The giant machine designed to recreate conditions that existed moments after the big bang will attempt to run with enough energy to break a world record next week.
The Large Hadron Collider, at the European nuclear research organisation (Cern) on the outskirts of Geneva, is expected to generate beams of particles with three times more energy than has ever been achieved before.
The machine, which occupies 27 km circular tunnel 100m beneath the French-Swiss border, is expected to bring the speeding particles together within the next few weeks and continue operating until the end of 2011.
In January Cern managers told staff the machine will close for a year in 2012 for essential maintenance and to install failsafe systems designed to protect the machine when it runs at full power from 2013.
The £6bn collider was built to slam sub-atomic particles together at a maximum energy of 14 trillion electron volts (TeV), but the machine exploded soon after being switched on in September 2008.
That incident shut the collider down for more than a year, while engineers attended to repairs that cost an estimated £24m. In January Cern officials decided to operate the machine at half-power from later this month until the end of 2011.