Plans for Upgrading the CERN Proton Accelerator Complex

With the construction of the Large Hadron Collider (LHC) in its final phase at CERN, it is now time to prepare for increasing its performance as much as possible and for preparing for the future needs of physics. A basic plan has been proposed by the working group on "Proton Accelerators of the Future", using the input from an ad'hoc physics working group looking after "Physics Opportunities with Future Proton Accelerators". Apart from upgrades in the LHC itself, mainly in the optics of the insertions, the proposal is to renew the injector complex and significantly improve its characteristics. 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) with a ~4 GeV superconducting proton linac (SPL) as injector. The SPS itself will be upgraded for injection at 50 GeV and for better performance with high brightness beams. These proposals will be described as well as their potential for other uses like a neutrino facility.