Electropolishing Simulation on Full Scale Radio Frequency Elliptical Structures

This paper describes a methodology to simulate the electropolishing of a full scale radio frequency (RF) accelerating elliptical cavity through data acquired by means of a rotating disc electrode (RDE) in a three electrode set-up. The method combines laboratorial data from the RDE with computational simulation performed with Comsol Multiphysics® either for the primary and secondary current distribution as well as to account for the local effect of hydrodynamic perturbations. The results are compared with experimental data from the electropolishing of niobium 704 MHz and five cell cavity from the Superconducting Proton Linear Accelerator (SPL) R&D; project at CERN.