I.—Focusing of Electron Beams in Crossed Static Electric and Magnetic Fields

1962 ◽  
Vol 66 (1) ◽  
pp. 1-19
Author(s):  
P. S. Farago
Keyword(s):  
Magnetic Field ◽  
Electric Fields ◽  
Solid Angle ◽  
Scalar Potential ◽  
Charged Particles ◽  
Direction Parallel ◽  
Electric And Magnetic Fields ◽  
Double Focusing ◽  
The Magnetic Field ◽  
Focusing Properties

SynopsisIn a crossed static homogeneous electric and magnetic field charged particles describing trochoidal orbits in a plane perpendicular to the direction of the magnetic field are focused, but a beam emitted by a point source in a finite solid angle spreads out indefinitely in the direction parallel to the magnetic field. The essential characteristics of trochoidal orbits can be preserved if the superimposed magnetic and electric fields are two-dimensional and orthogonal, such as derived from a vector potential, say, Ax = A(y, z), Av = Az = O, and a scalar potential Ф(y, z)= const. A(y, z). The focusing properties of such a field combination depend on the distribution of the magnetic field only. Following some general considerations, specific examples of double focusing field distributions are given, and the electron motion in one of them is treated in detail.

EFFECT OF MAGNETIC FIELD NONUNIFORM ITIES ON THE PERFORMANCE OF DOUBLE-FOCUSING MASS SPECTROMETERS

1964 ◽  
Vol 42 (1) ◽  
pp. 103-112 ◽  
Author(s):  
L. A. Cambey ◽  
J. H. Ormrod ◽  
R. C. Barber
Keyword(s):  
Magnetic Field ◽  
Velocity Dispersion ◽  
Vertical Component ◽  
Mass Spectrometers ◽  
Double Focusing ◽  
The Magnetic Field ◽  
Focusing Properties ◽  
Interpretation Of Results

The effects of magnetic field nonuniformities on the focusing properties of the three types of magnetic field sectors commonly employed in mass spectrometers and spectrographs are discussed. Two types of magnetic field non-uniformities are considered: those in which the vertical component of the magnetic field, Bz, varies along the central ion path ("azimuthal nonuniformities") and those in which Bz is a function of the displacement in the direction normal to the central ion path ("radial nonuniformities"). To facilitate the interpretation of results, the ions entering the magnetic field are assumed to have the velocity dispersion required to form a velocity focus at the position of the direction focus (i.e., to give a double focus), if the magnetic field were uniform.

Proton acceleration in three-dimensional non-null magnetic reconnection

2016 ◽  
Vol 82 (5) ◽  
Author(s):  
Z. Akbari ◽  
M. Hosseinpour ◽  
M. A. Mohammadi
Keyword(s):  
Magnetic Field ◽  
Energy Distribution ◽  
Magnetic Reconnection ◽  
Electric Fields ◽  
Three Dimensional ◽  
Null Point ◽  
Proton Acceleration ◽  
Electric And Magnetic Fields ◽  
Field Lines ◽  
The Magnetic Field

In a three-dimensional non-null magnetic reconnection, the process of magnetic reconnection takes place in the absence of a null point where the magnetic field vanishes. By randomly injecting a population of 10 000 protons, the trajectory and energy distribution of accelerated protons are investigated in the presence of magnetic and electric fields of a particular model of non-null magnetic reconnection with the typical parameters for the solar corona. The results show that protons are accelerated along the magnetic field lines away from the non-null point only at azimuthal angles where the magnitude of the electric field is strongest and therefore particles obtain kinetic energies of the order of thousands of MeV and even higher. Moreover, the energy distribution of the population depends strongly on the amplitude of the electric and magnetic fields. Comparison shows that a non-null magnetic reconnection is more efficient in accelerating protons to very high GeV energies than a null-point reconnection.

Suppression of runaway of electrons in a Lorentz plasma. II. crossed electric and magnetic fields

1970 ◽  
Vol 4 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Barbara Abraham-Shrauner
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Collision Frequency ◽  
Uniform Electric Field ◽  
Drift Motion ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

Suppression of runaway of electrons in a weak, uniform electric field in a fully ionized Lorentz plasma by crossed magnetic and electric fields is analysed. A uniform, constant magnetic field parallel to a constant or harmonically time varying electric field does not alter runaway from that in the absence of the magnetic field. For crossed, constant fields the passage to runaway or to free motion as described by constant drift motion and spiral motion about the magnetic field is lengthened in time for strong magnetic fields. The new ‘runaway’ time scale is roughly the ratio of the cyclotron frequency to the collision frequency squared for cyclotron frequencies much greater than the collision frequency. All ‘runaway’ time scales may be given approximately by t2E Teff where tE is the characteristic time of the electric field and Teff is the ffective collision time as estimated from the appropriate component of the electrical conductivity.

Transmission line sanitary protective zones. Electromagnetic safety problems

2020 ◽  
pp. 736-736
Author(s):  
N. B. Rubtsova ◽  
A. Y. Tokarskiy
Keyword(s):  
Magnetic Field ◽  
Risk Factor ◽  
Transmission Lines ◽  
General Public ◽  
Field Component ◽  
Regulatory Requirements ◽  
Protection Zones ◽  
Electric And Magnetic Fields ◽  
Health Risk Factor ◽  
The Magnetic Field

The main problems of overhead and cable transmission lines with voltage >=110 kV electric and magnetic fields general public protection are presented. It is shown that it is necessary to develop regulatory requirements for these lines’ sanitary protection zones organization, taking into account the magnetic field component, because its possible health risk factor, up to carcinogenic.

The Function of Magnetic Field in a Magnetic-Electrochemical Compound Polishing

2010 ◽  
Vol 97-101 ◽  
pp. 4141-4145 ◽  
Author(s):  
Li Min Shi ◽  
Er Liang Liu ◽  
Yong Jiang Niu ◽  
Yu Quan Chen
Keyword(s):  
Magnetic Field ◽  
Mathematical Model ◽  
Concentration Polarization ◽  
Electrochemical Reaction ◽  
Charged Particles ◽  
Polishing Process ◽  
Electrical Field ◽  
Movement Model ◽  
The Mathematical Model ◽  
The Magnetic Field

Traditionally, the magnetic field is always vertical to the electrical field in a magnetic-electrochemical compound polishing.The magnetic field is set to parallel the electrical field in this paper. The mathematical model of the charged particles movement in a magnetic field is established through the analysis of its movement process when using Coulomb laws and Lorentz force. Through constructing the velocity formulation and loci formulation, the function of the magnetic field is proved. Because of the magnetic field, the concentration polarization of electrochemical reaction can be reduced more and the electrochemical reaction can be accelerated easily than the traditional polishing in which the magnetic field is vertical to the electrical field. Finally, to verify the model, the magnetic-electrochemical compound polishing process has been tested and the results, compared with those obtained from the model, have shown the movement model is reasonable and the analysis to function of magnetic field is correct.

scholarly journals Mapping of steady-state electric fields and convective drifts in geomagnetic fields – Part 1: Elementary models

2016 ◽  
Vol 34 (1) ◽  
pp. 55-65 ◽  
Author(s):  
A. D. M. Walker ◽  
G. J. Sofko
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Electric Field ◽  
Electric Fields ◽  
Magnetic Field Line ◽  
Geomagnetic Field ◽  
Geomagnetic Field Models ◽  
Spatial Derivatives ◽  
Field Lines ◽  
The Magnetic Field

Abstract. When studying magnetospheric convection, it is often necessary to map the steady-state electric field, measured at some point on a magnetic field line, to a magnetically conjugate point in the other hemisphere, or the equatorial plane, or at the position of a satellite. Such mapping is relatively easy in a dipole field although the appropriate formulae are not easily accessible. They are derived and reviewed here with some examples. It is not possible to derive such formulae in more realistic geomagnetic field models. A new method is described in this paper for accurate mapping of electric fields along field lines, which can be used for any field model in which the magnetic field and its spatial derivatives can be computed. From the spatial derivatives of the magnetic field three first order differential equations are derived for the components of the normalized element of separation of two closely spaced field lines. These can be integrated along with the magnetic field tracing equations and Faraday's law used to obtain the electric field as a function of distance measured along the magnetic field line. The method is tested in a simple model consisting of a dipole field plus a magnetotail model. The method is shown to be accurate, convenient, and suitable for use with more realistic geomagnetic field models.

Influence of time-variable solar wind on the response of Mercury’s magnetosphere

2021 ◽  
Author(s):  
Sae Aizawa ◽  
Nicolas André ◽  
Ronan Modolo ◽  
Elisabeth Werner ◽  
Jim Slavin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Charged Particles ◽  
Time Variable ◽  
Low Energy ◽  
Field Of View ◽  
Plasma Measurement ◽  
Electrons And Ions ◽  
Low Energy Electrons ◽  
The Magnetic Field

<p><span lang="EN-GB">BepiColombo is going to conduct its first Mercury flyby in October 2021. During this flyby,  plasma measurement will be obtained and bring new insights on the Hermean magnetosphere and its interaction with the Sun despite the limited field of view of the instruments during the cruise phase. Unlike Mariner-10 ion measurements will be obtained, and unlike MESSENGER, low energy electrons and ions will be measured simultaneously. In this study, we have revisited Mariner 10 and MESSENGER observations with the help of the global hybrid model LatHyS in order to understand the influence of time-variable solar wind and to constraint the plasma environment. We are able to reproduce the magnetic field observations of Mariner 10 along its trajectory with in particular two distinct signatures consisting of a quiet and disturbed state of the magnetosphere. In addition, the plasma spectrogram is also collected in the model and this enables us to detail the properties of the charged particles observed during the flyby. We will discuss all these signatures both in term of an interaction with a time-variable solar wind and localized processes occurring in the magnetosphere. We will then present the virtual sampling of both the magnetic field and plasma spectrogram along BepiColombo’s first Mercury flyby trajectory and discuss the possible signatures to be observed at that time.</span></p>

Magnetic Field Aligned Potentials as an Acceleration Mechanism at Jupiter

2021 ◽  
Author(s):  
Dave Constable ◽  
Licia Ray ◽  
Sarah Badman ◽  
Chris Arridge ◽  
Chris Lorch ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Temporal Evolution ◽  
Charged Particles ◽  
Uniform Mesh ◽  
Time Varying ◽  
Potential Structure ◽  
Field Aligned Current ◽  
Field Lines ◽  
The Magnetic Field ◽  
Insight Into

<p>Since arriving at Jupiter, Juno has observed instances of field-aligned proton and electron beams, in both the upward and downward current regions. These field-aligned beams are identified by inverted-V structures in plasma data, which indicate the presence of potential structures aligned with the magnetic field. The direction, magnitude and location of these potential structures is important, as it affects the characteristics of any resultant field-aligned current. At high latitudes, Juno has observed potentials of 100’s of kV occurring in both directions. Charged particles that are accelerated into Jupiter’s atmosphere and precipitate can excite aurora; likewise, particles accelerated away from the planet can contribute to the population of the magnetosphere.</p> <p>Using a time-varying 1-D spatial, 2-D velocity space Vlasov code, we examine magnetic field lines which extend from Jupiter into the middle magnetosphere. By applying and varying a potential difference at the ionosphere, we can gain insight into the effect these have on the plasma population, the potential structure, and plasma densities along the field line. Utilising a non-uniform mesh, additional resolution is applied in regions where particle acceleration occurs, allowing the spatial and temporal evolution of the plasma to be examined. Here, we present new results from our model, constrained, and compared with recent Juno observations, and examining both the upward and downward current regions.</p>

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