Studies of acoustic fields excited by a turn-type transmitter in a constant magnetic field

Abstract

Rigorous mathematical calculations are used to construct graphical dependences that characterize excitation of acoustic vibrations via the electrodynamic effect, which is one of the effects of the electromagnetic-acoustic (EMA) transformation. The calculations were performed using fundamental mathematical expressions, which were obtained in [1], and the plots were constructed for the diametrical plane with respect to the transmitter. A turn above the half-space in a constant magnetic field was chosen as the transmitter. Materials with sharply different electrophysical properties were considered. Calculations were performed for transducers of different dimensions (two limiting cases) and different values of the working gaps. It is shown that the displacement value consists of three summands: a force that is directed along the x axis, a force that is directed along the z axis, and a socalled electromagnetic-like wave. On the basis of the analysis of the obtained plots, it is shown that in all the considered cases, acoustic vibrations propagate as a narrow beam along the normal and the beam width increases as the gap increases.