气候变化领域集成服务门户(CCPortal): Time-resolved turbulent dynamo in a laser plasma

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DOI	10.1073/pnas.2015729118
	Time-resolved turbulent dynamo in a laser plasma
	Bott A.F.A.; Tzeferacos P.; Chen L.; Palmer C.A.J.; Rigby A.; Bell A.R.; Bingham R.; Birkel A.; Graziani C.; Froula D.H.; Katz J.; Koenig M.; Kunz M.W.; Li C.; Meinecke J.; Miniati F.; Petrasso R.; Park H.-S.; Remington B.A.; Reville B.; Ross J.S.; Ryu D.; Ryutov D.; Séguin F.H.; White T.G.; Schekochihin A.A.; Lamb D.Q.; Gregori G.
发表日期	2021
ISSN	00278424
卷号	118 期号:11
英文摘要	Understanding magnetic-field generation and amplification in turbulent plasma is essential to account for observations of magnetic fields in the universe. A theoretical framework attributing the origin and sustainment of these fields to the so-called fluctuation dynamo was recently validated by experiments on laser facilities in low-magnetic-Prandtl-number plasmas (Pm<1). However, the same framework proposes that the fluctuation dynamo should operate differently when Pm ≳ 1, the regime relevant to many astrophysical environments such as the intracluster medium of galaxy clusters. This paper reports an experiment that creates a laboratory Pm ≳ 1 plasma dynamo. We provide a time-resolved characterization of the plasma's evolution, measuring temperatures, densities, flow velocities, and magnetic fields, which allows us to explore various stages of the fluctuation dynamo's operation on seed magnetic fields generated by the action of the Biermann-battery mechanism during the initial drive-laser target interaction. The magnetic energy in structures with characteristic scales close to the driving scale of the stochastic motions is found to increase by almost three orders of magnitude and saturate dynamically. It is shown that the initial growth of these fields occurs at a much greater rate than the turnover rate of the driving-scale stochastic motions. Our results point to the possibility that plasma turbulence produced by strong shear can generate fields more efficiently at the driving scale than anticipated by idealized magnetohydrodynamics (MHD) simulations of the nonhelical fluctuation dynamo; this finding could help explain the large-scale fields inferred from observations of astrophysical systems. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Fluctuation dynamo; Laboratory astrophysics; Magnetic fields
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180221
作者单位	Department of Physics, University of Oxford, Oxford, OX1 3PU, United Kingdom; Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, United States; Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637, United States; Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627, United States; Laboratory for Laser Energetics, University of Rochester, Rochester, NY 14623, United States; School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, United Kingdom; Central Laser Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, United Kingdom; Department of Physics, University of Strathclyde, Glasgow, G4 0NG, United Kingdom; Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, IL 60439, United States; Laboratoire pour l'Utilisation des Laser Intenses, CNRS, Commiss...
推荐引用方式 GB/T 7714	Bott A.F.A.,Tzeferacos P.,Chen L.,et al. Time-resolved turbulent dynamo in a laser plasma[J],2021,118(11).
APA	Bott A.F.A..,Tzeferacos P..,Chen L..,Palmer C.A.J..,Rigby A..,...&Gregori G..(2021).Time-resolved turbulent dynamo in a laser plasma.Proceedings of the National Academy of Sciences of the United States of America,118(11).
MLA	Bott A.F.A.,et al."Time-resolved turbulent dynamo in a laser plasma".Proceedings of the National Academy of Sciences of the United States of America 118.11(2021).