scholarly journals The Influence of Magnetic Turbulence on the Energetic Particle Transport Upstream of Shock Waves

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 508
Author(s):  
Silvia Perri ◽  
Giuseppe Prete ◽  
Francesco Malara ◽  
Francesco Pucci ◽  
Gaetano Zimbardo

Energetic particles are ubiquitous in the interplanetary space and their transport properties are strongly influenced by the interaction with magnetic field fluctuations. Numerical experiments have shown that transport in both the parallel and perpendicular directions with respect to the background magnetic field is deeply affected by magnetic turbulence spectral properties. Recently, making use of a numerical model with three dimensional isotropic turbulence, the influence of turbulence intermittency and magnetic fluctuations on the energetic particle transport was investigated in the solar wind context. Stimulated by this previous theoretical work, here we analyze the parallel transport of supra-thermal particles upstream of interplanetary shock waves by using in situ particle flux measurements; the aim was to relate particle transport properties to the degree of intermittency of the magnetic field fluctuations and to their relative amplitude at the energetic particle resonant scale measured in the same regions. We selected five quasi-perpendicular and five quasi-parallel shock crossings by the ACE satellite. The analysis clearly shows a tendency to find parallel superdiffusive transport at quasi-perpendicular shocks, with a significantly higher level of the energetic particle fluxes than those observed in the quasi-parallel shocks. Furthermore, the occurrence of anomalous parallel transport is only weakly related to the presence of magnetic field intermittency.

2016 ◽  
Vol 459 (3) ◽  
pp. 3395-3406 ◽  
Author(s):  
F. Pucci ◽  
F. Malara ◽  
S. Perri ◽  
G. Zimbardo ◽  
L. Sorriso-Valvo ◽  
...  

2005 ◽  
Vol 35 (4) ◽  
pp. 647-652 ◽  
Author(s):  
P. Pommois ◽  
G. Zimbardo ◽  
P. Veltri

2020 ◽  
Vol 498 (4) ◽  
pp. 5517-5523
Author(s):  
P Rashed-Mohassel ◽  
M Ghorbanalilu

ABSTRACT Particle acceleration by plasma shock waves is investigated for a magnetized plasma cloud propagating in a non-uniform background magnetic field by means of analytical and numerical calculations. The mechanism studied here is mainly, magnetic trapping acceleration (MTA) which is previously investigated for a cloud moving through the uniform interstellar magnetic field (IMF). In this work, the acceleration is studied for a cloud moving in an antiparallel background field with spatial variations along the direction of motion. For negative variation, the cloud moves towards an antiparallel magnetic field with an increasing intensity, the trapped particle moves to locations with higher convective electric field and therefore gains more energy over time. For positive variation, the background field decreases to zero and changes into a parallel field with an increasing intensity. It is concluded that, when the background field vanishes, the MTA mechanism ceases and the particle escapes into the space. This leads to a bouncing acceleration which further increases energy of the gyrating particle. The two processes are followed by a shock drift acceleration, where due to the background magnetic field gradient, the particle drifts along the electric field and gains energy. Although for positive variation, three different mechanisms are involved, energy gain is less than in the case of a uniform background field.


1999 ◽  
Vol 39 (9Y) ◽  
pp. 1309-1319 ◽  
Author(s):  
B.C Stratton ◽  
R.V Budny ◽  
D.S Darrow ◽  
R.K Fisher ◽  
E.D Fredrickson ◽  
...  

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