scholarly journals Modeling of ion dynamics in the inner geospace during enhanced magnetospheric activity

2016 ◽  
Vol 34 (2) ◽  
pp. 171-185
Author(s):  
C. Tsironis ◽  
A. Anastasiadis ◽  
C. Katsavrias ◽  
I. A. Daglis
Keyword(s):  
Initial Conditions ◽  
Ion Dynamics ◽  
Particle Tracing ◽  
Kinematic Data ◽  
Ion Motion ◽  
Test Particles ◽  
Magnetospheric Currents ◽  
Solar Eruptions ◽  
Ion Species ◽  
Current Systems

Abstract. We investigate the effect of magnetic disturbances on the ring current buildup and the dynamics of the current systems in the inner geospace by means of numerical simulations of ion orbits during enhanced magnetospheric activity. For this purpose, we developed a particle-tracing model that solves for the ion motion in a dynamic geomagnetic field and an electric field due to convection, corotation and Faraday induction and which mimics reconfigurations typical to such events. The kinematic data of the test particles is used for analyzing the dependence of the system on the initial conditions, as well as for mapping the different ion species to the magnetospheric currents. Furthermore, an estimation of Dst is given in terms of the ensemble-averaged ring and tail currents. The presented model may serve as a tool in a Sun-to-Earth modeling chain of major solar eruptions, providing an estimation of the inner geospace response.

scholarly journals ZONE FOR COLLECTING THE IONS OF A GIVEN MASS RANGE IN THE PLASMA FILTER OF MASSES

2020 ◽  
pp. 185-190
Author(s):  
V.V. Katrechko ◽  
V.B. Yuferov ◽  
V.O. Ilichova ◽  
A.S. Svichkar ◽  
S.N. Khizhnyak
Keyword(s):  
Cyclotron Frequency ◽  
Initial Conditions ◽  
Radial Electric Field ◽  
Plasma Source ◽  
Mass Range ◽  
Molecular Ions ◽  
Variable Component ◽  
Mass Filter ◽  
Ion Motion ◽  
Ion Trajectory

The trajectories of motion for atomic and molecular ions of a given mass range (M = 232...277) in the plasma mass filter, which is currently being developed, are calculated. The influence of the initial conditions (energy, angle, radius) on the ion trajectory to determine the dimensions of the collector for actinides, the so-called “pocket”, is studied. It is shown that the variable component of the radial electric field, tuned to a frequency equal to half the ion cyclotron frequency for M = 238 allows target ions to enter the “pocket”. An analysis of the calculations showed that there are limitations on energy, angle, and radius related to the initial conditions for the ion motion, that must be taken into account when creating the plasma source for the plasma mass filter.

Effects of parallel ion dynamics on drift-Alfvén vortices in plasmas

1988 ◽  
Vol 39 (1) ◽  
pp. 151-155 ◽  
Author(s):  
P. K. Shukla
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Ion Dynamics ◽  
Ion Motion

Drift-Alfvén vortices are investigated, taking into account the nonlinear ion dynamics parallel to the external magnetic field. It is found that the parallel ion motion restricts the vortex speed.

scholarly journals Local Ion Dynamics in Polycrystalline β-LiGaO2: A Solid-State NMR Study

2017 ◽  
Vol 231 (7-8) ◽  
Author(s):  
C. Vinod Chandran ◽  
Kai Volgmann ◽  
Suliman Nakhal ◽  
Reinhard Uecker ◽  
Elena Witt ◽  
...  
Keyword(s):  
Solid State ◽  
Lithium Ion ◽  
Resonance Spectroscopy ◽  
Ion Dynamics ◽  
Energy Storage Devices ◽  
Ion Motion ◽  
Storage Devices ◽  
Nmr Study ◽  
Materials Used ◽  
Lithium Ion Conductors

AbstractSolid-state nuclear magnetic resonance spectroscopy is an efficient technique to characterize dynamics and structure of materials. It has been widely used to elucidate ion dynamics in lithium ion conductors. Fast moving lithium ions are needed in energy storage devices, whereas slow ion motion is exploited in some materials used, for example, as blankets in fusion reactors.

scholarly journals Efficient computational scheme for ion dynamics in RF-field of Paul trap

2019 ◽  
Vol 27 (4) ◽  
pp. 378-385
Author(s):  
Vladimir S. Melezhik
Keyword(s):  
Radio Frequency ◽  
Cold Atom ◽  
Paul Trap ◽  
Ion Traps ◽  
Computational Scheme ◽  
Time Interval ◽  
Ion Dynamics ◽  
Ion Motion ◽  
Hamilton Equations ◽  
Ion Collision

We have developed an efficient computational scheme for integration of the classical Hamilton equations describing the ion dynamics confined in the radio-frequency field of the Paul trap. It has permitted a quantitative treatment of cold atom-ion resonant collisions in hybrid atom-ion traps with taking into account unremovable ion micromotion caused by the radio-frequency fields (V.S. Melezhik et. al., Phys. Rev. A100, 063406 (2019)). The important element of the hybrid atom-ion systems is the electromagnetic Paul trap confining the charged ion. The oscillating motion of the confined ion is defined by two frequencies of the Paul trap. It is the frequency of the order of 100 kHz due to the constant electric field and the radio-frequency of about 1-2 MHz defined by the alternating electromagnetic field of the ion trap. The necessity to accurately treat the ion motion in the combined field with two time scales defined by these two very different frequencies has demanded to develop the stable computational scheme for integration of the classical Hamilton equations for the ion motion. Moreover, the scheme must be stable on rather long time-interval of the ion collision with the cold atom ∼ 10 × 2/ defined by the atomic trap frequency ∼ 10 kHz and in the moment of the atom-ion collision when the Hamilton equations are strongly coupled. The developed numerical method takes into account all these features of the problem and makes it possible to integrate the system of coupled quantum-semiclassical equations with the necessary accuracy and quantitatively describes the processes of atomic-ion collisions in hybrid traps, including resonance effects.

scholarly journals Simulation of Ion Motion at Atmospheric Pressure: Particle Tracing Versus Electrokinetic Flow

2011 ◽  
Vol 23 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Walter Wissdorf ◽  
Larissa Pohler ◽  
Sonja Klee ◽  
David Müller ◽  
Thorsten Benter
Keyword(s):  
Atmospheric Pressure ◽  
Electrokinetic Flow ◽  
Particle Tracing ◽  
Ion Motion

scholarly journals Nonlinear 1-D stationary flows in multi-ion plasmas – sonic and critical loci – solitary and "oscillatory" waves

2006 ◽  
Vol 24 (11) ◽  
pp. 3041-3057 ◽  
Author(s):  
E. M. Dubinin ◽  
K. Sauer ◽  
J. F. McKenzie
Keyword(s):  
Magnetic Field ◽  
Critical Points ◽  
Heavy Ion ◽  
Energy Functions ◽  
Ion Motion ◽  
Stationary Flows ◽  
Energy Integrals ◽  
Ion Cloud ◽  
Ion Species ◽  
The Magnetic Field

Abstract. One-dimensional stationary flows of a plasma consisting of two ion populations and electrons streaming against a heavy ion cloud are studied. The flow structure is critically governed by the position of sonic and critical points, at which the flow is shocked or choked. The concept of sonic and critical points is suitably generalized to the case of multi-ion plasmas to include a differential ion streaming. For magnetic field free flows, the sonic and critical loci in the (upx, uhx) space coincide. Amongst the different flow patterns for the protons and heavy ions, there is a possible configuration composed of a "heavy ion shock" accompanied by a proton rarefaction. The magnetic field introduces a "stiffness" for the differential ion streaming transverse to the magnetic field. In general, both ion fluids respond similarly in the presence of "ion obstacle"; the superfast (subfast) flows are decelerated (accelerated). The collective flow is choked when the dynamic trajectory (upx, uhx) crosses the critical loci. In specific regimes the flow contains a sequence of solitary structures and as a result, the flow is strongly bunched. In each such substructure the protons are almost completely replaced by the heavies. A differential ion streaming is more accessible in the collective flows oblique to the magnetic field. Such a flexibility of the ion motion is determined by the properties of energy integrals and the Bernoulli energy functions of each ion species. The structure of flows, oblique to the magnetic field, depends critically on the velocity regime and demonstrates a rich variety of solitary and oscillatory nonlinear wave structures. The results of the paper are relevant to the plasma and field environments at comets and planets through the interaction with the solar wind.

Non-turbulent electric fields in soliton and shock-like structures in magnetized plasmas

1973 ◽  
Vol 10 (1) ◽  
pp. 149-164 ◽  
Author(s):  
C. W. Mendel ◽  
T. P. Wright
Keyword(s):  
Electric Fields ◽  
Charge Separation ◽  
Ion Dynamics ◽  
New Treatment ◽  
Image Position ◽  
Ion Species ◽  
Pseudo Potential ◽  
The Magnetic Field ◽  
Scale Length

A new treatment of soliton and laminar shock-like structures in single ion species and counter-streaming plasmas in perpendicular magnetic fields is presented. Charge separation effects are treated exactly, and may become important for high Alfvén Mach number flows. The theory contains the familiar quasi-neutrality theory in the limit B20 ≪ Μ0nmec2 and the Longmire theory in the limit B20 ≫ Μ0nmec2. The introduction of the potential ψ as the primary dependent variable, instead of the magnetic field B, clarifies the role of ion dynamics. New pseudo-potential functions are defined which generate classes of solutions for single ion species, rigid piston problems, and multispecies problems. They also provide information about the evolution of particle piston solutions. Results include the fact that a small amount of resistivity allows shock solutions for very large Mach numbers, and for zero dissipation the parameterdoes not affect the solutions except in the scale length.

scholarly journals Dark Matter Inside and Around Binary Galaxies: Formation of Interacting Galaxies

1995 ◽  
Vol 164 ◽  
pp. 422-422
Author(s):  
J. Anosova ◽  
B.G. Anandarao
Keyword(s):  
Dark Matter ◽  
Binary Systems ◽  
Initial Conditions ◽  
Test Particles ◽  
Massive Binary Systems ◽  
Low Mass ◽  
Binary Galaxy ◽  
The Moment ◽  
The Masses ◽  
Three Body

We study here the dynamics of an extended shell of relatively low-mass (almost zero-mass) particles around massive binary systems by computer simulations in the framework of approximately restricted three-body problem. We examine a set of several initial conditions concerning the masses M1 and M2 of the binary components surrounded by N test particles in uniform random distribution on a spherical envelope of radius R expanding with a velocity V. We apply this model to binary galaxy systems with a halo of baryonic dark matter, e.g., massive black holes. It is shown that, initially, the shell expands isotropically with decreasing velocity and then, falls back into the system forming zones of compressed matter. At some moment of time there could be a collapse of these particles on to the heavier component of the binary. Further in time, a number of particles escape from the system. We consider a number of different models with different initial parameters. For models with smaller R and V, about one-half of the particles escape from the system; while for larger values the shell disrupts as a whole. The escaping particles form a collimated flow in the plane of the orbit of the binary. The position of the flow and the directions of motions depend on the position of the heavier component of the binary at the moment of the closest approach of the particles and on the ratio M1/M2.

scholarly journals Surface conductivity of Mercury provides current closure and may affect magnetospheric symmetry

2004 ◽  
Vol 22 (5) ◽  
pp. 1829-1837 ◽  
Author(s):  
P. Janhunen ◽  
E. Kallio
Keyword(s):  
Solar Wind ◽  
Hybrid Simulation ◽  
Surface Conductivity ◽  
The Other ◽  
Magnetospheric Currents ◽  
Surface Electrons ◽  
Simulation Results ◽  
Horizontal Variations ◽  
Current Systems ◽  
Conductivity Models

Abstract. We study what effect a possible surface conductivity of Mercury has on the closure of magnetospheric currents by making six runs with a quasi-neutral hybrid simulation. The runs are otherwise identical but use different synthetic conductivity models: run 1 has a fully conducting planet, run 2 has a poorly conducting planet ( m) and runs 3-6 have one of the hemispheres either in the dawn-dusk or day-night directions, conducting well, the other one being conducting poorly. Although the surface conductivity is not known from observations, educated guesses easily give such conductivity values that magnetospheric currents may close partly within the planet, and as the conductivity depends heavily on the mineral composition of the surface, the possibility of significant horizontal variations cannot be easily excluded. The simulation results show that strong horizontal variations may produce modest magnetospheric asymmetries. Beyond the hybrid simulation, we also briefly discuss the possibility that in the nightside there may be a lack of surface electrons to carry downward current, which may act as a further source of surface-related magnetospheric asymmetry. Key words. Magnetospheric physics (planetary magnetospheres; current systems; solar wind-magnetosphere interactions).6

Energetic ion dynamics near the cusp region of Mercury

2020 ◽  
Author(s):  
Eunjin Jang ◽  
Jiutong zhao ◽  
Chao Yue ◽  
Qiugang Zong ◽  
Ying Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Single Particle ◽  
Local Minimum ◽  
Energetic Particles ◽  
Ion Dynamics ◽  
Energetic Ions ◽  
Cusp Region ◽  
Test Particles ◽  
Field Geometry ◽  
The Magnetic Field

<p>Energetic ions in Mercury’s magnetosphere are very dynamic, just like in the magnetosphere of Earth. In this study, we have shown two energetic proton observations by MESSENGER near the cusp region of Mercury. For one case, we have observed large flux of energetic protons while the other case has almost no flux, indicating that the near cusp region may trap energetic particles under particular conditions. In order to understand that under what conditions the near cusp region of Mercury could trap energetic particles, we have traced the trajectories of single particle with different energies by using a modeled magnetic field, called KT17. Under different magnetic field geometry, the motions of single particle with various energies are different. The test particles can be trapped around the cusp region when the disturbance activity is strong, generating the magnetic field local minimum near the cusp region while the particles can’t be trapped and escape along the magnetic field through the dawn side cusp when there is little solar activity.</p>

Sign in / Sign up

Export Citation Format

Share Document