Transverse emittance blow-up from beam injection errors in synchrotrons with nonlinear feedback systems

The problem of transverse emittance blow-up from beam injection errors in synchrotrons with nonlinear feedback systems is considered. The relative emittance growth is calculated for linear and nonlinear feedback transfer functions. Effects of an increase of the damping decrement of the beam coherent oscillations and of a decrease of the coherent transverse amplitude spread of different bunches in case of the damper with a positive cubic term in the feedback transfer function are discussed. The text was submitted by the author in English.