Effect of the initial filling density on the critical current of in-situ Fe/MgB2 wires

Abstract

We report a comparative study on the fabrication of in-situ monofilamentary superconducting Fe sheathed MgB2 wires as a function of the initial tube filling density. The wire samples are fabricated by means of a standard Powder-in-Tube (PIT) method with two different initial powder filling densities. Transport measurements are applied under high magnetic fields, of up to 10 T, obtained in a Bitter magnet. We find that increasing the initial filling density improved the critical current of the Fe/MgB2 wires, and a high Ic (4.2 K) = 140 A at B = 5 T is achieved.