Correlations among Ions, Electrons, and Screened Potentials in a Hot Dilute Gas

The asymptotic pair correlations between charged particles, ions and electrons, in a hot dilute gas are found through the use of a perturbation theory for a system of molecules, where a molecule is specified by the totality of its bound and scattering states. The derived screened electrostatic potential (as well as the charge distribution) around an ion is given by ${\varphi }_i\mathrm{}\left(r\right)=\frac{(C_S{e}^{-{\kappa }_{S}r}+C_{O}cos{\kappa }_{O}r)}{r}$, where ${\kappa }_S>{\kappa }_O$, $\left|\frac{C_S}{C_O}\right|\gg 1$, thus leading to a main contribution from the Debye-Hückel—type term at moderately large distances, and from the oscillating Coulomb term mainly at very large distances. Since ${\kappa }_S$, ${\kappa }_O\propto \kappa ={\left(4\mathrm{}\pi \beta e^{2}n\right)}^{\frac{1}{2}}$, where $n$ is the molecular density, the oscillatory term is more pronounced at increasing densities.