MAGNETIZATION IN A GENERALIZED CRITICAL-STATE MODEL FOR TYPE-II SUPERCONDUCTORS

This paper describes the magnetization of type-ii superconductors in t he critical state, where the critical current density, J(c), has a fie ld dependence of the form J(c) (B) = J(0)/(1 + B/B-0)(n). Explicit for mulae are derived for the various branches of the complete high-field hysteresis loop. The geometry under consideration is that of an infini tely long rectangular bar placed in a parallel applied field. In the d iscussion, emphasis is put on the behaviour of the vertical width, Del ta M, of the hysteresis loop, and a simple graphical method to fit mod el parameters to experimental data is outlined.