Undergraduate Research at Jefferson Lab

Optimization of Bipolar Electropolishing for Niobium Accelerator Cavities

Student: Cynthia McCord

School: University of West Florida

Mentored By: Hui Tian

Although effective, the current polishing processes used for niobium accelerator cavities involve dangerous and environmentally hazardous electrolytes. In this project a safer technique, bipolar electropolishing is being investigated for these cavities. Bipolar electropolishing involves sending alternating anodic and cathodic pulses with corresponding off times through the niobium sample in a low viscosity HF free electrolyte. The anodic pulse grows a layer of surface oxide, and the cathodic pulse directly or chemically reduces this layer for material removal. The purpose of this project is to test different parameters for bipolar electropolishing of niobium to optimize and gain insight into the mechanism of the process.