Element Identification on the Surface of Inorganic Solids by Excimer Laser-Induced Emission Spectroscopy

1992 ◽  
Vol 46 (4) ◽  
pp. 587-592 ◽  
Author(s):  
D. Franzke ◽  
H. Klos ◽  
A. Wokaun
Keyword(s):  
Laser Energy ◽  
High Sensitivity ◽  
Laser Pulses ◽  
Atomic Emission ◽  
Emission Lines ◽  
Nonlinear Dependence ◽  
Absorption Length ◽  
Metallic Component ◽  
Incident Laser Energy ◽  
Pulse Energies

Intense atomic emission lines are observed when the surfaces of minerals, such as pyrite or zinc blende, are excited with UV laser pulses of 8 mJ energy, at a wavelength of 370 nm. The line spectra have been assigned to transitions of the metallic component of the material under investigation, in the neutral charge state of the corresponding atom; a few ionic emissions have also been detected. A nonlinear dependence of the emission intensity on incident laser energy, as well as the observation of transitions at energies higher than the incident photon energy, indicates that multiphoton processes are involved in the ablation and excitation process. The occurrence of the laser-induced emission phenomenon, at the pulse energies used, depends on characteristic properties of the material, such as absorption length, heat capacity, and enthalpy of vaporization. In the experiments, minor components contained in the naturally occurring minerals have been detected with high sensitivity. On the basis of this observation, the potential of the method for trace analysis has been explored. Test solutions containing an ion to be analyzed, such as Pb2+, have been applied to the surface of an ablatable copper or sulfur target. From the intensity of the recorded laser-induced Pb emission lines, a detection limit of less than 10 ppm or 35 mg/cm2 on the target has been deduced.

scholarly journals Super continuum generation in water doped with Homeopathic medicines

2021 ◽  
Vol 19 (1-2) ◽  
pp. 26-38
Author(s):  
Paresh K Joshi ◽  
Aditya K Dharmadhikari ◽  
Jayashree A Dharmadhikari ◽  
Praful M Barvalia
Keyword(s):  
Laser Energy ◽  
Visible Region ◽  
Area Under The Curve ◽  
Laser Pulses ◽  
Supercontinuum Generation ◽  
Linear Absorption ◽  
Continuum Generation ◽  
Incident Laser Energy ◽  
Significant Difference ◽  
Fs Laser

We have carried out systematic studies to investigate the effect on supercontinuum generation in water using 40 fs laser pulses when doped with Homeopathic medicines. We perform these studies using five series of medications with different levels of dilution (10-30 to 10-100000). We measure supercontinuum spectra that span from 400-1050 nm. We monitor the area under the curve in the range 450-750 nm for each sample at a fixed incident laser energy. Our observations indicate that the yield of supercontinuum generation, in water containing Homeopathic medicine is significantly different from that obtained in water containing plain ethanol. The measurement for different dilutions shows up to 7 times standard deviation variation in the yield of supercontinuum generation? Even though linear absorption in the UV-visible region does not show any significant difference for different Homeopathic medicines, the supercontinuum yield which depends on the effective nonlinear refractive index changes with different samples.

scholarly journals Conversion of laser light into soft X rays with 3-ns and 30-ps laser pulses

1991 ◽  
Vol 9 (2) ◽  
pp. 551-562 ◽  
Author(s):  
K. Eidmann ◽  
W. Schwanda
Keyword(s):  
Laser Light ◽  
Laser Energy ◽  
Short Pulse ◽  
Laser Pulses ◽  
X Rays ◽  
Incident Laser ◽  
X Ray ◽  
Transmission Grating ◽  
Incident Laser Energy ◽  
Temporal And Spatial

The X-ray emission from planar targets made of aluminum, copper, or gold irradiated by a frequency-doubled Nd laser (530-nm wavelength and 1012–1014-W/cm2 laser intensity) was measured at two pulse durations: 3 ns and 30 ps. We absolutely measured the X-ray emission with spectral, temporal, and spatial resolution in the wavelength range 3 Å < λ < 250 Å by using filtered bolometers, a transmission grating spectrometer, X-ray diodes, and an X-ray streak camera as diagnostics. In addition, the absorption of laser light was measured. For the short, 30-ps laser pulse the conversion of incident laser energy into X rays was considerably less than that with the long, 3-ns pulse. This is caused by less absorption of laser light and, in addition, by less conversion of absorbed laser energy into X rays in the case of the short pulse. The results are compared with numerical simulations performed with the MULTI hydrocode.

Characterization of Amethysts from Sukamara, Central Kalimantan, Using Laser-Induced Breakdown Spectroscopy (LIBS)

2020 ◽  
Vol 1 (2) ◽  
pp. 5-8
Author(s):  
Komang Gde Suastika, Heri Suyanto, Gunarjo, Sadiana, Darmaji
Keyword(s):  
Emission Intensity ◽  
Laser Energy ◽  
Emission Spectra ◽  
Atomic Emission ◽  
Laser Induced Breakdown Spectroscopy ◽  
Chemical Formula ◽  
Central Kalimantan ◽  
Breakdown Spectroscopy ◽  
Laser Induced Breakdown

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

scholarly journals Analytical model for the depth progress of percussion drilling with ultrashort laser pulses

2021 ◽  
Vol 127 (5) ◽  
Author(s):  
Daniel Holder ◽  
Rudolf Weber ◽  
Thomas Graf ◽  
Volkher Onuseit ◽  
David Brinkmeier ◽  
...  
Keyword(s):  
Analytical Model ◽  
Experimental Validation ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
Picosecond Pulses ◽  
Hole Depth ◽  
Laser Percussion Drilling ◽  
Pulse Energies ◽  
Ultrashort Laser ◽  
Percussion Drilling

AbstractA simplified analytical model is presented that predicts the depth progress during and the final hole depth obtained by laser percussion drilling in metals with ultrashort laser pulses. The model is based on the assumption that drilled microholes exhibit a conical shape and that the absorbed fluence linearly increases with the depth of the hole. The depth progress is calculated recursively based on the depth changes induced by the successive pulses. The experimental validation confirms the model and its assumptions for percussion drilling in stainless steel with picosecond pulses and different pulse energies.

Fourier Deconvolution of Overlapping Line Pairs in Inductively Coupled Plasma-Atomic Emission Spectrometry

1989 ◽  
Vol 43 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Eric H. Van Veen ◽  
M. Pieter Goudzwaard ◽  
Margaretha T. C. De Loos-Vollebregt ◽  
Leo De Galan
Keyword(s):  
Inductively Coupled Plasma ◽  
Gaussian Approximation ◽  
Signal To Noise Ratio ◽  
Detection Limits ◽  
Atomic Emission ◽  
Emission Lines ◽  
Emission Spectrometry ◽  
Plasma Atomic Emission Spectrometry ◽  
Spectral Window ◽  
Inductively Coupled

A deconvolution procedure utilizing Fourier transformation has been developed to reduce line overlap in ICP-AES. Line broadening is caused by physical processes and by instrumental broadening. Convenient deconvolution, however, turns out to be restricted to broadening common to the emission lines in the spectral window, i.e., to instrumental broadening. Deconvolution for the “true” instrumental broadening function and for a Gaussian approximation to this function yields similar results, but the former allows for fast automated data processing with regard to any spectral region and sample composition. A straightforward procedure is reported for the determination of this function independent of wavelength. At the present noise level, a twofold reduction in linewidth can be achieved for emission lines having a small physical width in comparison to the instrumental width. With data acquired from both a high- and a medium-resolution monochromator, results from overlapping line pairs show linear analytical curves and improved detection limits. Due to the decrease in signal-to-noise ratio on deconvolution, the detection limits measured for isolated lines cannot be attained.

scholarly journals Modification of Aerosol Gold Nanoparticles by Nanosecond Pulsed-Periodic Laser Radiation

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2701
Author(s):  
Kirill Khabarov ◽  
Messan Nouraldeen ◽  
Sergei Tichonov ◽  
Anna Lizunova ◽  
Alexey Efimov ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Radiation ◽  
Gas Flow ◽  
Laser Pulses ◽  
Radiation Absorption ◽  
Sintering Process ◽  
Spherical Nanoparticles ◽  
Shrinkage Curve ◽  
Size Modification ◽  
Pulse Energies

This study investigates the processes of interaction of nanosecond pulsed-periodic laser radiation with the flow of aerosol agglomerates of gold nanoparticles synthesized in a spark discharge. Nanoparticles in a gas flow are spatially separated nano-objects whose interaction with each other and with the walls of an experimental cell was insignificant. Therefore, the energy absorbed by nanoparticles was used only for their own heating with further shape and size modification and on heat transfer to the surrounding gas. In the research, we used laser radiation with wavelengths of 527 and 1053 nm at pulse energies up to 900 µJ and pulse repetition rates up to 500 Hz. The dynamics of changes in the nanoparticles size during their sintering process depending on the laser pulses energy is characterized by an S-shaped shrinkage curve. Complete sintering of the initial agglomerates with their transformation into spherical nanoparticles is achieved by a series of impacting laser pulses. The result of nanoparticles’ laser modification is largely determined by the pulse energy and the efficiency of the nanoparticles’ radiation absorption.

scholarly journals Preparation and Characterization of Lead Oxide Nanoparticles by Laser Ablation as Antibacterial Agent

2017 ◽  
Vol 14 (4) ◽  
pp. 801-807
Author(s):  
Baghdad Science Journal
Keyword(s):  
Laser Ablation ◽  
Lead Oxide ◽  
Laser Energy ◽  
Laser Pulses ◽  
Diffusion Method ◽  
Lead Target ◽  
Oxide Nanoparticles ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

In this work, lead oxide nanoparticles were prepared by laser ablation of lead target immersed in deionized water by using pulsed Nd:YAG laser with laser energy 400 mJ/pulse and different laser pulses. The chemical bonding of lead oxide nps was investigated by Fourier Transform Infrared (FTIR); surface morphology and optical properties were investigated by Scanning Electron Microscope (SEM) and UV-Visible spectroscopy respectively, and the size effect of lead oxide nanoparticles was studied on its antibacterial action against two types of bacteria Gram-negitive (Escherichia coli) and Gram-positive (Staphylococcusaurus) by diffusion method. The antibacterial property results show that the antibacterial activity of the Lead oxide NPs was inversely proportional to the size of the nanoparticles in both Gram-negative and Gram-positive, and also it has been found that Gram-positive bacteria possess have greater sensitivity and less resistance to the lead oxide nanoparticles compared with Gram-negative bacteria.

Computer Simulation of Pulsed Laser Ablation for YBaCuO Superconducting Films

1990 ◽  
Vol 191 ◽  
Author(s):  
Toshiyuki Nakamiya ◽  
Kenji Ebihara ◽  
P. K. John ◽  
B. Y. Tong
Keyword(s):  
Thin Films ◽  
Excimer Laser ◽  
Laser Energy ◽  
Pulsed Laser ◽  
The Finite Element Method ◽  
High Tc ◽  
One Dimensional ◽  
Incident Laser Energy ◽  
Krf Excimer Laser ◽  
Pulsed Laser Irradiation

ABSTRACTThe dynamics of melting and ablation of high Tc YBa2Cu3O7-x superconducting thin films flashed by a pulsed KrF excimer laser(λ=248nm) or a pulsed Nd-YAG laser (λ =1.06μ m) were studied numerically. The fundamental model during a pulsed laser irradiation was a one-dimensional heat conduction equation. The finite element method was applied to solve the equation including the temperature dependence of the thermal conductivity of YBaCuO thin films. In addition, the microstructure of YBa2Cu3O7-x bulk(l.5mm thick) flashed by a pulsed XeCl excimer laser (λ =308nm) was investigated by scanning electron microscopy (SEM) in order to estimate the threshold incident laser energy density for surface melting and ablation. The good agreements between the numerical calculations and the experimental results were obtained.

Effect of Focusing Plane on Laser Blow-off Shock Waves from Confined Aluminum and Copper Foils

2021 ◽  
Author(s):  
Nagaraju Guthikonda ◽  
Sai Shiva S ◽  
E. Manikanta ◽  
Kameswari P S L D ◽  
V. R. Ikkurthi ◽  
...  
Keyword(s):  
Laser Energy ◽  
Plasma Temperature ◽  
Laser Pulses ◽  
Ambient Air ◽  
Rear Side ◽  
Hydrodynamic Simulations ◽  
Enhanced Absorption ◽  
532 Nm ◽  
Lower Plasma Density ◽  
Good Agreement

Abstract We present results on the dynamics of laser-induced blow-off shockwave generation from the rear side of 20 µm thick aluminum and copper foil confined with a glass (BK7) substrate. These foils are irradiated by 10 ns, 532 nm laser pulses of energy 25 – 200 mJ corresponding to the intensity range 0.2 – 10 GW/cm2. The plasma temperature at the glass-foil interface is observed to play an important role in the coupling of laser energy to the foil. From our experiments and 1D hydrodynamic simulations, we confirm that moving the glass-foil interface away from the focal plane led to (a) enhanced absorption of the laser beam by the foil resulting in ~ 30 % higher blow-off shock velocities (b) significant changes in the material ejection in terms of increased blow-off mass of the foil (c) lower plasma density and temperatures. The material ejection as well as blow-off shock velocity is higher for Al compared to Cu. The simulated shock evolution in ambient air shows a reasonably good agreement with the experimental results.

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