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Time Resolved Magneto-Optical Imaging in High Frequency AC Currents of YBa2Cu3O7-delta Thin Films (Postprint)
Conference paper postprint 1 Jan 2004-1 Jan 2006
AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
Pagination or Media Count:
We present a time-resolved magneto-optical MO imaging study of high-temperature superconductor HTS in high-frequency alternating current AC regime. The evolution of the magnetic flux density distribution in YBa2Cu3O7-delta YBCO thin film samples is studied in small steps of the phase of the applied AC current. The flux distribution at 10 K exhibits instabilities including flux jumps and flux creep. A quantitative analysis of the data allows us to obtain the current density evolution. The current profile changes considerably with the phase differently from the prediction of the critical state model. These observations can be explained by the higher self-field at the sample edge and the effects of flux creep.
APPROVED FOR PUBLIC RELEASE