The biggest and most expensive machine ever built has finally been switched on. At 8.30am UK time, scientists at the CERN particle physics laboratory began their first attempt to fire a beam of particles around the Large Hadron Collider (LHC), the £3.6bn atom-smasher that will open a new window on the Universe.
The LHC team is initially trying to pass the proton beam around just one of the 27km ring’s eight sectors, to ensure it is properly lined up. A “beam-stopper”, or block, is in place at the end of the first sector, about 3km in, to prevent the particle stream from passing further around the accelerator.
Once the beam is aimed correctly and can be seen passing through the first sector, the team will remove the first beam-stopper, and attempt to fire protons around three-eights of the ring. Over the course of the day, they hope to get it to pass around the entire circuit without touching the sides, and thus to start circulating.
http://www.timesonline.co.uk/tol/news/uk/science/article4722261.ece