Alexander Bolshakov

LIBS Consult LLC

Laser-induced breakdown spectroscopy (LIBS) offers rapid, localized chemical analysis of solid or liquid materials with high spatial resolution in lateral and depth profiling, without the need for sample preparation. Principal component analysis and partial least squares algorithms were applied to identify a variety of complex organic and inorganic...

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique that can be used to detect and characterize materials. LIBS is easily performed by focusing a highly energetic laser pulse onto the surface of a solid or liquid, or into sample volume of a liquid, gas, or cloud of aerosolized particles. The resulting microplasma contains...

Laser Ablation Molecular Isotopic Spectrometry (LAMIS) is a direct and rapid technique that measures optical emission in laser-induced plasmas for isotopic analysis. LAMIS exploits relatively large isotope shifts in spectra of transient molecular isotopologues formed in laser ablation plasma. LAMIS can be performed without sample preparation at atm...

A new elegant technology was born and branded as Laser Ablation Molecular Isotopic Spectrometry (LAMIS). LAMIS shares all the same technical benefits of its predecessor Laser Induced Breakdown Spectroscopy (LIBS), including rapid analysis and the elimination of sample preparation. LIBS measures atomic emission spectra during the first microsecond a...

This article may be openly shared because it is the work created by US government employee, and is considered to be in public domain according to an agreement between Elsevier and the US government. The US government is the copyright owner. An abstract follows: ..... A prototype analyzer for the direct LIBS analysis of nebulized liquid samples was...

This chapter focuses on molecular laser-induced breakdown spectroscopy (LIBS). Of interest are applications in diverse fields that include plasma diagnostics, combustion diagnostics, molecular plasma spectroscopy, and selected astrophysics spectra analyses. Laser ablation molecular isotopic spectrometry (LAMIS) reveals favorable measurement opportu...

Populations of the 2p levels of neon at two He-Ne mixture pressures 2 and 11 kPa (figure)

Experimental set-up (figure)

Experimental set-up for LIF analysis of neon in helium (Ne in He)

Calibration curves for LIF analysis of neon in helium (Ne in He). Detection limit: LOD=0.3 ppb

Normalized LIF signal of neon and fluctuations of helium plasma (noise)

Calibration curves for LIF analysis of neon in helium (Ne in He). Detection limit for neon in helium LOD=0.3 ppb.

Enhancement of the emission intensity by a secondary electric pulse following a laser ablation pulse was investigated in application to the chemical analysis by Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Molecular Isotopic Spectrometry (LAMIS). A stable reheating pulsed discharge presumably sustained in a diffuse glow regime at...

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique that can be used to detect and characterize materials. LIBS is easily performed by focusing a highly energetic laser pulse onto the surface of a solid or liquid, or into sample volume of a liquid, gas, or cloud of aerosolized particles. The resulting microplasma contains...

In this study laser induced breakdown spectroscopy (LIBS) is used for elemental characterization of outcrop samples from the Marcellus Shale. Powdered samples were pressed to form pellets and used for LIBS analysis. Partial least squares regression (PLS-R) and univariate calibration curves were used for quantification of analytes. The matrix effect...

Quantitative determination of carbon isotopes using Laser Ablation Molecular Isotopic Spectrometry (LAMIS) is described. Optical emission of diatomic molecules CN and C-2 is used in these measurements. Two quantification approaches are presented: empirical calibration of spectra using a set of reference standards and numerical fitting of a simulate...

Laser ablation molecular isotopic spectrometry (LAMIS) involves measuring isotope-resolved molecular emission. Measurements of several key isotopes (hydrogen, boron, carbon, nitrogen, oxygen, and chlorine) in laser ablation plumes were demonstrated. Requirements for spectral resolution of the optical detection system could be significantly relaxed...

Laser induced plasma can be used for rapid optical diagnostics of electronic, optical, electro-optical, electro-mechanical and other structures. Plasma monitoring and diagnostics can be realized during laser processing in real time by means of measuring optical emission that originates from the pulsed laser-material interaction. In post-process app...

Laser ablation offers rapid micro-analysis with high spatial resolution about ~10 nm in depth and ~3 μm lateral. Structured materials can be mapped and depth-profiled for elemental and isotopic composition using LIBS or LA-ICP-MS without a need for sample preparation. Molecular structure of the sample can often be inferred by chemometric processing...

A concept of a compact device for analyzing key isotopic composition in surface materials without sample preparation is presented. This design is based on an advanced modification of Laser Induced Breakdown Spectroscopy (LIBS). First, we developed Laser Ablation Molecular Isotopic Spectrometry (LAMIS) that involves measuring isotope-resolved molecu...

An overview of laser plasma spectrochemistry is presented to demonstrate its wide range of capabilities. Laser plasmas offer the ability to perform elemental, isotopic, molecular, quantitative and qualitative sample analysis with sub-micron spatial resolution, and each feature can be measured at standoff distances. Obviously, these attributes are n...

Laser-induced breakdown spectroscopy (LIBS) offers rapid, localized chemical analysis of solid or liquid materials with high spatial resolution in lateral and depth profiling, without the need for sample preparation. Principal component analysis and partial least squares algorithms were applied to identify a variety of complex organic and inorganic...

Excitement over Laser-Induced Breakdown Spectroscopy (LIBS) is growing. LIBS offers several attractive features: rapid, localized chemical analysis with high spatial resolution in lateral and depth profiling, without the need for sample preparation. LIBS analyzes solid, liquid and gaseous samples. And LIBS analysis can be performed remotely from di...

A vertical-cavity surface-emitting diode laser is used as a tunable emission source to measure the radius-integrated gas temperature in an inductively coupled plasma reactor. Relevant data are obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon-nitrogen (3, 45, and 90% N2 in Ar) plasmas in t...

A spectrally tunable VCSEL (vertical cavity surface-emitting laser) was used as part of sensing hardware for measurements of the radial-integrated gas temperature inside an inductively coupled plasma reactor. The data were obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon/nitrogen plasmas...

Tendencies in five main branches of atomic spectrometry (absorption, emission, mass, fluorescence and ionization spectrometry) are considered. The first three techniques are the most widespread and universal, with the best sensitivity attributed to atomic mass spectrometry. In the direct elemental analysis of solid samples, the leading roles are no...

Tendencies in five main branches of atomic spectrometry (absorption, emission, mass, fluorescence and ionization spectrometry) are considered. The first three techniques are the most widespread and universal, with the best sensitivity attributed to atomic mass spectrometry. In the direct elemental analysis of solid samples, the leading roles are no...

The objective of a virtual impactor is to separate out the larger particles in a flow from the smaller particles in such a way that both sizes of particles are available for sampling. A jet of particle-laden air is accelerated toward a collection probe so that a small gap exists between the acceleration nozzle and the probe. A vacuum is applied to...

A vertical cavity surface-emitting laser diode (VCSEL) was used as a spectrally tunable emission source for measurements of the radial-integrated gas temperature inside an inductively coupled plasma reactor. The data were obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon/nitrogen plasmas (...

In order to study the sterilization capabilities of radio frequency driven low pressure oxygen plasmas, the radiative emission was recorded at various pressures and input powers. A distinct transition from the bright mode primarily inductively coupled to a dim mode primarily capacitively coupled was observed as the pressure was increased and/or the...

An oxygen plasma sustained at 13.56 MHz in a standardized reactor with a planar induction coil was used for biological decontamination experiments. Optical emission, mass spectrometry, Langmuir probe, and electrical measurements were applied to detection of chemical species and ion-energy and flux analysis. These diagnostics identified a plasma-mod...

Determination of temperature and densities of reactants near the developing features is important, since the structural synthesis is affected by characteristics of the local microenvironment. Consequently, sensors capable of nonintrusive monitoring with high sensitivity and high resolution are essential for real-time atomistic control of reaction k...

A VCSEL diode laser was used for determination of the radial-averaged gas temperature inside an inductively coupled plasma reactor. The data were derived from Doppler-broadened absorption by excited Ar atoms at 763.51 nm in argon and argon/nitrogen plasmas (3, 45, and 90% N2 in Ar). The results were compared to rotational temperature determined by...

In order to study the sterilization capabilities of radio frequency driven low pres- sure oxygen plasmas, the radiative emission was recorded at various pressures and input powers in an inductively coupled reactor. A distinct transition from the bright mode (pri- marily inductively coupled) to a dim mode (primarily capacitively coupled) was observe...

The effects of cold plasma on Deinococcus radiodurans, plasmid DNA, and model proteins were assessed using microbiological, spectrometric, and biochemical techniques. In low power O(2) plasma (approximately 25 W, approximately 45 mTorr, 90 min), D. radiodurans, a radiation-resistant bacterium, showed a 99.999% reduction in bioburden. In higher powe...

Optical emission spectra in the UV-visible (200-900 nm) and IR (1000-1300 nm) range from a RF (13.56 MHz) driven oxygen plasma are analyzed and the results are compared with the mass spectrometer and Langmuir probe data. The experiments were conducted in a GEC cell equipped with a planar induction coil at 165, 248 and 330 W of input RF power and at...

Oxygen plasma sustained at 13.56 MHz in a standardized reactor with a planar induction coil was used for biological sterilization experiments. Optical emission and mass spectrometry was applied for detection of excited species and ion energy/flux analysis. A plasma mode transition in the ranges of 13-67 Pa and 100-330 W was observed. At higher pres...

Oxygen plasmas generated in the gaseous electronics reference (GEC) cell, in which the 13.56 MHz radio-frequency (RF) power is coupled through a planar spiral induction coil, were studied by using Langmuir probe, mass spectrometry, and electrical measurements. The data were collected in the pressure range of 25-300 mTorr at RF powers 150-300 W. The...

Traces of gaseous impurities in permanent gases can be quantitatively determined by recording their fluorescence produced in a dual process of excitation in a plasma discharge combined with excitation in a resonant field of laser radiation. However, variations in the composition of the gas samples can cause systematic errors of determination. Such...

This study focuses on chemical-specific hazards as it relates to the beneficial use determination process and reuse practices. Waste classification is used to specify the handling and storage procedures that minimize impact to the environment. The major components in foundry sand are quartz sand (70-80%), clay (5-15%), additives (2-5%), and water (...

Inductively coupled plasma (ICP) discharges in chlorine, argon, and their mixtures sustained inside a spherical quartz container at atmospheric pressure have been investigated. Continua of radiative attachment of a free electron to a chlorine atom in ICP are elucidated and are utilized to derive a spatial profile of electron temperature. A qualitat...

Analysis of gases by a laser-induced fluorescence spectrometric method was investigated for the determination of trace impurities. Low detection limits for oxides of nitrogen were obtained, 0.5 p.p.b. for NO2 and 1 p.p.b. for NO. The fluorescence of neon excited from a metastable state was recorded as a pulsed discharge for the determination of Ne...

The relative concentrations of helium molecules in different vibrational states are measured by the method of laser excitation and the time dependences of the densities of metastable atoms and molecules of helium and of metastable neon atoms in the afterglow of a helium discharge are studied at a gas pressure of 4 kPa and temperature of 300 K. The...

Collisional transitions at 300 K within the 2p53p level system of neon are analyzed. Fluorescence from the 2p2–2p9 levels from excitation of the 2p2 level by a saturating laser pulse (588 nm) in the afterglow of a He-Ne mixture is measured. A system of differential kinetic equations is solved for the populations of each of the 2p2–2p5 levels and th...

Examined are the state and prospects of the laser-induced fluorescence analysis of inorganic gases and vapors, including both atomic and molecular fluorescence. Examples are given for fluorescence excitation in atomic vapors of many elements and diatomic molecular gases, volatiles, and radicals (including hydrides, chlorides, and oxides). Examples...

One method to achieve extremely low limits of detection of impurities is based on laser excitation of fluorescence of trace quantities of matter in the gas phase. Two variants of the laser-induced fluorescence determination of Ne in He were developed, demonstrating low limits of detection. The factors determining the establishment of the saturation...

Recent advances in the use of emission spectrometry for the analysis of gases are reviewed. Particular attention is given to the use of emission spectrometry in combination with physicochemical analytic techniques, such as gas adsorption chromatography and cryogenic collection of impurities on various sorbents. Such combined methods make it possibl...

The method of laser excitation of fluorescence is not directly applicable to analyze gaseous mixtures, since the vacuum ultraviolet region of spectrum is not accessible to present tunable lasers, and thus excitation of fluorescence from the ground state is impossible for the majority of gases. We demonstrated the possibility of decreasing the limit...

Techniques for CO2-laser local and layer-by-layer spectral isotope determination of nitrogen and carbon in solid substances are described. The analyzed sample is placed in a vacuum chamber, and a known quantity of heavy isotope of the analyte element is added to the chamber. Laser irradiation results in dilution of the initial gaseous mixture by th...