Latest news from the YETS: all restarting except the LHC

With the closure of the SPS at 3 p.m. on Friday, 19 February, maintenance work is now ongoing only at the LHC. All activities are on track for a smooth restart in a few weeks’ time.


At the LHC, all general maintenance activities are proceeding well and according to schedule. In particular, the electrical tests on the general emergency stops have been completed, while the cooling and ventilation maintenance, including leak repairs at various points, will be completed by the end of this week for the whole machine.

By the end of next week, the teams will also have completed the bakeout and commissioning of all the collimators, while the installation of coaxial cable for clock distribution for CMS TOTEM has been postponed to the Extended Year-End Technical Stop (EYETS), scheduled to start in December.

Following a recent decision, additional electrical tests of the circuits (ELQA and energy extraction insulation tests) for the whole machine have been added to the schedule.

The SPS is currently back in the hands of the Operations team and being prepared for its restart. All planned work was completed on schedule, as well as some additional unplanned activities that were still on going this week. The teams have changed 18 magnets (instead of the 16 originally planned) and have carried out an extensive campaign to identify and remove obsolete cables. A total of 633 IMPACT entries were created for this eight-week YETS.

For several weeks now, the PS and the PS Booster have been back in the hands of the Operations teams. Beams are due to return on 8 March.

by Antonella Del Rosso