Title :
Power dependencies of the surface impedance of Y-Ba-Cu-O
Author :
Halbritter, J. ; Numssen, K. ; Gaganidze, E.
Author_Institution :
Forschungszentrum Karlsruhe, Germany
fDate :
3/1/2001 12:00:00 AM
Abstract :
The application of HTS is obstructed by the nonlinear behavior of Z(T,f,Hrf) with rf field. The study of those nonlinearities profits by carefully calibrated rf measurements in the frequency and time domain, which yield δRS(H)∝Hn∝S(H). In contrast to δRS(H)∝Hn, the ratio r=δXS/δRS is independent of geometry factor and shows distinct T and f dependencies for various mechanisms and rf set-ups. The high power rf response in the frequency domain yields nonlinear resonance curves, n and r values. The time domain measurements give useful insight about dynamics of the underlying nonlinear mechanisms. The results r≈1 and n≈1-2 are in line with Josephson fluxons in weak links, which may interact with dc fluxons threading through the weak links
Keywords :
Josephson effect; barium compounds; flux-line lattice; frequency-domain analysis; high-frequency effects; high-temperature superconductors; surface conductivity; time-domain analysis; yttrium compounds; Josephson fluxons; Y-Ba-Cu-O; YBa2Cu3O7; dc fluxons; frequency domain; geometry factor; high power rf response; nonlinear behavior; nonlinear resonance curves; power dependencies; rf field; rf measurements; surface impedance; time domain; weak links; Couplings; Frequency domain analysis; Frequency measurement; Geometry; High temperature superconductors; Resonance; Surface impedance; Surface resistance; Time measurement; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
