Large Hadron Collider enters winter break: Next major upgrade soon
After another record year, the world's largest particle accelerator was shut down at the beginning of the week. The next major upgrade will begin in mid-2026.
(Image: © 2021 CERN, Samuel Joseph Hertzog)
The world's largest particle accelerator has begun its annual winter break after generating more particle collisions in 2025 than ever before. This was announced by the European Organization for Nuclear Research (CERN), which operates the Large Hadron Collider (LHC). Regarding the important key figure of so-called luminosity – which measures the number of particle encounters per area and time and makes comparisons possible – the research instrument has now exceeded 500 fb-1 (femtobarns-1), corresponding to a total of "approximately 50 million billion particle collisions." 2025 was also the last complete research year of the third run for the LHC: next year, it will only be activated for a few months before being upgraded over several years for even significantly more collisions.
Next major overhaul approaches
According to CERN, all four major instruments connected to the ring-shaped particle accelerator have functioned "extremely well." Data could be collected with an efficiency of over 90 percent. For the first time this year, special cycles of collisions between protons and oxygen particles, oxygen with oxygen, and neon with neon could be carried out, the research institution further writes. Initial analyses already point to exciting findings and show a new path for researching the so-called quark-gluon plasma, which appeared in the cosmos primarily shortly after the Big Bang.
The Large Hadron Collider is built in Geneva on the border between Switzerland and France in a ring-shaped tunnel. Among the greatest scientific successes of the world's largest research instrument is the detection of the predicted Higgs boson, for which it later received the Nobel Prize in Physics. In the long tunnel, protons are shot at each other with immense energies, and the connected large experiments ALICE, CMS, ATLAS, and LHCb then precisely analyze which particles are produced in these collisions. Through years of work, new insights into the fundamental properties of our universe are gained from the immense amounts of data.
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Due to the immense amount of electricity required for operation, the LHC is always shut down during the winter months, in addition to the multi-year breaks for instrument updates. The LHC was last shut down for an extended period in 2018 and upgraded for the energies achieved thereafter. Next June, the third run is scheduled to end and be converted into the High-Luminosity LHC. This will increase luminosity tenfold compared to the original value, and by the mid-2030s, for example, 15 million Higgs bosons should be produced, compared to about three million in 2017. A first test run was handled well this year but also highlighted the need for upgrades, according to CERN.
(mho)
