Beam Dynamics for a New 160 MeV $H^{-}$ Linac at CERN (LINAC4)

Linac4 is a normal conducting H- linac proposed at CERN to provide a higher proton flux to the CERN accelerator chain. It should replace the existing Linac2 as injector for the PS booster (PSB). The same machine can also operate in the future as the front end of the SPL, a 2.2 GeV superconducting linac with 1.8 mA average current. At present Linac4 consists of a Radio Frequency Quadrupole (RFQ), a chopper line, a Drift Tube Linac (DTL), and Cell Coupled DTL (CCDTL) all operating at 352.2 MHz and finally a Side Coupled Linac (SCL) at 704.4 MHz. This paper discusses the overall beam dynamics concept, presents the optics for the different sections of the machine and compares end-to-end simulations realised with two tracking codes (PATH and IMPACT). The influence of phase/energy errors is discussed and the challenging features in the current design are highlighted.