scholarly journals Generation of Magnetic Fields and Electric Currents in the Solar Photosphere

1990 ◽  
Vol 138 ◽  
pp. 273-277
Author(s):  
J.C. Henoux ◽  
B.V. Somov
Keyword(s):  
Magnetic Field ◽  
Radial Dependence ◽  
Field Energy ◽  
Solar Photosphere ◽  
Fluid Approximation ◽  
Flux Tubes ◽  
Magnetic Field Energy ◽  
Field Energy Density ◽  
Dc Current ◽  
The Magnetic Field

Velocities of electrons, ions and neutrals are computed in the three-fluid approximation for an axisymmetrical magnetic field. By prescribing a radial dependence of the velocity of neutrals in agreement with a downflow, the radial dependence of the magnetic field energy density is derived for a given set of values of the magnetic field at the central and external boundaries. Flux-tube cooling by advection of ionization energy is found to be significant. Vortices in the low photosphere could produce significant electric power and DC current intensity along the coronal magnetic lines of forces. The velocities of neutrals, the size and the number of flux-tubes required to power flares in plage regions, are estimated.

scholarly journals On the fractal nature of the magnetic field energy density in the solar wind

2007 ◽  
Vol 34 (15) ◽  
Author(s):  
B. Hnat ◽  
S. C. Chapman ◽  
K. Kiyani ◽  
G. Rowlands ◽  
N. W. Watkins
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Energy Density ◽  
Field Energy ◽  
Fractal Nature ◽  
Magnetic Field Energy ◽  
Field Energy Density ◽  
The Magnetic Field

scholarly journals Finite size scaling in the solar wind magnetic field energy density as seen by WIND

2002 ◽  
Vol 29 (10) ◽  
pp. 86-1-86-4 ◽  
Author(s):  
B. Hnat ◽  
S. C. Chapman ◽  
G. Rowlands ◽  
N. W. Watkins ◽  
W. M. Farrell
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Energy Density ◽  
Finite Size ◽  
Field Energy ◽  
Finite Size Scaling ◽  
Size Scaling ◽  
Magnetic Field Energy ◽  
Solar Wind Magnetic Field ◽  
Field Energy Density

scholarly journals PRESSURE OF DEGENERATE AND RELATIVISTIC ELECTRONS IN A SUPERHIGH MAGNETIC FIELD

2013 ◽  
Vol 28 (36) ◽  
pp. 1350138 ◽  
Author(s):  
ZHI FU GAO ◽  
NA WANG ◽  
QIU HE PENG ◽  
XIANG DONG LI ◽  
YUAN JIE DU
Keyword(s):  
Magnetic Field ◽  
Oblate Spheroid ◽  
Field Energy ◽  
Relativistic Electrons ◽  
Positive Contribution ◽  
High Electron ◽  
Electron Pressure ◽  
Magnetic Field Energy ◽  
Qed Effects ◽  
The Magnetic Field

Based on our previous work, we deduce a general formula for pressure of degenerate and relativistic electrons, Pe, which is suitable for superhigh magnetic fields, discuss the quantization of Landau levels of electrons, and consider the quantum electrodynamic (QED) effects on the equations of states (EOSs) for different matter systems. The main conclusions are as follows: Pe is related to the magnetic field B, matter density ρ, and electron fraction Ye; the stronger the magnetic field, the higher the electron pressure becomes; the high electron pressure could be caused by high Fermi energy of electrons in a superhigh magnetic field; compared with a common radio pulsar, a magnetar could be a more compact oblate spheroid-like deformed neutron star (NS) due to the anisotropic total pressure; and an increase in the maximum mass of a magnetar is expected because of the positive contribution of the magnetic field energy to the EOS of the star.

scholarly journals New Superconductivity and Theoretical Study on a New Phenomenon of Energy Source with Assistance of Initial Experiments

2018 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Magnetic Field ◽  
Energy Source ◽  
Electrostatic Field ◽  
Theoretical Study ◽  
Depletion Layer ◽  
Field Energy ◽  
Magnetic Field Energy ◽  
New Type ◽  
The Magnetic Field ◽  
A Current

We previously reported new superconductivity produced by an electrostatic field and a diffusion current in a semiconductor without refrigeration. In particular, the superconductivity was investigated theoretically and confirmed experimentally. Here, we determine that the derived superconducting quantum state can be reproduced in a capacitor. When circuits are formed with this new-type capacitor and diodes, a magnetic field is applied to the diodes’ depletion layer. The depletion layer is biased because of the conversion from the magnetic-field energy to electric-field energy, resulting in the diodes’ spontaneously emitting a current. Thus, the new-type capacitor is charged using no other energy source. This new phenomenon is described theoretically with assistance of initial experiments.

Variations in the ratio of particle to magnetic field energy density, as observed by Ulysses/HI-SCALE

1999 ◽  
Vol 24 (1-3) ◽  
pp. 79-81 ◽  
Author(s):  
G. Kasotakis ◽  
E.T. Sarris ◽  
P. Marhavilas ◽  
N. Sidiropoulos ◽  
P. Trochoutsos ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Energy Density ◽  
Field Energy ◽  
Magnetic Field Energy ◽  
Field Energy Density

The interaction between a weak magnetic field and a black hole

1977 ◽  
Vol 356 (1686) ◽  
pp. 351-362 ◽  
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Angular Momentum ◽  
Asymptotic Form ◽  
Rotation Axis ◽  
Field Energy ◽  
Magnetic Field Energy ◽  
Teukolsky Equation ◽  
Field Energy Density ◽  
Component Parallel

The problem investigated is: what happens to a rotating black hole sunk in a vacuum magnetic field, constantly aligned at angle γ to its rotation axis far from the hole? The Newman-Penrose quantities Φ 0 and ρ -2 Φ 2 , which describe the radiation parts of the external field, are obtained as solutions to the Teukolsky equation with appropriate boundary conditions. From these two quantities the complete distant asymptotic form of the electromagnetic field is constructed via the four-vector potential A i , it by using the method of Chandrasekhar. Changes in the angular momentum of the hole are calculated. The component perpendicular to the field decreases exponentially with time according to the law J ⊥ = ( J ⊥ ) initial exp (- t ⊤ -1 ), Where ⊤ -1 =16/3 π G 2 c -5 (mass of hole) x (distant magnetic field energy-density), while the component parallel to the field remains constant. No energy emerges from the hole, kinetic rotational energy instead transforming into irreducible mass. This is precisely the outcome known from study of the slowly rotating hole. Extension of the result is of astrophysical relevance, since a real black hole may be rotating relatively fast. And it is of some theoretical interest that terms of second and higher order in angular momentum make no difference to the spin-down behaviour.

scholarly journals The flux compression generator load parameters selection

2019 ◽  
Vol 28 ◽  
pp. 01002
Author(s):  
Mirosław Wołoszyn ◽  
Daniel Kowalak ◽  
Kazimierz Jakubiuk ◽  
Mikołaj Nowak
Keyword(s):  
Magnetic Field ◽  
Gain Factor ◽  
Current Gain ◽  
Field Energy ◽  
Simulation Research ◽  
Magnetic Field Energy ◽  
Flux Compression ◽  
Parameters Selection ◽  
Simulation Results ◽  
The Magnetic Field

Computer simulation results of the flux compression generator (FCG) loaded with an inductor has been presented in this paper. Simulation research has been performed in order to select the parameters of FCG load coil properly. The influence of the load inductance and resistance on the current gain factor and the magnetic field energy accumulated in a load coil has been investigated.

scholarly journals Research on Descaling Characteristics and Simulation Calculation of a Coaxial High-Frequency Electronic Descaling Device

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 789
Author(s):  
Yan Zhao ◽  
Lixin Zhang ◽  
Xin Zhao ◽  
Jin Liu ◽  
Ming Gao
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Magnetic Flux ◽  
High Frequency ◽  
Field Energy ◽  
Wave Excitation ◽  
Magnetic Field Energy ◽  
High Frequency Electromagnetic Field ◽  
The Magnetic Field ◽  
Peak Value

High-frequency electronic descaling devices are physical water treatment methods that use a high-frequency electromagnetic field to prevent and remove scale. The effectiveness of the method is verified by monitoring the growth of scale on the surface of heat exchange tubes. The microstructure of scale obtained from experiments is analyzed by scanning electron microscope (SEM), and the action characteristics of high-frequency electromagnetic fields on water are explored by observing the change of solution contact angle at different times. The experimental results show that the high-frequency electromagnetic field can slow down the scaling growth on the surface of heat exchange tubes by changing the morphology of scaling substances and the physicochemical properties of water. The cavity of the instrument is modeled and simulated by ANSYS Maxwell, and the three operating parameters, waveform, voltage and frequency, are changed respectively. The performance parameters of the cavity, such as magnetic field energy, electric field energy and magnetic flux, are calculated and compared, and then the more suitable operating parameters are selected to improve the performance of the instrument. The simulation results show that the high-frequency electromagnetic field generated by the anode rod in the axial position can be overlooked compared with the magnetic field energy. Square wave excitation produces greater magnetic field energy than using sine wave excitation, and as the voltage increases, the peak value of the magnetic field energy continues to rise and increases faster. With an increase in the frequency, the peak value of the magnetic field energy and magnetic flux peak will maintain a slight decrease over a certain frequency range. After this frequency range, the peak value of magnetic field energy and magnetic flux peak will decrease rapidly. This decrease is due to the relaxation caused by the change of the waveform direction. The influence of time and an increase in the frequency will significantly increase the influence of the relaxation time.

Tearing instability inside a 2D current sheet with a normal magnetic field

2021 ◽  
Author(s):  
Chen Shi ◽  
Anton Artemyev ◽  
Marco Velli ◽  
Anna Tenerani
Keyword(s):  
Magnetic Field ◽  
Magnetic Reconnection ◽  
Current Sheet ◽  
Normal Component ◽  
Field Energy ◽  
Tearing Mode ◽  
Magnetic Field Energy ◽  
Tearing Instability ◽  
The Magnetic Field ◽  
Normal Magnetic Field

<p>Magnetic reconnection converts the magnetic field energy into thermal and kinetic energies of the plasma. This process usually happens at extremely fast speed and is therefore believed to be a fundamental mechanism to explain various explosive phenomena such as coronal mass ejections and planetary magnetospheric storms. How magnetic reconnection is triggered from the large magnetohydrodynamic (MHD) scales remains an open question, with some theoretical and numerical studies showing the tearing instability to be involved. Observations in the Earth’s magnetotail and near the magnetopause show that a finite normal magnetic field is usually present inside the reconnecting current sheet. Besides, such a normal field may also exist in the solar corona. However, how this normal magnetic field modifies the tearing instability is not thoroughly studied. Here we discuss the linear tearing instability inside a two-dimensional current sheet with a normal component of magnetic field where the magnetic tension force is balanced by ion flows parallel and anti-parallel to the magnetic field. We solve the dispersion relation of the tearing mode with wave vector parallel to the reconnecting magnetic field. Our results confirm that the finite normal magnetic field stabilizes the tearing mode and makes the mode oscillatory instead of purely growing.</p>

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