Nonthermal effects on the Buneman instability in Lorentzian dusty plasmas

Abstract

The nonthermal effects on the Buneman instability due to the ion streaming are investigated in Lorentzian dusty plasmas. The growth rates and frequency of the Buneman instability are obtained as functions of the spectral index of the Lorentzian plasma. It is shown that the nonthermal effect suppresses the growth rates as well as the real frequency term of the unstable root. Hence, the growth rates of the Buneman instability in nonthermal plasmas are found to be always smaller than those in Maxwellian plasmas. It is also found that the nonthermal effects on the growth rates decrease with increasing wave number.The two-stream instability has been extensively investigated since this phenomenon is one of the most effective heating mechanisms in various plasmas. 1-4 It has been known that the Buneman instability is the two-stream instability of the electron-ion plasma. 3 In addition, the nonlinear effects associated with the two-stream instabilities have received much attention since these instabilities are connected with the turbulence of the plasma. 4 Moreover, the wave nonlinearities have been also extensively investigated in plasma physics since the nonlinear phenomena provide the useful information on the plasma media where the nonlinear plasma waves would propagate. In recent years, there has been a considerable interest in particle and wave dynamics and structures of complex plasmas containing the component of highly charged dust grains including the strong collective interactions. 5-7 Hence, the physical and chemical processes in various dusty plasmas have been extensively investigated in order to obtain the information on plasma parameters in dusty plasmas. 7 It has been also shown that the velocity distributions of dusty plasmas usually do not resemble the standard Maxwellian distribution functions but have more complicated figures illustrating high-energy tails which strongly deviate from simple Maxwellian distributions due to the temperature anisotropy caused by the coupling between plasmas and external fields. 8 In recent years, the generalized Lorentzian distribution or the kappa-distribution 9-12 has been of a great interest since it has been shown that the Lorentzian distribution is considerably useful for exploring various physical properties of nonthermal dusty plasmas. In these Lorentzian plasmas, the screened interaction potential would not be properly represented by the standard Debye-Hückel model due to the strong collective interactions of nonideal particles. 13 Thus, it can be expected that the Buneman instability in Lorentzian dusty plasmas would provide useful information on the resonant wave-particle interaction and nonthermal character of the Lorentzian plasma. Hence, in this paper we investigate the nonthermal effects on the Buneman instability for the streaming between the ions and charged dust grains in nonthermal Lorentzian dusty plasmas. The real part of the frequency and the growth rate for the Buneman instability are obtained as functions of the spectral index of the Lorentzian plasm...

Landau damping of Langmuir twisted waves with kappa distributed electrons

“…[25][26][27] These non-thermal charged particles in most of the cases are electrons and can be described well by using generalized Lorentzian or kappa (non-Maxwellian) distribution function. 28 In this paper, kinetic theory is applied to study the electron plasma waves in the presence of a perturbed electric field carrying orbital angular momentum for a non-Maxwellian plasma described by the generalized Lorentzian or kappa distribution function. The paper is composed of various sections.…”

Influence of magnetic field and density on the streaming instability in magnetized pair plasmas

“…where 'Im' stands for the imaginary part. Recently, the influence of nonthermal shielding on the Buneman instability caused by the streaming of ion fluid has been investigated in Lorentzian dusty plasmas [23]. However, the effects of magnetic field and density on the streaming instability due to the ion streaming in magnetized electron-positron pair plasmas has not been investigated as yet.…”

Landau damping of twisted waves in Cairns distribution with anisotropic temperature

“…Landau damping in unmagnetized kappa distributed plasma composed of electrons and positively and negatively charged ions was studied in ion-acoustic waves [17]. The Buneman instability affected by a nonthermal ion based on ion streaming was studied in Lorentzian dusty plasma [18]. The growth rates and the real frequency term of the unstable root were shown to be suppressed by the nonthermal effect.…”