COLLECTIVE PINNING AND THE MAGNETIZATION OF THE BEAN CRITICAL-STATE

The pinning force calculated from Larkin-Ovchinnikov collective pinning theory is used to determined the density profile (in one, two and three dimensions) of flux lines in the Bean critical state. In all cases one finds a result different from the conventional linear profile. The dependence of the corresponding magnetization on the external magnetic field is calculated. Strong single-particle pinning leads, in three dimensions, to a behaviour distinctly different from the collective pinning result.