Pulse signal detection in a focal area of a convergent wave front

Diffraction effects, taking place during nonlinear transformations in inhomogeneous acoustic fields, are experimentally investigated. The case of a convergent spherical wave front propagating in a uniform nonlinear medium, detection of an acoustic field in a focus, and receiving of the detected signal in the region of the initial wave front aperture are considered. A spherical piezoceramic transducer is used in the experiments as a focusing device. Broad-angle “nonlinear scattering” signals have been recorded at the experimental facility where a pulsed mode of focused transducer operation in water is implemented. The dependence of the amplitude of the signal, detected in the focal area, and its shape on the scattering direction, as well as on the distance between the focus and the receiving point, are studied.