Visualization of Coupling Current Paths in Striated YBCO-Coated Conductors at Frequencies up to 400 HZ
Abstract
The magnetic flux density component perpendicular to the broad tape face was mapped by miniature Hall probes in the vicinity of a striated YBCO-coated tape at frequencies of external magnetic field from 21 to 400 Hz, applied perpendicularly to the tape surface. For reasons of modeling the coupling current behaviour in tapes with a conductive substrate, we amplified the coupling current-amplitude by soldering 25 microns thick copper foil on the top of the filaments. The aim of this procedure was to decrease the transverse resistivity of the tape. The longitudinal components of the total currents flowing in the tape were calculated by an inverse method from the field map corresponding to the zero phase of the applied field. The diffusion lengths, characterizing the flux penetration into the tape, were determined for the respective frequencies. The experimentally determined diffusion length is in good accordance with theoretical models. While at 21 Hz both weak coupling currents and distinctive hysteretic currents of individual filaments are observed, at 400 Hz the coupling currents are predominant in this YBCO tape.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2008
- Accession Number
- ADA488275
Entities
People
- E. Demencik
- George A. Levin
- I. Vavra
- M. Polak
- P. Usak
- Paul N. Barnes
- S. Takacs
Organizations
- Air Force Research Laboratory