Numerical and experimental study of the second ejection from a grooved tin surface under laser-driven shock loading

•The second ejection under laser-driven shock loading is studied using the SPH method.•The laser-driven shock loading experiments for the second ejection are conducted.•The formation capability of the second jet increases with the time interval. In this paper, we perform a numerical and experimental study of the second ejection from a grooved tin surface under laser-driven shock loading. First, the second ejection under laser-driven shock loading is simulated using the smoothed particle hydrodynamics method, and the physical mechanism of this ejection event is investigated in detail. The numerical results reveal that the second ejection is dominated by successive Richtmyer-Meshkov instabilities created by the second incident shocks meeting the two density interfaces formed after the first ejection. The spatial structure of the second ejection is mainly characterized by the formation of a noticeable second jet with a head velocity much lower than that of the first microjet, and the root of the high-density jet slug is significantly enhanced, which is distinctly different from the conventional phase inversion under supported shocks. Then, laser-driven shock loading experiments for the second ejection are conducted and X-ray radiographic images of the second ejection are obtained. The main features of the simulation results for the second ejection are in good agreement with the experimental results, and the simulation results are verified by the laser-driven shock loading experiments. Additionally, the effects of the time interval on the second ejection are discussed. The formation capability of the second jet gradually increases with the time interval, and the cumulative area density gradually increases with the time interval and converges to a constant value.