Growth Rates of Parametric Instabilities Driven by Two Pumps,

Abstract

The parametric instability growth rate of ion acoustic and Langmuir waves, driven unstable by two uniform pumps near the Bohm-Gross frequency, is calculated as a function of pump amplitudes and frequencies. Two instability mechanisms can be identified: one corresponds to the usual, single pump parametric instabilities (decay and oscillating two stream) while the other is similar to that found in the Mathieu equation. The interaction between these two mechanisms results in a non-monotonic dependence of the growth rate on the pump amplitudes and frequencies: both cancellation and enhancement are obtained for various values of the parameters. An analytic study of the relevant dispersion relation using Hill's method is complemented by numerical studies in both the frequency and time domains. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1984
Accession Number
ADA139463

Entities

People

  • B. D. Fried
  • George J. Morales
  • J. L. Milovich

Organizations

  • University of California, Los Angeles

Tags

Communities of Interest

  • Air Platforms
  • Materials and Manufacturing Processes
  • Space

DTIC Thesaurus Topics

  • Acoustic Frequencies
  • Acoustic Waves
  • Differential Equations
  • Dispersion Relations
  • Electron Density
  • Electrons
  • Equations
  • Frequency
  • Frequency Domain
  • Ion Density
  • Parametric Instability
  • Resonance
  • Resonant Frequency
  • Scattering
  • Spectra
  • Time Domain
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Plasma Physics / Magnetohydrodynamics