Numerical transient analysis of a line-focus-beam ultrasonic microscope

With FD-TD method, we analyze a transient behavior of LFB (line focus beam) ultrasonic microscope numerically. Previous report, the source pressure was generated from the cylindrical concave transducer and investigated the interaction between the direct reflection wave from the sample solid and the leaky wave from the leaky surface acoustic wave propagating on the solid. In this report, we also consider the acoustic lens with cylindrical concave surface, which more resembles the LFB ultrasonic microscope in order to measure the characteristics of the solid by means of the conception of V(z) curve. One period sinusoidal particle velocity is given on the flat surface of the lens. Supposed that the cylindrical concave surface of the solid lens has 1.0 mm radius and an aperture half-angle 60°, center frequency of the 1 period sinusoidal input is 14.8 MHz.