Fully Noninductive Scenario Development in DIII-DUsing New Off-Axis Neutral Beam Injection Capability

New off-axis neutral beam injection (NBI) capability on DIII-D has expanded the range of achievable and sustainable current and pressure profiles of interest for developing the physics basis of steadystate scenarios in future tokamaks. Using off-axis NBI, plasmas have been produced with qmin between ~1.3 and ~2.5 to evaluate the suitability for steady-state operation (fNI INI/IP=1). These plasmas typically have broader current and pressure profiles and increased stability. Nearly stationary plasmas were sustained for two current profile relaxation timescales (3 s), with qmin 1.5 N 3.5, fNI and performance that projects to Q 5 in an ITER-size machine. The duration of the high N phase is limited only by the available NBI energy. Low-order tearing modes are absent and the predicted ideal-wall n=1 kink N limit is >4. This demonstrates performance close to that required for the ITER and FNSF-AT steady state missions with margin for further improvement. Furthermore these plasmas have been shown to be compatible with a divertor heat flux reduction technique that relies on neon injection into the private flux region to enhance radiated power. To achieve higher fNI, the bootstrap current fraction must be increased, and achieving higher N and higher qmin is expected to do this. High qmin>2 and N near 5 are also required for a DEMO steady state power plant solution. Experiments to produce plasmas with qmin>2 showed that the use of off-axis NBI results in higher sustained qmin, with qmin at a larger radius (i.e. a broader current profile), and a broader pressure profile. These changes increased the predicted ideal-wall n=1 kink mode N limit from N 3.5 to N 4. These plasmas typically achieved a maximum N=3.2 limited by the available NBI power and reduced confinement (H89<2) relative to similar plasmas with lower qmin and only on-axis NBI. Enhanced fast ion loss at high qmin is the likely cause.