Simulations of the Micro-Bunching Instability for SOLEIL and KARA Using Two Different VFP Solver Codes

The longitudinal dynamics of a bunched electron beam is an important aspect in the study of existing and the development of new electron storage rings. The dynamics depend on different beam parameters as well as on the interaction of the beam with its surroundings. A well established method for calculating the resulting dynamics is to numerically solve the Vlasov-Fokker-Planck equation. Depending on the chosen parameters and the considered wakefields and impedances, different effects can be studied. One common application is the investigation of the longitudinal micro-wave and micro-bunching instabilities. The latter occurs for short electron bunches due to self-interaction with their own emitted coherent synchrotron radiation (CSR). In this contribution, two different VFP solvers are used to simulate the longitudinal dynamics with a focus on the micro-bunching instability at the Soleil synchrotron and the KIT storage ring KARA (Karlsruhe Research Accelerator).