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

Proc Natl Acad Sci U S A. 2015 Jul 7;112(27):8211-5. doi: 10.1073/pnas.1502079112. Epub 2015 Jun 22.


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.

Keywords: galaxy clusters; laboratory analogues; lasers; magnetic fields; turbulence.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Astronomical Phenomena*
  • Computer Simulation
  • Galaxies*
  • Lasers
  • Magnetic Fields*
  • Models, Theoretical*
  • Solar System
  • Spectrum Analysis
  • Temperature
  • Thermodynamics