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LHC will run to end of 2012

LHC tunnel.jpgScientists at CERN are planning to run the world’s most powerful particle accelerator an extra year in a bold bid to find the Higgs particle, a critical part of the mechanism believed to endow other particles with mass.

The decision, which we anticipated in December, means that the Large Hadron Collider (LHC) will run to the end of 2012, rather than stopping in 2011 for a year-long shutdown to upgrade its energy. The plan is the culmination of a week-long meeting in Chamonix, France.

The machine will run at 7TeV through 2011, but could reach 8TeV in 2012 following safety checks. Researchers are concerned about the “copper stabilizers” that support superconducting connections inside the machine. The stabilizers are designed to safely shunt current away from superconducting wires inside the collider, should the wires loose their ability to carry current without resistance. But an investigation following a major accident in 2008 raised the possibility that bad solder joints could cause the stabilizers and wire to separate. If that happened, it could lead to a meltdown that would do massive damage to the machine. There are at least 80 bad an unknown number of stabilizers that need fixing, and it will take over a year to complete the repairs (You can read more about the problem in this excellent story by my arch-nemesis Adrian Cho, subscription required).

Those fixes will be needed before the LHC can reach its design energy of 14 TeV, but now, machine physicists believe that it could reach 8 TeV after some safety checks. The plan is to warm up the troubled sectors at the end of this year and pulse current through the machine while watching voltages carefully. That should give researchers a resistance measurement of the copper that will tell them whether its safe to run at 8TeV energies.

You might wonder why researchers at the LHC would choose to run at 7 or 8TeV rather than just making all the necessary fixes and ramping up to 14 TeV? The answer is that particle physics is as much about the quantity of data collected as it is about the energy of the collisions. Researchers think they have a good chance of spotting the Higgs at 7TeV, if they can collect enough collisions, and running the LHC an extra year will give them what they need. Additionally, the machine is running like a dream, and nobody wants to mess with it when it is on a roll.

The Chamonix workshop concludes today, and a final decision is expected by management on Monday afternoon, says CERN spokesperson James Gillies. “The formal decision will be taken then, but it’s pretty certain that we will run in 2012.”

Image: CERN


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