测量和原子氢和双原子分子ALO，C分析<sub> 2</sub>，CN和二氧化钛光谱承接激光诱导光学击穿
Summary
时间分辨原子和双原子分子种类正在使用激光诱导击穿光谱测量。光谱被收集在不同的时间延迟后生成的光学击穿等离子体用的Nd：YAG激光器的辐射，并进行分析，以推断出的电子密度和温度。
Abstract
在这项工作中，我们提出了原子和双原子光谱下激光诱导光学击穿时间分辨测量。一个典型的LIBS安排使用。这里我们采取了Nd：YAG激光器在10赫兹时的1064纳米的基波波长的频率。在14纳秒脉冲anenergy 190兆焦耳/脉冲都集中到一个50微米的光斑大小，以从光学击穿或在空气中激光烧蚀等离子体。该微束成像到0.6米光谱仪的入射狭缝，和光谱使用的是1,800条/ mm的光栅线性加剧二极管阵列和光学多道分析仪（OMA）或ICCD记录。令人感兴趣的是氢巴尔末一系列斯塔克展宽谱线来推断电子密度。我们还详细说明温度测量从铝一氧化碳（ALO）的双原子发射光谱，碳（C 2），氰（CN），和一氧化钛（二氧化钛）。
实验步骤包括瓦特avelength和灵敏度校准。所记录的分子光谱的分析，通过与表列线的长处数据的拟合来完成。此外，蒙特卡罗模拟型执行估计误差范围。时间分辨的测量是必需的瞬态等离子体中LIBS经常遇到的。
Introduction
激光诱导击穿光谱（LIBS）技术，具有1-5原子6-12和应用等离子13-20激光辐射产生的分子生物学研究。时间分辨光谱法是测定血浆的瞬态特性是必不可少的。温度和电子密度的名称，但两个等离子参数，可以测量所提供的等离子击穿合理的理论模型是可用的。从原子和分子分离排放的自由电子辐射使我们能够准确地探索瞬态现象。通过专注于一个特定的时间窗口，人们可以“冻结”等离子体衰变，从而获得精确的光谱指纹。 LIBS有各种应用，最近在LIBS诊断的兴趣显示了一个相当大的增加，当研究人员发表在该领域的数量来衡量。皮秒和飞秒产生的微束是正在进行研究兴趣，然而，历史上的实验LIBS安排利用纳秒激光辐射。
图1显示一个典型的实验装置为激光诱导击穿光谱。此协议中，功能击穿能量为初始束为75毫焦耳的脉冲的顺序，在1064纳米的红外线波长。此脉冲能量可以根据需要进行调整。该等离子体是由光谱仪分散并具有增强的线性二极管阵列和OMA或者，成像到一个强化2维电荷耦合器件（ICCD）测定图2示出了用于时间分辨实验的时序图：脉冲同步激光辐射与读出，激光脉冲触发，激光火了，门打开延时。
成功的时间分辨光谱，需要不同的校准程序。这些程序包括波长校准，回地校正，并且最重要的是，检测器的灵敏度校正。灵敏度校正数据是用于测量和模型化的光谱的比较重要的。为增加了信号 – 噪声比，多个激光诱导击穿事件记录。
Protocol
1。光学系统设置放置一个光束分离器在激光的出射，从而允许1,064 nm的波长的光通过，并反射所有其他瞬态激光辐射转换成一个光束转储。 放置一个高速PIN光电二极管检测器来记录激光辐射反射离开分束器的一部分。此检测器连接到示波器与同轴电缆监视光脉冲相对于触发由函数发生器和发生在Q-开关中的Nd：YAG激光器装置。 排列3的IR反射镜定位平行于光谱仪的狭缝的光束?…
Representative Results
LIBS技术利用脉冲激光照射充分离子化试样，形成等离子体。的气态物质的激光诱导击穿将创建为中心的激发光束的焦点区域等离子体，而在固体表面上的激光烧蚀将产生样品的表面上方的等离子体。等离子体是由聚焦的光辐射100 GW / cm 2的纳秒脉冲击穿的顺序生成的。以生产激光烧蚀等离子，通常为1毛/厘米2是绰绰有余了。感应等离子体辐射由分光仪分散。只有从光学击穿具…
Discussion
分辨测量协议和代表性成果的时间进一步讨论。它以同步的激光脉冲，产生10赫兹的速率，与增强线性二极管阵列和OMA（或ICCD）的50赫兹的工作频率是很重要的。此外，激光脉冲和开口的加剧线性二极管阵列（或备选ICCD）的栅极的精确的时序是至关重要的。波发生器，在本实验的原理图所示，是用于同步的激光脉冲，并加强其是通过光学多通道分析仪的线性二极管阵列的读出。脉冲发生器是用来?…
Disclosures
The authors have nothing to disclose.
Acknowledgements
作者感谢联办Hornkohl先生的兴趣和对双原子分子的谱线强度的计算探讨。这项工作是在部分由中心的激光应用在田纳西州空间研究院的支持。
Materials
| Custom Box | UTSI | None | Signal divider and conditioner. An oscilloscope can be used in place of this |
| Four Channel Digital Delay/Pulse Generator | Stanford Research Systems, Inc. | Model DG535 | Companies: Tequipment, diyAudio |
| Four Channel Color Digital Phosphor Oscilloscope | Tektronix | TDS 3054 | 500 MHz – 5 GS/sec, Companies: Amazon, Tektronix, Fluke, Agilent Technologies, Pico Technology |
| Wavetek FG3C Function Generator | Wavetek | FG3C | Companies: Tequipment, Stanford Research Systems, BK Precision |
| Nd:YAG Laser | Quanta-Ray | DCR-2A(10) PS | Laser radiation, Class IV. Companies: Lambda Photometrics, Continuum, Ellipse, Newport |
| Si Biased Detector | Thorlabs | DET10A/M | 200-1,100 nm, with ND10A reflective filter. Companies: Canberra, Edmund Optics |
| Nd:YAG Laser Line Mirror, 1,064 nm | Thorlabs | NB1-K13 | Companies: Edmund Optics, Newport |
| 1 in Fused Silica Bi-Convex Lens, uncoated | Newport | SBX031 | Companies: Edmund Optics, Thorlabs |
| 2 in Fused Silica Plano-Convex lens, uncoated | Newport | SPX049 | Convex lens, f/4. Companies: Edmund Optics, Thorlabs |
| Spectrograph | Instruments S.A. division Jobin-Yvon | HR 640 | Companies: Andor, Newport, Horiba |
| Manual and electronic controller for Spectrograph | Instruments S.A. division Jobin-Yvon | Model 980028 | Manual and electronic controller for Spectrograph |
| Mega 4000 | Mega | Model 129709 | Computer interface for Spectrograph |
| Gateway 2000 Crystal Scan 1024 monitor | Gateway | PMV14AC | Monitor for computer interface |
| 20 MHz Oscilloscope | BK Precision | Model 2125 | Companies: Amazon, Tektronix, Fluke, Agilent Technologies, Pico Technology |
| 6040 Universal Pulse Generator | Berkeley Nucleonics Corporation | Model 6040 | Companies: Agilent Technologies, Tektronix, Quantum Composers |
| Separate component to 6040 Universal Pulse Generator | Berkeley Nucleonics Corporation | Model 202 H | Separate component to 6040 Universal Pulse Generator |
| ICCD Camera | EG&G Parc | Model 46113 | Companies: Andor, Standford Computer Optics, LaVision, Hamamatsu |
| OMA III | EG&G Parc | Model 1460 | Spectral data acquisition and analysis. Unit discontinued, replaced by software installed on computers. |
References
- Miziolek, A. W., Palleschi, V., Schechter, I. . Laser Induced Breakdown Spectroscopy. , (2006).
- Cremers, D. E., Radziemski, L. J. . Handbook of laser-induced Breakdown Spectroscopy. , (2006).
- Singh, J. P., Thakur, S. N. . Laser Induced Breakdown Spectroscopy. , (2007).
- Hahn, D. W., Omenetto, N. Laser-induced breakdown spectroscopy (LIBS), Part I: review of basic diagnostics and plasma-particle iterations: still-challenging issues within the analytical plasma community. Appl. Spectrosc. 64, (2010).
- Hahn, D. W., Omenetto, N. Laser-induced breakdown spectroscopy (LIBS), Part II: review of instrumental and methodological approaches to material analysis and applications to different fields. Appl. Spectrosc. 66, 347 (2012).
- Parigger, C. G. Atomic and molecular emissions in laser-induced breakdown spectroscopy. Spectrochim. Acta Part B. 79, 4-16 (2013).
- Konjević, N., Lesage, A., Fuhr, J. R., Wiese, W. L. Experimental Stark widths and shifts for spectral lines of neutral and ionized atoms. J. Phys. Chem. Ref. Data. 31, 819-927 (2002).
- Oks, E. Stark broadening of hydrogen and hydrogen-like spectral lines in plasmas: the physical insight. Alpha Science Int. , (2006).
- Parigger, C. G., Dackman, M., Hornkohl, J. O. Time-resolved spectroscopy measurements of hydrogen-alpha, -beta, and -gamma emissions. Appl. Opt. 47, (2008).
- Parigger, C. G., Oks, E. Hydrogen Balmer series spectroscopy in laser-induced breakdown plasmas. Int. Rev. Atom. Mol. Phys. 1, 13-23 (2010).
- Lucena, A. D., Tobaria, L. M., Laserna, J. J. New challenges and insights in the detection and spectral identification of organic explosives by laser induced breakdown spectroscopy. Spectrochim. Acta Part B. 66 (1), 12-20 (2011).
- Swafford, L. D., Parigger, C. G. Measurement of hydrogen Balmer Series lines following laser-induced optical breakdown in laboratory air. Accepted, Int. Rev. Atom. Mol. Phys. 4 (1), (2013).
- Hornkohl, J. O., Nemes, L., Parigger, C. G., Nemes, L., Irle, S. Spectroscopy of Carbon Containing Diatomic Molecules. Spectroscopy, Dynamics and Molecular Theory of Carbon Plasmas and Vapor. , 113-165 (2011).
- Parigger, C., Hornkohl, J. O. Diatomic molecular spectroscopy with standard and anomalous commutators. Int. Rev. Atom. Mol. Phys. 1, 25-43 (2010).
- Parigger, C. G., Hornkohl, J. O. Computation of AlO emission spectra. Spectrochim. Acta Part A. 81, 404-411 (2011).
- Hermann, J., Peronne, A., Dutouquet, C. Analysis of the TiO-γ System for temperature measurements in laser-induced plasma. J. Phys. B: At. Mol. Opt. Phys. 34, 153-164 (2001).
- Woods, A. C., Parigger, C. G., Hornkohl, J. O. Measurements and analysis of titanium monoxide spectra in laser-induced plasma. Opt. Lett. 37, 5139-5141 (2012).
- Witte, M. J., Parigger, C. G. Measurement and analysis of carbon Swan spectra following laser-induced optical breakdown in air. Accepted, Int. Rev. Atom. Mol. Phys. 4 (1), (2013).
- Surmick, D. M., Parigger, C. G., Woods, A. C., Donaldson, A. B., Height, J. L., Gill, W. Analysis of emission Spectra of Aluminum Monoxide in a Solid Propellant Flame. Int. Rev. Atom. Mol. Phys. 3 (2), 2-137 (2012).
- Woods, A. C., Parigger, C. G. Time-resolved Temperature Inferences Utilizing the TiO A3φ→X3Δ Band in Laser-induced Plasma. Int. Rev. Atom. Mol. Phys. 3 (2), 103-111 (2012).
Tags
Cite This Article
Parigger, C. G., Woods, A. C., Witte, M. J., Swafford, L. D., Surmick, D. M. Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown. J. Vis. Exp. (84), e51250, doi:10.3791/51250 (2014).