JETP Letters: issues online

$<b>Secondary emission from a semi-infinite crystal are considered. Contribution to the emission amplitude originating from structural factor singularities are analyzed. Poles of structural factor determine the main contribution to the emission amplitude. The energy and angular distributions of the emission depends on the crystallographic orientation of the crystal surface and is characterized by a set of permitted vectors of reciprocal lattice. It is shown, that emission anisotropy related to the crystallographic directions is due to the coherent character of photoabsorption process and diffraction scattering leads only to relative change of the emission intensity in permitted low-index directions. The concrete calculations are performed for (100) and (111) surfaces of the diamond like lattice.</b>$

Secondary emission from a semi-infinite crystal are considered. Contribution to the emission amplitude originating from structural factor singularities are analyzed. Poles of structural factor determine the main contribution to the emission amplitude. The energy and angular distributions of the emission depends on the crystallographic orientation of the crystal surface and is characterized by a set of permitted vectors of reciprocal lattice. It is shown, that emission anisotropy related to the crystallographic directions is due to the coherent character of photoabsorption process and diffraction scattering leads only to relative change of the emission intensity in permitted low-index directions. The concrete calculations are performed for (100) and (111) surfaces of the diamond like lattice.