LHC 2011 - latest news

Week 20: Machine coordinators: Gianluigi Arduini, Bernhard Holzer.

Goals of the week: re-establish physics conditions, alignment of RPs, increase intensity

LHC coordination vistar

 

Day

Summary

Link to report from morning meeting

Monday, 23rd May
  • 08:00 restart, set up injection
08:30 meeting
Sunday, 22nd May
  • 07:00 Beam dump: end of STABLE BEAMS #1799: 25 pb-1. Record integrated luminosity in 24 hours: 33.33 pb-1
  • Power glitch at 09:09. Trip of sector 67 and 81
  • 11:00 - 13:00. Injection. Observation of blow-up dump and refill with lowr chormaticity
  • 14:24 Stable beams #1800: 912 bunches/train - Initial luminosity 9.4x1032 cm-2s-1
  • 15:40. ALICE solenoid trip and RF dump. End of fill #1800. 4.4 pb-1 in 1.4 h.
  • 20:40 Stable beams #1801: 912 bunches/train - Initial luminosity7.7x1032 cm-2s-1. Blow-up observed during the ramp B1V.
  • 21:27. RF dump. End of fill #1801.
  • 02:13. Stable beams #1802. 912 bunches/train - Initial luminosity1.1x1033 cm-2s-1
  • 05:25. RF dump. End of stable beams #1802.  11.3 pb-1 in 2 h.
.09:00 meeting
Saturday, 21st May
  • 3:08 stable beams, 768 x 768. 108 b/train. Initial luminosity: 7.5x1032 cm-2s-1.
  • 12:00 End of stable beams #1798. RF end of fill test. 18.9 pb-1 in 9 hours
  • 13:55 Beam dumped after RF test (switch
  • 15:00-18:00 Access for ATLAS and QPS piquet (reset of QPS controller)
  • 20:34 STABLE BEAMS #1799 - 912 bunches/train - Initial luminosity 8.5x1032 cm-2s-1. More than 1014 p/beam in collision.
09:00 meeting
Friday, 20th May
  • 7:44 beam dump due to cryo problem in point 81 (controller of DFBAA cryo-valves)
  • Luminosity until then 18.5 pb-1 in 8.1 h.
  • Access for replacement of the controller for the DFBAA cryo-valves
  • 12:00h restart: check injection losses for 72 bunch transfer / 108 bunch transfer
  • 14:00 injection of 768 x 768 bunches, dump for IP6 BPM interlock test
  • 15:00h injection of 768 x 768 bunches (108 bunch trains) for luminosity  ramp,squeeze, collisions
  • 16:00 stable luminosity
  • 16:46 beam dump, QPS problem in RQ10.L1.B1
  • 17:00-20:30 Investigations on Q10.L1QPS trip
  • 20:30-23:30 trip of triplet power converters. Recovery.
08:30 meeting
Thursday, 19th May
  • 00:00 - 01:00 loss maps at injection
  • 01:00 - 06:00 Attempts to fill for physics with 768 bunches/beam (72 bunches/train). Vacuum instabilities jn the triplet L8 related to beam screen temperature fluctuations.
  • 06:00 - 11:00 Investigations from vacuum and cryogenics
  • 11:20 Trip of sector 67 (QPS)
  • 11:20 - 15:00 Access for QPS intervention
  • 15:00-17:00 Setting-up of injection with 108 bunches
  • 17:00-20:00 Injection of large number of bunches
  • 20:00 1308 bunch/beam injected
  • 21:20 Beam dump due to vacuum spike close to D1.R2
  • 23:30 Stable beams #1795. Peak luminosity 7.7x1032 cm-2s-1.
08:30 meeting
Wednesday, 18th May
  • 01:00-06:30 Fill #1787 – 480 bunches with 72 bunches/train – 4.4x1032 cm-2s-1 initial luminosity – 3.4 pb-1 in 2.3 hours. End of fill test of measurement of transient beam loading when switching off a cavity.
  • 06:30 - 21:30 ALPHA/TOTEM roman pot beam based alignment.
  • Loss maps done (except off-momentum)
  • 21:30 - 24:00 - Ramp-down and modification of the acceleration rate for the RF frequency trims.
08:30 meeting
Tuesday, 17th May
  • 01:30-03:30 Access for replacing the power trigger unit of MKB B1
  • 03:30-05:00 pre-cycle and prepare for injection
  • 05:00-06:00 Injection of trains of 72 bunches for preparing the fill with 480 bunches. Losses at injection
  • 06:00 Start preparation for roman port alignment (ALPHA and TOTEM)
  • 10:00 3.5 TeV - colliding. Start roman pot alignment ...
  • 10:54 beam dump due to roman pot movement
  • 11:50 sector 81 & 12 tripped during pre-cycle (SPS main quadrupole power supply tests)
  • 13:06 end of pre-cycle, trip of sector 78
  • 13:00 - 18:00 Investigations on the trips of Sector 78 main quadrupoles.
  • 18:30 finally successful pre-cycle after restoring threshold on nQPS (B11.L8)
  • 18:30 No injection permit from CMS
  • 19:00 Injection of B2. Power converter problem on RBIH.610337
  • 19:30-01:00 Injection setting-up of up to 144 bunches/train
8:30 meeting
Monday, 16th May
  • Overnight Sunday to Monday: 50 ns inojection optimization, issues with transverse damper settings, ramp lost to electrical network glitch early morning
  • 11:26 STABLE BEAMS #1785 (228 bunches/beam - 36 bunches/injection) - peak lumi 1.9x1032 cm-2s-1
  • Length scale calibration in ATLAS
  • 15:00 ADJUST MODE: end of fill #1785 (1.8 pb-1) test to see effect of a trip of a klystron. Issues with logging of abort gap population
  • 17:00 Beams dumped by operator.
  • 17:30 trip of triplets power converters in point 8. Access for Power Converter piquest and for QPS piquet for replacement of QH power supply switch in Sector 56
  • 21:30 end of access.
  • 22:20 Accidental CMS operator dump
  • 22:30-23:30. Abort Gap Keeper check. Last bunch that can be systematically injected.
  • 23:30-01:30 Loss maps: Horizontal for B1 and B2. Vertical for B2. Off momentum@+/-1kHz for B2.
  • LBDS self-trigger. Access
8:30 meeting
VdM run summary (MFL)