Quantification of resistive wall instability for particle accelerator machines

Abstract

The aim of this study is to quantify longitudinal resistive wall impedances, corresponding wake functions, andwake potentials for different accelerator machines of interest. Accurate calculations of wake potentials by particle-in-cellcodes are extremely difficult for the investigated parameters; therefore, we use an analytical approach and consider largedomains with fine discretization for the required numerical integrations. The semianalytical wake potential computationsare benchmarked against numerical general purpose 2D/3D Maxwell solver software codes and a different analyticalapproach for a certain set of parameters. We report examples to illustrate limitations of wake potential estimations fromcoupling impedances, and computations for the machines using realistic beam parameters and machine conditions. Anumerical example where the aim is to find the wake potential of the machine from the 5% noisy impedance data isgiven.