CLIC-DR electron cloud build up simulations

This study investigates impact of beam pipe material and external magnetic field on electron cloud build up mechanism. The machine parameters are in the scope of CLIC damping rings. Two dierent filling schemes for 0.5 and 1 ns bunch spacings are considered. VSim Plasma Discharges and Plasma Acceleration package is employed to perform 2D electrostatic particle in cell simulations such that the space charge eect and Furman-Pivi secondary emission yield model are included in the computations. It is illustrated that the build up time varies due to bunch spacing while the external magnetic field influences the number of electrons generated by initial seeds. The evolution of generated secondary electrons due to bunch passes and the corresponding energy levels are presented in details.