Stimulated Brillouin backscatter (SBBS) instantaneous electromagnetic power reflectivity and the cumulative time-averaged reflectivity up to time (with ) from simulations with (a) , (b) , and (c) .
(Color online). Contours of the two-ion-wave decay growth rates normalized to are plotted as functions of (parallel to the propagation of the primary IAW) and for primary IAW amplitude , , .
SBBS reflectivity time histories for three simulations: 1D, 2D plane wave, and 2D Gaussian beam.
SBBS reflectivities in 1D and 2D (plane wave and Gaussian pump) as functions . (a) 1D and 2D plane wave. (b) 2D plane wave and Gaussian.
Longitudinal ion velocity distribution functions and phase space after saturation of SBBS in 1D, 2D with incident plane wave, and 2D with Gaussian beam. .
Longitudinal ion velocity distribution functions in the left and right thirds of the plasma domain and electric potential ( in 2D) vs in 1D and 2D (plane-wave pump) after saturation of SBBS.
Transverse ion velocity distribution functions from the left and right thirds of the simulation domain after saturation of SBBS for a 2D plane-wave case with showing heating.
Spectrum mode number for 1D simulation with showing primary IAW and its harmonics after saturation. for the primary SBBS IAW at this time.
Plots of vs time for the primary SBBS IAW with and the (in units of ) mode showing the growth and decay of the primary IAW and the growth of the mode accompanying the decay.
Streak spectra (contour plots of intensity vs frequency relative to sound frequency of the primary SBBS IAW and time ) for at two probe locations (a) and (b), and for the backscatter and forward scatter electromagnetic energy fluxes at the (c) left and (d) right system boundaries on the midline with .
(Color online). Contour plots of and at three times from the 2D plane-wave simulation with showing backward SBS dominating on the left side of the system and later in time forward SBS dominating the right side.
SBBS reflectivity for the 2D plane wave simulation with (a) allowing both forward and backward SBS and (b) allowing only backward SBS.
Plots of vs time for and or 1 (in units of ) for 2D plane-wave simulations with in (a), with forward scatter suppressed in (b), and no laser in (c).
Transverse ion velocity distribution functions corresponding to the three simulations shown in Fig. 13 showing significant transverse heating in the strong SBBS cases. with strong SBBS in (a) and (b). with no SBS in (c).
(a) Continuation of 2D simulation with at with lasers off and a perturbation added to study IAW damping. at averaged over vs time. (b) Same as in (a) for simulation with no laser and no SBS.
SBBS reflectivities vs time and streak spectra for at for (a) without and (b) with forward SBS showing that SBBS does not recover after scrambling ion positions and restarting.
(a) SBBS reflectivity and (b) at for and vs time with two restarts. The large amplitude IAW in (b) for is associated with forward SBS.
1D simulation of SBBS with and a “quiet” reset of the ion positions at showing reflectivity vs time; ion velocity phase space, and ion longitudinal velocity distribution functions in the left and middle thirds of the domain at .
1D simulation of SBBS with and initialized using the ion longitudinal velocities down-selected from in the 2D bcem33n simulation at after SBBS backscatter saturated and then extended over in 1D, showing reflectivity vs time; ion velocity phase space, and ion longitudinal velocity distribution functions in the left and middle thirds of the domain at .
(Color online). Contours for at three times showing the convective growth of ponderomotive filamentation with .
(Color online). SBBS reflectivities vs time and contours for and at showing self-focusing in 2D Gaussian-beam simulations with base line parameters: , , Be plasma (, ), , , , , , , 9.6, and 12.24.
(Color online). Streak spectra for electromagnetic (a) reflected power flux and (b) transmitted power flux vs light frequency and time for a 2D Gaussian-beam simulation with and the base line parameters listed in Fig. 21.
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