PARIS—Particle physicists and science fans everywhere knew that the European particle physics laboratory, CERN, near Geneva, Switzerland, would shut down the Large Hadron Collider (LHC), the world's largest atom smasher, for all of 2012 for repairs. Many expected that the shutdown would stretch to more than a year, which CERN officials confirmed today. But most probably did not expect CERN to idle all its other accelerators at the same time, shutting down a variety of smaller projects and forcing hundreds of scientists not working on the LHC to take an unanticipated break in data taking, as lab officials are considering. The longer shutdown could be a chance for U.S. scientists working on the Tevatron at Fermilab in Batavia, Illinois, if researchers there can persuade lab management to keep the machine going instead of shutting it down in 2011 as currently planned.
Most crucially, the CERN brass say the shutdown will allow them to redo thousands of unreliable solder connections between the accelerator's massive superconducting magnets and make other modifications. Today, Stephen Myers, CERN's director for accelerators and technology, presented a schedule to the 1000 physicists gathered here for the annual International Conference on High Energy Physics that the shutdown that shows the downtime stretching 15 months. Even with all that time, CERN will need all the workers it can get, which is why they may shut down all eight of the lab's accelerators. "Our plan is to stop all of the accelerators at CERN and redeploy manpower," Myers says. The final decision on that proposal must be made by the CERN Council, which comprises representatives from the lab's 20 member nations.
That will most likely come as hard news to hundreds of physicists working on smaller experiments fed by those other accelerators, such as the 200 working on the OPERA neutrino experiment in the underground Gran Sasso National Laboratory in Italy. For a year, CERN will stop sending a beam of neutrinos to Gran Sasso, turn off the flow of antiprotons for antihydrogen experiments, and cease the production of radioactive isotopes for nuclear science experiments. But that's a price CERN is willing to pay to get the LHC running at full energy and intensity, Myers says: "Our priority is the LHC." He notes that CERN also stopped all of its accelerators in 2005 to focus on problems in the LHC's construction.
The LHC cannot run at full energy until the problematic connections are reworked.

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