DEPENDENCE OF THE EFFICIENCY OF INHOMOGENEOUS MAGNETOSTRICTIVE ELECTROMAGNETIC-ACOUSTIC CONVERSION ON THE MACROSCOPIC PROPERTIES OF THE MEDIUM

We report the results of computation of the direct electromagnetic-aco ustic conversion (EMAC) of a high-frequency spatially inhomogeneous el ectromagnetic field, generated by inductive systems, into an inhomogen eous bulk acoustic field in a magnetostrictive medium with arbitrary v alues of the magnetic permeability and electrical conductivity sigma. The degree to which the efficiency of generation of elastic vibrations varies over a wide range of those macroscopic parameters is illustrat ed. The maximum efficiency of excitation of longitudinal waves when on ly the ratio of the shear and electromagnetic wavelengths (i.e., the g eneralized parameter beta) changes is shown to lie in the range beta < 1 and the maximum efficiency of the shear wave, in the range beta > 1 . Variation of the parameter beta because of the magnetic permeability does not give such a result.