A detailed check of the world's most powerful atom smasher -- the Large Hadron Collider (LHC) -- has shown that it is 'performing well,' the European Organisation for Nuclear Research, known as CERN, has said on its website.

The atom smasher, running at a low energy, was restarted last Saturday. The first protons were injected into the LHC following a pre-New Year technical shutdown and travelled in both directions successfully.

'The circulating beams marked the end of a 10-week particle-free hiatus for the world's largest particle accelerator, during which LHC scientists and engineers prepared the machine for its biggest challenge yet, particle collisions at an energy of seven trillion electron volts (TeV),' Symmetry magazine said last week.

'The beams also mark the beginning of the LHC's first long run, expected to last until at least mid-year 2011,' it added.

In 2011, the collider will be shut down again to prepare it for its intended collision energy of 14 TeV.

The 4.9 billion dollar-international LHC project has involved more than 2,000 physicists from hundreds of universities and labs in 34 countries since 1984. Over 700 Russian physicists from 12 research institutes have taken part.

Experiments using the LHC were suspended in September 2008 shortly after a successful start, due to a malfunction of two superconducting magnets and a subsequent helium leak into the tunnel housing the device.

Work to repair and upgrade the collider after the breakdown cost almost 40 million dollars and took more than a year.

A system to protect it from such accidents, named the Quench Protection System, was installed, and the first beams were injected into the LHC Nov 20 last year.