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Nonlinear gyrokinetic simulations of the I-mode high confinement regime and comparisons with experimenta)
- Source :
- Prof. Whyte via Chris Sherratt
- Publication Year :
- 2017
-
Abstract
- For the first time, nonlinear gyrokinetic simulations of I-mode plasmas are performed and compared with experiment. I-mode is a high confinement regime, featuring energy confinement similar to H-mode, but without enhanced particle and impurity particle confinement [D. G. Whyte et al., Nucl. Fusion 50, 105005 (2010)]. As a consequence of the separation between heat and particle transport, I-mode exhibits several favorable characteristics compared to H-mode. The nonlinear gyrokinetic code GYRO [J. Candy and R. E. Waltz, J Comput. Phys. 186, 545 (2003)] is used to explore the effects of E × B shear and profile stiffness in I-mode and compare with L-mode. The nonlinear GYRO simulations show that I-mode core ion temperature and electron temperature profiles are more stiff than L-mode core plasmas. Scans of the input E × B shear in GYRO simulations show that E × B shearing of turbulence is a stronger effect in the core of I-mode than L-mode. The nonlinear simulations match the observed reductions in long wavelength density fluctuation levels across the L-I transition but underestimate the reduction of long wavelength electron temperature fluctuation levels. The comparisons between experiment and gyrokinetic simulations for I-mode suggest that increased E × B shearing of turbulence combined with increased profile stiffness are responsible for the reductions in core turbulence observed in the experiment, and that I-mode resembles H-mode plasmas more than L-mode plasmas with regards to marginal stability and temperature profile stiffness.<br />United States. Department of Energy (Contract No. DE-FC02-99ER54512-CMOD)<br />United States. Department of Energy. Office of Science (Contract No. DE-AC02- 05CH11231)
Details
- Database :
- OAIster
- Journal :
- Prof. Whyte via Chris Sherratt
- Notes :
- application/pdf, en_US
- Publication Type :
- Electronic Resource
- Accession number :
- edsoai.on1018415531
- Document Type :
- Electronic Resource