The 2011 LHC run is reviewed from the experiments perspective. The achievements directly related to physics production are summarized. This includes high luminosity p-p and Pb-Pb running, special activities (such as intermediate energy p-p physics, 90 m optics, luminosity calibrations) and other experiments (for example satellite-main bunch collisions in IP2, 25 ns stable beams tests, etc.).
The LHC Beam Operation workshop 2011 took place 12th - 14th December. The principle aims of the workshop were to review 2011 LHC beam commissioning and beam operations experience, and to look forward to the operation of the LHC in 2012. Issues covered include: availability; injection; operational performance; beam loss and machine protection;system performance; limitations; and the outlook for...
A critical evaluation of machine availability and performance analysis of the 2011 Run will be given. This will include both an analysis of the run in terms of the different operational modes, as well as a breakdown of the run in terms of downtime and faults. Detailed evaluation of systems with significant fault time will be addressed, and intended improvements discussed. In addition a survey...
Injection of 144 bunches into the LHC became fully operational during the 2011 run and a nominal injection of 288 bunches was accomplished during MD time. Several mitigation solutions were put in place to minimise losses from the transfer line (TL) collimators and losses from kicking debunched beam during injection. Nevertheless, shot-by-shot and bunch-by-bunch trajectory variations, as well...
The performance and experience with the LHC machine protection system during the 2011 run will be briefly summarized. Emphasis will be given to identify further potential improvements of the existing protection systems for the 2012 run alongside possibilities to allow for a more efficient strategy during the intensity ramp up whilst maintaining the required validation steps and dependability...
During the LHC run 2011, a tremendous progress has been made towards the machine operation with design parameters. In the same time, the run confirmed the sensitivity of the beam vacuum system to the machine parameters. As expected, a successful scrubbing period allowed mitigating the effects of the electron cloud giving room to an entire filling of the ring with 50 ns beams. In parallel...
Emittance measurements during the LHC proton run 2011 indicated a blow-up of 20 % to 30 % from LHC injection to collisions. This presentation will show the emittance preservation throughout the different parts of the LHC cycle and discuss the current limitations on emittance determination. An overview of emittance preservation through the injector complex as function of bunch intensity will...
