A1 Refereed original research article in a scientific journal
Acceleration of Energetic Particles Through Self-Generated Waves in a Decelerating Coronal Shock
Authors: Battarbee M, Laitinen T, Vainio R, Agueda N
Publication year: 2010
Journal: AIP Conference Proceedings
Book title : TWELFTH INTERNATIONAL SOLAR WIND CONFERENCE. AIP Conference Proceedings
Journal name in source: TWELFTH INTERNATIONAL SOLAR WIND CONFERENCE
Journal acronym: AIP CONF PROC
Volume: 1216
First page : 84
Last page: 87
Number of pages: 4
ISBN: 978-0-7354-0759-6
ISSN: 0094-243X
DOI: https://doi.org/10.1063/1.3395969
Abstract
We have developed a simulation model of particle acceleration in coronal shock waves. The model is based on a Monte Carlo method, where particles are traced in prescribed large-scale electromagnetic fields utilizing the guiding center approximation. The particles are scattered in the turbulence according to quasilinear theory, with the scattering amplitude directly proportional to the intensity of Alfven waves at gyro-resonant wavenumbers. The Alfven waves are traced simultaneously with the particles, so that the wave field is propagated outwards from the Sun using WKB propagation supplemented with a phenomenological wavenumber diffusion term and a growth rate computed from the net flux of the accelerated particles. We consider initial wave amplitudes small enough to allow rapid escape of particles from the shock to the ambient medium. Thus, in our model the Alfven waves responsible for the diffusive acceleration of particles are generated by the accelerated particles themselves. In this work, we study the effects of non-constant shock velocity and non-monotonic Alfven velocity on particle acceleration scenarios. We report in particular how the deceleration of a shock affects particle intensity and turbulence power evolution in the vicinity of the shock.
We have developed a simulation model of particle acceleration in coronal shock waves. The model is based on a Monte Carlo method, where particles are traced in prescribed large-scale electromagnetic fields utilizing the guiding center approximation. The particles are scattered in the turbulence according to quasilinear theory, with the scattering amplitude directly proportional to the intensity of Alfven waves at gyro-resonant wavenumbers. The Alfven waves are traced simultaneously with the particles, so that the wave field is propagated outwards from the Sun using WKB propagation supplemented with a phenomenological wavenumber diffusion term and a growth rate computed from the net flux of the accelerated particles. We consider initial wave amplitudes small enough to allow rapid escape of particles from the shock to the ambient medium. Thus, in our model the Alfven waves responsible for the diffusive acceleration of particles are generated by the accelerated particles themselves. In this work, we study the effects of non-constant shock velocity and non-monotonic Alfven velocity on particle acceleration scenarios. We report in particular how the deceleration of a shock affects particle intensity and turbulence power evolution in the vicinity of the shock.
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