Basic processes of plasma propulsion
Abstract
The current density distribution, flow, pressure, and density fields are calculated for a (quasi-) steady nozzle-type magnetoplasmadynamic (MPD) thruster, based on a partially two dimensional approach, assuming a fully singly ionized plasma with an iso-thermal electron and an adiabatic ion behavior. In addition, for a given current rise, the current contour lines and the flow, pressure, and density fields within the cylindrical flow discharge region are calculated as a function of time. II. In order to investigate the arc stability, a unique theoretical approach is presented which allows determination of the stability behavior of an arbitrarily shaped current-carrying plasma channel under various conditions. Based on this novel theory, the onset phenomenon observed in any nozzle-type MPD arc jets can be predicted; calculated and measured results agree favorably. The cathode attachment of electric arcs are theoretically and experimentally investigated. The erosion effects and the surface damage due to spots are discussed; they stem from evaporation, droplet ejection, and/or splashing. The most severe damage to the cathode surface occurs when many small spots cluster together and build one or even several larger spots which now cause melting and splashing.
- Publication:
-
Final Scientific Report
- Pub Date:
- January 1987
- Bibcode:
- 1987stut.reptQ....S
- Keywords:
-
- Arc Discharges;
- Current Density;
- Current Distribution;
- Magnetoplasmadynamics;
- Electric Arcs;
- Magnetohydrodynamic Flow;
- Plasma Engines;
- Plasma Propulsion;
- Adiabatic Conditions;
- Cathodes;
- Density Distribution;
- Electric Current;
- Flow Distribution;
- Ion Propulsion;
- Magnetohydrodynamic Stability;
- Plasmas (Physics);
- Surface Stability;
- Plasma Physics