Performance Evaluation of ERL Main Linac Tuner

We evaluated a slidejack tuner adopted as compact ERL Main Linac tuner. The frequency of cavity is disturbed by not only its Lorenz detuning but also michrophinics come from the outer disturbance. KEK tuner compensates the frequency by extending a cavity. Tuning is driven by two system, piezo and slidejack system. Slide-jack mechanism with long stroke drives coarsely piezo adjust precisely and fast. We tested performance of the tuners on operation.