Determination of gold fineness by laser induced breakdown spectroscopy with the simultaneous use of CW-CO2 and Q-SW Nd:YAG lasers

Shoursheini, S.Z.; Sajad, Batool; Parvin, Parviz

doi:10.1016/j.optlaseng.2009.07.016

Cited by 26 publications

(10 citation statements)

References 23 publications

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“…The experimental data and the stimulation validate that the local thermodynamic equilibrium condition is satisfied with plasmas of longer delay times. This depends on the plasma parameters such as the ambient gas, laser energy and pulse duration used in the experiments [27,28]. The most commonly used method to warrant the existence of LTE is the electron energy distribution function (EEDF) Maxwell distribution, and the McWhirter criterion [23,[29][30][31].…”

Section: The Local Thermodynamic Equilibrium and The Optical Thinnessmentioning

confidence: 99%

Influence of laser energy on the electron temperature of a laser-induced Mg plasma

Asamoah

Yao

2016

Appl. Phys. B

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radiations in this process are used for the identification of the elemental composition of the sample [7][8][9].LIBS offers many advantages over other spectroscopic techniques such as mass spectroscopy, electrode spark and inductively coupled plasma. Some of LIBS unique advantages include the ability to make in situ analysis even in hostile environment, remote sensing, little or no preparation of the sample, and multi-element analysis [10][11][12]. Based on these advantages, LIBS has been extensively investigated on several samples including liquids [13], gases [14] and as well from non-conducting and conducting solids [15].LIBS is also a spectroscopic technique for the determination of the density of electron, electron temperature and number densities of the plasma plume [16,17]. Laserinduced plasma temperatures are influenced by various experimental conditions such as ambient surrounding, laser energy and laser pulse width. Most of the studies on LIBS temperatures report that the plasma temperature tends to increase with increasing laser energy, pulse width, laser wavelength and ambient pressure [18][19][20][21].Although LIBS has been employed successfully in several experimental and theoretical works, to analyze the spectroscopic composition of the samples, there are still many aspects which need to be investigated [6]. For example, Barthelemy et al. [22] investigated the influence of the laser parameters of an aluminum-induced plasma. They reported that the temperature slightly decreases at the plasma edge and close to the aluminum surface. This decrease in temperature at the plasma edge is basically caused by radiative cooling, while the decrease in temperature at the aluminum surface is as a result of thermal conduction. The authors also found that at the first microsecond of the ablation plume, the electron density was spatially homogeneous.Zhang et al.[23] also reported on the influence of laser parameters on plasma temperature. Their results predicted Abstract The magnesium plasma induced by a 1064-nm Q-switched Nd:YAG laser in atmospheric air was investigated. The evolution of the plasma was studied by acquiring spectral images at different laser energies and delay times. We observed that the intensities of the spectral lines decrease with larger delay times. The electron temperature was determined using the Boltzmann plot method. At a delay time of 100 ns and laser energy of 350 mJ, the electron temperature attained their highest value at 10164 K and then decreases slowly up to 8833.6 K at 500 ns. We found that the electron temperature of the magnesium plasma increases rapidly with increasing laser energy.

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Section: The Local Thermodynamic Equilibrium and The Optical Thinnessmentioning

confidence: 99%

Influence of laser energy on the electron temperature of a laser-induced Mg plasma

Asamoah

Yao

2016

Appl. Phys. B

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“…This study demonstrates the use of laserinduced breakdown spectroscopy (LIBS) [15], a spectroscopic technique to investigate the sources of variability in coating uniformity in tablets and which attempts to establish statistical significance, or lack thereof, of the possible causes. The LIBS technique finds application in a wide variety of areas such as the study of soil composition [16], polymers [17], minerals [18], metallic compounds [19,20], cosmetics [21], gaseous mixtures [22], construction materials [23], hazardous material detection [24], and traditional fuels such as coal [25], fuel cells [26], and biological tissues [27,28]. The pharmaceutical industry is beginning to consider this technique for in-line monitoring and product analysis applications.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Pharmaceutical Tablet Coating Uniformity by Laser-Induced Breakdown Spectroscopy (LIBS)

et al. 2011

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A laser-induced breakdown spectroscopy-based analytical methodology is developed to study tablet coating variability in pharmaceutical tablets. The method quantifies the amount of coating on a tablet by assigning an average coating thickness score to it. When tested using samples with different amounts of coating, the coating thickness scores showed direct correlation to the weight gain of the tablet, hence validating the analytical method. The relative significance of the processing parameters and the components of variability were computed using statistical techniques. The sampling frequency of laser shots was found to have no significant effect. The effect of the position of the laser pulse on the tablet surface was found to be significant; however, it was determined that this effect was due to the tablet curvature, which resulted in the laser optical path to intersect the coating diagonally. The variability between batches (lots) manufactured under the same processing conditions was not significant. The largest avoidable source of variability was the tablet-to-tablet component, possibly indicating the inadequate mixing performance of the coating device.

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“…4 shows that the plasma cools down relatively very fast from 0.92 eV up to 0.54 eV within 2500 ns. The electron density ( ) − n cm e 3 was calculated using Stark broadening of the Balmer H α line due to its major advantage to provide data in order to avoid self-absorption [24]. The linear Stark effect acting on hydrogen lines results in a large broadening; this reduces the relative uncertainty of the measurement with respect to the characteristic emissions from the other elements [25].…”

Section: Local Thermodynamic Equilibriummentioning

confidence: 99%

Quantitative analysis of Cu and Co adsorbed on fish bones via laser-induced breakdown spectroscopy

Rezk

Galmed

Abdelkreem

et al. 2016

Optics & Laser Technology

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Determination of gold fineness by laser induced breakdown spectroscopy with the simultaneous use of CW-CO2 and Q-SW Nd:YAG lasers

Cited by 26 publications

References 23 publications

Influence of laser energy on the electron temperature of a laser-induced Mg plasma

Influence of laser energy on the electron temperature of a laser-induced Mg plasma

Analysis of Pharmaceutical Tablet Coating Uniformity by Laser-Induced Breakdown Spectroscopy (LIBS)

Quantitative analysis of Cu and Co adsorbed on fish bones via laser-induced breakdown spectroscopy

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