Coherent Synchrotron Radiation and Microbunching Instability

Abstract

Emission of coherent synchrotron radiation (CSR) in dipole magnets by ultra-relativistic electron beams is treated. The CSR impact on beam energy distribution and transverse emittance is discussed, and methods for minimizing emittance growth are recalled. A qualitative explanation of the contribution of CSR to the microbunching instability is given. This instability is treated in some detail in the presence of longitudinal space-charge force and magnetic bunch-length compression. Special attention is given to the aforementioned collective effects such as for the production of high peak current bunches driving free-electron lasers.