Experimental and theoretical study of AC losses in variable asymmetrical magnetic environments

Abstract

Measurements of AC losses in a HTS-tape placed in between of two bulk magnetic shields of high permeability were performed by applying calorimetric techniques for various asymmetrical shielding arrangements. The experiment was supported by analytical calculations and finite-element simulations of the field and current distributions, based on the Bean model of the critical state. The simulated current and field profiles perfectly reproduce the analytic solutions known for certain shielding geometries. The evaluation of the consequent AC losses exhibits good agreement with measurements for the central position of the tape between the magnets but increasing discrepancy when the tape is approaching the shields. This can be explained by the increasing contribution of the eddy currents and magnetic hysteresis losses in the conducting shields.

13 pages, 4 figures

References in corpus (8)

• Computation of Losses in HTS Under the Action of Varying Magnetic Fields and Currents
• Overcritical states of a superconductor strip in a magnetic environment
• Improvement of critical current in MgB2/Fe wires by a ferromagnetic sheath
• Analytical investigation of magnetic field distributions around superconducting strips on ferromagnetic substrates
• General critical states in type-II superconductors
• Superconductor/ferromagnet heterostructures exhibit potential for significant reduction of hysteretic losses
• Field and current distributions and ac losses in superconducting strips
• Hysteretic ac losses in a superconductor strip between flat magnetic shields