LHC 2011 - latest news

Week 47: Machine coordinators: Barbara Holzer, Jorg Wenninger

Goals of the week: Pb-Pb physics, squeeze stability

 

Day

Summary

Link to report from morning meeting

Monday 28th Nov
  • 05:00 Dump fill 2340, integrated L ~6.5 ub-1.
  • 07:00 Flipping ALICE polarity to POSITIVE.
  • Preparing test ramp, squeeze, collisions.

8:30 meeting

Sunday 27th Nov
  • 00:00 Stable beams fill 2328, 4.8E26 cm-2s-1.
  • 06:10 Dump fill 2328, integrated L ~6 ub-1.
  • Access for QPS.
  • 12:30 Stable beams fill 2329, 4.5E26 cm-2s-1.
  • 18:15 Dump fill 2328, integrated L ~5.5 ub-1
  • 22:00 Stable beams fill 2340, 4.5E26 cm-2s-1.

9:00 meeting

Saturday 26th Nov
  • 03:30 Beam lost at start of ramp due to RF settings mismatch.
  • 06:30 Filling.
  • 08:00 Stable beams fill 2325, 4.2E26 cm-2s-1.
  • Conditions have stabilized for the cryo in Pt8. We can continue without warming up.
  • 13:45 Lost fill 2325, trip of S45. Integrated L ~ 5 ub-1.
  • Precyle, access for RF.Recover line 6B1.
  • 16:30 Filling. Problems with SPS RF.
  • 18:00 Filling for physics.
  • 20:00 Stable beams fill 2327, 4.5E26 cm-2s-1.
  • 20:30 Beam lost, LBDS B1 faulty. Integrated L ~0.8 ub-1.
  • 22:30 Injecting again.

9:00 meeting

Friday 25th Nov
  • 04:00 Dump fill 2320, integrated L ~5 ub-1.
  • 06:40 Dump during squeeze of IR2 due to unstable H tune measurement on B1 - trip of RQTFs.
  • 10:00 Dump during squeeze of IR2 due to unstable H tune measurement on B1 - trip of RQTFs. Again.
  • Access - source exchange.
  • Restart delayed due to problem with LINAC3.
  • 21:30 LINAC3 OK again, beam back in LEIR.
  • POPS down in PS.
  • 23:00 Ready to inject.
  • Problem with RF L6B1. Intervention needed

8:30 meeting

Thursday 24th Nov
  • 03:30 Dump fill 2318, integrated L ~5 ub-1.
  • 04:20 Ready to inject, problems with SPS RF for 200 ns beam.
  • 09:00 Stable beams fill 2319, 4.2E26 cm-2s-1.
  • 15:00 Moving to ADJUST.
  • Test of external crossing angle flip from -80 to +80 urad - successful: no problems with losses and lifetimes.
  • 16:00 Test of re-distribution of BFPP beam loss R5.B1 with a local H bump at Q11R5.B1. The losses are reduced by ~factor 5.
  • 17:40 Back to stable beams, problems with SPS RF.
  • 18:05 Dump fill 2319, integrated L ~5.5 ub-1.
  • 18:20 Lost cryo S23 due to temperature reading. Precycle.
  • 20:00 Injecting.
  • 22:45 Stable beams fill 2320, 4.2E26 cm-2s-1.

8:30 meeting

Wednesday 23rd Nov
  • 01:42 ready to inject but no beam from PS
  • 08:30 beam back in PS
  • 10:30 - 10:55 RF LINAC3 problems
  • 10:55 start filling
  • 13:00 Stable beams fill 2317, 4E26 cm-2s-1.
  • 16:20 TETRA repeater test - ON.
  • 17:30 TRETA repeater OFF.
  • 18:00 Dump beam, integrated L ~ 4.5 ub-1.
  • 22:00 Stable beams fill 2318, 4E26 cm-2s-1.

8:30 meeting

Tuesday 22nd Nov
  • 02:30 Refill.
  • 04:30 Stable beams fill 2315, 3.5E26 cm-2s-1.
  • 12:00 Dump fill 2315, integrated L ~5.5 ub-1.
  • 15:00 Ready to fill at injection, but no beam from PS.
  • 17:30 Filling
  • 19:35 Stable beams fill 2316
  • 22:25 Dump by RF (most likely a quench)

8:30 meeting

Monday 21st Nov
  • 08:45 Cryogenics S34 back. Problems access doors.
  • 10:30 Injecting pilot.
  • Orbit FB gain tests at injection.
  • 12:00 Ramp - dumped by RF interlock.M2B1.
  • 14:00 Undulator trip at injection, lost cryo conditions in ML4.
  • Instead of precycle of ML4, ramp and squeeze 2 probes. OFB tests at 3.5 TeV. Lost beam again on RF interlock, M1B2.
  • 18:30 Refill.
  • 21:00 Beam lost in squeeze due to OFB (gain increased x10).
  • 23:30 Stable beams fill 2314, 4E26 cm-2s-1.
  • 23:50 Beam dump, nQPS on RB.23.

8:30 meeting