JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
@inproceedings{bafia:srf2021-thptev016,
author = {D. Bafia and A. Grassellino and A.S. Romanenko},
title = {{The Role of Oxygen Concentration in Enabling High Gradients in Niobium SRF Cavities}},
booktitle = {Proc. SRF'21},
% booktitle = {Proc. 20th International Conference on RF Superconductivity (SRF'21)},
pages = {871--875},
eid = {THPTEV016},
language = {english},
keywords = {cavity, niobium, SRF, ECR, radio-frequency},
venue = {East Lansing, MI, USA},
series = {International Conference on RF Superconductivity},
number = {20},
publisher = {JACoW Publishing, Geneva, Switzerland},
month = {10},
year = {2022},
issn = {2673-5504},
isbn = {978-3-95450-233-2},
doi = {10.18429/JACoW-SRF2021-THPTEV016},
url = {https://jacow.org/srf2021/papers/thptev016.pdf},
abstract = {{We studied the role of O concentration with depth in the performance of Nb SRF cavities. An ensemble of electropolished 1.3 GHz cavities, which initially showed high field Q-slope (HFQS), was subjected to sequential testing and treatment with in-situ low temperature baking at various temperatures. We find that increasing the bake duration causes (i) an increase in the onset of HFQS until it is absent up to quench (ii) a non-monotonic relationship with the quench field (iii) an evolution of the RBCS toward a non-equilibrium behavior that drives anti-Q slope. Our data is qualitatively explained by assuming an O diffusion model and suggests that the mitigation of HFQS that arises from 120°C in-situ LTB is mediated by the diffusion of O from the native oxide which prevents the precipitation of proximity-coupled Nb nano-hydrides, in turn enabling higher quench fields. The decrease in quench field for cavities in which O has been diffused >90 nm from the RF surface may be due to a reduction of the field limit in the SS bilayer structure. We also suggest that the evolution of the RBCS occurs due to the absence of proximity coupled inclusions, bringing about non-equilibrium effects.}},
}