MODELING OF PULSED SOURCES OF MAGNETIC FIELD OF PORTABLE ULTRASONIC ELECTROMAGNETIC-ACOUSTIC TRANSDUCERS OR MEASUREMENTS, TESTING AND DIAGNOSTICS

Ultrasonic electromagnetic-acoustic transducers (EMAT) with permanent magnets are used to test ferromagnetic metal products. This leads to strong pressing of the EMAT to the metal, wear, and the appearance of coherent interference, which makes it impossible to carry out measurements and diagnostics. These disadvantages can be eliminated by introducing pulse magnets. The aim of the work is to determine rational geometric parameters of a pulse magnet for EMAT. To achieve this goal, a physical and mathematical problem was formulated and modeling was performed using the Comsol Multiphysics package. It was found that to ensure efficient operation of the EMAT, it is advisable to set the height of the pulse magnet within 50...60 mm, and the pole dimensions are 30x30...50x50 mm. Such parameters provide a quasi-stationary magnetic field induction value of at least 0.35 T in the range of ± 10 mm from the center of the pulse magnet pole.