By Ron Cowen
Efforts to begin operation of the Large Hadron Collider, set to become the world’s most powerful atom smasher, have suffered a major setback. A faulty electrical connection and helium leak in a section of the collider’s 27-kilometer-long tunnel have forced the accelerator into an early — and prolonged — winter hibernation.
CERN announced September 23 that the collider will be shut down until next spring. Repairing the section will take an estimated three to four weeks because it will require a warm-up to room temperature. By the time engineers could cool the section back down to 1.9 degrees above absolute zero, little time would remain to operate before the LHC’s scheduled winter shutdown. (Fuel costs make running the LHC during winter too expensive.)
“The time necessary for the investigation and repairs precludes a restart before CERN’s obligatory winter maintenance period, bringing the date for restart of the accelerator complex to early spring 2009,” according to a CERN press release. “LHC beams will then follow.”
The collider’s tunnel hosts several superconducting magnets. On September 19, a faulty electrical connection between two of these giant magnets in one section of the tunnel led to a major leak of helium, the LHC’s main coolant. Engineers will have to warm up the section in order to repair it.