A joint Fermilab/SLAC publication

LHC will not restart this week


Engineers and technicians may need to warm up and recool a section of the accelerator before they can introduce particles.

Photo of LHC tunnel
Maximilien Brice, CERN

The Large Hadron Collider will not restart this week, according to a statement from CERN.

Engineers and technicians are investigating an intermittent short circuit to ground in one of the machine’s magnet circuits. They identified the problem during a test run on March 21. It is a well understood issue, but one that could take time to resolve since it is in a cold section of the machine. The repair process may require warming up and re-cooling that part of the accelerator.

“Any cryogenic machine is a time amplifier,” says CERN’s Director for Accelerators, Frédérick Bordry, “so what would have taken hours in a warm machine could end up taking us weeks.”

Current indications suggest a delay of between a few days and several weeks. CERN's press office says a revised schedule will be announced as soon as possible.

The other seven of the machine’s eight sectors have successfully been commissioned to the 2015 operating energy of 6.5 trillion electron-volts per beam.

According to the statement, the impact on LHC operation will be minimal: 2015 is a year for fully understanding the performance of the upgraded machine with a view to full-scale physics running in 2016 through 2018.

“All the signs are good for a great Run II,” says CERN Director General Rolf Heuer. “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.”


Like what you see? Sign up for a free subscription to symmetry!


Latest news articles
CERN Courier

Acknowledging that the COVID-19 outbreak threatens the lives and health of hundreds of thousands of people, and affects the everyday lives of millions, the CERN Council has now agreed that it would not be appropriate to release the ESG update.


Many major facilities have essentially shut down, but some are soldiering on.


We’ve paired off eight elite kinds of magnets to battle for the win. Learn about each of the magnets then vote for your favorites in our Twitter polls (in thread).


Alyssa Frederick defended her thesis remotely before the coronavirus outbreak began. Here’s how.