Through nonequilibrium molecular dynamics simulations, we provide an atomic-scale picture of the dynamics of particles near the surface of a medium under ultra-strong shocks. This shows that the measured surface velocity v_f under ultra-strong shocks is actually the velocity of the critical surface at which the incident probe light is reflected, and v_f has a single-peaked structure. The doubling rule commonly used in the case of relatively weak shocks to determine particle velocity behind the shock front is generally not valid under ultra-strong shocks. After a short period of acceleration, v_f exhibits a long slowly decaying tail, which is not sensitive to the atomic mass of the medium. A scaling law for v_f is also proposed, and this may be used to improve the measurement of particle velocity u in future experiments.

中文翻译：

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超强冲击下介质表面附近颗粒的动力学

通过非平衡分子动力学模拟，我们提供了在超强冲击下介质表面附近粒子动力学的原子级图像。这表明在超强冲击下测得的表面速度v _f实际上是入射探针光在其反射的临界表面的速度，并且v _f具有单峰结构。在相对弱的冲击情况下，通常使用加倍规则来确定冲击前沿后方的粒子速度，在超强冲击情况下通常无效。经过短时间的加速后，v _f呈现出一条长而缓慢衰减的尾巴，该尾巴对介质的原子质量不敏感。v的缩放定律还提出了_f，并且可以在以后的实验中使用它来改善对粒子速度u的测量。