Hydrodynamic and atomistic studies in support of high power laser experiments for metal ejecta recollection and interactions

Abstract

Shock-driven material can emit a fine spray of ejecta from its free surface. Understanding the dynamic and interaction of the metal ejecta is important to areas of study as diverse as industrial safety, astrophysics, spacecraft shielding, additive manufacturing and inertial confinement fusion. In this work we present results from hydrodynamic simulation studies in support of designing experiments on the OMEGA and OMEGA-EP laser platforms. The initial experimental campaign was focused on developing a platform aimed at launching hypervelocity particles. We have used a finite element formulation with ALE3D (Arbitrary Lagragian Eulerian) code in support of this campaign. Fields like pressure and velocity of elements produced in the ablated part of material are computed using the FLASH radiation-hydrodynamic code. These are then used as input in a “handshaking” region ALE code to capture shock propagation and the dynamics of the particles. As the campaign has shifted towards producing the ejecta and studying its interaction we have also undertaken an atomistic study to reveal at the ab-initio level the physics of the formation of ejecta when grooves are present in the free surface. This will be included as a framework in a multiscale study relating atomistic with the hydrodynamic scale formation of the ejecta.