Iron Rayleigh-Taylor Laser Experiments Using Radiation-Hydrodynamics Codes

Kristen John, California Institute of Technology

The focus of this research is to study the strength of iron through Rayleigh-Taylor laser experiments using radiation-hydrodynamics codes. This involves studying the strength of iron at high pressures (>1 Mbar) and high strain rates (>100 s-1), which can only be done using laser facilities such as the Omega Laser in Rochester, N.Y. Our goal is to determine the strength of iron (and eventually other materials) at high pressures and high strain rates, to understand what happens at the phase transition in iron, and to stabilize/reduce Rayleigh-Taylor instability growth (via the material strength). We will do this by measuring the growth of Rayleigh-Taylor instabilities, which is accomplished by putting a ripple in the material and measuring the growth of the ripple. I have participated in similar experiments at Omega, and am currently working on the design of my experiments. To create this design, I am using radiation-hydrodynamics simulation codes that are used for the design and analysis of laboratory high energy-density experiments. With these codes, I can add features to my model so it reflects an actual experiment, understand how the different parameters affect the experiment, and eventually use the codes to design other laser experiments. Additionally, I am continuing to collaborate with LLNL (where I performed my practicum in summer 2011) to design these experiments. We are preparing for the first set of iron experiments, which are scheduled for August 2012 at Omega. Following these experiments, we will analyze the data and compare the experimental results to models. Simultaneously, I am also working on experiments at Caltech using gas guns and ballistic gelatin to recreate the Rayleigh-Taylor experiments on a small scale.

Abstract Author(s): K. John (Caltech), J. Belof (LLNL), H.S. Park (LLNL), B. Remington (LLNL), G. Ravichandran (Caltech)