Effect of the Extraction Kickers on the Beam Stability in the CERN SPS

Longitudinal beam instability in the CERN SPS is a major limitation in the ability to achieve the bunch intensities required for the goals of the High-Luminosity LHC project (HL-LHC). One of the major drivers in limiting the intensity of the machine is the broadband contribution to the beam-coupling impedance due to the kicker magnets. The extraction kickers (MKE) discussed in this paper are known to give a significant contribution to the overall longitudinal beam-coupling impedance. We present the results of bench measurements of the MKE's impedance to determine the accuracy of electromagnetic simulation models from which the impedance modelused for beam dynamics simulationsis constructed. In addition, we discuss the feasibility and implementation of beam measurements that can indicate the contribution of the MKE magnets to the longitudinal beam-coupling impedance of the SPS.