LHC 2011 - latest news

Week 49 Machine coordinators: J. Wenninger, B. Holzer (sick !)

Goals of the week: Pb-Pb physics, Quench test

 

Date

Summary

Link to report from morning meeting

Thursday 8th Dec
  • RP survey.
  • Xmas technical stop. General access in all points except Pt 3 & 7.

8:30 meeting

 

Wednesday 7th Dec
  • 01:30 New attempt of ramp with modified blow-up - failed again.
  • 03:00 STABLE BEAMS #2350 Initial luminosity 4x1026 cm-2s-1
  • 03:40 Beam dumped, S81 FPA.
  • 08:40 STABLE BEAMS #2351 Initial luminosity 4x1026 cm-2s-1
  • 10:20 Beam dumped, S45 trip.
  • Precycle. A few RF trips in the 'shadow'.
  • 14:00 Refill for physics.
  • 14:45 Beam dumped at end of injection due to trip of RF module M1B2.
  • 15:00 Not worth to refill - end of physics for 2012 !!!
  • Attempt to test the combined ramp and squeeze: failed due to absence of beam. The ion beam is lost between extraction of PS and injection into the SPS. Despite desperate efforts, it was not possible to restore the ion beam in the SPS.
  • 18:00 End of LHC run 2011.
  • 18:30 Switching off all circuits. LHC to access mode.

8:30 meeting

Tuesday 6th Dec
  • 06:00 Dump fill 2344.
  • QPS problem on B10.L2. Reset OK. Precycle.
  • Quench test with ions.
  • 3 attempts - no quench !
  • 16:00 Preparing for physics fill.
  • ADT gating test for BBQ - not successful.
  • 18:00 Ramp lost due to problem with longitudinal blowup settings.
  • 20:00 New ramp, again new blow-up failed, bunches became way too long at the start - problem with FB on bunch length.
  • 21:00 STABLE BEAMS #2349 Initial luminosity 4x1026 cm-2s-1
  • 22:40 Beam lost, trip of RF module M2B1.

8:30 meeting

Monday 5th Dec
  • 03:15 STABLE BEAMS #2343 Initial luminosity 5x1026 cm-2s-1
  • 09:30 Dump fill 2343.Integrated luminosity ~6 ub-1.
  • Ion quench test preparation.
  • 11:00 Beam scraping at injection for CMS.
  • 12:00 Electrical glitch due to fault on 18kV circuit breaker. Lost 4 sectors, RF, MKIs, ATLAS. Collimators in strange state.
  • 12:30 Second glitch when trying to switch back on. Lost cryo Pt18 as a consequence of the second glitch.
  • Waiting for cryo recovery.
  • 18:00 Cryo Pt18 recovered well ahead of initial prediction (24:00).
  • Preparing for physics.
  • 20:00 Injecting.
  • 23:00 STABLE BEAMS #2344 Initial luminosity 4.5x1026 cm-2s-1

8:30 meeting