Collisional and Landau damping of ion-acoustic waves in a two electron temperature plasma

The dispersion relation for a plasma with different ion and electron temperatures is solved numerically to obtain the frequency and the damping constant for ion-acoustic waves as a function of the wavenumber. It is shown that the commonly used expressions for these variables only apply if the parameter T = ziTe/Ti is larger than 20, and can lead to large errors if T is close to 1. (Here z1 is the ion charge, Te is the electron temperature, and Ti the ion temperature.) Tables and graphs of the frequency and damping as functions of the wavenumber are given for different values of T.

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Modulational instability of obliquely modulated ionacoustic waves in a two-electron-temperature plasma

Journal of Plasma Physics ◽

10.1017/s0022377800002452 ◽

1985 ◽

Vol 33 (2) ◽

pp. 209-217 ◽

Cited By ~ 6

Author(s):

Yashvir ◽

T. N. Bhatnagar ◽

S. R. Sharma

Keyword(s):

Electron Temperature ◽

Acoustic Waves ◽

Modulational Instability ◽

Perturbation Technique ◽

Collisionless Plasma ◽

Maximum Growth ◽

Maximum Growth Rate ◽

Ion Acoustic Waves ◽

Temperature Plasma ◽

Damping Rate

The unstable domain in the (k, Ø) plane for oblique modulation of ion-acoustic waves, in a two-electron-temperature plasma, is investigated using the KBM perturbation technique. It is shown that, in a collisionless plasma, the maximum growth rate for the modulational instability, for large carrier-wave amplitudes (a0 ≳ 0·1), exceeds the electron Landau damping rate for sufficiently oblique modulation.

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Modulational instability of obliquely modulated ion-acoustic waves in a collisional plasma with one- and two-electron-temperature distributions

Journal of Plasma Physics ◽

10.1017/s0022377800014434 ◽

1989 ◽

Vol 42 (03) ◽

pp. 379 ◽

Cited By ~ 3

Author(s):

M. K. Mishra ◽

R. S. Chhabra ◽

S. R. Sharma

Keyword(s):

Electron Temperature ◽

Acoustic Waves ◽

Modulational Instability ◽

Collisional Plasma ◽

Ion Acoustic Waves ◽

Temperature Distributions ◽

Ion Acoustic

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Ion-acoustic wave instability driven by drifting electrons in a generalized Lorentzian distribution

Journal of Plasma Physics ◽

10.1017/s002237780002434x ◽

1992 ◽

Vol 47 (3) ◽

pp. 445-464 ◽

Cited By ~ 62

Author(s):

Zhaoyue Meng ◽

Richard M. Thorne ◽

Danny Summers

Keyword(s):

Electron Temperature ◽

Acoustic Waves ◽

Debye Length ◽

High Energy ◽

Dispersion Function ◽

Electron Drift ◽

Kappa Distribution ◽

Ion Acoustic Waves ◽

High Energy Tail ◽

Ion Acoustic

A generalized Lorentzian (kappa) particle distribution function is useful for modelling plasma distributions with a high-energy tail that typically occur in space. The modified plasma dispersion function is employed to study the instability of ion-acoustic waves driven by electron drift in a hot isotropic unmagnetized plasma modelled by a kappa distribution. The real and imaginary parts of the wave frequency ω0 + ιγ are obtained as functions of the normalized wavenumber kλD, where λD is the electron Debye length. Marginal stability conditions for instability are obtained for different ion-to-electron temperature ratios. The results for a kappa distribution are compared with the classical results for a Maxwellian. In all cases studied the ion-acoustic waves are strongly damped at short wavelengths, kλD ≫ 1, but they can be destabilized at long wavelengths. The instability for both the kappa and Maxwellian distributions can be quenched by increasing the ion-electron temperature ratio Ti/Te. However, both the marginally unstable electron drift velocities and the growth rates of unstable waves can differ significantly between a generalized Lorentzian and a Maxwellian plasma; these differences are also influenced by the value of Ti/Te.

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