1. Department of Thermal Engineering, Tsinghua-BP Clean Energy Center, Tsinghua University, Beijing 100084, China 2. National Institute of Laser Enhanced Science, Cairo University, Cairo 12613, Egypt
The relatively low repeatability of laser-induced breakdown spectroscopy (LIBS) severely hinders its wide commercialization. In the present work, we investigate the optimization of LIBS system for repeatability improvement for both signal generation (plasma evolution) and signal collection. Timeintegrated spectra and images were obtained under different laser energies and focal lengths to investigate the optimum configuration for stable plasmas and repeatable signals. Using our experimental setup, the optimum conditions were found to be a laser energy of 250 mJ and a focus length of 100 mm. A stable and homogeneous plasma with the largest hot core area in the optimum condition yielded the most stable LIBS signal. Time-resolved images showed that the rebounding processes through the air plasma evolution caused the relative standard deviation (RSD) to increase with laser energies of>250 mJ. In addition, the emission collection was improved by using a concave spherical mirror. The line intensities doubled as their RSDs decreased by approximately 25%. When the signal generation and collection were optimized simultaneously, the pulse-to-pulse RSDs were reduced to approximately 3% for O(I), N(I), and H(I) lines, which are better than the RSDs reported for solid samples and showed great potential for LIBS quantitative analysis by gasifying the solid or liquid samples.
. [J]. Frontiers of Physics, 2018, 13(2): 135201.
Shuai Zhang, Sahar Sheta, Zong-Yu Hou, Zhe Wang. On the improvement of signal repeatability in laser-induced air plasmas. Front. Phys. , 2018, 13(2): 135201.
J. P.Singh and S. N.Thakur, Laser-Induced Breakdown Spectroscopy, Amsterdam: Elsevier Science, 2007
2
A.Cremersand L. J.Radziemski, Handbook of Laser- Induced Breakdown Spectroscopy, USA: John Wiley & Sons, 2006
3
Z.Wang, T. B.Yuan, Z. Y.Hou, W. D.Zhou, J. D.Lu, H. B.Ding, and X. Y.Zeng, Laser-induced breakdown spectroscopy in China, Front. Phys. 9(4), 419(2014) https://doi.org/10.1007/s11467-013-0410-0
4
Z. Z.Wang, Y.Deguchi, Z. Z.Zhang, Z.Wang, X. Y.Zeng, and J. J.Yan, Laser-induced breakdown spectroscopy in Asia, Front. Phys. 11(6), 114213(2016) https://doi.org/10.1007/s11467-016-0607-0
5
H. R.Griem, Plasma Spectroscopy, New York: McGraw-Hill, 1964
6
D. W.Hahnand N.Omenetto, Laser-Induced Breakdown Spectroscopy (LIBS), Part I: Review of basic diagnostics and plasma-particle interactions: Stillchallenging issues within the analytical plasma community, Appl. Spec. 64(12), 335A(2010) https://doi.org/10.1366/000370210793561691
7
D. N.Stratis, K. L.Eland, and S. M.Angel, Enhancement of aluminum, titanium, and iron in glass using pre-ablation spark dual-pulse LIBS, Appl. Spec. 54(12), 1719(2000) https://doi.org/10.1366/0003702001948871
8
D. N.Stratis, K. L.Eland, and S. M.Angel, Dual-pulse LIBS using a pre-ablation spark for enhanced ablation and emission, Appl. Spec. 54(9), 1270(2000) https://doi.org/10.1366/0003702001951174
9
R.Noll,C. F.Begemann, M.Brunk, S.Connemann, C.Meinhardt, M.Scharun, V.Sturm, J.Makowe, and C.Gehlen, Laser-induced breakdown spectroscopy expands into industrial applications, Spectrochim. Acta B At. Spectrosc. 93, 41(2014) https://doi.org/10.1016/j.sab.2014.02.001
10
A. K.Pathak, N. K.Rai, A.Singh, A. K.Rai, and P. K.Rai, Medical applications of laser induced breakdown spectroscopy, J. Phys. Conf. Seri. 548, 012007(2014) https://doi.org/10.1088/1742-6596/548/1/012007
11
S.Qiao, Y.Ding, D.Tian, L.Yao, and G.Yang, A review of laser-induced breakdown spectroscopy for analysis of geological materials, Appl. Spec. Revi. 50(1), 1 (2015) https://doi.org/10.1080/05704928.2014.911746
12
J.Peng, F.Liu, F.Zhou, K.Song, C.Zhang, L.Ye, and Y.He, Challenging applications for multi-element analysis by laser-induced breakdown spectroscopy in agriculture: A review, Trends Analyt. Chem. 85, 260(2016) https://doi.org/10.1016/j.trac.2016.08.015
13
A. K.Knight, N. L.Scherbarth, D. A.Cremers, and M. J.Ferris, Characterization of laser-induced breakdown spectroscopy (LIBS) for application to space exploration, Appl. Spec. 54(3), 331(2000) https://doi.org/10.1366/0003702001949591
14
R. S.Harmon, R. E.Russo, and R. R.Hark, Applications of laser-induced breakdown spectroscopy for geochemical and environmental analysis: A comprehensive review, Spectrochim. Acta B At. Spectrosc. 87, 11(2013) https://doi.org/10.1016/j.sab.2013.05.017
15
A.De Giacomoand O.De Pascale, Laser induced plasma spectroscopy by air spark ablation, Thin Solid Films453–454, 328(2004)
A.Chen, Y.Jiang, H.Liu, M.Jin, and D.Ding, Plume splitting and rebounding in a high-intensity CO2 laser induced air plasma, Phys. Plasmas19(7), 073302(2012) https://doi.org/10.1063/1.4737165
18
Z.Wang, T. B.Yuan, S. L.Lui, Z. Y.Hou, X. W.Li, Z.Li, and W. D.Ni, Major elements analysis in bituminous coals under different ambient gases by laserinduced breakdown spectroscopy with PLS modeling, Front. Phys. 7(6), 708(2012) https://doi.org/10.1007/s11467-012-0262-z
19
Z. Y.Hou, Z.Wang, J. M.Liu, W. D.Ni, and Z.Li, Signal quality improvement using cylindrical confinement for laser induced breakdown spectroscopy, Opt. Express21(13), 15974(2013) https://doi.org/10.1364/OE.21.015974
20
H.Yin, Z.Hou, T.Yuan, Z.Wang, W.Ni, and Z.Li, Application of spatial confinement for gas analysis using laser-induced breakdown spectroscopy to improve signal stability, J. Anal. At. Spectrom. 30(4), 922(2015) https://doi.org/10.1039/C4JA00437J
21
V.Motto-Ros, E.Negre, F.Pelascini, G.Panczer, and J.Yu, Precise alignment of the collection fiber assisted by real-time plasma imaging in laser-induced breakdown spectroscopy, Spectrochim. Acta B At. Spectrosc. 92, 60(2014) https://doi.org/10.1016/j.sab.2013.12.008
22
E.Tognoniand G.Cristoforetti, Signal and noise in Laser Induced Breakdown Spectroscopy: An introductory review, Opti. Lase. Tech. 79, 164(2016) https://doi.org/10.1016/j.optlastec.2015.12.010
23
Z.Haider, Y. B.Munajat, R.Kamarulzaman, and N.Shahami, Comparison of single pulse and double simultaneous pulse laser induced breakdown spectroscopy, Anal. Lett. 48(2), 308(2015) https://doi.org/10.1080/00032719.2014.940532
24
T.Ye, B.Xue,J.Song, Y.Lu, and R.Zheng, Stabilization of laser-induced plasma in bulk water using large focusing angle, Appl. Phys. Lett. 109(6), 6 (2016)
25
B.Ashrafkhani, M.Bahreini, and S. H.Tavassoli, Repeatability improvement of laser-induced breakdown spectroscopy using an auto-focus system, Opti. Spec. 118(5), 841(2015) https://doi.org/10.1134/S0030400X15050057
26
J.Cortez, B. B.Farias Filho, L. M.Fontes, C.Pasquini, I. M.Jr Raimundo, M. F.Pimentel, and F.de Souza Lins Borba, A simple device for lens-to-sample distance adjustment in laser-induced breakdown spectroscopy (LIBS), Appl. Spec. 71(4), 634(2017) https://doi.org/10.1177/0003702816687571
27
Y. L.Chen, J. W. L.Lewis, and C.Parigger, Spatial and temporal profiles of pulsed laser-induced air plasma emissions, J. Quant. Spectrosc. Radiat. Transf. 67(2), 91(2000) https://doi.org/10.1016/S0022-4073(99)00196-X
28
H.Zwicker, Evaluation of plasma parameters in optically thick plasmas. Plasma Diagnostics, 1968
29
C.Aragónand J.Aguilera, CSigma graphs: A new approach for plasma characterization in laser-induced breakdown spectroscopy, J. Quant. Spectrosc. Radiat. Transf.149, 90(2014) https://doi.org/10.1016/j.jqsrt.2014.07.026
30
T. D.Arber,K.Bennett, C. S.Brady, A.Lawrence-Douglas, M. G.Ramsay, N. J.Sircombe, P.Gillies, R. G.Evans, H.Schmitz, A. R.Bell, and C. P.Ridgers, Contemporary particle-in-cell approach to laser-plasma modelling, Plasma Phys. Contr. Fusion57(11), 113001(2015) https://doi.org/10.1088/0741-3335/57/11/113001
31
J. E.Carranzaand D. W.Hahn, Sampling statistics and considerations for single-shot analysis using laserinduced breakdown spectroscopy, Spectrochim. Acta B At. Spectrosc. 57(4), 779(2002) https://doi.org/10.1016/S0584-8547(02)00007-1
32
Y.Zuo, X.Wei, K.Zhou, X.Zeng, J.Su, Z.Jiao, N.Xie, and Z.Wu, Enhanced laser-induced plasma channels in air, Chin. Phys. B25(3), 035203(2016) https://doi.org/10.1088/1674-1056/25/3/035203
S. S.Harilal, C. V.Bindhu, M. S.Tillack, F.Najmabadi, and A. C.Gaeris, Plume splitting and sharpening in laser-produced aluminium plasma, J. Phys. D35(22), 2935(2002) https://doi.org/10.1088/0022-3727/35/22/307
35
S.Mahmood, R. S.Rawat, M. S. B.Darby, M.Zakaullah, S. V.Springham, T. L.Tan, and P.Lee, On the plume splitting of pulsed laser ablated Fe and Al plasmas, Phys. Plasmas17(10), 103105(2010) https://doi.org/10.1063/1.3491410
36
P.Yeatesand E. T.Kennedy, Spectroscopic diagnostics of plume rebound and shockwave dynamics of confined aluminum laser plasma plumes, Phys. Plasmas18(6), 063106 (2011) https://doi.org/10.1063/1.3602077
