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 - Junginger, T. ED - Saito, Kenji ED - Xu, Ting ED - Sakamoto, Naruhiko ED - Schaa, Volker R.W. ED - Thomas, Paul W. TI - Energy Barrier at Superconductor-Superconductor Interfaces 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 - In SUST 30 (12), 125012, we reported that coating a superconductor with a larger penetration depth on niobium can increase the field of first vortex penetration Hvp from niobium¿s lower critical field Hc1 to its superheating field Hsh. This was interpreted as an energy barrier at the superconductor-superconductor interface, analogous to the Bean-Livingston barrier at vacuum-superconductor interfaces. A smaller but significant increase in Hvp was observed for low-temperature baked (LTB) niobium. Results from muon spin rotation with variable implantation depth in the micrometer range and vibrating sample magnetometry (Scientific Reports 12 (1), 5522) suggest that the apparent Hvp increase in LTB niobium was due to surface pinning and not an actual Hvp increase. Low-energy muon spin rotation results further support that interpretation as a distinct bipartite magnetic screening profile is observed for actual bilayers (arXiv:2304.09360) but not for LTB niobium (PR Applied 19 (4), 044018 and arXiv:2305.02129). This suggests that the reason why some LTB niobium SRF cavities reach surface magnetic fields beyond Hc1 is specific to RF effects, such as the nucleation time. PB - JACoW Publishing CP - Geneva, Switzerland ER -