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Title: DYNAMICS OF HIGH ENERGY IONS AT A STRUCTURED COLLISIONLESS SHOCK FRONT

Abstract

Ions undergoing first-order Fermi acceleration at a shock are scattered in the upstream and downstream regions by magnetic inhomogeneities. For high energy ions this scattering is efficient at spatial scales substantially larger than the gyroradius of the ions. The transition from one diffusive region to the other occurs via crossing the shock, and the ion dynamics during this crossing is mainly affected by the global magnetic field change between the upstream and downstream region. We study the effects of the fine structure of the shock front, such as the foot-ramp-overshoot profile and the phase-standing upstream and downstream magnetic oscillations. We also consider time dependent features, including reformation and large amplitude coherent waves. We show that the influence of the spatial and temporal structure of the shock front on the dependence of the transition and reflection on the pitch angle of the ions is already weak at ion speeds five times the speed of the upstream flow.

Authors:
 [1]; ;  [2]
  1. Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva (Israel)
  2. Institute for Theoretical Physics and Astrophysics, University of Würzburg, Würzburg (Germany)
Publication Date:
OSTI Identifier:
22666080
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 825; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; AMPLITUDES; FINE STRUCTURE; INCLINATION; MAGNETIC FIELDS; OSCILLATIONS; SCATTERING; SHOCK WAVES; TIME DEPENDENCE; VELOCITY

Citation Formats

Gedalin, M., Dröge, W., and Kartavykh, Y. Y., E-mail: gedalin@bgu.ac.il. DYNAMICS OF HIGH ENERGY IONS AT A STRUCTURED COLLISIONLESS SHOCK FRONT. United States: N. p., 2016. Web. doi:10.3847/0004-637X/825/2/149.
Gedalin, M., Dröge, W., & Kartavykh, Y. Y., E-mail: gedalin@bgu.ac.il. DYNAMICS OF HIGH ENERGY IONS AT A STRUCTURED COLLISIONLESS SHOCK FRONT. United States. doi:10.3847/0004-637X/825/2/149.
Gedalin, M., Dröge, W., and Kartavykh, Y. Y., E-mail: gedalin@bgu.ac.il. Sun . "DYNAMICS OF HIGH ENERGY IONS AT A STRUCTURED COLLISIONLESS SHOCK FRONT". United States. doi:10.3847/0004-637X/825/2/149.
@article{osti_22666080,
title = {DYNAMICS OF HIGH ENERGY IONS AT A STRUCTURED COLLISIONLESS SHOCK FRONT},
author = {Gedalin, M. and Dröge, W. and Kartavykh, Y. Y., E-mail: gedalin@bgu.ac.il},
abstractNote = {Ions undergoing first-order Fermi acceleration at a shock are scattered in the upstream and downstream regions by magnetic inhomogeneities. For high energy ions this scattering is efficient at spatial scales substantially larger than the gyroradius of the ions. The transition from one diffusive region to the other occurs via crossing the shock, and the ion dynamics during this crossing is mainly affected by the global magnetic field change between the upstream and downstream region. We study the effects of the fine structure of the shock front, such as the foot-ramp-overshoot profile and the phase-standing upstream and downstream magnetic oscillations. We also consider time dependent features, including reformation and large amplitude coherent waves. We show that the influence of the spatial and temporal structure of the shock front on the dependence of the transition and reflection on the pitch angle of the ions is already weak at ion speeds five times the speed of the upstream flow.},
doi = {10.3847/0004-637X/825/2/149},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 825,
place = {United States},
year = {2016},
month = {7}
}