Meseck, A.; Poeplau, G.; van Rienen, U.: Numerical Studies on the Influence of Fill Patterns on Ion Clouds. In: Proceedings of 11th International Computational Accelerator Physics Conference (ICAP 2012) : Rostock-Warnemünde, Germany, August 19-24, 2012. , 2012. - ISBN 978-3-95450-116-8, p. 146-148
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Energy Recovery Linacs (ERLs) are the most promising candidates for next-generation light sources now under active development. An optimal performance of these machines requires the preservation of the high beam brightness generated in the injector. For this, the impact of the ionized residual gas on the beam has to be avoided as it causes instabilities and emittance growth. Obviously, the vacuum chamber has to be cleared out of ions but as the potential of the electron beam attracts the ions, it is not enough to install vacuum pumps. One measure for ion clearing are gaps in the bunch train long enough that the ions have time to escape the force of the bunch potential. In this paper, we present numerical studies of the behavior of an ion cloud that interacts with a bunch train. Especially, we consider different distributions for the particles in the bunch, different fill patterns and several mixtures of ions in the residual gas. The simulations are performed with the package MOEVE PIC Tracking. The presented numerical investigations take into account the parameters of the ERL BERLinPro with the objective to deduce appropriate measures for the design and operation of BERLinPro.