Acoustic scattering by a soft elliptic disk

In English Scattering from an acoustically soft elliptic disk is treated by means of the null field approach. It is shown that in the disk limit of a general ellipsoid the relevant matrix elements have a well-defined limit, and that the formulation is attractive for numerical calculations. In a separate section the low frequency expressions of the total cross section and the far field amplitude are also derived. The paper is closed by a presentation of a series of numerical calculations.