No interface energy barrier and increased surface pinning in low temperature baked niobium.

ABSTRACT: Superconducting Radio-Frequency cavities are currently made out of niobium. Niobium cavities are limited by the magnetic field on the cavity walls due to the entry of vortices at the field of first vortex penetration, H[Formula: see text]. Low temperature baking in vacuum or low pressure gas atmosphere removes the strong decrease of the quality factor with accelerating gradient (high field Q-slope). Some cavities reach surface magnetic field above the lower critical field H[Formula: see text]. One hypothesis for this performance increase is that the outer layer affected by the treatments acts as a barrier for vortex penetration (effective bilayer). Using a vibrating sample magnetometer the field of first flux penetration (H[Formula: see text]) was measured for Nb ellipsoids with various lo

SUBMITTER: Turner DA 

PROVIDER: S-EPMC8976006 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature