LHC 2011 - latest news

Week 25: Machine coordinators: Ralph Assmann, Jorg Wenninger

Goals of the week: Luminosity production - 1236 bunches

LHC coordination vistar

Day

Summary

Link to report from morning meeting

Monday, 27th June

  •  00:20 Stable beams #1890 1236b initial luminosity 1.25E33 cm-2s-1.

08:30 meeting

Sunday, 26th June

  • 08:30 Refill.
  • 09:40 Stable beams #1895 1236b initial luminosity 1.15E33 cm-2s-1.
  • 10:00 Beam dumped by vacuum in B2 IR4.
  • Increased vacuum intlk threshold from 4e-7 to 2e-6 on one IR4 gauge.
  • 11:30 refill delayed by booster septum problem.
  • 15:00 Stable beam #1896 1236b initial luminosity 1.15E33 cm-2s-1.
  • 16:40 Beam dumped, lost sector 34.
  • Access.
  • 22:00 Injection

09:00 meeting

 

Saturday, 25th June

  • Stable beams ongoing.
  • 13:09 Beam lost - cryo lost in Pt5. Integrated luminosity 45 pb-1.
  • Access for cryo, CMS, ALICE.
  • Patrol lost in Pt5 - as usual.
  • 18:00 machine closed.
  • 19:00 Injection.
  • 20:31 beam dumped at start of squeeze due to SIS interlock on beam position wrt TCSG. BPMSB.B4.R6B1 triggered when exceeding the limit of 1 mm (1.4 sigma).
  • 21:30 Lost cryo in Pt5 for short moment while at injection. Pre-cycle.
  • 23:00 refill
  • 01:00 Stable beams #1893 1236b.initial luminosity 1.15E33 cm-2s-1.
  • 01:40 Beam dumped by vacuum B2 in IR4. 1.8 pb-1.
  • 03:00 Refill.
  • 04:20 Stable beams #1894 1236b.initial luminosity 1.15E33 cm-2s-1.
  • 06:30 Beam dumped by vacuum in B2 IR4. 8 pb-1.

09:00 meeting

Friday, 24th June

  • Preparing to inject 1236. Small adjustments of the line steering for losses.
  • 11:00 Stable beam fill #1889 1236b, initial luminosity 1.26E33 cm-2s-1.
  • 13:45 fill #1889 dumped by AUG in TI2. 11 pb-1 integrated luminosity.
  • Access for AUG, QPS and RF.
  • 19:20 Beam back
  • 21:00 Controls problems during the squeeze.
  • 21:31 Flat top with 1236b
  • 22:53 Stable beams. Fill 1890 1236b, initial luminosity 1.15E33 cm-2s-1.

08:30 meeting

Thursday, 23rd June

  • Recovery ongoing. Access in various part of the ring.
  • 18:00 Cryo back. Precycling.
  • 20:00 Injection.
  • 20:15 Lost sector 81. Fip comm. problem.
  • 23:00 Injection steering, check of increased MKI pulse for B1.
  • Overnight loss maps. 2 klystron trips.

08:30 meeting

Wednesday, 22nd June

  • 02:00 Injection problem. Could be traced to an orbit correction on the SPS flat top.
  • No beam from 08:30 to 12:30.
  • Access.
  • 16:30 Lightning strike during preparation for beam. Cryo Pt8 lost compressor, all sectors off, etc etc

08:30 meeting

Tuesday, 21st June

  • Analysis of bunch by bunch injection oscillations from the previous fill reveals that the B1 injection kicker may not be timed correctly - last bunches seem to be kicked in V plane. Injection kicker pulse length increased by 200 ns on B1.
  • 18:15: fill #1883 dumped by SIS interlock (OFSU down), 47.5 pb-1 in around 18 hours.
  • Refill delayed due to RF problems (noise) in the SPS.

08:30 meeting
Cryo

Monday, 20th June

  • Cryo recovery. One compressor in Pt8 vibrates and is noisy - possible source of the oil filter clogging.
  • Beam screen bake-out on standalone magnets in IR8 (Q5, Q6).
  • 9:00 cryo back - pre-cycle.
  • 21:00 Injecting, steering TI2 and TI8.
  • 23:00 Filling 1092 b.
  • 00:15 Stable beams fill #1883 initial luminosity ~ 1.1E33 cm-2s-1.

08:30 meeting