scholarly journals Effect of magnetic field on plasma characteristics in magnetron discharge with hollow cathode

2021 ◽  
Vol 25 ◽  
pp. 125-130
Author(s):  
S.V. Klad’ko ◽  
◽  
N.P. Poluektov ◽  
I.I. Usatov ◽  
◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hollow Cathode ◽  
Permanent Magnets ◽  
Complex Geometry ◽  
Experimental Studies ◽  
Plasma Parameters ◽  
Magnetron Discharge ◽  
Plasma Characteristics ◽  
The Magnetic Field

The effect of magnetic field on plasma characteristics in a magnetron with a hollow cathode was carried out. The magnetic field in this device is of complex geometry, since it consists of many permanent magnets and an electromagnet. The calculated geometries of the magnetic field were used in experimental studies. Measurements have shown that the magnitude and geometry of the magnetic field have a strong effect on the plasma parameters.

MAIN CHARACTERISTICS ELECTRIC VIBRATORS BASED ON A LINEAR MOTOR WITH PERMANENT MAGNETS

2021 ◽  
Vol 4 (3) ◽  
pp. 4-10
Author(s):  
Kamoliddin Oqyolov ◽  
◽  
Nurzod Abduqodirov ◽  
Gulnoza Jalilova ◽  
Nuriddin Abduxakimov
Keyword(s):  
Magnetic Field ◽  
Permanent Magnets ◽  
Experimental Studies ◽  
Calculated Data ◽  
Linear Motor ◽  
Stator Winding ◽  
The Finite Element Method ◽  
Magnetic Forces ◽  
Electro Magnetic ◽  
The Magnetic Field

The design of an electric vibrator created on the basis of a linear motor with permanent magnets is considered, and the calculation of the magnetic field and the electromagnetic force acting on the motor armature is performed by the finite element method. The results of experimental studies confirming the reliability of the obtained calculated data are presented]. The purpose of this work is to study the distribution of the magnetic field and the electro-magnetic forces in a coaxial-linear permanent magnet electric motor (PM), which is the basis for the creation of avibration installationKeywords: vibration, magnets, magnetic induction, stator winding, electric vibrator

Radial Emission Profiles for a Hollow Cathode Glow Discharge in an Axial Magnetic Field

1989 ◽  
Vol 43 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Regis Simonneau ◽  
Richard Sacks
Keyword(s):  
Magnetic Field ◽  
Hollow Cathode ◽  
Neutral Atom ◽  
Permanent Magnets ◽  
Cathode Surface ◽  
Axial Magnetic Field ◽  
Cathode Plasma ◽  
Spatially Resolved ◽  
The Magnetic Field ◽  
The Continuum

Spatially resolved emission measurements are used to characterize the changes in plasma structure resulting from the application of an external magnetic field to an Ar hollow cathode plasma. The field is generated by ring-shaped permanent magnets which are coaxial with the cathode. The magnetic field is normal to the cathode surface and thus forms electron traps which reduce the rate of electron transport normal to the cathode surface. At lower lamp pressure, the magnetic field dramatically changes the spatial distribution of the continuum background and Ar ion radiation. Radiation from neutral-atom cathode material also is affected by the field. The magnetic field has less influence at higher pressure where collisional effects are larger.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

scholarly journals What Density of Magnetosheath Sodium Ions Can Provide the Observed Decrease in the Magnetic Field of the “Double Magnetopause” during the First MESSENGER Flyby?

Symmetry ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1168
Author(s):  
Elena Belenkaya ◽  
Ivan Pensionerov
Keyword(s):  
Magnetic Field ◽  
Analytical Approach ◽  
Field Structure ◽  
Sodium Ions ◽  
Plasma Parameters ◽  
Calculation Results ◽  
Magnetizing Current ◽  
The Magnetic Field ◽  
Density Excess

On 14 January 2008, the MESSENGER spacecraft, during its first flyby around Mercury, recorded the magnetic field structure, which was later called the “double magnetopause”. The role of sodium ions penetrating into the Hermean magnetosphere from the magnetosheath in generation of this structure has been discussed since then. The violation of the symmetry of the plasma parameters at the magnetopause is the cause of the magnetizing current generation. Here, we consider whether the change in the density of sodium ions on both sides of the Hermean magnetopause could be the cause of a wide diamagnetic current in the magnetosphere at its dawn-side boundary observed during the first MESSENGER flyby. In the present paper, we propose an analytical approach that made it possible to determine the magnetosheath Na+ density excess providing the best agreement between the calculation results and the observed magnetic field in the double magnetopause.

Resistive MHD modes in hollow cathodes external plasma

2021 ◽  
Author(s):  
Giulia Becatti ◽  
Francesco Burgalassi ◽  
Fabrizio Paganucci ◽  
Matteo Zuin ◽  
Dan M Goebel
Keyword(s):  
Magnetic Field ◽  
Hollow Cathode ◽  
Electric Propulsion ◽  
Axial Magnetic Field ◽  
Mhd Equations ◽  
Linear Perturbation ◽  
Plasma Parameters ◽  
Hollow Cathodes ◽  
Plume Region ◽  
Helical Mode

Abstract A significant number of plasma instabilities occur in the region just outside of hollow cathodes, depending on the injected gas flow, the current level and the application of an external magnetic field. In particular, the presence of an axial magnetic field induces a helical mode, affecting all the plasma parameters and the total current transported by the plasma. To explore the onset and behavior of this helical mode, the fluctuations in the plasma parameters in the current-carrying plume outside of a hollow cathode discharge have been investigated. The hollow cathode was operated at a current of 25 A, and at variable levels of propellant flow rate and applied magnetic fields. Electromagnetic probes were used to measure the electromagnetic fluctuations, and correlation analysis between each of the probe signals provided spatial-temporal characterization of the generated waves. Time-averaged plasma parameters, such as plasma potential and ion energy distribution function, were also collected in the near-cathode plume region by means of scanning emissive probe and retarding potential analyzer. The results show that the helical mode exists in the cathode plume at sufficiently high applied magnetic field, and is characterized by the presence of a finite electromagnetic component in the axial direction, detectable at discharge currents $\geq$ 25 A. A theoretical analysis of this mode reveals that one possible explanation is consistent with the hypotheses of resistive magnetohydrodynamics, which predicts the presence of helical modes in the forms of resistive kink. The analysis has been carried out by linear perturbation of the resistive MHD equations, from which it is possible to obtain the dispersion relation of the mode and find the $k-\omega$ unstable branch associated with the instability. These findings provided the basis for more detailed investigation of resistive MHD modes and their effect in the plume of hollow cathodes developed for electric propulsion application.

scholarly journals Experimental and numerical investigation of plasma parameters in the magnetosheath

2018 ◽  
Vol 145 ◽  
pp. 03003
Author(s):  
Polya Dobreva ◽  
Monio Kartalev ◽  
Olga Nitcheva ◽  
Natalia Borodkova ◽  
Georgy Zastenker
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Numerical Investigation ◽  
Euler Equations ◽  
Ideal Gas ◽  
Bow Shock ◽  
Plasma Parameters ◽  
Wind Spacecraft ◽  
The Magnetic Field ◽  
Good Agreement

We investigate the behaviour of the plasma parameters in the magnetosheath in a case when Interball-1 satellite stayed in the magnetosheath, crossing the tail magnetopause. In our analysis we apply the numerical magnetosheath-magnetosphere model as a theoretical tool. The bow shock and the magnetopause are self-consistently determined in the process of the solution. The flow in the magnetosheath is governed by the Euler equations of compressible ideal gas. The magnetic field in the magnetosphere is calculated by a variant of the Tsyganenko model, modified to account for an asymmetric magnetopause. Also, the magnetopause currents in Tsyganenko model are replaced by numericaly calulated ones. Measurements from WIND spacecraft are used as a solar wind monitor. The results demonstrate a good agreement between the model-calculated and measured values of the parameters under investigation.

scholarly journals Chiral Magneto-Electrochemistry

2018 ◽  
Vol 4 (3) ◽  
pp. 36 ◽  
Author(s):  
Anup Kumar ◽  
Prakash Mondal ◽  
Claudio Fontanesi
Keyword(s):  
Magnetic Field ◽  
Experimental Studies ◽  
Spin Accumulation ◽  
Chiral Molecules ◽  
Electrochemical System ◽  
Ferromagnetic Electrodes ◽  
Spin Polarized ◽  
The Magnetic Field ◽  
Research Domain

Magneto-electrochemistry (MEC) is a unique paradigm in science, where electrochemical experiments are carried out as a function of an applied magnetic field, creating a new horizon of potential scientific interest and technological applications. Over time, detailed understanding of this research domain was developed to identify and rationalize the possible effects exerted by a magnetic field on the various microscopic processes occurring in an electrochemical system. Notably, until a few years ago, the role of spin was not taken into account in the field of magneto-electrochemistry. Remarkably, recent experimental studies reveal that electron transmission through chiral molecules is spin selective and this effect has been referred to as the chiral-induced spin selectivity (CISS) effect. Spin-dependent electrochemistry originates from the implementation of the CISS effect in electrochemistry, where the magnetic field is used to obtain spin-polarized currents (using ferromagnetic electrodes) or, conversely, a magnetic field is obtained as the result of spin accumulation.

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