Energy Distribution of Electrons Ejected from Tungsten byHe+

The results of a calculation of the energy distribution of electrons ejected from tungsten by low-energy ${\mathrm{He}}^{+}$ are presented. The calculation is based on a mechanistic model of the process in which the ejected electrons are divided into two groups: (1) the electrons excited in the primary process that can escape directly; and (2) the electrons that escape because of interactions between the primary electrons and those of the band structure of the solid. Secondary electron data are used to predict the portion due to this second mechanism.