scholarly journals The mathematical modeling of magnetic systems with rectangular structure for different experiments

2021 ◽  
Author(s):  
R.V. Polyakova ◽  
E.E. Perepyolkin ◽  
A.D. Kovalenko ◽  
A.A. Tarelkin
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Field ◽  
Inverse Problem ◽  
Numerical Modeling ◽  
Magnetic Systems ◽  
Direct Problems ◽  
The Magnetic Field ◽  
Inverse Problem Of Magnetostatics ◽  
Optimal Construction ◽  
Design Construction

Design, construction and operation of the magnetic systems of some electrophysical setups require a preliminary mathematical modeling as well as a constant maintenance of mathematical modeling when debugging and operating the setups. While calculating the fields of the mentioned magnetic systems (on the base of solving a number of the direct problems of magnetostatics), we are concerned with the inverse problem of magnetostatics, namely, an optimal construction of the current elements and ferromagnetic yoke was found resulting in the expected distribution of the magnetic field. This work discusses the results on the numerical modeling of the distributing magnetic field for some modifications of the spectrometric magnet SP-94, SP-40 and the magnet of solenoid type, weach used in some experimental setups.

MATHEMATICAL MODELING OF TEMPERATURE EFFECT ON THE FAN CHART OF MAGNETOABSORPTION SPECTRUM IN SEMICONDUCTORS

2019 ◽  
pp. 104-115
Author(s):  
G. Gulyamov ◽  
U. I. Erkaboev ◽  
A. G. Gulyamov
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Field ◽  
Temperature Dependence ◽  
Density Of States ◽  
Landau Levels ◽  
Joint Density ◽  
Narrow Gap ◽  
Narrow Gap Semiconductors ◽  
Dispersion Law ◽  
The Magnetic Field

The article considers the oscillations of interband magneto-optical absorption in semiconductors with the Kane dispersion law. We have compared the changes in oscillations of the joint density of states with respect to the photon energy for different Landau levels in parabolic and non-parabolic zones. An analytical expression is obtained for the oscillation of the combined density of states in narrow-gap semiconductors. We have calculated the dependence of the maximum photon energy on the magnetic field at different temperatures. A theoretical study of the band structure showed that the magnetoabsorption oscillations decrease with an increase in temperature, and the photon energies nonlinearly depend on a strong magnetic field. The article proposes a simple method for calculating the oscillation of joint density of states in a quantizing magnetic field with the non-quadratic dispersion law. The temperature dependence of the oscillations joint density of states in semiconductors with non-parabolic dispersion law is obtained. Moreover, the article studies the temperature dependence of the band gap in a strong magnetic field with the non-quadratic dispersion law. The method is applied to the research of the magnetic absorption in narrow-gap semiconductors with nonparabolic dispersion law. It is shown that as the temperature increases, Landau levels are washed away due to thermal broadening and density of states turns into a density of states without a magnetic field. Using the mathematical model, the temperature dependence of the density distribution of energy states in strong magnetic fields is considered. It is shown that the continuous spectrum of the density of states, measured at the temperature of liquid nitrogen, at low temperatures turns into discrete Landau levels. Mathematical modeling of processes using experimental values of the continuous spectrum of the density of states makes it possible to calculate discrete Landau levels. We have created the three-dimensional fan chart of magneto optical oscillations of semiconductors with considering for the joint density of energy states. For a nonquadratic dispersion law, the maximum frequency of the absorbed light and the width of the forbidden band are shown to depend nonlinearly on the magnetic field. Modeling the temperature  dependence allowed us to determine the Landau levels in semiconductors in a wide temperature spectrum. Using the proposed model, the experimental results obtained for narrow-gap semiconductors are analyzed. The theoretical results are compared with experimental results.

Mathematical modeling of the nonlinear electrodynamics effect of signal delay in the magnetic field of pulsars

2015 ◽  
Vol 55 (11) ◽  
pp. 1857-1866 ◽  
Author(s):  
M. G. Gapochka ◽  
M. M. Denisov ◽  
I. P. Denisova ◽  
N. V. Kalenova ◽  
A. F. Korolev
Keyword(s):  
Mathematical Modeling ◽  
Magnetic Field ◽  
Nonlinear Electrodynamics ◽  
Signal Delay ◽  
The Magnetic Field

The interface of a uniform plasma enveloped by the magnetic field of a system of line currents

1969 ◽  
Vol 3 (4) ◽  
pp. 651-660 ◽  
Author(s):  
C. Sozou
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Complex Variable ◽  
Field Boundary ◽  
Equilibrium Configurations ◽  
Minimum Number ◽  
The Magnetic Field ◽  
Uniform Plasma

It is shown that complex variable transformations, suitable for obtaining the solution for the field boundary of a system of line currents confined in one cavity by a perfectly conducting uniform plasma, can be used for obtaining the solution to the inverse problem where a perfectly conducting uniform plasma is confined in one cavity by a system of line currents. It is deduced that the minimum number of line currents for confining (not stably) a plasma is two. The equilibrium configurations for several special but simple cases are investigated and discussed.

scholarly journals Accretion Disc Formation in Intermediate Polars

1996 ◽  
Vol 158 ◽  
pp. 161-164
Author(s):  
G. A. Wynn ◽  
A. R. King
Keyword(s):  
Magnetic Field ◽  
Accretion Disc ◽  
Local Magnetic Field ◽  
Magnetic Systems ◽  
X Ray ◽  
Accretion Flow ◽  
Intermediate Polars ◽  
X Ray Binaries ◽  
The Magnetic Field ◽  
Disc Formation

The large-scale accretion flow in the intermediate polars (IPs) is still a matter of vigorous debate. It is known that the magnetic field of the white dwarf (WD) controls the accretion flow close to the surface, channeling the plasma onto the polecaps and giving rise to X-ray emission modulated at the WD spin period (Pspin). After their discovery it was assumed that IPs were the WD analogues of the pulsing X-ray binaries, where a magnetic neutron star accretes from a disrupted accretion disc. However, a number of authors have pointed out that the criteria for disc formation in IPs are less certain than those for the X-ray binaries.The simplest possible criterion for disc formation in a binary is that the accretion flow should be able to orbit freely about the primary star (see Frank, King & Raine 1991 for a review). In non-magnetic systems this is merely the condition that the minimum approach distance of the free stream (Rmin) should exceed the radius of the primary. The situation in magnetic systems is more complex, as the magnetic field of the primary presents an obstacle to the infalling accretion stream. In many treatments of IPs it is assumed that the plasma stream is able to orbit freely about the WD until the ram pressure of the stream is of the same order as the magnetic pressureρv2~B2/8π, whereρis the stream density,vthe stream velocity andBthe local magnetic field strength. This condition fixes the magnetospheric radius,Rmag, inside which the magnetic field is assumed to thread the stream material and direct the accretion flow along the fieldlines.

scholarly journals Electromagnetic system for detection and localization of the miners caught by accident in mine

2016 ◽  
Author(s):  
Vira Pronenko ◽  
Fedir Dudkin
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Low Frequency ◽  
Emergency Situation ◽  
Field Measurements ◽  
Experimental Tests ◽  
Problem Solution ◽  
Electromagnetic System ◽  
Field Source ◽  
The Magnetic Field

Abstract. The profession of a miner is one of the most dangerous in the world. Among the main causes of the fatalities in the underground coal mines is the untimely alerting of the accident, as well as the lack of information for the rescuers about the actual location of the miners after the accident. In an emergency situation (failure or destruction of underground infrastructure), personnel search behind and beneath of blockage should be provided urgently. But none of the standard technologies (RFID, DECT, WiFi, emitting cable), which use the stationary technical devices in mines, provides the information about the people location caught by accident with necessary precision. The only technology that is able to provide guaranteed delivery of messages about the accident to the mine personnel, regardless of their location and under any destruction in the mine, is low-frequency radio technology able to operate through the thickness of rocks even if it is wet. The proposed new system for miners localization is based on solving the inverse problem that allows the magnetic field source coordinates determining using the data of magnetic field measurements. This approach is based on the measurement of the magnetic field radiated by the miner's responder beacon using two fixed and spaced three-component magnetic field receivers and next the inverse problem solution. As a result, the working model of the system for miner's beacon search and localization (MILES – miner's location emergency system) was developed and successfully tested. The paper presents the peculiarities of this development and the results of experimental tests.

scholarly journals Determination Transition Resistance of Cathode-Polarized Main Pipeline on Magnetometery Data

2021 ◽  
Vol 6 (6) ◽  
pp. 1729-1740
Author(s):  
Vladimir N. Krizsky ◽  
Pavel N. Alexandrov ◽  
Alexey A. Kovalskii ◽  
Sergey V. Victorov
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Cathodic Protection ◽  
Magnetic Induction ◽  
Solution Method ◽  
Main Pipeline ◽  
Induction Vector ◽  
Magnetic Induction Vector ◽  
Transition Resistance ◽  
The Magnetic Field

The article deals with the inverse problem of determining the transient resistance of the main pipeline insulating coating. For this, UAV measurements of the magnetic induction vector modulus of the magnetic field excited by the system of electrochemical cathodic protection of pipelines are used. The solution method is based on Tikhonov's method for finding the extremal of the regularizing functional. The developed algorithm is implemented in software. The results of computational experiments are presented.

scholarly journals Computer technology for interpreting vector measurements of the magnetic field

2021 ◽  
Vol 43 (5) ◽  
pp. 219-231
Author(s):  
T. L. Mikheevа ◽  
O. P. Lapinа
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Computer Technology ◽  
Initial Approximation ◽  
Field Vector ◽  
Automated System ◽  
Geological Interpretation ◽  
Algorithmic Support ◽  
Vector Information ◽  
The Magnetic Field

Computer technology is presented to solve the inverse problem of magnetic field vector measurements using software and algorithmic support for an automated system to interpret potential fields. The technology includes constructing a numerical model of the magnetic field of the studied area, forming an initial approximation model, assessing the depth of the sources and their magnetization. An approximation structure is used to describe the sources of anomalies (a set of uniformly magnetized polygonal prisms). To solve the problem, we used real vector measurements of the magnetic field by the components Xа, Ya, Zа, Та in the sections of Gruzsko South and Gruzsko Severnaya. Geologically, the area belongs to the central part of the Ukrainian Shield — the Kirovograd tectonic megablock. The area of work is confined to the Subotsko-Moshorin latitudinal fault zone. The possibility of comparing the results of the interpretation of anomalies on each profile by the components of the anomalous magnetic field increases the reliability of the geological interpretation of magnetic prospecting data compared to the interpretation of modular surveys. The presence of vector measurements greatly facilitates the ability to determine the parameters of anomalous objects, which makes it possible to obtain more reliable solutions to the inverse problem. The use of vector information makes it possible to localize geological sources more successfully, thereby reducing the amount of work.

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