RECENT RESULTS FROM Nb3Sn SINGLE CELL CAVITIES COATED AT JLAB
- College of William and Mary, Williamsburg, VA (United States)
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Old Dominion Univ., Norfolk, VA (United States)
- College of William and Mary, Williamsburg, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
Because of superior superconducting properties (Tc ~ 18.3K, Hs h ~ 425 mT and ? ~ 3.1 meV) compared to niobium, Nb3Sn promise better RF performance (Q0 and Eacc) and/or higher operating temperature (2 K Vs 4.2 K) for SRF cavities. Nb3Sn-coated SRF cavities are produced routinely by depositing a few micron-thick Nb3Sn films inside of Nb cavities via tin vapor diffu-sion technique. Early results from Nb3Sn cavities coat-ed with this technique exhibited precipitous low field Q-slope, also known as Wuppertal slope. Several Nb3Sn single cell cavities coated at JLab appeared to exhibit similar Q-slope. RF testing of cavities and ma-terials study of witness samples were continuously used to modify the coating protocol. At best condition, we were able to produce Nb3Sn cavity with Q0 in ex-cess of ? 5×1010 at 2 K and ? 2×1010 at 4 K up the ac-celerating gradient of ~15 MV/m, without any signifi-cant Q-slope. In this presentation, we will discuss re-cent results from several Nb3Sn coated single-cell cavities linked with material studies of witness sam-ples, coating process modifications and the possible causative factors to Wuppertal slope.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Nuclear Physics (NP)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1975499
- Report Number(s):
- JLAB-ACC-19-2982; DOE/OR/23177-6247
- Resource Relation:
- Conference: SRF2019 - Proceedings, Dresden, Germany, June 30, 2019
- Country of Publication:
- United States
- Language:
- English
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