How To Fix a Broken Collider: the LHC's Restart Checklist
Before scientists can put the Large Hadron Collider back to work this month solving the mysteries of particle physics, the LHC’s engineers face critical repairs to the $5-billion device. First up: Fix the 53 superconducting magnets trashed in September 2008 when a power cable broke, causing the magnets to warm above their –458˚F operating temperature and lose conductivity, or “quench.” Then pipes for helium coolant melted, further damaging the magnets. Here, the other key upgrades and a few of the thousand chores still to go: Drill eight-inch relief valves into half of the 1,232 dipole magnets that steer the proton beam around the track, to allow for a controlled pressure release in case of another leak. Install a new quench-protection system, which is 1,000 times as sensitive as its predecessor and shuts off the accelerator if it detects an abnormal voltage increase—an indicator of...