Gathering positive experience

Last Monday, the new CERN Machine Advisory Committee (CMAC) met for the first time, and we had good news to tell its members. Over the weekend, injection tests for both LHC beams were successfully carried out. In other words, we’ve had beam in the LHC for the first time since September 2008. That’s a good feeling, but it’s no reason for complacency. There’s still a long way to go before first physics at the new energy frontier.

As the Bulletin has reported over recent weeks, we’re gathering a lot of positive experience with the new quench detection and protection system (QPS), which is already allowing us to monitor the LHC far better than we were able to in the past. So far, the QPS for three of the LHC’s eight sectors has been put through its paces, and we’ve also power tested those sectors to 2000 amperes, the equivalent of around 1.2 TeV per beam. The next step is to slowly increase the current to 4000 amperes, and then on to 6000 amperes, the current needed for 3.5 TeV running. This will take a few weeks.

The road from here should take us to the first circulating beams of 2009 by the second half of November, with collisions at injection energy following soon after. If things go well, we may have the first high-energy collisions before the end-of-year break, which would be the best Christmas present I could wish for. Starting up a new accelerator is a complex process, however, and we’re modifying the LHC schedule on a weekly basis in the light of progress. Just last week, we detected a helium leak that diverted attention from other things. Thankfully that turned out to be manageable, and did not slow us down. Commissioning the LHC for 3.5 TeV is the top priority now, and will take several weeks.

The CMAC gave a strong vote of confidence to our prudent, step by step, approach to getting the LHC running again. At the end of the meeting I had a word with Thomas Roser, Chairman of the CMAC and Associate Chairman for Accelerators at the Brookhaven National Laboratory in the USA. "It’s good to see things going so smoothly at this stage in the project," he told me. And he should know, having lived through the start-up of another groundbreaking superconducting particle accelerator, Brookhaven’s RHIC, ten years ago.

Rolf Heuer