Latest Development of Electropolishing Optimization for 650 MHz Niobium Cavity
physics.acc-ph
/ Authors
V. Chouhan, D. Bice, D. Burk, S. Chandrasekaran, A. Cravatta, P. Dubiel, G. V. Eremeev, F. Furuta, O. Melnychuk, A. Netepenko
and 8 more authors
M. K. Ng, J. Ozelis, H. Park, T. Ring, G. Wu, B. Guilfoyle, M. P. Kelly, T. Reid
/ Abstract
Electropolishing (EP) of 1.3 GHz niobium superconducting RF cavities is conducted to achieve a desired smooth and contaminant-free surface that yields good RF performance. Achieving a smooth surface of a large-sized elliptical cavity with the standard EP conditions was found to be challenging. This work aimed to conduct a systematic parametric EP study to understand the effects of various EP parameters on the surface of 650 MHz niobium cavities used in the Proton Improvement Plan-II (PIP-II) linear accelerator. Parameters optimized in this study provided a smooth surface of the cavities. The electropolished cavity showed significantly a higher accelerating gradient meeting baseline requirement and qualified for further surface treatment to improve the cavity quality factor.