CERN confirms that LHC will run at 3.5 TeV

Physics Today : CERN’s Director General, Rolf Heuer has confirmed that the Large Hadron Collider will run at 3.5 TeV leading to collisions at 7 TeV when it is turned on in November."We’ve selected 3.5 TeV to start,” said 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 lower energies are because not all the magnets appear to be working at full strength, and the copper stabilizer connections cannot be run at the higher energies.Last year the LHC suffered a critical failure when one of the 10,000 high-current superconducting electrical connections failed. CERN has been cooling down and testing various sectors of the collider in order to track down the bad connectors.The tests on the final two sectors concluded last week and have revealed no more major problems. This means that no more repairs are necessary for safe running this year and next."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."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 in December 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.Gradually the machine will be raised up 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.