Shock Physics Analysis to Support Optical Signature Prediction in Hypervelocity Impacts

In a recent series of light-gas-gun experiments performed at Sandia National Laboratories, aluminum projectiles impacted titanium alloy plates at 6 km/s, with a variety of witness plates downstream. The radiative characteristics of the target debris cloud were measured using a combination of time-resolved visible emission spectroscopy and high-speed wavelength-filtered camera imagery. This paper will describe the analyses performed in support of the test series using the CTH shock-physics package from Sandia, discuss the methodology developed to port CTH results into radiation-physics codes, and provide comparisons between CTH results and experimental observations of debris-cloud shape. The combination of high-fidelity shock-physics analysis and high-fidelity spectral analysis of the shock-physics results represents a first-principles approach toward optical signature prediction in hypervelocity impacts.