Dynamic collision frequency for a two-component plasma

Starting from a generalized response theory, the inverse response function can be expressed in terms of equilibrium correlation functions for which a perturbation expansion is carried out. In the long-wavelength limit, this can be exploited to obtain an approximation for the dynamic collision frequency. Utilizing the Mermin ansatz, the dynamical structure factor is determined from the long-wavelength limit. The results are compared with classical simulation data. Different effective potentials which model the electron–ion interaction are discussed. It is shown that the high-frequency behaviour of the dynamic collision frequency is sensitive to the form of the chosen interaction.