The Large Hadron Collider reached an important milestone last weekend as a beam of ions was injected into the clockwise beam pipe. This is the first time particles have been inside the collider since September, 2008 when physicists were forced to shut down the system because of a massive failure. According to a CERN press release, lead ions were placed in the clockwise beam pipe on Friday October 23, but did not travel along the whole circumference of the LHC. CERN officials still hope for a restart in 2009, with the first circulating beam likely to be injected in mid-November, and the first high energy collisions occurring around mid-December.
CERN said that later last Friday the first beam of protons followed the same route — and then on Saturday protons were sent through the LHCb detector.
They reported all settings and parameters showed a perfect functioning of the machine. In the coming weeks, physicists hope to have the first circulating beam. Then hunt for the elusive Higgs particle will recommence.
Here is an interview with CERN director general Rolf-Dieter Heuer about the switch-on of the LHC.