Accession Number : ADA329607

Title :   Anomalous Ionization Studies: Investigations of the Critical Ioniaztion Velocity (CIV) Phenomenon in Space

Descriptive Note : Final rept. Feb 93-Mar 95

Corporate Author : PRINCETON UNIV NJ ELECTRIC PROPULSION LAB

Personal Author(s) : Choueiri, Edgar ; Jahn, Robert

PDF Url : ADA329607

Report Date : 28 JUN 1995

Pagination or Media Count : 100

Abstract : The research work we conducted under AFOSR support aimed at a detailed study of the fundamentals of the phenomenon of anomalous ionization and its relevance to plasma thrusters. Ionization can represent a major energy sink for plasma accelerators and can thus have a large impact on their thrust performance in general and efficiency in particular. In this project, we combined, analytical, numerical tools with space experiments in order to develop various complementary descriptions of the complex and fundamental problem of collective (or anomalous) ionization. We used the insight gained from these fundamental studies to develop a model for the role of collective ionization in plasma thrusters. The model relates the atomic physics associated with ionization to the collective plasma physics through a prescription of an electron energy distribution function (EDF) that can represents the effects of plasma instabilities namely the creation of suprathermal electron populations. The model is cast in terms of effective bulk and tail temperatures that allows the use of the model in macroscopic descriptions of plasma thrusters.

Descriptors :   *ARTIFICIAL SATELLITES, *THRUSTERS, *SPACE PROPULSION, *PLASMA ENGINES, SPACE ENVIRONMENTS, TAIL ASSEMBLIES, ELECTRONS, ELECTRON ENERGY, SPACE SHUTTLES, IONIZATION, SPECTRAL ENERGY DISTRIBUTION, NUCLEAR PHYSICS, IONIZATION POTENTIALS, PLASMA WAVES, PLASMA ACCELERATORS, PLASMA INSTABILITIES.

Subject Categories : Electric and Ion Propulsion
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE