Chamonix 2012 Workshop on LHC Performance: Chamonix, France 6 - 10 Feb 2012

During the Chamonix 2012 workshop on LHC performance, operation of the machine in 2012, activities during the first long shutdown LS1 aiming at peparing for operation at 7 TeV per beam and substantial long term upgrades of both the injector chain and the LHC have been discussed. After a session dedicated to observations and lessons from the run 2011, strategies for the run 2012 have been discussed in order to optimize the machine performance and, in particular, the maximum and integrated luminosity provided to the main experiments. Two session were dedicated to the preparation of the first long shutdown LS1 followed by a session aiming at optimizing the perfromance to be expected after this first shutdown. The last two session of the workshop were dedicated to substantial upgrades of the injector complex and the LHC aiming at increasing the integrated luminosity to 250 inverse femtobarn per year after implementation in a second long shutdown. Improvements of the injector complex comprise increased injection energies in the PS Booster and the PS, an upgrade of the SPS vacuum chamber to alleviate limitations due to electron cloud build up and many more upgrades required for the generation of beams with higher brightness and smaller meittances than possible with the present machines. Plans for the LHC comprise an upgrade of the interaction regions to allow for a smaller beta*, crab cavities for luminosity levelling and, upgrades of the collimation and other systems.