Author: Kelley, M.J.
Paper Title Page
TUP106 Effect of Surface Flow on Topography in Niobium Electropolishing 1038
 
  • M.J. Kelley, C.E. Reece
    JLAB, Newport News, Virginia, USA
  • L. Zhao
    The College of William and Mary, Williamsburg, USA
 
  Funding: This work has been supported by U.S. DOE Contract No. DE-AC05-06OR23177 to Jefferson Lab
Electropolishing (EP) is reliably delivering improved performance of multi-celled niobium SRF accelerator cavities, attributed to the smoother surface obtained. This superior leveling is a consequence of an etchant concentration gradient layer that arises in the HF-H2SO4 electrolyte adjacent to the niobium surface during polishing. Electrolyte circulation raises the prospect that fluid flow adjacent to the surface might affect the diffusion layer and impair EP performance. In this study, preliminary bench-top experiments with a moving electrode apparatus were conducted. We find that flow conditions approximating cavity EP show no effects attributable to depletion layer disruption.