Investigation of the Thomson Scattering/ECE discrepancy at high temperature on Alcator C-Mod and DIII-D

High temperature plasmas [$T_e\, (0) > 7$ keV] have been produced with ion cyclotron resonance heating at Alcator C-Mod and with neutral beam and fast wave heating at DIII-D. In optically thick tokamak plasmas, $T_e$ measurements made with Thomson Scattering (TS) and Electron Cyclotron Emission (ECE) diagnostics are typically in excellent agreement. However, past experiments at TFTR and JET have shown the existence of a disagreement between $T_e$ measured by TS and ECE when $T_e\geq 7$ keV, as well as evidence of distortions in the bulk of the electron distribution function. Preliminary results from the DIII-D and C-Mod experiments indicate no such discrepancy between TS and ECE when $T_e\, (0) > 7$ keV. Comparisons between TS and ECE measurements in high temperature DIII-D and C-Mod plasmas, and comparisons of measured ECE spectra with simulations, will be presented.