Numerical Evaluation of Pulsed Field Magnetization in a Bulk Superconductor Using Energy Minimization Technique

The magnetization property in a cylindrical superconductor exposed to an external pulsed magnetic field is numerically evaluated by means of the energy minimization. In order to estimate an increase in magnetic energy due to a current induction, the cross section of the superconductor perpendicular to the azimuthal direction is divided into a lot of tiny rectangular cells and all the inductances in the coaxial circular coils are calculated by summing up an interlinkage magnetic flux derived from the distribution of a vector potential. The interaction between the induced current and the external field is also taken into account in the numerical procedure. The influences of the histories of flux penetration and the aspect ratios of cross section on final trapped magnetic fields are investigated toward an optimal design of a bulk superconductor magnet.