Enhancement and stabilization of plasma using collinear long-short double-pulse laser-induced breakdown spectroscopy

• Published in: Spectrochimica acta. Part B: Atomic spectroscopy Vol. 142; pp. 14 - 22
• Main Authors: Cui, Minchao, Deguchi, Yoshihiro, Wang, Zhenzhen, Fujita, Yuki, Liu, Renwei, Shiou, Fang-Jung, Zhao, Shengdun
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.04.2018; Elsevier BV
• Subjects: Analytical methods; Collinear long-short DP-LIBS; Image enhancement; Iron and steel making; Laser beams; Laser induced breakdown spectroscopy; Laser plasmas; Lasers; Long-pulse-width laser; Neodymium lasers; Plasma; Plasma temperature; Pulse duration; Semiconductor lasers; Signal enhancement; Spectroscopy; Spectrum analysis; Stabilized plasma; Steel; Steel industry; Steel sample; Temperature; Width; YAG lasers; Stabilized plasma; Collinear long-short DP-LIBS; Signal enhancement; Long-pulse-width laser; Steel sample
• ISSN: 0584-8547; 1873-3565
• DOI: 10.1016/j.sab.2018.02.002

A collinear long-short dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) method was employed to enhance and stabilize the laser-induced plasma from steel sample. The long-pulse-width laser beam with the pulse width of 60μs was generated by a Nd: YAG laser which was operated at FR (free running) mode. The comparative experiments were carried out between single pulse LIBS (SP-LIBS) and long-short DP-LIBS. The recorded results showed that the emission intensities and the temperature of plasma were enhanced by long-short DP-LIBS. The plasma images showed that the plasma was bigger and had a longer lifetime in long-short DP-LIBS situation. Through the calculation of time-resolved plasma temperature and intensity ratio, it can be concluded that the plasma was stabilized by the long-pulse-width laser beam. The long-short DP-LIBS method also generated the stable plasma condition from the samples with different initial temperatures, which overcame the difficulties of LIBS in the online measurement for steel production line. [Display omitted] •A long-short DP-LIBS method was employed to enhance and stabilize the laser-induced plasma.•Compared with SP-LIBS, the plasma was bigger and had a longer lifetime in long-short DP-LIBS condition.•The plasma was maintained at a stable and high temperature using long-short DP-LIBS.•The measured spectra by long-short DP-LIBS showed a conformity at different initial temperatures of the sample.