Charge In Magnetic Field Research Articles

Charged particle coherent states in tomographic probability representation

The symplectic tomograms of coherent states of a charged particle moving in a constant uniform magnetic field are obtained in explicit form. The tomograms are shown to coincide with normal probability distributions of two random variables. The means and dispersions of the variables are found and expressed in terms of means and dispersions of the charged particle coordinates and momenta. The characteristic function of the tomographic probability distribution is found. The center of mass tomogram of the coherent state of charge in magnetic field is also found and the relation of the symplectic tomogram and the center of mass tomogram is established.

Transverse motion of charged particle with oscillating charge in magnetic field

It is established that a particle bearing an oscillating electric charge can exhibit transverse drift in a homogeneous magnetic field. This drift has a resonance character and cannot be eliminated even at small amplitudes of charge oscillations.

Motion of charged particles in magnetic fields created by symmetric configurations of wires

In this paper we study the motion of a charged particle in the presence of a magnetic field created by three different systems of wires: an infinite rectilinear filament, a circular wire and the union of both. In the first case we prove that the equations of motion are Liouville integrable and we provide a complete description of the trajectories, which turn out to be of helicoidal type. In the case of the circular wire we study some restricted motions and we show that there is a trapping region similar to the Van Allen inner radiation belt in the Earth magnetosphere. We prove the existence of quasi-periodic orbits using Moser’s twist theorem, and the existence of scattering trajectories using differential inequalities. We also provide numerical evidence of Hamiltonian chaos and chaotic scattering by computing several Poincaré sections, Lyapunov exponents, fractal basins and their fractal dimensions. A similar study is done for the third system, although quasi-periodic orbits are proved to exist only under certain (perturbative) assumptions. From the viewpoint of the applications we propose a magnetic trap based on these configurations. Furthermore, the circular wire system can be interpreted as a simplified model of the levitated magnetic dipole–one of the recent proposals to confine a hot plasma for fusion power generation–and hence our work provides a verification of confinement and quasi-periodicity, beyond the adiabatic approximation, for this plasma system. Apart from contributing to the rigorous theory of the motion of charges in magnetic fields, this paper illustrates that very simple magnetic configurations can give rise to complicated, even chaotic trajectories, thus posing the question of how the complexity of magnetic lines affects the complexity of particle motions.

Magnetocaloric effect in silver-doped lanthanum manganites

The temperature and magnetic-field dependences of the magnetocaloric effect (MCE) in silverdoped manganites La0.9Ag0.1MnO3, La0.8Ag0.2MnO3, and La0.8Ag0.15MnO3 have been studied. Giant variations in the temperature of samples have been observed in response to a magnetic field charge by δH = 26 kOe. The MCE peaks in these compounds are observed in the vicinity of room temperature. A relationship between the sample preparation conditions and the magnetocaloric characteristics of samples has been established.

Critical problems of equatorial electrojet

This paper describes the general features of the equatorial electrojet current over the magnetic equator based on ground geomagnetic observatory data, rocket borne magnetometer data, ground based HF and VHF sounding of the atmosphere. Also are described its association with magnetosphere currents, interplanetary magnetic field charges and with Equatorial Ionisation anomaly and plasma irregularities in the F region. Distinct unsolved problems of equatorial electrojet are pointed and suggestions of coordinated investigations are made to understand the highly complex nature of equatorial electrojet.

On the motion of a charge in a magnetic field

The motion of a charge in a uniform magnetic field can be solved easily using an 'extra' constant of the motion which the author calls the Landau vector. Various physical situations are considered.