LHC 2012 - latest news

Week 24: Machine coordinators: Ralph Assmann, Jan Uythoven

Plan for the week: Luminosity production

 

Date

Summary

Link to report from morning meeting

Monday 18 June

  •  00:34 Beam lost RF line 2B2. Lumi 66 pb-1

  •  Kickers cooling down. ATLAS water leak, access.

  • 05:15 Injecting again. MKI B2 vacuum interlock, looks like e-cloud again.

  • 10:29 Stable beams #2739. Initial lumi 6.3 cm-2s-1.

 08:30 meeting

Sunday 17 June

  • 13:40 Dump fill #2736 by OP. Integrated lumi 233 fb-1.

  • 14:30 Waiting for injection kickers to cool down.

  • Integrated lumi for 2012: 6.5 fb-1

  • 18:35 Injection kickers ok - injecting probes

  • 20:57 Stable beams #2737. Intial lumi 6.1e33 cm-2s-1

09:00 meeting

Saturday 16 June

  • 09:00 Stable beams ongoing. Lumi this fill so far 150 pb-1. MKI.8D 4.5 % above temperature threshold, flattening out.
  • 13:20 ALICE trip
  • 14:24 Beam dump by OP. Integrated lumi 204 pb-1.
  • 14:59 MKI8 at 105% of interlock level. Need to wait…
  • 17:33 Injection.
  • 18:03 Transfer line steering TI8. Filling was again slowed down by the poor beam quality (both for intensity and longitudinal parameters spread, despite a slight release by the SPS experts of the BQMSPS thresholds).
  • 19:18 Start ramp. B2H tune jumps between 2 peaks... RT trims are wavy. Trimmed the tune manually down by -0.003 in B2H. What the feedback was locked on did not move with the trims.
  • 20:07 Losses at the start of the collision beam process, beam 2 up to ~50% dump threshold.
  • 20:10 Stable beams #2736. Initial lumi: 6.5e33cm-2s-1. b1 lifetime was worse than that of beam 2, so trimmed Q1H up by 0.002.

09:30 meeting

RQX.L2 trip (R.Schmidt)

Friday 15 June

  • 01:11 Injection.
  • 02:42 Stable beams #2733. Initial lumi: 6.7e33 cm-2s-1.
  • 08:17 Reached 5.976/6.042 fb-1 (ATLAS/CMS) for 2012.
  • 15:54 Beam dumped, triplet RQX.L2 tripped. Delivered lumi 183 pb-1.
  • 17:30 MKI temperatures ok, waiting on EPC and precycle RQX.L2.
  • 19:45 Injection septum is misbehaving, getting FMCM RMSI.R8B2. 
  • Injection problems, longitudinal and transverse
  • 22:50 Stable beams #2734. Initial lumi 6.3e33 cm-2s-1

 08:30 meeting

Thursday 14 June

  • 01:30 MKI temperatures OK again. About one hours wait.
  • Some problems with PM.
  • 04:00 Fill #2729 Stable Beams. Initial lumi 6.5e33 cm-2s-1.
  • 07:29 Beams dumped by BLM self trigger. Integrated lumi 68 pb-1
  • 09:51 BLM card replaced, kickers cooled down. Injecting probes.
  • 10:55 Different BLM problem, again in point 1: changed fibre.
  • 12:02 Injecting again - some problems with beam from SPS.
  • 13:58 Beams dumped at beginning of Adjust due to high losses in IP7, already at the end of the squeeze.
  • 14:50 Injection. Bunch length problems in the injectors. Injector chain tuning.
  • 18:25 Injection. Quite long and unstable injection. Many injections inhibited due to bunch length!
  • 19:59 Beam at 4 TeV.
  • 20:29 Stable Beams #2732. Initial lumi: 6.6e33 cm-2s-1.
  • 22:20 Beam dumped. Integrated 40pb-1. QPS triggered on RQX.R1, fire heaters discharged, vacuum valves closed. SEU?

 08:30 meeting

Wednesday 13 June

  • 07:06 Beam dump. Produced 142 pb-1. Electrical perturbation. ALICE and LHCb tripped. 3 PC on FMCM.
  • 09:00 Update of RF synchro loop functions. Test of RF blow-up at injection.
  • 10:16 re-injecting probes and injection for physics
  • 11:41 Fill # 2728 Stable beams. Inital lumi's 6.5e33 cm-2s-1
  • 23:35 Beams dumped by operator. Integrated lumi about 170 pb-1

08:30 meeting

Tuesday 12 June

  • 00:30 to 02:12 CMS electrical problem – access – could not fix
  • 02:54 injecting for physics – dumped, access system wrong manipulation
  • Patrol and pre-cycle
  • 05:18 No beam from injectors – PS RF beam controller problem
  • 08:00 Probe beam back again
  • 09:44 Fill #2725 Stable beams. Initial lumi's 6.4e33 cm-2s-1.
  • 16:49 Beam dump. Produced 120 pb-1. Trip of S81.
  • 17:21 Access for CMS and ALICE. Parasitic: MKA test, QPS sector 78, LBDS TSA surveillance test, pulse MKD/MKB in local.
  • 19:10 End of access. Recycle.
  • 20:27 Injection.
  • 22:08 Stable beams #2726. 6.6e33 cm-2 s-1

08:30 meeting

Monday 11 June

  • 01:50 Stable beams Fill #2719, 6.3E33 cm-2s-1. Beam dumped after 3 minutes by a vacuum spike in Pt3.
  • Vac. expert increases thresholds in Pt3 from 1E-6 to 4E-6.
  • 04:07 Stable beams Fill #2720, 6.3E33 cm-2s-1.
  • 04:40 Beam dumped, RF B1 - circulator arc.  Integrated L 11 pb-1.
  • Waiting for MKI8 to cool down.
  • Refill.
  • 08:10 Beam dumped in the ramp by OP. OFB did not start its function and kept the injection orbit.
  • 08:50 Switch LHCb polarity to negative.
  • 09:28 Change of RBAC rules for OFSU and test afterwards.
  • 10:51 Start test ramp with 24 bunches - Optimised IP1 collision values incorporated.
  • 14:34 Fill #2723 Stable Beams.
  • 17:01 Dump due to trip of ROD.A81B1 (RR13) , followed by ROF.A81B1 and RSF1.A81B1, looks like a SEU. Int. lumi around 46 pb-1.
  • 20:03 Fill #2724 Stable Beams
  • 21:17 Dump due to electrical perturbation, triggered first FMCM on RD1.LR1 andheaters discharge on RQ10.R4. Int. lumi around 26 pb-1.
  • Waiting for quench heater to cool down -  access for ALICE.
  • 23:55 Access and pre-cycle finished

08:30 meeting