Survey of microinstability and simulated turbulent transport in NSTX

Linear gyrokinetic simulations demonstrate a large variety of microinstabilities are possible in NSTX. Microtearing modes are often unstable in the core region (r/a=0.5-0.8) of NBI heated H-modes. In cases without Lithium wall conditioning, the local E$\times $B shearing rates are larger than linear growth rates (r/a=0.5-0.6). Instead, the ETG instability (at electron scales) is unstable; nonlinear simulations in this region will be presented. Farther out (r/a=0.7-0.8), and in plasmas with Lithium wall conditioning, other ion scale instabilities can co-exist with, or dominate, microtearing modes. The nature of these ballooning modes is complicated and can exhibit ITG/TEM or KBM behavior depending on the MHD alpha parameter ($\alpha _{MHD} =-q^2R\nabla \beta )$. In limited cases tearing-parity ITG modes have also been identified. While non-linear simulations of these ``mixed-mode'' conditions are challenging, first attempts are underway. This work is supported by US DOE contract DE-AC02-09CH11466.