A preliminary characterization of applied-field MPD thruster plumesElectric probes, quantitative imaging, and emission spectroscopy were used to study the plume characteristics of applied-field MPD thrusters. The measurements showed that the applied magnetic field plays the dominant role in establishing the plume structure, followed in importance by the cathode geometry and propellant. The anode radius had no measurable impact on the plume characteristics. For all cases studied the plume was highly ionized, though spectral lines of neutral species were always present. Centerline electron densities and temperatures ranged from 2 x 10 to the 18th to 8 x 10 to the 18th cu m and from 7500 to 20,000 K, respectively. The plume was strongly confined by the magnetic field, with radial density gradients increasing monotonically with applied field strength. Plasma potential measurements show a strong effect of the magnetic field on the electrical conductivity and indicate the presence of radial current conduction in the plume.
Document ID
19910061175
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Myers, Roger M. (NASA Lewis Research Center Cleveland; Sverdrup Technology, Inc., Brook Park, OH, United States)
Wehrle, David (NASA Lewis Research Center Cleveland, OH, United States)
Vernyi, Mark (NASA Lewis Research Center Cleveland, OH, United States)
Biaglow, James (NASA Lewis Research Center Cleveland, OH, United States)
Reese, Shawn (NASA Lewis Research Center Cleveland, OH, United States)