Wakefields and HOMs studies of a superconducting cavity module with the CESR beam

Several aspects of the beam-cavity interaction were investigated in a beam test of the superconducting accelerating cavity module for the CESR upgrade: the time structure of the cavity wake potential, sampled with two bunches, the effect of the module on the total machine loss factor, and the influence of the cavity tuner position on the frequencies and damping times of coupled bunch modes. The spectra of some of higher-order modes excited by the beam were also recorded. The results are discussed.