Figure-Simulation of density fluctuations before the L-H transition for Hydrogen and Deuterium plasmas in the DIII-D tokamak using the BOUT++ code

Fig.1 Equilibrium generated by EFIT with kinetic constraints and the grids used in the BOUT++ simulationFig.2 The profiles for different discharges, i.e. Hydrogen (solid curves) and deuterium (dash curves) .Fig.3 The linear growth rate of the resistive ballooning modes (RBM), RBM with ion diamagnetic stabilizing effects and RBM with both ion diamagnetic effects and ExB flow for D and H plasmas, respectively.Fig.4 shows the growth rate of the ion mass effect. To investigate the isotopic effect, the ion atomic mass number was artificially changed from A=2 to A=2 while using the same D equilibrium and profiles.Fig.5 Scan of the radial electric field Er.Fig.6 Drift velocity for D plasmas.Fig.7 The wavenumber spectrum for Er scan in the linear stage in nonlinear simulation using D plasma equilibrium.Fig.8 The k-f spectrum of the BES measurements for D and H plasmas at the line-averaged density ∼1.5 × 1019 m−3.Fig.9 The k-f spectrum for an Er scan in the nonlinear phase in nonlinear simulation.Fig.10 The time evolution of the amplitude of the ion temperature and electron temperature fluctuations related to E × B (solid curves) and curvature drift (dash curves).Fig.11 The amplitude of the ion density fluctuations.The D plasma equilibrium and ion mass A = 1 are used during the Er scan.Fig.12 averaged radial fluxes of the simulation results.Black and dash curves stand for H and D plasma respectively. Dotted curves stand for the A = 1 case using D equilibrium and profiles.