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Sample records for induced plasma spectroscopy

  1. Laser-induced breakdown spectroscopy of tantalum plasma

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Sidra; Bashir, Shazia; Hayat, Asma; Khaleeq-ur-Rahman, M.; Faizan–ul-Haq [Centre for Advanced Studies in Physics, GC University, Lahore (Pakistan)

    2013-07-15

    Laser Induced Breakdown spectroscopy (LIBS) of Tantalum (Ta) plasma has been investigated. For this purpose Q-switched Nd: YAG laser pulses (λ∼ 1064 nm, τ∼ 10 ns) of maximum pulse energy of 100 mJ have been employed as an ablation source. Ta targets were exposed under the ambient environment of various gases of Ar, mixture (CO{sub 2}: N{sub 2}: He), O{sub 2}, N{sub 2}, and He under various filling pressure. The emission spectrum of Ta is observed by using LIBS spectrometer. The emission intensity, excitation temperature, and electron number density of Ta plasma have been evaluated as a function of pressure for various gases. Our experimental results reveal that the optical emission intensity, the electron temperature and density are strongly dependent upon the nature and pressure of ambient environment. The SEM analysis of the ablated Ta target has also been carried out to explore the effect of ambient environment on the laser induced grown structures. The growth of grain like structures in case of molecular gases and cone-formation in case of inert gases is observed. The evaluated plasma parameters by LIBS analysis such as electron temperature and the electron density are well correlated with the surface modification of laser irradiated Ta revealed by SEM analysis.

  2. Laser-induced breakdown spectroscopy of tantalum plasma

    International Nuclear Information System (INIS)

    Khan, Sidra; Bashir, Shazia; Hayat, Asma; Khaleeq-ur-Rahman, M.; Faizan–ul-Haq

    2013-01-01

    Laser Induced Breakdown spectroscopy (LIBS) of Tantalum (Ta) plasma has been investigated. For this purpose Q-switched Nd: YAG laser pulses (λ∼ 1064 nm, τ∼ 10 ns) of maximum pulse energy of 100 mJ have been employed as an ablation source. Ta targets were exposed under the ambient environment of various gases of Ar, mixture (CO 2 : N 2 : He), O 2 , N 2 , and He under various filling pressure. The emission spectrum of Ta is observed by using LIBS spectrometer. The emission intensity, excitation temperature, and electron number density of Ta plasma have been evaluated as a function of pressure for various gases. Our experimental results reveal that the optical emission intensity, the electron temperature and density are strongly dependent upon the nature and pressure of ambient environment. The SEM analysis of the ablated Ta target has also been carried out to explore the effect of ambient environment on the laser induced grown structures. The growth of grain like structures in case of molecular gases and cone-formation in case of inert gases is observed. The evaluated plasma parameters by LIBS analysis such as electron temperature and the electron density are well correlated with the surface modification of laser irradiated Ta revealed by SEM analysis

  3. Liquid steel analysis by laser-induced plasma spectroscopy

    International Nuclear Information System (INIS)

    Gruber, J.

    2002-11-01

    When a nanosecond pulsed laser is focused onto a sample and the intensity exceeds a certain threshold, material is vaporized and a plasma is formed above the sample surface. The laser-light becomes increasingly absorbed by inverse bremsstrahlung and by photo-excitation and photo-ionization of atoms and molecules. The positive feedback, by which the number of energetic electrons for ionization is increased in an avalanche-like manner under the influence of laser-light, is the so-called optical breakdown. Radiating excited atoms and ions within the expanding plasma plume produce a characteristic optical emission spectrum. A spectroscopic analysis of this optical emission of the laser-induced plasma permits a qualitative and quantitative chemical analysis of the investigated sample. This technique is therefore often called laser-induced plasma spectroscopy (LIPS) or laser-induced breakdown spectroscopy (LIBS). LIPS is a fast non-contact technique, by which solid, liquid or gaseous samples can be analyzed with respect to their chemical composition. Hence, it is an appropriate tool for the rapid in-situ analysis of not easily accessible surfaces for process control in industrial environments. In this work, LIPS was studied as a technique to determine the chemical composition of solid and liquid steel. A LIPS set-up was designed and built for the remote and continuous in-situ analysis of the steel melt. Calibration curves were prepared for the LIPS analysis of Cr, Mn, Ni and Cu in solid steel using reference samples with known composition. In laboratory experiments an induction furnace was used to melt steel samples in crucibles, which were placed at a working distance of 1.5 m away from the LIPS apparatus. The response of the LIPS system was monitored on-line during the addition of pure elements to the liquid steel bath within certain concentration ranges (Cr: 0.11 - 13.8 wt%, Cu: 0.044 - 0.54 wt%, Mn: 1.38 - 2.5 wt%, Ni: 0.049 - 5.92 wt%). The analysis of an element

  4. Time-resolved resonance fluorescence spectroscopy for study of chemical reactions in laser-induced plasmas.

    Science.gov (United States)

    Liu, Lei; Deng, Leimin; Fan, Lisha; Huang, Xi; Lu, Yao; Shen, Xiaokang; Jiang, Lan; Silvain, Jean-François; Lu, Yongfeng

    2017-10-30

    Identification of chemical intermediates and study of chemical reaction pathways and mechanisms in laser-induced plasmas are important for laser-ablated applications. Laser-induced breakdown spectroscopy (LIBS), as a promising spectroscopic technique, is efficient for elemental analyses but can only provide limited information about chemical products in laser-induced plasmas. In this work, time-resolved resonance fluorescence spectroscopy was studied as a promising tool for the study of chemical reactions in laser-induced plasmas. Resonance fluorescence excitation of diatomic aluminum monoxide (AlO) and triatomic dialuminum monoxide (Al 2 O) was used to identify these chemical intermediates. Time-resolved fluorescence spectra of AlO and Al 2 O were used to observe the temporal evolution in laser-induced Al plasmas and to study their formation in the Al-O 2 chemistry in air.

  5. Double pulse laser ablation and plasma: Laser induced breakdown spectroscopy signal enhancement

    International Nuclear Information System (INIS)

    Babushok, V.I.; DeLucia, F.C.; Gottfried, J.L.; Munson, C.A.; Miziolek, A.W.

    2006-01-01

    A review of recent results of the studies of double laser pulse plasma and ablation for laser induced breakdown spectroscopy applications is presented. The double pulse laser induced breakdown spectroscopy configuration was suggested with the aim of overcoming the sensitivity shortcomings of the conventional single pulse laser induced breakdown spectroscopy technique. Several configurations have been suggested for the realization of the double pulse laser induced breakdown spectroscopy technique: collinear, orthogonal pre-spark, orthogonal pre-heating and dual pulse crossed beam modes. In addition, combinations of laser pulses with different wavelengths, different energies and durations were studied, thus providing flexibility in the choice of wavelength, pulse width, energy and pulse sequence. The double pulse laser induced breakdown spectroscopy approach provides a significant enhancement in the intensity of laser induced breakdown spectroscopy emission lines up to two orders of magnitude greater than a conventional single pulse laser induced breakdown spectroscopy. The double pulse technique leads to a better coupling of the laser beam with the plasma plume and target material, thus providing a more temporally effective energy delivery to the plasma and target. The experimental results demonstrate that the maximum effect is obtained at some optimum separation delay time between pulses. The optimum value of the interpulse delay depends on several factors, such as the target material, the energy level of excited states responsible for the emission, and the type of enhancement process considered. Depending on the specified parameter, the enhancement effects were observed on different time scales ranging from the picosecond time level (e.g., ion yield, ablation mass) up to the hundred microsecond level (e.g., increased emission intensity for laser induced breakdown spectroscopy of submerged metal target in water). Several suggestions have been proposed to explain

  6. Analysis of relaxing laser-induced plasmas by absorption spectroscopy: Toward a new quantitative diagnostic technique

    International Nuclear Information System (INIS)

    Ribiere, M.; Cheron, B.G.

    2010-01-01

    Broad-band near UV absorption spectroscopy was used to analyze atmospheric laser-induced plasmas formed on metallic and refractory targets. When the common emission spectroscopy only provides the density of the radiating atomic excited states, the technique reported in this paper is able to achieve high spatial resolution in the measurement of absolute number densities in expanding laser-induced plasmas. The reliability and the versatility of this technique, which is based on the comparison between results of the numerical integration of the radiative transfer equation and experimental spectra, were tested on different targets. The evolutions in time and space of the absolute population of the plasma species originating from metallic alloys (Al-Mg and Cu-Ni) and refractory materials (C/SiC) were achieved over large time scales. Owing to its accuracy, this absorption technique (that we call 'LIPAS' for Laser Induced Plasma Absorption Spectroscopy) should bring a new and enhanced support to the validation of collisional-radiative models attempting to provide reliable evolutions of laser-induced plasmas.

  7. Application of Laser Induced Plasma Spectroscopy on Breast Cancer Diagnoses

    Science.gov (United States)

    Abd-Alfattah, A.; Eldakrouri, A. A.; Emam, H.; Azzouz, I. M.

    2013-03-01

    Worldwide, millions of breast cancer cases appear each year. It ranked as the first malignant tumors in Egypt. Breast cancer patients are at increased risk of developing malignant melanoma and cancers of the ovary, endometrium, colon, thyroid, and salivary glands because of similar hormonal and genetic factors. Therefore, early diagnosis by a quick and accurate method may have a great affect on healing. In this work, we investigate the feasibility of using LIPS as a simple, technique to diagnose breast cancer by measuring the concentration of trace elements in breast tissues. The accuracy of LIPS measurements was confirmed by carrying out another elemental analysis via atomic absorption spectroscopy (AAS) technique. The results obtained via these two techniques showed that the concentration of Ca, Cu, Fe, Zn and Mn in the malignant tissue cells are significantly enhanced. A voting algorithm was built for instantaneous decision of the diagnostic technique (normal or malignant). This study instigates developing a new diagnostic tool with potential use in vivo.

  8. Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment

    Science.gov (United States)

    Najarian, Maya L.; Chinni, Rosemarie C.

    2013-01-01

    This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

  9. Process analysis of recycled thermoplasts from consumer electronics by laser-induced plasma spectroscopy.

    Science.gov (United States)

    Fink, Herbert; Panne, Ulrich; Niessner, Reinhard

    2002-09-01

    An experimental setup for direct elemental analysis of recycled thermoplasts from consumer electronics by laser-induced plasma spectroscopy (LIPS, or laser-induced breakdown spectroscopy, LIBS) was realized. The combination of a echelle spectrograph, featuring a high resolution with a broad spectral coverage, with multivariate methods, such as PLS, PCR, and variable subset selection via a genetic algorithm, resulted in considerable improvements in selectivity and sensitivity for this complex matrix. With a normalization to carbon as internal standard, the limits of detection were in the ppm range. A preliminary pattern recognition study points to the possibility of polymer recognition via the line-rich echelle spectra. Several experiments at an extruder within a recycling plant demonstrated successfully the capability of LIPS for different kinds of routine on-line process analysis.

  10. Resonance-enhanced laser-induced plasma spectroscopy for sensitive elemental analysis: Elucidation of enhancement mechanisms

    International Nuclear Information System (INIS)

    Lui, S.L.; Cheung, N.H.

    2002-01-01

    When performing laser-induced plasma spectroscopy for elemental analysis, the analyte signal-to-noise ratio increased from four to over fifty if the plume was reheated by a dye laser pulse tuned to resonant absorption. Time-resolved studies showed that the enhancement was not due to resonance photoionization. Rather, efficient and controlled rekindling of a larger plume volume was the key mechanism. The signal-to-noise ratio further increased to over a hundred if the atmosphere was replaced by a low-pressure heavy inert gas. The ambient gas helped confine and thermally insulate the expanding vapor

  11. Determination of plasma temperature and electron density in river sediment plasma using calibration-free laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Austria, Elmer S. Jr.; Lamorena-Lim, Rheo B.

    2015-01-01

    Calibration-free laser-induced breakdown spectroscopy (CF-LIBS) technique is an approach used to quantitatively measure elemental composition of samples without the use of standard reference materials (SRMs). Due to the unavailability of most SRMs for specific samples, the CF-LIBS approach is steadily becoming more prevalent. CF-LIBS also minimizes interferences from the sample matrix by accounting spectral line intensifies of different elements. The first part of the CF-LIBS algorithm is the calculation of plasma temperature and electron density of the sample while the second part deals with the self-absorption correction and quantitative elemental analysis. In this study, the precursor parameters for the algorithm - plasma temperature and electron density - were measured through the neutral atom and ion line emissions of Fe and Cu in the time window of 0.1 to 10 μs. Plasma from river sediment samples were produced by a 1064 nm nanosecond pulsed Nd:YAG laser at atmospheric pressure. The plasma temperature and electron density were calculated from the Boltzmann plot and Saha-Boltzmann equation methods, respectively. These precursor parameters can be used in calculating the time window wherein the plasma is optically thin at local thermodynamic equilibrium (LTE) and for quantitative multi-elemental analysis. (author)

  12. Polarization mechanism in a ns laser-induced plasma spectroscopy of Al alloy

    Science.gov (United States)

    Aghababaei Nejad, Mahboobeh; Soltanolkotabi, Mahmood; Eslami Majd, Abdollah

    2018-01-01

    Polarization emission from aluminum alloy by ns laser-induced breakdown spectroscopy (LIBS) is carefully investigated in air using a non-gated CCD camera at integration time of 100 ms. First, the analysis reveals that the small polarization degree is the same for both continuum and discrete line emission spectra which also increases slowly with wavelength growth; second, laser fluence in the range of 347.81-550.10 J/cm2 has no significant changes in plasma polarization; and third, larger polarization in comparison with polarization introduced by preferential reflection of emission from the target surface (Fresnel reflectivity) is observed. The residual fluctuations of the anisotropic recombining plasma and the dynamic polarization of an ion's core are suggested as the possible main sources for observed polarized radiation in ns-LIBS.

  13. Diode-Laser Induced Fluorescence Spectroscopy of an Optically Thick Plasma in Combination with Laser Absorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    S. Nomura

    2013-01-01

    Full Text Available Distortion of laser-induced fluorescence profiles attributable to optical absorption and saturation broadening was corrected in combination with laser absorption spectroscopy in argon plasma flow. At high probe-laser intensity, saturated absorption profiles were measured to correct probe-laser absorption. At low laser intensity, nonsaturated absorption profiles were measured to correct fluorescence reabsorption. Saturation broadening at the measurement point was corrected using a ratio of saturated to non-saturated broadening. Observed LIF broadening and corresponding translational temperature without correction were, respectively, 2.20±0.05 GHz and 2510±100 K and corrected broadening and temperature were, respectively, 1.96±0.07 GHz and 1990±150 K. Although this correction is applicable only at the center of symmetry, the deduced temperature agreed well with that obtained by LAS with Abel inversion.

  14. New ways for the quantification by the laser-induced plasma spectroscopy

    International Nuclear Information System (INIS)

    Mueller, Maike

    2010-01-01

    Laser Induced Breakdown Spectroscopy (LIBS) is capable of a fast and multielement analysis of various samples types and matrices which makes the method particularly attractive for industrial process analysis. However, for LIBS to become well accepted as an analytical method some issues in calibration and understanding of the underlying transient plasma processes have to be solved. The objective of this work was to identify influential instrumental parameters and plasma conditions in order to improve the overall quantitative performance of LIBS. As the spectral sensitivity and signal-to-noise ratio of the detector represents a decisive element for the application of LIBS in an industrial environment, two detectors, an ICCD and CCD camera, were compared. In combination with a high-resolution echelle spectrograph, the superior or at least equivalent efficiency of the non-intensified CCD was experimentally demonstrated and supported by corresponding plasma simulations. Further investigations of the plasma expansion under different atmospheric conditions revealed that the geometry of observing the expanding plasma influences the sensitivity and reproducibility of the measurements considerably. The diagnostics of self-absorbed spectral lines and their use for calibration purposes were studied with a mirror-based duplication method and a statistical line shape analysis employing linear correlation. The linear correlation approach displayed good performance for identifying the on-set of self absorption in comparison to the duplication method. As matrixmatched reference materials are essential to validate laser ablation methods, two novel preparations of individual calibration standards based on a copper-and polyacrylamide matrix were tested for their applicability to LIBS. (orig.)

  15. On-line iron ore slurry monitoring using laser induced plasma spectroscopy

    International Nuclear Information System (INIS)

    Barrette, L.; Turmel, S.; Boivin, J.-A.; Sabsabi, M.; Martinovic, T.I.; Ouellet, G.

    1999-01-01

    In response to the need for a better control [Lb1] of the various additives used in the iron ore pellet making process, Laser-Induced Plasma Spectroscopy (LIPS) has been tested for the on-line monitoring of Si, AI, Ca, Mg, and C. This work shows that factors such as laser beam focusing, particle size, slurry density and mineralogical composition have to be taken into account to meet precision and accuracy requirements. An internal standardization (peak ratio) and an original multivariate calibration technique based on fuzzy logic concepts [Lb2] are [Lb3] used to minimize the effect of these factors. This paper describes the experimental set-up, the effect of influence factors and the results obtained both in the laboratory and in an iron ore plant. (author)

  16. Influences on the Emissions of Bacterial Plasmas Generated through Nanosecond Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Malenfant, Dylan J.

    In the past decade, laser-induced breakdown spectroscopy has been shown to provide compositional data that can be used for discrimination between bacterial specimens at the strain level. This work demonstrates the viability of this technique in a clinical setting. Studies were conducted to investigate the impact of emissions generated by a nitrocellulose filter paper background on the classification of four species: E. coli, S. epidermidis, M. smegmatis, and P. aeruginosa. Limits of detection were determined as 48+/-12 kCFU per ablation event for new mounting procedures using standard diagnostic laboratory techniques, and a device for centrifuge filtration was designed for sampling from low-titer bacterial suspensions. Plasma emissions from samples grown at biological levels of magnesium, zinc, and glucose were shown not to deviate from controls. A limit of detection for environmental zinc was found to be 11 ppm. Discrimination with heat-killed samples was demonstrated, providing a sterile diagnostic environment.

  17. Resonance-enhanced laser-induced plasma spectroscopy: ambient gas effects

    International Nuclear Information System (INIS)

    Lui, S.L.; Cheung, N.H.

    2003-01-01

    When performing laser-induced plasma spectroscopy for elemental analysis, the sensitivity could be significantly enhanced if the plume was resonantly rekindled by a dye laser pulse. The extent of the enhancement was found to depend on the ambient gas. Air, nitrogen, helium, argon and xenon at pressures ranging from vacuum to 1 bar were investigated. In vacuum, the analyte signal was boosted because of reduced cooling, but it soon decayed as the plume freely expanded. By choosing the right ambient gas at the right pressure, the expanding plume could be confined as well as thermally insulated to maximize the analyte signal. For instance, an ambient of 13 mbar xenon yielded a signal-to-noise ratio of 110. That ratio was 53 when the pellet was ablated in air, and decreased further to 5 if the dye laser was tuned off resonance

  18. The use of laser-induced plasma spectroscopy technique for the characterization of boiler tubes

    International Nuclear Information System (INIS)

    Nicolas, G.; Mateo, M.P.; Yanez, A.

    2007-01-01

    The present work focuses on the characterization of boiler tube walls using laser-induced plasma spectroscopy technique with visual inspection by optical and scanning electron microscopy of the cross-sections of these tubes. In a watertube boiler, water runs through tubes that are surrounded by a heating source. As a result, the water is heated to very high temperatures, causing accumulation of deposits on the inside surfaces of the tubes. These deposits play an important role in the efficiency of the boiler tube because they produce a reduction of the boiler heat rate and an increase in the number of tube failures. The objectives are to determine the thickness and arrangement of deposits located on the highest heat area of the boiler and compare them with tube parts where the heat flux is lower. The major deposits found were copper and magnetite. These deposits come mainly from the boiler feedwater and from the reaction between iron and water, and they do not form on the tube walls at a uniform rate over time. Their amount depends on the areas where they are collected. A Nd:YAG laser operating at 355 nm has been used to perform laser-induced plasma spectra and depth profiles of the deposits

  19. The use of laser-induced plasma spectroscopy technique for the characterization of boiler tubes

    Science.gov (United States)

    Nicolas, G.; Mateo, M. P.; Yañez, A.

    2007-12-01

    The present work focuses on the characterization of boiler tube walls using laser-induced plasma spectroscopy technique with visual inspection by optical and scanning electron microscopy of the cross-sections of these tubes. In a watertube boiler, water runs through tubes that are surrounded by a heating source. As a result, the water is heated to very high temperatures, causing accumulation of deposits on the inside surfaces of the tubes. These deposits play an important role in the efficiency of the boiler tube because they produce a reduction of the boiler heat rate and an increase in the number of tube failures. The objectives are to determine the thickness and arrangement of deposits located on the highest heat area of the boiler and compare them with tube parts where the heat flux is lower. The major deposits found were copper and magnetite. These deposits come mainly from the boiler feedwater and from the reaction between iron and water, and they do not form on the tube walls at a uniform rate over time. Their amount depends on the areas where they are collected. A Nd:YAG laser operating at 355 nm has been used to perform laser-induced plasma spectra and depth profiles of the deposits.

  20. Enhancement and stabilization of plasma using collinear long-short double-pulse laser-induced breakdown spectroscopy

    Science.gov (United States)

    Cui, Minchao; Deguchi, Yoshihiro; Wang, Zhenzhen; Fujita, Yuki; Liu, Renwei; Shiou, Fang-Jung; Zhao, Shengdun

    2018-04-01

    A collinear long-short dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) method was employed to enhance and stabilize the laser-induced plasma from steel sample. The long-pulse-width laser beam with the pulse width of 60 μs was generated by a Nd: YAG laser which was operated at FR (free running) mode. The comparative experiments were carried out between single pulse LIBS (SP-LIBS) and long-short DP-LIBS. The recorded results showed that the emission intensities and the temperature of plasma were enhanced by long-short DP-LIBS. The plasma images showed that the plasma was bigger and had a longer lifetime in long-short DP-LIBS situation. Through the calculation of time-resolved plasma temperature and intensity ratio, it can be concluded that the plasma was stabilized by the long-pulse-width laser beam. The long-short DP-LIBS method also generated the stable plasma condition from the samples with different initial temperatures, which overcame the difficulties of LIBS in the online measurement for steel production line.

  1. High spatial resolution in laser-induced breakdown spectroscopy of expanding plasmas

    International Nuclear Information System (INIS)

    Siegel, J.; Epurescu, G.; Perea, A.; Gordillo-Vazquez, F.J.; Gonzalo, J.; Afonso, C.N.

    2005-01-01

    We report a technique that is able to achieve high spatial resolution in the measurement of the temporal and spectral emission characteristics of laser-induced expanding plasmas. The plasma is imaged directly onto the slit of an imaging spectrograph coupled to a time-gated intensified camera, with the plasma expansion direction being parallel to the slit extension. In this way, a single hybrid detection system is used to acquire the spatial, spectral and temporal characteristics of the laser induced plasma. The parallel acquisition approach of this technique ensures a much better spatial resolution in the expansion direction, reproducibility and data acquisition speed than commonly obtained by sequential measurements at different distances from the target. We have applied this technique to study the laser-induced plasma in LiNbO 3 and Bi 12 Ge 1 O 20 , revealing phenomena not seen in such detail with standard instruments. These include extreme line broadening up to a few nanometers accompanied by self-absorption near the target surface, as well as different ablation and expansion dynamics for the different species ejected. Overall, the high precision and wealth of quantitative information accessible with this technique open up new possibilities for the study of fundamental plasma expansion processes during pulsed laser ablation

  2. Study of early laser-induced plasma dynamics: Transient electron density gradients via Thomson scattering and Stark Broadening, and the implications on laser-induced breakdown spectroscopy measurements

    International Nuclear Information System (INIS)

    Diwakar, P.K.; Hahn, D.W.

    2008-01-01

    To further develop laser-induced breakdown spectroscopy (LIBS) as an analytical technique, it is necessary to better understand the fundamental processes and mechanisms taking place during the plasma evolution. This paper addresses the very early plasma dynamics (first 100 ns) using direct plasma imaging, light scattering, and transmission measurements from a synchronized 532-nm probe laser pulse. During the first 50 ns following breakdown, significant Thomson scattering was observed while the probe laser interacted with the laser-induced plasma. The Thomson scattering was observed to peak 15-25 ns following plasma initiation and then decay rapidly, thereby revealing the highly transient nature of the free electron density and plasma equilibrium immediately following breakdown. Such an intense free electron density gradient is suggestive of a non-equilibrium, free electron wave generated by the initial breakdown and growth processes. Additional probe beam transmission measurements and electron density measurements via Stark broadening of the 500.1-nm nitrogen ion line corroborate the Thomson scattering observations. In concert, the data support the finding of a highly transient plasma that deviates from local thermodynamic equilibrium (LTE) conditions during the first tens of nanoseconds of plasma lifetime. The implications of this early plasma transient behavior are discussed in the context of plasma-analyte interactions and the role on LIBS measurements

  3. Modeling of plasma distortions by laser-induced ablation spectroscopy (LIAS) and implications for the interpretation of LIAS measurements

    Science.gov (United States)

    Tokar, M. Z.; Gierse, N.; Philipps, V.; Samm, U.

    2015-09-01

    For the interpretation of the line radiation observed from laser induced ablation spectroscopy (LIAS) such parameters as the density and temperature of electrons within very compact clouds of atoms and singly charged ions of ablated material have to be known. Compared to the local plasma conditions prior to the laser pulse, these can be strongly changed during LIAS since new electrons are generated by the ionisation of particles ejected from the irradiated target. Because of their transience and spatial inhomogeneity it is technically difficult to measure disturbances induced in the plasma by LIAS. To overcome this uncertainty a numerical model has been elaborated, providing a self-consistent description for the spreading of ablated particles and accompanying modifications in the plasma. The results of calculations for LIAS performed on carbon-containing targets in Ohmic and additionally heated discharges in the tokamak TEXTOR are presented. Due to the increase in the electron density the ‘ionisation per photon’ ratio, S/XB factor, is significantly enhanced compared to unperturbed plasma conditions. The impact of the amount of material ablated and of the plasma conditions before LIAS on the level of the S/XB-enhancement is investigated.

  4. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    International Nuclear Information System (INIS)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-01-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  5. The influence of laser-particle interaction in laser induced breakdown spectroscopy and laser ablation inductively coupled plasma spectrometry

    Science.gov (United States)

    Lindner, Helmut; Loper, Kristofer H.; Hahn, David W.; Niemax, Kay

    2011-02-01

    Particles produced by previous laser shots may have significant influence on the analytical signal in laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma (LA-ICP) spectrometry if they remain close to the position of laser sampling. The effects of these particles on the laser-induced breakdown event are demonstrated in several ways. LIBS-experiments were conducted in an ablation cell at atmospheric conditions in argon or air applying a dual-pulse arrangement with orthogonal pre-pulse, i.e., plasma breakdown in a gas generated by a focussed laser beam parallel and close to the sample surface followed by a delayed crossing laser pulse in orthogonal direction which actually ablates material from the sample and produces the LIBS plasma. The optical emission of the LIBS plasma as well as the absorption of the pre-pulse laser was measured. In the presence of particles in the focus of the pre-pulse laser, the plasma breakdown is affected and more energy of the pre-pulse laser is absorbed than without particles. As a result, the analyte line emission from the LIBS plasma of the second laser is enhanced. It is assumed that the enhancement is not only due to an increase of mass ablated by the second laser but also to better atomization and excitation conditions favored by a reduced gas density in the pre-pulse plasma. Higher laser pulse frequencies increase the probability of particle-laser interaction and, therefore, reduce the shot-to-shot line intensity variation as compared to lower particle loadings in the cell. Additional experiments using an aerosol chamber were performed to further quantify the laser absorption by the plasma in dependence on time both with and without the presence of particles. The overall implication of laser-particle interactions for LIBS and LA-ICP-MS/OES are discussed.

  6. The use of laser-induced shock wave plasma spectroscopy (LISPS) for examining physical characteristics of pharmaceutical products

    Energy Technology Data Exchange (ETDEWEB)

    Abdulmadjid, Syahrun Nur, E-mail: syahrun-madjid@yahoo.com; Lahna, Kurnia, E-mail: kurnialahna@gmail.com [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, Aceh (Indonesia); Desiyana, Lydia Septa, E-mail: lydia-septa@yahoo.com [Department of Pharmacy, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, Aceh (Indonesia)

    2016-03-11

    An experimental study has been performed to examine the physical characteristics of pharmaceutical products, such as tablet, by employing an emission plasma induced by Nd-YAG laser at a low pressure of Helium gas. The hardness of tablet is one of the parameters that examined during the production process for standard quality of pharmaceutical products. In the Laser-Induced Shock Wave Plasma Spectroscopy (LISPS), the shock wave has a significant role in inducing atomic excitation. It was known that, the speed of the shock wavefront depends on the hardness of the sample, and it correlates with the ionization rate of the ablated atoms. The hardness of the tablet is examined using the intensity ratio between the ion of Mg (II) 275.2 nm and the neutral of Mg (I) 285.2 nm emission lines detected from the laser-induced plasma. It was observed that the ratio changes with respect to the change in the tablet hardness, namely the ratio is higher for the hard tablet. Besides the ratio measurements, we also measured the depth profile of a tablet by focusing 60 shots of irradiation of laser light at a fixed position on the surface of the tablet. It was found that the depth profile varies differently with the hardness of the tablet. These experiment results show that the technique of LISPS can be applied to examine the quality of pharmaceutical products.

  7. The use of laser-induced shock wave plasma spectroscopy (LISPS) for examining physical characteristics of pharmaceutical products

    International Nuclear Information System (INIS)

    Abdulmadjid, Syahrun Nur; Lahna, Kurnia; Desiyana, Lydia Septa

    2016-01-01

    An experimental study has been performed to examine the physical characteristics of pharmaceutical products, such as tablet, by employing an emission plasma induced by Nd-YAG laser at a low pressure of Helium gas. The hardness of tablet is one of the parameters that examined during the production process for standard quality of pharmaceutical products. In the Laser-Induced Shock Wave Plasma Spectroscopy (LISPS), the shock wave has a significant role in inducing atomic excitation. It was known that, the speed of the shock wavefront depends on the hardness of the sample, and it correlates with the ionization rate of the ablated atoms. The hardness of the tablet is examined using the intensity ratio between the ion of Mg (II) 275.2 nm and the neutral of Mg (I) 285.2 nm emission lines detected from the laser-induced plasma. It was observed that the ratio changes with respect to the change in the tablet hardness, namely the ratio is higher for the hard tablet. Besides the ratio measurements, we also measured the depth profile of a tablet by focusing 60 shots of irradiation of laser light at a fixed position on the surface of the tablet. It was found that the depth profile varies differently with the hardness of the tablet. These experiment results show that the technique of LISPS can be applied to examine the quality of pharmaceutical products.

  8. Laser induced aluminiun plasma analysis by optical emission spectroscopy in a nitrogen background gas

    International Nuclear Information System (INIS)

    Chamorro, J C; Uzuriaga, J; Riascos, H

    2012-01-01

    We studied an Al plasma generated by a Nd:YAG laser with a laser fluence of 4 J/cm 2 , a wavelength of 1064 nm, energy pulse of 500 mJ and 10 Hz repetition rate. We studied their spectral characteristics at various ambient nitrogen pressures by optical emission spectroscopy (OES). The N 2 gas pressure was varied from 20 mTorr to 150 mTorr. In Al plume, both atomic and ionic spectra were observed. The electron temperature and electron number density of the plume as of the function ambient gas pressure were determined. The electron temperature was calculated by using the Boltzmann-plot method and the number density was calculated considering the stark effect as dominating on the emission lines.

  9. Nanoparticle Enhanced Laser Induced Breakdown Spectroscopy: Effect of nanoparticles deposited on sample surface on laser ablation and plasma emission

    International Nuclear Information System (INIS)

    De Giacomo, A.; Gaudiuso, R.; Koral, C.; Dell'Aglio, M.; De Pascale, O.

    2014-01-01

    In this paper the use of metallic nanoparticles (NPs) for improving Laser Induced Breakdown Spectroscopy (LIBS) is discussed. In the case of conductors an emission signal enhancement up to 1–2 orders of magnitude was obtained depositing NPs on the sample surface by drying a micro-drop of colloidal solution. The basic mechanisms of Nanoparticle Enhanced LIBS (NELIBS) were studied and the main causes of this significantly large enhancement were found to be related to the effect of NPs on the laser ablation process, in terms of a faster and more efficient production of seed electrons with respect to conventional LIBS. The characteristics of NELIBS-produced plasma were investigated by emission spectroscopy and spectrally resolved images. In spite of similar plasma parameters, the NELIBS plasma was found to have larger emission volume and longer persistence than the LIBS one. A method to determine NP concentration and size was also proposed, which involved depositing NPs on non-interacting substrates, and proved the feasibility of LIBS as a fast detection tool for a preliminary characterization of NPs. - Highlights: • Effect of NPs on sample surface enables instantaneous field emission. • More efficient ablation • LIBS emission enhancement up to 1–2 orders of magnitude • Possibility of NP characterization in terms of concentration and size

  10. 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.

  11. Distribution of Fe atom density in a dc magnetron sputtering plasma source measured by laser-induced fluorescence imaging spectroscopy

    Science.gov (United States)

    Shibagaki, K.; Nafarizal, N.; Sasaki, K.; Toyoda, H.; Iwata, S.; Kato, T.; Tsunashima, S.; Sugai, H.

    2003-10-01

    Magnetron sputtering discharge is widely used as an efficient method for thin film fabrication. In order to achieve the optimized fabrication, understanding of the kinetics in plasmas is essential. In the present work, we measured the density distribution of sputtered Fe atoms using laser-induced fluorescence imaging spectroscopy. A dc magnetron plasma source with a Fe target was used. An area of 20 × 2 mm in front of the target was irradiated by a tunable laser beam having a planar shape. The picture of laser-induced fluorescence on the laser beam was taken using an ICCD camera. In this way, we obtained the two-dimensional image of the Fe atom density. As a result, it has been found that the Fe atom density observed at a distance of several centimeters from the target is higher than that adjacent to the target, when the Ar gas pressure was relatively high. It is suggested from this result that some gas-phase production processes of Fe atoms are available in the plasma. This work has been performed under the 21st Century COE Program by the Ministry of Education, Culture, Sports, Science and Technology in Japan.

  12. Transversely Excited Atmospheric CO2 Laser-Induced Plasma Spectroscopy for the Detection of Heavy Metals in Soil

    Science.gov (United States)

    Khumaeni, A.; Sugito, H.; Setia Budi, W.; Yoyo Wardaya, A.

    2018-01-01

    A rapid detection of heavy metals in soil was presented by the metal-assisted gas plasma method using specific characteristics of a pulsed, transversely excited atmospheric (TEA) CO2 laser. The soil particles were placed in a hole made of acrylic plate. The sample was covered by a to prevent the soil particles from being blown off. The mesh also functioned to initiate a luminous plasma. When a TEA CO2 laser (1500 mJ, 200 ns) was focused on the soil sample, passing through the metal mesh, some of the laser energy was used to generate the gas plasma on the mesh surface, and the remaining laser energy was employed to ablate the soil particles. The fine, ablated soil particles moved into the gas plasma region to be dissociated and excited. Using this technique, analysis can be made with reduced sample pretreatment, and therefore a rapid analysis can be performed efficiently. The results proved that the signal to noise ratio (S/N) of the emission spectral lines is much better for the case of the present method (mesh method) compared to the case of standard laser-induced breakdown spectroscopy using the pellet method. Rapid detection of heavy metal elements in soil has been successfully carried out. The detection limits of Cu and Hg in soil were estimated to be 3 and 10 mg/kg, respectively. The present method has good potential for rapid and sensitive detection of heavy metals in soil samples.

  13. Optimal conditions for taking spectra of coffee beans plasma spectroscopy induced by laser (LIBS)

    International Nuclear Information System (INIS)

    Diaz Guerrero, A. M.; Flores Reyes; Ponce Cabrera, L. V.

    2016-01-01

    Coffee beans, arabica and robusta, from Mexico (Chiapas and Veracruz), Colombia, Kenya and Sumatra were analyzed by Laser-induced breakdown spectroscopy (LIBS). The time delay and pulse energy were varied in order to find the optimal conditions for taking spectra in coffee beans; finding that the increased visibility of the peaks and the lowest electronic background is observed with 1 s and 450 mJ. Spectra were taken in different regions of grain area to confirm its homogeneous composition. It was found that the intensity of the signal Ca is much higher than that of K in African coffee, lower in the coffee of America, and much lower in the coffee from Asia. (Author)

  14. Precise alignment of the collection fiber assisted by real-time plasma imaging in laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Motto-Ros, V., E-mail: vincent.motto-ros@univ-lyon1.fr [Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Negre, E. [Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); CRITT Matériaux Alsace, 19, rue de St Junien, 67305 Schiltigheim (France); Pelascini, F. [CRITT Matériaux Alsace, 19, rue de St Junien, 67305 Schiltigheim (France); Panczer, G.; Yu, J. [Institut Lumière Matière, UMR 5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France)

    2014-02-01

    Improving the repeatability and the reproducibility of measurement with laser-induced breakdown spectroscopy (LIBS) is one of the actual challenging issues faced by the technique to fit the requirements of precise and accurate quantitative analysis. Among the numerous factors influencing the measurement stability in short and long terms, there are shot-to-shot and day-to-day fluctuations of the morphology of the plasma. Such fluctuations are due to the high sensitivity of laser-induced plasma to experimental conditions including properties of the sample, the laser parameters as well as properties of the ambient gas. In this paper, we demonstrate that precise alignment of the optical fiber for the collection of the plasma emission with respect to the actual morphology of the plasma assisted by real-time imaging, greatly improves the stability of LIBS measurements in short as well as in long terms. The used setup is based on a plasma imaging arrangement using a CCD camera and a real-time image processing. The obtained plasma image is displayed in a 2-dimensional frame where the position of the optical fiber is beforehand calibrated. In addition, the setup provides direct sample surface monitoring, which allows a precise control of the distance between the focusing lens and the sample surface. Test runs with a set of 8 reference samples show very high determination coefficient for calibration curves (R{sup 2} = 0.9999), and a long term repeatability and reproducibility of 4.6% (relative standard deviation) over a period of 3 months without any signal normalization. The capacity of the system to automatically correct the sample surface position for a tilted or non-regular sample surface during a surface mapping measurement is also demonstrated. - Highlights: • Automated alignment of the collection fiber by real-time plasma imaging • High level control of experimental parameters in LIBS experiments • Improvement of the short and long term stability in LIBS

  15. Precise alignment of the collection fiber assisted by real-time plasma imaging in laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Motto-Ros, V.; Negre, E.; Pelascini, F.; Panczer, G.; Yu, J.

    2014-01-01

    Improving the repeatability and the reproducibility of measurement with laser-induced breakdown spectroscopy (LIBS) is one of the actual challenging issues faced by the technique to fit the requirements of precise and accurate quantitative analysis. Among the numerous factors influencing the measurement stability in short and long terms, there are shot-to-shot and day-to-day fluctuations of the morphology of the plasma. Such fluctuations are due to the high sensitivity of laser-induced plasma to experimental conditions including properties of the sample, the laser parameters as well as properties of the ambient gas. In this paper, we demonstrate that precise alignment of the optical fiber for the collection of the plasma emission with respect to the actual morphology of the plasma assisted by real-time imaging, greatly improves the stability of LIBS measurements in short as well as in long terms. The used setup is based on a plasma imaging arrangement using a CCD camera and a real-time image processing. The obtained plasma image is displayed in a 2-dimensional frame where the position of the optical fiber is beforehand calibrated. In addition, the setup provides direct sample surface monitoring, which allows a precise control of the distance between the focusing lens and the sample surface. Test runs with a set of 8 reference samples show very high determination coefficient for calibration curves (R 2 = 0.9999), and a long term repeatability and reproducibility of 4.6% (relative standard deviation) over a period of 3 months without any signal normalization. The capacity of the system to automatically correct the sample surface position for a tilted or non-regular sample surface during a surface mapping measurement is also demonstrated. - Highlights: • Automated alignment of the collection fiber by real-time plasma imaging • High level control of experimental parameters in LIBS experiments • Improvement of the short and long term stability in LIBS measurements

  16. Laser-induced breakdown spectroscopy (LIBS), part I: review of basic diagnostics and plasma-particle interactions: still-challenging issues within the analytical plasma community.

    Science.gov (United States)

    Hahn, David W; Omenetto, Nicoló

    2010-12-01

    Laser-induced breakdown spectroscopy (LIBS) has become a very popular analytical method in the last decade in view of some of its unique features such as applicability to any type of sample, practically no sample preparation, remote sensing capability, and speed of analysis. The technique has a remarkably wide applicability in many fields, and the number of applications is still growing. From an analytical point of view, the quantitative aspects of LIBS may be considered its Achilles' heel, first due to the complex nature of the laser-sample interaction processes, which depend upon both the laser characteristics and the sample material properties, and second due to the plasma-particle interaction processes, which are space and time dependent. Together, these may cause undesirable matrix effects. Ways of alleviating these problems rely upon the description of the plasma excitation-ionization processes through the use of classical equilibrium relations and therefore on the assumption that the laser-induced plasma is in local thermodynamic equilibrium (LTE). Even in this case, the transient nature of the plasma and its spatial inhomogeneity need to be considered and overcome in order to justify the theoretical assumptions made. This first article focuses on the basic diagnostics aspects and presents a review of the past and recent LIBS literature pertinent to this topic. Previous research on non-laser-based plasma literature, and the resulting knowledge, is also emphasized. The aim is, on one hand, to make the readers aware of such knowledge and on the other hand to trigger the interest of the LIBS community, as well as the larger analytical plasma community, in attempting some diagnostic approaches that have not yet been fully exploited in LIBS.

  17. Use of neutron diffraction and laser-induced plasma spectroscopy in integrated authentication methodologies of copper alloy artefacts

    International Nuclear Information System (INIS)

    Siano, S.; Bartol, L.; Mencaglia, A.A.; Agresti, J.; Miccio, M.

    2009-01-01

    The present study approaches the general problem of the authentication of copper alloy artefacts of art and historical interest using non-invasive analytical techniques. It aims to demonstrate that a suitable combination of time-of-flight neutron diffraction and laser-induced plasma spectroscopy in integrated multidisciplinary authentication methodologies can provide crucial data for discriminating between genuine archaeological objects and modern counterfeits. After introducing the methodology, which is dedicated in particular to copper alloy figurines of ancient style, two representative authentication case studies are discussed. The results of the work provide evidence that the combination of multiphase analysis using TOF-N D and elemental depth profiles provided by Lips makes it possible to solve most of the present authentication problems.

  18. Emission Characteristics of Laser-Induced Plasma Using Collinear Long and Short Dual-Pulse Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Wang, Zhenzhen; Deguchi, Yoshihiro; Liu, Renwei; Ikutomo, Akihiro; Zhang, Zhenzhen; Chong, Daotong; Yan, Junjie; Liu, Jiping; Shiou, Fang-Jung

    2017-09-01

    Collinear long and short dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) was employed to clarify the emission characteristics from laser-induced plasma. The plasma was sustained and became stable by the long pulse-width laser with the pulse width of 60 μs under free running (FR) conditions as an external energy source. Comparing the measurement results of stainless steel in air using single-pulse LIBS (SP-LIBS) and DP-LIBS, the emission intensity was markedly enhanced using DP-LIBS. The temperature of plasma induced by DP-LIBS was maintained at a higher temperature under different gate delay time and short pulse-width laser power conditions compared with those measured using short SP-LIBS. Moreover, the variation rates of plasma temperatures measured using DP-LIBS were also lower. The superior detection ability was verified by the measurement of aluminum sample in water. The spectra were clearly detected using DP-LIBS, whereas it cannot be identified using SP-LIBS of short and long pulse widths. The effects of gate delay time and short pulse-width laser power were also discussed. These results demonstrate the feasibility and enhanced detection ability of the proposed collinear long and short DP-LIBS method.

  19. Measurement of spatially resolved gas-phase plasma temperatures by optical emission and laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Davis, G.P.; Gottscho, R.A.

    1983-01-01

    Knowledge of the energy distributions of particles in glow discharges is crucial to the understanding and modeling of plasma reactors used in microelectronic manufacturing. Reaction rates, available product channels, and transport phenomena all depend upon the partitioning of energy in the discharge. Because of the nonequilibrium nature of glow discharges, however, the distribution of energy among different species and among different degrees of freedom cannot be characterized simply by one temperature. The extent to which different temperatures are needed for each degree of freedom and for each species is not known completely. How plasma operating conditions affect these energy distributions is also an unanswered question. We have investigated the temperatures of radicals, ions, and neutrals in CCl 4 , CCl 4 /N 2 (2%), and N 2 discharges. In the CCl 4 systems, we probed the CCl rotational and vibrational energy distributions by laser-induced fluorescence spectroscopy. The rotational distribution always appeared to be thermal but under identical operating conditions was found to be roughly-equal400 K colder than the vibrational distribution. The rotational temperature at any point in the discharge was strongly dependent upon both applied power and surface temperature. Thermal gradients as large as 10 2 K mm -1 were observed near electrode surfaces but the bulk plasmas were isothermal. When 2% N 2 was added to a CCl 4 discharge, N 2 second positive emission was observed and used to estimate the N 2 rotational temperature. The results suggest that emission from molecular actinometers can be used to measure plasma temperatures, providing such measurements are not made in close proximity to surfaces

  20. Assessment of Laser Induced Ablation Spectroscopy (LIAS) as a method for quantitative in situ surface diagnostic in plasma environments

    International Nuclear Information System (INIS)

    Gierse, Niels Hannes Gustav

    2014-01-01

    In this work Laser Induced Ablation Spectroscopy (LIAS) is investigated as an in situ plasma surface interaction diagnostic for fusion reactors and fusion experiments. In LIAS an intensive laser pulse is used to ablate the material under investigation during plasma operation. Ablation products penetrate into the edge region of the plasma and are excited and ionized. In case of molecules and clusters additionally dissociation occurs. The emitted line radiation is observed by radiometric calibrated spectroscopy. Results from LIAS of W/C/Al/D-mixed layers and amorphous hydrocarbon layers are presented. Using a fast camera system time resolved measurements of the LIAS.process could be performed, allowing investigation of the temporal behavior of excitation, dissociation and ionization processes. For Tungsten, 90% of the LIAS light is observed within 10±3 μs after the laser pulse. In case of carbon within 20±3 μs. Additionally separation in time of LIAS emission and the LIBS emission caused by the laser pulse at the surface within single measurements was demonstrated. This allows the separate analysis of both processes in a coaxial setup which is foreseen for future experiments. The inverse photon efficiency of the Balmer D_α-emission from LIAS of a-C:D-layers was found to be [(D)/(XB)]"a"-"C":"D""L""I""A""S"_→"D_D__α=71±7. The plasma perturbation due to LIAS was investigated by laser energy density variation when ablating W/C/Al/D.mixed layers. Local plasma perturbation is found to increase with laser energy density. Balmer H_γ/H_δ - line intensity ratio measurements only show for ohmic discharges and the case of the lowest central density signs of local plasma perturbation in LIAS of graphite samples. A simple analytical model for local plasma perturbation during LIAS is introduced and evaluated. Qualitative agreement between the model and the above reported experimental observations is found; a stronger influence on local conditions is found by tungsten

  1. Laser-induced plasma spectroscopy (LIPS): use of a geological tool in assessing bone mineral content.

    Science.gov (United States)

    Andrássy, László; Gomez, Izabella; Horváth, Ágnes; Gulyás, Katalin; Pethö, Zsófia; Juhász, Balázs; Bhattoa, Harjit Pal; Szekanecz, Zoltan

    2018-02-17

    Bone may be similar to geological formulations in many ways. Therefore, it may be logical to apply laser-based geological techniques in bone research. The mineral and element oxide composition of bioapatite can be estimated by mathematical models. Laser-induced plasma spectrometry (LIPS) has long been used in geology. This method may provide a possibility to determine the composition and concentration of element oxides forming the inorganic part of bones. In this study, we wished to standardize the LIPS technique and use mathematical calculations and models in order to determine CaO distribution and bone homogeneity using bovine shin bone samples. We used polished slices of five bovine shin bones. A portable LIPS instrument using high-power Nd++YAG laser pulses has been developed (OpLab, Budapest). Analysis of CaO distribution was carried out in a 10 × 10 sampling matrix applying 300-μm sampling intervals. We assessed both cortical and trabecular bone areas. Regions of interest (ROI) were determined under microscope. CaO peaks were identified in the 200-500 nm wavelength range. A mathematical formula was used to calculate the element oxide composition (wt%) of inorganic bone. We also applied two accepted mathematical approaches, the Bartlett's test and frequency distribution curve-based analysis, to determine the homogeneity of CaO distribution in bones. We were able to standardize the LIPS technique for bone research. CaO concentrations in the cortical and trabecular regions of B1-5 bones were 33.11 ± 3.99% (range 24.02-40.43%) and 27.60 ± 7.44% (range 3.58-39.51%), respectively. CaO concentrations highly corresponded to those routinely determined by ICP-OES. We were able to graphically demonstrate CaO distribution in both 2D and 3D. We also determined possible interrelations between laser-induced craters and bone structure units, which may reflect the bone structure and may influence the heterogeneity of CaO distributions. By using two different

  2. Determination of Metals Present in Textile Dyes Using Laser-Induced Breakdown Spectroscopy and Cross-Validation Using Inductively Coupled Plasma/Atomic Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    K. Rehan

    2017-01-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS was used for the quantitative analysis of elements present in textile dyes at ambient pressure via the fundamental mode (1064 nm of a Nd:YAG pulsed laser. Three samples were collected for this purpose. Spectra of textile dyes were acquired using an HR spectrometer (LIBS2000+, Ocean Optics, Inc. having an optical resolution of 0.06 nm in the spectral range of 200 to 720 nm. Toxic metals like Cr, Cu, Fe, Ni, and Zn along with other elements like Al, Mg, Ca, and Na were revealed to exist in the samples. The %-age concentrations of the detected elements were measured by means of standard calibration curve method, intensities of every emission from every species, and calibration-free (CF LIBS approach. Only Sample 3 was found to contain heavy metals like Cr, Cu, and Ni above the prescribed limit. The results using LIBS were found to be in good agreement when compared to outcomes of inductively coupled plasma/atomic emission spectroscopy (ICP/AES.

  3. Plasma polarization spectroscopy

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Horimoto, Yasuhiro; Fujimoto, Takashi; Hasegawa, Noboru; Sukegawa, Kouta; Kawachi, Tetsuya

    2005-01-01

    The electron velocity distribution function (EVDF) in plasma can be anisotropic in laser-produced plasmas. We have developed a new technique to evaluate the polarization degree of the emission lines in the extreme vacuum ultra violet wavelength region. The polarization of the emission lines and the continuums from the lithium-like nitrogen and from helium- and hydrogen-like carbon in recombining plasma is evaluated. Particle simulation in the velocity space gives the time scale for relaxation of anisotropic EVDFs. (author)

  4. Atomic hydrogen and diatomic titanium-monoxide molecular spectroscopy in laser-induced plasma

    Science.gov (United States)

    Parigger, Christian G.; Woods, Alexander C.

    2017-03-01

    This article gives a brief review of experimental studies of hydrogen Balmer series emission spectra. Ongoing research aims to evaluate early plasma evolution following optical breakdown in laboratory air. Of interest is as well laser ablation of metallic titanium and characterization of plasma evolution. Emission of titanium monoxide is discussed together with modeling of diatomic spectra to infer temperature. The behavior of titanium particles in plasma draws research interests ranging from the modeling of stellar atmospheres to the enhancement of thin film production via pulsed laser deposition.

  5. Introduction to Plasma Spectroscopy

    CERN Document Server

    Kunze, H-J

    2009-01-01

    Based on lectures given at the Ruhr-University of Bochum for graduate students and postgraduates starting in plasma physics as well as from low- to high-density hot plasmas, this book introduces basic ideas and fundamental concepts and typical instrumentation from the X-ray to the infrared spectral regions

  6. Spectroscopic analysis of high protein nigella seeds (Kalonji) using laser-induced breakdown spectroscopy and inductively coupled plasma/optical emission spectroscopy

    Science.gov (United States)

    Rehan, Imran; Khan, M. Zubair; Ali, Irfan; Rehan, Kamran; Sultana, Sabiha; Shah, Sher

    2018-03-01

    The spectroscopic analysis of high protein nigella seeds (also called Kalonji) was performed using pulsed nanosecond laser-induced breakdown spectroscopy (LIBS) at 532 nm. The emission spectrum of Kalonji recorded with an LIBS spectrometer exposed the presence of various elements like Al, B, Ba, Ca, Cr, K, P, Mg, Mn, Na, Ni, S, Si, Cu, Fe, Ti, Sn, Sr, and Zn. The plasma parameters (electron temperature and electron density) were estimated using Ca-I spectral lines and their behavior were studied against laser irradiance. The electron temperature and electron density was observed to show an increasing trend in the range of 5802-7849 K, and (1.2-3.9) × 1017 cm- 3, respectively, in the studied irradiance range of (1.2-12.6) × 109 W/cm2. Furthermore, the effect of varying laser energy on the integrated signal intensities was also studied. The quantitative analysis of the detected elements was performed via the calibration curves drawn for all the observed elements through typical samples made in the known concentration in the Kalonji matrix, and by setting the concentration of P as the calibration. The validity of our LIBS findings was verified via comparison of the results with the concentration of every element find in Kalonji using the standard analytical tool like ICP/OES. The results acquired using LIBS and ICP/OES were found in fine harmony. Moreover, limit of detection was measured for toxic metals only.

  7. Double pulse laser induced breakdown spectroscopy of a solid in water: Effect of hydrostatic pressure on laser induced plasma, cavitation bubble and emission spectra

    Science.gov (United States)

    López-Claros, M.; Dell'Aglio, M.; Gaudiuso, R.; Santagata, A.; De Giacomo, A.; Fortes, F. J.; Laserna, J. J.

    2017-07-01

    There is a growing interest in the development of sensors use in exploration of the deep ocean. Techniques for the chemical analysis of submerged solids are of special interest, as they show promise for subsea mining applications where a rapid sorting of materials found in the sea bottom would improve efficiency. Laser-Induced Breakdown Spectroscopy (LIBS) has demonstrated potential for this application thanks to its unique capability of providing the atomic composition of submerged solids. Here we present a study on the parameters that affect the spectral response of metallic targets in an oceanic pressure environment. Following laser excitation of the solid, the plasma persistence and the cavitation bubble size are considerably reduced as the hydrostatic pressure increases. These effects are of particular concern in dual pulse excitation as reported here, where a careful choice of the interpulse timing is required. Shadowgraphic images of the plasma demonstrate that cavitation bubbles are formed early after the plasma onset and that the effect of hydrostatic pressure is negligible during the early stage of plasma expansion. Contrarily to what is observed at atmospheric pressure, emission spectra observed at high pressures are characterized by self-absorbed atomic lines on continuum radiation resulting from strong radiative recombination in the electron-rich confined environment. This effect is much less evident with ionic lines due to the much higher energy of the levels involved and ionization energy of ions, as well as to the lower extent of absorption effects occurring in the inner part of the plasma, where ionized species are more abundant. As a result of the smaller shorter-lived cavitation bubble, the LIBS intensity enhancement resulting from dual pulse excitation is reduced when the applied pressure increases.

  8. Secondary plasma formation after single pulse laser ablation underwater and its advantages for laser induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Gavrilović, M R; Cvejić, M; Lazic, V; Jovićević, S

    2016-06-07

    In this work we present studies of spatial and temporal plasma evolution after single pulse ablation of an aluminium target in water. The laser ablation was performed using 20 ns long pulses emitted at 1064 nm. The plasma characterization was performed by fast photography, the Schlieren technique, shadowgraphy and optical emission spectroscopy. The experimental results indicate the existence of two distinct plasma stages: the first stage has a duration of approximately 500 ns from the laser pulse, and is followed by a new plasma growth starting from the crater center. The secondary plasma slowly evolves inside the growing vapor bubble, and its optical emission lasts over several tens of microseconds. Later, the hot glowing particles, trapped inside the vapor cavity, were detected during the whole cycle of the bubble, where the first collapse occurs after 475 μs from the laser pulse. Differences in the plasma properties during the two evolution phases are discussed, with an accent on the optical emission since its detection is of primary importance for LIBS. Here we demonstrate that the LIBS signal quality in single pulse excitation underwater can be greatly enhanced by detecting only the secondary plasma emission, and also by applying long acquisition gates (in the order of 10-100 μs). The presented results are of great importance for LIBS measurements inside a liquid environment, since they prove that a good analytical signal can be obtained by using nanosecond pulses from a single commercial laser source and by employing cost effective, not gated detectors.

  9. Enhancement of laser-induced breakdown spectroscopy (LIBS) Detection limit using a low-pressure and short-pulse laser-induced plasma process.

    Science.gov (United States)

    Wang, Zhen Zhen; Deguchi, Yoshihiro; Kuwahara, Masakazu; Yan, Jun Jie; Liu, Ji Ping

    2013-11-01

    Laser-induced breakdown spectroscopy (LIBS) technology is an appealing technique compared with many other types of elemental analysis because of the fast response, high sensitivity, real-time, and noncontact features. One of the challenging targets of LIBS is the enhancement of the detection limit. In this study, the detection limit of gas-phase LIBS analysis has been improved by controlling the pressure and laser pulse width. In order to verify this method, low-pressure gas plasma was induced using nanosecond and picosecond lasers. The method was applied to the detection of Hg. The emission intensity ratio of the Hg atom to NO (IHg/INO) was analyzed to evaluate the LIBS detection limit because the NO emission (interference signal) was formed during the plasma generation and cooling process of N2 and O2 in the air. It was demonstrated that the enhancement of IHg/INO arose by decreasing the pressure to a few kilopascals, and the IHg/INO of the picosecond breakdown was always much higher than that of the nanosecond breakdown at low buffer gas pressure. Enhancement of IHg/INO increased more than 10 times at 700 Pa using picosecond laser with 35 ps pulse width. The detection limit was enhanced to 0.03 ppm (parts per million). We also saw that the spectra from the center and edge parts of plasma showed different features. Comparing the central spectra with the edge spectra, IHg/INO of the edge spectra was higher than that of the central spectra using the picosecond laser breakdown process.

  10. Characterization of the concurrent metabolic changes in brain and plasma during insulin-induced moderate hypoglycemia using 1H NMR spectroscopy in juvenile rats.

    Science.gov (United States)

    Ennis, Kathleen; Lusczek, Elizabeth; Rao, Raghavendra

    2017-07-13

    Treatment of hypoglycemia in children is currently based on plasma glucose measurements. This approach may not ensure neuroprotection since plasma glucose does not reflect the dynamic state of cerebral energy metabolism. To determine whether cerebral metabolic changes during hypoglycemia could be better characterized using plasma metabolomic analysis, insulin-induced acute hypoglycemia was induced in 4-week-old rats. Brain tissue and concurrent plasma samples were collected from hypoglycemic (N=7) and control (N=7) rats after focused microwave fixation to prevent post-mortem metabolic changes. The concentration of 29 metabolites in brain and 34 metabolites in plasma were determined using 1 H NMR spectroscopy at 700MHz and examined using partial least squares-discriminant analysis. The sensitivity of plasma glucose for detecting cerebral energy failure was assessed by determining its relationship to brain phosphocreatine. The brain and plasma metabolite profiles of the hypoglycemia group were distinct from the control group (brain: R 2 =0.92, Q 2 =0.31; plasma: R 2 =0.95, Q 2 =0.74). Concentration differences in glucose, ketone bodies and amino acids were responsible for the intergroup separation. There was 45% concordance between the brain and plasma metabolite profiles. Brain phosphocreatine correlated with brain glucose (control group: R 2 =0.86; hypoglycemia group: R 2 =0.59; pplasma glucose. The results confirm that plasma glucose is an insensitive biomarker of cerebral energy changes during hypoglycemia and suggest that a plasma metabolite profile is superior for monitoring cerebral metabolism. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Temporal follow-up of plasma parameter in an nuclear grade aluminum laser induced plasma at different laser energies by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Karki, Vijay; Singh, Manjeet; Sarkar, Arnab

    2015-07-01

    We report spectroscopic studies of laser induced plasma (LIP) produced by ns – 532 nm - Nd:YAG laser light pulses for different laser energies (35, 45 and 60 mJ) on an nuclear grade aluminum sample in air at atmospheric pressure. The temporal history of the plasma is obtained by recording the emission features at predetermined delays and at a fixed gate width (2.5 ì s). The temporal profiles of excitation temperature (T e ), ionization temperature (T ion ) and electron number density (N e ) were determined from Boltzmann plot, Saha-Boltzmann equation and Stark broadening method, respectively. T e , T ion and N e , shows a power law decay pattern with increasing acquisition time delay. T e has a positive correlation with laser energy, but the T ion and N e differ negligibly from one laser energy to another. Again the rate of decay of T e increases with increasing laser energy but that of T ion is much slower and independent of laser energy. The follow up of the local thermodynamic equilibrium (LTE) conditions were evaluated using both McWhirter criterion and T e /T ion ratio for different delays and different energies to determine the temporal range in which LTE is satisfied. Both the methods concluded very similar results except for very high energy and small delay conditions, where T e /T ion ratio deviates from unity indicating non-LTE condition. The relative transition probabilities of Al transition (3sp4s: 4 P 2/5 →3sp 2 : 4P 3/2,5/2 ) and (4s: 2 S 1/2 → 3p: 2 P 1/2,3/2 ) were estimated and are in excellent agreement with the Kurucz database. These investigations provide an insight to optimize various parameters during LIBS analysis of aluminum based matrices. (author)

  12. Non equilibrium atomic processes and plasma spectroscopy

    International Nuclear Information System (INIS)

    Kato, Takako

    2003-01-01

    Along with the technical progress in plasma spectroscopy, non equilibrium ionization processes have been recently observed. We study non local thermodynamic equilibrium and non ionization equilibrium for various kinds of plasmas. Specifically we discuss non equilibrium atomic processes in magnetically confined plasmas, solar flares and laser produced plasmas using a collisional radiative model based on plasma spectroscopic data. (author)

  13. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, J. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic)], E-mail: kaiser@fme.vutbr.cz; Galiova, M.; Novotny, K.; Cervenka, R. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Reale, L. [Faculty of Sciences, University of L' Aquila, Via Vetoio (Coppito 1), 67010 L' Aquila (Italy); Novotny, J.; Liska, M.; Samek, O. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Kanicky, V.; Hrdlicka, A. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Stejskal, K.; Adam, V.; Kizek, R. [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, 613 00 Brno (Czech Republic)

    2009-01-15

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 {mu}m in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  14. Zinc, lead and copper in human teeth measured by induced coupled argon plasma atomic emission spectroscopy (ICP-AES)

    Energy Technology Data Exchange (ETDEWEB)

    Chew, L.T.; Bradley, D.A. E-mail: D.A.Bradley@exeter.ac.uk; Mohd, Y.; Jamil, M

    2000-11-15

    Inductively Coupled Argon Plasma Atomic Emission Spectroscopy (ICP-AES) has been used to determine Pb, Zn and Cu levels in 47 exfoliated human teeth (all of which required extraction for orthodontic reasons). Lead concentrations for the group were 1.7 {mu}g (g tooth mass){sup -1} to 40.5 {mu}g (g tooth mass){sup -1}, with a median of 9.8 {mu}g (g tooth mass){sup -1}. A median lead level in excess of the group value was found for the teeth of six lorry drivers who were included in the study. A more significant enhancement was found for the seven subjects whose age was in excess of 60 years. The median values for Zn and Cu were 123.0 and 0.6 {mu}g (g tooth mass){sup -1} respectively. Present values for tooth-Zn are lower than published data for other ethnic groups.

  15. Modeling of low-temperature plasmas generated using laser-induced breakdown spectroscopy: the ChemCam diagnostic tool on the Mars Science Laboratory Rover

    Science.gov (United States)

    Colgan, James

    2016-05-01

    We report on efforts to model the low-temperature plasmas generated using laser-induced breakdown spectroscopy (LIBS). LIBS is a minimally invasive technique that can quickly and efficiently determine the elemental composition of a target and is employed in an extremely wide range of applications due to its ease of use and fast turnaround. In particular, LIBS is the diagnostic tool used by the ChemCam instrument on the Mars Science Laboratory rover Curiosity. In this talk, we report on the use of the Los Alamos plasma modeling code ATOMIC to simulate LIBS plasmas, which are typically at temperatures of order 1 eV and electron densities of order 10 16 - 17 cm-3. At such conditions, these plasmas are usually in local-thermodynamic equilibrium (LTE) and normally contain neutral and singly ionized species only, which then requires that modeling must use accurate atomic structure data for the element under investigation. Since LIBS devices are often employed in a very wide range of applications, it is therefore desirable to have accurate data for most of the elements in the periodic table, ideally including actinides. Here, we discuss some recent applications of our modeling using ATOMIC that have explored the plasma physics aspects of LIBS generated plasmas, and in particular discuss the modeling of a plasma formed from a basalt sample used as a ChemCam standard1. We also highlight some of the more general atomic physics challenges that are encountered when attempting to model low-temperature plasmas. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396. Work performed in conjunction with D. P. Kilcrease, H. M. Johns, E. J. Judge, J. E. Barefield, R. C. Wiens, S. M. Clegg.

  16. Calibration-free quantitative elemental analysis of meteor plasma using reference laser-induced breakdown spectroscopy of meteorite samples

    Science.gov (United States)

    Ferus, Martin; Koukal, Jakub; Lenža, Libor; Srba, Jiří; Kubelík, Petr; Laitl, Vojtěch; Zanozina, Ekaterina M.; Váňa, Pavel; Kaiserová, Tereza; Knížek, Antonín; Rimmer, Paul; Chatzitheodoridis, Elias; Civiš, Svatopluk

    2018-03-01

    Aims: We aim to analyse real-time Perseid and Leonid meteor spectra using a novel calibration-free (CF) method, which is usually applied in the laboratory for laser-induced breakdown spectroscopic (LIBS) chemical analysis. Methods: Reference laser ablation spectra of specimens of chondritic meteorites were measured in situ simultaneously with a high-resolution laboratory echelle spectrograph and a spectral camera for meteor observation. Laboratory data were subsequently evaluated via the CF method and compared with real meteor emission spectra. Additionally, spectral features related to airglow plasma were compared with the spectra of laser-induced breakdown and electric discharge in the air. Results: We show that this method can be applied in the evaluation of meteor spectral data observed in real time. Specifically, CF analysis can be used to determine the chemical composition of meteor plasma, which, in the case of the Perseid and Leonid meteors analysed in this study, corresponds to that of the C-group of chondrites.

  17. Investigation of excited states populations density of Hall thruster plasma in three dimensions by laser-induced fluorescence spectroscopy

    Science.gov (United States)

    Krivoruchko, D. D.; Skrylev, A. V.

    2018-01-01

    The article deals with investigation of the excited states populations distribution of a low-temperature xenon plasma in the thruster with closed electron drift at 300 W operating conditions were investigated by laser-induced fluorescence (LIF) over the 350-1100 nm range. Seven xenon ions (Xe II) transitions were analyzed, while for neutral atoms (Xe I) just three transitions were explored, since the majority of Xe I emission falls into the ultraviolet or infrared part of the spectrum and are difficult to measure. The necessary spontaneous emission probabilities (Einstein coefficients) were calculated. Measurements of the excited state distribution were made for points (volume of about 12 mm3) all over the plane perpendicular to thruster axis in four positions on it (5, 10, 50 and 100 mm). Measured LIF signal intensity have differences for each location of researched point (due to anisotropy of thruster plume), however the structure of states populations distribution persisted at plume and is violated at the thruster exit plane and cathode area. Measured distributions show that for describing plasma of Hall thruster one needs to use a multilevel kinetic model, classic model can be used just for far plume region or for specific electron transitions.

  18. Efficient plasma and bubble generation underwater by an optimized laser excitation and its application for liquid analyses by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Lazic, Violeta; Jovicevic, Sonja; Fantoni, Roberta; Colao, Francesco

    2007-01-01

    Laser-induced breakdown spectroscopy (LIBS) measurements were performed on bulk water solutions by applying a double-pulse excitation from a Q-Switched (QS) Nd:YAG laser emitting at 1064 nm. In order to optimize the LIBS signal, laser pulse energies were varied through changing of the QS trigger delays with respect to the flash-lamp trigger. We had noted that reduction of the first pulse energy from 92 mJ to 72 mJ drastically improves the signal, although the second pulse energy was also lowered from 214 mJ to 144 mJ. With lower pulse energies, limit of detection (LOD) for Mg in pure water was reduced for one order of magnitude (34 ppb instead of 210 ppb). In order to explain such a phenomenon, we studied the dynamics of the gas bubble generated after the first laser pulse through measurements of the HeNe laser light scattered on the bubble. The influence of laser energy on underwater bubble and plasma formation and corresponding plasma emission intensity were also studied by photographic technique. From the results obtained, we conclude that the optimal first pulse energy should be kept close to the plasma elongation threshold, in our case about 65 mJ, where the gas bubble has its maximum lateral expansion and the secondary plasma is still well-localized. The importance of a multi-pulse sequence on the LIBS signal was also analyzed, where the pulse sequence after the first QS aperture was produced by operating the laser close to the lasing threshold, with the consequent generation of relaxation oscillations. Low-energy multi-pulses might keep the bubble expansion large prior to the probing pulse, but preventing the formation of secondary weak plasmas in multiple sites, which reduces the LIBS signal. The short interval between the pre-pulses and the probing pulse is another reason for the observed LIBS signal enhancement

  19. New ways for the quantification by the laser-induced plasma spectroscopy; Neue Wege zur Quantifizierung mit der laserinduzierten Plasmaspektroskopie (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Maike

    2010-04-27

    Laser Induced Breakdown Spectroscopy (LIBS) is capable of a fast and multielement analysis of various samples types and matrices which makes the method particularly attractive for industrial process analysis. However, for LIBS to become well accepted as an analytical method some issues in calibration and understanding of the underlying transient plasma processes have to be solved. The objective of this work was to identify influential instrumental parameters and plasma conditions in order to improve the overall quantitative performance of LIBS. As the spectral sensitivity and signal-to-noise ratio of the detector represents a decisive element for the application of LIBS in an industrial environment, two detectors, an ICCD and CCD camera, were compared. In combination with a high-resolution echelle spectrograph, the superior or at least equivalent efficiency of the non-intensified CCD was experimentally demonstrated and supported by corresponding plasma simulations. Further investigations of the plasma expansion under different atmospheric conditions revealed that the geometry of observing the expanding plasma influences the sensitivity and reproducibility of the measurements considerably. The diagnostics of self-absorbed spectral lines and their use for calibration purposes were studied with a mirror-based duplication method and a statistical line shape analysis employing linear correlation. The linear correlation approach displayed good performance for identifying the on-set of self absorption in comparison to the duplication method. As matrixmatched reference materials are essential to validate laser ablation methods, two novel preparations of individual calibration standards based on a copper-and polyacrylamide matrix were tested for their applicability to LIBS. (orig.)

  20. Laser-induced breakdown spectroscopy for the analysis of plasma facing components of tokamaks: parametric study and calibration-free measurements

    International Nuclear Information System (INIS)

    Mercadier, L.

    2011-09-01

    During the operation of a nuclear fusion device like the future reactor ITER, a fraction of tritium is trapped in the plasma facing components and has to be measured in order to fulfill nuclear safety requirements. Laser-induced breakdown spectroscopy (LIBS) is proposed to achieve this measurement. The laser plasma produced on carbon fibre composite tiles from the Tore Supra reactor is analyzed via a parametric study: it has to have a temperature over 10000 K and an electron density over 10 17 cm -3 to optimize the application. A calibration-free procedure that takes into account self-absorption is proposed to determine the relative concentration of hydrogen from the experimental spectra. The time- and space-resolved spectral emission of the plasma plume is investigated and reveals the presence of a temperature gradient from the core towards the periphery. This gradient is taken into account and the H/C concentration ratio is deduced. The accuracy of the results is evaluated and discussed. The study of the D/H isotopic ratio under low pressure argon reveals the presence of plume segregation that leads to an error of about 50%, error that can partially be reduced. Tungsten materials are investigated and difficulties related to spectroscopic databases are discussed. Finally, the feasibility of LIBS analysis with depth resolution is validated for multilayered metallic samples. (author)

  1. Characteristics of laser-induced plasma under reduced background pressure with Doppler spectroscopy of excited atomic species near the shockwave front

    Science.gov (United States)

    Dojić, Dejan; Skočić, Miloš; Bukvić, Srdjan

    2018-03-01

    We present measurements of Laser Induced Plasma expansion relying on classical, laterally resolved spectroscopy. Easy observable Doppler splitting of Cu I 324.75 nm spectral line provides measurement of radial expansion velocity in a straightforward way. The measurements are conducted in atmosphere of air, argon and hydrogen at low pressure in the range 20-200 Pa. We found that expansion velocity is linearly decreasing if pressure of surrounding gas increases, with velocity/pressure slope nearly the same for all three gases. Copper atoms have the highest expansion speed in argon ( ∼ 50 km/s) and the smallest speed in air ( ∼ 42 km/s). It is found that expansion velocity increases linearly with irradiance, while intensity of the spectral line is quite insensitive to the laser irradiance.

  2. Fiber-optic laser-induced breakdown spectroscopy of zirconium metal in air: Special features of the plasma produced by a long-pulse laser

    Science.gov (United States)

    Matsumoto, Ayumu; Ohba, Hironori; Toshimitsu, Masaaki; Akaoka, Katsuaki; Ruas, Alexandre; Sakka, Tetsuo; Wakaida, Ikuo

    2018-04-01

    The decommissioning of the Tokyo Electric Power Company (TEPCO) Fukushima Daiichi Nuclear Power Plant is an essential issue in nuclear R&D. Fiber-optic laser-induced breakdown spectroscopy (Fiber-optic LIBS) could be used for in-situ elemental analysis of the inside of the damaged reactors. To improve the performances under difficult conditions, using a long-pulse laser can be an efficient alternative. In this work, the emission spectra of zirconium metal in air obtained for a normal-pulse laser (6 ns) and a long-pulse laser (100 ns) (wavelength: 1064 nm, pulse energy: 12.5 mJ, spot diameter: 0.35 mm) are compared to investigate the fundamental aspects of fiber-optic LIBS with the long-pulse laser. The spectral features are considerably different: when the long-pulse laser is used, the atomic and molecular emission is remarkably enhanced. The enhancement of the atomic emission at the near infrared (NIR) region would lead to the observation of emission lines with minimum overlapping. To understand the differences in the spectra induced respectively from the normal-pulse laser and the long-pulse laser, photodiode signals, time-resolved spectra, plasma parameters, emission from the ambient air, and emission regions are investigated, showing the particular characteristics of the plasma produced by the long-pulse laser.

  3. Laser-induced breakdown spectroscopy and inductively coupled plasma-mass spectrometry for determination of Cr in soils from Brits District, South Africa

    Directory of Open Access Journals (Sweden)

    A. A. Ambushe

    2015-10-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS is an emerging analytical technique, which can be used to perform elemental analysis of any material, irrespective of its physical state. In this study, the LIBS technique has been applied for quantification of total Cr in soil samples collected from polluted areas of Brits, North West Province, South Africa. A Q-switched neodymium-yttrium aluminium garnet (Nd-YAG laser (10 Hz, λ = 1064 nm was employed for generation of a laser-induced plasma on the surface of the soil sample. The atomic emission lines were recorded using an Andor Shamrock SR-303i spectrometer, fitted with an intensified charge-coupled device (ICCD camera. Detailed investigation of experimental parameters such as gate delay time, gate width and laser pulse energy was conducted. Soil samples were dried, finely ground, sieved and thereafter pelletized before LIBS analysis. Calibration curve for the quantification of Cr was constructed using certified reference materials of soils and sediments. The concentrations of Cr in soil samples varied from 111 to 3180 mg/kg. In order to test the validity of the LIBS results, inductively coupled plasma-mass spectrometry (ICP-MS was also employed for determination of Cr. The results obtained using LIBS were found to be in good agreement with those of ICP-MS.DOI: http://dx.doi.org/10.4314/bcse.v29i3.3

  4. Kinetics and spectroscopy of low temperature plasmas

    CERN Document Server

    Loureiro, Jorge

    2016-01-01

    This is a comprehensive textbook designed for graduate and advanced undergraduate students. Both authors rely on more than 20 years of teaching experience in renowned Physics Engineering courses to write this book addressing the students’ needs. Kinetics and Spectroscopy of Low Temperature Plasmas derives in a full self-consistent way the electron kinetic theory used to describe low temperature plasmas created in the laboratory with an electrical discharge, and presents the main optical spectroscopic diagnostics used to characterize such plasmas. The chapters with the theoretical contents make use of a deductive approach in which the electron kinetic theory applied to plasmas with basis on the electron Boltzmann equation is derived from the basic concepts of Statistical and Plasma Physics. On the other hand, the main optical spectroscopy diagnostics used to characterize experimentally such plasmas are presented and justified from the point of view of the Atomic and Molecular Physics. Low temperature plasmas...

  5. Proceedings of the Japan-US workshop on plasma polarization spectroscopy and the international seminar on plasma polarization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Takashi; Beiersdorfer, Peter [eds.

    1998-06-01

    The international meeting on Plasma Polarization Spectroscopy (PPS) was held in Kyoto during January 26-28, 1998. This Proceedings book includes the papers of the talks given at the meeting. These include: overviews of PPS from the aspects of atomic physics, and of plasma physics; several PPS and MSE (motional Stark effect) experiments on magnetically confined plasmas and a laser-produced plasma; polarized laser-induced fluorescence spectroscopy, several experiments on EBITs (electron beam ion trap) and their theoretical interpretations; polarized profiles of spectral lines, basic formulation of PPS; inelastic and elastic electron collisions leading to polarized atomic states; polarization in recombining plasma; relationship between the collisional polarization relaxation and the line broadening; and characteristics of the plasma produced by very short pulse and high power laser irradiation. The 19 of the presented papers are indexed individually. (J.P.N.)

  6. Qualitative and quantitative spectro-chemical analysis of dates using UV-pulsed laser induced breakdown spectroscopy and inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Mehder, A O; Habibullah, Y B; Gondal, M A; Baig, Umair

    2016-08-01

    Laser Induced Breakdown Spectroscopy (LIBS) is demonstrated for the spectral analysis of nutritional and toxic elements present in several varieties of date fruit samples available in the Saudi Arabia market. The method analyzes the optical emission of a test sample when subjected to pulsed laser ablation. In this demonstration, our primary focus is on calcium (Ca) and magnesium (Mg), as nutritional elements, and on chromium (Cr), as a toxic element. The local thermodynamic equilibrium (LTE) condition was confirmed prior to the elemental characterization of date samples to ensure accuracy of the LIBS analysis. This was achieved by measuring parameters associated with the plasma, such as the electron temperature and the electron number density. These plasma parameters aid interpretation of processes such as ionization, dissociation, and excitation occurring in the plasma plume formed by ablating the date palm sample. The minimum detection limit was established from calibration curves that involved plotting the LIBS signal intensity as a function of standard date samples with known concentrations. The concentration of Ca and Mg detected in different varieties of date samples was between 187 and 515 and 35-196mgL(-1) respectively, while Cr concentration measured between 1.72 and 7.76mgL(-1). In order to optimize our LIBS system, we have studied how the LIBS signal intensity depends on the incident laser energy and the delay time. In order to validate our LIBS analysis results, standard techniques such as inductively coupled plasma mass spectrometry (ICP-MS) were also applied on an identical (duplicate) date samples as those used for the LIBS analysis. The LIBS results exhibit remarkable agreement with those obtained from the ICP-MS analysis. In addition, the finger print wavelengths of other elements present in date samples were also identified and are reported here, which has not been previously reported, to the best of our knowledge. Copyright © 2016 Elsevier B

  7. Direct measurements of sample heating by a laser-induced air plasma in pre-ablation spark dual-pulse laser-induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Register, Janna; Scaffidi, Jonathan; Angel, S Michael

    2012-08-01

    Direct measurements of temperature changes were made using small thermocouples (TC), placed near a laser-induced air plasma. Temperature changes up to ~500 °C were observed. From the measured temperature changes, estimates were made of the amount of heat absorbed per unit area. This allowed calculations to be made of the surface temperature, as a function of time, of a sample heated by the air plasma that is generated during orthogonal pre-ablation spark dual-pulse (DP) LIBS measurements. In separate experiments, single-pulse (SP) LIBS emission and sample ablation rate measurements were performed on nickel at sample temperatures ranging from room temperature to the maximum surface temperature that was calculated using the TC measurement results (500 °C). A small, but real sample temperature-dependent increase in both SP LIBS emission and the rate of sample ablation was found for nickel samples heated up to 500 °C. Comparison of DP LIBS emission enhancement values for bulk nickel samples at room temperature versus the enhanced SP LIBS emission and sample ablation rates observed as a function of increasing sample temperature suggests that sample heating by the laser-induced air plasma plays only a minor role in DP LIBS emission enhancement.

  8. Temperature measurement of plasma-assisted flames: comparison between optical emission spectroscopy and 2-color laser induced fluorescence techniques

    KAUST Repository

    Lacoste, Deanna A.

    2015-03-30

    Accurate thermometry of highly reactive environments, such as plasma-assisted combustion, is challenging. With the help of conical laminar premixed methane-air flames, this study compares two thermometry techniques for the temperature determination in a combustion front enhanced by nanosecond repetitively pulsed (NRP) plasma discharges. Based on emission spectroscopic analysis, the results show that the rotational temperature of CH(A) gives a reasonable estimate for the adiabatic flame temperature, only for lean and stoichiometric conditions. The rotational temperature of N2(C) is found to significantly underestimate the flame temperature. The 2-color OH-PLIF technique gives correct values of the flame temperature.

  9. Temperature measurement of plasma-assisted flames: comparison between optical emission spectroscopy and 2-color laser induced fluorescence techniques

    KAUST Repository

    Lacoste, Deanna A.; Heitz, Sylvain A.; Moeck, Jonas P.

    2015-01-01

    Accurate thermometry of highly reactive environments, such as plasma-assisted combustion, is challenging. With the help of conical laminar premixed methane-air flames, this study compares two thermometry techniques for the temperature determination in a combustion front enhanced by nanosecond repetitively pulsed (NRP) plasma discharges. Based on emission spectroscopic analysis, the results show that the rotational temperature of CH(A) gives a reasonable estimate for the adiabatic flame temperature, only for lean and stoichiometric conditions. The rotational temperature of N2(C) is found to significantly underestimate the flame temperature. The 2-color OH-PLIF technique gives correct values of the flame temperature.

  10. Feasibility of generating a useful laser-induced breakdown spectroscopy plasma on rocks at high pressure: preliminary study for a Venus mission

    International Nuclear Information System (INIS)

    Arp, Zane A.; Cremers, David A.; Harris, Ronny D.; Oschwald, David M.; Parker, Gary R.; Wayne, David M.

    2004-01-01

    Laser-induced breakdown spectroscopy (LIBS) is being developed for future use on landers and rovers to Mars. The method also has potential for use on probes to other planets, the Moon, asteroids and comets. Like Mars, Venus is of strong interest because of its proximity to earth, but unlike Mars, conditions at the surface are far more hostile with temperatures in excess of 700 K and pressures on the order of 9.1 MPa (90 atm). These conditions present a significant challenge to spacecraft design and demand that rapid methods of chemical data gathering be implemented. The advantages of LIBS (e.g. stand-off and very rapid analysis) make the method particularly attractive for Venus exploration because of the expected short operational lifetimes (∼2 h) of surface instrumentation. Although the high temperature of Venus should pose no problem to the analytical capabilities of the LIBS spark, the demonstrated strong dependence of laser plasma characteristics on ambient gas pressures below earth atmospheric pressure requires that LIBS measurements be evaluated at the high Venus surface pressures. Here, we present a preliminary investigation of LIBS at 9.1 MPa for application to the analysis of a basalt rock sample. The results suggest the feasibility of the method for a Venus surface probe and that further study is justified

  11. Feasibility of generating a useful laser-induced breakdown spectroscopy plasma on rocks at high pressure: preliminary study for a Venus mission

    Energy Technology Data Exchange (ETDEWEB)

    Arp, Zane A.; Cremers, David A. E-mail: cremers_david@lanl.gov; Harris, Ronny D.; Oschwald, David M.; Parker, Gary R.; Wayne, David M

    2004-07-30

    Laser-induced breakdown spectroscopy (LIBS) is being developed for future use on landers and rovers to Mars. The method also has potential for use on probes to other planets, the Moon, asteroids and comets. Like Mars, Venus is of strong interest because of its proximity to earth, but unlike Mars, conditions at the surface are far more hostile with temperatures in excess of 700 K and pressures on the order of 9.1 MPa (90 atm). These conditions present a significant challenge to spacecraft design and demand that rapid methods of chemical data gathering be implemented. The advantages of LIBS (e.g. stand-off and very rapid analysis) make the method particularly attractive for Venus exploration because of the expected short operational lifetimes ({approx}2 h) of surface instrumentation. Although the high temperature of Venus should pose no problem to the analytical capabilities of the LIBS spark, the demonstrated strong dependence of laser plasma characteristics on ambient gas pressures below earth atmospheric pressure requires that LIBS measurements be evaluated at the high Venus surface pressures. Here, we present a preliminary investigation of LIBS at 9.1 MPa for application to the analysis of a basalt rock sample. The results suggest the feasibility of the method for a Venus surface probe and that further study is justified.

  12. Workshop on Models for Plasma Spectroscopy

    Science.gov (United States)

    1993-09-01

    A meeting was held at St. Johns College, Oxford from Monday 27th to Thursday 30th of September 1993 to bring together a group of physicists working on computational modelling of plasma spectroscopy. The group came from the UK, France, Israel and the USA. The meeting was organized by myself, Dr. Steven Rose of RAL and Dr. R.W. Lee of LLNL. It was funded by the U.S. European Office of Aerospace Research and Development and by LLNL. The meeting grew out of a wish by a group of core participants to make available to practicing plasma physicists (particularly those engaged in the design and analysis of experiments) sophisticated numerical models of plasma physics. Additional plasma physicists attended the meeting in Oxford by invitation. These were experimentalists and users of plasma physics simulation codes whose input to the meeting was to advise the core group as to what was really needed.

  13. Calibration-free quantitative elemental analysis of meteor plasma using reference laser-induced breakdown spectroscopy of meteorite samples

    Czech Academy of Sciences Publication Activity Database

    Ferus, Martin; Koukal, J.; Lenža, Libor; Srba, J.; Kubelík, Petr; Laitl, V.; Zanozina, Ekaterina M.; Váňa, Pavel; Kaiserová, Tereza; Knížek, Antonín; Rimmer, P.; Chatzitheodoridis, E.; Civiš, Svatopluk

    2017-01-01

    Roč. 2017, DEC 2017 (2017), č. článku 29950. E-ISSN 1432-0746 R&D Projects: GA ČR(CZ) GA14-12010S; GA ČR(CZ) GA18-27653S Grant - others:Akademie věd - GA AV ČR(CZ) R200401521; Akademie věd - GA AV ČR(CZ) R200401721; COST(XE) CM1104; COST(XE) TD1308; RFBR(RU) 16-32-00034 Institutional support: RVO:61388955 Keywords : astrochemistry * spectroscopic techniques * calibration-free LIBS * plasma simulation Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 5.014, year: 2016

  14. Ion induced Auger spectroscopy

    International Nuclear Information System (INIS)

    Thomas, E.W.; Legg, K.O.; Metz, W.A.

    1980-01-01

    Auger electron spectra are induced by impact of heavy ions (e.g. Ar + ) on surfaces; it has been suggested that analysis of such spectra would be a useful technique for surface analysis. We have examined the Auger spectra for various projectile-target combinations and present as representative data the spectra for 100 keV Ar + impact on Al, Cr, Mn, Fe and Co. For a projectile incident on a species of higher nuclear charge the spectrum is dominated by Auger lines from the projectile, broadened considerably by the Doppler effect due to the projectile's motion. The spectra are not characteristic of the target and therefore offer no opportunity for surface analysis. For a projectile incident on a target of lower nuclear charge the spectrum is that of the target species but the spectrum is consistent with the source being sputtered excited atoms; the Auger electrons do not come from the surface. We conclude that the ion induced Auger spectra are in general not a convenient method for surface analysis. (orig.)

  15. Investigation of local thermodynamic equilibrium of laser induced Al2O3–TiC plasma in argon by spatially resolved optical emission spectroscopy

    Directory of Open Access Journals (Sweden)

    K. Alnama

    2016-06-01

    Full Text Available Plasma plume of Al2O3–TiC is generated by third harmonic Q-switched Nd:YAG nanosecond laser. It is characterized using Optical Emission Spectroscopy (OES at different argon background gas pressures 10, 102, 103, 104 and 105 Pa. Spatial evolution of excitation and ionic temperatures is deduced from spectral data analysis. Temporal evolution of Ti I emission originated from different energy states is probed. The correlation between the temporal behavior and the spatial temperature evolution are investigated under LTE condition for the possibility to use the temporal profile of Ti I emission as an indicator for LTE validity in the plasma.

  16. Proceedings of the Japan-US workshop on plasma polarization spectroscopy and the fourth international symposium on plasma polarization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Takashi; Beiersdorfer, Peter [eds.

    2004-07-01

    The international meeting on Plasma Polarization Spectroscopy (PPS) was held at Kyoto University during February 4-6, 2004. This Proceedings book includes the summaries of the talks given in that meeting. Starting with the Overview talk by Csanak, the subjects cover: x-ray polarization experiments on z-pinches (plasma foci), and an x-pinch, a laser-produced plasma in a gas atmosphere, an interpretation of the polarized 1<- 0 x-ray laser line, polarization observation from various laser-produced plasmas including a recombining phase plasma, a report on the on-going project of a laser facility, several polarization observations on magnetically confined plasmas including the Large Helical Device and an ECR plasma, a new laser-induced fluorescence diagnostic method. On atomic physics side given are: various polarization measurements on EBIT, precision spectroscopy on the TEXTOR, user-friendly atomic codes. Instrumentation is also a subject of this book. The 18 of the presented papers are indexed individually. (J.P.N.)

  17. Plasma polarization spectroscopy. History and future prospects

    International Nuclear Information System (INIS)

    Fujimoto, Takashi

    2002-01-01

    An intuitive account is given of the polarized emission line of atoms and ions, both classically and quantum mechanically. Polarization is a result of the population imbalance among the magnetic sublevels, or of the alignment, in the upper level. The history of Plasma Polarization Spectroscopy (PPS) is reviewed. Various polarization phenomena are divided into three classes. For each of the classes, typical experiments undertaken so far are reviewed. The advantages, limitations, and challenges regarding PPS are discussed. (author)

  18. Plasmon-Induced Plasma Spectroscopy

    Science.gov (United States)

    2016-11-10

    is, no new vibrational bands are observed when MB is adsorbed on non- plasmonic surfaces (e.g. glass , platinum, aluminum and gold) and excited with...e.g., TeO2 that we have observed at ∼576.0 eV for samples exposed to air for longer times) are completely absent, and therefore none of the spectral...freshly prepared LB films for which signatures of TeO2 are absent in the XPS spectra. On the other hand, significant blue-shift and spectral broadening

  19. Spectroscopy of laser-produced plasmas

    Indian Academy of Sciences (India)

    It is a well-known fact that laser-induced breakdown spectroscopy (LIBS) has emerged as one of the best analytical techniques for multi-elemental compositional analysis of samples. We report assembling and optimization of LIBS set up using high resolution and broad-range echelle spectrograph coupled to an intensified ...

  20. Investigation on the role of air in the dynamical evolution and thermodynamic state of a laser-induced aluminium plasma by spatial- and time-resolved spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cristoforetti, G., E-mail: gabriele.cristoforetti@cnr.i [National Institute of Optics, Research Area of National Research Council, Via G.Moruzzi, 1 - 56124 Pisa (Italy); Lorenzetti, G.; Legnaioli, S.; Palleschi, V. [Institute of Chemistry of Organometallic Compounds, Research Area of National Research Council, Via G.Moruzzi, 1 - 56124 Pisa (Italy)

    2010-09-15

    The amount and the spatial distribution of air atoms and ions in a laser-induced plasma in ambient air provide important information about the formation of the plasma and its successive evolution history. For this reason, in the present work, the air mixing in a laser-induced plasma in air at atmospheric pressure and its influence on its thermodynamic evolution were studied. Information about spatial distributions of atoms and ions from Al, N and O were achieved by Abel-inverted spectra in the plume. The occurrence of LTE in the plume was also assessed by the utilization of theoretical criteria, and by the analysis of experimental spectra. Aluminium atoms and ions were found to be in LTE, while nitrogen and oxygen were not because of their longer times of relaxation toward equilibrium. Nitrogen was found to be over-ionized with respect to Saha-Eggert equilibrium, indicating that the plasma is recombining. Experimental observations suggest that the concentration of air species in the plasma is larger than that of aluminium, even in the region closer to the target, where the aluminium lines are stronger. In the front part of the plume only emission lines from air species were observed. The results suggest that a Laser-Supported Detonation (LSD) regime occurs during the trailing part of the laser pulse, resulting in the strong inclusion into the plasma of air elements. In this scenario, also the thermodynamic history of the plume is affected by the predominance of air species.

  1. Comparative study of Nd:YAG laser-induced breakdown spectroscopy and transversely excited atmospheric CO2 laser-induced gas plasma spectroscopy on chromated copper arsenate preservative-treated wood.

    Science.gov (United States)

    Khumaeni, Ali; Lie, Zener Sukra; Niki, Hideaki; Lee, Yong Inn; Kurihara, Kazuyoshi; Wakasugi, Motoomi; Takahashi, Touru; Kagawa, Kiichiro

    2012-03-01

    Taking advantage of the specific characteristics of a transversely excited atmospheric (TEA) CO(2) laser, a sophisticated technique for the analysis of chromated copper arsenate (CCA) in wood samples has been developed. In this study, a CCA-treated wood sample with a dimension of 20 mm × 20 mm and a thickness of 2 mm was attached in contact to a nickel plate (20 mm × 20 mm × 0.15 mm), which functions as a subtarget. When the TEA CO(2) laser was successively irradiated onto the wood surface, a hole with a diameter of approximately 2.5 mm was produced inside the sample and the laser beam was directly impinged onto the metal subtarget. Strong and stable gas plasma with a very large diameter of approximately 10 mm was induced once the laser beam had directly struck the metal subtarget. This gas plasma then interacted with the fine particles of the sample inside the hole and finally the particles were effectively dissociated and excited in the gas plasma region. By using this technique, high precision and sensitive analysis of CCA-treated wood sample was realized. A linear calibration curve of Cr was successfully made using the CCA-treated wood sample. The detection limits of Cr, Cu, and As were estimated to be approximately 1, 2, and 15 mg/kg, respectively. In the case of standard LIBS using the Nd:YAG laser, the analytical intensities fluctuate and the detection limit was much lower at approximately one-tenth that of TEA CO(2) laser. © 2012 Optical Society of America

  2. Filament-induced remote surface ablation for long range laser-induced breakdown spectroscopy operation

    International Nuclear Information System (INIS)

    Rohwetter, Ph.; Stelmaszczyk, K.; Woeste, L.; Ackermann, R.; Mejean, G.; Salmon, E.; Kasparian, J.; Yu, J.; Wolf, J.-P.

    2005-01-01

    We demonstrate laser induced ablation and plasma line emission from a metallic target at distances up to 180 m from the laser, using filaments (self-guided propagation structures ∼ 100 μm in diameter and ∼ 5 x 10 13 W/cm 2 in intensity) appearing as femtosecond and terawatt laser pulses propagating in air. The remarkable property of filaments to propagate over a long distance independently of the diffraction limit opens the frontier to long range operation of the laser-induced breakdown spectroscopy technique. We call this special configuration of remote laser-induced breakdown spectroscopy 'remote filament-induced breakdown spectroscopy'. Our results show main features of filament-induced ablation on the surface of a metallic sample and associated plasma emission. Our experimental data allow us to estimate requirements for the detection system needed for kilometer-range remote filament-induced breakdown spectroscopy experiment

  3. Micro-spectrochemical analysis of document paper and gel inks by laser ablation inductively coupled plasma mass spectrometry and laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Trejos, Tatiana, E-mail: trejost@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); International Forensic Research Institute (IFRI), Florida International University, Miami, FL 3319 (United States); Flores, Alejandra, E-mail: aflor017@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); Almirall, Jose R., E-mail: almirall@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199 (United States); International Forensic Research Institute (IFRI), Florida International University, Miami, FL 3319 (United States)

    2010-11-15

    Current methods used in document examinations are not suitable to associate or discriminate between sources of paper and gel inks with a high degree of certainty. Nearly non-destructive, laser-based methods using laser induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used to improve the forensic comparisons of gel inks, ballpoint inks and document papers based on similarities in elemental composition. Some of the advantages of these laser-based methods include minimum sample consumption/destruction, high sensitivity, high selectivity and excellent discrimination between samples from different origins. Figures of merit are reported including limits of detection, precision, homogeneity at a micro-scale and linear dynamic range. The variation of the elemental composition in paper was studied within a single sheet, between pages from the same ream, between papers produced by the same plant at different time intervals and between seventeen paper sources produced by ten different plants. The results show that elemental analysis of paper by LIBS and LA-ICP-MS provides excellent discrimination (> 98%) between different sources. Batches manufactured at weekly and monthly intervals in the same mill were also differentiated. The ink of more than 200 black pens was analyzed to determine the variation of the chemical composition of the ink within a single pen, between pens from the same package and between brands of gel inks and ballpoint inks. Homogeneity studies show smaller variation of elemental compositions within a single source than between different sources (i.e. brands and types). It was possible to discriminate between pen markings from different brands and between pen markings from the same brand but different model. Discrimination of {approx} 96-99% was achieved for sets that otherwise would remain inseparable by conventional methods. The results show that elemental analysis, using either LA

  4. Micro-spectrochemical analysis of document paper and gel inks by laser ablation inductively coupled plasma mass spectrometry and laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Trejos, Tatiana; Flores, Alejandra; Almirall, Jose R.

    2010-01-01

    Current methods used in document examinations are not suitable to associate or discriminate between sources of paper and gel inks with a high degree of certainty. Nearly non-destructive, laser-based methods using laser induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) were used to improve the forensic comparisons of gel inks, ballpoint inks and document papers based on similarities in elemental composition. Some of the advantages of these laser-based methods include minimum sample consumption/destruction, high sensitivity, high selectivity and excellent discrimination between samples from different origins. Figures of merit are reported including limits of detection, precision, homogeneity at a micro-scale and linear dynamic range. The variation of the elemental composition in paper was studied within a single sheet, between pages from the same ream, between papers produced by the same plant at different time intervals and between seventeen paper sources produced by ten different plants. The results show that elemental analysis of paper by LIBS and LA-ICP-MS provides excellent discrimination (> 98%) between different sources. Batches manufactured at weekly and monthly intervals in the same mill were also differentiated. The ink of more than 200 black pens was analyzed to determine the variation of the chemical composition of the ink within a single pen, between pens from the same package and between brands of gel inks and ballpoint inks. Homogeneity studies show smaller variation of elemental compositions within a single source than between different sources (i.e. brands and types). It was possible to discriminate between pen markings from different brands and between pen markings from the same brand but different model. Discrimination of ∼ 96-99% was achieved for sets that otherwise would remain inseparable by conventional methods. The results show that elemental analysis, using either LA-ICP-MS or

  5. Atomic processes relevant to polarization plasma spectroscopy

    International Nuclear Information System (INIS)

    Fujimoto, T.; Koike, F.; Sakimoto, K.; Okasaka, R.; Kawasaki, K.; Takiyama, K.; Oda, T.; Kato, T.

    1992-04-01

    When atoms (ions) are excited anisotropically, polarized excited atoms are produced and the radiation emitted by these atoms is polarized. From the standpoint of plasma spectroscopy research, we review the existing data for various atomic processes that are related to the polarization phenomena. These processes are: electron impact excitation, excitation by atomic and ionic collisions, photoexcitation, radiative recombination and bremsstrahlung. Collisional and radiative relaxation processes of atomic polarization follow. Other topics included are: electric-field measurement, self alignment, Lyman doublet intensity ratio, and magnetic-field measurement of the solar prominence. (author)

  6. Multichannel euv spectroscopy of high temperature plasmas

    International Nuclear Information System (INIS)

    Fonck, R.J.

    1983-11-01

    Spectroscopy of magnetically confined high temperature plasmas in the visible through x-ray spectral ranges deals primarily with the study of impurity line radiation or continuum radiation. Detailed knowledge of absolute intensities, temporal behavior, and spatial distributions of the emitted radiation is desired. As tokamak facilities become more complex, larger, and less accessible, there has been an increased emphasis on developing new instrumentation to provide such information in a minimum number of discharges. The availability of spatially-imaging detectors for use in the vacuum ultraviolet region (especially the intensified photodiode array) has generated the development of a variety of multichannel spectrometers for applications on tokamak facilities

  7. Plasma polarization spectroscopy. Time resolved spectroscopy in soft x-ray region on recombining plasma

    International Nuclear Information System (INIS)

    Iwamae, Atsushi; Hasuo, Masahiro; Atake, Makoto; Hasegawa, Noboru; Kawachi, Tetsuya

    2007-01-01

    We present an experimental study of polarization of emission radiations from recombining plasmas generated by the interaction of 60 fs ultra-short laser pulses with a gas jet. Time-resolved spectroscopy with a temporal resolution of 5 ps with repetitive accumulation is used to follow the recombination time histories. (author)

  8. Laser induced breakdown spectroscopy in water | Boudjemai ...

    African Journals Online (AJOL)

    Sparks were generated in water by the focused beam of a Q-switched Nd:YAG laser Na and Cu aqueous solutions exhibited fluorescence signal on the decaying edge of plasma emission at their respective characteristic resonance lines. Potential of the laser plasma spectroscopy for in-situ pollution monitoring in natural ...

  9. X-ray spectroscopy from fusion plasmas

    International Nuclear Information System (INIS)

    Glenzer, S H.

    1998-01-01

    Our understanding of laser energy coupling into laser-driven inertial confinement fusion targets largely depends on our ability to accurately measure and simulate the plasma conditions in the underdense corona and in high density capsule implosions. X-ray spectroscopy is an important technique which has been applied to measure the total absorption of laser energy into the fusion target, the fraction of laser energy absorbed by hot electrons, and the conditions in the fusion capsule in terms of density and temperature. These parameters provide critical benchmarking data for performance studies of the fusion target and for radiation-hydrodynamic and laser-plasma interaction simulations. Using x-ray spectroscopic techniques for these tasks has required its application to non-standard conditions where kinetics models have not been extensively tested. In particular, for the conditions in high density implosions, where electron temperatures achieve 1 - 2 keV and electron densities reach 10 24 cm -3 evolving on time scales of 21 cm -3 and which am independently diagnosed with Thomson scattering and stimulated Raman scattering. We find that kinetics modeling is in good agreement with measured intensities of the dielectronic satellites of the He-β line (n= l-3) of Ar XVII. Applying these findings to the experimental results of capsule implosions provides additional evidence of temperature gradients at peak compression

  10. Development of microwave-enhanced spark-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Ikeda, Yuji; Moon, Ahsa; Kaneko, Masashi

    2010-01-01

    We propose microwave-enhanced spark-induced breakdown spectroscopy with the same measurement and analysis processes as in laser-induced breakdown spectroscopy, but with a different plasma generation mechanism. The size and lifetime of the plasma generated can contribute to increased measurement accuracy and expand its applicability to industrial measurement, such as an exhaust gas analyzer for automobile engine development and its regulation, which has been hard to operate by laser at an engineering evaluation site. The use of microwaves in this application helps lower the cost, reduce the system size, and increase the ease of operation to make it commercially viable. A microwave frequency of 2.45 GHz was used to enhance the volume and lifetime of the plasma at atmospheric condition even at elevated pressure.

  11. Light-induced ion-acoustic instability of rarefied plasma

    International Nuclear Information System (INIS)

    Krasnov, I.V.; Sizykh, D.V.

    1987-01-01

    A new method of ion-acoustic instability excitation under the effect of coherent light, resonance to ion quantum transitions on collisionless plasma, is suggested. The light-induced ion-acoustic instability (LIIAI) considered is based on the induced progressive nonequilibrium resonance particles in the field of travelling electromagnetic wave. Principal possibility to use LIIAI in high-resolution spectroscopy and in applied problems of plasma physics, related to its instability, is pointed out

  12. Measurement of OH free radical in magnetized sheet plasma crossed with vertical gas-flow by laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Tonegawa, Akira; Takatori, Masahiko; Kobayashi, Yukihiro; Kawamura, Kazutaka; Takayama, Kazuo

    1997-01-01

    We demonstrated the production of OH free radicals in an argon magnetized sheet plasma crossed with vertical gas-flow mixed with an oxygen gas O 2 and a hydrogen gas H 2 . The density and the rotational-vibrational temperature of the OH free radicals were measured by a laser-induced fluorescence (LIF). The density of OH free radicals increases with increasing O 2 gas-flow, while the high energy part of the electron-energy-distribution-function f e (E) above 8 eV decreases. These results suggest the high energy part of f e (E) is contributed to the dissociation of O 2 and the production of OH free radicals. (author)

  13. 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.)

  14. Features of laser spectroscopy and diagnostics of plasma ions in high magnetic fields

    International Nuclear Information System (INIS)

    Semerok, A F; Fomichev, S V

    2003-01-01

    Laser induced fluorescence and laser absorption spectroscopies of plasma ions in high magnetic fields have been investigated. Both the high degree of Zeeman splitting of the resonant transitions and the ion rotational movement drastically change the properties of the resonance interaction of the continuous wave laser radiation with ions in highly magnetized plasma. Numerical solution of the density matrix equation for a dissipative two-level system with time-dependent detuning from resonance was used to analyse this interaction. A theoretical simulation was performed and compared with the experimental results obtained from the laser spectroscopy diagnostics of barium plasma ions in high magnetic fields in the several tesla range

  15. Laser-Induced Breakdown Spectroscopy Infrared Emission From Inorganic and Organic Substances

    National Research Council Canada - National Science Library

    Yang, C.S; Brown, E; Hommerich, U; Trivedi, S. B; Snyder, A. P; Samuels, A. C

    2006-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been established as a powerful method for identifying trace elemental contaminants by analyzing the atomic spectral emission lines that result subsequent to plasmas generated by laser power...

  16. Plasma generation induced by triboelectrification

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Michelsen, Poul

    2009-01-01

    A gas discharge plasma can be induced by triboelectrification around a sliding contact. The detailed physical mechanism of triboelectrification is unknown, but an empirical classification scheme can be referred to in practice. It is reported that intense ultra-violet emission from a plasma...... is observed adjacent to the sliding contact, of which the location has a gap ranging from approximately 1 μm to 11 μm. When the gap is short enough, a theory predicts that the breakdown voltage can monotonically decrease with a decrease in the gap. However, when the gap is comparable to electron’s mean free...

  17. Emission spectroscopy on a supersonically expanding argon/silane plasma

    NARCIS (Netherlands)

    Meeusen, G.J.; Ershov-Pavlov, E.A.; Meulenbroeks, R.F.G.; Sanden, van de M.C.M.; Schram, D.C.

    1992-01-01

    Results from emission spectroscopy measurements on an Ar/SiH/sub 4/ plasma jet which is used for fast deposition of amorphous hydrogenated silicon are presented. The jet is produced by allowing a thermal cascaded arc plasma in argon (I=60 A, V=80 V, Ar flow=60 scc/s and pressure 4*10/sup 4/ Pa) to

  18. Laser-induced breakdown spectroscopy fundamentals and applications

    CERN Document Server

    Noll, Reinhard

    2012-01-01

    This book is a comprehensive source of the fundamentals, process parameters, instrumental components and applications of laser-induced breakdown spectroscopy (LIBS). The effect of multiple pulses on material ablation, plasma dynamics and plasma emission is presented. A heuristic plasma modeling allows to simulate complex experimental plasma spectra. These methods and findings form the basis for a variety of applications to perform quantitative multi-element analysis with LIBS. These application potentials of LIBS have really boosted in the last years ranging from bulk analysis of metallic alloys and non-conducting materials, via spatially resolved analysis and depth profiling covering measuring objects in all physical states: gaseous, liquid and solid. Dedicated chapters present LIBS investigations for these tasks with special emphasis on the methodical and instrumental concepts as well as the optimization strategies for a quantitative analysis. Requirements, concepts, design and characteristic features of LI...

  19. Artificial neural networks for plasma spectroscopy analysis

    International Nuclear Information System (INIS)

    Morgan, W.L.; Larsen, J.T.; Goldstein, W.H.

    1992-01-01

    Artificial neural networks have been applied to a variety of signal processing and image recognition problems. Of the several common neural models the feed-forward, back-propagation network is well suited for the analysis of scientific laboratory data, which can be viewed as a pattern recognition problem. The authors present a discussion of the basic neural network concepts and illustrate its potential for analysis of experiments by applying it to the spectra of laser produced plasmas in order to obtain estimates of electron temperatures and densities. Although these are high temperature and density plasmas, the neural network technique may be of interest in the analysis of the low temperature and density plasmas characteristic of experiments and devices in gaseous electronics

  20. Optical Emission Spectroscopy of High-Power Laser-Induced Dielectric Breakdown in Molecular Gases and Their Mixtures: Investigating Early Stages of Plasma Chemical Action in Planetary Atmospheres

    Czech Academy of Sciences Publication Activity Database

    Cihelka, Jaroslav; Matulková, Irena; Sovová, Kristýna; Kamas, Michal; Kubelík, Petr; Ferus, Martin; Juha, Libor; Civiš, Svatopluk

    2009-01-01

    Roč. 39, 3-4 (2009), s. 227-227 ISSN 0169-6149 R&D Projects: GA MŠk LC510; GA MŠk(CZ) LC528; GA ČR GA203/06/1278; GA MŠk LA08024 Institutional research plan: CEZ:AV0Z40400503; CEZ:AV0Z10100523 Keywords : planetary atmosphere * lasers * spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.053, year: 2009

  1. Analysis of organic vapors with laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Nozari, Hadi; Tavassoli, Seyed Hassan; Rezaei, Fatemeh

    2015-01-01

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor

  2. Analysis of organic vapors with laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nozari, Hadi; Tavassoli, Seyed Hassan [Laser and Plasma Research Institute, Shahid Beheshti University, G. C, 1983963113 Evin, Tehran (Iran, Islamic Republic of); Rezaei, Fatemeh, E-mail: fatemehrezaei@kntu.ac.ir [Department of Physics, K. N. Toosi University of Technology, 15875-4416 Shariati, Tehran (Iran, Islamic Republic of)

    2015-09-15

    In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

  3. Investigation of metal ions in fusion plasmas using emission spectroscopy

    International Nuclear Information System (INIS)

    Tale, I.

    2005-01-01

    Full text: The Latvian and Portugal Associations are performing development of advanced plasma - facing system using the liquid metal limiter. The objectives of this project require study of the influence of the liquid metal limiter on the main plasma parameters, including concentration of evaporated metal atoms in plasma. The fusion plasmas are related to the dense hot plasmas. The required average ion temperature according to the ITER project (International Thermonuclear Experimental Reactor) is 8,0 keV (9,3 x 10 7 0 K), the average electron temperature - 8,9 keV (1,04 x 10 8 0 K). Plasma temperature operated in the research tokamak ISSTOK, involved in testing of liquid metal limiter concept is considerably less, being of order of 10 50 K. The ionization degree of metal atoms considerably depends on the plasma ion temperature. Density of metal vapours in plasma can be estimated using the following two spectroscopic methods: The fluorescence of the multiple ionised metal ions in steady state concentration; The charge exchange emission during ionisation of evaporated metal ions. In the first step of development of testing system of metal vapours the equipment and instrumentation for charge exchange spectroscopy of Ga and In has been elaborated taking into account the following features of plasma emission. The Ga emission lines occur on the background high temperature plasma black body emission and stray light. Radial distribution of Ga in plasma in the facing plane of Ga flux is desirable

  4. Contributions to process monitoring by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Rusak, David Alexander

    1998-12-01

    When a pulsed laser of sufficient energy and pulse duration is brought to a focus, multi-photon ionization creates free electrons in the focal volume. These electrons are accelerated in a process known as inverse Bremsstrahlung and cause collisional ionization of species in the focal volume. More charge carriers are produced and the process continues for the duration of the laser pulse. The manifestation of this process is a visible spark or plasma which typically lasts for tens of microseconds. This laser-induced plasma can serve as a source in an atomic emission experiment. Because the composition of the plasma is determined in large part by the environment in which it forms, elements in the laser target can be determined spectroscopically. The goal of a laser-induced breakdown spectroscopy (LIBS) experiment is to establish a relationship between the concentration of an element of interest in the target and the intensity of light emitted from the laser-induced plasma at a wavelength characteristic of that element. Because LIBS requires only optical access to the sample and can perform elemental determinations in solids, liquids, or gases with little sample preparation, there is interest in using it as an on-line technique for process monitoring in a number of industrial applications. However, before the technique becomes useful in industrial applications, many issues regarding instrumentation and data analysis need to be addressed in the lab. The first two chapters of this dissertation provide, respectively, the basics of the atomic emission experiment and a background of laser-induced breakdown spectroscopy. The next two chapters examine the effect of target water content on the laser-induced plasma and the use of LIBS for analysis of aqueous samples. Chapter 5 describes construction of a fiber optic LIBS probe and its use to study temporal electron number density evolution in plasmas formed on different metals. Chapter 6 is a study of excitation, vibrational

  5. Whispering Gallery Mode Spectroscopy as a Diagnostic for Dusty Plasmas

    International Nuclear Information System (INIS)

    Thieme, G.; Basner, R.; Ehlbeck, J.; Roepcke, J.; Maurer, H.; Kersten, H.; Davies, P. B.

    2008-01-01

    Whispering-gallery-mode spectroscopy is being assessed as a diagnostic method for the characterisation of size and chemical composition of spherical particles levitated in a plasma. With a pulsed laser whispering gallery modes (cavity resonances) are excited in individual microspheres leading to enhanced Raman scattering or fluorescence at characteristic wavelengths. This method can be used to gain specific information from the particle surface and is thus of great interest for the characterisation of layers deposited on microparticles, e.g. in molecular plasmas. We present investigations of different microparticles in air and results from fluorescent particles levitated in an Argon rf plasma.

  6. Polarization plasma spectroscopy (PPS) viewed from plasma physics and fusion research

    International Nuclear Information System (INIS)

    Ida, Katsumi

    1998-01-01

    Recently the measurements of poloidal magnetic field become important in plasma physics and nuclear fusion research, since an improved confinement mode associating with a negative magnetic shear has been found. The polarization plasma spectroscopy is recognized to be a useful tool to measure poloidal magnetic field and pitch angle of magnetic field. (author)

  7. Plasma polarization spectroscopy: past, present, and future - a subjective view

    International Nuclear Information System (INIS)

    Csanak, G.

    2004-01-01

    I describe how I got into the field of plasma polarization spectroscopy (PPS), how the PPS Workshops started, and how the whole field got consolidated and strengthened. Subsequently I describe what kind of present theoretical and experimental activities I am aware of. Finally I explain why I think that the future of PPS is bright. (author)

  8. Electron cyclotron emission spectroscopy on thermonuclear plasmas

    International Nuclear Information System (INIS)

    Tubbing, B.J.D.

    1987-01-01

    Analysis of electron cyclotron emission (ECE) enables one to infer the radial profile of the electron temperature in tokamaks. The Dutch FOM institute for plasma physics has designed, built, installed and operated a grating polychromator for ECE measurements at JET. This thesis deals with a few instrumental aspects of this project and with applications of ECE measurements in tokamak physics studies. Ch. 3 and 4 deal with the wave transport in ECE systems. In Ch. 3 a method is developed to infer the mode conversion, which is a source for transmission losses, in a waveguide component from the antenna pattern of its exit aperture. In Ch. 4 the design and manufacture of the waveguide transition system to the grating polychromator are described. In Ch. 5 a method is reported for calibration of the spectrometers, based on the use of a microwave source which simulates a large area blackbody of very high temperature. The feasibility of the method is tested by applying it to two different ECE systems. In Ch. 6 a study of heat pulse propagation in tokamak plasma's, based on measurement of the electron temperature with the grating polychromator, is presented. 105 refs.; 48 figs.; 8 tabs

  9. Study of a novel indolin-2-ketone compound Z24 induced hepatotoxicity by NMR-spectroscopy-based metabonomics of rat urine, blood plasma, and liver extracts

    International Nuclear Information System (INIS)

    Wang Quanjun; Jiang Ying; Wu Chunqi; Zhao Jianyu; Yu Shouzhong; Yuan Benli; Yan Xianzhong; Liao Mingyang

    2006-01-01

    Antiangiogenic compound has been believed to be an ideal drug in the current cancer biological therapy, but the angiogenesis inhibitors suffer setback for unknown toxicity now. A novel synthetic indolin-s-ketone small molecular compound, 3Z-3-[( 1 H-pyrrol-2-yl)-methylidene]-1-(1-piperidinylmethyl)-1,3-2H-indol-2-one (Z24) can inhibit angiogenesis in new blood vessels. The hepatotoxicity effects of Z24 oral administration (dosed at 60, 130 and 200 mg/kg) have been investigated in female Wistar rats by using metabonomic analysis of 1 H NMR spectra of urine, plasma and liver extracts, as well as by clinical chemistry analysis, liver histopathology and electron micrographs examination. The 1 H NMR spectra of the biofluids were analyzed visually and via pattern recognition by using principal component analysis. The metabonomic trajectory analysis on the time-related hepatotoxicity of Z24 was carried out based on the 1 H NMR spectra of urine samples, which were collected daily predose and postdose over an 8-day period. Urinary excretion of citrate, lactate, 2-oxo-glutarate and succinate increased following Z24 dosing. Increased plasma levels of lactate, TMAO and lipid were observed, with concomitant decrease in the level of glucose and phosphatidylcholine. Metabolic profiling on aqueous soluble extracts of liver tissues with the high dose level of Z24 showed an increase in lactate and glutamine, together with a decrease in glucose, glycogen and choline. On the other hand, studies on lipid soluble extracts of liver tissues with the high dose level of Z24 showed increased level in lipid triglycerides and decreased level in unsaturated fatty acids and phosphatidylcholine. Moreover, the most notable effect of Z24 on the metabolism was the reduction in the urinary levels of creatinine and TMAO and the increase in acetate, citrate, succinate and 2-oxo-glutamate with time dependence. The results indicate that in rats Z24 inhibits mitochondrial function through altering the

  10. On helicon wave induced radial plasma transport

    International Nuclear Information System (INIS)

    Petrzilka, V.

    1993-04-01

    Estimates of helicon wave induced radial plasma transport are presented. The wave induced transport grows or decreases in dependence on the sign of the azimuthal wave number; these changes in transport may play an important role in helicon wave plasma sources. (author) 5 figs., 18 refs

  11. Evaluation of two-beam spectroscopy as a plasma diagnostic

    International Nuclear Information System (INIS)

    Billard, B.D.

    1980-04-01

    A two-beam spectroscopy (TBS) system is evaluated theoretically and experimentally. This new spectroscopic technique uses correlations between components of emitted light separated by a small difference in angle of propagation. It is thus a non-perturbing plasma diagnostic which is shown to provide local (as opposed to line-of-sight averaged) information about fluctuations in the density of light sources within a plasma - information not obtainable by the usual spectroscopic methods. The present design is an improvement on earlier systems proposed in a thesis by Rostler

  12. Study of optical emission spectroscopy with inductively coupled plasma torch

    International Nuclear Information System (INIS)

    Bauer, M.

    1982-01-01

    Inductively coupled plasma optical emission spectroscopy is an excellent tool for quantitative multielement trace analysis. This paper describes the performance of a computer-controlled sequential measurement system. Chemical and ionization interferences are shown to be negligible due to the characteristics of the inductively coupled plasma, spectral interferences are eliminated by using a high-resolution monochromator and computer data handling. Good accuracy is achieved for most of the interesting elements, as is shown from both an interlaboratory test and from comparison of the results of water samples from the rivers Elbe and Weser with those achieved with neutron activation and X-ray fluorescence analysis. (orig.) [de

  13. Polarization spectroscopy on laser-produced plasmas and Z-pinch plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong E. [POSTECH, Kyungbuk (Korea); Baronova, Elena O. [RRC Kurchatov Institute, Nuclear Fusion Institute, Moscow (Russian Federation); Jakubowski, Lech [Soltan Institute for Nuclear Studies, Swierk-Otwock (Poland)

    2002-08-01

    PPS experiments on laser-produced plasmas are reviewed. Polarization is interpreted in terms of the anisotropic velocity distribution of electrons due to non-local transport. The polarization of an x-ray laser, and recent results regarding the recombining plasma are also presented. X-ray polarization spectroscopy experiments on heliumlike ion lines from a vacuum spark and from a plasma focus are presented: in both cases, the resonance line of the heliumlike ions shows polarization in the direction perpendicular to the discharge axis. Two possible interpretations are suggested. (author)

  14. Plasma control using neural network and optical emission spectroscopy

    International Nuclear Information System (INIS)

    Kim, Byungwhan; Bae, Jung Ki; Hong, Wan-Shick

    2005-01-01

    Due to high sensitivity to process parameters, plasma processes should be tightly controlled. For plasma control, a predictive model was constructed using a neural network and optical emission spectroscopy (OES). Principal component analysis (PCA) was used to reduce OES dimensionality. This approach was applied to an oxide plasma etching conducted in a CHF 3 /CF 4 magnetically enhanced reactive ion plasma. The etch process was systematically characterized by means of a statistical experimental design. Three etch outputs (etch rate, profile angle, and etch rate nonuniformity) were modeled using three different approaches, including conventional, OES, and PCA-OES models. For all etch outputs, OES models demonstrated improved predictions over the conventional or PCA-OES models. Compared to conventional models, OES models yielded an improvement of more than 25% in modeling profile angle and etch rate nonuniformtiy. More than 40% improvement over PCA-OES model was achieved in modeling etch rate and profile angle. These results demonstrate that nonreduced in situ data are more beneficial than reduced one in constructing plasma control model

  15. Special issue on the spectroscopy of transient plasmas

    Science.gov (United States)

    Bailey, James; Hoarty, David; Mancini, Roberto; Yoneda, Hitoki

    2015-01-01

    Experimental and theoretical papers are invited for a special issue of Journal of Physics B: Atomic, Molecular and Optical Physics on Spectroscopy of Transient Plasmas, covering plasma conditions produced by pulsed laboratory sources including for example, short and long pulse lasers; pulsed power devices; FELs; XFELs and ion beams. The full range of plasma spectroscopy from the optical range up to high energy bremsstrahlung radiation will be covered. The deadline for submitting to this special issue is 1 March 2015. (Expected web publication: autumn 2015). Late submissions will be considered for the journal, but may not be included in the special issue. All submitted articles will be fully refereed to the journal's usual high standards. Upon publication, the issue will be widely promoted to the atomic, molecular and optical physics community, ensuring that your work receives maximum visibility. Articles should be submitted at http://mc04.manuscriptcentral.com/jphysb-iop. Should you have any questions regarding the preparation of manuscripts or the suitability of your work for this Issue, please do not hesitate to contact the J. Phys. B: At. Mol. Opt. Editorial team (jphysb@iop.org). We look forward to hearing from you and hope that we can welcome you as a contributing author.

  16. Laser-induced breakdown spectroscopy for quantification of heavy metals in soils and sediments

    CSIR Research Space (South Africa)

    Ambushe, AA

    2010-09-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS) will be used to determine the contents of heavy metals in soils and sediments. LIBS results will be compared with the results obtained by inductively coupled plasma-optical emission spectrometry (ICP...

  17. Elemental analysis of soils using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) with multivariate discrimination: tape mounting as an alternative to pellets for small forensic transfer specimens.

    Science.gov (United States)

    Jantzi, Sarah C; Almirall, José R

    2014-01-01

    Elemental analysis of soil is a useful application of both laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) in geological, agricultural, environmental, archeological, planetary, and forensic sciences. In forensic science, the question to be answered is often whether soil specimens found on objects (e.g., shoes, tires, or tools) originated from the crime scene or other location of interest. Elemental analysis of the soil from the object and the locations of interest results in a characteristic elemental profile of each specimen, consisting of the amount of each element present. Because multiple elements are measured, multivariate statistics can be used to compare the elemental profiles in order to determine whether the specimen from the object is similar to one of the locations of interest. Previous work involved milling and pressing 0.5 g of soil into pellets before analysis using LA-ICP-MS and LIBS. However, forensic examiners prefer techniques that require smaller samples, are less time consuming, and are less destructive, allowing for future analysis by other techniques. An alternative sample introduction method was developed to meet these needs while still providing quantitative results suitable for multivariate comparisons. The tape-mounting method involved deposition of a thin layer of soil onto double-sided adhesive tape. A comparison of tape-mounting and pellet method performance is reported for both LA-ICP-MS and LIBS. Calibration standards and reference materials, prepared using the tape method, were analyzed by LA-ICP-MS and LIBS. As with the pellet method, linear calibration curves were achieved with the tape method, as well as good precision and low bias. Soil specimens from Miami-Dade County were prepared by both the pellet and tape methods and analyzed by LA-ICP-MS and LIBS. Principal components analysis and linear discriminant analysis were applied to the multivariate data

  18. Electric Propulsion Induced Secondary Mass Spectroscopy

    Science.gov (United States)

    Amini, Rashied; Landis, Geoffrey

    2012-01-01

    A document highlights a means to complement remote spectroscopy while also providing in situ surface samples without a landed system. Historically, most compositional analysis of small body surfaces has been done remotely by analyzing reflection or nuclear spectra. However, neither provides direct measurement that can unambiguously constrain the global surface composition and most importantly, the nature of trace composition and second-phase impurities. Recently, missions such as Deep Space 1 and Dawn have utilized electric propulsion (EP) accelerated, high-energy collimated beam of Xe+ ions to propel deep space missions to their target bodies. The energies of the Xe+ are sufficient to cause sputtering interactions, which eject material from the top microns of a targeted surface. Using a mass spectrometer, the sputtered material can be determined. The sputtering properties of EP exhaust can be used to determine detailed surface composition of atmosphereless bodies by electric propulsion induced secondary mass spectroscopy (EPI-SMS). EPI-SMS operation has three high-level requirements: EP system, mass spectrometer, and altitude of about 10 km. Approximately 1 keV Xe+ has been studied and proven to generate high sputtering yields in metallic substrates. Using these yields, first-order calculations predict that EPI-SMS will yield high signal-to-noise at altitudes greater than 10 km with both electrostatic and Hall thrusters.

  19. Apparatus, system, and method for laser-induced breakdown spectroscopy

    Science.gov (United States)

    Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

    2014-11-18

    In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

  20. Emission spectroscopy of highly ionized high-temperature plasma jets

    Energy Technology Data Exchange (ETDEWEB)

    Belevtsev, A A; Chinnov, V F; Isakaev, E Kh [Associated Institute for High Temperatures, Russian Academy of Sciences Izhorskaya 13/19, Moscow, 125412 (Russian Federation)

    2006-08-01

    This paper deals with advanced studies on the optical emission spectroscopy of atmospheric pressure highly ionized high-temperature argon and nitrogen plasma jets generated by a powerful arc plasmatron. The emission spectra are taken in the 200-1000 nm range with a spectral resolution of {approx}0.01-0.02 nm. The exposure times are 6 x 10{sup -6}-2 x 10{sup -2} s, the spatial resolution is 0.02-0.03 mm. The recorded jet spectra are abundant in spectral lines originating from different ionization stages. In nitrogen plasmas, tens of vibronic bands are also observed. To interpret and process these spectra such that plasma characteristics can be derived, a purpose-developed automated processing system is applied. The use of a CCD camera at the spectrograph output allows a simultaneous recording of the spectral and chord intensity distributions of spectral lines, which can yet belong to the overlapped spectra of the first and second orders of interference. The modern optical diagnostic means and methods used permit the determination of spatial distributions of electron number densities and temperatures and evaluation of rotational temperatures. The radial profiles of the irradiating plasma components can also be obtained. Special attention is given to the method of deriving rotational temperatures using vibronic bands with an incompletely identified rotational structure.

  1. Applying Quantum Cascade Laser Spectroscopy in Plasma Diagnostics

    Directory of Open Access Journals (Sweden)

    Jürgen Röpcke

    2016-07-01

    Full Text Available The considerably higher power and wider frequency coverage available from quantum cascade lasers (QCLs in comparison to lead salt diode lasers has led to substantial advances when QCLs are used in pure and applied infrared spectroscopy. Furthermore, they can be used in both pulsed and continuous wave (cw operation, opening up new possibilities in quantitative time resolved applications in plasmas both in the laboratory and in industry as shown in this article. However, in order to determine absolute concentrations accurately using pulsed QCLs, careful attention has to be paid to features like power saturation phenomena. Hence, we begin with a discussion of the non-linear effects which must be considered when using short or long pulse mode operation. More recently, cw QCLs have been introduced which have the advantage of higher power, better spectral resolution and lower fluctuations in light intensity compared to pulsed devices. They have proved particularly useful in sensing applications in plasmas when very low concentrations have to be monitored. Finally, the use of cw external cavity QCLs (EC-QCLs for multi species detection is described, using a diagnostics study of a methane/nitrogen plasma as an example. The wide frequency coverage of this type of QCL laser, which is significantly broader than from a distributed feedback QCL (DFB-QCL, is a substantial advantage for multi species detection. Therefore, cw EC-QCLs are state of the art devices and have enormous potential for future plasma diagnostic studies.

  2. Titanium monoxide spectroscopy following laser-induced optical breakdown

    International Nuclear Information System (INIS)

    Parigger, Christian G.; Woods, Alexander C.; Keszler, Anna; Nemes, László; Hornkohl, James O.

    2012-01-01

    This work investigates Titanium Monoxide (TiO) in ablation-plasma by employing laser-induced breakdown spectroscopy (LIBS) with 1 to 10 TW/cm 2 irradiance, pulsed, 13 nanosecond, Q-switched Nd:YAG laser radiation at the fundamental wavelength of 1064 nm. The analysis of TiO is based on our first accurate determination of transition line strengths for selected TiO A-X, B-X, and E-X transitions, particularly TiO A-X γ and B-X γ′ bands. Electric dipole line strengths for the A 3 Φ-X 3 δ and B 3 Π-X 3 δ bands of TiO are computed. The molecular TiO spectra are observed subsequent to laser-induced breakdown (LIB). We discuss analysis of diatomic molecular spectra that may occur simultaneously with spectra originating from atomic species. Gated detection is applied to investigate the development in time of the emission spectra following LIB. Collected emission spectra allow one to infer micro-plasma parameters such as temperature and electron density. Insight into the state of the micro-plasma is gained by comparing measurements with predictions of atomic and molecular spectra. Nonlinear fitting of recorded and computed diatomic spectra provides the basis for molecular diagnostics, while atomic species may overlap and are simultaneously identified. Molecular diagnostic approaches similar to TiO have been performed for diatomic molecules such as AlO, C 2 , CN, CH, N 2 , NH, NO and OH.

  3. Quantitative plasma spectroscopy at JET and Extrap-T1

    International Nuclear Information System (INIS)

    Zastrow, K.D.

    1993-01-01

    Studies in quantitative plasma spectroscopy are performed on the Joint European Torus (JET) in Culham, Great-Britain and on the Extrap-T1 reversed-field pinch (RFP) in Stockholm. The model concepts that form the basis of these studies are reviewed. At JET, spectra of He-like nickel are observed with a high-resolution X-ray crystal spectrometer. The experimental line intensity ratios of satellite lines to the resonance line are compared with theoretical data. The agreement is found to be good, with the exception of the excitation of dipole-forbidden lines. The spectrum is also used to derive central ion temperature, central toroidal rotation and nickel concentration based upon a model for the radial emission. The results are compared with those from an independent diagnostic, charge-exchange recombination spectroscopy (CWRS). Theoretically predicted cross section effects on the CXRS data are verified. On Extrap-T1, vacuum ultraviolet (VUV) spectra and visible spectra are analysed. From these, thermodynamic quantities of the plasma are derived, like electron temperature, impurity concentrations and particle fluxes. The oxygen ionization balance is measured and compared to calculations with a collisional-dielectronic model with metastable resolution, both in 0-dimensional time-dependent and transport model calculations. The performance of the RFP discharges investigated in terms of radiative power loss and energy and particle confinement properties. The scaling of the energy confinement time with plasma current, pinch parameter and electron density is found to be dominated by the dynamo activity needed to sustain the RFP configuration. The scaling of the particle confinement time, on the other hand, is dominated by pressure-driven activity associated with the regulation of β

  4. RMP-Flutter-Induced Pedestal Plasma Transport

    Energy Technology Data Exchange (ETDEWEB)

    Callen, J. D.; Hegna, C., E-mail: callen@engr.wisc.edu [University of Wisconsin, Madison (United States); Cole, A. J. [Columbia University, New York (United States)

    2012-09-15

    Full text: Plasma toroidal rotation can prevent or limit reconnection of externally applied resonant magnetic perturbation (RMP) fields {delta}B on rational magnetic flux surfaces. Hence, it causes the induced radial perturbations to vanish or be small there, and thereby inhibits magnetic island formation and stochasticity in the edge of high (H-mode) confinement tokamak plasmas. However, the radial component of the spatial magnetic flutter induced by RMP fields off rational surfaces causes a radial electron thermal diffusivity of (1/2)({delta}B{sub p}/B){sup 2} times a magnetic-shear-influenced effective parallel electron thermal diffusivity. The resultant RMP-flutter-induced electron thermal diffusivity can be comparable to experimentally inferred values at the top of H-mode pedestals. This process also causes a factor of about 3 smaller RMP-induced electron density diffusivity there. Because this electron density transport is non-ambipolar, it produces a toroidal torque on the plasma, which is usually in the co-current direction. Kinetic-based cylindrical screw-pinch and toroidal models of these RMP-flutter-induced plasma transport effects have been developed. The RMP-induced increases in these diffusive plasma transport processes are typically spatially inhomogeneous in that they are strongly peaked near the rational surfaces in low collisionality pedestals, which may lead to resonant sensitivities to the local safety factor q. The effects can be large enough to reduce the radially averaged gradients of the electron temperature and density at the top of H-mode edge pedestals, and modify the plasma toroidal rotation and radial electric field there. At high collisionality the various effects are less strongly peaked at rational surfaces and thus less likely to exhibit RMP-induced resonant behavior. These RMP-flutter-induced plasma transport processes provide a new paradigm for developing an understanding of how RMPs modify the pedestal structure to stabilize

  5. Assessment of high precision, high accuracy Inductively Coupled Plasma-Optical Emission Spectroscopy to obtain concentration uncertainties less than 0.2% with variable matrix concentrations

    International Nuclear Information System (INIS)

    Rabb, Savelas A.; Olesik, John W.

    2008-01-01

    The ability to obtain high precision, high accuracy measurements in samples with complex matrices using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy (HP-ICP-OES) was investigated. The Common Analyte Internal Standard (CAIS) procedure was incorporated into the High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method to correct for matrix-induced changes in emission intensity ratios. Matrix matching and standard addition approaches to minimize matrix-induced errors when using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy were also assessed. The High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method was tested with synthetic solutions in a variety of matrices, alloy standard reference materials and geological reference materials

  6. Discrimination of forensic trace evidence using laser induced breakdown spectroscopy

    Science.gov (United States)

    Bridge, Candice Mae

    Elemental analysis in forensic laboratories can be tedious and many trace evidence items are not analyzed to determine their elemental composition. Presently, scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDS) is the primary analytical tool for determining the elemental composition of trace evidence items. However, due to the time it takes to obtain the required vacuum and the limited number of samples that can be analyzed at any one time, SEM-EDS can be impractical for a high volume of evidence items. An alternative instrument that can be used for this type of analysis is laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). While LA-ICP-MS is a very precise and quantitative analytical method that determines elemental composition based on isotopic mass measurements; however, the instrumentation is relatively expensive and therefore is budgetarily prohibitive for many forensic laboratories. It is the purpose of this research to evaluate an inexpensive instrument that can potentially provide rapid elemental analysis for many forensic laboratories. Laser induced breakdown spectroscopy (LIBS) is an analytical method that meets these requirements and offers information about the elemental composition based on ionic, atomic and diatomic molecular emissions.

  7. Laser induced breakdown spectroscopy for applications in nuclear industry

    International Nuclear Information System (INIS)

    Suri, B.M.

    2010-01-01

    There are several analytical techniques employing laser spectroscopy - each with its own distinctive potential. Laser Induced Breakdown Spectroscopy (LIBS) is one such technique which is attractive in view of its relative compactness and simplicity (in configuration), remote and online analysis (with no sample handling requirement) and high spatial resolution allowing compositional map or homogeneity analysis. In this technique, a high power pulsed (mostly nanosecond) laser is employed to irradiate the sample causing spark emission, characteristics of the sample composition, which is collected using suitable optics and analysed spectroscopically. Remote and online capability is derived from long distance delivery of laser beams and collection of emitted light by fibres or conventional optics. Since laser can be focused sharply on the target, it can facilitate compositional mapping. Beam Technology Development Group at BARC had initiated work on LIBS of nuclear materials several years ago. Recently the challenge of online monitoring of radioactive waste vitrification plant in a hot cell has been taken up. The theoretical and experimental work done by the group related to instrument development, plasma characterization, quantitative compositional analysis of ternary alloys and uranium vitrified glass samples (comprising more than dozen elements) are described. The future plans for setting up online glass homogeneity monitoring facility are also described. This should fulfill an important demand for optimization of vitrification process. Various other demands of nuclear industry are also reviewed

  8. Remote metal analysis by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Duckworth, A.

    1996-01-01

    This paper describes a new technique by which the composition of irradiated or inaccessible reactor components can be determined remotely. The technique uses very short duration, high energy laser pulses at a wavelength which can be transmitted down an optical fibre to ablate a tiny plasma from the surface of a metal component. Light from the plasma is collected by a second fibre and returned to a spectrometer where it is split into the characteristic emission wavelengths of the elements in the sample. Comparison of the emission line amplitude for a particular element with that of a chosen calibration line can be used to deduce the concentration of the element in the sample. The technique has been used successfully to differentiate between different highly radioactive control rod batches at Sizewell ''A'' and Hinkley Point ''A'' Power Stations. The material analysis accuracy is comparable with that obtained from electron microphobe analysis and other direct spectroscopic methods. However, by analysing the mild steel control rod casing material remotely, difficult sample removal becomes unneccessary and the integrity of the component remains essentially unaltered. In addition, removal of deposits or surface corrosion is incorporated very neatly into the process. These factors make remote laser induced breakdown spectroscopy an ideal tool for material analysis in the nuclear environment. (UK)

  9. Remote metal analysis by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Duckworth, A.

    1996-01-01

    This paper describes a new technique by which the composition of irradiated or inaccessible reactor components can be determined remotely. The technique uses very short duration, high energy laser pulses at a wavelength which can be transmitted down an optical fibre to ablate a tiny plasma from the surface of a metal component. Light from the plasma is collected by a second fibre and returned to a spectrometer where it is split into the characteristic emission wavelengths of the elements in the sample. Comparison of the emission line amplitude for a particular element with that of a chosen calibrationline can be used to deduce the concentration of the element in the sample. The technique has been used successfully to differentiate between highly radioactive control rod batches at Sizewell 'A' and Hinkley Point 'A Power Stations. The material analysis accuracy is comparable with that obtained from electron microprobe analysis and other direct spectroscopic methods. However, by analysing the mild steel control rod casing material remotely, difficult sample removal becomes unnecessary and the integrity of the component remains essentially unaltered. In addition, removal of deposits or surface corrosion is incorporated very neatly into the process. These factors make remote laser induced breakdown spectroscopy an ideal tool for material analysis in the nuclear environment. (Author)

  10. Laser induced fluorescence spectroscopy for FTU

    International Nuclear Information System (INIS)

    Hughes, T.P.

    1995-07-01

    Laser induced fluorescence spectroscopy (LIFS) is based on the absorption of a short pulse of tuned laser light by a group of atoms and the observation of the resulting fluorescence radiation from the excited state. Because the excitation is resonant it is very efficient, and the fluorescence can be many times brighter than the normal spontaneous emission, so low number densities of the selected atoms can be detected and measured. Good spatial resolution can be achieved by using a narrow laser beam. If the laser is sufficiently monochromatic, and it can be tuned over the absorption line profile of the selected atoms, information can also be obtained about the velocities of the atoms from the Doppler effect which can broaden and shift the line. In this report two topics are examined in detail. The first is the effect of high laser irradiance, which can cause 'power broadening' of the apparent absorption line profile. The second is the effect of the high magnetic field in FTU. Detailed calculations are given for LIFS of neutral iron and molybdenum atoms, including the Zeeman effect, and the implementation of LIFS for these atoms on FTU is discussed

  11. Medical Applications of Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Pathak, A K; Rai, N K; Singh, Ankita; Rai, A K; Rai, Pradeep K; Rai, Pramod K

    2014-01-01

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail

  12. Cascade generation in Al laser induced plasma

    Science.gov (United States)

    Nagli, Lev; Gaft, Michael; Raichlin, Yosef; Gornushkin, Igor

    2018-05-01

    We found cascade IR generation in Al laser induced plasma. This generation includes doublet transitions 3s 25s 2S1/2 → 3s24p 2P1/2,3/2 → 3s24s 2S1/2; corresponding to strong lines at 2110 and 2117 nm, and much weaker lines at 1312-1315 nm. The 3s25s2S 1/2 starting IR generation level is directly pumped from the 3s23p 2P3/2 ground level. The starting level for UV generation at 396.2 nm (transitions 3s24s 2S1/2 → 4p 2P3/2) is populated due to the fast collisional processes in the plasma plume. These differences led to different time and special dependences on the lasing in the IR and UV spectral range within the aluminum laser induced plasma.

  13. Magnetic-flutter-induced pedestal plasma transport

    International Nuclear Information System (INIS)

    Callen, J.D.; Hegna, C.C.; Cole, A.J.

    2013-01-01

    Plasma toroidal rotation can limit reconnection of externally applied resonant magnetic perturbation (RMP) fields δB on rational magnetic flux surfaces. Hence it causes the induced radial perturbations δB ρ to be small there, thereby inhibiting magnetic island formation and stochasticity at the top of pedestals in high (H-mode) confinement tokamak plasmas. However, the δB ρ s induced by RMPs increase away from rational surfaces and are shown to induce significant sinusoidal radial motion (flutter) of magnetic field lines with a radial extent that varies linearly with δB ρ and inversely with distance from the rational surface because of the magnetic shear. This produces a radial electron thermal diffusivity that is (1/2)(δB ρ /B 0 ) 2 times a kinetically derived, electron-collision-induced, magnetic-shear-reduced, effective parallel electron thermal diffusivity in the absence of magnetic stochasticity. These low collisionality flutter-induced transport processes and thin magnetic island effects are shown to be highly peaked in the vicinity of rational surfaces at the top of low collisionality pedestals. However, the smaller but finite level of magnetic-flutter-induced electron heat transport midway between rational surfaces is the primary factor that determines the electron temperature difference between rational surfaces at the pedestal top. The magnetic-flutter-induced non-ambipolar electron density transport can be large enough to push the plasma toward an electron density transport root. Requiring ambipolar density transport is shown to determine the radial electric field, the plasma toroidal rotation (via radial force balance), a reduced electron thermal diffusivity and increased ambipolar density transport in the pedestal. At high collisionality the various flutter effects are less strongly peaked at rational surfaces and generally less significant. They are thus less likely to exhibit flutter-induced resonant behaviour and transition toward an

  14. Magnetic-flutter-induced pedestal plasma transport

    Science.gov (United States)

    Callen, J. D.; Hegna, C. C.; Cole, A. J.

    2013-11-01

    Plasma toroidal rotation can limit reconnection of externally applied resonant magnetic perturbation (RMP) fields δB on rational magnetic flux surfaces. Hence it causes the induced radial perturbations δBρ to be small there, thereby inhibiting magnetic island formation and stochasticity at the top of pedestals in high (H-mode) confinement tokamak plasmas. However, the δBρs induced by RMPs increase away from rational surfaces and are shown to induce significant sinusoidal radial motion (flutter) of magnetic field lines with a radial extent that varies linearly with δBρ and inversely with distance from the rational surface because of the magnetic shear. This produces a radial electron thermal diffusivity that is (1/2)(δBρ/B0)2 times a kinetically derived, electron-collision-induced, magnetic-shear-reduced, effective parallel electron thermal diffusivity in the absence of magnetic stochasticity. These low collisionality flutter-induced transport processes and thin magnetic island effects are shown to be highly peaked in the vicinity of rational surfaces at the top of low collisionality pedestals. However, the smaller but finite level of magnetic-flutter-induced electron heat transport midway between rational surfaces is the primary factor that determines the electron temperature difference between rational surfaces at the pedestal top. The magnetic-flutter-induced non-ambipolar electron density transport can be large enough to push the plasma toward an electron density transport root. Requiring ambipolar density transport is shown to determine the radial electric field, the plasma toroidal rotation (via radial force balance), a reduced electron thermal diffusivity and increased ambipolar density transport in the pedestal. At high collisionality the various flutter effects are less strongly peaked at rational surfaces and generally less significant. They are thus less likely to exhibit flutter-induced resonant behaviour and transition toward an electron

  15. Saturation spectroscopy of an optically opaque argon plasma

    Science.gov (United States)

    Eshel, Ben; Rice, Christopher A.; Perram, Glen P.

    2018-02-01

    A pure argon (Ar) plasma formed by a capacitively coupled radio-frequency discharge was analyzed using Doppler-free saturation spectroscopy. The expected line shape was a characteristic of sub-Doppler spectra in the presence of velocity-changing collisions, a narrow Lorentzian centered on a Doppler pedestal, but the observed line shapes contain a multi-peak structure, attributed to opacity of the medium. Laser absorption and inter-modulated fluorescence spectroscopy measurements were made to validate opacity as a driving factor of the observed line shapes. Spectral line shapes are further complicated by the spatial dependence of the pump laser, probe laser and of the absorbing medium, as well as the large absorbance of the transition under investigation. A numerical line shape was derived by accounting for the spatial variation of the pump and probe with a saturated line shape obtained from the rate equations for an equivalent two-level system. This simulated line shape shows good qualitative agreement with the trends observed in the data.

  16. [Study on physical deviation factors on laser induced breakdown spectroscopy measurement].

    Science.gov (United States)

    Wan, Xiong; Wang, Peng; Wang, Qi; Zhang, Qing; Zhang, Zhi-Min; Zhang, Hua-Ming

    2013-10-01

    In order to eliminate the deviation between the measured LIBS spectral line and the standard LIBS spectral line, and improve the accuracy of elements measurement, a research of physical deviation factors in laser induced breakdown spectroscopy technology was proposed. Under the same experimental conditions, the relationship of ablated hole effect and spectral wavelength was tested, the Stark broadening data of Mg plasma laser induced breakdown spectroscopy with sampling time-delay from 1.00 to 3.00 micros was also studied, thus the physical deviation influences such as ablated hole effect and Stark broadening could be obtained while collecting the spectrum. The results and the method of the research and analysis can also be applied to other laser induced breakdown spectroscopy experiment system, which is of great significance to improve the accuracy of LIBS elements measuring and is also important to the research on the optimum sampling time-delay of LIBS.

  17. A comparative study of the laser induce breakdown spectroscopy in single- and double-pulse laser geometry

    International Nuclear Information System (INIS)

    Sun Duixiong; Su Maogen; Dong Chenzhong; Wen Guanhong; Cao Xiangnian

    2013-01-01

    A time resolved laser induced breakdown spectroscopy technique (LIBS) was used for the investigation of emission signal enhancement on double-pulse LIBS. Two Q-switched Nd:YAG lasers at 1064 nm wavelength have been employed to generate laser-induced plasma on aluminium-based alloys. The plasma emission signals were recorded by spectrometer with ICCD detector. Spectral response calibration was performed by using deuterium and tungsten halogen lamps. Time evolution of the plasma temperature and electron density was investigated in SP and DP experiments. Based on the investigation of plasma parameters, the enhancements of emission line intensities were investigated, and the mechanisms of it were discussed. (author)

  18. Charge exchange recombination spectroscopy as a plasma diagnostic tool

    International Nuclear Information System (INIS)

    Fonck, R.J.

    1984-12-01

    Intensity and line profile measurements of the spectra of light hydrogenic ion which are excited by charge exchange reactions with fast neutral atoms are being widely used as diagnostics for fusion plasma research. This technique, which is referred to as charge exchange recombination spectroscopy, allows measurements of the densities of fully stripped impurity ions and particle transport coefficients with only minor uncertainties arising from atomic processes. The excitation of long wavelength transitions in light ions such as He + , C 5+ , and O 7+ allows relatively easy measurements of ion velocity distributions to determine ion temperatures and plasma rotation velocities. Among its advantages for such measurements are the facts that fiber optic coupling between a remote spectrometer and the immediate reactor environment is possible in many cases. The measurement is localized by the intersection region of a neutral beamline and viewing sightline, and intrinsic ions can be used so that injection of potentially perturbing impurities can be avoided. A particularly challenging application of this technique lies in the diagnosis of alpha particles expected to be produced in the present generation of Q approx. = 1 tokamak experiments

  19. Atomic data for beam-stimulated plasma spectroscopy in fusion plasmas

    International Nuclear Information System (INIS)

    Marchuk, O.; Biel, W.; Schlummer, T.; Ralchenko, Yu.; Schultz, D. R.

    2013-01-01

    Injection of high energy atoms into a confined plasma volume is an established diagnostic technique in fusion research. This method strongly depends on the quality of atomic data for charge-exchange recombination spectroscopy (CXRS), motional Stark effect (MSE) and beam-emission spectroscopy (BES). We present some examples of atomic data for CXRS and review the current status of collisional data for parabolic states of hydrogen atoms that are used for accurate MSE modeling. It is shown that the collisional data require knowledge of the excitation density matrix including the off-diagonal matrix elements. The new datasets for transitions between parabolic states are used in an extended collisional-radiative model. The ratios between the σ- and π-components and the beam-emission rate coefficients are calculated in a quasi-steady state approximation. Good agreement with the experimental data from JET is found which points out to strong deviations from the statistical distribution for magnetic sublevels

  20. Peculiarities of plasma homeostasis in the patients with rectal cancer according to laser correlation spectroscopy findings

    International Nuclear Information System (INIS)

    Byilenko, O.A.; Bazhora, Yu.Yi.; Sokolov, V.M.; Andronov, D.Yu.

    1997-01-01

    Laser correlation spectroscopy was used to investigate plasma homeostasis in 82 patients with rectal cancer. The spectra of the blood plasma from 21 donors of the transfusion station were used as the control. The blood plasma homeostasis changes reheated with laser correlation spectrometry in the patients with rectal cancer allow to use them for diagnosis of this pathology

  1. Prospects for laser-induced breakdown spectroscopy for biomedical applications: a review.

    Science.gov (United States)

    Singh, Vivek Kumar; Rai, Awadhesh Kumar

    2011-09-01

    We review the different spectroscopic techniques including the most recent laser-induced breakdown spectroscopy (LIBS) for the characterization of materials in any phase (solid, liquid or gas) including biological materials. A brief history of the laser and its application in bioscience is presented. The development of LIBS, its working principle and its instrumentation (different parts of the experimental set up) are briefly summarized. The generation of laser-induced plasma and detection of light emitted from this plasma are also discussed. The merit and demerits of LIBS are discussed in comparison with other conventional analytical techniques. The work done using the laser in the biomedical field is also summarized. The analysis of different tissues, mineral analysis in different organs of the human body, characterization of different types of stone formed in the human body, analysis of biological aerosols using the LIBS technique are also summarized. The unique abilities of LIBS including detection of molecular species and calibration-free LIBS are compared with those of other conventional techniques including atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy and mass spectroscopy, and X-ray fluorescence.

  2. Laser induced breakdown spectroscopy (LIBS) as a rapid tool for material analysis

    International Nuclear Information System (INIS)

    Hussain, T; Gondal, M A

    2013-01-01

    Laser induced breakdown spectroscopy (LIBS) is a novel technique for elemental analysis based on laser-generated plasma. In this technique, laser pulses are applied for ablation of the sample, resulting in the vaporization and ionization of sample in hot plasma which is finally analyzed by the spectrometer. The elements are identified by their unique spectral signatures. LIBS system was developed for elemental analysis of solid and liquid samples. The developed system was applied for qualitative as well as quantitative measurement of elemental concentration present in iron slag and open pit ore samples. The plasma was generated by focusing a pulsed Nd:YAG laser at 1064 nm on test samples to study the capabilities of LIBS as a rapid tool for material analysis. The concentrations of various elements of environmental significance such as cadmium, calcium, magnesium, chromium, manganese, titanium, barium, phosphorus, copper, iron, zinc etc., in these samples were determined. Optimal experimental conditions were evaluated for improving the sensitivity of developed LIBS system through parametric dependence study. The laser-induced breakdown spectroscopy (LIBS) results were compared with the results obtained using standard analytical technique such as inductively couple plasma emission spectroscopy (ICP). Limit of detection (LOD) of our LIBS system were also estimated for the above mentioned elements. This study demonstrates that LIBS could be highly appropriate for rapid online analysis of iron slag and open pit waste.

  3. Laser induced breakdown spectroscopy (LIBS) as a rapid tool for material analysis

    Science.gov (United States)

    Hussain, T.; Gondal, M. A.

    2013-06-01

    Laser induced breakdown spectroscopy (LIBS) is a novel technique for elemental analysis based on laser-generated plasma. In this technique, laser pulses are applied for ablation of the sample, resulting in the vaporization and ionization of sample in hot plasma which is finally analyzed by the spectrometer. The elements are identified by their unique spectral signatures. LIBS system was developed for elemental analysis of solid and liquid samples. The developed system was applied for qualitative as well as quantitative measurement of elemental concentration present in iron slag and open pit ore samples. The plasma was generated by focusing a pulsed Nd:YAG laser at 1064 nm on test samples to study the capabilities of LIBS as a rapid tool for material analysis. The concentrations of various elements of environmental significance such as cadmium, calcium, magnesium, chromium, manganese, titanium, barium, phosphorus, copper, iron, zinc etc., in these samples were determined. Optimal experimental conditions were evaluated for improving the sensitivity of developed LIBS system through parametric dependence study. The laser-induced breakdown spectroscopy (LIBS) results were compared with the results obtained using standard analytical technique such as inductively couple plasma emission spectroscopy (ICP). Limit of detection (LOD) of our LIBS system were also estimated for the above mentioned elements. This study demonstrates that LIBS could be highly appropriate for rapid online analysis of iron slag and open pit waste.

  4. Wavelength comparison for laser induced breakdown spectroscopy caries detection

    Science.gov (United States)

    Amaral, Marcello M.; Raele, Marcus P.; Ana, Patrícia A.; Núñez, Sílvia C.; Zamataro, Claudia B.; Zezell, Denise M.

    2018-02-01

    Laser Induced Breakdown Spectroscopy (LIBS) is a technique capable to perform elemental analyses of a variety of samples, independent of matter state. Other spectroscopy techniques may require a destructive and time-consuming sample preparation. On the other hand, LIBS is a less destructive technique with no (or considerably less) sample preparation, using a relatively simple experimental setup. LIBS also provides a multielement analysis into one single spectrum acquisition, applying a Nd:YAG short-pulsed laser to ensure the stoichiometry between the sample and the generated plasma. LIBS have been applied on the study of carious lesions using a Nd:YAG into its fundamental emission at 1064 nm. It was shown that ratio of P/Ca and Zn/Ca can be used to monitor the cariogenic process. Another minor elements, e.g. C and Cu, associated with bacteria biofilm were also measured with the Nd:YAG laser. The fundamental wavelength emission (1064 nm) of Nd:YAG is coincident with a hydroxyapatite transmission window and it may affect the result. In order to address this issue a study used the second harmonic of the Nd:YAG laser at 532 nm. It was show that it is also possible perform LIBS on carious lesion using the Nd:YAG at 532 nm. However, there is not a work direct comparing the LIBS at 532 nm and 1064 nm for carious lesion detection. So, the aim of this work was to investigate the influence of laser wavelength on the LIBS performance for carious lesion detection. In both cases the carious lesion was detected with the advantage of no interference with hydroxyapatite at 532 nm.

  5. Laser-induced breakdown spectroscopy analysis of asbestos

    International Nuclear Information System (INIS)

    Caneve, L.; Colao, F.; Fabbri, F.; Fantoni, R.; Spizzichino, V.; Striber, J.

    2005-01-01

    Laser-induced breakdown spectroscopy was applied to test the possibility of detecting and identifying asbestos in different samples in view of the perspective at field operation without sample preparation which is peculiar to this technique. Several like-resin materials were first investigated by laser-induced breakdown spectroscopy, in order to find an asbestos container assuring safe laboratory operation during the material characterization aimed to identify indicators suitable for a quick identification on field. Successively, spectra of asbestos samples of both in serpentine and amphibole forms were measured and the variability in elemental composition was calculated from the emission spectra. Ratios of intensities of characteristic elements were tested as indicators for asbestos recognition. Laser-induced breakdown spectroscopy results were compared with those obtained by analyzing the same asbestos samples with a scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy, a good correlation was found for Mg/Si and Fe/Si, thus showing the capability of laser-induced breakdown spectroscopy as a diagnostic tool for this category of materials. In particular, it was demonstrated that the method based on two indicators derived from laser-induced breakdown spectroscopy intensity ratios allows to discriminate between asbestos and cements in single shot measurements suitable to field operation

  6. Direct measurements of neutral density depletion by two-photon absorption laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Aanesland, A.; Liard, L.; Leray, G.; Jolly, J.; Chabert, P.

    2007-01-01

    The ground state density of xenon atoms has been measured by spatially resolved laser-induced fluorescence spectroscopy with two-photon excitation in the diffusion chamber of a magnetized Helicon plasma. This technique allows the authors to directly measure the relative variations of the xenon atom density without any assumptions. A significant neutral gas density depletion was measured in the core of the magnetized plasma, in agreement with previous theoretical and experimental works. It was also found that the neutral gas density was depleted near the radial walls

  7. Scrape-off layer-induced beam density fluctuations and their effect on beam emission spectroscopy

    Science.gov (United States)

    Moulton, D.; Marandet, Y.; Tamain, P.; Dif-Pradalier, G.

    2015-07-01

    A statistical model is presented to calculate the magnitude of beam density fluctuations generated by a turbulent scrape-off layer (SOL). It is shown that the SOL can induce neutral beam density fluctuations of a similar magnitude to the plasma density fluctuations in the core, potentially corrupting beam emission spectroscopy measurements. The degree of corruption is quantified by combining simulations of beam and plasma density fluctuations inside a simulated measurement window. A change in pitch angle from the separatrix to the measurement window is found to reduce the effect of beam fluctuations, whose largest effect is to significantly reduce the measured correlation time.

  8. Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Farooq W A; Atif M; Tawfik W; Alsalhi M S; Alahmed Z A; Sarfraz M; Singh J P

    2014-01-01

    Laser-induced breakdown spectroscopy (LIBS) technique has been applied to investigate two different types of bacteria, Escherichia coli (B1) and Micrococcus luteus (B2) deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, Cl, Fe, Al, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria. (plasma technology)

  9. Forensic comparative glass analysis by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Bridge, Candice M.; Powell, Joseph; Steele, Katie L.; Sigman, Michael E.

    2007-01-01

    Glass samples of four types commonly encountered in forensic examinations have been analyzed by laser-induced breakdown spectroscopy (LIBS) for the purpose of discriminating between samples originating from different sources. Some of the glass sets were also examined by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Refractive index (RI) measurements were also made on all glass samples and the refractive index data was combined with the LIBS and with the LA-ICP-MS data to enhance discrimination. The glass types examined included float glass taken from front and side automobile windows (examined on the non-float side), automobile headlamp glass, automobile side-mirror glass and brown beverage container glass. The largest overall discrimination was obtained by employing RI data in combination with LA-ICP-MS (98.8% discrimination of 666 pairwise comparisons at 95% confidence), while LIBS in combination with RI provided a somewhat lower discrimination (87.2% discrimination of 1122 pairwise comparisons at 95% confidence). Samples of side-mirror glass were less discriminated by LIBS due to a larger variance in emission intensities, while discrimination of side-mirror glass by LA-ICP-MS remained high

  10. Measurement of Irradiated Pyroprocessing Samples via Laser Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Phongikaroon, Supathorn [Virginia Commonwealth Univ., Richmond, VA (United States)

    2016-10-31

    The primary objective of this research is to develop an applied technology and provide an assessment to remotely measure and analyze the real time or near real time concentrations of used nuclear fuel (UNF) dissolute in electrorefiners. Here, Laser-Induced Breakdown Spectroscopy (LIBS), in UNF pyroprocessing facilities will be investigated. LIBS is an elemental analysis method, which is based on the emission from plasma generated by focusing a laser beam into the medium. This technology has been reported to be applicable in the media of solids, liquids (includes molten metals), and gases for detecting elements of special nuclear materials. The advantages of applying the technology for pyroprocessing facilities are: (i) Rapid real-time elemental analysis|one measurement/laser pulse, or average spectra from multiple laser pulses for greater accuracy in < 2 minutes; (ii) Direct detection of elements and impurities in the system with low detection limits|element specific, ranging from 2-1000 ppm for most elements; and (iii) Near non-destructive elemental analysis method (about 1 g material). One important challenge to overcome is achieving high-resolution spectral analysis to quantitatively analyze all important fission products and actinides. Another important challenge is related to accessibility of molten salt, which is heated in a heavily insulated, remotely operated furnace in a high radiation environment with an argon atmosphere.

  11. Optical emission spectroscopy of carbon laser plasma ion source

    Science.gov (United States)

    Balki, Oguzhan; Rahman, Md. Mahmudur; Elsayed-Ali, Hani E.

    2018-04-01

    Carbon laser plasma generated by an Nd:YAG laser (wavelength 1064 nm, pulse width 7 ns, fluence 4-52 J cm-2) is studied by optical emission spectroscopy and ion time-of-flight. Up to C4+ ions are detected with the ion flux strongly dependent on the laser fluence. The increase in ion charge with the laser fluence is accompanied by observation of multicharged ion lines in the optical spectra. The time-integrated electron temperature Te is calculated from the Boltzmann plot using the C II lines at 392.0, 426.7, and 588.9 nm. Te is found to increase from ∼0.83 eV for a laser fluence of 22 J cm-2 to ∼0.90 eV for 40 J cm-2. The electron density ne is obtained from the Stark broadened profiles of the C II line at 392 nm and is found to increase from ∼ 2 . 1 × 1017cm-3 for 4 J cm-2 to ∼ 3 . 5 × 1017cm-3 for 40 J cm-2. Applying an external electric field parallel to the expanding plume shows no effect on the line emission intensities. Deconvolution of ion time-of-flight signal with a shifted Maxwell-Boltzmann distribution for each charge state results in an ion temperature Ti ∼4.7 and ∼6.0 eV for 20 and 36 J cm-2, respectively.

  12. Metal surface nitriding by laser induced plasma

    Science.gov (United States)

    Thomann, A. L.; Boulmer-Leborgne, C.; Andreazza-Vignolle, C.; Andreazza, P.; Hermann, J.; Blondiaux, G.

    1996-10-01

    We study a nitriding technique of metals by means of laser induced plasma. The synthesized layers are composed of a nitrogen concentration gradient over several μm depth, and are expected to be useful for tribological applications with no adhesion problem. The nitriding method is tested on the synthesis of titanium nitride which is a well-known compound, obtained at present by many deposition and diffusion techniques. In the method of interest, a laser beam is focused on a titanium target in a nitrogen atmosphere, leading to the creation of a plasma over the metal surface. In order to understand the layer formation, it is necessary to characterize the plasma as well as the surface that it has been in contact with. Progressive nitrogen incorporation in the titanium lattice and TiN synthesis are studied by characterizing samples prepared with increasing laser shot number (100-4000). The role of the laser wavelength is also inspected by comparing layers obtained with two kinds of pulsed lasers: a transversal-excited-atmospheric-pressure-CO2 laser (λ=10.6 μm) and a XeCl excimer laser (λ=308 nm). Simulations of the target temperature rise under laser irradiation are performed, which evidence differences in the initial laser/material interaction (material heated thickness, heating time duration, etc.) depending on the laser features (wavelength and pulse time duration). Results from plasma characterization also point out that the plasma composition and propagation mode depend on the laser wavelength. Correlation of these results with those obtained from layer analyses shows at first the important role played by the plasma in the nitrogen incorporation. Its presence is necessary and allows N2 dissociation and a better energy coupling with the target. Second, it appears that the nitrogen diffusion governs the nitriding process. The study of the metal nitriding efficiency, depending on the laser used, allows us to explain the differences observed in the layer features

  13. In situ measurements of fuel retention by laser induced desorption spectroscopy in TEXTOR

    Science.gov (United States)

    Zlobinski, M.; Philipps, V.; Schweer, B.; Huber, A.; Stoschus, H.; Brezinsek, S.; Samm, U.; TEXTOR Team

    2011-12-01

    In future fusion devices such as ITER tritium retention due to tritium co-deposition in mixed material layers can be a serious safety problem. Laser induced desorption spectroscopy (LIDS) can measure the hydrogen content of hydrogenic carbon layers locally on plasma-facing components, while hydrogen is used as a tritium substitute. For several years, this method has been applied in the TEXTOR tokamak in situ during plasma operation to monitor the hydrogen content in space and time. This work shows the LIDS signal reproducibility and studies the effects of different plasma conditions, desorption distances from the plasma and different laser energies using a dedicated sample with constant hydrogen amount. Also the LIDS signal evaluation procedure is described in detail and the detection limits for different conditions in the TEXTOR tokamak are estimated.

  14. Determination of a brass alloy concentration composition using calibration-free laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Achouri, M.; Baba-Hamed, T.; Beldjilali, S. A., E-mail: sidahmed.beldjilali@univ-usto.dz; Belasri, A. [Université des Sciences et de la Technologie d’Oran Mohamed Boudiaf USTO-MB, LPPMCA (Algeria)

    2015-09-15

    Laser-induced breakdown spectroscopy (LIBS) is a technique that can provide qualitative and quantitative measurements of the characteristics of irradiated metals. In the present work, we have calculated the parameters of the plasma produced from a brass alloy sample under the action of a pulsed Nd: YAG laser operating at 1064 nm. The emission lines of copper atoms (Cu I), zinc atoms (Zn I), and lead atoms (Pb I), which are elements of a brass alloy composition, were used to investigate the parameters of the brass plasma. The spectral profiles of Cu, Zn, and Pb lines have been used to extract the electron temperature and density of the brass alloy plasma. The characteristics of Cu, Zn, and Pb were determined quantatively by the calibration-free LIBS (CF-LIBS) method considering for accurate analysis that the laser-induced ablated plasma is optically thin in local thermodynamic equilibrium conditions and the plasma ablation is stoichiometric. The Boltzmann plot method was used to evaluate the plasma temperature, and the Stark broadened profiles were used to determine the electron density. An algorithm based on the experimentally measured values of the intensity of spectral lines and the basic laws of plasma physics was developed for the determination of Cu, Zn, and Pb concentrations in the brass sample. The concentrations C{sub CF-LIBS} calculated by CF-LIBS and the certified concentrations C{sub certified} were very close.

  15. Combination of laser-induced breakdown spectroscopy and Raman spectroscopy for multivariate classification of bacteria

    Czech Academy of Sciences Publication Activity Database

    Procházka, D.; Mazura, M.; Samek, Ota; Rebrošová, K.; Pořízka, P.; Klus, J.; Procházková, P.; Novotný, J.; Novotný, K.; Kaiser, J.

    2018-01-01

    Roč. 139 (2018), s. 6-12 ISSN 0584-8547 R&D Projects: GA ČR(CZ) GA15-20645S; GA ČR(CZ) GA16-12477S; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : laser-induced breakdown spectroscopy * Raman spectroscopy * chemometrics * bacteria Impact factor: 3.241, year: 2016

  16. Plasma-cavity ringdown spectroscopy for analytical measurement: Progress and prospectives

    Science.gov (United States)

    Zhang, Sida; Liu, Wei; Zhang, Xiaohe; Duan, Yixiang

    2013-07-01

    Plasma-cavity ringdown spectroscopy is a powerful absorption technique for analytical measurement. It combines the inherent advantages of high sensitivity, absolute measurement, and relative insensitivity to light source intensity fluctuations of the cavity ringdown technique with use of plasma as an atomization/ionization source. In this review, we briefly describe the background and principles of plasma-cavity ringdown spectroscopy(CRDS) technology, the instrumental components, and various applications. The significant developments of the plasma sources, lasers, and cavity optics are illustrated. Analytical applications of plasma-CRDS for elemental detection and isotopic measurement in atomic spectrometry are outlined in this review. Plasma-CRDS is shown to have a promising future for various analytical applications, while some further efforts are still needed in fields such as cavity design, plasma source design, instrumental improvement and integration, as well as potential applications in radical and molecular measurements.

  17. Towards reconstruction of overlapping fingerprints using plasma spectroscopy

    Science.gov (United States)

    Yang, Jun-Ho; Choi, Soo-Jin; Yoh, Jack J.

    2017-08-01

    Chemical analysis is commonly used in the field of forensic science where the precise discrimination of primary evidence is of significant importance. Laser-Induced Breakdown Spectroscopy (LIBS) exceeds other spectroscopic methods in terms of the time required for pre- and post-sample preparation, the insensitivity to sample phase state be it solid, liquid, or gas, and the detection of two-dimensional spectral mapping from real time point measurements. In this research, fingerprint samples on various surface materials are considered in the chemical detection and reconstruction of fingerprints using the two-dimensional LIBS technique. Strong and distinct intensities of specific wavelengths represent visible ink, natural secretion of sweat, and contaminants from the environment, all of which can be present in latent fingerprints. The particular aim of the work presented here is to enhance the precision of the two-dimensional recreation of the fingerprints present on metal, plastic, and artificially prepared soil surface using LIBS with principal component analysis. By applying a distinct wavelength discrimination for two overlapping fingerprint samples, separation into two non-identical chemical fingerprints was successfully performed.

  18. Spatially resolved emission spectroscopic investigation of microwave-induced reactive low-power plasma jets

    International Nuclear Information System (INIS)

    Arnold, Thomas; Grabovski, Sergey; Schindler, Axel; Wagner, Hans-Erich

    2004-01-01

    A microwave-induced Ar/SF 6 plasma jet is characterized by means of optical emission spectroscopy. Rotational temperatures from unresolved N 2 bands and excitation temperatures from Fe lines as well as electron densities (H β Stark broadening) have been estimated along the plasma jet axis using a side-on configuration. The SF 6 gas flow rate and chamber pressure were varied from 10 to 250 sccm and 20 to 500 mbar, respectively. Three characteristic jet regions have been observed: the plasma ignition zone, followed by the gas mixing zone and a relaxing zone

  19. Detection and evaluation of uranium in different minerals by gamma spectrometry and laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Sergani, F.M.; Khedr, M.A.; Harith, M.A.; El Mongy, S.A.

    2004-01-01

    Analysis, detection and evaluation of source nuclear materials (e.g. uranium) in different minerals by sensitive techniques are a vital objective for uranium exploration, nuclear materials extraction, processing and verification. In this work, uranium in different geological formations was determined using gamma spectrometry and laser induced breakdown spectroscopy (LIBS). The investigated samples were collected from different regions distributed all over Egypt. The samples were then prepared for non-destructive analysis. A hyper pure germanium detector was used to measure the emitted gamma rays of uranium and its daughters in the samples. The concentrations of uranium in ppm (μg/g) in the investigated samples are given and discussed in this work. The highest uranium concentration (4354.9 ppm) was found in uranophane samples of Gattar rocks. In Laser induced breakdown spectroscopy (LIBS) technique, plasma was formed by irradiating the rock surface with focused Q-switched Nd:Yag laser pulses of 7 ns pulse duration at the fundamental wavelength (1064 nm). Atoms and ions originating from the rock surface are excited and ionized in the laser produced hot plasma (∝10 000 K). The plasma emission spectral line is characteristic of the elements present in the plasma and allows identification of the uranium in the uranophane mineral. The strong atomic line at 424.2 nm is used for the qualitative identification of uranium. It can be mentioned that the elevated levels of uranium in some of the investigated uranophane samples are of great economic feasibility to be extracted. (orig.)

  20. Optimization of laser-induced breakdown spectroscopy for coal powder analysis with different particle flow diameters

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Shunchun, E-mail: epscyao@scut.edu.cn [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China); State Key Laboratory of Pulsed Power Laser Technology, Electronic Engineering Institute, Hefei 230037 (China); Xu, Jialong; Dong, Xuan; Zhang, Bo; Zheng, Jianping [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China); Lu, Jidong, E-mail: jdlu@scut.edu.cn [School of Electric Power, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    2015-08-01

    The on-line measurement of coal is extremely useful for emission control and combustion process optimization in coal-fired plant. Laser-induced breakdown spectroscopy was employed to directly analyze coal particle flow. A set of tapered tubes were proposed for beam-focusing the coal particle flow to different diameters. For optimizing the measurement of coal particle flow, the characteristics of laser-induced plasma, including optical breakdown, the relative standard deviation of repeated measurement, partial breakdown spectra ratio and line intensity, were carefully analyzed. The comparison of the plasma characteristics among coal particle flow with different diameters showed that air breakdown and the random change in plasma position relative to the collection optics could significantly influence on the line intensity and the reproducibility of measurement. It is demonstrated that the tapered tube with a diameter of 5.5 mm was particularly useful to enrich the coal particles in laser focus spot as well as to reduce the influence of air breakdown and random changes of plasma in the experiment. - Highlights: • Tapered tube was designed for beam-focusing the coal particle flow as well as enriching the particles in laser focus spot. • The characteristics of laser-induced plasma of coal particle flow were investigated carefully. • An appropriate diameter of coal particle flow was proven to benefit for improving the performance of LIBS measurement.

  1. Laser-induced breakdown spectroscopy measurement of a small fraction of rhenium in bulk tungsten

    Science.gov (United States)

    Nishijima, D.; Ueda, Y.; Doerner, R. P.; Baldwin, M. J.; Ibano, K.

    2018-03-01

    Laser-induced breakdown spectroscopy (LIBS) of bulk rhenium (Re) and tungsten (W)-Re alloy has been performed using a Q-switched Nd:YAG laser (wavelength = 1064 nm, pulse width ∼4-6 ns, laser energy = 115 mJ). It is found that the electron temperature, Te, of laser-induced Re plasma is lower than that of W plasma, and that Te of W-Re plasma is in between Re and W plasmas. This indicates that material properties affect Te in a laser-induced plasma. For analysis of W-3.3%Re alloy, only the strongest visible Re I 488.9 nm line is found to be used because of the strong enough intensity without contamination with W lines. Using the calibration-free LIBS method, the atomic fraction of Re, cRe, is evaluated as a function of the ambient Ar gas pressure, PAr. At PAr 10 Torr due to spectral overlapping of the Re I 488.9 nm line by an Ar II 488.9 nm line.

  2. Railgun system using a laser-induced plasma armature

    International Nuclear Information System (INIS)

    Onozuka, M.; Oda, Y.; Azuma, K.

    1996-01-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun. copyright 1996 American Institute of Physics

  3. Railgun system using a laser-induced plasma armature

    Science.gov (United States)

    Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo

    1996-05-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun.

  4. Railgun system using a laser-induced plasma armature

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Oda, Y.; Azuma, K. [Mitsubishi Heavy Industries, Ltd., 3-3-1, Minatomirai, Nishi-ku, Yokohama 220-84 (Japan)

    1996-05-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun. {copyright} {ital 1996 American Institute of Physics.}

  5. Emission Spectroscopy of OH Radical in Water-Argon Arc Plasma Jet

    Czech Academy of Sciences Publication Activity Database

    Mašláni, Alan; Sember, Viktor

    2014-01-01

    Roč. 2014, April (2014), "952138"-"952138" ISSN 2314-4920 R&D Projects: GA ČR GAP205/11/2070 Institutional support: RVO:61389021 Keywords : Emission spectroscopy * OH radical * arc plasma jet Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.538, year: 2014 http://www.hindawi.com/journals/jspec/2014/952138/abs/

  6. 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)

  7. Proceedings of the 3rd US-Japan Workshop on Plasma Polarization Spectroscopy

    International Nuclear Information System (INIS)

    Beiersdorfer, P; Flyimoto, T

    2002-01-01

    The third US-Japan Workshop on Plasma Polarization Spectroscopy was held at the Lawrence Livermore National Laboratory in Livermore, California, on June 18-21, 2001. The talks presented at this workshop are summarized in these proceedings. The papers cover both experimental investigation and applications of plasma polarization spectroscopy as well as the theoretical foundation and formalisms to understand and describe the polarization phenomena. The papers give an overview of the history of plasma polarization spectroscopy, derive the formal aspects of polarization spectroscopy, including the effects of electric and magnetic fields, discuss spectra perturbed by intense microwave fields, charge exchange, and dielectronic recombination, and present calculations of various collisional excitation and ionization cross sections and the modeling of plasma polarization spectroscopy phenomena. Experimental results are given from the WT-3 tokamak, the MST reverse field pinch, the Large Helical Device, the GAMMA 10 mirror machine, the Nevada Terrawatt Facility, the Livermore EBIT-II electron beam ion trap, and beam-foil spectroscopy. In addition, results were presented from studies of several laser-produced plasma experiments and new instrumental techniques were demonstrated

  8. Influence of Lead on the Interpretation of Bone Samples with Laser-Induced Breakdown Spectroscopy

    Directory of Open Access Journals (Sweden)

    Abdolhamed Shahedi

    2016-01-01

    Full Text Available This study is devoted to tracing and identifying the elements available in bone sample using Laser-Induced Breakdown Spectroscopy (LIBS. The bone samples were prepared from the thigh of laboratory rats, which consumed 325.29 g/mol lead acetate having 4 mM concentration in specified time duration. About 76 atomic lines have been analyzed and we found that the dominant elements are Ca I, Ca II, Mg I, Mg II, Fe I, and Fe II. Temperature curve and bar graph were drawn to compare bone elements of group B which consumed lead with normal group, group A, in the same laboratory conditions. Plasma parameters including plasma temperature and electron density were determined by considering Local Thermodynamic Equilibrium (LTE condition in the plasma. An inverse relationship has been detected between lead absorption and elements like Calcium and Magnesium absorption comparing elemental values for both the groups.

  9. Overview of applications of Laser-Induced Breakdown Spectroscopy (LIBS)

    International Nuclear Information System (INIS)

    Cremers, D.A.

    1987-01-01

    Laser-induced breakdown spectroscopy (LIBS) is a method of performing elemental analyses of solids, liquids, and gases using the microplasma produced by a focused laser pulse. Because the microplasma is formed by optical radiation, LIBS has some important advantages compared to conventional laboratory based analytical methods. Three applications are discussed which use the LIBS method. 6 refs., 8 figs., 2 tabs

  10. Formation dynamics of UV and EUV induced hydrogen plasma

    NARCIS (Netherlands)

    Dolgov, A.A.; Lee, Christopher James; Yakushev, O.; Lopaev, D.V.; Abrikosov, A.; Krivtsun, V.M.; Zotovich, A.; Bijkerk, F.

    2014-01-01

    The comparative study of the dynamics of ultraviolet (UV) and extreme ultraviolet (EUV) induced hydrogen plasma was performed. It was shown that for low H2 pressures and bias voltages, the dynamics of the two plasmas are significantly different. In the case of UV radiation, the plasma above the

  11. Remote imaging laser-induced breakdown spectroscopy and laser-induced fluorescence spectroscopy using nanosecond pulses from a mobile lidar system.

    Science.gov (United States)

    Grönlund, Rasmus; Lundqvist, Mats; Svanberg, Sune

    2006-08-01

    A mobile lidar system was used in remote imaging laser-induced breakdown spectroscopy (LIBS) and laser-induced fluorescence (LIF) experiments. Also, computer-controlled remote ablation of a chosen area was demonstrated, relevant to cleaning of cultural heritage items. Nanosecond frequency-tripled Nd:YAG laser pulses at 355 nm were employed in experiments with a stand-off distance of 60 meters using pulse energies of up to 170 mJ. By coaxial transmission and common folding of the transmission and reception optical paths using a large computer-controlled mirror, full elemental imaging capability was achieved on composite targets. Different spectral identification algorithms were compared in producing thematic data based on plasma or fluorescence light.

  12. Calculation of the spatial resolution in two-photon absorption spectroscopy applied to plasma diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Lechuga, M. [Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, 47011-Valladolid (Spain); Laser Processing Group, Instituto de Óptica “Daza de Valdés,” CSIC, 28006-Madrid (Spain); Fuentes, L. M. [Departamento de Física Aplicada, Universidad de Valladolid, 47011-Valladolid (Spain); Grützmacher, K.; Pérez, C., E-mail: concha@opt.uva.es; Rosa, M. I. de la [Departamento de Física Teórica, Atómica y Óptica, Universidad de Valladolid, 47011-Valladolid (Spain)

    2014-10-07

    We report a detailed characterization of the spatial resolution provided by two-photon absorption spectroscopy suited for plasma diagnosis via the 1S-2S transition of atomic hydrogen for optogalvanic detection and laser induced fluorescence (LIF). A precise knowledge of the spatial resolution is crucial for a correct interpretation of measurements, if the plasma parameters to be analysed undergo strong spatial variations. The present study is based on a novel approach which provides a reliable and realistic determination of the spatial resolution. Measured irradiance distribution of laser beam waists in the overlap volume, provided by a high resolution UV camera, are employed to resolve coupled rate equations accounting for two-photon excitation, fluorescence decay and ionization. The resulting three-dimensional yield distributions reveal in detail the spatial resolution for optogalvanic and LIF detection and related saturation due to depletion. Two-photon absorption profiles broader than the Fourier transform-limited laser bandwidth are also incorporated in the calculations. The approach allows an accurate analysis of the spatial resolution present in recent and future measurements.

  13. Calculation of the spatial resolution in two-photon absorption spectroscopy applied to plasma diagnosis

    International Nuclear Information System (INIS)

    Garcia-Lechuga, M.; Fuentes, L. M.; Grützmacher, K.; Pérez, C.; Rosa, M. I. de la

    2014-01-01

    We report a detailed characterization of the spatial resolution provided by two-photon absorption spectroscopy suited for plasma diagnosis via the 1S-2S transition of atomic hydrogen for optogalvanic detection and laser induced fluorescence (LIF). A precise knowledge of the spatial resolution is crucial for a correct interpretation of measurements, if the plasma parameters to be analysed undergo strong spatial variations. The present study is based on a novel approach which provides a reliable and realistic determination of the spatial resolution. Measured irradiance distribution of laser beam waists in the overlap volume, provided by a high resolution UV camera, are employed to resolve coupled rate equations accounting for two-photon excitation, fluorescence decay and ionization. The resulting three-dimensional yield distributions reveal in detail the spatial resolution for optogalvanic and LIF detection and related saturation due to depletion. Two-photon absorption profiles broader than the Fourier transform-limited laser bandwidth are also incorporated in the calculations. The approach allows an accurate analysis of the spatial resolution present in recent and future measurements.

  14. Analysis of two colliding laser-produced plasmas by emission spectroscopy and fast photography

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Ake, C., E-mail: citlali.sanchez@ccadet.unam.m [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-186, Mexico D.F., C.P. 04510 (Mexico); Mustri-Trejo, D. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-186, Mexico D.F., C.P. 04510 (Mexico); Garcia-Fernandez, T. [Universidad Autonoma de la Ciudad de Mexico, Prolongacion San Isidro 151, Col. San Lorenzo Tezonco, Mexico DF, C.P. 09790 (Mexico); Villagran-Muniz, M. [Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-186, Mexico D.F., C.P. 04510 (Mexico)

    2010-05-15

    In this work two colliding laser-induced plasmas (LIP) on Cu and C were studied by means of time resolved emission spectroscopy and fast photography. The experiments were performed using two opposing parallel targets of Cu and C in vacuum, ablated with two synchronized ns lasers. The results showed an increased emission intensity from copper ions Cu II (368.65, 490.97, 493.16, 495.37 and 630.10 nm) and Cu III (374.47 and 379.08 nm) due to the ionization that occurs during collisions of Cu and C species. It was found that the optimum delay between pulses, which yields the maximum emission enhancement of Cu ions, depends on the sampling distance. On the other hand, the emission intensity of C lines, C II (426.70 nm), C III (406.99 and 464.74 nm) and C IV (465.83 nm), decreased and the formation of C{sub 2} molecules was observed. A comparison between the temporal evolution of the individual plasmas and their collision performed by combining imaging and the time resolved emission diagnostics, revealed an increase of the electron temperature and electron density and the splitting of the plume into slow and fast components.

  15. Plasma-cavity ringdown spectroscopy for analytical measurement: Progress and prospectives

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Sida; Liu, Wei [Research Center of Analytical Instrumentation, Analytical and Testing Center, College of Chemistry, Sichuan University, Chengdu (China); Zhang, Xiaohe [College of Water Resources and Hydropower, Sichuan University, Chengdu (China); Duan, Yixiang, E-mail: yduan@scu.edu.cn [Research Center of Analytical Instrumentation, Analytical and Testing Center, College of Chemistry, Sichuan University, Chengdu (China)

    2013-07-01

    Plasma-cavity ringdown spectroscopy is a powerful absorption technique for analytical measurement. It combines the inherent advantages of high sensitivity, absolute measurement, and relative insensitivity to light source intensity fluctuations of the cavity ringdown technique with use of plasma as an atomization/ionization source. In this review, we briefly describe the background and principles of plasma-cavity ringdown spectroscopy(CRDS) technology, the instrumental components, and various applications. The significant developments of the plasma sources, lasers, and cavity optics are illustrated. Analytical applications of plasma-CRDS for elemental detection and isotopic measurement in atomic spectrometry are outlined in this review. Plasma-CRDS is shown to have a promising future for various analytical applications, while some further efforts are still needed in fields such as cavity design, plasma source design, instrumental improvement and integration, as well as potential applications in radical and molecular measurements. - Highlights: • Plasma-based cavity ringdown spectroscopy • High sensitivity and high resolution • Elemental and isotopic measurements.

  16. High resolution X-ray spectroscopy of thermal plasmas

    International Nuclear Information System (INIS)

    Canizares, C.R.

    1990-01-01

    This paper concentrates on reviewing highlights of the Focal Plane Crystal Spectrometer (FPCS) results on thermal plasmas, particularly supernova remnants (SNRs) and clusters of galaxies from the Einstein observatory. During Einstein's short but happy life, we made over 400 observations with the FPCS of 40 different objects. Three quarters of these were objects in which the emission was primarily from optically thin thermal plasma, primarily supernova remnants (SNRs) and clusters of galaxies. Thermal plasmas provide an excellent illustration of how spectral data, particularly high resolution spectral data, can be an important tool for probing the physical properties of astrophysical objects. (author)

  17. Plasma wave detection in laser spectroscopy and gas chromatography

    International Nuclear Information System (INIS)

    Franzke, J.; Irmer, A. von; Veza, D.; Niemax, K.

    1995-01-01

    Frequency changes of plasma oscillations in low-pressure discharges are used for sensitive detection of atomic or molecular trace gases. Analyte selectivity can be either obtained by resonant laser excitation or by gas chromatography

  18. Spectroscopy of X-ray Photoionized Plasmas in the Laboratory

    Science.gov (United States)

    Liedahl, Duane A.; Loisel, Guillaume; Bailey, James E.; Nagayama, Taisuke; Hansen, Stephanie B.; Rochau, Gregory; Fontes, Christopher J.; Mancini, Roberto; Kallman, Timothy R.

    2018-06-01

    The physical processes operating in astrophysical plasmas --- heating, cooling, ionization, recombination, level population kinetics, and radiation transport --- are all accessible to observation in the laboratory. What distinguishes X-ray photoionized plasmas from the more common case of high-temperature collisionally-ionized plasmas is the elevated level of importance of the radiation/matter interaction. The advent of laboratory facilities with the capability to generate high-powered X-ray sources has provided the means by which to study this interaction, which is also fundamental to active galactic nuclei and other accretion-powered objects. We discuss recent and ongoing experiments, with an emphasis on X-ray spectroscopic measurements of silicon plasmas obtained at the Sandia Z Pulsed Power Facility.

  19. Characterisation of a micro-plasma device sensor using electrical measurements and emission spectroscopy

    International Nuclear Information System (INIS)

    Mariotti, D.

    2002-04-01

    This thesis reports on research undertaken on the characterisation of a micro-plasma device to be used for gas analysis by mean of plasma emission spectroscopy. The work covers aspects related to the micro-plasma electrical and optical emission parameters, and their importance for the utilisation of the micro-plasma device in gas analysis. Experimental results have been used to analyse the fundamental micro-plasma processes and to develop a model, which could provide additional information. This dissertation contains a general literature review of topics related to plasma physics, plasma emission spectroscopy, gas analysis (chemical analysis and artificial olfaction) and other micro-plasma applications. Experimental work focuses on two main areas: electrical measurements and emission measurements. Firstly, electrical measurements are taken and interpretations are given. Where necessary, new theoretical treatments are suggested in order to describe better the physical phenomena. Plasma emission has been considered under different working conditions. This allowed the characterisation of the micro-plasma emission and also a better understanding of the micro-plasma processes. On the basis of the experimental data obtained and other assumptions a model has been developed. A computer simulation based on this model provided additional useful information on the micro- plasma behaviour. The first fundamental implication of this new research is the peculiar behaviour of the micro-plasma. This micro-plasma exhibited deviations from Paschen law and strong dependency on cathode material, which contributed to the formation of a low current stable regime. These results have been followed by physical interpretations and theoretical descriptions. The second implication is the establishment of the boundaries and of the influencing parameters for plasma emission spectroscopy as an analytical tool in this particular micro-plasma. From the applied perspective this study has shown that

  20. Optical spectroscopy of free-propagating plasma and its interaction with tungsten targets in PF-1000 facility

    Energy Technology Data Exchange (ETDEWEB)

    Skladnik-Sadowska, E.; Malinowski, K. [The Andrzej Soltan Institute for Nuclear Studies, IPJ, 05-400 Otwock-Swierk (Poland); Sadowski, M.J. [The Andrzej Soltan Institute for Nuclear Studies, IPJ, 05-400 Otwock-Swierk (Poland)] [Institute of Plasma Physics and Laser Microfusion, IPPLM, 01-497 Warsaw (Poland); Kubkowska, M.; Jakubowska, K.; Paduch, M.; Scholz, M. [Institute of Plasma Physics and Laser Microfusion, IPPLM, 01-497 Warsaw (Poland); Garkusha, I.E.; Ladygina, M.; Tereshin, V.I. [Institute of Plasma Physics, NSC KIPT, 61-108 Kharkov (Ukraine)

    2011-07-01

    The paper reports on optical spectroscopy of pulsed plasma streams during their free propagation within a vacuum chamber and their interaction with tungsten targets. Experiments were performed with the PF-1000 facility and particular attention was paid to improvements in spectroscopic diagnostics techniques. In contrary to preliminary studies, the recent spectroscopic measurements of the free plasma streams were carried out perpendicular to the z-axis and at a larger distance from the electrode outlet. The center of the observation quartz-window was located at z = 30 cm in order to observe first a pure deuterium-plasma stream, and later on some heavy impurities which might reach that distance with a delay induced by differences in their production and time-of-flight. The recorded spectral lines were identified by means of a Kurucz database. It was confirmed that at the pure D{sub 2}-filling the PF-1000 facility emits first the deuterium-plasma stream and one can observe intense deuterium Balmer lines, but at a distance z = 30 cm, after about 2 microseconds there appear many impurity lines originating mainly from the Cu-electrodes, i.e. Cu-lines. The second part of the experiment concerned the spectroscopic measurements of metal plasma 'pillow' produced by the plasma stream impinging upon a solid target made of pure tungsten. The described measurements enabled the most intense spectral lines to be identified. This document is composed of an abstract followed by the slides of the presentation

  1. Determination of Rare Earth Elements in Geological Samples Using Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Bhatt, Chet R; Jain, Jinesh C; Goueguel, Christian L; McIntyre, Dustin L; Singh, Jagdish P

    2018-01-01

    Laser-induced breakdown spectroscopy (LIBS) was used to detect rare earth elements (REEs) in natural geological samples. Low and high intensity emission lines of Ce, La, Nd, Y, Pr, Sm, Eu, Gd, and Dy were identified in the spectra recorded from the samples to claim the presence of these REEs. Multivariate analysis was executed by developing partial least squares regression (PLS-R) models for the quantification of Ce, La, and Nd. Analysis of unknown samples indicated that the prediction results of these samples were found comparable to those obtained by inductively coupled plasma mass spectrometry analysis. Data support that LIBS has potential to quantify REEs in geological minerals/ores.

  2. Impurity diagnosis of a KSTAR graphite divertor tile using laser induced breakdown spectroscopy technique

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minju; Cho, Min Sang; Cho, Byoung Ick, E-mail: bicho@gist.ac.kr

    2017-04-15

    Laser induced breakdown spectroscopy (LIBS) has been tested to diagnose impurity elements on a Korea Superconducting Tokamak Advanced Research (KSTAR) divertor tile. Spectral lines of various impurity elements such as iron, chromium, and nickel were detected from the divertor surface. The variation of spectra with consecutive laser pulses demonstrates the potential for depth profiling analysis for the deposited impurity layer. The LIBS plasma parameters have been qualitatively determined from analysis of the relative line intensities and linewidths for each element. The validity of this analysis has been checked with atomic spectral simulations.

  3. Roughness effects on the hydrogen signal in laser-induced breakdown spectroscopy

    DEFF Research Database (Denmark)

    Rapin, W.; Bousquet, B.; Lasue, J.

    2017-01-01

    On Mars, Laser-Induced Breakdown Spectroscopy (LIBS) as performed by the ChemCam instrument can be used to measure the hydrogen content of targets in situ, under a low pressure CO2 atmosphere. However, unexpected variations observed in the Martian dataset suggest an effect related to target...... to hydrogen, as other emission lines in the spectra are not affected. The increase of the signal could be related to an addition of hydrogen to the plasma due to interaction with the surrounding target surface, yet the exact physical process to explain such effect remains to be identified. More generally...

  4. Investigations of GMAW plasma by optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zielinska, S [Instytut Fizyki im. Mariana Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Musiol, K [Instytut Fizyki im. Mariana Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Dzierzega, K [Instytut Fizyki im. Mariana Smoluchowskiego, Uniwersytet Jagiellonski, ulica Reymonta 4, 30-059 Krakow (Poland); Pellerin, S [LASEP, Faculte des Sciences-Bourges, Universite d' Orleans, BP 4043, 18028 Bourges Cedex (France); Valensi, F [LASEP, Faculte des Sciences-Bourges, Universite d' Orleans, BP 4043, 18028 Bourges Cedex (France); Izarra, Ch de [LASEP, Faculte des Sciences-Bourges, Universite d' Orleans, BP 4043, 18028 Bourges Cedex (France); Briand, F [CTAS - Air Liquide Welding, Rue des Epluches, Saint Ouen l' Aumone (France)

    2007-11-15

    We report on investigations of gas metal arc welding plasma operated in pure argon and in a mixture of argon and CO{sub 2} at a dc current of 326 A. The spatially resolved electron densities and temperatures were directly obtained by measuring the Stark widths of the Ar I 695.5 nm and Fe I 538.3 nm spectral lines. Our experimental results show a reduction of the plasma conductivity and transfer from spray arc to globular arc operation with increasing CO{sub 2} concentration. Although the electron density n{sub e} increases while approaching the core of the plasma in the spray-arc mode, a drop in the electron temperature T{sub e} is observed. Moreover, the maximum T{sub e} that we measure is about 13 000 K. Our experimental results differ from the Haidar model where T{sub e} is always maximum on the arc axis and its values exceed 20 000 K. These discrepancies can be explained as a result of underestimation of the amount of metal vapours in the plasma core and of the assumption of local thermal equilibrium plasma in the model.

  5. fabrics induced by cold plasma treatments

    Indian Academy of Sciences (India)

    Some selective cold plasma processing modify specific surface properties of ... obtain information on the chemical and physical processing involved in ... charges of suitable gases. such plasma species can give rise to several concurrent.

  6. Plasma diagnostics in the CECI device through visible spectroscopy

    International Nuclear Information System (INIS)

    Ueda, M.; Kayama, M.E.; Aso, Y.

    1991-11-01

    In this paper we discuss the application of a visible spectrometer which was used to diagnose a plasma produced in an RFP device, called CECI. A Jobin Yvon, HR-640 S spectrometer with a photomultiplier detector was used to measure the Doppler broadening of lines emitted by the plasma, and allowed to measure the ion temperatures of the order of 2-3 eV. The electron temperature of 40-50 eV was determined by the method of He I line intensity ratio. The spectroscopically determined ion temperature is in better accordance with the 10 eV electron temperature obtained with an electrostatic probe. The line emissions of He II, H I, C II and O II were compared with signals from other diagnostics, and their correlations indicated the presence of MHD instabilities in the plasma. (author)

  7. Applications of laser-induced gratings to spectroscopy and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Rohlfing, E.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program has traditionally emphasized two principal areas of research. The first is the spectroscopic characterization of large-amplitude motion on the ground-state potential surface of small, transient molecules. The second is the reactivity of carbonaceous clusters and its relevance to soot and fullerene formation in combustion. Motivated initially by the desire to find improved methods of obtaining stimulated emission pumping (SEP) spectra of transients, most of our recent work has centered on the use of laser-induced gratings or resonant four-wave mixing in free-jet expansions. These techniques show great promise for several chemical applications, including molecular spectroscopy and photodissociation dynamics. The author describes recent applications of two-color laser-induced grating spectroscopy (LIGS) to obtain background-free SEP spectra of transients and double resonance spectra of nonfluorescing species, and the use of photofragment transient gratings to probe photodissociation dynamics.

  8. Biopolymer nanostructures induced by plasma irradiation and metal sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Juřík, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Malinský, P.; Macková, A. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Prague 25068 (Czech Republic); Faculty of Science, J.E. Purkyně University, Ústí nad Labem (Czech Republic); Kasálková, N. Slepičková; Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

    2014-08-01

    Modification based on polymer surface exposure to plasma treatment exhibits an easy and cheap technique for polymer surface nanostructuring. The influence of argon plasma treatment on biopolymer poly(L-lactide acid (PLLA) will be presented in this paper. The combination of Ar{sup +} ion irradiation, consequent sputter metallization (platinum) and thermal annealing of polymer surface will be summarized. The surface morphology was studied using atomic force microscopy. The Rutherford Backscattering Spectroscopy and X-ray Photoelectron Spectroscopy were used as analytical methods. The combination of plasma treatment with consequent thermal annealing and/or metal sputtering led to the change of surface morphology and its elemental ratio. The surface roughness and composition has been strongly influenced by the modification parameters and metal layer thickness. By plasma treatment of polymer surface combined with consequent annealing or metal deposition can be prepared materials applicable both in tissue engineering as cell carriers, but also in integrated circuit manufacturing.

  9. High resolution X-ray spectroscopy of laser generated plasmas

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Skobelev, I.Yu.; Rosmej, F.B.

    1999-01-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.)

  10. Electron temperature measurements in lowdensity plasmas by helium spectroscopy

    International Nuclear Information System (INIS)

    Brenning, N.

    1977-09-01

    This method to use relative intensities of singlet and triplet lines of neutral helium to measure electron temperature in low-density plasmas is examined. Calculations from measured and theoretical data about transitions in neutral helium are carried out and compared to experimental results. It is found that relative intensities of singlet and triplet lines from neutral helium only can be used for TE determination in low-density, short-duration plasmas. The most important limiting processes are excitation from the metastable 2 3 S level and excitation transfer in collisions between electrons and excited helium atoms. An evaluation method is suggested, which minimizes the effect of these processes. (author)

  11. High resolution X-ray spectroscopy of laser generated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A.Ya.; Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo (Russian Federation); Rosmej, F.B. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik

    1999-11-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.) 28 refs.

  12. Analysis of organic pollutant degradation in pulsed plasma by coherent anti-Stokes Raman spectroscopy

    International Nuclear Information System (INIS)

    Bratescu, Maria Antoneta; Hieda, Junko; Umemura, Tomonari; Saito, Nagahiro; Takai, Osamu

    2011-01-01

    The degradation of p-benzoquinone (p-BQ) in water was investigated by the coherent anti-Stokes Raman spectroscopy (CARS) method, in which the change of the anti-Stokes signal intensity corresponding to the vibrational transitions of the molecule is monitored during and after solution plasma processing (SPP). In the beginning of SPP treatment, the CARS signal intensity of the ring vibrational molecular transitions at 1233 and 1660 cm -1 increases under the influence of the electric field of the plasma, depending on the delay time between the plasma pulse and the laser firing pulse. At the same time, the plasma contributes to the degradation of p-BQ molecules by generating hydrogen and hydroxyl radicals, which decompose p-BQ into different carboxylic acids. After SPP, the CARS signal intensity of the vibrational bands of p-BQ ceased and the degradation of p-BQ was confirmed by UV-visible absorption spectroscopy and liquid chromatography analysis.

  13. Collisional-radiative model: a plasma spectroscopy theory for experimentalists

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Takashi [Kyoto Univ. (Japan); Sawada, Keiji

    1997-01-01

    The rate equation describing the population n(p) of an excited (and the ground state) level p of ions immersed in plasma is shown. In 1962, the method of quasi-steady state solution (collisional-radiative model) was proposed. Its idea is explained. The coupled differential equations reduce to a set of coupled linear equations for excited levels. The solution of these coupled equations is presented. The equations giving the ionization and recombination of this system of ions under consideration are described in terms of the effective rate coefficients. The collisional-radiative ionization and recombination rate coefficients are expressed in terms of the population coefficients for p > 1. As for ionizing plasma, the excited level populations, the populations, the population distribution among the excited levels, two regimes of the excited levels, the dominant flows of electrons among the levels and so on are shown. As for recombining plasma, the excited level populations, the population distribution among the excited levels, the dominant flows of electrons and so on are shown. Ionization balance plasma may be considered. (K.I.)

  14. Emission spectroscopy of hydrogen molecules in technical and divertor plasmas

    International Nuclear Information System (INIS)

    Fantz, U.

    2002-01-01

    The paper gives an overview of the diagnostics of hydrogen molecules in technical plasmas (MW and RF discharges) and in divertor plasmas of fusion experiments (ASDEX Upgrade / Tokamak at the Max-Planck-Institut fuer Plasmaphysik in Garching near Munich, Germany). The Fulcher transition in the visible spectral range was chosen for analysis since this is the most prominent band in the spectrum of molecular hydrogen. Examples for diagnostics of molecular densities will be given, and the problems arising in the interpretation of spectra will be discussed. In divertor plasmas the diagnostics of molecular.uxes will be introduced and the contribution of molecules to the plasma recombination will be discussed. Results for vibrational populations in the ground state and the correlation to the upper Fulcher state will be given, providing an electron temperature diagnostic. Finally, the in.uence of surfaces (high-grade steel and graphite) on vibrational populations and on re.ection coe.cients of atoms will be shown. Special attention is given on a comparison of the isotopes hydrogen and deuterium. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  15. Induction plasma-sprayed photocatalytically active titania coatings and their characterisation by micro-Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Burlacov, I.; Jirkovský, Jaromír; Muller, M.; Heimann, R. B.

    2006-01-01

    Roč. 201, 1-2 (2006), s. 255-264 ISSN 0257-8972 Grant - others:European Communities(XE) EVKI-2002-30025 Institutional research plan: CEZ:AV0Z40400503 Source of funding: R - rámcový projekt EK Keywords : titania (anatase) coatings * induction plasma spraying * suspension plasma spraying * Raman spectroscopy Subject RIV: CG - Electrochemistry Impact factor: 1.559, year: 2006

  16. X-ray Spectroscopy of Hot Dense Plasmas: Experimental Limits, Line Shifts and Field Effects

    International Nuclear Information System (INIS)

    Renner, Oldrich; Sauvan, Patrick; Dalimier, Elisabeth; Riconda, Caterina; Rosmej, Frank B.; Weber, Stefan; Nicolai, Philippe; Peyrusse, Olivier; Uschmann, Ingo; Hoefer, Sebastian; Kaempfer, Tino; Loetzsch, Robert; Zastrau, Ulf; Foerster, Eckhart; Oks, Eugene

    2008-01-01

    High-resolution x-ray spectroscopy is capable of providing complex information on environmental conditions in hot dense plasmas. Benefiting from application of modern spectroscopic methods, we report experiments aiming at identification of different phenomena occurring in laser-produced plasma. Fine features observed in broadened profiles of the emitted x-ray lines and their satellites are interpreted using theoretical models predicting spectra modification under diverse experimental situations.

  17. Time-resolved tunable diode laser absorption spectroscopy of pulsed plasma

    Czech Academy of Sciences Publication Activity Database

    Adámek, Petr; Olejníček, Jiří; Čada, Martin; Kment, Š.; Hubička, Zdeněk

    2013-01-01

    Roč. 38, č. 14 (2013), s. 2428-2430 ISSN 0146-9592 R&D Projects: GA MŠk LH12045; GA ČR(CZ) GAP205/11/0386; GA MŠk LD12002; GA MŠk LH12043 Institutional support: RVO:68378271 Keywords : diode laser s * plasma diagnostics * absorption spectroscopy * time resolved Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 3.179, year: 2013

  18. P 8: Table-top instrumentation for time-resolved luminescence spectroscopy of solids excited by soft X-ray from a laser induced plasma source and/or UV-VIS laser

    International Nuclear Information System (INIS)

    Bruza, P.; Fidler, V.; Nikl, M.

    2010-01-01

    The design and use of a novel, table-top UV-VIS luminescence spectrometer with two excitation sources is described: a soft X-ray/XUV pulse excitation from the laser-produced plasma in gas puff target of about 4 ns duration, and a conventional N 2 pulse laser excitation at 337 nm (or any other UV-VIS pulse laser excitation). The XUV plasma source generates photons of either quasi-monochromatic (N target, E = 430 eV) or wide (Ar target, E = 200 ∼ 600 eV) spectral range. A combination of both X-ray/XUV and UV-VIS excitation in one experimental apparatus allows to perform comparative luminescence spectra and kinetics measurements under the same experimental conditions. In order to demonstrate the spectrometer, the UV-VIS luminescence spectra and decay kinetics of cerium doped Lu 3 Al 5 O 12 single crystal (LuAG:Ce) scintillator excited by XUV and UV radiation were acquired. Luminescence of doped Ce 3+ ions was studied under XUV 430 eV excitation from the laser-produced nitrogen plasma, and compared with the luminescence under 337 nm (3,68 eV) UV excitation from nitrogen laser. In the former case the excitation energy is deposited in the LuAG host, while in the latter the 4f-5d transition of Ce 3+ is directly excited. Furthermore, LuAG:Ce single crystals and single crystalline films luminescence decay profiles are compared and discussed. (authors)

  19. Evaluation of minor element concentrations in potatoes using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Beldjilali, S.; Borivent, D.; Mercadier, L.; Mothe, E.; Clair, G.; Hermann, J.

    2010-01-01

    We have performed spectroscopic analysis of the plasma generated by Nd:YAG laser irradiation of flesh and skin of fresh potatoes. From the spectra recorded with an Echelle spectrometer 11 minor elements have been identified. Their relative concentrations were estimated by comparing the measured spectra to the spectral radiance computed for a plasma in local thermal equilibrium. According the moderate plasma temperature of about 6500 K at the time of spectroscopic observation, the electrons are essentially generated by the ionization of the minor metal atoms, making plasma modeling possible although the organic elements may be out of equilibrium. Among the spectral lines selected for the analysis, the Na I 588.99 and 589.59 nm doublet was found to be partially self-absorbed allowing us to estimate the number density of sodium atoms. The value was found to agree with the number density predicted by the plasma model. As a result, the relative concentrations of the detected minor elements have been estimated for both the flesh and skin of the potatoes. Among these, aluminum and silicon were found to have relatively large mass fractions in the potato skin whereas their presence was not detected in the flesh. The present study shows that laser-induced breakdown spectroscopy is a promising tool to measure the elemental composition of fresh vegetables without any sample preparation.

  20. Review of x-ray spectroscopy from laser-produced plasmas

    International Nuclear Information System (INIS)

    Kauffman, R.L.

    1987-09-01

    Recent progress in x-ray spectroscopy from laser plasmas is reviewed. Advances in the use of K-shell spectra as a diagnostic tool is discussed. Much activity in understanding complex spectra especially from Ne I and Ni I isoelectronic series have been made. Much of the progress has been due to observation of amplification from Δn = O transitions from these configurations. The spectroscopy will be discussed and examples of spectra of the amplified lines will be shown. Finally, recent work on using x-ray spectroscopy to diagnose high density implosions will be discussed. 33 refs

  1. Local thermodynamic equilibrium in a laser-induced plasma evidenced by blackbody radiation

    Science.gov (United States)

    Hermann, Jörg; Grojo, David; Axente, Emanuel; Craciun, Valentin

    2018-06-01

    We show that the plasma produced by laser ablation of solid materials in specific conditions has an emission spectrum that is characterized by the saturation of the most intense spectral lines at the blackbody radiance. The blackbody temperature equals the excitation temperature of atoms and ions, proving directly and unambiguously a plasma in local thermodynamic equilibrium. The present investigations take benefit from the very rich and intense emission spectrum generated by ablation of a nickel-chromium-molybdenum alloy. This alternative and direct proof of the plasma equilibrium state re-opens the perspectives of quantitative material analyses via calibration-free laser-induced breakdown spectroscopy. Moreover, the unique properties of this laser-produced plasma promote its use as radiation standard for intensity calibration of spectroscopic instruments.

  2. CN emission spectroscopy study of carbon plasma in nitrogen environment

    International Nuclear Information System (INIS)

    Abdelli-Messaci, S.; Kerdja, T.; Bendib, A.; Malek, S.

    2005-01-01

    Spectroscopic emission diagnostics of a carbon plasma created by an excimer KrF laser pulse at three laser fluences (12, 25 and 32 J/cm 2 ) is performed under nitrogen ambient at pressures of 0.5 and 1 mbar. By following the time evolution of the radical CN spectral emission profiles, we notice, at a certain distance from the target surface, the existence of twin peaks for the time of flight distribution. This double structure depends on laser fluence and gas pressure parameters. The first peak moves forward in relation with the plasma expansion whereas the second peak moves backward and it is attributed to CN species undergoing oscillations or reflected shocks

  3. Proton nuclear magnetic resonance spectroscopy of plasma lipoproteins in malignancy

    International Nuclear Information System (INIS)

    Nabholtz, J.M.; Rossignol, A.; Farnier, M.; Gambert, P.; Tremeaux, J.C.; Friedman, S.; Guerrin, J.

    1988-01-01

    A recent study described a method of detecting malignant tumors by water-supressed proton nuclear magnetic resonance (1 H NMR) study of plasma. We performed a similar study of the W 1/2, a mean of the full width at half height of the resonances of the methyl and methylene groups of the lipids of plasma lipoproteins which is inversely related to the spin-spin apparent relaxation time (T 2 * ). W 1/2 values were measured at a fixed baseline width of 310 Hz. The study was prospective and blinded and comprised 182 subjects consisting of 40 controls, 68 patients with untreated malignancies, 45 with malignant tumors undergoing therapy and 29 benign tumor patients. No differences were seen between any groups that could serve as a basis for a useful clinical test. The major difficulty in the determination of W 1/2 was due to interference of metabolite protons (particularly lactate) within the lipoprotein resonance signal. Triglyceride level was seen to correlate inversely with W 1/2 within malignant patient groups. These discrepant results may be related to differing triglyceride-rich very low density lipoprotein (VLDL) levels in the ;atient populations of each study. We conclude that the water-suppressed 1H NMR of plasma lipoproteins is not a valid measurement for assessing malignancy. (orig.)

  4. On the potential of CARS spectroscopy in low-temperature plasma diagnostics

    International Nuclear Information System (INIS)

    Ambrazyavichyus, A.B.; Gladkov, S.M.; Grigajtis, Yu.P.; Koroteev, N.I.

    1989-01-01

    The principles of coherent anti-Stokes Raman spectroscopy (CARS) and its application to the diagnostics of technological plasmas are briefly discussed. THe CARS spectrometer is described, developed in IPTPE, Caunas for investigations of a nitrogen plasma stream generated by an industrial plasmatron, and several CARS spectra of nitrogen molecules are presented. As the CARS signal from vibrational-rotational energy levels decreases substantially at plasma temperatures above 2000 K, an alternative scheme using electronlevels of atoms or ions has to be used. To test the method, CARS signals from the lines of the first nitrogen ion were studied in a low-voltage spark discharge. (J.U.)

  5. Local Thermodynamic Equilibrium in Laser-Induced Breakdown Spectroscopy: Beyond the McWhirter criterion

    International Nuclear Information System (INIS)

    Cristoforetti, G.; De Giacomo, A.; Dell'Aglio, M.; Legnaioli, S.; Tognoni, E.; Palleschi, V.; Omenetto, N.

    2010-01-01

    In the Laser-Induced Breakdown Spectroscopy (LIBS) technique, the existence of Local Thermodynamic Equilibrium (LTE) is the essential requisite for meaningful application of theoretical Boltzmann-Maxwell and Saha-Eggert expressions that relate fundamental plasma parameters and concentration of analyte species. The most popular criterion reported in the literature dealing with plasma diagnostics, and usually invoked as a proof of the existence of LTE in the plasma, is the McWhirter criterion [R.W.P. McWhirter, in: Eds. R.H. Huddlestone, S.L. Leonard, Plasma Diagnostic Techniques, Academic Press, New York, 1965, pp. 201-264]. However, as pointed out in several papers, this criterion is known to be a necessary but not a sufficient condition to insure LTE. The considerations reported here are meant to briefly review the theoretical analysis underlying the concept of thermodynamic equilibrium and the derivation of the McWhirter criterion, and to critically discuss its application to a transient and non-homogeneous plasma, like that created by a laser pulse on solid targets. Specific examples are given of theoretical expressions involving relaxation times and diffusion coefficients, as well as a discussion of different experimental approaches involving space and time-resolved measurements that could be used to complement a positive result of the calculation of the minimum electron number density required for LTE using the McWhirter formula. It is argued that these approaches will allow a more complete assessment of the existence of LTE and therefore permit a better quantitative result. It is suggested that the mere use of the McWhirter criterion to assess the existence of LTE in laser-induced plasmas should be discontinued.

  6. A rate-equation model for polarized laser-induced fluorescence to measure electric field in glow discharge He plasmas

    International Nuclear Information System (INIS)

    Takiyama, K.; Watanabe, M.; Oda, T.

    1998-01-01

    Possibility of applying polarized laser-induced fluorescence (LIF) spectroscopy for measuring the electric field in a plasma with a large collisional depolarization has been investigated. A rate equation model including the depolarization process was employed to analyze the time evolution of LIF polarization components. The polarized LIF pulse shapes observed in the sheath of a He glow discharge plasma were successfully reproduced, and the electric field distribution was obtained with high accuracy. (author)

  7. Vibrational emission analysis of the CN molecules in laser-induced breakdown spectroscopy of organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Bravo, Ángel; Delgado, Tomás; Lucena, Patricia; Laserna, J. Javier, E-mail: laserna@uma.es

    2013-11-01

    Laser-induced breakdown spectroscopy (LIBS) of organic materials is based on the analysis of atomic and ionic emission lines and on a few molecular bands, the most important being the CN violet system and the C{sub 2} Swan system. This paper is focused in molecular emission of LIBS plasmas based on the CN (B{sup 2}Σ–X{sup 2}Σ) band, one of the strongest emissions appearing in all carbon materials when analyzed in air atmosphere. An analysis of this band with sufficient spectral resolution provides a great deal of information on the molecule, which has revealed that valuable information can be obtained from the plume chemistry and dynamics affecting the excitation mechanisms of the molecules. The vibrational emission of this molecular band has been investigated to establish the dependence of this emission on the molecular structure of the materials. The paper shows that excitation/emission phenomena of molecular species observed in the plume depend strongly on the time interval selected and on the irradiance deposited on the sample surface. Precise time resolved LIBS measurements are needed for the observation of distinctive CN emission. For the organic compounds studied, larger differences in the behavior of the vibrational emission occur at early stages after plasma ignition. Since molecular emission is generally more complex than that involving atomic emission, local plasma conditions as well as plume chemistry may induce changes in vibrational emission of molecules. As a consequence, alterations in the distribution of the emissions occur in terms of relative intensities, being sensitive to the molecular structure of every single material. - Highlights: • Vibrational emission of CN species in laser-induced plasmas has been investigated. • Distribution of vibrational emission of CN has been found to be time dependent. • Laser irradiance affects the vibrational distribution of the CN molecules. • Plume chemistry controls the excitation mechanisms of CN

  8. 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

  9. New enhanced sensitivity infrared laser spectroscopy techniques applied to reactive plasmas and trace gas detection

    NARCIS (Netherlands)

    Welzel, S.

    2009-01-01

    Infrared laser absorption spectroscopy (IRLAS) employing both tuneable diode and quantum cascade lasers (TDLs, QCLs) has been applied with both high sensitivity and high time resolution to plasma diagnostics and trace gas measurements. TDLAS combined with a conventional White type multiple pass cell

  10. An experimental facility for microwave induced plasma processing of materials

    International Nuclear Information System (INIS)

    Patil, D.S.; Ramachandran, K.; Bhide, A.L.; Venkatramani, N.

    1997-01-01

    Microwave induced plasma processing offers many advantages over conventional processes. However this technology is in the development stage. This report gives a detailed information about a microwave plasma processing facility (2.45 GHz, 700 W) set up in the Laser and Plasma Technology Division. The equipment details and the results obtained on deposition of diamond like carbon (DLC) thin films and surface modification of polymer PET (polyethylene terephthalate) using this facility are given in this report. (author)

  11. Optical Emission Spectroscopy of an Atmospheric Pressure Plasma Jet During Tooth Bleaching Gel Treatment.

    Science.gov (United States)

    Šantak, Vedran; Zaplotnik, Rok; Tarle, Zrinka; Milošević, Slobodan

    2015-11-01

    Optical emission spectroscopy was performed during atmospheric pressure plasma needle helium jet treatment of various tooth-bleaching gels. When the gel sample was inserted under the plasma plume, the intensity of all the spectral features increased approximately two times near the plasma needle tip and up to two orders of magnitude near the sample surface. The color change of the hydroxylapatite pastille treated with bleaching gels in conjunction with the atmospheric pressure plasma jet was found to be in correlation with the intensity of OH emission band (309 nm). Using argon as an additive to helium flow (2 L/min), a linear increase (up to four times) of OH intensity and, consequently, whitening (up to 10%) of the pastilles was achieved. An atmospheric pressure plasma jet activates bleaching gel, accelerates OH production, and accelerates tooth bleaching (up to six times faster).

  12. Quantitative detection of plasma-generated radicals in liquids by electron paramagnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Tresp, H; Hammer, M U; Winter, J; Reuter, S; Weltmann, K-D

    2013-01-01

    In this paper the qualitative and quantitative detection of oxygen radicals in liquids after plasma treatment with an atmospheric pressure argon plasma jet by electron paramagnetic resonance spectroscopy is investigated. Absolute values for · OH and O 2 ·- radical concentration and their net production rate in plasma-treated liquids are determined without the use of additional scavenging chemicals such as superoxide dismutase (SOD) or mannitol (D-MAN). The main oxygen-centred radical generation in PBS was found to originate from the superoxide radical. It is shown that hidden parameters such as the manufacturer of chemical components could have a big influence on the comparability and reproducibility of the results. Finally, the effect of a shielding gas device for the investigated plasma jet with a shielding gas composition of varying oxygen-to-nitrogen ratio on radical generation after plasma treatment of phosphate-buffered saline solution was investigated. (paper)

  13. Laser-induced gas plasma machining

    Energy Technology Data Exchange (ETDEWEB)

    Elhadj, Selim; Bass, Isaac Louis; Guss, Gabriel Mark; Matthews, Manyalibo J.

    2017-10-17

    Techniques for removing material from a substrate are provided. A laser beam is focused at a distance from the surface to be treated. A gas is provided at the focus point. The gas is dissociated using the laser energy to generate gas plasma. The substrate is then brought in contact with the gas plasma to enable material removal.

  14. Production and Characterization of Femtosecond-Laser-Induced Air Plasma

    National Research Council Canada - National Science Library

    Armbruster, David R

    2008-01-01

    .... A beam expander was used to expand the beam to a diameter of approximately 6.5 mm, and the beam was focused through a 25 mm focal length achromatic lens to produce laser-induced plasma in ambient air...

  15. ZnO nanostructures induced by microwave plasma

    Directory of Open Access Journals (Sweden)

    Khaled A. Elsayed

    2015-07-01

    Full Text Available Microwave induced hydrogen plasma is used to fabricate ZnO thin films at low ambient gas pressure and controlled oxygen content in the gas mixture. The emission spectra have been observed. Optical emission spectroscopy was used to identify the chemical reaction mechanism. Structural quality of the so-obtained nanoparticles was studied by X-ray diffraction (XRD and high resolution scanning electron microscopy (SEM. SEM results showed that nanorods were formed in the process, and XRD results along with nanorod dimensions obtained from SEM are consistent with the formation of single and poly-crystalline ZnO nanorods. The alignment of these nanorods with respect to the substrates depends on the lattice mismatch between ZnO and the glass substrate. The minimum crystallite grain size as obtained from the SEM measurements was ∼24 nm and the average diameter is 70 nm with a length of 1–2 μm. The deposited ZnO thin films have a wide energy band gap that equals ∼3 eV.

  16. Combination of laser-induced breakdown spectroscopy and Raman spectroscopy for multivariate classification of bacteria

    Science.gov (United States)

    Prochazka, D.; Mazura, M.; Samek, O.; Rebrošová, K.; Pořízka, P.; Klus, J.; Prochazková, P.; Novotný, J.; Novotný, K.; Kaiser, J.

    2018-01-01

    In this work, we investigate the impact of data provided by complementary laser-based spectroscopic methods on multivariate classification accuracy. Discrimination and classification of five Staphylococcus bacterial strains and one strain of Escherichia coli is presented. The technique that we used for measurements is a combination of Raman spectroscopy and Laser-Induced Breakdown Spectroscopy (LIBS). Obtained spectroscopic data were then processed using Multivariate Data Analysis algorithms. Principal Components Analysis (PCA) was selected as the most suitable technique for visualization of bacterial strains data. To classify the bacterial strains, we used Neural Networks, namely a supervised version of Kohonen's self-organizing maps (SOM). We were processing results in three different ways - separately from LIBS measurements, from Raman measurements, and we also merged data from both mentioned methods. The three types of results were then compared. By applying the PCA to Raman spectroscopy data, we observed that two bacterial strains were fully distinguished from the rest of the data set. In the case of LIBS data, three bacterial strains were fully discriminated. Using a combination of data from both methods, we achieved the complete discrimination of all bacterial strains. All the data were classified with a high success rate using SOM algorithm. The most accurate classification was obtained using a combination of data from both techniques. The classification accuracy varied, depending on specific samples and techniques. As for LIBS, the classification accuracy ranged from 45% to 100%, as for Raman Spectroscopy from 50% to 100% and in case of merged data, all samples were classified correctly. Based on the results of the experiments presented in this work, we can assume that the combination of Raman spectroscopy and LIBS significantly enhances discrimination and classification accuracy of bacterial species and strains. The reason is the complementarity in

  17. Laser-induced breakdown spectroscopy theory and applications

    CERN Document Server

    Perini, Umberto

    2014-01-01

    This book deals with the Laser-Induced Breakdown Spectroscopy (LIBS), a widely used atomic emission spectroscopy technique for elemental analysis of materials. It is based on the use of a high-power, short pulse laser excitation. The book is divided into two main sections: the first one concerning theoretical aspects of the technique, the second one describing the state of the art in applications of the technique in different scientific/technological areas. Numerous examples of state of the art applications provide the readers an almost complete scenario of the LIBS technique. The LIBS theoretical aspects are reviewed. The book helps the readers who are less familiar with the technique to understand the basic principles. Numerous examples of state of the art applications give an almost complete scenario of the LIBS technique potentiality. These examples of applications may have a strong impact on future industrial utilization. The authors made important contributions to the development of this field.

  18. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wattieaux, G., E-mail: gaetan.wattieaux@laplace.univ-tlse.fr; Yousfi, M.; Merbahi, N.

    2013-11-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10{sup 14} cm{sup −3}, the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the

  19. Optical emission spectroscopy for quantification of ultraviolet radiations and biocide active species in microwave argon plasma jet at atmospheric pressure

    International Nuclear Information System (INIS)

    Wattieaux, G.; Yousfi, M.; Merbahi, N.

    2013-01-01

    This work deals with absorption and mainly emission spectrometry of a microwave induced surfatron plasma jet launched in ambient air and using an Argon flow carrier gas. The Ar flow rate varies between 1 and 3 L/min and the microwave power between 40 and 60 W. The analysis of the various spectra has led to the determination of the ozone and atomic oxygen concentrations, ultraviolet (UV) irradiance separating UVA, UVB and UVC, gas temperature, plasma electron density and excitation temperature. Most of these diagnostics are spatially resolved along the plasma jet axis. It is shown more particularly that rotational temperature obtained from OH(A-X) spectra ranges between 800 K to 1000 K while the apparent temperature of the plasma jet remains lower than about 325 K which is compatible with biocide treatment without significant thermal effect. The electron density reaches 1.2 × 10 14 cm −3 , the excitation temperature is about 4000 K, the UVC radiation represents only 5% of the UV radiations emitted by the device, the ozone concentration is found to reach 88 ± 27 ppm in the downstream part of the plasma jet at a distance of 30 mm away from the quartz tube outlet of the surfatron and the atomic oxygen concentration lies between 10 and 80 ppm up to a distance of 20 mm away from the quartz tube outlet. Ozone is identified as the main germicidal active species produced by the device since its concentration is in accordance with bacteria inactivation durations usually reported using such plasma devices. Human health hazard assessment is carried out all along this study since simple solutions are reminded to respect safety standards for exposures to ozone and microwave leakage. In this study, an air extraction unit is used and a Faraday cage is set around the quartz tube of the surfatron and the plasma jet. These solutions should be adopted by users of microwave induced plasma in open air conditions because according to the literature, this is not often the case

  20. In situ Raman spectroscopy for growth monitoring of vertically aligned multiwall carbon nanotubes in plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Labbaye, T.; Gaillard, M.; Lecas, T.; Kovacevic, E.; Boulmer-Leborgne, Ch.; Guimbretière, G. [GREMI, Université-CNRS, BP6744, 45067 Orléans Cedex 2 (France); Canizarès, A.; Raimboux, N.; Simon, P.; Ammar, M. R., E-mail: mohamed-ramzi.ammar@cnrs-orleans.fr [CNRS, CEMHTI UPR3079, Univ. Orléans, F-45071 Orléans Cedex 2 (France); Strunskus, T. [Institute of Material Science, Chritian-Albrechts-University of Kiel, D-24143 Kiel (Germany)

    2014-11-24

    Portable and highly sensitive Raman setup was associated with a plasma-enhanced chemical vapor deposition reactor enabling in situ growth monitoring of multi-wall carbon nanotubes despite the combination of huge working distance, high growth speed and process temperature and reactive plasma condition. Near Edge X-ray absorption fine structure spectroscopy was used for ex situ sample analysis as a complementary method to in situ Raman spectroscopy. The results confirmed the fact that the “alternating” method developed here can accurately be used for in situ Raman monitoring under reactive plasma condition. The original analytic tool can be of great importance to monitor the characteristics of these nanostructured materials and readily define the ultimate conditions for targeted results.

  1. Laser-induced plasmas as an analytical source for quantitative analysis of gaseous and aerosol systems: Fundamentals of plasma-particle interactions

    Science.gov (United States)

    Diwakar, Prasoon K.

    2009-11-01

    Laser-induced Breakdown Spectroscopy (LIBS) is a relatively new analytical diagnostic technique which has gained serious attention in recent past due to its simplicity, robustness, and portability and multi-element analysis capabilities. LIBS has been used successfully for analysis of elements in different media including solids, liquids and gases. Since 1963, when the first breakdown study was reported, to 1983, when the first LIBS experiments were reported, the technique has come a long way, but the majority of fundamental understanding of the processes that occur has taken place in last few years, which has propelled LIBS in the direction of being a well established analytical technique. This study, which mostly focuses on LIBS involving aerosols, has been able to unravel some of the mysteries and provide knowledge that will be valuable to LIBS community as a whole. LIBS processes can be broken down to three basic steps, namely, plasma formation, analyte introduction, and plasma-analyte interactions. In this study, these three steps have been investigated in laser-induced plasma, focusing mainly on the plasma-particle interactions. Understanding plasma-particle interactions and the fundamental processes involved is important in advancing laser-induced breakdown spectroscopy as a reliable and accurate analytical technique. Critical understanding of plasma-particle interactions includes study of the plasma evolution, analyte atomization, and the particle dissociation and diffusion. In this dissertation, temporal and spatial studies have been done to understand the fundamentals of the LIBS processes including the breakdown of gases by the laser pulse, plasma inception mechanisms, plasma evolution, analyte introduction and plasma-particle interactions and their influence on LIBS signal. Spectral measurements were performed in a laser-induced plasma and the results reveal localized perturbations in the plasma properties in the vicinity of the analyte species, for

  2. Data array acquisition and joint processing in local plasma spectroscopy

    International Nuclear Information System (INIS)

    Ekimov, K.; Luizova, L.; Soloviev, A.; Khakhaev, A.

    2005-01-01

    The setup and software for optical emission spectroscopy with spatial and temporal resolutions were developed. The automated installation includes LabView compatible instrument interfaces. The algorithm of joint data processing is based on principal component method and allows the increase in stability of results of the radial transform and the instrument distortion elimination in the presence of noises. The system is applied to diagnostics of the arc discharge in mercury vapors with the addition of thallium. The distributions of ground state and excited mercury atoms, excited thallium atoms and electron density over the arc cross section have been measured on the basis of analysis of spectral line shapes. The Saha balance between electron and high lying excited states densities was checked. An unexpected broadening of some thallium spectral lines was found out

  3. Study by optical spectroscopy of the interaction between a hydrogen multi-polar plasma and a gallium arsenide surface

    International Nuclear Information System (INIS)

    Ferdinand, Robin

    1990-01-01

    The objective of this research thesis has been to understand which are the involved species during the deoxidation-passivation stage of the processing of gallium arsenide platelets used in semiconductor industry. The author describes problems related to the presence of oxides, and highlights the benefit of using a hydrogen multi-polar plasma to softly remove surface oxides. The experimental set-up is notably characterised by the role of magnetic confinement and its influence on plasma. A theoretical model is then developed for a better understanding of chemical and physical-chemical reactions occurring in the hydrogen plasma. Based on the use of the Boltzmann equation, the model calculates the electron energy distribution function, and allows the follow-up of species present in the plasma with respect to available and accessible parameters (pressure, discharge current, discharge voltage). A spectroscopic study of the hydrogen plasma is then reported, and the numerical model is validated by interpreting line shapes of the hydrogen Balmer series. A second experimental approach, based on electrostatic probes, is implemented, and the Laframboise theory is applied to this technique and allows electronic and ionic densities, and electron temperature to be determined. Experimental and numerical results are compared. All this leads to the study of the interaction of plasma with a sample, with a first step of study of a mixture plasma containing 85 per cent of hydrogen and 15 per cent of arsine, in order to get a general knowledge of emissions related to the presence of AsH 3 . Finally, interaction studies are performed by using laser-induced fluorescence and conventional space-resolved optical spectroscopy

  4. Quantitative Classification of Quartz by Laser Induced Breakdown Spectroscopy in Conjunction with Discriminant Function Analysis

    Directory of Open Access Journals (Sweden)

    A. Ali

    2016-01-01

    Full Text Available A responsive laser induced breakdown spectroscopic system was developed and improved for utilizing it as a sensor for the classification of quartz samples on the basis of trace elements present in the acquired samples. Laser induced breakdown spectroscopy (LIBS in conjunction with discriminant function analysis (DFA was applied for the classification of five different types of quartz samples. The quartz plasmas were produced at ambient pressure using Nd:YAG laser at fundamental harmonic mode (1064 nm. We optimized the detection system by finding the suitable delay time of the laser excitation. This is the first study, where the developed technique (LIBS+DFA was successfully employed to probe and confirm the elemental composition of quartz samples.

  5. Laser induced breakdown spectroscopy library for the Martian environment

    International Nuclear Information System (INIS)

    Cousin, A.; Forni, O.; Maurice, S.; Gasnault, O.

    2011-01-01

    The NASA Mars Science Laboratory rover will carry the first Laser Induced Breakdown Spectroscopy experiment in space: ChemCam. We have developed a laboratory model which mimics ChemCam's main characteristics. We used a set of target samples relevant to Mars geochemistry, and we recorded individual spectra. We propose a data reduction scheme for Laser Induced Breakdown Spectroscopy data incorporating de-noising, continuum removal, and peak fitting. Known effects of the Martian atmosphere are confirmed with our experiment: better Signal-to-Noise Ratio on Mars compared to Earth, narrower peak width, and essentially no self-absorption. The wavelength shift of emission lines from air to Mars pressure is discussed. The National Institute of Standards and Technology vacuum database is used for wavelength calibration and to identify the elemental lines. Our Martian database contains 1336 lines for 32 elements: H, Li, Be, B, C, N, O, F, Na, Mg, Al, Si, P, S, Cl, K, Ar, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Rb, Sr, Cs, Ba, and Pb. It is a subset of the National Institute of Standards and Technology database to be used for Martian geochemistry. Finally, synthetic spectra can be built from the Martian database. Correlation calculations help to distinguish between elements in case of uncertainty. This work is used to create tools and support data for the interpretation of ChemCam results. - Highlights: ► Chemcam: first Laser Induced Breakdown Spectroscopy technique on Mars. ► Creation of a LIBS specific database to ChemCam on Mars. ► Data reduction scheme is proposed. ► Best signal under Martian conditions. ► LIBS emission lines database: subset of NIST database for Martian geochemistry.

  6. Modelling of microwave induced plasmas : the interplay between electromagnetism, plasma chemistry and transport

    NARCIS (Netherlands)

    Jimenez-Diaz, M.

    2011-01-01

    In this thesis we report on a theoretical/numerical study that is concerned with Microwave Induced Plasmas (MIPs) in general, and the application of a MIP to the Plasma-activated Chemical Vapour Deposition (PCVD) process that is used at Draka Comteq for the production of optical fibres in

  7. Evaluation of self-absorption coefficients of aluminum emission lines in laser-induced breakdown spectroscopy measurements

    International Nuclear Information System (INIS)

    El Sherbini, A.M.; El Sherbini, Th.M.; Hegazy, H.; Cristoforetti, G.; Legnaioli, S.; Palleschi, V.; Pardini, L.; Salvetti, A.; Tognoni, E.

    2005-01-01

    In quantitative Laser Induced Breakdown Spectroscopy (LIBS) measurements it is essential to account for the effect of self-absorption on the emission lines intensity. In order to quantify this effect, in this paper we propose a simple method for evaluating the ratio between the actual measured line intensity and the intensity expected in absence of self-absorption and, if necessary, correcting the effect of self-absorption on line intensity. The method, based on a homogeneous plasma model, is applicable when the plasma electron density is known and in particular to lines whose Stark broadening parameter is available

  8. Electron beam induced emission from carbon plasmas

    International Nuclear Information System (INIS)

    Whetstone, S.; Kammash, T.

    1989-01-01

    Plasma use as a lasing medium has many potential advantages over conventional techniques including increased power levels and greater wavelength ranges. The basic concept is to heat and then rapidly cool a plasma forcing inversion through bottleneck creation between the recombination reaction populating a given energy level and the subsequent decay processes. Much effort has been devoted to plasmas heated by lasers and pinch devices. The authors are concerned here with electron beam heated plasmas focusing on the CIV 5g-4f transition occurring at 2530 Angstroms. These studies were initiated to provide theoretical support for experiments being performed at the University of Michigan using the Michigan Electron Long-Pulse Beam Accelerator (MELBA)

  9. Frequency domain and wavelet analysis of the laser-induced plasma shock waves

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Miloš, E-mail: milosb@ff.bg.ac.rs; Nikolić, Zoran

    2015-08-01

    In addition to optical emission, another trace of interest that laser-induced plasma provides is a form of acoustic feedback. The acoustic emission (AE) signals were obtained using both microphone and piezo transducers. This kind of optoacoustic signals have some distinct features resembling the short, burst-like sounds, that may differ significantly depending mainly on the sample exposed and irradiance applied. Experiments were performed on atmospheric pressure by irradiating various metallic samples. The recorded waveforms were examined and numerically processed. Single-shot acoustical spectra have shown significant potential of providing valuable supplementary information regarding plasma propagation dynamics. Moreover, the general approach suggests the possibility of making the whole measurement system cost-effective and portable. - Highlights: • We report acoustical waveform, and acoustical spectroscopy measurements and analysis in a laser-induced plasma of a different metals in air. • Both piezo and microphone transducer were used. • The acoustical spectra of the emission were obtained when the sample (and plasma) were enclosed in experimental chamber. • The acquired acoustical spectra are time-integrated and the frequency peaks were sharp and relatively isolated. • Finally, both time and frequency resolved wavelet spectrogram present a novel method of observing laser-induced plasma behavior.

  10. ICRF induced edge plasma convection in ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [Max Planck Institute for Plasma Physics, Garching/Greifswald (Germany); University of Ghent, Ghent (Belgium); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Feng, Yuehe; Lunt, Tilmann; Jacquot, Jonathan; Coster, David; Bilato, Roberto; Bobkov, Volodymyr; Ochoukov, Roman [Max Planck Institute for Plasma Physics, Garching/Greifswald (Germany); Noterdaeme, Jean-Marie [Max Planck Institute for Plasma Physics, Garching/Greifswald (Germany); University of Ghent, Ghent (Belgium); Colas, Laurent [CEA, IRFM, Saint-Paul-Lez-Durance (France); Collaboration: ASDEX Upgrade Team

    2016-07-01

    Ion Cyclotron Range of Frequency (ICRF) heating is one of the main auxiliary plasma heating methods in tokamaks. It relies on the fast wave to heat the plasma. However the slow wave can also be generated parasitically. The parallel electric field of the slow wave can induce large biased plasma potential through sheath rectification. The rapid variation of this rectified potential across the magnetic field can cause significant E x B convection in the Scrape-Off Layer (SOL). The ICRF induced convection can affect the SOL density, influence the ICRF power coupling and enhance the strength of plasma-wall interactions. To explore these physics, we not only show the experimental evidences in ASDEX Upgrade, but also present the associated simulation results with the 3D edge plasma fluid code EMC3-Eirene. Further simulations via combination of EMC3-Eirene and a sheath code SSWICH in an iterative and quasi self-consistent way can give good predictions for future experiments.

  11. A Simple LIBS (Laser-Induced Breakdown Spectroscopy) Laboratory Experiment to Introduce Undergraduates to Calibration Functions and Atomic Spectroscopy

    Science.gov (United States)

    Chinni, Rosemarie C.

    2012-01-01

    This laboratory experiment introduces students to a different type of atomic spectroscopy: laser-induced breakdown spectroscopy (LIBS). LIBS uses a laser-generated spark to excite the sample; once excited, the elemental emission is spectrally resolved and detected. The students use LIBS to analyze a series of standard synthetic silicate samples…

  12. Experimental study of radiative energy transport in dense plasmas by emission and absorption spectroscopy

    International Nuclear Information System (INIS)

    Dozieres, Maylis

    2016-01-01

    This PhD work is an experimental study, based on emission and absorption spectroscopy of hot and dense nanosecond laser-produced plasmas. Atomic physics in such plasmas is a complex subject and of great interest especially in the fields of astrophysics or inertial confinement fusion. On the atomic physics point of view, this means determining parameters such as the average ionization or opacity in plasmas at given electronic temperature and density. Atomic physics codes then need of experimental data to improve themselves and be validated so that they can be predictive for a wide range of plasmas. With this work we focus on plasmas whose electronic temperature varies from 10 eV to more than a hundred and whose density range goes from 10 -5 ato10 -2 g/cm 3 . In this thesis, there are two types of spectroscopic data presented which are both useful and necessary to the development of atomic physics codes because they are both characteristic of the state of the studied plasma: 1) some absorption spectra from Cu, Ni and Al plasmas close to local thermodynamic equilibrium; 2) some emission spectra from non local thermodynamic equilibrium plasmas of C, Al and Cu. This work highlights the different experimental techniques and various comparisons with atomic physics codes and hydrodynamics codes. (author) [fr

  13. Transition probabilities for lines of Cr II, Na II and Sb I by laser produced plasma atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Gonzalez, A. M.; Ortiz, M.; Campos, J.

    1995-01-01

    Absolute transition probabilities for lines of CR II, Na II and Sb I were determined by emission spectroscopy of laser induced plasmas. the plasma was produced focusing the emission of a pulsed Nd-Yag laser on solid samples containing the atom in study. the light arising from the plasma region was collected by and spectrometer. the detector used was a time-resolved optical multichannel analyzer (OMA III EG and G). The wavelengths of the measured transitions range from 2000 sto 4100 A. The spectral resolution of the system was 0. 2 A. The method can be used in insulators materials as Cl Na crystals and in metallic samples as Al-Cr and Sn-Sn alloys. to avoid self-absorption effects the alloys were made with low Sb or Cr content. Relative transition probabilities have been determined from measurements of emission-line intensities and were placed on an absolute scale by using, where possible, accurate experimental lifetime values form the literature or theoretical data. From these measurements, values for plasma temperature (8000-24000 K), electron densities (∼∼ 10''16 cm ''-3) and self-absorption coefficients have been obtained. (Author) 56 refs

  14. Transition probabilities for lines of Cr II, Na II and Sb I by laser produced plasma atomic emission spectroscopy

    International Nuclear Information System (INIS)

    Gonzalez, A.M.; Ortiz, M.; Campos, J.

    1995-09-01

    Absolute transition probabilities for lines of Cr II, Na II and Sb I were determined by emission spectroscopy of laser induced plasmas. The plasma was produced focusing the emission of a pulsed Nd-Yag laser on solid samples containing the atom in study. The light arising from the plasma region was collected by and spectrometer. the detector used was a time-resolved optical multichannel analyzer (OMA III EG and G). The wavelengths of the measured transitions range from 2000 to 4100 A. The spectral resolution of the system was 0.2 A. The method can be used in insulators materials as Cl Na crystals and in metallic samples as Al-Cr and Sn-Sb alloys. To avoid self-absorption effects the alloys were made with low Sb or Cr content. Relative transition probabilities have been determined from measurements of emission-line intensities and were placed on an absolute scale by using, where possible, accurate experimental lifetime values form the literature or theoretical data. From these measurements, values for plasma temperature (8000-24000K), electron densities (approx 10 ''16 cm''-3) and self-absorption coefficients have been obtained

  15. The investigation of order–disorder transition process of ZSM-5 induced by spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Liang [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China); Wang, Lianjun, E-mail: wanglj@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China); Jiang, Wan [Engineering Research Center of Advanced Glasses Manufacturing Technology, MOE, Donghua University, 2999 North Renmin Road, Songjiang, Shanghai 201620 (China); Lin, He, E-mail: linhe@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhangheng Road, Pudong, Shanghai 200120 (China)

    2014-04-01

    Based on the amorphization of zeolites, an order–disorder transition method was used to prepare silica glass via Spark Plasma Sintering (SPS). In order to get a better understanding about the mechanism of amorphization induced by SPS, the intermediate products in this process were prepared and characterized by different characterization techniques. X-ray diffraction and High-energy synchrotron X-ray scattering show a gradual transformation from ordered crystal to glass. Local structural changes in glass network including Si–O bond length, O–Si–O bond angle, size of rings, coordination were detected by Infrared spectroscopy and {sup 29}Si magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. Topologically ordered, amorphous material with a different intermediate-range structure can be obtained by precise control of intermediate process which can be expected to optimize and design material. - Graphical abstract: Low-density, ordered zeolites collapse to the rigid amorphous glass through spark plasma sintering. The intermediate-range structure formed in the process of order–disorder transition may give rise to specific property. - Highlights: • Order–disorder transition process of ZSM-5 induced by spark plasma sintering was investigated using several methods including XRD, High-energy synchrotron X-ray scattering, SAXS, IR, NMR, ect. • Order–disorder transition induced by SPS was compared with TIA and PIA. • Three stages has been divided during the whole process. • The collapse temperature range which may give rise to intermediate-range structure has been located.

  16. Quantitative analysis of Al-Si alloy using calibration free laser induced breakdown spectroscopy (CF-LIBS)

    Science.gov (United States)

    Shakeel, Hira; Haq, S. U.; Aisha, Ghulam; Nadeem, Ali

    2017-06-01

    The quantitative analysis of the standard aluminum-silicon alloy has been performed using calibration free laser induced breakdown spectroscopy (CF-LIBS). The plasma was produced using the fundamental harmonic (1064 nm) of the Nd: YAG laser and the emission spectra were recorded at 3.5 μs detector gate delay. The qualitative analysis of the emission spectra confirms the presence of Mg, Al, Si, Ti, Mn, Fe, Ni, Cu, Zn, Sn, and Pb in the alloy. The background subtracted and self-absorption corrected emission spectra were used for the estimation of plasma temperature as 10 100 ± 300 K. The plasma temperature and self-absorption corrected emission lines of each element have been used for the determination of concentration of each species present in the alloy. The use of corrected emission intensities and accurate evaluation of plasma temperature yield reliable quantitative analysis up to a maximum 2.2% deviation from reference sample concentration.

  17. Some historic and current aspects of plasma diagnostics using atomic spectroscopy

    Science.gov (United States)

    Hutton, Roger; Zou, Yaming; Andersson, Martin; Brage, Tomas; Martinson, Indrek

    2010-07-01

    In this paper we give a short introduction to the use of atomic spectroscopy in plasma diagnostics. Both older works and exciting new branches of atomic physics, which have relevance to diagnostics, are discussed. In particular we focus on forbidden lines in Be-like ions, lines sensitive to magnetic fields and levels which have a lifetime dependence on the nuclear spin of the ion, i.e. f-dependent lifetimes. Finally we mention a few examples of where tokamaks, instead of needing atomic data, actually provide new data and lead to developments in atomic structure studies. This paper is dedicated to the memory of Nicol J Peacock (1931-2008), a distinguished plasma scientist who contributed much to the field of spectroscopy applied to plasma, and in particular, fusion plasma diagnostics. During the final stages of the preparation of this paper Professor Indrek Martinson passed away peacefully in his sleep on 14 November 2009. Indrek will be greatly missed by many people, both for his contributions to atomic spectroscopy and for his great kindness and friendliness, which many of us experienced.

  18. Laboratory feasibility study of fusion vessel inner wall chemical analysis by Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Almaviva, Salvatore; Caneve, Luisa; Colao, Francesco; Fantoni, Roberta; Maddaluno, Giorgio

    2012-01-01

    Graphical abstract: Laser-Induced-Breakdown-Spectroscopy was used for the determination of the atomic composition of multilayered samples simulating the tiles of plasma facing components in the next generation fusion machines. Highlights: ► Description and characterization of an LIBS set-up for diagnostics in fusion machines. ► Identification of atomic composition of multilayered tiles simulating plasma facing components. ► Qualitative applicability of the Calibration Free method for quantitative analysis. ► Feasibility of large scale application in the processes of control during the tiles fabrication. ► Feasibility of erosion monitoring during operation of fusion machines. - Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is nowadays a well established tool for qualitative, semi-quantitative and quantitative analyses of surfaces, with micro-destructive characteristics and capabilities for stratigraphy. LIBS is an appealing technique compared with many other types of elemental analysis thanks to the set up versatility facilitating non-invasive and remote analyses, as well as suitability to diagnostics in harsh environments. In this work, LIBS capabilities were used for the determination of the atomic composition of multilayered samples simulating the tiles of plasma facing components in the next generation fusion machines such as ITER. A new experimental setup was designed and realized in order to optimize the characteristics of an LIBS system working at low pressure and remotely, as it should be for an in situ system to be applied in monitoring the erosion and redeposition phenomena occurring on the inner walls of a fusion device. The effects of time delay and laser fluence on LIBS sensitivity at reduced pressure were examined, looking for operational conditions suitable to analytical applications. The quantitative analysis of some atomic species in the superficial layer has been carried out using a Calibration Free (CF) approach in the time

  19. Emission spectroscopy of argon ferrocene mixture jet in a low pressure plasma reactor

    International Nuclear Information System (INIS)

    Tiwari, N.; Tak, A.K.; Chakravarthy, Y.; Shukla, A.; Meher, K.C.; Ghorui, S.; Thiyagarajan, T.K.

    2015-01-01

    Emission spectroscopy is employed to measure the plasma temperature and species identification in a reactor used for studying homogenous nucleation and growth of iron nano particle. Reactor employs segmented non transferred plasma torch mounted on water cooled cylindrical chamber. The plasma jet passes through graphite nozzle and expands in low pressure reactor. Ferrocene is fed into the nozzle where it mixes with Argon plasma jet. A high resolution spectrograph (SHAMROCK 303i, resolution 0.06 nm) has been used to record the spectra over a wide range. Identification of different emission lines has been done using NIST database. Lines from (700 to 860nm) were considered for calculation of temperature. Spectra were recorded for different axial location, pressure and power. Temperature was calculated using Maxwell Boltzman plot method. Variation in temperature with pressure and location is presented and possible reasons for different behaviour are explored. (author)

  20. Comparison endpoint study of process plasma and secondary electron beam exciter optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stephan Thamban, P. L.; Yun, Stuart; Padron-Wells, Gabriel; Hosch, Jimmy W.; Goeckner, Matthew J. [Department of Mechanical Engineering, University of Texas at Dallas, 800W Campbell Road, Richardson, Texas 75080 (United States); Department of Electrical Engineering, University of Texas at Dallas, 800W Campbell Road, Richardson, Texas 75080 (United States); Verity Instruments, Inc., 2901 Eisenhower Street, Carrollton, Texas 75007 (United States); Department of Mathematical Sciences, University of Texas at Dallas, 800 W Campbell Road, Richardson, Texas 75080 (United States)

    2012-11-15

    Traditionally process plasmas are often studied and monitored by optical emission spectroscopy. Here, the authors compare experimental measurements from a secondary electron beam excitation and direct process plasma excitation to discuss and illustrate its distinctiveness in the study of process plasmas. They present results that show excitations of etch process effluents in a SF{sub 6} discharge and endpoint detection capabilities in dark plasma process conditions. In SF{sub 6} discharges, a band around 300 nm, not visible in process emission, is observed and it can serve as a good indicator of etch product emission during polysilicon etches. Based on prior work reported in literature the authors believe this band is due to SiF{sub 4} gas phase species.

  1. Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma

    International Nuclear Information System (INIS)

    Ribic, B.; DebRoy, T.; Burgardt, P.

    2011-01-01

    During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.

  2. Spectroscopy of strontium Rydberg states using electromagnetically induced transparency

    International Nuclear Information System (INIS)

    Mauger, S; Millen, J; Jones, M P A

    2007-01-01

    We report on the all-optical detection of Rydberg states in an effusive atomic beam of strontium atoms using electromagnetically induced transparency (EIT). Using narrow-linewidth CW lasers we obtain an EIT linewidth of 5 MHz. To illustrate the high spectroscopic resolution offered by this method, we have measured isotope shifts of the 5s18d 1 D 2 and 5s19s 1 S 0 Rydberg states. This technique could be applied to high-resolution, non-destructive measurements of ultra-cold Rydberg gases and plasmas. (fast track communication)

  3. Establishment of the laser induced breakdown spectroscopy in a vacuum atmosphere for a accuracy improvement

    International Nuclear Information System (INIS)

    Kim, Seung Hyun; Kim, H. D.; Shin, H. S.

    2009-06-01

    This report describes the fundamentals of the Laser Induced Breakdown Spectroscopy(LIBS), and it describes the quantitative analysis method in the vacuum condition to obtain a high measurement accuracy. The LIBS system employs the following major components: a pulsed laser, a gas chamber, an emission spectrometer, a detector, and a computer. When the output from a pulsed laser is focused onto a small spot on a sample, an optically induced plasma, called a laser-induced plasma (LIP) is formed at the surface. The LIBS is a laser-based sensitive optical technique used to detect certain atomic and molecular species by monitoring the emission signals from a LIP. This report was described a fundamentals of the LIBS and current states of research. And, It was described a optimization of measurement condition and characteristic analysis of a LIP by measurement of the fundamental metals. The LIBS system shows about a 0.63 ∼ 5.82% measurement errors and calibration curve for the 'Cu, Cr and Ni'. It also shows about a 5% less of a measurement errors and calibration curve for a Nd and Sm. As a result, the LIBS accuracy for a part was little improved than preexistence by the optimized condition

  4. Time-Resolved Spectroscopy Diagnostic of Laser-Induced Optical Breakdown

    Directory of Open Access Journals (Sweden)

    Christian G. Parigger

    2010-01-01

    Full Text Available Transient laser plasma is generated in laser-induced optical breakdown (LIOB. Here we report experiments conducted with 10.6-micron CO2 laser radiation, and with 1.064-micron fundamental, 0.532-micron frequency-doubled, 0.355-micron frequency-tripled Nd:YAG laser radiation. Characterization of laser induced plasma utilizes laser-induced breakdown spectroscopy (LIBS techniques. Atomic hydrogen Balmer series emissions show electron number density of 1017 cm−3 measured approximately 10 μs and 1 μs after optical breakdown for CO2 and Nd:YAG laser radiation, respectively. Recorded molecular recombination emission spectra of CN and C2 Swan bands indicate an equilibrium temperature in excess of 7000 Kelvin, inferred for these diatomic molecules. Reported are also graphite ablation experiments where we use unfocused laser radiation that is favorable for observation of neutral C3 emission due to reduced C3 cation formation. Our analysis is based on computation of diatomic molecular spectra that includes accurate determination of rotational line strengths, or Hönl-London factors.

  5. Applications of inductively coupled plasma spectroscopy to geochemical reconnaissance for uranium exploration

    International Nuclear Information System (INIS)

    Cagle, G.W.; Butz, T.R.

    1980-01-01

    The analysis of large numbers of natural groundwater and stream sediment samples by Inductively Coupled Plasma (ICP) Spectroscopy has been applied to a geochemical reconnaissance program as part of the National Uranium Resource Evaluation Program. Approximately 25 elements have been determined in over 60,000 samples by ICP analysis. These data are combined with additional measurements obtained by atomic absorption, colorimetry, neutron activation, and fluorescence spectroscopy. Results are presented and interpreted in terms of the uranium favorability of areas in Texas where this survey has been completed

  6. Exploring the temporally resolved electron density evolution in extreme ultra-violet induced plasmas

    International Nuclear Information System (INIS)

    Van der Horst, R M; Beckers, J; Nijdam, S; Kroesen, G M W

    2014-01-01

    We measured the electron density in an extreme ultra-violet (EUV) induced plasma. This is achieved in a low-pressure argon plasma by using a method called microwave cavity resonance spectroscopy. The measured electron density just after the EUV pulse is 2.6 × 10 16  m −3 . This is in good agreement with a theoretical prediction from photo-ionization, which yields a density of 4.5 × 10 16  m −3 . After the EUV pulse the density slightly increases due to electron impact ionization. The plasma (i.e. electron density) decays in tens of microseconds. (fast track communication)

  7. Recent trends in atomic spectrometry with microwave-induced plasmas

    International Nuclear Information System (INIS)

    Broekaert, Jose A.C.; Siemens, Volker

    2004-01-01

    The state-of-the-art and trends of development in atomic spectrometry with microwave-induced plasmas (MIPs) since the 1998s are presented and discussed. This includes developments in devices for producing microwave plasma discharges, with reference also to miniaturized systems as well as to progress in sample introduction for microwave-induced plasmas, such as pneumatic and ultrasonic nebulization using membrane desolvation, to the further development of gaseous analyte species generation systems and to both spark and laser ablation (LA). The features of microwave-induced plasma mass spectrometry (MIP-MS) as an alternative to inductively coupled plasma (ICP)-MS are discussed. Recent work on the use of microwave-induced plasma atomic spectrometry for trace element determinations and monitoring, their use as tandem sources and for particle sizing are discussed. Recent applications of the coupling of gas chromatography and MIP atomic spectrometry for the determination of organometallic compounds of heavy metals such as Pb, Hg, Se and Sn are reviewed and the possibilities of trapping for sensitivity enhancement, as required for many applications especially in environmental work, are showed at the hand of citations from the recent literature

  8. Remote in-situ laser-induced breakdown spectroscopy using optical fibers

    Science.gov (United States)

    Marquardt, Brian James

    The following dissertation describes the development of methods for performing remote Laser-Induced Breakdown Spectroscopy (LIBS) using optical fibers. Studies were performed to determine the optimal excitation and collection parameters for remote LIBS measurements of glasses, soils and paint. A number of fiber-optic LIBS probes were developed and used to characterize various samples by plasma emission spectroscopy. A novel method for launching high-power laser pulses into optical fibers without causing catastrophic failure is introduced. A systematic study of a number of commercially available optical fibers was performed to determine which optical fibers were best suited for delivering high-power laser pulses. The general design of an all fiber-optic LIBS probe is described and applied to the determination of Pb in soil. A fiber-optic probe was developed for the microanalysis of solid samples remotely by LIBS, Raman spectroscopy and Raman imaging. The design of the probe allows for real-time sample imaging in-situ using coherent imaging fibers. This allows for precise atomic emission and Raman measurements to be performed remotely on samples in hostile or inaccessible environments. A novel technique was developed for collecting spectral plasma images using an acousto-optic tunable filter (AOTF). The spatial and temporal characteristics of the plasma were studied as a function of delay time. From the plasma images the distribution of Pb emission could be determined and fiber-optic designs could be optimized for signal collection. The performance of a two fiber LIBS probe is demonstrated for the determination of the amount of lead in samples of dry paint. It is shown that dry paint samples can be analyzed for their Pb content in-situ using a fiber-optic LIBS probe with detection limits well below the levels currently regulated by the Consumer Products Safety Commission. It is also shown that these measurements can be performed on both latex and enamel paints, and

  9. Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Sivanandan S.; Brumfield, Brian E.; LaHaye, Nicole L.; Hartig, Kyle C.; Phillips, Mark C.

    2018-04-20

    This review article covers the present status of isotope detection through emission, absorption, and fluorescence spectroscopy of atoms and molecules in a laser-produced plasma formed from a solid sample. A description of the physics behind isotope shifts in atoms and molecules is presented, followed by the physics behind solid sampling of laser ablation plumes, optical methods for isotope measurements, the suitable physical conditions of laser-produced plasma plumes for isotopic analysis, and the current status. Finally, concluding remarks will be made on the existing gaps between previous works in the literature and suggestions for future work.

  10. Time-resolved spectroscopy of plasma resonances in highly excited silicon and germanium

    International Nuclear Information System (INIS)

    Huang, C.Y.; Malvezzi, A.M.; Bloembergen, N.; Kurz, H.

    1985-01-01

    The dynamics of the electron-hole plasma in silicon and germanium samples irradiated by 20 ps. 532 nm laser pulses has been investigated in the near infrared by the time-resolved picosecond optical spectroscopy. The experimental reflectivities and transmission are compared with the predictions of the thermal model for degenerate carrier distributions through the Drude formalism. Above a certain fluence, a significant deviation between measured and calculated values indicates a strong increase of the recombination rate as soon as the plasma resonances become comparable with the band gaps. These new plasmon-aided recombination channels are particularly pronounced in germanium. 15 refs., 8 figs

  11. Conversion electron Moessbauer spectroscopy of plasma immersion ion implanted H13 tool steel

    International Nuclear Information System (INIS)

    Terwagne, G.; Hutchings, R.

    1994-01-01

    Conversion electron Moessbauer spectroscopy (CEMS) has been used to investigate nitride formation in AISI-H13 tool steel after treatment by plasma immersion ion implantation (PI 3 ) at 350 C. With only slight variation in the plasma conditions, it is possible to influence the kinetics of nitride precipitation so as to obtain nitrogen concentrations that range from those associated with ε-Fe 2 N through ε-Fe 3 N to γ'-Fe 4 N. The CEMS results enable a more definite identification of the nitrides than that obtained by glancing-angle X-ray diffraction and nuclear reaction analysis alone. (orig.)

  12. Conversion electron Mössbauer spectroscopy of plasma immersion ion implanted H13 tool steel

    Science.gov (United States)

    Terwagne, G.; Collins, G. A.; Hutchings, R.

    1994-12-01

    Conversion electron Mössbauer spectroscopy (CEMS) has been used to investigate nitride formation in AISI-H13 tool steel after treatment by plasma immersion ion implantation (PI3) at 350 °C. With only slight variation in the plasma conditions, it is possible to influence the kinetics of nitride precipitation so as to obtain nitrogen concentrations that range from those associated with ɛ-Fe2N through ɛ-Fe3N to γ'-Fe4N. The CEMS results enable a more definite identification of the nitrides than that obtained by glancing-angle X-ray diffraction and nuclear reaction analysis alone.

  13. Time variations of hf induced plasma waves

    International Nuclear Information System (INIS)

    Showen, R.L.

    1976-01-01

    Intense plasma waves are generated by an HF pump wave in an ionospheric heating experiment at the Arecibo Observatory. These plasma waves can be observed as enhancements to the ion and plasma lines of the incoherent backscatter echo. The enhancements can be three or four orders of magnitude more intense than the unenhanced lines, and tend to fluctuate wildly. Both the purely growing and the decay mode parametric instabilities are present. When the pump wave is turned on abruptly the enhancements develop in time in a repeatable manner. A rather remarkable feature on time scales of seconds is an overshoot in instability power. These overshoots occur frequently but not universally and last for 1 to 6 seconds. They can have a magnitude from ten to hundreds of times the average instability level. Field aligned irregularities may be the cause of the overshoots. The overshoots appear definitely related to an unusually rapid rise in measured electron temperature that cannot be understood in terms of ohmic energy deposition. On time scales of milliseconds there is a ''mini-overshoot'' before the growth of the instability to a large value. The spectral details also change in a striking manner. The instabilities can first be detected 2 to 4 msec after the pump wave turn-on. The decay mode is present as well as a broad featureless ''noise bump'', which partially sharpens into a line as time progresses. These changes of the spectra in time seem to run counter to the currently accepted theories of plasma wave saturation

  14. The Spectral Emission Characteristics of Laser Induced Plasma on Tea Samples

    International Nuclear Information System (INIS)

    Zheng Peichao; Shi Minjie; Wang Jinmei; Liu Hongdi

    2015-01-01

    Laser induced breakdown spectroscopy (LIBS) provides a useful technique for food security as well as determining nutrition contents. In this paper, optical emission studies of laser induced plasma on commercial tea samples were carried out. The spectral intensities of Mg, Mn, Ca, Al, C and CN vibration bands varying with laser energy and the detection delay time of an intensified charge coupled device were studied. In addition, the relative concentrations of six microelements, i.e., Mg, Mn, Ca, Al, Na and K, were analyzed semi-quantitatively as well as H, for four kinds of tea samples. Moreover, the plasma parameters were explored, including electron temperature and electron number density. The electron temperature and electron number density were around 11000 K and 10 17 cm −3 , respectively. The results show that it is reasonable to consider the LIBS technique as a new method for analyzing the compositions of tea leaf samples. (paper)

  15. Characterization of gaseous species in scanning atmospheric rf plasma with transmission infrared spectroscopy

    International Nuclear Information System (INIS)

    Kim, Seong H.; Kim, Jeong Hoon; Kang, Bang-Kwon

    2008-01-01

    A scanning atmospheric radio-frequency (rf) plasma was analyzed with transmission infrared (IR) spectroscopy. The IR analyses were made for the plasmas used for hydrophobic coating deposition and superhydrophobic coating deposition processes. Since the rf plasma was generated in a small open space with a high gas flow rate in ambient air, the density of gas-phase molecules was very high and the plasma-generated reactive species seemed to undergo various reactions in the gas phase. So, the transmission IR spectra of the scanning atmospheric rf plasma were dominated by gas-phase reaction products, rather than plasma-generated intermediate species. In the CH 4 /He plasma used for hydrophobic coating deposition, C 2 H 6 , C 2 H 2 , and a small amount of C 2 H 4 as well as CO were detected in transmission IR. The intensities of these peaks increased as the rf power increased. The CO formation is due to the activation of oxygen and water in the air. In the CF 4 /H 2 /He plasma used for deposition of superhydrophobic coatings, C 2 F 6 , CF 3 H, COF 2 , and HF were mainly detected. When the H 2 /CF 4 ratio was ∼0.5, the consumption of CF 4 was the highest. As the H 2 /CF 4 ratio increased higher, the C 2 F 6 production was suppressed while the CF 3 H peak grew and the formation of CH 4 were detected. In both CH 4 /He and CF 4 /H 2 /He plasma systems, the undissociated feed gas molecules seem to be highly excited vibrationally and rotationally. The information on plasma-generated reactive species and their reactions was deduced from the distribution of these gas-phase reaction products

  16. Feasibility of laser-induced breakdown spectroscopy (LIBS) for classification of sea salts.

    Science.gov (United States)

    Tan, Man Minh; Cui, Sheng; Yoo, Jonghyun; Han, Song-Hee; Ham, Kyung-Sik; Nam, Sang-Ho; Lee, Yonghoon

    2012-03-01

    We have investigated the feasibility of laser-induced breakdown spectroscopy (LIBS) as a fast, reliable classification tool for sea salts. For 11 kinds of sea salts, potassium (K), magnesium (Mg), calcium (Ca), and aluminum (Al), concentrations were measured by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the LIBS spectra were recorded in the narrow wavelength region between 760 and 800 nm where K (I), Mg (I), Ca (II), Al (I), and cyanide (CN) band emissions are observed. The ICP-AES measurements revealed that the K, Mg, Ca, and Al concentrations varied significantly with the provenance of each salt. The relative intensities of the K (I), Mg (I), Ca (II), and Al (I) peaks observed in the LIBS spectra are consistent with the results using ICP-AES. The principal component analysis of the LIBS spectra provided the score plot with quite a high degree of clustering. This indicates that classification of sea salts by chemometric analysis of LIBS spectra is very promising. Classification models were developed by partial least squares discriminant analysis (PLS-DA) and evaluated. In addition, the Al (I) peaks enabled us to discriminate between different production methods of the salts. © 2012 Society for Applied Spectroscopy

  17. The development of a distributed computing environment for the design and modeling of plasma spectroscopy experiments

    International Nuclear Information System (INIS)

    Nash, J.K.; Eme, W.G.; Lee, R.W.; Salter, J.M.

    1994-10-01

    The design and analysis of plasma spectroscopy experiments can be significantly complicated by relatively routine computational tasks arising from the massive amount of data encountered in the experimental design and analysis stages of the work. Difficulties in obtaining, computing, manipulating and visualizing the information represent not simply an issue of convenience -- they have a very real limiting effect on the final quality of the data and on the potential for arriving at meaningful conclusions regarding an experiment. We describe ongoing work in developing a portable UNIX environment shell with the goal of simplifying and enabling these activities for the plasma-modeling community. Applications to the construction of atomic kinetics models and to the analysis of x-ray transmission spectroscopy will be shown

  18. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    Energy Technology Data Exchange (ETDEWEB)

    Srungaram, Pavan K.; Ayyalasomayajula, Krishna K.; Yu-Yueh, Fang; Singh, Jagdish P., E-mail: singh@icet.msstate.edu

    2013-09-01

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS.

  19. Comparison of laser induced breakdown spectroscopy and spark induced breakdown spectroscopy for determination of mercury in soils

    International Nuclear Information System (INIS)

    Srungaram, Pavan K.; Ayyalasomayajula, Krishna K.; Yu-Yueh, Fang; Singh, Jagdish P.

    2013-01-01

    Mercury is a toxic element found throughout the environment. Elevated concentrations of mercury in soils are quite hazardous to plants growing in these soils and also the runoff of soils to nearby water bodies contaminates the water, endangering the flora and fauna of that region. This makes continuous monitoring of mercury very essential. This work compares two potential spectroscopic methods (laser induced breakdown spectroscopy (LIBS) and spark induced breakdown spectroscopy (SIBS)) at their optimum experimental conditions for mercury monitoring. For LIBS, pellets were prepared from soil samples of known concentration for generating a calibration curve while for SIBS, soil samples of known concentration were used in the powder form. The limits of detection (LODs) of Hg in soil were calculated from the Hg calibration curves. The LOD for mercury in soil calculated using LIBS and SIBS is 483 ppm and 20 ppm, respectively. The detection range for LIBS and SIBS is discussed. - Highlights: • We compared SIBS and LIBS for mercury (Hg) measurements in soil. • Hg 546.07 nm line was selected for both LIBS and SIBS measurements. • Limit of detection for Hg was found to be 20 ppm with SIBS and 483 ppm with LIBS

  20. Dynamics of the spatial electron density distribution of EUV-induced plasmas

    Science.gov (United States)

    van der Horst, R. M.; Beckers, J.; Osorio, E. A.; Banine, V. Y.

    2015-11-01

    We studied the temporal evolution of the electron density distribution in a low pressure pulsed plasma induced by high energy extreme ultraviolet (EUV) photons using microwave cavity resonance spectroscopy (MCRS). In principle, MCRS only provides space averaged information about the electron density. However, we demonstrate here the possibility to obtain spatial information by combining multiple resonant modes. It is shown that EUV-induced plasmas, albeit being a rather exotic plasma, can be explained by known plasma physical laws and processes. Two stages of plasma behaviour are observed: first the electron density distribution contracts, after which it expands. It is shown that the contraction is due to cooling of the electrons. The moment when the density distribution starts to expand is related to the inertia of the ions. After tens of microseconds, the electrons reached the wall of the cavity. The speed of this expansion is dependent on the gas pressure and can be divided into two regimes. It is shown that the acoustic dominated regime the expansion speed is independent of the gas pressure and that in the diffusion dominated regime the expansion depends reciprocal on the gas pressure.

  1. Dynamics of the spatial electron density distribution of EUV-induced plasmas

    International Nuclear Information System (INIS)

    Van der Horst, R M; Beckers, J; Banine, V Y; Osorio, E A

    2015-01-01

    We studied the temporal evolution of the electron density distribution in a low pressure pulsed plasma induced by high energy extreme ultraviolet (EUV) photons using microwave cavity resonance spectroscopy (MCRS). In principle, MCRS only provides space averaged information about the electron density. However, we demonstrate here the possibility to obtain spatial information by combining multiple resonant modes. It is shown that EUV-induced plasmas, albeit being a rather exotic plasma, can be explained by known plasma physical laws and processes. Two stages of plasma behaviour are observed: first the electron density distribution contracts, after which it expands. It is shown that the contraction is due to cooling of the electrons. The moment when the density distribution starts to expand is related to the inertia of the ions. After tens of microseconds, the electrons reached the wall of the cavity. The speed of this expansion is dependent on the gas pressure and can be divided into two regimes. It is shown that the acoustic dominated regime the expansion speed is independent of the gas pressure and that in the diffusion dominated regime the expansion depends reciprocal on the gas pressure. (fast track communication)

  2. Space-resolved vacuum ultra-violet spectroscopy on T.F.R. Tokamak plasmas

    International Nuclear Information System (INIS)

    1978-01-01

    Results are reported of space-resolved vacuum-ultraviolet spectroscopy (between 100 A and 2000A) on T.F.R. Tokamak plasmas and examples are given of profiles for both heavy and light impurity ions. The experimental method and the associated uncertainties and problems are stressed. The great importance of numerical calculations in the interpretation of the impurity profiles is pointed out. (author)

  3. Self-absorption influence on the optical spectroscopy of zinc oxide laser produced plasma

    Energy Technology Data Exchange (ETDEWEB)

    De Posada, E; Arronte, M A; Ponce, L; Rodriguez, E; Flores, T [Centro de Investigacion en Ciencia Aplicada y TecnologIa Avanzada-Unidad Altamira, Tamaulipas (Mexico); Lunney, J G, E-mail: edeposada@ipn.mx [School of Physics, Trinity College Dublin (Ireland)

    2011-01-01

    Optical spectroscopy is used to study the laser ablation process of ZnO targets. It is demonstrated that even if Partial Local Thermal Equilibrium is present, self absorption process leads to a decrease of recorded lines emission intensities and have to be taken into account to obtain correct values of such parameters. It is presented a method that combines results of both Langmuir probe technique and Anisimov model to obtain correct values of plasma parameters.

  4. Inductively coupled plasma for atomic emission spectroscopy at the Savannah River Plant

    International Nuclear Information System (INIS)

    Coleman, J.T.

    1986-01-01

    The Savannah River Plant atomic emission spectroscopy laboratory has been in operation for over 30 years. Routine analytical methods and instrumentation are being replaced with current technology. Laboratory renovation will include the installation of contained dual excitation sources (inductively coupled plasma and d-c arc) with a direct reading spectrometer. The instrument will be used to provide impurity analyses of plutonium, uranium, and other nuclear fuel cycle materials

  5. Micro spatial analysis of seashell surface using laser-induced breakdown spectroscopy and Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yuan; Li, Yuandong; Li, Ying [Optics and Optoelectronics Lab, Ocean University of China, Qingdao 266100 (China); Wang, Yangfan; Wang, Shi; Bao, Zhenmin [Life Science College, Ocean University of China, Qingdao 266003 (China); Zheng, Ronger, E-mail: rzheng@ouc.edu.cn [Optics and Optoelectronics Lab, Ocean University of China, Qingdao 266100 (China)

    2015-08-01

    The seashell has been studied as a proxy for the marine researches since it is the biomineralization product recording the growth development and the ocean ecosystem evolution. In this work a hybrid of Laser Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy was introduced to the composition analysis of seashell (scallop, bivalve, Zhikong). Without any sample treatment, the compositional distribution of the shell was obtained using LIBS for the element detection and Raman for the molecule recognition respectively. The elements Ca, K, Li, Mg, Mn and Sr were recognized by LIBS; the molecule carotene and carbonate were identified with Raman. It was found that the LIBS detection result was more related to the shell growth than the detection result of Raman. The obtained result suggested the shell growth might be developing in both horizontal and vertical directions. It was indicated that the LIBS–Raman combination could be an alternative way for the shell researches. - Highlights: • A LIBS–Raman hybrid system was developed. • A seashell has been analyzed for the elementary and molecular distribution with a system. • The shell growth development was studied on the surface and in the depth.

  6. Characterization of laser-induced breakdown spectroscopy (LIBS) for application to space exploration

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Andrew K. [Group CST-1, MS J565, Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Scherbarth, Nancy L. [Group CST-1, MS J565, Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Cremers, David A. [Group CST-1, MS J565, Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Ferris, Monty J. [Group CST-1, MS J565, Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2000-03-01

    Early in the next century, several space missions are planned with the goal of landing craft on asteroids, comets, the Moon, and Mars. To increase the scientific return of these missions, new methods are needed to provide (1) significantly more analyses per mission lifetime, and (2) expanded analytical capabilities. One method that has the potential to meet both of these needs for the elemental analysis of geological samples is laser-induced breakdown spectroscopy (LIBS). These capabilities are possible because the laser plasma provides rapid analysis and the laser pulse can be focused on a remotely located sample to perform a stand-off measurement. Stand-off is defined as a distance up to 20 m between the target and laser. Here we present the results of a characterization of LIBS for the stand-off analysis of soils at reduced air pressures and in a simulated Martian atmosphere (5-7 torr pressure of CO{sub 2}) showing the feasibility of LIBS for space exploration. For example, it is demonstrated that an analytically useful laser plasma can be generated at distances up to 19 m by using only 35 mJ/pulse from a compact laser. Some characteristics of the laser plasma at reduced pressure were also investigated. Temporally and spectrally resolved imaging showed significant changes in the plasma as the pressure was reduced and also showed that the analyte signals and mass ablated from a target were strongly dependent on pressure. As the pressure decreased from 590 torr to the 40-100 torr range, the signals increased by a factor of about 3-4, and as the pressure was further reduced the signals decreased. This behavior can be explained by pressure-dependent changes in the mass of material vaporized and the frequency of collisions between species in the plasma. Changes in the temperature and the electron density of the plasmas with pressure were also examined and detection limits for selected elements were determined. (c) 2000 Society for Applied Spectroscopy.

  7. Characterization of laser-induced breakdown spectroscopy (LIBS) for application to space exploration

    International Nuclear Information System (INIS)

    Knight, Andrew K.; Scherbarth, Nancy L.; Cremers, David A.; Ferris, Monty J.

    2000-01-01

    Early in the next century, several space missions are planned with the goal of landing craft on asteroids, comets, the Moon, and Mars. To increase the scientific return of these missions, new methods are needed to provide (1) significantly more analyses per mission lifetime, and (2) expanded analytical capabilities. One method that has the potential to meet both of these needs for the elemental analysis of geological samples is laser-induced breakdown spectroscopy (LIBS). These capabilities are possible because the laser plasma provides rapid analysis and the laser pulse can be focused on a remotely located sample to perform a stand-off measurement. Stand-off is defined as a distance up to 20 m between the target and laser. Here we present the results of a characterization of LIBS for the stand-off analysis of soils at reduced air pressures and in a simulated Martian atmosphere (5-7 torr pressure of CO 2 ) showing the feasibility of LIBS for space exploration. For example, it is demonstrated that an analytically useful laser plasma can be generated at distances up to 19 m by using only 35 mJ/pulse from a compact laser. Some characteristics of the laser plasma at reduced pressure were also investigated. Temporally and spectrally resolved imaging showed significant changes in the plasma as the pressure was reduced and also showed that the analyte signals and mass ablated from a target were strongly dependent on pressure. As the pressure decreased from 590 torr to the 40-100 torr range, the signals increased by a factor of about 3-4, and as the pressure was further reduced the signals decreased. This behavior can be explained by pressure-dependent changes in the mass of material vaporized and the frequency of collisions between species in the plasma. Changes in the temperature and the electron density of the plasmas with pressure were also examined and detection limits for selected elements were determined. (c) 2000 Society for Applied Spectroscopy

  8. Quantitative analysis of titanium concentration using calibration-free laser-induced breakdown spectroscopy (LIBS)

    Science.gov (United States)

    Zaitun; Prasetyo, S.; Suliyanti, M. M.; Isnaeni; Herbani, Y.

    2018-03-01

    Laser-induced breakdown spectroscopy (LIBS) can be used for quantitative and qualitative analysis. Calibration-free LIBS (CF-LIBS) is a method to quantitatively analyze concentration of elements in a sample in local thermodynamic equilibrium conditions without using available matrix-matched calibration. In this study, we apply CF-LIBS for quantitative analysis of Ti in TiO2 sample. TiO2 powder sample was mixed with polyvinyl alcohol and formed into pellets. An Nd:YAG pulsed laser at a wavelength of 1064 nm was focused onto the sample to generate plasma. The spectrum of plasma was recorded using spectrophotometer then compared to NIST spectral line to determine energy levels and other parameters. The value of plasma temperature obtained using Boltzmann plot is 8127.29 K and electron density from calculation is 2.49×1016 cm-3. Finally, the concentration of Ti in TiO2 sample from this study is 97% that is in proximity with the sample certificate.

  9. Calibration-Free Laser-Induced Breakdown Spectroscopy: State of the art

    Science.gov (United States)

    Tognoni, E.; Cristoforetti, G.; Legnaioli, S.; Palleschi, V.

    2010-01-01

    The aim of this paper is offering a critical review of Calibration-Free Laser-Induced Breakdown Spectroscopy (CF-LIBS), the approach of multi-elemental quantitative analysis of LIBS spectra, based on the measurement of line intensities and plasma properties (plasma electron density and temperature) and on the assumption of a Boltzmann population of excited levels, which does not require the use of calibration curves or matrix-matched standards. The first part of this review focuses on the applications of the CF-LIBS method. Quantitative results reported in the literature, obtained in the analysis of various materials and in a wide range of experimental conditions, are summarized, with a special emphasis on the departure from nominal composition values. The second part is a discussion of the simplifying assumptions which lie at the basis of the CF-LIBS algorithm (stoichiometric ablation and complete atomization, thermal equilibrium, homogeneous plasma, thin radiation, detection of all elements). The inspection of the literature suggests that the CF-LIBS method is more accurate in analyzing metallic alloys rather than dielectrics. However, the full exploitation of the method seems to be still far to come, especially for the lack of a complete characterization of the effects of experimental constraints. However, some general directions can be suggested to help the analyst in designing LIBS measurements in a way which is more suited for CF-LIBS analysis.

  10. Experimental investigation of ultraviolet laser induced plasma density and temperature evolution in air

    International Nuclear Information System (INIS)

    Thiyagarajan, Magesh; Scharer, John

    2008-01-01

    We present measurements and analysis of laser induced plasma neutral densities and temperatures in dry air by focusing 200 mJ, 10 MW high power, 193 nm ultraviolet ArF (argon fluoride) laser radiation to a 30 μm radius spot size. We examine these properties that result from multiphoton and collisional cascade processes for pressures ranging from 40 Torr to 5 atm. A laser shadowgraphy diagnostic technique is used to obtain the plasma electron temperature just after the shock front and this is compared with optical emission spectroscopic measurements of nitrogen rotational and vibrational temperatures. Two-color laser interferometry is employed to measure time resolved spatial electron and neutral density decay in initial local thermodynamic equilibrium (LTE) and non-LTE conditions. The radiating species and thermodynamic characteristics of the plasma are analyzed by means of optical emission spectroscopy (OES) supported by SPECAIR, a special OES program for air constituent plasmas. Core plasma rotational and vibrational temperatures are obtained from the emission spectra from the N 2 C-B(2+) transitions by matching the experimental spectrum results with the SPECAIR simulation results and the results are compared with the electron temperature just behind the shock wave. The plasma density decay measurements are compared with a simplified electron density decay model that illustrates the dominant three-and two-body recombination terms with good correlation

  11. Marangoni flows induced by atmospheric-pressure plasma jets

    International Nuclear Information System (INIS)

    Berendsen, C W J; Van Veldhuizen, E M; Kroesen, G M W; Darhuber, A A

    2015-01-01

    We studied the interaction of atmospheric-pressure plasma jets of Ar or air with liquid films of an aliphatic hydrocarbon on moving solid substrates. The hydrodynamic jet-liquid interaction induces a track of lower film thickness. The chemical plasma-surface interaction oxidizes the liquid, leading to a local increase of the surface tension and a self-organized redistribution of the liquid film. We developed a numerical model that qualitatively reproduces the formation, instability and coarsening of the flow patterns observed in the experiments. Monitoring the liquid flow has potential as an in-situ, spatially and temporally resolved, diagnostic tool for the plasma-liquid surface interaction. (paper)

  12. Laser-induced Breakdown Spectroscopy: A New Approach for Nanoparticle's Mapping and Quantification in Organ Tissue

    Science.gov (United States)

    Sancey, Lucie; Motto-Ros, Vincent; Kotb, Shady; Wang, Xiaochun; Lux, François; Panczer, Gérard; Yu, Jin; Tillement, Olivier

    2014-01-01

    Emission spectroscopy of laser-induced plasma was applied to elemental analysis of biological samples. Laser-induced breakdown spectroscopy (LIBS) performed on thin sections of rodent tissues: kidneys and tumor, allows the detection of inorganic elements such as (i) Na, Ca, Cu, Mg, P, and Fe, naturally present in the body and (ii) Si and Gd, detected after the injection of gadolinium-based nanoparticles. The animals were euthanized 1 to 24 hr after intravenous injection of particles. A two-dimensional scan of the sample, performed using a motorized micrometric 3D-stage, allowed the infrared laser beam exploring the surface with a lateral resolution less than 100 μm. Quantitative chemical images of Gd element inside the organ were obtained with sub-mM sensitivity. LIBS offers a simple and robust method to study the distribution of inorganic materials without any specific labeling. Moreover, the compatibility of the setup with standard optical microscopy emphasizes its potential to provide multiple images of the same biological tissue with different types of response: elemental, molecular, or cellular. PMID:24962015

  13. Optical spectroscopy of laser-produced plasmas for standoff isotopic analysis

    Science.gov (United States)

    Harilal, S. S.; Brumfield, B. E.; LaHaye, N. L.; Hartig, K. C.; Phillips, M. C.

    2018-06-01

    Rapid, in-field, and non-contact isotopic analysis of solid materials is extremely important to a large number of applications, such as nuclear nonproliferation monitoring and forensics, geochemistry, archaeology, and biochemistry. Presently, isotopic measurements for these and many other fields are performed in laboratory settings. Rapid, in-field, and non-contact isotopic analysis of solid material is possible with optical spectroscopy tools when combined with laser ablation. Laser ablation generates a transient vapor of any solid material when a powerful laser interacts with a sample of interest. Analysis of atoms, ions, and molecules in a laser-produced plasma using optical spectroscopy tools can provide isotopic information with the advantages of real-time analysis, standoff capability, and no sample preparation requirement. Both emission and absorption spectroscopy methods can be used for isotopic analysis of solid materials. However, applying optical spectroscopy to the measurement of isotope ratios from solid materials presents numerous challenges. Isotope shifts arise primarily due to variation in nuclear charge distribution caused by different numbers of neutrons, but the small proportional nuclear mass differences between nuclei of various isotopes lead to correspondingly small differences in optical transition wavelengths. Along with this, various line broadening mechanisms in laser-produced plasmas and instrumental broadening generated by the detection system are technical challenges frequently encountered with emission-based optical diagnostics. These challenges can be overcome by measuring the isotope shifts associated with the vibronic emission bands from molecules or by using the techniques of laser-based absorption/fluorescence spectroscopy to marginalize the effect of instrumental broadening. Absorption and fluorescence spectroscopy probe the ground state atoms existing in the plasma when it is cooler, which inherently provides narrower

  14. Revisiting the electrochemical impedance spectroscopy of magnesium with online inductively coupled plasma atomic emission spectroscopy.

    Science.gov (United States)

    Shkirskiy, Viacheslav; King, Andrew D; Gharbi, Oumaïma; Volovitch, Polina; Scully, John R; Ogle, Kevin; Birbilis, Nick

    2015-02-23

    The electrochemical impedance of reactive metals such as magnesium is often complicated by an obvious inductive loop with decreasing frequency of the AC polarising signal. The characterisation and ensuing explanation of this phenomenon has been lacking in the literature to date, being either ignored or speculated. Herein, we couple electrochemical impedance spectroscopy (EIS) with online atomic emission spectroelectrochemistry (AESEC) to simultaneously measure Mg-ion concentration and electrochemical impedance spectra during Mg corrosion, in real time. It is revealed that Mg dissolution occurs via Mg(2+) , and that corrosion is activated, as measured by AC frequencies less than approximately 1 Hz approaching DC conditions. The result of this is a higher rate of Mg(2+) dissolution, as the voltage excitation becomes slow enough to enable all Mg(2+) -enabling processes to adjust in real time. The manifestation of this in EIS data is an inductive loop. The rationalisation of such EIS behaviour, as it relates to Mg, is revealed for the first time by using concurrent AESEC. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Coherent structures induced by dielectric barrier discharge plasma actuator

    Science.gov (United States)

    Zhang, Xin; Li, Huaxing; Choi, Kwing So; Song, Longfei

    2017-11-01

    The structures of a flow field induced by a plasma actuator were investigated experimentally in quiescent air using high-speed Particle Image Velocimetry (PIV) technology. The motivation behind was to figure out the flow control mechanism of the plasma technique. A symmetrical Dielectric Barrier Discharge (DBD) plasma actuator was mounted on the suction side of the SC (2)-0714 supercritical airfoil. The results demonstrated that the plasma jet had some coherent structures in the separated shear layer and these structures were linked to a dominant frequency of f0 = 39 Hz when the peak-to-peak voltage of plasma actuator was 9.8 kV. The high speed PIV measurement of the induced airflow suggested that the plasma actuator could excite the flow instabilities which lead to production of the roll-up vortex. Analysis of transient results indicated that the roll-up vortices had the process of formation, movement, merging and breakdown. This could promote the entrainment effect of plasma actuator between the outside airflow and boundary layer flow, which is very important for flow control applications.

  16. Laser Induced Breakdown Spectroscopy, advances in resolution and portability

    International Nuclear Information System (INIS)

    Ponce, L.; Flores, T.; Arronte, M.; Moreira, L.; Hernandez, L. C.; Posada, E. de

    2009-01-01

    Laser Induced Breakdown Spectroscopy (LIBS), can be considered as one of the most dynamic and promising technique in the field of analytical spectroscopy. LIBS has turned into a powerful alternative for a wide front of applications, from the geological exploration to the industrial inspection, including the environmental monitoring, the biomedical analysis, the study of patrimonial works, the safety and defense. The advances in LIBS instrumentation have allowed improving gradually the analysis services and quality, on the basis of a better knowledge of the technology principles. Recently, systems of double pulse have facilitated a better dosing of energy, the improvement of the signal-noise relation and the study of the different process stages. Femtosecond lasers offers the possibility of study in detail the ablation and atomic emission processes. New advances like multi-pulse or multi-wavelength systems -in fact stilling without exploring, must offer new information to advance in this knowledge. Finally, which it does to this technology really attractive, is the aptitude to be employed in field conditions, or for the detection of the elementary composition at long distances. In this presentation there are discussed the designs of portable instrumentation, compact and low cost, which can improve substantially the LIBS possibilities. (Author)

  17. A Laser Induced Breakdown Spectroscopy application based on Local Thermodynamic Equilibrium assumption for the elemental analysis of alexandrite gemstone and copper-based alloys

    Energy Technology Data Exchange (ETDEWEB)

    De Giacomo, A. [Department of Chemistry, University of Bari, Via Orabona 4, 70126 Bari (Italy); Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Dell' Aglio, M. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Gaudiuso, R., E-mail: rosalba.gaudiuso@ba.imip.cnr.it [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Santagata, A. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Potenza, Via S. Loja, Zona Ind., 85050 Tito Scalo (PZ) (Italy); Senesi, G.S. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy); Rossi, M.; Ghiara, M.R. [Department of Earth Sciences, University of Naples ' Federico II' , Via Mezzocannone 8, 80134 Naples (Italy); Capitelli, F. [Institute of Crystallography - CNR, Via Salaria Km 29.300, 00015 Monterotondo (Roma) (Italy); De Pascale, O. [Institute of Inorganic Methodologies and Plasmas - CNR, U.O.S. Bari, Via Amendola 122/D, 70126 Bari (Italy)

    2012-04-04

    Graphical abstract: Self-calibrated analytical techniques based on the approximation of Local Thermodynamic Equilibrium (LTE) have been employed for the analysis of gemstones and copper-based alloys by LIBS (Laser Induced Breakdown Spectroscopy), with a special focus on LTE conditions in laser induced plasmas. Highlights: Black-Right-Pointing-Pointer Discussion of Local Thermodynamic Equilibrium (LTE) condition in laser-induced plasmas. Black-Right-Pointing-Pointer LIBS enables elemental analysis with self-calibrated LTE-based methods. Black-Right-Pointing-Pointer Be detection in alexandrite gemstone is made possible by LIBS. - Abstract: Laser Induced Breakdown Spectroscopy (LIBS) is an appealing technique to study laser-induced plasmas (LIPs), both from the basic diagnostics point of view and for analytical applications. LIPs are complex dynamic systems, expanding at supersonic velocities and undergoing a transition between different plasma regimes. If the Local Thermodynamic Equilibrium (LTE) condition is valid for such plasmas, several analytical methods can be employed and fast quantitative analyses can be performed on a variety of samples. In the present paper, a discussion about LTE is carried out and an innovative application to the analysis of the alexandrite gemstone is presented. In addition, a study about the influence of plasma parameters on the performance of LTE-based methods is reported for bronze and brass targets.

  18. Laser-induced breakdown spectroscopy (LIBS): a new spectrochemical technique

    International Nuclear Information System (INIS)

    Radziemski, L.J.; Loree, T.R.; Cremers, D.A.

    1982-01-01

    We have used the breakdown spark from a focused laser beam to generate analytically useful emission spectra of minor constituents in air and other carrier gases. The medium was sampled directly. It was not necessary to reduce the sample to solution nor to introduce electrodes. The apparatus is particularly simple; a pulsed laser, spectrometer, and some method for time resolution. The latter is essential in laser-induced-breakdown spectroscopy (LIBS) because of the strong early continuum. High temperatures in the spark result in vaporization of small particles, dissociation of molecules, and excitation of atomic and ionic spectra, including species which are normally difficult to detect. In one application, we have monitored beryllium in air at conventrations below 1 μg/m 3 , which is below 1 ppB (w/w). In another we have monitored chlorine and fluorine atoms in real time. LIBS has the potential for real-time direct sampling of contaminants in situ

  19. Detection of early caries by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Sasazawa, Shuhei; Kakino, Satoko; Matsuura, Yuji

    2015-07-01

    To improve sensitivity of dental caries detection by laser-induced breakdown spectroscopy (LIBS) analysis, it is proposed to utilize emission peaks in the ultraviolet. We newly focused on zinc whose emission peaks exist in ultraviolet because zinc exists at high concentration in the outer layer of enamel. It was shown that by using ratios between heights of an emission peak of Zn and that of Ca, the detection sensitivity and stability are largely improved. It was also shown that early caries are differentiated from healthy part by properly setting a threshold in the detected ratios. The proposed caries detection system can be applied to dental laser systems such as ones based on Er:YAG-lasers. When ablating early caries part by laser light, the system notices the dentist that the ablation of caries part is finished. We also show the intensity of emission peaks of zinc decreased with ablation with Er:YAG laser light.

  20. Some actinide speciation using laser induced photoacoustic spectroscopy

    International Nuclear Information System (INIS)

    Pollard, P.M.; McMillan, J.W.; Phillips, G.; Thomason, H.P.; Ewart, F.T.

    1988-01-01

    Laser induced photoacoustic spectroscopy is an attractive method for the speciation of actinides in solutions from nuclear disposal studies because it is essentially non-invasive and has a reasonably high sensitivity, down to ca 10 -8 M. A novel true dual beam system has been constructed and commissioned at Harwell with a performance at least equal to any others in existence. It is based on a XeCl excimer laser and a dye laser, beam splitter, two laser power monitors and photoacoustic cells. The wavelength scanning, data collection, and spectra processing and display are controlled by an Apricot computer. The sample and reference cells are housed in an inert atmosphere glove box. Early applications of the equipment described include measurements of Am and Np species under varying conditions of pH, Eh and carbonate concentration. The observations show some correlation with predictions made using the geochemical modelling code PHREEQE. (orig.)

  1. Analysis of fresco by laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Caneve, L.; Diamanti, A.; Grimaldi, F.; Palleschi, G.; Spizzichino, V.; Valentini, F.

    2010-01-01

    The laser-based techniques have been shown to be a very powerful tool for artworks characterization and are used in the field of cultural heritage for the offered advantages of minimum invasiveness, in situ applicability and high sensitivity. Laser induced breakdown spectroscopy, in particular, has been applied in this field to many different kinds of ancient materials with successful results. In this work, a fragment of a Roman wall painting from the archaeological area of Pompeii has been investigated by LIBS. The sample elemental composition resulting from LIBS measurements suggested the presence of certain pigments. The ratio of the intensities of different lines related to some characteristic elements is proposed as an indicator for pigment recognition. The depth profiling permitted to put in evidence the presence of successive paint layers with different compositions. A comparison with the results obtained by the microscopy inspection of the sample has been done.

  2. Atomic and ionic density measurement by laser absorption spectroscopy of magnetized or non-magnetized plasmas

    International Nuclear Information System (INIS)

    Le Gourrierec, P.

    1989-11-01

    Laser absorption spectroscopy is an appreciated diagnostic in plasma physics to measure atomic and ionic densities. We used it here more specifically on metallic plasmas. Firstly, a uranium plasma was created in a hollow cathode. 17 levels of U.I and U.II (12 for U.I and 5 for U.II) are measured by this method. The results are compared with the calculated levels of two models (collisional-radiative and LTE). Secondly, the theory of absorption in presence of a magnetic field is recalled and checked. Then, low-density magnetized plasma produced on our ERIC experiment (acronym for Experiment of Resonance Ionic Cyclotron), have been diagnosed successfully. The use of this technique on a low density plasma has not yet been published to our knowledge. The transverse temperature and the density of a metastable atomic level of a barium plasma has been derived. The evolution of a metastable ionic level of this element is studied in terms of two source parameters (furnace temperature and injected hyperfrequency power) [fr

  3. In situ deuterium inventory measurements of a-C:D layers on tungsten in TEXTOR by laser induced ablation spectroscopy

    International Nuclear Information System (INIS)

    Gierse, N; Brezinsek, S; Coenen, J W; Huber, A; Laengner, M; Möller, S; Nonhoff, M; Philipps, V; Pospieszczyk, A; Schweer, B; Sergienko, G; Xiao, Q; Zlobinski, M; Samm, U; Giesen, T F

    2014-01-01

    Laser induced ablation spectroscopy (LIAS) is a diagnostic to provide temporally and spatially resolved in situ measurements of tritium retention and material migration in order to characterize the status of the first wall in future fusion devices. In LIAS, a ns-laser pulse ablates the first nanometres of the first wall plasma-facing components into the plasma edge. The resulting line radiation by plasma excitation is observed by spectroscopy. In the case of the full ionizing plasma and with knowledge of appropriate photon efficiencies for the corresponding line emission the amount of ablated material can be measured in situ. We present the photon efficiency for the deuterium Balmer α-line resulting from ablation in TEXTOR by performing LIAS on amorphous hydrocarbon (a-C:D) layers deposited on tungsten substrate of thicknesses between 0.1 and 1.1 μm. An experimental inverse photon efficiency of [(D/(XB))] D α (EXP) a-C:D→ LIAS D =75.9±23.4 was determined. This value is a factor 5 larger than predicted values from the ADAS database for atomic injection of deuterium under TEXTOR plasma edge conditions and about twice as high, assuming normal wall recycling and release of molecular deuterium and break-up of D 2 via the molecular ion which is usually observed at the high temperature tokamak edge (T e  > 30 eV). (paper)

  4. Structural characterization of H plasma-doped ZnO single crystals by positron annihilation spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Anwand, Wolfgang; Brauer, Gerhard; Cowan, Thomas E. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Grambole, Dieter; Skorupa, Wolfgang [Institut fuer Ionenstrahlphysik und Materialforschung, Forschungszentrum Dresden-Rossendorf, P.O. Box 510 119, 01314 Dresden (Germany); Cizek, Jakub; Kuriplach, Jan; Prochazka, Ivan [Department of Low Temperature Physics, Charles University, V Holesovickach 2, 18000 Prague (Czech Republic); Egger, Werner; Sperr, Peter [Institut fuer Angewandte Physik und Messtechnik, Fakultaet fuer Luft- und Raumfahrttechnik, Universitaet der Bundeswehr, Heisenbergweg 39, 85579 Neubiberg (Germany)

    2010-11-15

    Nominally undoped, hydrothermally grown ZnO single crystals have been investigated before and after exposure to remote H plasma. Structural characterizations have been made by various positron annihilation spectroscopies (continuous and pulsed slow positron beams, conventional lifetime). The content of bound hydrogen (H-b) before and after the remote H plasma treatment at the polished side of the crystals was determined at depths of 100 and 600 nm, respectively, using nuclear reaction analysis. At a depth of 100 nm, H-b increased from (11.8{+-}2.5) to (48.7{+-}7.6) x 10{sup 19} cm{sup -3} after remote H plasma treatment, whereas at 600 nm no change in H-b was observed. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Spectroscopy and atomic physics of highly ionized Cr, Fe, and Ni for tokamak plasmas

    Science.gov (United States)

    Feldman, U.; Doschek, G. A.; Cheng, C.-C.; Bhatia, A. K.

    1980-01-01

    The paper considers the spectroscopy and atomic physics for some highly ionized Cr, Fe, and Ni ions produced in tokamak plasmas. Forbidden and intersystem wavelengths for Cr and Ni ions are extrapolated and interpolated using the known wavelengths for Fe lines identified in solar-flare plasmas. Tables of transition probabilities for the B I, C I, N I, O I, and F I isoelectronic sequences are presented, and collision strengths and transition probabilities for Cr, Fe, and Ni ions of the Be I sequence are given. Similarities of tokamak and solar spectra are discussed, and it is shown how the atomic data presented may be used to determine ion abundances and electron densities in low-density plasmas.

  6. Analyzing silver concentration in soil using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Prasetyo, S.; Isnaeni; Zaitun; Mitchell, K.; Suliyanti, M. M.; Herbani, Y.

    2018-03-01

    Determination of concentration of heavy metal ions in soil, such as silver, is very important to study soil pollution levels. Several techniques have been developed to determine silver ion concentration in soil. In this paper, we utilized laser-induced breakdown spectroscopy (LIBS) to study silver concentration in soil. We used four different data analysis methods to calculate silver concentration. In this case, we prepared soil samples with different silver ion concentrations from 400 ppm to 1000 ppm. Our analysis was focused on the 843.15 nm silver atomic absorption line. We found that plasma intensity increased as silver concentration increased. Our findings were based on our analysis using four different analysis methods. We believe that these analysis methods are able to calculate silver concentration in soil using LIBS.

  7. Analysis of material collected on swipes using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Chinni, Rosemarie; Cremers, David A.; Multari, Rosalie

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) was evaluated to determine elements collected on swipes as surface contamination. A series of long laser plasmas formed along the swipe surface (Post-it paper) interrogated the collected contamination. LIBS detection limits, determined for the elements Ag, As, Ba, Be, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Sr, and Zn on swipes (2 cm 2 area), ranged from 0.002 μg (Be) to 1.46 μg (Pb). The elements were introduced as constituents of synthetic silicate particles serving as a contaminant dust stimulant. The average predicted mass was within 16% of the actual mass on the swipe. The efficiency of collecting particles from surfaces including plastic, Formica, and Al metal was also evaluated. The ability to detect and differentiate two amino acids on a swipe from each other and from the swipe using chemometric modeling techniques was also demonstrated.

  8. Roughness effects on the hydrogen signal in laser-induced breakdown spectroscopy

    DEFF Research Database (Denmark)

    Rapin, W.; Bousquet, B.; Lasue, J.

    2017-01-01

    On Mars, Laser-Induced Breakdown Spectroscopy (LIBS) as performed by the ChemCam instrument can be used to measure the hydrogen content of targets in situ, under a low pressure CO2 atmosphere. However, unexpected variations observed in the Martian dataset suggest an effect related to target...... roughness. Here, we present a series of laboratory experiments that reproduce the effect observed on Mars and explore possible causes. We show that the hydrogen peak intensity increases significantly with increasing exposure of the target surface to the LIBS plasma, and that these variations are specific......, this effect should be taken into account for the quantification of hydrogen in any LIBS applications where the roughness of the target is significant....

  9. Speciation analysis on Eu(3) in aqueous solution using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Hotokezaka, H.; Tanaka, S.; Nagasaki, S.

    2001-01-01

    Investigation of the chemical behaviour of lanthanides and actinides in the geosphere is important for the safety assessment of high-level radioactive waste disposal. However, determination of speciation for lanthanides and actinides is difficult, because it is too hard to distinguish between metal ion and colloidal metal in aqueous solution. Laser-induced breakdown spectroscopy (LIBS) can detect both ions and microparticles of metals in aqueous solution, especially, high sensitive to microparticles. In this study, we analysed Eu(III) ion and Eu 2 O 3 particle in aqueous solution by LIBS, and measured the hydrolysis behaviour of Eu(III) in aqueous solution. Furthermore, we tried to detect the plasma emission of Eu(III) ions sorbed on TiO 2 particles, and also tried to observe the adsorption behaviour of Eu(III) ions onto TiO 2 particles in aqueous solution. (authors)

  10. Evaluation of laser induced breakdown spectroscopy for the determination of macronutrients in plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Trevizan, Lilian Cristina [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba-SP (Brazil)], E-mail: lilian@conectcor.com.br; Santos, Dario [Universidade Federal de Sao Paulo - UNIFESP, Rua Prof. Artur Riedel 275, 09972-270, Diadema-SP (Brazil); Elgul Samad, Ricardo; Dias Vieira, Nilson [Centro de Lasers e Aplicacoes, IPEN/CNEN-SP, Av. Prof. Lineu Prestes 2242, 05508-000, Sao Paulo-SP (Brazil); Seimi Nomura, Cassiana [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia 166, 09210-170, Santo Andre-SP (Brazil); Nunes, Lidiane Cristina [Departamento de Quimica, Universidade Federal de Sao Carlos, Rod. Washington Luis, km 235, 13565-905, Sao Carlos-SP (Brazil); Rufini, Iolanda Aparecida; Krug, Francisco Jose [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Av. Centenario 303, 13416-000, Piracicaba-SP (Brazil)

    2008-10-15

    Laser induced breakdown spectroscopy (LIBS) has become an analytical tool for the direct analysis of a large variety of materials in order to provide qualitative and/or quantitative information. However, there is a lack of information for LIBS analysis of agricultural and environmental samples. In this work a LIBS system has been evaluated for the determination of macronutrients (P, K, Ca, Mg) in pellets of vegetal reference materials. An experimental setup was designed by using a Nd:YAG laser operating at 1064 nm and an Echelle spectrometer with ICCD detector. The plasma temperature was estimated by Boltzmann plots and instrumental parameters such as delay time, lens-to-sample distance and pulse energy were evaluated. Certified reference materials as well as reference materials were used for analytical calibrations of P, K, Ca, and Mg. Most results of the direct analysis of plant samples by LIBS were in reasonable agreement with those obtained by ICP OES after wet acid decomposition.

  11. Evaluation of laser induced breakdown spectroscopy for the determination of macronutrients in plant materials

    International Nuclear Information System (INIS)

    Trevizan, Lilian Cristina; Santos, Dario; Elgul Samad, Ricardo; Dias Vieira, Nilson; Seimi Nomura, Cassiana; Nunes, Lidiane Cristina; Rufini, Iolanda Aparecida; Krug, Francisco Jose

    2008-01-01

    Laser induced breakdown spectroscopy (LIBS) has become an analytical tool for the direct analysis of a large variety of materials in order to provide qualitative and/or quantitative information. However, there is a lack of information for LIBS analysis of agricultural and environmental samples. In this work a LIBS system has been evaluated for the determination of macronutrients (P, K, Ca, Mg) in pellets of vegetal reference materials. An experimental setup was designed by using a Nd:YAG laser operating at 1064 nm and an Echelle spectrometer with ICCD detector. The plasma temperature was estimated by Boltzmann plots and instrumental parameters such as delay time, lens-to-sample distance and pulse energy were evaluated. Certified reference materials as well as reference materials were used for analytical calibrations of P, K, Ca, and Mg. Most results of the direct analysis of plant samples by LIBS were in reasonable agreement with those obtained by ICP OES after wet acid decomposition

  12. Optical and structural properties of plasma-treated Cordyceps bassiana spores as studied by circular dichroism, absorption, and fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Geon Joon, E-mail: gjlee@kw.ac.kr; Sim, Geon Bo; Choi, Eun Ha [Plasma Bioscience Research Center/Department of Electrical and Biological Physics, Kwangwoon University, Seoul 139-701 (Korea, Republic of); Kwon, Young-Wan [KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 136-701 (Korea, Republic of); Kim, Jun Young; Jang, Siun; Kim, Seong Hwan, E-mail: piceae@naver.com [Department of Microbiology and Institute of Basic Sciences, Dankook University, Cheonan 330-714 (Korea, Republic of)

    2015-01-14

    To understand the killing mechanism of fungal spores by plasma treatment, the optical, structural, and biological properties of the insect pathogenic fungus Cordyceps bassiana spores were studied. A nonthermal atmospheric-pressure plasma jet (APPJ) was used to treat the spores in aqueous solution. Optical emission spectra of the APPJ acquired in air indicated emission peaks corresponding to hydroxyl radicals and atomic oxygen. When the APPJ entered the aqueous solution, additional reactive species were derived from the interaction of plasma radicals with the aqueous solution. Fluorescence and absorption spectroscopy confirmed the generation of hydroxyl radicals and hydrogen peroxide in the plasma-activated water (PAW). Spore counting showed that plasma treatment significantly reduced spore viability. Absorption spectroscopy, circular dichroism (CD) spectroscopy, and agarose gel electrophoresis of the DNA extracted from plasma-treated spores showed a reduction in spore DNA content. The magnitude of the dip in the CD spectrum was lower in the plasma-treated spores than in the control, indicating that plasma treatment causes structural modifications and/or damage to cellular components. Tryptophan fluorescence intensity was lower in the plasma-treated spores than in the control, suggesting that plasma treatment modified cell wall proteins. Changes in spore viability and DNA content were attributed to structural modification of the cell wall by reactive species coming from the APPJ and the PAW. Our results provided evidence that the plasma radicals and the derived reactive species play critical roles in fungal spore inactivation.

  13. [Discussion on diagenesis of Xilingang pluton-constrained by X-ray Fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy].

    Science.gov (United States)

    Tang, Yu-Kun; Chen, Guo-Neng; Zhang, Ke; Huang, Hai-Hua

    2013-05-01

    The results on Xilingang pluton, mainly consisting of red beds, granites containing numerous debris of red beds and granites, obtained by X-ray fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy show: (1) Xilingang pluton from red beds, granites containing numerous debris of red beds to granites has obvious characteristics of decreasing silicon and alkali content, and rising ignition loss, dark mineral content and oxidation index; (2) Chondrite-normalized REE distribution curves and primitive mantle-normalized spider diagram for trace elements of redbed, granites containing numerous debris of red beds and granites have a good consistency, the distribution characteristics of elements are similar to Nanling transformation-type granite; (3) The value of Raman spectrogram characteristic peak of quartz crystal in Xilingang granite decreased from the center of quartz crystal, and FWHM is steady. According to the above, the authors believe that Xilingang granite formed was related to in-situ melting of red beds and underlying strata and magma consolidation. Volatile components were discharged continuously, and oxidation index decreased gradually in the melting process. In the process of diagenesis, the top of pluton tend to be an ongoing silicon and alkali increase, while TFeO and MgO continue to migrate to bottom, and crystallization environment is a relatively closed and steady system.

  14. Quantitative analysis of chromium concentration in nickel based alloys by laser induced breakdown spectroscopy at atmospheric pressure using a nanosecond ultraviolet Nd:YAG laser

    International Nuclear Information System (INIS)

    Gupta, G.P.; Suri, B.M.; Verma, A.; Sundararaman, M.; Unnikrishnan, V.K.; Alti, K.; Kartha, V.B.; Santhosh, C.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been well recognized as a simple, fast and direct analytical technique of elemental analysis of multi-element materials by a number of research groups all over the world. It is based on the focusing of a high-power pulsed laser beam with a power density > 100 MW/cm 2 onto a sample surface followed by optical emission spectroscopy of the plasma produced over the surface. In the present work, they have carried out the quantitative analysis of chromium in nickel-based-alloys using laser-induced breakdown spectroscopy (LIBS) in air at atmospheric pressure. In the present work the quantitative analysis of chromium in nickel-based-alloys using laser-induced break-down spectroscopy (LIBS) in air at atmospheric pressure has been carried out

  15. Conduction spectroscopy of a proximity induced superconducting topological insulator

    Science.gov (United States)

    Stehno, M. P.; Hendrickx, N. W.; Snelder, M.; Scholten, T.; Huang, Y. K.; Golden, M. S.; Brinkman, A.

    2017-09-01

    The combination of superconductivity and the helical spin-momentum locking at the surface state of a topological insulator (TI) has been predicted to give rise to p-wave superconductivity and Majorana bound states. The superconductivity can be induced by the proximity effect of a s-wave superconductor (S) into the TI. To probe the superconducting correlations inside the TI, dI/dV spectroscopy has been performed across such S-TI interfaces. Both the alloyed Bi1.5Sb0.5Te1.7Se1.3 and the stoichiometric BiSbTeSe2 have been used as three-dimensional TI. In the case of Bi1.5Sb0.5Te1.7Se1.3, the presence of disorder induced electron-electron interactions can give rise to an additional zero-bias resistance peak. For the stoichiometric BiSbTeSe2 with less disorder, tunnel barriers were employed in order to enhance the signal from the interface. The general observations in the spectra of a large variety of samples are conductance dips at the induced gap voltage, combined with an increased sub-gap conductance, consistent with p-wave predictions. The induced gap voltage is typically smaller than the gap of the Nb superconducting electrode, especially in the presence of an intentional tunnel barrier. Additional uncovered spectroscopic features are oscillations that are linearly spaced in energy, as well as a possible second order parameter component.

  16. Plasma polarization spectroscopy on the ECR helium plasma in a cusp magnetic field

    International Nuclear Information System (INIS)

    Sato, T.; Iwamae, A.; Fujimoto, T.; Uchida, M.; Maekawa, T.

    2004-01-01

    Helium emission lines have been observed on the ECR plasma in a cusp field with the polarized components resolved. The polarization map is constructed for the 501.6 nm (2 1 S-3 1 P) line emission. Lines from n 1 P and n 1 D levels are strongly polarized and those from n 3 D levels are weakly polarized. As the helium pressure increases the polarization degree decreases. (author)

  17. Femtosecond laser-induced breakdown spectroscopy of sea water

    International Nuclear Information System (INIS)

    Ilyin, Alexey A.; Golik, Sergey S.

    2013-01-01

    The composition of the line and band spectra of the plasma induced by a femtosecond laser pulse on the surface of sea water is determined. The temporal behaviors of the intensity of the continuum and the Ca II, Mg II and Na I lines are investigated. It is shown that the time dependence of the intensity of the Na I line is described by a monoexponential function. The characteristic decay times of the line intensities of Mg II and Na I were used to estimate the three-body recombination times. Using these values, we estimate the electron number density and the feasibility of Local Thermodynamic Equilibrium (LTE) criterion. A method involving excitation rate constants is proposed for the comparison of detection limits. For a plasma generated on a liquid surface, the following relation among detection limits will be obtained: LOD(Na) 2 were recorded. • Recombination determines characteristic decay time of line intensity. • Three-body recombination time was used to estimate electron density. • Excitation rate constants allow to determine relation of detection limits

  18. Tenth International Colloquium on UV and X-Ray Spectroscopy of Astrophysical and Laboratory Plasmas

    Science.gov (United States)

    Silver, Eric H.; Kahn, Steven M.

    UV and X-ray spectroscopy of astrophysical and laboratory plasmas draws interest from many disciplines. Contributions from international specialists are collected together in this book from a timely recent conference. In astrophysics, the Hubble Space Telescope, Astro 1 and ROSAT observatories are now providing UV and X-ray spectra and images of cosmic sources in unprecedented detail, while the Yohkoh mission recently collected superb data on the solar corona. In the laboratory, the development of ion-trap facilities and novel laser experiments are providing vital new data on high temperature plasmas. Recent innovations in the technology of spectroscopic instrumentation are discussed. These papers constitute an excellent up-to-date review of developments in short-wavelength spectroscopy and offer a solid introduction to its theoretical and experimental foundations. These proceedings give an up-to-date review of developments in short-wavelength spectroscopy and offer a solid introduction to its theoretical and experimental foundations. Various speakers presented some of the first results from the high resolution spectrograph on the Hubble Space Telescope, the high sensitivity far ultraviolet and X-ray spectrometers of the ASTRO 1 Observatory, the imaging X-ray spectrometer on the ROSAT Observatory, and the high resolution solar X-ray spectrometer on Yohkoh. The development of ion trap devices had brought about a revolution in laboratory investigations of atomic processes in highly charged atoms. X-ray laser experiments had not only yielded considerable insight into electron ion interactions in hot dense plasmas, but also demonstrated the versatility of laser plasmas as laboratory X-ray sources. Such measurements also motivated and led to refinements in the development of large-scale atomic and molecular codes. On the instrumental side, the design and development of the next series of very powerful short wavelength observatories had generated a large number of

  19. Real-time qualitative study of forsterite crystal - Melt lithium distribution by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Lebedev, V. F.; Makarchuk, P. S.; Stepanov, D. N.

    2017-11-01

    A factor of lithium distribution between single-crystal forsterite (Cr,Li:Mg2SiO4) and its melt are studied by laser-induced breakdown spectroscopy. Lithium content in the crystalline phase is found to achieve a saturation at relatively low Li concentration in the melt (about 0.02%wt.). An algorithm and software are developed for real-time analysis of the studied spectra of lithium trace amounts at wide variation of the plasma radiation intensity. The analyzed plasma spectra processing method is based on the calculation of lithium emission part in the total emission of the target plasma for each recorded spectrum followed by the error estimation for the series of measurements in the normal distribution approximation.

  20. [Classification of results of studying blood plasma with laser correlation spectroscopy based on semiotics of preclinical and clinical states].

    Science.gov (United States)

    Ternovoĭ, K S; Kryzhanovskiĭ, G N; Musiĭchuk, Iu I; Noskin, L A; Klopov, N V; Noskin, V A; Starodub, N F

    1998-01-01

    The usage of laser correlation spectroscopy for verification of preclinical and clinical states is substantiated. Developed "semiotic" classifier for solving the problems of preclinical and clinical states is presented. The substantiation of biological algorithms as well as the mathematical support and software for the proposed classifier for the data of laser correlation spectroscopy of blood plasma are presented.

  1. Optical emission and mass spectroscopy of plasma processes in reactive DC pulsed magnetron sputtering of aluminium oxide

    Czech Academy of Sciences Publication Activity Database

    Novotný, Michal; Bulíř, Jiří; Pokorný, Petr; Bočan, Jiří; Fitl, Přemysl; Lančok, Ján; Musil, Jindřich

    2010-01-01

    Roč. 12, č. 3 (2010), 697-700 ISSN 1454-4164 R&D Projects: GA AV ČR IAA100100718; GA AV ČR KAN400100653; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : reactive magnetron sputtering * alumina * plasma spectroscopy * mass spectroscopy * optical emission spectroscopy Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

  2. Plasmid DNA damage induced by helium atmospheric pressure plasma jet

    Science.gov (United States)

    Han, Xu; Cantrell, William A.; Escobar, Erika E.; Ptasinska, Sylwia

    2014-03-01

    A helium atmospheric pressure plasma jet (APPJ) is applied to induce damage to aqueous plasmid DNA. The resulting fractions of the DNA conformers, which indicate intact molecules or DNA with single- or double-strand breaks, are determined using agarose gel electrophoresis. The DNA strand breaks increase with a decrease in the distance between the APPJ and DNA samples under two working conditions of the plasma source with different parameters of applied electric pulses. The damage level induced in the plasmid DNA is also enhanced with increased plasma irradiation time. The reactive species generated in the APPJ are characterized by optical emission spectra, and their roles in possible DNA damage processes occurring in an aqueous environment are also discussed.

  3. Plasma Wind Tunnel Investigation of European Ablators in Nitrogen/Methane Using Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ricarda Wernitz

    2013-01-01

    Full Text Available For atmospheric reentries at high enthalpies ablative heat shield materials are used, such as those for probes entering the atmosphere of Saturn’s moon Titan, such as Cassini-Huygens in December, 2004. The characterization of such materials in a nitrogen/methane atmosphere is of interest. A European ablative material, AQ60, has been investigated in plasma wind tunnel tests at the IRS plasma wind tunnel PWK1 using the magnetoplasma dynamic generator RD5 as plasma source in a nitrogen/methane atmosphere. The dimensions of the samples are 45 mm in length with a diameter of 39 mm. The actual ablator has a thickness of 40 mm. The ablator is mounted on an aluminium substructure. The experiments were conducted at two different heat flux regimes, 1.4 MW/m2 and 0.3 MW/m2. In this paper, results of emission spectroscopy at these plasma conditions in terms of plasma species’ temperatures will be presented, including the investigation of the free-stream species, N2 and N2+, and the major erosion product C2, at a wavelength range around 500 nm–600 nm.

  4. Helium temperature measurements in a hot filament magnetic mirror plasma using high resolution Doppler spectroscopy

    Science.gov (United States)

    Knott, S.; McCarthy, P. J.; Ruth, A. A.

    2016-09-01

    Langmuir probe and spectroscopic diagnostics are used to routinely measure electron temperature and density over a wide operating range in a reconfigured Double Plasma device at University College Cork, Ireland. The helium plasma, generated through thermionic emission from a negatively biased tungsten filament, is confined by an axisymmetric magnetic mirror configuration using two stacks of NdFeB permanent magnets, each of length 20 cm and diameter 3 cm placed just outside the 15 mm water cooling jacket enclosing a cylindrical vacuum vessel of internal diameter 25 cm. Plasma light is analysed using a Fourier Transform-type Bruker spectrometer with a highest achievable resolution of 0.08 cm-1 . In the present work, the conventional assumption of room temperature ions in the analysis of Langmuir probe data from low temperature plasmas is examined critically using Doppler spectroscopy of the 468.6 nm He II line. Results for ion temperatures obtained from spectroscopic data for a variety of engineering parameters (discharge voltage, gas pressure and plasma current) will be presented.

  5. Radiation-induced defects in chalcogenide glasses characterized by combined optical spectroscopy, XPS and PALS methods

    International Nuclear Information System (INIS)

    Shpotyuk, O.; Kovalskiy, A.; Jain, H.; Golovchak, R.; Zurawska, A.

    2007-01-01

    Temperature-dependent optical absorption spectroscopy, high-resolution X-ray photoelectron spectroscopy and positron annihilation lifetimes spectroscopy are utilized to understand radiation-induced changes in Ge-Sb-S chalcogenide glasses. Theoretically predicted topological scheme of γ-induced coordination defect formation in stoichiometric Ge 23.5 Sb 11.8 S 64.7 glass composition is supported by these measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Laser-induced incandescence applied to dusty plasmas

    NARCIS (Netherlands)

    van de Wetering, F.M.J.H.; Oosterbeek, W.; Beckers, J.; Nijdam, S.; Kovacevic, E.; Berndt, J.

    2016-01-01

    This paper reports on the laser heating of nanoparticles (diameters ≤1 μm) confined in a reactive plasma by short (150 ps) and intense (~63 mJ) UV (355 nm) laser pulses (laser-induced incandescence, LII). Important parameters such as the particle temperature and radius follow from analysis of the

  7. Application of mid-infrared tuneable diode laser absorption spectroscopy to plasma diagnostics: a review

    International Nuclear Information System (INIS)

    Roepcke, J; Lombardi, G; Rousseau, A; Davies, P B

    2006-01-01

    Within the last decade mid-infrared absorption spectroscopy over a region from 3 to 17μm and based on tuneable lead salt diode lasers, often called tuneable diode laser absorption spectroscopy or TDLAS, has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry in molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has led to further applications of TDLAS because most of these compounds and their decomposition products are infrared active. TDLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetic phenomena. Information about gas temperature and population densities can also be derived from TDLAS measurements. A variety of free radicals and molecular ions have been detected by TDLAS. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of quantum cascade lasers (QCLs) offers an attractive new option for the monitoring and control of industrial plasma processes. The aim of the present paper is threefold: (i) to review recent achievements in our understanding of molecular phenomena in plasmas (ii) to report on selected studies of the spectroscopic properties and kinetic behaviour of radicals and (iii) to describe the current status of advanced instrumentation for TDLAS in the mid-infrared

  8. Application of Laser Induced Breakdown Spectroscopy under Polar Conditions

    Science.gov (United States)

    Clausen, J. L.; Hark, R.; Bol'shakov, A.; Plumer, J.

    2015-12-01

    Over the past decade our research team has evaluated the use of commercial-off-the-shelf laser-induced breakdown spectroscopy (LIBS) for chemical analysis of snow and ice samples under polar conditions. One avenue of research explored LIBS suitability as a detector of paleo-climate proxy indicators (Ca, K, Mg, and Na) in ice as it relates to atmospheric circulation. LIBS results revealed detection of peaks for C and N, consistent with the presence of organic material, as well as major ions (Ca, K, Mg, and Na) and trace metals (Al, Cu, Fe, Mn, Ti). The detection of Ca, K, Mg, and Na confirmed that LIBS has sufficient sensitivity to be used as a tool for characterization of paleo-climate proxy indicators in ice-core samples. Techniques were developed for direct analysis of ice as well as indirect measurements of ice via melting and filtering. Pitfalls and issues of direct ice analysis using several cooling techniques to maintain ice integrity will be discussed. In addition, a new technique, laser ablation molecular isotopic spectroscopy (LAMIS) was applied to detection of hydrogen and oxygen isotopes in ice as isotopic analysis of ice is the main tool in paleoclimatology and glaciology studies. Our results demonstrated that spectra of hydroxyl isotopologues 16OH, 18OH, and 16OD can be recorded with a compact spectrograph to determine hydrogen and oxygen isotopes simultaneously. Quantitative isotopic calibration for ice analysis can be accomplished using multivariate chemometric regression as previously realized for water vapor. Analysis with LIBS and LAMIS required no special sample preparation and was about ten times faster than analysis using ICP-MS. Combination of the two techniques in one portable instrument for in-field analysis appears possible and would eliminate the logistical and cost issues associated with ice core management.

  9. A spectrum standardization approach for laser-induced breakdown spectroscopy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhe, E-mail: zhewang@mail.tsinghua.edu.cn; Li Lizhi; West, Logan; Li Zheng, E-mail: lz-dte@tsinghua.edu.cn; Ni Weidou

    2012-02-15

    This paper follows and completes a previous presentation of a spectrum normalization method for laser-induced breakdown spectroscopy (LIBS) measurements by converting the experimentally recorded line intensity at varying operational conditions to the intensity that would be obtained under a 'standard state' condition, characterized by a standard plasma temperature, electron number density, and total number density of the interested species. At first, for each laser shot and corresponding spectrum, the line intensities of the interested species are converted to the intensity at a fixed plasma temperature and electron number density, but with varying total number density. Under this state, if the influence of changing plasma morphology is neglected, the sum of multiple spectral line intensities for the measured element is proportional to the total number density of the specific element. Therefore, the fluctuation of the total number density, or the variation of ablation mass, can be compensated for by applying the proportional relationship. The application of this method to Cu in 29 brass alloy samples, showed an improvement over the commonly applied normalization method with regard to measurement precision and accuracy. The average relative standard deviation (RSD) value, average value of the error bar, R{sup 2}, root mean square error of prediction (RMSEP), and average value of the maximum relative error were: 5.29%, 0.68%, 0.98, 2.72%, 16.97%, respectively, while the above parameter values for normalization with the whole spectrum area were: 8.61%, 1.37%, 0.95, 3.28%, 29.19%, respectively. - Highlights: Black-Right-Pointing-Pointer Intensity converted into an ideal standard plasma state for uncertainty reduction. Black-Right-Pointing-Pointer Ablated mass fluctuations compensated by variation of sum of multiple intensities. Black-Right-Pointing-Pointer A spectrum standardization model established. Black-Right-Pointing-Pointer Results in both uncertainty

  10. Analysis of explosive and other organic residues by laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lazic, V., E-mail: lazic@frascati.enea.i [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (RM) (Italy); Palucci, A. [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (RM) (Italy); Jovicevic, S. [Institute of Physics, 11080 Belgrade, Pregrevica 118 (Serbia); Poggi, C.; Buono, E. [ENEA, FIS-LAS, Via. E. Fermi 45, 00044 Frascati (RM) (Italy)

    2009-10-15

    With the aim of realizing a compact instrument for detection of energetic materials at trace levels, laser induced breakdown spectroscopy was applied on residues from nine explosives in air surroundings. Different potentially interfering organic materials were also analyzed. The residues were not uniformly distributed on an aluminum support and single-shot discrimination was attempted. For a single residue type, large shot-to-shot fluctuations of the line intensity ratios characteristic for organic samples were observed, which made material classification difficult. It was found that both atomic and molecular emission intensities, as well as their ratios, are strongly affected by an amount of the ablated support material, which mainly determines the plasma temperature. With respect to the spectra from the clean support, emission intensities of atomic oxygen and nitrogen are always reduced in the presence of an organic material, even if its molecules contain these elements. This was attributed to chemical reactions in a plasma containing carbon or its fragments. Hydrogen atomic emission depends strongly on the local humidity above the sampled point and its line intensity shows shot to shot variations up to 50%, also on a homogeneous sample. It is argued that shock waves generated by previous spatially and/or temporally close laser pulses blow away a relatively heavy water aerosol, which later diffuses slowly back towards the sampled point. C{sub 2} and CN exhibit a peak emission behavior with atomic Al emission, and their variable ratio indicates an existence of different formation or removal mechanisms from the plasma, depending on the plasma parameters and on the composition of the organic residue. On the basis of these observations, an attempt is made to establish a suitable procedure for data analysis and to determine the optimal experimental conditions, which would allow for discrimination of explosives from other, potentially interfering, residues.

  11. Real-time imaging, spectroscopy, and structural investigation of cathodic plasma electrolytic oxidation of molybdenum

    Energy Technology Data Exchange (ETDEWEB)

    Stojadinović, Stevan, E-mail: sstevan@ff.bg.ac.rs; Tadić, Nenad; Šišović, Nikola M.; Vasilić, Rastko [Faculty of Physics, University of Belgrade, Studentski trg 12-16, 11000 Belgrade (Serbia)

    2015-06-21

    In this paper, the results of the investigation of cathodic plasma electrolytic oxidation (CPEO) of molybdenum at 160 V in a mixed solution of borax, water, and ethylene glycol are presented. Real-time imaging and optical emission spectroscopy were used for the characterization of the CPEO. During the process, vapor envelope is formed around the cathode and strong electric field within the envelope caused the generation of plasma discharges. The spectral line shape analysis of hydrogen Balmer line H{sub β} (486.13 nm) shows that plasma discharges are characterized by the electron number density of about 1.4 × 10{sup 21 }m{sup −3}. The electron temperature of 15 000 K was estimated by measuring molybdenum atomic lines intensity. Surface morphology, chemical, and phase composition of coatings formed by CPEO were characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and x-ray diffraction. The elemental components of CPEO coatings are Mo and O and the predominant crystalline form is MoO{sub 3}.

  12. A distributed atomic physics database and modeling system for plasma spectroscopy

    International Nuclear Information System (INIS)

    Nash, J.K.; Liedahl, D.; Chen, M.H.; Iglesias, C.A.; Lee, R.W.; Salter, J.M.

    1995-08-01

    We are undertaking to develop a set of computational capabilities which will facilitate the access, manipulation, and understanding of atomic data in calculations of x-ray spectral modeling. In this present limited description we will emphasize the objectives for this work, the design philosophy, and aspects of the atomic database, as a more complete description of this work is available. The project is referred to as the Plasma Spectroscopy Initiative; the computing environment is called PSI, or the ''PSI shell'' since the primary interface resembles a UNIX shell window. The working group consists of researchers in the fields of x-ray plasma spectroscopy, atomic physics, plasma diagnostics, line shape theory, astrophysics, and computer science. To date, our focus has been to develop the software foundations, including the atomic physics database, and to apply the existing capabilities to a range of working problems. These problems have been chosen in part to exercise the overall design and implementation of the shell. For successful implementation the final design must have great flexibility since our goal is not simply to satisfy our interests but to vide a tool of general use to the community

  13. Variations of helicon wave induced radial plasma transport in different experimental conditions

    International Nuclear Information System (INIS)

    Petrzilka, V.

    1993-08-01

    Variations of the helicon wave induced radial plasma transport are presented in dependence on values of the plasma radius, magnetostatic field, plasma density, frequency of the helicon wave and on the ion charge. 22 refs., 14 figs

  14. Changes in the biomechanical properties of a single cell induced by nonthermal atmospheric pressure micro-dielectric barrier discharge plasma.

    Science.gov (United States)

    Choi, Hyeongwon; Choi, Eun Ha; Kim, Kyung Sook

    2017-10-01

    Mechanical properties of a single cell are closely related to the fate and functions of the cell. Changes in mechanical properties may cause diseases or cell apoptosis. Selective cytotoxic effects of nonthermal atmospheric pressure micro-dielectric barrier discharge (DBD) plasma have been demonstrated on cancer cells. In this work, changes in the mechanical properties of a single cell induced by nonthermal atmospheric pressure micro-DBD plasma were investigated using atomic force microscopy (AFM). Two cervical cancer cell lines (HeLa and SiHa) and normal human fibroblast cells (HFBs) were exposed to micro-DBD plasma for various exposure times. The elasticity of a single cell was determined by force-distance curve measurement using AFM. Young's modulus was decreased by plasma treatment for all cells. The Young's modulus of plasma-treated HeLa cells was decreased by 75% compared to nontreated HeLa cells. In SiHa cells and HFBs, elasticity was decreased slightly. Chemical changes induced by the plasma treatment, which were observed by Raman spectroscopy, were also significant in HeLa cells compared to SiHa cells and HFBs. These results suggested that the molecular changes induced by micro-DBD plasma were related to cell mechanical changes. © 2017 Wiley Periodicals, Inc.

  15. Detection of boron in simulated corrosion products by using a laser induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Song, K.; Yeon, J-W.; Jung, S-H.; Hwang, J.; Jung, E-C.

    2010-01-01

    In nuclear power plants, many methods for detection of coolant leakage have been developed and employed for the safe operation. However, these methods have many limitations for analyzing and dealing with the corrosion products due to the high radioactivity. LIBS (Laser-induced breakdown spectroscopy) offer a remote and on-site elemental analysis including the boron in the corrosion products with no sample preparation. In this study, we investigated the feasibility of detecting boron and analyzing an elemental composition of boron-containing iron oxides with the LIBS, in order to develop a coolant leakage detection system. First, we prepared five different boron-containing iron oxides and the element ratios were determined by using ICP-AES (inductive coupled plasma-atomic emission spectrometer). After this, the laser induced emission spectra of these iron oxides were obtained by using a 266 nm Nd:YAG laser. The B/Fe ratios of the oxides were determined by comparing the intensities of the B emission peak at 249.844 nm with those of the Fe peak at 250.217 nm as an internal reference. It was confirmed that the B contents in the oxides could be analyzed over 0.1 wt% by the laser induced breakdown spectroscopic technique. (author)

  16. Utilizing Laser-Induced Breakdown Spectroscopy Method to recognize chemical composition of low-carbon steel in NH3(NO)4 material

    Science.gov (United States)

    Saud Oraibi, Nissan

    2018-05-01

    A standoff laser Induced Break down Spectroscopy (L.I.B.S) technique has been used to characterization the organic material such as NH3(NO)4, a Q-switched Nd:YAG laser (1064 nm wavelength, 9 ns pulse width and 1 Hz repetition rate, 300 mJ is focused to the targets to generate plasma. HR 4000 CG-UV-NIR spectrum analyzer was used to collect the generated plasma emissions, specific signature of each targets material can be obtained by analysis the plasma emission spectrum Peak ratio analysis technique is used for the identification of energetic materials.

  17. Laser Induced Fluorescence Spectroscopy of Neutral and Ionized Polycyclic Aromatic Hydrocarbons in the Cosmic Simulation Chamber

    Science.gov (United States)

    Bejaoui, Salma; Salama, Farid; Contreras, Cesar; Sciamma O'Brien, Ella; Foing, Bernard; Pascale, Ehrenfreund

    2015-01-01

    Polycyclic aromatic hydrocarbon (PAH) molecules are considered the best carriers to account for the ubiquitous infrared emission bands. PAHs have also been proposed as candidates to explain the diffuse interstellar bands (DIBs), a series of absorption features seen on the interstellar extinction curve and are plausible carriers for the extended red emission (ERE), a photoluminescent process associated with a wide variety of interstellar environments. Extensive efforts have been devoted over the past two decades to characterize the physical and chemical properties of PAH molecules and ions in space. Absorption spectra of PAH molecules and ions trapped in solid matrices have been compared to the DIBs. Absorption spectra of several cold, isolated gas-phase PAHs have also been measured under experimental conditions that mimic the interstellar conditions. The purpose of this study is to provide a new dimension to the existing spectroscopic database of neutral and single ionized PAHs that is largely based on absorption spectra by adding emission spectroscopy data. The measurements are based on the laser induced fluorescence (LIF) technique and are performed with the Pulsed Discharge Nozzle (PDN) of the COSmIC laboratory facility at NASA Ames laboratory. The PDN generates a plasma in a free supersonic jet expansion to simulate the physical and the chemical conditions in interstellar environments. We focus, here, on the fluorescence spectra of large neutral PAHs and their cations where there is a lack of fluorescence spectroscopy data. The astronomical implications of the data (e.g., ERE) are examined.

  18. Investigations of plasma induced effects on the surface properties of lignocellulosic natural coir fibres

    Energy Technology Data Exchange (ETDEWEB)

    Praveen, K.M., E-mail: praveenkmiiucnn@gmail.com [International and Inter University Centre for Nano Science and Nanotechnology (IIUCNN), Mahatma Gandhi University, Kottayam, Kerala (India); Centre de Recherche C.Huygens, LIMATB (Laboratoired’Ingénierie des Matériaux de Bretagne), Université De Bretagne-Sud, Rue stMaudé – BP 92116, Cedex Lorient 56321 Lorient (France); Thomas, Sabu [International and Inter University Centre for Nano Science and Nanotechnology (IIUCNN), Mahatma Gandhi University, Kottayam, Kerala (India); Grohens, Yves [Centre de Recherche C.Huygens, LIMATB (Laboratoired’Ingénierie des Matériaux de Bretagne), Université De Bretagne-Sud, Rue stMaudé – BP 92116, Cedex Lorient 56321 Lorient (France); Mozetič, Miran; Junkar, Ita; Primc, Gregor [Department of Surface Engineering, Jozef Stefan Institute, Jamovacesta 39, Ljubljana 1000 (Slovenia); Gorjanc, Marija [Faculty of Natural Sciences and Engineering, University of Ljubljana, Aškerčeva 12, Ljubljana 1000 (Slovenia)

    2016-04-15

    Graphical abstract: Plasma induced changes on the morphology of coir fibres (Viewed and Analysed using scanning electron microscopy, Jeol JSM 7600 FEG). The O{sub 2} plasma treated fibre possessed increased hydrophilicity due to the chemical and physical changes induced by plasma. - Highlights: • Plasma-induced effects on the surface properties of lignocellulosic natural coir fibres were investigated. • The morphological study using SEM analysis also confirmed the surface changes which were observed after plasma treatment. • The water absorption studies show an increase of water absorption from 39% to around 100%. • The topographic measurements done using atomic force microscopy (AFM) showed etching of fibre wall, and this is responsible for higher water absorption. • XPS analysis reveals that the oxygen content measured for samples treated at 50 Pa increased from initial 18 at% to about 32 at%. - Abstract: The development of lignocellulosic natural-fibre-reinforced polymers composites are constrained by two limitations: the upper temperature at which the fibre can be processed and the significant differences between the surface energy of the fibre and the polymer matrix. Since the fibres and matrices are chemically different, strong adhesion at their interface is needed for the effective transfer of stress and bond distribution throughout the interface. The present study investigated the plasma induced effects on the surface properties of natural coir fibres. Weakly ionized oxygen plasma was created in two different discharge chambers by an inductively coupled radiofrequency (RF) discharge. The water absorption studies showed an increase of water sorption from 39% to 100%. The morphological study using scanning electron microscopy (SEM) analysis also confirmed the surface changes which were observed after the plasma treatment. The topographic measurements and phase imaging done using atomic force microscopy (AFM) indicated difference in topographic

  19. Plasma extraction by centrifugo-pneumatically induced gating of flow

    International Nuclear Information System (INIS)

    Burger, Robert; Ducrée, Jens; Reis, Nuno; Da Fonseca, João Garcia

    2013-01-01

    We present a novel valving mechanism to implement plasma extraction from whole blood on a centrifugal microfluidic ‘lab-on-a-disc’ platform. The new scheme is based on pressure-induced deflection of a liquid membrane which gates the centrifugally driven flow through a microfluidic structure. Compared to conventional concepts such as capillary burst valves, siphons or sacrificial materials, the valving structure presented here is represented by a compact, small-footprint design which obviates the need for (local) surface functionalization or hybrid materials integration, thus significantly reducing the complexity (and hence cost) of manufacture. As a pilot study of this new centrifugal flow control element, we demonstrate here the efficient separation of metered plasma from whole blood. While the flow is stopped, blood is separated into plasma and its cellular constituents by centrifugally induced sedimentation. After completion, the flow resumes by elevating the spinning frequency, providing up to 80% of the original plasma content to an overflow chamber within a short, 2 min interval. The amount of residual cells in the plasma amounts to less than 20 cells μl −1 . (paper)

  20. Local thermodynamic equilibrium considerations in powerchip laser-induced plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Merten, Jonathan A., E-mail: jmerten@astate.edu; Smith, Benjamin W., E-mail: bwsmith@chem.ufl.edu; Omenetto, Nicoló, E-mail: omenetto@chem.ufl.edu

    2013-05-01

    Time-resolved emission experiments are reported in the fast-decaying transient plasma induced by a microchip laser on an aluminum target in three different cover gases, i.e., air, argon and helium. The laser operates at 532 nm, with a repetition frequency of 1 kHz and a pulse width of less than 0.5 ns. The overall persistence of plasma emission is of the order of 100 ns. We examine the existence of local thermodynamic equilibrium (LTE) by evaluating the temporal criteria required (in addition to the McWhirter criterion), as recommended by Cristoforetti et al. (Spectrochim. Acta Part B 65, 2010, 86–95). The temporal criteria examine the evolution of temperature and electron number density and compare their rate of change to the rate at which electron collisions can thermalize the change. These considerations are used to determine time windows in which LTE may be present. Our results suggest that calibration-free LIBS measurements with these lasers may be possible for some elements at early times, especially under argon. - Highlights: ► Powerchip laser-induced plasma evolution is affected by cover gas. ► Plasma often out of LTE, despite fulfilling the McWhirter criterion ► Calibration-free LIBS may be possible with powerchip laser plasmas.

  1. Local thermodynamic equilibrium considerations in powerchip laser-induced plasmas

    International Nuclear Information System (INIS)

    Merten, Jonathan A.; Smith, Benjamin W.; Omenetto, Nicoló

    2013-01-01

    Time-resolved emission experiments are reported in the fast-decaying transient plasma induced by a microchip laser on an aluminum target in three different cover gases, i.e., air, argon and helium. The laser operates at 532 nm, with a repetition frequency of 1 kHz and a pulse width of less than 0.5 ns. The overall persistence of plasma emission is of the order of 100 ns. We examine the existence of local thermodynamic equilibrium (LTE) by evaluating the temporal criteria required (in addition to the McWhirter criterion), as recommended by Cristoforetti et al. (Spectrochim. Acta Part B 65, 2010, 86–95). The temporal criteria examine the evolution of temperature and electron number density and compare their rate of change to the rate at which electron collisions can thermalize the change. These considerations are used to determine time windows in which LTE may be present. Our results suggest that calibration-free LIBS measurements with these lasers may be possible for some elements at early times, especially under argon. - Highlights: ► Powerchip laser-induced plasma evolution is affected by cover gas. ► Plasma often out of LTE, despite fulfilling the McWhirter criterion ► Calibration-free LIBS may be possible with powerchip laser plasmas

  2. Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy for the noninvasive analysis of transparent samples and gemstones.

    Science.gov (United States)

    Koral, C; Dell'Aglio, M; Gaudiuso, R; Alrifai, R; Torelli, M; De Giacomo, A

    2018-05-15

    In this paper, Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy is applied to transparent samples and gemstones with the aim to overcome the laser induced damage on the sample. We propose to deposit a layer of AuNPs on the sample surface by drying a colloidal solution before ablating the sample with a 532 nm pulsed laser beam. This procedure ensures that the most significant fraction of the beam, being in resonance with the AuNP surface plasmon, is mainly absorbed by the NP layer, which in turn results the breakdown to be induced on NPs rather than on the sample itself. The fast explosion of the NPs and the plasma induction allow the ablation and the transfer in the plasma phase of the portion of sample surface where the NPs were placed. The employed AuNPs are prepared in milliQ water without the use of any chemical stabilizers by Pulsed Laser Ablation in Liquids (PLAL), in order to obtain a strict control of composition and impurities, and to limit possible spectral interferences (except from Au emission lines). Therefore with this technique it is possible to obtain, together with the emission signal of Au (coming from atomized NPs), the emission spectrum of the sample, by limiting or avoiding the direct interaction of the laser pulse with the sample itself. This approach is extremely useful for the elemental analysis by laser ablation of high refractive index samples, where the laser pulse on an untreated surface can otherwise penetrate inside the sample, generate breakdown events below the superficial layer, and consequently cause cracks and other damage. The results obtained with NELIBS on high refractive index samples like glasses, tourmaline, aquamarine and ruby are very promising, and demonstrate the potentiality of this approach for precious gemstones analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Plasma plume induced during laser welding of Magnesium alloys

    International Nuclear Information System (INIS)

    Hoffman, J.; Szymanski, Z.; Azharonok, V.

    2005-01-01

    assuming a certain realistic radial temperature distribution and calculating the corresponding synthetic line profile, which, subsequently, is compared to the experimental one. It has been assumed that the radial temperature profile is either Gaussian or triangular, since they are close to the solution of the time-dependent heat transfer equation with a Gaussian source. Owing to relatively high electron density, N e >10 22 m -3 , it can be assumed that a laser-induced plasma is in a state of local thermal equilibrium (LTE). The boundary temperature of 3 kK is assumed. The plasma diameter is 1.0-2.0 mm depending on the distance from the surface. The profile of the spectral line P λ is given by the Voigt function resulting from the convolution of a Gaussian (Doppler effect) and Lorenzian (Stark effect) profile. The synthetic line profiles are calculated for each plasma radius and added along the plasma diameter to get the total profiles. The maximum temperature is varied until the total synthetic profiles fit well the experimental ones and full widths of both profiles are the same. (author)

  4. Development of a laser-induced plasma probe to measure gas phase plasma signals at high pressures and temperatures

    International Nuclear Information System (INIS)

    Gounder, J.D.; Kutne, P.; Meier, W.

    2012-01-01

    The ability of laser induced breakdown spectroscopy (LIBS) technique for on line simultaneous measurement of elemental concentrations has led to its application in a wide number of processes. The simplicity of the technique allows its application to harsh environments such as present in boilers, furnaces and gasifiers. This paper presents the design of a probe using a custom optic which transforms a round beam into a ring (Donut) beam, which is used for forming a plasma in an atmosphere of nitrogen at high pressure (20 bar) and temperature (200 °C). The LIBS experiments were performed using a high pressure cell to characterize and test the effectiveness of the donut beam transmitted through the LIBS probe and collect plasma signal in back scatter mode. The first tests used the second harmonic of a Nd:YAG laser, pulse width 7 ns, to form a plasma in nitrogen gas at five different pressures (1, 5, 10, 15 and 20 bar) and three different gas temperatures (25, 100 and 200 °C). The uniqueness of this probe is the custom made optic used for reshaping the round laser beam into a ring (Donut) shaped laser beam, which is fed into the probe and focused to form a plasma at the measurement point. The plasma signal is collected and collimated using the laser focusing lens and is reflected from the laser beam axis onto an achromatic lens by a high reflection mirror mounted in the center section of the donut laser beam. The effect of gas pressure and temperature on N(I) lines in the high pressure cell experiment shows that the line intensity decreases with pressure and increases with temperature. Mean plasma temperature was calculated using the ratios of N(I) line intensities ranging from 7400 K to 8900 K at 1 bar and 2400 K to 3200 K at 20 bar for the three different gas temperatures. The results show that as a proof of principle the donut beam optics in combination with the LIBS probe can be used for performing extensive LIBS measurements in well controlled laboratory

  5. Development of a laser-induced plasma probe to measure gas phase plasma signals at high pressures and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Gounder, J.D., E-mail: James.Gounder@dlr.de; Kutne, P.; Meier, W.

    2012-08-15

    The ability of laser induced breakdown spectroscopy (LIBS) technique for on line simultaneous measurement of elemental concentrations has led to its application in a wide number of processes. The simplicity of the technique allows its application to harsh environments such as present in boilers, furnaces and gasifiers. This paper presents the design of a probe using a custom optic which transforms a round beam into a ring (Donut) beam, which is used for forming a plasma in an atmosphere of nitrogen at high pressure (20 bar) and temperature (200 Degree-Sign C). The LIBS experiments were performed using a high pressure cell to characterize and test the effectiveness of the donut beam transmitted through the LIBS probe and collect plasma signal in back scatter mode. The first tests used the second harmonic of a Nd:YAG laser, pulse width 7 ns, to form a plasma in nitrogen gas at five different pressures (1, 5, 10, 15 and 20 bar) and three different gas temperatures (25, 100 and 200 Degree-Sign C). The uniqueness of this probe is the custom made optic used for reshaping the round laser beam into a ring (Donut) shaped laser beam, which is fed into the probe and focused to form a plasma at the measurement point. The plasma signal is collected and collimated using the laser focusing lens and is reflected from the laser beam axis onto an achromatic lens by a high reflection mirror mounted in the center section of the donut laser beam. The effect of gas pressure and temperature on N(I) lines in the high pressure cell experiment shows that the line intensity decreases with pressure and increases with temperature. Mean plasma temperature was calculated using the ratios of N(I) line intensities ranging from 7400 K to 8900 K at 1 bar and 2400 K to 3200 K at 20 bar for the three different gas temperatures. The results show that as a proof of principle the donut beam optics in combination with the LIBS probe can be used for performing extensive LIBS measurements in well controlled

  6. Independent component analysis classification of laser induced breakdown spectroscopy spectra

    International Nuclear Information System (INIS)

    Forni, Olivier; Maurice, Sylvestre; Gasnault, Olivier; Wiens, Roger C.; Cousin, Agnès; Clegg, Samuel M.; Sirven, Jean-Baptiste; Lasue, Jérémie

    2013-01-01

    The ChemCam instrument on board Mars Science Laboratory (MSL) rover uses the laser-induced breakdown spectroscopy (LIBS) technique to remotely analyze Martian rocks. It retrieves spectra up to a distance of seven meters to quantify and to quantitatively analyze the sampled rocks. Like any field application, on-site measurements by LIBS are altered by diverse matrix effects which induce signal variations that are specific to the nature of the sample. Qualitative aspects remain to be studied, particularly LIBS sample identification to determine which samples are of interest for further analysis by ChemCam and other rover instruments. This can be performed with the help of different chemometric methods that model the spectra variance in order to identify a the rock from its spectrum. In this paper we test independent components analysis (ICA) rock classification by remote LIBS. We show that using measures of distance in ICA space, namely the Manhattan and the Mahalanobis distance, we can efficiently classify spectra of an unknown rock. The Mahalanobis distance gives overall better performances and is easier to manage than the Manhattan distance for which the determination of the cut-off distance is not easy. However these two techniques are complementary and their analytical performances will improve with time during MSL operations as the quantity of available Martian spectra will grow. The analysis accuracy and performances will benefit from a combination of the two approaches. - Highlights: • We use a novel independent component analysis method to classify LIBS spectra. • We demonstrate the usefulness of ICA. • We report the performances of the ICA classification. • We compare it to other classical classification schemes

  7. Degree of dissociation measured by FTIR absorption spectroscopy applied to VHF silane plasmas

    International Nuclear Information System (INIS)

    Sansonnens, L.; Howling, A.A.; Hollenstein, C.

    1997-10-01

    In situ Fourier transform infrared (FTIR) absorption spectroscopy has been used to determine the fractional depletion of silane in a radio-frequency (rf) glow discharge. The technique used a simple single pass arrangement and was implemented in a large area industrial reactor for deposition of amorphous silicon. Measurements were made on silane plasmas for a range of excitation frequencies. It was observed that at constant plasma power, the fractional depletion increased from 35% at 13.56 MHz to 70% at 70 MHz. With a simple model based on the density continuity equations in the gas phase, it was shown that this increase is due to a higher dissociation rate and is largely responsible for the observed increase in the deposition rate with the frequency. (author) 5 figs., 30 refs

  8. Versatile software for semiautomatic analysis and processing of laser-induced plasma spectra

    International Nuclear Information System (INIS)

    Mateo, M.P.; Nicolas, G.; Pinon, V.; Alvarez, J.C.; Ramil, A.; Yanez, A.

    2005-01-01

    The present article describes the main characteristics and operations of SALIPS (software for the analysis of laser-induced plasma spectra), a computer program designed for use in Spectroscopy. During the last years laser-induced plasma spectroscopy (LIPS) has grown in popularity and different applications have been developed in several fields. However, until now there is no software reported to perform the recognition of the elemental composition of a generic sample from its LIP spectrum, which must be achieved by hand in a tedious comparative process of experimental peaks with emission lines from databases. For this reason, a computer program that includes several tools to provide a semi-automatic identification of the peaks of a LIP spectrum has been developed. The program, written in Microsoft registered Visual Basic registered code, has a user-friendly graphical interface and is a flexible tool that enables to handle, edit, copy and print a quick presentation of the data including automatically the identification results in the graph. SALIPS also provides some physical properties of the elements and includes algorithms for performing the simulation of spectra. The potential of the program is illustrated with some examples

  9. Effective laser-induced breakdown spectroscopy (LIBS) detection using double pulse at optimum configuration.

    Science.gov (United States)

    Choi, Soo Jin; Yoh, Jack J

    2011-08-01

    A short laser pulse is irradiated on a sample to create a highly energetic plasma that emits light of a specific peak wavelength according to the material. By identifying different peaks for the analyzed samples, their chemical composition can be rapidly determined. The characteristics of the laser-induced breakdown spectroscopy (LIBS) plasma are strongly dependent on the ambient conditions. Research aimed at enhancing LIBS intensity is of great benefit in advancing LIBS for the exploration of harsh environments. By using double-pulse LIBS, the signal intensity of Al and Ca lines was enhanced by five times compared to the single-pulse signal. Also, the angles of the target and detector are adjusted to simulate samples of arbitrary shape. We verified that there exists an optimal angle at which specific elements of a test sample may be detected with stronger signal intensity. We provide several optimum configurations for the LIBS system for maximizing the signal intensity for the analysis of a nonstandard aluminum sample.

  10. Geometrical effects in data collection and processing for calibration-free laser-induced breakdown spectroscopy

    Science.gov (United States)

    Shabanov, S. V.; Gornushkin, I. B.

    2018-01-01

    Data processing in the calibration-free laser-induced breakdown spectroscopy (LIBS) is usually based on the solution of the radiative transfer equation along a particular line of sight through a plasma plume. The LIBS data processing is generalized to the case when the spectral data are collected from large portions of the plume. It is shown that by adjusting the optical depth and width of the lines the spectra obtained by collecting light from an entire spherical homogeneous plasma plume can be least-square fitted to a spectrum obtained by collecting the radiation just along a plume diameter with a relative error of 10-11 or smaller (for the optical depth not exceeding 0.3) so that a mismatch of geometries of data processing and data collection cannot be detected by fitting. Despite the existence of such a perfect least-square fit, the errors in the line optical depth and width found by a data processing with an inappropriate geometry can be large. It is shown with analytic and numerical examples that the corresponding relative errors in the found elemental number densities and concentrations may be as high as 50% and 20%, respectively. Safe for a few found exceptions, these errors are impossible to eliminate from LIBS data processing unless a proper solution of the radiative transfer equation corresponding to the ray tracing in the spectral data collection is used.

  11. Evaluation of laser induced breakdown spectroscopy for cadmium determination in soils

    International Nuclear Information System (INIS)

    Santos, Dario; Nunes, Lidiane C.; Trevizan, Lilian C.; Godoi, Quienly; Leme, Flavio O.; Braga, Jez Willian B.; Krug, Francisco Jose

    2009-01-01

    Cadmium is known to be a toxic agent that accumulates in the living organisms and present high toxicity potential over lifetime. Efforts towards the development of methods for microanalysis of environmental samples, including the determination of this element by graphite furnace atomic absorption spectrometry (GFAAS), inductively coupled plasma optical emission spectrometry (ICP OES), and inductively coupled plasma-mass spectrometry (ICP-MS) techniques, have been increasing. Laser induced breakdown spectroscopy (LIBS) is an emerging technique dedicated to microanalysis and there is a lack of information dealing with the determination of cadmium. The aim of this work is to demonstrate the feasibility of LIBS for cadmium detection in soils. The experimental setup was designed using a laser Q-switched (Nd:YAG, 10 Hz, λ = 1064 nm) and the emission signals were collimated by lenses into an optical fiber coupled to a high-resolution intensified charge-coupled device (ICCD)-echelle spectrometer. Samples were cryogenically ground and thereafter pelletized before LIBS analysis. Best results were achieved by exploring a test portion (i.e. sampling spots) with larger surface area, which contributes to diminish the uncertainty due to element specific microheterogeneity. Calibration curves for cadmium determination were achieved using certified reference materials. The metrological figures of merit indicate that LIBS can be recommended for screening of cadmium contamination in soils.

  12. The detection of He in tungsten following ion implantation by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Shaw, G.; Bannister, M.; Biewer, T. M.; Martin, M. Z.; Meyer, F.; Wirth, B. D.

    2018-01-01

    Laser-induced breakdown spectroscopy (LIBS) results are presented that provide depth-resolved identification of He implanted in polycrystalline tungsten (PC-W) targets by a 200 keV He+ ion beam, with a surface temperature of approximately 900 °C and a peak fluence of 1023 m-2. He retention, and the influence of He on deuterium and tritium recycling, permeation, and retention in PC-W plasma facing components are important questions for the divertor and plasma facing components in a fusion reactor, yet are difficult to quantify. The purpose of this work is to demonstrate the ability of LIBS to identify helium in tungsten; to investigate the sensitivity of laser parameters including, laser energy and gate delay, that directly influence the sensitivity and depth resolution of LIBS; and to perform a proof-of-principle experiment using LIBS to measure relative He intensities as a function of depth. The results presented demonstrate the potential not only to identify helium but also to develop a methodology to quantify gaseous impurity concentration in PC-W as a function of depth.

  13. All-fiber-coupled laser-induced breakdown spectroscopy sensor for hazardous materials analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bohling, Christian [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); SECOPTA GmbH, Ostendstr. 25, 12459 Berlin (Germany)], E-mail: c.bohling@pe.tu-clausthal.de; Hohmann, Konrad [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany)], E-mail: k.hohmann@pe.tu-clausthal.de; Scheel, Dirk [Systektum GmbH, Arnold-Sommerfeld-Str. 6, 38678 Clausthal-Zellerfeld (Germany)], E-mail: d.scheel@systektum.de; Bauer, Christoph [LaserAnwendungsCentrum (LAC) Technische Universitaet Clausthal, Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld (Germany)], E-mail: c.bauer@pe.tu-clausthal.de; Schippers, Wolfgang [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany)], E-mail: w.schippers@pe.tu-clausthal.de; Burgmeier, Joerg [LaserAnwendungsCentrum (LAC) Technische Universitaet Clausthal, Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld (Germany)], E-mail: j.burgmeier@pe.tu-clausthal.de; Willer, Ulrike [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); LaserAnwendungsCentrum (LAC) Technische Universitaet Clausthal, Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld (Germany)], E-mail: u.willer@pe.tu-clausthal.de; Holl, Gerhard [Wehrwissenschaftliches Institut fuer Werk-, Explosiv- und Betriebsstoffe (WIWEB), Grosses Cent, 53913, Swisttal (Germany)], E-mail: gerhardholl@bwb.orgd; Schade, Wolfgang [Institut fuer Physik und Physikalische Technologien, Technische Universitaet Clausthal, Leibnizstrasse 4, 38678 Clausthal-Zellerfeld (Germany); LaserAnwendungsCentrum (LAC) Technische Universitaet Clausthal, Arnold-Sommerfeld-Strasse 6, 38678 Clausthal-Zellerfeld (Germany)], E-mail: w.schade@pe.tu-clausthal.de

    2007-12-15

    An all-fiber-coupled laser-induced breakdown spectroscopy (LIBS) sensor device is developed. A passively Q-switched Cr{sup 4+}Nd{sup 3+}:YAG microchip laser is amplified within an Yb fiber amplifier, thus generating high power laser pulses (pulse energy E{sub p} = 0.8 mJ, wavelength {lambda} = 1064 nm, repetition rate f{sub rep.} = 5 kHz, pulse duration t{sub p} = 1.2 ns). A passive (LMA) optical fiber is spliced to the active fiber of an Yb fiber amplifier for direct guiding of high power laser pulses to the sensor tip. In front of the sensor a plasma is generated on the surface to be analyzed. The plasma emission is collected by a set of optical fibers also integrated into the sensor tip. The spectrally resolved LIBS spectra are processed by application of principal component analysis (PCA) and analyzed together with the time-resolved spectra with neural networks. Such procedure allows accurate analysis of samples by LIBS even for materials with similar atomic composition. The system has been tested successfully during field measurements at the German Armed Forces test facility at Oberjettenberg. The LIBS sensor is not restricted to anti-personnel mine detection but has also the potential to be suitable for analysis of bulk explosives and surface contaminations with explosives, e.g. for the detection of improvised explosive devices (IEDs)

  14. Quantitative analysis of lead in aqueous solutions by ultrasonic nebulizer assisted laser induced breakdown spectroscopy

    Science.gov (United States)

    Zhong, Shi-Lei; Lu, Yuan; Kong, Wei-Jin; Cheng, Kai; Zheng, Ronger

    2016-08-01

    In this study, an ultrasonic nebulizer unit was established to improve the quantitative analysis ability of laser-induced breakdown spectroscopy (LIBS) for liquid samples detection, using solutions of the heavy metal element Pb as an example. An analytical procedure was designed to guarantee the stability and repeatability of the LIBS signal. A series of experiments were carried out strictly according to the procedure. The experimental parameters were optimized based on studies of the pulse energy influence and temporal evolution of the emission features. The plasma temperature and electron density were calculated to confirm the LTE state of the plasma. Normalizing the intensities by background was demonstrated to be an appropriate method in this work. The linear range of this system for Pb analysis was confirmed over a concentration range of 0-4,150ppm by measuring 12 samples with different concentrations. The correlation coefficient of the fitted calibration curve was as high as 99.94% in the linear range, and the LOD of Pb was confirmed as 2.93ppm. Concentration prediction experiments were performed on a further six samples. The excellent quantitative ability of the system was demonstrated by comparison of the real and predicted concentrations of the samples. The lowest relative error was 0.043% and the highest was no more than 7.1%.

  15. Elemental analysis of cotton by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schenk, Emily R.; Almirall, Jose R.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the elemental characterization of unprocessed cotton. This research is important in forensic and fraud detection applications to establish an elemental fingerprint of U.S. cotton by region, which can be used to determine the source of the cotton. To the best of our knowledge, this is the first report of a LIBS method for the elemental analysis of cotton. The experimental setup consists of a Nd:YAG laser that operates at the fundamental wavelength as the LIBS excitation source and an echelle spectrometer equipped with an intensified CCD camera. The relative concentrations of elements Al, Ba, Ca, Cr, Cu, Fe, Mg, and Sr from both nutrients and environmental contributions were determined by LIBS. Principal component analysis was used to visualize the differences between cotton samples based on the elemental composition by region in the U.S. Linear discriminant analysis of the LIBS data resulted in the correct classification of >97% of the cotton samples by U.S. region and >81% correct classification by state of origin.

  16. Portable LED-induced autofluorescence spectroscopy for oral cancer diagnosis

    Science.gov (United States)

    Yan, Yung-Jhe; Huang, Ting-Wei; Cheng, Nai-Lun; Hsieh, Yao-Fang; Tsai, Ming-Hsui; Chiou, Jin-Chern; Duann, Jeng-Ren; Lin, Yung-Jiun; Yang, Chin-Siang; Ou-Yang, Mang

    2017-04-01

    Oral cancer is a serious and growing problem in many developing and developed countries. To improve the cancer screening procedure, we developed a portable light-emitting-diode (LED)-induced autofluorescence (LIAF) imager that contains two wavelength LED excitation light sources and multiple filters to capture ex vivo oral tissue autofluorescence images. Compared with conventional means of oral cancer diagnosis, the LIAF imager is a handier, faster, and more highly reliable solution. The compact design with a tiny probe allows clinicians to easily observe autofluorescence images of hidden areas located in concave deep oral cavities. The ex vivo trials conducted in Taiwan present the design and prototype of the portable LIAF imager used for analyzing 31 patients with 221 measurement points. Using the normalized factor of normal tissues under the excitation source with 365 nm of the central wavelength and without the bandpass filter, the results revealed that the sensitivity was larger than 84%, the specificity was not smaller than over 76%, the accuracy was about 80%, and the area under curve of the receiver operating characteristic (ROC) was achieved at about 87%, respectively. The fact shows the LIAF spectroscopy has the possibilities of ex vivo diagnosis and noninvasive examinations for oral cancer.

  17. Analysis of human nails by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Hosseinimakarem, Zahra; Tavassoli, Seyed Hassan

    2011-05-01

    Laser-induced breakdown spectroscopy (LIBS) is applied to analyze human fingernails using nanosecond laser pulses. Measurements on 45 nail samples are carried out and 14 key species are identified. The elements detected with the present system are: Al, C, Ca, Fe, H, K, Mg, N, Na, O, Si, Sr, Ti as well as CN molecule. Sixty three emission lines have been identified in the spectrum that are dominated by calcium lines. A discriminant function analysis is used to discriminate among different genders and age groups. This analysis demonstrates efficient discrimination among these groups. The mean concentration of each element is compared between different groups. Correlation between concentrations of elements in fingernails is calculated. A strong correlation is found between sodium and potassium while calcium and magnesium levels are inversely correlated. A case report on high levels of sodium and potassium in patients with hyperthyroidism is presented. It is shown that LIBS could be a promising technique for the analysis of nails and therefore identification of health problems.

  18. Laser-induced breakdown spectroscopy in industrial and security applications

    International Nuclear Information System (INIS)

    Bol'shakov, Alexander A.; Yoo, Jong H.; Liu Chunyi; Plumer, John R.; Russo, Richard E.

    2010-01-01

    Laser-induced breakdown spectroscopy (LIBS) offers rapid, localized chemical analysis of solid or liquid materials with high spatial resolution in lateral and depth profiling, without the need for sample preparation. Principal component analysis and partial least squares algorithms were applied to identify a variety of complex organic and inorganic samples. This work illustrates how LIBS analyzers can answer a multitude of real-world needs for rapid analysis, such as determination of lead in paint and children's toys, analysis of electronic and solder materials, quality control of fiberglass panels, discrimination of coffee beans from different vendors, and identification of generic versus brand-name drugs. Lateral and depth profiling was performed on children's toys and paint layers. Traditional one-element calibration or multivariate chemometric procedures were applied for elemental quantification, from single laser shot determination of metal traces at ∼10 μg/g to determination of halogens at 90 μg/g using 50-shot spectral accumulation. The effectiveness of LIBS for security applications was demonstrated in the field by testing the 50-m standoff LIBS rasterizing detector.

  19. Aluminum alloy analysis using microchip-laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Freedman, Andrew [Center for Sensor Systems and Technologies, Aerodyne Research, Inc., 45 Manning Road Billerica, MA, 01821-3976 (United States)]. E-mail: af@aerodyne.com; Iannarilli, Frank J. [Center for Sensor Systems and Technologies, Aerodyne Research, Inc., 45 Manning Road Billerica, MA, 01821-3976 (United States); Wormhoudt, Joda C. [Center for Sensor Systems and Technologies, Aerodyne Research, Inc., 45 Manning Road Billerica, MA, 01821-3976 (United States)

    2005-08-31

    A laser induced breakdown spectroscopy-based apparatus for the analysis of aluminum alloys which employs a microchip laser and a handheld spectrometer with an ungated, non-intensified CCD array has been built and tested. The microchip laser, which emits low energy pulses (4-15 {mu}J) at high repetition rates (1-10 kHz) at 1064 nm, produces, when focused, an ablation crater with a radius on the order of only 10 {mu}m. The resulting emission is focused onto an optical fiber connected to 0.10 m focal length spectrometer with a spectral range of 275-413 nm. The apparatus was tested using 30 different aluminum alloy reference samples. Two techniques for constructing calibration curves from the data, peak integration and partial least squares regression, were quantitatively evaluated. Results for Fe, Mg, Mn, Ni, Si, and Zn indicated limits of detection (LOD) that ranged from 0.05 to 0.14 wt.% and overall measurement errors which varied from 0.06 to 0.18 wt.%. Higher limits of detection and overall error for Cu (> 0.3 wt.%) were attributed to analysis problems associated with the presence of optically thick lines and a spectral interference from Zn. Improvements in design and component sensitivity should increase overall performance by at least a factor of 2, allowing for dependable aluminum alloy classification.

  20. Laser-Induced Breakdown Spectroscopy of Cinematographic Film

    Science.gov (United States)

    Oujja, M.; Abrusci, C.; Gaspard, S.; Rebollar, E.; Amo, A. del; Catalina, F.; Castillejo, M.

    Laser-induced breakdown spectroscopy (LIBS) was used to characterize the composition of black-and-white, silver-gelatine photographic films. LIB spectra of samples and reference gelatine (of various gel strengths, Bloom values 225 and 75 and crosslinking degrees) were acquired in vacuum by excitation at 266 nm. The elemental composition of the gelatine used in the upper protective layer and in the underlying emulsion is revealed by the stratigraphic analysis carried out by delivering successive pulses on the same spot of the sample. Silver (Ag) lines from the light-sensitive silver halide salts are accompanied by iron, lead and chrome lines. Fe and Pb are constituents of film developers and Cr is included in the hardening agent. The results demonstrate the analytical capacity of LIBS for study and classification of different gelatine types and the sensitivity of the technique to minor changes in gelatine composition. In addition LIBS analysis allows extracting important information on the chemicals used as developers and hardeners of archival cinematographic films.

  1. Analysis of bakery products by laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Bilge, Gonca; Boyacı, İsmail Hakkı; Eseller, Kemal Efe; Tamer, Uğur; Çakır, Serhat

    2015-08-15

    In this study, we focused on the detection of Na in bakery products by using laser-induced breakdown spectroscopy (LIBS) as a quick and simple method. LIBS experiments were performed to examine the Na at 589 nm to quantify NaCl. A series of standard bread sample pellets containing various concentrations of NaCl (0.025-3.5%) were used to construct the calibration curves and to determine the detection limits of the measurements. Calibration graphs were drawn to indicate functions of NaCl and Na concentrations, which showed good linearity in the range of 0.025-3.5% NaCl and 0.01-1.4% Na concentrations with correlation coefficients (R(2)) values greater than 0.98 and 0.96. The obtained detection limits for NaCl and Na were 175 and 69 ppm, respectively. Performed experimental studies showed that LIBS is a convenient method for commercial bakery products to quantify NaCl concentrations as a rapid and in situ technique. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Electromagnetically induced transparency in high-temperature magnetoactive plasma

    International Nuclear Information System (INIS)

    Kryachko, A.Yu.; Litvak, A.G.; Tokman, M.D.

    2002-01-01

    The classical analog of the presently popular in the quantum electronics effect of the electromagnetically induced transparency (EIT) is studied. The EIT effect is considered for the electron-cyclotron waves in the plasma with the finite temperature. The expression for the effective index of the electromagnetic wave refraction is identified and the dispersion law and this wave absorption under the EIT conditions are studied. It is shown, that accounting for the thermal motion, which radically changes the behavior of the signal wave dispersion curves in the EIT area, as compared with the cold plasma case [ru

  3. 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)

  4. Atomic data of Ti II from laser produced Ti plasmas by optical emission spectroscopy

    International Nuclear Information System (INIS)

    Refaie, A.I.; Farrag, A.A.; El Sharkawy, H.; El Sherbini, T.M.

    2005-06-01

    In the present study, the emission spectrum of titanium produced from laser induced plasma has been measured at different distances from the target. The Titanium target is irradiated by using the high power Q-switched Nd:YAG laser (λ=1064 nm) that generates energy 750 mJ/pulse of duration rate 6 ns and repetition rate 10 Hz in vacuum and at different distances. The variation of the distance from the target affects the measured plasma parameters, i.e. the electron density, the ion temperature and the velocity distribution. The electron density increases with the increase of the distance from the target. At a distance 0.6 mm from the target it decreases to 2.28·10 16 cm -3 . The temperature increases with the distance from the get until a distance of 1 mm, after that it decreases. It is found that the plasma velocity increases with the distance then it decreases again. Then, Energy levels and transition probabilities for 3d 2 4p →(3d 2 4s + 3d 3 ) lines have been determined by measurement of emission line intensities from an optically thin laser produced plasma of Ti II in vacuum. Calculations with intermediate coupling using Hartree-Fock wave functions have been carried out in order to place the experimental data on an absolute scale and also to evaluate the lifetimes. The plasma parameters in different regions of the plasma plume have been measured and used to obtain further transition probabilities. (author)

  5. Time-resolved spectroscopy of nonequilibrium ionization in laser-produced plasmas

    International Nuclear Information System (INIS)

    Marjoribanks, R.S.

    1988-01-01

    The highly transient ionization characteristic of laser-produced plasmas at high energy densities has been investigated experimentally, using x-ray spectroscopy with time resolution of less than 20 ps. Spectroscopic diagnostics of plasma density and temperature were used, including line ratios, line profile broadening and continuum emission, to characterize the plasma conditions without relying immediately on ionization modeling. The experimentally measured plasma parameters were used as independent variables, driving an ionization code, as a test of ionization modeling, divorced from hydrodynamic calculations. Several state-of-the-art streak spectrographs, each recording a fiducial of the laser peak along with the time-resolved spectrum, characterized the laser heating of thin signature layers of different atomic numbers imbedded in plastic targets. A novel design of crystal spectrograph, with a conically curved crystal, was developed. Coupled with a streak camera, it provided high resolution (λ/ΔΛ > 1000) and a collection efficiency roughly 20-50 times that of planar crystal spectrographs, affording improved spectra for quantitative reduction and greater sensitivity for the diagnosis of weak emitters. Experimental results were compared to hydrocode and ionization code simulations, with poor agreement. The conclusions question the appropriateness of describing electron velocity distributions by a temperature parameter during the time of laser illumination and emphasis the importance of characterizing the distribution more generally

  6. Inductively coupled plasma emission spectroscopy. Part II: applications and fundamentals. Volume 2

    International Nuclear Information System (INIS)

    Boumans, P.W.J.M.

    1987-01-01

    This is the second part of the two-volume treatise by this well-known and respected author. This volume reviews applications of inductively coupled plasma atomic emission spectroscopy (ICP-AES), summarizes fundamental studies, and compares ICP-AES methods with other methods of analysis. The first six chapters are devoted to specific fields of application, including the following: metals and other industrial materials, geology, the environment, agriculture and food, biology and clinical analysis, and organic materials. The chapter on the analysis of organic materials also covers the special instrumental considerations required when organic solvents are introduced into an inductively coupled plasma. A chapter on the direct analysis of solids completes the first part of this volume. Each of the applications chapters begins with a summary of the types of samples that are encountered in that field, and the kinds of problems that an elemental analysis can help to solve. This is followed by a tutorial approach covering applicability, advantages, and limitations of the methods. The coverage is thorough, including sample handling, storage, and preparation, acid, and fusion dissolution, avoiding contamination, methods of preconcentration, the types of interferences that can be expected and ways to reduce them, and the types of ICP plasmas that are used. The second half of the volume covers fundamental studies of ICP-AES: basic processes of aerosol generation, plasma modeling and computer simulation, spectroscopic diagnostics, excitation mechanisms, and discharge characteristics. This section introduces the experimental and modeling methods that have been used to obtain fundamental information about ICPs

  7. Electromagnetic diagnostics of ECR-Ion Sources plasmas: optical/X-ray imaging and spectroscopy

    Science.gov (United States)

    Mascali, D.; Castro, G.; Altana, C.; Caliri, C.; Mazzaglia, M.; Romano, F. P.; Leone, F.; Musumarra, A.; Naselli, E.; Reitano, R.; Torrisi, G.; Celona, L.; Cosentino, L. G.; Giarrusso, M.; Gammino, S.

    2017-12-01

    Magnetoplasmas in ECR-Ion Sources are excited from gaseous elements or vapours by microwaves in the range 2.45-28 GHz via Electron Cyclotron Resonance. A B-minimum, magnetohydrodynamic stable configuration is used for trapping the plasma. The values of plasma density, temperature and confinement times are typically ne= 1011-1013 cm-3, 01 eVSilicon Drift detectors with high energy resolution of 125 eV at 5.9 keV have been used for the characterization of plasma emission at 02spectroscopy with a spatial resolution down to 30 μm and an energy resolution down to 140 eV at 5.9 keV . In parallel, imaging in the optical range and spectroscopic measurements have been carried out. Relative abundances of H/H2 atoms/molecules in the plasmas have been measured for different values of neutral pressure, microwave power and magnetic field profile (they are critical for high-power proton sources).

  8. Diagnostics of helium plasma by collisional-radiative modeling and optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Wonwook; Kwon, Duck-Hee [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    Optical diagnostics for the electron temperature (T{sub e}) and the electron density (n{sub e}) of fusion plasma is important for understanding and controlling the edge and the divertor plasmas in tokamak. Since the line intensity ratio method using the collisional-radiative modeling and OES (optical emission spectroscopy) is simple and does not disturb the plasma, many fusion devices with TEXTOR, JET, JT-60U, LHD, and so on, have employed the line intensity ratio method as a basic diagnostic tool for neutral helium (He I). The accuracy of the line intensity ratio method depends on the reliability of the cross sections and rate coefficients. We performed state-of-the-art R-matrix calculations including couplings up to n=7 states and the distorted wave (DW) calculations for the electron-impact excitation (EIE) cross sections of He I using the flexible atomic code (FAC). The collisional-radiative model for He I was constructed using the calculated the cross sections. The helium collisional-radiative model for He I was constructed to diagnose the electron temperature and the electron density of the plasma. The electron temperature and density were determined by using the line intensity ratio method.

  9. Laser induced spectroscopy breakdown (LIBS) application to heavy metal detection in soils; Applicazioni della tecnica Laser induced breakdown spectroscopy (LIBS) alla determinazione dei metalli pesanti nei suoli

    Energy Technology Data Exchange (ETDEWEB)

    Barbini, R.; Fantoni, R.; Palucci, A.; Ribezzo, S.; Colao, F. [ENEA, Centro Ricerche Frascati, Frascati, RM (Italy). Div. Fisica Applicata; Capitelli, F. [Bari, Univ., Bari (Italy). Dipt. di Biologia e Chimica Agroforestale ed Ambientale

    2000-07-01

    LIBS (Laser induced breakdown spectroscopy) is a new spectroscopic technique suitable to the use in the analysis of samples of environmental interest, such as soils and rocks, and of industrial interest, such as alloys. Results dealing with the application of the technique to heterogeneous soil samples certified by Ispra Joint Research Centre in the contest of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) with an agronomical interest are presented in this report. In the LIBS technique, a high power laser beam is focused onto the sample in order to generate a small volume of plasma at its surface. Emissions from single atomic species are collected by a lens system coupled to an optical fiber bundle, dispersed on a monochromator and analyzed by an iCCD. the identification and the assignment of emission lines relevant to single atomic species allows to determine the sample elemental composition and, after calibration against reference samples, to perform quantitative analysis for a large number of species. This technique requires no sample pre-treatment, a part from eventually compacting powders by mechanical press. This is a considerable advantage with respect to traditional spectroscopic techniques, such as the ICP (Inductively Coupled Plasma) which needs sample mineralization by acid attack. Measurements performed on soil samples by means of the LIBS technique at ENEA Frascati were compared with the results obtained by ICP, which is considered a traditional technique for this kind of analysis. Results showed a general overestimation of the LIBS values with respect to the ICP ones, probably due to differences in lytologic matrix between the analyzed samples and the standard. The phenomenon is usually referred to the matrix effect, which is held responsible for the deviation from linearity between single element concentration and its row intensity. The effect is due to local plasma density variations and limit the correlation between the plasma elemental composition

  10. A Simple Device for Lens-to-Sample Distance Adjustment in Laser-Induced Breakdown Spectroscopy (LIBS).

    Science.gov (United States)

    Cortez, Juliana; Farias Filho, Benedito B; Fontes, Laiane M; Pasquini, Celio; Raimundo, Ivo M; Pimentel, Maria Fernanda; de Souza Lins Borba, Flávia

    2017-04-01

    A simple device based on two commercial laser pointers is described to assist in the analysis of samples that present uneven surfaces and/or irregular shapes using laser-induced breakdown spectroscopy (LIBS). The device allows for easy positioning of the sample surface at a reproducible distance from the focusing lens that conveys the laser pulse to generate the micro-plasma in a LIBS system, with reproducibility better than ±0.2 mm. In this way, fluctuations in the fluence (J cm -2 ) are minimized and the LIBS analytical signals can be obtained with a better precision even when samples with irregular surfaces are probed.

  11. A study of oxidative stress induced by non-thermal plasma-activated water for bacterial damage

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qian; Ma, Ruonan; Tian, Ying [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Liang, Yongdong; Feng, Hongqing [College of Engineering, Peking University, Beijing 100871 (China); Zhang, Jue; Fang, Jing [Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); College of Engineering, Peking University, Beijing 100871 (China)

    2013-05-20

    Ar/O{sub 2} (2%) cold plasma microjet was used to create plasma-activated water (PAW). The disinfection efficacy of PAW against Staphylococcus aureus showed that PAW can effectively disinfect bacteria. Optical emission spectra and oxidation reduction potential results demonstrated the inactivation is attributed to oxidative stress induced by reactive oxygen species in PAW. Moreover, the results of X-ray photoelectron spectroscopy, atomic absorption spectrometry, and transmission electron microscopy suggested that the chemical state of cell surface, the integrity of cell membrane, as well as the cell internal components and structure were damaged by the oxidative stress.

  12. A study of oxidative stress induced by non-thermal plasma-activated water for bacterial damage

    International Nuclear Information System (INIS)

    Zhang, Qian; Ma, Ruonan; Tian, Ying; Liang, Yongdong; Feng, Hongqing; Zhang, Jue; Fang, Jing

    2013-01-01

    Ar/O 2 (2%) cold plasma microjet was used to create plasma-activated water (PAW). The disinfection efficacy of PAW against Staphylococcus aureus showed that PAW can effectively disinfect bacteria. Optical emission spectra and oxidation reduction potential results demonstrated the inactivation is attributed to oxidative stress induced by reactive oxygen species in PAW. Moreover, the results of X-ray photoelectron spectroscopy, atomic absorption spectrometry, and transmission electron microscopy suggested that the chemical state of cell surface, the integrity of cell membrane, as well as the cell internal components and structure were damaged by the oxidative stress.

  13. Testing a laser-induced breakdown spectroscopy technique on the Arctic sediments

    Science.gov (United States)

    Han, D.; Nam, S. I.

    2017-12-01

    Physical and geochemical investigations coupled with the Laser-induced Breakdown Spectroscopy (LIBS) were performed on three surface sediment cores (ARA03B/24BOX, ARA02B/01(A)MUC, ARA02B/02MUC and ARA02B/03(A)MUC) recovered from the western Arctic Ocean (Chukchi Sea) during IBRV ARON expeditions in 2012. The LIBS technique was applied to carry out elemental chemical analysis of the Arctic sediments and compared with that measured by ITRAX X-ray fuorescence (XRF) core scanning. LIBS and XRF have shown similar elemental composition within each sediment core. In this study, mineral composition (XRD), grain size distribution and organic carbon content as well as elemental composition (LIBS) were all considered to understand paleoenvironmental changes (ocean circulation, sea-ice drift, iceberg discharge, and etc.) recorded in the Arctic Holocene sediment. Quantitative LIBS analysis shows a gradually varying distribution of the elements along the sampled core and clear separation between the cores. The cores are geochemically characterized by elevated Mn profile. The gradient of mineral composition and grain sizes among the cores shows regional distribution and variation in sedimentary condition due to geological distance between East Siberian and North America. The present study reveals that a LIBS technique can be employed for in-situ sediment analyses for the Arctic Ocean. Furthermore, LIBS does not require costly equipment, trained operators, and complicated sample pre-treatment processes compared to Atomic absorption spectroscopy (AAS) and inductively coupled plasma emission spectroscopy (ICP), and also known to show relatively high levels of sensitivity, precision, and distinction than XRF analysis, scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), and electron probe X-ray microanalysis (EPMA).

  14. Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1968-01-01

    This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.

  15. Decreased plasma levels of the endothelial protective sphingosine-1-phosphate are associated with dengue-induced plasma leakage

    NARCIS (Netherlands)

    Michels, M.; Japtok, L.; Alisjahbana, B.; Wisaksana, R.; Sumardi, U.; Puspita, M.; Kleuser, B.; Mast, Q. de; Ven, A.J.A.M. van der

    2015-01-01

    BACKGROUND: A transient endothelial hyperpermeability is a hallmark of severe dengue infections. Sphingosine-1-phosphate (S1P) maintains vascular integrity and protects against plasma leakage. We related plasma S1P levels to dengue-induced plasma leakage and studied mechanisms that may underlie the

  16. Effect of laser pulse energies in laser induced breakdown spectroscopy in double-pulse configuration

    International Nuclear Information System (INIS)

    Benedetti, P.A.; Cristoforetti, G.; Legnaioli, S.; Palleschi, V.; Pardini, L.; Salvetti, A.; Tognoni, E.

    2005-01-01

    In this paper, the effect of laser pulse energy on double-pulse laser induced breakdown spectroscopy signal is studied. In particular, the energy of the first pulse has been changed, while the second pulse energy is held fixed. A systematic study of the laser induced breakdown spectroscopy signal dependence on the interpulse delay is performed, and the results are compared with the ones obtained with a single laser pulse of energy corresponding to the sum of the two pulses. At the same time, the crater formed at the target surface is studied by video-confocal microscopy, and the variation in crater dimensions is correlated to the enhancement of the laser induced breakdown spectroscopy signal. The results obtained are consistent with the interpretation of the double-pulse laser induced breakdown spectroscopy signal enhancement in terms of the changes in ambient gas pressure produced by the shock wave induced by the first laser pulse

  17. Characteristics of indirect laser-induced plasma from a thin film of oil on a metallic substrate

    Science.gov (United States)

    Xiu, Jun-Shan; Bai, Xue-Shi; Motto-Ros, Vincent; Yu, Jin

    2015-04-01

    Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that Al emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0 μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.

  18. Spectroscopy

    CERN Document Server

    Walker, S

    1976-01-01

    The three volumes of Spectroscopy constitute the one comprehensive text available on the principles, practice and applications of spectroscopy. By giving full accounts of those spectroscopic techniques only recently introduced into student courses - such as Mössbauer spectroscopy and photoelectron spectroscopy - in addition to those techniques long recognised as being essential in chemistry teaching - sucha as e.s.r. and infrared spectroscopy - the book caters for the complete requirements of undergraduate students and at the same time provides a sound introduction to special topics for graduate students.

  19. On the improvement of signal repeatability in laser-induced air plasmas

    Science.gov (United States)

    Zhang, Shuai; Sheta, Sahar; Hou, Zong-Yu; Wang, Zhe

    2018-04-01

    The relatively low repeatability of laser-induced breakdown spectroscopy (LIBS) severely hinders its wide commercialization. In the present work, we investigate the optimization of LIBS system for repeatability improvement for both signal generation (plasma evolution) and signal collection. Timeintegrated spectra and images were obtained under different laser energies and focal lengths to investigate the optimum configuration for stable plasmas and repeatable signals. Using our experimental setup, the optimum conditions were found to be a laser energy of 250 mJ and a focus length of 100 mm. A stable and homogeneous plasma with the largest hot core area in the optimum condition yielded the most stable LIBS signal. Time-resolved images showed that the rebounding processes through the air plasma evolution caused the relative standard deviation (RSD) to increase with laser energies of > 250 mJ. In addition, the emission collection was improved by using a concave spherical mirror. The line intensities doubled as their RSDs decreased by approximately 25%. When the signal generation and collection were optimized simultaneously, the pulse-to-pulse RSDs were reduced to approximately 3% for O(I), N(I), and H(I) lines, which are better than the RSDs reported for solid samples and showed great potential for LIBS quantitative analysis by gasifying the solid or liquid samples.

  20. Synthesis of surfactant-free electrostatically stabilized gold nanoparticles by plasma-induced liquid chemistry

    Science.gov (United States)

    Patel, J.; Němcová, L.; Maguire, P.; Graham, W. G.; Mariotti, D.

    2013-06-01

    Plasma-induced non-equilibrium liquid chemistry is used to synthesize gold nanoparticles (AuNPs) without using any reducing or capping agents. The morphology and optical properties of the synthesized AuNPs are characterized by transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy. Plasma processing parameters affect the particle shape and size and the rate of the AuNP synthesis process. Particles of different shapes (e.g. spherical, triangular, hexagonal, pentagonal, etc) are synthesized in aqueous solutions. In particular, the size of the AuNPs can be tuned from 5 nm to several hundred nanometres by varying the initial gold precursor (HAuCl4) concentration from 2.5 μM to 1 mM. In order to reveal details of the basic plasma-liquid interactions that lead to AuNP synthesis, we have measured the solution pH, conductivity and hydrogen peroxide (H2O2) concentration of the liquid after plasma processing, and conclude that H2O2 plays the role of the reducing agent which converts Au+3 ions to Au0 atoms, leading to nucleation growth of the AuNPs.

  1. Plasma surface reflectance spectroscopy for non-invasive and continuous monitoring of extracellular component of blood

    Science.gov (United States)

    Sakota, Daisuke; Takatani, Setsuo

    2012-04-01

    To achieve the quantitative optical non-invasive diagnosis of blood during extracorporeal circulation therapies, the instrumental technique to extract extracellular spectra from whole blood was developed. In the circuit, the continuous blood flow was generated by a centrifugal blood pump. The oxygen saturation was maintained 100% by an oxygenator. The developed glass optical flow cell was attached to the outlet tubing of the oxygenator. The halogen lamp including the light from 400 to 900 nm wavelength was used for the light source. The light was guided into an optical fiber. The light emitted by the fiber was collimated and emitted to the flow cell flat surface at the incident angle of 45 degrees. The light just reflected on the boundary between inner surface of the flow cell and plasma at 45 degrees was detected by the detection fiber. The detected light was analyzed by a spectral photometer. The obtained spectrum from 400 to 600nm wavelength was not changed with respect to the hematocrit. In contrast, the signal in the spectral range was changed when the plasma free hemoglobin increased. By using two spectral range, 505+/-5 nm and 542.5+/-2.5 nm, the differential spectrum was correlated with the free hemoglobin at R2=0.99. On the other hand, as for the hematocrit, the differential spectrum was not correlated at R2=0.01. Finally, the plasma free hemoglobin was quantified with the accuracy of 22+/-19mg/dL. The result shows that the developed plasma surface reflectance spectroscopy (PSRS) can extract the plasma spectrum from flowing whole blood.

  2. Multivariate methods for analysis of environmental reference materials using laser-induced breakdown spectroscopy

    Directory of Open Access Journals (Sweden)

    Shikha Awasthi

    2017-06-01

    Full Text Available Analysis of emission from laser-induced plasma has a unique capability for quantifying the major and minor elements present in any type of samples under optimal analysis conditions. Chemometric techniques are very effective and reliable tools for quantification of multiple components in complex matrices. The feasibility of laser-induced breakdown spectroscopy (LIBS in combination with multivariate analysis was investigated for the analysis of environmental reference materials (RMs. In the present work, different (Certified/Standard Reference Materials of soil and plant origin were analyzed using LIBS and the presence of Al, Ca, Mg, Fe, K, Mn and Si were identified in the LIBS spectra of these materials. Multivariate statistical methods (Partial Least Square Regression and Partial Least Square Discriminant Analysis were employed for quantitative analysis of the constituent elements using the LIBS spectral data. Calibration models were used to predict the concentrations of the different elements of test samples and subsequently, the concentrations were compared with certified concentrations to check the authenticity of models. The non-destructive analytical method namely Instrumental Neutron Activation Analysis (INAA using high flux reactor neutrons and high resolution gamma-ray spectrometry was also used for intercomparison of results of two RMs by LIBS.

  3. Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Elizabeth J. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Barefield, James E., E-mail: jbarefield@lanl.gov [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berg, John M. [Manufacturing Engineering and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Clegg, Samuel M.; Havrilla, George J.; Montoya, Velma M.; Le, Loan A.; Lopez, Leon N. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze depleted uranium and thorium oxide powders and uranium ore as a potential rapid in situ analysis technique in nuclear production facilities, environmental sampling, and in-field forensic applications. Material such as pressed pellets and metals, has been extensively studied using LIBS due to the high density of the material and more stable laser-induced plasma formation. Powders, on the other hand, are difficult to analyze using LIBS since ejection and removal of the powder occur in the laser interaction region. The capability of analyzing powders is important in allowing for rapid analysis of suspicious materials, environmental samples, or trace contamination on surfaces since it most closely represents field samples (soil, small particles, debris etc.). The rapid, in situ analysis of samples, including nuclear materials, also reduces costs in sample collection, transportation, sample preparation, and analysis time. Here we demonstrate the detection of actinides in oxide powders and within a uranium ore sample as both pressed pellets and powders on carbon adhesive discs for spectral comparison. The acquired LIBS spectra for both forms of the samples differ in overall intensity but yield a similar distribution of atomic emission spectral lines. - Highlights: • LIBS analysis of mixed actinide samples: depleted uranium oxide and thorium oxide • LIBS analysis of actinide samples in powder form on carbon adhesive discs • Detection of uranium in a complex matrix (uranium ore) as a precursor to analyzing uranium in environmental samples.

  4. Time-resolved ultraviolet laser-induced breakdown spectroscopy for organic material analysis

    Energy Technology Data Exchange (ETDEWEB)

    Baudelet, Matthieu; Boueri, Myriam [Laboratoire de Spectrometrie Ionique et Moleculaire, Universite Claude Bernard Lyon 1, UMR CNRS 5579, 43, Bd. du 11 Novembre 1918, F-69622 Villeurbanne Cedex (France); Yu Jin [Laboratoire de Spectrometrie Ionique et Moleculaire, Universite Claude Bernard Lyon 1, UMR CNRS 5579, 43, Bd. du 11 Novembre 1918, F-69622 Villeurbanne Cedex (France)], E-mail: jin.yu@lasim.univ-lyon1.fr; Mao, Samuel S; Piscitelli, Vincent; Xianglei, Mao; Russo, Richard E [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2007-12-15

    Ultraviolet pulses (266 nm) delivered by a quadrupled Nd:YAG laser were used to analyze organic samples with laser-induced breakdown spectroscopy (LIBS). We present characteristics of the spectra obtained from organic samples with special attentions on the emissions of organic elements, O and N, and molecular bonds CN. The choice of these atomic or molecular species is justified on one hand, by the importance of these species to specify organic or biological materials; and on the other hand by the possible interferences with ambient air when laser ablation takes place in the atmosphere. Time-resolved LIBS was used to determine the time-evolution of line intensity emitted from these species. We demonstrate different kinetic behaviors corresponding to different origins of emitters: native atomic or molecular species directly vaporized from the sample or those generated through dissociation or recombination due to interaction between laser-induced plasma and air molecules. Our results show the ability of time-resolved UV-LIBS for detection and identification of native atomic or molecular species from an organic sample.

  5. Laser Induced Fluorescence Diagnostic for the Plasma Couette Experiment

    Science.gov (United States)

    Katz, Noam; Skiff, Fred; Collins, Cami; Weisberg, Dave; Wallace, John; Clark, Mike; Garot, Kristine; Forest, Cary

    2010-11-01

    The Plasma Couette Experiment (PCX) at U. Wisconsin-Madison consists of a rotating high-beta plasma and is well-suited to the study of flow-driven, astrophysically-relevant plasma phenomena. PCX confinement relies on alternating rings of 1kG permanent magnets and the rotation is driven by electrode rings, interspersed between the magnets, which provide an azimuthal ExB. I will discuss the development of a laser-induced fluorescence diagnostic (LIF) to characterize the ion distribution function of argon plasmas in PCX. The LIF system--which will be scanned radially--will be used to calibrate internal Mach probes, as well as to measure the time-resolved velocity profile, ion temperature and density non-perturbatively. These diagnostics will be applied to study the magneto-rotational instability in a plasma, as well as the buoyancy instability thought to be involved in producing the solar magnetic field. This work is supported by NSF and DOE.

  6. Characterization of cinematographic films by Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Gaspard, S.; Oujja, M.; Rebollar, E.; Abrusci, C.; Catalina, F.; Castillejo, M.

    2007-01-01

    The emulsion-coated transparent plastic-base film has been the main carrier for production and preservation of motion picture contents since the 19th century. The knowledge of the composition of black and white silver gelatine cinematographic films is of great importance for the characterization of the photographic process and for identifying the optimum conditions for conservation. A cinematographic film is a multi-component system that consists of a layer of photographic emulsion overcoating a polymeric support (plasticized cellulose triacetate) and a protective transparent cross-linked gelatine layer coating the emulsion. In the present work, Laser Induced Breakdown Spectroscopy (LIBS) is used to characterize the composition of the materials of cinematographic films. LIB spectra of film samples and of different individual film components, polymeric support and reference gelatines, were acquired in vacuum by excitation at 266 nm (Q-switched Nd:YAG laser, 6 ns, 10 Hz). In the cinematographic film, silver lines from the light-sensitive silver halide salts of the photographic emulsion are accompanied by iron, lead, chrome and phosphorus lines. Iron and lead are constituents of film developers, chrome is included in the composition of the hardening agents and phosphorus has its origin in the plasticizer used in the polymeric support. By applying successive pulses on the same spot of the film sample, it was possible to observe through stratigraphic analysis the different layers composition. Additionally, the results obtained reveal the analytical capacity of LIBS for the study and classification of the different gelatine types and qualities used for the protecting layer and the photographic emulsion

  7. 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

  8. Feasibility of Trace Alcohol Congener Detection and Identification Using Laser-Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Zhang Jialiang; Wang Shangmin; Zhao Lixian; Liu Liying; Wang Dezhen

    2014-01-01

    In this paper, a feasible scheme is reported for the detection and identification of trace alcohol congeners that have identical elemental composition using laser-induced breakdown spectroscopy (LIBS). In the scheme, an intensive pulsed laser is used to break down trace alcohol samples and the optical emission spectra of the induced plasma are collected for the detection and identification of alcohol molecules. In order to prepare trace alcohol samples, pure ethanol or methanol is bubbled by argon carrier gas and then mixed into matrix gases. The key issue for the scheme is to constitute indices from the LIBS data of the alcohol samples. Two indices are found to be suitable for alcohol detection and identification. One is the emission intensity ratio (denoted as H/C) of the hydrogen line (653.3 nm) to the carbon line (247.9 nm) for identification and the other is the ratio of the carbon line (as C/Ar) or the hydrogen line (as H/Ar) to the argon lines (866.7 nm) for quantitative detection. The calibration experiment result shows that the index H/C is specific for alcohol congeners while almost being independent of alcohol concentration. In detail, the H/C keeps a specific constant of 34 and 23 respectively for ethanol and methanol. In the meanwhile, the C/Ar and H/Ar indices respond almost linearly to the alcohol concentration below 1300 ppm, and are therefore competent for concentration measurement. With the indices, trace alcohol concentration measurement achieves a limit of 140 ppm using a laser pulse energy of 300 mJ. (plasma technology)

  9. Accuracy enhancement of laser induced breakdown spectra using permittivity and size optimized plasma confinement rings.

    Science.gov (United States)

    Li, An; Guo, Shuai; Wazir, Nasrullah; Chai, Ke; Liang, Liang; Zhang, Min; Hao, Yan; Nan, Pengfei; Liu, Ruibin

    2017-10-30

    The inevitable problems in laser induced breakdown spectroscopy are matrix effect and statistical fluctuation of the spectral signal, which can be partly avoided by utilizing a proper confined unit. The dependences of spectral signal enhancement on relative permittivity were studied by varying materials to confine the plasma, which include polytetrafluoroethylene(PTFE), nylon/dacron, silicagel, and nitrile-butadiene rubber (NBR) with the relative permittivity 2.2, ~3.3, 3.6, 8~13, 15~22. We found that higher relative permittivity rings induce stronger enhancement ability, which restricts the energy dissipation of plasma better and due to the reflected electromagnetic wave from the wall of different materials, the electromagnetic field of plasma can be well confined and makes the distribution of plasma more orderly. The spectral intensities of the characteristic lines Si I 243.5 nm and Si I 263.1 nm increased approximately 2 times with relative permittivity values from 2.2 to ~20. The size dependent enhancement of PTFE was further checked and the maximum gain was realized by using a confinement ring with a diameter size of 5 mm and a height of 3 mm (D5mmH3mm), and the rings with D2mmH1mm and D3mmH2mm also show higher enhancement factor. In view of peak shift, peak lost and accidental peaks in the obtained spectra were properly treated in data progressing; the spectral fluctuation decreased drastically for various materials with different relative permittivities as confined units, which means the core of plasma is stabilized, attributing to the confinement effect. Furthermore, the quantitative analysis in coal shows wonderful results-the prediction fitting coefficient R 2 reaches 0.98 for ash and 0.99 for both volatile and carbon.

  10. Molecular signatures in femtosecond laser-induced organic plasmas: comparison with nanosecond laser ablation.

    Science.gov (United States)

    Serrano, Jorge; Moros, Javier; Laserna, J Javier

    2016-01-28

    During the last few years, laser-induced breakdown spectroscopy (LIBS) has evolved significantly in the molecular sensing area through the optical monitoring of emissions from organic plasmas. Large efforts have been made to study the formation pathways of diatomic radicals as well as their connections with the bonding framework of molecular solids. Together with the structural and chemical-physical properties of molecules, laser ablation parameters seem to be closely tied to the observed spectral signatures. This research focuses on evaluating the impact of laser pulse duration on the production of diatomic species that populate plasmas of organic materials. Differences in relative intensities of spectral signatures from the plasmas of several organic molecules induced in femtosecond (fs) and nanosecond (ns) ablation regimes have been studied. Beyond the abundance and origin of diatomic radicals that seed the plasma, findings reveal the crucial role of the ablation regime in the breakage pattern of the molecule. The laser pulse duration dictates the fragments and atoms resulting from the vaporized molecules, promoting some formation routes at the expense of other paths. The larger amount of fragments formed by fs pulses advocates a direct release of native bonds and a subsequent seeding of the plasma with diatomic species. In contrast, in the ns ablation regime, the atomic recombinations and single displacement processes dominate the contribution to diatomic radicals, as long as atomization of molecules prevails over their progressive decomposition. Consequently, fs-LIBS better reflects correlations between strengths of emissions from diatomic species and molecular structure as compared to ns-LIBS. These new results entail a further step towards the specificity in the analysis of molecular solids by fs-LIBS.

  11. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

    Full Text Available We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  12. Laser-Induced Breakdown Spectroscopy (LIBS for Monitoring the Formation of Hydroxyapatite Porous Layers

    Directory of Open Access Journals (Sweden)

    Daniel Sola

    2017-12-01

    Full Text Available Laser-induced breakdown spectroscopy (LIBS is applied to characterize the formation of porous hydroxyapatite layers on the surface of 0.8CaSiO3-0.2Ca3(PO42 biocompatible eutectic glass immersed in simulated body fluid (SBF. Compositional and structural characterization analyses were also conducted by field emission scanning electron microscopy (FESEM, energy dispersive X-ray spectroscopy (EDX, and micro-Raman spectroscopy.

  13. Laser-Induced Breakdown Spectroscopy (LIBS) for Monitoring the Formation of Hydroxyapatite Porous Layers

    OpenAIRE

    Sola, Daniel; Paulés, Daniel; Grima, Lorena; Anzano, Jesús

    2017-01-01

    Laser-induced breakdown spectroscopy (LIBS) is applied to characterize the formation of porous hydroxyapatite layers on the surface of 0.8CaSiO3-0.2Ca3(PO4)2 biocompatible eutectic glass immersed in simulated body fluid (SBF). Compositional and structural characterization analyses were also conducted by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and micro-Raman spectroscopy.

  14. Comparing predictive ability of Laser-Induced Breakdown Spectroscopy to Near Infrared Spectroscopy for soil texture and organic carbon determination

    DEFF Research Database (Denmark)

    Knadel, Maria; Peng, Yi; Gislum, René

    Soil organic carbon (SOC) and texture have a practical value for agronomy and the environment. Thus, alternative techniques to supplement or substitute for the expensive conventional analysis of soil are developed. Here the feasibility of laser-induced breakdown spectroscopy (LIBS) to determine SOC...... and texture was tested and compared with near infrared spectroscopy (NIRS) technique and traditional laboratory analysis. Calibration models were developed on 50 topsoil samples. For all properties except silt, higher predictive ability of LIBS than NIRS models was obtained. Successful calibrations indicate...... that LIBS can be used as a fast and reliable method for SOC and texture estimation....

  15. Laser induced breakdown spectroscopy of the uranium including calcium. Time resolved measurement spectroscopic analysis (Contract research)

    International Nuclear Information System (INIS)

    Akaoka, Katsuaki; Maruyama, Youichiro; Oba, Masaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

    2010-05-01

    For the remote analysis of low DF TRU (Decontamination Factor Transuranic) fuel, Laser Breakdown Spectroscopy (LIBS) was applied to uranium oxide including a small amount of calcium oxide. The characteristics, such as spectrum intensity and plasma excitation temperature, were measured using time-resolved spectroscopy. As a result, in order to obtain the stable intensity of calcium spectrum for the uranium spectrum, it was found out that the optimum observation delay time of spectrum is 4 microseconds or more after laser irradiation. (author)

  16. Time- and space-resolved spectroscopic characterization of laser-induced swine muscle tissue plasma

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, J.J. [Departamento de Química-Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Diaz, L., E-mail: luis.diaz@csic.es [Instituto de Estructura de la Materia, CFMAC, CSIC, Serrano 121, 28006 Madrid (Spain); Martinez-Ramirez, S. [Instituto de Estructura de la Materia, CFMAC, CSIC, Serrano 121, 28006 Madrid (Spain); Caceres, J.O. [Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense, Cuidad Universitaria, 28040 Madrid (Spain)

    2015-09-01

    The spatial-temporal evolution of muscle tissue sample plasma induced by a high-power transversely excited atmospheric (TEA) CO{sub 2} pulsed laser at vacuum conditions (0.1–0.01 Pa) has been investigated using high-resolution optical emission spectroscopy (OES) and imaging methods. The induced plasma shows mainly electronically excited neutral Na, K, C, Mg, H, Ca, N and O atoms, ionized C{sup +}, C{sup 2+}, C{sup 3+}, Mg{sup +}, Mg{sup 2+}, N{sup +}, N{sup 2+}, Ca{sup +}, O{sup +} and O{sup 2+} species and molecular band systems of CN(B{sup 2}Σ{sup +}–X{sup 2}Σ{sup +}), C{sub 2}(d{sup 3}Π{sub g}–a{sup 3}Π{sub u}), CH(B{sup 2}Σ{sup −}–X{sup 2}Π; A{sup 2}Δ–X{sup 2}Π), NH(A{sup 3}Π–X{sup 3}Σ{sup −}), OH(A{sup 2}Σ{sup +}–X{sup 2} Σ{sup +}), and CaOH(B{sup 2}Σ{sup +}–X{sup 2}Σ{sup +}; A{sup 2}Π–X{sup 2}Σ{sup +}). Time-resolved two-dimensional emission spectroscopy is used to study the expanded distribution of different species ejected during ablation. Spatial and temporal variations of different atoms and ionic excited species are reported. Plasma parameters such as electron density and temperature were measured from the spatio-temporal analysis of different species. Average velocities of some plasma species were estimated. - Highlights: • LIBS of swine muscle tissue sample generated by CO{sub 2} laser pulses has been done for the first time. • Average velocities of some plasma species have been calculated from spatial and temporally resolved 2D OES images. • Electron density (~ 9 × 10{sup 17} cm{sup -3}) has been studied with spatial and temporal resolution. • Temporal evolution of the plasma temperature has been calculated by means of Boltzmann plots.

  17. Reactions of nitroxide radicals in aqueous solutions exposed to non-thermal plasma: limitations of spin trapping of the plasma induced species

    Science.gov (United States)

    Gorbanev, Yury; Stehling, Nicola; O'Connell, Deborah; Chechik, Victor

    2016-10-01

    Low temperature (‘cold’) atmospheric pressure plasmas have gained much attention in recent years due to their biomedical effects achieved through the interactions of plasma-induced species with the biological substrate. Monitoring of the radical species in an aqueous biological milieu is usually performed via electron paramagnetic resonance (EPR) spectroscopy using various nitrone spin traps, which form persistent radical adducts with the short-lived radicals. However, the stability of these nitroxide radical adducts in the plasma-specific environment is not well known. In this work, chemical transformations of nitroxide radicals in aqueous solutions using a model nitroxide 4-oxo-TEMPO were studied using EPR and LC-MS. The kinetics of the nitroxide decay when the solution was exposed to plasma were assessed, and the reactive pathways proposed. The use of different scavengers enabled identification of the types of reactive species which cause the decay, indicating the predominant nitroxide group reduction in oxygen-free plasmas. The 2H adduct of the PBN spin trap (PBN-D) was shown to decay similarly to the model molecule 4-oxo-TEMPO. The decay of the spin adducts in plasma-treated solutions must be considered to avoid rendering the spin trapping results unreliable. In particular, the selectivity of the decay indicated the limitations of the PTIO/PTI nitroxide system in the detection of nitric oxide.

  18. Nanoparticle detection in aqueous solutions using Raman and Laser Induced Breakdown Spectroscopy

    NARCIS (Netherlands)

    Sovago, M.; Buis, E.-J.; Sandtke, M.

    2013-01-01

    We show the chemical identification and quantification of the concentration and size of nanoparticle (NP) dispersions in aqueous solutions by using a combination of Raman Spectroscopy and Laser Induced Breakdown Spectroscopy (LIBS). The two spectroscopic techniques are applied to demonstrate the NP

  19. Laser resonant ionization spectroscopy and laser-induced resonant fluorescence spectra of samarium atom

    International Nuclear Information System (INIS)

    Jin, Changtai

    1995-01-01

    We have measured new high-lying levels of Sm atom by two-colour resonant photoionisation spectroscopy; we have observed the isotope shifts of Sm atom by laser-induced resonant fluorescence spectroscopy; the lifetime of eight low-lying levels of Sm atom were measured by using pulsed laser-Boxcar technique in atomic beam.

  20. Optogalvanic spectroscopy

    International Nuclear Information System (INIS)

    Pianarosa, P.; Demers, Y.; Gagne, J.M.

    1983-01-01

    Laser induced optogalvanic spectroscopy in a hollow cathode-produced plasma has been used to resolve the isotopic structure of some absorption lines in uranium. We have shown that the optogalvanic signal associated with any isotope can be related to the concentration of that isotope in a multi-isotopic sample. From the results we have obtained, optogalvanic spectroscopy of sputtered samples appears to be an interesting approach to the isotopic analysis of both natural and enriched uranium and could easily be applied to the analysis of other fissile elements, such as the plutonium isotopes

  1. Pre-concentration of Cr, Mn, Fe and Co of water sea and analysis by plasma emission spectroscopy - DCP

    International Nuclear Information System (INIS)

    Ferreira, E.M.M.

    1985-01-01

    Studies of separation and pre-concentration methods of chromium, manganese, iron and cobalt from seawater, that allow use control methods of 5 1 Cr, 5 4 Mn, 5 5 , 5 9 Fe, 5 8 , 5 9 Co with a better sensibility and the determination of this elements by atomic absorption spectroscopy or plasma emission spectroscopy are described. This methods of seawater analysis will use near the region of Angra I reactor. (author)

  2. Spectroscopy of beryllium-like nitrogen ions by laser-induced recombination

    International Nuclear Information System (INIS)

    Uhlenberg, G.

    1996-04-01

    The following topics were dealt with: Rydberg spectroscopy of beryllium-like nitrogen (N 3+ ) by laser-induced recombination, transition enrgies, Rydberg level shift, configuration interaction, laser intensity effect, laser band width

  3. Quantitative mixture fraction measurements in combustion system via laser induced breakdown spectroscopy

    KAUST Repository

    Mansour, Mohy S.; Imam, Hisham; Elsayed, Khaled A.; Elbaz, Ayman M.; Abbass, Wafaa

    2015-01-01

    Laser induced breakdown spectroscopy (LIBS) technique has been applied to quantitative mixture fraction measurements in flames. The measured spectra of different mixtures of natural gas and air are used to obtain the calibration parameters for local

  4. Laser-produced lithium plasma as a narrow-band extended ultraviolet radiation source for photoelectron spectroscopy.

    Science.gov (United States)

    Schriever, G; Mager, S; Naweed, A; Engel, A; Bergmann, K; Lebert, R

    1998-03-01

    Extended ultraviolet (EUV) emission characteristics of a laser-produced lithium plasma are determined with regard to the requirements of x-ray photoelectron spectroscopy. The main features of interest are spectral distribution, photon flux, bandwidth, source size, and emission duration. Laser-produced lithium plasmas are characterized as emitters of intense narrow-band EUV radiation. It can be estimated that the lithium Lyman-alpha line emission in combination with an ellipsoidal silicon/molybdenum multilayer mirror is a suitable EUV source for an x-ray photoelectron spectroscopy microscope with a 50-meV energy resolution and a 10-mum lateral resolution.

  5. Investigations of the cathode region of an argon arc plasma by degenerate four-wave mixing laser spectroscopy and optical emission spectroscopy

    International Nuclear Information System (INIS)

    Dzierzega, K; Pokrzywka, B; Pellerin, S

    2004-01-01

    Degenerate four-wave mixing (DFWM) laser spectroscopy was used in local studies of atmospheric pressure argon plasma generated in a free-burning arc. The results of plasma diagnostics using the DFWM method were compared to the results obtained with optical emission measurements. In the cathode region of the arc the maxima of both the DFWM signal and the emission coefficient for the 696.5 nm Ar I line depend on the distance from the cathode tip. This effect proves the departure of the plasma state from local thermal equilibrium (LTE) as it has been reported by many authors. On the other hand the Stark shifts of the 696.5 nm Ar I line determined by the DFWM method in relation to plasma diagnostic results show no deviations from LTE on the arc axis down to 1.0 mm from the cathode tip

  6. In situ x-ray photoelectron spectroscopy and capacitance voltage characterization of plasma treatments for Al{sub 2}O{sub 3}/AlGaN/GaN stacks

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Xiaoye; Lucero, Antonio; Azcatl, Angelica; Kim, Jiyoung; Wallace, Robert M. [Department of Materials Science and Engineering, University of Texas at Dallas, Richardson, Texas 75080 (United States)

    2014-07-07

    We investigate the Al{sub 2}O{sub 3}/AlGaN/GaN metal-oxide-semiconductor structure pretreated by O{sub 2} anneals, N{sub 2} remote plasma, and forming gas remote plasma prior to atomic layer deposition of Al{sub 2}O{sub 3} using in situ X-ray photoelectron spectroscopy, low energy electron diffraction, and capacitance- voltage measurements. Plasma pretreatments reduce the Ga-oxide/oxynitride formation and the interface state density, while inducing a threshold voltage instability.

  7. Quantum cascade laser absorption spectroscopy with the amplitude-to-time conversion technique for atmospheric-pressure plasmas

    International Nuclear Information System (INIS)

    Yumii, Takayoshi; Kimura, Noriaki; Hamaguchi, Satoshi

    2013-01-01

    The NO 2 concentration, i.e., density, in a small plasma of a nitrogen oxide (NOx) treatment reactor has been measured by highly sensitive laser absorption spectroscopy. The absorption spectroscopy uses a single path of a quantum cascade laser beam passing through a plasma whose dimension is about 1 cm. The high sensitivity of spectroscopy is achieved by the amplitude-to-time conversion technique. Although the plasma reactor is designed to convert NO in the input gas to NO 2 , it has been demonstrated by this highly sensitive absorption spectroscopy that NO 2 in a simulated exhaust gas that enters the reactor is decomposed by the plasma first and then NO 2 is formed again, possibly more than it was decomposed, through a series of gas-phase reactions by the time the gas exits the reactor. The observation is consistent with that of an earlier study on NO decomposition by the same type of a plasma reactor [T. Yumii et al., J. Phys. D 46, 135202 (2013)], in which a high concentration of NO 2 was observed at the exit of the reactor.

  8. Quantitative plasma spectroscopy in a resistive shell reversed-field pinch

    International Nuclear Information System (INIS)

    Hedqvist, Anders

    1999-10-01

    The subject addressed in this thesis is quantitative plasma spectroscopy. Measurements of electron temperature and impurity ion density, performed at EXTRAP-T2, are aimed to investigate the effects of operating a reversed- field pinch with a resistive shell and a graphite wall. The spectroscopic measurements are analyzed with a collisional-radiative model and a consistency check is performed for the measurements and the model itself. The resistive shell results in wall-locked modes, enhanced plasma-wall interaction and degraded confinement. Measurements of vacuum ultraviolet resonant transitions of carbon and oxygen show that the local heating of the wall, at the position of the locking, leads to influxes of hydrogen and impurities, resulting in a cold and resistive plasma. Effects on the local scale are also observed. Spatially-resolved measurements of line emission originating from charge exchange collisions are used to investigate the change in neutral hydrogen profile. Temporal correlations between soft x-ray emission and poloidal loop voltage at the position of the wall-locked modes are observed and in connection, a decrease in central electron temperature, indicating there is a direct energy loss channel between the center and the edge. The hydrogen recycling properties of the graphite wall are investigated in an isotope exchange experiment. The density of the hydrogen isotopes are measured from spectral line emission and compared with recycling models. In charge exchange collisions between fully stripped chlorine and thermal deuterium, observed in JET plasmas, only a single n-level is populated. This is different from most ions and may be used to test models for calculating charge exchange collision cross-sections

  9. Characterization of Modified Tapioca Starch in Atmospheric Argon Plasma under Diverse Humidity by FTIR Spectroscopy

    Science.gov (United States)

    Deeyai, P.; Suphantharika, M.; Wongsagonsup, R.; Dangtip, S.

    2013-01-01

    Tapioca is economical crop grown in Thailand and continues to be one of the major sources of starch. Nowadays, tapioca starch has been widely used in industrial applications, however the native form of starch has limited the applications. Thus scientists try to modify the properties of starch for increasing the stability of the granules, pastes to low pH, heat, and shear during the food process. We modify the tapioca starch by plasma treatment under an argon atmosphere. The degree of modification is determined by following water content in the starch granules. The tablet samples of native starch are also prepared and compared with the plasma treated starch. Before plasma treatment, the starch tablets are stored under three different relative humilities (RH) including 11%, 68%, and 78%RH, respectively. The samples are characterized using FTIR spectroscopy associated with the degree of cross-linking. The results show that the water molecules are engulfed into the starch structure in two ways, a tight bond and a weak absorption of water molecules which is represented at two wave number of 1630 cm-1 and 3272 cm-1, respectively. The degree of cross-linking can be identified from the relative intensity of these two peaks with the C—O—H peak at 993 cm-1. The results show that the degree of cross-linking increase in the plasma treated starch. The degree of cross-linking of the treated starch with high relative humidity is less than that of the treated starch with low relative humidity.

  10. Characterization of Modified Tapioca Starch in Atmospheric Argon Plasma under Diverse Humidity by FTIR Spectroscopy

    International Nuclear Information System (INIS)

    Deeyai, P.; Suphantharika, M.; Wongsagonsup, R.; Dangtip, S.

    2013-01-01

    Tapioca is economical crop grown in Thailand and continues to be one of the major sources of starch. Nowadays, tapioca starch has been widely used in industrial applications, however the native form of starch has limited the applications. Thus scientists try to modify the properties of starch for increasing the stability of the granules, pastes to low pH, heat, and shear during the food process. We modify the tapioca starch by plasma treatment under an argon atmosphere. The degree of modification is determined by following water content in the starch granules. The tablet samples of native starch are also prepared and compared with the plasma treated starch. Before plasma treatment, the starch tablets are stored under three different relative humilities (RH) including 11%, 68%, and 78%RH, respectively. The samples are characterized using FTIR spectroscopy associated with the degree of cross-linking. The results show that the water molecules are engulfed into the starch structure in two ways, a tight bond and a weak absorption of water molecules which is represented at two wave number of 1630 cm −1 and 3272 cm −1 , respectively. The degree of cross-linking can be identified from the relative intensity of these two peaks with the C—O—H peak at 993 cm −1 . The results show that the degree of cross-linking increase in the plasma treated starch. The degree of cross-linking of the treated starch with high relative humidity is less than that of the treated starch with low relative humidity

  11. Quantitative plasma spectroscopy in a resistive shell reversed-field pinch

    Energy Technology Data Exchange (ETDEWEB)

    Hedqvist, Anders

    1999-10-01

    The subject addressed in this thesis is quantitative plasma spectroscopy. Measurements of electron temperature and impurity ion density, performed at EXTRAP-T2, are aimed to investigate the effects of operating a reversed- field pinch with a resistive shell and a graphite wall. The spectroscopic measurements are analyzed with a collisional-radiative model and a consistency check is performed for the measurements and the model itself. The resistive shell results in wall-locked modes, enhanced plasma-wall interaction and degraded confinement. Measurements of vacuum ultraviolet resonant transitions of carbon and oxygen show that the local heating of the wall, at the position of the locking, leads to influxes of hydrogen and impurities, resulting in a cold and resistive plasma. Effects on the local scale are also observed. Spatially-resolved measurements of line emission originating from charge exchange collisions are used to investigate the change in neutral hydrogen profile. Temporal correlations between soft x-ray emission and poloidal loop voltage at the position of the wall-locked modes are observed and in connection, a decrease in central electron temperature, indicating there is a direct energy loss channel between the center and the edge. The hydrogen recycling properties of the graphite wall are investigated in an isotope exchange experiment. The density of the hydrogen isotopes are measured from spectral line emission and compared with recycling models. In charge exchange collisions between fully stripped chlorine and thermal deuterium, observed in JET plasmas, only a single n-level is populated. This is different from most ions and may be used to test models for calculating charge exchange collision cross-sections.

  12. Surface chemistry of plasma-assisted atomic layer deposition of Al2O3 studied by infrared spectroscopy

    NARCIS (Netherlands)

    Langereis, E.; Keijmel, J.; Sanden, van de M.C.M.; Kessels, W.M.M.

    2008-01-01

    The surface groups created during plasma-assisted atomic layer deposition (ALD) of Al2O3 were studied by infrared spectroscopy. For temperatures in the range of 25–150 °C, –CH3 and –OH were unveiled as dominant surface groups after the Al(CH3)3precursor and O2 plasma half-cycles, respectively. At

  13. ELM-Induced Plasma Wall Interactions in DIII-D

    International Nuclear Information System (INIS)

    Rudakov, D.L.; Boedo, J.A.; Yu, J.H.; Brooks, N.H.; Fenstermacher, M.E.; Groth, M.; Hollmann, E.M.; Lasnier, C.J.; McLean, A.G.; Moyer, R.A.; Stangeby, P.C.; Tynan, G.R.; Wampler, W.R.; Watkins, J.G.; West, W.P.; Wong, C.C.; Zeng, L.; Bastasz, R.J.; Buchenauer, D.; Whaley, J.

    2008-01-01

    Intense transient fluxes of particles and heat to the main chamber components induced by edge localized modes (ELMs) are of serious concern for ITER. In DIII-D, plasma interaction with the outboard chamber wall is studied using Langmuir probes and optical diagnostics including a fast framing camera. Camera data shows that ELMs feature helical filamentary structures localized at the low field side of the plasma and aligned with the local magnetic field. During the nonlinear phase of an ELM, multiple filaments are ejected from the plasma edge and propagate towards the outboard wall with velocities of 0.5-0.7 km/s. When reaching the wall, filaments result in 'hot spots'--regions of local intense plasma-material interaction (PMI) where the peak incident particle and heat fluxes are up to 2 orders of magnitude higher than those between ELMs. This interaction pattern has a complicated geometry and is neither toroidally nor poloidally symmetric. In low density/collisionality H-mode discharges, PMI at the outboard wall is almost entirely due to ELMs. In high density/collisionality discharges, contributions of ELMs and inter-ELM periods to PMI at the wall are comparable. A Midplane Material Evaluation Station (MiMES) has been recently installed in order to conduct in situ measurements of erosion/redeposition at the outboard chamber wall, including those caused by ELMs

  14. Complete chemical analysis of produced water by modern inductively coupled plasma spectroscopy (ICP)

    Energy Technology Data Exchange (ETDEWEB)

    Graham, G M; Sorbie, K S; Johnston, A; Boak, L S

    1997-12-31

    ICP (Inductively Coupled Plasma) spectroscopy is recognised as a very effective tool for monitoring ion compositions in many different waters. It has also been used by a number of laboratories to determine residual levels of phosphonate (PH) scale inhibitors in produced waters, based on phosphorus content. Until recently, it had not been used effectively to monitor phosphino-polycarboxylate (PPCA) returns. Large errors had frequently been observed where it had been applied. The poor detection limits and accuracy obtained for PPCA inhibitors relates to much lower amount of phosphorus present when compared with a typical phosphonate inhibitor. This paper demonstrates the effectiveness of IPC detection for PPCA and other phosphorus containing inhibitors by the use of modern instruments without the need of pre-treatment. 6 refs., 3 figs., 10 tabs.

  15. High average power, highly brilliant laser-produced plasma source for soft X-ray spectroscopy.

    Science.gov (United States)

    Mantouvalou, Ioanna; Witte, Katharina; Grötzsch, Daniel; Neitzel, Michael; Günther, Sabrina; Baumann, Jonas; Jung, Robert; Stiel, Holger; Kanngiesser, Birgit; Sandner, Wolfgang

    2015-03-01

    In this work, a novel laser-produced plasma source is presented which delivers pulsed broadband soft X-radiation in the range between 100 and 1200 eV. The source was designed in view of long operating hours, high stability, and cost effectiveness. It relies on a rotating and translating metal target and achieves high stability through an on-line monitoring device using a four quadrant extreme ultraviolet diode in a pinhole camera arrangement. The source can be operated with three different laser pulse durations and various target materials and is equipped with two beamlines for simultaneous experiments. Characterization measurements are presented with special emphasis on the source position and emission stability of the source. As a first application, a near edge X-ray absorption fine structure measurement on a thin polyimide foil shows the potential of the source for soft X-ray spectroscopy.

  16. 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.

  17. Three-dimensional modeling of beam emission spectroscopy measurements in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Guszejnov, D.; Pokol, G. I. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); Pusztai, I. [Nuclear Engineering, Applied Physics, Chalmers University of Technology, SE-412 96 Goeteborg (Sweden); Refy, D.; Zoletnik, S. [MTA Wigner FK RMI, Association EURATOM, Pf. 49, H-1525 Budapest (Hungary); Lampert, M. [Department of Nuclear Techniques, Budapest University of Technology and Economics, Association EURATOM, H-1111 Budapest (Hungary); MTA Wigner FK RMI, Association EURATOM, Pf. 49, H-1525 Budapest (Hungary); Nam, Y. U. [National Fusion Research Institute, Gwahangno 113, Daejeon 305-333 (Korea, Republic of)

    2012-11-15

    One of the main diagnostic tools for measuring electron density profiles and the characteristics of long wavelength turbulent wave structures in fusion plasmas is beam emission spectroscopy (BES). The increasing number of BES systems necessitated an accurate and comprehensive simulation of BES diagnostics, which in turn motivated the development of the Rate Equations for Neutral Alkali-beam TEchnique (RENATE) simulation code that is the topic of this paper. RENATE is a modular, fully three-dimensional code incorporating all key features of BES systems from the atomic physics to the observation, including an advanced modeling of the optics. Thus RENATE can be used both in the interpretation of measured signals and the development of new BES systems. The most important components of the code have been successfully benchmarked against other simulation codes. The primary results have been validated against experimental data from the KSTAR tokamak.

  18. Method validation in plasma source optical emission spectroscopy (ICP-OES) - From samples to results

    International Nuclear Information System (INIS)

    Pilon, Fabien; Vielle, Karine; Birolleau, Jean-Claude; Vigneau, Olivier; Labet, Alexandre; Arnal, Nadege; Adam, Christelle; Camilleri, Virginie; Amiel, Jeanine; Granier, Guy; Faure, Joel; Arnaud, Regine; Beres, Andre; Blanchard, Jean-Marc; Boyer-Deslys, Valerie; Broudic, Veronique; Marques, Caroline; Augeray, Celine; Bellefleur, Alexandre; Bienvenu, Philippe; Delteil, Nicole; Boulet, Beatrice; Bourgarit, David; Brennetot, Rene; Fichet, Pascal; Celier, Magali; Chevillotte, Rene; Klelifa, Aline; Fuchs, Gilbert; Le Coq, Gilles; Mermet, Jean-Michel

    2017-01-01

    Even though ICP-OES (Inductively Coupled Plasma - Optical Emission Spectroscopy) is now a routine analysis technique, requirements for measuring processes impose a complete control and mastering of the operating process and of the associated quality management system. The aim of this (collective) book is to guide the analyst during all the measurement validation procedure and to help him to guarantee the mastering of its different steps: administrative and physical management of samples in the laboratory, preparation and treatment of the samples before measuring, qualification and monitoring of the apparatus, instrument setting and calibration strategy, exploitation of results in terms of accuracy, reliability, data covariance (with the practical determination of the accuracy profile). The most recent terminology is used in the book, and numerous examples and illustrations are given in order to a better understanding and to help the elaboration of method validation documents

  19. Radiation-induced defects in chalcogenide glasses characterized by combined optical spectroscopy, XPS and PALS methods

    Energy Technology Data Exchange (ETDEWEB)

    Shpotyuk, O. [Institute of Physics of Jan Dlugosz University, 13/15 al. Armii Krajowej, Czestochowa 42201 (Poland); Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Lviv Institute of Materials of SRC ' ' Carat' ' , 202, Stryjska str., 79031 Lviv (Ukraine); Kovalskiy, A.; Jain, H. [Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Golovchak, R. [Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Lviv Institute of Materials of SRC ' ' Carat' ' , 202, Stryjska str., 79031 Lviv (Ukraine); Zurawska, A. [Opole University of Technology, 75, Ozimska str., Opole 45370 (Poland)

    2007-03-15

    Temperature-dependent optical absorption spectroscopy, high-resolution X-ray photoelectron spectroscopy and positron annihilation lifetimes spectroscopy are utilized to understand radiation-induced changes in Ge-Sb-S chalcogenide glasses. Theoretically predicted topological scheme of {gamma}-induced coordination defect formation in stoichiometric Ge{sub 23.5}Sb{sub 11.8}S{sub 64.7} glass composition is supported by these measurements. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. In situ semi-quantitative analysis of polluted soils by laser-induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Ismaël, Amina; Bousquet, Bruno; Michel-Le Pierrès, Karine; Travaillé, Grégoire; Canioni, Lionel; Roy, Stéphane

    2011-05-01

    Time-saving, low-cost analyses of soil contamination are required to ensure fast and efficient pollution removal and remedial operations. In this work, laser-induced breakdown spectroscopy (LIBS) has been successfully applied to in situ analyses of polluted soils, providing direct semi-quantitative information about the extent of pollution. A field campaign has been carried out in Brittany (France) on a site presenting high levels of heavy metal concentrations. Results on iron as a major component as well as on lead and copper as minor components are reported. Soil samples were dried and prepared as pressed pellets to minimize the effects of moisture and density on the results. LIBS analyses were performed with a Nd:YAG laser operating at 1064 nm, 60 mJ per 10 ns pulse, at a repetition rate of 10 Hz with a diameter of 500 μm on the sample surface. Good correlations were obtained between the LIBS signals and the values of concentrations deduced from inductively coupled plasma atomic emission spectroscopy (ICP-AES). This result proves that LIBS is an efficient method for optimizing sampling operations. Indeed, "LIBS maps" were established directly on-site, providing valuable assistance in optimizing the selection of the most relevant samples for future expensive and time-consuming laboratory analysis and avoiding useless analyses of very similar samples. Finally, it is emphasized that in situ LIBS is not described here as an alternative quantitative analytical method to the usual laboratory measurements but simply as an efficient time-saving tool to optimize sampling operations and to drastically reduce the number of soil samples to be analyzed, thus reducing costs. The detection limits of 200 ppm for lead and 80 ppm for copper reported here are compatible with the thresholds of toxicity; thus, this in situ LIBS campaign was fully validated for these two elements. Consequently, further experiments are planned to extend this study to other chemical elements and other

  1. Influence of sample temperature on the expansion dynamics and the optical emission of laser-induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Eschlböck-Fuchs, S.; Haslinger, M.J.; Hinterreiter, A.; Kolmhofer, P.; Huber, N. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Rössler, R. [voestalpine Stahl GmbH, A-4031 Linz (Austria); Heitz, J. [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria); Pedarnig, J.D., E-mail: johannes.pedarnig@jku.at [Christian Doppler Laboratory for Laser-Assisted Diagnostics, Institute of Applied Physics, Johannes Kepler University Linz, A-4040 Linz (Austria)

    2013-09-01

    We investigate the influence of sample temperature on the dynamics and optical emission of laser induced plasma for various solid materials. Bulk aluminum alloy, silicon wafer, and metallurgical slag samples are heated to temperature T{sub S} ≤ 500 °C and ablated in air by Nd:YAG laser pulses (wavelength 1064 nm, pulse duration approx. 7 ns). The plasma dynamics is investigated by fast time-resolved photography. For laser-induced breakdown spectroscopy (LIBS) the optical emission of plasma is measured by Echelle spectrometers in combination with intensified CCD cameras. For all sample materials the temporal evolution of plume size and broadband plasma emission vary systematically with T{sub S}. The size and brightness of expanding plumes increase at higher T{sub S} while the mean intensity remains independent of temperature. The intensity of emission lines increases with temperature for all samples. Plasma temperature and electron number density do not vary with T{sub S}. We apply the calibration-free LIBS method to determine the concentration of major oxides in slag and find good agreement to reference data up to T{sub S} = 450 °C. The LIBS analysis of multi-component materials at high temperature is of interest for technical applications, e.g. in industrial production processes. - Highlights: • Size and emission of laser-induced plasma increase with sample temperature Ts. • Mean optical intensity of plasma is independent of Ts. • Plasma temperature and electron number density do not vary with Ts. • Major oxides in steel slag are quantified up to Ts = 450 °C. • Industrial steel slags are analyzed by calibration-free LIBS method.

  2. Signal enhancement in collinear double-pulse laser-induced breakdown spectroscopy applied to different soils

    Energy Technology Data Exchange (ETDEWEB)

    Nicolodelli, Gustavo, E-mail: gunicolodelli@hotmail.com [Embrapa Instrumentation, Rua XV de Novembro, 1452, CEP 13560-970 São Carlos, SP (Brazil); Senesi, Giorgio Saverio, E-mail: giorgio.senesi@imip.cnr.it [Institute of Inorganic Methodologies and Plasmas, CNR, Bari, 70126 Bari (Italy); Romano, Renan Arnon, E-mail: renan.romano@gmail.com [Embrapa Instrumentation, Rua XV de Novembro, 1452, CEP 13560-970 São Carlos, SP (Brazil); Physics Institute of São Carlos, University of São Paulo, IFSC-USP, Av. Trabalhador são-carlense, 400 Pq. Arnold Schimid, 13566-590 São Carlos, SP (Brazil); Oliveira Perazzoli, Ivan Luiz de, E-mail: ivanperazzoli@hotmail.com [Embrapa Instrumentation, Rua XV de Novembro, 1452, CEP 13560-970 São Carlos, SP (Brazil); Milori, Débora Marcondes Bastos Pereira, E-mail: debora.milori@embrapa.br [Embrapa Instrumentation, Rua XV de Novembro, 1452, CEP 13560-970 São Carlos, SP (Brazil)

    2015-09-01

    Laser-induced breakdown spectroscopy (LIBS) is a well-known consolidated analytical technique employed successfully for the qualitative and quantitative analysis of solid, liquid, gaseous and aerosol samples of very different nature and origin. Several techniques, such as dual-pulse excitation setup, have been used in order to improve LIBS's sensitivity. The purpose of this paper was to optimize the key parameters as excitation wavelength, delay time and interpulse, that influence the double pulse (DP) LIBS technique in the collinear beam geometry when applied to the analysis at atmospheric air pressure of soil samples of different origin and texture from extreme regions of Brazil. Additionally, a comparative study between conventional single pulse (SP) LIBS and DP LIBS was performed. An optimization of DP LIBS system, choosing the correct delay time between the two pulses, was performed allowing its use for different soil types and the use of different emission lines. In general, the collinear DP LIBS system improved the analytical performances of the technique by enhancing the intensity of emission lines of some elements up to about 5 times, when compared with conventional SP-LIBS, and reduced the continuum emission. Further, the IR laser provided the best performance in re-heating the plasma. - Highlights: • The correct choice of the delay time between the two pulses is crucial for the DP system. • An optimization of DP LIBS system was performed allowing its use for different soil and the use of different emission lines. • The DP LIBS system improved the analytical performances of the technique up to about 5 times, when compared with SP LIBS. • The IR laser provided the best performance in re-heating the plasma.

  3. X-ray spectroscopic characterization of laser produced hot dense plasmas; Caracterisation par spectroscopie X de plasmas chauds et denses crees par lasers de puissance

    Energy Technology Data Exchange (ETDEWEB)

    Kontogiannopoulos, N

    2007-12-15

    In this work we performed experiments of emission and absorption spectroscopy of laser produced plasmas, to provide well characterized spectral data which permit to benchmark atomic physics codes. More precisely, we produced xenon and krypton plasmas in NLTE (non local thermodynamic equilibrium) conditions and studied their emission spectra. In a second experiment, we characterized the absorption spectra of zinc sulfide and aluminium plasmas in LTE (local thermodynamic equilibrium) conditions.The first two chapters give an outline of the theory involved in the study of the emission and absorption plasma spectroscopy. Chapter 1 describes the different atomic processes occurring in a plasma. The LTE and the NLTE statistics ruling the equilibrium of the atomic processes are presented. Then, we give a brief description of the different codes of plasma atomic physics used in the analysis of our experimental data, namely HULLAC, SCO and TRANSPEC/AVERROES. In Chapter 2 the macroscopic theory of the radiation transport through a plasma is given. We describe also the self-similar model of Basko and the view factor approach, which permits us to calculate the heating conditions of the absorption foils achieved in the interior of the spherical gold cavity. Chapter 3 gives a description of the instruments used for realizing the two experiments, as well as the technical characteristics of the LULI2000 laser facility used to perform the experiments. Chapter 4 presents the experiment realized to characterize the emission spectra of the xenon and krypton plasmas in NLTE, as well the analysis of the experimental data with TRANSPEC/AVERROES. Finally, the experiment for measuring the absorption spectrum of the ZnS plasma mixture and the analysis of the experimental data with the code SCO are given in Chapter 5.

  4. Investigations of plasma induced effects on the surface properties of lignocellulosic natural coir fibres

    Science.gov (United States)

    Praveen, K. M.; Thomas, Sabu; Grohens, Yves; Mozetič, Miran; Junkar, Ita; Primc, Gregor; Gorjanc, Marija

    2016-04-01

    The development of lignocellulosic natural-fibre-reinforced polymers composites are constrained by two limitations: the upper temperature at which the fibre can be processed and the significant differences between the surface energy of the fibre and the polymer matrix. Since the fibres and matrices are chemically different, strong adhesion at their interface is needed for the effective transfer of stress and bond distribution throughout the interface. The present study investigated the plasma induced effects on the surface properties of natural coir fibres. Weakly ionized oxygen plasma was created in two different discharge chambers by an inductively coupled radiofrequency (RF) discharge. The water absorption studies showed an increase of water sorption from 39% to 100%. The morphological study using scanning electron microscopy (SEM) analysis also confirmed the surface changes which were observed after the plasma treatment. The topographic measurements and phase imaging done using atomic force microscopy (AFM) indicated difference in topographic features and etching of coir wall, which points to the removal of the first layer of coir fibre. X-ray photoelectron spectroscopy (XPS) analysis revealed that the oxygen content measured for samples treated at 50 Pa increased from initial 18% to about 32%.

  5. Synthesis of surfactant-free electrostatically stabilized gold nanoparticles by plasma-induced liquid chemistry

    International Nuclear Information System (INIS)

    Patel, J; Maguire, P; Mariotti, D; Němcová, L; Graham, W G

    2013-01-01

    Plasma-induced non-equilibrium liquid chemistry is used to synthesize gold nanoparticles (AuNPs) without using any reducing or capping agents. The morphology and optical properties of the synthesized AuNPs are characterized by transmission electron microscopy (TEM) and ultraviolet–visible spectroscopy. Plasma processing parameters affect the particle shape and size and the rate of the AuNP synthesis process. Particles of different shapes (e.g. spherical, triangular, hexagonal, pentagonal, etc) are synthesized in aqueous solutions. In particular, the size of the AuNPs can be tuned from 5 nm to several hundred nanometres by varying the initial gold precursor (HAuCl 4 ) concentration from 2.5 μM to 1 mM. In order to reveal details of the basic plasma–liquid interactions that lead to AuNP synthesis, we have measured the solution pH, conductivity and hydrogen peroxide (H 2 O 2 ) concentration of the liquid after plasma processing, and conclude that H 2 O 2 plays the role of the reducing agent which converts Au +3 ions to Au 0 atoms, leading to nucleation growth of the AuNPs. (paper)

  6. Modeling of Plasma-Induced Ignition and Combustion

    National Research Council Canada - National Science Library

    Boyd, Iain D; Keidar, Michael

    2008-01-01

    .... Phenomena that must be considered in an electrothermal chemical gun model include the initial capillary plasma properties, the plasma-air interaction, plasma sheath effects, and the plasma-propellant interaction itself...

  7. Environmental samples analysis by Atomic Absorption Spectrophotometry and Inductively Coupled Plasma-Optical Emission Spectroscopy

    International Nuclear Information System (INIS)

    Popescu, I.V.; Iordan, M.; Stihi, C.; Bancuta, A.; Busuioc, G.; Dima, G.; Ciupina, V.; Belc, M.; Vlaicu, Gh.; Marian, R.

    2002-01-01

    Biological samples are interesting from many aspects of environmental monitoring. By analyzing tree leaves conclusions can be drown regarding the metal loading in the growth medium. So that, starting from assumption that the pollution factors from environmental medium can modify the normal concentration of elements, we decided to control the presence of toxic elements and the deviation from normal state of elements in leaves of different trees from areas situated at different distances of pollution source. The aim of this work is to determine the elemental composition of tree leaves using Atomic Absorption Spectrophotometry (AAS) method and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) method. Using AAS spectrophotometer SHIMADZU we identified and determined the concentration of: Cd, Co, Cu, Zn, Mn, Cr, Fe, Se, Pb with an instrumental error less than 1% for most of the elements analyzed. The same samples were analyzed by ICP-OES spectrometer, BAIRD ICP2070-Sequential Plasma spectrometer. We identified and determined in leaves of different trees the concentration of Mg, Ca, and Sr with a precision less than 6%. (authors)

  8. Preliminary results of in situ laser-induced breakdown spectroscopy for the first wall diagnostics on EAST

    Science.gov (United States)

    Hu, Zhenhua; Li, Cong; Xiao, Qingmei; Liu, Ping; Fang, Ding; Mao, Hongmin; Wu, Jing; Zhao, Dongye; Ding, Hongbin; Luo, Guang-Nan; EAST Team

    2017-02-01

    Post-mortem methods cannot fulfill the requirement of monitoring the lifetime of the plasma facing components (PFC) and measuring the tritium inventory for the safety evaluation. Laser-induced breakdown spectroscopy (LIBS) is proposed as a promising method for the in situ study of fuel retention and impurity deposition in a tokamak. In this study, an in situ LIBS system was successfully established on EAST to investigate fuel retention and impurity deposition on the first wall without the need of removal tiles between plasma discharges. Spectral lines of D, H and impurities (Mo, Li, Si, … ) in laser-induced plasma were observed and identified within the wavelength range of 500-700 nm. Qualitative measurements such as thickness of the deposition layers, element depth profile and fuel retention on the wall are obtained by means of in situ LIBS. The results demonstrated the potential applications of LIBS for in situ characterization of fuel retention and co-deposition on the first wall of EAST. Supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB105002, 2015GB109001, and 2013GB109005), National Natural Science Foundation of China (Nos. 11575243, 11605238, 11605023), Chinesisch-Deutsches Forschungs Project (GZ765), and Korea Research Council of Fundamental Science and Technology (KRCF) under the international collaboration & research in Asian countries (PG1314).

  9. Applications of ultra-short pulsed laser ablation: thin films deposition and fs/ns dual-pulse laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Teghil, R; De Bonis, A; Galasso, A; Santagata, A; Albano, G; Villani, P; Spera, D; Parisi, G P

    2008-01-01

    In this paper, we report a survey of two of the large number of possible practical applications of the laser ablation performed by an ultra-short pulse laser, namely pulsed laser deposition (PLD) and fs/ns dual-pulse laser-induced breakdown spectroscopy (DP-LIBS). These applications differ from those using just longer pulsed lasers as a consequence of the distinctive characteristics of the plasma produced by ultra-short laser beams. The most important feature of this plasma is the large presence of particles with nanometric size which plays a fundamental role in both applications.

  10. Determination of hazardous ingredients in personal care products using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Abrar, M.; Iqbal, T.; Fahad, M.; Andleeb, M.; Farooq, Z.; Afsheen, S.

    2018-05-01

    In the present work, the laser-induced breakdown spectroscopy technique is applied to explore the concentration of toxic elements present in cosmetic materials. The elemental analysis of chromium (Cr), magnesium (Mg), cadmium (Cd) and lead (Pb) are selected as major elements and manganese (Mn), sodium (Na), potassium (P), sulfur (S), silicon (Si) and titanium (Ti) as minor elements in cosmetic products. In this technique, a plasma plume is generated by using an Nd:YAG Laser of 532 nm wavelength and spectral lines for the respective samples are observed. Four different samples of cosmetic products are selected, i.e. two samples for lipstick and two for eyeshadow. The observed spectral lines of all major and minor elements are used to calculate their concentration in all samples through the intensity ratio method. Among selected lipstick and eyeshadow samples, one sample is branded, and one is collected from the local market. It is observed that chromium, magnesium and lead have strong spectral lines and consequently show high concentration. The calculated concentrations are then compared to permissible limits set by the Food and Drug Administration with regard to the cosmetics industry. The concentration of these toxic elements in selected local cosmetic samples exceeds the safe permissible limit for human use and could lead to serious health problems.

  11. Microanalysis of tool steel and glass with laser-induced breakdown spectroscopy

    Science.gov (United States)

    Loebe, Klaus; Uhl, Arnold; Lucht, Hartmut

    2003-10-01

    A laser microscope system for the microanalytical characterization of complex materials is described. The universal measuring principle of laser-induced breakdown spectroscopy (LIBS) in combination with echelle optics permits a fast simultaneous multielement analysis with a possible spatial resolution below 10 pm. The developed system features completely UV-transparent optics for the laser-microscope coupling and the emission beam path and enables parallel signal detection within the wavelength range of 200-800 nm with a spectral resolution of a few picometers. Investigations of glass defects and tool steels were performed. The characterization of a glass defect in a tumbler by a micro-LIBS line scan, with use of a 266-nm diode-pumped Nd:YAG laser for excitation, is possible by simple comparison of plasma spectra of the defect and the surrounding area. Variations in the main elemental composition as well as impurities by trace elements are detected at the same time. Through measurement of the calibration samples with the known concentration of the corresponding element, a correlation between the intensity of spectral lines and the element concentration was also achieved. The change of elemental composition at the transient stellite solder of tool steels has been determined by an area scan. The two-dimensional pictures show abrupt changes of the element distribution along the solder edge and allow fundamental researches of dynamic modifications (e.g., diffusion) in steel.

  12. Characterization and forensic analysis of soil samples using laser-induced breakdown spectroscopy (LIBS).

    Science.gov (United States)

    Jantzi, Sarah C; Almirall, José R

    2011-07-01

    A method for the quantitative elemental analysis of surface soil samples using laser-induced breakdown spectroscopy (LIBS) was developed and applied to the analysis of bulk soil samples for discrimination between specimens. The use of a 266 nm laser for LIBS analysis is reported for the first time in forensic soil analysis. Optimization of the LIBS method is discussed, and the results compared favorably to a laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) method previously developed. Precision for both methods was LIBS limits of detection were LIBS method successfully discriminated samples from two different sites in Dade County, FL. Analysis of variance, Tukey's post hoc test and Student's t test resulted in 100% discrimination with no type I or type II errors. Principal components analysis (PCA) resulted in clear groupings of the two sites. A correct classification rate of 99.4% was obtained with linear discriminant analysis using leave-one-out validation. Similar results were obtained when the same samples were analyzed by LA-ICP-MS, showing that LIBS can provide similar information to LA-ICP-MS. In a forensic sampling/spatial heterogeneity study, the variation between sites, between sub-plots, between samples and within samples was examined on three similar Dade sites. The closer the sampling locations, the closer the grouping on a PCA plot and the higher the misclassification rate. These results underscore the importance of careful sampling for geographic site characterization.

  13. Influence of Ambient Gas on Laser-Induced Breakdown Spectroscopy of Uranium Metal

    International Nuclear Information System (INIS)

    Zhang Dacheng; Ma Xinwen; Wang Shulong; Zhu Xiaolong

    2015-01-01

    Laser-induced breakdown spectroscopy (LIBS) is regarded as a suitable method for the remote analysis of materials in any phase, even in an environment with high radiation levels. In the present work we used the third harmonic pulse of a Nd:YAG laser for ablation of uranium metal and measured the plasma emission with a fiber-optic spectrometer. The LIBS spectra of uranium metal and their features in different ambient gases (i.e., argon, neon, oxygen, and nitrogen) at atmospheric pressure were studied. Strong continuum spectrum and several hundreds of emission lines from UI and UII were observed. It is found that the continuum spectrum observed in uranium not only comes from bremsstrahlung emission but is also due to the complex spectrum of uranium. The influence of ambient gas and the gas flow rate for ablation of uranium metal was investigated. The experimental results indicate that the intensity of the uranium lines was enhanced in argon and nitrogen. However, the intensity of uranium lines was decreased in oxygen due to the generation of UO and other oxides. The results also showed that the highest intensity of uranium lines were obtained in argon gas with a gas flow rate above 2.5 L/min. The enhanced mechanism in ambient gas and the influence of the gas flow rate were analyzed in this work. (paper)

  14. Rapid Analysis of Ash Composition Using Laser-Induced Breakdown Spectroscopy (LIBS)

    Energy Technology Data Exchange (ETDEWEB)

    Tyler L. Westover

    2013-01-01

    Inorganic compounds are known to be problematic in the thermochemical conversion of biomass to syngas and ultimately hydrocarbon fuels. The elements Si, K, Ca, Na, S, P, Cl, Mg, Fe, and Al are particularly problematic and are known to influence reaction pathways, contribute to fouling and corrosion, poison catalysts, and impact waste streams. Substantial quantities of inorganic species can be entrained in the bark of trees during harvest operations. Herbaceous feedstocks often have even greater quantities of inorganic constituents, which can account for as much as one-fifth of the total dry matter. Current methodologies to measure the concentrations of these elements, such as inductively coupled plasma-optical emission spectrometry/mass spectrometry (ICP-OES/MS) are expensive in time and reagents. This study demonstrates that a new methodology employing laser-induced breakdown spectroscopy (LIBS) can rapidly and accurately analyze the inorganic constituents in a wide range of biomass materials, including both woody and herbaceous examples. This technique requires little or no sample preparation, does not consume any reagents, and the analytical data is available immediately. In addition to comparing LIBS data with the results from ICP-OES methods, this work also includes discussions of sample preparation techniques, calibration curves for interpreting LIBS spectra, minimum detection limits, and the use of internal standards and standard reference materials.

  15. Development of laser induced breakdown spectroscopy for studying erosion, deposition, and fuel retention in ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Paris, Peeter; Piip, Kaarel [Institute of Physics, University of Tartu, Tartu (Estonia); Hakola, Antti [VTT Technical Research Centre of Finland, Espoo (Finland); Laan, Matti, E-mail: matti.laan@ut.ee [Institute of Physics, University of Tartu, Tartu (Estonia); Aints, Märt [Institute of Physics, University of Tartu, Tartu (Estonia); Koivuranta, Seppo; Likonen, Jari [VTT Technical Research Centre of Finland, Espoo (Finland); Lissovski, Aleksandr [Institute of Physics, University of Tartu, Tartu (Estonia); Mayer, Matej [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Neu, Rudolf [Max-Planck-Institut für Plasmaphysik, Garching (Germany); Technische Universität München, Fachgebt Plasma-Material-Wechelwirkung, Garching (Germany); Rohde, Volker; Sugiyama, Kazuyoshi [Max-Planck-Institut für Plasmaphysik, Garching (Germany)

    2015-10-15

    Highlights: • LIBS development for in situ monitoring of first walls of fusion reactors. • Testing of samples extracted from the divertor tiles of ASDEX Upgrade. • Reliable detection of deuterium depth profiles. • A method of LIBS data processing which allows to find the elemental depth profiles. • Comparison of LIBS results with those of other surface characterization methods. - Abstract: The paper deals with the development of laser induced breakdown spectroscopy (LIBS) into an in situ method for studying erosion/deposition processes at the first walls of fusion reactors. To this end, samples extracted from the divertor tiles of ASDEX Upgrade after the 2009 plasma operations were analyzed using LIBS for their composition and the results were compared with other post mortem deposition data. Quantitative depth profiles for the elemental concentrations were extracted from LIBS spectra by applying a novel data processing method. In addition, both multiline and multispot averaging procedures were applied to reduce fluctuations in the data. The LIBS concentration profiles matched qualitatively with those given by secondary ion mass spectrometry and quantitatively with the ion-beam data. The deuterium content of the samples could be reliably determined if the surface densities were >10{sup 17} at/cm{sup 2}.

  16. 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.

  17. Cold plasma interactions with plants: Morphing and movements of Venus flytrap and Mimosa pudica induced by argon plasma jet.

    Science.gov (United States)

    Volkov, Alexander G; Xu, Kunning G; Kolobov, Vladimir I

    2017-12-01

    Low temperature (cold) plasma finds an increasing number of applications in biology, medicine and agriculture. In this paper, we report a new effect of plasma induced morphing and movements of Venus flytrap and Mimosa pudica. We have experimentally observed plasma activation of sensitive plant movements and morphing structures in these plants similar to stimulation of their mechanosensors in vivo. Application of an atmospheric pressure argon plasma jet to the inside or outside of a lobe, midrib, or cilia in Dionaea muscipula Ellis induces trap closing. Treatment of Mimosa pudica by plasma induces movements of pinnules and petioles similar to the effects of mechanical stimulation. We have conducted control experiments and simulations to illustrate that gas flow and UV radiation associated with plasma are not the primary reasons for the observed effects. Reactive oxygen and nitrogen species (RONS) produced by cold plasma in atmospheric air appear to be the primary reason of plasma-induced activation of phytoactuators in plants. Some of these RONS are known to be signaling molecules, which control plants' developmental processes. Understanding these mechanisms could promote plasma-based technology for plant developmental control and future use for plant protection from pathogens. Our work offers new insight into mechanisms which trigger plant morphing and movement. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Atomic hydrogen and argon ground state density determination in a recombining plasma using visible light absorption spectroscopy

    NARCIS (Netherlands)

    Otorbaev, D.K.; Buuron, A.J.M.; Sanden, van de M.C.M.; Meulenbroeks, R.F.G.; Schram, D.C.

    1995-01-01

    The atomic radical density in the first excited state, obtained by the technique of optical absorption spectroscopy, and a simple kinetic model are used to determine the radical ground state density in a recombining expanding plasma. The kinetic model used does not require knowledge of the shape of

  19. Laser photothermal spectroscopy of light-induced absorption

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, L A [Institute of Cryptography, Communications and Informatics, Moscow (Russian Federation)

    2013-01-31

    Basic methods of laser photothermal spectroscopy, which are used to study photoinduced absorption in various media, are briefly considered. Comparative analysis of these methods is performed and the latest results obtained in this field are discussed. Different schemes and examples of their practical implementation are considered. (review)

  20. Confinement effects of shock waves on laser-induced plasma from a graphite target

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Feiling; Liang, Peipei; Yang, Xu; Cai, Hua; Wu, Jiada; Xu, Ning; Ying, Zhifeng; Sun, Jian, E-mail: jsun@fudan.edu.cn [Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China)

    2015-06-15

    The spatial confinement effects of shock waves on the laser-induced plasma (LIP) from a graphite target in air were studied by probe beam deflection (PBD) measurements and optical emission spectroscopy (OES). A clear relationship between the confinement of the LIP by the shock wave and the effects on the LIP emission was observed, and the underlying mechanisms are discussed. PBD monitoring revealed that the laser-ablation induced shock wave could be well analogized to the shock wave generated by a point explosion and would be reflected by a block. OES measurements indicated that the optical emission of the LIP exhibited significant variations with the block placement. A first enhancement and then a fast decay of CN molecular emission as well as a suppression of carbon atomic emission were observed in the presence of the block. The results revealed that the reflected shock wave spatially confined the expansion of the LIP and compressed the LIP after encountering it, pushing back the species of the LIP and changing the density of the LIP species including luminous carbon atoms and CN molecules. It is suggested that the change of the LIP emission is attributed to the density variation of the LIP species due to the compression of the LIP and the reactions occurring in the plasma.

  1. Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules.......This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules....

  2. Laser-Induced Breakdown Spectroscopy for Qualitative Analysis of Metals in Simulated Martian Soils

    Science.gov (United States)

    Mowry, Curtis; Milofsky, Rob; Collins, William; Pimentel, Adam S.

    2017-01-01

    This laboratory introduces students to laser-induced breakdown spectroscopy (LIBS) for the analysis of metals in soil and rock samples. LIBS employs a laser-initiated spark to induce electronic excitation of metal atoms. Ensuing atomic emission allows for qualitative and semiquantitative analysis. The students use LIBS to analyze a series of…

  3. X-Ray photoelectron spectroscopy analysis of plasma-polymer interactions for development of low-damage plasma processing of soft materials

    International Nuclear Information System (INIS)

    Setsuhara, Yuichi; Cho, Ken; Shiratani, Masaharu; Sekine, Makoto; Hori, Masaru

    2010-01-01

    Plasma-polymer interactions have been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS) of polyethyleneterephthalate (PET) films, which have been exposed to argon plasmas driven by low-inductance antenna modules as a parameter of ion energy. The AFM images indicated that the argon plasma exposure exhibited a significant change in surface roughness. The XPS analyses suggested that the degradation of chemical bonding structure and/or bond scission of PET could be effectively suppressed in the plasma exposures with ion energies below 6 eV. However, significant degradations of O = C-O bond, C-O bond and phenyl group were observed with increasing ion energy above 6 eV.

  4. Highly sensitive analysis of boron and lithium in aqueous solution using dual-pulse laser-induced breakdown spectroscopy.

    Science.gov (United States)

    Lee, Dong-Hyoung; Han, Sol-Chan; Kim, Tae-Hyeong; Yun, Jong-Il

    2011-12-15

    We have applied a dual-pulse laser-induced breakdown spectroscopy (DP-LIBS) to sensitively detect concentrations of boron and lithium in aqueous solution. Sequential laser pulses from two separate Q-switched Nd:YAG lasers at 532 nm wavelength have been employed to generate laser-induced plasma on a water jet. For achieving sensitive elemental detection, the optimal timing between two laser pulses was investigated. The optimum time delay between two laser pulses for the B atomic emission lines was found to be less than 3 μs and approximately 10 μs for the Li atomic emission line. Under these optimized conditions, the detection limit was attained in the range of 0.8 ppm for boron and 0.8 ppb for lithium. In particular, the sensitivity for detecting boron by excitation of laminar liquid jet was found to be excellent by nearly 2 orders of magnitude compared with 80 ppm reported in the literature. These sensitivities of laser-induced breakdown spectroscopy are very practical for the online elemental analysis of boric acid and lithium hydroxide serving as neutron absorber and pH controller in the primary coolant water of pressurized water reactors, respectively.

  5. Elemental analysis of bead samples using a laser-induced plasma at low pressure

    International Nuclear Information System (INIS)

    Lie, Tjung Jie; Kurniawan, Koo Hendrik; Kurniawan, Davy P.; Pardede, Marincan; Suliyanti, Maria Margaretha; Khumaeni, Ali; Natiq, Shouny A.; Abdulmadjid, Syahrun Nur; Lee, Yong Inn; Kagawa, Kiichiro; Idris, Nasrullah; Tjia, May On

    2006-01-01

    An Nd:YAG laser (1064 nm, 8 ns, 30 mJ) was focused on various types of fresh, fossilized white coral and giant shell samples, including samples of imitation shell and marble. Such samples are extremely important as material for preparing prayer beads that are extensively used in the Buddhist faith. The aim of this research was to develop a non-destructive method to distinguish original beads from their imitations by means of spectral measurements of the carbon, hydrogen, sodium and magnesium emission intensities and by measuring the hardness of the sample using the ratio between Ca (II) 396.8 nm and Ca (I) 422.6 nm. Based on these measurements, original fresh coral beads can be distinguished from any imitation made from hard wood. The same technique was also effective in distinguishing beads made of shell from its imitation. A spectral analysis of bead was also performed on a fossilized white coral sample and the result can be used to distinguish to some extent the fossilized white coral beads from any imitation made from marble. It was also found that the plasma plume should be generated at low ambient pressure to significantly improve the hydrogen and carbon emission intensity and also to avoid energy loss inside the crater during laser irradiation at atmospheric pressure. The results of this study confirm that operating the laser-induced plasma spectroscopy at reduced ambient pressure offers distinct advantage for bead analysis over the conventional laser-induced breakdown spectroscopy (LIBS) technique operated at atmospheric pressure

  6. Elemental analysis of bead samples using a laser-induced plasma at low pressure

    Energy Technology Data Exchange (ETDEWEB)

    Lie, Tjung Jie [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Kurniawan, Koo Hendrik [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia)]. E-mail: kurnia18@cbn.net.id; Kurniawan, Davy P. [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Pardede, Marincan [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Suliyanti, Maria Margaretha [Graduate Program in Opto Electrotechniques and Laser Applications, Faculty of Engineering, The University of Indonesia, 4 Salemba Raya, Jakarta 10430 (Indonesia); Khumaeni, Ali [Department of Physics, Faculty of Mathematics and Natural Sciences, Diponegoro University, Tembalang Campus, Semarang 50275 (Indonesia); Natiq, Shouny A. [Department of Physics, Faculty of Mathematics and Natural Sciences, Diponegoro University, Tembalang Campus, Semarang 50275 (Indonesia); Abdulmadjid, Syahrun Nur [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23116 (Indonesia); Lee, Yong Inn [Physics Department, Chonbuk National University, Chonju 561-756, South Korea (Korea); Kagawa, Kiichiro [Department of Physics, Faculty of Education and Regional Studies, Fukui University, 9-1 bunkyo 3-chome, Fukui 910-8507 (Japan); Idris, Nasrullah [Department of Physics, Faculty of Education and Regional Studies, Fukui University, 9-1 bunkyo 3-chome, Fukui 910-8507 (Japan); Tjia, May On [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha, Bandung 40132 (Indonesia)

    2006-01-15

    An Nd:YAG laser (1064 nm, 8 ns, 30 mJ) was focused on various types of fresh, fossilized white coral and giant shell samples, including samples of imitation shell and marble. Such samples are extremely important as material for preparing prayer beads that are extensively used in the Buddhist faith. The aim of this research was to develop a non-destructive method to distinguish original beads from their imitations by means of spectral measurements of the carbon, hydrogen, sodium and magnesium emission intensities and by measuring the hardness of the sample using the ratio between Ca (II) 396.8 nm and Ca (I) 422.6 nm. Based on these measurements, original fresh coral beads can be distinguished from any imitation made from hard wood. The same technique was also effective in distinguishing beads made of shell from its imitation. A spectral analysis of bead was also performed on a fossilized white coral sample and the result can be used to distinguish to some extent the fossilized white coral beads from any imitation made from marble. It was also found that the plasma plume should be generated at low ambient pressure to significantly improve the hydrogen and carbon emission intensity and also to avoid energy loss inside the crater during laser irradiation at atmospheric pressure. The results of this study confirm that operating the laser-induced plasma spectroscopy at reduced ambient pressure offers distinct advantage for bead analysis over the conventional laser-induced breakdown spectroscopy (LIBS) technique operated at atmospheric pressure.

  7. Plasma-induced field emission study of carbon nanotube cathode

    Directory of Open Access Journals (Sweden)

    Yi Shen

    2011-10-01

    Full Text Available An investigation on the plasma-induced field emission (PFE properties of a large area carbon nanotube (CNT cathode on a 2 MeV linear induction accelerator injector is presented. Experimental results show that the cathode is able to emit intense electron beams. Intense electron beams of 14.9–127.8  A/cm^{2} are obtained from the cathode. The CNT cathode desorbs gases from the CNTs during the PFE process. The fast cathode plasma expansion affects the diode perveance. The amount of outgassing is estimated to be 0.06–0.49  Pa·L, and the ratio of outgassing and electron are roughly calculated to be within the range of 170–350 atoms per electron. The effect of the outgassing is analyzed, and the outgassing mass spectrum of the CNT cathode has been studied during the PFE. There is a significant desorption of CO_{2}, N_{2}(CO, and H_{2} gases, which plays an important role during the PFE process. All the experiments demonstrate that the outgassing plays an important role in the formation of the cathode plasma. Moreover, the characteristic turn-on time of the CNT cathode was measured to be 39 ns.

  8. Use of emission spectroscopy as a tool for optimization of plasma hearth operation for hazardous waste thermal treatment

    International Nuclear Information System (INIS)

    Monts, D.L.; Bauman, L.E.; Lengel, R.K.; Wang, W.; Lin, J.; Cook, R.L.; Shepard, W.S.

    1994-01-01

    Thermal processing of mixed wastes by plasma hearth vitrification requires optimization of and continuous monitoring of plasma hearth operation. A series of investigations utilizing emission spectroscopy has been initiated to characterize the plasma of a 96 kW plasma hearth in order to determine optimum conditions for monitoring and hence controlling plasma hearth performance. The plasma hearth test stand is based upon a 96 kW, transferred arc plasma torch. The torch is mounted in a vacuum vessel through an electrically operated XYZ Gimbal mount. The peak operating power depends on the gas used for the plasma. The operational limits for DC voltage are 180 V to 550 V; and the current is operated at a constant value, selectable in the range from 72 to 200 amps. The plasma arc length can be varied from 2.5 cm to 25 cm, and is dependent on the supply voltage and the process gas used. The arc current and voltage, gas pressure, cooling water flow, and cooling water temperature are monitored and stored by a PC-based data acquisition system. Five optical ports are available for making optical diagnostic measurements

  9. Validation studies on quick analysis of MOX fuel by combination of laser induced breakdown spectroscopy and ablation resonance absorption spectroscopy

    International Nuclear Information System (INIS)

    Wakaida, Ikuo; Akaoka, Katsuaki; Miyabe, Masabumi; Kato, Masaaki; Otobe, Haruyoshi; Ohoba, Hironori; Khumaeni, Ali

    2014-01-01

    Research and development of laser based quick analysis without chemical analysis and neutron measurement for next-generation Minor Actinide containing MOX fuel has been carried out, and the basic performances by using un-irradiated MOX fuel were demonstrated. The glove box had been re-constructed and specialized for laser spectroscopy, and the remote spectroscopy of MOX sample contained several concentrations of Pu was performed. In elemental analysis by Laser Induced Breakdown Spectroscopy (LIBS) with high resolution spectrometer, relative error of 2.9% at 30% Pu and the detection lower limit of 2500ppm in natural U oxide were demonstrated with the operation time of 5 min. In isotope ratio analysis by Ablation Resonance Absorption Spectroscopy, tunable semiconductor laser system was constructed, and the performances such as relative deviation less than 1% in the ratio of "2"4"0Pu/"2"3"9Pu and the sensitivity of 30-100ppm in natural U were also accomplished with laser operation time of 3 to 5min. As for an elemental analysis of the simulated liquid sample, ultra-thin laminate flow was experimented as LIBS target, and the sensitivity comparable to conventional ICP-AES was confirmed. Present study includes the result of the entrusted project by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT). (author)

  10. Local thermodynamic equilibrium and related metrological issues involving collisional-radiative model in laser-induced aluminum plasmas

    International Nuclear Information System (INIS)

    Travaille, G.; Peyrusse, O.; Bousquet, B.; Canioni, L.; Pierres, K. Michel-Le; Roy, S.

    2009-01-01

    We present a collisional-radiative approach of the theoretical analysis of laser-induced breakdown spectroscopy (LIBS) plasmas. This model, which relies on an optimized effective potential atomic structure code, was used to simulate a pure aluminum plasma. The description of aluminum involved a set of 220 atomic levels representative of three different stages of ionization (Al 0 , Al + and Al ++ ). The calculations were carried for stationary plasmas, with input parameters (n e and T e ) ranging respectively between 10 13-18 cm -3 and 0.3-2 eV. A comparison of our atomic data with some existing databases is made. The code was mainly developed to address the validity of the local thermodynamic equilibrium (LTE) assumption. For usual LIBS plasma parameters, we did not reveal a sizeable discrepancy of the radiative equilibrium of the plasma towards LTE. For cases where LTE was firmly believed to stand, the Boltzmann plot outputs of this code were used to check the physical accuracy of the Boltzmann temperature, as it is currently exploited in several calibration-free laser-induced breakdown spectroscopy (CF-LIBS) studies. In this paper, a deviation ranging between 10 and 30% of the measured Boltzmann temperature to the real excitation temperature is reported. This may be due to the huge dispersion induced on the line emissivities, on which the Boltzmann plots are based to extract this parameter. Consequences of this fact on the CF-LIBS procedure are discussed and further insights to be considered for the future are introduced.

  11. Laser-induced plasma spectrometry: truly a surface analytical tool

    International Nuclear Information System (INIS)

    Vadillo, Jose M.; Laserna, J.

    2004-01-01

    For a long period, analytical applications of laser induced plasma spectrometry (LIPS) have been mainly restricted to overall and quantitative determination of elemental composition in bulk, solid samples. However, introduction of new compact and reliable solid state lasers and technological development in multidimensional intensified detectors have made possible the seeking of new analytical niches for LIPS where its analytical advantages (direct sampling from any material irrespective of its conductive status without sample preparation and with sensitivity adequate for many elements in different matrices) could be fully exploited. In this sense, the field of surface analysis could take advantage from the cited advantages taking into account in addition, the capability of LIPS for spot analysis, line scan, depth-profiling, area analysis and compositional mapping with a single instrument in air at atmospheric pressure. This review paper outlines the fundamental principles of laser-induced plasma emission relevant to sample surface studies, discusses the experimental parameters governing the spatial (lateral and in-depth) resolution in LIPS analysis and presents the applications concerning surface examination

  12. Kr II laser-induced fluorescence for measuring plasma acceleration.

    Science.gov (United States)

    Hargus, W A; Azarnia, G M; Nakles, M R

    2012-10-01

    We present the application of laser-induced fluorescence of singly ionized krypton as a diagnostic technique for quantifying the electrostatic acceleration within the discharge of a laboratory cross-field plasma accelerator also known as a Hall effect thruster, which has heritage as spacecraft propulsion. The 728.98 nm Kr II transition from the metastable 5d(4)D(7/2) to the 5p(4)P(5/2)(∘) state was used for the measurement of laser-induced fluorescence within the plasma discharge. From these measurements, it is possible to measure velocity as krypton ions are accelerated from near rest to approximately 21 km/s (190 eV). Ion temperature and the ion velocity distributions may also be extracted from the fluorescence data since available hyperfine splitting data allow for the Kr II 5d(4)D(7/2)-5p(4)P(5/2)(∘) transition lineshape to be modeled. From the analysis, the fluorescence lineshape appears to be a reasonable estimate for the relatively broad ion velocity distributions. However, due to an apparent overlap of the ion creation and acceleration regions within the discharge, the distributed velocity distributions increase ion temperature determination uncertainty significantly. Using the most probable ion velocity as a representative, or characteristic, measure of the ion acceleration, overall propellant energy deposition, and effective electric fields may be calculated. With this diagnostic technique, it is possible to nonintrusively characterize the ion acceleration both within the discharge and in the plume.

  13. Combining Raman and laser induced breakdown spectroscopy by double pulse lasing.

    Science.gov (United States)

    Lednev, Vasily N; Pershin, Sergey M; Sdvizhenskii, Pavel A; Grishin, Mikhail Ya; Fedorov, Alexander N; Bukin, Vladimir V; Oshurko, Vadim B; Shchegolikhin, Alexander N

    2018-01-01

    A new approach combining Raman spectrometry and laser induced breakdown spectrometry (LIBS) within a single laser event was suggested. A pulsed solid state Nd:YAG laser running in double pulse mode (two frequency-doubled sequential nanosecond laser pulses with dozens microseconds delay) was used to combine two spectrometry methods within a single instrument (Raman/LIBS spectrometer). First, a low-energy laser pulse (power density far below ablation threshold) was used for Raman measurements while a second powerful laser pulse created the plasma suitable for LIBS analysis. A short time delay between two successive pulses allows measuring LIBS and Raman spectra at different moments but within a single laser flash-lamp pumping. Principal advantages of the developed instrument include high quality Raman/LIBS spectra acquisition (due to optimal gating for Raman/LIBS independently) and absence of target thermal alteration during Raman measurements. A series of high quality Raman and LIBS spectra were acquired for inorganic salts (gypsum, anhydrite) as well as for pharmaceutical samples (acetylsalicylic acid). To the best of our knowledge, the quantitative analysis feasibility by combined Raman/LIBS instrument was demonstrated for the first time by calibration curves construction for acetylsalicylic acid (Raman) and copper (LIBS) in gypsum matrix. Combining ablation pulses and Raman measurements (LIBS/Raman measurements) within a single instrument makes it an efficient tool for identification of samples hidden by non-transparent covering or performing depth profiling analysis including remote sensing. Graphical abstract Combining Raman and laser induced breakdown spectroscopy by double pulse lasing.

  14. Laser-induced breakdown spectroscopy for in situ qualitative and quantitative analysis of mineral ores

    International Nuclear Information System (INIS)

    Pořízka, P.; Demidov, A.; Kaiser, J.; Keivanian, J.; Gornushkin, I.; Panne, U.; Riedel, J.

    2014-01-01

    In this work, the potential of laser-induced breakdown spectroscopy (LIBS) for discrimination and analysis of geological materials was examined. The research was focused on classification of mineral ores using their LIBS spectra prior to quantitative determination of copper. Quantitative analysis is not a trivial task in LIBS measurement because intensities of emission lines in laser-induced plasmas (LIP) are strongly affected by the sample matrix (matrix effect). To circumvent this effect, typically matrix-matched standards are used to obtain matrix-dependent calibration curves. If the sample set consists of a mixture of different matrices, even in this approach, the corresponding matrix has to be known prior to the downstream data analysis. For this categorization, the multielemental character of LIBS spectra can be of help. In this contribution, a principal component analysis (PCA) was employed on the measured data set to discriminate individual rocks as individual matrices against each other according to their overall elemental composition. Twenty-seven igneous rock samples were analyzed in the form of fine dust, classified and subsequently quantitatively analyzed. Two different LIBS setups in two laboratories were used to prove the reproducibility of classification and quantification. A superposition of partial calibration plots constructed from the individual clustered data displayed a large improvement in precision and accuracy compared to the calibration plot constructed from all ore samples. The classification of mineral samples with complex matrices can thus be recommended prior to LIBS system calibration and quantitative analysis. - Highlights: • Twenty seven igneous rocks were measured on different LIBS systems. • Principal component analysis (PCA) was employed for classification. • The necessity of the classification of the rock (ore) samples prior to the quantification analysis is stressed. • Classification based on the whole LIP spectra and

  15. Laser-induced breakdown spectroscopy for in situ qualitative and quantitative analysis of mineral ores

    Energy Technology Data Exchange (ETDEWEB)

    Pořízka, P. [BAM, Federal Institute for Materials Research and Testing, Richard Willstätter-Straße 11, D-12489 Berlin (Germany); Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 61669 Brno (Czech Republic); Demidov, A. [BAM, Federal Institute for Materials Research and Testing, Richard Willstätter-Straße 11, D-12489 Berlin (Germany); Kaiser, J. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technická 2896/2, 61669 Brno (Czech Republic); Keivanian, J. [Institute for Mining, Technical University Clausthal, Erzstraße 18, 38678 Clausthal-Zellerfeld (Germany); Gornushkin, I. [BAM, Federal Institute for Materials Research and Testing, Richard Willstätter-Straße 11, D-12489 Berlin (Germany); Panne, U. [BAM, Federal Institute for Materials Research and Testing, Richard Willstätter-Straße 11, D-12489 Berlin (Germany); Chemistry Department, Humboldt Univerisät zu Berlin, Brook-Taylor-Straße 2, D-12489 Berlin (Germany); Riedel, J., E-mail: jens.riedel@bam.de [BAM, Federal Institute for Materials Research and Testing, Richard Willstätter-Straße 11, D-12489 Berlin (Germany)

    2014-11-01

    In this work, the potential of laser-induced breakdown spectroscopy (LIBS) for discrimination and analysis of geological materials was examined. The research was focused on classification of mineral ores using their LIBS spectra prior to quantitative determination of copper. Quantitative analysis is not a trivial task in LIBS measurement because intensities of emission lines in laser-induced plasmas (LIP) are strongly affected by the sample matrix (matrix effect). To circumvent this effect, typically matrix-matched standards are used to obtain matrix-dependent calibration curves. If the sample set consists of a mixture of different matrices, even in this approach, the corresponding matrix has to be known prior to the downstream data analysis. For this categorization, the multielemental character of LIBS spectra can be of help. In this contribution, a principal component analysis (PCA) was employed on the measured data set to discriminate individual rocks as individual matrices against each other according to their overall elemental composition. Twenty-seven igneous rock samples were analyzed in the form of fine dust, classified and subsequently quantitatively analyzed. Two different LIBS setups in two laboratories were used to prove the reproducibility of classification and quantification. A superposition of partial calibration plots constructed from the individual clustered data displayed a large improvement in precision and accuracy compared to the calibration plot constructed from all ore samples. The classification of mineral samples with complex matrices can thus be recommended prior to LIBS system calibration and quantitative analysis. - Highlights: • Twenty seven igneous rocks were measured on different LIBS systems. • Principal component analysis (PCA) was employed for classification. • The necessity of the classification of the rock (ore) samples prior to the quantification analysis is stressed. • Classification based on the whole LIP spectra and

  16. Characterizing Hohlraum Plasma Conditions at the National Ignition Facility (NIF) Using X-ray Spectroscopy

    Science.gov (United States)

    Barrios, Maria Alejandra

    2015-11-01

    Improved hohlraums will have a significant impact on increasing the likelihood of indirect drive ignition at the NIF. In indirect-drive Inertial Confinement Fusion (ICF), a high-Z hohlraum converts laser power into a tailored x-ray flux that drives the implosion of a spherical capsule filled with D-T fuel. The x-radiation drive to capsule coupling sets the velocity, adiabat, and symmetry of the implosion. Previous experiments in gas-filled hohlraums determined that the laser-hohlraum energy coupling is 20-25% less than modeled, therefore identifying energy loss mechanisms that reduce the efficacy of the hohlraum drive is central to improving implosion performance. Characterizing the plasma conditions, particularly the plasma electron temperature (Te) , is critical to understanding mechanism that affect the energy coupling such as the laser plasma interactions (LPI), hohlraum x-ray conversion efficiency, and dynamic drive symmetry. The first Te measurements inside a NIF hohlraum, presented here, were achieved using K-shell X-ray spectroscopy of an Mn-Co tracer dot. The dot is deposited on a thin-walled CH capsule, centered on the hohlraum symmetry axis below the laser entrance hole (LEH) of a bottom-truncated hohlraum. The hohlraum x-ray drive ablates the dot and causes it to flow upward, towards the LEH, entering the hot laser deposition region. An absolutely calibrated streaked spectrometer with a line of sight into the LEH records the temporal history of the Mn and Co X-ray emission. The measured (interstage) Lyα/ Heα line ratios for Co and Mn and the Mn-Heα/Co-Heα isoelectronic line ratio are used to infer the local plasma Te from the atomic physics code SCRAM. Time resovled x-ray images perpendicular to the hohlraum axis record the dot expansion and trajectory into the LEH region. The temporal evolution of the measured Te and dot trajectory are compared with simulations from radiation-hydrodynamic codes. This work was performed under the auspices of the U

  17. Laser induced spectroscopy breakdown (LIBS) application to heavy metal detection in soils

    International Nuclear Information System (INIS)

    Barbini, R.; Fantoni, R.; Palucci, A.; Ribezzo, S.; Colao, F.; Capitelli, F.

    2000-01-01

    LIBS (Laser induced breakdown spectroscopy) is a new spectroscopic technique suitable to the use in the analysis of samples of environmental interest, such as soils and rocks, and of industrial interest, such as alloys. Results dealing with the application of the technique to heterogeneous soil samples certified by Ispra Joint Research Centre in the contest of heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) with an agronomical interest are presented in this report. In the LIBS technique, a high power laser beam is focused onto the sample in order to generate a small volume of plasma at its surface. Emissions from single atomic species are collected by a lens system coupled to an optical fiber bundle, dispersed on a monochromator and analyzed by an iCCD. the identification and the assignment of emission lines relevant to single atomic species allows to determine the sample elemental composition and, after calibration against reference samples, to perform quantitative analysis for a large number of species. This technique requires no sample pre-treatment, a part from eventually compacting powders by mechanical press. This is a considerable advantage with respect to traditional spectroscopic techniques, such as the ICP (Inductively Coupled Plasma) which needs sample mineralization by acid attack. Measurements performed on soil samples by means of the LIBS technique at ENEA Frascati were compared with the results obtained by ICP, which is considered a traditional technique for this kind of analysis. Results showed a general overestimation of the LIBS values with respect to the ICP ones, probably due to differences in lytologic matrix between the analyzed samples and the standard. The phenomenon is usually referred to the matrix effect, which is held responsible for the deviation from linearity between single element concentration and its row intensity. The effect is due to local plasma density variations and limit the correlation between the plasma elemental composition

  18. Elemental profiling of laser cladded multilayer coatings by laser induced breakdown spectroscopy and energy dispersive X-ray spectroscopy

    Science.gov (United States)

    Lednev, V. N.; Sdvizhenskii, P. A.; Filippov, M. N.; Grishin, M. Ya.; Filichkina, V. A.; Stavertiy, A. Ya.; Tretyakov, R. S.; Bunkin, A. F.; Pershin, S. M.

    2017-09-01

    Multilayer tungsten carbide wear resistant coatings were analyzed by laser induced breakdown spectroscopy (LIBS) and energy dispersive X-ray (EDX) spectroscopy. Coaxial laser cladding technique was utilized to produce tungsten carbide coating deposited on low alloy steel substrate with additional inconel 625 interlayer. EDX and LIBS techniques were used for elemental profiling of major components (Ni, W, C, Fe, etc.) in the coating. A good correlation between EDX and LIBS data was observed while LIBS provided additional information on light element distribution (carbon). A non-uniform distribution of tungsten carbide grains along coating depth was detected by both LIBS and EDX. In contrast, horizontal elemental profiling showed a uniform tungsten carbide particles distribution. Depth elemental profiling by layer-by-layer LIBS analysis was demonstrated to be an effective method for studying tungsten carbide grains distribution in wear resistant coating without any sample preparation.

  19. Temperature dependence on plasma-induced damage and chemical reactions in GaN etching processes using chlorine plasma

    Science.gov (United States)

    Liu, Zecheng; Ishikawa, Kenji; Imamura, Masato; Tsutsumi, Takayoshi; Kondo, Hiroki; Oda, Osamu; Sekine, Makoto; Hori, Masaru

    2018-06-01

    Plasma-induced damage (PID) on GaN was optimally reduced by high-temperature chlorine plasma etching. Energetic ion bombardments primarily induced PID involving stoichiometry, surface roughness, and photoluminescence (PL) degradation. Chemical reactions under ultraviolet (UV) irradiation and chlorine radical exposure at temperatures higher than 400 °C can be controlled by taking into account the synergism of simultaneous photon and radical irradiations to effectively reduce PID.

  20. 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.

  1. 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.

  2. Velocity gradient induced line splitting in x-ray emission accompanying plasma-wall interaction

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Michal; Renner, Oldřich; Liska, R.

    2013-01-01

    Roč. 125, Aug (2013), s. 38-44 ISSN 0022-4073 R&D Projects: GA ČR GAP205/10/0814; GA ČR GAP205/11/0571 Institutional support: RVO:68378271 Keywords : laser-produced plasmas * x-ray spectroscopy * plasma-wall interaction * spectral line profiles * Doppler shift * ion velocity gradients Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.288, year: 2013

  3. Quantitative analysis by laser-induced breakdown spectroscopy based on generalized curves of growth

    Energy Technology Data Exchange (ETDEWEB)

    Aragón, C., E-mail: carlos.aragon@unavarra.es; Aguilera, J.A.

    2015-08-01

    A method for quantitative elemental analysis by laser-induced breakdown spectroscopy (LIBS) is proposed. The method (Cσ-LIBS) is based on Cσ graphs, generalized curves of growth which allow including several lines of various elements at different concentrations. A so-called homogeneous double (HD) model of the laser-induced plasma is used, defined by an integration over a single-region of the radiative transfer equation, combined with a separated treatment for neutral atoms (z = 0) and singly-charged ions (z = 1) in Cσ graphs and characteristic parameters. The procedure includes a criterion, based on a model limit, for eliminating data which, due to a high line intensity or concentration, are not well described by the HD model. An initial procedure provides a set of parameters (βA){sup z}, (ηNl){sup z}, T{sup z} and N{sub e}{sup z} (z = 0, 1) which characterize the plasma and the LIBS system. After characterization, two different analytical procedures, resulting in relative and absolute concentrations, may be applied. To test the method, fused glass samples prepared from certified slags and pure compounds are analyzed. We determine concentrations of Ca, Mn, Mg, V, Ti, Si and Al relative to Fe in three samples prepared from slags, and absolute concentrations of Fe, Ca and Mn in three samples prepared from Fe{sub 2}O{sub 3}, CaCO{sub 3} and Mn{sub 2}O{sub 3}. The accuracy obtained is 3.2% on the average for relative concentrations and 9.2% for absolute concentrations. - Highlights: • Method for quantitative analysis by LIBS, based on Csigma graphs • Conventional calibration is replaced with characterization of the LIBS system. • All elements are determined from measurement of one or two Csigma graphs. • The method is tested with fused glass disks prepared from slags and pure compounds. • Accurate results for relative (3.2%) and absolute concentrations (9.2%)

  4. The optimisation of an intense Z-pinch discharge as a plasma source for absorption spectroscopy investigations

    International Nuclear Information System (INIS)

    Sandolache, Gabriela; Zoita, Vasile; Iova, Iancu; Fleurier, Claude; Hong, Dunpin; Bauchire, Jean Marc

    2002-01-01

    The characterisation of the low voltage circuit breaker arc from the optical and plasma physics points of view represents an element of importance for understanding the operating mechanism and the current interruption process. The development of the broad band optical absorption spectroscopy method seems to be well adapted in order to perform the circuit breaker arc analysis. A pulsed power device based on a Z-pinch type discharge has been developed as a plasma source for absorption spectroscopy investigations. The spatial extension of this radiation source, its brightness, reproducibility are well adapted to characterize the circuit-breaker arc. In addition, a very short emission period compared to the lifetime of the arc discharge provides an excellent time resolution for the absorption spectroscopy method. The first compression phase of the linear pinch produced in argon has been studied from the point of view of its use as a light source. The initial pressure of argon was varied from 0.5 to 2 mbar and the condenser bank energy from 5.1 to 8.7 kJ. The characterization of the emitted radiation, especially the influence of the condenser bank voltage and the argon pressure on the discharge has been studied. Collapse dynamics of the argon compressional pinch and the spectrally resolved continuum emission at the time of maximum compression have been observed. A very satisfactory plasma source optimisation has been achieved that fulfils the conditions required for the absorption spectroscopy method. (authors)

  5. Raman spectroscopy of poly (3-hydroxybutyrate) modified with poly (vinyl acetate) by radiation- induced copolymerization

    International Nuclear Information System (INIS)

    Gonzalez, Maykel; Galego Fernandez, Norma; Ortiz del Toro, Pedro; Rapado, Manuel; Paredes

    2007-01-01

    Poly (3-hydroxybutyrate) (PHB) is an important material used in the field of medicine. However in common conditions, PHB has some deficiencies. It is very brittle and slightly hydrophobic polymer. This somewhat limit its applications. Radiation chemistry can be used to improve its chemical properties. In the present study, the substrate, modified by radiation-induced graft copolymerization with vinyl acetate (VAc), was characterized using FTIR and Raman spectroscopy. FTIR spectroscopy did not reveal any significant bands but Raman spectroscopy revealed the formation of a new band that characterize the material

  6. C-13 NMR spectroscopy of plasma reduces interference of hypertriglyceridemia in the H-1 NMR detection of malignancy

    International Nuclear Information System (INIS)

    Fossell, E.T.; Hall, F.M.; McDonagh, J.

    1991-01-01

    The authors have previously described the application of water-suppressed proton nuclear magnetic resonance (H-1 NMR) spectroscopy of plasma for detection of malignancy. Subsequently, hypertriglyceridemia has been identified as a source of false positive results. Here is described a confirmatory, adjunctive technique -analysis of the carbon-13 (C-13) NMR spectrum of plasma- which also identifies the presence of malignancy but is not sensitive to the plasma triglyceride level. Blinded plasma samples from 480 normal donors and 208 patients scheduled for breast biopsy were analyzed by water-suppressed H-1 and C-13 NMR spectroscopy. Triglyceride levels were also measured. Among the normal donors, there were 38 individuals with hypertriglyceridemia of whom 18 had results consistent with malignancy by H-1 NMR spectroscopy. However, the C-13 technique reduced the apparent H-1 false positive rate from 7.0 to 0.6 percent. Similarly, in the breast biopsy cohort, C-13 reduced the false positive rate from 2.8 to 0.9 percent. Furthermore, the accuracy of the combined H-1/C-13 test in this blinded study was greater than 96 percent in 208 patients studied. (author). 27 refs.; 5 figs.; 4 tabs

  7. Quantitative analysis of essential oils of Thymus daenensis using laser-induced fluorescence and Raman spectroscopy.

    Science.gov (United States)

    Khoshroo, H; Khadem, H; Bahreini, M; Tavassoli, S H; Hadian, J

    2015-11-10

    Laser-induced fluorescence and Raman spectroscopy are used for the investigation of different genotypes of Thymus daenensis native to the Ilam province of Iran. Different genotypes of T. daenensis essential oils, labeled T1 through T7, possess slight differences with regard to the composition of the thymol. The gas chromatography-mass spectrometry (GC-MS) method is performed to determine the concentration of each constituent as a reference method. The Raman spectra of different concentrations of pure thymol dissolved in hexane as standard samples are obtained via a laboratory prototype Raman spectroscopy setup for the calculation of the calibration curve. The regression coefficient and limit of detection are calculated. The possibility of the differentiation of different genotypes of T. daenensis is also examined by laser-induced fluorescence spectroscopy, although we do not know the exact amounts of their components. All the fluorescence spectral information is used jointly by cluster analysis to differentiate between 7 genotypes. Our results demonstrate the acceptable precision of Raman spectroscopy with GC-MS and corroborate the capacity of Raman spectroscopy in applications in the quantitative analysis field. Furthermore, the cluster analysis results show that laser-induced fluorescence spectroscopy is an acceptable technique for the rapid classification of different genotypes of T. daenensis without having any previous information of their exact amount of constituents. So, the ability to rapidly and nondestructively differentiate between genotypes makes it possible to efficiently select high-quality herbs from many samples.

  8. VUV absorption spectroscopy of a Penning surface-plasma H- source

    International Nuclear Information System (INIS)

    Pitcher, E.J.

    1992-01-01

    Because H - is efficiently neutralized at high energies, these beams are ideally suited to applications where energetic neutral beams of particles are required to propagate across magnetic fields. A class of sources that holds great promise for meeting the stringent requirements for these beams is the surface-plasma source (SPS), and in particular, the Penning type of SPS. It has been conjectured that atomic hydrogen plays an important role in both H - formation and transport in these sources. Understanding the interdependence of atomic hydrogen properties and those of H - , and how this relationship might be exploited to improve source performance is the motivation for this research. An overview of SPS's is presented. Previous measurements on the discharge are reviewed. Absorption spectroscopy is discussed. Techniques that may potentially be used to measure the properties of H - in the discharge are discussed. The two absorption spectrometers used in this experiment are described. Measurements of ground-state atomic hydrogen density and temperature in a Penning SPS are presented. These measurements are the first of this kind for this type of discharge. An upper limit on the H - density in the extraction region of the source is measured by the application of a novel diagnostic technique: the hydrogen atom density following H - photodetachment by a Nd:YAG beam is measured and compared to the equilibrium atomic density. A simple model is derived that describes the dependence of the atomic temperature on the externally-controlled parameters of discharge current and H 2 gas flow. The measured atomic density is considered in light of the widely-accepted hypothesis of the mechanism for H - formation. The measured upper limit of the H - density is used to infer the potential of the discharge plasma relative to the source anode

  9. Modeling of plasma plume induced during laser welding

    International Nuclear Information System (INIS)

    Moscicki, T.; Hoffman, J.; Szymanski, Z.

    2005-01-01

    During laser welding, the interaction of intense laser radiation with a work-piece leads to the formation of a long, thin, cylindrical cavity in a metal, called a keyhole. Generation of a keyhole enables the laser beam to penetrate into the work-piece and is essential for deep welding. The keyhole contains ionized metal vapour and is surrounded by molten material called the weld pool. The metal vapour, which flows from the keyhole mixes with the shielding gas flowing from the opposite direction and forms a plasma plume over the keyhole mouth. The plasma plume has considerable influence on the processing conditions. Plasma strongly absorbs laser radiation and significantly changes energy transfer from the laser beam to a material. In this paper the results of theoretical modelling of plasma plume induced during welding with CO 2 laser are presented. The set of equations consists of equation of conservation of mass, energy, momentum and the diffusion equation: ∂ρ/∂t + ∇·(ρ ρ ν =0; ∂(ρE)/∂t + ∇·( ρ ν (ρE + p)) = ∇ (k eff ∇T - Σ j h j ρ J j + (τ eff · ρ ν )) + Σ i κ i I i - R; ∂/∂t(ρ ρ ν ) + ∇· (ρ ρ ν ρ ν ) = - ∇p + ∇(τ) + ρ ρ g + ρ F, where τ is viscous tensor τ = μ[(∇ ρ ν + ∇ ρT ν )-2/3∇· ρ ν I]; ∂/∂t(ρY i ) + ∇·(ρ ρ ν Y i ) = ∇·ρD i,m ∇T i ; where μ ν denotes velocity vector, E - energy, ρ mass density; k - thermal conductivity, T- temperature, κ - absorption coefficient, I i local laser intensity, R - radiation loss function, p - pressure, h j enthalpy, J j - diffusion flux of j component, ν g - gravity, μ F - external force, μ - dynamic viscosity, I - unit tensor, Y i - mass fraction of iron vapor in the gas mixture, D i,m - mass diffusion coefficient. The terms k eff and τ eff contain the turbulent component of the thermal conductivity and the viscosity, respectively. All the material functions are functions of the temperature and mass fraction only. The equations

  10. High-intensity xenon plasma discharge lamp for bulk-sensitive high-resolution photoemission spectroscopy.

    Science.gov (United States)

    Souma, S; Sato, T; Takahashi, T; Baltzer, P

    2007-12-01

    We have developed a highly brilliant xenon (Xe) discharge lamp operated by microwave-induced electron cyclotron resonance (ECR) for ultrahigh-resolution bulk-sensitive photoemission spectroscopy (PES). We observed at least eight strong radiation lines from neutral or singly ionized Xe atoms in the energy region of 8.4-10.7 eV. The photon flux of the strongest Xe I resonance line at 8.437 eV is comparable to that of the He Ialpha line (21.218 eV) from the He-ECR discharge lamp. Stable operation for more than 300 h is achieved by efficient air-cooling of a ceramic tube in the resonance cavity. The high bulk sensitivity and high-energy resolution of PES using the Xe lines are demonstrated for some typical materials.

  11. spectroscopy

    African Journals Online (AJOL)

    Aghomotsegin

    2015-10-14

    Oct 14, 2015 ... characterized by using phenotypic, API and Fourier transform infrared (FTIR) spectroscopy methods. One hundred and fifty-seven (157) strains were isolated from 13 cheese samples, and identification test was performed for 83 strains. At the end of the study, a total of 22 Lactococcus sp., 36 Enterecoccus ...

  12. Easy measurement of diffusion coefficients of EGFP-tagged plasma membrane proteins using k-space Image Correlation Spectroscopy

    DEFF Research Database (Denmark)

    Christensen, Eva Arnspang; Koffman, Jennifer Skaarup; Marlar, Saw

    2014-01-01

    Lateral diffusion and compartmentalization of plasma membrane proteins are tightly regulated in cells and thus, studying these processes will reveal new insights to plasma membrane protein function and regulation. Recently, k-Space Image Correlation Spectroscopy (kICS)1 was developed to enable...... routine measurements of diffusion coefficients directly from images of fluorescently tagged plasma membrane proteins, that avoided systematic biases introduced by probe photophysics. Although the theoretical basis for the analysis is complex, the method can be implemented by nonexperts using a freely...... to the correlation function yields the diffusion coefficient. This paper provides a step-by-step guide to the image analysis and measurement of diffusion coefficients via kICS. First, a high frame rate image sequence of a fluorescently labeled plasma membrane protein is acquired using a fluorescence microscope Then...

  13. 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

  14. Transition probabilities for lines of Cr II, Na II and Sb I by laser produced plasma atomic emission spectroscopy; Probabilidades de transicion de algunos niveles de Cr II, Na II y Sb I medediante espectroscopia de plasma producidos por laser

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, A. M.; Ortiz, M.; Campos, J.

    1995-07-01

    Absolute transition probabilities for lines of CR II, Na II and Sb I were determined by emission spectroscopy of laser induced plasmas. the plasma was produced focusing the emission of a pulsed Nd-Yag laser on solid samples containing the atom in study. the light arising from the plasma region was collected by and spectrometer. the detector used was a time-resolved optical multichannel analyzer (OMA III EG and G). The wavelengths of the measured transitions range from 2000 sto 4100 A. The spectral resolution of the system was 0. 2 A. The method can be used in insulators materials as Cl Na crystals and in metallic samples as Al-Cr and Sn-Sn alloys. to avoid self-absorption effects the alloys were made with low Sb or Cr content. Relative transition probabilities have been determined from measurements of emission-line intensities and were placed on an absolute scale by using, where possible, accurate experimental lifetime values form the literature or theoretical data. From these measurements, values for plasma temperature (8000-24000 K), electron densities ({approx}{approx} 10''16 cm ''-3) and self-absorption coefficients have been obtained. (Author) 56 refs.

  15. High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

    Science.gov (United States)

    Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

    2013-04-01

    High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

  16. Spectroscopic Investigations of Highly Charged Tungsten Ions - Atomic Spectroscopy and Fusion Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Clementson, Joel [Lund Univ. (Sweden)

    2010-05-01

    The spectra of highly charged tungsten ions have been investigated using x-ray and extreme ultraviolet spectroscopy. These heavy ions are of interest in relativistic atomic structure theory, where high-precision wavelength measurements benchmark theoretical approaches, and in magnetic fusion research, where the ions may serve to diagnose high-temperature plasmas. The work details spectroscopic investigations of highly charged tungsten ions measured at the Livermore electron beam ion trap (EBIT) facility. Here, the EBIT-I and SuperEBIT electron beam ion traps have been employed to create, trap, and excite tungsten ions of M- and L-shell charge states. The emitted spectra have been studied in high resolution using crystal, grating, and x-ray calorimeter spectrometers. In particular, wavelengths of n = 0 M-shell transitions in K-like W55+ through Ne-like W64+, and intershell transitions in Zn-like W44+ through Co-like W47+ have been measured. Special attention is given to the Ni-like W46+ ion, which has two strong electric-dipole forbidden transitions that are of interest for plasma diagnostics. The EBIT measurements are complemented by spectral modeling using the Flexible Atomic Code (FAC), and predictions for tokamak spectra are presented. The L-shell tungsten ions have been studied at electron-beam energies of up to 122 keV and transition energies measured in Ne-like W64+ through Li-like W71+. These spectra constitute the physics basis in the design of the ion-temperature crystal spectrometer for the ITER tokamak. Tungsten particles have furthermore been introduced into the Sustained Spheromak Physics Experiment (SSPX) spheromak in Livermore in order to investigate diagnostic possibilities of extreme ultraviolet tungsten spectra for the ITER divertor. The spheromak measurement and spectral modeling using FAC suggest that tungsten ions in charge states around Er-like W6+ could be useful for

  17. Laser Induced Fluorescence of Helium Ions in a Helicon Plasma

    Science.gov (United States)

    Compton, C. S.; Biloui, C.; Hardin, R. A.; Keesee, A. M.; Scime, E. E.; Boivin, R.

    2003-10-01

    The lack of a suitable Laser Induced Fluorescence (LIF) scheme for helium ions at visible wavelengths has prevented LIF from being employed in helium plasmas for measurements of ion temperature and bulk ion flow speeds. In this work, we will discuss our attempts to perform LIF of helium ions in a helicon source plasma using an infrared, tunable diode laser operating at 1012.36 nm. The infrared transition corresponds to excitation from the n = 4 level (4f ^2F) to the n = 5 (5g ^2G) level of singly ionized helium and therefore requires substantial electron temperatures (> 10 eV) to maintain an adequate ion population in the n = 4 state. Calculations using a steady state coronal model predict that the n = 4 state population will be 25% larger than the n = 5 population for our experimental conditions. The fluorescence decay from the n = 5 (5f ^2F) level of singly ionized helium level to the n = 3 (3d ^2D) level at 320.31 nm is monitored as the diode laser is swept through 10 GHz around the 1012.36 nm line. Note that the fluorescence emission requires a collisionally coupled transition between two different n = 5 quantum states. We will also present measurements of the emission intensities of both the 1012.36 nm and the 320.31 nm lines as a function of source neutral pressure, rf power, and plasma density. This work supported by the U.S. DoE EPSCoR Lab Partnership Program.

  18. Quantitative analysis of toxic metals lead and cadmium in water jet by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Cheri, M. Sadegh; Tavassoli, S. H.

    2011-03-20

    Laser-induced breakdown spectroscopy (LIBS) has been applied to the analysis of toxic metals Pb and Cd in Pb(NO{sub 3}){sub 2} and Cd(NO{sub 3}){sub 2}.4H{sub 2}O aqueous solutions, respectively. The plasma is generated by focusing a nanosecond Nd:YAG ({lambda}=1064 nm) laser on the surface of liquid in the homemade liquid jet configuration. With an assumption of local thermodynamic equilibrium (LTE), calibration curves of Pb and Cd were obtained at different delay times between 1 to 5 {mu}s. The temporal behavior of limit of detections (LOD) was investigated and it is shown that the minimum LODs for Pb and Cd are 4 and 68 parts in 10{sup 6} (ppm), respectively. In order to demonstrate the correctness of the LTE assumption, plasma parameters including plasma temperature and electron density are evaluated, and it is shown that the LTE condition is satisfied at all delay times.

  19. KARAKTERISASI SPEKTRUM UNSUR Cu UNTUK MENGHITUNG INTENSITAS EMISI ATOM FUNGSI WAKTU TUNDA DENGAN MENGGUNAKAN METODE LASER INDUCED BREAKDOWN SPECTROSCOPY (LIBS

    Directory of Open Access Journals (Sweden)

    Wulansari Efrilinda Diah

    2013-08-01

    Full Text Available Laser-Induced Breakdown Spectroscopy (LIBS is a spectroscopic method is highly reliable for atomic spectrochemical analysis both qualitatively and quantitatively. To achieve this, be aware of the detection parameters, one of which is a function of the atom emission intensity of detection delay time. In this study, plasma is generated by focusing the Nd-YAG laser (1064 nm, 7 ns on the surface of solid Cu sample with 99.99% purity level at 1 atm pressure air environment. Plasma emission spectrometer was arrested by elements of Cu + HR 2500 with specifications: (wavelength range 200-870 nm, resolution 0.1 nm (FWHM, 7 detector CCDs with a combined 14.336 pixels with variation detection delay time 0, 0.5, 1, 1.5, and 2 microseconds after the plasma formation and the energy varies the 60-160mJ. The data showed that the value of the Cu atom emission intensity 521.8 nm of the most highly visible on detection delay time decreased to 0.5 microseconds and detection delay time 2 microseconds. Based on these data it can be concluded that the characterization of the elements Cu to calculate the intensity was in the range of 100-140 mJ laser energy and time delay detection of 0.5 microseconds.

  20. Accuracy Enhancement of Raman Spectroscopy Using Complementary Laser-Induced Breakdown Spectroscopy (LIBS) with Geologically Mixed Samples.

    Science.gov (United States)

    Choi, Soojin; Kim, Dongyoung; Yang, Junho; Yoh, Jack J

    2017-04-01

    Quantitative Raman analysis was carried out with geologically mixed samples that have various matrices. In order to compensate the matrix effect in Raman shift, laser-induced breakdown spectroscopy (LIBS) analysis was performed. Raman spectroscopy revealed the geological materials contained in the mixed samples. However, the analysis of a mixture containing different matrices was inaccurate due to the weak signal of the Raman shift, interference, and the strong matrix effect. On the other hand, the LIBS quantitative analysis of atomic carbon and calcium in mixed samples showed high accuracy. In the case of the calcite and gypsum mixture, the coefficient of determination of atomic carbon using LIBS was 0.99, while the signal using Raman was less than 0.9. Therefore, the geological composition of the mixed samples is first obtained using Raman and the LIBS-based quantitative analysis is then applied to the Raman outcome in order to construct highly accurate univariate calibration curves. The study also focuses on a method to overcome matrix effects through the two complementary spectroscopic techniques of Raman spectroscopy and LIBS.

  1. X-ray imaging crystal spectroscopy for use in plasma transport research

    Science.gov (United States)

    Reinke, M. L.; Podpaly, Y. A.; Bitter, M.; Hutchinson, I. H.; Rice, J. E.; Delgado-Aparicio, L.; Gao, C.; Greenwald, M.; Hill, K.; Howard, N. T.; Hubbard, A.; Hughes, J. W.; Pablant, N.; White, A. E.; Wolfe, S. M.

    2012-11-01

    This research describes advancements in the spectral analysis and error propagation techniques associated with x-ray imaging crystal spectroscopy (XICS) that have enabled this diagnostic to be used to accurately constrain particle, momentum, and heat transport studies in a tokamak for the first time. Doppler tomography techniques have been extended to include propagation of statistical uncertainty due to photon noise, the effect of non-uniform instrumental broadening as well as flux surface variations in impurity density. These methods have been deployed as a suite of modeling and analysis tools, written in interactive data language (IDL) and designed for general use on tokamaks. Its application to the Alcator C-Mod XICS is discussed, along with novel spectral and spatial calibration techniques. Example ion temperature and radial electric field profiles from recent I-mode plasmas are shown, and the impact of poloidally asymmetric impurity density and natural line broadening is discussed in the context of the planned ITER x-ray crystal spectrometer.

  2. Improved Fast, Deep Record Length, Time-Resolved Visible Spectroscopy of Plasmas Using Fiber Grids

    Science.gov (United States)

    Brockington, S.; Case, A.; Cruz, E.; Williams, A.; Witherspoon, F. D.; Horton, R.; Klauser, R.; Hwang, D.

    2017-10-01

    HyperV Technologies is developing a fiber-coupled, deep record-length, low-light camera head for performing high time resolution spectroscopy on visible emission from plasma events. By coupling the output of a spectrometer to an imaging fiber bundle connected to a bank of amplified silicon photomultipliers, time-resolved spectroscopic imagers of 100 to 1,000 pixels can be constructed. A second generation prototype 32-pixel spectroscopic imager employing this technique was constructed and successfully tested at the University of California at Davis Compact Toroid Injection Experiment (CTIX). Pixel performance of 10 Megaframes/sec with record lengths of up to 256,000 frames ( 25.6 milliseconds) were achieved. Pixel resolution was 12 bits. Pixel pitch can be refined by using grids of 100 μm to 1000 μm diameter fibers. Experimental results will be discussed, along with future plans for this diagnostic. Work supported by USDOE SBIR Grant DE-SC0013801.

  3. Determination of Dynamics of Plant Plasma Membrane Proteins with Fluorescence Recovery and Raster Image Correlation Spectroscopy.

    Science.gov (United States)

    Laňková, Martina; Humpolíčková, Jana; Vosolsobě, Stanislav; Cit, Zdeněk; Lacek, Jozef; Čovan, Martin; Čovanová, Milada; Hof, Martin; Petrášek, Jan

    2016-04-01

    A number of fluorescence microscopy techniques are described to study dynamics of fluorescently labeled proteins, lipids, nucleic acids, and whole organelles. However, for studies of plant plasma membrane (PM) proteins, the number of these techniques is still limited because of the high complexity of processes that determine the dynamics of PM proteins and the existence of cell wall. Here, we report on the usage of raster image correlation spectroscopy (RICS) for studies of integral PM proteins in suspension-cultured tobacco cells and show its potential in comparison with the more widely used fluorescence recovery after photobleaching method. For RICS, a set of microscopy images is obtained by single-photon confocal laser scanning microscopy (CLSM). Fluorescence fluctuations are subsequently correlated between individual pixels and the information on protein mobility are extracted using a model that considers processes generating the fluctuations such as diffusion and chemical binding reactions. As we show here using an example of two integral PM transporters of the plant hormone auxin, RICS uncovered their distinct short-distance lateral mobility within the PM that is dependent on cytoskeleton and sterol composition of the PM. RICS, which is routinely accessible on modern CLSM instruments, thus represents a valuable approach for studies of dynamics of PM proteins in plants.

  4. Atomization efficiency and photon yield in laser-induced breakdown spectroscopy analysis of single nanoparticles in an optical trap

    Science.gov (United States)

    Purohit, Pablo; Fortes, Francisco J.; Laserna, J. Javier

    2017-04-01

    Laser-induced breakdown spectroscopy (LIBS) was employed for investigating the influence of particle size on the dissociation efficiency and the absolute production of photons per mass unit of airborne solid graphite spheres under single-particle regime. Particles of average diameter of 400 nm were probed and compared with 2 μm particles. Samples were first catapulted into aerosol form and then secluded in an optical trap set by a 532 nm laser. Trap stability was quantified before subjecting particles to LIBS analysis. Fine alignment of the different lines comprising the optical catapulting-optical trapping-laser-induced breakdown spectroscopy instrument and tuning of excitation parameters conditioning the LIBS signal such as fluence and acquisition delay are described in detail with the ultimate goal of acquiring clear spectroscopic data on masses as low as 75 fg. The atomization efficiency and the photon yield increase as the particle size becomes smaller. Time-resolved plasma imaging studies were conducted to elucidate the mechanisms leading to particle disintegration and excitation.

  5. Temperature-induced transitions in disordered proteins probed by NMR spectroscopy

    DEFF Research Database (Denmark)

    Kjærgaard, Magnus; Poulsen, Flemming Martin; Kragelund, Birthe Brandt

    2012-01-01

    Intrinsically disordered proteins are abundant in nature and perform many important physiological functions. Multidimensional NMR spectroscopy has been crucial for the understanding of the conformational properties of disordered proteins and is increasingly used to probe their conformational...... ensembles. Compared to folded proteins, disordered proteins are more malleable and more easily perturbed by environmental factors. Accordingly, the experimental conditions and especially the temperature modify the structural and functional properties of disordered proteins. NMR spectroscopy allows analysis...... of temperature-induced structural changes at residue resolution using secondary chemical shift analysis, paramagnetic relaxation enhancement, and residual dipolar couplings. This chapter discusses practical aspects of NMR studies of temperature-induced structural changes in disordered proteins....

  6. Nuclear Fusion Effects Induced in Intense Laser-Generated Plasmas

    Directory of Open Access Journals (Sweden)

    Lorenzo Torrisi

    2013-01-01

    Full Text Available Deutered polyethylene (CD2n thin and thick targets were irradiated in high vacuum by infrared laser pulses at 1015W/cm2 intensity. The high laser energy transferred to the polymer generates plasma, expanding in vacuum at supersonic velocity, accelerating hydrogen and carbon ions. Deuterium ions at kinetic energies above 4 MeV have been measured by using ion collectors and SiC detectors in time-of-flight configuration. At these energies the deuterium–deuterium collisions may induce over threshold fusion effects, in agreement with the high D-D cross-section valuesaround 3 MeV energy. At the first instants of the plasma generation, during which high temperature, density and ionacceleration occur, the D-D fusions occur as confirmed by the detection of mono-energetic protonsand neutrons with a kinetic energy of 3.0 MeV and 2.5 MeV, respectively, produced by the nuclear reaction. The number of fusion events depends strongly on the experimental set-up, i.e. on the laser parameters (intensity, wavelength, focal spot dimension, target conditions (thickness, chemical composition, absorption coefficient, presence of secondary targets and used geometry (incidence angle, laser spot, secondary target positions.A number of D-D fusion events of the order of 106÷7 per laser shot has been measured.

  7. Induced Compton scattering of a laser in an inhomogeneous plasma

    International Nuclear Information System (INIS)

    Liu, C.S.; Tripathi, V. K.

    2003-01-01

    A laser propagating through a high temperature low density plasma undergoes induced Compton backscattering involving the coupling of the laser pump and the scattered electromagnetic wave via the resonant electrons or the resistive quasimode. The region of nonlinear interaction is localized due to plasma inhomogeneity. At short density scale lengths when the interaction region is strongly localized and resonant electrons quickly move out of it, the electron distribution function remains Maxwellian and Compton reflectivity is significant at laser intensity >10 16 W/cm 2 . In gentle density gradients the resonant electrons are trapped in the ponderomotive and self-consistent potential well of the quasimode as they enter the interaction region. The ones with velocity v z p (v p being the phase velocity of the ponderomotive wave propagating along z direction) are accelerated to v p while those with v z >v p are retarded to v p . Since the number of the former is more than that of the latter there is a net momentum transfer to electrons. Momentum and action conservation lead to a reflectivity, R, that initially goes as the square of pump intensity, then rises gradually at higher intensity. R decreases rapidly with v th /v p , where v th is the thermal velocity of electrons

  8. Can black hole superradiance be induced by galactic plasmas?

    Science.gov (United States)

    Conlon, Joseph P.; Herdeiro, Carlos A. R.

    2018-05-01

    Highly spinning Kerr black holes with masses M = 1- 100M⊙ are subject to an efficient superradiant instability in the presence of bosons with masses μ ∼10-10-10-12eV. We observe that this matches the effective plasma-induced photon mass in diffuse galactic or intracluster environments (ωpl ∼10-10-10-12eV). This suggests that bare Kerr black holes within galactic or intracluster environments, possibly even including the ones produced in recently observed gravitational wave events, are unstable to formation of a photon cloud that may contain a significant fraction of the mass of the original black hole. At maximal efficiency, the instability timescale for a massive vector is milliseconds, potentially leading to a transient rate of energy extraction from a black hole in principle as large as ∼1055ergs-1. We discuss possible astrophysical effects this could give rise to, including a speculative connection to Fast Radio Bursts.

  9. Influence of Er:YAG and Nd:YAG wavelengths on laser-induced breakdown spectroscopy measurements under air or helium atmosphere

    International Nuclear Information System (INIS)

    Detalle, Vincent; Sabsabi, Mohamad; St-Onge, Louis; Hamel, Andre; Heon, Rene

    2003-01-01

    Laser-induced breakdown spectroscopy (LIBS) is widely dependent on the conditions of its implementation in terms of laser characteristics (wavelength, energy, and pulse duration), focusing conditions, and surrounding gas. In this study two wavelengths, 1.06 and 2.94 μm, obtained with Nd:YAG and Er:YAG lasers, respectively, were used for LIBS analysis of aluminum alloy samples in two conditions of surrounding gas. The influence of the laser wavelength on the laser-produced plasma was studied for the same irradiance by use of air or helium as a buffer gas at atmospheric pressure. We used measurements of light emission to determine the temporally resolved space-averaged electron density and plasma temperature in the laser-induced plasma. We also examined the effect of laser wavelength in two different ambient conditions in terms of spectrochemical analysis by LIBS. The results indicate that the effect of the surrounding gas depends on the laser wavelength and the use of an Er:YAG laser could increase linearity by limiting the leveling in the calibration curve for some elements in aluminum alloys. There is also a significant difference between the plasma induced by the two lasers in terms of electron density and plasma temperature

  10. Effect of ablation photon energy on the distribution of molecular species in laser-induced plasma from polymer in air

    Energy Technology Data Exchange (ETDEWEB)

    Lei, W.Q. [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai (China); Universite de Lyon, F-69622, Lyon, France, Universite Lyon 1, Villeurbanne, CNRS, UMR5579, LASIM (France); Ma, Q.L.; Motto-Ros, V.; Bai, X.S. [Universite de Lyon, F-69622, Lyon, France, Universite Lyon 1, Villeurbanne, CNRS, UMR5579, LASIM (France); Zheng, L.J. [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai (China); Zeng, H.P., E-mail: hpzeng@phy.ecnu.edu.cn [State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai (China); Yu, J., E-mail: Jin.Yu@lasim.univ-lyon1.fr [Universite de Lyon, F-69622, Lyon, France, Universite Lyon 1, Villeurbanne, CNRS, UMR5579, LASIM (France)

    2012-07-15

    Distribution of molecular species, C{sub 2} and CN, in laser-induced plasma from a polymer target (polyvinyl chloride: PVC) was observed for ablation with 266 nm and 355 nm pulses. The influence of ablation photon energy on the distribution of molecular species in the plasma has been thus studied. Time- and space-resolved emission spectroscopy was used for the observation which led to the determination of emission intensity profiles of C{sub 2} molecule and CN radical for different delays after the impact of the laser pulse on the target. The profiles of related elements, C, N, and excitation temperature in the plasma were further determined to correlate with those of molecular emission intensity. Different behaviors were clearly observed between plasmas induced by pulses with the two different wavelengths chosen to be close each other in the near ultraviolet (UV). A closer analysis shows the photon energy corresponding to 266 nm pulse of 4.66 eV is larger than bond energies of all the chemical bonds in the studied polymer, while that of 355 nm radiation of 3.49 eV is smaller than or in the same range of the involved bond energies. Observed different behaviors suggest therefore different ablation mechanisms of polymer by laser radiation, and consequently different channels of molecule formation in the plasma. Observation of the morphology of the craters on the target surface left by laser ablation confirmed further different ablation mechanisms with the two used wavelengths. - Highlights: Black-Right-Pointing-Pointer The profiles of C{sub 2} and CN in a plasma induced from a PVC target were determined. Black-Right-Pointing-Pointer Different behaviors were observed for ablation with 266 nm and 355 nm pulses. Black-Right-Pointing-Pointer Different molecule formation channels were used to interpret such behaviors. Black-Right-Pointing-Pointer The morphology of the craters confirmed further the different ablation mechanisms.

  11. Characterization of an Atmospheric-Pressure Argon Plasma Generated by 915 MHz Microwaves Using Optical Emission Spectroscopy

    Directory of Open Access Journals (Sweden)

    Robert Miotk

    2017-01-01

    Full Text Available The paper presents the investigations of an atmospheric-pressure argon plasma generated at 915 MHz microwaves using the optical emission spectroscopy (OES. The 915 MHz microwave plasma was inducted and sustained in a waveguide-supplied coaxial-line-based nozzleless microwave plasma source. The aim of presented investigations was to estimate parameters of the generated plasma, that is, excitation temperature of electrons Texc, temperature of plasma gas Tg, and concentration of electrons ne. Assuming that excited levels of argon atoms are in local thermodynamic equilibrium, Boltzmann method allowed in determining the Texc temperature in the range of 8100–11000 K. The temperature of plasma gas Tg was estimated by comparing the simulated spectra of the OH radical to the measured one in LIFBASE program. The obtained Tg temperature ranged in 1200–2800 K. Using a method based on Stark broadening of the Hβ line, the concentration of electrons ne was determined in the range from 1.4 × 1015 to 1.7 × 1015 cm−3, depending on the power absorbed by the microwave plasma.

  12. Space-resolved analysis of trace elements in fresh vegetables using ultraviolet nanosecond laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Juve, Vincent; Portelli, Richard; Boueri, Myriam; Baudelet, Matthieu; Yu Jin

    2008-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been applied to analyze trace elements contained in fresh vegetables. A quadrupled Nd:YAG laser is used in the experiments for ablation. Analyzed samples come from local markets and represent frequently consumed vegetables. For a typical root vegetable, such as potato, spectral analysis of the plasma emission reveals more than 400 lines emitted by 27 elements and 2 molecules, C 2 and CN. Among these species, one can find trace as well as ultra-trace elements. A space-resolved analysis of several trace elements with strong emissions is then applied to typical root, stem and fruit vegetables. The results from this study demonstrate the potential of an interesting tool for botanical and agricultural studies as well for food quality/safety and environment pollution assessment and control

  13. Study on the effect of beam propagation through atmospheric turbulence on standoff nanosecond laser induced breakdown spectroscopy measurements.

    Science.gov (United States)

    Laserna, J J; Reyes, R Fernández; González, R; Tobaria, L; Lucena, P

    2009-06-08

    We report on an experimental study of the effect of atmospheric turbulence on laser induced breakdown spectroscopy (LIBS) measurements. The characteristics of the atmosphere dictate specific performance constraints to this technology. Unlike classical laboratory LIBS systems where the distance to the sample is well known and characterized, LIBS systems working at several tens of meters to the target have specific atmospheric propagation conditions that cause the quality of the LIBS signals to be affected to a significant extent. Using a new LIBS based sensor system fitted with a nanosecond laser emitting at 1064 nm, propagation effects at distances of up to 120 m were investigated. The effects observed include wander and scintillation in the outgoing laser beam and in the return atomic emission signal. Plasmas were formed on aluminium targets. Average signal levels and signal fluctuations are measured so the effect of atmospheric turbulence on LIBS measurements is quantified.

  14. Laser-induced breakdown spectroscopy used to detect endophyte-mediated accumulation of metals by tall fescue

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madhavi Z.; Stewart, Arthur J.; Gwinn, Kimberley D.; Waller, John C.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to determine the impact of endophyte (Neotyphodium sp.) infection on elemental composition of tall fescue (Festuca arundinacea). Leaf material from endophyte-infected (E+) and endophyte-free (E-) tall fescue populations in established plots was examined. Leaf-tissue digestates were also tested for metals, by inductively coupled plasma (ICP) mass spectrometry (MS). Seven of eleven metals (Ca, Mg, Fe, Mn, Cu, Ni, and Zn) were measured by both techniques at concentrations great enough for a reliable comparison. Mg, Zn, and Cd, a toxic metal that can be present in forage, were readily detected by LIBS, even though Cd concentrations in the plants were below levels typically achieved using ICP MS detection. Implications of these results for research on forage analysis and phytoremediation are discussed.

  15. Matrix effect on emission/current correlated analysis in laser-induced breakdown spectroscopy of liquid droplets

    International Nuclear Information System (INIS)

    Huang, J.-S.; Ke, C.-B.; Lin, K.-C.

    2004-01-01

    We have investigated influence of matrix salts on the liquid droplets by laser-induced breakdown spectroscopy (LIBS). An electrospray ionization technique coupled with LIBS is employed to generate the microdroplets of the Na sample solution with various matrix salts added. A sequence of single-shot time-resolved LIB emission signals is detected. The LIB signal intensity integrated within a gate linearly correlates with the plasma-induced current response obtained simultaneously on a single-shot basis. The slopes thus obtained increase with the sample concentration, but appear to be irrespective of different matrix salts, added up to a 2000 mg/l concentration. The matrix salts involved have the same K + cation but different anions. Given a laser radiation emitting at 355 nm with the energy fixed at 23±1 mJ, a limit of detection (LOD) of 1.0 mg/l may be achieved for the Na analysis. The current normalization might have probably taken into account the ablated amount of the sample and the plasma temperature. Accordingly, the LIB/current correlated analysis becomes efficient to suppress the signal fluctuation, improve the LOD determination, and concurrently correct the matrix effect

  16. Calibration-free laser-induced breakdown spectroscopy for ...

    Indian Academy of Sciences (India)

    journal of. August 2012 physics pp. 299–310. Calibration-free laser-induced ... for quantitative analysis of materials, illustrated by CF-LIBS applied to a ..... The authors are thankful to BRNS, DAE, Govt. of India for the financial support provided.

  17. Trace element quantification of lead based roof sheets of historical monuments by Laser Induced Breakdown Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Syvilay, D., E-mail: delphine.syvilay@culture.gouv.fr [LRMH USR 3224, 29 rue de Paris, 77420 Champs-sur-Marne (France); Texier, A. [LRMH USR 3224, 29 rue de Paris, 77420 Champs-sur-Marne (France); Arles, A.; Gratuze, B. [IRAMAT, 3D, rue de la Férollerie, 45071 Orléans Cedex 2 (France); Wilkie-Chancellier, N.; Martinez, L.; Serfaty, S. [SATIE, UMR CNRS 8029, Université de Cergy-Pontoise, ENS Cachan, 95000 Cergy-Pontoise Cedex (France); Detalle, V. [LRMH USR 3224, 29 rue de Paris, 77420 Champs-sur-Marne (France)

    2015-01-01

    The aim of this paper is to identify the different periods of construction or restoration of the lead roof of a historic monument. Trace elements in a lead matrix can be a signature of the metallurgical processes, allowing identification of a specific time period for the production of the lead used to build the roof. The ability of LIBS (Laser Induced Breakdown Spectroscopy) to detect such trace elements in a lead matrix is therefore explored and checked by comparing its results with LA-ICP-MS as a reference method (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry). Concentrations of 263 samples were compared between LIBS and LA-ICP-MS data and their correlation was evaluated. Another way to compare their results is also suggested by combining PCA (Principal Component Analysis) and GIS (Geographic Information System). As a result statistical mappings were created, highlighting metallurgical groups of samples across the roof of the building. This innovative approach links concentration and spatial location resulting in an easily interpretable graphical presentation of the data. The results of both spectrometry methods lead to similar conclusions with distinctive areas of different lead compositions and by extension different lead dating across the roof. But since LIBS is portable we can conclude that it is a suitable and reliable instrument for in-situ applications on historic monuments. - Highlights: • Quantification of trace elements (Ag, Bi, Cu and Sn) in a lead matrix by LIBS and LA-ICP-MS • Low limit of detection for Ag, Bi, Cu and Sn by using LIBS portable instrumentation • Set up a specific data processing combining PCA and GIS for cultural heritage application • Comparison of LIBS and LA-ICP-MS results with 263 samples • 488 samples analyzed by LIBS.

  18. Wavelength dependence of laser induced breakdown spectroscopy (LIBS) on questioned document investigation.

    Science.gov (United States)

    Elsherbiny, Nany; Aied Nassef, O

    2015-07-01

    The fast and nearly non-destructive criteria of laser induced breakdown spectroscopy (LIBS) technique has been exploited for forensic purposes, specifically, document investigation. The dependence of the optical emission spectra of different black gel ink samples on the excitation laser wavelength, namely the visible wavelength at λ=532 nm and the IR wavelength at λ=1064 nm, was studied. The inks of thirty black gel-ink pens comprising ten brands were analyzed to determine the variation of the chemical composition of ink and to discriminate among them with minimum mass removal and minimum damage to the document's paper. Under the adopted experimental conditions, the ability of the visible LIBS to differentiate among the different ink samples was successful compared to IR LIBS at the same laser pulse energy (~25 mJ/pulse, laser fluence is ~1400J·cm(-2) for visible laser and ~1100J·cm(-2) for IR laser) which could be attributed to the IR absorption effects by the black ink. However, the visible LIBS produces deeper crater with respect to that produced by IR LIBS. Applying IR LIBS with higher pulse energy of ~87mJ (laser fluence is ~4100J·cm(-2)), identification and differentiation of the adopted samples was performed with producing a larger-diameter but superficial crater. The plasma parameters are discussed at the adopted experimental conditions. The results support the potential of LIBS technique using both the visible and IR lasers to be commercially developed for forensic document examination. Copyright © 2015 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium

    International Nuclear Information System (INIS)

    Senesi, G.S.; Dell'Aglio, M.; Gaudiuso, R.; De Giacomo, A.; Zaccone, C.; De Pascale, O.; Miano, T.M.; Capitelli, M.

    2009-01-01

    Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation

  20. Heavy metal concentrations in soils as determined by laser-induced breakdown spectroscopy (LIBS), with special emphasis on chromium.

    Science.gov (United States)

    Senesi, G S; Dell'Aglio, M; Gaudiuso, R; De Giacomo, A; Zaccone, C; De Pascale, O; Miano, T M; Capitelli, M

    2009-05-01

    Soil is unanimously considered as one of the most important sink of heavy metals released by human activities. Heavy metal analysis of natural and polluted soils is generally conducted by the use of atomic absorption spectroscopy (AAS) or inductively coupled plasma optical emission spectroscopy (ICP-OES) on adequately obtained soil extracts. Although in recent years the emergent technique of laser-induced breakdown spectroscopy (LIBS) has been applied widely and with increasing success for the qualitative and quantitative analyses of a number of heavy metals in soil matrices with relevant simplification of the conventional methodologies, the technique still requires further confirmation before it can be applied fully successfully in soil analyses. The main objective of this work was to demonstrate that new developments in LIBS technique are able to provide reliable qualitative and quantitative analytical evaluation of several heavy metals in soils, with special focus on the element chromium (Cr), and with reference to the concentrations measured by conventional ICP spectroscopy. The preliminary qualitative LIBS analysis of five soil samples and one sewage sludge sample has allowed the detection of a number of elements including Al, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Si, Ti, V and Zn. Of these, a quantitative analysis was also possible for the elements Cr, Cu, Pb, V and Zn based on the obtained linearity of the calibration curves constructed for each heavy metal, i.e., the proportionality between the intensity of the LIBS emission peaks and the concentration of each heavy metal in the sample measured by ICP. In particular, a triplet of emission lines for Cr could be used for its quantitative measurement. The consistency of experiments made on various samples was supported by the same characteristics of the laser-induced plasma (LIP), i.e., the typical linear distribution confirming the existence of local thermodynamic equilibrium (LTE) condition, and similar excitation

  1. Ultraviolet versus infrared: Effects of ablation laser wavelength on the expansion of laser-induced plasma into one-atmosphere argon gas

    International Nuclear Information System (INIS)

    Ma Qianli; Motto-Ros, Vincent; Laye, Fabrice; Yu Jin; Lei Wenqi; Bai Xueshi; Zheng Lijuan; Zeng Heping

    2012-01-01

    Laser-induced plasma from an aluminum target in one-atmosphere argon background has been investigated with ablation using nanosecond ultraviolet (UV: 355 nm) or infrared (IR: 1064 nm) laser pulses. Time- and space-resolved emission spectroscopy was used as a diagnostics tool to have access to the plasma parameters during its propagation into the background, such as optical emission intensity, electron density, and temperature. The specific feature of nanosecond laser ablation is that the pulse duration is significantly longer than the initiation time of the plasma. Laser-supported absorption wave due to post-ablation absorption of the laser radiation by the vapor plume and the shocked background gas plays a dominant role in the propagation and subsequently the behavior of the plasma. We demonstrate that the difference in absorption rate between UV and IR radiations leads to different propagation behaviors of the plasma produced with these radiations. The consequence is that higher electron density and temperature are observed for UV ablation. While for IR ablation, the plasma is found with lower electron density and temperature in a larger and more homogenous axial profile. The difference is also that for UV ablation, the background gas is principally evacuated by the expansion of the vapor plume as predicted by the standard piston model. While for IR ablation, the background gas is effectively mixed to the ejected vapor at least hundreds of nanoseconds after the initiation of the plasma. Our observations suggest a description by laser-supported combustion wave for the propagation of the plasma produced by UV laser, while that by laser-supported detonation wave for the propagation of the plasma produced by IR laser. Finally, practical consequences of specific expansion behavior for UV or IR ablation are discussed in terms of analytical performance promised by corresponding plasmas for application with laser-induced breakdown spectroscopy.

  2. Generation of electromagnetic pulses from plasma channels induced by femtosecond light strings

    OpenAIRE

    Cheng, Chung-Chieh; Wright, E. M.; Moloney, J. V.

    2000-01-01

    We present a model that elucidates the physics underlying the generation of an electromagnetic pulse from a femtosecond laser induced plasma channel. The radiation pressure force from the laser pulse spatially separates the ionized electrons from the heavier ions and the induced dipole moment subsequently oscillates at the plasma frequency and radiates an electromagnetic pulse.

  3. Induced magnetic-field effects in inductively coupled plasmas

    International Nuclear Information System (INIS)

    Cohen, R.H.; Rognlien, T.D.

    1995-01-01

    In inductive plasma sources, the rapid spatial decay of the electric field arising from the skin effect produces a large radio frequency (RF) magnetic field via Faraday's law. We previously determined that this magnetic field leads to a reduction of the electron density in the skin region, as well as a reduction in the collisionless heating rate. The electron deficit leads to the formation of an electrostatic potential which pulls electrons in to restore quasineutrality. Here we calculate the electron density including both the induced and electrostatic fields. If the wave frequency is not too low, the ions respond only to the averaged fields, and hence the electrostatic field is oscillatory, predominantly at the second harmonic of the applied field. We calculate the potential required to establish a constant electron density, and compare with numerical orbit-code calculations. For times short compared to ion transit times, the quasineutral density is just the initial ion density. For timescales long enough that the ions can relax, the density profile can be found from the solution of fluid equations with an effective (ponderomotive-like) potential added. Although the time-varying electrostatic potential is an extra source of heating, the net effect of the induced magnetic and electrostatic fields through trapping, early turning, and direct heating is a significant reduction in collisionless heating for parameters of interest

  4. Analysis of laser-induced breakdown spectroscopy spectra: The case for extreme value statistics

    International Nuclear Information System (INIS)

    Michel, Anna P.M.; Chave, Alan D.

    2007-01-01

    In most instances, laser-induced breakdown spectroscopy (LIBS) spectra are obtained through analog accumulation of multiple shots in the spectrometer CCD. The average acquired in the CCD at a given wavelength is assumed to be a good representation of the population mean, which in turn is implicitly regarded to be the best estimator for the central value of the distribution of the spectrum at the same wavelength. Multiple analog accumulated spectra are taken and then in turn averaged wavelength-by-wavelength to represent the final spectrum. In this paper, the statistics of single-shot and analog accumulated LIBS spectra of both solids and liquids were examined to evaluate whether the spectrum averaging approach is statistically defensible. At a given wavelength, LIBS spectra are typically drawn from a Frechet extreme value distribution, and hence the mean of an ensemble of LIBS spectra is not necessarily an optimal summary statistic. Under circumstances that are broadly general, the sample mean for LIBS data is statistically inconsistent and the central limit theorem does not apply. This result appears to be due to very high shot-to-shot plasma variability in which a very small number of spectra are high in intensity while the majority are very weak, yielding the extreme value form of the distribution. The extreme value behavior persists when individual shots are analog accumulated. An optimal estimator in a well-defined sense for the spectral average at a given wavelength follows from the maximum likelihood method for the extreme value distribution. Example spectra taken with both an Echelle and a Czerny-Turner spectrometer are processed with this scheme to create smooth, high signal-to-noise summary spectra. Plasma imaging was used in an attempt to visually understand the observed variability and to validate the use of extreme value statistics. The data processing approach presented in this paper is statistically reliable and should be used for accurate

  5. Moessbauer spectroscopy study on the corrosion resistance of plasma nitrided ASTM F138 stainless steel in chloride solution

    International Nuclear Information System (INIS)

    Souza, S.D. de; Olzon-Dionysio, M.; Basso, R.L.O.; Souza, S. de

    2010-01-01

    Plasma nitriding of ASTM F138 stainless steel samples has been carried out using dc glow discharge under 80% H 2 -20% N 2 gas mixture, at 673 K, and 2, 4, and 7 h time intervals, in order to investigate the influence of treatment time on the microstructure and the corrosion resistance properties. The samples were characterized by scanning electron microscopy, glancing angle X-ray diffraction and conversion electron Moessbauer spectroscopy, besides electrochemical tests in NaCl aerated solution. A modified layer of about 6 μm was observed for all the nitrided samples, independent of nitriding time. The X-ray diffraction analysis shows broad γ N phase peaks, signifying a great degree of nitrogen supersaturation. Besides γ N, the Moessbauer spectroscopy results indicated the occurrence of γ' and ε phases, as well as some other less important phases. Corrosion measurements demonstrate that the plasma nitriding time affects the corrosion resistance and the best performance is reached at 4 h treatment. It seems that the ε/γ' fraction ratio plays an important role on the resistance corrosion. Additionally, the Moessbauer spectroscopy was decisive in this study, since it was able to identify and quantify the iron phases that influence the corrosion resistance of plasma nitrided ASTM F138 samples.

  6. A special cell morphology of saccharomyces cerevisiae induced by low-temperature plasma

    International Nuclear Information System (INIS)

    Ling Dajun; Cao Jinxiang

    2003-01-01

    A special cell morphology, cavity-like cells, was found in posterities of Saccharomyces cerevisiae treated by low-temperature air plasma with different powers. The feature of the special morphology indicates that the cavity-like cells may be formed by cellular mutation effect induced by the plasma, instead of direct cellular damage by the plasma. The results suggest that the cellular mutation effect of the low-temperature plasma is a complex process

  7. Experimental investigation of silicon photomultipliers as compact light readout systems for gamma-ray spectroscopy applications in fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nocente, M., E-mail: massimo.nocente@mib.infn.it; Gorini, G. [Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola,” EURATOM-ENEA-CNR Association, Milano (Italy); Fazzi, A.; Lorenzoli, M.; Pirovano, C. [Dipartimento di Energia, CeSNEF, Politecnico di Milano, Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Milano (Italy); Tardocchi, M. [Istituto di Fisica del Plasma “P. Caldirola,” EURATOM-ENEA-CNR Association, Milano (Italy); Cazzaniga, C.; Rebai, M. [Dipartimento di Fisica “G. Occhialini,” Università degli Studi di Milano-Bicocca, Milano (Italy); Uboldi, C.; Varoli, V. [Dipartimento di Energia, CeSNEF, Politecnico di Milano, Milano (Italy)

    2014-11-15

    A matrix of Silicon Photo Multipliers has been developed for light readout from a large area 1 in. × 1 in. LaBr{sub 3} crystal. The system has been characterized in the laboratory and its performance compared to that of a conventional photo multiplier tube. A pulse duration of 100 ns was achieved, which opens up to spectroscopy applications at high counting rates. The energy resolution measured using radioactive sources extrapolates to 3%–4% in the energy range E{sub γ} = 3–5 MeV, enabling gamma-ray spectroscopy measurements at good energy resolution. The results reported here are of relevance in view of the development of compact gamma-ray detectors with spectroscopy capabilities, such as an enhanced gamma-ray camera for high power fusion plasmas, where the use of photomultiplier is impeded by space limitation and sensitivity to magnetic fields.

  8. High-temperature laser induced spectroscopy in nuclear steam generators

    International Nuclear Information System (INIS)

    Allmon, W.E.; Berthold, J.W.

    1990-01-01

    This patent describes an apparatus for conducting optical spectroscopy in a hostile environment. It comprises: a source of high intensity light; an optical fiber connected to the source of high intensity light for transmitting light therefrom. The optical fiber having an end for discharging light onto a material to be spectroscopically analyzed; a sheath defining a space around at least a part of the optical fiber carrying the end of the optical fiber for shielding the optical fiber from the hostile environment; a window in the sheath for closing the space and for passing light transmitted through the end of the optical fiber out of the sheath; light detector means for detecting and spectroscopically analyzing emitted light from the material; an optical fiber means for transmitting the emitted light from the material to the light detector means; a standardization module for containing a sample having a known composition and being exposed to known temperature and pressure conditions; an additional optical fiber connected to the module for transmitting light to the sample in the module; multiplexer means; and additional optical fiber means for returning light from the module to the detector through the multiplexer means

  9. Investigation of the differentiation of ex vivo nerve and fat tissues using laser-induced breakdown spectroscopy (LIBS): Prospects for tissue-specific laser surgery.

    Science.gov (United States)

    Mehari, Fanuel; Rohde, Maximillian; Kanawade, Rajesh; Knipfer, Christian; Adler, Werner; Klämpfl, Florian; Stelzle, Florian; Schmidt, Michael

    2016-10-01

    In the present study, the elemental compositions of fat and nerve tissue during their plasma mediated laser ablation are studied in the context of tissue differentiation for laser surgery applications by using Laser-Induced Breakdown Spectroscopy (LIBS). Tissue samples of porcine fat and nerve were prepared as ex vivo experimental objects. Plasma mediated laser ablation is performed using an Nd : YAG laser in open air and under normal stray light conditions. The performed measurements suggest that the two tissue types show a high similarity in terms of qualitat