Microwave Emission and Electron Temperature in the Maryland Centrifugal Experiment

Abstract

The use of two magnetised plasma waves as electron temperature diagnostics for the Maryland centrifugal ecperiment (MCX) are explored. First, microwave emission in the whistler mode is examined and ultimately found to be a poor candidate for diagnostic purposes owing to reflections from elsewhere in the plasma confusing the signal. Second, the electron Bernstein wave is found to offer promise as means to measure the radial electron temperature profile. Several numeric codes are developed to analyze the observed microwave emission and calculate the elec- tron temperature profile. Measurements of electron Bernstein wave emission indicate that the electrons in the plasma attain temperatures close to 100 eV. Clear evidence is shown that the measurements are not influenced by reflections or emission from hot (Te > 1keV) superthermal electrons. The measured electron temperature is shown to be in reasonable agreement with recent measurements of the plasma ion temperature.