Acoustic-Based Spectral Correction Method for Laser-Induced Breakdown Spectroscopy in High Temperature Environment
CHAI Shu1, PENG Hai-meng1, WU Wen-dong1, 2*
1. Institute of Thermal Energy Engineering, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
2. Interdisciplinary Research Center for Engineering Science, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Abstract：The fluctuations of laser-induced breakdown spectroscopy (LIBS) signals to compromise its quantitative measurement. Acoustic-based spectral correction method has been successfully used in reducing the fluctuations, but up to now, not been studied in high-temperature environments. In this work, the plasmas were generated in a high-temperature environment produced by a methane/air premixed flame. The absorbed energies were measured, and the spectral and acoustic signals were collected simultaneously under different laser incident energies. The compression half of acoustic waveforms was corrected by N shape shockwave theory, then the pulse integral intensity (PII) was used to correct the spectra. The uncertainty of LIBS signals was reduced significantly. Strong linear correlations were found between the absorbed energy and laser energy with the laser energy range of 80~280 mJ, under 1 150 and 1 350 K. The coefficient of determination (R2) was 0.997 9 and 0.998 9, respectively. As the laser energy increased from 80 to 280 mJ, the relative standard deviation (RSD) of absorbed energy decreased from 33.17% to 6.68% under 1 150 K and 34.20% to 6.79% under 1 350 K. Under fixed laser energy, the absorbed energy of plasma under 1 350 K was lower than that under 1 150 K due to the sparser gas density. Because the spectral and acoustic signals were transferred from the internal energy of plasma, they are more related to the absorbed energy than laser energy. The linear correlations between absorbed energy and spectral signals and between absorbed energy and acoustic signals were established. Under 1 150 K, the plasma absorbed energy was 69.24 mJ, and the R2 between absorbed energy and H 656 nm, N 746 nm, and O 777 nm was 0.996 1, 0.988 9, and 0.994 8, respectively. Moreover, the R2 between absorbed energy and PII was 0.991 6. Under 1 350 K, the R2 between absorbed energy and H 656 nm, N 746 nm, and O777 nm was 0.997 5, 0.977 5, and 0.988 7, respectively. Furthermore, The R2 between absorbed energy and PII was 0.988 0. Subsequently, the spectral signals were corrected by PII, showing that the fluctuations of LIBS signals can be reduced significantly with the absorbed energy less than 100 mJ. When the laser incident energy was 160 mJ, under 1 150 K, the absorbed energy was 69.24 mJ, RSD of H 656 nm, N 746 nm, and O 777 nm were reduced from uncorrected 16.14%, 21.26%, and 17.24% into corrected 8.75%, 9.15%, and 8.50%, respectively. Under 1 350 K,the absorbed energy was 66.92 mJ, RSD of H 656 nm, N 746 nm, and O 777 nm were reduced from uncorrected 18.22%,24.85%, and 19.13% into corrected 8.46%, 9.52%, and 8.84%, respectively. There sults show that the proposed acoustic-based spectral correction method can effectively reduce the measurement uncertainty of LIBS under high-temperature environment.
Key words：LIBS; High temperature; Acoustic; Spectral correction
[1] Xin Yong, Sun Lanxiang, Yang Zhijia, et al. Frontiers of Physics, 2016, 11(5): 115207.
[2] Guo Jinjia, Lu Yuan, Cheng Kai, et al. Applied Optics, 2017, 56(29): 8196.
[3] Qiao Shujun, Ding Yu, Tian Di, et al. Applied Spectroscopy Reviews, 2015, 50(1): 1.
[4] Zhang Zhifei, Li Tie, Xue Xuefeng, et al. Spectrochimica Acta Part B: Atomic Spectroscopy, 2019, 161: 105706.
[5] Kiefer J, Troger J W, Li Z S, et al. Combustion and Flame, 2012, 159(12): 3576.
[6] Liu Yingzu, Wang Zhihua, Xia Jun, et al. Proceedings of the Combustion Institute, 2019, 37(3): 2681.
[7] McGann Brendan, Carter Campbell D, Ombrello Timothy M, et al. Proceedings of the Combustion Institute, 2017, 36(2): 2857.
[8] Liu Yingzu, Wan Kaidi, He Yong, et al. Fuel, 2020, 260: 116346.
[9] Ren Yihua, Wei Jili, Li Shuiqing. Proceedings of the Combustion Institute, 2019, 37(1): 935.
[10] Anderson Ryan B, Morris Richard V, Clegg Samuel M, et al. Icarus, 2011, 215(2): 608.
[11] Zhang Deng, Chu Yanwu, Ma Shixiang, et al. Analytica Chimica Acta, 2020, 1107: 14.
[12] Feng Jie, Wang Zhe, Li Zheng, et al. Spectrochimica Acta Part B: Atomic Spectroscopy, 2010, 65(7): 549.
[13] Wiens R C, Maurice S, Robinson S H, et al. Space Science Reviews, 2021, 217(1): 4(doi: org/10.1007/S11214-020-00777-5).
[14] Chide Baptiste, Maurice Sylvestre, Murdoch Naomi, et al. Spectrochimica Acta Part B: Atomic Spectroscopy, 2019, 153: 50.
[15] Huang Fuzhen, Tian Ye, Li Ying, et al. Applied Optics, 2021, 60(6): 1595.
[16] Wu Wendong, Adeosun Adewale, Axelbaum Richard L. Proceedings of the Combustion Institute, 2019, 37(2): 1409.
[17] Wu Wendong, Axelbaum Richard L. Proceedings of the Combustion Institute, 2021, 38(1): 1665.
[18] Sun Lanxiang, Yu Haibin. Spectrochimica Acta Part B: Atomic Spectroscopy, 2009, 64(3): 278.
[19] Radziemski Leon J, Loree Thomas R, Cremers David A, et al. Analytical Chemistry, 1983, 55(8): 1246.
[20] Wu Wendong, Chai Shu, Zhou Yuegui. Applied Optics, 2022, 61(7): 1734.
[21] Karzova M M, Yuldashev P V, Khokhlova V A, et al. The Journal of the Acoustical Society of America, 2015, 137(6): 3244.
[22] Wright Wayne M. The Journal of the Acoustical Society of America, 1983, 73(6): 1948.
