Laser mass-spectrometry for online diagnosis of reactive plasmas with many species.
Laser mass-spectrometry for online diagnosis of reactive plasmas with many species.
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DOI：
10.1063/1.3600798
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
C. Feng;Liang Gao;Jiahong Liu;Lei Zhang;H. Ding
中科院分区：
文献类型：
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作者：
C. Feng;Liang Gao;Jiahong Liu;Lei Zhang;H. Ding
本研究的目的是将分子束飞行时间质谱（TOF）技术与激光光谱技术相结合，设计一套反应等离子体环境诊断系统。TOF质谱仪和脉冲激光器的组合有利于诊断中间物种分布，因为它们允许同时但单独记录不同物种的光谱。在等离子体系统中，处于电子基态或低激发态的中间物质被共振激光激发泵浦到更高的能级，然后，用第二激光系统电离是可能的，这可以容易地被TOF分析仪检测到。电离本身仅用作观察这些状态的激发的检测机制。通过这种方法，可以确定具有状态选择性和质量选择性的中间物种的种群分布。此外，在这篇文章中，一个灵活的数据采集和自动控制系统的基础上LABVIEW的设计，集成所有的独立的测量仪器，包括一个飞行时间光谱仪，激光系统，高性能示波器，数字延迟发生器到一个单一的个人计算机为基础的控制单元。此外，一个虚拟的Boxcar积分器与数百个通道已被开发，以增强信号，同时过滤掉随机噪声。最后讨论了该技术在等离子体诊断中的应用前景。
The purpose of this study is to design a diagnostic system for reactive plasma environment by combining molecular-beam time-of-flight (TOF) mass spectroscopy with laser spectroscopy technique. The combination of TOF mass spectrometers and pulsed lasers is favorable in the diagnosis of intermediate species distribution since they allow the simultaneous but separate recording of the spectra of different species. In the plasma system, the intermediate species in electronic ground state or low lying excited state is pumped to higher energy level with resonant laser excitation, and then, the ionization with a second laser system is possible which can readily be detected by the TOF analyzer. The ionization itself is only used as a detection mechanism for the observation of the excitation of these states. In this manner, the population distribution of intermediate species can be determined with state-selective and mass-selective feature. Also, in this article, a flexible data acquisition and automatic control system based on LABVIEW was designed to integrate all the stand-alone measurement instruments including a TOF spectrometer, a laser system, a high performance oscilloscope, and a digital delay generator into a single personal computer-based control unit. Moreover, a virtual Boxcar integrator with hundreds of channels has been developed to enhance the signal while filtering out the random noises. Finally, the many potentials of this technique in the application of plasma diagnosis will be discussed.