Upgrade Issues for the Cern Accelerator Complex

The Large Hadron Collider (LHC) at CERN is at a very advanced stage of hardware commissioning and the first beam collisions in the experiments are expected during the year 2008. In line with the recommendations issued in 2006 by the European Strategy Group for Particle Physics, work has now started for maximizing the physics reach of the LHC and for preparing for other foreseeable needs. Beyond upgrades in the LHC itself, mainly in the optics of the insertions, the injector complex has to be renewed to deliver beam with upgraded characteristics with a high reliability. In a first phase, a new 160 MeV H linac (“Linac4”) will be built to replace the present 50 MeV proton linac (Linac2) and extensive consolidation will be made. In a second phase, the present 26 GeV PS and its set of injectors (Linac2 + PSB) are planned to be replaced with a ~50 GeV synchrotron (“PS2”) using a ~4 GeV superconducting proton linac (“SPL”) as injector. The SPS itself will also be the subject of major improvements, to be able to cope with a 50 GeV injection energy and with beams of much higher brightness. These proposals are described as well as their potential to evolve and fit the needs of future facilities for radioactive ions and/or neutrinos.