The LHC's dress rehearsal goes with a hitch.

• Tom Feilden
• Tue 9 Sep 08, 03:09 PM
• Source: BBC
  

The LHC's dress rehearsal goes with a hitch.

Things are hotting up in the main control room here at Cern. We've just been through a full dress rehearsal for the big "switch on" of the Large Hadron Collider - due to take place at 8.30 tomorrow morning.
I watched on a giant computer screen alongside dozens of scientists and technicians as a beam of protons was fired down a linear accelerator, slung round two synchotrons to pick up energy, and finally dumped at the gates of the LHC.
Tomorrow those gates will be open, and - if all goes well - the first proton beam will shoot clockwise round all 27 kilometres of the LHC at very nearly the speed of light.
But it could have been very different. Last night a component on one of the cryogenics units - which cool the core of the machine to minus 271 degrees - snapped, and two sections of the LHC began to warm up again.
"It's just a little piece of wire about six inches long," operations group leader Paul Collier told me.
"But it just goes to show what can go wrong with a machine of this size and complexity."

The problem has now been fixed, and the temperature in both sections is falling back towards absolute zero. "Fingers crossed," Paul Collier says. "We're still on course for tomorrow. But if it happens again now we'll be in a lot of trouble".

But after all, something should go wrong in a dress rehearsal if it's going to be all right on the night...