Geneva - Scientists have again pushed back the restart date of the giant particle accelerator along the French-Swiss border by another six weeks, CERN announced, saying even this schedule was "tight."

By September, the Large Hadron Collider (LHC) should be operational again with particle collisions set to take place about a month later, the announcement made late Monday said.

The LHC, operated by the European Organization for Nuclear Research - known by its French acronym CERN - has been turned off since September last year following a malfunction which caused damage to integral parts just about a week after the first experiment.

The delay in restarting was said to be mostly related to the installation of better safety and protection systems.

Scientists have been working to create the LHC for about 20 years, and are aiming to send two proton beams into direct head-on collision nearly at the speed of light. They hope this will recreate conditions just after the Big Bang, which most scientists accept as the origin of the universe.

Once the machine was operational again, hydrogen atoms would again be inserted into the LHC and sent around a 27-kilometre ring, in a tunnel 90 metres below ground.

The collision of the atoms' protons would take place within a month and discoveries would be likely over the following year. (dpa)