This study explores the feasibility of in situ Lithium (Li) analysis in Magnesium-Lithium (MgLi) alloys using Laser-Induced Breakdown Spectroscopy (LIBS). It focuses on two Li emission lines: Li I 670.8 nm (resonance) and Li I 610.
View Article and Find Full Text PDFThis study introduces a novel and simple way to suppress the self-absorption effect in laser-induced breakdown spectroscopy (LIBS) by utilizing a defocusing laser irradiation technique. For this purpose, a Nd:YAG laser with a wavelength of 1,064 nm and repetition rate of 10 Hz with energy in the range of 10 mJ-50 mJ was used. The laser irradiation was focused by using a 150-mm-focal-length plano-convex lens onto the sample surface under defocusing of approximately -6 mm.
View Article and Find Full Text PDFLaser-induced breakdown spectroscopy (LIBS) to detect the light elements such as lithium (Li) and boron (B) and heavy elements such as copper (Cu) and lead (Pb) in raw fish samples is reported in this work. This is made possible by understanding that the soft target absorbs recoil energy and as a result, the ablated atoms gushing from the soft target do not acquire sufficient speed to form a shock wave. In order to overcome this problem, we set a subtarget on the back of the soft target so as to produce the repulsion force by which the gushing speed of the ablated atoms is increased, yielding a sufficiently high plasma temperature or sufficiently large thermal energy needed for the excitation of the ablated atoms.
View Article and Find Full Text PDFThis study is aimed at elucidating the physical processes responsible for the excellent spectral qualities in terms of full width at half-maximum (fwhm) and signal-to-noise (S/N) ratio shown in a special double pulse laser-induced spectroscopy. Apart from the use of atmospheric He ambient gas, the achievement is due to the first laser for generating He gas plasma and the subsequent use of the second laser pulse for target ablation, in opposite order of the two-laser operations in conventional double pulse LIBS. This setup allows adjustments of the many experimental parameters to yield the optimal condition resulting in 0.
View Article and Find Full Text PDFPresented in this paper are the results of an experimental study on the laser induced plasma emission of a number of CN free samples (urea, sucrose) with 40 mJ pulse energy using He and N₂ ambient gases. It is shown that the CN emission has its exclusive sources in the molecules produced as the result of chemical bonding either between the ablated C and N ions in the He plasma or between the ablated C and dissociated N from the N₂ ambient gas. The emission intensities in both cases are found to have the highest values at the low gas pressure of 2 kPa.
View Article and Find Full Text PDFWe have conducted an experimental study exploring the possible application of laser-induced breakdown spectroscopy (LIBS) for practical and highly sensitive detection of metal impurities in water. The spectrochemical measurements were carried out by means of a 355 nm Nd-YAG laser within N and He gas at atmospheric pressures as high as 2 kPa. The aqueous samples were prepared as thin films deposited on indium-tin oxide (ITO) glass by an electrolysis process.
View Article and Find Full Text PDFA systematic study has been performed on the spectral characteristics of the full spectrum of He emission lines and their time-dependent behaviors measured from the He gas plasmas generated by a nanosecond neodymium-doped yttrium aluminum garnet laser. It is shown that among the major emission lines observed, the triplet He(I) 587.6 nm emission line stands out as the most prominent and long-lasting line, associated with de-excitation of the metastable triplet (S = 1) excited state (1s(1) 3d(1)).
View Article and Find Full Text PDFAn experimental study has been performed on the pressure-dependent plasma emission intensities in Ar, He, and N2 surrounding gases with the plasma induced by either nanosecond (ns) or picosecond (ps) yttrium aluminum garnet laser. The study focused on emission lines of light elements such as H, C, O, and a moderately heavy element of Ca from an agate target. The result shows widely different pressure effects among the different emission lines, which further vary with the surrounding gases used and also with the different ablation laser employed.
View Article and Find Full Text PDFAn experimental study of ultraviolet (UV) laser-induced plasma spectroscopy (LIPS) on Ti samples with low-pressure surrounding He gas has been carried out to demonstrate its applicability to quantitative micro-analysis of deuterium impurities in titanium without the spectral interference from the ubiquitous surface water. This was achieved by adopting the optimal experimental condition ascertained in this study, which is specified by 5 mJ laser energy, 10 Torr helium pressure, and 1-50 mus measurement window, which resulted in consistent D emission enhancement and effective elimination of spectral interference from surface water. As a result, a linear calibration line exhibiting a zero intercept was obtained from Ti samples doped with various D impurity concentrations.
View Article and Find Full Text PDFThis experiment was carried out to address the need for overcoming the difficulties encountered in hydrogen analysis by means of plasma emission spectroscopy in atmospheric ambient gas. The result of this study on zircaloy-4 samples from a nuclear power plant demonstrates the possibility of attaining a very sharp emission line from impure hydrogen with a very low background and practical elimination of spectral contamination of hydrogen emission arising from surface water and water vapor in atmospheric ambient gas. This was achieved by employing ultrapure ambient helium gas as well as the proper defocusing of the laser irradiation and a large number of repeated precleaning laser shots at the same spot of the sample surface.
View Article and Find Full Text PDFIt is found in this work that variation of laser power density in low-pressure plasma spectrochemical analysis of hydrogen affects sensitively the hydrogen emission intensity from the unwanted and yet ubiquitous presence of ambient water. A special experimental setup has been devised to allow the simple condition of focusing/defocusing the laser beam on the sample surface. When applied to zircaloy-4 samples prepared with various hydrogen impurity concentrations using low-pressure helium surrounding gas, good-quality hydrogen emission lines of very high signal to background ratios were obtained with high reproducibility under weakly focused or largely defocused laser irradiation.
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