Rational Approximations for the Microfield Distributions in Mildly Correlated, Multicomponent Plamas

We consider using low-order rational polynomials to approximate microelectric field distribution in plasmas at varying levels of accuracy. Departing from the usual Padé prescription, we quote several such expressions providing increasing levels of approximation for the microfield distribution in an uncorrelated plasma with singly charged ions, the Holtsmark distribution. We then generalize the approximations to accommodate multiply charged ions, mixtures of ions with different charges, and with the help of asymptotic approximations, mixtures of ions accounting for finite plasma effects. The expressions are able to reproduce the tabulated results of Hooper, Held & Deutsch, and Pfennig & Trefftz and coworkers to ∼ 1− 2% relative error. Subroutines for evaluating the microfield distributions in mildly correlated binary plasmas written in C and FORTRAN accompany these notes. ∗email: [email protected]