• E.N. Zaplatin
  FZJ, Jülich
• C. Compton, W. Hartung, M.J. Johnson, F. Marti, J.C. Oliva, J. Popielarski, R.C. York
  NSCL, East Lansing, Michigan

A superconducting linac for re-acceleration of exotic ions is under development at Michigan State University. Two types of superconducting quarter-wave resonators (80.5 MHz, optimum beta = 0.041 and 0.085) will be used for re-acceleration to energies of up to 3 MeV per nucleon initially, with a subsequent upgrade path to 12 MeV per nucleon. Structural design is an important aspect of the overall cavity and cryomodule implementation. The structural design must include stiffening elements, the tuning mechanism, and the helium vessel. The main mechanical design optimization goal is to minimize the shift in the cavity's resonant frequency due to the Lorentz force, bath pressure fluctuations, and microphonic excitation. Structural analyses of the MSU quarter-wave resonators will be presented in this paper. Stiffening measures will be explored. The numerical predictions will be compared to test results on prototype cavities.