GENEVA - Scientists running the world's largest atom smasher used the $10 billion machine's accelerator to speed up proton beams for the first time Tuesday, in a step toward experiments about the makeup of the universe.

"It was just a preliminary test," said James Gillies, spokesman for the European Organization for Nuclear Research. But the machine showed it could raise the energy of the proton beams whizzing around the massive machine by an initial 10 per cent.

"It's good," Gillies said in an interview. "It's all going very well."

The new step in the startup phase indicated continued smooth operation of the Large Hadron Collider since its repairs following a spectacular collapse last year.

It followed a speedy startup beginning Friday night when the LHC injected the first beams, later getting them to run in both directions and even record the first proton collisions at high energy to test the detectors of what that will reveal about the insides of the subatomic particles and forces.

Gillies said Tuesday that the energy of the proton beam was increased to 540 from 450 billion electron volts, still a long way from the power that will be needed for new discoveries in the makeup of the universe and matter.

"They set in process the procedure to ramp the machine up to the 1.2 TeV (trillion electron volts) that we want to get to this year," Gillies said. That would make the LHC the world's most powerful collider, overtaking the Tevatron at Fermilab near Chicago, which operates at 1 trillion electron volts.

The accelerator automatically stopped when it rose to about 540 billion electron volts, about 90 billion electron volts more than the energy at which the Large Hadron Collider has been operating so far, Gillies said. That ended the initial run of attempts with the machine, which has been stopped so physical checks and any needed improvements can be done, he said.

The first science test of the LHC will come in the first two months of 2010, when scientists plan to start deliberately crashing protons into each other to see what they can discover about the makeup of the universe and its tiniest particles.

The collisions - seen by massive detectors - were a side effect of collisions when the beams travelling in opposite directions crossed in the detectors, which recorded them at "experiments" in rooms the size of cathedrals about 100 metres underground around the collider.