An Adiabatic Fluid Electron Particle-in-Cell Code for Simulating Ion-Driven Parametric Instabilities

Vu, H. X.

doi:10.1006/jcph.1996.0069

Cited by 17 publications

(35 citation statements)

References 10 publications

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“…Earlier work on the theory and simulation of SBS has shown the importance of wave breaking and ion trapping, [1][2][3][4][6][7][8][9][10][11][12] harmonic generation, [13][14][15] and secondary instability of the ion wave. [1][2][3][4][5] In 1D simulations of SBBS, the inclusion of kinetic electrons has made a difference in the saturation of SBBS.…”

Section: Introductionmentioning

confidence: 99%

Effects of ion-ion collisions and inhomogeneity in two-dimensional kinetic ion simulations of stimulated Brillouin backscattering

et al. 2006

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Langdon, and E.A. Williams, Phys. Plasmas 4, 956 (1997)] hybrid code (kinetic particle ions and Boltzmann fluid electrons) have been used to investigate the saturation of stimulated Brillouin backscatter (SBBS) instability including the effects of ion-ion collisions and inhomogeneity. Ion-ion collisions tend to increase ion-wave dissipation, which decreases the gain exponent for stimulated Brillouin backscattering; and the peak Brillouin backscatter reflectivities tend to decrease with increasing collisionality in the simulations. Two types of Langevin-operator, ion-ion collision models were implemented in the simulations. In both models used the collisions are functions of the local ion temperature and density, but the collisions have no velocity dependence in the first model. In the second model, the collisions are also functions of the energy of the ion that is being scattered so as to represent a Fokker-Planck collision operator. Collisions decorrelate the ions from the acoustic waves in SBS, which disrupts ion trapping in the acoustic wave. Nevertheless, ion trapping leading to a hot ion tail and two-dimensional physics that allows the SBS ion waves to nonlinearly scatter remain robust saturation mechanisms for SBBS in a high-gain limit over a range of ion collisionality. SBS 2 backscatter in the presence of a spatially nonuniform plasma flow is also investigated.Simulations show that depending on the sign of the spatial gradient of the flow relative to the backscatter, ion trapping effects that produce a nonlinear frequency shift can enhance (auto-resonance) or decrease (anti-auto-resonance) reflectivities in agreement with theoretical arguments. PACS: 52.38.-r 52.65.Rr 3

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Section: Introductionmentioning

confidence: 99%

Effects of ion-ion collisions and inhomogeneity in two-dimensional kinetic ion simulations of stimulated Brillouin backscattering

et al. 2006

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“…In Eqs. (2), the electron response has been averaged over the laser time scale, and the ion response has likewise been averaged over the electron time scale [31][32][33]. It can be shown, within the framework of kinetic theory, that by eliminating the high-frequency components of the electric field under whose influence the ions are advanced, one has: (a) eliminated ionelectron collisions completely and (b) reduced the ion velocity diffusion substantially.…”

Section: Rpic Modelmentioning

confidence: 99%

“…It can be shown that in the limit where high-frequency instabilities are not important, RPIC reduces to the aforementioned hybrid model [31][32][33].…”

Section: Introductionmentioning

confidence: 95%

“…Due to a multitude of spatial and temporal scales that exist in such plasmas and the fact that the external driving electromagnetic field is of high frequency, general-purpose explicit, implicit, and hybrid particle-in-cell (PIC) algorithms [6,30] are either incapable of simulating the actual physics, or computationally inefficient. In recent works [31][32][33], a special-purpose hybrid PIC model was presented in which the electrons are modeled as an adiabatic fluid with an arbitrary ratio of specific heats γ , and the electromagnetic field model is based on a temporal envelope approximation. This hybrid PIC model was implemented in three dimensions on a CRAY-T3D with 512 processors and was shown to model ion Landau damping, finite-Debye-length effects, aperiodically driven stimulated Brillouin scattering (SBS), and the interaction between SBS and the filamentation instability (FI) correctly [31][32][33].…”

Section: Introductionmentioning

confidence: 99%

“…In recent works [31][32][33], a special-purpose hybrid PIC model was presented in which the electrons are modeled as an adiabatic fluid with an arbitrary ratio of specific heats γ , and the electromagnetic field model is based on a temporal envelope approximation. This hybrid PIC model was implemented in three dimensions on a CRAY-T3D with 512 processors and was shown to model ion Landau damping, finite-Debye-length effects, aperiodically driven stimulated Brillouin scattering (SBS), and the interaction between SBS and the filamentation instability (FI) correctly [31][32][33]. However, this hybrid model does not include electron kinetic effects and is therefore inadequate for situations in which high-frequency parametric instabilities, such as stimulated Raman scattering, play a significant role.…”

Section: Introductionmentioning

confidence: 99%

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