Intensity distributions of enhanced H emission from laser-induced low-pressure He plasma and a suggested He-assisted excitation mechanism
Intensity distributions of enhanced H emission from laser-induced low-pressure He plasma and a suggested He-assisted excitation mechanism
复制标题
DOI：
10.1063/1.3195087
复制
发表时间：
2009-08-15
影响因子：
3.2
通讯作者：
Tjia, May On
中科院分区：
文献类型：
--
作者：
Lie, Zener Sukra;Pardede, Marincan;Tjia, May On
实验研究了在氮气和氦气环境中，激光烧蚀低气压等离子体产生的氢发射强度在氮气和氦气氛中的空间分布。在……里面。除了证实了先前在环境氦气体中观察到的强度增强效应外，沿等离子体膨胀方向测量的氢和氦发射强度还显示出显著的扩展的空间分布，在等离子体远端附近出现了意想不到的极大值，在那里可用激波产生的热激发能量应该已经显著减少。这一“反常”特征必然意味着，除了众所周知的激波激发过程外，还存在一个额外的激发过程，该过程负责低压环境气体中重原子的等离子体发射。对数据的进一步分析导致了一种可能的物理机制，解释了氦亚稳态激发态对本实验中观察到的异常现象的可能贡献。(C)2009年美国物理研究所。[DOI：10.1063/1.3195087]
An experimental study was conducted on the spatial distributions of hydrogen emission intensities from low-pressure plasmas generated by laser ablation of zircaloy-4 and black stone targets in nitrogen and helium ambient gases. In. addition to confirming the previously observed intensity enhancement effect in ambient helium gas, the hydrogen and helium emission intensities measured along the plasma expansion direction revealed remarkable extended spatial distributions featuring unexpected maxima near the far end of the plasma where the available shock-wave generated thermal excitation energy should have been significantly reduced. This "anomalous" feature necessarily implied the presence of an additional excitation process beside the well known shock-wave excitation process which is responsible for the plasma emission of heavy atoms in low-pressure ambient gas. Further analysis of the data led to a suggested physical mechanism explaining the possible contribution of a helium metastable excited state to the unusual phenomenon observed in this experiment. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3195087]