Large Hadron Collider Back Online Following Two-Year-Plus Refit
The news of the LHC's firing back to life was especially gratifying, as early last week it looked as though the resumption of proton-smashing by the LHC would be delayed another few months when a short circuit was uncovered in one of the Collider's dipole circuits mere days before particle finding work was set to resume. Engineers, though, quickly located the problem - a small piece of metal debris - and removed it, and the LHC restart was right back on track.
A complex instrument such as the LHC takes some time to come back online, and for the past few weeks it has been prepared to once again receive beams of protons shooting around the 17-mile Collider at nearly the speed of light. Then, at 10:41 GMT+1 on Easter Sunday the first beam of protons made a circuit around the $4.4bn LHC, with a second beam completing a lap in the other direction at 12:27 without incident.

The Large Hadron Collider restart was accomplished with relatively weak beams of protons, however within weeks the energy of the beams will be juked up to the target level of 13 TeV (teraelectronvolts) — almost twice the level possible before the refit — with the resumption of actual particle collisions set for June.