Title: Laboratory evidence of dynamo amplification of magnetic fields in a turbulent plasma,
Abstract: Magnetic fields are ubiquitous in the Universe. Extragalactic disks, halos
and clusters have consistently been shown, via diffuse radio-synchrotron
emission and Faraday rotation measurements, to exhibit magnetic field strengths
ranging from a few nG to tens of $\mu$G. The energy density of these fields is
typically comparable to the energy density of the fluid motions of the plasma
in which they are embedded, making magnetic fields essential players in the
dynamics of the luminous matter. The standard theoretical model for the origin
of these strong magnetic fields is through the amplification of tiny seed
fields via turbulent dynamo to the level consistent with current observations.
Here we demonstrate, using laser-produced colliding plasma flows, that
turbulence is indeed capable of rapidly amplifying seed fields to near
equipartition with the turbulent fluid motions. These results support the
notion that turbulent dynamo is a viable mechanism responsible for the observed
present-day magnetization of the Universe.