Fig. 4

Dipole field of a discrete sphere and comparison to the analytical solution at \(f=2\) MHz. a comparison of the dipole profile (in central xy-plane perpendicular to z) calculated numerically using Eq. (5) with the analytical solution given by Eq. (4); (\(\chi _\mathrm{s}=5.0 \times 10^{-6}\), \(\chi _w=-9 \times 10^{-6}\)), b central xz cross section of the internal field