Accession Number : AD0778076

Title :   Electroacoustic Probe Results Obtained in an Argon Afterglow Plasma for a Planar Geometry.

Descriptive Note : Physical sciences research papers,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS L G HANSCOM FIELD MASS

Personal Author(s) : Karas,Nicholas V.

Report Date : 02 NOV 1973

Pagination or Media Count : 56

Abstract : Experimental data resulting from an investigation of the electroacoustic probe in an argon afterglow plasma for a planar geometry indicates the value of the probe as a diagnostic tool. It is suited to airborne payloads because of its small size and rugged construction. In carrying out the study, some of the parameters that were varied were the pressure (range = 100 to 1000 micro m), input power to the probe (range = 40 dB), and frequency of input signal (350 to 600 MHz). The effect of changing physical dimensions of the probe was also considered. Electroacoustic probe predictions of the electron density gradients close to a surface were found to compare closely with the electron density gradients obtained with a floating double Langmuir probe. Treating the electroacoustic probe as similar to a resonant circuit produced some preliminary results that show up as familiar Q values. Both linear and nonlinear responses of the electroacoustic probe are illustrated. One nonlinear phenomenon--induced oscillations in sections of the resonance curve--is discussed in detail. (Author)

Descriptors :   *Plasmas(Physics), Electroacoustic transducers, Langmuir probes, Electron density, Afterglows, Atmosphere entry, Plasma sheaths, Argon

Subject Categories : Test Facilities, Equipment and Methods
      Plasma Physics and Magnetohydrodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE