A new surface-wave EMAT design of enhanced transduction efficiency

One of the main drawbacks of EMATs is their inefficiency in generating ultrasounds. To solve this problem, a new surface-wave EMAT design, whose magnet width is less than the coil, is proposed. The principle of the new EMAT is studied based on finite element simulation, which indicates that the EMAT is more efficient by taking advantage of both horizontal and vertical magnetic fields of the magnet. Experiment verified that the amplitude of the ultrasonic signal generated by the EMAT has been enhanced by about 53.7%. The potentials and limitations of the new design have also been discussed.