The effect of ExB is investigated by scaling the ExB flow shear rates. In the simulations results presented below, the ExB flow shear rate is scaled by the factor of 2 (164510T17) and by the factor of 5 (164510T18). Very small effect on both electron and ion temperatures is found at the first time of interest:
The ion temperature is affected somewhat more at later time when the ExB flow shear is increased by the factor of 5:
The density profiles and the plasma equilibrium are not evolved in our TRANSP simulations of the DIII-D discharge 164410. Any experimental uncertainties for these two quantities can affect the predicted electron and ion temperature profiles. The experimental q and ne profiles at the times of interest are given below.
The electron density profiles at 4.1 sec (dashed curve) and 5.01 sec (solid curve).
The q profiles at 4.1 sec (dashed curve) and 5.01 sec (solid curve).
In order to test the effect of experimental density and q- profiles on the predicted temperature profiles, the U-files for density and q-profiles have been modified. In particular, in the simulation 164510T11 the q-profile from 3.5 sec to 5.1 sec is set to the experimental profile at 4.1 sec. In the simulation 164510T15, the q-profile from 3.5 sec to 5.01 sec is set to the experimental profile at 5.01 sec. In the first simulation, the agreement between experimental and predicted profile at 5.01 sec is examined. In the second simulation, the agreement at 4.1 sec is examined.
Use of the experimental q-profile at 5.01 as a constant profile from 3.5 sec to 5.1 sec, made the agreement with the experimental data better at 4.1 sec:
Use of the experimental q-profile at 4.1 as a constant profile from 3.5 sec to 5.01, made the agreement with the experimental data worth at 5.01 sec:
Similar study with the plasma density profiles (simulations 164510T12 and 164510T14) show a relatively weak dependence on the plasma density profiles.
The DIII-D discharge 164510 is a high plasma current discharge with two times of interest at t=4.1 sec with the plasma current 0.9 MA and at t=5.01 sec with the plasma current 1.05 MA.
The MMM7.1 model in the TRANSP code has been used to model this discharge. At both times, the electron and ion temperatures are found to be under-predicted. The MMM7.1 has also failed to reproduce the internal transport barrier observed in the ion channel of transport.
The electron temperature profile at 4.1 sec predicted with the MMM7.1 model (solid curve) and experimental profile (dashed curve).
The ion temperature profile at 4.1 sec predicted with the MMM7.1 model (solid curve) and experimental profile (dashed curve).
The electron temperature profile at 5.01 sec predicted with the MMM7.1 model (solid curve) and experimental profile (dashed curve)
The ion temperature profile at 5.01 sec predicted with the MMM7.1 model (solid curve) and experimental profile (dashed curve).
There is a strong ion thermal transport driven by ion temperature gradient modes at both times of interest:
Ion thermal diffusivities at 4.1 sec (solid curve) and 5.01 sec (dashed curve).
The electron thermal transport is smaller than the ion thermal transport.
Electron thermal diffusivities from Weiland component of MMM7.1 at 4.1 sec (solid curve) and 5.01 sec (dashed curve).
The contribution from the ETG component is also relatively small and does not change much between two times of interest.
Electron thermal diffusivities from the ETG component at 4.1 sec (solid curve) and 5.01 sec (dashed curve).
It is likely that the model over-predict the ion thermal transport driven by ITG modes in this plasma parameter regime.
