排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
A. V. Filippov A. G. Zagorodny A. I. Momot A. F. Pal A. N. Starostin 《Journal of Experimental and Theoretical Physics》2007,104(1):147-161
An asymptotic theory for the screening of the electric field of a dust particle or a spherical probe in a plasma with an external steady and/or internal (proportional to the electron density) gas ionization source has been developed for the first time. It has been established that the screening of the charge of a spherical body adsorbing the charge of the incident plasma particles is described by a superposition of two exponentials with different screening constants. The two exponentials are retained even in the absence of nonequilibrium fluxes on the macroparticle and only in the special case of an isothermal plasma does the screening become Debye one. The screening length is determined by the ratio of the electron-ion, βei, and Langevin, βL = 4πeμi (where μi is the ion mobility), recombination coefficients. If βL ? βei, then it is much larger than the electron Debye length. The ions in an isothermal plasma have been found to give the same contribution to the screening as the electrons if the electron-ion recombination coefficient exceeds the Langevin ion recombination coefficient by a factor of 2 or more, βei ≥ 2βL. The Vlasov equation is used to analyze the asymptotic behavior of the macroparticle potential in a collisionless plasma. 相似文献
2.
Viktor Gerasimenko Vyacheslav Shtyk Anatoly Zagorodny 《Central European Journal of Physics》2011,9(1):71-77
Evolution equations for marginal generalized microscopic phase densities are introduced. The evolution equations for average
values of microscopic phase densities are derived and a solution of the initial-value problem for the hydrodynamic type hierarchy
obtained is constructed. 相似文献
3.
It is proved that the Kubo formula for the conductivity σ(ω) is valid at real frequencies ω. On this basis, an exact relation is derived for the static conductivity σst of the Coulomb system. It is shown that the static conductivity is determined by the time correlation function in the limit t→∞. It is proved that the permittivity ε(ω) satisfies the Kramers-Kronig relations which take into account a singularity associated with static conductivity. 相似文献
4.
The problem of screening a moving charged dust particle is analyzed in the model of point sinks. Typical time scales for the formation of a polarization cloud around the moving macroscopic particle are found using the three-dimensional integral transform with respect to the spatial coordinates and the Laplace transform in time. It is shown that the stationary potential of a moving charge has a dipole component dominating at sufficiently large distances. The force exerted on a moving charged macroscopic particle by the electric field of induced charges is calculated. It is shown that, in general, the direction of this force depends on the ratio between the transfer coefficient and the decay rate of plasma particles in the plasma. In the presence of sinks, a dust particle is accelerated by this force if the Langevin recombination rate for ions, β iL = 4πeμ i , exceeds the electron-ion recombination rate β ei . In the absence of sinks or if β ei > β iL this force is antiparallel to the dust-particle velocity. 相似文献
5.
The problem of calculating the electromagnetic field energy outside the transmission band is discussed. It is shown that the contribution of charged particles to the electromagnetic perturbation energy can be described in the general case in terms of the bilinear combination of the medium dielectric polarizability. An explicit form of such a contribution is found. The relations obtained are used to generalize Planck’s law to the case of an absorbing medium. 相似文献
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7.
An asymptotic theory of the screening of the dust-particle charge in a plasma with an external ionization source has been developed. It has been shown analytically that the screening of the charge of a dust particle adsorbing the charge of charged plasma particles that fall on it is not generally described by the Debye theory. The screening radius is determined by the relation between the coefficients βei and βL = 4πek i (k i is the ion mobility) of the electron-ion and Langevin recombinations, respectively. When βL ? β ei , the screening radius is much larger than the electron Debye radius. It has been shown that the contribution of the ion component of an isothermal plasma to screening is equal to the electron contribution if the coefficient of the electron-ion recombination is twice or more larger than the Langevin coefficient of the ion recombination, βei ≥ 2βL. 相似文献
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9.
Bohdan I. Lev Vyacheslav P. Ostroukh Vitalii B. Tymchyshyn Anatolii G. Zagorodny 《The European Physical Journal B - Condensed Matter and Complex Systems》2014,87(11):1-13
System of electrons on the liquid helium surface is considered. General methods for obtaining free energy functional for the systems in mean field approximation are developed. These methods applied for treating systems with particles arranged in a lattice. Thus obtained functional of free energy is analyzed. The localization distance for electron and conditions for existing square or triangular lattices as well as phase transition between them are obtained. 相似文献
10.
A. V. Filippov A. G. Zagorodny A. I. Momot A. F. Pal’ A. N. Starostin 《Journal of Experimental and Theoretical Physics》2009,108(3):497-515
Based on the model of point sinks, we consider the problem on the screening of the charge of a moving macroparticle in a nonequilibrium plasma. The characteristic formation times of the polarization cloud around such a macroparticle have been determined by the method of a three-dimensional integral Fourier transformation in spatial variables and a Laplace transformation in time. The screening effect is shown to be enhanced with increasing macroparticle velocity. We consider the applicability conditions for the model of point sinks and establish that the domain of applicability of the results obtained expands with decreasing gas ionization rate and macroparticle size. We consider the problem of charge screening at low velocities and establish that the stationary potential of the moving charge has a dipole component that becomes dominant at large distances. We show that the direction of the force exerted on the dust particle by the induced charges generally depends on the relationship between the transport and loss coefficients of the plasma particles in a plasma. When the Langevin ion recombination coefficient β iL = 4πeμ i exceeds the electron-ion recombination coefficient β ei , this force will accelerate the dust particles in the presence of sinks. In the absence of sinks or when β ei > β iL , this force will be opposite in direction to the dust particle velocity. We also consider the problem on the energy and force of interaction between a moving charged macroparticle and the induced charges. 相似文献