3-D field analysis of a superconducting bulk magnet

Magnetic field can be trapped in a superconducting bulk by using the field cooling method. In this paper, trapped field was calculated by 3-D numerica l analysis. The existing 1-D critical state model was expanded to 3-D. With this model and iteration method, the nonlinearity of J-E constitutive rela tion of a superconducting bulk was numerically modeled. The field cooling s ystem with a hexahedral bulk and cylindrical magnet, which is impossible to be analyzed by 2-D or axisymmetric numerical analysis, was analyzed by the presented method, Being compared with experimental data, the validity of t he presented method was verified. Finite element method was adopted for num erical calculation.