RF-transpond: A 1D coupled cold plasma wave and plasma transport model for ponderomotive force driven density modification parallel to B0

Abstract

The RF-Transpond code couples a fluid plasma transport solver with a frequency domain cold plasma RF wave solver in a 1D domain parallel to a strong background magnetic field. A ponderomotive force term proportional to parallel gradients in the electric field strength is included in the transport model in order to describe ponderomotive effects in the scrape-off layer (SOL) of fusion plasmas. The transport and wave codes are verified independently and a coupled case corresponding to experimental parameters from the LArge Plasma Device (LAPD) is presented. The density perturbation ratio Rn, calculated to describe ponderomotive force driven modifications, is up to 20% for the simulation inputs used. Program summaryProgram Title: rf-transpondCPC Library link to program files:https://doi.org/10.17632/xn3y2yx9wj.1Developer's repository link:https://github.com/rhealbarnett/rf-transpond.gitLicensing provisions: MITProgramming language: MatlabNature of problem: Self consistent coupled model describing ponderomotive force driven density modification in the near field of RF antennas.Solution method: The density and velocity solutions are calculated from the continuity and momentum transport equations, solved using a finite difference time domain method, which include a ponderomotive force term that depends on the radio frequency electric field. The frequency domain electric field solution is calculated from the cold plasma wave equation, solved using a finite difference frequency domain method, where the cold plasma dielectric tensor is a function of the density. The electric field and density couple the two models, providing self consistency.