Experimental demonstration of an inertial collimation mechanism in
  nested outflows
  Interaction between a central outflow and a surrounding wind is common in
astrophysical sources powered by accretion. Understanding how the interaction
might help to collimate the inner central outflow is of interest for assessing
astrophysical jet formation paradigms. In this context, we studied the
interaction between two nested supersonic plasma flows generated by focusing a
long pulse high-energy laser beam onto a solid target. A nested geometry was
created by shaping the energy distribution at the focal spot with a dedicated
phase plate. Optical and X-ray diagnostics were used to study the interacting
flows. Experimental results and numerical hydrodynamic simulations indeed show
the formation of strongly collimated jets. Our work experimentally confirms the
"shock-focused inertial confinement" mechanism proposed in previous theoretical
astrophysics investigations.
