Particle-based studies in support of high-power laser experiments to study metal ejecta interactions*

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, and inertial confinement fusion.
We present results from particle-based dynamics at atomistic as well as macro-scale simulation studies of the ejecta formation in the presence of grooves at the free surface as a result of a shock wave created at the ablator-metal interface. At the atomistic level, we use large scale simulations, ~ 10⁹ atoms, to extract values of pressure breakout and release, as well as ejecta mass and velocity density. The fractality of the ejecta ligaments is also being investigated.
At the macro-scale, we use Smooth Particle Hydrodynamics for the same conditions.
This provides valuable information to the experimental campaign on the OMEGA and OMEGA-EP lasers platforms for studying the ejecta formation. The metals studied are pure Cu and Sn. Time permitting, initial investigation of the effect of alloying will also be presented.