Development of Hybrid Scenario on DIII-D for Burning Plasma Devices

Experiments on DIII-D have extended the hybrid scenario towards the burning plasma regime by increasing the noninductive current fraction to nearly 100\%, and in separate experiments by incorporating edge localized mode (ELM) suppression. Strong core current drive by neutral beam injection and electron cyclotron heating reduced the loop voltage to 0.01~V in hybrids with normalized beta up to 3.5 and an H$_{98}$ factor of 1.4. This demonstrates the potential for hybrids as a high-beta, steady-state scenario that is not sensitive to alignment of the noninductive current profiles. For the first time, large type-I ELMs have been completely suppressed in hybrids at $q_{95}=3.6$ by applying edge resonant magnetic perturbations using $n=3$ internal coils. The ELM suppression lasted for 0.5-1.0 times the current redistribution time for normalized beta up to 2.5 and a fusion performance factor equivalent to $Q=10$ operation in ITER.