Electrical fault delays LHC start-up

Back down the tunnel: technicians will soon be repairing an electrical fault somewhere along the LHC. (Courtesy: CERN/Maximilien Brice)

By Hamish Johnston

Today I was planning to write a cheerful blog celebrating the first circulating proton beams in the Large Hadron Collider (LHC), but sadly the particle gods are not smiling down on CERN this week. Accelerator physicists in Geneva have identified an electrical fault in one of the collider’s magnet circuits and plans to restart the giant machine this week have been put on hold – possibly for several weeks.

While CERN says it is dealing with a “well-understood issue”, it is possible that the affected magnets will have to be warmed up from liquid-helium temperatures to fix the problem and then cooled back down again. “Any cryogenic machine is a time amplifier,” said CERN’s director for accelerators, Frédérick Bordry, “so what would have taken hours in a warm machine could end up taking us weeks.”

Given the previous disaster at the LHC caused by a bad electrical connector, I’m guessing that physicists will be happy to wait a few more weeks for the first possible glimpses of physics beyond the Standard Model .

CERN’s director-general Rolf Heuer put a positive spin on the setback: “All the signs are good for a great run 2. In the grand scheme of things, a few weeks’ delay in humankind’s quest to understand our universe is little more than the blink of an eye.”

In the meantime, you can keep up with the heating and re-cooling of magnets – and eventually the first collisions – at the LHC Dashboard. Just click on the “Cryo-Status” tab at the bottom of the page to see the temperatures of the various sectors of the collider.