A Fokker-Planck equation has been generalized to treat large-angle as well as small-angle binary collisions in plasmas. For moderately coupled plasmas [2≲ Coulomb logarithm (ln${\mathrm{\Lambda }}_{\mathit{b}}$)≲10], calculations have been made of the relaxation rates and transport coefficients. In general they differ from the standard (Braginskii) results by terms of order 1/ln${\mathrm{\Lambda }}_{\mathit{b}}$. Using a modified collision operator, a new vector potential that has a direct and practical connection to the Rosenbluth potentials is obtained. In addition, we calculate a reduced electron-ion collision operator that, for the first time, manifests the 1/ln${\mathrm{\Lambda }}_{\mathit{b}}$ corrections.

• Received 17 November 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.3063