Future Circular Collider

Its main goal is to study in detail the Higgs boson and its interactions with other known fundamental particles – it will be a “Higgs factory.” It will also study other aspects of nature at the infinitely small scale to search for the slightest deviations from the underlying theory and explore rare phenomena.

The objectives include:

• Measure the Higgs boson and other key particles with unmatched precision.
• Search for new particles, new forces and potential dark-matter candidates.
• Understand why matter dominates over antimatter in today’s Universe.
• Explore entirely new phenomena through gains in precision and sensitivity.

The FCC would be installed in an underground tunnel roughly the shape of a ring with a circumference of 91 km, located deep underground with shafts averaging 200 metres in depth. The FCC would be deeper than the current LHC and three times longer.

The tunnel alignment was selected, among other considerations, to allow the existing CERN accelerator complex to serve as a chain of pre-accelerators.

Below is a map of the route, which crosses the French departments of Ain and Haute-Savoie and the Swiss Canton of Geneva and passes under Lake Geneva.

There would be eight access points: one in Switzerland and seven in France.

The surface areas of the access points (called surface sites) would vary between 4 and 6 hectares, depending on their purpose.

The Future Circular Collider (FCC) is the approach that has been judged the most effective in terms of research for studying in depth the widest variety of promising topics in particle physics.

This choice follows a conceptual design report for the FCC that was submitted in 2020 as a contribution to the update of the European Strategy for Particle Physics. Following this, CERN was mandated by its Member States to carry out a technical and financial feasibility study of the FCC that would be ready for presentation during the next Strategy update in May 2026.

The current Strategy was adopted after the Higgs boson, the last undetected particle predicted by the Standard Model – which describes all known fundamental forces except gravitation – was discovered at the LHC.

To build on these achievements, the FCC would be an electron-positron collider that would serve as a “Higgs factory”, a facility specially designed to study Higgs bosons. This facility might later be converted into a proton–proton collider capable of reaching collision energies of up to 100 teraelectronvolts.

The main objective of CERN is fundamental research in particle physics. This type of research expands the limits of human knowledge to understand the fundamental building blocks and their interactions, which lets us draw conclusions about the history and the fate of the Universe.

Major advances come from new knowledge generated by fundamental research; without fundamental science, there is no applied science. For example, without Albert Einstein’s fundamental equation of general relativity there would be no such concrete everyday applications as GPS. Applications like lasers, integrated circuits and transistors are all based on discoveries from quantum research. 

The tools and technologies developed to carry out this research can have many direct applications for humankind, such as medical imaging and hadron therapy used for the treatment of certain cancers.

These technologies are transferred to society by the universities and institutes that participate in the collaborations and by CERN itself, in fields ranging from aerospace to security, environmental protection and cultural heritage. Read more here.

If approved, the FCC would come online around 2045.

In 2021, CERN’s Member and Associate Member States, including France and Switzerland, mandated the Feasibility Study. This followed a recommendation by the particle physics community in the 2020 update of the European Strategy for Particle Physics.

CERN, together with academic and industrial partners, is currently conducting research programmes on reuse of the material excavated during the tunnel construction. The aim is to make the best possible use of the material extracted from the subsoil, preferably locally.

A strategy for managing the material is being developed with stakeholders from the Host States (France and Switzerland), universities and companies with expertise in this field.

The current objective is to reuse most of the excavated material (around 70%)

locally to limit disturbance and storage. In addition, an estimated 15 % of the material will be undergo treatment at the extraction sites to make it suitable for reuse. The remaining material that cannot be used will be transported to specialised treatment and disposal centres.

Of the 85 % of material that can be recovered, the plan is to reuse it for the following purposes (numbers are estimates): 

• 10% to 20 % for the production of cement and concrete
• 40 % for use as quarry fill
• 30 % for use in agriculture, forestry and land and brownfield development; this figure may increase depending on the results of the OpenSkyLab project. 
• 10 % for other recovery channels (construction materials, rural roads, creation of covered trenches).

This approach is in line with the European Union’s action plan for the circular economy and complies with the best practices adopted by CERN’s two Host States (France and Switzerland).

The total quantity of material that would be excavated for the FCC is estimated at 6.3 million m³ in volume, or approximately 16.4 million tonnes over the construction period.

Per year, the FCC construction works would involve managing less than 2% of all material extracted annually in France and 0.1 of the material extracted annually in Switzerland.

CERN and its contracting companies are committed to making every attempt to keep disruption to residents to a minimum. The surface sites have already been chosen with a view to causing the least possible disturbance to the local community, the countryside, vistas and of course the wildlife. Lorries carrying excavated material would bypass residential roads as much as possible. Noise levels would be kept to a minimum. Measures would be taken to keep roads as clean as possible.

CERN aims to be a model environmentally responsible scientific laboratory, acting with transparency, accountability and sustainability. All activities linked to the FCC will follow these commitments and will comply with environmental rules in France and Switzerland and with EU legislation. These include wildlife, plants, soil quality, air quality, water resources, biodiversity, noise, dust and light pollution. Existing and planned local infrastructure will also be taken into account. The project will systematically apply the “avoid–reduce–offset” principle.

Read more here.

The tunnel itself would be underground and therefore not visible on the surface. Eight surface sites along the tunnel’s circumference would be visible: the four experimental sites would each occupy up to 8 hectares, and the four technical sites up to 5 hectares each, including their landscaping to help them blend into the surroundings.

The cost of the FCC with four interaction points is estimated to be 15 billion CHF, spread over a period of about 12 years, with the civil engineering for the tunnel representing about one third. This investment would be firstly based on CERN’s recurrent budget, spread over many years and shared among CERN’s Member States and international partners. Additional funding may come from other institutional and private contributions. Private donors have already pledged 860 million euros and the FCC is ranked first among 11 possible ‘moonshot projects’ for Europe in the European Commission’s Multiannual Financial Framework (2028-2034).

The FCC would create an estimated 50 billion CHF of direct and indirect economic effects, including 4 billion CHF in the surrounding area through added household spending. The cost–benefit ratio is estimated at 1.2, meaning that for every 1 CHF spent, there will be a return of 1.2 CHF – in short, the project is expected to create more value than it costs.