Atom-smasher restart delayed further: CERN

Europe's giant atom-smasher, which broke down only days after being switched on with great fanfare, is not expected to restart before the middle of next year, the operators said Monday.

The Large Hadron Collider (LHC), a multi-billion dollar machine designed to shed light on the "Big Bang" which scientists say gave birth to the universe, is still being worked on, a spokesman for the European Organisation for Nuclear Research (CERN) said.

No start-up was planned before the end of May, James Gillies told AFP, adding that an assessment would be made when CERN's governing council meets on December 12.

Hitherto CERN officials had indicated that the LHC could be operational again by the end of April 2009.

The LHC took nearly 20 years to complete and cost six billion Swiss francs (3.76 billion euros, 5.46 billion dollars) to build in a tunnel complex under the Franco-Swiss border.

It was switched on amid much excitement on September 10, but was shut down again on September 19 after a large helium leak.

"The time necessary for the investigation and repairs precludes a restart before CERN's obligatory winter maintenance period, bringing the date for restart of the accelerator complex to early spring 2009," CERN said at the time in a statement.

But Gillies said the maintenance period would last until the end of May.

"There is still a lot of work to do and we want to be sure that everything is in order before starting up," he said. "We will start up the LHC again as soon as possible."

The LHC is a 27-kilometre (16.9-mile) circular tunnel in which parallel beams of protons accelerate close to the speed of light.

It aims to resolve some of the greatest questions surrounding fundamental matter, such as how particles acquire mass and how they were forged some 13.7 billion years ago.