- R&D 100 Awards
The patented FARADAYIC HF-FREE ElectroPolishing process is directed toward surface finishing of niobium superconducting radio frequency (SRF) cavities. Due to the properties inherent in niobium, it is the most widely-used material for SRF cavity preparation. The attractive low-loss property of high-field radio frequency superconductivity is a nanoscale near-surface phenomenon. Maximizing the useful accelerating electric fields in these structures requires minimizing local microscopic enhancements of the surface magnetic field. Consequently, the interior surface of niobium cavities must be extremely smooth in order to achieve optimal cavity performance. In contrast to conventional electropolishing based on direct current (or voltage) electric fields, the FARADAYIC HF-FREE ElectroPolishing process is based on pulse reverse or “bipolar” electric fields. In the pulse reverse current process, an anodic or forward current pulse is followed by an off-time, which is followed by a cathodic or reverse pulse.