Various important upgrades were planned for WP5 in LS2: a first phase of the impedance-reduction program for the secondary and primary collimators in IR7 and the deployment of the dispersion suppressor collimators around IR2 and IR7. Together with the activity related to the consolidation of the collimation program, 22 new collimators were produced successfully, including spare units.

A critical milestone was achieved in Dec. 2020, when the last 2 planned collimators were installed. This completed the planned installation works for WP5, which involved the installation of 8 new secondary collimators (TCSPMs) in IR7, 2 dispersion suppressor collimators (TCLDs) around IP2. In addition, 4 primary collimators of IR7 were replaced with the new design TCPPM that adds in-jaws beam position monitors and new low-impedance material, un-coated Molybdenum-Graphite, the same used — with Mo coating — for the TCSPMs. Two new passive absorbers were also installed in IR7 to improve the lifetime of the warm magnets that are subject to heavy radiation doses.

The installation of the TCLD collimators around IR7 has been postponed following the decision not to install the 11 T dipoles in LS2. Crystal collimation instead will be used for ion beam collimation in Run 3. This poses a new challenge for WP5, as we are now planning an upgrade of the crystal collimation system in IR7, with new installations already planned in the YETS2021-22 to prepare the first year of operation in 2022. Stay tuned! 

By S. Redaelli, WP5 Leader, and I. Lamas, TCD section.

Related photos: link.