For FEL projects based on a superconducting linac operating in CW mode, the RF
power optimization finally comes up against the microphonics disturbances,
which result in an unpredictable detuning of the cavities. A new piezoelectric
tuner was developed and mounted on a TTF 9-cells cavity with an appropriate
instrumentation. This system enables a full characterization of the disturbances
and the tuner behavior. Modeling, simulations and experimental validations were
carried out to demonstrate the feasibility of a feedback compensation for a multi-cell
cavity. The results also bring to some recommendations that may overcome the
limitations pointed out in the present experimentation. |
