Friday 19 September 2008


Yesterday, CERN was buzzing with rumours that the first LHC collisions should take place during the week-end. This morning, however, there was a major quench in Sector 3-4. As you can see here, some magnets in the affected sector are now at almost 100K. LHC-progress addicts report that pretty scaring entries were appearing in the LHC logbook this morning (fire alarm, power failure, helium leaking into the tunnel), though all the record seems to be deleted now. Although there has been no official news so far, this problem appears to be serious (unlike all the problems reported by the media earlier this week) and may cause a lot of delay. It is not certain if operation will be resumed before the winter shutdown. So you can relax for the moment.

Update: there is a press release explaining what happened:
During commissioning (without beam) of the final LHC sector (sector 34) at high current for operation at 5 TeV, an incident occurred at mid-day on Friday 19 September resulting in 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 crucial information is
(...)it is already clear that the sector will have to be warmed up for repairs to take place. This implies a minimum of two months down time for the LHC operation...
In fact, warming up and cooling of one sector usually takes 3 months, so there is little hope for a beam before the winter shutdown (end of November).

Update 2: :-(


De Bunker said...

The comments on Physics World are mind-boggling.

It continues to baffle me why the first response by many people to science news articles is to assume that everyone involved is a complete idiot.

Anonymous said...

BBC News now says the damage is so bad it will take a couple of months to repair:

Can anyone in the know comment?

Anonymous said...

Seems true... CERN press release

Anonymous said...

was this LHC breakdown predicted by Holger B. Nielsen, Masao Ninomiya, arXiv:0707.1919?

Anonymous said...

Only if it keeps breaking down again and again and again. ;)