The First Long Shutdown (LS1) for the LHC

The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown, which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. A detailed CERN-wide resource-loaded schedule was prepared aiming at resuming LHC physics in early 2015, while the rest of the CERN complex will gradually start up again in the second half of 2014.\nThe paper describes the preparation phase with the prioritisation of the activities, the building of the teams and the planning of the shutdown. Then, it gives an overview of the injector activities and the main projects in the LHC. The decision to restart at 6.5 TeV after the LS1 is recalled.