After 13 months of repairs and modifications, the world’s largest particle smasher is once again ready to start circulating particles, officials at the European particle physics laboratory, CERN, near Geneva, Switzerland, announced today. The guts of the Large Hadron Collider’s (LHC’s) more than 1700 large superconducting magnets have been cooled with liquid helium to a frigid 1.9 K, and now that the 35,000 metric tons of hardware are cold, physicists can soon resume feeding particles into the machine’s twin rings, says CERN spokesperson James Gillies. “Were back to the more-routine steps that we went through last year,” he says. “So the first injection tests should begin next week.”
The LHC is designed to smash protons together at energies seven times as high as any previous particle collisions in hopes of discovering new particles and even new dimensions of space. The $5.5 billion accelerator broke down last fall just 9 days after physics first passed particles all the way around its two rings, and researchers have been busy fixing it ever since. Physicists are on track to have beams zipping through LHC’s two rings in late November and to collide the counter-circulating beams at a low energy in December. But with many systems to check—including new systems to protect the machine against a repeat of last year’s catastrophe—researcher may not achieve higher energy collisions for data taking until early next year, Gillies says. “There’s still a possibility for December, but more realistically it’s looking like January,” he says. Even then, just to be on the safe side, officials have limited the energy to half of the LHC’s design maximum.