| Paper | Title | Page |
|---|---|---|
| TUPTB020 | Surface Properties and RF Performance of Vapor Diffused Nb₃Sn on Nb after Sequential Anneals below 1000 °C | 433 |
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| Nb₃Sn is a next-generation superconducting material that can be used for future superconducting radiofrequency (SRF) accelerator cavities, promising better performance, cost reduction, and higher operating temperature than Nb. The Sn vapor diffusion method is currently the most preferred and successful technique to coat niobium cavities with Nb₃Sn. Among post-coating treatments to optimize the coating quality, higher temperature annealing without Sn is known to degrade Nb₃Sn because of Sn loss. We have investigated Nb₃Sn/Nb samples briefly annealed at 800-1000 °C, for 10 and 20 minutes to potentially improve the surface to enhance the performance of Nb₃Sn-coated cavities. Following the sample studies, a coated single-cell cavity was sequentially annealed at 900 °C and tested its performance each time, improving the cavity’s quality factor relatively. This paper summarizes the sample studies and discusses the RF test results from sequentially annealed SRF Nb₃Sn/Nb cavity. | ||
| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-TUPTB020 | |
| About • | Received ※ 19 June 2023 — Revised ※ 29 June 2023 — Accepted ※ 01 July 2023 — Issue date ※ 07 July 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| WEPWB052 | Temperature, RF Field, and Frequency Dependence Performance Evaluation of Superconducting Niobium Half-Wave Coaxial Cavity | 691 |
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Funding: This is authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05- 06OR23177 Recent advancement in superconducting radio frequency cavity processing techniques, with diffusion of impurities within the RF penetration depth, resulted in high quality factor with increase in quality factor with increasing accelerating gradient. The increase in quality factor is the result of a decrease in the surface resistance as a result of nonmagnetic impurities doping and change in electronic density of states. The fundamental understanding of the dependence of surface resistance on frequency and surface preparation is still an active area of research. Here, we present the result of RF measurements of the TEM modes in a coaxial half-wave niobium cavity resonating at frequencies between 0.3 - 1.3 GHz. The temperature dependence of the surface resistance was measured between 4.2 K and 1.6 K. The field dependence of the surface resistance was measured at 2.0 K. The baseline measurements were made after standard surface preparation by buffered chemical polishing. |
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| DOI • | reference for this paper ※ doi:10.18429/JACoW-SRF2023-WEPWB052 | |
| About • | Received ※ 18 June 2023 — Revised ※ 24 June 2023 — Accepted ※ 26 June 2023 — Issue date ※ 20 July 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |