On the Issue of Drift Instability of Charged Aerosols in Plasma of Noctilucent Clouds

Plasma Physics Reports - The drift instability is considered of charged ice aerosols in noctilucent clouds, which form in the lower ionosphere. The dispersion relation was solved in the...     

Nonlinear Wave Interaction with Positron Beam in a Relativistic Plasma: Evaluation of Hypersonic Dust Ion Acoustic Waves

Plasma Physics Reports - We studied the propagation of small-amplitude dust ion acoustic (DIA) solitary waves in four-component relativistic plasma comprised of nonthermal electrons, mobile...     

Nonlinear Theory of Aperiodic Instabilities of a Plasma Crystal

Plasma Physics Reports - The nonlinear stage of aperiodic instabilities of a single-layer plasma crystal with a triangular lattice is studied theoretically. Depending on the parameters of the...     

Model of a Plasma Layer Formed by an Electron Beam

Plasma Physics Reports - Results are presented of the particle-in-cell numerical simulations by the KARAT code of the formation of a plasma–beam discharge in the absence of both the...     

Density Profile of a Plasma Layer Formed by an Electron Beam

Plasma Physics Reports - Results of particle-in-cell simulation of the formation of a near-wall plasma layer produced by an ionization source remote from the chamber walls are verified...     

Trapping and Scattering of a Relativistic Charged Particle by Resonance in a Magnetic Field and an Electromagnetic Wave

A study is made of the dynamics of a relativistic charged particle in an electromagnetic wave (with an electrostatic component) in a constant uniform magnetic field. A system with a high-frequency wave is a Hamiltonian system with two degrees of freedom and with fast and slow variables. The trapping of a particle into resonance and its scattering on resonance in such a system is described.     

Cherenkov Excitation of Spatial Waves by a Straight Nonrelativistic Electron Beam in a Plasma Waveguide

The problem of the excitation of plasma waves by a thin-walled annular electron beam in a waveguide filled entirely with a plasma is analyzed in the quasistatic approximation. The instability growth rates are derived and are studied as functions of the waveguide parameters. The evolution of different seed perturbations in the nonlinear stage of the instability is investigated.     

Elevated Uptake of Plasma Macromolecules by Regions of Arterial Wall Predisposed to Plaque Instability in a Mouse Model

Atherosclerosis may be triggered by an elevated net transport of lipid-carrying macromolecules from plasma into the arterial wall. We hypothesised that whether lesions are of the thin-cap fibroatheroma (TCFA) type or are less fatty and more fibrous depends on the degree of elevation of transport, with greater uptake leading to the former. We further hypothesised that the degree of elevation can depend on haemodynamic wall shear stress characteristics and nitric oxide synthesis. Placing a tapered cuff around the carotid artery of apolipoprotein E -/- mice modifies patterns of shear stress and eNOS expression, and triggers lesion development at the upstream and downstream cuff margins; upstream but not downstream lesions resemble the TCFA. We measured wall uptake of a macromolecular tracer in the carotid artery of C57bl/6 mice after cuff placement. Uptake was elevated in the regions that develop lesions in hyperlipidaemic mice and was significantly more elevated where plaques of the TCFA type develop. Computational simulations and effects of reversing the cuff orientation indicated a role for solid as well as fluid mechanical stresses. Inhibiting NO synthesis abolished the difference in uptake between the upstream and downstream sites. The data support the hypothesis that excessively elevated wall uptake of plasma macromolecules initiates the development of the TCFA, suggest that such uptake can result from solid and fluid mechanical stresses, and are consistent with a role for NO synthesis. Modification of wall transport properties might form the basis of novel methods for reducing plaque rupture.     

Generation of a Beam of Fast Electrons,Plasma Bremsstrahlung,and Characteristic Radiation in a High-Current Z-Pinch

Plasma Physics Reports - The generation of accelerated electron beams in a high-current Z-pinch formed by the implosion of wire cylindrical tungsten arrays on an Angara-5-1 facility is studied. The...     

Calculation of the Electrophoretic Mobility of a Particle Bearing Bound Polyelectrolyte Using the Nonlinear Poisson-Boltzmann Equation

A numerical method for determining the electrophoretic mobility of a polyelectrolyte-coated particle is presented. The particle surface is modeled as having a permeable layer of polyelectrolyte molecules anchored to its surface. Fluid flow within the polyelectrolyte layer is subject to Stokes drag arising from the polyelectrolyte segments. The method allows arbitrary distribution of polymer segments and charge density normal to the surface to be used. The hydrodynamic plane of shear may also be varied. The potential profile is determined by a numerical solution to the nonlinearized Poisson-Boltzmann equation. The potential profile is then used in a numerical solution to the Navier-Stokes equation to give the required mobility. The use of the nonlinearized Poisson-Boltzmann equation extends the results to higher charge density/lower ionic strength conditions than previous treatments. The surface potentials and mobilities for three limiting charge distributions are compared for both the linear and nonlinear treatments to delimit the range of validity of the linear treatment. The utility of the numerical, nonlinear treatment is demonstrated by an improved fit to the electrophoretic mobility of human erythrocytes as a function of ionic strength in the range 10 to 150 mM.     

2D Full-Wave Simulation of the Propagation and Absorption of a Microwave Beam in the L-2M Stellarator Plasma

Plasma Physics Reports - A 2D full-wave-model is developed and a 2D numerical code is designed to calculate the propagation and absorption of an X-polarized microwave beam in magnetized plasma with...     

A Study on the Improvement of Etch Uniformity in an Ion Beam Etcher with a Magnetized Inductively Coupled Plasma Source

Plasma Physics Reports - A magnetized inductively coupled plasma ion beam etcher (MICP-IBE) was designed by employing electromagnets around the etcher (IBE). A magnetic field can be set up such...     

On the Possibility of Generating Harmonics of the Electron Plasma Frequency in the Solar Atmosphere due to Explosive Instability in a System of Interpenetrating Electron and Ion Flows

An alternative mechanism is proposed for the generation of harmonics of the electron plasma frequency due to the development of explosive instability in a system of interpenetrating electron and proton flows in the solar atmosphere. The efficiency of the new mechanism in comparison with the earlier discussed mechanisms involving multistage processes of nonlinear interaction of waves in plasma is determined. It is shown that the development of explosive instability can lead to the excitation of the second and third harmonics of the plasma frequency with comparable amplitudes.