Dependence of Electron and Ion Transport on $T_e/T_i$ in Low Collisionality QH-mode Plasmas

Core electron/ion thermal transport and its dependence on ITG/TEM/ETG-scale turbulence are examined in high temperature, strongly rotating QH-mode plasmas, at ITER-relevant collisionality ($\nu_e^* \sim 0.05$). To simulate central electron heating by $\alpha$-particles, ECH has been used to achieve $0.6 \leq T_e/T_i \leq 1.1$. ITG/TEM-scale density fluctuations remain virtually unchanged, while electron temperature fluctuations, and gyroBohm-normalized electron and ion diffusivities increase with $T_e/T_i$. Linear stability calculations support a transition to a TEM-dominated regime due to increased $T_e/T_i$ and a reduced ion temperature gradient $R/L_{Ti}$ with ECH. Initial GYRO nonlinear calculations will be shown. At reduced toroidal rotation, ITG-dominated QH-mode plasmas [$T_e(0)/T_i(0)\sim 0.6$] exhibit 20\% increased global energy confinement time and $\beta_N$,