| Title |
Microstructure Development in a Cold Worked SRF Niobium Sheet After Heat Treatments |
| Authors |
- S. Balachandran, P. Dhakalpresenter, A-M. Valente-Feliciano
JLab, Newport News, Virginia, USA
- T.R. Bieler
Michigan State University, East Lansing, Michigan, USA
- S. Chetri, P.J. Lee
NHMFL, Tallahassee, Florida, USA
- Z.L. Thune
MSU, East Lansing, USA
|
| Abstract |
Bulk Nb for TESLA shaped SRF cavities is a mature technology. Significant advances are in order to push Q₀’s to 10¹0⁻¹¹(T= 2K), and involve modifications to the sub-surface Nb layers by impurity doping. In order to achieve the lowest surface resistance any trapped flux needs to be expelled for cavities to reach high Q₀’s. There is clear evidence that cavities fabricated from polycrystalline sheets meeting current specifications require higher temperatures beyond 800 °C leads to better flux expulsion, and hence improves Q₀. Recently, cavities fabricated with a non-traditional Nb sheet with initial cold work due to cold rolling expelled flux better after 800 °C/3h heat treatment than cavities fabricated using fine-grain poly-crystalline Nb sheets. Here, we analyze the microstructure development in Nb from the vendor supplied cold work non- annealed sheet that was fabricated into an SRF cavity as a function of heat treatment building upon the methodology development to analyze microstructure being developed by the FSU-MSU-UT, Austin-JLAB collaboration. The results indicate correlation between full recrystallization and better flux expulsion.
|
| Funding |
Jefferson Science Associates, LLC under U.S. DOE Grant DEAC05-06OR23177, U.S. DOE, Office of HEP under Grant DE-SC0009960, and NHMFL through NSF Grant DMR-1644779 and the State of Florida. |
| Paper |
download MOPMB041.PDF [2.317 MB / 6 pages] |
| Cite |
download ※ BibTeX
※ LaTeX
※ Text/Word
※ RIS
※ EndNote |
| Conference |
SRF2023 |
| Series |
International Conference on RF Superconductivity (21st) |
| Location |
Grand Rapids, MI, USA |
| Date |
25-30 June 2023 |
| Publisher |
JACoW Publishing, Geneva, Switzerland |
| Editorial Board |
Kenji Saito (FRIB, MSU, East Lansing, MI, USA); Ting Xu (FRIB, MSU, East Lansing, MI, USA); Naruhiko Sakamoto (RIKEN, Wako, Japan); Volker R.W. Schaa (GSI, Darmstadt, Germany); Paul W. Thomas (FRIB, MSU, East Lansing, MI, USA) |
| Online ISBN |
978-3-95450-234-9 |
| Online ISSN |
2673-5504 |
| Received |
19 June 2023 |
| Revised |
23 June 2023 |
| Accepted |
26 June 2023 |
| Issue Date |
09 July 2023 |
| DOI |
doi:10.18429/JACoW-SRF2023-MOPMB041 |
| Pages |
191-196 |
| Copyright |
 Published by JACoW Publishing under the terms of the Creative Commons Attribution 4.0 International license. Any further distribution of this work must maintain attribution to the author(s), the published article's title, publisher, and DOI. |
|
