Feature - (Almost) starting up the LHC: a view from the front lines
On Thursday, 8 August, CERN announced that it would make the first attempt to circulate a beam in the Large Hadron Collider (LHC) on 10 September, with the first test scheduled for the weekend of 9 August.
To find out what it is like from the point of view of those actually building the LHC and installing the equipment, iSGTW caught up with Mike Lamont of LHC Machine Operations for a few minutes, just before workers were about to start the initial steps of a preliminary, low-energy, “pre-startup.”
iSGTW: What are your feelings, after all this time and effort?
Lamont: “At the moment, my general feeling is an overwhelming one of relief, actually. We’ve pulled all the bits together; we’ve got the ring more or less cooled now; we’re underway.”
“We’re up to our necks with the detail—and the devil is in the details—but overall I’m feeling relieved.”
iSGTW: If you had to take a guess, what would you expect the LHC to find?
iSGTW: What do you see as the role of grid computing in all this?
iSGTW: Where do things stand right now?
(laughs) “This is as exciting as it gets.”
—Dan Drollette, iSGTW
Overview: what's involved
Starting up such a machine is not as simple as flipping a switch. Commissioning is a long process that starts with the cooling down of each of the machine’s eight sectors. This is followed by the electrical testing of the 1600 superconducting magnets and their individual powering to nominal operating current. These steps are followed by the powering together of all the circuits of each sector, and then of the eight independent sectors in unison in order to operate as a single machine.
By the end of July, this work was approaching completion, with all eight sectors at their operating temperature of 1.9 degrees above absolute zero (-271°C). The next phase in the process is synchronization of the LHC with the Super Proton Synchrotron (SPS) accelerator, which forms the last link in the LHC’s injector chain. Timing between the two machines has to be accurate to within a fraction of a nanosecond.
After the first synchronization, or injection, test on the weekend of 9 August,for the clockwise-circulating LHC beam, the second test will follow over the coming weeks. Tests will continue into September to ensure that the entire machine is ready to accelerate and collide beams at an energy of 5 TeV per beam, the target energy for 2008.
Force majeure notwithstanding, the LHC will see its first circulating beam on 10 September at the injection energy of 450 GeV (0.45 TeV).
Once stable circulating beams have been established, they will be brought into collision, and the final step will be to commission the LHC’s acceleration system to boost the energy to 5 TeV, taking particle physics research to a new frontier.
‘We’re finishing a marathon with a sprint,’ said LHC project leader Lyn Evans. ‘It’s been a long haul, and we’re all eager to get the LHC research programme underway.’