Electron Heating and Confinement Measurements in the EBT-S Toroidal Core Plasma with Thomson Scattering

A ruby-laser Thomson-scattering system, designed for very low-electron-density applications, has shown electron temperature ($T_e$) and density ($n_e$) profiles in the Elmo Bumpy Torus-Scale toroidal plasma to be flat, with $T_e$ values from 50 to 500 eV and $n_e$ values from 0.5 to 2.2×${10}^{12}$ ${\mathrm{cm}}^{-3\mathrm{}}$. Scaling of $T_e$ and $n_e$ with microwave power and background pressure is discussed. Electron-energy confinement times are derived and are found to scale approximately linearly with power for times up to 4 ms.