The critical current of NbTi multifilamentary wire: a comparison between critical current densities using AC magnetization techniques (J/sub CM/) and DC transport measurement (J/sub CT/) throughout the superconducting phase

Abstract

AC magnetization measurements are presented for transverse field orientation on a NbTi standard reference material supplied by the National Bureau of Standards. These data, generated in DC background fields for the range 0<B<10 T, and 4.2 K<T<T/sub c/, are interpreted using the Bean-Campbell analysis to determine the critical current density (J/sub cm/) throughout the superconducting phase. An estimate of the electric field criterion at which transport critical current (J/sub ct/) measurements must be compared with J/sub cm/ is determined. Good agreement is obtained for the field and temperature dependence of the critical current using these complementary techniques.<<ETX>>