A fast algorithm for calculating the critical state in superconductors

A method is presented for calculating the critical state profiles in bulk superconductors. It can be used for asymmetric samples in non‐uniform fields and for transport currents as well as magnetisation. In this technique the sample starts with no current flowing. Elements carrying Jc are then inserted at the point of maximum vector potential and the field recalculated. The process is continued until the external field is screened from the interior. As an example the force on a magnet above a cylindrical puck is calculated.