A non-equilibrium model for laser-generated plasmas is used to represent collinear dual nano-second-pulse interactions. In the specific case considered, the breakdown is initiated with an ultraviolet (UV) laser pulse at 266 nm, which pre-ionizes the gas, and it is followed by a near-infrared (NIR) pulse at 1064 nm, which deposits significant energy into the ionized mixture. The model is validated against corresponding experiments, and simulation results are interrogated to understand key features of the plasma-kernel dynamics and the post-discharge hydrodynamics. The hydrodynamics of the non-equilibrium plasma is governed by the two-temperature Navier–Stokes equations accounting for both multiphoton ionization and inverse bremsstrahlung. The interaction between the laser beam and the plasma is modeled based on the radiative transfer equation. The temporal and spatial offsets of the two pulses can generate ionization kernels with different topology and dynamics. It is show...

中文翻译：

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共线双脉冲激光光学击穿与能量沉积

激光产生等离子体的非平衡模型用于表示共线双纳秒脉冲相互作用。在所考虑的特定情况下，击穿始于266 nm的紫外（UV）激光脉冲，该脉冲使气体预电离，然后是1064 nm的近红外（NIR）脉冲，该脉冲会沉积大量能量进入离子化混合物。该模型针对相应的实验进行了验证，并询问了模拟结果以了解等离子体核动力学和放电后流体动力学的关键特征。非平衡等离子体的流体动力学受两个温度的Navier–Stokes方程控制，该方程考虑了多光子电离和逆致辐射。激光束与等离子体之间的相互作用基于辐射传递方程建模。两个脉冲的时间和空间偏移会生成具有不同拓扑和动力学的电离内核。显示...