Nanoscale Electrodynamic Response of Nb Superconductors

Abstract

Our objective is to study the extreme and local electrodynamic properties of Niobium (Nb), and to relate these properties to specific defects that limit the ultimate RF performance of superconducting radio frequency (SRF) cavities made from Nb. Specifically, we wish to develop a microscopic measure of the response of Nb to RF magnetic fields up to the critical field (Hc) at microwave frequencies (few GHz), and at temperatures down to 4.2 K. In order to image the local electromagnetic response in the GHz frequency regime, a magnetic writer from a commercial hard drive is integrated into the near field microwave microscope and operates with the Nb sample in the superconducting state. The microwave response of Nb thin films from a mesoscopic area are found through linear and nonlinear microwave measurements.

5 pages, 6 figures, Applied Superconductivity Conference (ASC) 2012, Portland, Oregon

References in corpus (7)

• Dynamics of vortex penetration, jumpwise instabilities and nonlinear surface resistance of type-II superconductors in strong rf fields
• Magnetic Pinning of Vortices in a Superconducting Film: The (anti)vortex-magnetic dipole interaction energy in the London approximation
• Doping-Dependent Nonlinear Meissner Effect and Spontaneous Currents in High-Tc Superconductors
• Microwave Nonlinearities of an Isolated Long YBa_2Cu_3O_(7-d) Bi-crystal Grain Boundary
• Pinning and creation of vortices in superconducting films by a magnetic dipole
• Phase-sensitive Harmonic Measurements of Microwave Nonlinearities in Cuprate Thin Films
• Nonlinear Near-Field Microwave Microscope For RF Defect Localization in Superconductors

Cited by in corpus (9)

• Time-dependent Ginzburg-Landau treatment of RF Magnetic Vortices in Superconductors: Vortex-Semiloops in a Spatially Nonuniform Magnetic Field
• High Frequency Nonlinear Response of Superconducting Cavity-Grade Nb surfaces
• Nanoscale Nonlinear Radio Frequency Properties of Bulk Nb : Origins of Extrinsic Nonlinear Effects
• Near-Field Microwave Magnetic Nanoscopy of Superconducting Radio Frequency Cavity Materials
• Imaging the paramagnetic nonlinear Meissner effect in nodal gap superconductor
• Microscopic Examination of SRF-quality Nb Films through Local Nonlinear Microwave Response
• Modeling the nanoscale linear response of superconducting thin films measured by a scanning probe microwave microscope
• Microwave Microscope Studies of Trapped Vortex Dynamics in Superconductors
• Microscopic Investigation of rf Vortex Nucleation in Nb3Sn Films Using a Near-Field Magnetic Microwave Microscope