Minutes of TREX 17/12/2021 - preliminary version prepared by Josef Sestak

1. General matters

• Request of the LMC to present Forward Physics readiness by February 2022.
• TREX will call for a dedicated meeting to make a summary by January 2022 (date to be decided).

2. Round table for Forward experiments

• CMS ZDC
  • Presentation attached in INDICO.
  • ZDC will prepare and by January discuss internally proposition for new cable routing from the bunker zone. Presentation of the ECR to the LMC should come by beginning of the 2022 (January-February).
  • The change should be ideally implemented for Run 3 however it is not sure whether the time and access constraints allows it.
  • Sorina asked for access by 15th of January for inspection of the zone to make a precise estimation of material and manpower needed. This should be no problem for the machine coordination.
• ATLAS ALPHA&AFP
  • Ivan confirmed the readiness of the Alpha for Run3.
  • There will be still some activities from the side of AFP by the January (TBC).
• ATLAS ZDC
  • Presentation attached in INDICO.
• TOTEM
  • Joachim commented on the readiness of the TOTEM.
  • Installation of the detector packages in progress.
  • Some delay is possible due to the power-cuts in test facility.
  • Additional access after 15th February may be needed to cover all the activities. Short access (one day) will be appreciated not just during the YETS but also during the OP. This will be discussed together with LHC coordination and OP.
• FASER
  • ECR for additional shielding blocks was presented at the LMC.
  • Coordination and transport are aware. Activity still feasible by YETS.
  • All other activities are completed.
• No comments from BRAN, MOEDAL and SND.

Discussion on the schedule with Marzia and Matteo. Baseline is to allow access till 15th of February. Additional access slots may be possible after this date however these needs to be announced to OP and discussed on the individual basis.

3. Recap on integration constraints in the 234m region

• Presentation attached in INDICO.
• Paolo presented two possible integration solutions for zone between Q6 and DFBA.
• Main limitation is presence of DQR modules and cooling station.
• Existing ALPHA stations fits within the slots between DQRs however the request was to use spare reservation of 800mm as in case of P5 (discussion of Maciej, Paolo and Ludo).
• Continue with the studies (not currently HL-LHC baseline) and express potentially the interest of experiments for future spare reservations etc.
• Maciej also asked what is the expected evolution in terms of position of ALPHA racks (currently at RR). Paolo said that he will check this.

4. Update on radiation levels at LSS from Run 4

• Presentation attached in INDICO.
• Paolo presented evolution of the radiation levels in the LSS1 at the recombination region.
• There are three possible strategies to be adopted for the cabling at these regions, general purpose (with risk of early failure), radiation tolerant, radiation hard.
• Zone around the TAXN is already extremely occupied and there may be no space for possible new patch panels.

Discussion between Paolo, Peter, Ludo and Sorina. Ludo stressed importance of having a dedicated follow-up with Paolo on this topic to see what will be the ATS decision regarding new Radiation Tolerant category. Forward physics should adopt the same principles as the machine (applications to be assessed individually based on the criticality of the service, accessibility etc.).

5. Asset replacement request

• Presentation attached in INDICO.
• Stephan presented the new ATS approach to track exchange of the spares in the machine.
• This process will be applicable as well in case of the experimental devices in the LHC tunnel.

6. Validation of the redundant UPS

• Presentation attached in INDICO.
• Alain has presented motivation and modus operandi for test of the F1/F2 non-backed distribution lines as well as the F4 UPS backed lines.
• TREX should pass information to all stakeholders potentially impacted by the tests (schedule within the presentation).
• Owners of the equipment must register themselves to mailing list ups-warning-notifications@cern.ch

7. YETS, activities related to Forward experiments & access requests

• Presentation attached in INDICO.
• Maria gave an overview on the schedule of the YETS and important milestones.
• Important dates for CV and EL maintenance are available on slide 5.
• Status of the Forward Physics activities followed by the coordination in wrapped on slide 6.

8. AOB

No AOB raised. Next TREX by January 2022.

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