Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-25T01:01:56.293Z Has data issue: false hasContentIssue false

The scaling of collisionless magnetic reconnection in an electron–positron plasma with non-scalar pressure

Published online by Cambridge University Press:  20 December 2012

M. HOSSEINPOUR
Affiliation:
Department of Atomic and Molecular Physics, Faculty of Physics, University of Tabriz, Tabriz, Iran (hosseinpour@tabrizu.ac.ir)
M. A. MOHAMMADI
Affiliation:
Department of Atomic and Molecular Physics, Faculty of Physics, University of Tabriz, Tabriz, Iran (hosseinpour@tabrizu.ac.ir)
S. BIABANI
Affiliation:
Department of Atomic and Molecular Physics, Faculty of Physics, University of Tabriz, Tabriz, Iran (hosseinpour@tabrizu.ac.ir)

Abstract

Collisionless magnetic reconnection via tearing instability in non-relativistic electron–positron (pair) plasma with an anisotropic pressure is investigated. The equilibrium magnetic field is considered to be sheared force-free, and a set of linearized collisionless Magnetohydrodynamics equations describes the evolution of reconnection dynamics. A linear analytical analysis, based on scaling, demonstrates that in such a pair plasma, breaking the frozen in flow constraint for field lines can be mainly provided by the non-gyrotropic pressure of electrons and positrons (rather than the particle bulk inertia) when the current sheet width is smaller than the particle Larmor radius (Δx < rL). This condition is satisfied when β > d2 (d = cp is the particle skin-depth with the electron/positron frequency ωp and β = 8πP(0)/B02 ⪡ 1). Meanwhile, on top of the Lorentz force and in the absence of the reconnection facilitating mechanism of the Hall effect, non-scalar pressure force can accelerate bulk plasma into the diffusion region at the scale lengths of the order of dx. Therefore, the respective regime of tearing instability proceeds much faster compared with the case of an isotropic pressure with a new dimensionless growth rate of (γτA) ~ d.

Type
Papers
Copyright
Copyright © Cambridge University Press 2012 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bessho, N. and Bhattacharjee, A. 2005 Collisionless reconnection in an electron-positron plasma. Phys. Rev. Lett. 95, 245001.CrossRefGoogle Scholar
Bessho, N. and Bhattacharjee, A. 2007 Fast collisionless reconnection in electron-positron plasmas. Phys. Plasmas 14, 056503.CrossRefGoogle Scholar
Bessho, N. and Bhattacharjee, A. 2010 Fast magnetic reconnection in low-density electron-positron plasmas. Phys. Plasmas 17, 102104.CrossRefGoogle Scholar
Cai, H., Li, D. and Zheng, J. 2009 Tearing modes with pressure gradient effect in pair plasmas. Phys. Plasmas 16, 042106.CrossRefGoogle Scholar
Daughton, W. and Karimabadi, H. 2007 Collisionless magnetic reconnection in large-scale electron-positron plasmas. Phys. Plasmas 14, 072303.CrossRefGoogle Scholar
Drenkhahn, G. 2002 Acceleration of GRB outflows by Poynting flux dissipation. Astron. Astrophys. 387, 714.CrossRefGoogle Scholar
Furth, H. P., Killeen, J. and Rosenbluth, M. N. 1963 Finite-resistivity instabilities of a sheet pinch. Phys. Fluids 6, 459.CrossRefGoogle Scholar
Greaves, R. G. and Surko, C. M. 1995 An electron-positron beam-plasma experiment. Phys. Rev. Lett. 75, 3846.CrossRefGoogle ScholarPubMed
Hosseinpour, M. and Vekstein, G. 2008 Collisionless forced magnetic reconnection in an electron-positron plasma. Phys. Plasmas 15, 022904.CrossRefGoogle Scholar
Karlicky, M. 2008 Separation of accelerated electrons and positrons in the relativistic reconnection. Astrophys. J. 674, 12111216.CrossRefGoogle Scholar
Larrabee, D. A., Lovelace, R. V. E. and Romanova, M. M. 2003 Lepton acceleration by relativistic collisionless magnetic reconnection. Astrophys. J. 586, 72.CrossRefGoogle Scholar
Lesch, H. and Birk, G. T. 1998 On the origin of extended nonthermal optical emission in extragalactic jets. Astrophys. J. 499, 167171.CrossRefGoogle Scholar
Lewis, W., Antiochos, S. and Drake, J. (eds.) 2012 Magnetic Reconnection: Theoretical and Observational Perspectives. New York: Springer.CrossRefGoogle Scholar
Lyubarsky, Y. and Kirk, J. 2001 Reconnection in a striped pulsar wind. Astrophys. J. 547, 437.CrossRefGoogle Scholar
Pedersen, T. S.et al. 2012 Plans for the creation and studies of electron-positron plasmas in a stellarator. New J. Phys. 14, 035010.CrossRefGoogle Scholar
Priest, E. and Forbes, T. 2000 Magnetic Reconnection: MHD Theory and Applications. Cambridge, UK: Cambridge University Press.CrossRefGoogle Scholar
Pritchett, P. 1995 The collisionless coalescence instability with two-species and in-plane current effects. Phys. Plasmas 2, 2664.CrossRefGoogle Scholar
Shukla, P. K., Jammalamadaka, S. and Stenflo, L. 1996 Inertia driven tearing modes in electron-positron plasmas. Astrophys. Space Sci. 240, 153156CrossRefGoogle Scholar
Shukla, P. K., Yu, M. U. and Stenflo, L., 1986 Nonlinear connective motion in a rotating magnetized electron-positron plasma. Astrophys. Space Sci. 127, 371.CrossRefGoogle Scholar
Stenflo, L., Shukla, P. K. and Yu, M. U. 1986 Nonlinear propagation of electromagnetic waves in magnetized electron-positron plasmas. Astrophys. Space Sci. 117, 303.CrossRefGoogle Scholar
Wardle, J. F. C., Homan, D. C., Ojha, R. and Roberts, D. H. 1998 Electron-positron jets associated with the quasar 3C 279. Nature 395, 457461.CrossRefGoogle Scholar
Yamada, M., Kulsrud, R. and Ji, H. 2010 Magnetic reconnection. Rev. Mod. Phys. 82, 603664.CrossRefGoogle Scholar
Yu, M. U., Shukla, P. K. and Stenflo, L. 1986 Alfven vortices in a strongly magnetized electron-positron plasma. Astrophys. J. 309, L63.CrossRefGoogle Scholar
Zenitani, S., Hesse, M. and Klimas, A. 2009 Two-fluid magnetohydrodynamic simulations of relativistic magnetic reconnection. Astrophys. J. 696, 1385.CrossRefGoogle Scholar
Zenitani, S. and Hoshino, M. 2001 The generation of non-thermal particles in relativistic magnetic reconnection of pair plasmas. Astrophys. J. 562, L63.CrossRefGoogle Scholar
Zweibel, E. G. and Yamada, M. 2009 Magnetic reconnection in astrophysical and laboratory plasmas. Ann. Rev. Astron. Astrophys. 47, 291332.CrossRefGoogle Scholar