Minutes and Summary

Main purpose of the meeting: This meeting is again dedicated to short-term activities and post-TS1 planning.

Filip (Introduction)

• Slide 3. MD1 will start on Tuesday at 3pm and ends on Sunday at 3pm. MD1 will be followed by two shifts of low intensity OP commissioning work (see Jorg’s slide). 

• Slide 5. Repeated fill number: experiments should decide what is best. The LHC will skip fill number 8897, LPC will handle it internally. 

• Slide 6. No clear culprit identified in the room for the different in luminosity (>4-5%) between ATLAS/CMS

  • After discussion at MPP’s last Friday, a possible implementation of leveling by changing the crossing angle by 5% is under study and possible soon approval.

• Slide 7. INDIVs will be kept for the ramp-up filling schemes (2 up to 1800b, then 1, then when agreed, the INDIV will be removed for the filling scheme shown in the slide).

• Slide 8. Does not seem necessary to perform any bakeout during TS1. 

  • ATLAS’s background measurement is indeed improving as the vacuum around the valve reconditions. 

• Slide 10. See Jorg’s slides about the schedule after TS1.

• Slide 11. See Jorg’s slides about details regarding VdM1.

• Slide 13. MPP proposal for post-TS1 ramp-up plan to be presented at Wendesday next LMC. 

  • Experiments asked to have a look and send feedback if needed.

• Slide 14. Roderik commented that opening TCL6 open for the 48h before the very high beta* run should be ok

  • To allow for “cool-down”, possible to investigate some OP work in the shift(s) before the high beta* run to minimize the impact on ALFA

  • The run, as of now, is *not* shifted in the planning.

    • However, if ALFA will not be able to take good data in actual background conditions then we will rediscuss whether the run to be shifted. It cannot be decided before seeing the first beams.

    • Mario asked about plans for the background measurement. Jorg commented that it cannot be done before week 27 (28 would be better).

      • Silvia - ATLAS commented that the background test should also be done AFP retracted and TCL6 (more) open. 

    • Mario suggested having a follow-up meeting, possibly at the end of this week.

    • Filip commented that indeed if the shift would be possible, then the background measurement can be done in week 29 and then there would be enough time. 

  • Stable Beams declaration is contentious as the machine is not validated for SB. 

    • ATLAS commented “that it would help a lot, but if it is difficult it can be dealt with”

 

Jorg (post-TS1 planning and activities).

• Slide 3.

  • AFP alignment to be discussed, as it makes more sense to do it closer to when data will be taken (closer to VdM2, as anyway lossmaps will be done in September). 

  • Alignment of TOTEM RP will be discussed at the next LMC and if approved, then it will be needed. 

  • Roderik asked if anything is planned for the new crystal collimator that has been installed in TS1. 

    • Filip commented that a slot will be found and discussed. The earlier the better and when a cool down fill is needed and when people are available in those time slots.

• Slide 4. 

  • If de-squeeze to 3/6km available, then after 120m commissioning can then just continue to full de-squeeze. Ideally, then the entire post-MD1 pre-TS1 period can be filled as cool-down shifts.

• Slide 5.

  • Note access for T2 removal in CMS slotted for Monday 26 morning. 

  • Witold and Filip noted that 140b calibration transfer fill should be done before the 75b fill.

  • Silvia commented that in the 400b fill, they need more than 2 hours for the low mu fill. 

  • It is now agreed that the AFP alignment will happen later towards VDM2

  • If TOTEM RP alignment will happen, ideally should be done before the lossmaps

• Clarified that for the 120m beta* run, SB will not be declared. 

 

ATLAS (Silvia) 

• Slide 5. 

  • AFP BBA will not happen now. Optics is the same as in 2022.

  • Agreed on a plan for the background  measuring in week 29. 

• Slide 6.

  • More discussion will happen this and next week regarding the plan for the triplet polarity change.

    • New optics with improved acceptance (also in IP1) should be available and will come soon.

  • More discussion will happen in September regarding physics and detectors,

    • Current baseline is that if the inversion of the polarity happens, then AFP and PPS will have zero acceptance.

    • Mario commented that there are plans for PPS to rotate the pots in the horizontal plan and if the triplet polarity change happens then the rotation of the pots will be requested. 

• Slide 7. 

  • Filip was informed that work has happened (on non-factorization effects), but no conclusions are available yet. 

 

ALICE (Sarah) 

• Slide 6. Filip commented that a shift is needed by the machine, the ramp-up fills would be the best moment. 

 

LHCb (Elena)

• Filip commented that the mini-Vdm for LHCb (+/-3 sigma) will be slotted in the ATLAS/CMS VdM scans.

 

CMS (Gaelle)

• Jorg and Michi commented that a “check” on the fill number change will be studied. 

• No clear indication from CMS on the bigger difference that is observed between ATLAS/CMS

  • Filip commented that post-TS1 we would like to freeze the calibration changes, until a big change is observed (result from VDM?). 

AoB:

• Michi commented that after TS1 they would like to transmit DOROS via the secondary system if the primary fails. This will come as an array via DIP. 

  • Filip asked Michi to compile the request in an e-mail and circulate it. 

• Next meeting is planned for Friday 23rd June at 2pm, before the post-TS1 work.