Status of the Stony Brook Superconducting Heavy-Ion Linac

The present status of the Stony Brook Superconducting Heavy-Ion Linear Accelerator is described, with emphasis on recent operational results with a prototype unit of the accelerator. The basic LINAC elements are independently-phased lead-plated copper split-loop resonators operating at 151.7 MHz and optimized for velocities of either ß=v/c= 0.055 or ß=0.10. Resonators are grouped in units of either 4 low-ß or 3 high-ß resonators in compact cryostat modules separated by room-temperature quadrupole-doublet lenses. The LINAC consisting of 4 low-ß and 7 high-ß modules injected with heavy ions of mass A¿16-100 from the Stony Brook EN tandem will produce an additional energy gain of ~18 MeV per unit charge with a total heat dissipation at 4.5K of <300 Watts. In recent tests with low-ß prototype units, individual resonators were operated continuously at accelerating gradients in excess of 3.5 MV/m, and were phase and amplitude stabilized at 3.0 MV/ m using 175 Watts of RF power. Helium-temperature dissipation at 3.0 MV/m is ~8 Watts after helium-gas conditioning. The prototype low-ß module was used to accelerate a 30 Mev 16O5+ beam to ~35 MeV.