Characterization of a Magnetically Contained Hot Filament Plasma Source with a Wide-Sweeping Langmuir Probe

Ionospheric plasma research in the Space and Atmospheric Instrumentation Laboratory’s Space Plasma Chamber has been hindered by the lack of a suitable plasma diagnostic instrument and understanding of its hot-filament plasma source. This thesis describes efforts made to remedy both problems. A wide-range Sweeping Langmuir Probe was developed with a ±35 V sweeping range to fully analyze ion and electron saturation regions in the entire IV curve. A method was derived to estimate the chamber source’s filament temperatures. The new Langmuir probe was integrated into a refurbished automated system designed in Python to measure plasma parameters for various chamber conditions, culminating in creating several maps of densities and temperatures throughout the chamber. It was shown that the updated source produces plasma within the LEO range of densities and temperatures. The work towards this thesis involved schematic capture in National Instrument’s Multisim, circuit simulation in LTspice, board layout design in National Instrument’s Ultiboard, the board population, calibration, testing, and finally, data analysis of the captured curves. In addition, a filament temperature method was calculated and calibrated, and the framework of a software control system was adapted for automated instrument sampling in the plasma chamber.