The 21N-moment multi-temperature coefficients for Zhdanov closure

TL;DR

This paper derives comprehensive 21N-moment multi-temperature collision coefficients for the Boltzmann collision operator, enhancing plasma modeling accuracy by extending existing single-temperature coefficients to multi-temperature scenarios.

Contribution

It introduces the first derivation of 21N-moment multi-temperature collision coefficients using the Sonine-Hermite polynomial approach, filling a key gap in plasma physics literature.

Findings

Derived general collision coefficients in terms of Chapman-Cowling integrals.

Provided specific coefficients for Coulomb potential with Debye cutoff.

Facilitates implementation in current plasma fluid simulation packages.

Abstract

We provide the 21N-moment multi-temperature collision coefficients for the Boltzmann collision operator using the Sonine-Hermite polynomial ansatz in the style of Zhdanov et al. First, we outline the general derivation method. Then, we provide the collision coefficients in the most general form in terms of the Chapman-Cowling integrals for any potential of interaction for the 21N-moment approximation. Then, we provide the the collision coefficients for the specific case of the approximated Coulomb potential cross-section with Debye cutoff. These coefficients help in order to find easy implementation in current SOL/edge fluid packages which currently implement the 21N-moment single-temperature coefficients. This provides the completion of a missing link in the current literature.