Haney Matthew, Snieder Roel
Department of Geophysics and Center for Wave Phenomena, Colorado School of Mines, Golden, CO 80401, USA.
Phys Rev Lett. 2003 Aug 29;91(9):093902. doi: 10.1103/PhysRevLett.91.093902. Epub 2003 Aug 27.
The validity of the diffusion approximation for the intensity of multiply scattered waves is tested with numerical simulations in a strongly scattering 2D medium of finite extent. We show that the diffusion equation underestimates the intensity and attribute this to both the neglect of recurrent scattering paths and interference within diffusion theory. We present a theory to quantify this discrepancy based on counting all possible scattering paths between point scatterers. Interference phenomena, due to loop paths, are incorporated in a way similar to coherent backscattering.
在有限范围的强散射二维介质中，通过数值模拟测试了多重散射波强度扩散近似的有效性。我们表明，扩散方程低估了强度，并将其归因于扩散理论中对递归散射路径和干涉的忽略。我们提出了一种基于计算点散射体之间所有可能散射路径来量化这种差异的理论。由于环形路径引起的干涉现象，其纳入方式类似于相干背散射。
