Characteristics of normal conducting artificial pins in Nb-Ti multifilamentary composites

In order to reveal flux pinning characteristics for different pinning materials in superconductors, Nb-Ti multifilamentary composites having different materials, Nh, Ta, Cu-Ni and Cu introduced as artificial pinning centers (APC) were studied. Magnetization was measured to analyze critical temperature Te and to obtain magnetic field dependence of pinning force density FP, The pr properties for APC are different from each other, in spite of almost the same design of pins. A simulation for the distribution of superconducting order parameter using a S-N multilayer model under a significant proximity effect was carried out on the basis of the G-L theory. The flux pinning properties calculated From the order parameter simulations were compared with those of experimental results. Qualitative agreement between them was obtained.