ISSN:
1089-7674
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The spatial, spectral, and statistical properties of the high-frequency (ω∼ωpe) electrostatic fluctuations in an unmagnetized, statistically stable, beam-driven, strongly turbulent plasma are investigated experimentally and the results are compared to the two-component model of Robinson and Newman. The fluctuations are found to consist of low-level wave activity 〈W〉∼10−2–10−3 punctuated by semiperiodic, intense, spiky field events 〈W〉∼1, where 〈W〉 is the normalized wave intensity. The low-level wave activity has a spectral spread Δk/k∼Δω/ω∼30%, dispersion relation vbeam∼ω/k, and correlation length lc(approximate)3λES, where λES is the electrostatic wavelength, and shows evidence of low-intensity parametric decay products. The intense field events, on the other hand, show little correlation for l〉λES, have a full width at half maximum of lf〈40λD, where λD is the Debye length, and are nonpropagating. The results indicate that the two-component model, and the Zakharov equations to which the model was originally verified, give an accurate description of strong Langmuir turbulence. © 2001 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1328356
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