The Milne-type solution for multiple scattering phenomena in the P1 approximation

Considering the multiple scattering from a highly inhomogeneous medium occupying a half-space, a solution of the Bethe-Salpeter equation is obtained using the Wiener-Hopf method. The result obtained generalizes the well-known Milne solution to the case of anisotropic single-scattering in the P-1 approximation. The dependence of the coherent backscattering on the anisotropy parameter is derived directly and shown to differ essentially from that predicted by the diffusion approximation. Initial slopes of coherent backscattering as well as temporal correlation function are found to be in fair agreement with known experimental data.