Highlights of CERN history

1949  During the European Cultural Conference at Lausanne, the French physicist and Nobel prize-winner Louis de Broglie proposes the creation of a European science laboratory.

1950  At the 5th General Conference of UNESCO held in Florence, the American physicist and Nobel prize-winner Isidore Rabi puts forward a resolution, which is unanimously adopted, authorising the Director General of UNESCO, “to assist and encourage the formation and organization of regional centres and laboratories in order to increase and make more fruitful the international collaboration of scientists ...”.

1952  After two UNESCO Conferences are held on the subject, 11 European governments sign an agreement setting up a provisional ‘Conseil européen pour la Recherche nucléaire’ (CERN). At a meeting of the CERN council in Amsterdam, a site near Geneva is selected for the planned laboratory.

1954  The European Organization for Nuclear Research is formally created on 29 September, when sufficient ratifications of the Convention establishing CERN are obtained from Member States, thus dissolving the ‘provisional’ CERN. The acronym CERN, however, is retained.

1955 Twelve founding Member States ratify the Convention: Federal Republic of Germany, Belgium, Denmark, France, Greece, Italy, Norway, The Netherlands, United Kingdom, Sweden, Switzerland and Yugoslavia. Yugoslavia leaves the Organization in 1961 for financial reasons. Austria and Spain join CERN in 1959 and 1961 respectively—Spain leaves the Organization in 1969 but rejoins in 1983. Finland and Poland join in 1991, Hungary in 1992, the Czech and Slovak Republics in 1993, and Bulgaria in 1999 bringing the number of Member States to 20.

1957  The 600 MeV Synchro-Cyclotron begins operation. One of the first experimental achievements is the long-awaited observation of the decay of a pion directly into an electron and a neutrino.

1959  First operation of the 28 GeV Proton Synchrotron (PS), which is for a time the highest energy accelerator in the world. In the same year, the first experiments using neutrino beams are carried out; this field of research eventually becomes a speciality of the physics programme at CERN.

1963  First bubble chamber pictures of neutrino interactions are taken. Neutrino physics benefits greatly from fast ejection of protons from the Synchrotron, which is achieved for the first time ever during May this year.

1965  Agreement with French authorities is signed in September on extending the CERN site over the French border. In December, the Council approves the construction of the Intersecting Storage Rings (ISR) on this extension of the site.

1967  CERN commissions one of the world's finest facilities for the study of very short-lived nuclei—the Isotope Separator On-line (ISOLDE). An agreement between CERN, France and Germany covers the construction of a 3.7 metre hydrogen bubble chamber equipped with the largest superconducting magnet in the world. During its working life from 1973 to 1984, the ‘Big European Bubble Chamber’ (BEBC) takes over 6 million photographs.

1968  Invention of multiwire proportional chambers and drift chambers—representing some of the most important advances in the domain of electronic particle detectors. Georges Charpak is awarded the Nobel Prize for Physics in 1992 for this invention.

1971  Approval of proposal to build a second laboratory adjoining the existing site in France and Switzerland for the construction of a new Super Proton Synchrotron (SPS) which is initially planned to reach an energy of 300 GeV. Although at first administratively separate, the two CERN laboratories are united in January 1976.

1972  A four ring 800 MeV Booster is completed to increase the injection energy of the PS. With the booster and a new Linac, which starts operation in 1978, the PS machine exceeds its design intensity by more than a thousand times.

1973  First important discoveries from the experiments at the ISR emerge: protons grow in size as their energy is increased; and colliding protons can produce diffraction patterns rather like those of light bending around a disc, thus showing the wave nature of the proton. It is with the French-built Gargamelle bubble chamber in a neutrino beam at the Proton Synchrotron (PS) that one of CERN's greatest physics discoveries is made: it is found that neutrinos can interact with another particle without changing into a muon. This behaviour is known as the ‘neutral current interaction’ and is the discovery that opens the door to what is known as ‘new physics’. It has great implications for the theoretical ideas about the fundamental forces of physics. In particular, it gives strong support to the theory that attempts to unite our understanding of the weak force—governing such phenomena as radioactivity—with the familiar electromagnetic force.

1976  Start of operation of the Super Proton Synchrotron (SPS). As with the ISR, machine construction is completed ahead of schedule and within the authorised budget. The accelerator performance improves rapidly so that the design intensity is exceeded and at the end of 1978 the peak energy is taken to 500 GeV.

1978  Experiments at CERN show how beam quality and intensity can be improved using the ‘stochastic cooling technique’, enabling intense beams of antiprotons to be accelerated and stored.

1981  Conversion of the SPS into a proton-antiproton collider and the building of two experimental areas (UA-1 and UA-2) where data from the collisions can be taken. From then on, the operation of the SPS is divided between this collider mode and fixed-target physics. The first proton-antiproton collisions at an energy of 2 x 270 GeV are seen in July 1981, a few months after the start-up of the new Antiproton Accumulator ring (AA), where stochastic cooling is applied to produce the antiproton beam. The Member States authorise construction of the Large Electron-Positron collider (LEP) for an initial operating energy of 50 GeV per beam.

1983  Discovery of the W bosons (January) and the Z boson (May)—the carriers of the weak nuclear force—confirms the theory of electro-weak interactions and unifies the weak and electromagnetic forces. In September, the ground-breaking ceremony for LEP takes place in the presence of the French and Swiss Presidents, Mr. François Mitterrand and Mr. Pierre Aubert. LEP is the largest scientific instrument ever constructed, with a circumference of 27 kilometres.

1984  Carlo Rubbia and Simon van der Meer receive the Nobel Prize for Physics for their experimental work on proton-antiproton collisions that culminated in the discovery of the W boson and Z boson at CERN in 1983.

1989  In August, LEP starts up. In October, only two months after the first collisions in LEP, CERN makes a very important physics discovery. After an extremely accurate measurement of the width of the Z boson, CERN physicists announce that the fundamental building blocks of matter consist of only three families of particles. On 13 November, LEP is officially inaugurated by Heads of State and Science Ministers from CERN Member States and other countries involved in the CERN experimental programme.

1991  In December, CERN's Council delegates agree unanimously that the Large Hadron Collider (LHC) is the right machine for further significant advance in the field of high-energy physics research and for the future of CERN.

1992  Georges Charpak, a CERN physicist, is awarded the Nobel Prize for Physics for the invention of the multiwire proportional chamber which enables physicists to make major progress in the tracking of particles and which is now used for many medical applications.

1993  The first conference of the WWW (World-Wide Web) is held at CERN. The Web was invented by CERN scientist Tim Berners-Lee and has caused the current Internet explosion.

1994  The years from 1989 are marked by the success of LEP experiments. The outstanding result is the precision measurement of the Z resonance parameters: over the period from 1989 to 1993 the four LEP detectors—ALEPH, DELPHI, L3 and OPAL—reconstructed more than 10 million Z decays. On 16 December the CERN Council gave the go-ahead for the construction of the Large Hadron Collider (LHC).

1995  The first atoms of antihydrogen are created in the Low Energy Antiproton Ring (LEAR). Antiprotons from LEAR hit a Xenon gas target. In these collisions positrons are created, some of which join with the antiprotons, thus creating an atom of antihydrogen. After making a generous contribution to the LHC project, Japan becomes an observer at CERN Council.

1996  LEP is upgraded to run at the W pair production threshold of 163 GeV. Further upgrades will take LEP energy to 200 GeV by 1999.

1997  After agreeing to provide significant financial contributions to the LHC, the USA becomes an observer at CERN Council.

1998  Following approval from French and Swiss governments, civil engineering for the LHC gets under way. The first full-scale 15-metre prototype LHC bending magnet arrives at CERN.

1999  The industrial production of the ATLAS toroid magnet system, the largest in the world, starts with the manufacture of the superconducting cables. Also the first magnets for the transfer lines of the LHC arrive from Russia. Composed of 540 magnets, the transfer lines will transport beams from the Super Proton Synchrotron (SPS) accelerator to the LHC.

2000  LEP is shut down after running for 11 years to make way for the LHC. A final burst of excitement occurred a few months prior to the scheduled shut down when one collaboration reported findings of a Higgs boson signal; however, it was not enough evidence to keep LEP in operation. Also the first LHC elements, financed by the special contribution of the USA, cross the Atlantic and are delivered to CERN, while the first of the short straight-sections of the LHC successfully pass a test at full intensity. Four hundred and twenty short straight-sections, containing, among others, quadrupole magnets, will focus the beams.

2001  The European DataGrid project (EDG) is launched two years after the idea was born in Annapolis, USA. The project tests a networking infrastructure for the future computing grid. The Grid must connect tens of thousands of computers worldwide to serve scientific projects like the LHC. The production of the 12 million steel collars for the LHC main magnets starts. These collars ensure the mechanical rigidity of the magnets.

2002  The first octupole correction magnet is delivered. In addition to the 1232 main dipole magnets that will curve the trajectory of the protons and the 400 focussing quadrupoles, the LHC will be equipped with some 5000 corrector magnets. The last piece of LEP goes up to the surface. In 14 months of dismantling, 40 000 tonnes of material were removed from the 27-kilometre tunnel.

2003  The assembly of the LHCb experiment begins with the descent of the experiment’s two magnet coils into the underground experimental area. Also the first magnet for the LHC manufactured in the USA arrives at CERN. The USA must provide about 20 special superconducting magnets within the framework of its special contribution to the LHC.

2004  The lower part of the central barrel of ATLAS's tile hadronic calorimeter was lowered into the ATLAS cavern. This is the first active piece of a detector to be moved underground. Half of the superconducting cable needed for the LHC magnets has been produced.

2005  After being assembled at the end of 2004, ALICE’s dipole magnet for the muon spectrometer is tested successfully in the underground hall of the experiment. The CMS cavern is inaugurated, marking the end of the civil engineering work for the LHC. This 53-metres long, 27-metres wide and 24-metres high hall is hidden 100 metres underground and required six years to build.

2006  The new CERN Control Centre, which combines all the control rooms for the accelerators, the cryogenics and the technical infrastructure, starts operation. The LHC will be controlled from here. ATLAS combines two of the three parts of its inner detector barrel, the semiconductor tracker and the transition radiation tracker, through a long and meticulous operation.

2007  The ALICE time projection chamber is transported to the experimental cavern. The gap between the structure and the shaft wall is only 10 centimetres! The largest section of the CMS detector weighing as much as 5 jumbo jets (1920 tonnes) makes its dramatic descent into the experiment's cavern. This marks the halfway point of the detector lowering process for the experiment.

2008  The LHC made the headlines in 2008: first beams circulated in the machine on 10 September, making it the main news item on TV, radio, the internet and in newspapers. Nine days later, however, a faulty connection between two superconducting magnets led to the release of a large amount of helium into the LHC tunnel and forced the machine to shut down for repairs.

2009  CERN is busy repairing and testing the LHC. A number of magnets had to be replaced, electrical connections were tested and new monitoring and protection systems installed to pave the way for a safe restart, scheduled to begin after mid-November. With Rolf-Dieter Heuer, CERN also has a new Director-General. VIP visits this year included the film crew for Hollywood movie 'Angels and Demons', partly set at CERN.

2010  After a safe restart, the first high-energy collisions at 3.4 TeV are expected at the end of 2009 or the beginning of 2010. The LHC's four experiments are ready to take their first collision data to start answering questions such as what gives matter its mass, what the invisible 96% of the Universe is made of or why nature prefers matter to antimatter. The LHC is scheduled to run with energies up to 5 TeV until its regular winter shutdown at the end of the year.