(Color online) The profiles of the electron and ion temperatures, the plasma density, and the neutral gas density are plotted in the closed field line region from to the separatrix with the outboard radial distance as the flux coordinate. The error bars correspond to the standard deviation of the quantities along the flux surface. This figure shows that plasma temperatures and density have little poloidal variation at the core-edge coupling point, justifying the use of a flux-surface averaged model. Note, however, that the neutral gas density, not evolved in the core, is not poloidally uniform as the coupling interface is approached.
(Color online) Waveforms for DIII-D shot 118897 shows the time over which the simulation is performed. The neutral beam power (a) raises the stored energy (b). The signal (c) indicates the transition to H-mode and the first ELM occurrence. The density (d) and temperatures (e) at the top of the pedestal shows the formation that occurs.
(Color online) Power sources for electrons and ions (left) and plasma particle source (right). The dashed line indicated the location of the core-edge coupling. Total beam power for ions (I) is 1.78 MW, for electrons (E) 2.21 MW and Ohmic heating (O) is 0.93 MW and radiation loss (R) is 0.40 MW. Net particle injection rate is s−1. Out of these, the fraction of particles into the core is s−1. Rest ( s−1) should be accounted for in the edge.
(Color online) Initial density (left) and temperature (right) profiles for electrons (black, E) and ions (red, I) for shot 118897 at 1555 ms. The blue dashed lines (left) indicate the core-edge interface, the green dashed line (middle) the separatrix and the cyan line (right) the start of transition from predictive to interpretive fluxes.
(Color online) UEDGE diffusivities from interpretive calculations. Red (D) line, black (E) line , and blue (I) line . The sudden drop in the diffusivities, specially in D, comes about from the transpor barrier needed in the formation of the pedestal. These diffusivities are held constant in the simulations performed in this paper.
(Color online) Final experimental (red, E) and simulation results (black, S) for plasma density. The red dashed line shows the initial profile. The density is seen to increase but does not reach the experimentally measured value. Tuning the gas puff to supply an additional fueling source can lead to higher density buildup at the pedestal as shown later in the paper. The 2D plot shows the poloidal variation in the edge.
(Color online) Final experimental (red, E) and simulation results (black, S) for electron temperature at 35 ms. The red dashed line shows the initial profile. The electron temperature compares well with the experimental results. The 2D plot shows the poloidal variation of the electron temperature in the edge.
(Color online) Final experimental (red, E) and simulation results (black, S) for temperature at 35 ms. The red dashed line shows the initial profile. The ion temperature is over-predicted at the pedestal but under-predicted at the axis. The 2D plot shows the poloidal variation of the ion temperature in the edge.
(Color online) Density profile variation with different gas-puff strength specified as equivalent amperes. The different lines are as follows. Red, 0: no gas-puff, black, 1: 100, magenta, 2: 250, light-blue, 3: 400, and blue, 4: 500. The dark green line (E) is the experimentally measured density profile. The pedestal density increases linearly with the gas-puff strength but, in the simulation time-scale, does not penetrate deep into the core.
(Color online) Electron temperature profile variation with different gas-puff strength specified as equivalent amperes. The different lines are labeled as in Fig. 9 and are as follows. Red: no gas-puff, black: 100, magenta: 250, light-blue: 400, and blue: 500. The dark green line is the experimentally measured electron temperature profile. Corresponding the increasing density in the pedestal, the electron temperature decreases as the gas-puff does not add any energy into the plasma but is simply a particle source.
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