LHC 2012 - latest news

Week 43: Machine coordinators: Gianluigi Arduini, Eva Barbara Holzer

Luminosity production and 1km b* run

Date

Summary

Link to report from morning meeting

Monday 29 October
  • VdM scan CMS end of fill 3236
08:30 meeting
Sunday 28 October
  • 04:30 (winter time): electrical perturbation on 18 kV in point 1 effect of EDF perturbations. Trip of RD1.LR1 & LR5 and RD34.LR3 trip (we were going to dump anyway…). End of fill #3232. ~160 pb-1 in 10.5 h.
  • 05:30 Ready at injection. No injection permit from LHCb
  • 06:00-06:34 Storm of electrical glitches: several trips (RDs, LHCb dipole, RBs)
  • 09:00 Pre-cycle
  • 11:11 Beam dump at start of ramp due to noise on MKD generator
  • 13:20-14:20 Access (ATLAS, LBDS). No beam in the SPS.
  • 15:30 Beam back in the SPS
  • 16:00-16:30. Test of gated BBQ on B2
  • 18:09 STABLE BEAMS #3236. Initial luminosity 7.3x10^33 cm-2s-1, ALICE: 7.7E30 cm-2s-1
09:00 meeting
Saturday 27 October
  • 03:37 stable beams fill 3229; Initial luminosities ATLAS/CMS: ~7.6 E33 cm-2s-1, ALICE very low at  ~3E30 cm-2s-1. Integrated lumi in 4h23’: ATLAS/CMS: 87 pb-1
  • 7:58 beam dump by LBDS B2, access needed; access for undulator repair in parallel. 
  • 10:32 LBDS ASIBUS card (safety bus) replaced
  • 11:50 Undulator (L&R of point 4) power converters repaired. Synchrotron light monitors available at low energy. Insert BSRT mirror for B2 (F. Roncarolo)
  • 14::33 STABLE BEAMS #3231. Initial luminosity ~7.4x1033 cm-2s-1
  • 16:29 Trip of RCBWV5.L7B1. End of fill #3231. ~32 pb-1 in 2 hours
  • 18:50 STABLE BEAMS #3232. Initial luminosity ~7.4x1033 cm-2s-1
09:00 meeting
Friday 26 October
  • 00:26 Trip of RCBXV3.R5 (power converter): End of fill #3223. 34 pb-1 in 1.5h
  • 02:00-02:30 Access for repair of RCBXV3.R5 power converter
  • 04:30 Issue with batch-by-batch longitudinal blow-up: bunch length continuously increasing experts called:
  • 05:20 Filling again
  • 06:37 STABLE BEAMS #3225 Initial luminosity ~7.5x1033 cm-2s-1
  • 06:39 losses (800ms) in point 4, BSRT region. Beam dump.
  • 09:18 stable beams fill 3266; Peak luminosity ATLAS/CMS: 7E33 cm-2s-1; Integrated lumi in 1h46’: ATLAS/CMS: ~38 pb-1
  • 11:05 Programmed dump for power grid intervention EDF-SIG
  • ~12:00 ATLAS toroid tripped; lost cryo in pt 2; undulators tripped
  • many accesses; a couple of tripps when switching back on requiring some more accesses; both udulators off
  • 23:30 - 1:30 set-up with pilot and steering of injection lines
08:30 meeting
Thursday 25 October
  • 08:30 stop of high beta* run, dumping the rest of the beams
  • changing LHCb polarity and testing new OFSU version
  • 09:30-11:30 Pilot ramp with 2x6 bunches/beam for check after LHCb polarity reversal
  • 12:30 PS Setting-up to increase satellites for ALICE completed
  • 12:30 Batch-by-batch longitudinal blow-up in operation
  • 13:22 LHCb trigger during injection of B2 (3rd 144 batch)
  • 13:30 – 14:00 Steering lines
  • 14:08 Spurious dump of LSS6 BPMs during pilot injection
  • 15:59 STABLE BEAMS #3220 Initial luminosity 6.7x1033 cm-2s-1.
  • 16:23 Trip of the 60 A correctors in sector 56 due to a loss of the 60 A power permit.End of fill #3220. 8.4 pb-1 in 24 mins
  • 19:30 Again LHCb trigger at injection of Beam 2
  • 20:00 Reduction of the bunch length at PS extraction. No improvement: again LHCb trigger. Decided to revert back to previous PS longitudinal set-up with reduced satellites.
  • 22:53 STABLE BEAMS #3223. Initial luminosity ~7x1033 cm-2s-1
  • 00:26 Trip of RCBXV3.R5 (power converter): End of fill #3223. 34 pb-1 in 1.5 h
08:30 meeting
Wednesday 24 October
  • Ready for injection at 01:00
  • 03:40 Stable beams #3214. Initial luminosity 6.5x1033 cm-2s-1
  • 09:05 Dump fill #3214 after 5.5 hours. 95 pb-1.
  • 9:45 RSD1.A67B2 tripped during ramp down
  • 10:30 start of high beta*; Fill 3215; 3 bunches + pilot (total intensity: 2.7E11 p)
  • 12:10  reached 1000m beta*
  • 16:40 beam dump: Spurious opening of QPS switch on RB.A67
  • 20:00 continue high beta* with the injection for fill 3216
  • ~23:15 start of data taking 
08:30 meeting + Cryo slides
Tuesday 23 October
  • 01:22 STABLE BEAMS #3209
  • Peak luminosity ATLAS/CMS: ~7E33 cm-2s-1
  • 03:55 EDF glitch. FMCM trigger (RD1.LR1). Integrated lumi in 2h32’: ATLAS/CMS: ~52 pb-1
  • 6:35 stable beams fill 3210 Luminosity >7.3E33 cm-2s-1
  • 09:44 MKB_B2 ion pump tripped. Vacuum spike leading to beam dump system internal fault and beam dump. End of physics #3210. 66 pb-1 in 3.1 h
  • 10:19 – 14:46 – Faulty sensor on a turbine of a warm compressor in point 8 tripping twice and leading to loss of cryo start/maintain of the matching section R8 (Sector 81). Sensor disabled (SW-wise and HW-wise). Had to pre-cycle twice
  • 15:00 – 16:30 Commissioning of batch by batch longitudinal blow-up
  • 18:23 Stable beams #3212
  • 19:19 Trip of power converter RQT12.R1B2. End of fill 3212. 22 pb-1 in ~1 h
  • Access required for power converter replacement
  • Problem with PAD UJ16. Intervention of access piquet.
  • 22:49 Intervention on RQT12.R1B2 and on PAD completed. Patrol
08:30 meeting
Monday 22 October
  • 01:50h stable beams fill 3207 L0=7.7 e33
  • 06:10h Beam Dump - power converter communication problem in 78.
  • End fill 3207: 88 pb-1 in 4h27m
  • 13:30 STABLE BEAMS #3208. Peak luminosity 6.5x10^33 cm2s-1
  • 17:41 beam dump due to trip of RD2.L5 (QPS)
  • 18:11 Trip of sector 23. Access required for replacement of the control card of current lead temperature sensor
  • 22:25 Access finished
08:30 meeting