Modelling Control Loops for SPS-LHC Beam Transfer Studies

In the HL-LHC era, the injection of SPS beams might lead to beam losses and RF power limitations in the LHC. An accurate simulation model of both the SPS and LHC control loops in the longitudinal beam dynamics simulator BLonD is indispensable for estimating these beam losses and power limitations. This thesis presents simulation models and benchmarks for the SPS and LHC cavity controllers that control the RF voltage in amplitude and phase in the SPS and LHC accelerating cavities, in high beam-loading conditions. High-intensity, multi-bunch beam distributions can be accurately modelled in the SPS using the SPS cavity controller model, which will be necessary for future beam transfer studies. The SPS model was found to show good agreement with beam measurement data and measurements of the LHC cavity loop transfer functions were accurately reproduced by the LHC cavity loop model.