Current diffusion, heat transport modelling, and linear gyrokinetic stability analysis have been carried out on a set of seven hybrid discharges from AUG, DIII-D, JET and JT-60U, in order to gain better understanding of the physics underlying this promising candidate scenario for ITER. Within this dataset, the GLF23 model has a higher accuracy than the Weiland model in predicting the temperature profiles in the region 0.3 < ρ < 0.8. The core heat transport appears to be similar between hybrid discharges and standard H-modes, and also among hybrid discharges with very different H factors. Projections to ITER show that Q = 10 can be obtained with the hybrid scenario using an alternative scaling without β degradation. However, additional off-axis current drive and current profile control might be needed for the ITER hybrid scenario, in order to achieve its full potential for high βN on extended duration.
Simulation of the hybrid and steady state advanced operating modes in ITER