Implementation of multi-component Zhdanov closure in SOLEDGE3X

Abstract

The multi-component fluid closure derived by Zhdanov is implemented in the fluid code SOLEDGE3X-EIRENE to deal with arbitrary edge plasma composition. The closure assumes no distinction in between species such as light vs heavy species separation. The work of Zhdanov is rewritten in a matrix form in order to clearly link friction forces and heat fluxes to the different species velocities and temperature gradients.

Progress in edge plasma turbulence modelling—hierarchy of models from 2D transport application to 3D fluid simulations in realistic tokamak geometry

“…The species temperature T is used to compute species pressure p = nT and species total energy E = 3 2 nT + 1 2 mnv 2 . Parallel viscosity ν , parallel heat conductivity κ , parallel friction force in between species R , parallel heat flux due to inter-species collisions h and energy equipartition term Q take values computed by Zhdanov collisional closure for multi-component plasmas [5,9,10,11]. For a simple hydrogenic plasma, Braginskiis closure can also be used.…”

“…The implementation of the different operators has been verified using the method of manufactured solution [11].…”

The 21N‐moment multi‐temperature collision coefficients for Zhdanov closure

“…[5] This is important for modelling impurity dynamics because impurities may be present as a significant fraction of the background plasma species, or, in case of deuterium-tritium plasmas, tritium, being a main ion species, cannot be modelled as trace over an existing deuterium-electron plasma. The Zhdanov closure is already implemented, though only using single-temperature collision coefficients at the plasma common temperature, in SOL/edge simulators such as Soledge3x-EIRENE, [1,6,7] SOLPS, [8][9][10] B2-EIRENE, [11] and EDGE2D. [12] Generally, the depth of the closure is represented by the number of moments, that is, 5N-moment, 13N-moment, 21N-moment, or 29N-moment, where N represents the number of species.…”

Impact of the improved parallel kinetic coefficients on the helium and neon transport in SOLPS‐ITER for ITER

“…[3] For example, this method can be used for deuterium and tritium mixture simulations in future and present machines. [5] It is important to mention that multi-temperature generalization of this method is in progress for the SOLEDGE3X-EIRENE code. [6,7] In the present paper, a new Grad-Zhdanov module based on the improved approach [8] and complete Grad-Zhdanov method [3,8] has been implemented in the SOLPS-ITER code (Section 2).…”