Current distribution and ac loss for a superconducting rectangular strip with in phase alternating current and applied field

摘要

The case of ac transport at in-phase alternating applied magnetic fields fora superconducting rectangular strip with finite thickness has beeninvestigated. The applied magnetic field is considered perpendicular to thecurrent flow. We present numerical calculations assuming the critical statemodel of the current distribution and ac loss for various values of aspectratio, transport current and applied field amplitude. A rich phenomenology isobtained due to the metastable nature of the critical state. We perform adetailed comparison with the analytical limits and we discuss theirapplicability for the actual geometry of superconducting conductors. We alsodefine a loss factor which allow a more detailed analysis of the ac behaviorthan the ac loss. Finally, we compare the calculations with experiments,showing a significant qualitative and quantitative agreement without anyfitting parameter.