School of Physics and Information Technology, Shaanxi Normal University, Xi'an, PR China.
Ultrasound Med Biol. 2012 Nov;38(11):2007-17. doi: 10.1016/j.ultrasmedbio.2012.06.014. Epub 2012 Sep 12.
Based on the finite series method, the Gaussian beam is expanded as spherical functions and the beam coefficient of a Gaussian beam is obtained. A new expression for the acoustic radiation force function, which is the radiation force per unit energy density and unit cross-sectional surface area for a sphere in a Gaussian beam, is presented in this paper. Numerical results for the radiation force function of a Gaussian beam incident upon the spherical particles are presented for rigid spheres, liquid spheres and elastic spheres immersed in water to illustrate the theory. The radiation force function vs. ka curve, ka being the radius times the wavenumber in the surrounding medium, is discussed for different beam widths. The acoustic radiation force function is determined by the parameters of the particles, with liquid spheres having smaller values than those for rigid and elastic spheres. The beam width also affects the acoustic radiation force function. When the radius of the sphere is larger than the beam width, the beam width has greater effects on the radiation force. This analysis helps analyzing and understanding the effects of the acoustic Gaussian beams on spherical objects.
基于有限级数法，将高斯光束展开为球函数，得到高斯光束的光束系数。本文提出了一种新的声辐射力函数表达式，它是单位能量密度和单位横截面积在高斯光束中球体的辐射力。针对刚性球体、液体球体和弹性球体在水中的情况，给出了高斯光束入射到球形粒子上的辐射力函数的数值结果，以验证理论。针对不同的光束宽度，讨论了辐射力函数与 ka 的关系曲线，ka 是周围介质中半径与波数的乘积。辐射力函数由粒子的参数决定，液体球体的数值小于刚性球体和弹性球体的数值。光束宽度也会影响声辐射力函数。当球体的半径大于光束宽度时，光束宽度对辐射力的影响更大。这种分析有助于分析和理解高斯光束对球形物体的影响。
