Two-dimensional investigation of characteristic parameters and their gradients for the self-generated electric and magnetic fields of laser-induced zirconium plasma

Two-dimensional diagnosis of laser-induced zirconium(Zr)plasma has been experimentally performed using the time-of-flight method by employing Faraday cups in addition to electric and magnetic probes.The characteristic parameters of laser-induced Zr plasma have been evaluated as a function of different laser irradiances ranging from 4.5 to 11.7 GW cm-2 at different axial positions of 1–4 cm with a fixed radial distance of 2 cm.A well-supporting correlation between the plume parameters and the laser-plasma-produced spontaneous electric and magnetic(E and B)fields was established.The measurements of the characteristic parameters and spontaneously induced fields were observed to have an increasing trend with the increasing laser irradiance.However,when increasing the spatial distance in both the axial and radial directions,the plasma parameters(electron/ion number density,temperature and kinetic energy)did not show either continuously increasing or decreasing trends due to various kinetic and dynamic processes during the spatial evolution of the plume.However,the E and B fields were observed to be always diffusing away from the target.The radial component of electron number densities remained higher than the axial number density component,whereas the axial ion number density at all laser irradiances and axial distances remained higher than the radial ion number density.The higher axial self-generated electric field(SGEF)values than radial SGEF values are correlated with the effective charge-separation mechanism of electrons and ions.The generation of a self-generated magnetic field is observed dominantly in the radial direction at increasing laser irradiance as compared to the axial one due to the deflection of fast-moving electrons and the persistence of two-electron temperature on the radial axis.

Electromagnetic Fields and Induced Voltages on Underground Pipeline in the Vicinity of AC Traction System

Various regulations, aimed at the protection of human beings and electrical equipment against possible adverse effects resulting from exposure to electromagnetic fields, have been issued in many countries. Most of them are based on safety guidelines published by international expert groups. In this paper, electric and magnetic fields are calculated in the vicinity of 25 kV traction line supplying railway traction systems. Calculation results are compared to exposure limits specified by safety guidelines and regulations. Possible countermeasures for reduction of electromagnetic fields are proposed. Also, this paper presents a method for calculation of the induced voltages to an underground gas pipeline from a neighbouring 25 kV electric traction overhead line in case of short circuit. Calculations are performed with EMTP-ATP software. Possible countermeasures for reduction of induced voltages are proposed.

Resonances of a hydrogen atom in strong parallel electric and magnetic fields using B-spline basis sets

The B-spline basis set plus complex scaling method is applied to the numerical calculation of the exact resonance parameters Er and Г/2 of a hydrogen atom in parallel electric and magnetic fields. The method can calculate the ground and higher excited resonances accurately and efficiently. The resonance parameters with accuracies of 10^-9 - 10^-12 for hydrogen atom in parallel fields with different field strengths and symmetries are presented and compared with previous ones. Extension to the calculation of Rydberg atom in crossed electric and magnetic fields and of atomic double excited states in external electric fields is discussed.

Research on hydrokinetics characteristics of rotating pipe fluid in the crossed electric and magnetic field

The rotating pipe fluid in the crossed electric and magnetic field not only suffered the forces in the steady condition, but also suffered Coriolis force, centrifugal force because of rotation and electromagnetic volume force. The motion equation of fluid and the hydrokinetics equations of rotating pipe were described in the Cartesians coordinates. The equations showed that the solutions to hydrokinetics equations of rotating pipe in the crossed electric and magnetic electromagnetic field were highly complicated and numerical calculations were also astronomical. The pressure distribution and temperature distribution of one dimension were solved using the electromagnetic equations set. The results showed that the fluid in rotating pipe was in the asymmetrical pressure field and temperature field because it was in the energy exchange and thermo-electrical coupling course. The primary characteristic of flow course could be expressed using the proposed hydrokinetics equations.

Heun Functions Describing Fermions Evolving in Parallel Electric and Magnetic Fields

The present work deals with the behavior of fermions moving in a static magnetic induction and a time-harmonic electric field, both oriented along Oz. For the ultra-relativistic particles described by a Heun double confluent equation, we derive the corresponding wave functions and the conserved current density components.

Electron Transport Behavior in a Mirror Magnetic Field and a Uniform Electric Field

A Monte Carlo simulation technique has been used to model the electron transport' behavior, especially the electron density and energy distributions under the influence of a mirror magnetic field and a uniform electric field in a positive column of helium direct current(DC) gas discharge Graphs showing the electron density and energy distributions, and the percentage of electrons that reach the wall and the end of the positive column are presented. The results indicate that the mirror magnetic field can control the electron transport behavior in the positive column which are in good agreement with experimental results.

Electron-Cyclotron Laser Using Free-Electron Two-Quantum Stark Radiation in a Strong Uniform Axial Magnetic Field and an Alternating Axial Electric Field in a Voltage-Supplied Pill-Box Cavity

We consider the radiation from the beam electrons traveling in a strong uniform axial magnetic field and an axial alternating electric field of wavelength Aw generated by a voltage-supplied pill-box cavity. The beam electrons emit genuine laser radiation that propagates only in the axial direction through free-electron two- quantum Stark radiation. We find that laser radiation takes place only at the expense of the axial kinetic energy when Aw 〈〈 c/（ωc/γ）, where ωc/γ is the relativistic electron--cyclotron frequency. We formulate the laser power based on quantum-wiggler electrodynamics, and envision a laser of length lore with estimated power 0.1 GW/（kA） in the 10-4 cm wavelength range.

Electric field control of deterministic current-induced magnetization switching in a hybrid ferromagnetic/ferroelectric structure

Subject Code:F04 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Wang Kaiyou(王开友)from the Institute of Semiconductors,Chinese Academy of Sciences demonstrates all-electric and programmable manipulations of ferromagnetic bits without external

Microstructure evolution of immiscible alloy solidified under the effect of composite electric and magnetic fields

Solidification experiments were performed with Lead-Aluminum immiscible alloy under the effect of composite electric and magnetic fields(CEMFs).The results demonstrate that CEMFs not only decrease the size of minority phase particles(MPPs)but also promote a more uniform distribution of the MPPs.A theoretical model was built to describe the microstructure evolution during cooling the immiscible alloy.The solidification process of Pb-0.4 wt.%Al alloy under the effect of the CEMFs was simulated.The numerical results are well consistent with the experimental data.These results demonstrate that CEMFs affect the solidification process through changing melt convection and the nucleation behavior of minority phase droplets(MPDs).On one hand,the CEMFs can inhibit the convection and lead to the homogeneous distribution of MPPs along the radial direction of the sample.On the other hand,the CEMFs can increase the nucleation driving force for the MPDs,which decreases the average radius of MPDs and boosts the formation of dispersed solidification structures.This research indicates that the application of CEMFs is a promising strategy for controlling the microstructure of immiscible alloys.

Chiral symmetry restoration and deconfinement in the contact interaction model of quarks with parallel electric and magnetic fields

We study the impact of steady,homogeneous,and external parallel electric and magnetic field strengths(eE||eB)on the chiral symmetry breaking-restoration and confinement-deconfinement phase transition.We also sketch the phase diagram of quantum chromodynamics(QCD)at a finite temperature T and in the presence of background fields.The unified formalism for this study is based on the Schwinger-Dyson equations,symmetry preserving vector-vector contact interaction model of quarks,and an optimal time regularization scheme.At T=0,in the purely magnetic case(i.e.,eE→0),we observe the well-known magnetic catalysis effect.However,in a pure electric field background(eB→0),the electric field tends to restore the chiral symmetry and deconfinement above the pseudo-critical electric field eE^(x,C)_(c).In the presence of both eE and eB,we determine the magnetic catalysis effect in the particular region where eB dominates over eE,whereas we observe the chiral inhibition(or electric chiral rotation)effect when eE overshadows eB.At finite T,in the pure electric field case,the phenomenon of inverse electric catalysis appears to exist in the proposed model.Conversely,for a pure magnetic field background,we observe the magnetic catalysis effect in the mean-field approximation and inverse magnetic catalysis with eB-dependent coupling.The combined effects of eE and eB on the pseudo-critical T^(x,C)_(c)yields an inverse electromagnetic catalysis,with and without an eB-dependent effective coupling of the model.The findings of this study agree well with the already predicted results obtained via lattice simulations and other reliable effective models of QCD.

Anisotropic transport properties in the phase-separated La_(0.67)Ca_(0.33)MnO_3/NdGaO_3 (001) films

The anisotropic transport property was investigated in a phase separation La（0.67）Ca（0.33）MnO3（LCMO） film grown on（001）-oriented Nd GaO3（NGO） substrate. It was found that the resistivity along the b-axis is much higher than that along the a-axis. Two resistivity peaks were observed in the temperature dependent measurement along the b-axis, one located at 91 K and the other centered at 165 K. Moreover, we also studied the response of the resistivities along the two axes to various electric currents, magnetic fields, and light illuminations. The resistivities along the two axes are sensitive to the magnetic field. However, the electric current and light illumination can influence the resistivity along the b-axis obviously, but have little effect on the resistivity along the a-axis. Based on these results, we believe that an anisotropicstrain-controlled MnO6 octahedra shear-mode deformation may provide a mechanism of conduction filaments paths along the a-axis, which leads to the anisotropic transport property.

Photon Structure and Wave Function from the Vector Potential Quantization

A photon structure is advanced based on the experimental evidence and the vector potential quantization at a single photon level. It is shown that the photon is neither a point particle nor an infinite wave but behaves rather like a local “wave-corpuscle” extended over a wavelength, occupying a minimum quantization volume and guided by a non-local vector potential real wave function. The quantized vector potential oscillates over a wavelength with circular left or right polarization giving birth to orthogonal magnetic and electric fields whose amplitudes are proportional to the square of the frequency. The energy and momentum are carried by the local wave-corpuscle guided by the non-local vector potential wave function suitably normalized.

Stellar structure of magnetars

Magnetars are strong magnetized neutron stars which could emit quiescent X-ray, repeating burst of soft gamma ray, and even the giant flares. We investigate the effects of magnetic fields on the structure of isolated magnetars. The stellar structure together with the magnetic field configuration can be obtained at the same time within a self-consistent procedure. The magnetar mass and radius are found to be weakly enhanced by the strong magnetic fields. Unlike other previous investigations, the magnetic field is unable to violate the mass limit of the neutron stars.