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.

Nonlinear evolution of a wave packet propagating along a hot magnetoplasma column

1987 ◽  
Vol 37 (1) ◽  
pp. 107-115
Author(s):  
B. Ghosh ◽  
K. P. Das
Keyword(s):  
Magnetic Field ◽  
Multiple Scales ◽  
Nonlinear Evolution ◽  
Axial Magnetic Field ◽  
Modulational Instability ◽  
Wave Train ◽  
Dielectric Medium ◽  
Ion Effects ◽  
The Magnetic Field ◽  
Uniform Plasma

The method of multiple scales is used to derive a nonlinear Schrödinger equation, which describes the nonlinear evolution of electron plasma ‘slow waves’ propagating along a hot cylindrical plasma column, surrounded by a dielectric medium and immersed in an essentially infinite axial magnetic field. The temperature is included as well as mobile ion effects for ail possible modes of propagation along the magnetic field. From this equation the condition for modulational instability for a uniform plasma wave train is determined.

Fast magnetic field penetration into low resistivity plasma

2017 ◽  
Vol 83 (1) ◽  
Author(s):  
Amnon Fruchtman
Keyword(s):  
Magnetic Field ◽  
Energy Dissipation ◽  
Electric Field ◽  
Density Gradient ◽  
Magnetic Energy ◽  
Measured Velocity ◽  
Magnetic Field Penetration ◽  
The Magnetic Field ◽  
Uniform Plasma ◽  
Field Penetration

Penetration of a magnetic field into plasma that is faster than resistive diffusion can be induced by the Hall electric field in a non-uniform plasma. This mechanism explained successfully the measured velocity of the magnetic field penetration into pulsed plasmas. Major related issues have not yet been resolved. Such is the theoretically predicted, but so far not verified experimentally, high magnetic energy dissipation, as well as the correlation between the directions of the density gradient and of the field penetration.

scholarly journals Nonlinear translational symmetric equilibria relevant to the L–H transition

2012 ◽  
Vol 79 (3) ◽  
pp. 257-265 ◽  
Author(s):  
Ap. KUIROUKIDIS ◽  
G. N. THROUMOULOPOULOS
Keyword(s):  
Magnetic Field ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Plasma Flow ◽  
Sufficient Condition ◽  
Sheared Flow ◽  
Equilibrium Configurations ◽  
Shafranov Equation ◽  
The Impact ◽  
The Magnetic Field

AbstractNonlinear z-independent solutions to a generalized Grad–Shafranov equation (GSE) with up to quartic flux terms in the free functions and incompressible plasma flow non-parallel to the magnetic field are constructed quasi-analytically. Through an ansatz, the GSE is transformed to a set of three ordinary differential equations and a constraint for three functions of the coordinate x, in Cartesian coordinates (x,y), which then are solved numerically. Equilibrium configurations for certain values of the integration constants are displayed. Examination of their characteristics in connection with the impact of nonlinearity and sheared flow indicates that these equilibria are consistent with the L–H transition phenomenology. For flows parallel to the magnetic field, one equilibrium corresponding to the H state is potentially stable in the sense that a sufficient condition for linear stability is satisfied in an appreciable part of the plasma while another solution corresponding to the L state does not satisfy the condition. The results indicate that the sheared flow in conjunction with the equilibrium nonlinearity plays a stabilizing role.

scholarly journals Formation of an elongated plasma column by a magnetic confinement of a laser-produced plasma

1992 ◽  
Vol 10 (4) ◽  
pp. 767-776 ◽  
Author(s):  
T. Pisarczyk ◽  
A. Faryński ◽  
H. Fiedorowicz ◽  
P. Gogolewski ◽  
M. Kuśnierz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Laser Plasma ◽  
Plasma Column ◽  
Target Region ◽  
X Ray ◽  
Laser Probing ◽  
Single Turn ◽  
Magnetic Coils ◽  
The Magnetic Field ◽  
Uniform Plasma

In this article, we present the formation of an elongated plasma column by combining a laser plasma with an external magnetic field. The laser plasma is produced by irradiating solid targets with a focused Nd-glass laser. The targets were placed on the axis of the two, single-turn magnetic coils, which provided a magnetic field up to 500 kg in the target region. The expanding laser plasma is confined by the magnetic field and an elongated and uniform plasma column is formed on the axis of the coils. The plasma column emits strong, soft X-ray radiation. The pinhole photographs show that the plasma column is at least 5 mm long. To study the interaction of the expanding laser plasma with a magnetic field, the laser probing diagnostic was used.

scholarly journals Side-conditioned axisymmetric equilibria with incompressible flows

2008 ◽  
Vol 74 (3) ◽  
pp. 327-344 ◽  
Author(s):  
G. N. THROUMOULOPOULOS ◽  
H. TASSO ◽  
G. POULIPOULIS
Keyword(s):  
Magnetic Field ◽  
Incompressible Flows ◽  
Plasma Temperature ◽  
Magnetic Axis ◽  
Toroidal Shell ◽  
Initial Value ◽  
Magnetic Field Topology ◽  
Equilibrium Configurations ◽  
Magnetic Surfaces ◽  
The Magnetic Field

AbstractAxisymmetric equilibria with incompressible flows of arbitrary direction are studied in the framework of magnetohydrodynamics under a variety of physically relevant side conditions consisting, for example, in that the plasma temperature or the magnetic field modulus are uniform on magnetic surfaces. To this end a set of pertinent nonlinear ordinary differential equations (ODEs) are transformed to quasilinear ODEs and the respective initial value problem is solved numerically with appropriately determined initial values near the magnetic axis. Several equilibrium configurations are then constructed surface by surface. It turns out that in addition to the usual configurations with a magnetic axis, the non-field aligned flow results to novel toroidal shell equilibria in which the plasma is confined within a couple of magnetic surfaces. In addition, the flow affects the elongation and triangularity of the magnetic surfaces and opens up the possibility of changing the magnetic field topology by creating double toroidal shell-like configurations.

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.

scholarly journals Electromagnetic system for detection and localization of miners caught in mine accidents

2016 ◽  
Vol 5 (2) ◽  
pp. 561-566 ◽  
Author(s):  
Vira Pronenko ◽  
Fedir Dudkin
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Radio Frequency Identification ◽  
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 fatalities in underground coal mines are the delayed alert of the accident and the lack of information regarding the actual location of the miners after the accident. In an emergency situation (failure or destruction of underground infrastructure), personnel search behind and beneath blockage needs to be performed urgently. However, none of the standard technologies – radio-frequency identification (RFID), Digital Enhanced Cordless Telecommunications (DECT), Wi-Fi, emitting cables, which use the stationary technical devices in mines – provide information about the miners location with the necessary precision. The only technology that is able to provide guaranteed delivery of messages to mine personnel, regardless of their location and under any destruction in the mine, is low-frequency radio technology, which is able to operate through the thickness of rocks even if they are wet. The proposed new system for miner localization is based on solving the inverse problem of determining the magnetic field source coordinates 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 the inverse problem solution. As a result, a working model of the system for miner's beacon search and localization (MILES – MIner's Location Emergency System) was developed and successfully tested. This paper presents the most important aspects of this development and the results of experimental tests.

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