이명재 교수

The Landau damping of dust acoustic waves propagating in a dusty plasma modeled by a Lorentzian (kappa) distribution for electrons and ions, and by a Maxwellian distribution for the dust grains is kinetically investigated. The dust acoustic waves are found in the range of kvd≪ω≪kvi≪kve, where vα is the thermal velocity of species α(=i,e,d). The damping rate is shown to be dependent on the spectral index κ as well as the ratio of ion density to electron. The maximum Landau damping rate is derived

Abstract The nonthermal effects on the variation of the Shannon entropy for the atomic states are investigated in astrophysical Lorentzian plasmas. The screened atomic wave functions, energy eigenvalues, and effective screening lengths for the hydrogen atom in Lorentzian plasmas are obtained by the Rayleigh–Ritz method. The Shannon entropies for the ground and excited states in astrophysical Lorentzian plasmas are also obtained as functions of the spectral index, effective screening lengths, and

The integral of the kinetic electrostatic surface wave dispersion relation is evaluated to determine the wave frequency and the corresponding Landau damping rate for the surface mode of dust ion-acoustic waves including the effect of ion temperature by using the general perturbation and the transverse truncation methods. It is demonstrated that the increase in ion temperature enhances the wave frequency. The effect of ion temperature is more prominent in the range of large wave numbers, and the

The dispersion relation for a dust ion-acoustic surface wave is obtained for the semi-bounded dusty plasma containing elongated and rotating charged dust particles. The equilibrium plasma velocity distribution function is taken to be Lorentzian. Dust particles are assumed to be cold. The result shows that the frequency of the dust ion-acoustic surface wave propagating at the plasma-vacuum interface can be lowered by the increase of the angular rotation frequency of the elongated dust particles i

The effects of magnetic field strength on low-frequency surface ion plasma wave are investigated in semi-bounded magnetized dusty plasmas. The dispersion relation of the surface ion plasma wave is obtained by the plasma dielectric function with the specular reflection boundary condition. The results show that a transition from linear increase into the final level, i. e., the occurrence of a wave resonance. At a given frequency the phase velocity stays almost constant as long as the frequency rem

The dispersion relation and the growth rate of a dust ion-acoustic wave propagating in a complex superthermal plasma containing elongated and rotating dust particles are kinetically investigated by employing Vlasov–Maxwell equations. The negatively charged dust particles are assumed to rotate around an axis perpendicular to the direction of elongation. The condition for an unstable dust ion-acoustic wave is obtained in terms of the rotation frequency and the wave number. In the low frequency reg

The influence of collision-dominated electrons on multi-mode Hasegawa space-charge waves are investigated in a complex plasma containing streaming ions. The dispersion relation for the multi-mode Hasegawa space-charge wave propagating in a cylindrical waveguide filled with dusty plasma containing collision-dominated electrons and streaming ions is derived by using the fluid equations and Poisson's equation which lead to a Bessel equation. By the boundary condition, the roots of the Besse

The integral of the kinetic electrostatic surface wave dispersion relation is asymptotically evaluated to determine the frequencies of the normal modes and the corresponding Landau damping for the high frequency surface electron plasma wave and the low frequency surface ion acoustic wave. The asymptotically calculated Landau damping rates apply to the limiting cases of k x e << 1 and k x e >> 1 where k x is the wavenumber and e is the electron Debye length. We also calculate Landau damping rate

The dispersion relation of dust-acoustic surface waves (DASW) propagating on the interface betwen a vacuum and a semi-bounded dusty Lorentzian plasma is derived using a standard kinetic approach. The real and the imaginary parts of the wave frequency ωr+iγ are obtained as functions of the scaled wave number μkkxλD,where μk = (2k-3)/(2k-1)with k being the spectral index of the Lorentzian distribution function and λD being the total Debye length of ions and electrons. The wave displays Landau damp

The dispersion relation for modified dust ion-acoustic surface waves in the magnetized dusty plasma containing the rotating dust grains is derived, and the effects of magnetic field configuration on the resonant growth rate are investigated. We present the results that the resonant growth rates of the wave would increase with the ratio of ion plasma frequency to cyclotron frequency as well as with the increase of wave number for the case of perpendicular magnetic field configuration when the ion

The influence of Kohn singularity on the occurrence scattering time for the electron-ion interaction is investigated in degenerate quantum collisional plasmas. The first-order eikonal analysis is used to obtain the scattering amplitude and the occurrence scattering time. The result shows that the Friedel oscillation due to the Kohn singularity suppresses the advance phenomena of occurrence scattering time in both forward and backward scattering domains. It is shown that the increase of plasmon e

저온 플라즈마를 간단하게 해석할 수 있는 0D 모델을 유도 결합 플라즈마 용기에 적용하여 실험 결과와 비교 분석하였다. 량뮤어 탐침으로 전자 에너지 분포 함수를 측정하여 구한 플라즈마 밀도와 전자 온도를 0D 모델과 비교하였다. 플라즈마 밀도의 경우, 실제 측정값이 모델에서 계산된 밀도의 약 50% 정도로 낮았고 전자 온도의 경우 1.5 배 정도 큰 값을 가졌다. 0D 모델에서 고려하지 않은 비 맥스웰 전자 분포, 기체 온도 효과, 전력 효율 등 몇 가지 요인들을 고려하여 모델을 다시 계산한 결과, 측정 값과 모델 값의 차이가 현저히 줄었다. 더 정확한 모델을 위해서는 이러한 요인들을 고려되어야 함을 알 수 있다.

The dispersion relation for a dust ion-acoustic surface wave propagating at the plasma-vacuum interface of semi-bounded Maxwellian complex plasma containing elongated and rotating dust particles is kinetically derived by employing Vlasov-Maxwell equations. The result shows that the frequency of the dust ion-acoustic surface wave is noticeably suppressed by the dust rotation in the range k_xλ_e > 0.5 where kx is the wave number parallel to the interface and e is the electron Debye length. For k_x