Atom localization via controlled spontaneous emission in a five-level atomic system

International Nuclear Information System (INIS)

Wang Zhiping; Yu Benli; Zhu Jun; Cao Zhigang; Zhen Shenglai; Wu Xuqiang; Xu Feng

2012-01-01

We investigate the one- and two-dimensional atom localization behaviors via spontaneous emission in a coherently driven five-level atomic system by means of a radio-frequency field driving a hyperfine transition. It is found that the detecting probability and precision of atom localization behaviors can be significantly improved via adjusting the system parameters. More importantly, the two-dimensional atom localization patterns reveal that the maximal probability of finding an atom within the sub-wavelength domain of the standing waves can reach unity when the corresponding conditions are satisfied. As a result, our scheme may be helpful in laser cooling or the atom nano-lithography via atom localization. - Highlights: ► One- and two-dimensional atom localization behaviors via spontaneous emission in five-level atoms are investigated. ► An assisting radio-frequency field is used to control the atom localization behaviors. ► High-precision and high-resolution two-dimensional atom localization can be realized in this scheme.

0.5 to 6 MeV Ar ion induced X-ray emission in view to analytical application

International Nuclear Information System (INIS)

Tenorio Castilleros, M.D.

1979-01-01

A study of the X-ray emission induced by 0.5 to 6 MeV Ar ions has been realized in view of multielemental analytical applications. The historical development of the use of heavy ion induced X-ray emission in analysis and the theoretical background of inner-shell ionization in heavy ion-atom collisions are described. The emission of non characteristic X-rays and the effects related to the penetration of heavy ions in matter are also related. The experimental part contains a description of the experimental devices and of the X-ray spectra fitting method. Thick target yields as a function of the target Z and the Ar ion energy are reported. The analytical possibilities are examined and an application to the analysis of Si and Cl in cadmium telluride crystals is given [fr

Characterization of near-infrared nonmetal atomic emission from an atmospheric helium microwave-induced plasma using a Fourier transform spectrophotometer

International Nuclear Information System (INIS)

Hubert, J.; Van Tra, H.; Chi Tran, K.; Baudais, F.L.

1986-01-01

A new approach for using Fourier transform spectroscopy (FTS) for the detection of atomic emission from an atmospheric helium plasma has been developed and the results obtained are described. Among the different types of plasma source available, the atmospheric pressure microwave helium plasma appears to be an efficient excitation source for the determination of nonmetal species. The more complete microwave plasma emission spectra of Cl, Br, I, S, O, P, C, N, and He in the near-infrared region were obtained and their corrected relative emission intensities are reported. This makes qualitative identification simple, and aids in the quantitative analysis of atomic species. The accuracy of the emission wavelengths obtained with the Fourier transform spectrophotometer was excellent and the resolution provided by the FTS allowed certain adjacent emission lines to be adequate for analytical applications

Directional emission of single photons from small atomic samples

DEFF Research Database (Denmark)

Miroshnychenko, Yevhen; V. Poulsen, Uffe; Mølmer, Klaus

2013-01-01

We provide a formalism to describe deterministic emission of single photons with tailored spatial and temporal profiles from a regular array of multi-level atoms. We assume that a single collective excitation is initially shared by all the atoms in a metastable atomic state, and that this state i...... is coupled by a classical laser field to an optically excited state which rapidly decays to the ground atomic state. Our model accounts for the different field polarization components via re-absorption and emission of light by the Zeeman manifold of optically excited states.......We provide a formalism to describe deterministic emission of single photons with tailored spatial and temporal profiles from a regular array of multi-level atoms. We assume that a single collective excitation is initially shared by all the atoms in a metastable atomic state, and that this state...

In-situ determination of cross-over point for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Chan, George C.-Y.; Hieftje, Gary M.

2008-01-01

A novel method is described for overcoming plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry (ICP-AES). The method is based on measurement of the vertically resolved atomic emission of analyte within the plasma and therefore requires the addition of no reagents to the sample solution or to the plasma. Plasma-related matrix effects enhance analyte emission intensity low in the plasma but depress the same emission signal at higher positions. Such bipolar behavior is true for all emission lines and matrices that induce plasma-related interferences. The transition where the enhancement is balanced by the depression (the so-called cross-over point) results in a spatial region with no apparent matrix effects. Although it would be desirable always to perform determinations at this cross-over point, its location varies between analytes and from matrix to matrix, so it would have to be found separately for every analyte and for every sample. Here, a novel approach is developed for the in-situ determination of the location of this cross-over point. It was found that the location of the cross-over point is practically invariant for a particular analyte emission line when the concentration of the matrix was varied. As a result, it is possible to determine in-situ the location of the cross-over point for all analyte emission lines in a sample by means of a simple one-step sample dilution. When the original sample is diluted by a factor of 2 and the diluted sample is analyzed again, the extent of the matrix effect is identical (zero) between the original sample and the diluted sample at one and only one location - the cross-over point. This novel method was verified with several single-element matrices (0.05 M Na, Ca, Ba and La) and some mixed-element matrices (mixtures of Na-Ca, Ca-Ba, and a plant-sample digest). The inaccuracy in emission intensity due to the matrix effect could be as large as - 30% for conventional measurements in the

Formulating analytic expressions for atomic collision cross sections

International Nuclear Information System (INIS)

Tabata, Tatsuo; Kubo, Hirotaka; Sataka, Masao

2003-08-01

Methods to formulate analytic expression for atomic collision cross sections as a function of projectile energy are described on the basis of the experiences of the data compilation work for more than 20 years. Topics considered are the choice of appropriate functional forms for the expressions and optimization of adjustable parameters. To make extrapolation possible, functions to be used should have the form with reasonable asymptotic behavior. In this respect, modified Green-McNeal formulas have been found useful for various atomic collision cross sections. For ionization processes, a modified Lotz formula has often given a good fit. The ALESQ code for least-squares fits has been convenient to optimize adjustable parameters in analytic expressions. (author)

Flame emission spectrometry using atomic absorption apparatus. I. Determination of Sr in sea water

International Nuclear Information System (INIS)

Aizawa, S.; Yoshimura, E.; Hamachi, M.; Haraguchi, H.; Dokiya, Y.; Fuwa, K.

1976-01-01

Flame emission determination of Sr in seawater was studied using an ordinary atomic absorption apparatus. The analytical line 4607 A was used with a background correction at 4616 A. The ionization was negligible in an air acetylene flame with seawater, and the interference of H 2 SO 4 was eliminated using the higher part of the flame. Sr concentration of seawater of Tokyo Bay and Sagami Bay has been determined

Liquid-Arc/Spark-Excitation Atomic-Emission Spectroscopy

Science.gov (United States)

Schlagen, Kenneth J.

1992-01-01

Constituents of solutions identified in situ. Liquid-arc/spark-excitation atomic-emission spectroscopy (LAES) is experimental variant of atomic-emission spectroscopy in which electric arc or spark established in liquid and spectrum of light from arc or spark analyzed to identify chemical elements in liquid. Observations encourage development of LAES equipment for online monitoring of process streams in such industries as metal plating, electronics, and steel, and for online monitoring of streams affecting environment.

Emission spectrum of a harmonically trapped Λ-type three-level atom

International Nuclear Information System (INIS)

Guo Hong; Tang Pei

2013-01-01

We theoretically investigate the emission spectrum for a Λ-type three-level atom trapped in the node of a standing wave. We show that the atomic center-of-mass motion not only directly affects the peak number, peak position, and peak height in the atomic emission spectrum, but also influences the effects of the cavity field and the atomic initial state on atomic emission spectrum. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Studies on the spectral interference of gadolinium on different analytes in inductively coupled plasma atomic emission spectroscopy

International Nuclear Information System (INIS)

Sengupta, Arijit; Thulasidas, S.K.; Natarajan, V.; Airan, Yougant

2015-01-01

Due to the multi-electronic nature, rare earth elements are prone to exhibit spectral interference in ICP-AES, which leads to erroneous determination of analytes in presence of such matrix. This interference is very significant, when the analytes are to be determined at trace level in presence of emission rich matrix elements. An attempt was made to understand the spectral interference of Gd on 29 common analytes like Ag, Al, B, Ba, Bi, Ca, Cd, Ce, Co, Cr, Cu, Dy, Fe, Ga, Gd, In, La, Li, Lu, Mg, Mn, Na, Nd, Ni, Pb, Pr, Sr, Tl and Zn using ICP-AES with capacitive Charged Coupled Device (CCD) as detector. The present study includes identification of suitable interference free analytical lines of these analytes, evaluation of correction factor for each analytical line and determination of tolerance levels of these analytical lines along with the ICP-AES based methodology for simultaneous determination of Gd. Based on the spectral interference study, an ICP-AES based method was developed for the determination of these analytes at trace level in presence of Gd matrix without chemical separation. Further the developed methodology was validated using synthetic samples prepared from commercially available reference material solution of individual element; the results were found to be satisfactory. The method was also compared with other existing techniques

Spectrochemical analysis by atomic absorption and emission

National Research Council Canada - National Science Library

Lajunen, Lauri

1992-01-01

... of these techniques. Inductively coupled plasma mass spectrometry (ICP-MS) has become a 'hot' analytical technique during the last few years, and is being used in many branches of science. Since the publication of my previous book 'Atomispektrometria' (in Finnish) in 1986, various techniques in analytical atomic spectroscopy have undergone significant dev...

Inductively coupled plasma as atomization, excitation and ionization sources in analytical atomic spectrometry

International Nuclear Information System (INIS)

Kawaguchi, Hiroshi

1996-01-01

Studies on inductively coupled plasma (ICP) for atomic emission and mass spectrometry accomplished in our laboratory since 1978 are reviewed. In emission spectrometry, the characteristics of the plasma are studied concerning the spatial profiles of spectral line intensity, axial profiles of gas and excitation temperatures, spectral line widths and matrix effect. The studies are particularly emphasized on the instrumentation such as developments of plasma generator, emission spectrometers, water-cooled torches and sample introduction methods. A slew-scan type spectrometer developed in these works represents a predecessor of the current commercial spectrometers. An ICP mass spectrometer was first developed in Japan in this laboratory in 1984. Non-spectroscopic interference of this method was found to have the correlation with the atomic weight of the matrix element. Plasma gases other than argon such as nitrogen and oxygen were used for the ICP to evaluate their performance in mass spectrometry as for the sensitivity and interferences. (author). 63 refs

Trace determination of antimony by hydride generation atomic absorption spectrometry with analyte preconcentration/atomization in a dielectric barrier discharge atomizer

Czech Academy of Sciences Publication Activity Database

Zurynková, Pavla; Dědina, Jiří; Kratzer, Jan

2018-01-01

Roč. 1010, JUN (2018), s. 11-19 ISSN 0003-2670 R&D Projects: GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * Stibane * atomization and preconcentration Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

Photoionization of Endohedral Atoms: Collective, Reflective and Collateral Emissions

International Nuclear Information System (INIS)

Chakraborty, Himadri S.; McCune, Matthew A.; Hopper, Dale E.; Madjet, Mohamed E.; Manson, Steven T.

2009-01-01

The photoionization properties of a fullerene-confined atom differ dramatically from that of an isolated atom. In the low energy region, where the fullerene plasmons are active, the electrons of the confined atom emerge through a collective channel carrying a significant chunk of plasmon with it. The photoelectron angular distribution of the confined atom however shows far lesser impact of the effect. At higher energies, the interference between two single-electron ionization channels, one directly from the atom and another reflected off the fullerene cage, producuces oscillatory cross sections. But for the outermost atomic level, which transfers some electrons to the cage, oscillations are further modulated by the collateral emission from the part of the atomic charge density transferred to the cage. These various modes of emissions are studied for the photoionization of Ar endohedrally confined in C 60 .

Two-dimensional sub-half-wavelength atom localization via controlled spontaneous emission.

Science.gov (United States)

Wan, Ren-Gang; Zhang, Tong-Yi

2011-12-05

We propose a scheme for two-dimensional (2D) atom localization based on the controlled spontaneous emission, in which the atom interacts with two orthogonal standing-wave fields. Due to the spatially dependent atom-field interaction, the position probability distribution of the atom can be directly determined by measuring the resulting spontaneously emission spectrum. The phase sensitive property of the atomic system leads to quenching of the spontaneous emission in some regions of the standing-waves, which significantly reduces the uncertainty in the position measurement of the atom. We find that the frequency measurement of the emitted light localizes the atom in half-wavelength domain. Especially the probability of finding the atom at a particular position can reach 100% when a photon with certain frequency is detected. By increasing the Rabi frequencies of the driving fields, such 2D sub-half-wavelength atom localization can acquire high spatial resolution.

Utilization of atomic emission spectroscopy methods for determination of rare earth elements

International Nuclear Information System (INIS)

Kubova, J.; Polakovicova, J.; Medved, J.; Stresko, V.

1997-01-01

The authors elaborated and applied procedures for rare earth elements (REE) determination using optical emission spectrograph with D.C arc excitation and ICP atomic emission spectrometry.Some of these analytical method are described. The proposed procedure was applied for the analysis of different types of geological materials from several Slovak localities. The results the REE determination were used for e.g. investigation of REE distribution in volcanic rocks, rhyolite tuffs with uranium-molybdenum mineralization, sandstones with heavy minerals accumulations, phosphatic sandstones, granites, quartz-carbonate veins and in the meteorite found in the locality Rumanova. The REE contents were determined in 19 mineral water sources and the results obtained by the both mentioned methods compared. The total REE contents in the analysed mineral water samples were between 2 · 10 -7 and 3 · 10 -5 g dm -3

Evaluation of the analytic performance of laboratories: inter-laboratorial study of the spectroscopy of atomic absorption

International Nuclear Information System (INIS)

Wong Wong, S. M.

1996-01-01

The author made an inter-laboratorial study, with the participation of 18 national laboratories, that have spectrophotometer of atomic absorption. To evaluate the methods of analysis of lead, sodium, potasium, calcium, magnesium, zinc, copper, manganese, and iron, in the ambit of mg/l. The samples, distributed in four rounds to the laboratories, were prepared from primary patterns, deionized and distilled water. The study evaluated the homogeneity and stability, and verified its concentration, using as a reference method, the spectrometry method of Inductively Coupled Plasma emission (1CP). To obtain the characteristics of analytic performance, it applied the norm ASTM E 691. To evaluated the analytic performance, it used harmonized protocol of the International Union of Pure and applied chemistry (IUPAC). The study obtained the 29% of the laboratories had a satisfactory analytic performance, 9% had a questionable performance and 62% made an unsatisfactory analytic performance, according to the IUPAC norm. The results of the values of the characteristic performance method, show that there is no intercomparability between the laboratories, which is attributed to the different methodologies of analysis. (S. Grainger)

Theory of atomic spectral emission intensity

Science.gov (United States)

Yngström, Sten

1994-07-01

The theoretical derivation of a new spectral line intensity formula for atomic radiative emission is presented. The theory is based on first principles of quantum physics, electrodynamics, and statistical physics. Quantum rules lead to revision of the conventional principle of local thermal equilibrium of matter and radiation. Study of electrodynamics suggests absence of spectral emission from fractions of the numbers of atoms and ions in a plasma due to radiative inhibition caused by electromagnetic force fields. Statistical probability methods are extended by the statement: A macroscopic physical system develops in the most probable of all conceivable ways consistent with the constraining conditions for the system. The crucial role of statistical physics in transforming quantum logic into common sense logic is stressed. The theory is strongly supported by experimental evidence.

THE EVOLUTION OF ATOMIC SPECTROSCOPY IN MEASURING TOXIC CONTAMINANTS

Science.gov (United States)

Three decades of study of environmental conditions necessary for the protection of freshwateraquatic life have been limited by the development and application of analytical methodology utilizing atomic adsorption, atomic fluorescence, and atomic emission spectroscopy.The...

Quantitative criterion for quantum interference within spontaneous emission modification of a driven ladder atom

International Nuclear Information System (INIS)

Liu Jiaren; Zhang Zhiyi; Xiao George; Grover, C P

2003-01-01

The spontaneous emission spectrum of a ladder three-level atom with an upper transition driven by a coherent field is calculated under a universal model where various decays, any incoherent pumping and coherent driving are taken into account. The analytical expression for the spectrum profile is given on the basis of the quantum regression theorem. To our knowledge, it is the first time that the quantitative criterion condition Ω ab - γ ac vertical bar, under which quantum destructive interference induced by the coherent driving field occurs, is deduced for the modification of spontaneous emission from the middle level to the ground level. The roles and limits of incoherent pumping, coherent driving and experimental configuration are discussed for realizing the quantum interference and reducing the Doppler effects

Optical emissions from oxygen atom reactions with adsorbates

Science.gov (United States)

Oakes, David B.; Fraser, Mark E.; Gauthier-Beals, Mitzi; Holtzclaw, Karl W.; Malonson, Mark; Gelb, Alan H.

1992-12-01

Although most optical materials are inert to the ambient low earth orbit environment, high velocity oxygen atoms will react with adsorbates to produce optical emissions from the ultraviolet into the infrared. The adsorbates arise from chemical releases or outgassing from the spacecraft itself. We have been investigating kinetic and spectral aspects of these phenomenon by direct observation of the 0.2 to 13 micrometers chemiluminescence from the interaction of a fast atomic oxygen beam with a continuously dosed surface. The dosing gases include fuels, combustion products and outgassed species such as unsymmetrical dimethylhydrazine (UDMH), NO, H2O and CO. The surface studied include gold and magnesium fluoride. In order to relate the results to actual spacecraft conditions these phenomena have been explored as a function of O atom velocity, dosant flux and substrate temperature. UDMH dosed surfaces exhibit spectra typical (wavelength and intensity) of carbonaceous surfaces. The primary emitters are CO, CO2, and OH. H2O dosed surfaces are dominated by OH and /or H2O emission while CO dosed surfaces are dominated by CO and CO2 emissions. The nitric oxide dosed surface produces a glow from 0.4 to 5.4 micrometers due to NO2* continuum emission. The emission was observed to increase by a factor of two upon cooling the surface from 20 degree(s)C to -35 degree(s)C.

Direct determination of sodium, potassium, chromium and vanadium in biodiesel fuel by tungsten coil atomic emission spectrometry

International Nuclear Information System (INIS)

Dancsak, Stacia E.; Silva, Sidnei G.; Nóbrega, Joaquim A.; Jones, Bradley T.; Donati, George L.

2014-01-01

Graphical abstract: -- Highlights: •Direct analysis of biodiesel on a tungsten coil atomizer. •Determination of Na, K, Cr and V by tungsten coil atomic emission spectrometry. •Sample dilution with methanol or ethanol. •Ten-microliter sample aliquots and limits of detection between 20 and 90 μg kg −1 . •Low consumption of reagents, samples and gases in a 140 s per run procedure. -- Abstract: High levels of sodium and potassium can be present in biodiesel fuel and contribute to corrosion, reduced performance and shorter engine lifetime. On the other hand, trace amounts of chromium and vanadium can increase the emission of pollutants during biodiesel combustion. Sample viscosity, immiscibility with aqueous solutions and high carbon content can compromise biodiesel analyzes. In this work, tungsten filaments extracted from microscope light bulbs are used to successively decompose biodiesel's organic matrix, and atomize and excite the analytes to determine sodium, potassium, chromium and vanadium by tungsten coil atomic emission spectrometry (WCAES). No sample preparation other than simple dilution in methanol or ethanol is required. Direct analysis of 10-μL sample aliquots using heating cycles with less than 150 s results in limits of detection (LOD) as low as 20, 70, 70 and 90 μg kg −1 for Na, K, Cr and V, respectively. The procedure's accuracy is checked by determining Na and K in a biodiesel reference sample and carrying out spike experiments for Cr and V. No statistically significant differences were observed between reference and determined values for all analytes at a 95% confidence level. The procedure was applied to three different biodiesel samples and concentrations between 6.08 and 95.6 mg kg −1 for Na and K, and between 0.22 and 0.43 mg kg −1 for V were obtained. The procedure is simple, fast and environmentally friendly. Small volumes of reagents, samples and gases are used and no residues are generated. Powers of detection are

Direct determination of sodium, potassium, chromium and vanadium in biodiesel fuel by tungsten coil atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Dancsak, Stacia E. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Silva, Sidnei G.; Nóbrega, Joaquim A. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, São Carlos, SP (Brazil); Jones, Bradley T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Donati, George L., E-mail: georgedonati@yahoo.com.br [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States)

2014-01-02

Graphical abstract: -- Highlights: •Direct analysis of biodiesel on a tungsten coil atomizer. •Determination of Na, K, Cr and V by tungsten coil atomic emission spectrometry. •Sample dilution with methanol or ethanol. •Ten-microliter sample aliquots and limits of detection between 20 and 90 μg kg{sup −1}. •Low consumption of reagents, samples and gases in a 140 s per run procedure. -- Abstract: High levels of sodium and potassium can be present in biodiesel fuel and contribute to corrosion, reduced performance and shorter engine lifetime. On the other hand, trace amounts of chromium and vanadium can increase the emission of pollutants during biodiesel combustion. Sample viscosity, immiscibility with aqueous solutions and high carbon content can compromise biodiesel analyzes. In this work, tungsten filaments extracted from microscope light bulbs are used to successively decompose biodiesel's organic matrix, and atomize and excite the analytes to determine sodium, potassium, chromium and vanadium by tungsten coil atomic emission spectrometry (WCAES). No sample preparation other than simple dilution in methanol or ethanol is required. Direct analysis of 10-μL sample aliquots using heating cycles with less than 150 s results in limits of detection (LOD) as low as 20, 70, 70 and 90 μg kg{sup −1} for Na, K, Cr and V, respectively. The procedure's accuracy is checked by determining Na and K in a biodiesel reference sample and carrying out spike experiments for Cr and V. No statistically significant differences were observed between reference and determined values for all analytes at a 95% confidence level. The procedure was applied to three different biodiesel samples and concentrations between 6.08 and 95.6 mg kg{sup −1} for Na and K, and between 0.22 and 0.43 mg kg{sup −1} for V were obtained. The procedure is simple, fast and environmentally friendly. Small volumes of reagents, samples and gases are used and no residues are generated

Methods for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry

Science.gov (United States)

Chan, George C. Y. [Bloomington, IN; Hieftje, Gary M [Bloomington, IN

2010-08-03

A method for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry (ICP-AES). ICP-AES analysis is performed across a plurality of selected locations in the plasma on an unknown sample, collecting the light intensity at one or more selected wavelengths of one or more sought-for analytes, creating a first dataset. The first dataset is then calibrated with a calibration dataset creating a calibrated first dataset curve. If the calibrated first dataset curve has a variability along the location within the plasma for a selected wavelength, errors are present. Plasma-related errors are then corrected by diluting the unknown sample and performing the same ICP-AES analysis on the diluted unknown sample creating a calibrated second dataset curve (accounting for the dilution) for the one or more sought-for analytes. The cross-over point of the calibrated dataset curves yields the corrected value (free from plasma related errors) for each sought-for analyte.

Flagging and correcting non-spectral matrix interferences with spatial emission profiles and gradient dilution in inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Cheung, Yan; Schwartz, Andrew J.; Chan, George C.-Y.; Hieftje, Gary M.

2015-01-01

Matrix interference remains one of the most daunting challenges commonly encountered in inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the present study, a method is described that enables identification and correction of matrix interferences in axial-viewed ICP-AES through a combination of spatial mapping and on-line gradient dilution. Cross-sectional emission maps of the plasma are used to indicate the presence of non-spectral (plasma-related and sample-introduction-related) matrix interferences. In particular, apparent concentrations of an analyte species determined at various radial locations in the plasma differ in the presence of a matrix interference, which allows the interference to be flagged. To correct for the interference, progressive, on-line dilution of the sample, performed by a gradient high-performance liquid-chromatograph pump, is utilized. The spatially dependent intensities of analyte emission are monitored at different levels of sample dilution. As the dilution proceeds, the matrix-induced signal variation is reduced. At a dilution where the determined concentrations become independent of location in the plasma, the matrix interference is minimized. - Highlights: • Non-spectral matrix interference in ICP-AES is flagged and minimized. • Emission from different locations of the plasma are collected simultaneously. • Spatially dependent determined concentrations indicate the presence of interference. • Gradient dilution is performed on both calibration standards and sample. • Optimal dilution factor to minimize interference is found as dilution increases

Flagging and correcting non-spectral matrix interferences with spatial emission profiles and gradient dilution in inductively coupled plasma-atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Cheung, Yan; Schwartz, Andrew J.; Chan, George C.-Y.; Hieftje, Gary M., E-mail: hieftje@indiana.edu

2015-08-01

Matrix interference remains one of the most daunting challenges commonly encountered in inductively coupled plasma-atomic emission spectrometry (ICP-AES). In the present study, a method is described that enables identification and correction of matrix interferences in axial-viewed ICP-AES through a combination of spatial mapping and on-line gradient dilution. Cross-sectional emission maps of the plasma are used to indicate the presence of non-spectral (plasma-related and sample-introduction-related) matrix interferences. In particular, apparent concentrations of an analyte species determined at various radial locations in the plasma differ in the presence of a matrix interference, which allows the interference to be flagged. To correct for the interference, progressive, on-line dilution of the sample, performed by a gradient high-performance liquid-chromatograph pump, is utilized. The spatially dependent intensities of analyte emission are monitored at different levels of sample dilution. As the dilution proceeds, the matrix-induced signal variation is reduced. At a dilution where the determined concentrations become independent of location in the plasma, the matrix interference is minimized. - Highlights: • Non-spectral matrix interference in ICP-AES is flagged and minimized. • Emission from different locations of the plasma are collected simultaneously. • Spatially dependent determined concentrations indicate the presence of interference. • Gradient dilution is performed on both calibration standards and sample. • Optimal dilution factor to minimize interference is found as dilution increases.

Contribution to the study of X-ray emission induced by accelerated bromine and krypton ions and possibilities of analytical applications

International Nuclear Information System (INIS)

Tenorio Castilleros, M.D.

1986-01-01

In view of analytical applications the X-ray emission induced by 3 to 85 MeV Br and Kr ions has been studied. Thick target yields have been measured and ionization cross section for K and L shells have been calculated. The X-ray emission rates and energy shifts have also been determined. The results are discussed in the frame of the actually existing models for inner shell ionization in atomic collisions. As a practical application azteque ceramics have been analyzed. The possibilities and the difficulties of the technic are emphasized [fr

Validation of an analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals in soil.

Science.gov (United States)

Frentiu, Tiberiu; Ponta, Michaela; Hategan, Raluca

2013-03-01

The aim of this paper was the validation of a new analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals (Ag, Cd, Co, Cr, Cu, Ni, Pb and Zn) in soil after microwave assisted digestion in aqua regia. Determinations were performed on the ContrAA 300 (Analytik Jena) air-acetylene flame spectrometer equipped with xenon short-arc lamp as a continuum radiation source for all elements, double monochromator consisting of a prism pre-monocromator and an echelle grating monochromator, and charge coupled device as detector. For validation a method-performance study was conducted involving the establishment of the analytical performance of the new method (limits of detection and quantification, precision and accuracy). Moreover, the Bland and Altman statistical method was used in analyzing the agreement between the proposed assay and inductively coupled plasma optical emission spectrometry as standardized method for the multielemental determination in soil. The limits of detection in soil sample (3σ criterion) in the high-resolution continuum source flame atomic absorption spectrometry method were (mg/kg): 0.18 (Ag), 0.14 (Cd), 0.36 (Co), 0.25 (Cr), 0.09 (Cu), 1.0 (Ni), 1.4 (Pb) and 0.18 (Zn), close to those in inductively coupled plasma optical emission spectrometry: 0.12 (Ag), 0.05 (Cd), 0.15 (Co), 1.4 (Cr), 0.15 (Cu), 2.5 (Ni), 2.5 (Pb) and 0.04 (Zn). Accuracy was checked by analyzing 4 certified reference materials and a good agreement for 95% confidence interval was found in both methods, with recoveries in the range of 94-106% in atomic absorption and 97-103% in optical emission. Repeatability found by analyzing real soil samples was in the range 1.6-5.2% in atomic absorption, similar with that of 1.9-6.1% in optical emission spectrometry. The Bland and Altman method showed no statistical significant difference between the two spectrometric

High-precision atom localization via controllable spontaneous emission in a cycle-configuration atomic system.

Science.gov (United States)

Ding, Chunling; Li, Jiahua; Yu, Rong; Hao, Xiangying; Wu, Ying

2012-03-26

A scheme for realizing two-dimensional (2D) atom localization is proposed based on controllable spontaneous emission in a coherently driven cycle-configuration atomic system. As the spatial-position-dependent atom-field interaction, the frequency of the spontaneously emitted photon carries the information about the position of the atom. Therefore, by detecting the emitted photon one could obtain the position information available, and then we demonstrate high-precision and high-resolution 2D atom localization induced by the quantum interference between the multiple spontaneous decay channels. Moreover, we can achieve 100% probability of finding the atom at an expected position by choosing appropriate system parameters under certain conditions.

Analytical quality control services of the International Atomic Energy Agency

International Nuclear Information System (INIS)

Suschny, O.

1986-01-01

The International Atomic Energy Agency provides quality control services to analytical laboratories. These services which include the provision of reference materials and the organisation of intercomparisons are rendered for the purpose of assisting laboratories in determining the accuracy of their analytical work. The following classes of materials are presently available: nuclear materials, environmental materials, animal and plant materials, materials for biomedical studies and materials of marine origin. (orig.) [de

Analytic cross sections for collisions of H, H2, He and Li atoms and ions with atoms and molecules. 3

International Nuclear Information System (INIS)

Ito, Rinsuke; Tabata, Tatsuo; Shirai, Toshizo; Phaneuf, R.A.

1995-07-01

Analytic expressions fitted to Barnett's recommended data are given for the collision cross sections of H, H 2 , He, and Li atoms and ions colliding with atoms and molecules. The collisions treated are ionization collisions, charge-production collisions, electron-loss collisions, and electron detachment collisions. The analytic expressions use the semiempirical functional forms proposed by Green and McNeal and some modified forms to make it possible not only to interpolate but also to extrapolate the recommended data. (author)

An analytical method for computing atomic contact areas in biomolecules.

Science.gov (United States)

Mach, Paul; Koehl, Patrice

2013-01-15

We propose a new analytical method for detecting and computing contacts between atoms in biomolecules. It is based on the alpha shape theory and proceeds in three steps. First, we compute the weighted Delaunay triangulation of the union of spheres representing the molecule. In the second step, the Delaunay complex is filtered to derive the dual complex. Finally, contacts between spheres are collected. In this approach, two atoms i and j are defined to be in contact if their centers are connected by an edge in the dual complex. The contact areas between atom i and its neighbors are computed based on the caps formed by these neighbors on the surface of i; the total area of all these caps is partitioned according to their spherical Laguerre Voronoi diagram on the surface of i. This method is analytical and its implementation in a new program BallContact is fast and robust. We have used BallContact to study contacts in a database of 1551 high resolution protein structures. We show that with this new definition of atomic contacts, we generate realistic representations of the environments of atoms and residues within a protein. In particular, we establish the importance of nonpolar contact areas that complement the information represented by the accessible surface areas. This new method bears similarity to the tessellation methods used to quantify atomic volumes and contacts, with the advantage that it does not require the presence of explicit solvent molecules if the surface of the protein is to be considered. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.

Ultrafast atomic process in X-ray emission by using inner-shell ionization method for sodium and carbon atoms

Energy Technology Data Exchange (ETDEWEB)

Moribayashi, Kengo; Sasaki, Akira; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment

1998-07-01

An ultrafast inner-shell ionization process with X-ray emission stimulated by high-intensity short-pulse X-ray is studied. Carbon and sodium atoms are treated as target matter. It is shown that atomic processes of the target determine the necessary X-ray intensity for X-ray laser emission as well as the features of X-ray laser such as wavelength and duration time. The intensity also depends on the density of initial atoms. Furthermore, we show that as the intensity of X-ray source becomes high, the multi-inner-shell ionization predominates, leading to the formation of hollow atoms. As the density of hollow atoms is increased by the pumping X-ray power, the emission of X-rays is not only of significance for high brightness X-ray measurement but also is good for X-ray lasing. New classes of experiments of pump X-ray probe and X-ray laser are suggested. (author)

A simple analytical model for electronic conductance in a one dimensional atomic chain across a defect

International Nuclear Information System (INIS)

Khater, Antoine; Szczesniak, Dominik

2011-01-01

An analytical model is presented for the electronic conductance in a one dimensional atomic chain across an isolated defect. The model system consists of two semi infinite lead atomic chains with the defect atom making the junction between the two leads. The calculation is based on a linear combination of atomic orbitals in the tight-binding approximation, with a single atomic one s-like orbital chosen in the present case. The matching method is used to derive analytical expressions for the scattering cross sections for the reflection and transmission processes across the defect, in the Landauer-Buttiker representation. These analytical results verify the known limits for an infinite atomic chain with no defects. The model can be applied numerically for one dimensional atomic systems supported by appropriate templates. It is also of interest since it would help establish efficient procedures for ensemble averages over a field of impurity configurations in real physical systems.

The relation of double peaks, observed in quartz hydride atomizers, to the fate of free analyte atoms in the determination of arsenic and selenium by atomic absorption spectrometry

International Nuclear Information System (INIS)

D'Ulivo, Alessandro; Dedina, Jiri

2002-01-01

The mechanism at the origin of double peaks formation in quartz hydride atomizers were investigated by continuous flow hydride generation atomic absorption spectrometry. Arsenic and selenium were used as model analytes. The effect of atomization mode (flame-in-gas-shield (FIGS), miniature diffusion flame and double flame (DF)) and some experimental parameters as oxygen supply rate for microflame and the distance from atomization to free atoms detection point, were investigated on the shape of both analytical signals and calibration graphs. Rollover of calibration graphs and double peak formation are strictly related each to the other and could be observed only in FIGS atomizer mode under some particular conditions. A mechanism based on incomplete atomization of hydrides cannot explain the collected experimental evidences because the microflame of FIGS is able to produce quantitative atomization of large amount of hydrides even at supply rate of oxygen close to extinction threshold of microflame. The heterogeneous gas-solid reactions between finely dispersed particles, formed by free atom recombination, and the free atoms in the gaseous phase are at the origin of double peak formation

Analytical local electron-electron interaction model potentials for atoms

International Nuclear Information System (INIS)

Neugebauer, Johannes; Reiher, Markus; Hinze, Juergen

2002-01-01

Analytical local potentials for modeling the electron-electron interaction in an atom reduce significantly the computational effort in electronic structure calculations. The development of such potentials has a long history, but some promising ideas have not yet been taken into account for further improvements. We determine a local electron-electron interaction potential akin to those suggested by Green et al. [Phys. Rev. 184, 1 (1969)], which are widely used in atom-ion scattering calculations, electron-capture processes, and electronic structure calculations. Generalized Yukawa-type model potentials are introduced. This leads, however, to shell-dependent local potentials, because the origin behavior of such potentials is different for different shells as has been explicated analytically [J. Neugebauer, M. Reiher, and J. Hinze, Phys. Rev. A 65, 032518 (2002)]. It is found that the parameters that characterize these local potentials can be interpolated and extrapolated reliably for different nuclear charges and different numbers of electrons. The analytical behavior of the corresponding localized Hartree-Fock potentials at the origin and at long distances is utilized in order to reduce the number of fit parameters. It turns out that the shell-dependent form of Green's potential, which we also derive, yields results of comparable accuracy using only one shell-dependent parameter

Trends in tungsten coil atomic spectrometry

Science.gov (United States)

Donati, George L.

Renewed interest in electrothermal atomic spectrometric methods based on tungsten coil atomizers is a consequence of a world wide increasing demand for fast, inexpensive, sensitive, and portable analytical methods for trace analysis. In this work, tungsten coil atomic absorption spectrometry (WCAAS) and tungsten coil atomic emission spectrometry (WCAES) are used to determine several different metals and even a non-metal at low levels in different samples. Improvements in instrumentation and new strategies to reduce matrix effects and background signals are presented. Investigation of the main factors affecting both WCAAS and WCAES analytical signals points to the importance of a reducing, high temperature gas phase in the processes leading to atomic cloud generation. Some more refractory elements such as V and Ti were determined for the first time by double tungsten coil atomic emission spectrometry (DWCAES). The higher temperatures provided by two atomizers in DWCAES also allowed the detection of Ag, Cu and Sn emission signals for the first time. Simultaneous determination of several elements by WCAES in relatively complex sample matrices was possible after a simple acid extraction. The results show the potential of this method as an alternative to more traditional, expensive methods for fast, more effective analyses and applications in the field. The development of a new metallic atomization cell is also presented. Lower limits of detection in both WCAAS and WCAES determinations were obtained due to factors such as better control of background signal, smaller, more isothermal system, with atomic cloud concentration at the optical path for a longer period of time. Tungsten coil-based methods are especially well suited to applications requiring low sample volume, low cost, sensitivity and portability. Both WCAAS and WCAES have great commercial potential in fields as diverse as archeology and industrial quality control. They are simple, inexpensive, effective

Infrared (1-12 μm) atomic and molecular emission signatures from energetic materials using laser-induced breakdown spectroscopy

Science.gov (United States)

Kumi Barimah, E.; Hömmerich, U.; Brown, E.; Yang, C. S.-C.; Trivedi, S. B.; Jin, F.; Wijewarnasuriya, P. S.; Samuels, A. C.; Snyder, A. P.

2013-05-01

Laser-induced breakdown spectroscopy (LIBS) is a powerful analytical technique to detect the elemental composition of solids, liquids, and gases in real time. For example, recent advances in UV-VIS LIBS have shown great promise for applications in chemical, biological, and explosive sensing. The extension of conventional UVVIS LIBS to the near-IR (NIR), mid-IR (MIR) and long wave infrared (LWIR) regions (~1-12 μm) offers the potential to provide additional information due to IR atomic and molecular signatures. In this work, a Q-switched Nd: YAG laser operating at 1064 nm was employed as the excitation source and focused onto several chlorate and nitrate compounds including KClO3, NaClO3, KNO3, and NaNO3 to produce intense plasma at the target surface. IR LIBS studies on background air, KCl , and NaCl were also included for comparison. All potassium and sodium containing samples revealed narrow-band, atomic-like emissions assigned to transitions of neutral alkali-metal atoms in accordance with the NIST atomic spectra database. In addition, first evidence of broad-band molecular LIBS signatures from chlorate and nitrate compounds were observed at ~10 μm and ~7.3 μm, respectively. The observed molecular emissions showed strong correlation with FTIR absorption spectra of the investigated materials.

The design and characteristics of direct current glow discharge atomic emission source operated with plain and hollow cathodes

International Nuclear Information System (INIS)

Qayyum, A.; Mahmood, M.I.

2008-01-01

A compact direct current glow discharge atomic emission source has been designed and constructed for analytical applications. This atomic emission source works very efficiently at a low-input electrical power. The design has some features that make it distinct from that of the conventional Grimm glow discharge source. The peculiar cathode design offered greater flexibility on size and shape of the sample. As a result the source can be easily adopted to operate in Plain or Hollow Cathode configuration. I-V and spectroscopic characteristics of the source were compared while operating it with plain and hollow copper cathodes. It was observed that with hollow cathode, the source can be operated at a less input power and generates greater Cu I and Cu II line intensities. Also, the intensity of Cu II line rise faster than Cu I line with argon pressure for both cathodes. But the influence of pressure on Cu II lines was more significant when the source is operated with hollow cathode

Analytic structure of the wave function for a hydrogen atom in an analytic potential

International Nuclear Information System (INIS)

Hill, R.N.

1984-01-01

The rate of convergence of an approximate method for solving Schroedinger's equation depends on the ability of the approximating sequence to mimic the analytic structure of the unknown exact wave function. Thus a knowledge of the analytic structure of the wave function can be of great value when approximation schemes are designed. Consider the Schroedinger equation [- 1/2 del 2 -r -1 +V(r)]Psi(r) = EPsi(r) for a hydrogen atom in a potential V(r). The general theory of elliptic partial differential equations implies that Psi is analytic at regular points, but no general theory is available at singular points. The present paper investigates the Coulomb singular point at r = 0 and shows that, if V(r) = V 1 (x, y, z)+rV 2 (x, y, z) where V 1 and V 2 are analytic functions of x, y, z at x = y = z = 0, then the wave function has the form Psi(r) = Psi 1 (x, y, z)+rPsi 2 (x, y, z) where Psi 1 and Psi 2 are analytic functions of x, y, z at x = y = z = 0

Sb(III) and Sb(V) separation and analytical speciation by a continuous tandem on-line separation device in connection with inductively coupled plasma atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Menendez Garcia, A. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.; Perez Rodriguez, M.C. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.; Sanchez Uria, J.F. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.; Sanz-Medel, A. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.

1995-09-01

A sensitive, precise and automated non-chromatographic method for Sb(III) and Sb(V) analytical speciation based on a continuous tandem on-line separation device in connection with inductively coupled plasma-atomic emission (ICP-AES) detection is proposed. Two on-line successive separation steps are included into this method: a continuous liquid-liquid extraction of Sb(III) with ammonium pyrrolidine dithiocarbamate (APDC) into methylisobuthylketone (MIBK), followed by direct stibine generation from the organic phase. Both separation steps are carried out in a continuous mode and on-line with the ICP-AES detector. Optimization of experimental conditions for the tandem separation and ICP-AES detection are investigated in detail. Detection limits for Sb(III) were 3 ng.mL{sup -1} and for Sb(V) 8 ng.mL{sup -1}. Precisions observed are in the range {+-} 5%. The proposed methodology has been applied to Sb(III) and Sb(V) speciation in sea-water samples. (orig.)

Inductively coupled plasma-atomic emission spectroscopy

International Nuclear Information System (INIS)

Winge, R.K.; Fassel, V.A.; Peterson, V.J.; Floyd, M.A.

1985-01-01

This atlas of inductively coupled plasma-atomic emission spectroscopy records the spectra of the elements in a way that would reveal the general nature of the spectra, in all their simplicity or complexity; and offers a definitive summary of the most prominent spectral lines of the elements, i.e., those most likely to be useful for the determination of trace and ultratrace concentrations; it provides reliable estimates, based on the recorded experimental spectra, of the powers of detection of the listed prominent lines; and assesses the very important problem of spectral interferences. The atlas is composed of three main sections. Part I is concerned with the historical aspects of compilations of spectral information. Part II is based on 232 wavelength scans of 70 elements. Each of the wavelength scans covers an 80 nm spectral region. These scans allow a rapid comparison of the background and spectral line intensities emitted in the ICP and provide a ready means for identification of the most prominent lines of each element and for estimation of the trace element analytical capabilities of these lines. A listing of 973 prominent lines with associated detection limits is also presented. Part III addresses the problem of spectral interferences. On this topic a detailed collection of coincidence profiles is presented for 281 of the most prominent lines, each with profiles of ten of the most prevalent concomitants superimposed. (Auth.)

Analytical transition-matrix treatment of electric multipole polarizabilities of hydrogen-like atoms

International Nuclear Information System (INIS)

Kharchenko, V.F.

2015-01-01

The direct transition-matrix approach to the description of the electric polarization of the quantum bound system of particles is used to determine the electric multipole polarizabilities of the hydrogen-like atoms. It is shown that in the case of the bound system formed by the Coulomb interaction the corresponding inhomogeneous integral equation determining an off-shell scattering function, which consistently describes virtual multiple scattering, can be solved exactly analytically for all electric multipole polarizabilities. Our method allows to reproduce the known Dalgarno–Lewis formula for electric multipole polarizabilities of the hydrogen atom in the ground state and can also be applied to determine the polarizability of the atom in excited bound states. - Highlights: • A new description for electric polarization of hydrogen-like atoms. • Expression for multipole polarizabilities in terms of off-shell scattering functions. • Derivation of integral equation determining the off-shell scattering function. • Rigorous analytic solving the integral equations both for ground and excited states. • Study of contributions of virtual multiple scattering to electric polarizabilities

Accuracy and Precision in Elemental Analysis of Environmental Samples using Inductively Coupled Plasma-Atomic Emission Spectrometry

International Nuclear Information System (INIS)

Quraishi, Shamsad Begum; Chung, Yong-Sam; Choi, Kwang Soon

2005-01-01

Inductively Coupled Plasma-Atomic Emission Spectrometry followed by micro-wave digestion have been performed on different environmental Certified Reference Materials (CRMs). Analytical results show that accuracy and precision in ICP-AES analysis were acceptable and satisfactory in case of soil and hair CRM samples. The relative error of most of the elements in these two CRMs is within 10% with few exceptions and coefficient of variation is also less than 10%. Z-score as an analytical performance was also within the acceptable range (±2). ICP-AES was found as an inadequate method for Air Filter CRM due to incomplete dissolution, low concentration of elements and very low mass of the sample. However, real air filter sample could have been analyzed with high accuracy and precision by increasing sample mass during collection. (author)

Validated analytical modeling of diesel engine regulated exhaust CO emission rate

Directory of Open Access Journals (Sweden)

Waleed F Faris

2016-06-01

Full Text Available Albeit vehicle analytical models are often favorable for explainable mathematical trends, no analytical model has been developed of the regulated diesel exhaust CO emission rate for trucks yet. This research unprecedentedly develops and validates for trucks a model of the steady speed regulated diesel exhaust CO emission rate analytically. It has been found that the steady speed–based CO exhaust emission rate is based on (1 CO2 dissociation, (2 the water–gas shift reaction, and (3 the incomplete combustion of hydrocarbon. It has been found as well that the steady speed–based CO exhaust emission rate based on CO2 dissociation is considerably less than the rate that is based on the water–gas shift reaction. It has also been found that the steady speed–based CO exhaust emission rate based on the water–gas shift reaction is the dominant source of CO exhaust emission. The study shows that the average percentage of deviation of the steady speed–based simulated results from the corresponding field data is 1.7% for all freeway cycles with 99% coefficient of determination at the confidence level of 95%. This deviation of the simulated results from field data outperforms its counterpart of widely recognized models such as the comprehensive modal emissions model and VT-Micro for all freeway cycles.

Determination of daily intake of elements from Philippine total diet samples using inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Leon, G.C. de; Shiraishi, K.; Kawamura, H.; Igaraishi, Y.; Palattao, M.V.; Azanon, E.M.

1990-10-01

Total diet samples were analyzed for major elements (Na, K, Ca, Mg, P) and some minor trace elements (Fe, Zn, Mn, Al, Sr, Cu, Ba, Yt) using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Samples analyzed were classified into sex and age groups. Results for some elements (Na, K, Mg, Zn, Cu, Mn) were compared with values from Bataan dietary survey calculated using the Philippine composition table. Exceot for Na, analytical results were similar to calculated values. Analytical results for Ca and Fe were also compared with the values from Food and Nutrition Research Institute. In general, values obtained in the study were lower than the FNRI values. Comparison of the analytical and calculated results with the Japanese and ICRP data showed that Philippine values were lower than foreign values. (Auth.). 22 refs., 9 tabs

Gas Atomization of Aluminium Melts: Comparison of Analytical Models

Directory of Open Access Journals (Sweden)

Georgios Antipas

2012-06-01

Full Text Available A number of analytical models predicting the size distribution of particles during atomization of Al-based alloys by N2, He and Ar gases were compared. Simulations of liquid break up in a close coupled atomizer revealed that the finer particles are located near the center of the spray cone. Increasing gas injection pressures led to an overall reduction of particle diameters and caused a migration of the larger powder particles towards the outer boundary of the flow. At sufficiently high gas pressures the spray became monodisperse. The models also indicated that there is a minimum achievable mean diameter for any melt/gas system.

Analytic properties of the relativistic Thomas-Fermi equation and the total energy of atomic ions

International Nuclear Information System (INIS)

March, N.H.; Senatore, G.

1985-06-01

The analytic properties of solutions of the relativistic Thomas-Fermi equation which tend to zero at infinity are first examined, the neutral atom solution being a member of this class. A new length is shown to enter the theory, proportional to the square root of the fine structure constant. This information is used to develop a perturbation expansion around the neutral atom solution, corresponding to positive atomic ions with finite but large radii. The limiting law relating ionic radius to the degree of ionization is thereby displayed in functional form, and solved explicitly to lowest order in the fine structure constant. To embrace this knowledge of heavy positive ions, as well as results from the one-electron Dirac equation, a proposal is then advanced as to the analytic form of the relativistic total energy E(Z,N) of an atomic ion with nuclear charge Ze and total number of electrons N. The fact that, for N>1, the nucleus is known only to bind Z+n electrons, where n is 1 or 2, indicates non-analyticity in the complex Z plane, represented by a circle of radius Z approx.= N. Such non-analyticity is also a property of the non-relativistic energy derived from the many-electron Schroedinger equation. The relativistic theory, however, must also embody a second type of non-analyticity associated with the known property for N=1 that the Dirac equation predicts electron-positron pair production when the electronic binding energy becomes equal to twice the electron rest mass energy. This corresponds to a second circle of non-analyticity in E(Z,N), and hence to a Taylor-Laurent expansion of this quantity in the atomic number Z. The relation of this expansion to the Layzer-Bahcall series is finally discussed. (author)

Semi-analytical wave functions in relativistic average atom model for high-temperature plasmas

International Nuclear Information System (INIS)

Guo Yonghui; Duan Yaoyong; Kuai Bin

2007-01-01

The semi-analytical method is utilized for solving a relativistic average atom model for high-temperature plasmas. Semi-analytical wave function and the corresponding energy eigenvalue, containing only a numerical factor, are obtained by fitting the potential function in the average atom into hydrogen-like one. The full equations for the model are enumerated, and more attentions are paid upon the detailed procedures including the numerical techniques and computer code design. When the temperature of plasmas is comparatively high, the semi-analytical results agree quite well with those obtained by using a full numerical method for the same model and with those calculated by just a little different physical models, and the result's accuracy and computation efficiency are worthy of note. The drawbacks for this model are also analyzed. (authors)

Simultaneous determination of Cr, Ga, In and V in soil and water samples by tungsten coil atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Donati, George L.; Kron, Benjamin E. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Jones, Bradley T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States)], E-mail: jonesbt@wfu.edu

2009-06-15

Tungsten coil atomic emission spectrometry is employed for the simultaneous determination of Cr, Ga, In, and V. Both V and In are detected by this technique for the first time. The atomizer is a simple, inexpensive tungsten filament extracted from a mass-produced, commercially-available 150 W, 15 V microscope bulb. A 25 {mu}l sample aliquot is placed directly on the coil and a small constant-current power source is used to carefully dry, ash and atomize the sample. Analytical signals are detected with a Czerny-Turner spectrograph and a charge coupled device detector. Multiple emission lines from all 4 elements are monitored simultaneously in a 54 nm spectral window. Concentration limits of detection are in the {mu}g l{sup - 1} range for all elements, and the absolute limits of detection are 0.2, 2, 0.5, and 10 ng for Cr, Ga, In, and V, respectively. Even lower values may be obtained by combining the signals for the multiple emission lines of a single element. The method precision is typically better than 5.0% relative standard deviation, and sometimes as good as 0.95% (Ga). Standard reference materials of soil and water are used to check the method accuracy. After a simple acid extraction, the values determined by the method presented no significant difference from the reported values at the 95% confidence level.

Analytical chemistry department. Annual report, 1977

International Nuclear Information System (INIS)

Knox, E.M.

1978-09-01

The annual report describes the analytical methods, analyses and equipment developed or adopted for use by the Analytical Chemistry Department during 1977. The individual articles range from a several page description of development and study programs to brief one paragraph descriptions of methods adopted for use with or without some modification. This year, we have included a list of the methods incorporated into our Analytical Chemistry Methods Manual. This report is organized into laboratory sections within the Department as well as major programs within General Atomic Company. Minor programs and studies are included under Miscellaneous. The analytical and technical support activities for GAC include gamma-ray spectroscopy, radiochemistry, activation analysis, gas chromatography, atomic absorption, spectrophotometry, emission spectroscopy, x-ray diffractometry, electron microprobe, titrimetry, gravimetry, and quality control. Services are provided to all organizations throughout General Atomic Company. The major effort, however, is in support of the research and development programs within HTGR Generic Technology Programs ranging from new fuel concepts, end-of-life studies, and irradiated capsules to fuel recycle studies

Comparison of 4 analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs

OpenAIRE

2011-01-01

Abstract Different techniques for the determination of total tin in beverage and canned food by atomic spectrometry were compared. The performance characteristics of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Hydride Generation Inductively Coupled Plasma Atomic Emission Spectrometry (HG-ICP-AES), Electrothermal Atomization Atomic Absorption Spectrometry (ETA-AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) were determined in term of linearity, ...

Atom-number squeezing and bipartite entanglement of two-component Bose-Einstein condensates: analytical results

Energy Technology Data Exchange (ETDEWEB)

Jin, G R; Wang, X W; Li, D; Lu, Y W, E-mail: grjin@bjtu.edu.c [Department of Physics, Beijing Jiaotong University, Beijing 100044 (China)

2010-02-28

We investigate spin dynamics of a two-component Bose-Einstein condensate with weak Josephson coupling. Analytical expressions of atom-number squeezing and bipartite entanglement are presented for atom-atom repulsive interactions. For attractive interactions, there is no number squeezing; however, the squeezing parameter is still useful to recognize the appearance of Schroedinger's cat state.

Analytic of elements for the determination of soil->plant transfer factors

International Nuclear Information System (INIS)

Liese, T.

1985-02-01

This article describes a part of the conventional analytical work, which was done to determine soil to plant transfer factors. The analytical methods, the experiments to find out the best way of sample digestion and the resulting analytical procedures are described. Analytical methods are graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). In case of ICP-AES the necessity of right background correction and correction of the spectral interferences is shown. The reliability of the analytical procedure is demonstrated by measuring different kinds of standard reference materials and by comparison of AAS and AES. (orig./HP) [de

Frequency lock of a dye laser emission on iron atomic line top

International Nuclear Information System (INIS)

Durand, P.

1995-03-01

The aim of this thesis is to realize a frequency lock of a dye laser emission on iron atomic line top. To reach that goal, the author first presents the calculation of atomic vapour density by means of laser absorption ratio measure and studies the dye laser working. It is then necessary to find a device giving the required precision on the frequency of the absorption line choosen. It is obtained thanks to the atomic line reconstitution by optogalvanic effect which gives the reference. Besides, the author presents the necessity of a laser emission power regulation which is obtained thanks to a device including an acoustic and optic modulator. A reliable and accurate captor is choosen and adjusted testing various hollow cathode lamps. The method to obtain the frequency lock of laser emission on iron atomic line top is described. (TEC). 18 refs., 64 figs

Theory of atomic spectral emission intensity

International Nuclear Information System (INIS)

Yngstroem, S.

1989-02-01

The theoretical derivation of a new spectral line intensity formula for atomic radiative emission is presented. The theory is based on first principles of quantum physics and statistical physics. It is argued that the formulation of the theory provides a very good example of the manner in which quantum logic transforms into common sense logic. The theory is strongly supported by experimental evidence. (author) (16 refs.)

Trace determination of antimony by hydride generation atomic absorption spectrometry with analyte preconcentration/atomization in a dielectric barrier discharge atomizer.

Science.gov (United States)

Zurynková, Pavla; Dědina, Jiří; Kratzer, Jan

2018-06-20

Atomization conditions for antimony hydride in the plasma atomizer based on a dielectric barrier discharge (DBD) with atomic absorption spectrometric detection were optimized. Argon was found as the best discharge gas under a flow rate of 50 mL min - 1 while the DBD power was optimum at 30 W. Analytical figures of merit including interference study of As, Se and Bi have been subsequently investigated and the results compared to those found in an externally heated quartz tube atomizer (QTA). The limit of detection (LOD) reached in DBD (0.15 ng mL -1  Sb) is comparable to that observed in QTA (0.14 ng mL -1  Sb). Finally, possibility of Sb preconcentration by stibane in situ trapping in a DBD atomizer was studied. For trapping time of 300 s, the preconcentration efficiency and LOD, respectively, were 103 ± 2% and 0.02 ng mL -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

Study of uranium matrix interference on ten analytes using inductively coupled plasma atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ghazi, A.A.; Qamar, S.; Atta, M.A. (A.Q. Khan Research Labs., Rawalpindi (Pakistan))

1993-08-01

Maximum allowable concentrations of 12 elements in uranium hexafluoride feed for enrichment to reactor grade material (about 3%), vary from 1 to 100 ppm ([mu]g/g). Using an inductively coupled plasma atomic emission spectrometer, 51 lines of tine of these elements (B, Cr, Mo, P, Sb, Si, Ta, Ti, V and W) has been studied with a uranium matrix to investigate the matrix interference on the basis of signal to background (SBR), and background to background ratios (BBR). Detection limits and limits of quantitative determination (LQDs) were calculated for these elements in a uranium matrix using SBR and relative standard deviation of the background signal (RSD[sub B]) approach. In almost all cases, the uranium matrix interference reduces the SBRs to the extent that direct trace analysis is impossible. A uranium sample having known concentrations of impurities (around LQDs) was directly analysed with results that showed reasonable accuracy and precision. (Author).

Cooling atoms with extraresonant stimulated emission below the Doppler limit

International Nuclear Information System (INIS)

Shevy, Y.

1989-01-01

The process of cooling atoms with radiation pressure is well understood in terms of absorption and spontaneous emission of fluorescence photons. This process imposes a lower limit on the minimum equilibrium temperature of laser cooled two level atoms of K b T = ℎΓ 21 /2 (the Doppler limit), where Γ 21 is the excited state decay rate to the ground state. At high laser intensity, it has been demonstrated that the stimulated emission process changes the sign of the force to a heating force at the red side of the atomic resonance and to a cooling force at blue detunings. Although this stimulated force is more efficient than the radiation pressure force, it has been generally accepted that this force cannot lead to lower equilibrium temperatures due to the large heating caused by diffusion of momentum at high intensity. These conclusions are valid only when the sole damping mechanism is the excited state decay to the ground state by spontaneous emission. However, when the atomic system is opened, i.e., is allowed to decay to other levels, or the dipole decay rate is altered by dephasing events, the stimulated force is dramatically modified. Under this conditions the stimulated force can occur at lower laser intensity and can even reverse sign to provide damping at the red side of resonance. These phenomena originate from extraresonances in the stimulated emission process between the two counterpropagating waves. These resonances appear as a dispersive feature in pump probe spectra (Two Wave Mixing) and are closely related to the extraresonances in four wave mixing studied originally by Bloembergen and co-workers. This paper establishes this connection and the potential of these phenomena for laser cooling. The implications of these results to the recently observed ultra-cold Na and Cs atoms are also discussed

Inductively coupled plasma--atomic emission spectrometry: trace elements in oil matrices

Energy Technology Data Exchange (ETDEWEB)

Peterson, Charlie Albert [Iowa State Univ., Ames, IA (United States)

1977-12-01

The simultaneous determination of up to 20 trace elements in various oil matrices by inductively coupled plasma-atomic emission spectrometry is reported. The oil matrices investigated were lubricating oils (for wear metals), fuel oil, centrifuged coal liquefaction product, crude soybean oil, and commercial edible oils. The samples were diluted with appropriate organic solvents and injected into the plasma as an aerosol generated by a pneumatic nebulization technique. Detection limits of the 28 elements studied ranged from 0.0006 to 9 μg/g with the majority falling in the 0.01 to 0.1 μg/g range. Analytical calibration curves were linear over at least two orders of magnitude and for some elements this linearity extended over 4.5 orders of magnitude. Relevant data on precision and accuracy are included. Because metals often occur as particles in lubricating oil and coal liquefaction products, the effect of particles on the analytical results was examined. Wear metal particles in used oil did not appear to affect the analytical results. However, incomplete recovery relative to organometallic reference solutions was obtained for iron particles with a nominal mean diameter of 3.0 μm suspended in oil. It was shown that the following factors contributed to incomplete recovery for the particles: settling of the suspended particles in the flask, a difference in nebulization efficiency between particle suspensions and organometallic solutions, and indications of incomplete vaporization of the larger particles in the plasma.

Development of the Flame Test Concept Inventory: Measuring Student Thinking about Atomic Emission

Science.gov (United States)

Bretz, Stacey Lowery; Murata Mayo, Ana Vasquez

2018-01-01

This study reports the development of a 19-item Flame Test Concept Inventory, an assessment tool to measure students' understanding of atomic emission. Fifty-two students enrolled in secondary and postsecondary chemistry courses were interviewed about atomic emission and explicitly asked to explain flame test demonstrations and energy level…

A separation method to overcome the interference of aluminium on zinc determination by inductively coupled plasma atomic emission spectroscopy

OpenAIRE

Jesus, Djane S. de; Korn, Maria das Graças Andrade; Ferreira, Sergio Luis Costa; Carvalho, Marcelo Souza de

2000-01-01

Texto completo: acesso restrito. p.389–394 The use of polyurethane foam (PUF) to separate zinc from large amounts of aluminium and its determination by inductively coupled plasma atomic emission spectroscopy technique (ICP-AES) in aluminium matrices is described. The proposed method is based on the solid-phase extraction of the zinc(II) cation as a thiocyanate complex. Parameters such as effect of pH on zinc sorption, zinc desorption from the foam and analytical features of the procedure w...

Determination of trace elements in soy milk using ICP atomic emission spectrometry

International Nuclear Information System (INIS)

Tanaka, Satoko; Chayama, Kenji

2009-01-01

The present study investigated the optimal method for the multi-element quantification of 9 elements in soy milk: calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc. Results obtained using ICP atomic emission spectrometry were compared with those obtained by atomic absorption spectrometry, which is the standard method. The same sample was measured using both ICP atomic emission spectrometry and atomic absorption spectrometry. The percentage of minerals recovered by ICP atomic emission spectrometry ranged from 99.3% to 102%, which was equivalent to that by atomic absorption spectrometry. Therefore, a good result with standard deviation was obtained. The mineral contents of 16 samples of commercially-available soy milk products were measured. The Cu content was significantly proportional to the amount of soybean solids (P < 0.001). Moreover, although relation-ships did not attain statistical significance, the consents of Fe, Zn, K, Mg and P were proportional to the amount of soybean solids, and were highest in soy milk, followed by prepared soy milk and so milk beverage. The Ca content of modified soy milk was significantly higher than that of soy milk and soy milk-based beverages (P < 0.001). Furthermore, the Na content in soy milk was significantly lower. (author)

Matrix digestion of soil and sediment samples for extraction of lead, cadmium and antimony and their direct determination by inductively coupled plasma-mass spectrometry and atomic emission spectrometry

International Nuclear Information System (INIS)

Chattopadhyay, P.; Fisher, A.S.; Henon, D.N.; Hill, S.J.

2004-01-01

An environmentally friendly and simple method has been developed for complete digestion of lead, cadmium and antimony from soil samples using a magnesium nitrate assisted dry ashing procedure. Statistical data for a series of experiments with standard reference materials are presented, and precision values are found to be comparable for inductively coupled plasma-mass spectrometry and for inductively coupled plasma-atomic emission spectrometry. From a single digest solution all analytes are quantified without involving any preconcentration routes. Inter-method comparison of inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) shows that the probability of the results being different is less than 99 %. (author)

Induced absorption and stimulated emission in a driven two-level atom

International Nuclear Information System (INIS)

Mavroyannis, C.

1992-01-01

We have considered the induced processes that occur in a driven two-level atom, where a laser photon is absorbed and emitted by the ground and by the excited states of the atom, respectively. In the low-intensity limit of the laser field, the induced spectra arising when a laser photon is absorbed by the ground state of the atom consist of two peaks describing induced absorption and stimulated-emission processes, respectively, where the former prevails over the latter. Asymmetry of the spectral lines occurs at off-resonance and its extent depends on the detuning of the laser field. The physical. process where a laser photon is emitted by the excited state is the reverse of that arising from the absorption of a laser photon by the ground state of the atom. The former differs from the latter in that the emission of a laser photon by the excited state occurs in the low frequency regime and that the stimulated-emission process prevails over that of the induced absorption. In this case, amplification of ultrashort pulses is likely to occur without the need of population inversion between the optical transitions. The computed spectra are graphically presented and discussed. (author)

LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

International Nuclear Information System (INIS)

Seidel, C.M.; Jain, J.; Owens, J.W.

2009-01-01

This report describes the installation, testing, and acceptance of the Waste Treatment and Immobilization Plant (WTP) procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste (HLW) samples in a hot cell environment. The work was completed by the Analytical Process Development (APD) group in accordance with Task Order 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S Laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method

Analytical model for relativistic corrections to the nuclear magnetic shielding constant in atoms

International Nuclear Information System (INIS)

Romero, Rodolfo H.; Gomez, Sergio S.

2006-01-01

We present a simple analytical model for calculating and rationalizing the main relativistic corrections to the nuclear magnetic shielding constant in atoms. It provides good estimates for those corrections and their trends, in reasonable agreement with accurate four-component calculations and perturbation methods. The origin of the effects in deep core atomic orbitals is manifestly shown

Analytical model for relativistic corrections to the nuclear magnetic shielding constant in atoms

Energy Technology Data Exchange (ETDEWEB)

Romero, Rodolfo H. [Facultad de Ciencias Exactas, Universidad Nacional del Nordeste, Avenida Libertad 5500 (3400), Corrientes (Argentina)]. E-mail: rhromero@exa.unne.edu.ar; Gomez, Sergio S. [Facultad de Ciencias Exactas, Universidad Nacional del Nordeste, Avenida Libertad 5500 (3400), Corrientes (Argentina)

2006-04-24

We present a simple analytical model for calculating and rationalizing the main relativistic corrections to the nuclear magnetic shielding constant in atoms. It provides good estimates for those corrections and their trends, in reasonable agreement with accurate four-component calculations and perturbation methods. The origin of the effects in deep core atomic orbitals is manifestly shown.

Plasma-related matrix effects in inductively coupled plasma--atomic emission spectrometry by group I and group II matrix-elements

International Nuclear Information System (INIS)

Chan, George C.-Y.; Chan, W.-T.

2003-01-01

The effects of Na, K, Ca and Ba matrices on the plasma excitation conditions in inductively coupled plasma-atomic emission spectrometry (ICP-AES) were studied. Normalized relative intensity was used to indicate the extent of the plasma-related matrix effects. The group I matrices have no effects on the plasma excitation conditions. In contrast, the group II matrices depress the normalized relative intensities of some spectral lines. Specifically, the Group II matrices have no effects on the normalized relative intensity of atomic lines of low upper energy level (soft lines), but reduce the normalized relative intensity of some ionic lines and atomic lines of high energy level (hard lines). The Group II matrices seem to shift the Saha balance of the analytes only; no shift in the Boltzmann balance was observed experimentally. Moreover, for some ionic lines with sum of ionization and excitation potentials close to the ionization potential of argon (15.75 eV), the matrix effect is smaller than other ionic lines of the same element. The reduced matrix effects may be attributed qualitatively to charge transfer excitation mechanism of these ionic lines. Charge transfer reaction renders ionic emission lines from the quasi-resonant levels similar in characteristics of atomic lines. The contribution of charge transfer relative to excitation by other non-specific excitation mechanisms (via Saha balance and Boltzmann balance) determines the degree of atomic behavior of a quasi-resonant level. A significant conclusion of this study is that plasma-related matrix effect depends strongly on the excitation mechanism of a spectral line. Since, in general, more than one excitation mechanism may contribute to the overall excitation of an emission line, the observed matrix effects reflect the sum of the effects due to individual excitation mechanisms. Excitation mechanisms, in addition to the often-used total excitation energy, should be considered in matrix effect studies

Combustor exhaust-emissions and blowout-limits with diesel number 2 and Jet A fuels utilizing air-atomizing and pressure-atomizing nozzles

Science.gov (United States)

Ingebo, R. D.; Norgren, C. T.

1975-01-01

The effect of fuel properties on exhaust emissions and blowout limits of a high-pressure combustor segment is evaluated using a splash-groove air-atomizing fuel injector and a pressure-atomizing simplex fuel nozzle to burn both diesel number 2 and Jet A fuels. Exhaust emissions and blowout data are obtained and compared on the basis of the aromatic content and volatility of the two fuels. Exhaust smoke number and emission indices for oxides of nitrogen, carbon monoxide, and unburned hydrocarbons are determined for comparison. As compared to the pressure-atomizing nozzle, the air-atomizing nozzle is found to reduce nitrogen oxides by 20%, smoke number by 30%, carbon monoxide by 70%, and unburned hydrocarbons by 50% when used with diesel number 2 fuel. The higher concentration of aromatics and lower volatility of diesel number 2 fuel as compared to Jet A fuel appears to have the most detrimental effect on exhaust emissions. Smoke number and unburned hydrocarbons are twice as high with diesel number 2 as with Jet A fuel.

Determination numbers of ionized atoms from emission and absorption lines

International Nuclear Information System (INIS)

Alizadeh Azimi, A.; Shokouhi, N.

2002-01-01

Saha, M., (1920) estimated that salter chromosphere is not only due to radiation from neutral atoms, but from ionized atoms. The failure to observe these stellar lines in the laboratory was attributed to internal temperature and pressure about 10* E + 6 K 10* E-7 atm. In this research we found that emission lines of ionized atoms (like Cs) could be measured in laboratory condition, (about 10* E-3 atm and 2000 K) by using Graphite France Atomic Absorption with injection 124 u g C sel. We calculated the numbers of ionized atoms from Bottzman law. We also measured these numbers from area under the energy-time curve

Superradiant cascade emissions in an atomic ensemble via four-wave mixing

Energy Technology Data Exchange (ETDEWEB)

Jen, H.H., E-mail: sappyjen@gmail.com

2015-09-15

We investigate superradiant cascade emissions from an atomic ensemble driven by two-color classical fields. The correlated pair of photons (signal and idler) is generated by adiabatically driving the system with large-detuned light fields via four-wave mixing. The signal photon from the upper transition of the diamond-type atomic levels is followed by the idler one which can be superradiant due to light-induced dipole–dipole interactions. We then calculate the cooperative Lamb shift (CLS) of the idler photon, which is a cumulative effect of interaction energy. We study its dependence on a cylindrical geometry, a conventional setup in cold atom experiments, and estimate the maximum CLS which can be significant and observable. Manipulating the CLS of cascade emissions enables frequency qubits that provide alternative robust elements in quantum network. - Highlights: • Superradiance from a cascade atomic transition. • Correlated photon pair generation via four-wave mixing. • Dynamical light–matter couplings in a phased symmetrical state. • Cooperative Lamb shift in a cylindrical atomic ensemble.

Coherent effects on two-photon correlation and directional emission of two two-level atoms

International Nuclear Information System (INIS)

Ooi, C. H. Raymond; Kim, Byung-Gyu; Lee, Hai-Woong

2007-01-01

Sub- and superradiant dynamics of spontaneously decaying atoms are manifestations of collective many-body systems. We study the internal dynamics and the radiation properties of two atoms in free space. Interesting results are obtained when the atoms are separated by less than half a wavelength of the atomic transition, where the dipole-dipole interaction gives rise to new coherent effects, such as (a) coherence between two intermediate collective states, (b) oscillations in the two-photon correlation G (2) , (c) emission of two photons by one atom, and (d) the loss of directional correlation. We compare the population dynamics during the two-photon emission process with the dynamics of single-photon emission in the cases of a Λ and a V scheme. We compute the temporal correlation and angular correlation of two successively emitted photons using the G (2) for different values of atomic separation. We find antibunching when the atomic separation is a quarter wavelength λ/4. Oscillations in the temporal correlation provide a useful feature for measuring subwavelength atomic separation. Strong directional correlation between two emitted photons is found for atomic separation larger than a wavelength. We also compare the directionality of a photon spontaneously emitted by the two atoms prepared in phased-symmetric and phased-antisymmetric entangled states vertical bar ±> k 0 =e ik 0 ·r 1 vertical bar a 1 ,b 2 >±e ik 0 ·r 2 vertical bar b 1 ,a 2 > by a laser pulse with wave vector k 0 . Photon emission is directionally suppressed along k 0 for the phased-antisymmetric state. The directionality ceases for interatomic distances less than λ/2

Calculation of spontaneous emission from a V-type three-level atom in photonic crystals using fractional calculus

International Nuclear Information System (INIS)

Huang, Chih-Hsien; Hsieh, Wen-Feng; Wu, Jing-Nuo; Cheng, Szu-Cheng; Li, Yen-Yin

2011-01-01

Fractional time derivative, an abstract mathematical operator of fractional calculus, is used to describe the real optical system of a V-type three-level atom embedded in a photonic crystal. A fractional kinetic equation governing the dynamics of the spontaneous emission from this optical system is obtained as a fractional Langevin equation. Solving this fractional kinetic equation by fractional calculus leads to the analytical solutions expressed in terms of fractional exponential functions. The accuracy of the obtained solutions is verified through reducing the system into the special cases whose results are consistent with the experimental observation. With accurate physical results and avoiding the complex integration for solving this optical system, we propose fractional calculus with fractional time derivative as a better mathematical method to study spontaneous emission dynamics from the optical system with non-Markovian dynamics.

On the deviation from the sech2 superradiant emission law in a two-level atomic system

International Nuclear Information System (INIS)

Goncalves, A.E.

1990-01-01

The atomic superradiant emission is treated in the single particle mean field approximation. A single particle Hamiltonian, which represents a dressed two-level atom in a radiation field, can be obtained and it is verified that it describes the transient regime of the emission process. While the line shape emission for a bare atom follows the sech 2 law, for the dressed atom the line shape deviates appreciably from this law and it is verified that the deviation depends crucially on the ratio of the dynamic frequency shift to the transition frequency. This kind of deviation is observed in experimental results. (Author) [pt

Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Zhang, Duo, E-mail: zhangduo10@gmail.com [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Li, Jiahua, E-mail: huajia_li@163.com [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Ding, Chunling; Yang, Xiaoxue [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-05-21

The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

International Nuclear Information System (INIS)

Zhang, Duo; Li, Jiahua; Ding, Chunling; Yang, Xiaoxue

2012-01-01

The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

Phonon dispersion on Ag (100) surface: A modified analytic embedded atom method study

International Nuclear Information System (INIS)

Zhang Xiao-Jun; Chen Chang-Le

2016-01-01

Within the harmonic approximation, the analytic expression of the dynamical matrix is derived based on the modified analytic embedded atom method (MAEAM) and the dynamics theory of surface lattice. The surface phonon dispersions along three major symmetry directions, and XM-bar are calculated for the clean Ag (100) surface by using our derived formulas. We then discuss the polarization and localization of surface modes at points X-bar and M-bar by plotting the squared polarization vectors as a function of the layer index. The phonon frequencies of the surface modes calculated by MAEAM are compared with the available experimental and other theoretical data. It is found that the present results are generally in agreement with the referenced experimental or theoretical results, with a maximum deviation of 10.4%. The agreement shows that the modified analytic embedded atom method is a reasonable many-body potential model to quickly describe the surface lattice vibration. It also lays a significant foundation for studying the surface lattice vibration in other metals. (paper)

Investigation of an alternating current plasma as an element selective atomic emission detector for high-resolution capillary gas chromatography and as a source for atomic absorption and atomic emission spectrometry

Science.gov (United States)

Ombaba, Jackson M.

This thesis deals with the construction and evaluation of an alternating current plasma (ACP) as an element-selective detector for high resolution capillary gas chromatography (GC) and as an excitation source for atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES). The plasma, constrained in a quartz discharge tube at atmospheric pressure, is generated between two copper electrodes and utilizes helium as the plasma supporting gas. The alternating current plasma power source consists of a step-up transformer with a secondary output voltage of 14,000 V at a current of 23 mA. The device exhibits a stable signal because the plasma is self-seeding and reignites itself every half cycle. A tesla coil is not required to commence generation of the plasma if the ac voltage applied is greater than the breakdown voltage of the plasma-supporting gas. The chromatographic applications studied included the following: (1) the separation and selective detection of the organotin species, tributyltin chloride (TBT) and tetrabutyltin (TEBT), in environmental matrices including mussels (Mvutilus edullus) and sediment from Boston Harbor, industrial waste water and industrial sludge, and (2) the detection of methylcyclopentadienyl manganesetricarbonyl (MMT) and similar compounds used as gasoline additives. An ultrasonic nebulizer (common room humidifier) was utilized as a sample introduction device for aqueous solutions when the ACP was employed as an atomization source for atomic absorption spectrometry and as an excitation source for atomic emission spectrometry. Plasma diagnostic parameters studied include spatial electron number density across the discharge tube, electronic, excitation and ionization temperatures. Interference studies both in absorption and emission modes were also considered. Figures of merits of selected elements both in absorption and emission modes are reported. The evaluation of a computer-aided optimization program, Drylab GC, using

Three-dimensional time-dependent computer modeling of the electrothermal atomizers for analytical spectrometry

Science.gov (United States)

Tsivilskiy, I. V.; Nagulin, K. Yu.; Gilmutdinov, A. Kh.

2016-02-01

A full three-dimensional nonstationary numerical model of graphite electrothermal atomizers of various types is developed. The model is based on solution of a heat equation within solid walls of the atomizer with a radiative heat transfer and numerical solution of a full set of Navier-Stokes equations with an energy equation for a gas. Governing equations for the behavior of a discrete phase, i.e., atomic particles suspended in a gas (including gas-phase processes of evaporation and condensation), are derived from the formal equations molecular kinetics by numerical solution of the Hertz-Langmuir equation. The following atomizers test the model: a Varian standard heated electrothermal vaporizer (ETV), a Perkin Elmer standard THGA transversely heated graphite tube with integrated platform (THGA), and the original double-stage tube-helix atomizer (DSTHA). The experimental verification of computer calculations is carried out by a method of shadow spectral visualization of the spatial distributions of atomic and molecular vapors in an analytical space of an atomizer.

CANAS '01 - Colloquium analytical atomic spectroscopy; CANAS '01 - Colloquium Analytische Atomspektroskopie. Programm. Kurzfassungen der Vortraege und Poster

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The main topics of the meeting on analytical atom spectroscopy were: optical atom spectrometry, x-ray fluorescence analysis, absorption spectroscopy, icp mass spectroscopy, trace analysis, sampling, sample preparation and quality assurance.

Atomic emission spectroscopy for the on-line monitoring of incineration processes

International Nuclear Information System (INIS)

Timmermans, E.A.H.; Groote, F.P.J. de; Jonkers, J.; Gamero, A.; Sola, A.; Mullen, J.J.A.M. van der

2003-01-01

A diagnostic measurement system based on atomic emission spectroscopy has been developed for the purpose of on-line monitoring of hazardous elements in industrial combustion gases. The aim was to construct a setup with a high durability for rough and variable experimental conditions, e.g. a strongly fluctuating gas composition, a high gas temperature and the presence of fly ash and corrosive effluents. Since the setup is primarily intended for the analysis of combustion gases with extremely high concentrations of pollutants, not much effort has been made to achieve low detection limits. It was found that an inductively coupled argon plasma was too sensitive to molecular gas introduction. Therefore, a microwave induced plasma torch, compromising both the demands of a high durability and an effective evaporation and excitation of the analyte was used as excitation source. The analysis system has been installed at an industrial hazardous waste incinerator and successfully tested on combustion gases present above the incineration process. Abundant elements as zinc, lead and sodium could be easily monitored

Spontaneous emission spectrum of a four-level atom coupled by three kinds of reservoirs

International Nuclear Information System (INIS)

Yang Dong; Wang Jian; Zhang, Hanzhuang; Yao Jinbo

2007-01-01

A model of a four-level atom embedded in a double-band photonic crystal (PC) is presented. The atomic transitions from the upper two levels to the lower two levels are coupled by the same reservoir which is assumed in turn to be isotropic PC modes, anisotropic PC modes and free vacuum modes. The effects of the fine structure of the atomic ground state levels and the quantum interference on the spontaneous emission spectrum of an atom are investigated in detail. Most interestingly, it is shown for the first time that new spontaneous emission lines are produced from the fine splitting of atomic ground state levels in the isotropic PC case. Quantum interference induces additional narrow spontaneous lines near the transition from the empty upper level to the lower levels

Delta-electron emission in fast heavy ion atom collisions

International Nuclear Information System (INIS)

Schmidt-Boecking, H.; Ramm, U.; Berg, H.; Kelbch, C.; Feng Jiazhen; Hagmann, S.; Kraft, G.; Ullrich, J.

1991-01-01

The δ-electron emission processes occuring in fast heavy ion atom collisons are explained qualitatively. The different spectral structures of electron emission arising from either the target or the projectile are explained in terms of simple models of the kinetics of momentum transfer induced by the COULOMB forces. In collisions of very heavy ions with matter, high nuclear COULOMB forces are created. These forces lead to a strong polarization of the electronic states of the participated electrons. The effects of this polarization are discussed. (orig.)

Abstracts of the 2. Brazilian Meeting on Analytical Chemistry

International Nuclear Information System (INIS)

Curtius, A.J.

1983-01-01

Abstracts of theoretical and experimental works on Qualitative and Quantitative Analytical Chemistry are presented. Among the various analytical techniques used, emphasis is given to: neutron activation analysis, crystal doping and annealing, isotopic tracing, fission tracks detection, atomic absorption spectrophotometry, emission spectroscopy with induced coupled plasma, X-ray diffraction, nuclear magnetic resonance, mass spectrometry, polarography, ion exchange and/or thin-layer chromatography, electrodeposition, potentiometric titration and others. (C.L.B) [pt

Distorted wave models applied to electron emission study in ion-atom collisions at intermediate and high energies

International Nuclear Information System (INIS)

Fainstein, P.D.

1989-01-01

The electron emission from different atoms induced by impact of multicharged bare ions at intermediate and high energies is studied. To perform these studies, the continuum distorted wave-eikonal initial state model is used. With this distorted wave model, analytical expressions are obtained for the transition amplitudes as a function of the transverse momentum transfer for hydrogen targets in an arbitrary initial state and for every any orbital of a multielectronic target represented as a linear combination of Slater type orbitals. With these expressions, the different cross sections which are compared with the experimental data available are numerically calculated. The results obtained for different targets and projectiles and the comparison with other theoretical models and experimental data allows to explain the electron emission spectra and to predict new effects which have not been measured so far. The results of the present work permit to view the ionization process as the evolution of the active electron in the combined field of the target and projectile nuclei. (Author) [es

Palladium emissions in the environment: analytical methods, environmental assessment and health effects

National Research Council Canada - National Science Library

Alt, Friedrich; Zereini, Fathi

2006-01-01

... (Eds)). But there is a clear lack of information concerning palladium. It is very important to condense the present state of research findings from emission to potential health risks for the environment and humans. Very important is the chapter about analytical determination of palladium, which shows clearly the problems of several analytic...

LASER ABLATION-INDUCTIVELY COUPLED PLASMA-ATOMIC EMISSION SPECTROSCOPY STUDY AT THE 222-S LABORATORY USING HOT-CELL GLOVE BOX PROTOTYPE SYSTEM

International Nuclear Information System (INIS)

Lockrem, L.L.; Owens, J.W.; Seidel, C.M.

2009-01-01

This report describes the installation, testing and acceptance of the Waste Treatment and Immobilization Plant procured laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES) system for remotely analyzing high-level waste samples in a hot cell environment. The 2005-003; ATS MP 1027, Management Plan for Waste Treatment Plant Project Work Performed by Analytical Technical Services. The APD group at the 222-S laboratory demonstrated acceptable turnaround time (TAT) and provide sufficient data to assess sensitivity, accuracy, and precision of the LA-ICP-AES method

Cobalt as chemical modifier to improve chromium sensitivity and minimize matrix effects in tungsten coil atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Silva, Sidnei G. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P.O. Box 676, São Carlos, SP 13560-970 (Brazil); Donati, George L., E-mail: georgedonati@yahoo.com.br [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Santos, Luana N. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P.O. Box 676, São Carlos, SP 13560-970 (Brazil); Jones, Bradley T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Nóbrega, Joaquim A. [Group of Applied Instrumental Analysis, Department of Chemistry, Federal University of São Carlos, P.O. Box 676, São Carlos, SP 13560-970 (Brazil)

2013-05-30

Graphical abstract: -- Highlights: •Charge transfer reactions increase the population of Cr{sup +}. •Chromium ions and electrons recombine to form excited-state Cr atoms. •A 10-fold improvement in LOD is observed for Cr emission measurements. •The two-step ionization/excitation mechanism improves sensitivity and accuracy. •High concentrations of Co also minimize matrix effects. -- Abstract: Cobalt is used as chemical modifier to improve sensitivity and minimize matrix effects in Cr determinations by tungsten coil atomic emission spectrometry (WCAES). The atomizer is a tungsten filament extracted from microscope light bulbs. A solid-state power supply and a handheld CCD-based spectrometer are also used in the instrumental setup. In the presence of 1000 mg L{sup −1} Co, WCAES limit of detection for Cr (λ = 425.4 nm) is calculated as 0.070 mg L{sup −1}; a 10-fold improvement compared to determinations without Co modifier. The mechanism involved in such signal enhancement is similar to the one observed in ICP OES and ICP-MS determinations of As and Se in the presence of C. Cobalt increases the population of Cr{sup +} by charge transfer reactions. In a second step, Cr{sup +}/e{sup −} recombination takes place, which results in a larger population of excited-state Cr atoms. This alternative excitation route is energetically more efficient than heat transfer from atomizer and gas phase to analyte atoms. A linear dynamic range of 0.25–10 mg L{sup −1} and repeatability of 3.8% (RSD, n = 10) for a 2.0 mg L{sup −1} Cr solution are obtained with this strategy. The modifier high concentration also contributes to improving accuracy due to a matrix-matching effect. The method was applied to a certified reference material of Dogfish Muscle (DORM-2) and no statistically significant difference was observed between determined and certified Cr values at a 95% confidence level. Spike experiments with bottled water samples resulted in recoveries between 93% and

Teleporting the one-qubit state via two-level atoms with spontaneous emission

Energy Technology Data Exchange (ETDEWEB)

Hu Mingliang, E-mail: mingliang0301@xupt.edu.cn, E-mail: mingliang0301@163.com [School of Science, Xi' an University of Posts and Telecommunications, Xi' an 710061 (China)

2011-05-14

We study quantum teleportation via two two-level atoms coupled collectively to a multimode vacuum field and prepared initially in different atomic states. We concentrated on the influence of the spontaneous emission, collective damping and dipole-dipole interaction of the atoms on fidelity dynamics of quantum teleportation and obtained the region of spatial distance between the two atoms over which the state can be teleported nonclassically. Moreover, we showed through concrete examples that entanglement of the channel state is the prerequisite but not the only essential quantity for predicting the teleportation fidelity.

Effect of atomic initial phase difference on spontaneous emission of an atom embedded in photonic crystal

International Nuclear Information System (INIS)

Bing, Zhang; Xiu-Dong, Sun; Xiang-Qian, Jiang

2010-01-01

We investigate the effect of initial phase difference between the two excited states of a V-type three-level atom on its steady state behaviour of spontaneous emission. A modified density of modes is introduced to calculate the spontaneous emission spectra in photonic crystal. Spectra in free space are also shown to compare with that in photonic crystal with different relative positions of the excited levels from upper band-edge frequency. It is found that the initial phase difference plays an important role in the quantum interference property between the two decay channels. For a zero initial phase, destructive property is presented in the spectra. With the increase of initial phase difference, quantum interference between the two decay channels from upper levels to ground level turns to be constructive. Furthermore, we give an interpretation for the property of these spectra. (atomic and molecular physics)

Measurement of fluorescence emission spectrum of few strongly driven atoms using an optical nanofiber.

Science.gov (United States)

Das, Manoj; Shirasaki, A; Nayak, K P; Morinaga, M; Le Kien, Fam; Hakuta, K

2010-08-02

We show that the fluorescence emission spectrum of few atoms can be measured by using an optical nanofiber combined with the optical heterodyne and photon correlation spectroscopy. The observed fluorescence spectrum of the atoms near the nanofiber shows negligible effects of the atom-surface interaction and agrees well with the Mollow triplet spectrum of free-space atoms at high excitation intensity.

Electron and X-ray emission in collisions of multiply charged ions and atoms

International Nuclear Information System (INIS)

Woerlee, P.H.

1979-01-01

The author presents experimental results of electron and X-ray emission following slow collisions of multiply charged ions and atoms. The aim of the investigation was to study the mechanisms which are responsible for the emission. (G.T.H.)

Localization of the relative position of two atoms induced by spontaneous emission

International Nuclear Information System (INIS)

Zheng, L.; Li, C.; Li, Y.; Sun, C.P.

2005-01-01

We reexamine the back-action of emitted photons on the wave packet evolution about the relative position of two cold atoms. We show that photon recoil resulting from the spontaneous emission can induce the localization of the relative position of the two atoms through the entanglement between the spatial motion of individual atoms and their emitted photons. The obtained result provides a more realistic model for the analysis of the environment-induced localization of a macroscopic object

An analytic study of applying Miller cycle to reduce NOx emission from petrol engine

International Nuclear Information System (INIS)

Wang Yaodong; Lin Lin; Roskilly, Anthony P.; Zeng Shengchuo; Huang, Jincheng; He Yunxin; Huang Xiaodong; Huang Huilan; Wei Haiyan; Li Shangping; Yang Jing

2007-01-01

An analytic investigation of applying Miller cycle to reduce nitrogen oxides (NO x ) emissions from a petrol engine is carried out. The Miller cycle used in the investigation is a late intake valve closing version. A detailed thermodynamic analysis of the cycle is presented. A comparison of the characters of Miller cycle with Otto cycle is presented. From the results of thermodynamic analyses, it can be seen that the application of Miller cycle is able to reduce the compression pressure and temperature in the cylinder at the end of compression stroke. Therefore, it lowers down the combustion temperature and NO x formation in engine cylinder. These results in a lower exhaust temperature and less NO x emissions compared with that of Otto cycle. The analytic results also show that Miller cycle ratio is a main factor to influence the combustion temperature, and then the NO x emissions and the exhaust temperature. The results from the analytic study are used to analyse and to compare with the previous experimental results. An empirical formula from the previous experimental results that showed the relation of NO x emissions with the exhaust temperature at different engine speed is presented. The results from the study showed that the application of Miller cycle may reduce NO x emissions from petrol engine

Semi-automatic determination of tin in marine materials by continuous flow hydride generation inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Feng Yonglai; Narasaki, Hisataki; Chen Hongyuan; Tian Liching

1997-01-01

A semi-automated continuous flow hydride generation system with inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of tin in marine materials. The effects of acids (H 2 SO 4 and HCl) were studied. The analytical parameters were thoroughly investigated. Under optimized conditions, the detection limit is 0.4 ng/ml. Interferences from transition elements were investigated and seven masking reagents were tested. L-cysteine hydrochloride monohydrate (1%) was used to mask the interferences from foreign ions. Finally, the accuracy, checked with a marine standard reference material obtained from the National Research Council (NRC), was within the certified value. (orig.). With 6 figs., 4 tabs

Visible Light Emission from Atomic Scale Patterns Fabricated by the Scanning Tunneling Microscope

DEFF Research Database (Denmark)

Thirstrup, C.; Sakurai, M.; Stokbro, Kurt

1999-01-01

Scanning tunneling microscope (STM) induced light emission from artificial atomic scale structures comprising silicon dangling bonds on hydrogen-terminated Si(001) surfaces has been mapped spatially and analyzed spectroscopically in the visible spectral range. The light emission is based on a novel...

Emission Spectrum Property of Modulated Atom-Field Coupling System

International Nuclear Information System (INIS)

Gao Yun-Feng; Feng Jian; Li Yue-Ke

2013-01-01

The emission spectrum of a two-level atom interacting with a single mode radiation field in the case of periodic oscillation coupling coefficient is investigated. A general expression for the emission spectrum is derived. The numerical results for the initial field in pure number stare are calculated. It is found that the effect of the coupling coefficient modulation on the spectral structure is very obvious in the case of a low modulation frequency and larger amplitude when the initial field is vacuum, which is potentially useful for exploring a modulated light source. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Determination of rare earth elements by liquid chromatography/inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Yoshida, K.; Haraguchi, H.

1984-01-01

Inductively coupled plasma atomic emission spectrometry (ICP-AES) interfaced with high-performance liquid chromatography (HPLC) has been applied to the determination of rare earth elements. ICP-AES was used as an element-selective detector for HPLC. The separation of rare earth elements with HPLC helped to avoid erroneous analytical results due to spectral interferences. Fifteen rare earth elements (Y and 14 lanthanides) were determined selectively with the HPLC/ICP-AES system using a concentration gradient method. The detection limits with the present HPLC/ICP-AES system were about 0.001-0.3 μg/mL with a 100-μL sample injection. The calibration curves obtained by the peak height measurements showed linear relationships in the concentration range below 500 μg/mL for all rare earth elements. A USGS rock standard sample, rare earth ores, and high-purity lanthanide reagents (>99.9%) were successfully analyzed without spectral interferences

[Applications of atomic emission spectrum from liquid electrode discharge to metal ion detection].

Science.gov (United States)

Mao, Xiu-Ling; Wu, Jian; Ying, Yi-Bin

2010-02-01

The fast and precise detection of metal ion is an important research project concerning studies in diverse academic fields and different kinds of detecting technologies. In the present paper, the authors review the research on atomic emission spectrum based on liquid electrode discharge and its applications in the detection of metal ion. In the first part of this paper the principles and characteristics of the methods based on electrochemistry and spectroscopy were introduced. The methods of ion-selective electrode (ISE), anodic stripping voltammetry, atomic emission spectrum and atomic absorption spectrum were included in this part and discussed comparatively. Then the principles and characteristics of liquid electrode spectra for metal ion detection were introduced. The mechanism of the plasma production and the characteristics of the plasma spectrum as well as its advantages compared with other methods were discussed. Secondly, the authors divided the discharge system into two types and named them single liquid-electrode discharge and double-liquid electrode respectively, according to the number of the liquid electrode and the configuration of the discharge system, and the development as well as the present research status of each type was illustrated. Then the characteristics and configurations of the discharge systems including ECGD, SCGD, LS-APGD and capillary discharge were discussed in detail as examples of the two types. By taking advantage of the technology of atomic emission spectrum based on liquid electrode discharge, the detecting limit of heavy metals such as copper, mercury and argent as well as active metal ions including sodium, potass and magnesium can achieve microg x L(-1). Finally, the advantages and problems of the liquid-electrode discharge applied in detection of metal ion were discussed. And the applications of the atomic emission spectrum based on liquid electrode discharge were prospected.

Inductively coupled plasma atomic emission spectrometric determination of tin in canned food.

Science.gov (United States)

Sumitani, H; Suekane, S; Nakatani, A; Tatsuka, K

1993-01-01

Various canned foods were digested sequentially with HNO3 and HCl, diluted to 100 mL, and filtered, and then tin was determined by inductively coupled plasma atomic emission spectrometry (ICP/AES). Samples of canned Satsuma mandarin, peach, apricot, pineapple, apple juice, mushroom, asparagus, evaporated milk, short-necked clam, spinach, whole tomato, meat, and salmon were evaluated. Sample preparations did not require time-consuming dilutions, because ICP/AES has wide dynamic range. The standard addition method was used to determine tin concentration. Accuracy of the method was tested by analyzing analytical standards containing tin at 2 levels (50 and 250 micrograms/g). The amounts of tin found for the 50 and 250 micrograms/g levels were 50.5 and 256 micrograms/g, respectively, and the repeatability coefficients of variation were 4.0 and 3.8%, respectively. Recovery of tin from 13 canned foods spiked at 2 levels (50 and 250 micrograms/g) ranged from 93.9 to 109.4%, with a mean of 99.2%. The quantitation limit for tin standard solution was about 0.5 microgram/g.

Emission Channeling Studies of the Lattice Site of Oversized Alkali Atoms Implanted in Metals

CERN Multimedia

2002-01-01

% IS340 \\\\ \\\\ As alkali atoms have the largest atomic radius of all elements, the determination of their lattice configuration following implantation into metals forms a critical test for the various models predicting the lattice site of implanted impurity atoms. The site determination of these large atoms will especially be a crucial check for the most recent model that relates the substitutional fraction of oversized elements to their solution enthalpy. Recent exploratory $^{213}$Fr and $^{221}$Fr $\\alpha$-emission channeling experiments at ISOLDE-CERN and hyperfine interaction measurements on Fr implanted in Fe gave an indication for anomalously large substitutional fractions. To investigate further the behaviour of Fr and other alkali atoms like Cs and Rb thoroughly, more on-line emission channeling experiments are needed. We propose a number of shifts for each element, where the temperature of the implanted metals will be varied between 50$^\\circ$ and 700$^\\circ$~K. Temperature dependent measurements wi...

Elaboration in the area of geochemistry and analytical chemistry

International Nuclear Information System (INIS)

Mirsaidov, U.M.

2002-01-01

In this article of book the analytical organic reagents, the method of leading cobalt in to coloured condition, the method of photo-metrical nickel determination, X-ray spectrum and atomic emission spectral analysis, pre-sorting of aluminium raw material samples, roentgen fluorescent determination of formative elements in rocks was investigated

CANAS '01 - Colloquium analytical atomic spectroscopy; CANAS '01 - Colloquium Analytische Atomspektroskopie. Programm. Kurzfassungen der Vortraege und Poster

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The main topics of the meeting on analytical atom spectroscopy were: optical atom spectrometry, x-ray fluorescence analysis, absorption spectroscopy, icp mass spectroscopy, trace analysis, sampling, sample preparation and quality assurance.

Superradiators created atom by atom

Science.gov (United States)

Meschede, Dieter

2018-02-01

High radiation rates are usually associated with macroscopic lasers. Laser radiation is “coherent”—its amplitude and phase are well-defined—but its generation requires energy inputs to overcome loss. Excited atoms spontaneously emit in a random and incoherent fashion, and for N such atoms, the emission rate simply increases as N. However, if these atoms are in close proximity and coherently coupled by a radiation field, this microscopic ensemble acts as a single emitter whose emission rate increases as N2 and becomes “superradiant,” to use Dicke's terminology (1). On page 662 of this issue, Kim et al. (2) show the buildup of coherent light fields through collective emission from atomic radiators injected one by one into a resonator field. There is only one atom ever in the cavity, but the emission is still collective and superradiant. These results suggest another route toward thresholdless lasing.

An Analytical Model for Adsorption and Diffusion of Atoms/Ions on Graphene Surface

Directory of Open Access Journals (Sweden)

Yan-Zi Yu

2015-01-01

Full Text Available Theoretical investigations are made on adsorption and diffusion of atoms/ions on graphene surface based on an analytical continuous model. An atom/ion interacts with every carbon atom of graphene through a pairwise potential which can be approximated by the Lennard-Jones (L-J potential. Using the Fourier expansion of the interaction potential, the total interaction energy between the adsorption atom/ion and a monolayer graphene is derived. The energy-distance relationships in the normal and lateral directions for varied atoms/ions, including gold atom (Au, platinum atom (Pt, manganese ion (Mn2+, sodium ion (Na1+, and lithium-ion (Li1+, on monolayer graphene surface are analyzed. The equilibrium position and binding energy of the atoms/ions at three particular adsorption sites (hollow, bridge, and top are calculated, and the adsorption stability is discussed. The results show that H-site is the most stable adsorption site, which is in agreement with the results of other literatures. What is more, the periodic interaction energy and interaction forces of lithium-ion diffusing along specific paths on graphene surface are also obtained and analyzed. The minimum energy barrier for diffusion is calculated. The possible applications of present study include drug delivery system (DDS, atomic scale friction, rechargeable lithium-ion graphene battery, and energy storage in carbon materials.

Mercury determination in non- and biodegradable materials by cold vapor capacitively coupled plasma microtorch atomic emission spectrometry.

Science.gov (United States)

Frentiu, Tiberiu; Mihaltan, Alin I; Ponta, Michaela; Darvasi, Eugen; Frentiu, Maria; Cordos, Emil

2011-10-15

A new analytical system consisting of a low power capacitively coupled plasma microtorch (20 W, 13.56 MHz, 150 ml min(-1) Ar) and a microspectrometer was investigated for the Hg determination in non- and biodegradable materials by cold-vapor generation, using SnCl(2) reductant, and atomic emission spectrometry. The investigated miniaturized system was used for Hg determination in recyclable plastics from electronic equipments and biodegradable materials (shopping bags of 98% biodegradable polyethylene and corn starch) with the advantages of easy operation and low analysis costs. Samples were mineralized in HNO(3)-H(2)SO(4) mixture in a high-pressure microwave system. The detection limits of 0.05 ng ml(-1) or 0.08 μg g(-1) in solid sample were compared with those reported for other analytical systems. The method precision was 1.5-9.4% for Hg levels of 1.37-13.9 mg kg(-1), while recovery in two polyethylene certified reference materials in the range 98.7 ± 4.5% (95% confidence level). Copyright © 2011 Elsevier B.V. All rights reserved.

Mercury determination in non- and biodegradable materials by cold vapor capacitively coupled plasma microtorch atomic emission spectrometry

International Nuclear Information System (INIS)

Frentiu, Tiberiu; Mihaltan, Alin I.; Ponta, Michaela; Darvasi, Eugen; Frentiu, Maria; Cordos, Emil

2011-01-01

Highlights: → Use of a miniaturized analytical system with microtorch plasma for Hg determination. → Determination of Hg in non- and biodegradable materials using cold vapor generation. → Figures of merit and advantages of the miniaturized system for Hg determination. - Abstract: A new analytical system consisting of a low power capacitively coupled plasma microtorch (20 W, 13.56 MHz, 150 ml min -1 Ar) and a microspectrometer was investigated for the Hg determination in non- and biodegradable materials by cold-vapor generation, using SnCl 2 reductant, and atomic emission spectrometry. The investigated miniaturized system was used for Hg determination in recyclable plastics from electronic equipments and biodegradable materials (shopping bags of 98% biodegradable polyethylene and corn starch) with the advantages of easy operation and low analysis costs. Samples were mineralized in HNO 3 -H 2 SO 4 mixture in a high-pressure microwave system. The detection limits of 0.05 ng ml -1 or 0.08 μg g -1 in solid sample were compared with those reported for other analytical systems. The method precision was 1.5-9.4% for Hg levels of 1.37-13.9 mg kg -1 , while recovery in two polyethylene certified reference materials in the range 98.7 ± 4.5% (95% confidence level).

Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

Science.gov (United States)

Zhang, Duo; Li, Jiahua; Ding, Chunling; Yang, Xiaoxue

2012-05-01

The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission.

Atomic emission and atomic fluorescence spectroscopy in the direct current plasma

International Nuclear Information System (INIS)

Hendrick, M.S.

1985-01-01

The Direct Current Plasma (DCP) was investigated as a source for Atomic Emission (AE) and Atomic Fluorescence Spectrometry (AFS). The DCP was optimized for AE analyses using simplex optimization and Box-Behnken partial factorial experimental design, varying argon flows, and plasma position. Results were compared with a univariate search carried out in the region of the simplex optimum. Canonical analysis demonstrated that no true optimum exists for sensitivity, precision, or drift. A stationary ridge, where combinations of conditions gave comparable instrumental responses, was found. The DCP as an excitation source for AFS in a flame was used for diagnostic studies of the DCP. Moving the aerosol introduction tube behind the DCP with respect to the flame improved the characteristics of the DCP as a narrow line source, although self-absorption was observed at high concentrations of metal salt solutions in the DCP. Detection limits for Cd, Co, Cr, Cu, Fe, Mg, Mn, Zn, and Ni were in the low ng/mL region. Theoretical expressions for scatter correction with a two-line technique were derived, although no correction was necessary to achieve accurate results for standard reference materials

Nuclear and nuclear related analytical methods applied in environmental research

International Nuclear Information System (INIS)

Popescu, Ion V.; Gheboianu, Anca; Bancuta, Iulian; Cimpoca, G. V; Stihi, Claudia; Radulescu, Cristiana; Oros Calin; Frontasyeva, Marina; Petre, Marian; Dulama, Ioana; Vlaicu, G.

2010-01-01

Nuclear Analytical Methods can be used for research activities on environmental studies like water quality assessment, pesticide residues, global climatic change (transboundary), pollution and remediation. Heavy metal pollution is a problem associated with areas of intensive industrial activity. In this work the moss bio monitoring technique was employed to study the atmospheric deposition in Dambovita County Romania. Also, there were used complementary nuclear and atomic analytical methods: Neutron Activation Analysis (NAA), Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). These high sensitivity analysis methods were used to determine the chemical composition of some samples of mosses placed in different areas with different pollution industrial sources. The concentrations of Cr, Fe, Mn, Ni and Zn were determined. The concentration of Fe from the same samples was determined using all these methods and we obtained a very good agreement, in statistical limits, which demonstrate the capability of these analytical methods to be applied on a large spectrum of environmental samples with the same results. (authors)

Atomic carbon emission from photodissociation of CO2. [planetary atmospheric chemistry

Science.gov (United States)

Wu, C. Y. R.; Phillips, E.; Lee, L. C.; Judge, D. L.

1978-01-01

Atomic carbon fluorescence, C I 1561, 1657, and 1931 A, has been observed from photodissociation of CO2, and the production cross sections have been measured. A line emission source provided the primary photons at wavelengths from threshold to 420 A. The present results suggest that the excited carbon atoms are produced by total dissociation of CO2 into three atoms. The cross sections for producing the O I 1304-A fluorescence through photodissociation of CO2 are found to be less than 0.01 Mb in the wavelength region from 420 to 835 A. The present data have implications with respect to photochemical processes in the atmospheres of Mars and Venus.

Micro-Crater Laser Induced Breakdown Spectroscopy--an Analytical approach in metals samples

Energy Technology Data Exchange (ETDEWEB)

Piscitelli, Vincent [UCV- Laboratorio de Espectroscopia Laser, Caracas (Venezuela); Lawrence Berkeley National laboratory, Berkeley, US (United States); Gonzalez, Jhanis; Xianglei, Mao; Russo, Richard [Lawrence Berkeley National laboratory, Berkeley, US (United States); Fernandez, Alberto [UCV- Laboratorio de Espectroscopia Laser, Caracas (Venezuela)

2008-04-15

The laser ablation has been increasing its popularity like as technique of chemical analysis. This is due to its great potentiality in the analysis of solid samples. On the way to contributing to the development of the technique, we in this work studied the laser induced breakdown spectroscopy (LIBS) in conditions of micro ablation for future studies of coverings and micro crates analysis. Craters between 2 and 7 micrometers of diameter were made using an Nd-YAG nanosecond laser in their fundamental emission of 1064 nm. In order to create these craters we use an objective lens of long distance work and 0.45 of numerical aperture. The atomic emission versus the energy of the laser and its effect on the size of craters was study. We found that below 3 micrometers although there was evidence of material removal by the formation of a crater, it was no detectable atomic emission for our instruments. In order to try to understand this, curves of size of crater versus plasma temperature using the Boltzmann distribution graphs taking the Copper emission lines in the visible region were made. In addition calibration curves for Copper and aluminum were made in two different matrices; one of it was a Cu/Zn alloy and the other a Zinc Matrix. The atomic lines Cu I (521.78 nm) and Al I (396.15 nm) was used. From the Calibration curve the analytical limit of detection and other analytical parameters were obtained.

Toward improved understanding and control in analytical atomic spectrometry

Science.gov (United States)

Hieftje, Gary M.

1989-01-01

As with most papers which attempt to predict the future, this treatment will begin with a coverage of past events. It will be shown that progress in the field of analytical atomic spectrometry has occurred through a series of steps which involve the addition of new techniques and the occasional displacement of established ones. Because it is difficult or impossible to presage true breakthroughs, this manuscript will focus on how such existing methods can be modified or improved to greatest advantage. The thesis will be that rational improvement can be accomplished most effectively by understanding fundamentally the nature of an instrumental system, a measurement process, and a spectrometric technique. In turn, this enhanced understanding can lead to closer control, from which can spring improved performance. Areas where understanding is now lacking and where control is most greatly needed will be identified and a possible scheme for implementing control procedures will be outlined. As we draw toward the new millennium, these novel procedures seem particularly appealing; new high-speed computers, the availability of expert systems, and our enhanced understanding of atomic spectrometric events combine to make future prospects extremely bright.

Comparison in the analytical performance between krypton and argon glow discharge plasmas as the excitation source for atomic emission spectrometry.

Science.gov (United States)

Wagatsuma, Kazuaki

2009-04-01

The emission characteristics of ionic lines of nickel, cobalt, and vanadium were investigated when argon or krypton was employed as the plasma gas in glow discharge optical emission spectrometry. A dc Grimm-style lamp was employed as the excitation source. Detection limits of the ionic lines in each iron-matrix alloy sample were compared between the krypton and the argon plasmas. Particular intense ionic lines were observed in the emission spectra as a function of the discharge gas (krypton or argon), such as the Co II 258.033 nm for krypton and the Co II 231.707 nm for argon. The explanation for this is that collisions with the plasma gases dominantly populate particular excited levels of cobalt ion, which can receive the internal energy from each gas ion selectively, for example, the 3d(7)4p (3)G(5) (6.0201 eV) for krypton and the 3d(7)4p (3)G(4) (8.0779 eV) for argon. In the determination of nickel as well as cobalt in iron-matrix samples, more sensitive ionic lines could be found in the krypton plasma rather than the argon plasma. Detection limits in the krypton plasma were 0.0039 mass% Ni for the Ni II 230.299-nm line and 0.002 mass% Co for the Co II 258.033-nm line. However, in the determination of vanadium, the argon plasma had better analytical performance, giving a detection limit of 0.0023 mass% V for the V II 309.310-nm line.

Measurement of Apparent Temperature in Post-Detonation Fireballs Using Atomic Emission Spectroscopy

Science.gov (United States)

2011-02-01

thermometric species into burners.3,12 Interestingly, Wilkin- son et al.6 have recently observed Al atomic emission lines in the spectrum of aluminum...candidate thermometric species must produce several strong emission lines in the spectrum that originate from different upper energy levels in order to...allow the populations of the associated states to be determined. Barium nitrate was chosen as a thermometric impurity for the current work since Ba

Analytical Solutions of Temporal Evolution of Populations in Optically-Pumped Atoms with Circularly Polarized Light

Directory of Open Access Journals (Sweden)

Heung-Ryoul Noh

2016-03-01

Full Text Available We present an analytical calculation of temporal evolution of populations for optically pumped atoms under the influence of weak, circularly polarized light. The differential equations for the populations of magnetic sublevels in the excited state, derived from rate equations, are expressed in the form of inhomogeneous second-order differential equations with constant coefficients. We present a general method of analytically solving these differential equations, and obtain explicit analytical forms of the populations of the ground state at the lowest order in the saturation parameter. The obtained populations can be used to calculate lineshapes in various laser spectroscopies, considering transit time relaxation.

Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

Science.gov (United States)

Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

1987-01-01

Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

Time-resolved X-ray scattering by electronic wave packets: analytic solutions to the hydrogen atom

DEFF Research Database (Denmark)

Simmermacher, Mats; Henriksen, Niels Engholm; Møller, Klaus Braagaard

2017-01-01

Modern pulsed X-ray sources permit time-dependent measurements of dynamical changes in atoms and molecules via non-resonant scattering. The planning, analysis, and interpretation of such experiments, however, require a firm and elaborated theoretical framework. This paper provides a detailed...... description of time-resolved X-ray scattering by non-stationary electronic wave packets in atomic systems. A consistent application of the Waller-Hartree approximation is discussed and different contributions to the total differential scattering signal are identified and interpreted. Moreover......, it is demonstrated how the scattering signal of wave packets in the hydrogen atom can be expressed analytically. This permits simulations without numerical integration and establishes a benchmark for both efficiency and accuracy. Based on that, scattering patterns of an exemplary wave packet in the hydrogen atom...

Atomic hydrogen determination in medium-pressure microwave discharge hydrogen plasmas via emission actinometry

International Nuclear Information System (INIS)

Geng Zicai; Xu Yong; Yang Xuefeng; Wang Weiguo; Zhu Aimin

2005-01-01

Atomic hydrogen plays an important role in the chemical vapour deposition of functional materials, plasma etching and new approaches to the chemical synthesis of hydrogen-containing compounds. This work reports experimental determinations of atomic hydrogen in microwave discharge hydrogen plasmas formed from the TM 01 microwave mode in an ASTeX-type reactor, via optical emission spectroscopy using Ar as an actinometer. The relative intensities of the H atom Balmer lines and Ar-750.4 nm emissions as functions of input power and gas pressure have been investigated. At an input microwave power density of 13.5 W cm -3 , the approximate hydrogen dissociation fractions calculated from electron-impact excitation and quenching cross sections in the literature, decreased from ∼0.08 to ∼0.03 as the gas pressure was increased from 5 to 25 Torr. The influences of the above cross sections, and the electron and gas temperatures of the plasmas on the determination of the hydrogen dissociation fraction data have been discussed

Spatial Dependent Spontaneous Emission of an Atom in a Semi-Infinite Waveguide of Rectangular Cross Section

Science.gov (United States)

Song, Hai-Xi; Sun, Xiao-Qi; Lu, Jing; Zhou, Lan

2018-01-01

We study a quantum electrodynamics (QED) system made of a two-level atom and a semi-infinite rectangular waveguide, which behaves as a perfect mirror in one end. The spatial dependence of the atomic spontaneous emission has been included in the coupling strength relevant to the eigenmodes of the waveguide. The role of retardation is studied for the atomic transition frequency far away from the cutoff frequencies. The atom-mirror distance introduces different phases and retardation times into the dynamics of the atom interacting resonantly with the corresponding transverse modes. It is found that the upper state population decreases from its initial as long as the atom-mirror distance does not vanish, and is lowered and lowered when more and more transverse modes are resonant with the atom. The atomic spontaneous emission can be either suppressed or enhanced by adjusting the atomic location for short retardation time. There are partial revivals and collapses due to the photon reabsorbed and re-emitted by the atom for long retardation time. Supported by National Natural Science Foundation of China under Grant Nos. 11374095, 11422540, 11434011, and 11575058, National Fundamental Research Program of China (the 973 Program) under Grant No. 2012CB922103, and Hunan Provincial Natural Science Foundation of China under Grant No. 11JJ7001

Pyrolysis gas chromatographic atomic emission detection for sediments, coals and other petrochemical precursors

Energy Technology Data Exchange (ETDEWEB)

Seeley, J.A.; Zeng, Y.D.; Uden, P.C.; Eglinton, T.I.; Ericson, I. (Massachusetts University, Amherst, MA (USA). Dept. of Chemistry)

1992-09-01

On-line flash pyrolysis coupled to a capillary gas chromatograph for the characterization of marine sediments, coals and other heterogeneous solid samples is described. A helium microwave-induced plasma is used for chromatographic detection by atomic emission spectrometry. Simultaneous multi-element detection is achieved with a photodiode array detector. The optical path of the gas chromatographic atomic emission detector is purged with helium, allowing simultaneous, sensitive detection of atomic emission from sulfur 181 nm, phosphorous 186 nm, arsenic 189 nm, selenium 196 nm and carbon 193 nm. Several sediment and coal samples have been analysed for their carbon, nitrogen, sulfur, oxygen, phosphorous, arsenic and selenium content. Qualitative information indicating the occurrence and distribution of these elements in the samples can be used to gauge the relative stage of diagenetic evolution of the samples and provide information on their depositional environment. In some instances the chromatographic behaviour of the compounds produced upon pyrolysis is improved through on-line alkylation. This on-line derivatization is achieved by adding liquid reagents to the pyrolysis probe or by adding liquid reagents to the pyrolysis probe or by adding solid reagents either to the solid sample or by packing the reagent in the injection port of the chromatograph.

First-principles dynamics treatment of light emission in collisions between alkali-metal atom and noble-gas atom collisions at 10keV

Science.gov (United States)

Pacheco, Alexander B.; Reyes, Andrés; Micha, David A.

2006-12-01

Collision-induced light emission during the interaction of an alkali-metal atom and a noble-gas atom is treated within a first-principles, or direct, dynamics approach that calculates a time-dependent electric dipole for the whole system, and spectral emission cross sections from its Fourier transform. These cross sections are very sensitive to excited diatomic potentials and a source of information on their shape. The coupling between electronic transitions and nuclear motions is treated with atomic pseudopotentials and an electronic density matrix coupled to trajectories for the nuclei. A recently implemented pseudopotential parametrization scheme is used here for the ground and excited states of the LiHe system, and to calculate state-to-state dipole moments. To verify the accuracy of our new parameters, we recalculate the integral cross sections for the LiHe system in the keV energy regime and obtain agreement with other results from theory and experiment. We further present results for the emission spectrum from 10keV Li(2s)+He collisions, and compare them to experimental values available in the region of light emitted at 300-900nm .

Mercury determination in non- and biodegradable materials by cold vapor capacitively coupled plasma microtorch atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Frentiu, Tiberiu, E-mail: ftibi@chem.ubbcluj.ro [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Mihaltan, Alin I., E-mail: alinblaj2005@yahoo.com [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Ponta, Michaela, E-mail: mponta@chem.ubbcluj.ro [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Darvasi, Eugen, E-mail: edarvasi@chem.ubbcluj.ro [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Frentiu, Maria, E-mail: frentiu.maria@yahoo.com [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Cordos, Emil, E-mail: emilcordos@gmail.com [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania)

2011-10-15

Highlights: {yields} Use of a miniaturized analytical system with microtorch plasma for Hg determination. {yields} Determination of Hg in non- and biodegradable materials using cold vapor generation. {yields} Figures of merit and advantages of the miniaturized system for Hg determination. - Abstract: A new analytical system consisting of a low power capacitively coupled plasma microtorch (20 W, 13.56 MHz, 150 ml min{sup -1} Ar) and a microspectrometer was investigated for the Hg determination in non- and biodegradable materials by cold-vapor generation, using SnCl{sub 2} reductant, and atomic emission spectrometry. The investigated miniaturized system was used for Hg determination in recyclable plastics from electronic equipments and biodegradable materials (shopping bags of 98% biodegradable polyethylene and corn starch) with the advantages of easy operation and low analysis costs. Samples were mineralized in HNO{sub 3}-H{sub 2}SO{sub 4} mixture in a high-pressure microwave system. The detection limits of 0.05 ng ml{sup -1} or 0.08 {mu}g g{sup -1} in solid sample were compared with those reported for other analytical systems. The method precision was 1.5-9.4% for Hg levels of 1.37-13.9 mg kg{sup -1}, while recovery in two polyethylene certified reference materials in the range 98.7 {+-} 4.5% (95% confidence level).

Atomic emission spectroscopy for the on-line monitoring of incineration processes

NARCIS (Netherlands)

Timmermans, E.A.H.; de Groote, F.P.J.; Jonkers, J.; Gamero, A.; Sola, A.; Mullen, van der J.J.A.M.

2003-01-01

A diagnostic measurement system based on atomic emission spectroscopy has been developed for the purpose of on-line monitoring of hazardous elements in industrial combustion gases. The aim was to construct a setup with a high durability for rough and variable experimental conditions, e.g. a strongly

Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

International Nuclear Information System (INIS)

Marschner, Karel; Musil, Stanislav; Dědina, Jiří

2015-01-01

A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH 4 in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l −1 and 1.0 ng l −1 , respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l −1

Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

Energy Technology Data Exchange (ETDEWEB)

Marschner, Karel, E-mail: karel.marschner@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 8, 128 43 Prague (Czech Republic); Musil, Stanislav; Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

2015-07-01

A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH{sub 4} in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l{sup −1} and 1.0 ng l{sup −1}, respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l{sup −1}.

Laser-excited atomic fluorescence spectrometry in a pressure-controlled electrothermal atomizer.

Science.gov (United States)

Lonardo, R F; Yuzefovsky, A I; Irwin, R L; Michel, R G

1996-02-01

A theoretical model was developed to describe the loss of analyte atoms in graphite furnaces during atomization. The model was based on two functions, one that described the supply of analyte by vaporization, and another that described the removal of the analyte by diffusion. Variation in working pressure was shown to affect the competition between these two processes. Optimal atomization efficiency was predicted to occur at a pressure where the supply of the analyte was maximized, and gas phase interactions between the analyte and matrix were minimized. Experiments to test the model included the direct determination of phosphorus and tellurium in nickel alloys and of cobalt in glass. In all cases, reduction in working pressure from atmospheric pressure to 7 Pa decreased sensitivity by 2 orders of magnitude, but improved temporal peak shape. For the atomization of tellurium directly from a solid nickel alloy, and the atomization of cobalt from an aqueous solution, no change in sensitivity was observed as the working pressure was reduced from atmospheric pressure to approximately 70 kPa. If a reduction in working pressure affected only the diffusion of the analyte, poorer sensitivity should have been obtained. Only a commensurate increase in analyte vaporization could account for maintained sensitivity at lower working pressures. Overall, analyte vaporization was not dramatically improved at reduced working pressures, and maximum atomization efficiency was found to occur near atmospheric pressure.

Emission and electron transitions in an atom interacting with an ultrashort electromagnetic pulse

International Nuclear Information System (INIS)

Matveev, V.I.

2003-01-01

Electron transitions and emission of an atom interacting with a spatially inhomogeneous ultrashort electromagnetic pulse are considered. The excitation and ionization probabilities are obtained as well as the spectra and cross sections of the reemission of such a pulse by atoms. By way of an example, one- and two-electron inelastic processes accompanying the interaction of ultrashort pulses with hydrogen- and helium-like atoms are considered. The developed technique makes it possible to take into account exactly the spatial nonuniformity of the ultrashort pulse field and photon momenta in the course of reemission

Gas chromatography of organic microcontaminants using atomic emission and mass spectrometric detection combined in one instrument (GC-AED/MS)

NARCIS (Netherlands)

Mol, H.G.J.; Hankemeier, T.; Brinkman, U.A.T.

1999-01-01

This study describes the coupling of an atomic-emission detector and mass-spectrometric detector to a single gas chromatograph. Splitting of the column effluent enables simultaneous detection by atomic-emission detection (AED) and mass spectrometry (MS) and yields a powerful system for the target

Abstracts of the 1. Brazilian Meeting on Analytical Chemistry

International Nuclear Information System (INIS)

Curtius, A.J.

1982-01-01

Abstracts from experimental studies on analytical chemistry are presented. Several techniques have been used, such as: neutron activation analysis, potentiometry, optical emission spectroscopy, alpha and gamma spectroscopy, atomic absorption spectrophotometry, radiometric analysis, fission track detection, complexometry and others. Samples analysed are of various kinds: environmental materials (soil, water, air), rocks, coal, lanthanide complexes, polycarbonates and synthetic quartz. (C.L.B.) [pt

Secondary electron emission from Au by medium energy atomic and molecular ions

CERN Document Server

Itoh, A; Obata, F; Hamamoto, Y; Yogo, A

2002-01-01

Number distributions of secondary electrons emitted from a Au metal surface have been measured for atomic and molecular ions of H sup + , He sup + , C sup + , N sup + , O sup + , H sup + sub 2 , H sup + sub 3 , HeH sup + , CO sup + and O sup + sub 2 in the energy range 0.3-2.0 MeV. The emission statistics obtained are described fairly well by a Polya function. The Polya parameter b, determining the distribution shape, is found to decrease monotonously with increasing emission yield gamma, revealing a surprising relationship of b gamma approx 1 over the different projectile species and impact energies. This finding supports certainly the electron cascading model. Also we find a strong negative molecular effect for heavier molecular ions, showing a significant reduction of gamma compared to the estimated values using constituent atomic projectile data.

Optimization and development of the instrumental parameters for a method of multielemental analysis through atomic spectroscopy emission, for the determination of My, Fe Mn and Cr

International Nuclear Information System (INIS)

Lanzoni Vindas, E.

1998-01-01

This study optimized the instrumental parameters of a method of multielemental (sequential) analysis, through atomic emission, for the determination of My, Fe,Mn and Cr. It used the factorial design at two levels and the method of Simplex optimization, that permitted the determination of the four cations under the same instrumental conditions. The author studied an analytic system, in which the conditions were not lineal between instrumental answers and the concentration, having to make adjustment of the calibration curves in homocedastic and heterocedastic conditions. (S. Grainger)

New analytical treatment for a kind of two dimensional integrals in ion-atom collisions

International Nuclear Information System (INIS)

Yang Qifeng; Kuang Yurang

1994-01-01

A kind of two-dimensional integrals, separated from two-center matrix elements in ion-atom collisions, is analytically integrated by introducing the Laplace transform into the integrals and expressed by the modified Bessel functions. The traditional Feynman transform is very complicated for this kind of more general integrals related to the excited state capture

Analysis of bauxite by inductively coupled plasma-atomic emission spectroscopy

Science.gov (United States)

Barnes, Ramon M.; Mahanti, Himansu S.

Methods are described for the analysis of bauxite by inductively coupled plasma (ICP) emission spectroscopy. Bauxite samples were dissolved either in HCl, HNO 3, and HF at 160°C in all-PTFE bomb or fused with NaOH. Spectral lines were selected after examination of experimental wavelength scans at each potential analyte wavelength. Limits of detection, background equivalent concentration, and analytical figures of merit were established. The accuracy of the method was confirmed by determining 17 elements in NBS-SRM bauxite samples. Silicon in HF solutions was analyzed using a modified ICP torch with a graphite injector tube, an inert nebulizer using PTFE capillary tubes, and a PTFE spray chamber.

Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium

International Nuclear Information System (INIS)

Li Jiahua; Liu Jibing; Qi Chunchao; Chen Aixi

2006-01-01

We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. Rev. A 73, 033811 (2006)], since no rigorous conditions are required

Ab-initio modeling of an iron laser-induced plasma: Comparison between theoretical and experimental atomic emission spectra

International Nuclear Information System (INIS)

Colgan, J.; Judge, E.J.; Kilcrease, D.P.; Barefield, J.E.

2014-01-01

We report on efforts to model the Fe emission spectrum generated from laser-induced breakdown spectroscopy (LIBS) measurements on samples of pure iron oxide (Fe 2 O 3 ). Our modeling efforts consist of several components. We begin with ab-initio atomic structure calculations performed by solving the Hartree–Fock equations for the neutral and singly ionized stages of Fe. Our energy levels are then adjusted to their experimentally known values. The atomic transition probabilities and atomic collision quantities are also computed in an ab-initio manner. We perform LTE or non-LTE calculations that generate level populations and, subsequently, an emission spectrum for the iron plasma for a range of electron temperatures and electron densities. Such calculations are then compared to the experimental spectrum. We regard our work as a preliminary modeling effort that ultimately strives towards the modeling of emission spectra from even more complex samples where less atomic data are available. - Highlights: • LIBS plasma of iron oxide • Ab-initio theoretical Modeling • Discussion of LTE versus non-LTE criteria and assessment • Boltzmann plots for Fe—determination of when LTE is a valid assumption • Emission spectra for Fe—comparison of theoretical modeling and measurement: good agreement obtained

Halogenated salicylaldehyde azines: The heavy atom effect on aggregation-induced emission enhancement properties

International Nuclear Information System (INIS)

Chen, Xiao-tong; Tong, Ai-jun

2014-01-01

This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. For this purpose, a series of halogenated salicylaldehyde azine derivatives, namely, chloro-salicylaldehyde azine (1), bromo-salicylaldehyde azine (2) and iodo-salicylaldehyde azine (3) are synthesized. 1 and 2 display typical AIEE characteristics of salicylaldehyde azine compounds; whereas for the iodo-substituent in 3, is found to be effective “external” heavy atom quenchers to salicylaldehyde azine fluorescence in aggregated state. Based on its weak fluorescence in aggregated state and relative strong fluorescence in dispersed state, 3 can also be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction. -- Highlights: • This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. • Chloro- and bromo-salicylaldehyde display typical AIEE properties of salicylaldehyde azine, whereas the iodo-substitute quenches AIEE in aggregated state. • Iodo-salicylaldehyde can be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction

Time-dependent first-principles study of angle-resolved secondary electron emission from atomic sheets

Science.gov (United States)

Ueda, Yoshihiro; Suzuki, Yasumitsu; Watanabe, Kazuyuki

2018-02-01

Angle-resolved secondary electron emission (ARSEE) spectra were analyzed for two-dimensional atomic sheets using a time-dependent first-principles simulation of electron scattering. We demonstrate that the calculated ARSEE spectra capture the unoccupied band structure of the atomic sheets. The excitation dynamics that lead to SEE have also been revealed by the time-dependent Kohn-Sham decomposition scheme. In the present study, the mechanism for the experimentally observed ARSEE from atomic sheets is elucidated with respect to both energetics and the dynamical aspects of SEE.

Curve resolution and figures of merit estimation for determination of trace elements in geological materials by inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Lorber, A.; Harel, A.; Goldbart, Z.; Brenner, I.B.

1987-01-01

In geochemical analysis using inductively coupled plasma atomic emission spectrometry (ICP-AES), spectral interferences and background enhancement in response to sample concomitants are the main cause of deterioration of the limit of detection (LOD) and inaccuracy of the determination at the trace and minor element levels. In this account, the authors describe the chemometric procedure of curve resolution for compensating for these sources of error. A newly developed method for calculating figures of merit is used to evaluate the correction procedure, test the statistical significance of the determined concentration, and determine LODs for each sample. The technique involves scanning the vicinity of the spectral line of the analyte. With prior knowledge of potential spectral interferences, deconvolution of the overlapped response is possible. Analytical data for a wide range of geological standard reference materials demonstrate the effectiveness of the chemometric techniques. Separation of 0.002 nm spectral coincidence, employing a 0.02 nm resolution spectrometer, is demonstrated

Fourier transform infrared emission spectra of atomic rubidium: g- and h-states

Czech Academy of Sciences Publication Activity Database

Civiš, Svatopluk; Ferus, Martin; Kubelík, Petr; Chernov, Vladislav E.; Zanozina, Ekaterina M.

2012-01-01

Roč. 45, č. 17 (2012), s. 175002 ISSN 0953-4075 R&D Projects: GA AV ČR IAAX00100903 Institutional support: RVO:61388955 Keywords : Fourier transform infrared emission spectra * atomic rubidium * physical chemistry Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.031, year: 2012

Optical emission studies of atomic and ionic species in the ionized sputter-deposition process of magnesium oxide thin films

International Nuclear Information System (INIS)

Matsuda, Y.; Koyama, Y.; Iwaya, M.; Shinohara, M.; Fujiyama, H.

2005-01-01

Planar magnetron (PM) power and ICP-RF power dependences of the optical emission intensities of excited atomic and ionic species in the reactive ionized sputter-deposition of magnesium oxide (MgO) thin films were investigated. With the increase in PM power at constant ICP-RF power, Mg I emission intensity increased and Ar I emission intensity gradually decreased. With the increase in ICP-RF power at constant PM power, the Mg I emission intensity increased at lower ICP-RF power and then gradually decreased at higher ICP-RF power; on the contrary, Ar I emission intensity monotonically increased. Emission intensity of atomic oxygen was negligibly small compared with those of Mg I and Ar I under the metallic sputtering mode condition

Automated installation for atomic emission determination of gold, silver and platinum group metals

International Nuclear Information System (INIS)

Zayakina, S.B.; Anoshin, G.N.; Gerasimov, P.A.; Smirnov, A.V.

1999-01-01

An automated installation for the direct atomic emission determination of silver, gold and platinum-group metals (Ru) in geological and geochemical materials with software for automated data acquisition and handling is designed and developed. The installation consists of a DFS-458 diffraction spectrograph, a MAES-10 multichannel analyzer of emission spectra, and a dual-jet plasmatron. A library of spectral lines of almost all elements excited in the dual-jet plasmatron is complied [ru

Weak-field asymptotic theory of tunneling ionization: benchmark analytical results for two-electron atoms

International Nuclear Information System (INIS)

Trinh, Vinh H; Morishita, Toru; Tolstikhin, Oleg I

2015-01-01

The recently developed many-electron weak-field asymptotic theory of tunneling ionization of atoms and molecules in an external static electric field (Tolstikhin et al 2014, Phys. Rev. A 89, 013421) is extended to the first-order terms in the asymptotic expansion in field. To highlight the results, here we present a simple analytical formula giving the rate of tunneling ionization of two-electron atoms H − and He. Comparison with fully-correlated ab initio calculations available for these systems shows that the first-order theory works quantitatively in a wide range of fields up to the onset of over-the-barrier ionization and hence is expected to find numerous applications in strong-field physics. (fast track communication)

Double differential distributions of electron emission in ion-atom and electron-atom collisions using an electron spectrometer

International Nuclear Information System (INIS)

Misra, Deepankar; Thulasiram, K.V.; Fernandes, W.; Kelkar, Aditya H.; Kadhane, U.; Kumar, Ajay; Singh, Yeshpal; Gulyas, L.; Tribedi, Lokesh C.

2009-01-01

We study electron emission from atoms and molecules in collisions with fast electrons and heavy ions (C 6+ ). The soft collision electrons (SE), two center electron emission (TCEE), the binary encounter (BE) events and the KLL Auger lines along with the elastically scattered peaks (in electron collisions) are studied using a hemispherical electrostatic electron analyzer. The details of the measurements along with description of the spectrometer and data acquisition system are given. The angular distributions of the low energy (few eV) electrons in soft collisions and the binary encounter electrons at keV energies are compared with quantum mechanical models based on the first Born (B1) and the continuum distorted wave-Eikonal initial state approximation (CDW-EIS).

Continuous atom laser with Bose-Einstein condensates involving three-body interactions

Energy Technology Data Exchange (ETDEWEB)

Carpentier, A V; Michinel, H; Novoa, D [Area de Optica, Facultade de Ciencias de Ourense, Universidade de Vigo, As Lagoas s/n, Ourense, ES-32004 (Spain); Olivieri, D N, E-mail: avcarpentier@uvigo.e [Area de Linguaxes e sistemas informaticos, Escola Superior de EnxenerIa Informatica, Universidade de Vigo, As Lagoas s/n, Ourense, ES-32004 (Spain)

2010-05-28

We demonstrate, through numerical simulations, the emission of a coherent continuous matter wave of constant amplitude from a Bose-Einstein condensate in a shallow optical dipole trap. The process is achieved by spatial control of the variations of the scattering length along the trapping axis, including elastic three-body interactions due to dipole interactions. In our approach, the outcoupling mechanism is atomic interactions, and thus, the trap remains unaltered. We calculate analytically the parameters for the experimental implementation of this continuous wave atom laser.

Ultra fast atomic process in X-ray emission by inner-shell ionization

Energy Technology Data Exchange (ETDEWEB)

Moribayashi, Kengo; Sasaki, Akira [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Tajima, T

1998-03-01

An ultra-fast atomic process together with X-ray emission by inner-shell ionization using high intensity (10{sup 18} W/cm{sup 2}) short pulse (20fs) X-ray is studied. A new class of experiment is proposed and a useful pumping source is suggested. In this method, it is found that the gain value of X-ray laser amounts to larger than 1000(1/cm) with use of the density of 10{sup 22}/cm{sup 3} of carbon atom. Electron impact ionization effect and initial density effect as well as intensity of pumping source effect are also discussed. (author)

Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D.

2008-03-29

To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.

Use of gradient dilution to flag and overcome matrix interferences in axial-viewing inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Cheung, Yan; Schwartz, Andrew J.; Hieftje, Gary M.

2014-01-01

Despite the undisputed power of inductively coupled plasma-atomic emission spectrometry (ICP-AES), its users still face serious challenges in obtaining accurate analytical results. Matrix interference is perhaps the most important challenge. Dilution of a matrix-containing sample is a common practice to reduce matrix interference. However, determining the optimal dilution factor requires tedious and time-consuming offline sample preparation, since emission lines and the effect of matrix interferences are affected differently by the dilution. The current study exploits this difference by employing a high-performance liquid chromatography gradient pump prior to the nebulizer to perform on-line mixing of a sample solution and diluent. Linear gradient dilution is performed on both the calibration standard and the matrix-containing sample. By ratioing the signals from two emission lines (from the same or different elements) as a function of dilution factor, the analyst can not only identify the presence of a matrix interference, but also determine the optimal dilution factor needed to overcome the interference. A ratio that does not change with dilution signals the absence of a matrix interference, whereas a changing ratio indicates the presence of an interference. The point on the dilution profile where the ratio stabilizes indicates the optimal dilution factor to correct the interference. The current study was performed on axial-viewing ICP-AES with o-xylene as the solvent

Ultratrace determination of lead by hydride generation in-atomizer trapping atomic absorption spectrometry: Optimization of plumbane generation and analyte preconcentration in a quartz trap-and-atomizer device

Energy Technology Data Exchange (ETDEWEB)

Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz

2012-05-15

A compact trap-and-atomizer device and a preconcentration procedure based on hydride trapping in excess of oxygen over hydrogen in the collection step, both constructed and developed previously in our laboratory, were employed to optimize plumbane trapping in this device and to develop a routine method for ultratrace lead determination subsequently. The inherent advantage of this preconcentration approach is that 100% preconcentration efficiency for lead is reached in this device which has never been reported before using quartz or metal traps. Plumbane is completely retained in the trap-and-atomizer device at 290 Degree-Sign C in oxygen-rich atmosphere and trapped species are subsequently volatilized at 830 Degree-Sign C in hydrogen-rich atmosphere. Effect of relevant experimental parameters on plumbane trapping and lead volatilization are discussed, and possible trapping mechanisms are hypothesized. Plumbane trapping in the trap-and-atomizer device can be routinely used for lead determination at ultratrace levels reaching a detection limit of 0.21 ng ml{sup -1} Pb (30 s preconcentration, sample volume 2 ml). Further improvement of the detection limit is feasible by reducing the blank signal and increasing the trapping time. - Highlights: Black-Right-Pointing-Pointer In-atomizer trapping HG-AAS was optimized for Pb. Black-Right-Pointing-Pointer A compact quartz trap-and-atomizer device was employed. Black-Right-Pointing-Pointer Generation, preconcentration and atomization steps were investigated in detail. Black-Right-Pointing-Pointer 100% preconcentration efficiency for lead was reached. Black-Right-Pointing-Pointer Routine analytical method was developed for Pb determination (LOD of 0.2 ng ml{sup -1} Pb).

Models of the Dynamics of Spatially Separated Broadband Electromagnetic Fields Interacting with Resonant Atoms

Science.gov (United States)

Basharov, A. M.

2018-03-01

The Markov model of spontaneous emission of an atom localized in a spatial region with a broadband electromagnetic field with zero photon density is considered in the conditions of coupling of the electromagnetic field with the broadband field of a neighboring space. The evolution operator of the system and the kinetic equation for the atom are obtained. It is shown that the field coupling constant affects the rate of spontaneous emission of the atom, but is not manifested in the atomic frequency shift. The analytic expression for the radiative decay constant for the atom is found to be analogous in a certain sense to the expression for the decay constant for a singly excited localized ensemble of identical atoms in the conditions when the effect of stabilization of its excited state by the Stark interaction with the vacuum broadband electromagnetic field is manifested. The model is formulated based on quantum stochastic differential equations of the non- Wiener type and the generalized algebra of the Ito differential of quantum random processes.

Analysis of an atom laser based on the spatial control of the scattering length

International Nuclear Information System (INIS)

Carpentier, Alicia V.; Michinel, Humberto; Rodas-Verde, Maria I.; Perez-Garcia, Victor M.

2006-01-01

In this paper we analyze atom lasers based on the spatial modulation of the scattering length of a Bose-Einstein condensate. We demonstrate, through numerical simulations and approximate analytical methods, the controllable emission of matter-wave bursts and study the dependence of the process on the spatial shape of the scattering length along the axis of emission. We also study the role of an additional modulation of the scattering length in time

Atomic imaging by x-ray-fluorescence holography and electron-emission holography: A comparative theoretical study

International Nuclear Information System (INIS)

Len, P.M.; Thevuthasan, S.; Fadley, C.S.; Kaduwela, A.P.; Van Hove, M.A.

1994-01-01

We consider from a theoretical viewpoint the direct imaging of atoms at and near the surfaces of solids by both x-ray-fluorescence holography (XFH) and electron-emission holography (EEH). The more ideal nature of x-ray scattering makes XFH images superior to those in single-energy EEH. The overlap of real and twin features for pairs of atoms at ±a can cause their XFH or EEH atomic images to cancel for certain combinations of wave vector and |a|. The relative merits of XFH and EEH for structure studies are considered

Mass and emission spectrometry in the Analytical Chemistry Division of Oak Ridge National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Smith, D.H. (ed.)

1978-11-01

The capabilities of the Mass and Emission Spectrometry Section of the Analytical Chemistry Division of Oak Ridge National Laboratory are described. Many different areas of mass spectrometric expertise are represented in the section: gas analysis, high abundance sensitivity measurements, high- and low-resolution organic analyses, spark source trace constituent analysis, and ion microprobe analysis of surfaces. These capabilities are complemented by emission spectrometry. The instruments are described along with a few applications, some of which are unique.

Mass and emission spectrometry in the Analytical Chemistry Division of Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Smith, D.H.

1978-11-01

The capabilities of the Mass and Emission Spectrometry Section of the Analytical Chemistry Division of Oak Ridge National Laboratory are described. Many different areas of mass spectrometric expertise are represented in the section: gas analysis, high abundance sensitivity measurements, high- and low-resolution organic analyses, spark source trace constituent analysis, and ion microprobe analysis of surfaces. These capabilities are complemented by emission spectrometry. The instruments are described along with a few applications, some of which are unique

Comparative measurements of mineral elements in milk powders with laser-induced breakdown spectroscopy and inductively coupled plasma atomic emission spectroscopy.

Science.gov (United States)

Lei, W Q; El Haddad, J; Motto-Ros, V; Gilon-Delepine, N; Stankova, A; Ma, Q L; Bai, X S; Zheng, L J; Zeng, H P; Yu, J

2011-07-01

Mineral elements contained in commercially available milk powders, including seven infant formulae and one adult milk, were analyzed with inductively coupled plasma atomic emission spectrometry (ICP-AES) and laser-induced breakdown spectroscopy (LIBS). The purpose of this work was, through a direct comparison of the analytical results, to provide an assessment of the performance of LIBS, and especially of the procedure of calibration-free LIBS (CF-LIBS), to deal with organic compounds such as milk powders. In our experiments, the matrix effect was clearly observed affecting the analytical results each time laser ablation was employed for sampling. Such effect was in addition directly observed by determining the physical parameters of the plasmas induced on the different samples. The CF-LIBS procedure was implemented to deduce the concentrations of Mg and K with Ca as the internal reference element. Quantitative analytical results with CF-LIBS were validated with ICP-AES measurements and nominal concentrations specified for commercial milks. The obtained good results with the CF-LIBS procedure demonstrate its capacity to take into account the difference in physical parameters of the plasma in the calculation of the concentrations of mineral elements, which allows a significant reduction of the matrix effect related to laser ablation. We finally discuss the way to optimize the implementation of the CF-LIBS procedure for the analysis of mineral elements in organic materials.

Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

International Nuclear Information System (INIS)

Swaczyna, Paweł; Bzowski, Maciej

2017-01-01

Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10 6 times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

Modeling Emission of Heavy Energetic Neutral Atoms from the Heliosphere

Energy Technology Data Exchange (ETDEWEB)

Swaczyna, Paweł; Bzowski, Maciej, E-mail: pswaczyna@cbk.waw.pl [Space Research Centre of the Polish Academy of Sciences (CBK PAN), Bartycka 18A, 00-716 Warsaw (Poland)

2017-09-10

Observations of energetic neutral atoms (ENAs) are a fruitful tool for remote diagnosis of the plasma in the heliosphere and its vicinity. So far, instruments detecting ENAs from the heliosphere were configured for observations of hydrogen atoms. Here, we estimate emissions of ENAs of the heavy chemical elements helium, oxygen, nitrogen, and neon. A large portion of the heliospheric ENAs is created in the inner heliosheath from neutralized interstellar pick-up ions (PUIs). We modeled this process and calculated full-sky intensities of ENAs for energies 0.2–130 keV/nuc. We found that the largest fluxes among considered species are expected for helium, smaller for oxygen and nitrogen, and smallest for neon. The obtained intensities are 50–10{sup 6} times smaller than the hydrogen ENA intensities observed by IBEX . The detection of heavy ENAs will be possible if a future ENA detector is equipped with the capability to measure the masses of observed atoms. Because of different reaction cross-sections among the different species, observations of heavy ENAs can allow for a better understanding of global structure of the heliosphere as well as the transport and energization of PUIs in the heliosphere.

Position Dependent Spontaneous Emission Spectra of a Λ-Type Atomic System Embedded in a Defective Photonic Crystal

International Nuclear Information System (INIS)

Entezar, S. Roshan

2012-01-01

We investigate the position dependent spontaneous emission spectra of a Λ-type three-level atom with one transition coupled to the free vacuum reservoir and the other one coupled to a double-band photonic band gap reservoir with a defect mode in the band gap. It is shown that, for the atom at the defect location, we have a two-peak spectrum with a wide dark line due to the strong coupling between the atom and the defect mode. While, when the atom is far from the defect location (or in the absence of the defect mode), the spectrum has three peaks with two dark lines due to the coupling between the atom and the photonic band gap reservoir with the largest density of states near the band edges. On the other hand, we have a four-peak spectrum for the atom at the space in between. Moreover, the average spontaneous emission spectra of the atoms uniformly embedded in high dielectric or low dielectric regions are described. It is shown that the atoms embedded in high (low) dielectric regions far from the defect location, effectively couple to the modes of the lower (upper) photonic band. However, the atoms embedded in high dielectric or low dielectric regions at the defect location, are coupled mainly to the defect modes. While, the atoms uniformly embedded in high (low) dielectric regions with a normal distance from the defect location, are coupled to both of defect and lower (upper) photonic band modes. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Experimental evaluation of analyte excitation mechanisms in the inductively coupled plasma

International Nuclear Information System (INIS)

Lehn, Scott A.; Hieftje, Gary M.

2003-01-01

The inductively coupled plasma (ICP) is a justifiably popular source for atomic emission spectrometry. However, despite its popularity, the ICP is still only partially understood. Even the mechanisms of analyte excitation remain unclear; some energy levels are quite clearly populated by charge transfer while others might be populated by electron-ion recombination, by electron impact, or by Penning processes. Distinguishing among these alternatives is possible by means of a steady-state kinetics approach that examines correlations between the emission of a selected atom, ion, or level and the local number densities of species assumed to produce the excitation. In an earlier investigation, strong correlations were found between either calcium atom or ion emission and selected combinations of calcium atom or ion number densities and electron number densities in the plasma. However, all radially resolved data employed in the earlier study were produced from Abel inversion and from measurements that were crude by today's standards. Now, by means of tomographic imaging, laser-saturated atomic fluorescence, and Thomson and Rayleigh scattering, it is possible to measure the required radially resolved data without Abel inversion and with far greater fidelity. The correlations previously studied for calcium have been investigated with these more reliable data. Ion-electron recombination, either radiative or with argon as a third body, was determined to be the most likely excitation mechanism for calcium atom, while electron impact appeared to be the most important process to produce excite-state calcium ions. These results were consistent with the previous study. However, the present study suggests that collisional deactivation, rather than radiative decay, is the most likely mode of returning both calcium atoms and ions to the ground state

Analytical Chemistry Laboratory Progress Report for FY 1994

Energy Technology Data Exchange (ETDEWEB)

Green, D.W.; Boparai, A.S.; Bowers, D.L. [and others

1994-12-01

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1994 (October 1993 through September 1994). This annual report is the eleventh for the ACL and describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. The ACL also has a research program in analytical chemistry, conducts instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems. Some routine or standard analyses are done, but it is common for the Argonne programs to generate unique problems that require significant development of methods and adaption of techniques to obtain useful analytical data. The ACL has four technical groups -- Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis -- which together include about 45 technical staff members. Talents and interests of staff members cross the group lines, as do many projects within the ACL. The Chemical Analysis Group uses wet- chemical and instrumental methods for elemental, compositional, and isotopic determinations in solid, liquid, and gaseous samples and provides specialized analytical services. Major instruments in this group include an ion chromatograph (IC), an inductively coupled plasma/atomic emission spectrometer (ICP/AES), spectrophotometers, mass spectrometers (including gas-analysis and thermal-ionization mass spectrometers), emission spectrographs, autotitrators, sulfur and carbon determinators, and a kinetic phosphorescence uranium analyzer.

The impact of molecular emission in compositional depth profiling using Glow Discharge-Optical Emission Spectroscopy

International Nuclear Information System (INIS)

Bengtson, Arne

2008-01-01

The scope of this paper is to investigate and discuss how molecular emission can affect elemental analysis in glow discharge optical emission (GD-OES), particularly in compositional depth profiling (CDP) applications. Older work on molecular emission in glow discharges is briefly reviewed, and the nature of molecular emission spectra described. Work on the influence of hydrogen in the plasma, in particular elevated background due to a continuum spectrum, is discussed. More recent work from sputtering of polymers and other materials with a large content of light elements in a Grimm type source is reviewed, where substantial emission has been observed from several light diatomic molecules (CO, CH, OH, NH, C 2 ). It is discussed how the elevated backgrounds from such molecular emission can lead to significant analytical errors in the form of 'false' depth profile signals of several atomic analytical lines. Results from a recent investigation of molecular emission spectra from mixed gases in a Grimm type glow discharge are presented. An important observation is that dissociation and subsequent recombination processes occur, leading to formation of molecular species not present in the original plasma gas. Experimental work on depth profiling of a polymer coating and a thin silicate film, using a spectrometer equipped with channels for molecular emission lines, is presented. The results confirm that molecular emission gives rise to apparent depth profiles of elements not present in the sample. The possibilities to make adequate corrections for such molecular emission in CDP of organic coatings and very thin films are discussed

The impact of molecular emission in compositional depth profiling using Glow Discharge-Optical Emission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Bengtson, Arne [Corrosion and Metals Research Institute, Dr. Kristinas vaeg 48, Stockholm (Sweden)], E-mail: arne.bengtson@kimab.com

2008-09-15

The scope of this paper is to investigate and discuss how molecular emission can affect elemental analysis in glow discharge optical emission (GD-OES), particularly in compositional depth profiling (CDP) applications. Older work on molecular emission in glow discharges is briefly reviewed, and the nature of molecular emission spectra described. Work on the influence of hydrogen in the plasma, in particular elevated background due to a continuum spectrum, is discussed. More recent work from sputtering of polymers and other materials with a large content of light elements in a Grimm type source is reviewed, where substantial emission has been observed from several light diatomic molecules (CO, CH, OH, NH, C{sub 2}). It is discussed how the elevated backgrounds from such molecular emission can lead to significant analytical errors in the form of 'false' depth profile signals of several atomic analytical lines. Results from a recent investigation of molecular emission spectra from mixed gases in a Grimm type glow discharge are presented. An important observation is that dissociation and subsequent recombination processes occur, leading to formation of molecular species not present in the original plasma gas. Experimental work on depth profiling of a polymer coating and a thin silicate film, using a spectrometer equipped with channels for molecular emission lines, is presented. The results confirm that molecular emission gives rise to apparent depth profiles of elements not present in the sample. The possibilities to make adequate corrections for such molecular emission in CDP of organic coatings and very thin films are discussed.

Solid phase microextraction capillary gas chromatography combined with furnace atomization plasma emission spectrometry for speciation of mercury in fish tissues

International Nuclear Information System (INIS)

Grinberg, Patricia; Campos, Reinaldo C.; Mester, Zoltan; Sturgeon, Ralph E.

2003-01-01

The use of solid phase microextraction in conjunction with tandem gas chromatography-furnace atomization plasma emission spectrometry (SPME-GC-FAPES) was evaluated for the determination of methylmercury and inorganic mercury in fish tissue. Samples were digested with methanolic potassium hydroxide, derivatized with sodium tetraethylborate and extracted by SPME. After the SPME extraction, species were separated by GC and detected by FAPES. All experimental parameters were optimized for best separation and analytical response. A repeatability precision of typically 2% can be achieved with long-term (3 months) reproducibility precision of 4.3%. Certified Reference Materials DORM-2, DOLT-2 and TORT-2 from the National Research Council of Canada were analyzed to verify the accuracy of this technique. Detection limits of 1.5 ng g -1 for methylmercury and 0.7 ng g -1 for inorganic mercury in biological tissues were obtained

In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy

Science.gov (United States)

Braymen, Steven D.

1996-06-11

A method and apparatus for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization.

Atomic absorption spectrophotometry in perspective

International Nuclear Information System (INIS)

Soffiantini, V.

1981-01-01

Atomic absorption spectrophotometry is essentially an analytical technique used for quantitative trace metal analysis in a variety of materials. The speed and specificity of the technique is its greatest advantage over other analytical techniques. What atomic absorption spectrophotometry can and cannot do and its advantages and disadvantages are discussed, a summary of operating instructions are given, as well as a summary of analytical interferences. The applications of atomic absorption spectrophotometry are also shortly discussed

Low-frequency-field-induced spontaneous-emission interference in a two-level atom placed in an anisotropic photonic crystal

International Nuclear Information System (INIS)

Li Gaoxiang; Evers, Joerg; Keitel, Christoph H

2005-01-01

We investigate the spontaneous-emission properties of a two-level atom embedded in a three-dimensional anisotropic photonic crystal. In addition to the modified density of states, the atom is driven by a coherent intense low-frequency field (LFF), which creates additional multiphoton decay channels with the exchange of two low-frequency photons and one spontaneous photon during an atomic transition. Due to the low frequency of the applied field, the various transition pathways may interfere with each other and thus give rise to a modified system dynamics. We find that even if all the atomic (bare and induced) transition frequencies are in the conducting band of the photonic crystal, there still may exist a photon-atom bound state in coexistence with propagating modes. The system also allows us to generate narrow lines in the spontaneous-emission spectrum. This spectrum is a function of the distance of the observer from the atom due to the band gap in the photonic crystal. The system properties depend on three characteristic frequencies, which are influenced by quantum interference effects. Thus these results can be attributed to a combination of interference and band-gap effects

Combination of the ionic-to-atomic line intensity ratios from two test elements for the diagnostic of plasma temperature and electron number density in Inductively Coupled Plasma Atomic Emission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Tognoni, E. [Istituto per i Processi Chimico-Fisici, Area della Ricerca del Consiglio Nazionale delle Ricerche Via Moruzzi 1, 56124 Pisa (Italy)], E-mail: tognoni@ipcf.cnr.it; Hidalgo, M.; Canals, A. [Departamento de Quimica Analitica, Nutricion y Bromatologia. Universidad de Alicante. Apdo. 99, 03080, Alicante (Spain); Cristoforetti, G.; Legnaioli, S.; Salvetti, A.; Palleschi, V. [Istituto per i Processi Chimico-Fisici, Area della Ricerca del Consiglio Nazionale delle Ricerche Via Moruzzi 1, 56124 Pisa (Italy)

2007-05-15

In Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) spectrochemical analysis, the MgII(280.270 nm)/MgI(285.213 nm) ionic to atomic line intensity ratio is commonly used as a monitor of the robustness of operating conditions. This approach is based on the univocal relationship existing between intensity ratio and plasma temperature, for a pure argon atmospheric ICP in thermodynamic equilibrium. In a multi-elemental plasma in the lower temperature range, the measurement of the intensity ratio may not be sufficient to characterize temperature and electron density. In such a range, the correct relationship between intensity ratio and plasma temperature can be calculated only when the complete plasma composition is known. We propose the combination of the line intensity ratios of two test elements (double ratio) as an effective diagnostic tool for a multi-elemental low temperature LTE plasma of unknown composition. In particular, the variation of the double ratio allows us discriminating changes in the plasma temperature from changes in the electron density. Thus, the effects on plasma excitation and ionization possibly caused by introduction of different samples and matrices in non-robust conditions can be more accurately interpreted. The method is illustrated by the measurement of plasma temperature and electron density in a specific analytic case.

Charging induced emission of neutral atoms from NaCl nanocube corners

International Nuclear Information System (INIS)

Ceresoli, Davide; Zykova-Timan, Tatyana; Tosatti, Erio

2008-01-01

Detachment of neutral cations/anions from solid alkali halides can in principle be provoked by donating/subtracting electrons to the surface of alkali halide crystals, but generally constitutes a very endothermic process. However, the amount of energy required for emission is smaller for atoms located in less favorable positions, such as surface steps and kinks. For a corner ion in an alkali halide cube the binding is the weakest, so it should be easier to remove that atom, once it is neutralized. We carried out first principles density functional calculations and simulations of neutral and charged NaCl nanocubes, to establish the energetics of extraction of neutralized corner ions. Following hole donation (electron removal) we find that detachment of neutral Cl corner atoms will require a limited energy of about 0.8 eV. Conversely, following the donation of an excess electron to the cube, a neutral Na atom is extractable from the corner at the lower cost of about 0.6 eV. Since the cube electron affinity level (close to that a NaCl(100) surface state, which we also determine) is estimated to lie about 1.8 eV below vacuum, the overall energy balance upon donation to the nanocube of a zero-energy electron from vacuum will be exothermic. The atomic and electronic structure of the NaCl(100) surface, and of the nanocube Na and Cl corner vacancies are obtained and analyzed as a byproduct

Critical comparison of performances of inductively coupled plasma atomic emission spectrometry and neutron activation analysis for the determination of elements in human lungs

International Nuclear Information System (INIS)

Alimonti, A.; Coni, E.; Caroli, S.; Sabbioni, E.; Nicolaou, G.E.; Pietra, R.

1989-01-01

A study was carried out to assess the performance of inductively coupled plasma atomic emission spectrometry (ICP-AES) and neutron activation analysis (NAA) techniques for determining reference values for Al, Cd, Cr, Cu, Mg, Mn, V and Zn in human lungs of urban non-smoking subjects. Experimental data were subjected to the usual basic statistical tests to evaluate the respective merits of the two basically different analytical techniques. Both approaches, if used under carefully optimised experimental conditions, can yield reliable results affected only minimally by systematic and random errors. On the other hand, on a more routine basis, particular attention should be paid to elements such as Al, Cd and V which may pose some problems with both techniques. (author)

Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

NARCIS (Netherlands)

Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

1998-01-01

A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC

Method development for the determination of calcium, copper, magnesium, manganese, iron, potassium, phosphorus and zinc in different types of breads by microwave induced plasma-atomic emission spectrometry.

Science.gov (United States)

Ozbek, Nil; Akman, Suleyman

2016-06-01

A novel method was developed for the determination of calcium, magnesium, potassium, iron, copper, zinc, and manganese and phosphorous in various kinds of breads samples sold in Turkey by microwave plasma-atomic emission spectrometry (MIP-AES). Breads were dried at 100 °C for one day, ground thoroughly and then digested using nitric acid/hydrogen per oxide (3:1). The analytes in certified reference wheat flour and maize flour samples were determined in the uncertainty limits of the certified values as well as the analytes added to the mixture of ground bread and acid mixture prior to digestion were recovered quantitatively (>90%). Therefore, all determinations were made by linear calibration technique using aqueous standards. The LOD values for Ca, Cu, Fe, K, Mg, Mn, P and Zn were 13.1, 0.28, 4.47, 118, 1.10, 0.41, 7550 and 3.00 ng mL(-1), respectively. No spectral interference was detected at the working wavelengths of the analytes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Atomic emission lines in the near ultraviolet; hydrogen through krypton, section 2

Science.gov (United States)

Kelly, R. L.

1979-01-01

A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those lines which were actually observed in emission or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional lines up to 3500 Angstroms. Only lines of stripped atoms are reported; no molecular bands are included.

Atomic emission lines in the near ultraviolet; hydrogen through krypton, section 1

Science.gov (United States)

Kelly, R. L.

1979-01-01

A compilation of spectra from the first 36 elements was prepared from published literature available through October 1977. In most cases, only those lines which were actually observed in emission or absorption are listed. The wavelengths included range from 2000 Angstroms to 3200 Angstroms with some additional lines up to 3500 Angstroms. Only lines of stripped atoms are reported; no molecular bands are included.

Direct atomic-emission determination of tungsten in molybdenum oxide in dc arc

International Nuclear Information System (INIS)

Zolotareva, N.I.; Grazhulene, S.S.

2007-01-01

A method of direct atomic-emission determination of tungsten impurity in molybdenum trioxide of high purity in dc arc is presented. Chemically active additives of elementary sulfur and gallium oxide are used to optimize W evaporation rate and residence time in the arc plasma. The procedure is easy to use and provides the limit of W determination at a level of 2x10 -4 wt. % [ru

Analytical Model of the Nonlinear Dynamics of Cantilever Tip-Sample Surface Interactions for Various Acoustic-Atomic Force Microscopies

Science.gov (United States)

Cantrell, John H., Jr.; Cantrell, Sean A.

2008-01-01

A comprehensive analytical model of the interaction of the cantilever tip of the atomic force microscope (AFM) with the sample surface is developed that accounts for the nonlinearity of the tip-surface interaction force. The interaction is modeled as a nonlinear spring coupled at opposite ends to linear springs representing cantilever and sample surface oscillators. The model leads to a pair of coupled nonlinear differential equations that are solved analytically using a standard iteration procedure. Solutions are obtained for the phase and amplitude signals generated by various acoustic-atomic force microscope (A-AFM) techniques including force modulation microscopy, atomic force acoustic microscopy, ultrasonic force microscopy, heterodyne force microscopy, resonant difference-frequency atomic force ultrasonic microscopy (RDF-AFUM), and the commonly used intermittent contact mode (TappingMode) generally available on AFMs. The solutions are used to obtain a quantitative measure of image contrast resulting from variations in the Young modulus of the sample for the amplitude and phase images generated by the A-AFM techniques. Application of the model to RDF-AFUM and intermittent soft contact phase images of LaRC-cp2 polyimide polymer is discussed. The model predicts variations in the Young modulus of the material of 24 percent from the RDF-AFUM image and 18 percent from the intermittent soft contact image. Both predictions are in good agreement with the literature value of 21 percent obtained from independent, macroscopic measurements of sheet polymer material.

High Precision Seawater Sr/Ca Measurements in the Florida Keys by Inductively Coupled Plasma Atomic Emission Spectrometry: Analytical Method and Implications for Coral Paleothermometry

Science.gov (United States)

Khare, A.; Kilbourne, K. H.; Schijf, J.

2017-12-01

Standard methods of reconstructing past sea surface temperatures (SSTs) with coral skeletal Sr/Ca ratios assume the seawater Sr/Ca ratio is constant. However, there is little data to support this assumption, in part because analytical techniques capable of determining seawater Sr/Ca with sufficient accuracy and precision are expensive and time consuming. We demonstrate a method to measure seawater Sr/Ca using inductively coupled plasma atomic emission spectrometry where we employ an intensity ratio calibration routine that reduces the self- matrix effects of calcium and cancels out the matrix effects that are common to both calcium and strontium. A seawater standard solution cross-calibrated with multiple instruments is used to correct for long-term instrument drift and any remnant matrix effects. The resulting method produces accurate seawater Sr/Ca determinations rapidly, inexpensively, and with a precision better than 0.2%. This method will make it easier for coral paleoclimatologists to quantify potentially problematic fluctuations in seawater Sr/Ca at their study locations. We apply our method to test for variability in surface seawater Sr/Ca along the Florida Keys Reef Tract. We are collecting winter and summer samples for two years in a grid with eleven nearshore to offshore transects across the reef, as well as continuous samples collected by osmotic pumps at four locations adjacent to our grid. Our initial analysis of the grid samples indicates a trend of decreasing Sr/Ca values offshore potentially due to a decreasing groundwater influence. The values differ by as much as 0.05 mmol/mol which could lead to an error of 1°C in mean SST reconstructions. Future work involves continued sampling in the Florida Keys to test for seasonal and interannual variability in seawater Sr/Ca, as well as collecting data from small reefs in the Virgin Islands to test the stability of seawater Sr/Ca under different geologic, hydrologic and hydrographic environments.

Recent Studies on the Speciation and Determination of Mercury in Different Environmental Matrices Using Various Analytical Techniques

Directory of Open Access Journals (Sweden)

Lakshmi Narayana Suvarapu

2017-01-01

Full Text Available This paper reviews the current research on the speciation and determination of mercury by various analytical techniques, including the atomic absorption spectrometry (AAS, voltammetry, inductively coupled plasma optical emission spectrometry (ICP-OES, ICP-mass spectrometry (MS, atomic fluorescence spectrometry (AFS, spectrophotometry, spectrofluorometry, and high performance liquid chromatography (HPLC. Approximately 96 research papers on the speciation and determination of mercury by various analytical instruments published in international journals since 2015 were reviewed. All analytical parameters, including the limits of detection, linearity range, quality assurance and control, applicability, and interfering ions, evaluated in the reviewed articles were tabulated. In this review, we found a lack of information in speciation studies of mercury in recent years. Another important conclusion from this review was that there were few studies regarding the concentration of mercury in the atmosphere.

Angle and Spin Resolved Auger Emission Theory and Applications to Atoms and Molecules

CERN Document Server

Lohmann, Bernd

2009-01-01

The Auger effect must be interpreted as the radiationless counterpart of photoionization and is usually described within a two-step model. Angle and spin resolved Auger emission physics deals with the theoretical and numerical description, analysis and interpretation of such types of experiments on free atoms and molecules. This monograph derives the general theory applying the density matrix formalism and, in terms of irreducible tensorial sets, so called state multipoles and order parameters, for parameterizing the atomic and molecular systems, respectively. Propensity rules and non-linear dependencies between the angular distribution and spin polarization parameters are included in the discussion. The numerical approaches utilizing relativistic distorted wave (RDWA), multiconfigurational Dirac-Fock (MCDF), and Greens operator methods are described. These methods are discussed and applied to theoretical predictions, numerical results and experimental data for a variety of atomic systems, especially the rare...

Comparison of excitation mechanisms in the analytical regions of a high-power two-jet plasma

International Nuclear Information System (INIS)

Zaksas, Natalia P.

2015-01-01

Excitation mechanisms in the analytical regions of a high-power two-jet plasma were investigated. A new plasmatron recently developed was applied in this work. The Boltzmann population of excited levels of Fe atoms and ions was observed in both analytical regions, before and after the jet confluence, as well as in the jet confluence, which proves excitation of atoms and ions by electron impact. The disturbance of local thermodynamic equilibrium in all regions of the plasma flow was deduced on the basis of considerable difference in Fe atomic and ionic excitation temperatures. Such a difference is most likely to be caused by contribution of metastable argon to atom ionization. The region before the jet confluence has the greatest difference in Fe atomic and ionic excitation temperatures and is more non-equilibrium than the region after the confluence due to comparatively low electron and high metastable argon concentrations. Low electron concentration in this region provides lower background emission than in the region after the jet confluence, which leads to better detection limits for the majority of elements. - Highlights: • Excitation mechanisms were investigated in the analytical regions of a high-power TJP. • Boltzmann population of excited levels of Fe atoms and ions takes place in all regions of the plasma flow. • The considerable difference in Fe atomic and ionic excitation temperatures occurs. • Penning ionization by metastable argon results in disturbance of LTE in the plasma. • The region before the jet confluence is more non-equilibrium than after that

Mobile environment for an emission spectrometer

Science.gov (United States)

Radziak, Kamil; Litwin, Dariusz; Galas, Jacek; Tyburska-Staniewska, Anna; Ramsza, Andrzej

2017-08-01

The paper describes a mobile application to be used in a chemical analytical laboratory. The program running under the control of Android operating system allows for preview of measurements recorded by the emission spectrometer. Another part of the application monitors operational and configuration parameters of the device in real time. The first part of this paper includes an overview of the atomic spectrometry. The second part contains a description of the application and its further potential development direction.

New analytical methodology to reach the actinide determination accuracy ({+-} 2%) required by the OSMOSE program

Energy Technology Data Exchange (ETDEWEB)

Boyer-Deslys, V.; Combaluzier, T.; Dalier, V.; Martin, J.C.; Viallesoubranne, C. [DRCP/SE2A/LAMM, CEA/VALRHO - Marcoule, BP 17171, 30207 Bagnols-sur-Ceze (France); Crozet, M. [LEHA, CEA/VALRHO - Marcoule, BP 17171, 30207 Bagnols-sur-Ceze (France)

2008-07-01

This article describes the analytical procedure optimized by LAMM (Laboratory for Analysis and Materials Methodology) in order to characterize the actinide-doped pellets used in the Osmose (Oscillation in Minerve of isotopes in eupraxis spectra) program (developed for transmutation reactor physics). Osmose aims at providing precise experimental data (absorption cross sections) for heavy nuclides (atomic mass from 232 to 245). This procedure requires the use of the analytical equipment and expertise of the LAMM: TIMS (Thermal Ionization Mass Spectrometer), ICP (Inductively Coupled Plasma) QMS (Quadrupole Mass Spectrometer), SFMS (Sector Field Mass Spectrometer), AES (Atomic Emission Spectrometer), alpha spectrometry and photo-gravimetric analysis. These techniques have met all the specification requirements: extended uncertainties (k=2) below {+-} 2% on the uranium and dopant concentrations, the impurity concentration and the americium-241 concentration.

An expression for the atomic fluorescence and thermal-emission intensity under conditions of near saturation and arbitrary self-absorption

NARCIS (Netherlands)

Omenetto, N.; Winefordner, J.D.; Alkemade, C.T.J.

An expression for the effect of self-absorption on the fluorescence and thermal emission intensities is derived by taking into account stimulated emission. A simple, idealized case is considered, consisting of a two level atomic system, in a flame, homogeneous with respect to temperature and

Hydrogen-like atom in laser field: Invariant atomic parameters in the ground state

International Nuclear Information System (INIS)

Bondarev, I.V.; Kuten, S.A.

1994-07-01

The invariant atomic parameters (dynamical vector and tensor polarizabilities) of hydrogen-like atom in the ground 1S 1/2 state are calculated analytically by means of the Laplace transform of the radial Schroedinger equation. The obtained analytical expressions have been written in the compact form as a sum of linear and squared combinations of Gauss hypergeometric functions 2 F 1 . The frequency dependence of the invariant atomic parameters is analyzed. (author). 24 refs, 1 fig

Thermodynamics of atomic and ionized hydrogen: analytical results versus equation-of-state tables and Monte Carlo data.

Science.gov (United States)

Alastuey, A; Ballenegger, V

2012-12-01

We compute thermodynamical properties of a low-density hydrogen gas within the physical picture, in which the system is described as a quantum electron-proton plasma interacting via the Coulomb potential. Our calculations are done using the exact scaled low-temperature (SLT) expansion, which provides a rigorous extension of the well-known virial expansion-valid in the fully ionized phase-into the Saha regime where the system is partially or fully recombined into hydrogen atoms. After recalling the SLT expansion of the pressure [A. Alastuey et al., J. Stat. Phys. 130, 1119 (2008)], we obtain the SLT expansions of the chemical potential and of the internal energy, up to order exp(-|E_{H}|/kT) included (E_{H}≃-13.6 eV). Those truncated expansions describe the first five nonideal corrections to the ideal Saha law. They account exactly, up to the considered order, for all effects of interactions and thermal excitations, including the formation of bound states (atom H, ions H^{-} and H_{2}^{+}, molecule H_{2},⋯) and atom-charge and atom-atom interactions. Among the five leading corrections, three are easy to evaluate, while the remaining ones involve well-defined internal partition functions for the molecule H_{2} and ions H^{-} and H_{2}^{+}, for which no closed-form analytical formula exist currently. We provide accurate low-temperature approximations for those partition functions by using known values of rotational and vibrational energies. We compare then the predictions of the SLT expansion, for the pressure and the internal energy, with, on the one hand, the equation-of-state tables obtained within the opacity program at Livermore (OPAL) and, on the other hand, data of path integral quantum Monte Carlo (PIMC) simulations. In general, a good agreement is found. At low densities, the simple analytical SLT formulas reproduce the values of the OPAL tables up to the last digit in a large range of temperatures, while at higher densities (ρ∼10^{-2} g/cm^{3}), some

On I(5577 Å and I (7620 Å auroral emissions and atomic oxygen densities

Directory of Open Access Journals (Sweden)

R. L. Gattinger

1996-07-01

Full Text Available A model of auroral electron deposition processes has been developed using Monte Carlo techniques to simulate electron transport and energy loss. The computed differential electron flux and pitch angle were compared with in situ auroral observations to provide a check on the accuracy of the model. As part of the energy loss process, a tally was kept of electronic excitation and ionization of the important atomic and molecular states. The optical emission rates from these excited states were computed and compared with auroral observations of η(3914 Å, η(5577 Å, η(7620 Å and η(N2VK. In particular, the roles played by energy transfer from N2(A3Σ+u and by other processes in the excitation of O(1S and O2(b1Σ+g were investigated in detail. It is concluded that the N2(A3Σ+u mechanism is dominant for the production of OI(5577 Å in the peak emission region of normal aurora, although the production efficiency is much smaller than the measured laboratory value; above 150 km electron impact on atomic oxygen is dominant. Atomic oxygen densities in the range of 0.75±0.25 MSIS-86 [O] were derived from the optical comparisons for auroral latitudes in mid-winter for various levels of solar and magnetic activity.

Ultratrace determination of tin by hydride generation in-atomizer trapping atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Průša, Libor [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Hlavova 8, Prague 2, CZ 128 43 Czech Republic (Czech Republic); Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

2013-12-04

Graphical abstract: -- Highlights: •In-atomizer trapping HG-AAS was optimized for Sn. •A compact quartz trap-and-atomizer device was employed. •Generation, preconcentration and atomization steps were investigated in detail. •Hundred percent preconcentration efficiency for tin was reached. •Routine analytical method was developed for Sn determination (LOD of 0.03 ng mL{sup −1} Sn). -- Abstract: A quartz multiatomizer with its inlet arm modified to serve as a trap (trap-and-atomizer device) was employed to trap tin hydride and subsequently to volatilize collected analyte species with atomic absorption spectrometric detection. Generation, atomization and preconcentration conditions were optimized and analytical figures of merit of both on-line atomization as well as preconcentration modes were quantified. Preconcentration efficiency of 95 ± 5% was found. The detection limits reached were 0.029 and 0.14 ng mL{sup −1} Sn, respectively, for 120 s preconcentration period and on-line atomization mode without any preconcentration. The interference extent of other hydride forming elements (As, Se, Sb and Bi) on tin determination was found negligible in both modes of operation. The applicability of the developed preconcentration method was verified by Sn determination in a certified reference material as well as by analysis of real samples.

Development of inductively coupled plasma atomic emission spectrometry for palladium and Rhodium determination in platinum-based alloy

International Nuclear Information System (INIS)

Kovacevic, R.; Todorovic, M.; Manojlovic, D.; Mutic, J.

2008-01-01

Inductively coupled plasma atomic emission spectroscopy with internal standardization was applied for the analysis of an in-house reference platinum alloy containing palladium and rhodium (approximately 5% by weight). In order to compensate for variations in signal recovery due to matrix interferences, and therefore to improve the precision, platinum. the major component, was chosen as an internal standard. Quantitative analysis was based on calibration using a set of matrix-matched calibration standards with and without employing the internal standard. These results were compared with those obtained by X-ray fluorescence spectroscopy. The results for both techniques were in a good agreement, although the precision was slightly better in the inductively coupled plasma atomic emission spectroscopy technique, with or without the internal standard

Determination of metal impurities in MOX powder by direct current arc atomic emission spectroscopy. Application of standard addition method for direct analysis of powder sample

International Nuclear Information System (INIS)

Furuse, Takahiro; Taguchi, Shigeo; Kuno, Takehiko; Surugaya, Naoki

2016-12-01

Metal impurities in MOX powder obtained from uranium and plutonium recovered from reprocessing process of spent nuclear fuel have to be determined for its characterization. Direct current arc atomic emission spectroscopy (DCA-AES) is one of the useful methods for direct analysis of powder sample without dissolving the analyte into aqueous solution. However, the selection of standard material, which can overcome concerns such as matrix matching, is quite important to create adequate calibration curves for DCA-AES. In this study, we apply standard addition method using the certified U_3O_8 containing known amounts of metal impurities to avoid the matrix problems. The proposed method provides good results for determination of Fe, Cr and Ni contained in MOX samples at a significant quantity level. (author)

Determination of heavy metals in solid emission and immission samples using atomic absorption spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Fara, M.; Novak, F. [EGU Prague, PLC, Bichovice, Prague (Czechoslovakia)

1995-12-01

Both flame and electrothermal methods of atomic absorption spectroscopy (AAS) have been applied to the determination of Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, TI, Se, V and Zn in emission and emission (deposition) samples decomposed in open PTFE test-tubes by individual fuming-off hydrofluoric, perchloroic and nitric acid. An alternative hydride technique was also used for As and Se determination and Hg was determined using a self-contained AAS analyzer. A graphite platform proved good to overcome non-spectral interferences in AAS-ETA. Methods developed were verified by reference materials (inc. NBS 1633a).

CHIANTI—AN ATOMIC DATABASE FOR EMISSION LINES. XIII. SOFT X-RAY IMPROVEMENTS AND OTHER CHANGES

International Nuclear Information System (INIS)

Landi, E.; Young, P. R.; Dere, K. P.; Del Zanna, G.; Mason, H. E.

2013-01-01

The CHIANTI spectral code consists of two parts: an atomic database and a suite of computer programs in Python and IDL. Together, they allow the calculation of the optically thin spectrum of astrophysical objects and provide spectroscopic plasma diagnostics for the analysis of astrophysical spectra. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, ionization, and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7.1 has been released, which includes improved data for several ions, recombination rates, and element abundances. In particular, it provides a large expansion of the CHIANTI models for key Fe ions from Fe VIII to Fe XIV to improve the predicted emission in the 50-170 Å wavelength range. All data and programs are freely available at http://www.chiantidatabase.org and in SolarSoft, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

Effect of Cs and Li atom adsorption on MgO: Secondary emission and work function

International Nuclear Information System (INIS)

Bagraev, N.T.; Borisov, V.L.

1980-01-01

Adsorption of Cs and Li atoms on the surface of single crystal magnesium oxide films has been investigated using Auger, LEED and contact difference techniques. A decreased work function for a single crystal MgO film grown on the Mo (100) face was observed to be accompanied by an increased secondary electron emission yield shown to be due to a larger escape depth for secondary electrons. LEED showed well ordered layers of adsorbed Cs on the MgO film surface. A model to explain the behaviour of Cs atoms on the film surface is proposed. It is shown that the stability of the Cs coating is not dependent on a prolonged bombardment of the film by incident electron beams of high current density. Depositing and implanting of thin single crystal MgO films with Li were found to result in an increased secondary electron emission yield, with Li adsorption on the MgO film surface being disordered. (orig.)

Preconcentration of uranium, thorium, zirconium, titanium, molybdenum and vanadium with oxine supported on microcrystalline naphthalene and their determinations by inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Naveen Kumar, P.; Sanjay Kumar; Vijay Kumar; Nandakishore, S.S.; Bangroo, P.N.

2013-01-01

A sensitive and rapid method for the determination of uranium, thorium, zirconium, titanium, molybdenum and vanadium by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solid-liquid extraction with microcrystalline naphthalene is developed. Analytes were quantitatively adsorbed as their oxinate complexes on naphthalene and determined by ICP-AES after stripping with 2 M HCl. The effect of various experimental parameters such as pH, reagent amounts, naphthalene amount and stripping conditions on the determination of these elements was investigated in detail. Under the optimized experimental conditions, the detection limits of this method for U (VI), Th (IV), Zr (IV), Ti (IV), Mo (VI) and V (V) were 20.0 ng mL -1 and the relative standard deviations obtained for three replicate determinations at a concentration of 1.0 µg mL -1 were 1.5-3.0%. The proposed method has been applied in the analysis of SY-2, SY-3 and pre-analysed samples for U, Th, Zr, Ti, Mo and V the analytical results are in good agreement with recommended values. (author)

Computationally efficient analytic representations of relativistic bound-bound, bound-unbound and unbound-unbound transition matrix elements of hydrogenic atoms

International Nuclear Information System (INIS)

Soldatov, A.; Seke, J.; Adam, G.; Polak, M.

2008-01-01

Full text: A closed analytic form for relativistic transition matrix elements between bound-bound, bound-unbound and unbound-unbound relativistic eigenstates of hydrogenic atoms by using the plane-wave expansion for the electromagnetic-field vector potential was derived in a form convenient for large-scale numerical calculations in QED. By applying the obtained formulae, these transition matrix elements can be evaluated analytically and numerically. These exact matrix elements, which to our knowledge have not been calculated as yet, are of great importance in the analysis of various atom-field interaction processes where retardation effects cannot be ignored. The ultimate goal of the ongoing research is to develop a general universal calculation technique for Seke's approximation and renormalization method in QED, for which the usage of the plane vector expansion for the vector potential is a preferable choice. However, our primary interest lies in the Lamb-shift calculation. Our nearest objective is to carry out the plain-style relativistic calculations of the Lamb shift of the energy levels of hydrogen-like atoms and ions from first principles in the second and higher perturbative orders, using the corresponding convenient as well as novel expressions for the magnitude in question as they stand, i.e. without any additional approximations. Due to that there is no way to achieve all the above-declared goals without recourse to large-scale laborious and time-consuming high-precision numerical calculations, having the transition matrix elements of all possible types in an analytic, convenient for their efficient numerical evaluation form, would be highly advantageous and even unavoidable, especially for calculations of various QED effects in higher perturbative orders be it, equally, in traditional or novel approach. (author)

Determination of rare earth elements in aluminum by inductively coupled plasma-atomic emission spectroscopy

International Nuclear Information System (INIS)

Mahanti, H.S.; Barnes, R.M.

1983-01-01

Inductively coupled plasma-atomic emission spectroscopy is evaluated for the determination of 14 rare earth elements in aluminum. Spectral line interference, limit of detection, and background equivalent concentration values are evaluated, and quantitative recovery is obtained from aluminum samples spiked with rare earth elements. The procedure is simple and suitable for routine process control analysis. 20 references, 5 tables

Amplitudes and state parameters from ion- and atom-atom excitation processes

International Nuclear Information System (INIS)

Andersen, T.; Horsdal-Pedersen, E.

1984-01-01

This chapter examines single collisions between two atomic species, one of which is initially in a 1 S state (there is only one initial spin channel). The collisions are characterized by a definite scattering plane and a definite orientation. Topics considered include an angular correlation between scattered particles and autoionization electrons or polarized photons emitted from states excited in atomic collisions (photon emission, electron emission, selectivity excited target atoms), experimental methods for obtaining information on the alignment and orientation parameters of atoms or ions excited in specific collisions, results of experiments and numerical calculations (quasi-oneelectron systems, He + -He collisions, other collision systems), and future aspects and possible applications of the polarizedphoton, scattered-particle coincidence techniques to atomic spectroscopy

Modification and control of the spontaneous emission from an M-type atom embedded in an anisotropic photonic crystal

International Nuclear Information System (INIS)

Ding Chunling; Li Jiahua; Yang Xiaoxue; Lue Xinyou

2011-01-01

We describe the spontaneous emission properties of an M-type five-level atom embedded in a photonic crystal (PC), which is coherently driven by two external laser fields. It leads to two types of quantum interference: reservoir-induced interference and laser-induced interference. Considering different detunings of atomic transition frequencies from band edges, we reveal some interesting phenomena such as spectral-line enhancement, spectral-line suppression, spectral-line narrowing, reservoir-induced cancellation of spontaneous emission and the appearance of dark lines, which originate from the quantum interference effects and the control of external laser fields. These investigations suggest possible applications in quantum optics, optical communications and in the fabrication of novel optoelectronic devices.

A computational study on tuning the field emission and electronic properties of BN nanocones by impurity atom doping

Science.gov (United States)

Ahmadi, S.; Delir Kheirollahi Nezhad, P.; Hosseinian, A.; Vessally, E.

2018-06-01

We have inspected the effect of substituting a boron or nitrogen atom of a BN nanocone (BNNC) by two impurity atoms with lower and higher atomic numbers based on the density functional theory calculations. Our results explain the experimental observations in a molecular level. Orbital and partial density of states analyses show that the doping processes increase the electrical conductivity by creating new states within the gap of BNNC as follows: BeB > ON > CB > CN. The electron emission current from the surface of BNNC is improved after the CB and BeB dopings, and it is decreased by CN and ON dopings. The BeB and CN dopings make the BNNC a p-type semiconductor and the CB and ON dopings make it an n-type one in good agreement with the experimental results. The ON and BeB doping processes are suggested for the field emission current, and electrical conductivity enhancement, respectively.

CHIANTI—AN ATOMIC DATABASE FOR EMISSION LINES. XII. VERSION 7 OF THE DATABASE

International Nuclear Information System (INIS)

Landi, E.; Del Zanna, G.; Mason, H. E.; Young, P. R.; Dere, K. P.

2012-01-01

The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

CHIANTI-AN ATOMIC DATABASE FOR EMISSION LINES. XII. VERSION 7 OF THE DATABASE

Energy Technology Data Exchange (ETDEWEB)

Landi, E. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Del Zanna, G.; Mason, H. E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Young, P. R. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA, 22030 (United States); Dere, K. P. [School of Physics, Astronomy and Computational Sciences, MS 6A2, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States)

2012-01-10

The CHIANTI spectral code consists of an atomic database and a suite of computer programs to calculate the optically thin spectrum of astrophysical objects and carry out spectroscopic plasma diagnostics. The database includes atomic energy levels, wavelengths, radiative transition probabilities, collision excitation rate coefficients, and ionization and recombination rate coefficients, as well as data to calculate free-free, free-bound, and two-photon continuum emission. Version 7 has been released, which includes several new ions, significant updates to existing ions, as well as Chianti-Py, the implementation of CHIANTI software in the Python programming language. All data and programs are freely available at http://www.chiantidatabase.org, while the Python interface to CHIANTI can be found at http://chiantipy.sourceforge.net.

An Atomically Precise Au10 Ag2 Nanocluster with Red-Near-IR Dual Emission.

Science.gov (United States)

Lei, Zhen; Guan, Zong-Jie; Pei, Xiao-Li; Yuan, Shang-Fu; Wan, Xian-Kai; Zhang, Jin-Yuan; Wang, Quan-Ming

2016-08-01

A red-near-IR dual-emissive nanocluster with the composition [Au10 Ag2 (2-py-C≡C)3 (dppy)6 ](BF4 )5 (1; 2-py-C≡C is 2-pyridylethynyl, dppy=2-pyridyldiphenylphosphine) has been synthesized. Single-crystal X-ray structural analysis reveals that 1 has a trigonal bipyramidal Au10 Ag2 core that contains a planar Au4 (2-py-C≡C)3 unit sandwiched by two Au3 Ag(dppy)3 motifs. Cluster 1 shows intense red-NIR dual emission in solution. The visible emission originates from metal-to-ligand charge transfer (MLCT) from silver atoms to phosphine ligands in the Au3 Ag(dppy)3 motifs, and the intense NIR emission is associated with the participation of 2-pyridylethynyl in the frontier orbitals of the cluster, which is confirmed by a time-dependent density functional theory (TD-DFT) calculation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of the elemental composition of cyanobacteria cells and cell fractions by atomic emission and atomic absorption spectrometry

International Nuclear Information System (INIS)

Sedykh, Eh.M.; Lyabusheva, O.A.; Bannykh, L.N.; Tambiev, A.Kh.

2005-01-01

An approach to studying the elemental composition of cyanobacteria Spirulina platensis and Nostoc commune using a set of complementary analytical methods (ICP-AES, PAAS, and ETAAS) was proposed . The procedures were adapted for the determination of macro- and microelements (Na, K, Mg, Ca, Fe, Mn, Cu, Mo, Zn, B, and Se) in the biomass of cyanobacteria and separated cell fractions (chloroform and water-methanol extracts and precipitates). The conditions for the mineralization of biological materials were optimized for autoclave and microwave sample preparation procedures. The evaporation and atomization of Se and Mo in a graphite furnace in the presence of chloroform and methanol were studied [ru

Effect of atomic-state coherence and spontaneous emission on three-level dynamics

International Nuclear Information System (INIS)

Cardimona, D.A.

1990-01-01

For a three-level atom in the ssV configuration (i.e., having two excited states each dipole-coupled to a common ground state), we have found a particular linear combination of bare-atom states in which Rabi oscillations and their associated collapses and revivals do not occur. Moving to a dressed-state picture, we discover that this particular linear combination state is just that dressed state which is decoupled from all the field modes. It is a dressed state for which the transition dipole moments with the other dressed states are zero. The existence of this decoupled dressed state depends on the tuning of the dressing laser field, which in turn depends on the bare-atom excited-state dipole moments and energy-level separation. When we include spontaneous emission, the population decays from the other dressed states into this decoupled state and remains coherently trapped there, producing a system that experiences no dynamical behavior. This is exact for δ-function photon statistics (i.e., if there is no intensity uncertainty). The trapping becomes less perfect as the photon statistics are allowed to have a greater bandwidth. Also, if the applied field is tuned incorrectly, the spontaneous realignment of the atomic state amplitudes does not result in a totally decoupled dressed state, and the dynamics proceed normally

An analytical model accounting for tip shape evolution during atom probe analysis of heterogeneous materials.

Science.gov (United States)

Rolland, N; Larson, D J; Geiser, B P; Duguay, S; Vurpillot, F; Blavette, D

2015-12-01

An analytical model describing the field evaporation dynamics of a tip made of a thin layer deposited on a substrate is presented in this paper. The difference in evaporation field between the materials is taken into account in this approach in which the tip shape is modeled at a mesoscopic scale. It was found that the non-existence of sharp edge on the surface is a sufficient condition to derive the morphological evolution during successive evaporation of the layers. This modeling gives an instantaneous and smooth analytical representation of the surface that shows good agreement with finite difference simulations results, and a specific regime of evaporation was highlighted when the substrate is a low evaporation field phase. In addition, the model makes it possible to calculate theoretically the tip analyzed volume, potentially opening up new horizons for atom probe tomographic reconstruction. Copyright © 2015 Elsevier B.V. All rights reserved.

Clustering of germanium atoms in silica glass responsible for the 3.1 eV emission band studied by optical absorption and X-ray absorption fine structure analysis

International Nuclear Information System (INIS)

Yoshida, Tomoko; Muto, Shunsuke; Yuliati, Leny; Yoshida, Hisao; Inada, Yasuhiro

2009-01-01

Correlation between the 3.1 eV emission band and local atomic configuration was systematically examined for Ge + implanted silica glass by UV-vis optical absorption spectroscopy and X-ray absorption fine structure (XAFS) analysis. The 2.7 eV emission band, commonly observed in defective silica, was replaced by the sharp and intense 3.1 eV emission band for the Ge + fluence > 2 x 10 16 cm -2 , in which UV-vis absorption spectra suggested clustering of Ge atoms with the size ∼1 nm. XAFS spectroscopy indicated that the Ge atoms were under coordinated with oxygen atoms nearly at a neutral valence state on average. The present results are consistent with the previous ESR study but imply that the small Ge clusters rather than the O=Ge: complexes (point defects) are responsible for the 3.1 eV emission band.

Analytical estimation of emission zone mean position and width in organic light-emitting diodes from emission pattern image-source interference fringes

International Nuclear Information System (INIS)

Epstein, Ariel; Tessler, Nir; Einziger, Pinchas D.; Roberts, Matthew

2014-01-01

We present an analytical method for evaluating the first and second moments of the effective exciton spatial distribution in organic light-emitting diodes (OLED) from measured emission patterns. Specifically, the suggested algorithm estimates the emission zone mean position and width, respectively, from two distinct features of the pattern produced by interference between the emission sources and their images (induced by the reflective cathode): the angles in which interference extrema are observed, and the prominence of interference fringes. The relations between these parameters are derived rigorously for a general OLED structure, indicating that extrema angles are related to the mean position of the radiating excitons via Bragg's condition, and the spatial broadening is related to the attenuation of the image-source interference prominence due to an averaging effect. The method is applied successfully both on simulated emission patterns and on experimental data, exhibiting a very good agreement with the results obtained by numerical techniques. We investigate the method performance in detail, showing that it is capable of producing accurate estimations for a wide range of source-cathode separation distances, provided that the measured spectral interval is large enough; guidelines for achieving reliable evaluations are deduced from these results as well. As opposed to numerical fitting tools employed to perform similar tasks to date, our approximate method explicitly utilizes physical intuition and requires far less computational effort (no fitting is involved). Hence, applications that do not require highly resolved estimations, e.g., preliminary design and production-line verification, can benefit substantially from the analytical algorithm, when applicable. This introduces a novel set of efficient tools for OLED engineering, highly important in the view of the crucial role the exciton distribution plays in determining the device performance.

Analytical estimation of emission zone mean position and width in organic light-emitting diodes from emission pattern image-source interference fringes

Energy Technology Data Exchange (ETDEWEB)

Epstein, Ariel, E-mail: ariel.epstein@utoronto.ca; Tessler, Nir, E-mail: nir@ee.technion.ac.il; Einziger, Pinchas D. [Department of Electrical Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Roberts, Matthew, E-mail: mroberts@cdtltd.co.uk [Cambridge Display Technology Ltd, Building 2020, Cambourne Business Park, Cambourne, Cambridgeshire CB23 6DW (United Kingdom)

2014-06-14

We present an analytical method for evaluating the first and second moments of the effective exciton spatial distribution in organic light-emitting diodes (OLED) from measured emission patterns. Specifically, the suggested algorithm estimates the emission zone mean position and width, respectively, from two distinct features of the pattern produced by interference between the emission sources and their images (induced by the reflective cathode): the angles in which interference extrema are observed, and the prominence of interference fringes. The relations between these parameters are derived rigorously for a general OLED structure, indicating that extrema angles are related to the mean position of the radiating excitons via Bragg's condition, and the spatial broadening is related to the attenuation of the image-source interference prominence due to an averaging effect. The method is applied successfully both on simulated emission patterns and on experimental data, exhibiting a very good agreement with the results obtained by numerical techniques. We investigate the method performance in detail, showing that it is capable of producing accurate estimations for a wide range of source-cathode separation distances, provided that the measured spectral interval is large enough; guidelines for achieving reliable evaluations are deduced from these results as well. As opposed to numerical fitting tools employed to perform similar tasks to date, our approximate method explicitly utilizes physical intuition and requires far less computational effort (no fitting is involved). Hence, applications that do not require highly resolved estimations, e.g., preliminary design and production-line verification, can benefit substantially from the analytical algorithm, when applicable. This introduces a novel set of efficient tools for OLED engineering, highly important in the view of the crucial role the exciton distribution plays in determining the device performance.

Analyticity of the density of electronic wavefunctions

DEFF Research Database (Denmark)

Fournais, Søren; Hoffmann-Ostenhof, Maria; Hoffmann-Ostenhof, Thomas

2004-01-01

We prove that the electronic densities of atomic and molecular eigenfunctions are real analytic in R^3 away from the nuclei.......We prove that the electronic densities of atomic and molecular eigenfunctions are real analytic in R^3 away from the nuclei....

Exact results for emission from one and two atoms in an ideal cavity at multiphoton resonance

International Nuclear Information System (INIS)

Fam Le Kien; Shumovskij, A.S.; Tran Quang.

1987-01-01

The emission from the system of one or two two-level atoms in an ideal cavity with one mode at mutiphoton resonance is examined. Exact results for the two-time dipole correlation function and the time-dependent spectra of multiphoton-induced fluorescence are presented

Localization of the antimony impurity atoms in the PbTe lattice determined by the Moessbauer emission spectroscopy

International Nuclear Information System (INIS)

Masterov, V.F.; Nasredinov, F.S.; Nemov, S.A.; Seregin, P.P.; Troitskaya, N.N.; Bondarevskij, S.I.

1997-01-01

The 119 Sb ( 119m Sn) emission Moessbauer spectroscopy has shown that a localization of the antimony impurity atoms in the PbTe lattice is affected by the conductivity type of the host material, the antimony atoms occupied mainly anion and cation sites in n-type and p-type samples, respectively. The 119 Sn impurity in the anion sublattice of PbTe formed an decay. Its charge state was shown to be independent of the Fermi level position

Metastable argon atom density in complex argon/acetylene plasmas determined by means of optical absorption and emission spectroscopy

International Nuclear Information System (INIS)

Sushkov, Vladimir; Herrendorf, Ann-Pierra; Hippler, Rainer

2016-01-01

Optical emission and absorption spectroscopy has been utilized to investigate the instability of acetylene-containing dusty plasmas induced by growing nano-particles. The density of Ar(1s 5 ) metastable atoms was derived by two methods: tunable diode laser absorption spectroscopy and with the help of the branching ratio method of emitted spectral lines. Results of the two techniques agree well with each other. The density of Ar(1s 3 ) metastable atoms was also measured by means of optical emission spectroscopy. The observed growth instability leads to pronounced temporal variations of the metastable and other excited state densities. An analysis of optical line ratios provides evidence for a depletion of free electrons during the growth cycle but no indication for electron temperature variations. (paper)

Internal standardization in atomic-emission spectrometry using inductively coupled plasma

International Nuclear Information System (INIS)

Moore, G.L.

1985-01-01

The principle of internal standardization has been used in quantitative analytical emission spectroscopy since 1925 to minimize the errors arising from fluctuations in sample preparation, excitation-source conditions, and detection parameters. Although modern spectroscopic excitation sources are far more stable and electronic detection methods are more precise than before, the system for the introduction of the sample in spectrometric analysis using inductively coupled plasma (ICP) introduces significant errors, and internal standardization can still play a useful role in improving the overall precision of the analytical results. The criteria for the selection of the elements to be used as internal standards in arc and spark spectrographic analysis apply to a much lesser extent in ICP-spectrometric analysis. Internal standardization is recommended for use in routine ICP-simultaneous spectrometric analysis to improve its accuracy and precision and to provide a monitor for the reassurance of the analyst. However, the selection of an unsuitable reference element can result in misuse of the principle of internal standardization and, although internal standardization can be applied when a sequential monochromator is used, the main sources of error will not be minimized

Atomic emission spectroscopy

Science.gov (United States)

Andrew, K. H.

1975-01-01

The relationship between the Slater-Condon theory and the conditions within the atom as revealed by experimental data was investigated. The first spectrum of Si, Rb, Cl, Br, I, Ne, Ar, and Xe-136 and the second spectrum of As, Cu, and P were determined. Methods for assessing the phase stability of fringe counting interferometers and the design of an autoranging scanning system for digitizing the output of an infrared spectrometer and recording it on magnetic tape are described.

Emission of H- fragments from collisions of OH+ ions with atoms and molecules

International Nuclear Information System (INIS)

Juhasz, Z.; Sulik, B.

2010-01-01

Compete text of publication follows. Detailed measurement of the kinematics of positive fragment ions from molecular collisions pro-vide useful information about the collision dynamics (see e.g. and references therein). In the present work, we turn our attention to negative fragments. Double differential emission spectra of negative charged particles have been measured in collisions of OH + ions with gas jets of Ar atoms and acetone (CH 3 -CO-CH 3 ) molecules at 7 keV impact energy. Among the emitted electrons, a relatively strong contribution of H - ions has been observed in both collision systems. According to a kinematic analysis, the observed H - ions were produced in close atom-atom collisions. For acetone, these ions originated from both the projectile and the target. The present ion impact energy range falls in the distal region of the Bragg peak. Therefore, a non negligible H - production in biological tissues could be relevant for ion therapy and for radiolysis in general. The present experiments were conducted at the 14.5 GHz Electron Cyclotron Resonance (ECR) ion source of the ARIBE facility, at the Grand Accelerateur National d'Ions Lourds (GANIL) in Caen, France. The molecular OH + ions were produced by introducing water vapor in the ECR plasma chamber. The extracted ions were collimated to a diameter of 2.5 mm before entering the collision chamber. In its center, the OH + projectiles crossed an effusive gas jet of either argon atoms or acetone molecules. In the collision area, the density of the gas target was typically of 10 13 cm -3 . The electrons and negative ions produced in the collision were detected by means of a single-stage spectrometer consisting of an electrostatic parallel-plate analyzer. Spectra taken at 30 deg observation angle are shown in Figure 1. Contributions from H - appear in clearly visible peaks. Kinematics shows that the peak at 410 eV in both panels is due emission of H - ions moving with nearly the projectile velocity. An H

On I(5577 Å and I (7620 Å auroral emissions and atomic oxygen densities

Directory of Open Access Journals (Sweden)

R. L. Gattinger

Full Text Available A model of auroral electron deposition processes has been developed using Monte Carlo techniques to simulate electron transport and energy loss. The computed differential electron flux and pitch angle were compared with in situ auroral observations to provide a check on the accuracy of the model. As part of the energy loss process, a tally was kept of electronic excitation and ionization of the important atomic and molecular states. The optical emission rates from these excited states were computed and compared with auroral observations of η(3914 Å, η(5577 Å, η(7620 Å and η(N₂VK. In particular, the roles played by energy transfer from N₂(A³Σ⁺_u and by other processes in the excitation of O(¹S and O₂(b¹Σ⁺_g were investigated in detail. It is concluded that the N₂(A³Σ⁺_u mechanism is dominant for the production of OI(5577 Å in the peak emission region of normal aurora, although the production efficiency is much smaller than the measured laboratory value; above 150 km electron impact on atomic oxygen is dominant. Atomic oxygen densities in the range of 0.75±0.25 MSIS-86 [O] were derived from the optical comparisons for auroral latitudes in mid-winter for various levels of solar and magnetic activity.

Study of thermoelectron emission of oxidized tungsten sponge in cesium atom flow

International Nuclear Information System (INIS)

Tursunmetov, K.A.; Sabirov, A.K.

1993-01-01

Thermoelectron emission of a tungsten sponge with 30-40% porosity is studied. The tungsten sponge is produced of fine-grain tungsten powder (diameter - 1-2 μm) according to standard technology. It is shown that tungsten sponge oxidation at T=1000 K with subsequent heating in vacuum at T=1100 K allows one to obtain the minimal stable and reproducible work function at the level of 1.03-1.05 eV in a flux of cesium atoms. Estimations show that effective emitting surface is 15-20 times as much as the polycrystal surface

Line-emission cross sections for the charge-exchange reaction between fully stripped carbon and atomic hydrogen in tokamak plasma

International Nuclear Information System (INIS)

Ida, K.; Kato, T.

1992-01-01

Line-emission cross sections of the charge-exchange reaction between fully stripped carbon and atomic hydrogen are measured in the energy range of 18 - 38 keV/amu in tokamak plasmas. The energy dependence of the emission cross sections for the transition of Δn = 8 - 7 and Δn = 7 - 6 and their ratios are compared with theoretical calculations. (author)

Building and analyzing models from data by stirred tank experiments for investigation of matrix effects caused by inorganic matrices and selection of internal standards in Inductively Coupled Plasma-Atomic Emission Spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Grotti, Marco [Dipartimento di Chimica e Chimica Industriale, Via Dodecaneso 31, 16146 Genova (Italy)], E-mail: grotti@chimica.unige.it; Paredes, Eduardo; Maestre, Salvador; Todoli, Jose Luis [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, 03080, Alicante (Spain)

2008-05-15

Interfering effects caused by inorganic matrices (inorganic acids as well as easily ionized elements) in inductively coupled plasma-atomic emission spectroscopy have been modeled by regression analysis of experimental data obtained using the 'stirred tank method'. The main components of the experimental set-up were a magnetically-stirred container and two peristaltic pumps. In this way the matrix composition was gradually and automatically varied, while the analyte concentration remained unchanged throughout the experiment. An inductively coupled plasma spectrometer with multichannel detection based on coupled charge device was used to simultaneously measure the emission signal at several wavelengths when the matrix concentration was modified. Up to 50 different concentrations were evaluated in a period of time of 10 min. Both single interfering species (nitric, hydrochloric and sulphuric acids, sodium and calcium) and different mixtures (aqua regia, sulfonitric mixture, sodium-calcium mixture and sodium-nitric acid mixture) were investigated. The dependence of the emission signal on acid concentration was well-fitted by logarithmic models. Conversely, for the easily ionized elements, 3-order polynomial models were more suitable to describe the trends. Then, the coefficients of these models were used as 'signatures' of the matrix-related signal variations and analyzed by principal component analysis. Similarities and differences among the emission lines were highlighted and discussed, providing a new insight into the interference phenomena, mainly with regards to the combined effect of concomitants. The combination of the huge amount of data obtained by the stirred tank method in a short period of time and the speed of analysis of principal component analysis provided a judicious means for the selection of the optimal internal standard in inductively coupled plasma-atomic emission spectroscopy.

The use of double laser pulses for the atomic-emission spectral estimation of uranium content in biological samples

International Nuclear Information System (INIS)

Patapovich, M.P.; Umreiko, D.S.; Zajogin, A.P.; Buloichik, J.I.

2012-01-01

This paper is aimed at the development of the techniques for estimation of the uranium content in biological objects (hair) using the atomic-emission laser analysis with a sufficient accuracy and high processing rate. (authors)

An Investigation on the Extraction and Quantitation of a Hexavalent Chromium in Acrylonitrile Butadiene Styrene Copolymer (ABS) and Printed Circuit Board (PCB) by Ion Chromatography Coupled with Inductively Coupled Plasma Atomic Emission Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Nam, Sang Ho; Kim, Yu Na [Mokpo National University, Muan (Korea, Republic of)

2012-06-15

A hexavalent chromium (Cr (VI)) is one of the hazardous substances regulated by the RoHS. The determination of Cr (VI) in various polymers and printed circuit board (PCB) has been very important. In this study, the three different analytical methods were investigated for the determination of a hexavalent chromium in Acrylonitrile Butadiene Styrene copolymer (ABS) and PCB. The results by three analytical methods were obtained and compared. An analytical method by UV-Visible spectrometer has been generally used for the determination of Cr (VI) in a sample, but a hexavalent chromium should complex with diphenylcarbazide for the detection in the method. The complexation did make an adverse effect on the quantitative analysis of Cr (VI) in ABS. The analytical method using diphenylcarbazide was also not applicable to printed circuit board (PCB) because PCB contained lots of irons. The irons interfered with the analysis of hexavalent chromium because those also could complex with diphenylcarbazide. In this study, hexavalent chromiums in PCB have been separated by ion chromatography (IC), then directly and selectively detected by inductively coupled plasma atomic emission spectrometry (ICP-AES). The quantity of Cr (VI) in PCB was 0.1 mg/kg

Search for two-photon emission from 2S states of low-Z muonic atoms

International Nuclear Information System (INIS)

Carter, A.L.; Hincks, E.P.; Cox, C.R.; Dodson, G.W.; Eckhause, M.; Kane, J.R.; Rushton, A.M.; Siegel, R.T.; Welsh, R.E.; Hargrove, C.K.; Mes, H.; Dixit, M.S.; National Research Council of Canada, Ottawa, Ontario)

1983-01-01

A search for two-photon emission from 2S states of low-Z muonic atoms has been made. Intrinsic Ge detectors were positioned around target of Li, Be, B, or their hydrides, or a vessel containing B 2 H 6 , H 2 , or O 2 . Upper limits on the fraction of stopping muons which formed metastable 2S states range from approx.= 10 - 3 to 10 - 5 . (orig.)

Atomic emission spectroscopic investigations for determining depth profiles at boride layers on iron materials

International Nuclear Information System (INIS)

Danzer, K.; Marx, G.

1980-01-01

A combination of atomic emission spectroscopic surface analysis and mechanical removement of defined surface areas in layers by grinding yields information about the depth distribution of boron in iron. In addition, the evaluation with the aid of the two-dimensional variance analysis leads to statements on the homogeneous distribution within individual layers at different depth. The results obtained in this way are in agreement with those of other methods

Determination of bismuth by dielectric barrier discharge atomic absorption spectrometry coupled with hydride generation: Method optimization and evaluation of analytical performance

Czech Academy of Sciences Publication Activity Database

Kratzer, Jan; Boušek, J.; Sturgeon, R. E.; Mester, Z.; Dědina, Jiří

2014-01-01

Roč. 86, č. 19 (2014), s. 9620-9625 ISSN 0003-2700 Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.636, year: 2014

Problems, possibilities and limitations of inductively coupled plasma atomic emission spectrometry in the determination of platinum, palladium and rhodium in samples with different matrix composition

Energy Technology Data Exchange (ETDEWEB)

Petrova, P.; Velichkov, S. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria); Velitchkova, N. [Geological Institute, Bulgarian Academy of Sciences, Acad. G. Bontchev Str., bl.24, 1113 Sofia (Bulgaria); Havezov, I. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria); Daskalova, N., E-mail: das15482@svr.igic.bas.b [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bontchev Str. bl. 11, 1113 Sofia (Bulgaria)

2010-02-15

The economic and geological importance of platinum group of elements has led to the development of analytical methods to quantify them in different types of samples. In the present paper the quantitative information for spectral interference in radial viewing 40.68 MHz inductively coupled plasma atomic emission spectrometry in the determination of Pt, Pd and Rh in the presence of complex matrix, containing Al, Ca, Fe, Mg, Mn, P and Ti as matrix constituents was obtained. The database was used for optimum line selections. By using the selected analysis lines the following detection limits in ng g{sup -1} were obtained: Pt 1700, Pd-1440, Rh-900. The reached detection limits determine the possibilities and limitation of the direct ICP-AES method in the determination of Pt, Pd and Rh in geological and environmental materials. The database for spectral interferences in the presence of aluminum can be used for the determination of platinum group of elements in car catalysts. The accuracy of the analytical results was experimentally demonstrated by two certified reference materials that were analyzed: SARM 7, Pt ore and recycled auto-catalyst certified reference material SRM 2556.

Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

Directory of Open Access Journals (Sweden)

Hery Suyanto

2016-08-01

Full Text Available A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns and picosecond (ps lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS using He ambient gas.

Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

Energy Technology Data Exchange (ETDEWEB)

Suyanto, Hery [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Pardede, Marincan [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Hedwig, Rinda [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Marpaung, Alion Mangasi [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, Rawamangun, Jakarta 12440 (Indonesia); Ramli, Muliadi [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Lie, Tjung Jie; Kurniawan, Koo Hendrik, E-mail: kurnia18@cbn.net.id [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Abdulmadjid, Syahrun Nur [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Tjia, May On [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha,Bandung 40132 (Indonesia); Kagawa, Kiichiro [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Fukui Science Education Academy, Takagi Chuo 2 chome, Fukui 910-0804 (Japan)

2016-08-15

A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns) and picosecond (ps) lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE) mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS) using He ambient gas.

Study of interferences in the atomic - absorption and emission of barium in nitrous oxide/acetylene flame

International Nuclear Information System (INIS)

Curtius, A.J.; Couto, M.I.

1979-01-01

The interferences of several ions that are present in oifield water and sea water in the atomic absorption and emission of barium were investigated. It was verified that the interferences of sodium, potassium, calcium, strontium and chloride are the most important. The indirect method for the determination of sulfate by measuring barium by atomic absorption after precipitating barium sulfate with an excess of barium chloride, should not be used for highly salted matrix. To avoid the interferences that are not compensated by an ionization supressor, the measurement of barium by the standard addition method or a previous sulfate separation is recommended. (Author) [pt

Evaluation of radioactive emissions of lignite-fired power plants in Turkey using the Analytic Hierarchy Process

International Nuclear Information System (INIS)

Bueke, Tayfun

2013-01-01

Radioactive emissions of 13 lignite-fired power plants in Turkey are of great concern to the public and to scientists alike. The purpose of this study is to evaluate these power plants, according to their radioactive emissions by using the Analytic Hierarchy Process. Control criteria are in particular 226 Ra, 232 Th, 40 K and 238 U emissions from the power plants. These control criteria are weighted according to the objective assessment. The calculations are repeated for three different objective assessments of control criteria namely the mortality risk coefficients for inhalation, ingestion, external exposure of 226 Ra, 232 Th, 40 K and 238 U. It has been calculated that the Can lignite-fired power plant is ranking first while the Soma-B plant is ranking last according to the radioactive emissions of the power plants when the average of three different objective control criteria are used in the calculations. (orig.)

Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

International Nuclear Information System (INIS)

Ataman, O. Yavuz

2008-01-01

Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C 0 , where the change in characteristic mass, m 0 , can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as E max , maximum enhancement factor; E t , enhancement for 1.0 minute sampling and E v , enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps

Radiative double electron capture in fast heavy ion-atom collisions

International Nuclear Information System (INIS)

Yakhontov, V.L.; Amusia, M.Ya.

1996-01-01

Two-electron capture with emission of a single photon (TESP) in collisions of highly charged ions with light atoms is considered. Such a process is actually a time-reversed double photoionization but occurring at specific kinematics. In the lowest order in the inter-electron interaction, the TESP probability is determined by two diagrams which are evaluated analytically by means of the Coulomb Green function. The calculated ratio of the TESP and single recombination cross sections is in fair agreement with the data obtained in the recent experimental study of this phenomena. (orig.)

Mineral distribution in rice: Measurement by Microwave Plasma Atomic Emission Spectroscopy (MP-AES)

International Nuclear Information System (INIS)

Ramos, Nerissa C.; Ramos, R.G.A.; Quirit, L.L.; Arcilla, C.A.

2015-01-01

Microwave Plasma Atomic Emission Spectroscopy (MP-AES) is a new technology with comparable performance and sensitivity to Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Both instrument use plasma as the energy source that produces atomic and ionic emission lines. However, MP-AES uses nitrogen as the plasma gas instead of argon which is an additional expense for ICP-OES. Thus, MP-AES is more economical. This study quantified six essential minerals (Se, Zn, Fe, Cu, Mn and K) in rice using MP-AES. Hot plate digestion was used for sample extraction and the detection limit for each instrument was compared with respect to the requirement for routine analysis in rice. Black, red and non-pigmented rice samples were polished in various intervals to determine the concentration loss of minerals. The polishing time corresponds to the structure of the rice grains such as outer bran layer (0 to 15), inner bran layer (15 to 30), outer endosperm layer (30 to 45), and middle endosperm layer (45 to 60). Results of MP-AES analysis showed that black rice had all essential materials (except K) in high concentration at the outer bran layer. The red and non-pigmented rice samples on the other hand, contained high levels of Se, Zn, Fe, and Mn in the whole bran portion. After 25 seconds, the mineral concentrations remained constant. The concentration of Cu however, gave consistent value in all polishing intervals, hence Cu might be located in the inner endosperm layer. Results also showed that K was uniformly distributed in all samples where 5% loss was consistently observed for every polishing interval. Therefore, the concentration of K was also affected by polishing time. Thus, the new MP-AES technology with comparable performance to ICP-OES is a promising tool for routine analysis in rice. (author)

Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios

Energy Technology Data Exchange (ETDEWEB)

Yang, Tzu-Ting, E-mail: d89844001@ntu.edu.tw [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China); Lin, Shaw-Tao [Department of Applied Chemistry, Providence University, No. 200 Chung-Chi Rd., Salu Dist., Taichung City 43301, Taiwan (China); Lin, Tser-Sheng [Department of Safety, Health, and Environmental Engineering, National United University, 2 Lien Da, Maioli 360, Taiwan (China); Chung, Hua-Yi [Department of Environmental Engineering and Health, Yuanpei University, No. 306, Yuanpei St., Hsin Chu 30015, Taiwan (China)

2015-02-15

The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0 L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17–78.72 mg/g, 26,139.80–35,932.98 and 5735.22–13,431.51 ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26–83.70% and 16.30–29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82–797.76 ng/g) was approximately 6.92–25.08 times higher than that of the gaseous phase (26.27–36.07 ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO{sub 3}) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency. - Highlights: • PAHs emissions are influenced by mosquito coils containing various atomic H/C ratios. • The PAHs generated by burning mosquito coils mainly occur in the gaseous phase. • Total TEQ emission factors of PAHs mainly consisted of the particulate phase (> 87%). • The BaP and BaA accounted for 71.13–77.28% of the total TEQ emission factors. • Special PAH ratios were regarded as characteristic ratios for burning mosquito coil.

Determination of trace elements in Egyptian cane sugar (Deshna Factories) by neutron activation, atomic absorption spectrophotometric and inductively coupled plasma-atomic emission spectrometric analysis

International Nuclear Information System (INIS)

Awadallah, R.M.; Sherif, M.K.; Mohamed, A.E.; Grass, F.

1986-01-01

Multielement instrumental neutron activation (INAA), inductively coupled plasma-atomic emission spectrometric (ICP-AES) and atomic absorption spectrophotometric (AAS) analyses were utilized for the determination of Ag, Al, As, Au, Ba, Be, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in sugar cane plant, raw juice, juice in different stages, syrup, deposits, molasses, A, B and C sugar, refinery 1 and 2 sugar, and in soil samples picked up from the immediate vicinity of the cane plant roots at surface, 30 and 60 cm depth, respectively. (author)

Search for two-photon emission from 2S states of low-Z muonic atoms

Energy Technology Data Exchange (ETDEWEB)

Carter, A.L.; Hincks, E.P. (Carleton Univ., Ottawa, Ontario (Canada). Dept. of Physics); Cox, C.R.; Dodson, G.W.; Eckhause, M.; Kane, J.R.; Rushton, A.M.; Siegel, R.T.; Welsh, R.E. (College of William and Mary, Williamsburg, VA (USA). Dept. of Physics); Hargrove, C.K.

1983-05-12

A search for two-photon emission from 2S states of low-Z muonic atoms has been made. Intrinsic Ge detectors were positioned around target of Li, Be, B, or their hydrides, or a vessel containing B/sub 2/H/sub 6/, H/sub 2/, or O/sub 2/. Upper limits on the fraction of stopping muons which formed metastable 2S states range from approximately = 10/sup -3/ to 10/sup -5/.

A COUPLED CHEMISTRY-EMISSION MODEL FOR ATOMIC OXYGEN GREEN AND RED-DOUBLET EMISSIONS IN THE COMET C/1996 B2 HYAKUTAKE

International Nuclear Information System (INIS)

Bhardwaj, Anil; Raghuram, Susarla

2012-01-01

The green (5577 Å) and red-doublet (6300, 6364 Å) lines are prompt emissions of metastable oxygen atoms in the 1 S and 1 D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H 2 O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O( 1 S) and O( 1 D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H 2 O to the green (red) line emission is 30%-70% (60%-90%), while CO 2 and CO are the next potential sources contributing 25%-50% ( 1 S) to O( 1 D) would be around 0.03 (±0.01) if H 2 O is the main source of oxygen lines, whereas it is ∼0.6 if the parent is CO 2 . Our calculations suggest that the yield of O( 1 S) production in the photodissociation of H 2 O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

Upgradation of an Apple IIe based DC arc atomic emission spectrometer to a PC based system

International Nuclear Information System (INIS)

Sampathkumar, R.; Ravindranath, S.V.G.; Patil, P.B.; Deshpande, S.S.; Saha, T.K.; Handu, V.K.

2004-01-01

The analysis of Uranium metal and its compounds used as reactor fuel for the presence of impurities especially Cd and B which have a high neutron capture cross section is routinely performed in Spectroscopy Division. The DC Arc Atomic Emission Spectrometer in the Division was employing an Apple IIe computer for performing the control and data acquisition jobs. The system was upgraded to a PC based data acquisition system and the necessary software to perform the spectro chemical analysis has been developed. This becomes necessary in a scenario where the commercially available Atomic Emission Spectrometers are no longer equipped with DC arc source. Also the Apple IIe computer which was performing the control and data acquisition has gone obsolete and its spares are no longer available. Therefore, to derive the benefits of using DC arc as excitation source the system was upgraded to a PC based system. This paper describes the upgraded system and the various software features relating to the mode of data acquisition, method of analysis, data processing etc. implemented as required by the analysts. (author)

Evaluation of radioactive emissions of lignite-fired power plants in Turkey using the Analytic Hierarchy Process

Energy Technology Data Exchange (ETDEWEB)

Bueke, Tayfun [Mugla Sitki Kocman Univ., Mugla (Turkey). Dept. of Energy Systems Engineering

2013-11-15

Radioactive emissions of 13 lignite-fired power plants in Turkey are of great concern to the public and to scientists alike. The purpose of this study is to evaluate these power plants, according to their radioactive emissions by using the Analytic Hierarchy Process. Control criteria are in particular {sup 226}Ra, {sup 232}Th, {sup 40}K and {sup 238}U emissions from the power plants. These control criteria are weighted according to the objective assessment. The calculations are repeated for three different objective assessments of control criteria namely the mortality risk coefficients for inhalation, ingestion, external exposure of {sup 226}Ra, {sup 232}Th, {sup 40}K and {sup 238}U. It has been calculated that the Can lignite-fired power plant is ranking first while the Soma-B plant is ranking last according to the radioactive emissions of the power plants when the average of three different objective control criteria are used in the calculations. (orig.)

Level population measurements on analyte atom and ion excited states in the inductively coupled plasma

International Nuclear Information System (INIS)

Walker, Z.H.; Blades, M.W.

1986-01-01

During the past decade a number of publications dealing with fundamental studies of the inductively coupled plasma (ICP) have appeared in the literature. The purpose of many of these investigations has been to understand the nature of the interaction between the plasma gas and the analyte. The general conclusion drawn from these studies has been that the ICP is very close to Local Thermodynamic Equilibrium (LTE), but that some deviations from LTE do occur. Recent studies by the authors' have been directed towards the measurement of analyte atom and ion excited state level populations with the objective of obtaining a better understanding of both ionization and excitation in the ICP discharge and the extent to which such processes contribute to a non-equilibrium state. Further discussion is drawn from similar measurements made on elements with low ionization potentials, such as Barium, as well as on elements such as Iron in the presence of Easily Ionizable Elements (EIE's). The spatial and power dependences of such measurements are also discussed

Lithium determination in whole blood by flame atomic emission spectrometry

International Nuclear Information System (INIS)

Rahman, S.; Khalid, N.; Nasimullah; Iqbal, M.Z.

2003-01-01

A simple and rapid method for the determination of lithium in whole blood using Flame atomic emission spectrometry is described. No sample preparation was required apart from dilution with 0.02 N HNO/sub 3/. The reliability of the method was determined by analyzing Standard Reference Material (SRM) under identical experimental conditions and comparing the determined lithium concentration with the reported value. These were in good agreement with each other. The determined range of lithium in the whole blood of fifty-six healthy adult volunteers (28 males and 28 females) were 13.1 - 47.8 mg L-1. The determined average concentration of lithium in whole blood was compared with the reported values of other countries. The data was statistically analyzed with respect to sex and different age groups. (author)

Particle transport in a He-microchip plasma atomic emission system with an ultrasonic nebulizer for aqueous sample introduction

Energy Technology Data Exchange (ETDEWEB)

Oh, Joosuck [Department of Chemistry, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do, 448-701 (Korea, Republic of); Lim, H.B. [Department of Chemistry, Dankook University, 126 Jukjeon-dong, Suji-gu, Yongin-si, Gyeonggi-do, 448-701 (Korea, Republic of)], E-mail: plasma@dankook.ac.kr

2008-11-15

The transport efficiency of dried particles generated from an ultrasonic nebulizer (USN) was studied to improve the analytical performance of a lab-made, He-microchip plasma system, in which a quartz tube ({approx} 1 mm i.d.) was positioned inside the central channel of a poly(dimethylsiloxane) (PDMS) polymer chip. The polymer microchip plasma has the advantages of low cost, small size, easy handling and design, and self-ignition with long stabilization (> 24 h). However, direct introduction of aqueous solution into the microplasma for the detection of metals remains problematic due to plasma instability. In addition, the much smaller size of the system can cause signal suppression due to low transport efficiency. Therefore, knowledge of particle transport efficiency in this microplasma system is required to enhance the sensitivity and stability. The weight of transported particles in the range of 0.02 to 10 mg m{sup -3} was measured using a piezobalance with a precision of 0.4-17.8%, depending on the operating conditions. The significant effects of the USN operating conditions and the physical properties of the tubing, namely, length, inner diameter and surface characteristics, on the number of particles transported from the nebulizer to the microplasma were studied. When selected metals, such as Na, Mg and Pb, at a concentration of 5 mg L{sup -1} were nebulized, transported particles were obtained with a mass range of 0.5-5 mg m{sup -3}, depending on atomic weights. For application of the He-rf-microplasma, the atomic emission system was optimized by changing both the radio frequency (rf) power (60-200 W) and cooling temperature of the USN (- 12-9 deg. C). The limits of detection obtained for K, Na and Cu were 0.26, 0.22, and 0.28 mg L{sup -1}, respectively. These results confirmed the suitable stability and sensitivity of the He-rf-PDMS microchip plasma for application as an atomization source.

Analytical computation of prompt gamma ray emission and detection for proton range verification

International Nuclear Information System (INIS)

Sterpin, E; Vynckier, S; Janssens, G; Smeets, J; Stappen, François Vander; Prieels, D; Priegnitz, Marlen; Perali, Irene

2015-01-01

A prompt gamma (PG) slit camera prototype recently demonstrated that Bragg Peak position in a clinical proton scanned beam could be measured with 1–2 mm accuracy by comparing an expected PG detection profile to a measured one. The computation of the expected PG detection profile in the context of a clinical framework is challenging but must be solved before clinical implementation. Obviously, Monte Carlo methods (MC) can simulate the expected PG profile but at prohibitively long calculation times. We implemented a much faster method that is based on analytical processing of precomputed MC data that would allow practical evaluation of this range monitoring approach in clinical conditions.Reference PG emission profiles were generated with MC simulations (PENH) in targets consisting of either 12 C, 14 N, 16 O, 31 P or 40 Ca, with 10% of 1 H. In a given geometry, the local PG emission can then be derived by adding the contribution of each element, according to the local energy of the proton obtained by continuous slowing down approximation and the local composition. The actual incident spot size is taken into account using an optical model fitted to measurements and by super sampling the spot with several rays (up to 113). PG transport in the patient/camera geometries and the detector response are modelled by convolving the PG production profile with a transfer function. The latter is interpolated from a database of transfer functions fitted to MC data (PENELOPE) generated for a photon source in a cylindrical phantom with various radiuses and a camera placed at various positions.As a benchmark, the analytical model was compared to MC and experiments in homogeneous and heterogeneous phantoms. Comparisons with MC were also performed in a thoracic CT. For all cases, the analytical model reproduced the prediction of the position of the Bragg peak computed with MC within 1 mm for the camera in nominal configuration. When compared to measurements, the shape of the

Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

Energy Technology Data Exchange (ETDEWEB)

Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)], E-mail: ataman@metu.edu.tr

2008-08-15

Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C{sub 0}, where the change in characteristic mass, m{sub 0}, can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as E{sub max}, maximum enhancement factor; E{sub t}, enhancement for 1.0 minute sampling and E{sub v}, enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps.

Study of the analytic quality in the determinations of Cr, Fe, Mn, Cu, Zn, Pb and Hg through conventional and nuclear analytical techniques in mosses of the MATV

International Nuclear Information System (INIS)

Caballero S, B.

2013-01-01

To evaluate the environmental risks of air pollution and to facilitate the decision-making for control, is necessary to have the capacity to generate data with analytical quality. A comparison between nuclear (Neutron activation analysis and total reflection X-ray fluorescence spectrometry) and no nuclear analytical techniques (atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry) for simultaneous determination of metal content (Cr, Cu, Fe, Hg, Mn, Pb and Zn) in mosses from Metropolitan Area of the Toluca Valley (MATV) was performed. Epiphytic mosses (Fabriona ciliaris and Leskea angustata) were sampled in two campaigns, 16 sites (urban, transition and natural) and were prepared for each technique. The biological certified reference materials were used for the quality control and to evaluate accuracy, precision, linearity, detection and quantification limits. Results show that nuclear analytical techniques and no nuclear applied in chemical analysis of Cr, Cu, Fe, Hg, Mn, Pb and Zn in moss from MATV are comparable and therefore all of these can potentially be used for this purpose. However, if its considered both, the performance parameters and economic/operational characteristics is widely recommended inductively coupled plasma optical emission spectrometry, conventional analytical technique, which showed the highest analytical grade quality. Also were observed spatial and temporal variations in the concentrations of Cr, Cu, Fe, Hg, Mn, Pb and Zn in mosses from MATV and was discussed its potential origin. The urban sites had the highest concentration of anthropogenic elements as Cr, Cu, Fe, Hg, Pb and Zn because are strongly impacted by roads with high vehicle traffic. (Author)

Rapid analysis of mixed waste samples via the optical emission from laser initiated microplasmas

International Nuclear Information System (INIS)

Barefield, J.E. II; Ferran, M.D.; Cremers, D.A.

1993-01-01

Wavelength resolved optical emission from laser initiated microplasmas in samples containing Pu, Am, Pb, Cr, and Be was used to determine elemental compositions. Traditionally, samples of this type are analyzed by neutron activation, X-ray fluorescence, atomic absorption (AA), inductively coupled plasma - atomic emission spectroscopy (ICP-AES), and inductively coupled plasma mass spectroscopy (ICP-MS). Analysis via the traditional analytical spectroscopic techniques involves extensive sample separation and preparation which results in the generation of significant quantities of additional waste. In the laser based method, little to no sample preparation is required. The method is essentially waste free since only a few micrograms of material is removed from the sample in the generation of the microplasma. Detection limits of the laser based method typically range between subppm to tens of ppM. In this report, the optical emission from samples containing Pu, Am, Pb, Cr, and Be will be discussed. we will also discuss the essential elements of the analysis method

Noise-immune cavity-enhanced analytical atomic spectrometry — NICE-AAS — A technique for detection of elements down to zeptogram amounts

International Nuclear Information System (INIS)

Axner, Ove; Ehlers, Patrick; Hausmaninger, Thomas; Silander, Isak; Ma, Weiguang

2014-01-01

Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is a powerful technique for detection of molecular compounds in gas phase that is based on a combination of two important concepts: frequency modulation spectroscopy (FMS) for reduction of noise, and cavity enhancement, for prolongation of the interaction length between the light and the sample. Due to its unique properties, it has demonstrated unparalleled detection sensitivity when it comes to detection of molecular constituents in the gas phase. However, despite these, it has so far not been used for detection of atoms, i.e. for elemental analysis. The present work presents an assessment of the expected performance of Doppler-broadened (Db) NICE-OHMS for analytical atomic spectrometry, then referred to as noise-immune cavity-enhanced analytical atomic spectrometry (NICE-AAS). After a description of the basic principles of Db-NICE-OHMS, the modulation and detection conditions for optimum performance are identified. Based on a previous demonstrated detection sensitivity of Db-NICE-OHMS of 5 × 10 −12 cm −1 Hz −1∕2 (corresponding to a single-pass absorbance of 7 × 10 −11 over 10 s), the expected limits of detection (LODs) of Hg and Na by NICE-AAS are estimated. Hg is assumed to be detected in gas phase directly while Na is considered to be atomized in a graphite furnace (GF) prior to detection. It is shown that in the absence of spectral interferences, contaminated sample compartments, and optical saturation, it should be feasible to detect Hg down to 10 zg/cm 3 (10 fg/m 3 or 10 −5 ng/m 3 ), which corresponds to 25 atoms/cm 3 , and Na down to 0.5 zg (zg = zeptogram = 10 −21 g), representing 50 zg/mL (parts-per-sextillion, pps, 1:10 21 ) in liquid solution (assuming a sample of 10 μL) or solely 15 atoms injected into the GF, respectively. These LODs are several orders of magnitude lower (better) than any previous laser-based absorption technique previously demonstrated

Surface and electron emission properties of hydrogen-free diamond-like carbon films investigated by atomic force microscopy

International Nuclear Information System (INIS)

Liu Dongping; Zhang, Sam; Ong, S.-E.; Benstetter, Guenther; Du Hejun

2006-01-01

In this study, we have deposited hydrogen-free diamond-like carbon (DLC) films by using DC magnetron sputtering of graphite target at various r.f. bias voltages. Surface and nanoscale emission properties of these DLC films have been investigated using a combination of atomic force microscopy (AFM)-based nanowear tests and conducting-AFM, by simultaneously measuring the topography and the conductivity of the samples. Nanowear tests show that these DLC films are covered with the thin (1.5-2.0 nm) graphite-like layers at surfaces. Compared to the film bulk structure, the graphite-like surface layers are more conductive. The graphite-like surface layers significantly influence the electron emission properties of these films. Low-energy carbon species can be responsible for the formation of graphite-like surface layers. Nanoscale electron emission measurements have revealed the inhomogeneous emission nature of these films. The low-field emission from these films can be attributed to the existence of sp 2 -configured nanoclusters inside the films

Determination of trace elements in maifanite by outer cover electrode atomic emission spectrometry

Institute of Scientific and Technical Information of China (English)

LI Jianqiang; LU Yiqiang; JIANG Wei

2005-01-01

Maifanite is a nature medicinal stone used in many fields for long time. The research on it showed that there are many trace elements in maifanite. In this paper, 36 trace elements in maifanite were determined by outer cover electrode atomic emission spectrometry, and the determination conditions were studied systematically. The results show that the concentrafions of elements, which are beneficial to human health, are higher, and the elements harmful to people health such as As, Cd, Hg, Cr, and Pb are tiny in maifanite. The precision and the accuracy were also discussed.

Initial state dependence of low-energy electron emission in fast ion atom collisions

International Nuclear Information System (INIS)

Moshammer, R.; Schmitt, W.; Kollmus, H.; Ullrich, J.; Fainstein, P.D.; Hagmann, S.

1999-06-01

Single and multiple ionization of Neon and Argon atoms by 3.6 MeV/u Au 53+ impact has been explored in kinematically complete experiments. Doubly differential cross sections for low-energy electron emission have been obtained for defined charge state of the recoiling target ion and the receding projectile. Observed target specific structures in the electron continuum are attributable to the nodal structure of the initial bound state momentum distribution. The experimental data are in excellent accord with CDW-EIS single ionization calculations if multiple ionization is considered appropriately. (orig.)

Refurbishment of an Analytical Laboratory Hot Cell Facility

International Nuclear Information System (INIS)

Rosenberg, K.; Henslee, S.P.; Michelbacher, J.A.; Coleman, R.M.

1997-01-01

An Analytical Laboratory Hot Cell (ALHC) Facility at Argonne National Laboratory-West (ANL-W) was in service for nearly thirty years. In order to comply with DOE regulations governing such facilities and meet ANL-W programmatic requirements, a major refurbishment effort was undertaken. All penetrations within the facility were sealed; the ventilation system was redesigned, upgraded and replaced; the manipulators were replaced; the hot cell windows were removed, refurbished, and reinstalled; all hot cell utilities were replaced; a lead-shielded glovebox housing an Inductively Coupled Plasma - Atomic Emission Spectrometer (ICP-AES) System was interfaced with the hot cells, and a new CO2 fire suppression system and other ALHC support equipment were installed

Atom spectroscopy

International Nuclear Information System (INIS)

Kodling, K.

1981-01-01

Experiments on atom photoabsorption spectroscopy using synchrotron radiation in the 10-1000 eV range are reviewed. Properties of the necessary synchrotron radiation and the experiment on absorption spectroscopy are briefly described. Comparison with other spectroscopy methods is conducted. Some data on measuring photoabsorption, photoelectron emission and atom mass spectra are presented [ru

Quenching of the OH and nitrogen molecular emission by methane addition in an Ar capacitively coupled plasma to remove spectral interference in lead determination by atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Frentiu, T., E-mail: ftibi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Ponta, M., E-mail: mponta@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Mihaltan, A.I., E-mail: alinblaj2005@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Darvasi, E., E-mail: edarvasi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Frentiu, M., E-mail: frentiu.maria@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Cordos, E., E-mail: emilcordos@gmail.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania)

2010-07-15

A new method is proposed to remove the spectral interference on elements in atomic fluorescence spectrometry by quenching of the molecular emission of the OH radical (A{sup 2{Sigma}+} {yields} X{sup 2{Pi}}) and N{sub 2} second positive system (C{sup 3{Pi}}{sub u} {yields} B{sup 3{Sigma}}{sub g}) in the background spectrum of medium power Ar plasmas. The experiments were carried out in a radiofrequency capacitively coupled plasma (275 W, 27.12 MHz) by CH{sub 4} addition. The quenching is the result of the high affinity of OH radical for a hydrogen atom from the CH{sub 4} molecule and the collisions of the second kind between nitrogen excited molecules and CH{sub 4}, respectively. The decrease of the emission of N{sub 2} second positive system in the presence of CH{sub 4} is also the result of the deactivation of the metastable argon atoms that could excite the nitrogen molecules. For flow rates of 0.7 l min{sup -1} Ar with addition of 7.5 ml min{sup -1} CH{sub 4}, the molecular emission of OH and N{sub 2} was completely removed from the plasma jet spectrum at viewing heights above 60 mm. The molecular emission associated to CH and CH{sub 2} species was not observed in the emission spectrum of Ar/CH{sub 4} plasma in the ultraviolet range. The method was experimented for the determination of Pb at 283.31 nm by atomic fluorescence spectrometry with electrodeless discharge lamp and a multichannel microspectrometer. The detection limit was 35 ng ml{sup -1}, 2-3 times better than in atomic emission spectrometry using the same plasma source, and similar to that in hollow cathode lamp microwave plasma torch atomic fluorescence spectrometry.

Upgrade for detection system of JARREL ASH 70-000 atomic emission spectrography with source of arc - spark

International Nuclear Information System (INIS)

Santa Cruz D E; Grau F N; Bellavigna H J; Garavaglia R N; Fernandez R O; Servant R

2012-01-01

Methodologies used in spectrochemical analysis have showed breakthroughs in last decades due to the newest digital technologies. The simultaneous determination of multiple elements in a short time has been allowed by the development of solid state multichannel detectors. Since its beginning CNEA has developed several spectroscopic methodologies that have been applied to the area of fuels and specific materials of the nuclear activity. The Analytical Chemistry Department has an atomic emission spectrograph with a source of arc/spark whose focal length is 3.4 meters and a spectral dispersion from 2.5 to 5 A/mm. This equipment was originally equipped with photographic detection. This feature although allowed the simultaneous detection of multiple elements, their response (photographic plate) has been not linear and their data's treatment has been very complex. Two alternatives of digital detection have been examined: CCD2 and CMOS3 according to the progress achieved in the instrumentation that is applied to similar techniques. After exhaustive evaluation an arrangement of 9 linear CCD detectors located in the focal plane originally occupied by 2 x10 inch photographic plates was chosen. The software provided by the manufacturer has been insufficient for cover our analytical necessities due to the requirements of our instrumental application. This led to develop an own program for our applications. Today, our detection system includes an assembly of 7 detectors and an acquisition program with basic control that has been developed in-house. Calibration curves for some chemical elements have shown very promising results, the sensitivity has increased at least 10 times and an important improvement of accuracy of the measurements has also been achieved thanks to our modification. An upgrade with an associated database that will allow obtaining spectra in 3D configuration and extend the instrumental capabilities to second order is being prepared (author)

A COUPLED CHEMISTRY-EMISSION MODEL FOR ATOMIC OXYGEN GREEN AND RED-DOUBLET EMISSIONS IN THE COMET C/1996 B2 HYAKUTAKE

Energy Technology Data Exchange (ETDEWEB)

Bhardwaj, Anil; Raghuram, Susarla, E-mail: bhardwaj_spl@yahoo.com, E-mail: anil_bhardwaj@vssc.gov.in, E-mail: raghuramsusarla@gmail.com [Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum 695022 (India)

2012-03-20

The green (5577 Angstrom-Sign ) and red-doublet (6300, 6364 Angstrom-Sign ) lines are prompt emissions of metastable oxygen atoms in the {sup 1}S and {sup 1}D states, respectively, that have been observed in several comets. The value of the intensity ratio of green to red-doublet (G/R ratio) of 0.1 has been used as a benchmark to identify the parent molecule of oxygen lines as H{sub 2}O. A coupled chemistry-emission model is developed to study the production and loss mechanisms of the O({sup 1}S) and O({sup 1}D) atoms and the generation of red and green lines in the coma of C/1996 B2 Hyakutake. The G/R ratio depends not only on photochemistry, but also on the projected area observed for cometary coma, which is a function of the dimension of the slit used and the geocentric distance of the comet. Calculations show that the contribution of photodissociation of H{sub 2}O to the green (red) line emission is 30%-70% (60%-90%), while CO{sub 2} and CO are the next potential sources contributing 25%-50% (<5%). The ratio of the photoproduction rate of O({sup 1} S) to O({sup 1} D) would be around 0.03 ({+-}0.01) if H{sub 2}O is the main source of oxygen lines, whereas it is {approx}0.6 if the parent is CO{sub 2}. Our calculations suggest that the yield of O({sup 1} S) production in the photodissociation of H{sub 2}O cannot be larger than 1%. The model-calculated radial brightness profiles of the red and green lines and G/R ratios are in good agreement with the observations made on the comet Hyakutake in 1996 March.

Noise-immune cavity-enhanced analytical atomic spectrometry - NICE-AAS - A technique for detection of elements down to zeptogram amounts

Science.gov (United States)

Axner, Ove; Ehlers, Patrick; Hausmaninger, Thomas; Silander, Isak; Ma, Weiguang

2014-10-01

Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) is a powerful technique for detection of molecular compounds in gas phase that is based on a combination of two important concepts: frequency modulation spectroscopy (FMS) for reduction of noise, and cavity enhancement, for prolongation of the interaction length between the light and the sample. Due to its unique properties, it has demonstrated unparalleled detection sensitivity when it comes to detection of molecular constituents in the gas phase. However, despite these, it has so far not been used for detection of atoms, i.e. for elemental analysis. The present work presents an assessment of the expected performance of Doppler-broadened (Db) NICE-OHMS for analytical atomic spectrometry, then referred to as noise-immune cavity-enhanced analytical atomic spectrometry (NICE-AAS). After a description of the basic principles of Db-NICE-OHMS, the modulation and detection conditions for optimum performance are identified. Based on a previous demonstrated detection sensitivity of Db-NICE-OHMS of 5 × 10- 12 cm- 1 Hz- 1/2 (corresponding to a single-pass absorbance of 7 × 10- 11 over 10 s), the expected limits of detection (LODs) of Hg and Na by NICE-AAS are estimated. Hg is assumed to be detected in gas phase directly while Na is considered to be atomized in a graphite furnace (GF) prior to detection. It is shown that in the absence of spectral interferences, contaminated sample compartments, and optical saturation, it should be feasible to detect Hg down to 10 zg/cm3 (10 fg/m3 or 10- 5 ng/m3), which corresponds to 25 atoms/cm3, and Na down to 0.5 zg (zg = zeptogram = 10- 21 g), representing 50 zg/mL (parts-per-sextillion, pps, 1:1021) in liquid solution (assuming a sample of 10 μL) or solely 15 atoms injected into the GF, respectively. These LODs are several orders of magnitude lower (better) than any previous laser-based absorption technique previously demonstrated under atmospheric

Electrothermal atomization laser-excited atomic fluorescence spectroscopy for the determination of indium

International Nuclear Information System (INIS)

Aucelio, R.Q.; Smith, B.W.; Winefordner, J.D.

1998-01-01

A dye laser pumped by a high-repetition-rate copper vapor laser was used as the excitation source to determine indium at parts-per-trillion level by electrothermal atomization laser-excited atomic fluorescence spectrometry (ETA-LEAFS). A comparison was made between wall atomization, in pyrolytic and nonpyrolytic graphite tubes, and platform atomization. The influence of several chemical modifiers either in solution or precoated in the graphite tube was evaluated. The influence of several acids and NaOH in the analyte solution was also studied. Optimization of the analytical conditions was carried out to achieve the best signal-to-background ratio and consequently an absolute limit of detection of 1 fg. Some possible interferents of the method were evaluated. The method was evaluated by determining indium in blood, urine, soil, and urban dust samples. Recoveries between 99.17 and 109.17% are reported. A precision of 4.1% at the 10 ng g -1 level in water standards was achieved. copyright 1998 Society for Applied Spectroscopy

Unexpected role of excess noise in spontaneous emission

International Nuclear Information System (INIS)

Lamprecht, C.; Ritsch, H.

2002-01-01

A single inverted two-level atom is used as a theoretical model for a quantum noise detector to investigate fundamental properties of excess noise in an unstable optical resonator. For a symmetric unstable spherical mirror cavity, we develop an analytic quantum description of the field in terms of a complete set of normalizable biorthogonal quasimodes and adjoint modes. Including the interaction with a single two-level atom leads to a description analogous to the Jaynes-Cummings model with modified coupling constants. One finds a strong position and geometry-dependent atomic decay probability proportional to the square root √(K) of the excess noise factor K at the cavity center. Introducing an additional homogeneous gain one recovers the K-fold emission enhancement that has been predicted before for the linewidth of an unstable cavity laser. We find that excess noise may be viewed as a spatial redistribution of the field quantum noise inside the resonator. Taking a position average of the atomic decay rate over the cavity volume leads to a cancellation of the excess noise enhancement

Analytical solution for the normal emission portion of the averaged Yarkovsky-O'Keefe-Radzvieskii-Paddack coefficient for a single facet

Science.gov (United States)

Albuja, Antonella A.; Scheeres, Daniel J.

2015-02-01

The Yarkovsky-O'Keefe-Radzvieskii-Paddack (YORP) effect has been well studied for asteroids. This paper develops an analytic solution to find the normal emission YORP component for a single facet. The solution presented here does not account for self-shadowing or self-heating. The YORP coefficient for all facets can be summed together to find the total coefficient of the asteroid. The normal emission component of YORP has been shown to be the most important for asteroids and it directly affects the rate of change of the asteroid's spin period. The analytical solution found is a sole function of the facet's geometry and the obliquity of the asteroid. This solution is universal for any facet and its orientation. The behaviour of the coefficient is analysed with this analytical solution. The closed-form solution is used to find the total YORP coefficient for the asteroids Apollo and 1998 ML14 whose shape models are composed of different numbers of facets. The results are then compared to published results and those obtained through numerical quadrature for validation.

Spectral emissivity of tungsten: analytic expressions for the 340-nm to 2.6-μm spectral region

International Nuclear Information System (INIS)

Pon, R.M.; Hessler, J.P.

1984-01-01

To correct emission spectra a standard radiance source is often used to determine the spectral responsivity of the detection system. In the near-UV, visible, and near-IR spectral regions the most common radiance standard is a tungsten strip lamp calibrated by a standards laboratory. For day-to-day experiments where slightly less accuracy is acceptable, a less expensive uncalibrated lamp is useful. In this case, the radiant temperature T/sub r/ of the lamp is measured with an optical pyrometer, generally at a single wavelength such as 650 nm, and the source spectral radiance L(λ) is calculated from L(λ) = tau(λ)epsilon(λ,T)L/sub B/(λ,T). The transmittance of the source is tau(λ), the spectral emissivity is epsilon(λ,T), and L/sub B/(λ,T) is the spectral distribution of blackbody radiation, Planck's radiation law. To obtain the true temperature T, Wien's approximation is employed. To conveniently calibrate a system, especially one which utilizes a microcomputer, it is advantageous to have analytic expressions for the spectral emissivity of tungsten. Although Larrabee has published such expressions, they are limited to the 450-800-nm spectral region. To obtain analytic expressions from 340 nm to 2.6 μm they have used the measurements of DeVos. Although DeVos's results differ by 2% from those of Larrabee, this difference is assumed to be acceptable

Plasma emission induced by an Nd-YAG laser at low pressure on solid organic sample, its mechanism, and analytical application

International Nuclear Information System (INIS)

Suliyanti, Maria Margaretha; Sardy, Sar; Kusnowo, Anung; Hedwig, Rinda; Abdulmadjid, Syahrun Nur; Kurniawan, Koo Hendrik; Lie, T.J.; Pardede, Marincan; Kagawa, Kiichiro; Tjia, M.O.

2005-01-01

An Nd-YAG laser (1064 nm, 120 mJ, 8 ns) was focused on various types of solid organic samples such as a black acrylic plate, a black polyvinyl chloride plastic sheet, and a methoxy polyaniline film coated on the surface of a glass substrate, under a surrounding air pressure of 2 Torr. A modulated plasma technique was used to study the mechanism of excitation of the emission of the organic material. As a result, we conclude that ablated atoms and molecules are excited by a shock-wave mechanism, similar to the case of hard samples such as metal. The ablation speed of hydrogen emission (H I 656.2 nm) was examined and the results show that the release speed of the ablated atoms is relatively low (less than Mach 10) and persists for a longer period of time (around 1 μs); this phenomenon can be understood by assuming that the soft target absorbs recoil energy, causing a low release speed of ablated atoms which would form the shock wave. This was overcome by placing a subtarget on the back of the soft sample so as to enhance the repelling force, thus increasing the release speed of the atoms. A possible application of the low-pressure plasma on an organic solid was demonstrated in the detection of chlorine in a black polyvinyl chloride plastic sheet

A new atomization cell for trace metal determinations by tungsten coil atomic spectrometry

Energy Technology Data Exchange (ETDEWEB)

Donati, G.L., E-mail: georgedonati@yahoo.com.br [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Wildman, R.B.; Jones, B.T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States)

2011-02-28

A new metallic atomization cell is used for trace metal determinations by tungsten coil atomic absorption spectrometry and tungsten coil atomic emission spectrometry. Different protecting gas mixtures are evaluated to improve atomic emission signals. Ar, N{sub 2}, CO{sub 2} and He are used as solvents, and H{sub 2} and C{sub 2}H{sub 2} as solutes. A H{sub 2}/Ar mixture provided the best results. Parameters such as protecting gas flow rate and atomization current are also optimized. The optimal conditions are used to determine the figures of merit for both methods and the results are compared with values found in the literature. The new cell provides a better control of the radiation reaching the detector and a small, more isothermal environment around the atomizer. A more concentrated atomic cloud and a smaller background signal result in lower limits of detection using both methods. Cu (324.7 nm), Cd (228.8 nm) and Sn (286.3 nm) determined by tungsten coil atomic absorption spectrometry presented limits of detection as low as 0.6, 0.1, and 2.2 {mu}g L{sup -1}, respectively. For Cr (425.4 nm), Eu (459.4 nm) and Sr (460.7 nm) determined by tungsten coil atomic emission spectrometry, limits of detection of 4.5, 2.5, and 0.1 {mu}g L{sup -1} were calculated. The method is used to determine Cu, Cd, Cr and Sr in a water standard reference material. Results for Cu, Cd and Cr presented no significant difference from reported values in a 95% confidence level. For Sr, a 113% recovery was obtained.

ATOMIC CARBON IN THE UPPER ATMOSPHERE OF TITAN

International Nuclear Information System (INIS)

Zhang, X.; Yung, Y. L.; Ajello, J. M.

2010-01-01

The atomic carbon emission C I line feature at 1657 A ( 3 P 0 J - 3 P J ) in the upper atmosphere of Titan is first identified from the airglow spectra obtained by the Cassini Ultra-violet Imaging Spectrograph. A one-dimensional photochemical model of Titan is used to study the photochemistry of atomic carbon on Titan. Reaction between CH and atomic hydrogen is the major source of atomic carbon, and reactions with hydrocarbons (C 2 H 2 and C 2 H 4 ) are the most important loss processes. Resonance scattering of sunlight by atomic carbon is the dominant emission mechanism. The emission intensity calculations based on model results show good agreement with the observations.

Time evolution, Lamb shift, and emission spectra of spontaneous emission of two identical atoms

International Nuclear Information System (INIS)

Wang Dawei; Li Zhenghong; Zheng Hang; Zhu Shiyao

2010-01-01

A unitary transformation method is used to investigate the dynamic evolution of two multilevel atoms, in the basis of symmetric and antisymmetric states, with one atom being initially prepared in the first excited state and the other in the ground state. The unitary transformation guarantees that our calculations are based on the ground state of the atom-field system and the self-energy is subtracted at the beginning. The total Lamb shifts of the symmetric and antisymmetric states are divided into transformed shift and dynamic shift. The transformed shift is due to emitting and reabsorbing of virtual photons, by a single atom (nondynamic single atomic shift) and between the two atoms (quasi-static shift). The dynamic shift is due to the emitting and reabsorbing of real photons, by a single atom (dynamic single atomic shift) and between the two atoms (dynamic interatomic shift). The emitting and reabsorbing of virtual and real photons between the two atoms result in the interatomic shift, which does not exist for the one-atom case. The spectra at the long-time limit are calculated. If the distance between the two atoms is shorter than or comparable to the wavelength, the strong coupling between the two atoms splits the spectrum into two peaks, one from the symmetric state and the other from the antisymmetric state. The origin of the red or blue shifts for the symmetric and antisymmetric states mainly lies in the negative or positive interaction energy between the two atoms. In the investigation of the short time evolution, we find the modification of the effective density of states by the interaction between two atoms can modulate the quantum Zeno and quantum anti-Zeno effects in the decays of the symmetric and antisymmetric states.

Theory of analytical curves in atomic fluorescence flame spectrometry

NARCIS (Netherlands)

Hooymayers, H.P.

An explicit expression for the intensity of atomic resonance fluorescence as a function of atomic concentration in a flame is derived under certain idealized conditions. The expression is generally valid for a pure Doppler absorption line profile as well as for a combined Doppler and collisional

Atomic fluorescence spectrometry with the inductively coupled plasma

International Nuclear Information System (INIS)

Omenetto, N.; Winefordner, J.D.

1987-01-01

Atomic fluorescence spectrometry (AFS) is based on the radiational activation of atoms and ions produced in a suitable atomizer (ionizer) and the subsequent measurement of the resulting radiational deactivation, called fluorescence. Atomic fluorescence spectrometry has been of considerable interest to researchers in atomic spectrometry because of its use for both analytical and diagnostic purposes. Unfortunately, the analytical applications of AFS have suffered from the lack of commercial instrumentation until the recent marketing of the Baird multiple-element, hollow cathode lamp-excited inductively coupled plasma system. This chapter is concerned strictly with the use of the inductively coupled plasma (ICP) as a cell and as a source for AFS. Many of the major references concerning the ICP in analytical AFS are categorized in Table 9.1, along with several reviews and diagnostical studies. For more detailed discussions of the fundamental aspects of AFS, the reader is referred to previous reviews

Sputtering of copper atoms by keV atomic and molecular ions A comparison of experiment with analytical and computer based models

CERN Document Server

Gillen, D R; Goelich,

2002-01-01

Non-resonant multiphoton ionisation combined with quadrupole and time-of-flight analysis has been used to measure energy distributions of sputtered copper atoms. The sputtering of a polycrystalline copper target by 3.6 keV Ar sup + , N sup + and CF sub 2 sup + and 1.8 keV N sup + and CF sub 2 sup + ion bombardment at 45 deg. has been investigated. The linear collision model in the isotropic limit fails to describe the high energy tail of the energy distributions. However the TRIM.SP computer simulation has been shown to provide a good description. The results indicate that an accurate description of sputtering by low energy, molecular ions requires the use of computer simulation rather than analytical approaches. This is particularly important when considering plasma-surface interactions in plasma etching and deposition systems.

Inhibition of collective spontaneous decay and superradiance in an ensemble of sufficiently high quantity of excited identical atoms

International Nuclear Information System (INIS)

Basharov, A.M.

2011-01-01

New effects of suppression of the collective spontaneous emission and superradiance have been predicted. At a certain number N of ensemble atoms, the Stark interaction with a vacuum field was shown as being high enough for the excited N-atom ensemble to be stabilized with respect to the collective decay. The result was derived analytically as a consequence of applying the quantum stochastic differential equations to the description of the atomic dynamics in vacuum, where the Stark interaction operator is expressed in terms of the quantum Poisson process. -- Highlights: → Enhancement of the Stark interaction of N atoms ensemble with vacuum, with N rising. → Representation of the Stark interaction as the quantum Poisson process. → Collective spontaneous decay and superradiance under the strong Stark interaction. → Inhibition of superradiance at a certain number of ensemble atoms. → Analysis of superradiance experiments in terms of inhibition of collective decay.

Measurement of visible and UV emission from Energetic Neutral Atom Precipitation (ENAP), on Spacelab

Science.gov (United States)

Tinsley, B. A.

1980-01-01

The charge exchange of plasmaspheric ions and exospheric H and O and of solar wind ions with exospheric and interplanetary H are sources of precipitating neutrals whose faint emission may be observed by the imaging spectrometric observatory during dark periods of the SL-1 orbit. Measurements of the interactions of these precipitating atoms with the thermosphere are needed to evaluate the heating and ionization effects on the atmosphere as well as the selective loss of i energetic ions from the sources (predominantly the ring current).

Electromagnetic transitions in the atom

International Nuclear Information System (INIS)

Ulehla, I.; Suk, M.; Trka, Z.

1990-01-01

Methods to achieve excitation of atoms are outlined and conditions necessary for the occurrence of electromagnetic transitions in the atomic shell are given. Radiative transitions between the energy states of the atom include stimulated absorption, spontaneous emission, and stimulated emission. Selection rules applying to the majority of observed transitions are given. The parity concept is explained. It is shown how the electromagnetic field and its interaction with the magnetic moment of the atom lead to a disturbance of the energy states of the atom and the occurrence of various electro-optical and magneto-optical phenomena. The Stark effect and electron spin resonance are described. X-rays and X-ray spectra, the Auger effect and the internal photoeffect are also dealt with. The principle of the laser is explained. (M.D.). 22 figs., 1 tab

Spectroscopy stepping stones

International Nuclear Information System (INIS)

Hammer, M.R.; Sturman, B.T.

2003-01-01

Determining the elemental composition of samples has long been a basic task of analytical science. Some very powerful and convenient approaches are based on the wavelength-specific absorption or emission of light by gas-phase atoms. Techniques briefly described as examples of analytical atomic spectrometry include atomic emission and absorption spectroscopy, inductively coupled plasma emission and mass spectroscopy and laser induced breakdown spectrometry

The use of atomic spectroscopy in the pharmaceutical industry for the determination of trace elements in pharmaceuticals.

Science.gov (United States)

Lewen, Nancy

2011-06-25

The subject of the analysis of various elements, including metals and metalloids, in the pharmaceutical industry has seen increasing importance in the last 10-15 years, as modern analytical instrumentation has afforded analysts with the opportunity to provide element-specific, accurate and meaningful information related to pharmaceutical products. Armed with toxicological data, compendial and regulatory agencies have revisited traditional approaches to the testing of pharmaceuticals for metals and metalloids, and analysts have begun to employ the techniques of atomic spectroscopy, such as flame- and graphite furnace atomic absorption spectroscopy (FAAS, Flame AA or FAA and GFAAS), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS), to meet their analytical needs. Newer techniques, such as laser-induced breakdown spectroscopy (LIBS) and Laser Ablation ICP-MS (LAICP-MS) are also beginning to see wider applications in the analysis of elements in the pharmaceutical industry.This article will provide a perspective regarding the various applications of atomic spectroscopy in the analysis of metals and metalloids in drug products, active pharmaceutical ingredients (API's), raw materials and intermediates. The application of atomic spectroscopy in the analysis of metals and metalloids in clinical samples, nutraceutical, metabolism and pharmacokinetic samples will not be addressed in this work. Copyright © 2010 Elsevier B.V. All rights reserved.

Analytical spectroscopy. Analytical Chemistry Symposia Series, Volume 19

International Nuclear Information System (INIS)

Lyon, W.S.

1984-01-01

This book contains papers covering several fields in analytical chemistry including lasers, mass spectrometry, inductively coupled plasma, activation analysis and emission spectroscopy. Separate abstracting and indexing was done for 64 papers in this book

[Study on the method for the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current arc full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES)].

Science.gov (United States)

Hao, Zhi-hong; Yao, Jian-zhen; Tang, Rui-ling; Zhang, Xue-mei; Li, Wen-ge; Zhang, Qin

2015-02-01

The method for the determmation of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current are full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES) was established. Direct current are full spectrum direct reading atomic emission spectrometer with a large area of solid-state detectors has functions of full spectrum direct reading and real-time background correction. The new electrodes and new buffer recipe were proposed in this paper, and have applied for national patent. Suitable analytical line pairs, back ground correcting points of elements and the internal standard method were selected, and Ge was used as internal standard. Multistage currents were selected in the research on current program, and each current set different holding time to ensure that each element has a good signal to noise ratio. Continuous rising current mode selected can effectively eliminate the splash of the sample. Argon as shielding gas can eliminate CN band generating and reduce spectral background, also plays a role in stabilizing the are, and argon flow 3.5 L x min(-1) was selected. Evaporation curve of each element was made, and it was concluded that the evaporation behavior of each element is consistent, and combined with the effects of different spectrographic times on the intensity and background, the spectrographic time of 35s was selected. In this paper, national standards substances were selected as a standard series, and the standard series includes different nature and different content of standard substances which meet the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples. In the optimum experimental conditions, the detection limits for B, Mo, Ag, Sn and Pb are 1.1, 0.09, 0.01, 0.41, and 0.56 microg x g(-1) respectively, and the precisions (RSD, n=12) for B, Mo, Ag, Sn and Pb are 4.57%-7.63%, 5.14%-7.75%, 5.48%-12.30%, 3.97%-10.46%, and 4.26%-9.21% respectively. The analytical accuracy was

Impact of population and economic growth on carbon emissions in Taiwan using an analytic tool STIRPAT

Directory of Open Access Journals (Sweden)

Jong-Chao Yeh

2017-01-01

Full Text Available Carbon emission has increasingly become an issue of global concern because of climate change. Unfortunately, Taiwan was listed as top 20 countries of carbon emission in 2014. In order to provide appropriate measures to control carbon emission, it appears that there is an urgent need to address how such factors as population and economic growth impact the emission of carbon dioxide in any developing countries. In addition to total population, both the percentages of population living in urban area (i.e., urbanization percentage, and non-dependent population may also serve as limiting factors. On the other hand, the total energy-driven gross domestic production (GDP and the percentage of GDP generated by the manufacturing industries are assessed to see their respective degree of impact on carbon emission. Therefore, based on the past national data in the period 1990–2014 in Taiwan, an analytic tool of Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT was employed to see how well those aforementioned factors can describe their individual potential impact on global warming, which is measured by the total amount of carbon emission into the atmosphere. Seven scenarios of STIRPAT model were proposed and tested statistically for the significance of each proposed model. As a result, two models were suggested to predict the impact of carbon emission due to population and economic growth by the year 2025 in Taiwan.

Atomic parity violation in heavy alkalis: detection by stimulated emission for cesium and traps for cold francium

Energy Technology Data Exchange (ETDEWEB)

Sanguinetti, St

2004-07-01

The present work deals with the recent advances of atomic spectroscopy experiments on cesium and francium, which aim at precise parity violation (PV) measurements in these atoms. Within the framework of a 'double-badged thesis', the candidate devoted himself on the one hand to the preliminary PV measurement (8% accuracy) of the present Cs experiment at the Kastler-Brossel laboratory in Paris and on the other hand to the preparation of a Fr radioactive atomic sample (production and trapping) at the LNL (INFN) in Italy. The two experiments are at very different stages. The measurements reported for cesium were actually made possible thanks to the work initiated in 1991, for the PV detection by stimulated emission. The Italian experiment is instead in a beginning stage: in order to probe the properties of francium, which is unstable, a number of atoms large enough has to be first produced and collected. The PV schemes which proved to be well suited for cesium are a solid starting point for the case of francium. (author)

Atomic mass spectrometry

International Nuclear Information System (INIS)

Sanz-Medel, A.

1997-01-01

The elemental inorganic analysis seems to be dominated today by techniques based on atomic spectrometry. After an evaluation of advantages and limitations of using mass analysers (ion detectors) versus conventional photomultipliers (photon detector) a brief review of the more popular techniques of the emerging Atomic Mass spectrometry is carried out. Their huge potential for inorganic trace analysis is such that in the future we could well witness how this end of the century and millennium marked the fall of the photons empire in Analytical Atomic Spectrometry. (Author)

Experimental evidence of state-selective charge transfer in inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Chan, George C.-Y.; Hieftje, Gary M.

2004-01-01

State-selective charge-transfer behavior was observed for Fe, Cr, Mn and Cu in inductively coupled plasma (ICP)-atomic emission spectrometry. Charge transfer from Ar + to Fe, Cr and Mn is state-selective because of inefficient collisional mixing of the quasiresonant charge-transfer energy levels with nearby levels. This low efficiency is the consequence of differences in electronic configuration of the core electrons. The reason for state-selective charge-transfer behavior to Cu is not clear, although a tentative explanation based on efficiency of intramultiplet and intermultiplet mixing for this special case is offered

Collision-produced atomic states

International Nuclear Information System (INIS)

Andersen, N.; Copenhagen Univ.

1988-01-01

The last 10-15 years have witnessed the development of a new, powerful class of experimental techniques for atomic collision studies, allowing partial or complete determination of the state of the atoms after a collision event, i.e. the full set of quantum-mechanical scattering amplitudes or - more generally - the density matrix describing the system. Evidently, such studies, involving determination of alignment and orientation parameters, provide much more severe tests of state-of-the-art scattering theories than do total or differential cross section measurements which depend on diagonal elements of the density matrix. The off-diagonal elements give us detailed information about the shape and dynamics of the atomic states. Therefore, close studies of collision-produced atomic states are currently leading to deeper insights into the fundamental physical mechanisms governing the dynamics of atomic collision events. The first part of the lectures deals with the language used to describe atomic states, while the second part presents a selection of recent results for model systems which display fundamental aspects of the collision physics in particularly instructive ways. I shall here restrict myself to atom-atom collisions. The discussion will be focused on states decaying by photon emission though most of the ideas can be easily modified to include electron emission as well. (orig./AH)

Simple analytical expressions for the analysis of the phase-dependent electromagnetically induced transparency in a double-Λ atomic scheme

International Nuclear Information System (INIS)

Dimitrijević, J; Arsenović, D

2012-01-01

We study a double-Λ atomic scheme that interacts with four laser light beams so that a closed loop of radiation-induced transitions is formed. When specific relations for field phases, frequencies and amplitudes are satisfied, coherent superpositions (the so-called ‘dark states’) can be formed in a double-Λ, which leads to the well-known effect of electromagnetically induced transparency (EIT). If the interaction scheme in a double-Λ system is such that a closed loop is formed, the relative phase of the laser light fields becomes very important. We analyze here the effect of the lasers' relative phase on the EIT in double-Λ configuration of levels. The theoretical study of interactions of lasers with a double-Λ atomic scheme is commonly conducted by solving the optical Bloch equations (OBEs). We use here a perturbative method for solving OBEs, where the interaction of lasers with double-Λ is considered a perturbation. An advantage of the perturbative method is that it generally produces simpler solutions, and analytical expressions can be obtained. We present analytical expressions for the lower-order corrections of the EIT signal. Our results show that the EIT by the perturbative method can be approximated by the sum of products of complex Lorentzians. Through these expressions, we see in what way the relative phase affects the overall EIT profile. (paper)

Quantum chaos in atom optics

International Nuclear Information System (INIS)

D'Arcy, Michael Brendan

2002-01-01

This thesis presents an account of experimental and numerical investigations of two quantum systems whose respective classical analogues are chaotic. These are the δ-kicked rotor, a paradigm in classical chaos theory, and the novel δ-kicked accelerator, created by application of a constant external acceleration or torque to the rotor. The experimental realisation of these systems has been achieved by the exposure of laser-cooled caesium atoms to approximate δ-kicks from a pulsed, high-intensity, vertical standing wave of laser light. Gravity's effect on the atoms can be controlled by appropriate shifting of the profile of the standing wave. Numerical simulations of the systems are based on a diffractive model of the potential's effect. Each system's dynamics are characterised by the final form of the momentum distribution and the dependence of the atoms' mean kinetic energy on the number and time period of the δ-kicks. The phenomena of dynamical localisation and quantum resonances in the δ-kicked rotor, which have no counterparts in the system's classical analogue, are observed and investigated. Similar experiments on the δ-kicked accelerator reveal the striking phenomenon of the quantum accelerator mode, in which a large momentum is transferred to a substantial fraction of the atomic ensemble. This feature, absent in the system's classical analogue, is characterised and an analytic explanation is presented. The effect on each quantum system of decoherence, introduced through spontaneous emission in the atoms, is examined and comparison is made with the results of classical simulations. While having little effect on the classical systems, the level of decoherence used is found to degrade quantum signatures of behaviour. Classical-like behaviour is, to some extent, restored, although significant quantum features remain. Possible applications of the quantum accelerator mode are discussed. These include use as a tool in atom optics and interferometry, a

Analytic tests and their relation to jet fuel thermal stability

Energy Technology Data Exchange (ETDEWEB)

Heneghan, S.P.; Kauffman, R.E. [Univ. of Dayton Research Institute, OH (United States)

1995-05-01

The evaluation of jet fuel thermal stability (TS) by simple analytic procedures has long been a goal of fuels chemists. The reason is obvious: if the analytic chemist can determine which types of material cause his test to respond, the refiners will know which materials to remove to improve stability. Complicating this quest is the lack of an acceptable quantitative TS test with which to compare any analytic procedures. To circumvent this problem, we recently compiled the results of TS tests for 12 fuels using six separate test procedures. The results covering a range of flow and temperature conditions show that TS is not as dependent on test conditions as previously thought. Also, comparing the results from these tests with several analytic procedures shows that either a measure of the number of phenols or the total sulfur present in jet fuels is strongly indicative of the TS. The phenols have been measured using a cyclic voltammetry technique and the polar material by gas chromatography (atomic emission detection) following a solid phase extraction on silica gel. The polar material has been identified as mainly phenols (by mass spectrometry identification). Measures of the total acid number or peroxide concentration have little correlation with TS.

Complex operator method of the hydrogen atom

International Nuclear Information System (INIS)

Jiang, X.

1989-01-01

Frequently the hydrogen atom eigenvalue problem is analytically solved by solving a radial wave equation for a particle in a Coulomb field. In this article, complex coordinates are introduced, and an expression for the energy levels of the hydrogen atom is obtained by means of the algebraic solution of operators. The form of this solution is in accord with that of the analytical solution

Bohmian picture of Rydberg atoms

Indian Academy of Sciences (India)

Abstract. Unlike the previous theoretical results based on standard quantum mechanics that established the nearly elliptical shapes for the centre-of-mass motion in Rydberg atoms using numerical simulations, we show analytically that the Bohmian trajectories in Rydberg atoms are nearly elliptical.

Simultaneous detection of selenium by atomic fluorescence and sulfur by molecular emission by flow-injection hydride generation with on-line reduction for the determination of selenate, sulfate and sulfite

Energy Technology Data Exchange (ETDEWEB)

Tyson, J.F., E-mail: tyson@chem.umass.edu [Department of Chemistry, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Palmer, C.D. [Lead Poisoning Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Empire State Plaza, Albany, NY 12201-0509 (United States)

2009-10-12

An inductively coupled plasma atomic fluorescence spectrometry (ICP-AFS) instrument, was modified so that it was capable of monitoring transient chromatographic or flow-injection profiles and that sulfur molecular emission and selenium atomic fluorescence could be monitored simultaneously in an argon-hydrogen diffusion flame on a glass burner. The analytes were introduced as hydrogen selenide and hydrogen sulfide, generated on a flow-injection manifold. Selenate was reduced to hydride-forming selenite by microwave-assisted on-line reaction with hydrochloric acid, and sulfate, or sulfite, was reduced to hydride-forming sulfide by a mixture of hydriodic acid, acetic acid and sodium hypophosphite. The effects of the nature of reducing agent, flow rate, microwave power and coil length were studied. The limit of detection (3 s) for selenium was 10 {mu}g L{sup -1}, and for sulfide was 70 {mu}g L{sup -1} (200-{mu}L injection volume). The calibration was linear for selenium up to 2 mg L{sup -1} and to 10 mg L{sup -1} for sulfide. The throughput was 180 h{sup -1}. The three sulfur species could be differentiated on the basis of reactivity at various microwave powers.

Objective and subjective evaluation of power plants and their non-radioactive emissions using the analytic hierarchy process

International Nuclear Information System (INIS)

Chatzimouratidis, Athanasios I.; Pilavachi, Petros A.

2007-01-01

Non-nuclear power plant emissions are of great concern to the public and to scientists alike. As energy demand tends to rise rapidly, especially in the developing countries, the negative effects to human health and to the environment from gaseous emissions together with hazardous particulate matter released by power plants can no longer be ignored. In this study, the impact of non-radioactive emissions is evaluated with the Analytic Hierarchy Process (AHP) by synthesizing objective and subjective criteria. There are five main emissions to be evaluated, non-methane volatile organic compounds (NMVOC), carbon dioxide equivalent (CO 2 -eq), nitrogen oxides (NO x ), sulphur dioxide (SO 2 ) and particulates or particulate matter (PM). Objective evaluation is achieved by expressing the impact of each emission released in monetary terms following generally accepted market rules, international agreements and protocols. That is, the Euro per kilogram of each emission exceeding a specific limit that should be paid as a penalty for environmental pollution and human health damage. Subjective assessment requires an intuitive expression of the percentage of damage to human health and to the ecosystem that each emission causes. Sensitivity analysis is then used in order to examine how change of input data affects final results. Finally, 10 main types of power plant are evaluated according to the level and kind of emissions they release. These types are coal/lignite, oil, natural gas turbine, natural gas combined cycle (NGCC), nuclear, hydro, wind, photovoltaic, biomass and geothermal

Rocket-borne EUV-visible emission measurements

International Nuclear Information System (INIS)

Schmidtke, G.; Baker, K.D.; Stasek, G.

1982-01-01

Two rocket-borne experiments for measuring EUV atmospheric emissions have been conducted. The first measured emissions at 391.4 nm and 557.7 nm, and the second measured emissions in the range from 50 to 650 nm. Height profiles of selected auroral emissions from atomic oxygen at 130.4 nm (exhibiting resonant radiation diffusion) and from atomic oxygen at 557.7 nm, and from neutral and ionized molecular nitrogen are shown. Some details of the recorded spectra are given. In the shorter wavelength regions, emissions from atomic oxygen and nitrogen dominate. Over 140 nm, Lyman-Birge-Hopfield bands, second positive bands and Vegard-Kaplan bands of molecular nitrogen contribute most strongly except for some atomic lines. The Lyman-Birge-Hopfield bands of molecular nitrogen are relatively weak during the auroral arc as compared to the diffuse aurora

Analytical characterization of high-level mixed wastes using multiple sample preparation treatments

International Nuclear Information System (INIS)

King, A.G.; Baldwin, D.L.; Urie, M.W.; McKinley, S.G.

1994-01-01

The Analytical Chemistry Laboratory at the Pacific Northwest Laboratory in Richland, Washington, is actively involved in performing analytical characterization of high-level mixed waste from Hanford's single shell and double shell tank characterization programs. A full suite of analyses is typically performed on homogenized tank core samples. These analytical techniques include inductively-coupled plasma-atomic emission spectroscopy, total organic carbon methods and radiochemistry methods, as well as many others, all requiring some type of remote sample-preparation treatment to solubilize the tank sludge material for analysis. Most of these analytical methods typically use a single sample-preparation treatment, inherently providing elemental information only. To better understand and interpret tank chemistry and assist in identifying chemical compounds, selected analytical methods are performed using multiple sample-preparation treatments. The sample preparation treatments used at Pacific Northwest Laboratory for this work with high-level mixed waste include caustic fusion, acid digestion, and water leach. The type of information available by comparing results from different sample-prep treatments includes evidence for the presence of refractory compounds, acid-soluble compounds, or water-soluble compounds. Problems unique to the analysis of Hanford tank wastes are discussed. Selected results from the Hanford single shell ferrocyanide tank, 241-C-109, are presented, and the resulting conclusions are discussed

Study of atomic and condensed atomic indices for reactive sites of ...

Indian Academy of Sciences (India)

Unknown

function indices in the framework of the AIM method of Bader.15 The atomic and group ... P Kolandaivel et al. 592. FF values. One of the reasons, they have argued, is that according to the analytic definition of FF it is valid only when ∆N → 0. In that case, the fluctuation in ..... In their work, they have concluded that the N atom ...

Liquid sample introduction in inductively coupled plasma atomic emission and mass spectrometry — Critical review

International Nuclear Information System (INIS)

Bings, N.H.; Orlandini von Niessen, J.O.; Schaper, J.N.

2014-01-01

Inductively coupled plasma optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS) can be considered as the most important tools in inorganic analytical chemistry. Huge progress has been made since the first analytical applications of the ICP. More stable RF generators, improved spectrometers and detection systems were designed along with the achievements gained from advanced microelectronics, leading to overall greatly improved analytical performance of such instruments. In contrast, for the vast majority of cases liquid sample introduction is still based on the pneumatic principle as described in the late 19th century. High flow pneumatic nebulizers typically demand the use of spray chambers as “aerosol filters” in order to match the prerequisites of an ICP. By this, only a small fraction of the nebulized sample actually contributes to the measured signal. Hence, the development of micronebulizers was brought forward. Those systems produce fine aerosols at low sample uptake rates, but they are even more prone for blocking or clogging than conventional systems in the case of solutions containing a significant amount of total dissolved solids (TDS). Despite the high number of publications devoted to liquid sample introduction, it is still considered the Achilles' heel of atomic spectrometry and it is well accepted, that the technology used for liquid sample introduction is still far from ideal, even when applying state-of-the-art systems. Therefore, this review is devoted to offer an update on developments in the field liquid sample introduction that had been reported until the year 2013. The most recent and noteworthy contributions to this field are discussed, trends are highlighted and future directions are outlined. The first part of this review provides a brief overview on theoretical considerations regarding conventional pneumatic nebulization, the fundamentals on aerosol generation and discusses characteristics of aerosols ideally

Liquid sample introduction in inductively coupled plasma atomic emission and mass spectrometry — Critical review

Energy Technology Data Exchange (ETDEWEB)

Bings, N.H., E-mail: bings@uni-mainz.de; Orlandini von Niessen, J.O.; Schaper, J.N.

2014-10-01

Inductively coupled plasma optical emission spectroscopy (ICP-OES) and mass spectrometry (ICP-MS) can be considered as the most important tools in inorganic analytical chemistry. Huge progress has been made since the first analytical applications of the ICP. More stable RF generators, improved spectrometers and detection systems were designed along with the achievements gained from advanced microelectronics, leading to overall greatly improved analytical performance of such instruments. In contrast, for the vast majority of cases liquid sample introduction is still based on the pneumatic principle as described in the late 19th century. High flow pneumatic nebulizers typically demand the use of spray chambers as “aerosol filters” in order to match the prerequisites of an ICP. By this, only a small fraction of the nebulized sample actually contributes to the measured signal. Hence, the development of micronebulizers was brought forward. Those systems produce fine aerosols at low sample uptake rates, but they are even more prone for blocking or clogging than conventional systems in the case of solutions containing a significant amount of total dissolved solids (TDS). Despite the high number of publications devoted to liquid sample introduction, it is still considered the Achilles' heel of atomic spectrometry and it is well accepted, that the technology used for liquid sample introduction is still far from ideal, even when applying state-of-the-art systems. Therefore, this review is devoted to offer an update on developments in the field liquid sample introduction that had been reported until the year 2013. The most recent and noteworthy contributions to this field are discussed, trends are highlighted and future directions are outlined. The first part of this review provides a brief overview on theoretical considerations regarding conventional pneumatic nebulization, the fundamentals on aerosol generation and discusses characteristics of aerosols ideally

X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

International Nuclear Information System (INIS)

Sanford, T.W.L.; Mosher, D.; De Groot, J.S.

1996-01-01

Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single-exploded-wire discharges on Gamble-II suggest a common nonthermal-production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission. (author). 3 figs., 10 refs

X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

International Nuclear Information System (INIS)

Sanford, T.W.L.; Mosher, D.; De Groot, J.S.

1996-01-01

Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single- exploded-wire discharges on Gamble-II suggest a common nonthermal- production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly- collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission

Spectrum of a one-atom laser in photonic crystals

International Nuclear Information System (INIS)

Florescu, Lucia

2006-01-01

The emission spectrum of a single-emitter laser in a photonic crystal is presented. We consider a coherently pumped two-level emitter strongly coupled to a high-quality microcavity engineered within a photonic crystal. We show that the cavity spectrum consists of both elastic and inelastic components, for which we derive analytical expressions. Our study reveals enhanced, spectrally narrower emission resulting from the radiation reservoir of the photonic crystal. The cavity field spectral characteristics are fundamentally distinct from those of a corresponding microcavity in ordinary vacuum. At high pump intensities and for large discontinuities in the photon density of states between Mollow spectral components of atomic resonance fluorescence, the emitted intensity originating from the elastic spectral component increases with the intensity of the pump and the elastic component dominates the spectrum. In the case of a vanishing photon density of states in the spectral range surrounding the lower Mollow sideband and no dipolar dephasing, the cavity spectrum is elastic

Analytical theory for the nuclear level shift of hadronic atoms

International Nuclear Information System (INIS)

Kudryavtsev, A.E.; Lisin, V.I.; Popov, V.S.

1982-01-01

The spectrum problem in the Coulomb potential distorted at small distances is considered. Nuclear shifts of 3-levels in p anti p and Σ - p atoms are calculated. The probabilities of radiative transitions from p-states to the shifted s-states in hadronic atom are also given. It is shown that the reconstruction of atomic levels switches to oscillation regime when absorption increases. The limits of applicability of the perturbation theory in terms of the scattering length for different values of absorption is discussed. An exactly solvable model, Coulomb plus Yamaguchi potential, is considered

Acoustic emission and magnification of atomic lines resolution for laser breakdown of salt water in ultrasound field

International Nuclear Information System (INIS)

Bulanov, Alexey V.; Nagorny, Ivan G.

2015-01-01

Researches of the acoustic effects accompanying optical breakdown in a water, generated by the focused laser radiation with power ultrasound have been carried out. Experiments were performed by using 532 nm pulses from Brilliant B Nd:YAG laser. Acoustic radiation was produced by acoustic focusing systems in the form hemisphere and ring by various resonance frequencies of 10.7 kHz and 60 kHz. The experimental results are obtained, that show the sharply strengthens effects of acoustic emission from a breakdown zone by the joint influence of a laser and ultrasonic irradiation. Essentially various thresholds of breakdown and character of acoustic emission in fresh and sea water are found out. The experimental result is established, testifying that acoustic emission of optical breakdown of sea water at presence and at absence of ultrasound essentially exceeds acoustic emission in fresh water. Atomic lines of some chemical elements like a Sodium, Magnesium and so on were investigated for laser breakdown of water with ultrasound field. The effect of magnification of this lines resolution for salt water in ultrasound field was obtained

Field electron emission spectrometer combined with field ion/electron microscope as a field emission laboratory

International Nuclear Information System (INIS)

Shkuratov, S.I.; Ivanov, S.N.; Shilimanov, S.N.

1996-01-01

The facility, combining the field ion microscope, field electron emission microscope and field electron emission spectrometer, is described. Combination of three methodologies makes it possible to carry out the complete cycle of emission studies. Atom-plane and clean surface of the studied samples is prepared by means of field evaporation of the material atom layers without any thermal and radiation impact. This enables the study of atom and electron structure of clean surface of the wide range materials, the study whereof through the field emission methods was previously rather difficult. The temperature of the samples under study changes from 75 up to 2500 K. The energy resolution of the electron analyzer equals 30 MeV. 19 refs., 10 figs

Gold volatile species atomization and preconcentration in quartz devices for atomic absorption spectrometry

Czech Academy of Sciences Publication Activity Database

Arslan, Y.; Musil, Stanislav; Matoušek, Tomáš; Kratzer, Jan; Dědina, Jiří

103-104, JAN-FEB (2015), s. 155-163 ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : gold * volatile species generation * quartz atomizers * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015

Atom-at-a-time chemistry

International Nuclear Information System (INIS)

Nagame, Yuichiro

2009-01-01

Several techniques of the analytical chemistry in 'Atom-at-a-time chemistry' for transactinide elements have been developed. In this report a representative example in these techniques is introduced with the results. The contents are the single-atom chemistry, the chemical experiments on transactinide elements, liquid phase chemistry (the ion exchange behavior of Rutherfordium), gas phase chemistry (the chemistry of atomic No.112 element), and future development. (M.H.)

Evaluation of an improved atomic data basis for carbon in UEDGE emission modeling for L-mode plasmas in DIII-D

Energy Technology Data Exchange (ETDEWEB)

Muñoz Burgos, J.M., E-mail: munozj@fusion.gat.com [Oak Ridge Institute for Science and Education, Oak Ridge, TN 37831-0117 (United States); Leonard, A.W. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Loch, S.D.; Ballance, C.P. [Auburn University, Auburn, AL 36849 (United States)

2013-07-15

New scaled carbon atomic electron-impact excitation data is utilized to evaluate comparisons between experimental measurements and fluid emission modeling of detached plasmas at DIII-D. The C I and C II modeled emission lines for 909.8 and 514.7 nm were overestimated by a factor of 10–20 than observed experimentally for the inner leg, while the outer leg was within a factor of 2. Due to higher modeled emissions, a previous study using the UEDGE code predicted that a higher amount of carbon was required to achieve a detached outboard divertor plasma in L-mode at DIII-D. The line emission predicted by using the new scaled carbon data yields closer results when compared against experiment. We also compare modeling and measurements of D{sub α} emission from neutral deuterium against predictions from newly calculated R-Matrix with pseudostates data available at the ADAS database.

Characterization of petroleum distillates by GC-AED (coupling with gas chromatography and atomic emission detection); Caracterisation des distillats petroliers par couplage chromatographie en phase gazeuse et detection par emission atomique

Energy Technology Data Exchange (ETDEWEB)

Baco, F.

1997-05-21

This thesis describes the characterization of atmospheric petroleum distillates (kerosenes and gas-oils) and vacuum distillates by hyphenated technic of Gas Chromatography and Atomic Emission Detector (GC-AED). A gas chromatographic simulated distillation, which gives the weight % of sample as a function of the petroleum cut temperature, was adapted to the GC-AED to obtain an original information about the elemental composition profile. After generalities, historic of the development of the instrument and the first petroleum applications are described. In the experimental part, analytical conditions used, different technics of characterisation of distillates and the base of samples analyzed are exposed. After a study of the GC-AED`s performances for the target elements (C, H, S, N), a quantitative method for the elemental analysis of distillates was developed and validated at three levels: total elemental analysis, simulated distillation and elemental composition as a function of the distillation profile. Finally, different ways for the applications of the GC-AED in order to characterize the distillates were explored, in particular to classify products and predict some petroleum properties (cetane number, density,...). The more interesting outlook seems to be the prediction of some properties as a function of the distillation profile. (author) 155 refs.

Antiprotonic-hydrogen atoms

International Nuclear Information System (INIS)

Batty, C.J.

1989-07-01

Experimental studies of antiprotonic-hydrogen atoms have recently made great progress following the commissioning of the low energy antiproton facility (LEAR) at CERN in 1983. At the same time our understanding of the atomic cascade has increased considerably through measurements of the X-ray spectra. The life history of the p-bar-p atom is considered in some detail, from the initial capture of the antiproton when stopping in hydrogen, through the atomic cascade with the emission of X-rays, to the final antiproton annihilation and production of mesons. The experiments carried out at LEAR are described and the results compared with atomic cascade calculations and predictions of strong interaction effects. (author)

Multielement detection limits and sample nebulization efficiencies of an improved ultrasonic nebulizer and a conventional pneumatic nebulizer in inductively coupled plasma-atomic emission spectrometry

International Nuclear Information System (INIS)

Olson, K.W.; Haas, W.J. Jr.; Fassel, V.A.

1977-01-01

Two important aspects of the analytical performance of a newly developed ultrasonic nebulizer and a specially designed pneumatic nebulizer have been compared for use in inductively coupled plasma--atomic emission spectroscopy (ICP-AES). The ultrasonic nebulizer, when combined with a conventional aerosol desolvation apparatus, provided an order of magnitude or more improvement in simultaneous multielement detection limits as compared to those obtained when the pneumatic nebulizer was used either with or without desolvation. Application of a novel method for direct measurement of the overall efficiency of nebulization to the two systems showed that an approximately tenfold greater rate of sample delivery to the plasma torch was primarily responsible for the superior detection limits afforded by the ultrasonic nebulizer. A unique feature of the ultrasonic nebulizer described is the protection against chemical attack which is achieved by completely enclosing the transducer in an acoustically coupled borosilicate glass cylinder. Direct sample introduction, convenient sample change, and rapid cleanout are other important characteristics of the system which make it an attractive alternate to pneumatic nebulizer systems

Direct determination of beryllium, cadmium, lithium, lead and silver in thorium nitrate solution by electrothermal atomization atomic absorption spectrometry

International Nuclear Information System (INIS)

Thulasidas, S.K.; Kulkarni, M.J.; Porwal, N.K.; Page, A.G.; Sastry, M.D.

1988-01-01

An electrothermal atomization atomic absorption spectrometric (ET-AAS) method is developed for the direct determination of Ag, Be, Cd, Li and Pb in thorium nitrate solution. The method offers detection of sub-nanogram amounts of these analytes in 100-microgram thorium samples with a precision of around 10%. A number of spiked samples and pre-analyzed ThO 2 samples have been analyzed to evaluate the performance of the analytical methods developed here

Elemental analysis using instrumental neutron activation analysis and inductively coupled plasma atomic emission spectrometry: a comparative study

International Nuclear Information System (INIS)

Chung, Yong Sam; Choi, Kwang Soon; Moon, Jong Hwa; Kim, Sun Ha; Lim, Jong Myoung; Kim, Young Jin; Quraishi, Shamshad Begum

2003-05-01

Elemental analyses for certified reference materials were carried out using instrumental neutron activation analysis and inductively coupled plasma-atomic emission spectrometry. Five Certified Reference Materials (CRM) were selected for the study on comparative analysis of environmental samples. The CRM are Soil (NIST SRM 2709), Coal fly ash (NIST SRM 1633a), urban dust (NIST SRM 1649a) and air particulate on filter media (NIST SRM 2783 and human hair (GBW 09101)

Construction of a quartz spherical analyzer: application to high-resolution analysis of the Ni Kα emission spectrum

International Nuclear Information System (INIS)

Honnicke, Marcelo Goncalves; Cusatis, Cesar

2016-01-01

The construction and characterization of a focusing X-ray spherical analyzer based on α-quartz 44̄04 are presented. For this study, the performance of the analyzer was demonstrated by applying it to a high-resolution X-ray spectroscopy study of theKα_1_,_2emission spectrum of Ni. An analytical representation based on physical grounds was assumed to model the shape of the X-ray emission lines. Satellite structures assigned to 3dspectator hole transitions were resolved and determined as well as their relative contribution to the emission spectrum. The present results on 1s"-"13d"-"1shake probabilities support a recently proposed calculation framework based on a multi-configuration atomic model.

Emission spectrochemical analysis

International Nuclear Information System (INIS)

Rives, R.D.; Bruks, R.R.

1983-01-01

The emission spectrochemical method of analysis based on the fact that atoms of elements can be excited in the electric arc or in the laser beam and will emit radiation with characteristic wave lengths is considered. The review contains the data on spectrochemical analysis, of liquids geological materials, scheme of laser microprobe. The main characteristics of emission spectroscopy, atomic absorption spectroscopy and X-ray fluorescent analysis, are aeneralized

Atomic inner-shell physics

International Nuclear Information System (INIS)

Crasemann, B.

1985-01-01

This book discusses: relativistic and quantum electrodynamic effects on atomic inner shells; relativistic calculation of atomic transition probabilities; many-body effects in energetic atomic transitions; Auger Electron spectrometry of core levels of atoms; experimental evaluation of inner-vacancy level energies for comparison with theory; mechanisms for energy shifts of atomic K-X rays; atomic physics research with synchrotron radiation; investigations of inner-shell states by the electron energy-loss technique at high resolution; coherence effects in electron emission by atoms; inelastic X-ray scattering including resonance phenomena; Rayleigh scattering: elastic photon scattering by bound electrons; electron-atom bremsstrahlung; X-ray and bremsstrahlung production in nuclear reactions; positron production in heavy-ion collisions, and X-ray processes in heavy-ion collisions

Inductively coupled plasma--atomic emission spectroscopy: an evaluation of the use of nitrogen--argon admixtures as plasma discharge atmospheres

International Nuclear Information System (INIS)

Zalewski, J.C.

1979-01-01

The effects of the use of nitrogen in either the plasma coolant or aerosol carrier gas flows on the physical and spectrochemical properties of the inductively coupled plasma (ICP) were examined. While the plasma operated with nitrogen in the coolant flow exhibited a stability comparable to that of the argon plasma, the use of nitrogen in the aerosol carrier gas flow resulted in a plasma that was less stable. The detection limits obtained for the three plasmas exhibited a similar trend. In addition, the use of nitrogen--argon admixtures in the plasma coolant gas flow yielded an increase in both the net analyte and the background emission intensities when the corresponding argon and nitrogen--argon plasmas were operated under various conditions. Furthermore, the effect of aluminum on the Ca II (393.4 nm) spectral line was reported for the 1000/1 Al/Ca molar ratio. At an observation height of 15 mm, the signal depressions were 4 and 14% for the nitrogen--argon and the argon plasmas, respectively. The above experimental evidence suggested that the operation of the ICP with an Ar--N 2 coolant gas might be hotter than the argon plasma currently in use in this laboratory. The demountable plasma torch designed in collaboration with K. Olson yielded detection limits for 15 elements and 19 spectral lines that were approximately within a factor of two of those obtained with the torch of fused quartz design. The design also appeared to offer a more readily initiated plasma discharge. The experimental evidence presented supports the utilization of nitrogen--argon admixtures in the plasma coolant gas flow as alternate discharge atmospheres for inductively coupled plasma--atomic emission spectroscopy. In contrast, the experimental evidence shows that there is a deterioration in both physical and spectrochemical properties of plasmas operated with a nitrogen aerosol carrier gas

Low energy atom-atom collisions

International Nuclear Information System (INIS)

Child, M.S.

1980-01-01

The semiclassical theory of atom-atom potential scattering and of low energy inelastic atom-atom scattering is reviewed. Particular attention is given to the origin and interpretation of rainbow structure, diffraction oscillations and exchange oscillations in the potential scattering differential cross-section, and to the glory structure and symmetry oscillations in the integral cross-section. Available methods for direct inversion of the cross-section data to recover the potential are reviewed in some detail. The theory of non-adiabatic transitions is introduced by a short discussion of interaction mechanisms and of diabetic and adiabatic representations. Analytical S matrix elements are presented for two state curve-crossing (Landau-Zener-Stuckelberg), Demkov and Nikitin models. The relation between Stuckelberg oscillations in the S matrix and in the differential cross-section is discussed in terms of interference between trajectories belonging to two different classical deflection functions. The energy dependences of the inelastic integral cross-section for curve-crossing and Demkov type transitions are also discussed. Finally the theory is reviewed in relation to a recent close-coupled study of fine structure transitions in F( 2 P) + Xe( 2 S) scattering

Plasmas applied atomic collision physics, v.2

CERN Document Server

Barnett, C F

1984-01-01

Applied Atomic Collision Physics, Volume 2: Plasmas covers topics on magnetically confined plasmas. The book starts by providing the history of fusion research and describing the various approaches in both magnetically and inertially confined plasmas. The text then gives a general discussion of the basic concepts and properties in confinement and heating of a plasma. The theory of atomic collisions that result in excited quantum states, particularly highly ionized impurity atoms; and diverse diagnostic topics such as emission spectra, laser scattering, electron cyclotron emission, particle bea

Use of magnesium as a test element for inductively coupled plasma atomic emission spectrometry diagnosis

International Nuclear Information System (INIS)

Mermet, J.M.

1991-01-01

To optimize atomization and ionization processes in an inductively coupled plasma used as a source in atomic emission spectrometry, the Mg II 280.270-nm/Mg I 285-213-nm line intensity ratio is used. A theoretic ratio is calculated assuming a local thermodynamic equilibrium.A review of previously published experimental values of the ratio is given as a function of the parameters influencing the energy transfer between the plasma and injected species. In particular, the effects of the power, the carrier gas flow-rate, the i.d. of the torch injector, the use of a sheathing gas and the presence of hydrogen are described. Values of the ratio close to the theoretical values are obtained with a high power (>1.4 kW), a lower carrier gas flow-rate ( -1 ) and a large i.d. of the injector (>2 mm). This optimization can also be applied to the minimization of interference effects due to the presence of sodium. (author). 64 refs.; 9 figs.; 1 tab

Spectra of alkali atoms

International Nuclear Information System (INIS)

Santoso, Budi; Arumbinang, Haryono.

1981-01-01

Emission spectra of alkali atoms has been determined by using spectrometer at the ultraviolet to infra red waves range. The spectra emission can be obtained by absorption spectrophotometric analysis. Comparative evaluations between experimental data and data handbook obtained by spark method were also presented. (author tr.)

Analytical framework of 'atoms for sustainable development'

International Nuclear Information System (INIS)

Lee, Tae Joon

2010-01-01

The term of 'Atoms for Sustainable Development' constantly pursues the increasing contribution of nuclear energy to the sustainable development which is providing an external kindling to the so-called nuclear renaissance. This paper explores a conceptual framework and a set of its elemental proxies to analyse the sustainable competitiveness of the nuclear energy system with a classification of the economic, environmental and social dimensions. (authors)

Determination of Rare Earth Elements in Thai Monazite by Inductively Coupled Plasma and Nuclear Analytical techniques

International Nuclear Information System (INIS)

Busamongkol, Arporn; Ratanapra, Dusadee; Sukharn, Sumalee; Laoharojanaphand, Sirinart

2003-10-01

The inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the determination of individual rare-earth elements (REE) was evaluated by comparison with instrumental neutron activation analysis (INAA) and x-ray fluorescence spectrometry (XRF). The accuracy and precision of INAA and ICP-AES were evaluated by using standard reference material IGS-36, a monazite concentrate. For INAA, the results were close to the certified value while ICP-AES were in good agreement except for some low concentration rare earth. The techniques were applied for the analysis of some rare earth elements in two Thai monazite samples preparing as the in-house reference material for the Rare Earth Research and Development Center, Chemistry Division, Office of Atoms for Peace. The analytical results obtained by these techniques were in good agreement with each other

Determination of trace amounts of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment by inductively coupled plasma atomic emission spectrometry after iron matrix removal with extractant-contained resin

International Nuclear Information System (INIS)

Xu Yuyu; Zhou Jianfeng; Wang Guoxin; Zhou Jinfan; Tao Guanhong

2007-01-01

Inductively coupled plasma atomic emission spectrometry (ICP-AES) was applied to the determination of lead, arsenic, nickel and cobalt in high-purity iron oxide pigment. Samples were dissolved with hydrochloric acid and hydrogen peroxide. The digest was passed through a column, which was packed with a polymer resin containing a neutral organophosphorus extractant, tri-n-butylphosphate. Iron was sorbed selectively on the resin and the analytes of interest passed through the column, allowing the effective separation of them from the iron matrix. Conditions of separation were optimized. The detection limits (3σ) in solution were 10, 40, 7 and 5 μg L -1 , and in pigment were 0.2, 0.8, 0.14 and 0.1 mg kg -1 for lead, arsenic, cobalt and nickel, respectively. The recoveries ranged from 95% to 107% when sample digests were spiked with 5 μg of the analytes of interest, and relative standard deviations (n = 6) were 1.5-17.6% for the determination of the spiked samples. The method was successfully applied to the determination of trace amounts of these elements in high-purity iron oxide pigment samples

Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

Science.gov (United States)

Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

2016-01-01

Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

Atom beams split by gentle persuasion

International Nuclear Information System (INIS)

Pool, R.

1994-01-01

Two different research teams have taken a big step toward atom interferometry. They have succeeded in splitting atomic beams by using atoms in spin states that neither absorb nor reemit laser light. By proper adjustment of experimental conditions, atoms are changed from one spin state to another, without passing through the intermediary excited state. The atoms in essence absorb momentum from the laser photons, without absorption or emission of photons. The change in momentum deflects atoms in the proper spin state

High-Activity ICP-AES Measurements in the ATALANTE Facility Applied to Analytical Monitoring of an Extraction Test

International Nuclear Information System (INIS)

Esbelin, E.; Boyer-Deslys, V.; Beres, A.; Viallesoubranne, C.

2008-01-01

The Material Analysis and Metrology Laboratory (LAMM) of the Cea's Atalante complex ensures analytical monitoring of enhanced separation tests. Certain fission products, actinides and lanthanides were assayed by ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy) in the CBA shielded analysis line. These analyses were particularly effective for controlling the Diamex test, and contributed to its success. The Diamex process consists in extracting the actinides and lanthanides from a Purex raffinate using a diamide, DMDOHEMA, followed by stripping at low acidity. The major elements analyzed during the test were Am, Nd, Mo, Fe, and Zr

Effect of inelastic energy losses on development of atom-atom collision cascades

International Nuclear Information System (INIS)

Marinyuk, V.V.; Remizovich, V.S.

2001-01-01

The problem of influence of inelastic energy losses (ionization braking) of particles on the development of atom-atom collision cascades in infinite medium was studied theoretically. Main attention was paid to study of angular and energy distributions of primary ions and cascade atoms in the presence of braking. Analytical calculations were made in the assumption that single scattering of particles occurs by solid balls law, while the value of electron braking ability of a medium is determined by the Lindhard formula. It is shown that account of braking (directly when solving the Boltzmann transport equation) changes in principle the previously obtained angular and energy spectra of ions and cascade atoms. Moreover, it is the braking that is the determining factor responsible for anisotropy of angular distributions of low-energy primary ions and cascade atoms [ru

16. Hot dense plasma atomic processes

International Nuclear Information System (INIS)

Werner, Dappen; Totsuji, H.; Nishii, Y.

2002-01-01

This document gathers 13 articles whose common feature is to deal with atomic processes in hot plasmas. Density functional molecular dynamics method is applied to the hydrogen plasma in the domain of liquid metallic hydrogen. The effects of the density gradient are taken into account in both the electronic kinetic energy and the exchange energy and it is shown that they almost cancel with each other, extending the applicability of the Thomas-Fermi-Dirac approximation to the cases where the density gradient is not negligible. Another article reports about space and time resolved M-shell X-ray measurements of a laser-produced gas jet xenon plasma. Plasma parameters have been measured by ion acoustic and electron plasma waves Thomson scattering. Photo-ionization becomes a dominant atomic process when the density and the temperature of plasmas are relatively low and when the plasma is submitted to intense external radiation. It is shown that 2 plasmas which have a very different density but have the same ionization parameters, are found in a similar ionization state. Most radiation hydrodynamics codes use radiative opacity data from available libraries of atomic data. Several articles are focused on the determination of one group Rosseland and Planck mean analytical formulas for several single elements used in inertial fusion targets. In another paper the plasma density effect on population densities, effective ionization, recombination rate coefficients and on emission lines from carbon and Al ions in hot dense plasma, is studied. The last article is devoted to a new atomic model in plasmas that considers the occupation probability of the bound state and free state density in the presence of the plasma micro-field. (A.C.)

Terrestrial energetic neutral atom emissions and the ground-based geomagnetic indices: First daylong observations by IBEX

Science.gov (United States)

Ogasawara, K.; Dayeh, M. A.; Fuselier, S. A.; Goldstein, J.; McComas, D. J.; Valek, P. W.

2017-12-01

We report daylong continuous observations of bright terrestrial energetic neutral atom (ENA) emissions in the energy of 0.5-6.0 keV by Interstellar Boundary Explorer (IBEX). The unique vantage point of IBEX, 48 Earth radii (Re) from the dawn/dusk side, made an unprecedented long duration monitoring of ENAs possible from almost stable locations. This type of observation is difficult with the other ENA imager satellites since they are orbiting closer to the Earth in shorter periods. The studied energy range is unique due to the coverage of the transition from the solar wind plasma to the magnetospheric particles with a single sensor. In addition, the Coulomb decay becomes important for the protons with energy less than 1 keV. In order to minimize contamination from the sub-solar magnetosphere or the cusp emissions, we focused on two events when the auroral electrojet (AE) index exceeded 300 nT in this study. We will also show the ENA images from Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) in support of the IBEX observations. We found a significant correlation between the observed ENA profile and the AE indices, whose correlation coefficients were maximized at >0.75 for >1.4 keV energy. There are systematic differences between two events in terms of AU, AL, and Asy-H correlations: One event has the stronger AU correlation than AL and the Asy-H correlation, suggesting partial ring current contribution. The other has the stronger AL correlation than AU without Asy-H correlation, which suggests substorm related ENA emissions. On the contrary, we could not find a meaningful correlation with Sym-H for these two events. The other important finding is the decay time of these ENA emissions. The observed e-folding decay time, 2 to 4 hours for most of the energy bands, was a little shorter than the conventional ring-current decay time (typically >6 hours) expected from the charge exchange and the field-line curvature effect, suggesting the stronger effect of the

Dressed-state analysis of efficient two-dimensional atom localization in a four-level atomic system

International Nuclear Information System (INIS)

Wang, Zhiping; Yu, Benli

2014-01-01

We investigate two-dimensional atom localization via spontaneous emission in a four-level atomic system. It is found that the detection probability and precision of two-dimensional atom localization can be significantly improved due to the interference effect between the spontaneous decay channels and the dynamically induced quantum interference generated by the probe and composite fields. More importantly, a 100% probability of finding an atom within the sub-half-wavelength domain of the standing waves can be reached when the corresponding conditions are satisfied. As a result, our scheme may be helpful in laser cooling or atom nano-lithography via atom localization. (paper)

Coexistence of photonic and atomic Bose-Einstein condensates in ideal atomic gases

Directory of Open Access Journals (Sweden)

N. Boichenko

2015-12-01

Full Text Available We have studied conditions of photon Bose-Einstein condensate formation that is in thermodynamic equilibrium with ideal gas of two-level Bose atoms below the degeneracy temperature. Equations describing thermodynamic equilibrium in the system were formulated; critical temperatures and densities of photonic and atomic gas subsystems were obtained analytically. Coexistence conditions of these photonic and atomic Bose-Einstein condensates were found. There was predicted the possibility of an abrupt type of photon condensation in the presence of Bose condensate of ground-state atoms: it was shown that the slightest decrease of the temperature could cause a significant gathering of photons in the condensate. This case could be treated as a simple model of the situation known as "stopped light" in cold atomic gas. We also showed how population inversion of atomic levels can be created by lowering the temperature. The latter situation looks promising for light accumulation in atomic vapor at very low temperatures.

Analytical formulae for total cross sections for electron scattering by atoms (N, O, F, Ne, P, S, Cl, Ar, As, Se, Br, Kr) between 0.5-10 keV

International Nuclear Information System (INIS)

Williart, A.

2001-01-01

Analytical formulae for total cross sections for electron scattering by atoms which are close to the noble gases (Ne, Ar and Kr), for electron energies ranging from 0.5 to 10 keV, have been obtained in this study. We have shown, previously, that molecular total cross sections, at these energies, depend on target polarizability and the number of target electrons. A similar behaviour has been supposed for total cross sections of some atoms (N, O, F, P, S, Cl, As, Se and Br). The obtained expression depends on atomic parameters and it is based in some correlation derived from noble gases. The applicability of the formula has been checked by comparison with available data for atomic oxygen. (orig.)

Analytical formulae for total cross sections for electron scattering by atoms (N, O, F, Ne, P, S, Cl, Ar, As, Se, Br, Kr) between 0.5-10 keV

Energy Technology Data Exchange (ETDEWEB)

Williart, A. [Univ. Nacional de Educacion a Distancia, Madrid (Spain). Dept. de Fisica de los Materiales; Garcia, G. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain)

2001-10-01

Analytical formulae for total cross sections for electron scattering by atoms which are close to the noble gases (Ne, Ar and Kr), for electron energies ranging from 0.5 to 10 keV, have been obtained in this study. We have shown, previously, that molecular total cross sections, at these energies, depend on target polarizability and the number of target electrons. A similar behaviour has been supposed for total cross sections of some atoms (N, O, F, P, S, Cl, As, Se and Br). The obtained expression depends on atomic parameters and it is based in some correlation derived from noble gases. The applicability of the formula has been checked by comparison with available data for atomic oxygen. (orig.)

Developments in the application of atomic spectroscopy to trace metal analysis

International Nuclear Information System (INIS)

Fuavao, V.A.

1983-01-01

A method is described for the determination of selenium in horse blood by generation, atomization and analysis of the selenium hydride. A pooled horse blood sample which contained 8.8 μg 1 -1 of selenium exhibited a precision of analysis of 4.32% for ten replicate analyses. A study of the sensitivity of nonresonance and resonance lines of ytterbium utilizing microboat and platform atomization was investigated. Increases of at least twofold for all nonresonance lines were observed. Microboat sensitivity fell between that of the wall and the platform. Alternative surfaces of electrothermal atomization atomic absorption spectrophotometry (ETAAS) and the thermodynamic process for atom formation in ETAAS were investigated. Sensitivities for carbide-formation elements such as ytterbium and molybdenum and other noncarbide formation elements were determined by precoating graphite tubes and inserting collars. An improvement in analytical sensitivity and reduction in memory effect compared to commercially available pyrolytic graphite tubes were observed for all except the molybdenum analyte where a depression in analytical sensitivity resulted. The useful lifetime (analysis cycles) of all surfaces (except metal collars) were recorded at 250 to 400 cycles with acceptable and comparable precisions. A method is described for proposing the thermodynamic process in IL655 ETAAS. Appearance temperatures of analytes and free energy were studied and two major pathways were found operative: 1) thermal dissociation of the analyte oxide; 2) carbon reduction of the oxide followed by atomization of the free metal

Determination of trace amounts of cerium in paint by inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Wong, K.L.

1981-01-01

The determination of Ce in paint by inductively coupled plasma atomic emission spectrometry (ICP-OES) is described, and the detection limit of ICP-OES of 0.0004 ppM is compared with that of other methods. The effects of the major elemental components of paint, Si, Pb, Cr, and Na on the ICP-OES determination of Ce were studied. The interference of 400 ppM of the other ions on the determination of 10 ppM Ce was small (0 to 3% error). The method is applicable to the range of 0.2 to 700 ppM Ce

Analytical Absorption Cross-Section for Photon by a Hydrogen 2s Atom

International Nuclear Information System (INIS)

Ndinya, Boniface Otieno; Okeyo, Stephen Onyango

2011-01-01

We calculate the absorption cross-section for photon by a hydrogen 2s atom using the quantum-classical approximation for the total photo cross-section of many electron atoms. With the application of the first-order term of the Baker-Hausdorf expansion, the absorption cross-section for the hydrogen 2s atom decreases to a minimum, the Cooper pair minimum, at low photon energy. Such a minimum is absent in the exact absorption cross-section for photon by a hydrogen 2s atom. We have extended the calculation for the absorption cross-section of the hydrogen 2s atom using the quantum-classical approximation for the total photo cross-section of many electron to include the second-order term of the Baker-Hausdorf expansion and observed a great reduction in the dip associated with the Cooper pair minimum at the zero crossing. (atomic and molecular physics)

Energy dependence of the ionization of highly excited atoms by collisions with excited atoms

International Nuclear Information System (INIS)

Shirai, T.; Nakai, Y.; Nakamura, H.

1979-01-01

Approximate analytical expressions are derived for the ionization cross sections in the high- and low-collision-energy limits using the improved impulse approximation based on the assumption that the electron-atom inelastic-scattering amplitude is a function only of the momentum transfer. Both cases of simultaneous excitation and de-excitation of one of the atoms are discussed. The formulas are applied to the collisions between two excited hydrogen atoms and are found very useful for estimating the cross sections in the wide range of collisions energies

The relation of double peaks, observed in quartz hydride atomizers, to the fate of free atoms in the determination of arsenic and selenium by atomic absorption spectrometry

Czech Academy of Sciences Publication Activity Database

D'Ulivo, A.; Dědina, Jiří

2002-01-01

Roč. 57, č. 12 (2002), s. 2069-2079 ISSN 0584-8547 R&D Projects: GA ČR GA203/01/0453 Institutional research plan: CEZ:AV0Z4031919 Keywords : hydride atomization * hydride generation * atomic absortion spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.695, year: 2002

Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Perring, Loic; Basic-Dvorzak, Marija [Department of Quality and Safety Assurance, Nestle Research Centre, P.O. Box 44, Vers chez-les-Blanc, 1000, Lausanne (Switzerland)

2002-09-01

Tin is considered to be a priority contaminant by the Codex Alimentarius Commission. Tin can enter foods either from natural sources, environmental pollution, packaging material or pesticides. Higher concentrations are found in processed food and canned foods. Dissolution of the tinplate depends on the of food matrix, acidity, presence of oxidising reagents (anthocyanin, nitrate, iron and copper) presence of air (oxygen) in the headspace, time and storage temperature. To reduce corrosion and dissolution of tin, nowadays cans are usually lacquered, which gives a marked reduction of tin migration into the food product. Due to the lack of modern validated published methods for food products, an ICP-AES (Inductively coupled plasma-atomic emission spectroscopy) method has been developed and evaluated. This technique is available in many laboratories in the food industry and is more sensitive than atomic absorption. Conditions of sample preparation and spectroscopic parameters for tin measurement by axial ICP-AES were investigated for their ruggedness. Two methods of preparation involving high-pressure ashing or microwave digestion in volumetric flasks were evaluated. They gave complete recovery of tin with similar accuracy and precision. Recoveries of tin from spiked products with two levels of tin were in the range 99{+-}5%. Robust relative repeatabilities and intermediate reproducibilities were <5% for different food matrices containing >30 mg/kg of tin. Internal standard correction (indium or strontium) did not improve the method performance. Three emission lines for tin were tested (189.927, 283.998 and 235.485 nm) but only 189.927 nm was found to be robust enough with respect to interferences, especially at low tin concentrations. The LOQ (limit of quantification) was around 0.8 mg/kg at 189.927 nm. A survey of tin content in a range of canned foods is given. (orig.)

Determination of lithium and potassium in uranium oxide powders and pellets by Flame Atomic Emission Spectrometric method

International Nuclear Information System (INIS)

Jat, J.R.; Balaji Rao, Y.; Prasada Rao, G.; Prahlad, B.

2012-01-01

The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI 4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI 4 , is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO 2 powder and pellets on regular basis

Experiments in atomic and applied physics using synchrotron radiation

International Nuclear Information System (INIS)

Jones, K.W.

1987-01-01

A diverse program in atomic and applied physics using x rays produced at the X-26 beam line at the Brookhaven National Synchrotron Light Source is in progress. The atomic physics program studies the properties of multiply-ionized atoms using the x rays for photo-excitation and ionization of neutral atoms and ion beams. The applied physics program builds on the techniques and results of the atomic physics work to develop new analytical techniques for elemental and chemical characterization of materials. The results are then used for a general experimental program in biomedical sciences, geo- and cosmochemistry, and materials sciences. The present status of the program is illustrated by describing selected experiments. Prospects for development of new experimental capabilities are discussed in terms of a heavy ion storage ring for atomic physics experiments and the feasibility of photoelectron microscopy for high spatial resolution analytical work. 21 refs., 11 figs., 2 tabs

Transfer behavior of quantum states between atoms in photonic crystal coupled cavities

International Nuclear Information System (INIS)

Zhang Ke; Li Zhiyuan

2010-01-01

In this article, we discuss the one-excitation dynamics of a quantum system consisting of two two-level atoms each interacting with one of two coupled single-mode cavities via spontaneous emission. When the atoms and cavities are tuned into resonance, a wide variety of time-evolution behaviors can be realized by modulating the atom-cavity coupling strength g and the cavity-cavity hopping strength λ. The dynamics is solved rigorously via the eigenproblem of an ordinary coupled linear system and simple analytical solutions are derived at several extreme situations of g and λ. In the large hopping limit where g >λ, the time-evolution behavior of the system is characterized by the usual slowly varying carrier envelope superimposed upon a fast and violent oscillation. At a certain instant, the energy is fully transferred from the one quantum subsystem to the other. When the two interaction strengths are comparable in magnitude, the dynamics acts as a continuous pulse having irregular frequency and line shape of peaks and valleys, and the complicated time-evolution behaviors are ascribed to the violent competition between all the one-excitation quantum states. The coupled quantum system of atoms and cavities makes a good model to study cavity quantum electrodynamics with great freedoms of many-body interaction.

Modern atomic physics

CERN Document Server

Natarajan, Vasant

2015-01-01

Much of our understanding of physics in the last 30-plus years has come from research on atoms, photons, and their interactions. Collecting information previously scattered throughout the literature, Modern Atomic Physics provides students with one unified guide to contemporary developments in the field. After reviewing metrology and preliminary material, the text explains core areas of atomic physics. Important topics discussed include the spontaneous emission of radiation, stimulated transitions and the properties of gas, the physics and applications of resonance fluorescence, coherence, cooling and trapping of charged and neutral particles, and atomic beam magnetic resonance experiments. Covering standards, a different way of looking at a photon, stimulated radiation, and frequency combs, the appendices avoid jargon and use historical notes and personal anecdotes to make the topics accessible to non-atomic physics students. Written by a leader in atomic and optical physics, this text gives a state-of-the...

Correlated charge-changing ion-atom collisions

International Nuclear Information System (INIS)

Tanis, J.A.

1992-04-01

This report summarizes the progress and accomplishments in accelerator atomic physics research supported by DOE grant DE-FG02-87ER13778 from March 16, 1991 through March 15, 1992. This work involves the experimental investigation of fundamental atomic processes in collisions of charged projectiles with neutral targets or electrons, with particular emphasis on two-electron interactions and electron correlation effects. Processes involving combinations of excitation, ionization, and charge transfer are investigated utilizing coincidence techniques in which projectiles charge-changing events are associated with x-ray emission, target recoil ions, or electron emission. New results have been obtained for studies involving (1) resonant recombination of atomic ions, (2) double ionization of helium, and (3) continuum electron emission. Experiments were conducted using accelerators at the Lawrence Berkeley Laboratory, Argonne National Laboratory, Michigan State University, Western Michigan University, and the Institute of Nuclear Research, Debrecen, Hungary. Brief summaries of work completed and work in progress are given in this report

Investigation of plasma-related matrix effects in inductively coupled plasma-atomic emission spectrometry caused by matrices with low second ionization potentials-identification of the secondary factor

International Nuclear Information System (INIS)

Chan, George C.-Y.; Hieftje, Gary M.

2006-01-01

Plasma-related matrix effects induced by a comprehensive list of matrix elements (a total of fifty-one matrices) in inductively coupled plasma-atomic emission spectrometry were investigated and used to confirm that matrix effects caused by elements with a low second ionization potential are more severe than those from matrix elements having a low first ionization potential. Although the matrix effect is correlated unambiguously with the second ionization potential of a matrix, the correlation is not monotonic, which suggests that at least one other factor is operative. Through study of a large pool of matrix elements, it becomes possible to identify another critical parameter that defines the magnitude of the matrix effect; namely the presence of low-lying energy levels in the doubly charged matrix ion. Penning ionization by Ar excited states is proposed as the dominant mechanism for both analyte ionization/excitation and matrix effects; matrices with a low second ionization potential can effectively quench the population of Ar excited states through successive Penning ionization followed by ion-electron recombination and lead to more severe matrix effects

Squeezing effects of an atom laser: Beyond the linear model

International Nuclear Information System (INIS)

Jing Hui; Ge Molin; Chen Jingling

2002-01-01

We investigate the quantum dynamics and statistics of an atom laser by taking into account binary atom-atom collisions. The rotating wave approximation Hamiltonian of the system is solved analytically . We show that the nonlinear atom-atom interactions could yield periodic quadrature squeezing effects in the atom laser output beam, although the input radio frequency field is in a Glauber coherent state

Sensitivity improvement for antimony determination by using in-situ atom trapping in a slotted quartz tube and flame atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Titretir, Serap, E-mail: serap.titretir@inonu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Inoenue University, 44280 Malatya (Turkey); S Latin-Small-Letter-Dotless-I k, Ahmet Inanc [Department of Chemistry, Faculty of Arts and Sciences, Inoenue University, 44280 Malatya (Turkey); Arslan, Yasin [Department of Chemistry, Faculty of Arts and Sciences, Mehmet Akif Ersoy University, Istiklal Yerleskesi, 15030 Burdur (Turkey); Ataman, O. Yavuz [Department of Chemistry, Faculty of Arts and Sciences, Middle East Technical University, 06800 Ankara (Turkey)

2012-11-15

Significant improvement has been achieved for antimony determination using a slotted quartz tube (SQT) as an atom trap (AT) for in situ preconcentration and flame atomic absorption spectrometry (FAAS). The suggested technique consists of trapping analyte species during ordinary nebulization followed by releasing the collected analyte via introducing organic solvent. Procedures and analytical figures of merit have been presented for the techniques called FAAS, SQT-FAAS and finally SQT-AT-FAAS with the relevant comparisons. Analytical parameters, namely composition of the aqueous medium, sample flow rate, flame conditions, distance between burner head and SQT, sampling period and type of organic solvent and its volume have been optimized. Using SQT-AT-FAAS, a sensitivity enhancement of 369 fold has been obtained, 3 s limit of detection was 3.9 {mu}g L{sup -1} when 25.0 mL of sample was collected in 4.0 min. Interference effects of some elements on antimony signal were studied. - Highlights: Black-Right-Pointing-Pointer Atom trapping in a quartz tube was used for Sb with flame AAS. Black-Right-Pointing-Pointer An inexpensive, simple and sensitive analytical method was suggested for Sb. Black-Right-Pointing-Pointer Almost no background absorption was observed. Black-Right-Pointing-Pointer Range is in microgram per liter level.

Sensitivity improvement for antimony determination by using in-situ atom trapping in a slotted quartz tube and flame atomic absorption spectrometry

International Nuclear Information System (INIS)

Titretir, Serap; Şık, Ahmet İnanç; Arslan, Yasin; Ataman, O. Yavuz

2012-01-01

Significant improvement has been achieved for antimony determination using a slotted quartz tube (SQT) as an atom trap (AT) for in situ preconcentration and flame atomic absorption spectrometry (FAAS). The suggested technique consists of trapping analyte species during ordinary nebulization followed by releasing the collected analyte via introducing organic solvent. Procedures and analytical figures of merit have been presented for the techniques called FAAS, SQT-FAAS and finally SQT-AT-FAAS with the relevant comparisons. Analytical parameters, namely composition of the aqueous medium, sample flow rate, flame conditions, distance between burner head and SQT, sampling period and type of organic solvent and its volume have been optimized. Using SQT-AT-FAAS, a sensitivity enhancement of 369 fold has been obtained, 3 s limit of detection was 3.9 μg L −1 when 25.0 mL of sample was collected in 4.0 min. Interference effects of some elements on antimony signal were studied. - Highlights: ► Atom trapping in a quartz tube was used for Sb with flame AAS. ► An inexpensive, simple and sensitive analytical method was suggested for Sb. ► Almost no background absorption was observed. ► Range is in microgram per liter level.

Influence of asymmetries in the magnetic draping pattern at Titan on the emission of energetic neutral atoms

Science.gov (United States)

Kabanovic, Slawa; Feyerabend, Moritz; Simon, Sven; Meeks, Zachary; Wulms, Veit

2018-03-01

We model the emission of energetic neutral atoms (ENAs) that are generated by the interaction between energetic ions from Saturn's magnetosphere and neutrals from the upper atmosphere of the giant planet's largest moon Titan. The trajectories of the parent ions and the resulting ENA emission morphology are highly sensitive to the electromagnetic field configuration near the moon. We therefore compare the ENA emission pattern for spatially homogeneous fields to the emission obtained from a magnetohydrodynamic (MHD) and a hybrid (kinetic ions, fluid electrons) model of Titan's magnetospheric interaction, by computing the trajectories of several billion energetic test particles. While the MHD model takes into account the draping of the magnetic field lines around Titan, the hybrid approach also considers the significant asymmetries in the electromagnetic fields due to the large gyroradii of pick-up ions from Titan's ionosphere. In all three models, the upstream parameters correspond to the conditions during Cassini's TA flyby of Titan. The shape, magnitude, and location of the ENA emission maxima vary considerably between these three field configurations. The magnetic pile-up region at Titan's ramside deflects a large number of the energetic parent ions, thereby reducing the ENA flux. However, the draped magnetic field lines in Titan's lobes rotate the gyration planes of the incident energetic ions, thereby facilitating the observable ENA production. Overall, the ENA flux calculated for the MHD model is weaker than the emission obtained for the electromagnetic fields from the hybrid code. In addition, we systematically investigate the dependency of the ENA emission morphology on the energy of the parent ions and on the upstream magnetic field strength.

Analytical characteristics of a continuum-source tungsten coil atomic absorption spectrometer.

Science.gov (United States)

Rust, Jennifer A; Nóbrega, Joaquim A; Calloway, Clifton P; Jones, Bradley T

2005-08-01

A continuum-source tungsten coil electrothermal atomic absorption spectrometer has been assembled, evaluated, and employed in four different applications. The instrument consists of a xenon arc lamp light source, a tungsten coil atomizer, a Czerny-Turner high resolution monochromator, and a linear photodiode array detector. This instrument provides simultaneous multi-element analyses across a 4 nm spectral window with a resolution of 0.024 nm. Such a device might be useful in many different types of analyses. To demonstrate this broad appeal, four very different applications have been evaluated. First of all, the temperature of the gas phase was measured during the atomization cycle of the tungsten coil, using tin as a thermometric element. Secondly, a summation approach for two absorption lines for aluminum falling within the same spectral window (305.5-309.5 nm) was evaluated. This approach improves the sensitivity without requiring any additional preconcentration steps. The third application describes a background subtraction technique, as it is applied to the analysis of an oil emulsion sample. Finally, interference effects caused by Na on the atomization of Pb were studied. The simultaneous measurements of Pb and Na suggests that negative interference arises at least partially from competition between Pb and Na atoms for H2 in the gas phase.

Fine structure and analytical quantum-defect wave functions

International Nuclear Information System (INIS)

Kostelecky, V.A.; Nieto, M.M.; Truax, D.R.

1988-01-01

We investigate the domain of validity of previously proposed analytical wave functions for atomic quantum-defect theory. This is done by considering the fine-structure splitting of alkali-metal and singly ionized alkaline-earth atoms. The Lande formula is found to be naturally incorporated. A supersymmetric-type integer is necessary for finite results. Calculated splittings correctly reproduce the principal features of experimental values for alkali-like atoms

Analytical chemistry of actinides

International Nuclear Information System (INIS)

Chollet, H.; Marty, P.

2001-01-01

Different characterization methods specifically applied to the actinides are presented in this review such as ICP/OES (inductively coupled plasma-optical emission spectrometry), ICP/MS (inductively coupled plasma spectroscopy-mass spectrometry), TIMS (thermal ionization-mass spectrometry) and GD/OES (flow discharge optical emission). Molecular absorption spectrometry and capillary electrophoresis are also available to complete the excellent range of analytical tools at our disposal. (authors)

A numerical solution of the coupled proton-H atom transport equations for the proton aurora

International Nuclear Information System (INIS)

Basu, B.; Jasperse, J.R.; Grossbard, N.J.

1990-01-01

A numerical code has been developed to solve the coupled proton-H atom linear transport equations for the proton aurora. The transport equations have been simplified by using plane-parallel geometry and the forward-scattering approximations only. Otherwise, the equations and their numerical solutions are exact. Results are presented for the particle fluxes and the energy deposition rates, and they are compared with the previous analytical results that were obtained by using additional simplifying approximations. It is found that although the analytical solutions for the particle fluxes differ somewhat from the numerical solutions, the energy deposition rates calculated by the two methods agree to within a few percent. The accurate particle fluxes given by the numerical code are useful for accurate calculation of the characteristic quantities of the proton aurora, such as the ionization rates and the emission rates

Frequency shifts in spontaneous emission from two interacting atoms

International Nuclear Information System (INIS)

James, D.F.V.

1993-01-01

A model radiating system consisting of two atoms in close proximity is analyzed. This system demonstrates the influence of spatial coherence on the spectrum of the radiation field. Explicit expressions for the degree of coherence, the source spectrum, and the spectrum of the radiation field are derived. The results are discussed in terms of Wolf's work [Phys. Rev. Lett. 56, 1370 (1986)] on this effect, which can be considered in terms of a multiple-atom analog of the effects of radiation reaction on a single atom, i.e., spontaneous decay and the Lamb shift

Comparative studies of atomic independent-particle potentials

International Nuclear Information System (INIS)

Talman, J.D.; Ganas, P.S.; Green, A.E.S.

1979-01-01

A number of atomic properties are compared in various independent-particle models for atoms. The models studied are the Hartree-Fock method, a variationally optimized potential model, a parametrized analytic form of the same model, parametrized analytic models constructed to fit atomic energy levels, the so-called Hartree-Fock-Slater model, and the Xα model. The physical properties compared are single-particle energy levels, total energies, and dipole polarizabilities. The extent to which the virial theorem is satisfied in the different models is also considered. The atoms Be, Ne, Ar, Kr, and Xe and ions O v and Al iv hav been compared. The results show that the experimental properties can be well represented by several of the independent-particle models. Since it has been shown that the optimized potential models yield wavefunctions that are almost the same as Hartree-Fock wavefunctions, they provide a natural solution to the problem of extending the Hartree-Fock method to excited states

Line splitting and modified atomic decay of atoms coupled with N quantized cavity modes

Science.gov (United States)

Zhu, Yifu

1992-05-01

We study the interaction of a two-level atom with N non-degenerate quantized cavity modes including dissipations from atomic decay and cavity damps. In the strong coupling regime, the absorption or emission spectrum of weakly excited atom-cavity system possesses N + 1 spectral peaks whose linewidths are the weighted averages of atomic and cavity linewidths. The coupled system shows subnatural (supernatural) atomic decay behavior if the photon loss rates from the N cavity modes are smaller (larger) than the atomic decay rate. If N cavity modes are degenerate, they can be treated effectively as a single mode. In addition, we present numerical calculations for N = 2 to characterize the system evolution from the weak coupling to strong coupling limits.

Theoretical Atomic Physics code development IV: LINES, A code for computing atomic line spectra

International Nuclear Information System (INIS)

Abdallah, J. Jr.; Clark, R.E.H.

1988-12-01

A new computer program, LINES, has been developed for simulating atomic line emission and absorption spectra using the accurate fine structure energy levels and transition strengths calculated by the (CATS) Cowan Atomic Structure code. Population distributions for the ion stages are obtained in LINES by using the Local Thermodynamic Equilibrium (LTE) model. LINES is also useful for displaying the pertinent atomic data generated by CATS. This report describes the use of LINES. Both CATS and LINES are part of the Theoretical Atomic PhysicS (TAPS) code development effort at Los Alamos. 11 refs., 9 figs., 1 tab

Use of stirred tanks for studying matrix effects caused by inorganic acids, easily ionized elements and organic solvents in inductively coupled plasma atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Paredes, Eduardo [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Maestre, Salvador E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain); Todoli, Jose L. [Departamento de Quimica Analitica, Nutricion y Bromatologia, University of Alicante, 03080 Alicante (Spain)]. E-mail: jose.todoli@ua.es

2006-03-15

A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l{sup -1} in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l{sup -1} for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min.

Use of stirred tanks for studying matrix effects caused by inorganic acids, easily ionized elements and organic solvents in inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Paredes, Eduardo; Maestre, Salvador E.; Todoli, Jose L.

2006-01-01

A stirred tank was used for the first time to elucidate the mechanism responsible for inductively coupled plasma atomic emission spectroscopy (ICP-AES) matrix effects caused by inorganic, acids and easily ionized elements (EIEs), as well as organic, ethanol and acetic acid, compounds. In order to gradually increase the matrix concentration, a matrix solution was introduced inside a stirred container (tank) initially filled with an aqueous multielement standard. PolyTetraFluoroEthylene (PTFE) tubing was used to deliver the resulting solution to the liquid sample introduction system. Matrix concentration ranged from 0 to 2 mol l -1 in the case of inorganic acids (i.e., nitric, sulfuric, hydrochloric and a mixture of them), from 0 to about 2500 mg l -1 for EIEs (i.e., sodium, calcium and mixtures of both) and from 0% to 15%, w/w for organic compounds. Up to 40-50 different solutions were prepared and measured in a period of time shorter than 6-7 min. This investigation was carried out in terms of emission intensity and tertiary aerosols characteristics. The experimental setup used in the present work allowed to thoroughly study the effect of matrix concentration on analytical signal. Generally speaking, the experiments concerning tertiary aerosol characterization revealed that, in the case of inorganic acids and EIEs, the mechanism responsible for changes in aerosol characteristics was the droplet fission. In contrast, for organic matrices it was found that the interference was caused by a change in both aerosol transport and plasma thermal characteristics. The extent of the interferences caused by organic as well as inorganic compounds was compared for a set of 14 emission lines through a wide range of matrix concentrations. With a stirred tank, it is possible to choose an efficient internal standard for any given matrix composition. The time required to complete this procedure was shorter than 7 min

Number series of atoms, interatomic bonds and interface bonds defining zinc-blende nanocrystals as function of size, shape and surface orientation: Analytic tools to interpret solid state spectroscopy data

Directory of Open Access Journals (Sweden)

Dirk König

2016-08-01

Full Text Available Semiconductor nanocrystals (NCs experience stress and charge transfer by embedding materials or ligands and impurity atoms. In return, the environment of NCs experiences a NC stress response which may lead to matrix deformation and propagated strain. Up to now, there is no universal gauge to evaluate the stress impact on NCs and their response as a function of NC size dNC. I deduce geometrical number series as analytical tools to obtain the number of NC atoms NNC(dNC[i], bonds between NC atoms Nbnd(dNC[i] and interface bonds NIF(dNC[i] for seven high symmetry zinc-blende (zb NCs with low-index faceting: {001} cubes, {111} octahedra, {110} dodecahedra, {001}-{111} pyramids, {111} tetrahedra, {111}-{001} quatrodecahedra and {001}-{111} quadrodecahedra. The fundamental insights into NC structures revealed here allow for major advancements in data interpretation and understanding of zb- and diamond-lattice based nanomaterials. The analytical number series can serve as a standard procedure for stress evaluation in solid state spectroscopy due to their deterministic nature, easy use and general applicability over a wide range of spectroscopy methods as well as NC sizes, forms and materials.

Sub-microanalysis of solid samples with near-field enhanced atomic emission spectroscopy

Science.gov (United States)

Wang, Xiaohua; Liang, Zhisen; Meng, Yifan; Wang, Tongtong; Hang, Wei; Huang, Benli

2018-03-01

A novel approach, which we have chosen to name it as near-field enhanced atomic emission spectroscopy (NFE-AES), was proposed by introducing a scanning tunnelling microscope (STM) system into a laser-induced breakdown spectrometry (LIBS). The near-field enhancement of a laser-illuminated tip was utilized to improve the lateral resolution tremendously. Using the hybrid arrangement, pure metal tablets were analyzed to verify the performance of NFE-AES both in atmosphere and in vacuum. Due to localized surface plasmon resonance (LSPR), the incident electromagnetic field is enhanced and confined at the apex of tip, resulting in sub-micron scale ablation and elemental emission signal. We discovered that the signal-to-noise ratio (SNR) and the spectral resolution obtained in vacuum condition are better than those acquired in atmospheric condition. The quantitative capability of NFE-AES was demonstrated by analyzing Al and Pb in Cu matrix, respectively. Submicron-sized ablation craters were achieved by performing NFE-AES on a Si wafer with an Al film, and the spectroscopic information from a crater of 650 nm diameter was successfully obtained. Due to its advantage of high lateral resolution, NFE-AES imaging of micro-patterned Al lines on an integrated circuit of a SIM card was demonstrated with a sub-micron lateral resolution. These results reveal the potential of the NFE-AES technique in sub-microanalysis of solids, opening an opportunity to map chemical composition at sub-micron scale.

High-Activity ICP-AES Measurements in the ATALANTE Facility Applied to Analytical Monitoring of an Extraction Test

Energy Technology Data Exchange (ETDEWEB)

Esbelin, E.; Boyer-Deslys, V.; Beres, A.; Viallesoubranne, C. [CEA Marcoule, DEN/DRCP/SE2A/LAMM, BP17171, 30207 Bagnols-sur-Ceze (France)

2008-07-01

The Material Analysis and Metrology Laboratory (LAMM) of the Cea's Atalante complex ensures analytical monitoring of enhanced separation tests. Certain fission products, actinides and lanthanides were assayed by ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy) in the CBA shielded analysis line. These analyses were particularly effective for controlling the Diamex test, and contributed to its success. The Diamex process consists in extracting the actinides and lanthanides from a Purex raffinate using a diamide, DMDOHEMA, followed by stripping at low acidity. The major elements analyzed during the test were Am, Nd, Mo, Fe, and Zr.

Initial wavefunction dependence on atom interferometry phases

NARCIS (Netherlands)

Jansen, M.A.H.M.; Leeuwen, van K.A.H.

2008-01-01

In this paper we present a mathematical procedure to analytically calculate the output signal of a pulsed atom interferometer in an inertial field. Using the wellknown ABCD¿ method we take into account the full wave dynamics of the atoms with a first order treatment of the wavefront distortion by

Low Altitude Emission (LAE) of Energetic Neutral Atoms (ENA) Observed by TWINS and its Relation to the CINEMA CubeSat Mission

Science.gov (United States)

Bazell, D.; Sotirelis, T.; Nair, H.; Roelof, E. C.; Brandt, P. C.

2009-12-01

The brightest source of energetic neutral atoms (ENAs) at energies >1keV is low altitude emission (LAE) from ~200-400km near auroral latitudes where precipitating energetic ions undergo multiple atomic collisions with the monatomic (O) exosphere. This emission is many times brighter than that from the high-altitude ring current region where the energetic ions interact only weakly with the much less dense monatomic (H) hydrogen geocorona. The recently selected NSF CubeSat mission CINEMA [Lin et al., this special session] has, as part of its science payload (STEIN), an ENA imager covering energies 4-100keV. From a high-inclination ~800km orbit, STEIN will view the LAE four times during every 90 minutes. The NASA TWINS stereo ENA imagers (2-40keV) will also view the LAE from their Molniya orbits (apogee radius~7Re). We have been analyzing the TWINS ENA images of LAE and comparing them with in situ ion measurements (1-40keV) from DMSP spacecraft when their tracks take them under the ion precipitation regions imaged by TWINS. We have developed an ENA emissivity function that relates the directionally-dependent emergent ENA spectrum to that of the precipitating ions. The TWINS/DMSP direct comparisons show good agreement. We offer suggestions on joint observing strategies for CINEMA, TWINS and DMSP after the CINEMA launch in the second half of 2011.

Qualitative tissue differentiation by analysing the intensity ratios of atomic emission lines using laser induced breakdown spectroscopy (LIBS): prospects for a feedback mechanism for surgical laser systems.

Science.gov (United States)

Kanawade, Rajesh; Mahari, Fanuel; Klämpfl, Florian; Rohde, Maximilian; Knipfer, Christian; Tangermann-Gerk, Katja; Adler, Werner; Schmidt, Michael; Stelzle, Florian

2015-01-01

The research work presented in this paper focuses on qualitative tissue differentiation by monitoring the intensity ratios of atomic emissions using 'Laser Induced Breakdown Spectroscopy' (LIBS) on the plasma plume created during laser tissue ablation. The background of this study is to establish a real time feedback control mechanism for clinical laser surgery systems during the laser ablation process. Ex-vivo domestic pig tissue samples (muscle, fat, nerve and skin) were used in this experiment. Atomic emission intensity ratios were analyzed to find a characteristic spectral line for each tissue. The results showed characteristic elemental emission intensity ratios for the respective tissues. The spectral lines and intensity ratios of these specific elements varied among the different tissue types. The main goal of this study is to qualitatively and precisely identify different tissue types for tissue specific laser surgery. © 2015 The Authors. Journal of Biophotonics published by WILEY-VCH Verlag.

Fast calculator for X-ray emission due to Radiative Recombination and Radiative Electron Capture in relativistic heavy-ion atom collisions

Science.gov (United States)

Herdrich, M. O.; Weber, G.; Gumberidze, A.; Wu, Z. W.; Stöhlker, Th.

2017-10-01

In experiments with highly charged, fast heavy ions the Radiative Recombination (RR) and Radiative Electron Capture (REC) processes have significant cross sections in an energy range of up to a few GeV / u . They are some of the most important charge changing processes in collisions of heavy ions with atoms and electrons, leading to the emission of a photon along with the formation of the ground and excited atomic states. Hence, for the understanding and planning of experiments, in particular for X-ray spectroscopy studies, at accelerator ring facilities, such as FAIR, it is crucial to have a good knowledge of these cross sections and the associated radiation characteristics. In the frame of this work a fast calculator, named RECAL, for the RR and REC process is presented and its capabilities are demonstrated with the analysis of a recently conducted experiment at the Experimental Storage Ring (ESR) at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. A method is presented to determine unknown X-ray emission cross sections via normalization of the recorded spectra to REC cross sections calculated by RECAL.

Nuclear analytical methods for platinum group elements

International Nuclear Information System (INIS)

2005-04-01

Platinum group elements (PGE) are of special interest for analytical research due to their economic importance like chemical peculiarities as catalysts, medical applications as anticancer drugs, and possible environmental detrimental impact as exhaust from automobile catalyzers. Natural levels of PGE are so low in concentration that most of the current analytical techniques approach their limit of detection capacity. In addition, Ru, Rh, Pd, Re, Os, Ir, and Pt analyses still constitute a challenge in accuracy and precision of quantification in natural matrices. Nuclear analytical techniques, such as neutron activation analysis, X ray fluorescence, or proton-induced X ray emission (PIXE), which are generally considered as reference methods for many analytical problems, are useful as well. However, due to methodological restrictions, they can, in most cases, only be applied after pre-concentration and under special irradiation conditions. This report was prepared following a coordinated research project and a consultants meeting addressing the subject from different viewpoints. The experts involved suggested to discuss the issue according to the (1) application, hence, the concentration levels encountered, and (2) method applied for analysis. Each of the different fields of application needs special consideration for sample preparation, PGE pre-concentration, and determination. Additionally, each analytical method requires special attention regarding the sensitivity and sample type. Quality assurance/quality control aspects are considered towards the end of the report. It is intended to provide the reader of this publication with state-of-the-art information on the various aspects of PGE analysis and to advise which technique might be most suitable for a particular analytical problem related to platinum group elements. In particular, many case studies described in detail from the authors' laboratory experience might help to decide which way to go. As in many cases

Noble gas encapsulation into carbon nanotubes: Predictions from analytical model and DFT studies

Energy Technology Data Exchange (ETDEWEB)

Balasubramani, Sree Ganesh; Singh, Devendra; Swathi, R. S., E-mail: swathi@iisertvm.ac.in [School of Chemistry, Indian Institute of Science Education and Research Thiruvananthapuram (IISER-TVM), Kerala 695016 (India)

2014-11-14

The energetics for the interaction of the noble gas atoms with the carbon nanotubes (CNTs) are investigated using an analytical model and density functional theory calculations. Encapsulation of the noble gas atoms, He, Ne, Ar, Kr, and Xe into CNTs of various chiralities is studied in detail using an analytical model, developed earlier by Hill and co-workers. The constrained motion of the noble gas atoms along the axes of the CNTs as well as the off-axis motion are discussed. Analyses of the forces, interaction energies, acceptance and suction energies for the encapsulation enable us to predict the optimal CNTs that can encapsulate each of the noble gas atoms. We find that CNTs of radii 2.98 − 4.20 Å (chiral indices, (5,4), (6,4), (9,1), (6,6), and (9,3)) can efficiently encapsulate the He, Ne, Ar, Kr, and Xe atoms, respectively. Endohedral adsorption of all the noble gas atoms is preferred over exohedral adsorption on various CNTs. The results obtained using the analytical model are subsequently compared with the calculations performed with the dispersion-including density functional theory at the M06 − 2X level using a triple-zeta basis set and good qualitative agreement is found. The analytical model is however found to be computationally cheap as the equations can be numerically programmed and the results obtained in comparatively very less time.

Tuning excitation laser wavelength for secondary resonance in low-intensity phase-selective laser-induced breakdown spectroscopy for in-situ analytical measurement of nanoaerosols

Science.gov (United States)

Xiong, Gang; Li, Shuiqing; Tse, Stephen D.

2018-02-01

In recent years, a novel low-intensity phase-selective laser-induced breakdown spectroscopy (PS-LIBS) technique has been developed for unique elemental-composition identification of aerosolized nanoparticles, where only the solid-phase nanoparticles break down, forming nanoplasmas, without any surrounding gas-phase breakdown. Additional work has demonstrated that PS-LIBS emissions can be greatly enhanced with secondary resonant excitation by matching the excitation laser wavelength with an atomic transition line in the formed nanoplasma, thereby achieving low limits of detection. In this work, a tunable dye laser is employed to investigate the effects of excitation wavelength and irradiance on in-situ PS-LIBS measurements of TiO2 nanoaerosols. The enhancement factor by resonant excitation can be 220 times greater than that for non-resonant cases under similar conditions. Moreover, the emitted spectra are unique for the selected resonant transition lines for a given element, suggesting the potential to make precise phase-selective and analyte-selective measurements of nanoparticles in a multicomponent multiphase system. The enhancement factor by resonant excitation is highly sensitive to excitation laser wavelength, with narrow excitation spectral windows, i.e., 0.012 to 0.023 nm (FWHM, full width at half maximum) for Ti (I) neutral atomic lines, and 0.051 to 0.139 nm (FWHM) for Ti (II) single-ionized atomic lines. Boltzmann analysis of the emission intensities, temporal response of emissions, and emission dependence on excitation irradiance are investigated to understand aspects of the generated nanoplasmas such as temperature, local thermodynamic equilibrium (LTE), and excitation mechanism.

Study of emission episodes of urban aerosol by ion beam analytical techniques

International Nuclear Information System (INIS)

Angyal, A.; Kertesz, Zs.; Szikszai, Z.; Szoboszlai, Z.; Furu, E.; Csedreki, L.; Daroczi, L.

2010-01-01

Complete text of publication follows. Aerosol pollution has impact on the climate and on human health. Thus investigation of atmospheric aerosol is important in urban environment such as Debrecen. One of the main goals of our study was to define the sources of the particles. The hourly evolution of atmospheric aerosol concentration was used to identify sources of fine (aerodynamic diameter < 2,5 μm) and coarse (10 μm ≥ aerodynamic diameter ≥ 2.5 μm) urban particulate matter in Debrecen. In both size fractions sources were found which were characterized by high heavy metal content. In this study we provide accurate information of the sources of coarse mode heavy metals by using nuclear and scanning electron microscopy. Single particle analysis of chosen samples was carried out on the ATOMKI Scanning Nuclear Microprobe Facility. Elemental composition for Z ≥ 6, morphology and size of around 500 coarse mode particles were determined by Scanning Transmission Ion Microscopy, light-element PIXE and PIXE analytical methods. Furthermore Scanning Electron Microscopy (SEM) was used to investigate particles morphology. The main components of the particles were Na, K, Ca, S, P and Fe with traces of Ti, V, Cr, Mn, Ni, Cu, Zn, Co, Pb. S-rich particles were enriched in one or more of the following elements: Na, Ca, K, Fe, Zn. Trace metals (Mn, Cu, Zn, Cr) occurred together Fe supposedly originated from industrial emission or traffic. P appeared in the Ca-rich particles. Particles with high concentration of Ni were rich in V, Fe and S. Thus this source was identified as residual combustion. V-rich particles occurred together with Fe, Mn and Cr. Their possible source was industry. Pb was attached to Ca, Fe, S containing particles. As result of the SEM study the following particle types (Figure 1.) were identified: semitransparent material (S-K-rich, S-Zn-rich, PCa-rich), spherical (FeO, Fe-Ni-Cr-V-rich), cubic (KCl, CaCl) and crystalline (S-Ca-rich). The main sources of

Microwave-assisted versus conventional decomposition procedures applied to a ceramic potsherd standard reference material by inductively coupled plasma atomic emission spectrometry

Energy Technology Data Exchange (ETDEWEB)

Papadopoulou, D.N.; Zachariadis, G.A.; Anthemidis, A.N.; Tsirliganis, N.C.; Stratis, J.A

2004-03-03

Inductively coupled plasma atomic emission spectrometry (ICP-AES) is a powerful, sensitive analytical technique with numerous applications in chemical characterization including that of ancient pottery, mainly due to its multi-element character, and the relatively short time required for the analysis. A critical step in characterization studies of ancient pottery is the selection of a suitable decomposition procedure for the ceramic matrix. The current work presents the results of a comparative study of six decomposition procedures applied on a standard ceramic potsherd reference material, SARM 69. The investigated decomposition procedures included three microwave-assisted decomposition procedures, one wet decomposition (WD) procedure by conventional heating, one combined microwave-assisted and conventional heating WD procedure, and one fusion procedure. Chemical analysis was carried out by ICP-AES. Five major (Si, Al, Fe, Ca, Mg), three minor (Mn, Ba, Ti) and two trace (Cu, Co) elements were determined and compared with their certified values. Quantitation was performed at two different spectral lines for each element and multi-element matrix-matched calibration standards were used. The recovery values for the six decomposition procedures ranged between 75 and 110% with a few notable exceptions. Data were processed statistically in order to evaluate the investigated decomposition procedures in terms of recovery, accuracy and precision, and eventually select the most appropriate one for ancient pottery analysis.

Fully automated dissolution and separation methods for inductively coupled plasma atomic emission spectrometry rock analysis. Application to the determination of rare earth elements

International Nuclear Information System (INIS)

Govindaraju, K.; Mevelle, G.

1987-01-01

In rock analysis laboratories, sample preparation is a serious problem, or even an enormous bottleneck. Because this laboratory is production-oriented, this problem was attacked by automating progressively, different steps in rock analysis for major, minor and trace elements. This effort has been considerably eased by the fact that all sample preparation schemes in this laboratory for the past three decades have been based on an initial lithium borate fusion of rock samples and all analytical methods based on multi-element atomic emission spectrometry, with switch-over from solid analysis by arc/spark excitation to solution analysis by plasma excitation in 1974. The sample preparation steps which have been automated are: weighing of samples and fluxes, lithium borate fusion, dissolution and dilution of fusion products and ion-exchange separation of difficult trace elements such as rare earth elements (REE). During 1985 and 1986, these different unit operations have been assembled together as peripheral units in the form of a workstation, called LabRobStation. A travelling robot is the master of LabRobStation, with all peripheral units at its reach in 10 m 2 workspace. As an example of real application, the automated determination of REE, based on more than 8000 samples analysed during 1982 and 1986, is presented. (author)

Analytical dependence of effective atomic number on the elemental composition of matter and radiation energy in the range 10-1000 keV

Science.gov (United States)

Eritenko, A. N.; Tsvetiansky, A. L.; Polev, A. A.

2018-01-01

In the present paper, a universal analytical dependence of effective atomic number on the composition of matter and radiation energy is proposed. This enables one to consider the case of a strong difference in the elemental composition with respect to their atomic numbers over a wide energy range. The contribution of photoelectric absorption and incoherent and coherent scattering during the interaction between radiation and matter is considered. For energy values over 40 keV, the contribution of coherent scattering does not exceed approximately 10% that can be neglected at a further consideration. The effective atomic numbers calculated on the basis of the proposed relationships are compared to the results of calculations based on other methods considered by different authors on the basis of experimental and tabulated data on mass and atomic attenuation coefficients. The examination is carried out for both single-element (e.g., 6C, 14Si, 28Cu, 56Ba, and 82Pb) and multi-element materials. Calculations are performed for W1-xCux alloys (x = 0.35; x = 0.4), PbO, ther moluminescent dosimetry compounds (56Ba, 48Cd, 41Sr, 20Ca, 12Mg, and 11Na), and SO4 in a wide energy range. A case with radiation energy between the K- and L1-absorption edges is considered for 82Pb, 74W, 56Ba, 48Cd, and 38Sr. This enables to substantially simplify the calculation of the atomic number and will be useful in technical and scientific fields related to the interaction between X-ray/gamma radiation and matter.

Mechanism of selenium hydride atomization, fate of free atoms and temperature distribution in an argon shielded, highly fuel-rich, hydrogen-oxygen diffusion micro-flame studied by atomic absorption spectrometry

Czech Academy of Sciences Publication Activity Database

D'Ulivo, A.; Dědina, Jiří; Lampugnani, L.; Matoušek, Tomáš

2002-01-01

Roč. 17, č. 3 (2002), s. 253-257 ISSN 0267-9477 R&D Projects: GA ČR GA203/01/0453; GA ČR GA203/98/0754 Institutional research plan: CEZ:AV0Z4031919 Keywords : hydride atomization * hydride generation * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.250, year: 2002

Kinetic theory of beam-induced plasmas generalised to sophisticated atomic structures

International Nuclear Information System (INIS)

Peyraud-Cuenca, Nelly

1987-01-01

We present an analytic kinetic model available for all particle-beam-induced atomic plasmas, without any restriction on the distribution of electronic levels. The method is an iteration of the already known solution available only for the distribution of atomic levels as in the rare gases. We recall a universal atomic kinetic model which, independently of its applications to the study of efficient laser systems, might be a first step in the analytic investigation of molecular problems. Then, the iteration is systematically applied to all possible atomic structures whose number is increased by the non-local character of inelastic processes. We deduce a general analytic representation of the 'tail' of the electron distribution function as a ratio between non-local source terms and a combination of inelastic cross sections, from which we exhibit a physical interpretation and essential scaling laws. The theory is applied to sodium which is an important element in the research of efficient laser systems. (author)

Secondary electron emission of thin carbon foils under the impact of hydrogen atoms, ions and molecular ions, under energies within the MeV range

International Nuclear Information System (INIS)

Vidovic, Z.

1997-06-01

This work focuses on the study of the emission statistics of secondary electrons from thin carbon foils bombarded with H 0 , H 2 + and H 3 + projectiles in the 0.25-2.2 MeV energy range. The phenomenon of secondary electron emission from solids under the impact of swift ions is mainly due to inelastic interactions with target electrons. The phenomenological and theoretical descriptions, as well as a summary of the main theoretical models are the subject of the first chapter. The experimental set-up used to measure event by event the electron emission of the two faces of a thin carbon foil traversed by an energetic projectile is described in the chapter two. In this chapter are also presented the method and algorithms used to process experimental spectra in order to obtain the statistical distribution of the emitted electrons. Chapter three presents the measurements of secondary electron emission induced by H atoms passing through thin carbon foils. The secondary electron yields are studied in correlation with the emergent projectile charge state. We show the peculiar role of the projectile electron, whether it remains or not bound to the incident proton. The fourth chapter is dedicated to the secondary electron emission induced by H 2 + and H 3 + polyatomic ions. The results are interpreted in terms of collective effects in the interactions of these ions with solids. The role of the proximity of the protons, molecular ion fragments, upon the amplitude of these collective effects is evidenced from the study of the statistics of forward emission. These experiences allowed us to shed light on various aspects of atom and polyatomic ion inter-actions with solid surfaces. (author)

Development of an analytical model for the determination of 60Co in aqueous samples by atomic absorption and gamma spectrometry techniques

International Nuclear Information System (INIS)

Solis A, N. A.

2015-01-01

The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

Atom localization via phase and amplitude control of the driving field

International Nuclear Information System (INIS)

Ghafoor, Fazal; Qamar, Sajid; Zubairy, M. Suhail

2002-01-01

Control of amplitude and phase of the driving field in an atom-field interaction leads towards the strong line narrowing and quenching in the spontaneous emission spectrum. We exploit this fact for the atom localization scheme and achieve a much better spatial resolution in the conditional position probability distribution of the atom. Most importantly the quenching in the spontaneous emission manifests itself in reducing the periodicity in the conditional position probability distribution and hence the uncertainty in a particular position measurement of the single atom by a factor of 2

Analytical Chemistry Division : annual report (for) 1985

International Nuclear Information System (INIS)

Mahadevan, N.

1986-01-01

An account of the various activities of the Analytical Chemistry Division of the Bhabha Atomic Research Centre, Bombay, during 1985 is presented. The main function of the Division is to provide chemical analysis support to India's atomic energy programme. In addition, the Division also offers its analytical services, mostly for measurement of concentrations at trace levels to Indian industries and other research organization in the country. A list of these determinations is given. The report also describes the research and development (R and D) activities - both completed and in progress, in the form of individual summaries. During the year an ultra trace analytical laboratory for analysis of critical samples without contamination was set up using indigenous material and technology. Publications and training activities of the staff, training of the staff from other institution, guidance by the staff for post-graduate degree and invited talks by the staff are listed in the appendices at the end of the report. (M.G.B.)

Critical evaluation of analytical performance of atomic absorption spectrometry and inductively coupled plasma mass spectrometry for mercury determination

International Nuclear Information System (INIS)

Krata, A.; Bulska, E.

2005-01-01

The analytical performance of cold vapor atomic absorption spectrometry (CV AAS), graphite furnace atomic absorption spectrometry (GF AAS) and inductively coupled plasma mass spectrometry (ICP-MS) for mercury determination have been investigated with the use of two reference materials SRM 2710 Montana I Soil and BCR-144R (sewage sludge from domestic origin). The digestion conditions and their influence on determination of mercury have been studied. Samples were decomposed by microwave digestion in closed vessels with the use of HCl alone or mixture of HCl+HNO 3 +HF. The digestion solutions were analyzed by CV AAS using NaBH 4 as a reducing agent, by GF AAS with Pd or mixture of Pd/Rh as modifiers and by ICP-MS with Rh as internal standard. In the case of CV AAS, results were not dependent on digestion conditions. In the case of GF AAS and ICP-MS, results depended significantly on digestion conditions; in both cases, the use of the mixture of acids as defined above suppressed the signal of mercury. Therefore, in those cases, the microwave digestion with HCl is recommended. Detection limits of 0.003, 0.01 and 0.2 μg g -1 were achieved by ICP-MS, CV AAS and GF AAS, respectively

High-performance liquid chromatographic separation of biologically important arsenic species utilizing on-line inductively coupled argon plasma atomic emission spectrometric detection

Energy Technology Data Exchange (ETDEWEB)

Spall, W.D.; Lynn, J.G.; Andersen, J.L.; Valdez, J.G.; Gurley, L.R.

1986-06-01

An anion exchange, high-performance liquid chromatography technique using a 15-min linear gradient from water to 0.5 M ammonium carbonate to separate arsenite, arsenate, methylarsonic acid, and dimethylarsinic acid from neutral arsenic containing compounds was developed for application to a study of arsenic metabolism in cultured cell suspensions. Arsenic detection was accomplished by the direct coupling of the column effluent to an inductively coupled argon plasma atomic emission spectrometer (ICAP-AES) set to monitor the arsenic emission line at 197.19 nm. The analysis requires 20 min and is sensitive to as low as 60 ng of arsenic injected to the column.

Two-photon emission and multiphoton absorption by atoms

International Nuclear Information System (INIS)

Mu, X.

1988-01-01

This thesis consists of investigations of two problems concerning photon-atom interactions. The first topic deals with two-photon transitions in atomic inner shells. An independent-particle model has been used to describe the two-photon transitions between different inner-shell electron states. The first relativistic self-consistent-field calculation of these transition rates in Ag, Mo, and Xe has been carried out. The theoretical results are compared with recent measurements. Good agreement with measured rates is found except in some cases where more reliable experiments still need to be done. The second topic is multiphoton multiionization of atoms. The maximum entropy principle has been employed in this theoretical investigation. A detailed statistical analysis of measured ionic charge distributions produced in strong laser pulses has been carried out. The results of this analysis indicates that the charge-state distribution is a Poissonian, rather than the binomial which prevails under infrared radiation, and hence that ionization occurs stepwise during the pulse. This result is shown to be consistent with experimental data

Efficiency of entanglement of distant atoms by projective measurement

Energy Technology Data Exchange (ETDEWEB)

Olivares Renteria, Georgina; Zippilli, Stefano; Morigi, Giovanna [Departament de Fisica, Universitat Autonoma de Barcelona, 08193 Bellaterra (Spain); Rohde, Felix; Schuck, Carsten; Eschner, Juergen [ICFO - Institut de CIencies Fotoniques, 08860 Castelldefels, Barcelona (Spain)

2008-07-01

We compare the efficiency of two schemes for the preparation of entangled states of distant atoms. In these proposals the atoms do not interact and the entanglement is realized by means of the measurement of the scattered field which project the two atoms into the desired state. We quantify the efficiency of the schemes using the fidelity between the state of the system after the detection of a photon and an ideal entangled state of the two atoms. In the first scheme the atoms interact with two optical cavities and the enhanced probability of emission into the cavities allows for high detection efficiency. This scheme is limited by the finite probability of emission of two photons. Thus, even under the assumption of perfect detection efficiency, the fidelity of the scheme never reaches unity. In the second scheme emission of two photons is suppressed by low excitation strength, but the detection efficiency is low since the atoms scatter into free space and only a small fraction of the photons is measured. In this case the fidelity is conditioned on single-photon detection and results to be higher. The comparison is quantitatively evaluated for an ongoing experiment with two distant trapped single Ca+ ions.

Speciation of organotin compounds in waters and marine sediments using purge-and-trap capillary gas chromatography with atomic emission detection

International Nuclear Information System (INIS)

Campillo, Natalia; Aguinaga, Nerea; Vin-tilde as, Pilar; Lopez-Garcia, Ignacio; Hernandez-Cordoba, Manuel

2004-01-01

A procedure for the simultaneous determination of six organotin compounds, including methyl-, butyl- and phenyltins, in waters and marine sediments is developed. The analytes were leached from the solid samples into an acetic acid:methanol mixture by using an ultrasonic probe. The organotins were derivatized with sodium tetraethylborate (NaBEt 4 ) in the aqueous phase, stripped by a flow of helium, pre-concentrated in a trap and thermally desorbed. This was followed by capillary gas chromatography with microwave-induced plasma atomic emission spectrometry as the detection system (GC-AED). Each chromatographic run took 22 min, including the purge time. Calibration curves were obtained by plotting peak area versus concentration and the correlation coefficients for linear calibration were at least 0.9991. Detection limits ranged from 11 to 50 ng Sn l -1 for tributyltin and tetramethyltin, respectively. The seawater samples analyzed contained variable concentrations of mono-, di- and tributyl- and monophenyltin, ranging from 0.05 to 0.48 μg Sn l -1 , depending on the compound. Some of the sediments analyzed contained concentrations of dibutyl- and tributyltin of between 6.0 and 13.0 ng Sn g -1 . Analysis of the certified reference material PACS-2, as well as of spiked water and sediment samples showed the accuracy of the method. The proposed method is selective and reproducible, and is considered suitable for monitoring organotin compounds in water and sediment samples

Speciation of organotin compounds in waters and marine sediments using purge-and-trap capillary gas chromatography with atomic emission detection

Energy Technology Data Exchange (ETDEWEB)

Campillo, Natalia [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Aguinaga, Nerea [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Vin-tilde as, Pilar [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Lopez-Garcia, Ignacio [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain); Hernandez-Cordoba, Manuel [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, E-30071 Murcia (Spain)]. E-mail: hcordoba@um.es

2004-11-08

A procedure for the simultaneous determination of six organotin compounds, including methyl-, butyl- and phenyltins, in waters and marine sediments is developed. The analytes were leached from the solid samples into an acetic acid:methanol mixture by using an ultrasonic probe. The organotins were derivatized with sodium tetraethylborate (NaBEt{sub 4}) in the aqueous phase, stripped by a flow of helium, pre-concentrated in a trap and thermally desorbed. This was followed by capillary gas chromatography with microwave-induced plasma atomic emission spectrometry as the detection system (GC-AED). Each chromatographic run took 22 min, including the purge time. Calibration curves were obtained by plotting peak area versus concentration and the correlation coefficients for linear calibration were at least 0.9991. Detection limits ranged from 11 to 50 ng Sn l{sup -1} for tributyltin and tetramethyltin, respectively. The seawater samples analyzed contained variable concentrations of mono-, di- and tributyl- and monophenyltin, ranging from 0.05 to 0.48 {mu}g Sn l{sup -1}, depending on the compound. Some of the sediments analyzed contained concentrations of dibutyl- and tributyltin of between 6.0 and 13.0 ng Sn g{sup -1}. Analysis of the certified reference material PACS-2, as well as of spiked water and sediment samples showed the accuracy of the method. The proposed method is selective and reproducible, and is considered suitable for monitoring organotin compounds in water and sediment samples.

Fingerprinting of complex mixtures with the use of high performance liquid chromatography, inductively coupled plasma atomic emission spectroscopy and chemometrics

International Nuclear Information System (INIS)

Ni Yongnian; Peng Yunyan; Kokot, Serge

2008-01-01

The molecular and metal profile fingerprints were obtained from a complex substance, Atractylis chinensis DC-a traditional Chinese medicine (TCM), with the use of the high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. This substance was used in this work as an example of a complex biological material, which has found application as a TCM. Such TCM samples are traditionally processed by the Bran, Cut, Fried and Swill methods, and were collected from five provinces in China. The data matrices obtained from the two types of analysis produced two principal component biplots, which showed that the HPLC fingerprint data were discriminated on the basis of the methods for processing the raw TCM, while the metal analysis grouped according to the geographical origin. When the two data matrices were combined into a one two-way matrix, the resulting biplot showed a clear separation on the basis of the HPLC fingerprints. Importantly, within each different grouping the objects separated according to their geographical origin, and they ranked approximately in the same order in each group. This result suggested that by using such an approach, it is possible to derive improved characterisation of the complex TCM materials on the basis of the two kinds of analytical data. In addition, two supervised pattern recognition methods, K-nearest neighbors (KNNs) method, and linear discriminant analysis (LDA), were successfully applied to the individual data matrices-thus, supporting the PCA approach

Arsenic speciation in marine organisms: from the analytical methodology to the constitution of reference materials

Energy Technology Data Exchange (ETDEWEB)

El Moll, A. [Laboratoire de Chimie Minerale et Analytique, URA 405 du CNRS, E. H. I. C. S., 1 rue Blaise Pascal, F-67008 Strasbourg Cedex (France); Heimburger, R. [Laboratoire de Chimie Minerale et Analytique, URA 405 du CNRS, E. H. I. C. S., 1 rue Blaise Pascal, F-67008 Strasbourg Cedex (France); Lagarde, F. [Laboratoire de Chimie Minerale et Analytique, URA 405 du CNRS, E. H. I. C. S., 1 rue Blaise Pascal, F-67008 Strasbourg Cedex (France); Leroy, M.J.F. [Laboratoire de Chimie Minerale et Analytique, URA 405 du CNRS, E. H. I. C. S., 1 rue Blaise Pascal, F-67008 Strasbourg Cedex (France); Maier, E. [Commission of the European Communities, Measurements and Testing Programme (BCR), 75 rue Montoyer, B-1049 Brussels (Belgium)

1996-03-01

An analytical procedure for total arsenic and arsenic species quantification in marine organisms has been developed. Fresh materials are freeze-dried and reduced to powders before analysis. Arsenic is determined either by energy dispersive X-ray fluorescence (EDXRF) directly or by inductively coupled plasma optical emission spectrometry (ICP/OES) after microwave digestion. Arsenic speciation is performed on the extracted sample using liquid chromatography coupled to ICP/OES for arsenobetaine and arsenocholine determination and to the hydride generation-quartz furnace atomic absorption spectrometric technique for arsenite, arsenate, monomethylarsonic and dimethylarsinic acids quantification. Special precautions are taken to avoid losses or contaminations as well as to prevent analytical errors during the quantification stage. Other methods are applied and the corresponding results compared for each step of the procedure. The method is finally validated by means of intercomparison studies within the Measurements and Testing Programme of the European Community (formely BCR). (orig.). With 9 figs., 5 tabs.

Preparation and characterization of a new set of IAEA reference air filters using instrumental neutron activation analysis, proton-induced X-ray emission and Rutherford backscattering

Czech Academy of Sciences Publication Activity Database

Kučera, Jan; Havránek, Vladimír; Krausová, Ivana

2009-01-01

Roč. 281, č. 1 (2009), s. 123-129 ISSN 0236-5731. [9th International Conference on Nuclear Analytical Methods in the Life Sciences. Lisbon, 07.09.2008-12.09.2008] Institutional research plan: CEZ:AV0Z10480505 Keywords : Reference air filters * instrumental neutron activation analysis * Proton induced X-ray emission Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.631, year: 2009

Nuclear analytical techniques applied to the large scale measurements of atmospheric aerosols in the amazon region

International Nuclear Information System (INIS)

Gerab, Fabio

1996-03-01

This work presents the characterization of the atmosphere aerosol collected in different places of the Amazon Basin. We studied both the biogenic emission from the forest and the particulate material which is emitted to the atmosphere due to the large scale man-made burning during the dry season. The samples were collected during a three year period at two different locations in the Amazon, namely the Alta Floresta (MT) and Serra do Navio (AP) regions, using stacked unit filters. These regions represent two different atmospheric compositions: the aerosol is dominated by the forest natural biogenic emission at Serra do Navio, while at Alta Floresta it presents an important contribution from the man-made burning during the dry season. At Alta Floresta we took samples in gold in order to characterize mercury emission to the atmosphere related to the gold prospection activity in Amazon. Airplanes were used for aerosol sampling during the 1992 and 1993 dry seasons to characterize the atmospheric aerosol contents from man-made burning in large Amazonian areas. The samples were analyzed using several nuclear analytic techniques: Particle Induced X-ray Emission for the quantitative analysis of trace elements with atomic number above 11; Particle Induced Gamma-ray Emission for the quantitative analysis of Na; and Proton Microprobe was used for the characterization of individual particles of the aerosol. Reflectancy technique was used in the black carbon quantification, gravimetric analysis to determine the total atmospheric aerosol concentration and Cold Vapor Atomic Absorption Spectroscopy for quantitative analysis of mercury in the particulate from the Alta Floresta gold shops. Ionic chromatography was used to quantify ionic contents of aerosols from the fine mode particulate samples from Serra do Navio. Multivariate statistical analysis was used in order to identify and characterize the sources of the atmospheric aerosol present in the sampled regions. (author)

Some metals determination in beers by atomic emission spectrometry of induced argon plasma

International Nuclear Information System (INIS)

Matsushige, I.

1990-01-01

It was made the identification and determination of metals in brazilian bottled and canned beer, using atomic emission spectrometry with d.c. are and argon coupled plasma excitation sources. The elements Co, Cr, Cu, Fe, Pb and Zn were determined in beer samples, after treatment with HNO sub(3) conc. /H sub(2) O sub(2) (30%). In the determination of Co, Cr, Cu, Pb and Zn and alternative method using HNO sub(3) conc. /O sub(3) was proved be useful. The results obtained for Co, Cr, Cu, Fe, Pb and Zn were below the limits established by brazilian legislation, showing the good quality of the beer concerning the metals. The results of this work were requested by the previous Ministerio do Meio Ambiente e Urbanismo in order to contribute to review the brazilian legislation in foods and beverages about metals contents. (author)

Number series of atoms, interatomic bonds and interface bonds defining zinc-blende nanocrystals as function of size, shape and surface orientation: Analytic tools to interpret solid state spectroscopy data

Energy Technology Data Exchange (ETDEWEB)

König, Dirk, E-mail: dirk.koenig@unsw.edu.au [Integrated Materials Design Centre (IMDC) and School of Photovoltaic and Renewable Energy Engineering (SPREE), University of New South Wales, Sydney (Australia)

2016-08-15

Semiconductor nanocrystals (NCs) experience stress and charge transfer by embedding materials or ligands and impurity atoms. In return, the environment of NCs experiences a NC stress response which may lead to matrix deformation and propagated strain. Up to now, there is no universal gauge to evaluate the stress impact on NCs and their response as a function of NC size d{sub NC}. I deduce geometrical number series as analytical tools to obtain the number of NC atoms N{sub NC}(d{sub NC}[i]), bonds between NC atoms N{sub bnd}(d{sub NC}[i]) and interface bonds N{sub IF}(d{sub NC}[i]) for seven high symmetry zinc-blende (zb) NCs with low-index faceting: {001} cubes, {111} octahedra, {110} dodecahedra, {001}-{111} pyramids, {111} tetrahedra, {111}-{001} quatrodecahedra and {001}-{111} quadrodecahedra. The fundamental insights into NC structures revealed here allow for major advancements in data interpretation and understanding of zb- and diamond-lattice based nanomaterials. The analytical number series can serve as a standard procedure for stress evaluation in solid state spectroscopy due to their deterministic nature, easy use and general applicability over a wide range of spectroscopy methods as well as NC sizes, forms and materials.

Electron spectroscopy of collisional excited atoms

International Nuclear Information System (INIS)

Straten, P. van der.

1987-01-01

In this thesis measurements are described in which coincidences are detected between scattered projectiles and emitted electrons. This yields information on two-electron excitation processes. In order to show what can be learnt from coincidence experiments a detailed theoretical analysis is given. The transition amplitudes, which contain all the information, are introduced (ch.2). In ch.3 the experimental set-up is shown. The results for the Li + -He system are shown in ch. 7 and are compared with predictions based on the Molecular-Orbitalmodel which however does not account for two-excitation mechanisms. With the transition amplitudes also the wave function of the excited atom has been completely determined. In ch.8 the shape of the electron cloud, induced by the collision, is derived from the amplitudes. The relation between the oscillatory motion of this cloud after the collision and the correlation between the two electrons of the excited atom is discussed. In ch. 6 it is shown that the broad structures in the non-coincident energy spectra of the Li + -He system are erroneously interpretated as a result of electron emission from the (Li-He) + -quasimolecule. A model is presented which explains, based on the results obtained from the coincidence measurements, these broad structures. In ch. 4 the Post-Collision Interaction process is treated. It is shown that for high-energy collisions, in contrast with general assumptions, PCI is important. In ch. 5 the importance of PCI-processes in photoionization of atoms, followed by Auger decay, are studied. From the formulas derived in ch. 4 simple analytical results are obtained. These are applied to recent experiments and good agreement is achieved. 140 refs.; 55 figs.; 9 tabs

Spontaneous light emission in complex nanostructures

Science.gov (United States)

Blanco, L. A.; García de Abajo, F. J.

2004-05-01

The spontaneous emission of an excited atom surrounded by different materials is studied in the framework of a semiclassical approach, where the transition dipole moment acts as the source of the emission field. The emission in the presence of semiinfinite media, metallic nanorings, spheres, gratings, and other complex geometries is investigated. Strong emission enhancement effects are obtained in some of these geometries associated to the excitation of plasmons (e.g., in nanorings or spheres). Furthermore, the emission is shown to take place only along narrow angular distributions when the atom is located inside a low-index dielectric and near its planar surface, or when metallic nanogratings are employed at certain resonant wave lengths. In particular, axially symmetric gratings made of real silver metal are considered, and both emission rate enhancement and focused far-field emission are achieved simultaneously when the grating is decorated with further nanostructures.

An analytical expression for electron elastic scattering cross section from atoms and molecules in 1.0 keV to 1.0 MeV energy range

Energy Technology Data Exchange (ETDEWEB)

Yalcin, S. [Education Faculty, Kastamonu University, 37200 Kastamonu (Turkey)]. E-mail: yalcin@gazi.edu.tr; Gurler, O. [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Gultekin, A. [Physics Department, Faculty of Arts and Sciences, Uludag University, Gorukle Campus, 16059 Bursa (Turkey); Gundogdu, O. [School of Engineering, University of Surrey, Guildford, GU2 7XH (United Kingdom)]. E-mail: o.gundogdu@surrey.ac.uk

2006-07-31

In this Letter, an expression is presented to calculate elastic scattering cross sections for incident electrons as a function of both energy and atomic number in the energy range between 1 keV and 1 MeV for materials with effective atomic number between 3 and 18. The expression we present has a rather simple analytical form which gives accurate results that are in very good agreement with the results calculated by a relativistic partial-wave expansion method. Hence, this equation can be employed accurately and efficiently in a continuous manner, without the need to go through rather large look-up tables, thus making the whole process quick, efficient and removing possible computational errors that may arise from the efforts of interpolation.

An analytical expression for electron elastic scattering cross section from atoms and molecules in 1.0 keV to 1.0 MeV energy range

International Nuclear Information System (INIS)

Yalcin, S.; Gurler, O.; Gultekin, A.; Gundogdu, O.

2006-01-01

In this Letter, an expression is presented to calculate elastic scattering cross sections for incident electrons as a function of both energy and atomic number in the energy range between 1 keV and 1 MeV for materials with effective atomic number between 3 and 18. The expression we present has a rather simple analytical form which gives accurate results that are in very good agreement with the results calculated by a relativistic partial-wave expansion method. Hence, this equation can be employed accurately and efficiently in a continuous manner, without the need to go through rather large look-up tables, thus making the whole process quick, efficient and removing possible computational errors that may arise from the efforts of interpolation

Headspace solid-phase microextraction for the determination of volatile organic sulphur and selenium compounds in beers, wines and spirits using gas chromatography and atomic emission detection.

Science.gov (United States)

Campillo, Natalia; Peñalver, Rosa; López-García, Ignacio; Hernández-Córdoba, Manuel

2009-09-25

A rapid and solvent-free method for the determination of eight volatile organic sulphur and two selenium compounds in different beverage samples using headspace solid-phase microextraction and gas chromatography with atomic emission detection has been developed. The bonded carboxen/polydimethylsiloxane fiber was the most suitable for preconcentrating the analytes from the headspace of the sample solution. Volumes of 20 mL of undiluted beer were used while, in the case of wines and spirits, sample:water ratios of 5:15 and 2:18, respectively, were used, in order to obtain the maximum sensitivity. Quantitation was carried out by using synthetic matrices of beer and wine, and a spiked sample for spirits, and using ethyl methyl sulphide and isopropyl disulphide as internal standards. Detection limits ranged from 8 ng L(-1) to 40 ng mL(-1), depending on the compound and the beverage sample analyzed, with a fiber time exposure of 20 min at ambient temperature. The optimized method was successfully applied to different samples, some of the studied compounds being detected at concentration levels in the 0.04-152 ng mL(-1) range.

Ion-induced molecular emission of polymers: analytical potentialities of FTIR and mass spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Picq, V.; Balanzat, E. E-mail: balanzat@ganil.fr

1999-05-02

The release of small gaseous molecules is a general phenomenon of irradiated polymers. Polyethylene (PE), polypropylene (PP) and polybutene (PB) were irradiated with ions of different electronic stopping power. We show that the gas emission can provide important information on the damage process if a reliable chemical identification of the molecules released and accurate yield values are obtained. The outgassing products were analysed by two techniques: (1) by a novel set-up using a Fourier Transform Infrared (FTIR) analysis of the gas mixture released from the polymer film and (2) by residual gas analysis (RGA) with a quadrupole mass spectrometer. Comparing the analytical potentialities of both methods we come to the conclusion that the FTIR method gives a more straightforward and accurate determination of the chemical nature and of the yield of most of the released molecules. However, RGA provides complementary information on the gas release kinetics and also on the release of heavy hydrocarbon molecules and symmetric molecules like molecular hydrogen.

Mechanism of formation and spatial distribution of lead atoms in quartz tube atomizers

Science.gov (United States)

Johansson, M.; Baxter, D. C.; Ohlsson, K. E. A.; Frech, W.

1997-05-01

The cross-sectional and longitudinal spatial distributions of lead atoms in a quartz tube (QT) atomizers coupled to a gas chromatograph have been investigated. A uniform analyte atom distribution over the cross-section was found in a QT having an inner diameter (i.d.) of 7 mm, whereas a 10 mm i.d. QT showed an inhomogeneous distribution. These results accentuate the importance of using QTs with i.d.s below 10 mm to fulfil the prerequirement of the Beer—Lambert law to avoid bent calibration curves. The influence of the make up gas on the formation of lead atoms from alkyllead compounds has been studied, and carbon monoxide was found equally efficient in promoting free atom formation as hydrogen. This suggests that hydrogen radicals are not essential for mediating the atomization of alkyllead in QT atomizers at ˜ 1200 K. Furthermore, thermodynamic equilibrium calculations describing the investigated system were performed supporting the experimental results. Based on the presented data, a mechanism for free lead atom formation in continuously heated QT atomizers is proposed; thermal atomization occurs under thermodynamic equilibrium conditions in a reducing gas. The longitudinal atom distribution has been further investigated applying other make up gases, N 2 and He. These results show the effect of the influx of atmospheric oxygen on the free lead atom formation. Calculations of the partial pressure of oxygen in the atomizer gas phase assuming thermodynamic equilibrium have been undertaken using a convective-diffusional model.

Teleportation of an Unknown Atomic State via Adiabatic Passage

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

We propose a scheme for teleporting an unknown atomic state via adiabatic passage. Taking advantage of adiabatic passage, the atom has no probability of being excited and thus the atomic spontaneous emission is suppressed.We also show that the fidelity can reach 1 under certain condition.

Sample Preprocessing For Atomic Spectrometry

International Nuclear Information System (INIS)

Kim, Sun Tae

2004-08-01

This book gives descriptions of atomic spectrometry, which deals with atomic absorption spectrometry such as Maxwell-Boltzmann equation and Beer-Lambert law, atomic absorption spectrometry for solvent extraction, HGAAS, ETASS, and CVAAS and inductively coupled plasma emission spectrometer, such as basic principle, generative principle of plasma and device and equipment, and interferences, and inductively coupled plasma mass spectrometry like device, pros and cons of ICP/MS, sample analysis, reagent, water, acid, flux, materials of experiments, sample and sampling and disassembling of sample and pollution and loss in open system and closed system.

Synchrotron radiation in atomic physics

International Nuclear Information System (INIS)

Crasemann, B.

1998-01-01

Much of present understanding of atomic and molecular structure and dynamics was gained through studies of photon-atom interactions. In particular, observations of the emission, absorption, and scattering of X rays have complemented particle-collision experiments in elucidating the physics of atomic inner shells. Grounded on Max von Laue's theoretical insight and the invention of the Bragg spectrometer, the field's potential underwent a step function with the development of synchrotron-radiation sources. Notably current third-generation sources have opened new horizons in atomic and molecular physics by producing radiation of wide tunability and exceedingly high intensity and polarization, narrow energy bandwidth, and sharp time structure. In this review, recent advances in synchrotron-radiation studies in atomic and molecular science are outlined. Some tempting opportunities are surveyed that arise for future studies of atomic processes, including many-body effects, aspects of fundamental photon-atom interactions, and relativistic and quantum-electrodynamic phenomena. (author)

Atomization of volatile compounds for atomic absorption and atomic fluorescence spectrometry: On the way towards the ideal atomizer

International Nuclear Information System (INIS)

Dedina, Jiri

2007-01-01

This review summarizes and discusses the individual atomizers of volatile compounds. A set of criteria important for analytical praxis is used to rank all the currently existing approaches to the atomization based on on-line atomization for atomic absorption (AAS) and atomic fluorescence spectrometry (AFS) as well as on in-atomizer trapping for AAS. Regarding on-line atomization for AAS, conventional quartz tubes are currently the most commonly used devices. They provide high sensitivity and low baseline noise. Running and investment costs are low. The most serious disadvantage is the poor resistance against atomization interferences and often unsatisfactory linearity of calibration graphs. Miniature diffusion flame (MDF) is extremely resistant to interferences, simple, cheap and user-friendly. Its essential disadvantage is low sensitivity. A novel device, known as a multiatomizer, was designed to overcome disadvantages of previous atomizers. It matches performance of conventional quartz tubes in terms of sensitivity and baseline noise as well as in running and investment costs. The multiatomizer, however, provides much better (i) resistance against atomization interferences and (ii) linearity of calibration graphs. In-atomizer trapping enhances the sensitivity of the determination and eliminates the effect of the generation kinetics and of surges in gas flow on the signal shape. This is beneficial for the accuracy of the determination. It could also be an effective tool for reducing some interferences in the liquid phase. In-situ trapping in graphite furnaces (GF) is presently by far the most popular approach to the in-atomizer trapping. Its resistance against interferences is reasonably good and it can be easily automated. In-situ trapping in GF is a mature method well established in various application fields. These are the reasons to rank in-situ trapping in GF as currently the most convenient approach to hydride atomization for AAS. The recently suggested

Determination of gold in geological samples - the present and the future

International Nuclear Information System (INIS)

Feriancik, E.

1997-01-01

This paper reviews some analytical techniques which have been described for the gold analysis of geological materials: spectrophotometry; flame atomic absorption spectrometry; graphite coupled plasma atomic emission spectrometry; inductively coupled plasma atomic emission spectrometry; inductively coupled plasma-mass spectrometry; neutron activation; electro-analysis methods and fire assay

Atom-atom scattering under cylindrical harmonic confinement: Numerical and analytic studies of the confinement induced resonance

International Nuclear Information System (INIS)

Bergeman, T.; Moore, M.G.; Olshanii, M.

2003-01-01

It was recently predicted [Phys. Rev. Lett. 81, 938 (1998)10.1103/PhysRevLett.81.938] that atom-atom scattering under transverse harmonic confinement is subject to a 'confinement-induced resonance' where the effective one-dimensional coupling strength diverges at a particular ratio of the confinement and scattering lengths. As the initial prediction made use of the zero-range pseudopotential approximation, we now report numerical results for finite-range interaction potentials that corroborate this resonance. In addition, we now present a physical interpretation of this effect as a novel type of Feshbach resonance in which the transverse modes of the confining potential assume the roles of 'open' and 'closed' scattering channels

Tin Content Determination in Canned Fruits and Vegetables by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

Directory of Open Access Journals (Sweden)

Sanda Rončević

2012-01-01

Full Text Available Tin content in samples of canned fruits and vegetables was determined by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-OES, and it was compared with results obtained by standard method of flame atomic absorption spectrometry (AAS. Selected tin emission lines intensity was measured in prepared samples after addition of tartaric acid and followed by hydride generation with sodium borohydride solution. The most favorable line at 189.991 nm showed the best detection limit (1.9 μg L−1 and limit of quantification (6.4 μg kg−1. Good linearity and sensitivity were established from time resolved analysis and calibration tests. Analytical accuracy of 98–102% was obtained by recovery study of spiked samples. Method of standard addition was applied for tin determination in samples from fully protected tinplate. Tin presence at low-concentration range was successfully determined. It was shown that tenth times less concentrations of Sn were present in protected cans than in nonprotected or partially protected tinplate.

Research as a guide for curriculum development: An example from introductory spectroscopy. II. Addressing student difficulties with atomic emission spectra

Science.gov (United States)

Ivanjek, L.; Shaffer, P. S.; McDermott, L. C.; Planinic, M.; Veza, D.

2015-02-01

This is the second of two closely related articles (Paper I and Paper II) that together illustrate how research in physics education has helped guide the design of instruction that has proved effective in improving student understanding of atomic spectroscopy. Most of the more than 1000 students who participated in this four-year investigation were science majors enrolled in the introductory calculus-based physics course at the University of Washington (UW) in Seattle, WA, USA. The others included graduate and undergraduate teaching assistants at UW and physics majors in introductory and advanced physics courses at the University of Zagreb, Zagreb, Croatia. About half of the latter group were preservice high school physics teachers. Paper I describes how several conceptual and reasoning difficulties were identified among university students as they tried to relate a discrete line spectrum to the energy levels of atoms in a light source. This second article (Paper II) illustrates how findings from this research informed the development of a tutorial that led to improvement in student understanding of atomic emission spectra.

Analytical chemistry

International Nuclear Information System (INIS)

Choi, Jae Seong

1993-02-01

This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

Analytical chemistry

Energy Technology Data Exchange (ETDEWEB)

Choi, Jae Seong

1993-02-15

This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

Gold volatile species atomization and preconcentration in quartz devices for atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Arslan, Yasin [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Mehmet Akif Ersoy University, Faculty of Arts & Sciences, Chemistry Department, 15030 Burdur (Turkey); Musil, Stanislav; Matoušek, Tomáš; Kratzer, Jan [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Dědina, Jiří, E-mail: dedina@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

2015-01-01

The on-line atomization of gold volatile species was studied and the results were compared with thermodynamic calculations in several quartz atomizers, namely: diffusion flame, flame-in-gas-shield, flame-in-plain-tube, externally heated T-tube and externally heated flame-in-T-tube. Atomization mechanism in the explored devices is proposed, where volatile species are converted to thermodynamically stable AuH at elevated temperature over 500 °C and then atomized by an interaction with a cloud of hydrogen radicals. Because of its inherent simplicity and robustness, diffusion flame was employed as a reference atomizer. It yielded atomization efficiency of 70 to 100% and a very good long time reproducibility of peak area sensitivity: 1.6 to 1.8 s μg{sup −1}. Six and eleven times higher sensitivity, respectively, was provided by atomizers with longer light paths in the observation volume, i.e. externally heated T-tube and externally heated flame-in-T-tube. The latter one, offering limit of detection below 0.01 μg ml{sup −1}, appeared as the most prospective for on-line atomization. Insight into the mechanism of atomization of gold volatile species, into the fate of free atoms and into subsequent analyte transfer allowed to assess possibilities of in-atomizer preconcentration of gold volatile species: it is unfeasible with quartz atomizers but a sapphire tube atomizer could be useful in this respect. - Highlights: • On-line atomization of gold volatile species for AAS in quartz devices was studied. • Atomization mechanism was proposed and atomization efficiency was estimated. • Possibilities of in-atomizer preconcentration of gold volatile species were assessed.

Multiple microflame quartz tube atomizer: Study and minimization of interferences in quartz tube atomizers in hydride generation atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Moraes Flores, Erico Marlon de [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil)], E-mail: flores@quimica.ufsm.br; Medeiros Nunes, Adriane; Luiz Dressler, Valderi [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS (Brazil); Dedina, Jiri [Institute of Analytical Chemistry of the ASCR, v.v.i., Videnska 1083, CZ-142 20 Prague (Czech Republic)

2009-02-15

A systematic study was performed to evaluate the performance of a multiple microflame (MM) quartz tube atomizer (QTA) for minimizing interferences and to improve the extent of the calibration range using a batch system for hydride generation atomic absorption spectrometry (HG AAS). A comparison of the results with conventional QTA on the determination of antimony, arsenic, bismuth and selenium was performed. The interference of As, Bi, Se, Pb, Sn and Sb was investigated using QTA and MMQTA atomizers. Better performance was found for MMQTA, and no loss of linearity was observed up to 160 ng for Se and Sb and 80 ng for As, corresponding to an enhancement of two times for both analytes when compared to QTA (analyte mass refers to a volume of 200 {mu}l). For Bi, the linear range was the same for QTA and MMQTA (140 ng). With the exception of Bi, the tolerance limits for hydride-forming elements were improved more than 50% in comparison to the conventional QTA system, especially for the interferences of As, Sb and Se. However, for Sn as an interferent, no difference was observed in the determination of Se and Sb using the MMQTA system. The use of MMQTA-HG AAS complied with the relatively high sensitivity of conventional QTA and also provided better performance for interferences and the linear range of calibration.

Light emission from sputtered or backscattered atoms on tungsten surfaces under ion irradiation

International Nuclear Information System (INIS)

Sakai, Yasuhiro; Nogami, Keisuke; Kato, Daiji; Sakaue, Hiroyuki A.; Kenmotsu, Takahiko; Furuya, Kenji; Motohashi, Kenji

2013-01-01

We measured the intensity of light emission from sputtered atoms on tungsten surfaces under the irradiations of Kr"+ ion and Ar"+ ion, as a function of the perpendicular distance from the surface. Using the analysis of decay curve, we estimated the mean vertical velocity component in direction normal to the surface. We found that the estimated mean velocity had much differences according to the excited state. For example, although the estimated mean vertical velocity component normal to the surface from the 400.9 nm line((5d"5(6S)6p "7p_4→(5d"5(6S)6s "7S_3 transition) was 5.6±1.7 km/sec, that from the 386.8 nm line((5d"4(6S)6p "7D_4→(5d"5(6S)6s "7S_4 transition) was 2.8±1.0 km/sec. However, for different projectiles and energies, we found no remarkable changes in the velocity. (author)

Absorption properties of identical atoms

International Nuclear Information System (INIS)

Sancho, Pedro

2013-01-01

Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions

PREDICTION OF FORBIDDEN ULTRAVIOLET AND VISIBLE EMISSIONS IN COMET 67P/CHURYUMOV–GERASIMENKO

International Nuclear Information System (INIS)

Raghuram, Susarla; Galand, Marina; Bhardwaj, Anil

2016-01-01

Remote observation of spectroscopic emissions is a potential tool for the identification and quantification of various species in comets. The CO Cameron band (to trace CO 2 ) and atomic oxygen emissions (to trace H 2 O and/or CO 2 , CO) have been used to probe neutral composition in the cometary coma. Using a coupled-chemistry-emission model, various excitation processes controlling the CO Cameron band and different atomic oxygen and atomic carbon emissions have been modeled in comet 67P/Churyumov–Gerasimenko at 1.29 AU (perihelion) and at 3 AU heliocentric distances, which is being explored by ESA's Rosetta mission. The intensities of the CO Cameron band, atomic oxygen, and atomic carbon emission lines as a function of projected distance are calculated for different CO and CO 2 volume mixing ratios relative to water. Contributions of different excitation processes controlling these emissions are quantified. We assess how CO 2 and/or CO volume mixing ratios with respect to H 2 O can be derived based on the observed intensities of the CO Cameron band, atomic oxygen, and atomic carbon emission lines. The results presented in this work serve as baseline calculations to understand the behavior of low out-gassing cometary coma and compare them with the higher gas production rate cases (e.g., comet Halley). Quantitative analysis of different excitation processes governing the spectroscopic emissions is essential to study the chemistry of inner coma and to derive neutral gas composition

Cu determination in crude oil distillation products by atomic absorption and inductively coupled plasma mass spectrometry after analyte transfer to aqueous solution

Science.gov (United States)

Kowalewska, Zofia; Ruszczyńska, Anna; Bulska, Ewa

2005-03-01

Cu was determined in a wide range of petroleum products from crude oil distillation using flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICP-MS). Different procedures of sample preparation were evaluated: (i) mineralization with sulfuric acid in an open system, (ii) mineralization in a closed microwave system, (iii) combustion in hydrogen-oxygen flame in the Wickbold's apparatus, (iv) matrix evaporation followed by acid dissolution, and (v) acidic extraction. All the above procedures led to the transfer of the analyte into an aqueous solution for the analytical measurement step. It was found that application of FAAS was limited to the analysis of the heaviest petroleum products of high Cu content. In ICP-MS, the use of internal reference method (with Rh or In as internal reference element) was required to eliminate the matrix effects in the analysis of extracts and the concentrated solutions of mineralized heavy petroleum products. The detection limits (in original samples) were equal to, respectively, 10, 86, 3.3, 0.9 and 0.4 ng g - 1 in procedures i-v with ETAAS detection and 10, 78, 1.1 and 0.5 ng g - 1 in procedures i-iii and v with ICP-MS detection. The procedures recommended here were validated by recovery experiments, certified reference materials analysis and comparison of results, obtained for a given sample, in different ways. The Cu content in the analyzed samples was: 50-110 ng g - 1 in crude oil, oil, oil and 140-300 ng g - 1 in distillation residue.

Multielectron effects in atomic processes

International Nuclear Information System (INIS)

Amusia, M.Ya.; Chernysheva, L.V.

1999-01-01

One demonstrates a prominent role of electron collectivization in atoms and quasi-atomic formations. Paper discusses in detail the approximation of random phases with exchange enabling to take account of these effects. One points out the necessity to go outside the terms of the approximation when studying some processes via combination of the approximation with the theory of disturbances. The results of the recently conducted estimations of cross sections of photoionization of atomic iodine and of its positive and negative ions, Xe + single-electron photoionization, resonance-amplified emission of photons in electron collisions with atoms and quasi-atomic formations, non-dipole corrections to the angular distribution of photoelectrons, probabilities of two electron transitions where the whole amount of energy releases in the form of one photon, illustrate the role of the collective effects [ru

Positron production in heavy ion-atom collisions

International Nuclear Information System (INIS)

Kienle, P.

1985-08-01

Following an introduction into the concept of an atom with an overcritical field, established by a nucleus with a charge larger than 173, the spontaneous positron emission from such an atom with an 1s binding energy exceeding 2mc 2 is presented. Such a process, in which an electron is bound and a monoenergetic positron emitted turns the neutral into a charged vacuum. In a U-U di-nuclear system (Z=184) the spontaneous positron emission proceeds with an energy of about 300 keV corresponding to a decay time of 3x10 -19 sec. (orig./WL)

Spontaneous emission spectrum from a V-type three-level atom in a double-band photonic crystal

International Nuclear Information System (INIS)

Zhang Han Zhuang; Tang Sing Hai; Dong Po; He Jun

2002-01-01

The spontaneous emission spectrum from a V-type three-level atom embedded in a double-band photonic band gap (PBG) material has been investigated for the first time. Most interestingly it is shown that there is not only a black dark line, but also a narrow spontaneous line near the edges of the double photonic band. The positions of the dark line and narrow spontaneous line are near the transition from an empty upper level to a lower level. The lines stem from destructive and constructive quantum interferences, which induce population transfer between the two upper levels, in the PBG reservoirs. The effects of system parameters on the interference have been discussed in detail

Dynamics of atoms in strong laser fields I: A quasi analytical model in momentum space based on a Sturmian expansion of the interacting nonlocal Coulomb potential

Science.gov (United States)

Ongonwou, F.; Tetchou Nganso, H. M.; Ekogo, T. B.; Kwato Njock, M. G.

2016-12-01

In this study we present a model that we have formulated in the momentum space to describe atoms interacting with intense laser fields. As a further step, it follows our recent theoretical approach in which the kernel of the reciprocal-space time-dependent Schrödinger equation (TDSE) is replaced by a finite sum of separable potentials, each of them supporting one bound state of atomic hydrogen (Tetchou Nganso et al. 2013). The key point of the model is that the nonlocal interacting Coulomb potential is expanded in a Coulomb Sturmian basis set derived itself from a Sturmian representation of Bessel functions of the first kind in the position space. As a result, this decomposition allows a simple spectral treatment of the TDSE in the momentum space. In order to illustrate the credibility of the model, we have considered the test case of atomic hydrogen driven by a linearly polarized laser pulse, and have evaluated analytically matrix elements of the atomic Hamiltonian and dipole coupling interaction. For various regimes of the laser parameters used in computations our results are in very good agreement with data obtained from other time-dependent calculations.

Dynamics of atoms in strong laser fields I: A quasi analytical model in momentum space based on a Sturmian expansion of the interacting nonlocal Coulomb potential

Energy Technology Data Exchange (ETDEWEB)

Ongonwou, F., E-mail: fred.ongonwou@gmail.com [Département de Physique, Faculté des Sciences, Université des Sciences et Techniques de Masuku, B.P. 943 Franceville (Gabon); Tetchou Nganso, H.M., E-mail: htetchou@yahoo.com [Atoms and Molecules Laboratory, Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ), Faculty of Science, University of Douala, P.O. Box 8580, Douala (Cameroon); Ekogo, T.B., E-mail: tekogo@yahoo.fr [Département de Physique, Faculté des Sciences, Université des Sciences et Techniques de Masuku, B.P. 943 Franceville (Gabon); Kwato Njock, M.G., E-mail: mkwato@yahoo.com [Atoms and Molecules Laboratory, Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ), Faculty of Science, University of Douala, P.O. Box 8580, Douala (Cameroon)

2016-12-15

In this study we present a model that we have formulated in the momentum space to describe atoms interacting with intense laser fields. As a further step, it follows our recent theoretical approach in which the kernel of the reciprocal-space time-dependent Schrödinger equation (TDSE) is replaced by a finite sum of separable potentials, each of them supporting one bound state of atomic hydrogen (Tetchou Nganso et al. 2013). The key point of the model is that the nonlocal interacting Coulomb potential is expanded in a Coulomb Sturmian basis set derived itself from a Sturmian representation of Bessel functions of the first kind in the position space. As a result, this decomposition allows a simple spectral treatment of the TDSE in the momentum space. In order to illustrate the credibility of the model, we have considered the test case of atomic hydrogen driven by a linearly polarized laser pulse, and have evaluated analytically matrix elements of the atomic Hamiltonian and dipole coupling interaction. For various regimes of the laser parameters used in computations our results are in very good agreement with data obtained from other time-dependent calculations.

Analytical methods used at model facility

International Nuclear Information System (INIS)

Wing, N.S.

1984-01-01

A description of analytical methods used at the model LEU Fuel Fabrication Facility is presented. The methods include gravimetric uranium analysis, isotopic analysis, fluorimetric analysis, and emission spectroscopy

The influence of atomic alignment on absorption and emission spectroscopy

Science.gov (United States)

Zhang, Heshou; Yan, Huirong; Richter, Philipp

2018-06-01

Spectroscopic observations play essential roles in astrophysics. They are crucial for determining physical parameters in the universe, providing information about the chemistry of various astronomical environments. The proper execution of the spectroscopic analysis requires accounting for all the physical effects that are compatible to the signal-to-noise ratio. We find in this paper the influence on spectroscopy from the atomic/ground state alignment owing to anisotropic radiation and modulated by interstellar magnetic field, has significant impact on the study of interstellar gas. In different observational scenarios, we comprehensively demonstrate how atomic alignment influences the spectral analysis and provide the expressions for correcting the effect. The variations are even more pronounced for multiplets and line ratios. We show the variation of the deduced physical parameters caused by the atomic alignment effect, including alpha-to-iron ratio ([X/Fe]) and ionisation fraction. Synthetic observations are performed to illustrate the visibility of such effect with current facilities. A study of PDRs in ρ Ophiuchi cloud is presented to demonstrate how to account for atomic alignment in practice. Our work has shown that due to its potential impact, atomic alignment has to be included in an accurate spectroscopic analysis of the interstellar gas with current observational capability.

Ultratrace determination of lead in whole blood using electrothermal atomization laser-excited atomic fluorescence spectrometry.

Science.gov (United States)

Wagner, E P; Smith, B W; Winefordner, J D

1996-09-15

Laser-excited atomic fluorescence has been used to detect lead that was electrothermally atomized from whole blood in a graphite furnace. A 9 kHz repetition rate copper vapor laser pumped dye laser was used to excite the lead at 283.3 nm, and the resulting atomic fluorescence was detected at 405.8 nm. No matrix modification was used other than a 1:21 dilution of the whole blood with high-purity water. Using the atomic fluorescence peak area as the analytical measure and a background correction technique based upon a simultaneous measurement of the transmitted laser intensity, excellent agreement for NIST and CDC certified whole blood reference samples was obtained with aqueous standards. A limit of detection in blood of 10 fg/mL (100 ag absolute) was achieved.

Breakup of relativistic π+π- atoms in matter

International Nuclear Information System (INIS)

Afanasyev, L.G.; Tarasov, A.V.

1996-01-01

The relativistic motion of atoms formed by π+ and π- mesons in matter is considered. Exact analytic expressions for the form factors of hydrogenlike atoms for discrete-discrete transitions are obtained in a form convenient for numerical calculations. The total and transition cross sections for the interaction of π+π- atoms with matter are calculated in the Born approximation. The evolution of atomic-state populations is treated in terms of kinetic equations. The method of calculation makes it possible to obtain the populations of discrete atomic states, as well as the probability of transitions to the continuous spectrum (ionization). The proposed method yields the first experimental estimate of the lifetime of the π+π- atom

Structure of the Balmer jump. The isolated hydrogen atom

Science.gov (United States)

Calvo, F.; Belluzzi, L.; Steiner, O.

2018-06-01

Context. The spectrum of the hydrogen atom was explained by Bohr more than one century ago. We revisit here some of the aspects of the underlying quantum structure, with a modern formalism, focusing on the limit of the Balmer series. Aims: We investigate the behaviour of the absorption coefficient of the isolated hydrogen atom in the neighbourhood of the Balmer limit. Methods: We analytically computed the total cross-section arising from bound-bound and bound-free transitions in the isolated hydrogen atom at the Balmer limit, and established a simplified semi-analytical model for the surroundings of that limit. We worked within the framework of the formalism of Landi Degl'Innocenti & Landolfi (2004, Astrophys. Space Sci. Lib., 307), which permits an almost straight-forward generalization of our results to other atoms and molecules, and which is perfectly suitable for including polarization phenomena in the problem. Results: We analytically show that there is no discontinuity at the Balmer limit, even though the concept of a "Balmer jump" is still meaningful. Furthermore, we give a possible definition of the location of the Balmer jump, and we check that this location is dependent on the broadening mechanisms. At the Balmer limit, we compute the cross-section in a fully analytical way. Conclusions: The Balmer jump is produced by a rapid drop of the total Balmer cross-section, yet this variation is smooth and continuous when both bound-bound and bound-free processes are taken into account, and its shape and location is dependent on the broadening mechanisms.

Nanometer-scale isotope analysis of bulk diamond by atom probe tomography

NARCIS (Netherlands)

Schirhagl, R.; Raatz, N.; Meijer, J.; Markham, M.; Gerstl, S. S. A.; Degen, C. L.

2015-01-01

Atom-probe tomography (APT) combines field emission of atoms with mass spectrometry to reconstruct three-dimensional tomograms of materials with atomic resolution and isotope specificity. Despite significant recent progress in APT technology, application to wide-bandgap materials with strong

High-energy atomic physics

CERN Document Server

Drukarev, Evgeny G

2016-01-01

This self-contained text introduces readers to the field of high-energy atomic physics - a new regime of photon-atom interactions in which the photon energies significantly exceed the atomic or molecular binding energies, and which opened up with the recent advent of new synchrotron sources. From a theoretical point of view, a small-parameter characteristic of the bound system emerged, making it possible to perform analytic perturbative calculations that can in turn serve as benchmarks for more powerful numerical computations. The first part of the book introduces readers to the foundations of this new regime and its theoretical treatment. In particular, the validity of the small-parameter perturbation expansion and of the lowest-order approximation is critically reviewed. The following chapters then apply these insights to various atomic processes, such as photoionization as a many-body problem, dominant mechanisms for the production of ions at higher energies, Compton scattering and ionization accompanied b...

Calculated sputtering and atomic displacement cross-sections for applications to medium voltage analytical electron microscopy

International Nuclear Information System (INIS)

Bradley, C.R.; Zaluzec, N.J.

1987-08-01

The development of medium voltage electron microscopes having high brightness electron sources and ultra-high vacuum environments has been anticipated by the microscopy community now for several years. The advantages of such a configuration have been discussed to great lengths, while the potential disadvantages have for the most part been neglected. The most detrimental of these relative to microcharacterization are the effects of electron sputtering and atomic displacement to the local specimen composition. These effects have in the past been considered mainly in the high voltage electron microscope regime and generally were ignored in lower voltage instruments. Recent experimental measurements have shown that the effects of electron sputtering as well as radiation induced segregation can be observed in conventional transmission electron microscopes. It is, therefore, important to determine at what point the effects will begin to manifest themselves in the new generation of medium voltage analytical electron microscopes. In this manuscript we present new calculations which allow the individual experimentalist to determine the potential threshold levels for a particular elemental system and thus avoid the dangers of introducing artifacts during microanalysis. 12 refs., 3 figs

Charge degeneracy removal in the screened hydrogen atom

International Nuclear Information System (INIS)