  Operation of Superconducting Radio Frequency (SRF) cavities with high loaded
quality factors is becoming increasingly preferred for applications which
involve low beam loading including Energy Recovery Linacs (ERL). Vibration
induced microphonics detuning poses a major operational bottleneck in these low
bandwidth systems, adversely affecting field stability. Besides passive
measures of mitigating the vibration sources, modern SRF cavities are also
attached to fast tuners incorporating piezo-electric actuators. We demonstrate
the narrow band active noise control algorithm for realizing active resonance
control and propose a modification based on the Least Mean Square approach to
adaptively tune the control parameters and study it's stability and
performance. We discuss our experience of using passive mitigation techniques
while commissioning the Main Linac Cryomodule of the Cornell-BNL ERL Test
Accelerator (CBETA) and report a net reduction in peak detuning by more than a
factor of 2 in its unstiffened cavities. Finally, we demonstrate stable
performance of our resonance control system with consistent reduction of peak
microphonics detuning by almost a factor of 2 on multiple cavities.
