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Transition in electron physics of magnetic reconnection in weakly collisional plasma

Published online by Cambridge University Press:  06 November 2014

A. Le*
Affiliation:
SciberQuest, Inc., Del Mar, CA 92014, USA Center for Space Plasma Physics, Space Science Institute, Boulder, CO 80301, USA
J. Egedal
Affiliation:
Department of Physics, University of Wisconsin–Madison, Madison, WI 53706, USA
W. Daughton
Affiliation:
Los Alamos National Laboratory, Los Alamos, NM 87545, USA
V. Roytershteyn
Affiliation:
SciberQuest, Inc., Del Mar, CA 92014, USA
H. Karimabadi
Affiliation:
SciberQuest, Inc., Del Mar, CA 92014, USA
C. Forest
Affiliation:
Department of Physics, University of Wisconsin–Madison, Madison, WI 53706, USA
*
Email address for correspondence: ale@spacescience.org

Abstract

Using particle-in-cell (PIC) simulations with a Monte Carlo treatment of the Coulomb collision operator, we study the transition in electron dynamics of magnetic reconnection for various levels of collisionality. The weakly collisional cases considered all fall into the so-called Hall or kinetic regime. Nevertheless, collisions may still alter the electron kinetic physics characteristic of collisionless reconnection, where adiabatic trapping energizes the electrons and leads to strong anisotropy of the electron velocity distribution and pressure. This anisotropy can support extended current sheets, associated with secondary island formation and turbulent flux rope interactions in three dimensional systems. The collisional simulations demonstrate how weak collisions may modify or eliminate these electron structures in the kinetic regimes. While the reconnection rate is not sensitive to the collisionality in the range studied, we find that increasing collisionality reduces the level of electron energization near the reconnection site. Finally, the results provide guidance for new laboratory reconnection experiments that will access the weakly collisional regimes.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2014 

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References

REFERENCES

Aydemir, A. Y. 1992 Nonlinear studies of m=1 modes in high-temperature plasmas. Phys. Fluids B 4 (11), 34693472.Google Scholar
Birn, J. et al. 2001 Geospace environmental modeling (GEM) magnetic reconnection challenge. J. Geophys. Res. 106 (A3), 37153719.CrossRefGoogle Scholar
Bowers, K. J., Albright, B. J., Yin, L., Bergen, B. and Kwan, T. J. T. 2008 Ultrahigh performance three-dimensional electromagnetic relativistic kinetic plasma simulation. Phys. Plasmas 15 (5), 055 703.Google Scholar
Buchner, J and Zelenyi, L. M. 1989 Regular and chaotic charged-particle motion in magnetotail-like field reversals:1. Basic theory of trapped motion. J. Geophys. Res. 94 (A9), 11 82111 842.CrossRefGoogle Scholar
Burge, C. A., MacKinnon, A. L. and Petkaki, P. 2014 Effect of binary collisions on electron acceleration in magnetic reconnection. Astron. Astrophys. 561, A107, 13pp.Google Scholar
Chen, L. J. et al. 2009 Multispacecraft observations of the electron current sheet, neighboring magnetic islands, and electron acceleration during magnetotail reconnection. Phys. Plasmas 16 (5), 056 501.CrossRefGoogle Scholar
Daughton, W., Nakamura, T. K. M., Karimabadi, H., Roytershteyn, V. and Loring, B. 2014 Computing the reconnection rate in turbulent kinetic layers by using electron mixing to identify topology. Phys. Plasmas (1994-present) 21 (5), 052 307.Google Scholar
Daughton, W. and Roytershteyn, V. 2012 Emerging parameter space map of magnetic reconnection in collisional and kinetic regimes. Space Sci. Rev. 172 (1–4), 271282.Google Scholar
Daughton, W., Roytershteyn, V., Albright, B. J., Karimabadi, H., Yin, L. and Bowers, K. J. 2009a. Phys. Plasmas 16 (7), 072 117.Google Scholar
Daughton, W., Roytershteyn, V., Albright, B. J., Karimabadi, H., Yin, L. and Bowers, K. J. 2009b Transition from collisional to kinetic regimes in large-scale reconnection layers. Phys. Rev. Lett. 103 (6), 065 004.Google Scholar
Daughton, W., Roytershteyn, V., Karimabadi, H., Yin, L., Albright, B. J., Bergen, B. and Bowers, K. J. 2011 Role of electron physics in the development of turbulent magnetic reconnection in collisionless plasmas. Nature Phys. 7 (7), 539542.Google Scholar
Daughton, W., Scudder, J. and Karimabadi, H. 2006 Fully kinetic simulations of undriven magnetic reconnection with open boundary conditions. Phys. Plasmas 13 (7), 072 101.Google Scholar
Egedal, J., Daughton, W. and Le, A. 2012 Large-scale electron acceleration by parallel electric fields during magnetic reconnection. Nature Phys. 8 (4), 321324.Google Scholar
Egedal, J., Fox, W., Katz, N., Porkolab, M., Oieroset, M., Lin, R. P., Daughton, W. and Drake, J. F. 2008 Evidence and theory for trapped electrons in guide field magnetotail reconnection. J. Geophys. Res. 113 (6), A12 207.Google Scholar
Egedal, J., Le, A. and Daughton, W. 2013 A review of pressure anisotropy caused by electron trapping in collisionless plasma, and its implications for magnetic reconnection. Phys. Plasmas 20 (6), 061 201.Google Scholar
Goldman, M. V., Lapenta, G., Newman, D. L., Markidis, S. and Che, H. 2011 Jet deflection by very weak guide fields during magnetic reconnection. Phys. Rev. Lett. 107 (13), 135 001.Google Scholar
Hesse, M., Zenitani, S. and Klimas, A. 2008 The structure of the electron outflow jet in collisionless magnetic reconnection. Phys. Plasmas 15 (11), 112 102.Google Scholar
Hinton, F. L. and Hazeltine, R. D. 1976 Theory of plasma transport in toroidal confinement systems. Rev. Mod. Phys. 48 (2), 239308.CrossRefGoogle Scholar
Ji, H. and Daughton, W. 2011 Phase diagram for magnetic reconnection in heliophysical, astrophysical, and laboratory plasmas. Phys. Plasmas 18 (11), 111 207.Google Scholar
Karimabadi, H., Daughton, W. and Scudder, J. 2007 Multi-scale structure of the electron diffusion region. Geophys. Res. Lett. 34 (13), L13 104.CrossRefGoogle Scholar
Kulsrud, R. M. 2001 Magnetic reconnection: Sweet–Parker versus Petschek. Earth, Planets Space 53, 417422.Google Scholar
Le, A., Egedal, J., Daughton, W., Drake, J. F., Fox, W. and Katz, N. 2010 Magnitude of the Hall fields during magnetic reconnection. Geophys. Res. Lett. 37 (3), L03 106.Google Scholar
Le, A., Egedal, J., Daughton, W., Fox, W. and Katz, N. 2009 Equations of state for collisionless guide-field reconnection. Phys. Rev. Lett. 102 (8), 085 001.CrossRefGoogle ScholarPubMed
Le, A., Egedal, J., Ohia, O., Daughton, W., Karimabadi, H. and Lukin, V. S. 2013 Regimes of the electron diffusion region in magnetic reconnection. Phys. Rev. Lett. 110 (13), 135 004.Google Scholar
Ma, Z. W. and Bhattacharjee, A. 1996 Fast impulsive reconnection and current sheet intensification due to electron pressure gradients in semi-collisional plasmas. Geophys. Res. Lett. 23 (13), 16731676.CrossRefGoogle Scholar
Ng, J., Egedal, J., Le, A., Daughton, W. and Chen, L. J. 2011 Kinetic structure of the electron diffusion region in antiparallel magnetic reconnection. Phys. Rev. Lett. 106 (6).Google Scholar
Ohia, O., Egedal, J., Lukin, V. S., Daughton, W. and Le, A. 2012 Demonstration of anisotropic fluid closure capturing the kinetic structure of magnetic reconnection. Phys. Rev. Lett. 109 (11), 115 004.Google Scholar
Parker, E. N. 1957 Sweet's mechanism for merging magnetic fields in conducting fluids. J. Geophys. Res. 62 (4), 509520.Google Scholar
Priest, E. and Forbes, T. 2000 Magnetic Reconnection. Cambridge University Press.Google Scholar
Roytershteyn, V. et al. 2010 Driven magnetic reconnection near the Dreicer limit. Phys. Plasmas 17 (5), 055 706.Google Scholar
Shay, M. A., Drake, J. F. and Swisdak, M. 2007 Two-scale structure of the electron dissipation region during collisionless magnetic reconnection. Phys. Rev. Lett. 99 (15), 155 002.Google Scholar
Spitzer, L. and Härm, R. 1953 Transport phenomena in a completely ionized gas. Phys. Rev. 89 (5), 977981.Google Scholar
Takizuka, T. and Abe, H. 1977 A binary collision model for plasma simulation with a particle code. J. Comput. Phys. 25 (3), 205219.Google Scholar