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The recent detection of high energy gamma-rays coming from supernova remnants and active galactic nuclei has revived interest in the diffusive shock acceleration of electrons. In the present paper we examine the basis of the so-called…

Astrophysics · Physics 2007-05-23 Luke O'C Drury , Peter Duffy , David Eichler , Apostolos Mastichiadis

Electron injection at high Mach-number nonrelativistic perpendicular shocks is studied here for parameters that are applicable to young SNR shocks. Using high-resolution large-scale two-dimensional fully kinetic particle-in-cell (PIC)…

High Energy Astrophysical Phenomena · Physics 2019-06-12 Artem Bohdan , Jacek Niemiec , Martin Pohl , Yosuke Matsumoto , Takanobu Amano , Masahiro Hoshino

Particle transport, acceleration and energisation are phenomena of major importance for both space and laboratory plasmas. Despite years of study, an accurate theoretical description of these effects is still lacking. Validating models with…

Based on the particle-in-cell (PIC) plasma simulation method, the speed-limited PIC (SLPIC) method delivers faster kinetic plasma simulation in cases where the particle distributions evolve slowly compared with the maximum stable PIC…

Computational Physics · Physics 2019-01-09 Gregory R. Werner , Thomas G. Jenkins , Andrew M. Chap , John R. Cary

We discuss a semi-analytical solution of the transport equation for electrons at a non-relativistic shock in the presence of synchrotron energy losses. We calculate the spectrum of accelerated (test) particles at any point upstream and…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Pasquale Blasi

Particle-in-Cell (PIC) simulation codes have wide applicability to first-principles modeling of multidimensional nonlinear plasma phenomena, including wake-field accelerators. This review addresses both finite difference and pseudo-spectral…

Plasma Physics · Physics 2014-08-07 Brendan B. Godfrey

The theory and simulations of quasi-perpendicular and strictly perpendicular collisionless shocks are reviewed. The text is structured into the following sections and subsections: 1. Setting the frame, where the quasi-perpendicular shock…

Astrophysics · Physics 2008-05-16 R. A. Treumann , C. H. Jaroschek

Collisionless shocks occur in various fields of physics. In the context of space and astrophysics they have been investigated for many decades. However, a thorough understanding of shock formation and particle acceleration is still missing.…

Plasma Physics · Physics 2015-09-18 A. Stockem Novo , A. Bret , R. A. Fonseca , L. O. Silva

What are the mechanisms of particle acceleration and radiation, as well as magnetic field build up and decay in relativistic shocks are open questions with important implications to various phenomena in high energy astrophysics. While the…

High Energy Astrophysical Phenomena · Physics 2016-06-06 Evgeny V. Derishev , Tsvi Piran

The limits imposed on diffusive shock acceleration by upstream ion-neutral Alfven wave damping, and by ionisation and Coulomb losses of low energy particles, are calculated. Analytic solutions are given for the steady upstream wave…

Astrophysics · Physics 2008-02-03 L O'C Drury , P Duffy , J G Kirk

Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification…

High Energy Astrophysical Phenomena · Physics 2015-06-09 M E Dieckmann , G Murphy , A Meli , L O C Drury

Shock accelerated electrons are found in many astrophysical environments, and the mechanisms by which they are accelerated to high energies are still not completely clear. For relatively high Mach numbers, the shock is supercritical, and…

Space Physics · Physics 2018-10-17 D. Trotta , D. Burgess

Kinetic approaches provide an effective description of the process of particle acceleration at shock fronts and allow to take into account the dynamical reaction of the accelerated particles as well as the amplification of the turbulent…

Astrophysics · Physics 2009-11-13 Elena Amato , Pasquale Blasi , Stefano Gabici

Context. The diffusive shock acceleration mechanism has been widely accepted as the acceleration mechanism for galactic cosmic rays. While self-consistent hybrid simulations have shown how power-law spectra are produced, detailed…

High Energy Astrophysical Phenomena · Physics 2015-06-04 M. Wolff , R. C. Tautz

Influence of the plasma collisions on the laser-driven collisionless shock formation and subsequent ion acceleration is studied on the basis of two different collisional algorithms and their implementations in two well-known…

Plasma Physics · Physics 2019-07-12 Shikha Bhadoria , Naveen Kumar , Christoph H. Keitel

The most stringent test of theoretical models of the first-order Fermi mechanism at collisionless astrophysical shocks is a comparison of the theoretical predictions with observational data on particle populations. Such comparisons have…

Astrophysics · Physics 2009-10-28 Matthew G. Baring , Keith Ogilvie , Donald Ellison , Robert Forsyth

H-alpha emission from supernova remnants (SNRs) implies the existence of neutral hydrogens in the ambient medium. In the precursor of an SNR shock modified by cosmic rays (CRs), upstream plasmas are pushed by the CR pressure, but neutral…

High Energy Astrophysical Phenomena · Physics 2015-05-14 Yutaka Ohira , Fumio Takahara

The numerical solutions of nonlocal and local Boltzmann kinetic equations for the simulation of peripheral and central heavy ion reactions are compared. The experimental finding of enhancement of mid-rapidity matter shows the necessity to…

Nuclear Theory · Physics 2007-05-23 Klaus Morawetz

The localized deposition of the energy of a laser pulse, as it ablates a solid target, introduces high thermal pressure gradients in the plasma. The thermal expansion of this laser-heated plasma into the ambient medium (ionized residual…

Plasma Physics · Physics 2009-11-30 M E Dieckmann , G Sarri , L Romagnani , I Kourakis , M Borghesi

Stationary solutions to the problem of particle acceleration at shock waves in the non-linear regime, when the dynamical reaction of the accelerated particles on the shock cannot be neglected, are known to show a prominent energy flux…

Astrophysics · Physics 2015-05-13 D. Caprioli , P. Blasi , E. Amato