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Departure from MHD prescriptions in shock formation over a guiding magnetic field

Published online by Cambridge University Press:  09 August 2017

A. Bret*
Affiliation:
ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real, Spain
A. Pe'er
Affiliation:
Physics Department, University College Cork, Cork, Ireland
L. Sironi
Affiliation:
Department of Astronomy, Columbia University, New York, NY 10027, USA
M.E. Dieckmann
Affiliation:
Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden
R. Narayan
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51 Cambridge, MA 02138, USA
*
Address correspondence and reprint requests to: A. Bret, ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain and Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real, Spain. E-mail: antoineclaude.bret@uclm.es

Abstract

In plasmas where the mean-free-path is much larger than the size of the system, shock waves can arise with a front much shorter than the mean-free-path. These so-called “collisionless shocks” are mediated by collective plasma interactions. Studies conducted so far on these shocks found that although binary collisions are absent, the distribution functions are thermalized downstream by scattering on the fields, so that magnetohydrodynamics prescriptions may apply. Here we show a clear departure from this pattern in the case of Weibel shocks forming over a flow-aligned magnetic field. A micro-physical analysis of the particle motion in the Weibel filaments shows how they become unable to trap the flow in the presence of too strong a field, inhibiting the mechanism of shock formation. Particle-in-cell simulations confirm these results.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2017 

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References

REFERENCES

Bale, S.D., Mozer, F.S. & Horbury, T.S. (2003). Density-transition scale at quasiperpendicular collisionless shocks. Phys. Rev. Lett. 91, 265004.CrossRefGoogle ScholarPubMed
Blandford, R.D. & McKee, C.F. (1976). Fluid dynamics of relativistic blast waves. Phys. Fluids 19, 1130.CrossRefGoogle Scholar
Bret, A. (2012). CfA Plasma Talks. ArXiv:1205.6259.Google Scholar
Bret, A. (2015 a). Collisional behaviors of astrophysical collisionless plasmas. J. Plasma Phys. 81, 455810202.CrossRefGoogle Scholar
Bret, A. (2015 b). Particles trajectories in magnetic filaments. Phys. Plasmas 22, 072116.CrossRefGoogle Scholar
Bret, A. (2016 a). Hierarchy of instabilities for two counter-streaming magnetized pair beams. Phys. Plasmas 23, 062122.CrossRefGoogle Scholar
Bret, A. (2016 b). Particles trajectories in Weibel magnetic filaments with a flow-aligned magnetic field. J. Plasma Phys. 82, 905820403.CrossRefGoogle Scholar
Bret, A., Gremillet, L. & Dieckmann, M.E. (2010). Multidimensional electron beam-plasma instabilities in the relativistic regime. Phys. Plasmas 17, 120501.CrossRefGoogle Scholar
Bret, A., Stockem, A., Fiúza, F., Pérez Álvaro, E., Ruyer, C., Narayan, R. & Silva, L.O. (2013 a). The formation of a collisionless shock. Laser Part. Beams 31, 487491.CrossRefGoogle Scholar
Bret, A., Stockem, A., Fiuza, F., Ruyer, C., Gremillet, L., Narayan, R. & Silva, L.O. (2013 b). Collisionless shock formation, spontaneous electromagnetic fluctuations, and streaming instabilities. Phys. Plasmas 20, 042102.CrossRefGoogle Scholar
Bret, A., Stockem, A., Narayan, R. & Silva, L.O. (2014). Collisionless Weibel shocks: Full formation mechanism and timing. Phys. Plasmas 21, 072301.CrossRefGoogle Scholar
Bret, A., Stockem Novo, A., Narayan, R., Ruyer, C., Dieckmann, M.E. & Silva, L.O. (2016). Theory of the formation of a collisionless Weibel shock: pair vs. electron/proton plasmas. Laser Part. Beams 34, 362367.CrossRefGoogle Scholar
Buneman, O. (1993). Tristan: the 3-d electromagnetic particle code. In Computer Space Plasma Physics (Matsumoto, H. and Omura, Y., Eds.), p. 67. Tokyo: Terra Scientific.Google Scholar
Davidson, R.C., Hammer, D.A., Haber, I. & Wagner, C.E. (1972). Nonlinear development of electromagnetic instabilities in anisotropic plasmas. Phys. Fluids 15, 317.CrossRefGoogle Scholar
Dieckmann, M.E., Ahmed, H., Sarri, G., Doria, D., Kourakis, I., Romagnani, L., Pohl, M. & Borghesi, M. (2013). Parametric study of non-relativistic electrostatic shocks and the structure of their transition layer. Phys. Plasmas 20, 042111.CrossRefGoogle Scholar
Dieckmann, M.E. & Bret, A. (2017). Simulation study of the formation of a non-relativistic pair shock. J. Plasma Phys., 83, 905830104.CrossRefGoogle Scholar
Gerbig, D. & Schlickeiser, R. (2011). Jump conditions for relativistic magnetohydrodynamic shocks in a gyrotropic plasma. Astrophys. J. 733, 32.CrossRefGoogle Scholar
Grassi, A., Grech, M., Amiranoff, F., Pegoraro, F., Macchi, A. & Riconda, C. (2017). Electron Weibel instability in relativistic counterstreaming plasmas with flow-aligned external magnetic fields. Phys. Rev. E 95, 023203.CrossRefGoogle ScholarPubMed
Gurnett, D. & Bhattacharjee, A. (2005). Introduction to Plasma Physics: With Space and Laboratory Applications. Cambridge: Cambridge University Press.CrossRefGoogle Scholar
Lichnerowicz, A. (1976). Shock waves in relativistic magnetohydrodynamics under general assumptions. J. Math. Phys. 17, 21352142.CrossRefGoogle Scholar
Majorana, A. & Anile, A.M. (1987). Magnetoacoustic shock waves in a relativistic gas. Phys. Fluids 30, 30453049.CrossRefGoogle Scholar
Marcowith, A., Bret, A., Bykov, A., Dieckman, M.E., Drury, L., Lembège, B., Lemoine, M., Morlino, G., Murphy, G., Pelletier, G., Plotnikov, I., Reville, B., Riquelme, M., Sironi, L. & Stockem Novo, A. (2016). The microphysics of collisionless shock waves. Rep. Progr. Phys. 79, 046901.CrossRefGoogle ScholarPubMed
Park, H.-S., Ross, J.S., Huntington, C.M., Fiuza, F., Ryutov, D., Casey, D., Drake, R.P., Fiksel, G., Froula, D., Gregori, G., Kugland, N.L., Kuranz, C., Levy, M.C., Li, C.K., Meinecke, J., Morita, T., Petrasso, R., Plechaty, C., Remington, B., Sakawa, Y., Spitkovsky, A., Takabe, H. & Zylstra, A.B. (2016). Laboratory astrophysical collisionless shock experiments on Omega and NIF. J. Phys. Conf. Ser. 688, 012084.CrossRefGoogle Scholar
Pelletier, G., Bykov, A., Ellison, D. & Lemoine, M. (2017). Towards understanding the physics of collisionless relativistic shocks. Space Sci. Rev. 207, 319360.CrossRefGoogle Scholar
Petschek, H.E. (1958). Aerodynamic dissipation. Rev. Mod. Phys. 30, 966974.CrossRefGoogle Scholar
Ruyer, C., Gremillet, L., Bonnaud, G. & Riconda, C. (2017). A self-consistent analytical model for the upstream magnetic-field and ion-beam properties in Weibel-mediated collisionless shocks. Phys. Plasmas 24, 041409.CrossRefGoogle Scholar
Sagdeev, R. & Kennel, C. (1991). Collisionless shock waves. Sci. Am. (USA) 264, 4.Google Scholar
Sagdeev, R.Z. (1966). Cooperative phenomena and shock waves in collisionless plasmas. Rev. Plasma Phys. 4, 23.Google Scholar
Schwartz, S.J., Henley, E., Mitchell, J. & Krasnoselskikh, V. (2011). Electron temperature gradient scale at collisionless shocks. Phys. Rev. Lett. 107, 215002.CrossRefGoogle ScholarPubMed
Spitkovsky, A. (2005). Simulations of relativistic collisionless shocks: shock structure and particle acceleration. In Astrophysical Sources of High Energy Particles and Radiation, volume 801 of American Institute of Physics Conference Series (Bulik, T., Rudak, B. and Madejski, G., Eds.), pp. 345350. Melville, NY: AIP.Google Scholar
Spitkovsky, A. (2008). On the structure of relativistic collisionless shocks in electron–ion plasmas. Astrophys. J. Lett. 673, L39L42.CrossRefGoogle Scholar
Stockem, A., Fiuza, F., Bret, A., Fonseca, R. & Silva, L. (2014). Exploring the nature of collisionless shocks under laboratory conditions. Sci. Rep. 4, 3934.CrossRefGoogle ScholarPubMed
Stockem, A., Fiúza, F., Fonseca, R.A. & Silva, L.O. (2012). The impact of kinetic effects on the properties of relativistic electron–positron shocks. Plasma Phys. Controll. Fusion 54, 125004.CrossRefGoogle Scholar
Stockem, A., Lerche, I. & Schlickeiser, R. (2006). On the physical realization of two-dimensional turbulence fields in magnetized interplanetary plasmas. Astrophys. J. 651, 584.CrossRefGoogle Scholar
Stockem Novo, A., Bret, A., Fonseca, R.A. & Silva, L.O. (2015). Shock formation in electron-ion plasmas: mechanism and timing. Astrophys. J. Lett. 803, L29.CrossRefGoogle Scholar
Treumann, R.A. (2009). Fundamentals of collisionless shocks for astrophysical application, 1. Non-relativistic shocks. Astron. Astrophys. Rev. 17, 409535.CrossRefGoogle Scholar
Yuan, D., Li, Y., Liu, M., Zhong, J., Zhu, B., Li, Y., Wei, H., Han, B., Pei, X., Zhao, J., Li, F., Zhang, Z., Liang, G., Wang, F., Weng, S., Li, Y., Jiang, S., Du, K., Ding, Y., Zhu, B., Zhu, J., Zhao, G. & Zhang, J. (2017). Formation and evolution of a pair of collisionless shocks in counter-streaming flows. Sci. Rep. 7, 42915.CrossRefGoogle ScholarPubMed
Zel'dovich, I. & Raizer, Y. (2002). Physics of Shock Waves and High-Temperature Hydrodynamic Phenomena. Mineola: Dover Books on Physics, Dover Publications.Google Scholar