scholarly journals Multi-dimensional dynamics of stimulated Brillouin scattering in a laser speckle: Ion acoustic wave bowing, breakup, and laser-seeded two-ion-wave decay

2016 ◽  
Vol 23 (3) ◽  
pp. 032703 ◽  
Author(s):  
B. J. Albright ◽  
L. Yin ◽  
K. J. Bowers ◽  
B. Bergen
Keyword(s):  
Acoustic Wave ◽  
Brillouin Scattering ◽  
Stimulated Brillouin Scattering ◽  
Laser Speckle ◽  
Ion Acoustic Wave ◽  
Wave Decay ◽  
Ion Acoustic ◽  
Stimulated Brillouin

scholarly journals Excitation of nonlinear ion acoustic wave and stimulated Brillouin scattering of hollow Gaussian beam in relativistic plasma

2017 ◽  
Vol 35 (2) ◽  
pp. 226-233 ◽  
Author(s):  
P. Sharma
Keyword(s):  
Differential Equation ◽  
Acoustic Wave ◽  
Gaussian Beam ◽  
Brillouin Scattering ◽  
Collisionless Plasma ◽  
Stimulated Brillouin Scattering ◽  
Beam Width ◽  
Ion Acoustic Wave ◽  
Ion Acoustic ◽  
Stimulated Brillouin

AbstractIn the present work, excitation of nonlinear ion acoustic wave (IAW) in collisionless plasma by laser beam having null intensity at the center is examined considering relativistic nonlinearity. The differential equation for beam-width parameter is determined considering relativistic nonlinearity using the paraxial and Wentzel–Kramers–Brillouin approximations by the parabolic equation method. The propagation features of the IAW are found to be modified due to the nonlinearity present in the system. The hollow Gaussian beam (HGB) gets nonlinearly coupled with the seed IAW, results in excitation of nonlinear IAW. The interaction of nonlinear IAW with pump beam demonstrated stimulated Brillouin scattering (SBS) of HGB. It is found that the power of IAW and power of SBS is affected with the order of HGB. The power of IAW and backscattered power of SBS is determined analytically and numerically for various orders of HGB. It is found that the power of IAW and the backscattering is diminished for higher order of HGB.

scholarly journals Stimulated Brillouin backscattering of filamented hollow Gaussian beams

2013 ◽  
Vol 31 (4) ◽  
pp. 689-696 ◽  
Author(s):  
R.P. Sharma ◽  
Ram Kishor Singh
Keyword(s):  
Acoustic Wave ◽  
Gaussian Beam ◽  
Brillouin Scattering ◽  
Collisionless Plasma ◽  
Stimulated Brillouin Scattering ◽  
Ion Acoustic Wave ◽  
Ion Acoustic ◽  
Paraxial Ray ◽  
Stimulated Brillouin ◽  
Plasma Coupling

AbstractThis paper presents an investigation for excitation of ion acoustic wave and resulting stimulated Brillouin scattering in a collisionless plasma due to presence of a laser beam carrying null intensity at center (hollow Gaussian beam). In presence of ponderomotive nonlinearity, the pump beam get focused and affects the back stimulated Brillouin scattering process. To understand the nature of laser plasma coupling, a paraxial-ray approximation has been invoked for the propagation of the hollow Gaussian beam, ion acoustic wave, and stimulated Brillouin scattering. It is observed from the result that self-focusing and back reflectivity reduces for higher order of hollow Gaussian beam.

scholarly journals Controlled beat-wave Brillouin scattering in the ionosphere

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
B. Eliasson ◽  
A. Senior ◽  
M. Rietveld ◽  
A. D. R. Phelps ◽  
R. A. Cairns ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Ionospheric Plasma ◽  
Brillouin Scattering ◽  
Scale Model ◽  
Plasma Parameters ◽  
Ion Acoustic Wave ◽  
Electromagnetic Pump ◽  
Pump And Probe ◽  
Ion Acoustic ◽  
Stimulated Brillouin

AbstractStimulated Brillouin scattering experiments in the ionospheric plasma using a single electromagnetic pump wave have previously been observed to generate an electromagnetic sideband wave, emitted by the plasma, together with an ion- acoustic wave. Here we report results of a controlled, pump and probe beat-wave driven Brillouin scattering experiment, in which an ion-acoustic wave generated by the beating of electromagnetic pump and probe waves, results in electromagnetic sideband waves that are recorded on the ground. The experiment used the EISCAT facility in northern Norway, which has several high power electromagnetic wave transmitters and receivers in the radio frequency range. An electromagnetic pump consisting of large amplitude radio waves with ordinary (O) or extraordinary (X) mode polarization was injected into the overhead ionosphere, along with a less powerful probe wave, and radio sideband emissions observed on the ground clearly show stimulated Brillouin emissions at frequencies agreeing with, and changing with, the pump and probe frequencies. The experiment was simulated using a numerical full-scale model which clearly supports the interpretation of the experimental results. Such controlled beat-wave experiments demonstrate a way of remotely investigating the ionospheric plasma parameters.

Stimulated Brillouin scattering reduction induced by self-focusing for a single laser speckle interacting with an expanding plasma

2014 ◽  
Vol 21 (3) ◽  
pp. 032703 ◽  
Author(s):  
P. E. Masson-Laborde ◽  
S. Hüller ◽  
D. Pesme ◽  
Ch. Labaune ◽  
S. Depierreux ◽  
...  
Keyword(s):  
Brillouin Scattering ◽  
Stimulated Brillouin Scattering ◽  
Laser Speckle ◽  
Self Focusing ◽  
Single Laser ◽  
Stimulated Brillouin

scholarly journals Stimulated Brillouin backscattering of a ring-rippled laser beam in collisionless plasma

2015 ◽  
Vol 33 (3) ◽  
pp. 499-509 ◽  
Author(s):  
Gunjan Purohit ◽  
Priyanka Rawat
Keyword(s):  
Laser Beam ◽  
Narrow Range ◽  
Brillouin Scattering ◽  
Collisionless Plasma ◽  
Plasma Parameters ◽  
Ion Acoustic Wave ◽  
Coupled Equations ◽  
Ion Acoustic ◽  
Paraxial Ray ◽  
Stimulated Brillouin

AbstractThe effect of the propagation of a ring-rippled laser beam in the presence of relativistic and ponderomotive non-linearities on the excitation of ion-acoustic wave (IAW) and resulting stimulated Brillouin backscattering in collisionless plasma at relativistic powers is studied. To understand the nature of propagation of the ring ripple-like instability, a paraxial-ray approach has been invoked in which all the relevant parameters correspond to a narrow range around the irradiance maximum of the ring ripple. Modified coupled equations for growth of ring ripple in the plasma, generations of IAW and back-stimulated Brillouin scattering (SBS) are derived from fluid equations. These coupled equations are solved analytically and numerically to study the intensity of ring-rippled laser beam and excited IAW as well as back reflectivity of SBS in the plasma for various established laser and plasma parameters. It is found that the back reflectivity of SBS is enhanced due to the strong coupling between ring-rippled laser beam and the excited IAW. The results also show that the back reflectivity of SBS reduce for higher intensity of the laser beam.

scholarly journals Demonstrating the saturation of stimulated Brillouin scattering by ion acoustic decay using fully kinetic simulations

2015 ◽  
Vol 22 (9) ◽  
pp. 092116 ◽  
Author(s):  
T. Chapman ◽  
B. J. Winjum ◽  
S. Brunner ◽  
R. L. Berger ◽  
J. W. Banks
Keyword(s):  
Brillouin Scattering ◽  
Stimulated Brillouin Scattering ◽  
Ion Acoustic ◽  
Stimulated Brillouin

scholarly journals Determination of the electron temperature in the modified ionosphere over HAARP using the HF pumped Stimulated Brillouin Scatter (SBS) emission lines

2009 ◽  
Vol 27 (12) ◽  
pp. 4409-4427 ◽  
Author(s):  
P. A. Bernhardt ◽  
C. A. Selcher ◽  
R. H. Lehmberg ◽  
S. Rodriguez ◽  
J. Thomason ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Acoustic Wave ◽  
Electric Fields ◽  
Pump Wave ◽  
Scattered Wave ◽  
Matching Condition ◽  
Ion Acoustic Wave ◽  
Matching Conditions ◽  
Ion Acoustic ◽  
Stimulated Brillouin

Abstract. An ordinary mode electromagnetic wave can decay into an ion acoustic wave and a scattered electromagnetic wave by a process called stimulated Brillouin scatter (SBS). The first detection of this process during ionospheric modification with high power radio waves was reported by Norin et al. (2009) using the HAARP transmitter in Alaska. Subsequent experiments have provided additional verification of this process and quantitative interpretation of the scattered wave frequency offsets to yield measurements of the electron temperatures in the heated ionosphere. Using the SBS technique, electron temperatures between 3000 and 4000 K were measured over the HAARP facility. The matching conditions for decay of the high frequency pump wave show that in addition to the production of an ion-acoustic wave, an electrostatic ion cyclotron wave may also be produced by the generalized SBS processes. Based on the matching condition theory, the first profiles of the scattered wave amplitude are produced using the stimulated Brillouin scatter (SBS) matching conditions. These profiles are consistent with maximum ionospheric interactions at the upper-hybrid resonance height and at a region just below the plasma resonance altitude where the pump wave electric fields reach their maximum values.

Enhanced levels of stimulated Brillouin reflectivity from non-Maxwellian plasmas

2007 ◽  
Vol 73 (2) ◽  
pp. 159-166 ◽  
Author(s):  
M.S. BAWA'ANEH ◽  
T.J.M. BOYD
Keyword(s):  
Experimental Data ◽  
Acoustic Noise ◽  
Brillouin Scattering ◽  
Stimulated Brillouin Scattering ◽  
Temperature Gradients ◽  
Target Plasma ◽  
Ion Acoustic ◽  
Brillouin Gain ◽  
Stimulated Brillouin

Abstract.A model that counts for temperature gradients in the target plasma, which leads to higher ion acoustic noise and enhanced levels of stimulated Brillouin scattering (SBS) gain and SBS reflectivity, has been adopted. Enhanced Brillouin gain leading to higher SBS reflectivity levels has been computed for non-homogeneous, non-Maxwellian plasmas. SBS reflectivity levels obtained are higher than those predicted by linear convective gain theory by several orders of magnitude and coincide with the high values of experimental data known in literature, which could not be interpreted by the linear convective gain theory.

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