Abstract
A study of the DC I-V curves of BSCCO tapes exposed to AC perpendicular and parallel magnetic fields is presented. AC magnetic fields with amplitudes up to 700 G and frequencies from 1 to 430 Hz have been applied perpendicular and parallel to tapes carrying DC currents at T = 77 K. Both field orientations result in a significant DC electric field increase, in comparison to applying DC magnetic fields of the same intensity. However, the observed I-V curves behavior is different for the perpendicular and parallel cases. In the perpendicular case, we distinguish between two frequency regimes: for frequencies above 40 Hz, the observed I-V curves obey the empirical power law dependence with current density, JC, and power index, n, that strongly depend on the field amplitude. For frequencies below 20 Hz, the observed I-V curves deviate from power law description. In the parallel field case, the I-V curve can be regarded as a superposition of an additional DC voltage over the no field I-V curve. This additional voltage increases with increasing current, peaks near the critical current and decreases thereafter. The results are discussed assuming a narrowing down of the DC current path under the application of a perpendicular AC field. Shaking of the pinned vortices under the application of a parallel AC field is assumed for explaining the results in this case.
Original language | English |
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Pages (from-to) | 2891-2894 |
Number of pages | 4 |
Journal | IEEE Transactions on Applied Superconductivity |
Volume | 15 |
Issue number | 2 PART III |
DOIs | |
State | Published - Jun 2005 |
Bibliographical note
Funding Information:Manuscript received October 5, 2004. This work was supported in part by the Israeli Ministry of Infrastructure. The authors are with the Institute of Superconductivity, Department of Physics, Bar-Ilan University Ramat-Gan 52900, Israel (e-mail: [email protected]). Digital Object Identifier 10.1109/TASC.2005.848256 Fig. 1. Magnetic flux lines inside the tape for AC field magnetic field perpendicular to broad side of the tape. w is the width of the tape and b is a width of the central zone free of AC field.
Funding
Manuscript received October 5, 2004. This work was supported in part by the Israeli Ministry of Infrastructure. The authors are with the Institute of Superconductivity, Department of Physics, Bar-Ilan University Ramat-Gan 52900, Israel (e-mail: [email protected]). Digital Object Identifier 10.1109/TASC.2005.848256 Fig. 1. Magnetic flux lines inside the tape for AC field magnetic field perpendicular to broad side of the tape. w is the width of the tape and b is a width of the central zone free of AC field.
Funders | Funder number |
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Israeli Ministry of Infrastructure |
Keywords
- Ac field
- Bi-2223 tape
- Critical current
- I-v curve. © 2005 ieee