ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
This letter shows an unexpected phenomenon where a surface acoustic wave (Rayleigh wave) excited by a line source with a finite length on a solid sphere propagates along the great circle in a direction perpendicular to the line source without beam spreading due to diffraction. In experiments, a piezoelectric transducer, 1.5 mm in width and 20 mm in length, was glued on a surface of a glass ball, 80 mm in diameter, as a line source with a finite length. A beam of Rayleigh waves with frequencies centered at 1.1 MHz was excited in either direction perpendicular to the transducer length. A receiving transducer with a circular aperture, 2 mm in diameter, was used in direct contact with the surface to detect the distribution of vibration over the surface of the ball. It was observed that the excited Rayleigh wave propagated along a great circle of the ball for at least four roundtrips. The beam was confined within a narrow path around the ball, the width of which was no more than 20 mm. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1322056
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