Transport losses for different values of the background dc field. The loss curve of the virgin sample and the theoretical predictions by Norris are also shown.
Measured characteristic for the Ni–W substrate.
Losses in the Ni–W substrate as a function of the local field.
Penetration distance from the substrate’s edge of the front of the region corresponding to local fields greater than as a function of the applied field. Above this value of the field, the losses tend to saturate.
Losses of the tape decomposed to the “pure” losses in the superconductor (assumed to be the measured losses for a dc field of ) and losses in the substrate [computed by finite element method (FEM)]. The sum of the two contributions is very close to the curve of the virgin tape.
Magnetic susceptibility of the substrate as a function of the applied field. A continuous fit of the data points has been used in FEM simulations as a constitutive relation for the substrate material.
(Color online) Magnetic field profile for a dc applied field of in the presence of (a) superconductor only, (b) substrate only, and (c) both of them. In the third case, the field inside the substrate is much higher, about . Only the right half of the tape is shown.
Transport losses with a dc field turned on and off. Once the field is turned off, it is necessary to run twice a current ramp-up to to erase the memory of the trapped flux and obtain the original loss curve of the virgin sample.
(Color online) Calculated field distribution after removing the background dc field. Only the right half of the tape is shown.
ZFC and FC measurements for a background dc field of .
Losses obtained with different current ramps after removing a background dc field of (ZFC).
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