Linear and Nonlinear Gyrokinetic Electron Temperature Gradient Mode Simulations for NSTX Discharges and NSTX-U projections
C.F. Clauser, T. Rafiq, W. Guttenfelder, E. Schuster
Division of Plasma Physics (DPP) Annual Meeting of the American Physical Society (APS)
Spokane, WA, USA, October 17-21, 2022
Experiments on NSTX have demonstrated that electron thermal transport
dominates ion thermal transport. One of the modes that is responsible
for electron thermal transport is the electron temperature gradient
(ETG) mode. A series of NSTX discharges and NSTX-U projections were
analyzed to investigate the anomalous electron thermal transport caused
by ETG modes. The CGYRO code was employed for this purpose and simulations
were carried out in both electrostatic and electromagnetic limits. The
results were compared to earlier studies and extended to NSTX-U p
rojections to investigate low collisionality regimes. The gyrokinetic
ETGM thermal flux has been utilized to verify and calibrate a recently
developed fluid model [1] for electromagnetic toroidal ETG driven drift
mode. The fluid ETG model will be used as a component of the Multi-Mode
anomalous transport module [2] in the predictive integrated modeling
code TRANSP to predict time-dependent electron temperature profiles in
NSTX-U and conventional tokamak plasmas.
[1] T. Rafiq et al. Phys. Plasmas, under review for publication (2022)
[2] T. Rafiq et al. Phys. Plasmas 20, 032506 (2013)
*Supported by the US DOE DE-SC0021385 and DE-SC0013977.