Evolution of the stimulated Raman scattering instability in two-dimensional particle-in-cell simulations

Journal Article · Wed Sep 15 04:00:00 EDT 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3474619· OSTI ID:21432283

Masson-Laborde, P E; Casanova, M; Loiseau, P ^[1]; Rozmus, W; Peng, Z ^[2]; Pesme, D; Hueller, S; Chapman, T ^[3]; Bychenkov, V Yu ^[4]

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1. CEA, DAM, DIF, F-91297 Arpajon (France)
2. Department of Physics, Theoretical Physics Institute, University of Alberta, Edmonton, Alberta T6G 2G7 (Canada)
3. Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)
4. P. N. Lebedev Physics Institute, Russian Academy of Science, Leninskii pr. 53, 11991 Moscow (Russian Federation)

In the following work, we analyze one-dimensional (1D) and two-dimensional (2D) full particle-in-cell simulations of stimulated Raman scattering (SRS) and study the evolution of Langmuir waves (LWs) in the kinetic regime. It is found that SRS reflectivity becomes random due to a nonlinear frequency shift and that the transverse modulations of LWs are induced by (i) the Weibel instability due to the current of trapped particles and (ii) the trapped particle modulational instability (TPMI) [H. Rose, Phys. Plasmas 12, 12318 (2005)]. Comparisons between 1D and 2D cases indicate that the nonlinear frequency shift is responsible for the first saturation of SRS. After this transient interval of first saturation, 2D effects become important: a strong side-scattering of the light, caused by these transverse modulations of the LW and the presence of a nonlinear frequency shift, is observed together with a strong transverse diffusion. This leads to an increase of the Landau damping rate of the LW, contributing to the limiting of Raman backscattering. A model is developed that reproduces the transverse evolution of the magnetic field due to trapped particles. Based on a simple 1D hydrodynamic model, the growth rate for the Weibel instability of the transverse electrostatic mode and magnetic field is estimated and found to be close to the TPMI growth rate [H. Rose et al., Phys. Plasmas 15, 042311 (2008)].

• OSTI ID: 21432283
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 9 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DAMPING
EVOLUTION
INSTABILITY
LANDAU DAMPING
MAGNETIC FIELDS
PLASMA INSTABILITY
PLASMA SIMULATION
PLASMA WAVES
RAMAN EFFECT
SIMULATION
TWO-DIMENSIONAL CALCULATIONS