Plasma performance and operational space without ELMs in DIII-D

A database of DIII-D plasmas without edge-localized modes (ELMs) compares the operating space and plasma performance stationary no-ELM regimes found in conventional tokamaks: ELM suppression with resonant magnetic perturbations (RMPs), quiescent H-mode (QH, including wide-pedestal variant), improved confinement mode (I-mode), enhanced D-alpha (EDA-H), low-confinement (L-mode), negative triangularity L-mode (Neg-D). Operational is documented terms engineering physics parameters, revealing divergent constraints for each regime. Some operational discriminants (such as pedestal collisionality) are well known, while others, such low torque & safety factor, or high power density, less commonly emphasized. Normalized (confinement quality normalized pressure) also discriminate favor tolerant to DIII-D: RMP, QH, Neg-D. Absolute (volume-averaged pressure , time ?, triple product ) discriminates rise linearly IaB (a metric configuration strength, current I, minor radius a, field B that has units force), benefits from tolerance power. The highest using QH RMP regimes. Focusing on ITER-shaped plasmas, Q = 10 at 15 MA scaled global met some metrics (, ), but not others only thus far (?N pressure, H89,98 by scaling law, q95 factor). Though comparable found, (pped ? 2 pe,ped) very different. pped relatively low, best a core fraction alongside rotation, consistent an ExB shear enhancement. significantly higher than does correlate rotation. However, carbon fraction. While Neg-D absolute lower, owing elongation achieved far. Considering integration electron cyclotron heating, narrow, EDA-H open, pped/ (EDA-H QH) preserve performance. Only EDA-H, Neg-D, scenarios have approached divertor-compatible separatrix density conditions, preserving its compatibility both density. Comparison ELMing highlighted literature finds clearer correlation performance, reveals peak ELMs lower DIII-D, limits accessed so ELMs.