Particle Scattering in Magnetized Plasmas and Diffusive Shock Acceleration at Perpendicular Interplanetary Shock Waves

2011 ◽  
Author(s):  
Alexander Dosch ◽  
A. Shalchi ◽  
Vladimir Florinski ◽  
Jacob Heerikhuisen ◽  
Gary P. Zank ◽  
...  
2012 ◽  
Vol 8 (S294) ◽  
pp. 583-584
Author(s):  
Xin Wang ◽  
Yi-Hua Yan

AbstractObservations of the interplanetary shock provide us with strong evidences of particle acceleration to multi-MeV protons in a coronal mass ejection (CME). Diffusive shock acceleration (DSA) is an efficient mechanism for cosmic ray (CR). This work presents a dynamical Monte Carlo simulation of a CME-driven shock on 14-Dec-2006 by using a series of Gaussian scattering angular distributions. With the simulated results, we find that particle energy spectrum is affected by energy injection processes under the anisotropic scattering law.


2020 ◽  
Vol 494 (3) ◽  
pp. 3166-3176 ◽  
Author(s):  
T Vieu ◽  
S Gabici ◽  
V Tatischeff

ABSTRACT We model the diffusive shock acceleration of particles in a system of two colliding shock waves and present a method to solve the time-dependent problem analytically in the test-particle approximation and high energy limit. In particular, we show that in this limit the problem can be analysed with the help of a self-similar solution. While a number of recent works predict hard (E−1) spectra for the accelerated particles in the stationary limit, or the appearance of spectral breaks, we found instead that the spectrum of accelerated particles in a time-dependent collision follows quite closely the canonical E−2 prediction of diffusive shock acceleration at a single shock, except at the highest energy, where a hardening appears, originating a bumpy feature just before the exponential cut-off. We also investigated the effect of the reacceleration of pre-existing cosmic rays by a system of two shocks, and found that under certain conditions spectral features can appear in the cut-off region. Finally, the mathematical methods presented here are very general and could be easily applied to a variety of astrophysical situations, including for instance standing shocks in accretion flows, diverging shocks, backward collisions of a slow shock by a faster shock, and wind–wind or shock–wind collisions.


2020 ◽  
Author(s):  
Athanasios Kouloumvakos ◽  
Alexis P. Rouillard

<p>STEREO has provided over 10 yr of continuous monitoring of CMEs and CME-driven shock waves from the Sun to Earth-like distances, as well as multipoint measurements of SEPs in the keV to 100 MeV energy range. These observations have revealed a number of puzzling properties of SEPs. For instance, gradual and impulsive SEP events have been measured over extended ranges of longitudes by STEREO, sometimes extending over 360 degrees around the Sun. Multi-spacecraft remote-sensing observations have allowed us to perform shock wave modeling in 3D, and to derive and examine consistently critical shock parameters during their evolution. I will present a connection of the shocks/CMEs to SEP properties from multi-spacecraft in-situ measurements by alleviating projection effects, accounting for both the complexities of coronal shocks and how they are likely to connect magnetically with in-situ spacecraft. A comparison between the shock wave parameters derived from 3D modeling and observations, and SEP characteristics confirm predictions of diffusive shock acceleration, that efficient acceleration of SEPs should naturally occur at shock regions where the shock Mach number is high. I will also discuss how modeling shock waves and estimating their magnetic connectivity can be useful in future studies to determine the solar origin of particle events measured by Parker Solar Probe.</p>


Author(s):  
N. Shimada ◽  
T. Terasawa ◽  
M. Hoshino ◽  
T. Naito ◽  
H. Matsui ◽  
...  

1994 ◽  
Vol 142 ◽  
pp. 561-565
Author(s):  
Frank C. Jones

AbstractWe discuss the fundamental ideas of particle acceleration in plasma shocks with emphasis on those features that are required to produce the “universal” power-law spectrum. We compare shock acceleration with the more familiar second-order or stochastic acceleration and see that they are not too different in many respects. We discuss the features of shock acceleration that make it appealing and some of its problems as well.Subject headings: acceleration of particles — MHD — plasmas — shock waves


2004 ◽  
Vol 22 (8) ◽  
pp. 3063-3072 ◽  
Author(s):  
U. W. Langner ◽  
M. S. Potgieter

Abstract. The interest in the role of the solar wind termination shock and heliosheath in cosmic ray modulation studies has increased significantly as the Voyager 1 and 2 spacecraft approach the estimated position of the solar wind termination shock. The effect of the solar wind termination shock on charge-sign dependent modulation, as is experienced by galactic cosmic ray Helium (He++) and anomalous Helium (He+), is the main topic of this work, and is complementary to the previous work on protons, anti-protons, electrons, and positrons. The modulation of galactic and anomalous Helium is studied with a numerical model including a more fundamental and comprehensive set of diffusion coefficients, a solar wind termination shock with diffusive shock acceleration, a heliosheath and particle drifts. The model allows a comparison of modulation with and without a solar wind termination shock and is applicable to a number of cosmic ray species during both magnetic polarity cycles of the Sun. The modulation of Helium, including an anomalous component, is also done to establish charge-sign dependence at low energies. We found that the heliosheath is important for cosmic ray modulation and that its effect on modulation is very similar for protons and Helium. The local Helium interstellar spectrum may not be known at energies


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