Edge MSE measurements on the DIII-D tokamak

The edge motional Stark effect (MSE) diagnostic on DIII-D has recently been upgraded to provide better constraints on the current density in the outer half radius, including high-spatial resolution measurements in the H-mode pedestal. The channels have been upgraded with new bandpass filters with FWHM of 0.3 nm and $>$90$\%$ transmission at the central wavelength, and improved detector positioning. A spectrometer has been used to measure the $\sigma$ and $\pi$ lines for each of the edge channels to optimize the new filter selection. These upgrades are expected to improve our ability to assess current drive and stability in various DIII-D plasmas. Comparisons will be shown between the Sauter and NEO bootstrap current models and these new measurements in fully non-inductive plasmas. We will present calculations of the ideal MHD $\beta_N$-limit in various scenarios that use the improved measurements. Finally, changes in the edge pitch angle during ELMs are examined.