A boundary value problem of magnetostatic potential penetration into two ci
rcular apertures in a thick conducting plane is solved. The Hankel-transfor
m and mode-matching is used to represent the scattered potentials in rapidl
y-convergent series. The magnetic polarizability is rigorously derived and
presented in numerically efficient forms. Numerical computations are perfor
med to illustrate the field penetration and coupling behaviors in terms of
aperture geometry.