Minutes and Summary
Main purpose of the meeting:
Planning of 900 GeV commissioning runs
Introduction (Brian)
- LHC schedule on slide 3. First high energy collisions confirmed on July 5th (media event).
- overview of experimental requests of 450 GeV beams on slide 4/5
Comment of JW: multi_24b scheme: better go with indiv's until scrubbing has been done.
Comment of Stephane F.: beam-beam MD optics needs some more discussions (ongoing offline).
Intensity ramp-up on slides 6-9.
Slide 10: ramp-up filling schemes
Comment of JW: SPS still focussing on beam for scrubbing, BCMS comes later.
Next LPC meeting on June 13.
Slide 12: we should start to think about the VdM/LHCf planning in September
Comment from Witold: is any MPP validation needed with more than 3 bunches after TS1?
TBD. Would be good to understand the MPP requirements before discussing the detailed plan.
Comment from Stephane F. : for VdM: how much is it needed to have the witness IP? Why not having the other IPs separated?
Witold: head-on collisions in other IP used for cross-calibration of luminometers.
Update from OP (Jorg W.)
slide 1: main goals for the next 2 weeks.
SB collisions at 900 GeV foreseen around Friday this week.
Cryoplant reconfiguration for high heat load around June 8th.
slide 2: SB at injection:
configuration:
- no crossing angle in IP1/5
- external and internal crossing angles in IP5/8.
In beginning: nominal ring configuration, 1 bunch/injection.
AFP/PPS: need to know plans.
JW would like them in the loss map.
Comment from Mario D.: need operational sequence to be numbered very early. Collimation experts did not tell us that they wanted us in the loss map.
Collision setup on morning of May 24th.
Need some luminometer information, if possible.
First fills this week with 3-4 bunches of 1.1 E11 / beam
Requires quick loss maps and some aperture measurements.
Later can increase number of bunches.
Round table of experiment input
ATLAS (Joerg)
ready for SB collisions this week. Will provide some luminosity-proportial feedback.
No updates on summary of requests.
Horizontal muons:
Last LPC: mistake in number of events requested. Should be 1M per side.
Exact planning depends on ATLAS and collimation expert availability. Not on May 30/31.
CMS (Gaelle)
Last weekend: Issue noticed with handshake. CMS DCS experts working on it. Not preventing injection, but can prevent Tracker HV on when in SB.
Plans for SB: CMS fully on. PPS requested to be a little inserted (1 or 2 cm out of garage), to be seen.
Questions/requests:
- X-position of beamspot was off by 1mm in October 2021, will this be the same?
A(JW): a priory, yes, but let’s see.
- request a small emittance scan at each collision fill
Massi files: restarting the machinery in the coming weeks. Migration to EOS completed. Will test this week.
Description of 900 GeV non-linearity scans on slide 6/7.
Comment from Brian on non-linearity scan filling scheme: in 2021, we did have collisions in IP5/8. But may not be needed.
Comment from Witold: these scans can be very useful to check things for the beam-beam MD. Need to discuss this offline.
Comment from V. Balagura: LHCb interested in collisions all the time (commissioning).
LHCb (Federico)
VELO and SciFi commissioning: need regular access slot every week (daytime, weekday)
SMOG injection: to be rescheduled after OK from vacuum group. First test without beam on Wednesday.
450 GeV collisions: currently scheduled fills overcharged with tasks. Would like extra fills at 450 GeV in June.
Luminometers need few fills to be ready. Requires mini-VdM scan. 70 minutes programme. Some pre-warning needed so experts can be present.
ALICE (Federico)
ready for SB this week.
Caveat: TELL1 board (logic for handshakes) has a problem. Currently workaround. Working on replacing the board.
