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Collisionless plasma shocks are efficient sources of non-thermal particle acceleration in space and astrophysical systems. We use hybrid (kinetic ions -- fluid electrons) simulations to examine the non-linear feedback of the self-generated…

High Energy Astrophysical Phenomena · Physics 2020-12-16 Colby C. Haggerty , Damiano Caprioli

The concept of Dielectric Laser Acceleration (DLA) provides highest gradients among non-plasma particle accelerators. However, stable beam transport and staging have not been shown experimentally yet. We present a scheme that confines the…

Accelerator Physics · Physics 2018-11-28 Uwe Niedermayer , Thilo Egenolf , Oliver Boine-Frankenheim , Peter Hommelhoff

The present work considers a plane shock front propagating along a cylindrical jet. Electrons experience the diffusive shock acceleration around the shock front, and subsequently drift away into the downstream flow in which they emit most…

High Energy Astrophysical Phenomena · Physics 2018-07-04 Y. G. Zheng , G. B. Long , C. Y. Yang , J. M. Bai

We investigate the role of the form of the spatial diffusion coefficient in shock acceleration of fast particles. Referring to non-classical diffusion and using the results of numerical (hybrid) simulations tailored for the downstream shock…

Astrophysics · Physics 2008-11-25 R. A. Treumann

Recent observations of non-thermal X-rays from supernova remnants have been attributed to synchrotron radiation from the loss-steepened tail of a non-thermal distribution of electrons accelerated at the remnant blast wave. In diffusive…

Astrophysics · Physics 2009-11-10 S. P. Reynolds

Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Torbjörn Sundberg , Christopher T. Haynes , David Burgess , Christian X. Mazelle

We consider particle acceleration to high energy via diffusive shock acceleration in a simple, self-consistent shock in jet model for blazars. Electrons are assumed to be accelerated at a shock front in relativistic jets and radiate…

Astrophysics · Physics 2007-05-23 F. M. Rieger , J. G. Kirk , A. Mastichiadis

Understanding the conditions conducive to particle acceleration at collisionless, non-relativistic shocks is important for the origin of cosmic rays. We use hybrid (kinetic ions -- fluid electrons) kinetic simulations to investigate…

High Energy Astrophysical Phenomena · Physics 2023-09-07 Luca Orusa , Damiano Caprioli

Collisionless plasma shock theory, which applies for example to the afterglow of gamma ray bursts, still contains key issues that are poorly understood. In this paper we study charged particle dynamics in a highly relativistic collisionless…

Astrophysics · Physics 2009-11-10 C. B. Hededal , T. Haugboelle , J. Trier Frederiksen , Å. Nordlund

We investigate the diffusive shock acceleration in the presence of the non-resonant streaming instability introduced by Bell (2004). The numerical MHD simulations of the magnetic field amplification combined with the analytical treatment of…

Astrophysics · Physics 2009-11-13 V. N. Zirakashvili , V. S. Ptuskin

Recent gamma-ray observations show that middle aged supernova remnants (SNRs) interacting with molecular clouds (MCs) can be sources of both GeV and TeV emission. Based on the MC association, two scenarios have been proposed to explain the…

High Energy Astrophysical Phenomena · Physics 2016-09-13 Xiaping Tang , Roger A. Chevalier

Nonrelativistic electrostatic unmagnetized shocks are frequently observed in laboratory plasmas and they are likely to exist in astrophysical plasmas. Their maximum speed, expressed in units of the ion acoustic speed far upstream of the…

Plasma Physics · Physics 2015-06-15 ME Dieckmann , H Ahmed , G Sarri , D Doria , I Kourakis , L Romagnani , M Pohl , M Borghesi

Transport of fast electron in overdense plasmas is of key importance in high energy density physics. However, it is challenging to diagnose the fast electron transport in experiments. In this article, we study coherent transition radiation…

%context {Recent observations of hard X-rays and very high energy gamma-rays from a number of young shell type supernova remnants indicate the importance of detailed quantitative studies of energy spectra of relativistic electrons formed…

Astrophysics · Physics 2009-11-11 V. N. Zirakashvili , F. Aharonian

We use exact orbit integration to investigate particle acceleration in a Gauss field proxy of magnetohydrodynamic (MHD) turbulence. Regions where the electric current exceeds a critical threshold are declared to be `dissipative' and endowed…

Astrophysics · Physics 2007-05-23 Kaspar Arzner , Loukas Vlahos , Bernard Knaepen , Nicolas Denewet

The theory of diffusive acceleration of energetic particles at shock fronts assumes charged particles undergo spatial diffusion in a uniform magnetic field. If, however, the magnetic field is not uniform, but has a stochastic or braided…

Astrophysics · Physics 2007-05-23 J. G. Kirk , P. Duffy , Y. A. Gallant

We investigate laser induced nonsequential multiple ionization using a simple statistical model in which an electron recollides inelastically with its parent ion. In this collision, it thermalizes with the remaining $N-1$ bound electrons…

Atomic Physics · Physics 2007-05-23 C. Figueira de Morisson Faria , X. Liu

Observations of synchrotron radiation across a wide range of wavelengths provide clear evidence that electrons are accelerated to relativistic energies in supernova remnants (SNRs). However, a viable mechanism for the pre-acceleration of…

Astrophysics · Physics 2007-05-23 M. E. Dieckmann , K. G. McClements , S. C. Chapman , R. O. Dendy , L. O'C. Drury

In this paper, we propose a novel design of dielectric laser-driven accelerator (DLA) utilizing evanescent electric field of racetrack ring resonator structures. Driven by laser light with the correctly designed optical phase window,…

Cosmic rays are charged particles that are accelerated to relativistic speeds by astrophysical shocks. Numerical models have been successful in confirming the acceleration process for (quasi-)parallel shocks, which have the magnetic field…

High Energy Astrophysical Phenomena · Physics 2024-07-09 Allard Jan van Marle , Artem Bohdan , Anabella Araudo , Fabien Casse , Alexandre Marcowith
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