Large Hadron Collider Set for Major Upgrade Under New Leadership
Mark Thomson has taken on the role of director general at CERN, the renowned nuclear physics laboratory located near Geneva, Switzerland. Beginning January 1st, Thomson will oversee one of the most prestigious scientific institutions in the world, home to the Large Hadron Collider, the largest scientific instrument ever constructed.
The LHC operates deep underground in a 27-kilometer ring that straddles the French-Swiss border. The machine accelerates protons, the nuclei of hydrogen atoms, to nearly the speed of light. At four points around the ring, protons traveling in opposite directions collide with tremendous force. These collisions create showers of new particles that researchers record and analyze. The energy released in these impacts, governed by Einstein's famous equation E=mc2, generates more massive particles than could otherwise be observed.
Thomson's tenure will be defined largely by a significant engineering project. Beginning in June, the LHC will shut down for the first time under his leadership to undergo substantial upgrades known as the high-luminosity LHC project. The work involves installing powerful new superconducting magnets designed to compress the collider's proton beams and increase their brightness. Once complete, the upgraded machine will produce ten times more collisions than currently possible. The detectors will also be strengthened to better capture subtle signs of new physics that these collisions might reveal.
"It's an incredibly exciting project," Thomson says of the upgrade work. "It's more interesting than just sitting here with the machine hammering away." The shutdown will continue until near the end of his five-year term, but Thomson expressed optimism about the research that will follow. "The physics results will keep on coming," he noted, explaining that scientists will have substantial amounts of data to analyze during the shutdown period.
Beyond the immediate upgrade project, Thomson faces a longer-term challenge. The LHC is expected to reach the end of its operational life around 2041. CERN's member states will need to decide what comes next, with a major decision point arriving in 2028. The leading candidate is the Future Circular Collider, a machine more than three times larger than the LHC that would require a 91-kilometer circular tunnel bored up to 400 meters underground.
The FCC project reflects broader questions about Europe's future role in particle physics research. Other nations, including the United States and China, are developing their own advanced collider proposals. Thomson emphasized the importance of continued investment in fundamental research. "We've not got to the point where we have stopped making discoveries and the FCC is the natural progression," he said. "Our goal is to understand the universe at its most fundamental level, and this is absolutely not the time to give up."