Nonlinear Near-Field Microwave Microscope For RF Defect Localization in Superconductors

Abstract

Niobium-based Superconducting Radio Frequency (SRF) cavity performance is sensitive to localized defects that give rise to quenches at high accelerating gradients. In order to identify these material defects on bulk Nb surfaces at their operating frequency and temperature, it is important to develop a new kind of wide bandwidth microwave microscopy with localized and strong RF magnetic fields. By taking advantage of write head technology widely used in the magnetic recording industry, one can obtain ~200 mT RF magnetic fields, which is on the order of the thermodynamic critical field of Nb, on submicron length scales on the surface of the superconductor. We have successfully induced the nonlinear Meissner effect via this magnetic write head probe on a variety of superconductors. This design should have a high spatial resolution and is a promising candidate to find localized defects on bulk Nb surfaces and thin film coatings of interest for accelerator applications.

arXiv comment4 pages, 6 figures Journal-ref: 2010 Applied Superconductivity Conference

References in corpus (5)

• In situ epitaxial MgB2 thin films for superconducting electronics
• Spatially Resolved Nonlinearity Measurements of YBa${}_2$Cu${}_3$O${}_{7-d}$ Bi-crystal Grain Boundaries
• Microwave Nonlinearities of an Isolated Long YBa_2Cu_3O_(7-d) Bi-crystal Grain Boundary
• Phase-sensitive Harmonic Measurements of Microwave Nonlinearities in Cuprate Thin Films
• Study of Local Nonlinear Properties Using a Near-Field Microwave Microscope

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• High-Temperature Superconducting Spiral Resonator for Metamaterial Applications
• Nanoscale Nonlinear Radio Frequency Properties of Bulk Nb : Origins of Extrinsic Nonlinear Effects
• High Frequency Nonlinear Response of Superconducting Cavity-Grade Nb surfaces
• Nanoscale Electrodynamic Response of Nb Superconductors
• Near-Field Microwave Magnetic Nanoscopy of Superconducting Radio Frequency Cavity Materials
• Microwave Nonlinearity and Photoresponse of Superconducting Resonators with Columnar Defect Micro-Channels
• 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
• MgB2 nonlinear properties investigated under localized high rf magnetic field excitation-report 2
• Mgb2 Nonlinear Properties Investigated under Localized High RF Magnetic Field Excitation