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Summary form only given. Shear flows arise in many high-energy-density (HED) and astrophysical systems, yet few laboratory experiments have been carried out to study their evolution in these extreme environments. Fundamentally, shear flows can initiate mixing via the Kelvin-Helmholtz (KH) instability and may eventually drive a transition to turbulence. We present two dedicated shear flow experiments...
Shock waves driven above a threshold velocity near 100 km/s become strongly radiative, converting most of the incoming energy flux into radiation. We produce such shock waves in Xe or Ar by using a laser to shock, ionize, and accelerate a Be plate into a gas-filled shock tube. Structure develops in these systems due to both radiative energy transfer and hydrodynamic instability. We are conducting...
The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan is a focused effort to do predictive science in the regime of radiative hydrodynamics. The current plan with CRASH is to use 2D HYADES (or H2D) to model the laser-energy-deposition portion of the experiment, before passing the results to the CRASH code to be used as its initial conditions. HYADES is a Lagrangian Radiation...
Summary form only given. Radiative shocks occur in many high-energy density explosions, but prove difficult to create in laboratory experiments or to fully model with astrophysical codes. Here we describe an experiment significant to astrophysical shocks, which produces a driven, quasi-planar radiative shock in xenon gas at 6 mg/cc. A thin, low-Z disk is driven into a cylindrical volume of xenon gas...
Summary form only given. Our goal is to experimentally confirm or disprove the hypothesis that the Rayleigh-Taylor instability could be responsible for the observed transport of heavy elements from the core of SN1897A, a core-collapse supernova, into its outer layers. Observational astrophysicists have been unable to explain the X-ray or luminosity data from SN1987A. Strong hydrodynamic instabilities...
Summary form only given. Microchannel plates (MCPs) are used in a variety of imaging systems as a means of amplifying the incident radiation. Using a microchannel plate mount recently developed at the University of Michigan, the effects of a metal reflecting grid are explored. Employing the reflecting grid, we create a potential difference above the MCP input surface that forces ejected electrons...
Summary form only given. Microchannel plates (MCPs) are an essential component in an imaging diagnostic known as an X-ray framing camera, which is used extensively to image the plasma produced by radiation imploded targets at facilities such as NIF, Nike, Omega, and Z. An MCP is used to convert incident X-ray photons into electrons with gains of the order 102 to 104. These electrons are then accelerated...
Summary form only given. We have seen a sequence of recent experiments aimed at producing and studying radiative shocks. These experiments are opening the door to fundamental radiation hydrodynamic studies using laboratory tools. To complement such experiments, the author has done theoretical work, introducing new solution approaches that allow more complete treatment of some simple cases and providing...
Summary form only given. Our group has been studying radiative shocks using laser targets that contain a gas, most often xenon. Our motivation includes the production of conditions in the laboratory relevant to astrophysical phenomena and astrophysical simulation codes. A specific phenomenon of interest is the production of a dense, collapsed layer in a given material. Past experiments have consisted...
Summary form only given. Extensive studies of spectroscopic measurements of IADI (ion-acoustic decay instability) in laser-produced plasma have been made. The experiments were performed using the GDL (gas dynamic laser) laser facility at LLE and the Janus (Phoenix) laser and NOVA laser facilities at LLNL. The laser is incident normally onto a planar target (CH, Al, Cu, Mo and Au of 50-μm thickness)...
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