Magnetic field amplification in interstellar collisionless shock waves

Nature ◽  
1977 ◽  
Vol 266 (5604) ◽  
pp. 701-702 ◽  
Author(s):  
ROGER A. CHEVALIER
Keyword(s):  
Magnetic Field ◽  
Shock Waves ◽  
Collisionless Shock ◽  
Field Amplification

scholarly journals Computational Study of Magnetic Field Amplification in Laser-Produced Shock Waves Relevant to Supernova Remnants

2016 ◽  
Vol 688 ◽  
pp. 012035
Author(s):  
Ayako Ishii ◽  
Shiori Kishita ◽  
Naofumi Ohnishi ◽  
Yasuhiro Kuramitsu ◽  
Taichi Morita ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Shock Waves ◽  
Supernova Remnants ◽  
Computational Study ◽  
Field Amplification

A model for precursor structure in supercritical perpendicular, collisionless shock waves

1978 ◽  
Vol 20 (2) ◽  
pp. 265-279
Author(s):  
D. Sherwell ◽  
R. A. Cairns
Keyword(s):  
Magnetic Field ◽  
Shock Waves ◽  
Wave Velocity ◽  
Current Distribution ◽  
Trapped Ions ◽  
Collisionless Shock ◽  
Precursor Structure ◽  
Insight Into ◽  
A Current

Magnetosonic solitons may be given smooth increasing profiles by assuming the presence within the wave of a current distribution Jy(x) of trapped ions perpendicular to Bz(x) and the wave velocity Vx. Suitable ions are found immediately upstream of perpendicular, collisionless shock waves and these are coincident with the often observed ‘foot’ in magnetic field profiles of moderately supercritical shocks. By modelling Jy(x) we apply the theory to previous experiments where Jy(x) is observed, and are able to reproduce reasonably, and thus explain, the profiles in the foot. Insight into a number of features of fast shocks is obtained.

Effect of electron thermal anisotropy on the kinetic cross-field streaming instability

1984 ◽  
Vol 32 (1) ◽  
pp. 159-178 ◽  
Author(s):  
S. T. Tsai ◽  
M. Tanaka ◽  
J. D. Gaffey ◽  
E. H. Da Jornada ◽  
C. S. Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Shock Waves ◽  
Numerical Solutions ◽  
Collisionless Shock ◽  
Direction Transverse ◽  
Ambient Magnetic Field ◽  
Thermal Anisotropy ◽  
Analytical And Numerical Solutions ◽  
Streaming Instability

The investigation of the kinetic cross-field streaming instability, motivated by the research of collisionless shock waves and previously studied by Wu et al., is discussed more fully in the present work. Since, in the ramp region of a quasi-perpendicular shock, electrons can be preferentially heated in the direction transverse to the ambient magnetic field, it is both desirable and necessary to include the effect of the thermal anisotropy on the instability associated with a shock. The present study has found that Te⊥ > Te‖ can significantly enhance the peak growth rate of the cross-field streaming instability when the electron beta is sufficiently high. Furthermore, the present analysis also improves the analytical and numerical solutions previously obtained.

Ion dynamics in a perpendicular collisionless shock

1977 ◽  
Vol 17 (2) ◽  
pp. 265-279 ◽  
Author(s):  
D. Sherwell ◽  
R. A. Cairns
Keyword(s):  
Magnetic Field ◽  
Shock Waves ◽  
Dissipative Process ◽  
Ion Dynamics ◽  
Collisionless Shock ◽  
Collisionless Shocks ◽  
Ion Heating ◽  
Potential Jump ◽  
Electric And Magnetic Fields ◽  
The Mean

Some properties of perpendicular collisionless shocks are investigated, using a model in which the ion orbits in the shock are assumed to be determined by the average electric and magnetic fields in the shock. These fields are modelled, with the jump in magnetic field across the shock being determined by the conservation relations, and the potential jump determined self-consistently within the model, using the fact that the mean ion velocity downstream of the shock is determined by the conservation relations. Extensive numerical calculations of ion orbits show that effective ion heating can occur in the absence of any dissipative process, with the energy residing in non-Maxwellian velocity distributions in the downstream regions. Results on this and on a number of other features of shock waves, agree well with experiments.

scholarly journals Turbulent Magnetic Field Amplification behind Strong Shock Waves in GRB and SNR

2011 ◽  
Vol 7 (S279) ◽  
pp. 335-336
Author(s):  
Tsuyoshi Inoue
Keyword(s):  
Magnetic Field ◽  
Shock Wave ◽  
Shock Waves ◽  
Supernova Remnants ◽  
Gamma Ray ◽  
Three Dimensional ◽  
Strong Shock ◽  
Field Amplification ◽  
Field Lines ◽  
Strong Shock Waves

AbstractUsing three-dimensional (special relativistic) magnetohydrodynamics simulations, the amplification of magnetic field behind strong shock wave is studied. In supernova remnants and gamma-ray bursts, strong shock waves propagate through an inhomogeneous density field. When the shock wave hit a density bump or density dent, the Richtmyer-Meshkov instability is induced that cause a deformation of the shock front. The deformed shock leaves vorticity behind the shock wave that amplifies the magnetic field due to the stretching of field lines.

The generation of interpenetrating plasma flows in an expanding discharge

1976 ◽  
Vol 15 (2) ◽  
pp. 293-307 ◽  
Author(s):  
H. A. Davis ◽  
M. A. Mahdavi ◽  
R. H. Lovberg
Keyword(s):  
Magnetic Field ◽  
Shock Wave ◽  
Shock Waves ◽  
Electric Field ◽  
Electric Fields ◽  
Magnetic Disturbance ◽  
Collisionless Shock ◽  
Driving Field ◽  
Piston Speed ◽  
Electron Density And Temperature

We report on an experiment designed to study collisionless shock waves in an inverse pinch discharge using argon. A magnetic disturbance was generated which propagated ahead of the driving field at twice the piston speed. Measurements of the magnetic and electric field structures, electron density and temperature, as well as ion velocities revealed that the disturbance was produced by a beam of plasma moving through the ionized ambient plasma rather than by a true shock wave. Calculations of ion trajectories using measured electric fields demonstrated that the beam originated at small radii and early times, and was not the result of a steady specular reflexion from the piston field. It is concluded that the ions comprising this stream, which were collisionless relative to the ambient ions, did not couple to the background plasma even though a strong magnetic field was applied.

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.

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