Effective Demagnetization Factors of Diamagnetic Samples of Various Shapes

摘要

Effective demagnetization factors that connect total magnetic moment with theapplied magnetic field are calculated numerically for perfectly diamagneticsamples of various non-ellipsoidal shapes. The procedure is based oncalculating total magnetic moment using integration of the magnetic inductionover the entire space. The obtained results are relevant for superconductors(and conductors in AC field) when London penetration depth (or skin depth) ismuch smaller than the sample size. Simple but reasonably accurate approximateformulas are given for practical shapes including rectangular cuboids, finitecylinders in axial and transverse field as well as infinite rectangular andelliptical cross-section strips.