CERN, Geneva
The LHC transfer lines, injection and beam dump systems are equipped with a series of active and passive protection systems. These are designed to prevent as many failures as possible, for example through surveillance and interlocking, or to absorb any beam which is mis-kicked or mis-steered on passive absorbers. The commissioning, validation tests and performance of the different systems are described, and the implications for the protection of the LHC against different failures during beam transfer are discussed.
CERN, Geneva
The very demanding LHC beam parameters put very strict requirements on the beam quality along the SPS-to-LHC transfer. In particular, the budget for the emittance increase is very tight. During the LHC commissioning, the emittances have been measured in the SPS, the two SPS-to-LHC transfer lines and in the LHC. Preliminary results show the importance of a very well controlled beam steering in the transfer lines together with the need of a robust trajectory correction strategy in order to guarantee long-term reproducibility. Another source of emittance comes from the tilt mis¬match be¬tween the LHC and its trans¬fer lines which generates cou¬pling at in¬jec-tion into the LHC and in turn will contribute to emittance increase. Preliminary results are also discussed.
CERN, Geneva
After more than a year of repairing and preparing the Large Hadron Collider after a major technical problem, beams were injected again in November 2009. The commissioning plan for the 2009 to 2011 run was ambitious, aiming for centre-of-mass collision energies of 7 TeV and an integrated luminosity of 1 fb-1. To date the LHC has not disappointed its user group or its designers. The first energy ramp to 1.2 TeV took place only 1 1/2 weeks after the start-up. A short technical break at the beginning of 2010 was followed by a series of commissioning highlights, including beams at 3.5 TeV, first collisions at 3.5 TeV, collisions with squeezed beams and injection of nominal bunch intensity. The major challenge for 2010 is to prepare the machine for higher and higher intensities to reach the target integrated luminosity by the end of 2011. This talk will give a short introduction to the LHC and its challenges and then focus mainly on the commissioning strategy, the preparation, the commissioning highlights, the status of the LHC and the plans for the coming months.
