Conveners
Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures
- Marc Wenskat (DESY/Universität Hamburg)
Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures
- Marc Wenskat (DESY/Universität Hamburg)
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Ke Chen (Temple University)23/09/2026, 09:00Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
Superconducting RF cavities fabricated using MgB$_2$-coated Cu possess the potential to operate at higher temperatures and magnetic fields than SRF cavities made from Nb and Nb compounds. We report the ongoing efforts to develop MgB$_2$-coated Cu Superconducting RF cavities through the Hybrid Physical-Chemical Vapor Deposition technique. Microns-thick MgB$_2$ films coated on mockup 1.3 GHz...
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23. In-depth material studies of SIS multilayers for application using the new cavity-coating systemLea Preece (Universität Hamburg)23/09/2026, 09:25Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
Operating gradients more than twice as high as those in bulk Nb cavities as well as significantly higher Q-values can be achieved by using nm-thin SIS (superconducting-insulating-superconducting) multilayers on the inner surface of a cavity to delay the penetration of vortices. Based on this theory, the University of Hamburg focuses on Atomic Layer Deposition (ALD) for thin film deposition as...
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ryo katayama (High Energy Accelerator Research Organization)23/09/2026, 09:50Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
The maximum accelerating gradient, Eacc,max, of a superconducting radio- frequency (SRF) cavity is limited by the surface magnetic field at which a vortex avalanche occurs on the inner cavity surface. Theoretical studies predict that a superconducting–insulator–superconducting (S′–I–S) multilayer structure can effectively enhance the threshold field for vortex avalanche. Furthermore, an...
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Alexis Grassl (Cornell University)23/09/2026, 10:15Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
Zr-Nb alloys are a promising candidate for SRF cavities due to their reduced sensitivity to stoichiometric deviations, intrinsically smoother interfaces rising from their continuous phase with niobium, and large estimated coherence length. We present surface characterization of this material, introduce a method to coat SRF cavities with this alloy that overcomes the electrochemical instability...
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Alexis Grassl (Cornell University)23/09/2026, 11:05Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
The focus of next-generation SRF cavities has increasingly shifted towards materials capable of sustaining high-gradient continuous-wave operation at 4.2K. Material candidates capable of this feature need lower BCS resistance than niobium and must be free of defects that cause thermal instability and/or quench. Among these candidates, Nb3Sn has emerged as the leading alternative, while others...
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Malvika Tripathi (Fermi National Accelerator Laboratory)23/09/2026, 11:25Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
Here, we evaluate two co-sputtered compounds: Nb–Zr and Nb–Sn–Zr, as prospective superconducting materials for future RF cavity fabrication. We have studied how the crystal lattice structures, surface and bulk morphologies, oxidation states, and superconducting properties modify with variable Zr fraction, to determine the most useful range of Zr inclusions in these compounds for SRF...
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Dr Malvika Tripathi (Fermi National Accelerator Laboratory)23/09/2026, 11:45Beyond Nb & Nb3Sn: Alternate materials, multilayer SIS structures and functional layers
We investigated the superconducting properties of 200 nm thick Nb-Zr thin films with various Zr concentrations ranging from 0 to 22 at.%. 200 nm thick Nb-Zr thin films were deposited on c-plane sapphire substrates by magnetron sputtering at RT, and the microstructures and superconducting properties of the films were systematically analyzed by X-ray diffraction (XRD), transmission electron...
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23/09/2026, 12:05