On Friday, Sept. 19, at midday CERN time, one sector of the Large Hadron Collider warmed abnove superconducting temperature leading to the release of helium gas into the tunnel. The incident is likely due to a faulty electrical connection between two magnets, according to a CERN statement.
To repair the connection, the sector of magnets will need to be heated to room temperature. The heating, repair, and recooling process will take about two months to complete. CERN still hopes to have first collisions before the scheduled winter shutdown, which happens each year due to the much higher energy prices in the Geneva winter.
Last week, a power transformer on the surface failed, but was quickly replaced allowing the affected sector to be cooled again. These kinds of hiccoughs in starting up a large collider are not surprising as the LHC has millions of critical components. Every major accelerator and collider in past decades has faced these kinds of teething problems during the startup phase and scientists and engineers are confident that all issues with the LHC will be resolved satisfactorily.