Influence of the momentum compaction upon Landau cavity stability

A fourth-harmonic. "Landau" radiofrequency (RF) cavity suppresses coupled bunch instabilities and increases the beam lifetime of the Aladdin electron storage ring. When the storage ring is operated with a small momentum compaction, instabilities limit the utility of the Landau cavity. Analytic modeling and simulations suggest that instabilities result from fast mode-coupling between the dipole and quadrupole Robinson modes.