Transverse decoherence and emittance growth of ion bunches with space charge

The transverse decoherence of the bunch signal after an initial bunch displacement is an important process in synchrotrons and storage rings. It can be useful, for the diagnostic purposes, or undesirable. Coherent bunch oscillations can appear after the bunch-to-bucket transfer between synchrotrons and can lead to an emittance blow-up. In heavy ion and proton beams, like in SIS100 synchrotron of the FAIR project, transverse space charge can strongly modify the decoherence signals. The bunch oscillations produced by a transverse kick and the time evolution of the transverse emittance have been measured at the SIS18 synchrotron for different beam and machine parameters. For comparison, particle tracking simulations of transverse bunch decoherence and emittance increase due to chromaticity, nonlinearities and strong space-charge have been performed. The goal of these studies is a detailed understanding of the interplay of the different effects.