K. W. Shepard (Argonne National Laboratory), T. E. Tretyakova (Institute of Theoretical and Experimental Physics, Moscow)
A superconducting multi-ion-beam driver linac for an exotic beam facility has been described elsewhere[1]. The linac would accelerate all ions from protons to uranium to energies of 400 MeV/u and above, with a beam power of several hundred kilowatts. This paper describes the design of a group of superconducting accelerating structures for that portion of the linac for particle velocities less than 0.5c. Six different ion-accelerating rf cavity geometries have been developed to span the velocity range from .05c < b < .5c. The structures are designed for construction of niobium and superconducting operation at 4.3 K. The structures range in frequency from 58 to 350 MHz. The three lowest-velocity cavity types are of the coaxial quarter-wave line class, including two types of 4-gap interdigital cavity and one type of 2-gap cavity. The three higher-velocity cavity types are all two-drift-tube structures, of differing frequencies, but designed to fit the same size and shape of outer housing, in order to minimize construction and cryostat costs. Results of numeric simulation and also of warm model measurements will be presented.
[1] K. W. Shepard, et al., in Proc. of the 9th Workshop on RF Superconductivity, November 1-5, 1999, Santa Fe, New Mexico.
*Work supported by the U. S. Department of Energy, Nuclear Physics Division under contract W-31-109-ENG-38
Comments or Questions to
linac2000@slac.stanford.edu