Peculiarities of Shockwave Ejecta in the Presence of Gas in Front of a Free Surface of a Material

We report experimental results on studies of the interactions between various gases and the mass ejected from a shock accelerated surface. While such studies have been conducted in the past, data on such dynamic gas-ejecta interactions are incomplete. Therefore, along these lines, in the present work new comparative results are given concerning mass ejection from free surfaces of lead interfaced with vacuum or gas. The comparisons are made for the ejecta mass as a function of the surface roughness, the peak shockwave loading stress (amplitude) P S , and the release phase (state) of the post-shock metal.