Ion-acoustic envelope solitary waves in a very dense plasma comprised of the electrons, positrons and ions are investigated. For this purpose, the quantum hydrodynamic model and the Poisson equation are used. A modified nonlinear Schr¨odinger equation is derived by employing the reductive perturbation method. The effects of the quantum correction and of the positron density on the propagation and stability of the envelope solitary waves are examined. The nonplanar (cylindrical/spherical) geometry gives rise to an instability period. The latter cannot exist for planar case and it affected by the quantum parameters, as well as the positron density. The present investigation is relevant to white dwarfs.
|Number of pages||7|
|Journal||European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics|
|Publication status||Published - 9 Jan 2009|
- multicomponent and negative-ion plasmas
- electrostatic waves and oscillations
- nonlinear phenomena
- wave propagation