ИСТИНА

Modern ultrasonic imaging systems demonstrate high quality of the images obtained in non-aggressive media. Direct application of traditional systems under critical conditions, for example at high temperature, in the presence of chemically active media or an increased level of radiation, is often impossible. We propose an approach based on the concept of an "ultrasound endoscope" to remotely display the area of interest through a long beam of solid rods. Each rod serves as a waveguide that carries an ultrasonic pulse from one end located in an aggressive medium to the other end located at a distance in favorable conditions. The diameter of the rods is less than half the wavelength to ensure that the ultrasonic pulses used to form the image propagate as the lowest-order longitudinal mode, which is non-dispersive and much faster than other possible modes (bending and torsional motions). The feasibility of the proposed concept is illustrated by numerical modeling and experiments. The results of studies of the 1024-channel waveguide system of megahertz range made of a bundle of stainless steel rods are presented. The obtained images of millimeter-sized scatterers in water demonstrate high resolution of the proposed system. Work is supported by the RSF grant 17-72-10284.