Predictive Transport Analysis of JET and AUG Hybrid Scenarios
Hybrid scenarios in present machines are characterized by improved confinement compared to the IPB98(y,2) empirical scaling law expectations. A number of possibilities explaining this improvement have been proposed: reduction in deleterious MHD, pedestal confinement improvement, rotational shear turbulence suppression, increased turbulent thresholds due to qprofile shaping, and stiffness reduction at low magnetic shear. This work concentrates on isolating the impact of increased s/q at outer radii (where s is the magnetic shear) on core confinement in low-triangularity JET and ASDEX Upgrade (AUG) experiments. This is carried out by predictive heat and particle transport modelling using the integrated modelling code CRONOS coupled to the GLF23 turbulent transport model. This work aims to validate recent predictions of the ITER hybrid scenario also employing CRONOS/GLF23, where a high level of confinement and resultant fusion power sensitivity to the s/q profile was found.