London: Physicists at CERN, the European nuclear research center, have turned off the particle beams of the Large Hadron Collider for a two-year repair period.
The particle accelerator, which is best known for identifying a particle believed to be the Higgs boson or " God particle" in late 2012, will undergo an unprecedented period of upgrade and repair - dubbed "Long Shutdown 1" - that will allow it to be run at its full design energy for the first time, the Physicists said.
The LHC`s beams were "dumped" early on Thursday morning, but it will take until Saturday morning for the machine`s 1,734 magnets to warm up to room temperature, the BBC reported.
The machine ran at particle energies of 8 trillion electron-volts (teraelectronvolts; TeV) in 2012, up from the prior high point of 7TeV in 2011.
But after the repairing is completed, which is slated for the end of November 2014, it should be set to run at 14TeV - far and away the highest-energy collisions ever attempted by scientists.
"We have been running successfully, but only at half the maximum energy, because we can only safely run the magnets at half the design current," Tony Weidberg, a University of Oxford physicist who works on the LHC`s Atlas detector told BBC News.
A fault in 2008, just nine days after particle beams first circulated at the LHC, caused what is known as a "quench" in a number of the magnets, in turn resulting in a leak of liquid helium and sparking a repair operation that took more than a year.
"After the incident, the long-term plan was to get some running at intermediate energy and then have a long shut-down when we improve the connections between the magnets," Prof Weidberg revealed.
"That`s a major operation, because you have to warm up all these superconducting magnets and go in and do repairs," he added.
But the shut-down schedule also includes upgrades to all four of the LHC`s detectors, the shielding of electronics, and even an overhaul of the ventilation system of the tunnel that houses the main accelerator ring.
After the shut-down conclude, the system will be put through its paces and experiments are expected to resume in February or March 2015.