Reflection of fast electrons in DPO approximation of transport equation

Reflection of high energy electrons from solids is treated by the approximative analytic solution of linearized transport equation. For the scattering of electrons on target atoms determined by screened Coulomb interaction and energy loss defined by Be-the-Bloch formula, the mean number of large angle deflections of an electron before slowing down to rest has been introduced. The approach is applicable in wide range of electron energy - from several tens of keV to several MeV - and for materials where the mean number of large angle deflections is large. The isotropic approximation of collision integral is accepted and the Boltzmann equation in Laplace transformed form over relative path length is analytically treated by the ordinary DPN method. In the lowest order of approximation, we derived the expressions for energy distributions of backscattered electrons as well as particle and energy reflection coefficients. Comparison of our results with data of the computational bipartition model is presented. (author)