【Title】Computation and analysis of the Bessel beam scattering by a submerged elastic sphere

【Author】 LI Wei QU Hongfei SONG Zhiwei (Dept.of Naval Architecture and Ocean Eng.,Huazhong Univ.of Science and Technology Wuhan 430074)

【Abstract】Taking an elastic sphere for example,the acoustic scattering of a submerged object illuminated by a Bessel beam is studied.The partial wave series representation for an elastic sphere has been extended to the case of Bessel beam scattering.Referring to the scattering of a plane wave,the peak to peak intervals in backscattering form function caused by the interference of the specular wave and the Franz wave have been analyzed in geometry.The influence of the characteristic parameterβof a Bessel beam on the peak to peak intervals has been indicated,and a predictive formula of the peak to peak intervals has been established for the first time.Meanwhile the elastic scattering of each partial wave has been separated based on the Resonance Scattering Theory.The influence ofβon the pure elastic resonance has been studied further.The results show that selecting specificβcan reduce the contribution of a certain partial wave.Therefore the resonance at the corresponding frequency and the nearby region in the backscattering is remarkably suppressed.The work of this paper could be helpful to the applications of Bessel beams on the acoustic detection of submerged objects.