| Issue |
J. Phys. IV France
Volume 133, June 2006
|
|
|---|---|---|
| Page(s) | 1019 - 1023 | |
| DOI | https://doi.org/10.1051/jp4:2006133206 | |
| Published online | 16 June 2006 | |
J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 1019-1023
DOI: 10.1051/jp4:2006133206
Laboratory-astrophysics jet experiments at the omega laser facility
P.A. Rosen1, J.M. Foster1, R.J.R. Williams1, B.H. Wilde2, R.F. Coker2, B. Blue3, T.S. Perry3, P. Hartigan4, R.P. Drake5, K. Dannenberg5, A.M. Khokhlov6, A. Frank7 and J.P. Knauer71 Atomic Weapons Establishment, Aldermaston, Reading RG7 4PR, UK
2 Los Alamos National Laboratory, New Mexico 87545, USA
3 Lawrence Livermore National Laboratory, California 94550, USA
4 Rice University, Houston, Texas 77005, USA
5 University of Michigan, Ann Arbor, Michigan 48109-2143, USA
6 University of Chicago, Chicago, Illinois 60637, USA
7 University of Rochester, New York 14623, USA
Abstract
Supersonic collimated jets are ubiquitous phenomena in
astrophysics. Detailed information about astrophysical jets has
traditionally come only from telescopes, theoretical analysis and numerical,
resolution-limited, computer simulations which may not include all relevant
physical processes. However, large high-energy-density facilities, such as
the University of Rochester's Omega laser, now allow laboratory experiments
on macroscopic volumes of plasma of relevance to astrophysics, and we use
the laser to study the hydrodynamics of supersonic jets and bow shocks, with
the aim of increasing understanding of astrophysical jets. We present
results of an experiment in which a high-Mach-number, high-Reynolds-number
millimeter-sized jet is formed by hohraum-driven radiation ablation of a
125-
m-thickness titanium foil mounted over a 700-m-thickness
titanium washer with a central, cylindrical hole. Some of the resulting
shocked titanium expands, cools, and accelerates through the vacuum region
(the hole in the washer) and then enters a cylinder of low-density foam as a
jet. The jet is imaged using pinhole-apertured point-projection radiography.
Such complex experimental data provide a challenge for both astrophysical
and laser-plasma hydrocodes. Although the high Reynolds number of the jet
suggests that turbulence should develop, this behaviour cannot be reliably
modelled by present, resolution-limited simulations. In addition to
experimental results, we present data from 2D simulations which include the
use of sub-grid-scale mix models.
© EDP Sciences 2006