New Insight on Nitrogen Infusion Revealed by Successive Nanometric Material Removal
Mattia Checchin, Anna Grassellino, Martina Martinello, Oleksandr Melnychuk, Sam Posen, Alexander V. Romanenko, Dmitri A. Sergatskov · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 2018
In this study we present new insight on low temperature nitrogen infusion on bulk niobium superconducting radio-frequency (SRF) cavities. Nitrogen infusion is a thermal treatment recently discovered at Fermilab that allows to reach high accelerating gradients, of the order of 45MV/m, with high Q-factors, of the order of 2 · 10¹⁰. Detailed depth dependent RF studies (by means of subsequent HF rinses) and comparisonwith SIMS results pinpointed interstitial nitrogen as the responsible for the improved performance and uncovered the extension of its profile inside the material.