Workers have installed the last magnet for the world's new highest-energy particle smasher, the Large Hadron Collider (LHC). The installation marks an important milestone; however, researchers still may not get the collider completed in time to start it up in November as planned.
Under construction at the European particle physics laboratory, CERN, near Geneva, Switzerland, the LHC is arguably the biggest, most complex, and most ambitious science experiment ever attempted (Science, 23 March, p. 1652). The 27-kilometer-long collider will smash protons into protons at unprecedented energies. Out of the collisions could spring new fundamental particles, such as the long-sought Higgs boson, which is thought to give all other particles their mass. The LHC could also produce particles of dark matter, the mysterious stuff whose gravity holds the galaxies together, or even miniature black holes. But first physicists must get the $3.8 billion machine finished and running.
Workers could have lowered the last 15-meter-long, 35-metric-ton magnet into the tunnel a few weeks ago. But CERN officials held off to stage a ceremonial lowering to honor the team that installed the magnets, which are the heart of the machine. CERN Director General Robert Aymar notes that the team worked "day and, mostly, night and [on] weekends" to get the job done.
Even with all the major pieces in place researchers will be hard pressed to get the LHC running this year. They suffered a set-back last month when one of 24 key focusing magnets broke during a test because of a design flaw (Science, 6 April, p. 31). This week, researchers settled on a plan to fix the flaw without pulling the magnets out of the tunnel, says CERN's Lyndon Evans, who directs LHC construction.
Even discounting that problem, researchers are weeks behind schedule. Physicists had hoped to run the LHC for a month starting in November, before shutting down for the winter, when electricity costs spike. Banging out collisions during that "engineering run" would have allowed them to spot and fix problems before starting to take data in earnest next spring. Now, Evans says, even under the best of circumstances, researchers may have to forego the collisions and content themselves with just coaxing protons around the ring for a couple revolutions--which would be a bit like just starting a new car, instead of taking it for a test drive. Or researchers may have to give up on the engineering run altogether.
Lab officials will decide shortly whether there will be an engineering run or not, Evans says: "All these maybes, in a couple of weeks they will become facts."