On the motion of charged particles in a sheared force-free magnetic field

2002 ◽  
Vol 67 (2-3) ◽  
pp. 215-221 ◽  
Author(s):  
G. E. VEKSTEIN ◽  
N. A. BOBROVA ◽  
S. V. BULANOV
Keyword(s):  
Magnetic Field ◽  
Spatial Scale ◽  
Single Particle ◽  
Charged Particles ◽  
Magnetic Confinement ◽  
Larmor Radius ◽  
Field Variation ◽  
Particle Trajectories ◽  
Field Lines ◽  
Actual Particle

This paper considers single-particle trajectories in a planar sheared force-free magnetic field. A specific feature of this magnetic configuration is the absence of both gradient and curvature magnetic drifts, as well as a diamagnetic force along field lines. Therefore, in the framework of the drift approximation, the motion of the particle guiding centre does not feel the magnetic field's non-uniformity. Here we discuss how the latter affects actual particle trajectories, making them quite different from simple circular gyromotion even when the Larmor radius is small. It is also shown how magnetic confinement ceases to work when the Larmor radius becomes comparable to the spatial scale of the field variation.

scholarly journals 3D study of centrifugal acceleration in isotropic photon fields

2019 ◽  
Vol 28 (11) ◽  
pp. 1950141
Author(s):  
G. G. Bakhtadze ◽  
V. I. Berezhiani ◽  
Z. Osmanov
Keyword(s):  
Magnetic Field ◽  
Single Particle ◽  
Stable Equilibrium ◽  
Charged Particles ◽  
Relativistic Dynamics ◽  
Centrifugal Acceleration ◽  
Study Behavior ◽  
Field Lines ◽  
Particle Approach

In this paper, we study relativistic dynamics of charged particles corotating with prescribed trajectories, having the shape of dipolar magnetic field lines. In particular, we consider the role of the drag force caused by the photon field the forming of equilibrium positions of the charged particles. Alongside a single particle approach, we also study behavior of ensemble of particles in the context of stable positions. As we have shown, the together they create surfaces where particles are at stable equilibrium positions. In this paper, we examine these shapes and study parameters they depend on. It has been found that under certain conditions, there are two distinct surfaces with stable equilibrium positions.

Synchrotron Radiation Spectra

1972 ◽  
Vol 2 (3) ◽  
pp. 142-144 ◽  
Author(s):  
L. J. Gleeson ◽  
K. C. Westfold
Keyword(s):  
Magnetic Field ◽  
Synchrotron Radiation ◽  
Energy Distribution ◽  
Power Law ◽  
Uniform Magnetic Field ◽  
Charged Particles ◽  
Radiation Spectra ◽  
Field Lines

In this paper we give an account of the corrections that must be made to the formula for the emissivity ηf due to a power-law energy distribution of ultrarelativistic charged particles in a uniform magnetic field B0 in directions well away from the field lines when the effects of upper and lower cut-off values E2 and E1 in the energy distribution are not negligible.

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>

scholarly journals Particle trajectories in Weibel magnetic filaments with a flow-aligned magnetic field

2016 ◽  
Vol 82 (4) ◽  
Author(s):  
Antoine Bret
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Initial Velocity ◽  
Larmor Radius ◽  
Shock Formation ◽  
Incoming Flow ◽  
Particle Trajectories ◽  
Overlapping Region ◽  
Peak Field ◽  
Aligned Magnetic Field

For a Weibel shock to form, two plasma shells have to collide and trigger the Weibel instability. At saturation, this instability generates magnetic filaments in the overlapping region with peak field $B_{f}$. In the absence of an external guiding magnetic field, these filaments can block the incoming flow, initiating the shock formation, if their size is larger than the Larmor radius of the incoming particles in the peak field. Here we show that this result still holds in the presence of an external magnetic field $B_{0}$, provided it is not too high. Yet, for $B_{0}\gtrsim B_{f}/2$, the filaments become unable to stop any particle, regardless of its initial velocity.

scholarly journals New Radiation Formulae of Relativistic Electrons in Curved Magnetic Field Lines

2002 ◽  
Vol 199 ◽  
pp. 400-401
Author(s):  
Ya.M. Sobolev
Keyword(s):  
Magnetic Field ◽  
Charged Particles ◽  
Relativistic Electrons ◽  
Force Line ◽  
Radiation Mechanism ◽  
Field Lines

Radiation mechanism for relativistc charged particles spiraling along curved magnetic field is considered. Emission from many electron revolutions around force line is taken into account.

scholarly journals L-shell and energy dependence of magnetic mirror point of charged particles trapped in Earth’s magnetosphere

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Pankaj K. Soni ◽  
Bharati Kakad ◽  
Amar Kakad
Keyword(s):  
Magnetic Field ◽  
Charged Particles ◽  
Magnetic Mirror ◽  
Theoretical Expression ◽  
Neutral Atmosphere ◽  
Loss Cone ◽  
Field Lines ◽  
Mirror Point ◽  
The Magnetic Field ◽  
Shell Energy

Abstract In the Earth’s inner magnetosphere, there exist regions like plasmasphere, ring current, and radiation belts, where the population of charged particles trapped along the magnetic field lines is more. These particles keep performing gyration, bounce and drift motions until they enter the loss cone and get precipitated to the neutral atmosphere. Theoretically, the mirror point latitude of a particle performing bounce motion is decided only by its equatorial pitch angle. This theoretical manifestation is based on the conservation of the first adiabatic invariant, which assumes that the magnetic field varies slowly relative to the gyro-period and gyro-radius. However, the effects of gyro-motion cannot be neglected when gyro-period and gyro-radius are large. In such a scenario, the theoretically estimated mirror point latitudes of electrons are likely to be in agreement with the actual trajectories due to their small gyro-radius. Nevertheless, for protons and other heavier charged particles like oxygen, the gyro-radius is relatively large, and the actual latitude of the mirror point may not be the same as estimated from the theory. In this context, we have carried out test particle simulations and found that the L-shell, energy, and gyro-phase of the particles do affect their mirror points. Our simulations demonstrate that the existing theoretical expression sometimes overestimates or underestimates the magnetic mirror point latitude depending on the value of L-shell, energy and gyro-phase due to underlying guiding centre approximation. For heavier particles like proton and oxygen, the location of the mirror point obtained from the simulation deviates considerably (∼ 10°–16°) from their theoretical values when energy and L-shell of the particle are higher. Furthermore, the simulations show that the particles with lower equatorial pitch angles have their mirror points inside the high or mid-latitude ionosphere.

Single-particle trajectories in a cusped magnetic field

1991 ◽  
Vol 19 (3) ◽  
pp. 543-545 ◽  
Author(s):  
V. Selvarajan ◽  
K. Rajendran
Keyword(s):  
Magnetic Field ◽  
Single Particle ◽  
Particle Trajectories

Curvature Emission and Absorption: Single Particle Treatment

1992 ◽  
Vol 10 (1) ◽  
pp. 45-47 ◽  
Author(s):  
Q. Luo ◽  
D. B. Melrose
Keyword(s):  
Magnetic Field ◽  
Single Particle ◽  
Lorentz Factor ◽  
Radius Of Curvature ◽  
Maser Emission ◽  
Field Lines ◽  
The Magnetic Field

AbstractThe absorption counterpart of curvature emission is reexamined based on the Landau-Lifshitz approach. Early derivations led to the conclusion that maser emission is not possible, but these early derivations neglected a drift effect which was first discussed by Zheleznyakov and Shaposhnikov. When the drift effect is included, the derivation implies that curvature maser emission is possible. It is shown that for maser emission to be possible, the Lorentz factor needs to satisfy γ ≳ 103 for radius of curvature of the magnetic field lines RB ≈ 106 to 109cm and frequency ω ≈ 107 to 1011 s−1. Possible application to pulsars is discussed.

Nature-inspired position determination using inherent magnetic fields

TECHNOLOGY ◽  
2014 ◽  
Vol 02 (02) ◽  
pp. 161-170 ◽  
Author(s):  
Saber Taghvaeeyan ◽  
Rajesh Rajamani
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Measurement System ◽  
Internal Combustion Engines ◽  
Magnetic Sensor ◽  
Field Variation ◽  
Position Measurement ◽  
Hydraulic Cylinders ◽  
Accurate Position ◽  
Field Lines

Many creatures in nature, including butterflies, newts, and mole rats, use the Earth's inherent magnetic field for navigation. They use magnetic field lines and variations in field intensity to determine their geographical position. This paper seeks to apply similar techniques to measure the positions of individual ferromagnetic objects found all around us in everyday life. Ferromagnetic objects have inherent magnetic fields around them. We show here that the magnetic field variation around a ferromagnetic object can be modeled using purely the geometry of the object under consideration. By exploiting this model, the position of the object can be measured quite accurately using a small inexpensive magnetic sensor. Further, the use of just one additional redundant magnetic sensor can eliminate the need to calibrate the position measurement system. As demonstrated in the paper through a series of experimental results, the developed measurement system is applicable to accurate position measurement of small and large ferromagnetic objects, including cars on highways, oscillating pistons in internal combustion engines, pneumatic cylinders, hydraulic cylinders, as well as moving parts in many machines.

Sign in / Sign up

Export Citation Format

Share Document