Porous materials have many applications for laser–matter interaction experiments related to inertial confinement fusion. Obtaining new knowledge about the properties of the laser-produced plasma of porous media is a challenging task. In this work, we report, for the first time to the best of our knowledge, the time-dependent measurement of the reflected light of a terawatt laser pulse from the laser-produced plasma of low-Z foam material of overcritical density. The experiments have been performed with the ABC laser, with targets constituted by foam of overcritical density and by solid media of the same chemical composition. We implemented in the MULTI-FM code a model for the light reflection to reproduce and interpret the experimental results. Using the simulations together with the experimental results, we indicate a criterion for estimating the homogenization time of the laser-produced plasma, whose measurement is challenging with direct diagnostic techniques and still not achieved.

中文翻译：

---

低 Z 泡沫等离子体对高功率激光反射的时间依赖性测量

多孔材料在与惯性约束聚变相关的激光-物质相互作用实验中具有许多应用。获得有关激光产生的多孔介质等离子体特性的新知识是一项具有挑战性的任务。在这项工作中，据我们所知，我们首次报告了对来自激光产生的低浓度等离子体的太瓦激光脉冲的反射光的时间依赖性测量。Z超临界密度的泡沫材料。实验是使用 ABC 激光器进行的，目标由超临界密度的泡沫和相同化学成分的固体介质构成。我们在 MULTI-FM 代码中实现了光反射模型，以重现和解释实验结果。使用模拟和实验结果，我们指出了估计激光产生的等离子体的均质化时间的标准，其测量对于直接诊断技术具有挑战性并且仍未实现。