JACoW is a publisher in Geneva, Switzerland that publishes the proceedings of accelerator conferences held around the world by an international collaboration of editors.
TY - UNPB
AU - Asaduzzaman, M.
AU - Beverstock, D.R.
AU - Junginger, T.
AU - McFadden, R.M.L.
AU - Prokscha, T.
AU - Salman, Z.
AU - Suter, A.
AU - Valente-Feliciano, A-M.
ED - Saito, Kenji
ED - Xu, Ting
ED - Sakamoto, Naruhiko
ED - Schaa, Volker R.W.
ED - Thomas, Paul W.
TI - Experimental Evidence for Current Suppression in Superconducting Hetero Structures
J2 - Proc. of SRF2023, Grand Rapids, MI, USA, 25-30 June 2023
CY - Grand Rapids, MI, USA
T2 - International Conference on RF Superconductivity
T3 - 21
LA - english
AB - Coating Nb with thin layers of superconductors of higher penetration depth, than Nb have been proposed as a means of obtaining accelerating gradients (E_{acc}) of beyond Nb’s fundamental limit. Such heterostructures (which can also contain insulating layers between the superconductors) can potentially sustain their Meissner state above the superheating field, Bsh (of all the layers) due to the suppression of the Meissner screening current in the surface layer(s) induced by a counter-current in the substrate layer. We report evidence for counter-current flow in superconductor- superconductor (SS) Nb-Ti-N/Nb samples from depth-resolved measurements of their Meissner screening profiles at applied fields below or equal to 25 mT using the low energy muon spin rotation (LE-muSR) technique. Fits to the London model with appropriate boundary and continuity conditions determine the penetration depth of the Nb-Ti-N layers to be 182.5(31) nm in good agreement with literature values. Our results suggest that due to the strong suppression of the Meissner currents in the surface layer, multilayered structures of several superconducting and insulating layers are necessary to reach highest E_{acc}.
PB - JACoW Publishing
CP - Geneva, Switzerland
ER -