Topic
Bohm diffusion
About: Bohm diffusion is a research topic. Over the lifetime, 459 publications have been published within this topic receiving 12751 citations.
Papers published on a yearly basis
1 / 2
Papers
Book•
1 Jan 1974
TL;DR: In this article, the authors define the concept of debye shielding and define a set of criteria for plasmas in terms of temperature, debye Shielding, and debye shielding.
Abstract: 1. Introduction.- Occurrence of Plasmas in Nature.- Definition of Plasma.- Concept of Temperature.- Debye Shielding.- The Plasma Parameter.- Criteria for Plasmas.- Applications of Plasma Physics.- 2. Single-Particle Motions.- Uniform E and B Field.- Nonuniform B Field.- Nonuniform E Field.- TimeVarying E Field.- Time-Varying B Field.- Summary of Guiding Center Drifts.- Adiabatic Invariants.- 3. Plasmas as Fluids.- Relation of Plasma Physics to Ordinary Electromagnetics.- The Fluid Equation of Motion.- Fluid Drifts Perpendicular to B.- Fluid Drifts Parallel to B.- The Plasma Approximation.- 4. Waves in Plasmas.- Representation of Waves.- Group Velocity.- Plasma Oscillations.- Electron Plasma Waves.- Sound Waves.- Ion Waves.- Validity of the Plasma Approximation.- Comparison of Ion and Electron Waves.- Electrostatic Electron Oscillations Perpendicular to B.- Electrostatic Ion Waves Perpendicular to B.- The Lower Hybrid Frequency.- Electromagnetic Waves with B0 =.- Experimental Applications.- Electromagnetic Waves Perpendicular to B0.- Cutoffs and Resonances.- Electromagnetic Waves Parallel to B0.- Experimental Consequences.- Hydromagnetic Wave.- Magnetosonic Waves.- Summary of Elementary Plasma Waves.- The CMA Diagram.- 5. Diffusion and Resistivity.- Diffusion and Mobility in Weakly Ionized Gases.- Decay of a Plasma by Diffusion.- Steady State Solutions.- Recombination.- Diffusion Across a Magnetic Field.- Collisions in Fully Ionized Plasmas.- The Single-Fluid MHD Equations.- Diffusion in Fully Ionized Plasmas.- Solutions of the Diffusion Equation.- Bohm Diffusion and Neoclassical Diffusion.- 6. Equilibrium and Stability.- Introductio.- Hydromagnetic Equilibrium.- The Concept of ss.- Diffusion of Magnetic Field into a Plasma.- Classification of Instabilities.- Two-Stream Instability.- The "Gravitational" Instability.- Resistive Drift Waves.- 7. Introduction to Kinetic Theory.- The Meaning off(v).- Equations of Kinetic Theory.- Derivation of the Fluid Equations.- Plasma Oscillations and Landau Damping.- The Meaning of Landau Damping.- A Physical Derivation of Landau Damping.- BGK and Van Kampen Modes.- Experimental Verification.- Ion Landau Damping.- 8. Nonlinear Effects.- Sheaths.- Ion Acoustic Shock Waves.- The Ponderomotive Force.- Parametric Instabilities.- Plasma Echoes.- Nonlinear Landau Damping.- 9. Introduction to Controlled Fusion.- The Problem of Controlled Fusion.- Magnetic Confinement: Toruses.- Mirrors.- Pinches.- Laser-Fusion.- Plasma Heating.- Fusion Technology.- Summary.- Units.- Useful Constants and Formulas.- Useful Vector Relations.
1,468 citations
Book•
19 Jun 1974
TL;DR: In this paper, the authors present a preliminary analysis of the effect of an Adiabatic Invariant and a third invariant on a magnetospheric model of a single particle.
Abstract: I. Adiabatic Invariants and Magnetospheric Models.- I.1 Preliminary Considerations.- I.2 Action-Angle Variables.- I.3 Liouville's Theorem.- I.4 The Dipole Field.- I.5 The Distorted Field.- I.6 Magnetospheric Electric Fields.- I.7 Flux Mapping and Shell Tracing.- II. Pitch-Angle Diffusion.- II.1 Violation of an Adiabatic Invariant.- II.2 Collisions.- II.3 Wave-Particle Interactions.- II.4 Bounce Resonance.- II.5 Cyclotron Resonance.- II.6 Limit on Trapped Flux.- II.7 Weak Diffusion and Strong Diffusion.- III. Radial Diffusion.- III.1 Violation of the Third Invariant.- III.2 Magnetic Impulses.- III.3 Electrostatic Impulses.- III.4 Bounce Resonance.- III.5 Cyclotron Resonance.- III.6 Bohm Diffusion.- III.7 Shell Splitting.- III.8 Diffusion in More Than One Mode.- IV. Prototype Observations.- IV.1 Preliminary Considerations.- IV.2 Decay of Particle Flux (Inner Zone).- IV.3 Decay of Particle Flux (Outer Zone).- IV.4 Statistical Observations.- IV.5 Static Flux Profiles.- IV.6 Time-Varying Flux Profiles.- I V.7 Fluctuating Magnetospheric Fields.- IV.8 Drift Echoes.- V. Methods of Empirical Analysis.- V.1 Basic Objectives.- V.2 Pitch-Angle Eigenmodes.- V.3 Quadrature (Spatial).- V.4 Quadrature (Temporal).- V.5 Variational Method.- V.6 Temporal Integration.- V.7 Spatial Integration.- VI. Summary.- References.- Frequently used Symbols.
588 citations
TL;DR: In this article, the authors considered a plasma in which a Maxwellian distribution of electrons with thermal velocity ve and drift velocity vD is drifting relative to a MIMO distribution of ions with thermal velocities vi and thermal velocity vi, where the usual ion acoustic waves are stable, however, electrostatic ion cyclotron waves with ω ≅ Ωi are unstable.
Abstract: A plasma is considered in which a Maxwellian distribution of electrons with thermal velocity ve and drift velocity vD is drifting relative to a Maxwellian distribution of ions with thermal velocity vi. For vD ≲ ve the usual ion acoustic waves are stable, however, electrostatic ion cyclotron waves with ω ≅ Ωi are unstable for vD ≳ 5vi. In the case when 5vi ≲ vD ≲ ve, and Te/Ti < 2 the electrostatic ion cyclotron waves grow to a nonlinear equilibrium spectrum. This spectrum of waves leads to a diffusion of electrons across the field lines with a diffusion coefficient D = αρ2eΩe, where ρe is the electron Larmor radius and Ωe is the electron Larmor frequency. α, the ratio of the resulting diffusion coefficient to the Bohm diffusion coefficient, is given by a constant × (vD/ve)5(Te/Ti)2.
465 citations
TL;DR: Magnetospheric plasma instabilities, discussing pitch angle diffusion instabilities and auroral precipitation boundary location, radial diffusion and maximum dissipation limit are discussed in this paper, where the authors also discuss radial diffusion.
Abstract: Magnetospheric plasma instabilities, discussing pitch angle diffusion instabilities, auroral precipitation boundary location, radial diffusion and maximum dissipation limit
444 citations
TL;DR: Two mechanisms have been proposed for solar wind particle injection at the dayside magnetospheric cusps: magnetic merging and cross-field diffusion as mentioned in this paper, which are experimentally distinguishable in that they produce different latitudinal distributions of particles penetrating to the low-altitude cusp.
Abstract: Two mechanisms have been proposed for solar wind particle injection at the dayside magnetospheric cusps: magnetic merging and cross-field diffusion. These two mechanisms are experimentally distinguishable in that they produce different latitudinal distributions of particles penetrating to the low-altitude cusp. An examination of proton and electron measurements obtained by the AE-C satellite in the low-altitude dayside cusp reveals evidence of both types of injection processes. A majority of the injection events, especially the more intense fluxes, are best explained by a merging injection model in which cusp particles are confined to the poleward side of the last closed field line and have a characteristic energy that decreases with increasing latitudinal distance from the last closed field line. Less frequent and less intense injection events are better explained in terms of a diffusive injection of cusp particles onto closed dayside field lines with a characteristic energy that increases with increasing latitudinal distance from the last closed field line. Although diffusion appears to be quantitatively less important than merging in terms of the instantaneous particle injection rate, cross-field diffusion nevertheless appears to proceed at an unexpectedly fast rate, possibly exceeding the Bohm diffusion limit.
408 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 7 |
| 2020 | 6 |
| 2019 | 4 |
| 2018 | 5 |
| 2017 | 7 |
| 2016 | 11 |