Staged implementation of low-impedance collimation in IR7: plans for LS2

The HL-LHC upgrade baseline foresees to replace all secondary collimators of IR7 until LS3 in order to ensure a sufficient margin for beam stability with the high-brightness upgraded beams. The present TCSG design is based on a carbon-fibre composite (CFC) material and will be replaced with a new low-impedance design (TCSPM). The TCSPM design is based on a Molybdenum-Graphite (MoGr) composite material coated with pure Molybdenum. These collimators also embed in-jaw beam position monitors (BPMs) for a fast alignment and local orbit monitoring as well as an additional BPM for measurements of the orbit transverse to the collimation pane. A staged deployment strategy of the low-impedance upgrade is proposed that foresees to install 4 TCSPM collimators per beam in LS2 and the remaining 7 in LS3. In this note, the slots to be equipped with the TCSPM in LS2 are defined.