R amp;D Activities on Centrifugal Barrel Polishing of 1.3 GHz Niobium Cavities at DESY University of Hamburg

In this paper the status of research activities at ILCHiGrade Lab DESY University of Hamburg on Centrifugal Barrel Polishing CBP of 1.3 GHz Niobium Cavities is presented. We focus on CBP based on the polishing recipe reported by Fermi National Laboratory and Jefferson Lab [1]. The aim is to gain a better understanding of the limitations of this technique, detailed characterization of the treated surface after each polishing step using a coupon single cell cavity. Plastic deformations upon initial CBP steps, embedded polishing media and residual damage upon final polishing were investigated at different areas of the cavit