Will There Be LHC Beam This Year? September 23, 2008Posted by gordonwatts in CERN, LHC.
Well… I wrote this post last night – before the press release that arrived in my email this morning at 10:50am (pacific time) – there will be no beam in the LHC until early spring… I’ll leave the rest of the post below, though I don’t know if it has any value at this point… But I’m too lazy to write a new one!
I’m not privy to inside information (if I was I wouldn’t write this post!). But you can do the following calculation yourself.
The LHC is going to be down for 2 months. That means the machine will be cold and ready to start power up in mid November. The current winter shutdown will probably commence at the end of November. That means only two weeks of time to power the machine up, put beam back in, try collisions (at 900 GeV), sync up the RF system and perhaps try acceleration. 900 GeV, by the way, is the beam injection energy: one doesn’t have to commission the whole acceleration sequence in order to run the LHC at 900 GeV.
Not a lot of time. From the accelerator point of view I’m not sure it makes sense. ATLAS and CMS, as well as others, however, are probably dying for any data they can get their hands on. They have had a taste, but even a week of collisions at 900 GeV would go a long way to helping with the commissioning. That isn’t to say that both experiments won’t have plenty to do during the winter shutdown even if the collisions don’t occur. I believe both will want to open up their detectors and get inside to the parts that are not easily accessible, for example.
Finally, there is politics. Closing out the year without collisions will be “a tough beat”. The newspapers are watching everything we do and they will surely report on this as a disappointment. Scientifically (given the information I have – which is the same that everyone else has and is undoubtedly not complete), it seems like the case for beam this year is on thin ice.
This whole post is based on the premise that the problem that occurred is as the LHC accelerator division expects: something that will take one or two days to fix. If a magnet needs to be swapped out with a spare or something similar to that, then I’d guess we will almost certainly not have beam. We should have the answer to that question as soon as they have a look inside the magnet, which will occur when it is warm in a little less than a month. As CERN has said:
“It’s too early to say whether we’ll still be having collisions this year,” said James Gillies, chief of communications for CERN, in an e-mail message.
The winter shutdown is due to the very high electricity costs in Geneva. I’m used to electricity use spiking in the summer as everyone turns on their A/C. Anyone know what causes the high cost in Geneva during the winter?