A Modified Theory of Production of Secondary Electrons in Solids

A few difficulties in the previous theories of energy loss and secondary electron production by primary electrons in metals can be removed by replacing the Coulomb interaction between a primary electron and a lattice electron by a screened Coulomb interaction, such as required by the plasma theory. In the new theory Wooldridge's mechanism of secondary electron production seems to have lost most of its importance. The energy loss distribution due to the interaction with the conduction electrons of the metal is found to have a maximum at an energy loss slightly less than ($\frac{{\hslash }^2{k_m}^2}{2m}$), where $k_m$ is the value of the wave vector of the conduction electrons at the Fermi level. The theory is also applied to the bound electrons, and it is shown that the screened Coulomb interaction does not change the previous results very strongly. It is also shown that the polarization of the medium has only a small influence upon the previous results for insulators.