The validity of reduced-order turbulence models, QuaLiKiz [1] and TGLF [2], in the L-mode near-edge was investigated using both higher fidelity gyrokinetic code GENE [3] and integrated modelling simulations JINTRAC suite [4]. The dataset is based on seven NBI-heated JET-ILW deuterium discharges with different upper triangularity and densities just prior on H mode transition [5]. For the lower densities, the dominant turbulence is in the ITG/TEM regime. In unshaped geometry QuaLiKiz and TGLF are in good agreement with GENE. But shaped geometry impact being large in these radial regions, TGLF using the Miller parameters performs best. Except for an electron direction mode that stabilises with increasing density-gradient, found in one low d case only with GENE. At higher densities, drift-resistive turbulence is found with GENE, consistent with previous work [6,7]. The dominant modes at low wavenumbers are driven by main ion parallel and curvature dynamics. In TGLF, these resistive modes are not as dominant as in GENE while they are not presently implemented in QuaLiKiz. For the low density cases, heat flux driven modelling is performed with both QuaLiKiz and TGLF in the JINTRAC suite [4]. The predicted ion temperature up to the LCFS is in close agreement with measurement, while the electron temperature is underpredicted.
Validation of reduced-order turbulence modelling in the L-mode nearedge of the JET-ILW tokamak
Vincenzi P;
2023
Abstract
The validity of reduced-order turbulence models, QuaLiKiz [1] and TGLF [2], in the L-mode near-edge was investigated using both higher fidelity gyrokinetic code GENE [3] and integrated modelling simulations JINTRAC suite [4]. The dataset is based on seven NBI-heated JET-ILW deuterium discharges with different upper triangularity and densities just prior on H mode transition [5]. For the lower densities, the dominant turbulence is in the ITG/TEM regime. In unshaped geometry QuaLiKiz and TGLF are in good agreement with GENE. But shaped geometry impact being large in these radial regions, TGLF using the Miller parameters performs best. Except for an electron direction mode that stabilises with increasing density-gradient, found in one low d case only with GENE. At higher densities, drift-resistive turbulence is found with GENE, consistent with previous work [6,7]. The dominant modes at low wavenumbers are driven by main ion parallel and curvature dynamics. In TGLF, these resistive modes are not as dominant as in GENE while they are not presently implemented in QuaLiKiz. For the low density cases, heat flux driven modelling is performed with both QuaLiKiz and TGLF in the JINTRAC suite [4]. The predicted ion temperature up to the LCFS is in close agreement with measurement, while the electron temperature is underpredicted.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
