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

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 R_n, calculated to describe ponderomotive force driven modifications, is up to 20% for the simulation inputs used. Program summary: Program Title: rf-transpond CPC Library link to program files: https://doi.org/10.17632/xn3y2yx9wj.1 Developer's repository link: https://github.com/rhealbarnett/rf-transpond.git Licensing provisions: MIT Programming language: Matlab Nature 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.