Voir en


CERN celebrates 40th Anniversary

Geneva, 8 September 1994. On 29 September 1954 the European Organization for Nuclear Research (CERN)1 was created when sufficient ratifications of the Convention establishing CERN* were obtained from Member States. CERN's goals were clearly set out in Article II of this Convention: "The Organization shall provide for collaboration among European States in nuclear research of a pure scientific and fundamental character, and in research essentially related thereto. The Organization shall have no concern with work for military requirements and the results of its experimental and theoretical work shall be published or otherwise made generally available." This established from the very beginning the innovative concept of open international scientific co-operation which has been the foundation of the Laboratory's success over the last 40 years.

CERN is now the world's largest research laboratory with over 50% of all the active particle physicists in the world taking part in over 120 different research projects. 3000 staff members, 420 young students and fellows supported by the Organization and 5000 visiting physicists, engineers, computer experts and scientists specializing in a variety of front-line technologies are collaborating with CERN from 40 countries and 371 scientific institutions. Binding together the creativity of so many different nationalities, backgrounds and fields of research has established CERN as the global centre for High Energy Physics and set a precedent in scientific collaboration which has been followed by Europe's other fundamental research organizations (ESO, ESA, EMBL, ESRF).

The CERN staff have been the architects of this success and the celebrations of the 40th Anniversary have been designed as a thank you to the people whose commitment over the last 40 years has established CERN's reputation. For the whole day of 17 September CERN will be turned into an open-air fair for all the Organization's employees and their families. The festivities, opened by CERN Director-General Christopher Llewellyn Smith, include rides in helicopters, on ponies, on a miniature train, circus acts and physics demonstrations by the University of Amsterdam, involving as much smoke, noise and theatre as possible. There are exhibitions of photographs covering the history of the Laboratory and of portraits of CERN's five Nobel laureates by Renato Missaglia. Classical, jazz, rock, brass band, bagpipe and hunting horn concerts continue throughout the day - folk dancers, conjurors and demonstrations of climbing and rescue techniques will animate the normally rather austere roads of the CERN site. Some outside groups have been invited for the celebrations but the majority of the activities have been organized by CERN employees. CERN 's scientists have revealed hidden talents as, magicians, musicians, singers, and even croquet champions.

The scientific side of CERN has not been forgotten - Hubert Reeves and Alvaro de Rujula will lead a debate on the "The First Moments of the Universe"; there are demonstrations of 'virtual reality' projects, models of the huge detectors for CERN's next accelerator - the Large Hadron Collider (LHC) - and an exhibition of the Laboratory's scientific achievements.

CERN's history is bound up with the construction of the large accelerators: the Synchro-Cyclotron (SC, 1957) and the Proton Synchrotron (PS, 1959) were followed by the Intersecting Storage Rings (ISR, 1971) and the Super Proton Synchrotron (SPS, 1976). CERN's largest accelerator so far, the Large Electron-Positron storage ring (LEP), began operating in 1989. Existing machines are used as pre-accelerators for the next generation, meaning that major investments are exploited over a long period. CERN now possesses the world's most extensive interconnected system of accelerators and storage rings (see Appendix Highlights of CERN History). The LHC will be the first machine in the world in which quarks and gluons collide in the TeV energy range and represents the next step in High Energy Physics research. As CERN's first accelerators were catalysts for European collaboration, the LHC will set a precedent for a worlwide collaboration in physics research.

"Scientific research lives and flourishes in an atmosphere of freedom - freedom to doubt, freedom to enquire and freedom to discover. These are the conditions under which this new laboratory has been established"; these were the words written in 1954 by Sir Ben Lockspeiser, first President of the CERN Council. This is the atmosphere in which CERN has flourished for 40 years and in which the Organization looks forward to continuing successfully into the future.

Highlights of CERN's history


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.


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 ...".


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.


The European Organization for Nuclear Research is formally created on 29th 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.


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 and the Czech and Slovak Republics in 1993, bringing the number of Member States to 19.


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.


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.


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.


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.


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.


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


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.


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


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 which 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 which attempts to unite our understanding of the weak force - governing such phenomena as radioactivity - with the familiar electromagnetic force.


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.


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.


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.


Discovery of the W-bosons (January) and the Z-boson (May) - the carriers of the weak nuclear force - thus confirming the theory of electro-weak interactions and unifying 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.


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


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 Z0 particle, CERN physicists announce that the fundamental building blocks of matter consist of only three families of particles. On the 13th of 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.


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.


George 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.


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.

1. CERN, the European Laboratory for Particle Physics, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. Israel, the Russian Federation, Turkey, Yugoslavia (status suspended after UN embargo, June 1992), the European Commission and Unesco have observer status.