The stability of stimulated Brillouin scattering (SBS) in plasmas is investigated analytically fo... more The stability of stimulated Brillouin scattering (SBS) in plasmas is investigated analytically for the case of plasmas without flow. The mode-coupling equations are presented; parametric approximations are developed and tested using mode-coupling theory; and a strong-coupling approach is applied. The results of numerical calculations are presented graphically and discussed. It is shown that SBS backscatter can occur in plasmas without flow if ion-acoustic damping is of sufficient strength and scattered-wave negative feedback is present. In plasmas with only a one-side density jump, pulsations at high pump amplitudes are attributed to a self-induced negative distributed feedback. The implications of these findings for experimental results such as those obtained by Walsh and Baldis (1982) are considered.
Two isolated solar wind disturbances about 5 minutes in duration were detected aboard the Russian... more Two isolated solar wind disturbances about 5 minutes in duration were detected aboard the Russian spacecraft Phobos-2 upon its crossing the wake of the martian moon Deimos about 15,000 kilometers downstream from the moon on 1 February 1989. These plasma and magnetic events are interpreted as the inbound and outbound crossings of a Mach cone that is formed as a result of an effective interaction of the solar wind with Deimos. Possible mechanisms such as remanent magnetization, cometary type interaction caused by heavy ion or charged dust production, and unipolar induction resulting from the finite conductivity of the body are discussed. Although none of the present models is fully satisfactory, neutral gas emission through water loss by Deimos at a rate of about 10(23) molecules per second, combined with a charged dust coma, is favored.
Recently it was found the existence in plasma of a new class of stationary waves (Sauer et al., 2... more Recently it was found the existence in plasma of a new class of stationary waves (Sauer et al., 2001). These waves called oscillitons signify both its soliton and oscil- lating character. Generally, such coherent structures may appear in plasma if disper- sive curves in the w/k-k space have minimum or maximum at a finite wavenumber (phase and group standing waves). In particularly, such dispersion feature arises for low-frequency wave propagating obliquely to the magnetic field in a multi-ion plas- mas. Hydrogen atmosphere of Mars extends far beyond the bow shock and is exposed to the solar wind. Pickup protons originated from the atmosphere and assimilated to the solar wind create a bi-ion flow. A structure of nonlinear stationary waves propa- gating transverse and obliquely to the magnetic field in such bi-ion (proton-proton) plasma is investigated. In contrast to expansion techniques used for the description of weakly nonlinear waves, a fully nonlinear approach is applied in this...
The stability of stimulated Brillouin scattering (SBS) in plasmas is investigated analytically fo... more The stability of stimulated Brillouin scattering (SBS) in plasmas is investigated analytically for the case of plasmas without flow. The mode-coupling equations are presented; parametric approximations are developed and tested using mode-coupling theory; and a strong-coupling approach is applied. The results of numerical calculations are presented graphically and discussed. It is shown that SBS backscatter can occur in plasmas without flow if ion-acoustic damping is of sufficient strength and scattered-wave negative feedback is present. In plasmas with only a one-side density jump, pulsations at high pump amplitudes are attributed to a self-induced negative distributed feedback. The implications of these findings for experimental results such as those obtained by Walsh and Baldis (1982) are considered.
Two isolated solar wind disturbances about 5 minutes in duration were detected aboard the Russian... more Two isolated solar wind disturbances about 5 minutes in duration were detected aboard the Russian spacecraft Phobos-2 upon its crossing the wake of the martian moon Deimos about 15,000 kilometers downstream from the moon on 1 February 1989. These plasma and magnetic events are interpreted as the inbound and outbound crossings of a Mach cone that is formed as a result of an effective interaction of the solar wind with Deimos. Possible mechanisms such as remanent magnetization, cometary type interaction caused by heavy ion or charged dust production, and unipolar induction resulting from the finite conductivity of the body are discussed. Although none of the present models is fully satisfactory, neutral gas emission through water loss by Deimos at a rate of about 10(23) molecules per second, combined with a charged dust coma, is favored.
Recently it was found the existence in plasma of a new class of stationary waves (Sauer et al., 2... more Recently it was found the existence in plasma of a new class of stationary waves (Sauer et al., 2001). These waves called oscillitons signify both its soliton and oscil- lating character. Generally, such coherent structures may appear in plasma if disper- sive curves in the w/k-k space have minimum or maximum at a finite wavenumber (phase and group standing waves). In particularly, such dispersion feature arises for low-frequency wave propagating obliquely to the magnetic field in a multi-ion plas- mas. Hydrogen atmosphere of Mars extends far beyond the bow shock and is exposed to the solar wind. Pickup protons originated from the atmosphere and assimilated to the solar wind create a bi-ion flow. A structure of nonlinear stationary waves propa- gating transverse and obliquely to the magnetic field in such bi-ion (proton-proton) plasma is investigated. In contrast to expansion techniques used for the description of weakly nonlinear waves, a fully nonlinear approach is applied in this...
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