Characterization of the slow extraction frequency response

Abstract

The main physics program of the CERN Super Proton Synchrotron (SPS) is dedicated to the fixed target physics experiments hosted in the North experimental Area (NA). Protons are delivered to the NA via third-integer resonant slow extraction over an almost 5 s flattop. In order to maximize the usable intensity delivered to the experiments, the flux of extracted particles should be kept as constant as possible. This is a very general requirement for fixed target experiments served by synchrotrons. Power supply ripples are a well-known issue in resonant slow extraction, affecting the quality of the spill. A long-standing effort is ongoing at CERN to characterize the SPS slow extraction frequency response to its main power supplies. In this paper, beam dynamics simulations are employed to understand and characterize the process, combined with dedicated beam based measurements.