Last modified: 2015-07-02
Abstract
The acoustic resonance scattering of a zero-order Bessel beam by elastic spheroids immersed in water and centered along the beam axis is investigated. The T-matrix method is utilized to establish the Bessel acoustic scattering formulas through the harmonic expansion of Bessel beam. For a specific half-conical angle , the far-field backscattering form functions of spheroids with different materials and a variety of aspect ratios are curved versus the dimensionless frequency , where is the wave number in water and is the length of the spheroid. By subtracting an appropriate background from the total backscattering form functions, the corresponding resonance of the elastic spheroids can be determined. It is concluded that the T-matrix method is effective to calculate both the total and resonance backscattering fields under an end-on incident Bessel beam illumination. Moreover, by selecting appropriate half-conical angles, the excitation of certain resonance of elastic spheroids may be suppressed and this phenomenon may have some potential value in practical applications.