Studies of Ejecta Microjet Interaction Behavior over Phase Transition Boundaries*

Ejecta microjets have been an area of active study for the shock physics community for over sixty years because of their broad relevance to many fields, ranging from astrophysics to material science [1]. Microjets are generated when a strong shock releases from a surface with a feature, such as a groove, and causes the feature to invert as a limiting case of the Richtmyer-Meshkov Instability to form a propagating jet of material. Recent experiments performed at the OMEGA EP laser facility observed the interaction of two counter-propagating tin ejecta microjets for the first time and found that the interaction behavior varied as a function of shock pressure [2]; jets emerging from material shocked above 100 GPa were shown to interact strongly and generate a cloud around the interaction point, whereas jets generated from material shock-releasing near 10 GPa passed through each other unattenuated. In this work, we present on experiments performed to understand interacting jets generated over intermediate pressures, examining more closely the regime over which tin is expected to melt upon shock. The results from this work shed light on how material phase drives the interaction behavior of ejecta microjets. 

 

[1]  W. T. Buttler et al., J. Dyn. Behavior Mat. 3, 151 (2017).

[2] A. M. Saunders et al., PRL 127, 155002 (2021).