LS1 Report: Successful tests

At the PS Booster, the new beam dump and the associated shielding blocks surrounding it have been successfully installed and the installation of the beam transfer lines are now under way. The BI.SMH septum magnet has been successfully repaired following a confirmed vacuum leak.


At the PS, the consolidation of the seven main PS magnets has started, and the replacement of the old cooling and ventilation system continues to progress well. At the SPS, the replacement of the irradiated cables in Long Straight Section 1 (LSS1) of the SPS is now well under way and proceeding well.

At the LHC, the Superconducting Magnets and Circuits Consolidation (SMACC) project remains ongoing. The closure of internal sleeves has begun in sector 7-8, and the shunt installations, a major consolidation activity, are progressing well in sector 8-1. The equivalent of more than one sector's outer sleeves (W) have been closed, and leak tests are in progress in several sub-sectors. Seven sub-sectors have passed the tests and another seven will soon be tested.

The inspections to identify defects in the DFBA electrical feedboxes have been finalised: in total, four faulty ones have been identified, with damaged gimbal bellows that will need to be repaired. Two of these replacements are under way, which will require part of the DFBA at LHC Point 6 to be brought up and worked on at the surface in the coming weeks.

All 1,344 DN200 safety valves designed to release the helium in the event of pressure build-ups in the accelerator have been successfully installed.

The X-ray testing campaign in the tunnel, aimed at detecting faults in the machine’s cryogenic distribution system, is ahead of schedule with 80% of the tests already having been completed. Moreover, the first short circuit test campaign will start this week at LHC Point 4, validating the replacement of the water-cooled cables.

Lastly, 17 out of the 18 magnets being replaced in the accelerator have already been reconnected and have successfully passed their electrical tests.

by CERN Bulletin