The Large Hadron Collider (LHC) experiment has restarted after a 14-month pause, BBC reports Saturday.

The collider, the world largest particle accelerator, was stopped in September 2008 after functioning for just hours and needed to be repaired over a problem in its cooling system.

On Friday, engineers have made two stable proton beams circulate in opposite directions around the machine, while the team says they may increase the collider's energy to record-breaking levels over weekend.

The LHC is being used to smash together beams of protons in a bid to shed light on the nature of the Universe.

The collider is the world's largest machine and is housed in a 27 km-long circular tunnel beneath the French-Swiss border. The machine, operated by the European Organization for Nuclear Research (CERN), will create similar conditions to those which were present moments after the Big Bang.

During the experiment, scientists will search for signs of the Higgs boson, a sub-atomic particle that is crucial to our current understanding of physics. Although it is predicted to exist, scientists have never found it.

"It's great to see beams circulating in the LHC again," the CERN's director-general Rolf Heuer is quoted as saying while promising to open a bottle of champagne in case the weekend experiments prove successful.