Two-dimensional Electron Temperature Measurements Using Soft X-Ray Emission on the Compact Toroidal Hybrid

Electron temperature measurements are important in characterizing the equilibrium as well as MHD fluctuations in fusion plasmas. The Compact Toroidal Hybrid (CTH; $R_0 = 0.75\,$m, $a_p\sim 0.2\,$m, B$\leq 0.7\,$T, $n_e \leq 5~$x$~10^{19}\,$m$^{-3}$, $I_p \leq 80\,$kA, $T_e \leq 200~\,$eV) torsatron has an extensive collection of emissivity diagnostics: four pinhole type cameras, a bolometer, a spectrometer, and a prototype two-color camera. Improvements have been made on the current prototype two-color camera to reduce the electronic noise and ensure a light-tight camera housing. Amplifiers with a bandwidth of approximately $40\,$kHz have been implemented for study of both equilibrium and electron temperature fluctuations due to low frequency MHD activity. Electron temperature estimates from the SXR spectrometer, two-color camera, and conductivity measurements are compared. Two additional two-color cameras are currently under construction and will enable the tomographic reconstruction of the electron temperature.