Minutes and Summary

Main purpose of the meeting: Meeting dedicated to post-TS1 activities, special runs and VdM and intensity ramp-up. 

Filip (Introduction)

• Slide 3. Mario confirmed that T2 is installed. Seems to be working but Mario will confirm later this afternoon. 

• Slide 4. Packed schedule, however the access on Monday morning is fixed. Other activities can shift around (earlier or later).

  • Plan of activities for 120m should be clarified with collimation by today. 

    • Request to put a message on page 1 a few hours in advance to warn experts 

• Slide 6. Allocated 6 hours for data taking. If need to be extended, discussion will happen at the moment with the LPC. 

• Slide 8. VdM program

  • Setup/validation will need two validation fills.

• Slide 11.

  • Jorg reminded that ideally we should keep the same bunch intensity throughout the ramp (MPP dictates that it should be as similar as possible to what it will be used for the rest of the year). 

  • 3b fill must remain 3b so as not to activate too much the luminosity detectors ahead of the calibration transfer fill. 

  • Keep the 400b fill to 4 hours and spill over the leftover 2 hours in the 900b to optimize the programs. 

  • Idea is to squeeze ATLAS/CMS to 60cm, then bring one of the two experiments to low mu and then squeeze the other to 30cm. 

    • In total it is expected that it should be anyway 4-5 hours. 

  • CMS would like to have the low mu run in the same step: it will be added to the 900b step after the leftover bit from ATLAS. 

    • Request to prepare the trigger for both the 400b and the 900b in case the 400b needs to be longer for external reasons.

    • ATLAS will do the last hour of scans in the 900b if 400b will be dumped after 4 hours. 

  • ALICE low field data taking is preferred to be done at 1800b. However, they may need two fills with the same filling scheme and flipped polarity. 

    • Filip asked to optimize this, ALICE will look into it.

    • Other possibility would be to merge the 1200b and 1800b fills into two fills of 1500b. To be checked with MPP if this is a possible option.

  • ATLAS prefers the mu scan in the 2400b. CMS in the 1800b, to decouple the program vs ATLAS.

• Slide 13. 

  • Stefano for collimation will get all the information together and will come back.

  • Stefano confirms that first preliminary results show big reduction in background

  • Stefano asked what the collimation strategy is: crystal in the V and standard in H. 

    • Stefano will follow-up if the crystal can also be used in H, that would make the setup faster. Mario confirmed that the physics is in the V, while H is used for calibration. 

• Slide 14.

  • Witold reminded that experiments may need VdM during the pp reference run

    • More discussion will have to happen on this point and there is a bit of time to discuss

  • Jorg commented that some technical preparatory aspects would be desired to be done before the MD+TS to avoid during everything in the same 48h block

  • Jorg commented that to flip the polarity in ALICE is operationally complicated and a few things will be looked at.

    • ALICE confirmed that they would like both polarities. To be discussed.

• AoB: 

  • Filip reminded that regarding the polarity inversion of the triplet, the baseline is to prepare everything for the upcoming YETS, where a hardware test will be done as well as some physics validation that will happen in the LHC in September. No change will happen during the current year. 

    • This is the baseline to be approved on Wednesday at the LMC. 

 

LHCb (Federico on behalf of LHCb Run Coordination)

• Mario commented that we should keep in mind that LHCb will inject SMOG in teh 120m

  • If background is seen as bad then we will need to discuss

• BCM test monday after access

• Pre-data taking will need some scheduling and organization

 

ALICE (Sarah) 

• No Stable Beams declared in the 120m

• Sarah clarified that the low-field data taking needs 8 hours per fill

  • To be discussed and needs to be coordinated

  • Some care would be needed for the polarity flip nd the TPC state

• Sarah clarified that ZDC is only inserted in VdM and ions.

 

CMS (Andrea)

• Ramping up CMS magnet takes about 4 hours

• PU 68 should be ok in CMS with this number of bunches

• Witold expects that burnoff will be small and PU in ATLAS will be close to the target value

• CMS mu scan to be done in the 1800b

 

ATLAS Lumi (Witold)

• Slide 7. Michi commented that something must check the separations at low and high beta. 

• Slide 8. 

  • Target beta* will be calculated in the first hours of the calibration transfer fill. 

  • The scan will go to 0.5 sigmas. 

  • Preferred bunch intensity to 1.4-1.5x10^11 ppb

 

ATLAS (Catrin)

• Slide 4. More investigations needed to understand the drifts.