AI 中文总结
本研究建立纯铁多物理耦合模型，阐明等离子体屏蔽作用，捕捉等离子体演化，经与实验及现有程序对比，验证了全链条自洽建模方法的优越性。
AI 中文摘要
纳秒激光脉冲与金属材料的相互作用涉及多个复杂物理过程，构建能统一描述所有阶段的自洽模型颇具挑战。本研究建立了纯铁的多物理耦合模型，涵盖激光能量沉积、固液相变、气液界面动力学输运、等离子体膨胀与电离，以及光谱辐射。数值解采用分区方法，对靶体使用隐式紧致差分格式，对等离子体使用Mac-Cormack显式格式。模拟阐明了等离子体屏蔽的出现及其对蒸发过程的抑制作用，证实81.6%的早期烧蚀产物以超声速膨胀模式输运。该模型成功捕捉了等离子体羽从高温高电离态到低温中性原子态的完整演化，基于此的光谱计算显示辐射特性的动态演化：早期以离子线为主的强连续谱背景，后期连续谱衰减、原子线凸显并出现自吸收。自吸收的出现证明模型能有效捕捉等离子体空间不均匀性产生的光厚效应。通过将实验测量光谱与PrismSPECT、NIST LIBS光谱程序的计算结果进行系统对比，本模型在多通道定量评估中取得最高综合评分，验证了全链条自洽建模方法的必要性与优越性，尤其在描述等离子体不均匀性和辐射输运方面表现突出。
英文摘要
The interaction of nanosecond laser pulses with metallic materials involves multiple complex physical processes. It is challenging to construct a self-consistent model capable of uniformly describing all stages. This work establishes a multi-physics coupling model for pure iron, encompassing laser energy deposition, solid-liquid phase transition, gas-liquid interfacial kinetic transport, plasma expansion and ionization, and spectral radiation. The numerical solution adopts a partition method, utilizing an implicit compact difference scheme for the target and a Mac-Cormack explicit scheme for the plasma. The simulations elucidate the emergence of plasma shielding and its inhibitory effect on the evaporation process, thereby confirming that 81.6% of the early-stage ablation products are transported through a supersonic expansion mode. The model successfully captures the complete evolution of the plasma plume from a high-temperature, highly ionized state to a low-temperature, neutral atomic state. Based on this, spectral calculations demonstrate the dynamic evolution of radiative characteristics from an early stage featuring a strong continuum background dominated by ion lines to a later stage where the continuum attenuates, atomic lines become prominent, and self-absorption appears. The emergence of self-absorption proves the ability of the model to effectively capture the optical thickness effects arising from spatial inhomogeneity within the plasma. Through systematic comparison between experimentally measured spectra and calculated results from the PrismSPECT and NIST LIBS spectral programs, the model presented here achieves the highest comprehensive scores in quantitative evaluations of multiple channels. This validates the necessity and superiority of the full-chain self-consistent modeling approach, especially in describing plasma inhomogeneity and radiation transport.
CommentsPublished in Acta Physica Sinica. This is an English translated version of the original Chinese paper. 28 pages, 7 figures
Journal refZhou Y, Wu J, Sun H, et al. Coupling model of metallic target ablation-plasma evolution-radiation under nanosecond laser irradiation [J]. Acta Physica Sinica, 2026, 75(5): 050502
