Modulational instability and envelope excitation of ion-acoustic waves in quantum electron-positron-ion plasmas

Journal Article · Wed Jul 15 04:00:00 EDT 2009 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3192762· OSTI ID:21277293

Misra, A P; Bhowmik, C ^[1]; Shukla, P K ^[2]

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1. Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan 731 235 (India)
2. Institut fuer Theoretische Physik IV and Centre for Plasma Science and Astrophysics, Fakultaet fuer Physik and Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)

The theoretical study of modulational instability (MI) and localized envelope excitations of finite amplitude ion-acoustic waves (IAWs) is revisited in an unmagnetized quantum electron-positron-ion plasma. For this purpose, a one-dimensional nonlinear Schroedinger equation, which governs the slow modulation of IAW packets, is derived by using the standard reductive perturbations technique. Two parameters, defining the ratio of the electron to ion number density ({mu}) and the quantum coupling parameter (H) describing the ratio of the 'plasmonic energy density' to the Fermi energy density, are shown to play crucial roles in determining the modulational stability/MI domains, as well as for the existence of both bright and dark envelope solitons. It is found that the stability region increases (decreases) with increasing {mu}(H), whereas the MI region for the IAW mode shifts to larger (smaller) wave number k as the value of {mu}(H) increases. Moreover, the parameter H is shown to suppress the MI growth rate of the IAWs. The present results may be relevant to dense astrophysical plasmas (e.g., white dwarfs, where the electron-positron annihilation can be important, and where the particle density is of the order of 10{sup 34}-10{sup 35} m{sup -3}) as well as to the next generation intense laser solid density plasma experiments.

• OSTI ID: 21277293
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 7 Vol. 16; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRON-POSITRON INTERACTIONS
ELECTRONS
ENERGY DENSITY
ION ACOUSTIC WAVES
IONS
ONE-DIMENSIONAL CALCULATIONS
PERTURBATION THEORY
PLASMA DENSITY
PLASMA INSTABILITY
POSITRONS
QUANTUM PLASMA
SCHROEDINGER EQUATION
SOLITONS
WHITE DWARF STARS