National Spherical Torus Experiment (NSTX) Facility/Diagnostic Overview

The capabilities of the NSTX experimental facility and diagnostics continue to improve. The new TF joints are performing well at 4.5~kG. New in-board shaping coils were installed to produce plasmas with simultaneously high elongation $\sim 2.5$ and high triangularity $\sim 0.8$ needed for advanced operation. The EFC/RWM system with six external coils driven by three switching power amplifiers (1~kHz, 6~kA-turn) is now fully operational. With these new tools, we significantly expanded the NSTX operating parameters, achieving the highest controlled elongation of 2.75, a shape factor $q_{95}I_{p}/aB_{T}$ of 37~MA/m-T, plasma volume of 14~m$^{3}$, stored energy of 430~kJ, normalized beta of 7.4~\% MA/m-T, bootstrap current fraction of 60 \% at 700~kA, and longest plasma pulse length of 1.5~s or about 4 times the resistive skin time. In the area of the plasma diagnostics, ten additional Thomson scattering channels are providing detailed measurement of the H-mode pedestal and internal barrier regions. The 8 channel MSE diagnostic is providing crucial $j(r)$ measurements including high electron confinement reversed shear plasmas. A tangential microwave scattering system to measure electron-transport- relevant fluctuations is being commissioned.