FCC Week 2025, held in Vienna in May, was the first major collaboration meeting for the Future Circular Collider (FCC) project following the release of the FCC Feasibility Study Report in March. The event brought together more than 600 participants from 34 countries, highlighting the momentum building around CERN's proposed post-LHC research infrastructure.
The FCC is envisioned as a two-stage collider, hosted in a new 90.7-km tunnel in the Geneva basin. In the first phase, a precision electron-positron collider, the FCC-ee, would serve as a Higgs, electroweak and top-quark factory. It would later be succeeded by the FCC-hh, a 100-TeV hadron collider designed to extend the discovery potential far beyond that of the LHC. The comprehensive Feasibility Study Report, signed by more than 1400 authors, was submitted as input to the update of the European Strategy for Particle Physics and lays the groundwork for a strategic decision in 2026.
Throughout FCC Week, plenary and parallel sessions covered scientific goals, progress in detector R&D, accelerator design and sustainability planning. Discussions reflected the increasing maturity of the FCC design and the growing international collaboration supporting it, which now encompasses 162 institutes across 38 countries. Sessions also addressed the broader societal and industrial implications of the project. The week concluded with the FCC Awards, celebrating the work of early-career researchers. Prizes were awarded for innovations in beam optics, detector studies and simulation techniques, showcasing the next generation's role in shaping the FCC's future.
A highlight of the week was the Technology and Industry Day, organised in collaboration with the Austrian Federal Economic Chamber. Speakers presented compelling evidence of the FCC's socio-economic potential. From workforce development to innovation in cryogenics and computing, they underlined the FCC's potential to drive long-term industrial and educational returns.
Public engagement was also prominent. More than 800 students and visitors took part in activities at Vienna's Planetarium and Wiener Riesenrad, while more than 350 people attended the public event "The Higgs boson and our life" at the Austrian National Library, in which CERN's Director-General, the Vice President of the Austrian Academy of Sciences and the European Climate Pact Ambassador for Austria participated. An outdoor exhibition, "Code of the Universe", remains on display in Vienna, inviting the public to explore the beauty of physics through art.
Continuing the conversation at CERN
Following FCC Week in Vienna, two events took place at CERN on 27 May. A CERN community information meeting invited the personnel to discuss the results of the Feasibility Study and explore the next steps. The session drew significant interest, with those present in the Main Auditorium joined by around 1200 people connected via webcast, indicating a high level of engagement within the CERN community. A recording of the event will soon be available here (CERN login required).
Later that evening, the public event "Réunion d'information et d'échanges : Publication de l'étude de faisabilité du Futur collisionneur circulaire FCC" was held at CERN Science Gateway. This French-language event welcomed 170 attendees on site, with about 300 people following the live stream. Audience feedback highlighted strong appreciation for the speakers' ability to link fundamental research with societal issues, and many praised the accessible and thought-provoking presentations.
These events reflect CERN's commitment to transparency, community dialogue and public engagement as it prepares for a strategic decision on the FCC.
