The
paper presents an implementation technique to damp the microphonics in
superconducting resonators utilizing the coupling between the
electromagnetic and the mechanical modes of a resonator. In the
technique used the resonant frequency variations are fed back to
modulate the field amplitude through a suitable transfer function. Of
the two transfer functions used in the experiments, one emulates a
derivative action and is placed in a negative feedback configuration.
The other transfer function is essentially a parallel combination of
second order low pass filters and is used in a positive feedback
configuration. Experiments with the Quarter Wave resonators of IUAC, New
Delhi linac demonstrate that the damping of some of the modes increases
significantly with the introduction of this feedback leading to a
reduction in power required for field stabilization and quieter
operation of the RF control system.