Waves of Ionization in Low Pressure Molecular Gas Discharges.

Abstract

The dispersion of waves of ionization were studied in nitrogen and in carbon dioxide. The waves were excited by current modulation and the dispersion recorded using a time-space display method. In N2 and in CO2 the ionization waves were cathode to anode forward waves. Their dispersion is presented as a function of the gas pressure and of the discharge currents. The waves with finite group velocity were always attenuated in the pressure range studied (0.3 to 5 torr) but standing striations were obtained at the lower pressures without current modulation. However in the mixture N2-CO2, the discharge was very unstable and showed a broad-band spectrum of low frequency oscillations. These self-excited oscillations did not permit time-sampling diagnostics. A 0 to 100 kHz digital correlator was applied to determine the characteristics of these apparently random ionization waves. Results of this experiment are presented. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1969
Accession Number
AD0855851

Entities

People

  • Philip L. Newton

Organizations

  • Air Force Institute of Technology

Tags

DTIC Thesaurus Topics

  • Band Spectra
  • Carbon Dioxide
  • Correlators
  • Dispersions
  • Frequency
  • Gas Discharges
  • Group Velocity
  • Ionization
  • Modulation
  • Nitrogen
  • Oscillation
  • Sampling
  • Spectra
  • Striations
  • Wave Phenomena

Fields of Study

  • Physics

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Molecular Photonics/Laser Physics
  • Plasma Physics / Magnetohydrodynamics

Technology Areas

  • Space
  • Space - Hall-Effect Thruster