Developed turbulence and nonlinear amplification of magnetic fields in laboratory and astrophysical plasmas

Meinecke, Jena and Tzeferacos, Petros and Bell, Anthony and Bingham, Robert and Clarke, Robert and Churazov, Eugene and Crowston, Robert and Doyle, Hugo and Drake, R. Paul and Heathcote, Robert and Koenig, Michel and Kuramitsu, Yasuhiro and Kuranz, Carolyn and Lee, Dongwook and MacDonald, Michael and Murphy, Christopher and Notley, Margaret and Park, Hye-Sook and Pelka, Alexander and Ravasio, Alessandra and Reville, Brian and Sakawa, Youichi and Wan, Willow and Woolsey, Nigel and Yurchak, Roman and Miniati, Francesco and Schekochihin, Alexander and Lamb, Don and Gregori, Gianluca (2015) Developed turbulence and nonlinear amplification of magnetic fields in laboratory and astrophysical plasmas. Proceedings of the National Academy of Sciences, 112 (27). pp. 8211-8215. ISSN 0027-8424

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    Abstract

    The visible matter in the universe is turbulent and magnetized. Turbulence in galaxy clusters is produced by mergers and by jets of the central galaxies and believed responsible for the amplification of magnetic fields. We report on experiments looking at the collision of two laser-produced plasma clouds, mimicking, in the laboratory, a cluster merger event. By measuring the spectrum of the density fluctuations, we infer developed, Kolmogorov-like turbulence. From spectral line broadening, we estimate a level of turbulence consistent with turbulent heating balancing radiative cooling, as it likely does in galaxy clusters. We show that the magnetic field is amplified by turbulent motions, reaching a nonlinear regime that is a precursor to turbulent dynamo. Thus, our experiment provides a promising platform for understanding the structure of turbulence and the amplification of magnetic fields in the universe.