Status report on multi-cell superconducting cavity development for medium-velocity beams

The Rare Isotope Accelerator (RIA) is being designed to supply an intense beam of exotic isotopes for nuclear physics research. Superconducting cavities are to be used to accelerate the CW beam of heavy ions to 400 MeV per nucleon, with a beam power of up to 400 kW. Because of the varying beam velocity, several types of superconducting structures are needed. This paper covers the fabrication of three prototype RIA 6-cell /spl beta//sub g/ = 0.47 cavities and the RF tests on the first and second of these cavities.