Accession Number : ADA303444

Title :   Survey of PDP Data from PMG DELTA II.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Chi, Chia-Hwa

PDF Url : ADA303444

Report Date : JUN 1995

Pagination or Media Count : 124

Abstract : The Plasma Motor Generator (PMG) experiment was launched on 26 June 1993. The purpose was to verify the ability of the Hollow Cathode plasma contactor to provide a low impedance contact between the spacecraft and the ambient plasma. This thesis uses the data from Plasma Diagnostics Package (PDP) to study the effects of different modes on the rocket body. The electron data normally show a warm. or hot power law distribution with a characteristic energy of 10's eV. There is a consistent peak in the ion data at approx. 10 eV, which is also a peak in phase space density (distribution function). The average potential difference due to the varying bias (+65 and +0V) between rocket and ambient plasma is approx. 4 V. Subtle changes in the spectrum occur when the Far End Package (FEP) hollow cathode is switched off. Attempts were made to estimate the potential of the Delta rocket body. The variations in the data due to environmental (orbital) effects and the rapid sequencing of the PMG, made it difficult to analyze the data. The most of the measurements are interpreted as generated locally. The non-Maxwellian character of the electron distributions suggest a heating process has occurred. These processes may be due to collisions between gas or plasma einifled from the experiment and the ambient neutral oxygen, due to the high orbital energy of the system. (AN)

Descriptors :   *PLASMAS(PHYSICS), *PLASMA DIAGNOSTICS, IONOSPHERE, PEAK VALUES, MAGNETIC FIELDS, EARTH ORBITS, HIGH TEMPERATURE, ELECTRON DENSITY, THESES, VOLTAGE, CURRENT DENSITY, CHARGED PARTICLES, OXYGEN, MASS SPECTROMETERS, ELECTRICAL RESISTANCE, GAS DISCHARGES, BIAS, XENON, ELECTRON FLUX, MILITARY SATELLITES, PLASMA GENERATORS, SPACE CHARGE, DISTRIBUTION FUNCTIONS, ELECTRODYNAMICS, ION DENSITY, ELECTROSTATIC ANALYZERS, CATHODES(ELECTRON TUBES), IONIZED GASES, PLASMA ENGINES.

Subject Categories : Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE