Axisymmetric Gyrokinetic Simulations of the Lithium Tokamak Experiment (LTX) Scrape-Off Layer

Fluid simulations have been the predominant form of numerical exploration of the scrape-off layer (SOL) for years. Yet, fluid models are unable to capture kinetic effects such as the effects of trapped particles, which are important for determining confinement in collisionless plasmas. We therefore use the Gkeyll computational framework, the first successful full-f continuum electromagnetic gyrokinetic code on open field lines, to characterize temperature profile flattening in low-recycling scenarios in the Lithium Tokamak Experiment (LTX).

Here, we conduct 4-dimensional (2 spatial and 2 velocity dimensions) axisymmetric gyrokinetic simulations spanning the closed and open field regions of a limited plasma with parameters representative of LTX. We investigate enhanced electron confinement observed in the LTX-SOL as well as the steady state profiles observed in the low-recycling regime. These simulations could be used to predict temperature and density profiles given transport coefficients or to produce initial conditions for 5D turbulent Gkeyll simulations.