scholarly journals Magnetic field amplification and electron acceleration to near-energy equipartition with ions by a mildly relativistic quasi-parallel plasma protoshock

2010 ◽  
Vol 524 ◽  
pp. A84 ◽  
Author(s):  
G. C. Murphy ◽  
M. E. Dieckmann ◽  
A. Bret ◽  
L. O’ C. Drury
Keyword(s):  
Magnetic Field ◽  
Electron Acceleration ◽  
Field Amplification ◽  
Energy Equipartition

scholarly journals FIELD AMPLIFICATION, VORTEX FORMATION, AND ELECTRON ACCELERATION IN A PLASMA PROTOSHOCK: EFFECT OF ASYMMETRIC DENSITY PROFILE

2012 ◽  
Vol 08 ◽  
pp. 376-379
Author(s):  
GARETH C. MURPHY ◽  
MARK E. DIECKMANN ◽  
LUKE O'C DRURY
Keyword(s):  
Magnetic Field ◽  
Density Profile ◽  
Gamma Ray ◽  
Vortex Formation ◽  
Electron Acceleration ◽  
Gamma Ray Bursts ◽  
Relativistic Jets ◽  
Parallel Magnetic Field ◽  
Field Amplification ◽  
Energy Equipartition

Gamma ray bursts (GRBs) are thought to originate from highly relativistic jets. The fireball model predicts internal shocks in the jets, causing magnetic field to be amplified & particles to be accelerated. We model the effects of an asymmetric density configuration for an internal plasma collision in a quasi-parallel magnetic field. We measured electron acceleration & found that a tenuous population of electrons is accelerated to Lorentz factors of ~ 300 - close to energy equipartition with ions. We found that the filaments did not remain static, but were deflected by the Lorentz force & rolled up into small vortices, which themselves merge to form a larger current vortex.

scholarly journals Magnetic field amplification in newly-born neutron stars

1996 ◽  
Vol 160 ◽  
pp. 435-436
Author(s):  
H.-J. Wiebicke ◽  
U. Geppert
Keyword(s):  
Magnetic Field ◽  
Neutron Stars ◽  
Gravitational Collapse ◽  
Dipole Field ◽  
Numerical Calculations ◽  
Selection Effects ◽  
Thermoelectric Effects ◽  
Field Amplification ◽  
Seed Field ◽  
Flux Conservation

AbstractWe present a scenario of magnetic field (MF) evolution of newly-born neutron stars (NSs). Numerical calculations show that in the hot phase of young NSs the MF can be amplified by thermoelectric effects, starting from a moderately strong seed-field. Therefore, there is no need to assume a 1012G dipole field immediately after the gravitational collapse of the supernova (SN) event. The widely accepted scenario for such a field to be produced by flux conservation during the collapse is critically discussed. Instead, it can be generated by amplification and selection effects in the first 104yrs, and by the subsequent fast ohmic decay of higher multipole components, when the NS cools down.

MAGNETIC FIELD AMPLIFICATION BY RELATIVISTIC SHOCKS IN AN INHOMOGENEOUS MEDIUM

2012 ◽  
Vol 08 ◽  
pp. 364-367
Author(s):  
YOSUKE MIZUNO ◽  
MARTIN POHL ◽  
JACEK NIEMIEC ◽  
BING ZHANG ◽  
KEN-ICHI NISHIKAWA ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Inhomogeneous Medium ◽  
Magnetic Energy ◽  
Small Scale ◽  
Two Dimensional ◽  
Filamentary Structure ◽  
Field Amplification ◽  
Relativistic Shocks ◽  
Field Lines ◽  
Magnetohydrodynamic Simulations

We perform two-dimensional relativistic magnetohydrodynamic simulations of a mildly relativistic shock propagating through an inhomogeneous medium. We show that the postshock region becomes turbulent owing to preshock density inhomogeneity, and the magnetic field is strongly amplified due to the stretching and folding of field lines in the turbulent velocity field. The amplified magnetic field evolves into a filamentary structure in two-dimensional simulations. The magnetic energy spectrum is flatter than the Kolmogorov spectrum and indicates that the so-called small-scale dynamo is occurring in the postshock region. We also find that the amplitude of magnetic-field amplification depends on the direction of the mean preshock magnetic field.

Magnetic Field Amplification by Shocks in Turbulent Fluids

2007 ◽  
Vol 663 (1) ◽  
pp. L41-L44 ◽  
Author(s):  
J. Giacalone ◽  
J. R. Jokipii
Keyword(s):  
Magnetic Field ◽  
Field Amplification ◽  
Turbulent Fluids

Analysis and Experimental Study of Magnetic-Field Amplification by a Double Coil

2017 ◽  
Vol 64 (4) ◽  
pp. 3216-3226 ◽  
Author(s):  
Ai-ichiro Sasaki ◽  
Olivier Ouellette ◽  
Maxime Beaudry-Marchand ◽  
Akihiko Hirata ◽  
Hiroki Morimura
Keyword(s):  
Magnetic Field ◽  
Experimental Study ◽  
Field Amplification
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