Abstract
The nonlinear dynamics of electron-acoustic localized structures in a collisionless and unmagnetized plasma consisting of “cool” inertial electrons, “hot” electrons having a kappa distribution, and stationary ions is studied. The inertialess hot electron distribution thus has a long-tailed suprathermal (non-Maxwellian) form. A dispersion relation is derived for linear electron-acoustic waves. They show a strong dependence of the charge screening mechanism on excess suprathermality (through ?). A nonlinear pseudopotential technique is employed to investigate the occurrence of stationary-profile solitary waves, focusing on how their characteristics depend on the spectral index ?, and the hot-to-cool electron temperature and density ratios. Only negative polarity solitary waves are found to exist, in a parameter region which becomes narrower as deviation from the Maxwellian (suprathermality) increases, while the soliton amplitude at fixed soliton speed increases. However, for a constant value of the true Mach number, the amplitude decreases for decreasing ?.
Original language | English |
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Article number | 072902 |
Pages (from-to) | 072902/1-10 |
Number of pages | 10 |
Journal | Physics of Plasmas |
Volume | 18 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2011 |
ASJC Scopus subject areas
- Condensed Matter Physics