Laser-Induced Breakdown Spectroscopy for Polymer Identification

1998 ◽  
Vol 52 (3) ◽  
pp. 456-461 ◽  
Author(s):  
R. Sattmann ◽  
I. Mönch ◽  
H. Krause ◽  
R. Noll ◽  
S. Couris ◽  
...  

Laser-induced breakdown spectroscopy has been applied to polymer samples in order to investigate the possibility of using this method for the identification of different materials. The plasma emission spectra of high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), and polypropylene (PP) have been studied. Spectral features have been measured—for example, the 725.7 nm chlorine line, the 486.13 mm Hβ line, and the 247.86 nm carbon line—whose evaluation with neural networks permits identification accuracies between 90 and 100%, depending on polymer type.

2018 ◽  
Vol 33 (10) ◽  
pp. 1676-1682 ◽  
Author(s):  
Shunchun Yao ◽  
Lifeng Zhang ◽  
Kejing Yin ◽  
Kaijie Bai ◽  
Jialong Xu ◽  
...  

A scheme named the standard deviation method is presented for identifying the spectral data of a gas–solid flow based on laser-induced breakdown spectroscopy.


2020 ◽  
Vol 1 (2) ◽  
pp. 5-8
Author(s):  
Komang Gde Suastika, Heri Suyanto, Gunarjo, Sadiana, Darmaji

Abstract - Laser-Induced Breakdown Spectroscopy (LIBS) is one method of atomic emission spectroscopy using laser ablation as an energy source. This method is used to characterize the type of amethysts that originally come from Sukamara, Central Kalimantan. The result of amethyst characterization can be used as a reference for claiming the natural wealth of the amethyst. The amethyst samples are directly taken from the amethyst mining field in the District Gem Amethyst and consist of four color variations: white, black, yellow, and purple. These samples were analyzed by LIBS, using laser energy of 120 mJ, delay time detection of 2 μs and accumulation of 3, with and without cleaning. The purpose of this study is to determine emission spectra characteristics, contained elements, and physical characteristics of each amethyst sample. The spectra show that the amethyst samples contain some elements such as Al, Ca, K, Fe, Gd, Ba, Si, Be, H, O, N, Cl and Pu with various emission intensities. The value of emission intensity corresponds to concentration of element in the sample. Hence, the characteristics of the amethysts are based on their concentration value. The element with the highest concentration in all samples is Si, which is related to the chemical formula of SiO2. The element with the lowest concentration in all samples is Ca that is found in black and yellow amethysts. The emission intensity of Fe element can distinguish between white, purple, and yellow amethyst. If Fe emission intensity is very low, it indicates yellow sample. Thus, we may conclude that LIBS is a method that can be used to characterize the amethyst samples.Key words: amethyst, impurity, laser-induced, breakdown spectroscopy, characteristic, gemstones


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marincan Pardede ◽  
Indra Karnadi ◽  
Rinda Hedwig ◽  
Ivan Tanra ◽  
Javed Iqbal ◽  
...  

AbstractHigh-sensitivity detection of hydrogen (H) contained in zircaloy-4, a commonly used material for nuclear fuel containers, is crucial in a nuclear power plant. Currently, H detection is performed via gas chromatography, which is an offline and destructive method. In this study, we developed a technique based on metastable excited-state He-assisted excitation to achieve excellent quality of H emission spectra in double-pulse orthogonal laser-induced breakdown spectroscopy (LIBS). The production of metastable excited-state He atoms is optimized by using LiF as sub-target material. The results show a narrow full-width-at-half-maximum of 0.5 Å for the H I 656.2 nm emission line, with a detection limit as low as 0.51 mg/kg. Thus, using this novel online method, H in zircaloy-4 can be detected efficiently, even at very low concentrations.


2002 ◽  
Vol 56 (6) ◽  
pp. 689-698 ◽  
Author(s):  
G. W. Rieger ◽  
M. Taschuk ◽  
Y. Y. Tsui ◽  
R. Fedosejevs

This paper presents a study of laser-induced breakdown spectroscopy (LIBS) at low energies using KrF laser pulses of only 50–300 μJ. Very small focal spots with diameters of 5 to 20 μm are employed in order to achieve strong plasma emission. The focused intensities were in the range of 1.6 to 150 GW/cm2. The evolution of the micro-plasma progresses more rapidly in this energy range compared to conventional LIBS using mJ laser pulses. The optimum delay time for the detection of emission from minor constituent elements in aluminum is between 100 and 360 ns after the laser pulse hits the sample. The corresponding limits of detection are in the range of 2 to 450 ppm and are comparable to experiments that have used much higher laser energies. The amount of ablated material is significantly reduced using low laser energies and typical crater diameters are approximately 15–40 μm.


2019 ◽  
Vol 73 (10) ◽  
pp. 1228-1236
Author(s):  
John Lucchi ◽  
Mauro Martinez ◽  
Matthieu Baudelet

Laser-induced breakdown spectroscopy (LIBS) has recently demonstrated its unrivaled performance for broadband elemental imaging of surfaces. The dimensions of the laser sampling spot still being potentially larger than the interfaces of chemical domains, the plasma created at each location can be largely varying and inhomogeneous with contributions from the different sides of the interface. This variation can become problematic when imaging it on fiber bundles connected to multiple spectrometers. A spatially heterogeneous signal would lead to spatially dependent image on the fiber bundle causing inconsistent readings and loss of efficiency. Köhler illumination is used in this study to create a homogenous illumination, regardless of the source homogeneity, thus improving light collection efficiency. The performance of this approach was demonstrated with inhomogeneous spectral sources and applied to the LIBS analysis of a metallic interface, showing up to a sixfold improvement of the homogeneity of the plasma collection.


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