Passive Landau cavity for the LNLS light source electron ring

The electron storage ring at the LNLS light source at Brazil proposes the installation of a passive Landau cavity to alleviate its longitudinal coupled-bunch instabilities. Here, we compute the required shunt impedance of the higher-harmonic cavity, discuss the possible Robinson instability for the two-rf system, and estimate the fastest collective instabilities that can be damped. Finally we investigate the adjustment of rf voltage, synchronous phase, rf detuning, and other consequences in the event that the bunch intensity changes.