Thermal cyclotron radiation from a hot coronal loop with helical magnetic field

1994 ◽  
Vol 68 (1-4) ◽  
pp. 225-231 ◽  
Author(s):  
O. A. Sheiner ◽  
E. Ya. Zlotnik
Keyword(s):  
Magnetic Field ◽  
Coronal Loop ◽  
Cyclotron Radiation ◽  
Helical Magnetic Field ◽  
Thermal Cyclotron Radiation

scholarly journals A Helical Magnetic Field in the Jet of 3C 273

2002 ◽  
Vol 54 (3) ◽  
pp. L39-L43 ◽  
Author(s):  
Keiichi Asada ◽  
Makoto Inoue ◽  
Yutaka Uchida ◽  
Seiji Kameno ◽  
Kenta Fujisawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Helical Magnetic Field

Approaching to the ideal condition of plasma confinement by applying external resonant fields in IR-T1 tokamak

2015 ◽  
Vol 81 (3) ◽  
Author(s):  
Sakineh Meshkani ◽  
Mahmood Ghoranneviss ◽  
Mansoureh Lafouti
Keyword(s):  
Magnetic Field ◽  
Turbulent Transport ◽  
Edge Plasma ◽  
Ideal Condition ◽  
Plasma Confinement ◽  
Applied Bias ◽  
Inverse Results ◽  
Electric And Magnetic Field ◽  
Helical Magnetic Field ◽  
The Ideal

For understanding the effect of resonant helical magnetic field (RHF) and bias on the edge plasma turbulent transport, the radial and poloidal electric field (Er, EP), poloidal and toroidal magnetic field (BP, Br) were detected by the Langmuir probe, magnetic probe and diamagnetic loop. The poloidal, toroidal and radial velocity (VP, Vr, Vt) can be determined from the electric and magnetic field. In the present work, we have investigated the effect of the magnitude of bias (Vbias = 200v, Vbias = 320v) on Er, EP, BP, Bt, VP, Vr, Vt. Moreover, we applied RHF with L = 2, L = 3 and L = 2 and 3 and investigate the effect of the helical windings radius on above parameters. Also, the experiment was repeated by applying the positive biasing potentials and RHF's simultaneously. The results show that by applying bias to the plasma at t = 15 msec at r/a = 0.9, Er, BP and Bt increase while EP decreases. The best modification occurs at Vbias = 200v. By applying RHF to the plasma, both the electric and magnetic field vary. Er reaches the highest in the presence of RHF with L = 3. The same results are obtained for BP, Bt, VP and Vt. While the inverse results are obtained for EP and Vr. Finally, RHF and bias are applied simultaneously to the plasma. With applied bias with Vbias = 200v and RHF with L = 2 and 3, we reach to the ideal circumstance. The same results obtain in the situation with Vbias = 320v and RHF with L = 2 and 3.

Dependence of Coronal Loop Temperature on Loop Length and Magnetic Field Strength

2018 ◽  
Vol 868 (2) ◽  
pp. 116 ◽  
Author(s):  
R. B. Dahlburg ◽  
G. Einaudi ◽  
I. Ugarte-Urra ◽  
A. F. Rappazzo ◽  
M. Velli
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Coronal Loop ◽  
Loop Length

STATIONARY SHEATH OF FARADAY ROTATION IN THE JET OF 3C 120

2010 ◽  
Vol 19 (06) ◽  
pp. 917-922
Author(s):  
JOSÉ L. GÓMEZ ◽  
MAR ROCA-SOGORB ◽  
IVÁN AGUDO ◽  
ALAN P. MARSCHER ◽  
SVETLANA G. JORSTAD
Keyword(s):  
Magnetic Field ◽  
Faraday Rotation ◽  
Radio Galaxy ◽  
External Medium ◽  
Degree Of Polarization ◽  
Polarization Structure ◽  
Rotation Measure ◽  
Helical Magnetic Field ◽  
3C 120 ◽  
Two Fluid

We present a sequence of 12 monthly polarimetric multi-frequency VLBA observations of the radio galaxy 3C 120. The motion of multiple superluminal components allows the mapping of the polarization structure along most of the jet and across its width, revealing a coherent in time Faraday screen and RM-corrected polarization angles. Gradients in Faraday rotation and degree of polarization across the jet are observed, together with a localized region of high rotation measure superposed on this structure. This is explained as produced by the presence of a helical magnetic field in a two-fluid jet model, consisting of an inner emitting jet and a sheath containing nonrelativistic electrons. Interaction of the jet with the external medium would explain the confined region of enhanced Faraday rotation.

The Effect of Magnetic Field Spread and Temperature and Density Variations in Cyclotron Emission Regions

1987 ◽  
Vol 7 (2) ◽  
pp. 123-127 ◽  
Author(s):  
D. T. Wickramasinghe ◽  
Lilia Ferrario
Keyword(s):  
Magnetic Field ◽  
Point Source ◽  
Circular Polarization ◽  
White Dwarfs ◽  
Type Systems ◽  
Polar Cap ◽  
Cyclotron Radiation ◽  
Cyclotron Emission ◽  
Source Models ◽  
Accretion Shocks

AbstractWe discuss the properties of cyclotron radiation from accretion shocks located above the atmospheres of magnetic white dwarfs taking into account the effects of field spread and density and temparture structure. The models which are an improvement on previous point source models are shown to have characteristics that are in better overall agreement with the properties of AM Herculis type systems. Our calculations of the polarization properties of large polar cap emission regions are used to discuss the recent null measurements of circular polarization in DQ Herculis type systems.

scholarly journals Magnetized filament models for diverging plasma lenses

2020 ◽  
Vol 493 (2) ◽  
pp. 1736-1752
Author(s):  
Adam Rogers ◽  
Abdul Mohamed ◽  
Bailey Preston ◽  
Jason D Fiege ◽  
Xinzhong Er
Keyword(s):  
Magnetic Field ◽  
Column Density ◽  
Volume Density ◽  
Magnetized Plasma ◽  
Gravitational Lens ◽  
Line Of Sight ◽  
Density Distributions ◽  
Rotation Measure ◽  
Spherical Plasma ◽  
Helical Magnetic Field

ABSTRACT Spherical plasma lens models are known to suffer from a severe overpressure problem, with some observations requiring lenses with central pressures up to millions of times in excess of the ambient interstellar medium. There are two ways that lens models can solve the overpressure problem: a confinement mechanism exists to counter the internal pressure of the lens, or the lens has a unique geometry, such that the projected column-density appears large to an observer. This occurs with highly asymmetric models, such as edge-on sheets or filaments, with potentially low volume–density. In the first part of this work we investigate the ability of non-magnetized plasma filaments to mimic the magnification of sources seen behind spherical lenses and we extend a theorem from gravitational lens studies regarding this model degeneracy. We find that for plasma lenses, the theorem produces unphysical charge density distributions. In the second part of the work, we consider the plasma lens overpressure problem. Using magnetohydrodynamics, we develop a non self-gravitating model filament confined by a helical magnetic field. We use toy models in the force-free limit to illustrate novel lensing properties. Generally, magnetized filaments may act as lenses in any orientation with respect to the observer, with the most high-density events produced from filaments with axes near the line of sight. We focus on filaments that are perpendicular to the line of sight that show the toroidal magnetic field component may be observed via the lens rotation measure.

PRIMORDIAL MAGNETIC FIELD AND SPECTRAL DISTORTION OF COSMIC BACKGROUND RADIATION

1998 ◽  
Vol 07 (03) ◽  
pp. 489-498 ◽  
Author(s):  
DENIS PUY ◽  
PATRICK PETER
Keyword(s):  
Magnetic Field ◽  
Background Radiation ◽  
Cosmic Background Radiation ◽  
Spectral Distortion ◽  
Free Electrons ◽  
Cosmic Background ◽  
Cyclotron Radiation ◽  
Primordial Plasma ◽  
Primordial Magnetic Field ◽  
Recombination Epoch

The role played by a primordial magnetic field during the pre-recombination epoch is analysed through the cyclotron radiation (due to the free electrons) it might produce in the primordial plasma. We discuss the constraint implied by the measurement or lack thereof COBE on this primordial field.

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