Space and time behavior of backscattering instabilities in the modified decay regime

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Physics of Plasmas; (United States)

DOI:https://doi.org/10.1063/1.870585· OSTI ID:6929853

Mounaix, P ^[1]; Pesme, D ^[2]

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1. Centre de Physique Theorique, Ecole Polytechnique, 91128 Palaiseau Cedex (France)
2. Laboratoire pour l'Utilisation des Lasers Intenses, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

The space and time behavior of parametric backscattering instabilities is computed analytically in the so-called modified decay regime. The plasma is assumed to be homogeneous and of finite length. The propagation of the pump wave and its finite pulse duration both are taken into account, its depletion is ignored. The parametric growth is solved in terms of fluctuating initial and boundary conditions corresponding to thermal noise at equilibrium. Fluctuating source terms, representing spontaneous emission of waves, are accordingly retained in the coupled mode equations. The initial stage of the instability is investigated in detail; the time from which the time asymptotic concept of absolute or convective instability applies is computed. Approximate expressions for the fluctuations of the waves, that are uniformly valid for any gain factor and any time, are derived.

• OSTI ID: 6929853
• Journal Information: Physics of Plasmas; (United States), Journal Name: Physics of Plasmas; (United States) Vol. 1:8; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700340* -- Plasma Waves
Oscillations
& Instabilities-- (1992-)
700350 -- Plasma Production
Heating
Current Drive
& Interactions-- (1992-)
ABSOLUTE INSTABILITIES
BACKSCATTERING
BOUNDARY CONDITIONS
BRILLOUIN EFFECT
COHERENT SCATTERING
CONVECTIVE INSTABILITIES
DECAY INSTABILITY
ELECTROMAGNETIC RADIATION
FUNCTIONS
GREEN FUNCTION
HOMOGENEOUS PLASMA
INSTABILITY
LASER RADIATION
PARAMETRIC INSTABILITIES
PLASMA
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
RADIATIONS
RAMAN EFFECT
SCATTERING