London, Oct 17 : Investigation by CERN has revealed that the major helium leak that caused the Large Hadron Collider (LHC) to be shut down until the spring was caused by a faulty electrical connection between two magnets.
The LHC is the world's largest and highest energy particle accelerator complex, intended to collide opposing beams of protons with very high kinetic energy. The LHC circulated its first particle beams on 10 September 2008, but a few days later had to suspend operations due to equipment failure.
According to a report in the Times, inspections of the section of the atom-smasher that were damaged by the accident on September 19 have confirmed the suspected root of the problem, which has delayed its first particle collisions for several months.
Reprts indicate that a faulty connection between two magnets caused the leak out of helium, thus triggering a shutdown, which will delay LHC's operation for two months.
"This incident was unforeseen, but I am now confident that we can make the necessary repairs, ensure that a similar incident can not happen in the future and move forward to achieving our research objectives," said Robert Aymar, director general of CERN.
Proper safety procedures were in place at the time of the incident, and nobody was put at risk.
Further investigations are continuing, so that engineers can make recommendations about how to prevent a repeat.
The accident has caused so lengthy a delay because a section of the LHC's 17-mile (27km) tunnel had to be warmed up from 1.8 degree Celsius above absolute zero to close to room temperature to allow engineers to inspect the damage, a process that took several weeks.
It was not then possible to re-cool the tunnel before the particle accelerator's scheduled winter maintenance shutdown.
The first collisions, to calibrate detectors that could find the Higgs boson and solve mysteries of the Universe, have now been postponed until next year.
Despite the shutdown, the LHC will still be officially inaugurated on October 21.