked the later version's iconic "FRONT TOWARD ENEMY" marking. The mine was planted in the ground, using its three sharp legs, and aimed in the direction of enemy approach; at that point, it was fitted with an electrical blasting cap. The mine was triggered from a safe position, preferably to the side and rear. The mine was barely more than a prototype and was not considered a "reliable casualty producer"; like the Phoenix it had an effective range of only 90 ft.

MacLeod applied for a patent for the mine on 18 January 1956, and was granted it in February 1961. The patent was later the subject of a civil court case between MacLeod, the Army, and Aerojet, which further developed the Claymore design. MacLeod's case collapsed when photographs of the German Trenchmine prototype were produced as evidence of prior art.

Throner, Kennedy, Bledsoe, and Kincheloe at Aerojet
In 1954 Picatinny Arsenal issued a request for proposals (RFP) to improve the M18 as a more effective weapon. At Aerojet in the early 1950s, Guy C. Throner had independently come up with a design for a Claymore-like mine. He worked with Don Kennedy and the two men submitted a 30-page proposal in response to Picatinny's RFP. They were awarded a $375,000 development contract to improve the Claymore design. The Picatinny criteria for the weapon were as follows:
 * It must weigh less than 3.5 lb
 * It must throw enough fragments so that at a range of 55 yd it achieves a 100 percent strike rate on a 1.3 sqft target (man-sized)
 * The fragment area must not be more than 8 ft high and no more than 60 degrees wide
 * Fragments must have a velocity of 4000 ft per second providing 58 foot-pounds (79 joules) of kinetic energy delivered to the target.

The requirement for kinetic energy was based on the fact that 58-foot pounds is required to deliver a potentially lethal injury. Given the requirements of weight and fragment density, approximately 700 fragments were needed, with the ability to aim the mine with an accuracy of around 2 ft at the center of the target zone. The team at Aerojet were given access to all previous research into directional mines, including the M18 and the Phoenix, as well as German research. Dr. John Bledsoe led the initial project.

The original M18 mine fell far short of Picatinny's requirements. One of the first improvements was to replace the steel cubes with 7/32 in hardened 52100 alloy ball bearings. These performed poorly for two reasons. Firstly, the hardened steel balls spalled into fragments when hit by the shock of the explosion; the fragments were neither aerodynamic enough nor large enough to perform effectively. Secondly, the blast "leaked" between the balls, reducing their velocity.

A second problem was the curvature of the mine. This was determined experimentally by Bledsoe, through a large number of test firings. After Bledsoe left the project to work at the Rheem corporation, William Kincheloe, another engineer, came onto the Claymore project.

Kincheloe immediately suggested using softer 1/8 in steel "gingle" balls, which were used in the foundry process. They did not spall from the shock of the explosive, but deformed into a useful aerodynamic shape similar to a .22 rimfire projectile. Using a homemade chronograph, the engineers clocked the balls at 3775 ft/s. The second change was to use a poured plastic matrix to briefly contain the blast from the explosive, so that more of the blast energy was converted into projectile velocity. After a number of experiments, the engineers settled on Devcon-S steel-filled epoxy to hold the balls in place. With this change, the velocity improved to 3995 ft/s.

Technical challenges to overcome included developing a case to contain the corrosive C-3 explosive that would be durable enough to withstand months of field handling in wide temperature ranges. Using dyes to test various plastics for leaks, they found a suitable plastic called Durex 1661½, which could be easily molded into a case.

By the spring of 1956, Aerojet had a near-final design. It was awarded a pre-production contract for 1,000 M18A1 Claymores, designated T-48E1 during testing. The initial versions of the mine used two pairs of wire legs produced from number 9 (3 mm) wire. Later when production was ramped up, the design was changed to flat steel scissor, folding-type legs.

Early pre-production mines were triggered using a battery pack, which had been used with the M18. This was found to be undesirable for a number of reasons. Bill Kincheloe came up with the idea of using a "Tiny Tim" toggle generator, of the type used with a number of Navy rockets. Originally an aluminum box was used to hold the generator. Later a Philadelphia company, Molded Plastic Insulation Company, took over the manufacture of the firing device for the first large-scale production run producing a plastic device.

The sighting for the device was originally intended to be a cheap pentaprism device, which would allow the user to look down from above and see the sight picture. After locating a suitably low-cost device, the engineers found that fumes from either the C-3 explosive or the cement used to glue the sight to the top of the mine corroded the plastic mirrors, rendering them unusable. They adopted simple peep sights, which were later replaced by a knife blade sight.

Testing concluded that the mine was effective out to approximately 110 yd, being capable of hitting 10% of the attacking force. At 55 yd, this increased to 30%. The development project completed, the Aerojet team sent the project back to Picatinny. The Arsenal bid it out to various component suppliers. In 1960 it was type standardized as the M18A1. It was first used in Vietnam in the spring or early summer 1966.

Minor modifications were made to the mine during its service. A layer of tinfoil was added between the fragmentation matrix and the explosive. This slightly improves the fragment velocity, and protects the steel fragments from the corrosive explosive. A ferrite choke was added to prevent RF signals and lightning from triggering the mine.

M68 Inert Training Kit
The M68 kit is designed to familiarize personnel with the placement and arming of a real M18 directional mine. It comes with all the components of a real Claymore kit packed in an M7 bandolier. The light blue or black plastic M33 Inert Anti-Personnel Mine is the training and practice version of the M18A1 Claymore. Some inert mines were green with a light blue band. It does not contain an explosive or pyrotechnic filler of any kind. It is packed in a Claymore bag with inert M10 simulated detonator cap wire, an M57 "clacker" firing control, and an M40 circuit test kit.

Mini-Multi-Purpose Infantry Munition
In early 2015, the U.S. Army began testing a smaller version of the Claymore called the Mini-Multi-Purpose Infantry Munition (M-MPIMS). It weighs 2 lb and has a 50 m effective range, similar to the full-size Claymore. At its optimized range of 30 m, the fragmentation zone is 23 m wide and 2 m high, with a minimum of five hits per 1 m2. It has the surface space of an average smartphone and includes a Picatinny rail for camera, laser, or other attachments. The M-MPIMS is designed to be more controllable than the Claymore with less collateral damage, using an insensitive munitions explosive that is poured rather than packed for more uniform distribution results in more consistent blast pattern. Rear-safety distance has been decreased to 15 m and shelf life has been increased to 25 years.

International directional fragmentation AP mines
PADMINE is an anti-personnel directional fragmentation mine produced by the United Kingdom, similar to the Claymore in cosmetic design with two swivelling legs, inserted into soft-ground. Its lethality out to 50 meters arrives in the form of 650 steel balls and it is activated by remote control or trip wire.

The M18 directional fragmentation anti-personnel mine, developed by Cardoen of Chile, contains 626 grams of explosives, surrounded by 607 AP fragmentation units providing a 60 degree arc of fire, with a 50-250 meters lethal range.

Italy produces the DAF M6 and DAF M7 directional fragmentation mines, weighing 18 and 10 kilograms respectively, with trip wire or remote control detonation. Their appearance is similar to the Claymore mine.

National copies
A number of licensed and unlicensed copies of the mine have been produced.
 * 🇨🇦 Canada: C19 Defensive and Support Mine
 * 🇨🇱 Chile: M18
 * 🇨🇳 China: Type 66
 * 🇫🇮 Finland: Viuhkapanos (Fan Charge) VP 88, "heavier" VP 84 and VP 2010
 * 🇭🇺 Hungary: IHR-60
 * 🇮🇹 Italy: VS-DAFM 7
 * 🇵🇰 Pakistan: P5 Mk1
 * 🇵🇭 Philippines: M18A2
 * 🇵🇱 Poland: M18 Claymore
 * 🇷🇺 Russia: MON-50
 * 🇸🇦 Saudi Arabia: M18A/M18A1
 * 🇷🇸 Serbia: MRUD (Mina Rasprskavajućeg Usmerenog Dejstva)
 * 🇿🇦 South Africa:
 * Shrapnel mine No 2
 * Mini MS 803 mine
 * 🇰🇷 South Korea:
 * K440, slightly smaller than the Claymore with 770 fragments.
 * KM18A1
 * 🇸🇪 Sweden:
 * FFV-013
 * Försvarsladdning 21
 * LI-12/Truppmina 12
 * 🇹🇷 Turkey: M18 AP Mine
 * 🇺🇸 United States: Arms Tech MM-1 "Minimore", a smaller variant conceived for Special Forces use
 * Vietnam: MDH-C40

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Claymore mine