Beam Dynamics in the Superconducting Section of the SPL (120 MeV - 2.2 GeV)

After the decomissioning of LEP-2 a considerable amount of RF hardware becomes available and can be used for the construction of a high current superconducting proton linac [1]. The present design of the SPL uses four types of superconducting cavities (beta=0.52, 0.7, 0.8, and LEP) to accelerate a pulsed beam of 70 mA from 120 MeV up to 2.2 GeV. In this paper a beam dynamics layout for the superconducting section is presented. The layout is optimized to keep the overall linac length short and to ensure a stable steering of the beam. Multiparticle simulations have been carried out to analyse the proposed focusing structure, and to investigate emittance growth for the nominal case and for a mismatched input beam.