Preliminary minutes of the TREX 14-10-2022

1) Follow-up on the PPS proposal for Run 4 - no presentation given, only free discussion.

• DD and JB commented that they passed the inputs to VSC and waiting for a proposition of feasible layout.
• DD mentioned they are in the contact with survey for potential integration of FRAS solution.
• JS commented that the VSC has studied potential layout and passed the most viable solution to WP15 for integration.
• PF commented Only preliminary integration can be done by WP15, VSC will need to open its own job for detailed integration.
• Mechanical aperture question RDM Q4-Q5 movement with FRAS and static pot
• DD asked whether both Q4-Q5 pot stations needs to be equipped by BPM. RDM said that this is not clear for the moment. 
• JS commented that some of the stations containing only one pot are actually on the double frame. This occupies quite some space which may be used for the layout of the machine.
• PF summed up that the WP15 will held the discussion with VSC to agree on the preliminary appearance of the layout> In the meantime CT-PPS team should discuss aperture related question with RDM.

2) Upgrade of the IP2.X experimental beam vacuum during the LS3

Presentation given by Orlando Santos

• AT commented that the ALICE is fine with the proposition and appreciated some of the details in the new layout. However, he wants TREX gives the green-light as soon as possible as the BP is needed by beginning of the LS3.
• BS commented that the non-shielded bellows are affecting the impedance of the LHC machine and should be always very well justified. The height and number of convolutions should be minimized. Also, that DRFs are much more sensitive to the misalignment. JS commented the bellows will be optimized based on formability and criteria for plastic strain. DRFs can be in case of ALICE easily length-tuned from the Q1L2 side.
• RDM asked if there is a change compared to what was presented before. Arturo answered that this is still valid and the data on the positioning of the equipment were confirmed by LS2 experience.
• FSG commented that the machine protection due to MKI fault should be verified. RDM confirmed that this is the ABT who should give a green-light on the subject.
• A special TREX will be organized to give a final confirmation and LMC approval before the end of year.

3) YETS overview and preparation

Presentation given by Maria Barberan

• RJ comment access via PM18 SND, emulsion replacement intervention, extra iron blocks should be discussed (*comment incomplete)
• MR comment request from ZDC. RL commented that the planning is available. MB said that the access shall be seen in terms of RP VETO.

4) RPD/ZDC

Presentation given by Riccardo Longo

• Comment to be completed*