scholarly journals Evidence for particle acceleration in the magnetospheric cusp

2008 ◽  
Vol 26 (7) ◽  
pp. 1993-1997 ◽  
Author(s):  
J. Chen
Keyword(s):  
Electric Fields ◽  
Charged Particles ◽  
Magnetic Fluctuations ◽  
Adjacent Region ◽  
Left Hand ◽  
Power Spectral ◽  
Large Fluctuations ◽  
Magnetospheric Cusp ◽  
New Evidence ◽  
Resonant Acceleration

Abstract. New evidence reveals that the charged particles can be energized locally in the magnetospheric cusp. The power spectral density of the cusp magnetic fluctuations shows increases by up to four orders of magnitude in comparison to an adjacent region. Large fluctuations of the cusp electric fields have been observed with an amplitude of up to 350 mV/m. The measured left-hand polarization of the cusp electric field at ion gyro-frequencies indicates that the cyclotron resonant acceleration mechanism is working in this region. The cyclotron resonant acceleration can energize ions from keV to MeV in seconds.

scholarly journals Multi-spacecraft observations of small-scale fluctuations in density and fields in plasmaspheric plumes

2012 ◽  
Vol 30 (3) ◽  
pp. 623-637 ◽  
Author(s):  
H. Matsui ◽  
F. Darrouzet ◽  
J. Goldstein ◽  
P. A. Puhl-Quinn ◽  
Yu. V. Khotyaintsev ◽  
...  
Keyword(s):  
Electric Fields ◽  
Small Scale ◽  
Fast Mode ◽  
Magnetic Fluctuations ◽  
Density Enhancement ◽  
Non Local ◽  
Similar Location ◽  
Local Generation ◽  
Alfven Velocity ◽  
Measured Density

Abstract. In this event study, small-scale fluctuations in plasmaspheric plumes with time scales of ~10 s to minutes in the spacecraft frame are examined. In one event, plasmaspheric plumes are observed by Cluster, while IMAGE measured density enhancement at a similar location. Fluctuations in density exist in plumes as detected by Cluster and are accompanied by fluctuations in magnetic fields and electric fields. Magnetic fluctuations are transverse and along the direction of the plumes. The E/B ratio is smaller than the Alfvén velocity. Another similar event is briefly presented. We then consider physical properties of the fluctuations. Alfvén mode modulated by the feedback instability is one possibility, although non-local generation is likely. It is hard to show that the fluctuations represent a fast mode. Interchange motion is possible due to the consistency between measurements and expectations. The energy source could be a pressure or density gradient in plasmaspheric plumes. When more events are accumulated so that statistical analysis becomes feasible, this type of study will be useful to understand the time evolution of plumes.

Wave–particle interaction and enhanced precipitation of charged particles

1985 ◽  
Vol 63 (4) ◽  
pp. 445-452
Author(s):  
R. N. Singh ◽  
R. Prasad
Keyword(s):  
Electric Fields ◽  
Geomagnetic Field ◽  
Pitch Angle ◽  
Electron Flux ◽  
Particle Interaction ◽  
Charged Particles ◽  
Lower Ionosphere ◽  
Wave Interaction ◽  
Whistler Wave ◽  
Inhomogeneity Parameter

In addition to parallel electric fields, the distortions in the geomagnetic field have been considered in the study of resonant whistler wave interaction with gyrating charged particles. Mead axisymmetric distortions in the geomagnetic field have been considered and new expressions for the inhomogeneity parameter, αd, have been obtained. Considering the diffusion of charged particles in pitch angle, the variation in the precipitating electron flux under varying magnetospheric conditions has been computed. The variation in the distribution of trapped charged particles is shown to play an important role in controlling the electron flux precipitated into the lower ionosphere.

scholarly journals Outlook for the Future

2020 ◽  
pp. 797-825
Author(s):  
C. Joshi ◽  
A. Caldwell ◽  
P. Muggli ◽  
S. D. Holmes ◽  
V. D. Shiltsev
Keyword(s):  
Electric Fields ◽  
Charge Separation ◽  
Short Distance ◽  
Density Wave ◽  
Charged Particles ◽  
Electron Plasma ◽  
Longitudinal Component ◽  
Relativistic Wave ◽  
Electrons And Ions ◽  
Total Separation

AbstractThe charge separation between electrons and ions that exists within an electron plasma density wave can create large electric fields. In 1979 Tajima and Dawson first recognized that the longitudinal component of the field of a so-called “relativistic” wave (one propagating with a phase velocity close to c), could be used to accelerate charged particles to high energies in a short distance [1]. The accelerating gradient of such a plasma wave, Eo, can be approximated—assuming a total separation of electrons and ions in such a wave with wavelength λp = 2πc/ωp—as

scholarly journals Ionosphere monitoring sensor, placed on nanosatellites

2021 ◽  
pp. 54-65
Author(s):  
V.E. Dreyzin ◽  
◽  
Mohammed Al Kadhimi Ali Noori ◽  
V.E. Bondyrev ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Electric Fields ◽  
Ion Trap ◽  
Charged Particles ◽  
High Concentration ◽  
Existing Problems ◽  
The Core ◽  
Autonomous Operation ◽  
Electric And Magnetic Fields ◽  
Electrons And Ions

In this paper, we propose a sensor for the density and composition of the upper atmosphere (ionosphere), designed for installation on nanosatellites. The relevance and existing problems of direct instrumental studies of the ionosphere at altitudes of 150-500 km are shown. Of the existing types of vacuum meters, the most suitable for autonomous operation at these altitudes are ionization vacuum meters with inverse magnetron primary converters with a cold cathode. However, the existing industrial types of such vacuum meters are unsuitable for operation in the ionosphere due to high concentration of charged particles in the air, resulting in large distortions of the readings. In addition, they have large weight and size characteristics and energy consumption, which exclude the possibility of their installation on nanosatellites. To solve these problems, a mathematical model of the electrophysical processes, occurring in the core of such a converter, was developed which significantly reduced its weight and size characteristics and energy consumption. And to eliminate the influence of charged particles, it is equipped with an electron-ion trap, which additionally made it possible to measure the concentration of electrons and ions in the environment. The design of such a combined converter is described, and calculations of the electric and magnetic fields in the core of the vacuum gauge converter and the electric fields in the interelectrode space of the trap are performed. A method for calculating the current values of such a combined converter has been developed, which makes it possible to estimate the required measurement ranges of the sensor measuring channels. The results obtained allow us to proceed with its experimental design.

MAGNETOSPHERIC PARTICLE ACCELERATION AND X-RAY EMISSION OF PULSARS

2008 ◽  
Vol 17 (12) ◽  
pp. 2337-2350 ◽  
Author(s):  
SEVINÇ O. TAGIEVA ◽  
AKIN ANKAY ◽  
ARZU MERT ANKAY
Keyword(s):  
Energy Loss ◽  
Electric Fields ◽  
Supernova Remnants ◽  
Charged Particles ◽  
Coulombic Interaction ◽  
Dipole Radiation ◽  
X Ray ◽  
Radiation Wave ◽  
Power And Energy ◽  
Main Factor

In this paper, we analyze the available data on isolated X-ray pulsars, their wind nebulae, and the supernova remnants that are connected to some of these sources. It is shown that the electric fields of neutron stars tear off charged particles from the surface of the neutron star and trigger the acceleration of particles. The charged particles are accelerated mainly in the field of a magneto-dipole radiation wave. The power and energy spectra of the charged particles depend on the strength of the magneto-dipole radiation. Therefore, the X-ray radiation is strongly dependent on the rate of rotational energy loss and weakly dependent on the electric field intensity. Coulombic interaction between the charged particles is the main factor for the energy loss and the X-ray spectra of the charged particles.

Resonant acceleration of charged particles in the presence of random fluctuations

2011 ◽  
Vol 84 (4) ◽  
Author(s):  
Anton Artemyev ◽  
Dmitri Vainchtein ◽  
Anatoly Neishtadt ◽  
Lev Zelenyi
Keyword(s):  
Charged Particles ◽  
Random Fluctuations ◽  
Resonant Acceleration

scholarly journals Electric fields on a surface of constant negative curvature

2000 ◽  
Vol 20 (3) ◽  
pp. 681-696 ◽  
Author(s):  
F. BONETTO ◽  
G. GENTILE ◽  
V. MASTROPIETRO
Keyword(s):  
Electric Fields ◽  
Continuous Time ◽  
Automorphic Form ◽  
Negative Curvature ◽  
Contraction Rate ◽  
Average Volume ◽  
Constant Negative Curvature ◽  
Volume Contraction ◽  
Large Fluctuations ◽  
Anosov Flows

A one-parameter family of time reversible Anosov flows is studied; physically, it describes a particle moving on a surface of constant negative curvature under the action of an electric field (corresponding to an automorphic form) and of a ‘thermostatting’ force (given by Gauss's least-constraint principle). We show that the flows are dissipative, in the sense that the average volume contraction rate is positive and the Sinai–Ruelle–Bowen measure is singular with respect to the volume: therefore they verify the assumptions for the validity of the continuous time version of Gallavotti–Cohen's fluctuation theorem for the large fluctuations of the average volume contraction rate. If several independent electric fields are considered, it makes sense to ask for the validity of Onsager's reciprocity: we show, by explicitly computing the relevant transport coefficents, that it is indeed obeyed.

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