Preparing for the re-start

The end of a Council week is a good opportunity to bring you up to date with the status of the LHC, and I’m pleased to say that we had a good deal of positive news to report to the delegations today. The bottom line is that we remain on course to restart the LHC safely this year, albeit currently about 2-3 weeks later than we’d hoped at Chamonix.

This Council week has seen many important developments for our future. I am particularly pleased that Council approved the Medium Term Plan and budget for 2010 as presented by the management. This is a strong vote of confidence in all of you. The President of Council is reporting on Council business in this issue of the Bulletin, so I will focus on the status of the LHC.

A tremendous amount of work has been done to understand fully the splices in the LHC’s superconducting cable and copper stabilizers. One of these splices was the root cause of the incident last September that brought the LHC to a standstill. We’ve learned a great deal since then. It’s mostly good news but there’s also plenty of food for thought. The good news is that all the measurements done so far indicate that we will be ready by September or October to run the LHC safely in the range 4-5 TeV per beam. The food for thought is that the same tests tell us that before we can run safely above 5 TeV, more work is needed. This will be carried out in future shutdown periods.

Many of you will have heard, or seen on the LHC web pages, that we’re warming up sector 4-5. This will give us increased confidence that we fully understand the splices. We’re warming up this sector because we have developed a new non-invasive technique for investigating the splices. The sector has been measured at a temperature of 80 K, indicating at least one suspect splice. By warming the sector, the results of the test can be checked at room temperature, allowing us to confirm the reliability of the test at 80 K. If the 80 K measurements are confirmed, any suspect splices in this sector will be repaired. More importantly, validation of the 80K measurements will allow the splice resistance in the last three sectors to be measured at this temperature, thereby avoiding the time needed for re-warming. When these measurements are done, we’ll have to balance energy against time: 4 TeV should require no further repairs, for example, whereas 5 TeV could call for more work. The measurements in these last three sectors will allow us to make that decision, determining the initial operating energy of the LHC in the range 4-5 TeV, and the start date for the first run.

The Bulletin will continue to keep you up to date with LHC progress, and if you are interested in a full report, Steve Myers at CERN and Jim Strait at Fermilab will be making detailed presentations on 2 July. Steve’s presentation will be webcast at http://www.cern.ch/webcast.

Rolf Heuer