LHC 2012 - latest news

Week 40: Machine coordinators:Gianluigi Arduini, Mike Lamont

Plan for the week: Production..scrubbing run postponed - vacuum conditioning of new injection kicker incomplete - this would have slowed the scrubbing down considerably.

Date

Summary

Link to report from morning meeting
Monday 8 October
  • Over night: damper trips+MKI2 faulty
  • 02:58 Dump trigger from BLM.L1 (spurious)
  • 04:00-08:00 Preparation of MD and accesses for kicker, RF

08:30 meeting

 
Sunday 7 October
  • 06:30 fill 3135 lost to ALICE DIPOLE trip
  • Fill 3135: 158 pb-1 in 10h3m
  • 09:00 ATLAS have a gas leak in TRT detector - urgent access of ~1h required (LHC is anyway waiting for the injection kickers to cool down)
  • PS RF expert (H. Damerau) increasing longitudinal blow-up to enhance satellite population
  • 11:04 MKI kicker temperature below threshold
  • 11:00-11:40 Steering TI2/TI8. Some more losses at injection (satellites?)
  • 12:41 Loss of vacuum valve status in point 7 (Beam 2). Beam dump during the squeeze. Access required.
  • 15:23 Injecting after vacuum intervention
  • 17:03 STABLE BEAMS #3138. Initial luminosity ~7.3x1033 cm-2s-1
  • ALICE head-on luminosity reaching 1031 cm-2s-1  with enhanced satellites after further adjustment in the PS in the morning. No need to change filling scheme
 09:00 meeting
Saturday 6 October
  • 02:47 OP dump: ~187 pb-1 in 14.5 h. ~250 pb-1 in 24 h.
  • 05:38 STABLE BEAMS #3134. Initial luminosities: 6.77x1033 cm-2s-1.
  • 18:06 OP dump: fill 3134 177 pb-1 in 12h28m
  • 20:28 back in Stable beams: fill 3135 – initial luminosity: 7.11x1033 cm-2s-1
  • New record: Maximum Luminosity Delivered in one day 286.33 pb-1
 09:00 meeting
Friday 5 October
  • 00:42 End of access
  • 02:51 STABLE BEAMS#3131 Initial luminosity 6.5x1033 cm-2s-1
  • 06:19 UFO in sector 23 (BLMQI.31L3.B1I10_MQ) at 138% of dump threshold End of fill #3131. 67 pb-1 in 4.5 h
  • 08:16 Sector 81 trip RQ8.L1 (QPS noise)  - Precycle
  • 10:00 Injecting. Setting up of the damper gain modulation and BBQ gated measurement on beam 1.
  • 12:10 Colliding in IP1/5. Peak luminosity >7.5x1033 cm-2s-1.
  • 12:18 STABLE BEAMS #3133. Initial luminosity 7.3x1033 cm-2s-1.
  • 23:00 – 02:20 Bunch length variation
08:30 meeting
Thursday 4 October
  • 01:40 Injecting probes
  • 03:50 Stable beams fill 3129: Injected 1.63e11 ppb Initial luminosity: 6.72e33cm-2s-1
  • Beams dumped at 08:25 – cryo: lost communication with main refrigerator point 4 - cold compressor stop
  • Access for: installation of additional solenoids in point 8 close to MKI8, CMS, BSRA, BRAN in point 8, CV checks in point 4 and 8, EL in point 6 (UPS replacement), RF (instrumentation checks).
  • 17:45 Cryo recovered
  • 18:45 Start pre-cycle
  • 19:50 TI2 steering
  • 22:15 STABLE BEAMS#3130
  • 22:35 Vacuum valves in undefined position in IR7 (B1). Beam dump. End of fill 3130 after 20 mins (~6 pb-1)
  •  23:49 access in point 7 for vacuum piquet. Replaced faulty power supply for valve control crate.
08:30 meeting
Wednesday 3 October
  • 03:05 dry dump as requested by the kicker piquet, all looks fine
  • 03:30 – injecting physics beam
  • 03:50 beams dumped at 450 GeV. ¨Trip of PC of RQTD.A34B1
  • 05:45 Stable beams fill 3126. Initial luminosity: 7.16e33 cm-2s-1
  • 12:13 Trip of RQF.A45. End of fill 3126. 115 pb-1 in 6.5 hours.
  • 13:30-17:30  Access for: cryo in triplet R2 in point 2, BSRT/BSRA, power converters, vacuum in point 4, BRAN a,d diamond BLMs in point 8, ATLAS, TOTEM and QPS in point 5, ventilation door in UJ33, QPS in SEctor 81
  • 17:30 Pre-cycle
  • 19:00-20:30: setting-up of the beam in the injectors, transfer line steering
  • 22:36 STABLE BEAMS #3128. Initial luminosity 6.4e33 cm-2s-1
  • 22:51 Trip of RCBH29.R6B2 orbit corrector ==> SIS interlock. End of fill #3128. 5 pb-1 in 15 mins.
 08:30 meeting
Tuesday 2 October
  • 12:45 Fill 3121 dumped - 150 pb-1 after end of fill MD (long range beam beam)
  • 14:40-15:30 Extraction interlock (TT60)
  • 15:50 Filled the machine (limited to 1230 bunches)
  • 16:17 LBDS trip due to a corruption of the MKD-B1 internal safety ASIbus. Beam dump during the ramp
  • 18:20 inject again
  • 19:41 beam dumped on flat top after re-boot of BBQ front end
  • 20:40 Re-injecting
  • 22:30 Stable beams fill 3124
  • 23:31 Beam dumped - cryogenic conditions lost in IT.R2
  • MKB B2 faulty
 08:30 meeting
Monday 1 October
  • 03:13 beam dump by operation, exceptionally a natural end of fill
  • injection delayed, undulator reset required
  • Access: fault on inj kicker MKI8_D (electronics) - 300 V power supply
  • Access: sublimation on new injection kicker - point 8
  • 09:40 cycling
  • 11:15 probes in, start 25 ns injection set-up/ transverse damper set-up
  • 11:45 CMS - cryo problem - precautionary reduction to half normal solenoid current - recovery foreseen by midnight - perform full 25 ns injection set-up in shadow - should be able recuperate this time for physics on Thursday morning
  • 17:30 Damper setting-up completed for both beams and planes
  • 18:45 Beam 2: 72 bunches@25 ns injected
  • Fill #3121 Good luminosities in spite of the reduced number of bunches, thanks to higher intensity (1.62x1011 at injection) and small emittances (Q20)
  • 00:38 STABLE BEAMS CMS solenoid up just in time

08:30 meeting