Fundamental mode characteristics of ARES cavity under beam environment

Two types of ARES cavities were tested in the TRISTAN accumulation ring in KEK. In this paper, results relating to the fundamental mode in the accelerating cavity are reported. The status of the cavity, including the detuning frequency under beam loading and the output power from the coupling cavity damper, was measured at different beam current and with various bunch patterns. Its behavior agrees well with the calculation based on a coupled resonator model.