Accession Number : AD0729410

Title :   Ultrasonic Wave Generation and Propagation.

Descriptive Note : Final technical rept.,

Corporate Author : TENNESSEE UNIV KNOXVILLE ULTRASONICS LAB

Personal Author(s) : Breazeale,M. A.

Report Date : AUG 1971

Pagination or Media Count : 38

Abstract : The report covers four topics: (1) In 'Simplification of Apparatus to Diffract Light by Ultrasonic Waves,' it is shown that the laser is ideally suited to such measurements because the laser beam is small, intense, and collimated, each of which simplifies measurements. (2) The next three chapters deal with various aspects of ultrasonic parametric oscillations, including the nonlinear equation which probably describes the situation. The use of parametric oscillations to make a variable frequency transducer has not been practical. On the other hand, measurement of the threshold of parametric oscillation does offer promise of a means of measuring relative attenuation. (3) Diffraction lobes from the beam pattern of transducers can be eliminated quite simply in certain cases. This technique is described in Chapters V and VI. The analogous techniques in optics is referred to as 'apodization.' Therefore, it would be correct to refer to this ultrasonic technique as 'apodization of transducers.' The final chapter shows the way the apodized transducers can be used to make a detailed study of the energy redistribution in an ultrasonic beam reflected from a liquid-solid interface at the angle at which surface waves are generated. (Author)

Descriptors :   (*ULTRASONIC RADIATION, SOUND TRANSMISSION), INTERACTIONS, DIFFRACTION, LASERS, TRANSDUCERS, ATTENUATION, HARMONIC ANALYSIS

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE