Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9827667 | Journal of Atmospheric and Solar-Terrestrial Physics | 2005 | 7 Pages |
Abstract
Results from plasma wave experiments in spacecrafts give support to nonlinear interactions involving Langmuir, electromagnetic, and ion-acoustic waves in association with type III solar radio bursts. Starting from a general form of Zakharov equation (Zakharov, V.E., 1985. Collapse and self-focusing of Langmuir waves. Hand-book of Plasma Physics Cap.2, 81-121) the equations for electric fields and density fluctuations (density gratings) induced by a pair of counterpropagating Langmuir waves are obtained. We consider the coupling of four triplets. Each two triplets have in common the Langmuir pump wave (forward or backward wave) and a pair of independent density gratings. We numerically solve the dispersion relation for the system, extending the work of (Alves, M.V., Chian, A.C.L., Moraes, M.A.E., Abalde, J.R., Rizzato, F.B., 2002. A theory of the fundamental plasma emission of type- III solar radio bursts. Astronomy and Astrophysics 390, 351-357). The ratio of anti-Stokes (AS) (Ï0+Ï) to Stokes (S) (Ï0-Ï*) electromagnetic mode amplitudes is obtained as a function of the pump wave frequency, wave number, and energy. We notice that the simultaneous excitation of AS and S distinguishable modes, i.e., with Re{Ï}=Ïrâ 0, only occurs when the ratio between the pump wave amplitudes, r is â 1 and the pump wave vector k0 is <(13)W01/2, W0 being the forward pump wave energy. We also observe that the S mode always receives more energy.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geophysics
Authors
F.J.R. Simões Júnior, M.V. Alves, F.B. Rizzato,