Accession Number:

ADA179884

Title:

Basic Processes of Plasma Propulsion.

Descriptive Note:

Final scientific rept. 1 Aug 82-31 Jul 86,

Corporate Author:

STUTTGART UNIV (GERMANY F R) INSTR FUER RAUMFAHRTSYSTEME

Report Date:

1987-01-30

Pagination or Media Count:

112.0

Abstract:

The current density distribution, flow, pressure, and density fields are calculated for a quasi- steady nozzle-type 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 any measured results agree favorably. III. 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, andor 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.

Subject Categories:

  • Electric and Ion Propulsion

Distribution Statement:

APPROVED FOR PUBLIC RELEASE