Thermalization of subexcitation electrons in a medium with time dispersion

The slowing down process of light charged subexcitation particles of finite size in a medium with time dispersion is considered. The theory developed is applied to the slowing down of the secondary electrons knocked out by another energetic particle. Total energy loss is made up from the Debye losses, excitation of intraand intermolecular vibrations and the mutual Coulomb attraction between parent ion and knocked out lectron. In this case the process is essentially transient, and energy loss rate is explicitly time-dependent.