Transverse Instabilities Due to Wall Impedances in Storage Rings

RF voltages are induced by charged particle beams in the impedances of surrounding metallic or dielectric structures. These voltages may reinforce perturbations of the charge distribution and cause instabilities of a beam. Transverse oscillations are particularly dangerous, as the usually small transverse apertures of the vacuum chamber often lead to loss of part or all of the particle beam. In this review, we limit ourselves to a transverse instability of single bunches which has been observed rather recently in large electron positron storage rings and which has become known as transverse turbulence, fast head-tail effect or transverse modecoupling instability.