scholarly journals ON THE TILT ANGLE OF THE MAGNETIC FIELD AXIS FROM SUNSPOT MICROWAVE OBSERVATIONS

2018 ◽  
Author(s):  
N.A. Topchilo ◽  
◽  
N.G. Peterova ◽  
Keyword(s):  
Magnetic Field ◽  
Tilt Angle ◽  
Magnetic Field Axis ◽  
The Magnetic Field

scholarly journals Radiation Beaming in Pulsars

1971 ◽  
Vol 46 ◽  
pp. 455-456
Author(s):  
V. Canuto
Keyword(s):  
Magnetic Field ◽  
Neutron Star ◽  
Coming Out ◽  
Critical Magnetic Field ◽  
Zero Field ◽  
Ordinary Wave ◽  
Magnetic Field Axis ◽  
Field Lines ◽  
Star Surface ◽  
The Magnetic Field

It is usually considered that the beaming of the radiation coming out of a pulsar has to be strictly connected with the mechanism producing the radiation itself. We want to show that even when the emitting mechanism gives rise to an isotropically distributed radiation, the presence of a strong magnetic field will automatically beam the radiation preferentially along the magnetic field line rather than in any other direction. We have computed the Compton scattering and from that the opacity KH (K0 is the opacity for zero field). In Figure 1 the ratio KH/K0 is given vs. θ, the angle between the propagation vector and the magnetic field axis. Hq is a critical magnetic field numerically equal to 4.41 × 1013 G; Ne is the electron density. For the ordinary wave the opacity is reduced at θ = 0, while it is unaffected at θ = π/2 where KH → K0. Even at θ = π/4 the ratio KH/K0 is still ≃ 10−2, and a good beaming is still present. The values of the parameters are proper for a neutron star surface. It is to be noticed that the ratio KH/K0 is of the order of (ω/ωH)2 or [(kT/mc2)/(H/Hq]2. One therefore can conclude that the presence of a magnetic field itself assures the beaming of radiation along the field lines.

scholarly journals Comparative Study on Planetary Magnetosphere in the Solar System

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1673
Author(s):  
Ching-Ming Lai ◽  
Jean-Fu Kiang
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar System ◽  
Comparative Study ◽  
Magnetic Reconnection ◽  
Tilt Angle ◽  
Planetary Magnetosphere ◽  
Field Distributions ◽  
Mhd Simulations ◽  
The Magnetic Field

The magnetospheric responses to solar wind of Mercury, Earth, Jupiter and Uranus are compared via magnetohydrodynamic (MHD) simulations. The tilt angle of each planetary field and the polarity of solar wind are also considered. Magnetic reconnection is illustrated and explicated with the interaction between the magnetic field distributions of the solar wind and the magnetosphere.

Magnetically Tailored Arc and Glow Discharge Plasmas for Atomic Spectroscopy

1987 ◽  
Vol 41 (5) ◽  
pp. 833-843 ◽  
Author(s):  
K. Trivedi ◽  
S. Tanguay ◽  
M. Matties ◽  
R. Sacks
Keyword(s):  
Magnetic Field ◽  
Glow Discharge ◽  
Vertical Displacement ◽  
Atomic Spectroscopy ◽  
Radiative Properties ◽  
Current Channel ◽  
Drift Motion ◽  
Magnetic Field Axis ◽  
Discharge Plasmas ◽  
The Magnetic Field

Three magnetic field-plasma configurations are used to study the interaction of external magnetic fields with analytically useful plasma devices. First, a magnetic field oscillating at 60 Hz and normal to the electric field in a 12-A direct current arc plasma is used to obtain an Ē×B̄ drift motion of the arc current channel. This causes a periodic vertical displacement of the channel. Second, a cw magnetic field is used to alter the structure and radiative properties of a demountable glow discharge lamp that uses a center-post cathode. The magnetic field axis is parallel to the cathode axis, and the lamp is operated in a pseudo-magnetron mode. Third, a damped, oscillatory magnetic field produced by discharging a capacitor through a coil is used to alter the radiative characteristics of several commercial hollow cathode lamps. The magnetic field is parallel to the cathode axis, and again the lamps operate in a pseudo-magnetron mode. In all three systems, the presence of the magnetic field drastically alters the radiative properties of the plasmas.

scholarly journals Research on a novel magnetic tilt sensor designed using Hall elements and ferrofluid

2019 ◽  
Vol 70 (5) ◽  
pp. 406-411
Author(s):  
Yavuz Öztürk ◽  
Ismail Yariçi
Keyword(s):  
Magnetic Field ◽  
Hall Effect ◽  
Tilt Angle ◽  
Face To Face ◽  
Restoring Forces ◽  
Working Principle ◽  
Tilt Sensor ◽  
Hall Effect Sensors ◽  
Two Sides ◽  
The Magnetic Field

Abstract In this study, a simple, adjustable, bidirectional tilt sensor was designed using a pair of linear Hall effect sensors and magnets. Theoretical analysis and experimental results of the sensor system were presented. The working principle of the designed sensor is based on sensing the magnetic field of a mobile magnet which displaces with respect to the tilt angle. Two magnet sets were placed at the two ends of the system to apply repulsive restoring forces on the mobile magnet. The mobile magnet was coated with a light hydrocarbon based ferrofluid as a lubricant to reduce friction. Fixed Hall effect sensors were placed face to face at the two sides of the mobile magnet to monitor the magnetic field of the mobile magnet. It was shown that both experimentally and theoretically, it is possible to measure the approximate tilt angle linearly and quadratically by calculating the sum and difference of the Hall sensor voltages for the relatively small movements of the mobile magnet. Moreover, the system was also examined for the different sets of side magnets. For three different side magnet configurations, approximately 0.7, 1.1 and 1.68 V/rad sensitivity values were observed in the linear range.

scholarly journals Effect of Magnetic Field and Temperature on the Exchange Bias in Phase-Separated Nd1-xSrxCoO3(x=0.10, 0.15)

2015 ◽  
Vol 9 (1) ◽  
pp. 56-59 ◽  
Author(s):  
Yi-Yun Yang
Keyword(s):  
Magnetic Field ◽  
Exchange Bias ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Freezing Temperature ◽  
Solid State Reaction Method ◽  
Conventional Solid State Reaction ◽  
Magnetic Field Axis ◽  
Coexisting Phases ◽  
The Magnetic Field

The exchange bias phenomena of phase-separated Nd1-xSrxCoO3(x=0.10, 0.15) samples were systematically investigated in this paper. The samples were prepared using conventional solid state reaction method. When the NdSrCoO samples cooled down in magnetic field below freezing temperature, the hysteresis loops shifted along the magnetic field axis. Moreover, exchange bias of Nd1-xSrxCoO3 is strongly dependent on the field and the temperature. The influence of magnetic field on the relative ratio of the coexisting phases may be responsible for these behaviors. Therefore, our study confirmed that in phase-separated system, the exchange coupling at the interface between the ferromagnetism clusters and the spin glass regions may induce interfacial exchange anisotropy.

scholarly journals Unravelling the complex magnetosphere of the B star HD 133880 via wideband observation of coherent radio emission

2020 ◽  
Vol 499 (1) ◽  
pp. 702-709
Author(s):  
Barnali Das ◽  
Poonam Chandra ◽  
Gregg A Wade
Keyword(s):  
Magnetic Field ◽  
Radio Emission ◽  
Rotation Axis ◽  
Time Lag ◽  
Wide Frequency Range ◽  
Very Large Array ◽  
Magnetic Field Axis ◽  
Cyclotron Maser ◽  
Magnetic Stars ◽  
The Magnetic Field

ABSTRACT HD 133880 is one of the six hot magnetic stars known to produce coherent pulsed radio emission by the process of electron cyclotron maser emission (ECME). In this paper, we present observations of ECME from this star over a wide frequency range, covering nearly 300–4000 MHz with the Giant Metrewave Radio Telescope (GMRT) and the Karl G. Jansky Very Large Array (VLA). This study, which is the first of its kind, has led to the discovery of several interesting characteristics of the phenomenon and also of the host star. We find that the observable properties of ECME pulses, e.g. the time lag between right and left circularly polarized pulses, the amplitudes of the pulses, and their upper cut-off frequencies, appear to be dependent on the stellar orientation with respect to the line of sight. We suggest that all these phenomena, which are beyond the ideal picture, can be attributed to a highly azimuthally asymmetric matter distribution in the magnetosphere about the magnetic field axis, which is a consequence of both the high obliquity (the angle between rotation axis and the magnetic field axis) of the star and the deviation of the stellar magnetic field from a dipolar topology.

scholarly journals Quantum Relativistic Electron Gas Expanding in One Dimension

2017 ◽  
Vol 45 ◽  
pp. 1760045 ◽  
Author(s):  
Hugo Pérez Rojas ◽  
Elizabeth Rodríguez Querts ◽  
Aurora Pérez Martínez
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Vector Boson ◽  
Electron Gas ◽  
Electron System ◽  
One Dimension ◽  
Ferromagnetic Behavior ◽  
Boson Field ◽  
Magnetic Field Axis ◽  
The Magnetic Field

Under the action of field intensities around the Schwinger critical field, a dense electron gas behaves as unidimensional, exerting strong pressure along the applied field. We suggest a model for maintaining the magnetic field self-consistently, by assuming spin parallel pairing leading to a partial bosonization of the electron gas, which is described by a charged vector boson field, able to experience condensation, leading to a ferromagnetic behavior. Our aim is to suggest a possible quantum relativistic self-magnetized jet model. High frequency photons will be deviated also along paths parallel to the external field, leading to a model for a jet. Any addition of matter and/or energy to the electron system, would contribute to increase the kinetic energy along the magnetic field axis, an the jet may extend for long distances.

scholarly journals Optimal orientation for ionization chambers in MRgRT reference dosimetry

2017 ◽  
Vol 3 (2) ◽  
pp. 273-275
Author(s):  
Stefan Pojtinger ◽  
Oliver S. Dohm ◽  
Daniela Thorwarth
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Field ◽  
Linear Accelerator ◽  
Critical Issue ◽  
Resonance Imaging ◽  
Ionization Chambers ◽  
Optimal Orientation ◽  
Magnetic Field Axis ◽  
Medical Linear Accelerator ◽  
The Magnetic Field

AbstractThe interest in hybrid systems combining magnetic resonance imaging and medical linear accelerator (MR-Linac) is rapidly increasing due to the clinical availability of different systems. Reference dosimetry is a critical issue for integrating these devices into clinical practice. However, the response of ionization chambers changes according to the distinct orientation of the chamber with respect to the magnetic field. In this study, we have carried out Monte Carlo simulations to identify an optimal orientation for thimble type chambers in MRgRT reference dosimetry. Our findings suggest that an orientation where the chamber axis is parallel to the magnetic field axis should be preferred.

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