Influence of hydrodynamic behavior of laser ablation plume on cluster formation
Influence of hydrodynamic behavior of laser ablation plume on cluster formation
复制标题
激光烧蚀羽流的流体动力学行为对团簇形成的影响
DOI：
10.1016/j.egypro.2017.09.458
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Iwata Yasushi
中科院分区：
文献类型：
--
作者：
Ishikawa Yuta;Hasegawa Jun;Horioka Kazuhiko;Iwata Yasushi
我们进行了快速摄影的烧蚀羽流和质量分析所产生的集群。对烧蚀羽流的时间分辨观测表明，烧蚀羽流的行为随着背景氦气压力的变化而发生剧烈的变化。特别是当压力大于100 Pa时，羽流前缘出现较强的光辐射，表明羽流蒸气发生了强烈的压缩，漂移羽流的动能可能转化为压缩蒸气的热能。我们发现，这种羽流压缩过程可以通过引入一个椭圆形的空腔，这可能是由于收敛波的背景气体对焦点的椭圆形。TOF质谱表明，具有对应于Al、AlO、Al2和Al2O的质量的团簇在激光烧蚀腔中产生并向下游传输。然而，在目前的实验条件下，没有观察到由数十个原子组成的大铝团簇。
We conducted fast-photography of the ablation plume and mass analysis of generated clusters. Time-resolved observation of the ablation plumes showed that the behavior of the plume drastically changes depending on the background helium gas pressure. Particularly when the pressure was more than 100 Pa, a strong light emission from the front edge of the plume was observed, indicating that the strong compression of the plume vapor occurs and the kinetic energy of the drifting plume may be converted into the thermal energy of the compressed vapor. We found that this plume compression process could be enhanced by introducing an ellipsoidal cavity, which is due probably to converging waves in the background gas towards the focal point of the ellipsoid. A TOF mass spectroscopy indicated that clusters having a mass corresponding to Al, AlO, Al2, and Al2O were generated in the laser ablation cavity and transported downstream. However, large aluminum clusters consisting of more than a few tens of atoms were not observed in the present experimental condition.