NPR logo Technical Troubles Stall Particle Collider's Progress


Technical Troubles Stall Particle Collider's Progress

A scientist monitors a computer that tracks protons injected into the Large Hadron Collider, near Geneva, on Sept. 10. Fabrice Coffrini, Pool/AP hide caption

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Fabrice Coffrini, Pool/AP

The lab behind the world's most powerful particle accelerator says the machine will have to be shut down for two months for repairs.

The official startup of the Large Hadron Collider (LHC) was hailed by physicists around the world Sept. 10. A beam of subatomic particles successfully traveled all the way around the machine's tunnel, a critical step toward being able to complete collisions.

But since then, CERN, the Geneva-based lab that operates the collider, has been grappling with technical troubles that have delayed efforts to get the collider fully up and running.

First the lab reported that a 30-ton power transformer had failed, causing problems for a system that cools the collider. The malfunctioning transformer was quickly replaced.

Then, in a statement issued Sept. 20, CERN reported a large helium leak into the tunnel.

"Preliminary investigations indicate that the most likely cause of the problem was a faulty electrical connection between two magnets, which probably melted at high current, leading to mechanical failure," the statement said, adding that there would be "a minimum of two months' down time for LHC operation."

"What we should realize is that starting up the world's largest superconducting particle accelerator is an incredibly complicated job," said Judy Jackson, communication director at Fermilab, the national particle physics lab outside Chicago that is home to the Tevatron.

The Tevatron will hold the title of the world's most powerful collider until the Large Hadron Collider is fully operational.

"We know from our experience in starting up and operating [the Tevatron] that it's a very complex undertaking," Jackson said. "It takes enormous skills and talent. And we've been watching in admiration as our colleagues in Geneva start up the LHC."

Along the way, there are inevitably going to be some setbacks and some glitches, Jackson said. "They're absolutely normal and completely to be expected. They have an enormous program of tests and steps that they need to take in order to prepare for particle collisions."

The LHC is expected to be shut down during the winter, partly to save electricity, so this new delay means that experiments involving collisions may not be possible until next year.