Extreme diffusion limited electropolishing of niobium radiofrequency cavities

TL;DR

This paper presents a novel electropolishing technique using a modulated oscillating current waveform for niobium RF cavities, demonstrating reliable results across a range of frequencies and potential for multicell applications.

Contribution

It introduces a new electropolishing method with a specific current waveform that improves surface treatment of niobium RF cavities.

Findings

Achieved a stable, modulated current waveform during electropolishing

Demonstrated effective polishing across 500 MHz to 3.9 GHz frequencies

Potential extension to multicell cavity structures

Abstract

A deeply modulated, regular, continuous, oscillating current waveform is reliably and repeatably achieved during electropolishing of niobium single-cell elliptical radiofrequency cavities. Details of the technique and cavity test results are reported here. The method is applicable for cavity frequencies in the range 500 MHz to 3.9 GHz and can be extended to multicell structures.