scholarly journals Kinetic Evolution of Laser Ablating Alloy Materials

2021 ◽  
Vol 9 ◽  
Author(s):  
Junxiao Wang ◽  
Yang Zhao ◽  
Lei Zhang ◽  
Shuqing Wang ◽  
Maogen Su ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Energy ◽  
Laser Irradiance ◽  
Ablation Process ◽  
Plasma Parameters ◽  
Early Application ◽  
Theoretical Simulation ◽  
Breakdown Spectroscopy ◽  
Whole Process ◽  
Spatio Temporal

Through the theoretical simulation and analysis of the whole process of laser ablating target and producing plasma with high spatio-temporal resolution, it is helpful for people to gain a more complete understanding of the ablation process of target and the evolution process of plasma parameters, which has an important guiding role for the improvement and optimization of laser ablation technology. Alloys are commonly used in daily life, but there are few researches on laser-induced alloy targets at present. Therefore, based on the thermal model of laser ablation and the two-dimensional axisymmetric multi-species hydrodynamic model, the process of laser ablating Al-Mg alloy under atmospheric pressure argon is theoretically simulated, and the ablation process of alloy target and the spatio-temporal evolution results of plasma parameters under different laser irradiances are compared. At high laser irradiance, the melt and evaporation depth, laser energy absorption and plasma characterization parameters are much greater than those at low laser irradiance, and the species energy distribution at different laser irradiance also presents different trends. In addition, the velocity of different species is calculated according to the position-time diagram of the maximum emission intensity, and they expand at a constant speed during the studied time. These results can provide some theoretical guidance for the early application of laser-induced breakdown spectroscopy in metallurgy.

scholarly journals Characterizing laser-induced plasma generated from MgO/PVA solid targets-=SUP=-*-=/SUP=-

2019 ◽  
Vol 127 (7) ◽  
pp. 158
Author(s):  
T.K. Hamad ◽  
A.S. Jasim ◽  
H.T. Salloom
Keyword(s):  
Laser Energy ◽  
Second Harmonic ◽  
Plasma Electron ◽  
Poly Vinyl Alcohol ◽  
Laser Irradiance ◽  
Plasma Parameters ◽  
Laser Induced Plasma ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
532 Nm

AbstractThis contribution reports on the characterization of laser-induced plasma generated from the surface of magnesium oxide dispersed in Poly (vinyl alcohol) (MgO/PVA) pellet using laser induced breakdown spectroscopy. For this purpose, Nd:YAG Q-switched pulsed laser with energy ranging from 50 to 250 mJ, operating at both fundamental (1064 nm) and second harmonic (532 nm) was focused on the sample to generate plasma. Based on experimental results, emission lines of magnesium have been used to calculate the plasma parameters. The plasma electron temperature as a function of laser energy ranged from (8596–8900) K and (8000-8700) K, and the electron density from (1.12–1.8) × 10^16 cm^–3, (2.9–4.5) × 10^16 cm^–3 measured at 1064 nm and 532 nm, respectively. Although these values increased with the increase in laser irradiance, they showed different rates of increase with different wavelength dependency.

Sample temperature effect on laser ablation and analytical capabilities of laser induced breakdown spectroscopy

2019 ◽  
Vol 34 (3) ◽  
pp. 607-615 ◽  
Author(s):  
V. N. Lednev ◽  
M. Ya. Grishin ◽  
P. A. Sdvizhenskii ◽  
R. D. Asyutin ◽  
R. S. Tretyakov ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Temperature Effect ◽  
Sample Temperature ◽  
Laser Induced Breakdown Spectroscopy ◽  
Ablation Process ◽  
Breakdown Spectroscopy ◽  
Laser Ablation Process ◽  
Laser Induced Breakdown

The influence of sample temperature on the laser ablation process and analytical capabilities of laser induced breakdown spectroscopy (LIBS) was studied systematically.

scholarly journals DETERMINE EMISSIONS PLASMA IRON BY LASER-INDUCED BREAKDOWN SPECTROSCOPY IN ATMOSPHERIC ENVIRONMENT

2020 ◽  
pp. 100-106
Author(s):  
Baida M. AHMED ◽  
Shaimaa Hussein Abd MUSLIM ◽  
Muntadher Jawad KHOUDHAIR
Keyword(s):  
Laser Energy ◽  
Laser System ◽  
Emission Spectra ◽  
Laser Wavelength ◽  
Atmospheric Environment ◽  
Plasma Spectroscopy ◽  
Stark Broadening ◽  
Plasma Parameters ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

The plasma spectroscopy analysis for Iron induced plasma was carried out using a Q-switched Nd: YAG pulsed laser system. The Laser wavelength was (1064) nm, Emission spectra were obtained using different energies in the range (600-900) mJ. Electron temperatures are evaluated at different laser peak powers from Boltzmann (-1/KBT) and Suha equation, also, the electron densities are deduced using stark broadening. A limited number of suitable Fe lines are detected and the plasma parameters are discussed. The Electron temperatures of (Fe) are measured and were found to be in the range of (1.8–1.88) eV. It is observed in the case of iron the electron temperature is proportional with laser energy and the highest peak in (Fe) arrive at (55396.52). Keywords: Iron Plasma, Laser-Induced Plasma Spectroscopy, Plasma Parameters.

Laser-Induced Breakdown Spectroscopic (LIBS) Analysis of Trace Heavy Metals Enriched by Al2O3 Nanoparticles

2019 ◽  
Vol 73 (4) ◽  
pp. 380-386 ◽  
Author(s):  
Sheng Niu ◽  
Lijuan Zheng ◽  
Abdul Qayyum Khan ◽  
Heping Zeng
Keyword(s):  
Heavy Metals ◽  
Laser Ablation ◽  
Laser Wavelength ◽  
Spectral Lines ◽  
Detection Sensitivity ◽  
Al2o3 Nanoparticles ◽  
Laser Irradiance ◽  
Breakdown Spectroscopy ◽  
Relative Standard ◽  
Laser Induced Breakdown

We demonstrated a unique method for the detection of heavy metals, such as Ni, Cr, and Cd, at trace level in aqueous solutions by laser induced breakdown spectroscopy (LIBS) enriched by aluminum oxide (Al2O3) nanoparticles (NP) adsorption. Al2O3 NPs were used for the sample phase transformation and heavy metals pre-concentration because of its excellent adsorption capacity and sparse spectral lines. The influence of laser wavelength and laser irradiance on the signal intensity was investigated. With 45 mL solutions used for enrichment and adsorption, limits of detection obtained for Ni, Cr, and Cd were 9.61, 8.49, and 71.6 μg/L under 532 nm laser ablation, and 22.5, 20.4, and 83.8 μg/L under 1064 nm laser ablation, respectively. The relative standard deviations of all elements were about 12% or 13%. Moreover, Al2O3 NPs adsorption enrichment of target elements was verified and the detection sensitivity was improved by increasing the amount of sample solutions.

Analyses of Plasmas Produced by Laser Ablation of Fresh Aliments

2011 ◽  
Vol 227 ◽  
pp. 49-52 ◽  
Author(s):  
Sid Ahmed Beldjilali ◽  
Jörg Hermann ◽  
Tewfik Baba-Hamed ◽  
Ahmed Belasri
Keyword(s):  
Laser Ablation ◽  
Laser Energy ◽  
Emission Spectra ◽  
Mineral Elements ◽  
Spectral Lines ◽  
Local Thermal Equilibrium ◽  
Spectral Radiance ◽  
Standard Samples ◽  
Plasma Properties ◽  
Breakdown Spectroscopy

Detection and analysis of trace mineral elements in vegetables, and more generally in food by laser-induced breakdown spectroscopy (LIBS) promises applications with expected outcomes in nutrition quality. LIBS ensures contactless, real-time measurements of multielemental samples without any preparation of the samples surface. However, its application to analyses of aliments such as vegetables has one main drawback. Organic materials are strongly inhomogeneous and the physical properties that govern the processes of laser energy absorption, material ablation and plasma formation depend on a large number of parameters making calibration with standard samples impossible. This technique requires therefore a calibration-free approach that allows one to deduce the relative elemental concentrations from the intensities of spectral lines emitted from the laser-produced plasma. The main difficulty of such an approach is related to the temporal and spatial variation of the plasma properties. Therefore we have performed spectroscopic analysis of the plasma produced by Nd:Yag laser ablation of potato flesh and skin. The emission spectra recorded with an Echelle spectrometer with ICCD detector were compared to the spectral radiance computed for a plasma in local thermal equilibrium to deduce the mass fractions of the mineral elements.

Laser Ablation of Ti-Al Alloy in Vacuum and Air Environments

2012 ◽  
Vol 217-219 ◽  
pp. 2257-2264 ◽  
Author(s):  
Yue Hua Liu ◽  
Xiang Dong Liu ◽  
Ming Chen ◽  
Ming Wen Zhao
Keyword(s):  
High Power ◽  
Laser Energy ◽  
Optical Emission ◽  
Target Surface ◽  
Al Alloy ◽  
Laser Irradiance ◽  
Air Plasma ◽  
High Power Laser ◽  
Power Laser ◽  
Plasma Parameters

The time-resolved optical emission spectroscopy of Ti-Al alloy plasma produced by the Nd:YAG high-power laser pulses with wavelength of 1064nm was investigated both in air and vacuum conditions. The comparative studies gave detailed insights that the plasmas produced in air were much hotter and denser. The quantitative descriptions indeed suggested that a cascade avalanche process would be happen followed by air plasma firstly, before the laser impacting the target surface. On the other hand, the laser energy may be considerably attenuated via hotter and denser plasma, the amount of laser energy on the target surface remarkably decreased in air condition. In addition, at high-power laser irradiance levels, there was an auto regulatory area near the target surface and the plasma parameters tend to be saturated

High Intensity Laser Ablation of Titanium Target

2011 ◽  
Vol 227 ◽  
pp. 57-61 ◽  
Author(s):  
Kenza Yahiaoui ◽  
Tahar Kerdja ◽  
Smail Malek
Keyword(s):  
Laser Ablation ◽  
Laser Energy ◽  
Thin Film Deposition ◽  
Ablation Rate ◽  
Film Deposition ◽  
Laser Irradiance ◽  
Phase Explosion ◽  
Sem Images ◽  
Laser Breakdown ◽  
The Impact

In thin film deposition by pulsed laser ablation (PLD), the mass ablation rate depends on laser energy, on the pulse duration and on the thermodynamic properties of the ablated materials. In order to optimize the PLD technique and the films quality, the evolution of the amount of the ejected materials with laser irradiance, the SEM images of the laser impacts on the target and the ion yield in the vapour plume, were used. This allows us to predict the different mechanisms that are responsible to mass ablation according to laser irradiance which was ranging from 1.5108W/cm2 to 5.51010 W/cm2. Three diagnostics devices have been used: A quartz microbalance placed in front of the target, where the maximum of materials ejection occurs, a Scanning Electron Microscope (SEM) was used to show the impact morphology evolution with the laser irradiance and a charge collector, biased at negative voltage, was used to measure the ions yield and ions kinetic energy. The results show the evolution from normal evaporation mechanism at moderate laser irradiance to phase explosion mechanism at higher laser irradiance. Laser irradiance threshold for phase explosion onset is well determined by microbalance measurement, SEM micrographic pictures and the laser breakdown in the vapour plume was determined by the charge collector.

scholarly journals Effect of laser irradiance on the surface morphology and laser induced plasma parameters of zinc

2014 ◽  
Vol 32 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Mahreen Akram ◽  
Shazia Bashir ◽  
Asma Hayat ◽  
Khaliq Mahmood ◽  
Riaz Ahmad ◽  
...  
Keyword(s):  
Surface Modification ◽  
Electron Microscope ◽  
Laser Induced Breakdown Spectroscopy ◽  
Laser Irradiance ◽  
Plasma Parameters ◽  
Scanning Electron Microscope Analysis ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown ◽  
Electron Microscope Analysis ◽  
Scanning Electron

AbstractThe effect of laser-irradiance on the surface morphology and laser induced breakdown spectroscopy of zinc has been investigated by employing Nd:YAG laser (wavelength λ = 1064 nm, pulse duration t ~ 10 ns, and repetition rate = 10 Hz) under ambient environment of argon at a pressure of 20 Torr. For this purpose, zinc targets were exposed to various laser irradiances ranging from 13 GW/cm2 to 100 GW/cm2. Scanning electron microscope analysis has been performed to analyze the surface modification of irradiated zinc targets. Scanning electron microscope analysis revealed the formation of various kinds of structures such as ripples, cones, cavities, and wave like ridges at the center and peripheral regions of ablated zinc. In the central ablated region with increasing laser irradiance, the growth of distinct and well defined ripples is observed. Further increase in irradiance makes the appearance of these ripples diffusive and narrow. In order to correlate the plasma parameters with the surface modification, laser induced breakdown spectroscopy analysis has also been performed. The electron temperature and number density of zinc plasma have been evaluated at various laser irradiances. For both plasma parameters, an increasing trend up to a certain value of laser irradiance is observed which is due to enhanced energy deposition. Afterword a decreasing trend is achieved which is attributed to the shielding effect. With further increase in irradiance a saturation stage comes and almost no change in plasma parameters is observed. This saturation is explainable on the basis of the formation of a self-regulating regime near the target surface. A strong correlation between surface modification and plasma parameters is established.

MicroCT Imaging and In Vivo Temperature Elevations in Implanted Prostatic Tumors in Laser Photothermal Therapy Using Gold Nanorods

2012 ◽  
Vol 3 (2) ◽  
Author(s):  
N. Manuchehrabadi ◽  
A. Attaluri ◽  
H. Cai ◽  
R. Edziah ◽  
E. Lalanne ◽  
...  
Keyword(s):  
Gold Nanorods ◽  
Photothermal Therapy ◽  
Imaging System ◽  
Laser Energy ◽  
Gold Nanorod ◽  
Laser Irradiance ◽  
Theoretical Simulation ◽  
Microct Imaging ◽  
Laser Photothermal Therapy

In this study, in vivo animal experiments are performed on implanted xenograph prostatic tumors in nude mice to investigate enhanced laser energy absorption in the tumors by an intratumoral injection of gold nanorod solutions. In vivo temperature mapping of the tumors during laser photothermal therapy has shown the feasibility of elevating tumor temperatures higher than 50 °C using only 0.1 ml nanorod solution and a low laser irradiance of 1.6 W/cm2 incident on the tumor surface. The temperature profile suggests that normal tumor tissue still absorbs some amount of the laser energy without nanorod presence; however, the injected nanorods ensure that almost all the laser energy is absorbed and confined to the targeted tumors. The inverse relationship between the temperature elevations and the tumor size implies a relatively uniform spreading of the nanorods to the entire tumor, which is also shown by microcomputed tomography (microCT) imaging analyses. The feasibility of detecting 250 OD gold nanorod solution injected to the tumors is demonstrated via a high resolution microCT imaging system. Compared to other nanostructures, the gold nanorods used in this study do not accumulate surrounding the injection site. The relatively uniform deposition of the nanorods in the tumors observed by the microCT scans can be helpful in future study in simplifying theoretical simulation of temperature elevations in tumors during laser photothermal therapy.

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