CERN in a nutshell

What is CERN ?

CERN is the world's largest particle physics laboratory. Thousands of scientists from all over the world work together here to advance our knowledge of matter, its fundamental constituents and the forces that link them. Founded in 1954, CERN was one of the first European collaborations, uniting countries that had been fighting against one another during the Second World War. The number of Member States has now grown to 23. As it pursues its fundamental research, CERN pushes technological boundaries, trains countless scientists and, through the medium of science, contributes to the dialogue between nations. More information >>.

How does CERN work ?

CERN is a European organisation governed by a Council of Member State representatives. The Council sets the Organization's policy and is assisted by the Scientific Policy Committee and the Finance Committee. The Council appoints, for a five-year term, a Director-General who is responsible for implementing the Council's decisions and managing the Laboratory. The Director-General, currently Dr. Fabiola GIANOTTI, is assisted by a Directorate. More information >>

What equipment does CERN use?

Physicists use three main types of tool to carry out their research: accelerators, detectors and computers. Accelerators are powerful machines designed to accelerate particles to extremely high energies, causing them to smash into one another. CERN operates a complex consisting of several accelerators, the most powerful of which is the LHC (Large Hadron Collider), a ring 27 kilometres in circumference and buried 100 metres underground. Detectors are high-precision instruments that record data concerning the particles created during the collisions. The scientists then try to make sense of these collisions with the help of cutting-edge computing technology that collates, stores and analyses the data recorded by the detectors.

Who works at CERN?

CERN employs around 2 500 people – European civil servants from the 21 Member States – but its installations are available for use by research institutes all over the world. In total, almost 11 000 scientists of 100 different nationalities use CERN’s machines. The Laboratory also hosts several hundred students, fellows, apprentices and scientists seconded from other institutes. More information about working at CERN >>

What impact does CERN have on society?

CERN provides work, either directly or indirectly, for more people than any other international organisation in Geneva. The construction and maintenance of its installations is entrusted to commercial firms from the Member States, many of which are based in the local region. Also, the technologies developed to meet CERN's research needs benefit society as a whole. In addition to the invention of the Web, CERN's commitment to technology transfer  has driven progress in medical imaging and cancer treatment, industrial processes, information technologies and more.

Who owns the CERN sites?

CERN’s fenced sites (those that are in use) have a total surface area of 200 hectares – 80 in Switzerland and 120 in France – and a further 400 hectares have been made available by the Organization's two Host States. CERN plans to use this land for future projects; in the meantime, they remain either farmland or woodland. The money earned from renting this land to farmers is used to finance projects benefiting the public, such as cycle paths and fitness trails. These funds are managed by a CERN-Pays de Gex Consultation Committee, chaired by the sous-préfet of the Ain and also comprising a CERN representative, a farmers’ representative and the mayors of the communes concerned (Prévessin-Moëns, Saint-Genis-Pouilly and Cessy).

Why does CERN's name include the world 'nuclear'?

CERN was founded in 1954, when the main goal of fundamental physics research was to understand the centre of the atom, i.e. the nucleus, which is where the word ‘nuclear’ comes from. CERN's research, though, has nothing to do with nuclear energy or its applications. Today, since our understanding of matter goes beyond the nucleus of the atom, CERN can more accurately be described as the “European Laboratory for Particle Physics” – a name that we do sometimes use. More information >>

Who funds CERN's research?

CERN’s 21 Member States each pay a contribution to the CERN budget (which totalled 1 240 million Swiss francs in 2013). In addition, special contributions are made to specific projects by the Host States and by non-Member States wishing to be involved in particular areas of research. This is the case for the LHC. The majority of CERN’s budget is spent on the construction of its enormous scientific installations, which are available for use by all the participating countries. The costs of these machines are far more than one single country could afford. In addition, more than 600 institutes around the world work together to conduct experiments using CERN’s facilities, and these experiments are funded by the participating institutes.

Does CERN recruit?

Yes. While CERN’s workforce remains stable at around 2 400 full-time-equivalent members of personnel, vacancies are regularly advertised for posts in various fields, both technical and administrative. More information >>

Why do we sometimes see clouds of white smoke above the CERN sites?

The white clouds that you can sometimes see above the CERN sites come from one of two sources. They can come from the traditional cooling towers that are used to cool electrical power installations, for example, in which case the cloud is just water vapour. In other cases, they come from the LHC accelerator’s cooling system. In order to operate in a superconducting state, the LHC has to be cooled to -271°C. The first step in the cooling process involves introducing liquid nitrogen to cool the helium that will eventually circulate in the underground accelerator. During this process, the helium transfers its heat to the nitrogen, which thereby transforms from a liquid state to a gaseous state before being released into the atmosphere. The resultant cooling of the ambient air can momentarily create mist. This phenomenon is not at all dangerous since nitrogen is the main constituent of the air that we breathe, which is 78% nitrogen and 21% oxygen.

More information about CERN and the environment.

Why is the LHC underground?

The LHC uses the tunnel that was built to house CERN’s previous large accelerator, the LEP, which was dismantled in 2000. Digging an underground tunnel proved to be the best option for a 27-km machine, since it’s cheaper than acquiring land to build on at the surface and the impact on the landscape is minimised. In addition, the Earth’s crust provides good shielding against radiation.

Can the LHC's magnetic fields be dangerous?

Not at all. It is true that the magnetic fields created by the LHC machine and its experiments are very intense, but they are localised and contained. The machine's magnetic field is especially well contained within the accelerator. Even in the case of the experiments, the intensity of the field is very weak just a few metres away, and it decreases exponentially with distance. Since the magnetic fields are produced 100 metres underground, they are undetectable on the surface.

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