High-Speed Shielding Current Analysis in High-Temperature Superconducting Film with Cracks

摘要

A fast and stable method is proposed for calculating the shielding current density in a high-temperature superconducting film containing cracks. After discretized with the finite element method, the initial-boundary-value problem of the shielding current density reduces to semi-explicit differential algebraic equations (DAEs). Although the DAEs can be solved with standard ordinary-differential-equation (ODE) solvers, much CPU time is required for its numerical solution. In order to shorten the CPU time, a high-speed method is proposed. In the method, the block LU decomposition is incorporated into function evaluations in ODE solvers. A numerical code is developed on the basis of the proposed method and, as an application of the code, detectability of cracks by the scanning permanent-magnet method is numerically investigated.