Multi-scale Fluctuation Behavior During Balanced NBI H-mode in the DIII-D Tokamak

Using a unique array of diagnostics, the behavior of fluctuations over a broad range in wavenumber ($0 \leq k\rho_s \leq 10$) and for two different fields (density and electron temperature) during balanced NBI is examined. Simultaneous co- and counter-NBI is utilized to access H-mode with a minimum of total torque. The diagnostic set utilized includes FIR scattering, Doppler backscattering, correlation ECE, BES, reflectometry, and high-$k$ mm-wave backscattering. Near $r/a=0.6$ high-$k$ fluctuations ($k\sim 35$ cm$^{-1}$) increase substantially with NBI (x3) prior to and during the H-mode. Low-$k$ temperature fluctuations also increase with NBI ($r/a$=0.6-0.7) prior to decreasing at the LH transition. In contrast, intermediate $k$ density fluctuations appear relatively unchanged just prior to the LH. Analysis of flow activity ($E_r$, $E_r$ shear, and zonal flow), transport behavior from power balance, and comparison to linear gyrokinetic stability calculations (including sensitivity studies) will be presented.