Mass spectral measurements in the plume of an SPT-100 Hall thruster

Knowledge of the ion species emitted by the SPT-100 Hall thruster provides considerable insight to basic thruster performance. To gain detailed information concerning the composition of the plume plasma, a unique molecular beam mass spectrometer was constructed to interrogate the exhaust plume. An investigation using this technique yielded both the ionization fraction of the xenon propellant and a qualitative analysis of the minority plasma species attributed to ground-test facility interactions. The plasma was found to consist of 89% Xe+, 11% Xe2+, and 0.2% Xe3+. The existence of parasitic facility games including nitrogen, oxygen, and water vapor was documented, as well as trace carbon ions caused by sputtering of graphite surfaces in proximity of the thruster.

Duke Scholars

Author Alec Gallimore Thomas Lord Department of Mechanical Engineering and Materia ...