ULTRASONIC RADIATION FIELD OF A FOCUSING SPHERICAL SOURCE AT FINITE AMPLITUDES

A PZT 4 ceramic spherical cap with a radius of curvature of 30 cm has been used to produce a finite amplitude ultrasonic field in water at a frequency of 2.3 MHz. The field has been observed by a nonresonant probe with an active face of 18 in. diam. The fundamental, second, third, and fourth harmonics have been studied both along the axis of the beam and transverse to the axis. The axial values are compared with various theoretical analyses. © 1969, Acoustical Society of America. All rights reserved.