ATTENUATION OF ELECTRONS IN NONCRYSTALLINE SOLIDS

A comparison of the attenuation of electrons in non-crystalline solids as described by the transport theory (TT), using the transport length as obtained in a quasiclassical approach, and by Monte Carlo (MC) calculations based on relativistic Mott cross sections for elastic scattering is presented. Both approaches yield an exponential law for the electron escape probability for particles generated at great depths. An exact expression has been obtained by transport theory for the characteristic length of this exponential function, the so called attenuation parameter (AP). It has been shown that the AP depends only on two quantities: the inelastic and the transport mean free path. According to the MC results, this AP governs the electron attenuation over the entire depth range, but with a non-exponential law at small depths. The AP values have been calculated for 45 elements (ranging from Be to Au) at different energies in the 250-1500 eV range. Excellent agreement between the TT and the MC results has been found.