BACKSCATTERING OF FAST ELECTRONS FROM SOLIDS WITHIN A MULTIPLE COLLISION MODEL

Reflection of electrons from solids is treated by the approximate analytic solution of the linearized transport equation. Scattering of electrons on target atoms is determined by the screened Coulomb interaction and the energy loss due to interaction with target electrons is defined by Bethe-Bloch formula. The anisotropic P-3 approximation of the collision integral is utilized and the Bolzmann transport equation is Laplace transformed in relative path length and solved by applying the DP0 technique. The approach is applicable in a wide range of electron energy -from several tens of keV to several MeV- and for materials where the mean number of collisions of an electron with target atoms during slowing down is large. Analytic expressions for energy distribution of backscattered electrons as well as for the particle and energy reflection coefficients were derived. Comparison of our results with data of the computational bipartition model is presented.