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Direct visualization of iron sheath shielding effect in MgB_2 superconducting wires

Alexey V. Pan·Sihai Zhou·Shi Xue Dou·Hua Kun Liu
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Abstract

Local magneto-optical imaging and global magnetization measurement techniques were used in order to visualize shielding effects in the superconducting core of MgB_2 wires sheathed by ferromagnetic iron (Fe). The magnetic shielding can provide a Meissner-like state in the superconducting core in applied magnetic fields up to ~1T. The maximum shielding fields are shown to correlate with the saturation fields of magnetization in Fe-sheaths. The shielding has been found to facilitate the appearance of an overcritical state, which is capable of achieving a critical current density (J_c) in the core which is larger than J_c in the same wire without the sheath by a factor of ~2. Other effects caused by the magnetic interaction between the sheath and the superconducting core are discussed.

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Alexey V. Pan, Sihai Zhou, Shi Xue Dou, Hua Kun Liu. 2003-06-03. Direct visualization of iron sheath shielding effect in MgB_2 superconducting wires. https://doi.org/10.1088/0953-2048%2F16%2F10%2F101

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