Fluid & Gyrokinetic turbulence in open field-line, helical plasmas

Abstract

Two-fluid Braginskii codes have simulated open-field line turbulence for over a decade, and only recently has it become possible to study these systems with continuum gyrokinetic codes. This work presents a first-of-its-kind comparison between fluid and (long-wavelength) gyrokinetic models in open field-lines, using the GDB and Gkeyll codes to simulate interchange turbulence in the Helimak device at the University of Texas (T. N. Bernard, et. al., Phys. of Plasmas 26, 042301 (2019)). Partial agreement is attained in a number of diagnostic channels when the GDB sources and sheath boundary conditions (BCs) are selected carefully, especially the heat-flux BCs which can drastically alter the temperature. The radial profile of the fluctuation levels is qualitatively similar and quantitatively comparable on the low-field side, although statistics such as moments of the probability density function and the high-frequency spectrum show greater differences. This comparison indicates areas for future improvement in both simulations, such as sheath BCs, as well as improvements in GDB like particle conservation and spatially varying thermal conductivity, in order to achieve better fluid-gyrokinetic agreement and increase fidelity when simulating experiments.

References in corpus (14)

• BOUT++: a framework for parallel plasma fluid simulations
• Gyrokinetic projection of the divertor heat-flux width from present tokamaks to ITER
• Hermes: Global plasma edge fluid turbulence simulations
• Global turbulence simulations of the tokamak edge region with GRILLIX
• Gyrokinetic continuum simulation of turbulence in a straight open-field-line plasma
• Collisional transport across the magnetic field in drift-fluid models
• Full-$f$ gyrokinetic simulation of turbulence in a helical open-field-line plasma
• Nonlinear Gyrokinetic Coulomb Collision Operator
• Gyrokinetic full-f particle-in-cell simulations on open field lines with PICLS
• Gyrokinetic treatment of a grazing angle magnetic field
• Improved linearized model collision operator for the highly collisional regime
• Gyrokinetic continuum simulations of plasma turbulence in the Texas Helimak
• Discontinuous Galerkin schemes for a class of Hamiltonian evolution equations with applications to plasma fluid and kinetic problems
• Kinetic fluid moments closure for a magnetized plasma with collisions

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• Deep electric field predictions by drift-reduced Braginskii theory with plasma-neutral interactions based upon experimental images of boundary turbulence