Dynamics of laser-induced shock wave and cavitation during laser ablation of aliphatic nitroalkanes

Nanosecond time-resolved schlieren imaging is performed to investigate laser-induced breakdown in ni-tromethane, nitroethane and 1-nitropropane, and the associated dynamics of laser-induced shock waves and cavitation bubbles. The exothermic reactions upon decomposition and the chemical reactions in the vapor plume behind the shock front increase the shock wave velocity. The correlations of oxygen balance with shock wave velocity, bubble radius, lifetime and bubble energy are established. For instance, shock wave velocity is propor-tional to the negative inverse of oxygen balance. In addition, the bubble energy of nitroethane tends to saturate at high pulse energy.

Automated summary

Nanosecond time-resolved schlieren imaging was used to study laser-induced breakdown in ni-tromethane, nitroethane and 1-nitropropane, as well as the dynamics of associated shock waves and cavitation bubbles. The increase in shock wave velocity is due to exothermic reactions during decomposition and chemical reactions in the vapor plume behind the shock front. Correlations between oxygen balance and shock wave velocity, bubble radius, lifetime and bubble energy are established. For example, shock wave velocity is proportional to the negative inverse of oxygen balance. Additionally, the bubble energy of nitroethane saturates at high pulse energy.