An injector for a multi ion beam driver linac

An advanced facility for the production of exotic shortlived isotopes far from stability (RIA) could use as the driver a high power cw superconducting linac. Due to the wide range of particle velocities (/spl beta/=0.019-0.81), different cavity types are required. This paper describes a possible design for the injector portion (up to /spl beta/=0.1) of the driver linac. The proposed injector design consists of a multi-harmonic buncher, an RFQ (f=57.5 MHz), 4-gap fork resonators (f=57.5 MHz), and finally, 2-gap quarter wave resonators (f=86.25 MHz). The results of numerical simulations and a comparison different possible RFQ designs (4-vane, IH) are presented.