Multiple structure formation and molecule dynamics in transient plasmas generated by laser ablation of graphite
Multiple structure formation and molecule dynamics in transient plasmas generated by laser ablation of graphite
复制标题
DOI：
10.1016/j.sab.2020.105774
复制
发表时间：
2020-03-01
影响因子：
3.3
通讯作者：
Craciun, Valentin
中科院分区：
文献类型：
--
作者：
Irimiciuc, Stefan Andrei;Hodoroaba, Bianca Cristiana;Craciun, Valentin
利用互补光学诊断技术研究了纳秒激光烧蚀空气中石墨产生的瞬态等离子体，研究了碳激光等离子体（C-LPP）在膨胀阶段产生的复杂多重结构。通过ICCD快速相机成像研究了整体发射，并揭示了C-LPP的结构为具有不同演变的四种不同结构。在不同的膨胀方向上分析了C-LPP的动态，以了解主要CN优势结构和具有主导C-2发射的侧向“襟翼”的形成。通过空间和时间分辨的光学发射光谱，并使用玻尔兹曼图和斯塔克加宽方法的动力学和热能的产生的原子，离子和分子进行了研究。讨论了背景气体压力对分子碳结构形成的影响，找到了使C2生成量最大的最佳工作压力范围，并根据所获得的数据提出了C-PLL中复杂碳结构生成与背景气体的关系。
Transient plasmas generated by ns - laser ablation of graphite in air have been investigated by complementary optical diagnosis techniques to study complex multiple structures generated in carbon laser produced plasmas (C-LPP) during the expansion phase. The overall emission was investigated by ICCD fast camera imaging and revealed the structuring of C-LPP into four distinct structures with different evolutions. The dynamic of the C-LPP was analyzed on various expansion directions in order to understand the formation of the main CN dominant structure and of lateral "flaps" with dominant C-2 emission. The kinetic and thermal energies of the resulted atoms, ions and molecules were investigated by means of space-and time-resolved optical emission spectroscopy and using the Boltzmann plot and Stark broadening approaches. The effect of the background gas pressure on the formation of molecular carbon structures is discussed and an optimum range of working pressure which maximizes the generation of C-2 is found. Based on the acquired data a scenario for the complex carbon structures generation in C-PLL as function of the background gas is proposed.