Exact irreducible moments of the Landau collision operator in the random-velocity moment expansion
POSTER
Abstract
Exact moments of the Landau collision operator are calculated for the irreducible Hermite polynomials written in terms of the random-velocity variable. We present closed, algebraic formulas that reproduce the results for the total-velocity moment expansion\footnote{J.-Y. Ji and E. D. Held, Phys. Plasmas {\bf 13}, 102103 (2006).} and for the random-velocity moment expansion with the small mass-ratio approximation\footnote{J.-Y. Ji and E. D. Held, Phys. Plasmas {\bf 15}, 102101 (2008).}. The collisional moments can be applied in the derivations of Braginskii and integral closures for arbitrary relative flow velocity between electrons and ions. Modifications to Braginskii closures are discussed.
*The research was supported by the U.S. DOE under grant nos. DE-SC0014033, DE-SC0016256, and DE-FG02-04ER54746 and was performed in conjunction with the Plasma Science and Innovation (PSI) center and the Center for Tokamak Transient Simulations (CTTS).