• Sezgin, A. Ö.; Gonzalez Diaz-Palacio, I.; Jiang, X.; Keckert, S.; Knobloch, J.; Kugeler, O.; Ries, R.; Seiler, E.; Tikhonov, D.; Vogel, M.; Zierold, R.: HiPIMS-Coated Novel S(I)S Multilayers for SRF Cavities. In: Frank Zimmermann ... [Ed.] : IPAC2022 : Proceedings of the 13th International Particle Accelerator Conference, in Bangkok, Thailand, 12–17 June 2022Geneva: JACoW, 2022. - ISBN 978-3-95450-227-1, p. TUPOTK016/1-4
    https://accelconf.web.cern.ch/ipac2022/papers/tupotk016.pdf

Open Access Version

Abstract:
Pushing beyond the existing bulk niobium SRF cavities is indispensable along the path towards obtaining more sustainable next generation compact particle accelerators. One of the promising candidates to push the limits of the bulk niobium is thin film-based multilayer structures in the form of superconductor-insulator-superconductor (SIS). In this work, S(I)S multilayer structures were coated by high power impulse magnetron sputtering (HiPIMS), having industrial upscaling potential along with providing higher quality films with respect to conventional magnetron sputtering techniques (e.g., DCMS), combined with (PE)-ALD techniques for deposition of the ex-situ insulating layers. On the path towards formulating optimized recipes for these materials to be coated on the inner walls of (S)RF cavities, the research focuses on innovating the best performing S(I)S multilayer structures consisting of alternating superconducting thin films (e.g., NbN) with insulating layers of metal nitrides (e.g., AlN) and/or metal oxides (e.g., AlxO y) on niobium layers/substrates (i.e., Nb/AlN/NbN) in comparison to the so-called SS multilayer structures (i.e., Nb/NbN). This contribution presents the initial materials and superconducting and RF characterization results of the aforementioned multilayer systems on flat samples.