Hom Damping Optimization Design Studies for BESSY VSR Cavities

The BESSY VSR project is a future upgrade of the 3rd generation BESSY II light source. By using the same standard user optics, simultaneously long ca. 15ps and short ca. 1.5ps bunches will be stored. Thus, SRF higher harmonic cavities of the fundamental 500 MHz at two frequencies need to be installed in the BESSY II storage ring. This work describes the optimization studies for the waveguide based HOM dampers and the adjustable fundamental power coupler for the 1.5 GHz first SRF cavity prototyp