Some other things in this issue:
I just bought the rights to the Feynman ‘Messenger Lectures’ that he gave in Cornell [University] in the 1960s. The BBC filmed Feynman giving what I think are the best physics lectures I have ever seen. So we are going to make these lectures free for anyone to watch.
The bottom line is that we remain on course to restart the LHC safely this year, albeit at reduced energy.
A tremendous amount of work has been done to fully understand the splices in the LHC’s superconducting cable, one of which was the root cause of the incident last September that brought the LHC to a standstill. We’ve learned a great deal. 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 at around 4-5 TeV per beam. If new evidence appears in the meantime to suggest otherwise, we’ll modify the energy for this year’s run accordingly. The food for thought is that the same tests tell us that before we can run safely above 5 TeV, more work is needed, and this will be carried out in a shutdown starting in Autumn 2010.
Many of you will have heard, or seen on the LHC web pages, that we’re warming up sector 4-5. This sector can be warmed and re-cooled within the time remaining before we inject the first beam of 2009 into the LHC, and doing so 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 80K, indicating a suspect splice or splices. By warming the sector, the results of the test can be checked at room temperature, thereby validating the procedure at 80K. If the 80K measurements are validated, any suspect splices in this sector will be repaired.
From this, it sounds like the current plan is to not wam up the cold sectors, but reach a decision on what the highest energy they can safely run at in case of a quench, given their understanding of remaining problems with bad splices. This might mean running below the planned 5 TeV/beam.
Update: While the CERN DG indicates readiness of the LHC for start-up in “September or October”, the most up-to-date schedule (which somehow came into my possession this morning…) shows powering tests in sectors 4-5 and 8-1 going through the end of October, so machine checkout and first beam not until the beginning of November.
Update: There’s now a press release. According to this, they are now planning to start up at some energy in the range 4-5 TeV, currently 2-3 weeks behind schedule (so start-up second half of October).
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