Electron-acoustic solitary waves in the presence of a suprathermal electron component
Jul 21, 2011
10 pages
Published in:
- Phys.Plasmas 18 (2011) 072902
- Published: Jul 21, 2011
e-Print:
- 1107.5226 [astro-ph.SR]
DOI:
View in:
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Abstract: (arXiv)
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 \kappa). 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 \kappa, 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 \kappa.- 52.35.Sb
- 52.35.Mw
- 72.30.+q
- 52.35.Fp
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