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

作者：Meinecke Jena^*; Tzeferacos Petros; Bell Anthony; Bingham Robert; Clarke Robert; Churazov Eugene; Crowston Robert; Doyle Hugo; Drake R Paul; Heathcote Robert; Koenig Michel; Kuramitsu Yasuhiro; Kuranz Carolyn; Lee Dongwook; MacDonald Michael; Murphy Christopher; Notley Margaret; Park Hye Sook; Pelka Alexander; Ravasio Alessandra; Reville Brian; Sakawa Youichi; Wan Willow; Woolsey Nigel; Yurchak Roman; Miniati Francesco; Schekochihin Alexander; Lamb Don

来源：Proceedings of the National Academy of Sciences, 2015, 112(27): 8211-8215.

DOI：10.1073/pnas.1502079112

• galaxy clusters
• laboratory analogues
• lasers
• magnetic fields
• turbulence

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.

• 出版日期2015-7-7
• 单位中央民族大学