Characterization and coil test results for a multifilamentary NbTi conductor utilizing artificial pinning center technology

The introduction of pinning centers via the controlled addition of a second phase, with the correct size and spacing, has been proposed as a method for producing a material with optimum flux pinning and hence a higher critical current density in practical superconductors. The demonstration of such artificial pinning center (APC) materials has been the aim of recent collaborative efforts with several US manufacturers. This paper reports the coil test results for a multifilamentary NbTi conductor fabricated using an APC technique. The conductor showed improved performance compared to earlier APC conductors, and its performance is comparable to that found in conventional multifilamentary NbTi conductors. In addition to coil test results. results of low-field magnetization, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are reported and compared with similar results on conventional NbTi.<>