LS1 Report: Summer cool down

As the final LS1 activities are carried out in the machine, teams have been cooling down the accelerator sector by sector in preparation for beams.


The third sector of the LHC to be cooled down - sector 1-2 - has seen the process begin this week. During the cool-down phase, survey teams are measuring and smoothing (or realigning) the magnets at cold. By the end of August, five sectors of the machine will be in the process of cooling down, with one (sector 6-7) at cold.

The LHC Access Safety System (LASS) is now being commissioned, and will be validated during the DSO tests at the beginning of October. As teams consolidate the modifications made to LASS during the shutdown, many points were closed for testing purposes.

The CSCM (copper stabiliser continuity measurement) tests have been completed in the first sector (6-7) and no defect has been found. These results will be presented to the LHC Machine Committee next week. CSCM tests will start in the second sector in mid-August.

Following many months of effort, the teams are at last making good progress in the Long Straight Section. All beam instrumentation equipment around the warm part of the beam tube will be re-installed by the end of this week.

Elsewhere in the machine, teams are celebrating the completion (or near-completion) of work. The last pressure tests were carried out on Thursday, 31 July, and the last short circuit tests will be complete by mid-August.

The SPS beam dump replacement - announced in last week's LS1 Report - has been planned for mid-August.  Otherwise, work on the machine's hardware testing phase continues as scheduled.

by Katarina Anthony