P1M-6 Broad Band Ultrasonic Transducers Using Carbon Fiber Composites for a Backing Material

While the transducer which is applied to medical diagnostic systems or NDE systems is ringing, the long pulse durations degrade the axial resolution. The wave can be damped by attaching an acoustically absorbing material on the back of the transducer that couples of the ultrasonic energy out of the active element. If the acoustic impedance of the backing is closed to that of the element, the most of the energy will be coupled into the backing. As a result, the transducer will have a shorter pulse. In this study a method of fabricating carbon fiber composite materials for backing with controllable characteristics will be presented. Acoustic impedance of the backing ranged from 14 MRals to 34 MRals have been achieved by the composite materials. When one cycle tone burst wave was applied to the transducer, the reflected wave from a reflector was received with the same one