Simulation, measurement and mitigation of the beam induced power loss in the SPS injection kickers

The kickers, used to impart fast deflection to the beam in an accelerator, may suffer from high heating due to beam induced power loss created by their large impedance.In order to reduce the power loss in the SPS injection kickers (MKP-S and MKP-L), their impedance is investigated using the CST Wakefield Solver.Therefore in this work, the existing model of the MKP-S kicker is compared to measurements and then refined.The influence of transition pieces, installed inside the measured tank, is investigated employing simulations.The impact of the decoupling network, between the HV-conductor and the GND-conductor, is investigated using lumped element networks in the simulation.The effect on the impedance of measuring two kickers in series is investigated executing simulations.The improvements made to the MKP-S model are translated to the MKP-L model.The power loss reduction achievable through offsetting the beam out of the centre of the kickers aperture in the direction of the ground conductor is investigated by simulations for both kickers.The results are validated through measurements on the MKP-S: An MKP-L was not available for measurements.Calculations show that the maximal power loss reduction achievable by that measure for the MKP-L is 30%.Several serigraphy designs are introduced, simulated and their feasibility is discussed.The most promising concept, including also the transition pieces and thus shielding the cavities between themselves and the kicker, is realised as a prototype and measured.The measurements prove the impedance reduction through the serigraphy design.Calculations show that this serigraphy could reduce the power loss in the MKP-S by 45% in the MKP-L by 70%.Contents 4.3.Beam offset impedance measurements . . . . . .