The effective dynamically screened potential of a classical ion in a
stationary flowing quantum plasma at finite temperature is investigated. This
is a key quantity for thermodynamics and transport of dense plasmas in the warm
dense matter regime. To compute this potential a linear response description of
the electrons via the Mermin dielectric function is utilized with
electron-electron collisions taken into account via a relaxation time
approximation. The ion potential strongly deviates from the static Yukawa
potential exhibiting the familiar oscillatory structure with attractive minima
(wake potential). This potential is analyzed in detail for high-density plasmas
with values of the Brueckner parameter in the range $0.1 e r_s e 1$, for a
broad range of plasma temperature and electron streaming velocity. It is shown
that wake effects become weaker with increasing temperature of the electrons.
Finally, we obtain the minimal electron streaming velocity for which attraction
between ions occurs. This velocity turns out to be less than the electron Fermi
velocity. The observed effects should be of high relevance for transport under
warm dense matter conditions, in particular for laser-matter interaction,
electron-ion temperature equilibration and for stopping power.
Author(s): A. V. Ivlev, S. K. Zhdanov, M. Lampe, and G. E. Morfill
A theory of the mode-coupling instability (MCI) in a fluid two-dimensional complex plasma is developed. In analogy to the point-wake model of the wake-mediated interactions commonly used to describe MCI in two-dimensional crystals, the layer-wake model is employed for fluids. It is demonstrated that...
[Phys. Rev. Lett. 113, 135002] Published Tue Sep 23, 2014
In this study, we present a temporal multi-scale algorithm (TMA) for efficient fluid modeling of a
one-dimensional gas discharge with complex plasma chemistry. A helium dielectric barrier discharge
driven by a power source with a frequency of 25 kHz is used as an example to demonstrate the
superior capability of the TMA in accelerating fluid modeling simulations, while maintaining the
same accuracy as compared to lengthy benchmarking fluid modeling using a single time-scale approach.
The plasma chemistry considers 36 species and 121 reaction channels, which include some impurities
such as nitrogen (25 ppm), oxygen (10 ppm) and water vapor (1 ppm), in addition to the helium
itself. The results show that the runtime using the TMA can be dramatically reduced to 4% (25 times
faster) with a relative difference of spatially averaged number densities generally less than 1% for
all species between the TMA and the benchmarking cases when five initial cycles, five supplementary
cycles and ...
A theoretical investigation of dust-acoustic solitary waves in one-dimensional, collisionless, and unmagnetized dusty plasma consisting of ion fluid, trapped as well as free electrons, and charge fluctuating immobile dust particles is considered. The nonlinear dynamics of dust ion-acoustic waves, whose phase speed is much smaller (larger) than the electron (ion) thermal speed, propagating in such a dusty plasma system is investigated. The reductive perturbation method is employed to reduce the basic set of fluid equations to the Schamel and Schamel-Korteweg-de Vries-Burger (S-KdVB) equations. The Schamel and Schamel-KdVB equations are shown to be non-integrable using Painlevé analysis. The Bäcklund transformations and some new exact solutions are formally derived. Finally, we discussed the results in this paper.
Author(s): Ke Qiao, Jie Kong, Jorge Carmona-Reyes, Lorin S. Matthews, and Truell W. Hyde
Small quasi-two-dimensional dust clusters consisting of three to eleven particles are formed in an argon plasma under varying rf power. Their normal modes are investigated through their mode spectra obtained from tracking the particles’ thermal motion. Detailed coupling patterns between their horizo...
[Phys. Rev. E 90, 033109] Published Tue Sep 16, 2014
Author(s): Samiran Ghosh
The propagation of a nonlinear low-frequency mode in two-dimensional (2D) monolayer hexagonal dusty plasma crystal in presence of external magnetic field and dust-neutral collision is investigated. The standard perturbative approach leads to a 2D Korteweg-de Vries (KdV) soliton for the well-known du...
[Phys. Rev. E 90, 033108] Published Mon Sep 15, 2014
The present work investigates the wave propagation in collisional dusty plasmas in the presence of electric and magnetic field. It is shown that the dust ion-acoustic waves may become unstable to the reactive instability whereas dust-acoustic waves may suffer from both reactive and dissipative instabilities. If the wave phase speed is smaller than the plasma drift speed, the instability is of reactive type whereas in the opposite case, the instability becomes dissipative in nature. Plasma in the vicinity of dust may also become unstable to reactive instability with the instability sensitive to the dust material: dielectric dust may considerably quench this instability. This has implications for the dust charging and the use of dust as a probe in the plasma sheath.
We demonstrate that a consistent breakdown of the standard even–odd filling scheme in the Coulomb
blockade regime can be easily obtained in a quantum dot containing two wells strongly coupled by a
very transparent barrier. By exploiting a multi-gate configuration, we prove that a partial filling
of nearly degenerate orbitals can be controlled electrostatically. Singlet–triplet spin transitions
are demonstrated by low-temperature magneto-transport measurements.
We investigate the propagation characteristics of electrostatic dust-acoustic
(DA) solitary waves and shocks in a strongly coupled dusty plasma consisting of
intertialess electrons and ions, and strongly coupled inertial charged dust
particles. A generalized viscoelastic hydrodynamic model with the effects of
electrostatic dust pressure associated with the strong coupling of dust
particles, and a quantum hydrodynamic model with the effects of quantum forces
associated with the Bohm potential and the exchange-correlation potential for
electrons and ions are considered. Both the linear and weakly nonlinear theory
of DA waves are studied by the derivation and analysis of dispersion relations
as well as Korteweg-de Vries (KdV) and KdV-Burgers (KdVB)-like equations. It is
shown that in the kinetic regime ($\omega\tau_m\gg1$, where $\omega$ is the
wave frequency and $\tau_m$ is the viscoelastic relaxtation time), the
amplitude of the DA solitary waves decays slowly with time with the effect of a
small amount of dust viscosity. However, the DA shock-like perturbations can be
excited in the hydrodynamic regime with $\omega\tau_ml1$. The analytical and
numerical solutions of the KdV and KdVB equations are also presented and
analyzed with the system parameters.
We calculate interdiffusion coefficients in a two-component, weakly or
strongly coupled ion plasma (gas or liquid, composed of two ion species
immersed into a neutralizing electron background). We use an effective
potential method proposed recently by Baalrud and Daligaut [PRL, 110, 235001,
(2013)]. It allows us to extend the standard Chapman-Enskog procedure of
calculating the interdiffusion coefficients to the case of strong Coulomb
coupling. We compute binary diffusion coefficients for several ionic mixtures
and fit them by convenient expressions in terms of the generalized Coulomb
logarithm. These fits cover a wide range of plasma parameters spanning from
weak to strong Coulomb couplings. They can be used to simulate diffusion of
ions in ordinary stars as well as in white dwarfs and neutron stars.