Large Hadron Collider 'short circuit' could push restart back by weeks

A short circuit in the Large Hadron Collider has pushed back the restart date by a few weeks, Cern has announced.

The LHC was due to be fired back up after its two year hiatus this week, but an unforeseen problem in one of the machine's eight sectors has caused delays.

"LHC run 2 is coming ever closer," Cern said in a statement. "Seven of the machine's eight sectors have successfully been commissioned to the 2015 operating energy of 6.5 TeV per beam, and the eighth is not far behind.

"There will, however, be no circulating beam in the LHC this week. An intermittent short circuit to ground in one of the machine's magnet circuits was identified on 21 March and is under investigation."

They said the issue is well understood, but could take some time to resolve because it is in a cold section of the machine, so a repair might require warming up and re-cooling before it is fully restarted.

Frédérick Bordry, director for accelerators for Cern, said: "Any cryogenic machine is a time amplifier, so what would have taken hours in a warm machine could end up taking us weeks."

The organisation noted that the issue could be resolved in just a few days, but a full assessment is ongoing and a revised schedule will be announced soon.

Cern director general Rolf Heuer said: "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."

The second run of the LHC will provides scientists the opportunity to answer questions about theories like the Big Bang and on particles that acted as the building blocks of the universe. It will also look to find out about dark matter – the substance that makes up most of the universe.