Large Hadron Collider to start up at half power

Posted by Emma Woollacott

Geneva, Switzerland - The European Organization for Nuclear Research (CERN) is to have another shot at getting some useful information out of the Large Hadron Collider (LHC).

It aims to have the particle collider up and running again by November - albeit at half power, running at 3.5TeV per beam. Tests on its high-current electrical connections were completed last week, and indicated that no further repairs are necessary for safe running.

The LHC has suffered a series of problems since its first firing nearly a year ago, including electrical trouble and leaks in its vacuum tube.

"We've selected 3.5 TeV to start," said CERN's Director General, Rolf Heuer, "because it allows the LHC operators to gain experience of running the machine safely while opening up a new discovery region for the experiments."

The procedure for the 2009 start-up will be to inject and capture beams in each direction, take collision data for a few shifts at the injection energy, and then commission the ramp to higher energy. The first high-energy data should be collected a few weeks after the first beam of 2009 is injected.

The LHC will run at 3.5 TeV per beam until a significant data sample has been collected and the operations team has gained experience in running the machine. Thereafter, with the benefit of that experience, the energy will be taken towards 5 TeV per beam. At the end of 2010, the LHC will be run with lead ions for the first time. After that, the LHC will shut down and work will begin on moving the machine towards 7 TeV per beam.

"The LHC is a much better understood machine than it was a year ago," said Heuer. "We can look forward with confidence and excitement to a good run through the winter and into next year."