scholarly journals On the photon-pseudoscalar particle mixing in media and external fields

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Damian Ejlli
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
External Magnetic Field ◽  
Equations Of Motion ◽  
Magnetized Plasma ◽  
Arbitrary Direction ◽  
Particle Mixing ◽  
Field State ◽  
Pseudoscalar Particle ◽  
First Time

AbstractIn this work, I study the mixing of photons with pseudoscalar particles and vice-versa in the presence of an external magnetic field and a pseudoscalar field. I solve exactly for the first time in the literature the equations of motion of the electromagnetic field coupled with a pseudoscalar field in the presence of a constant magnetic field with arbitrary direction with respect to the direction of propagation of the fields in vacuum. In addition, I also solve exactly the equations of motion in a magnetized plasma/gas for perpendicular propagation with respect to the external magnetic field. By finding exact solutions to the equations of motion, I find exact expressions for the transition efficiencies of photons into pseudoscalar particles in different situations. The expressions of the transition efficiencies generalize and correct those previously found in the literature by using approximate WKB methods on solving the equations of motion. In the case when the direction of propagation of fields with respect to the external magnetic field is not perpendicular, a longitudinal state of the electromagnetic field is generated even in a magnetized vacuum. The appearance of the longitudinal electric field state could be used for laboratory searches of pseudoscalar particles such as the axion and/or axion-like particles.

scholarly journals Synthesis of cobalt nanowires in aqueous solution under an external magnetic field

2016 ◽  
Vol 7 ◽  
pp. 990-994 ◽  
Author(s):  
Xiaoyu Li ◽  
Lijuan Sun ◽  
Hu Wang ◽  
Kenan Xie ◽  
Qin Long ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Aqueous Solution ◽  
External Magnetic Field ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Chemical Reduction ◽  
Average Diameter ◽  
Firm Structure ◽  
Cobalt Nanowires ◽  
First Time

In contrast to the majority of related experiments, which are carried out in organic solvents at high temperatures and pressures, cobalt nanowires were synthesized by chemical reduction in aqueous solution with the assistance of polyvinylpyrrolidone (PVP) as surfactant under moderate conditions for the first time, while an external magnetic field of 40 mT was applied. Uniform linear cobalt nanowires with relatively smooth surfaces and firm structure were obtained and possessed an average diameter of about 100 nm with a coating layer of PVP. By comparison, the external magnetic field and PVP were proven to have a crucial influence on the morphology and the size of the synthesized cobalt nanowires. The prepared cobalt nanowires are crystalline and mainly consist of cobalt as well as a small amount of platinum. Magnetic measurements showed that the resultant cobalt nanowires were ferromagnetic at room temperature. The saturation magnetization (M s) and the coercivity (H c) were 112.00 emu/g and 352.87 Oe, respectively.

scholarly journals Low-Offset In-Plane Sensitive Hall Arrangement

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 713
Author(s):  
Siya Lozanova ◽  
Ivan Kolev ◽  
Avgust Ivanov ◽  
Chavdar Roumenin
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Output Voltage ◽  
Cross Coupling ◽  
The Novel ◽  
Temperature Drift ◽  
Low Offset ◽  
First Time ◽  
Single Configuration ◽  
Hall Elements

A novel in-plane sensitive Hall arrangement consisting of two identical n-Si three-contact (3C) elements and realized in a common technological process, is presented. In the solution, the minimization of the offset and its temperature drift is achieved by cross-coupling of the outer device contacts. This terminals’ connection provides equalizing currents between the two substrates which strongly compensate the inevitable difference in the electrical conditions in the two parts of the arrangement. As a result, the residual offset of both integrated Hall elements at the output Vout(0) and its temperature drift are strongly minimized. The residual offset is about 160 times smaller than the single-configuration one. The obtained output voltage-to-residual offset ratio at sensitivity of SRI ≈ 98 V/AT is very promising, reaching 6 × 103 at temperature T = 40 °C and induction 1 T. As a result, increased metrological accuracy for numerous applications is achieved. For a first time through the novel arrangement a suppression of sensitivity in the presence of external magnetic field could be achieved in order to obtain permanent offset information. This is one of the key results in the Hall device investigation.

Tunable properties of one-dimensional photonic crystals that incorporate a defect layer of a magnetized plasma

2017 ◽  
Vol 31 (31) ◽  
pp. 1750239 ◽  
Author(s):  
Arafa H. Aly ◽  
Hussein A. Elsayed ◽  
Ayman A. Ameen ◽  
S. H. Mohamed
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Plasma Layer ◽  
Photonic Band Gap ◽  
Defect Layer ◽  
Magnetized Plasma ◽  
Characteristic Matrix ◽  
Angle Of Incidence ◽  
One Dimensional ◽  
Photonic Band

In this paper, we theoretically investigate the transmittance characteristics of one-dimensional defective photonic crystal in microwave radiations based on the fundamentals of the characteristic matrix method. Here, the defect layer is magnetized plasma. The numerical results show the appearance of defect peaks inside the Photonic Band Gap. The external magnetic field has a significant effect on the permittivity of the defect layer. Therefore, the position and intensity of the defect peak are strongly affected by the external magnetic field. Moreover, we have investigated the different parameters on the defect peaks as the plasma density, the thickness of the plasma layer and the angle of incidence. Wherefore, the proposed structure could be the cornerstone for many applications in microwave regions such as narrowband filters.

scholarly journals Energy and momentum losses in the process of neutrino scattering on plasma electrons in the presence of a magnetic field

Open Physics ◽  
2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Nickolay Mikheev ◽  
Elena Narynskaya
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Electron Scattering ◽  
Volume Density ◽  
Neutrino Energy ◽  
Magnetized Plasma ◽  
Neutrino Scattering ◽  
Energy And Momentum

AbstractThe neutrino-electron scattering in a dense degenerate magnetized plasma under the conditions μ 2 > 2eB ≫ μE is investigated. The volume density of the neutrino energy and momentum losses due to this process are calculated. The results we have obtained demonstrate that plasma in the presence of an external magnetic field is more transparent for neutrino than for non-magnetized plasma. It is shown that neutrino scattering under conditions considered does not lead to the neutrino force acting on plasma.

scholarly journals Low-Temperature Behavior of the Specific Heat for an N-Spin Ferromagnetic Material in an External Magnetic Field

2018 ◽  
Vol 9 (3) ◽  
pp. 36
Author(s):  
Seung-Yeon Kim
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Specific Heat ◽  
Ferromagnetic Material ◽  
Low Energy ◽  
Temperature Behavior ◽  
Energy Structure ◽  
Schottky Anomaly ◽  
First Time

<p>A ferromagnetic material in the absence of an external magnetic field shows the peak of its specific heat in low temperature, called the Schottky anomaly, which is vital in understanding the low-energy structure of a given material. A general formula for the low-temperature behavior of the specific heat of an N-spin ferromagnetic material in an external magnetic field (the generalized Schottky anomaly) is obtained for the first time. Also, as a representative example of ferromagnetic materials in an external magnetic field, the low-temperature behavior of the specific heat for the Ising ferromagnet is studied.</p>

scholarly journals Structure of nonlinear whistlers moving through plasma at an angle to the magnetic field

2018 ◽  
Vol 4 (1) ◽  
pp. 25-28
Author(s):  
Геннадий Кичигин ◽  
Gennadiy Kichigin
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Numerical Solutions ◽  
Field Vector ◽  
Magnetized Plasma ◽  
Small Scale ◽  
Motion Direction ◽  
Magnetic Field Change ◽  
The Magnetic Field ◽  
Two Fluid

The paper presents solutions of two-fluid magnetic hydrodynamics equations describing small-scale fast magnetosonic stable waves — nonlinear whist-lers moving in a cold magnetized plasma at an angle α to the external magnetic field. At the fixed angle α, the Alfvén Mach number of the whistlers has a narrow range of allowed values. It has been found that when passing from extremely small Mach numbers to ex-tremely large ones, amplitudes and spatial structure of wave velocity components and whistler magnetic field change significantly. The range of angles of the motion direction of whistlers with respect to direction of the the external magnetic field vector is determined. Within this range, the obtained approximate analytical and numerical solutions are in satisfactory agreement.

scholarly journals Enhanced terahertz radiation generation by two-color laser pulses propagating in plasma

2016 ◽  
Vol 34 (2) ◽  
pp. 378-383 ◽  
Author(s):  
N.K. Verma ◽  
P. Jha
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Numerical Model ◽  
Laser Pulses ◽  
Magnetized Plasma ◽  
Thz Radiation ◽  
Homogeneous Plasma ◽  
One Dimensional ◽  
Radiation Generation ◽  
Transverse Electromagnetic

AbstractA one-dimensional (1D) numerical model for studying enhanced terahertz (THz) radiation generation by mixing of ordinary and extraordinary modes of two-color laser pulses propagating in magnetized plasma has been presented. The direction of the static external magnetic field is such that one of the two laser pulses propagates in the extraordinary mode, while the other pulse propagates in the ordinary mode, through homogeneous plasma. A transverse electromagnetic wave with frequency in the THz range is generated due to the presence of the external magnetic field. It is observed that larger amplitude THz radiation can be generated by mixing of the ordinary and extraordinary modes of the two-color laser pulses as compared with the single laser pulse propagating in the extraordinary mode. Further, 2D simulations using the XOOPIC code show that the fields obtained via simulation study are compatible with those obtained from the numerical model.

Pseudo-three-dimensional convective cell motion in a magnetized plasma

1984 ◽  
Vol 31 (2) ◽  
pp. 231-238 ◽  
Author(s):  
P. K. Shukla ◽  
M. Y. Yu
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Mode Coupling ◽  
Three Dimensional ◽  
Convective Cell ◽  
Magnetized Plasma ◽  
Space Plasmas ◽  
Linear And Nonlinear ◽  
Convective Cells ◽  
Cell Motion

Linear and nonlinear mechanisms for generating convective cells with finite but small parallel (to the external magnetic field B0) wavelength are presented. The problems of mode-coupling as well as quasi-steady nonlinear mode structures are analytically studied. Possible applications in space plasmas are discussed.

Far-Field Potential of a Test Charge in an Inhomogeneous and Magnetized Plasma

1974 ◽  
Vol 52 (3) ◽  
pp. 281-283 ◽  
Author(s):  
P. K. Shukla ◽  
K. H. Spatschek ◽  
M. Y. Yu
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Inhomogeneous Plasma ◽  
Field Potential ◽  
Magnetized Plasma ◽  
The Other ◽  
Far Field ◽  
Homogeneous Plasma ◽  
Test Charge ◽  
Stationary Test

It is shown that a stationary test charge in a magnetized inhomogeneous plasma has a far-field potential which falls off as the inverse cube of the distance between the test charge and an observer who is located in a direction perpendicular to both the density gradient and the external magnetic field. On the other hand, the effect of an external magnetic field parallel to the velocity of a slowly moving test charge in a homogeneous plasma is shown to be insignificant.

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