Spectra of ion acoustic plasma instability

Journal Article · Sat Oct 01 04:00:00 EDT 1977 · Phys. Fluids; (United States)

DOI:https://doi.org/10.1063/1.861771· OSTI ID:7218324

Ilic, D B

An experimental study of ion acoustic plasma turbulence in a collision-dominated positive column is presented. Linear theory predictions, which include ion Landau damping and the effects of a dc electric field, are shown to agree with measured values of convective growth rates. At high levels of turbulence, interferometric methods are not useful for studying the wave phase characteristics. Instead, the detailed spectral density for two-dimensional wave propagation, S (k,..omega..), is obtained by performing a two-dimensional spatial Fourier transform on sampled values of the frequency sweeps of the complex cross-power spectral density. The instability is found to be essentially one-dimensional, with the waves propagating along the direction of the electron drift velocity. The spectra are integrated numerically, and the energy density obtained is discussed in terms of two nonlinear models of saturated state of the instability. Time- and frequency-resolved power spectra are measured by sampling techniques, and compared to the predictions of linear theory. Temporal evolution of the phase characteristics is measured by a novel diagnostic technique.

• Research Organization: Institute for Plasma Research, Stanford University, Stanford, California 94305
• OSTI ID: 7218324
• Journal Information: Phys. Fluids; (United States), Journal Name: Phys. Fluids; (United States) Vol. 20:10; ISSN PFLDA
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700107* -- Fusion Energy-- Plasma Research-- Instabilities
700108 -- Fusion Energy-- Plasma Research-- Wave Phenomena
DAMPING
DISPERSION RELATIONS
FOURIER TRANSFORMATION
INSTABILITY
INSTABILITY GROWTH RATES
INTEGRAL TRANSFORMATIONS
ION ACOUSTIC WAVES
ION WAVE INSTABILITY
ION WAVES
LANDAU DAMPING
PLASMA INSTABILITY
PLASMA MICROINSTABILITIES
PLASMA WAVES
POWER
TRANSFORMATIONS
WAVE PROPAGATION