Perpendicular susceptibility of completely shielded elliptical and rectangular superconducting films

The perpendicular susceptibility -χ₀$-{\chi }_0$ of completely shielded elliptical and rectangular superconducting films with different aspect ratios has been calculated accurately. The obtained χ₀${\chi }_0$ may be compared with the measured low-field limit of ac susceptibility to check the quality of superconducting films, and used as a scaling parameter to obtain field amplitude dependent complex critical-state ac susceptibility.