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On the quasi-collisionality of plasmas with small-scale electric turbulence

Part of: Collisions in Collisionless Plasmas Focus on Plasma Astrophysics

Published online by Cambridge University Press:  18 April 2016

Brett D. Keenan Open the ORCID record for Brett D. Keenan [Opens in a new window]  and
Mikhail V. Medvedev
Brett D. Keenan*
Affiliation:
Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA
Mikhail V. Medvedev
Affiliation:
Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045, USA
*
†Email address for correspondence: bdkeenan@ku.edu
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Abstract

Chaotic electromagnetic fields are common in many relativistic plasma environments, where they can be excited by instabilities on kinetic spatial scales. When strong electric fluctuations exist on sub-electron scales, they may lead to small angle, stochastic deflections of the electrons’ pitch angles. Under certain conditions, this closely resembles the effect of Coulomb collisions in collisional plasmas. The electric pitch-angle diffusion coefficient acts as an effective collision – or ‘quasi-collision’ – frequency. We show that quasi-collisions may radically alter the expected radiative transport properties of candidate plasmas. In particular, we consider the quasi-collisional generalization of the classical Faraday effect.

Type
Research Article
Information
Journal of Plasma Physics , Volume 82 , Issue 2 , April 2016 , 305820201
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Copyright
© Cambridge University Press 2016 

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