Influence of vacuum region on AC losses in superconducting wires with 2D FEM formulated by self-magnetic field

The influence of effective vacuum part is numerically evaluated on AC losses in superconducting wires calculated by means of a two-dimensional finite element method, which is formulated with a self-magnetic field due to an induced current as unknown. In the present method, the high-resistivity metal around the wires is needed for the sake of the simplicity in program coding. The superconducting wires carry an alternating transport current or are exposed to an external AC magnetic field. The AC losses are numerically calculated for square and circular effective vacuum parts with wide ranges of the sizes and the resistivity. Relative errors in the obtained results are discussed as compared with conventional analytical predictions.