Narrowing the ITEP Pedestal Physics GAP with Strong Plasma Shaping at High Plasma Current on DIII-D

Combining high core performance with a dissipative divertor in an H-mode based fusion power plant (FPP) requires high pedestal pressure, p^PED, at high density, n_e^PED. These pedestals will be in a regime of high opacity to neutrals entering from the scrape off layer but low collisionality: conditions that are difficult to achieve simultaneously in present experiments. DIII-D will exploit the Super-H-mode regime at high plasma current, I_P, combined with strong plasma shaping to build a better understanding of the physics setting pedestal structure with more FPP relevant neutral opacity and collisionality. Modification of the divertor geometry is planned to allow density control in these high triangularity, high elongation, large minor radius discharges as well as an increase in toroidal field to extend Super-H-mode access to higher I_P. In the Super-H-mode regime p^PED increases with n_e^PED, I_P and triangularity, while Super-H access will be lost if the safety factor, q, is too low. High elongation and the optimal squareness are required also to relax the level of n_e^PED and T^PED control needed to enter the regime. Edge particle source widths down to 20% of the n_e^PED width at ν_*e ~ 0.5 with n_e^PED~1.6x10²⁰/m³, n_e^PED/n_G= 0.8 at I_P=2.3MA, q₉₅=4 may be achievable.