Programme for VDM measurements Friday Oct 15 Phase I: Getting ready 06:00 Started BI checks without beam (BCT) 07:03 S81+LHCb dipole tripped => precycle needed …. delay 09:45 Started filling… some probs with XPOC & filling scheme 11:35 16 bunches ready at 450 GeV, checked , 12:05 Ramp started 12:42 Squeeze started 13:05 Squeeze finished 13:12 Collapsed, optimize IPs…
Programme for VDM measurements Friday Oct 15 Phase II: VDM scans proper 13:43 Started IP8 vdm scans 14:58 Finished IP8 vdm scans 15:18 Started IP5 scans 16:17 Finished IP5 scans 16:31 Started IP2 scans 17:50 Finished IP2 scans IP5: +1 hour Oct 1
Programme for VDM measurements Friday Oct 15 Phase III: complementary measurements 17:55 Started IP8 length scale calibration 18:05 Finished IP8 length scale calibration 18:10 Started IP5 length scale calibration 18:26 Beam dump LBDS vac gauge off ???... one plane done, other plane just started Could not do (30 minutes more!): longitudinal scan Simon’s check of parallel IP optimisation and ALICE length scale calibration (no Silicon tracker)
Overview whole programme CMS scans LHCb scans ALICE scans
Overview all scans LHCb scans CMS scans ALICE scans
LHCb scans
CMS scans
ALICE scans
Did it go well ? Phase I: expected ~3hours , took ~7hours (3 ¾ hours lost by Pt8 trip) Phase II and III: What was originally planned to take ~5 ½ hours of stable beams was compressed into ~ 4 ¾ hours (excluding what could not be done due to dump) Beams were good, some more ghost charge (satellite bunches) than usual ? should not be a problem for this time (on the contrary?)
Summary Very good beam conditions (emittance, charge, special pattern…) but 3-4h delay du to pt 8 trip Completed all VDM Excellent support and participation from BI, OP, ABP, … online indications that beam current errors are small Still to do: length scale calibrations in IP5 and IP2 can be done in physics longitudinal scan tests can be done in physics, but better test once in a low intensity fill ? MANY THANKS