Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality

The dynamics of electron-plasma waves are described at arbitrary collisionality by considering the full Coulomb collision operator. The description is based on a Hermite-Laguerre decomposition of the velocity dependence of the electron distribution function. The damping rate, frequency, and eigenmode spectrum of electron-plasma waves are found as functions of the collision frequency and wavelength. A comparison is made between the collisionless Landau damping limit, the Lenard-Bernstein and Dougherty collision operators, and the electron-ion collision operator, finding large deviations in the damping rates and eigenmode spectra. A purely damped entropy mode, characteristic of a plasma where pitch-angle scattering effects are dominant with respect to collisionless effects, is shown to emerge numerically, and its dispersion relation is analytically derived. It is shown that such a mode is absent when simplified collision operators are used, and that like-particle collisions strongly influence the damping rate of the entropy mode.Comment: 23 pages, 10 figures, accepted for publication on Journal of Plasma Physic

SMART digital selective calling user interface on the base of Integration maritime navigation and radiocommunication equipment

High level solution S4 of the IMO E-navigation Strategy Implementation Plan provides integration and presentation of available information in graphical displays received via communication equipment. At the same time, the problem of the correct application of digital selective calling (DSC) operational procedures in navigation practice has existed since the introduction of the GMDSS and requires a solution. This problem may be resolved on the base of integration maritime navigation and radiocommunication equipment. The article proposes approach for practical realization of this integration by implementing a SMART (specific, measurable, assignable, realistic, and timely) DSC interface within S4. Using this approach the practical realisation integration of AIS – DSC – Information display was implemented. It makes possible implementation of user-friendly human-machine interface (HMI) for navigator. An experimental prototype of communication graphical interface is designed, which allows effective decision-making on radio communication control/monitoring. The use IEC 61162-1/2 (Maritime navigation and radiocommunication equipment – Digital interfaces) data transfer provides standard inter-module connections and eliminates the negative impact of the equipment diversity from different manufacturers by means uniform HMI implementation

Linear theory of electron-plasma waves at arbitrary collisionality

The dynamics of electron-plasma waves is described at arbitrary collisionality by considering the full Coulomb collision operator. The description is based on a Hermite–Laguerre decomposition of the velocity dependence of the electron distribution function. The damping rate, frequency and eigenmode spectrum of electron-plasma waves are found as functions of the collision frequency and wavelength. A comparison is made between the collisionless Landau damping limit, the Lenard–Bernstein and Dougherty collision operators and the electron–ion collision operator, finding large deviations in the damping rates and eigenmode spectra. A purely damped entropy mode, characteristic of a plasma where pitch-angle scattering effects are dominant with respect to collisionless effects, is shown to emerge numerically, and its dispersion relation is analytically derived. It is shown that such a mode is absent when simplified collision operators are used, and that like-particle collisions strongly influence the damping rate of the entropy mode. ©2019 Keywords: plasma wavesUS Department of Energy (Grant no. DE-FG02-91ER54109

Linear Theory of Electron-Plasma Waves at Arbitrary Collisionality

The dynamics of electron-plasma waves are described at arbitrary collisionality by considering the full Coulomb collision operator. The description is based on a Hermite- Laguerre decomposition of the velocity dependence of the electron distribution function. The damping rate, frequency, and eigenmode spectrum of electron-plasma waves are found as functions of the collision frequency and wavelength. A comparison is made between the collisionless Landau damping limit, the Lenard-Bernstein and Dougherty collision operators, and the electron-ion collision operator, finding large deviations in the damping rates and eigenmode spectra. A purely damped entropy mode, characteristic of a plasma where pitch-angle scattering effects are dominant with respect to collisionless effects, is shown to emerge numerically, and its dispersion relation is analytically derived. It is shown that such a mode is absent when simplified collision operators are used, and that like-particle collisions strongly influence the damping rate of the entropy mode