Sample records for laser-induced breakdown spectroscopy

  1. Laser-Induced Breakdown Spectroscopy

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    LIBS-1 Laser-Induced Breakdown Spectroscopy LIBS ANALYSIS OF METAL SURFACES Last updated: June 17, 2014 #12;LIBS-2 Laser­Induced Breakdown Spectroscopy (LIBS) LIBS ANALYSIS OF METAL SURFACES of species at a distance or in hard­to­reach or hazardous environments. Laser­Induced Breakdown Spectroscopy

  2. Laser-induced breakdown spectroscopy for specimen analysis

    DOE Patents [OSTI]

    Kumar, Akshaya; Yu-Yueh, Fang; Burgess, Shane C.; Singh, Jagdish P.

    2006-08-15T23:59:59.000Z

    The present invention is directed to an apparatus, a system and a method for detecting the presence or absence of trace elements in a biological sample using Laser-Induced Breakdown Spectroscopy. The trace elements are used to develop a signature profile which is analyzed directly or compared with the known profile of a standard. In one aspect of the invention, the apparatus, system and method are used to detect malignant cancer cells in vivo.

  3. Spatial confinement effects in laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Shen, X. K.; Sun, J.; Ling, H.; Lu, Y. F. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

    2007-08-20T23:59:59.000Z

    The spatial confinement effects in laser-induced breakdown of aluminum (Al) targets in air have been investigated both by optical emission spectroscopy and fast photography. A KrF excimer laser was used to produce plasmas from Al targets in air. Al atomic emission lines show an obvious enhancement in the emission intensity when a pair of Al-plate walls were placed to spatially confine the plasma plumes. Images of the Al plasma plumes showed that the plasma plumes evolved into a torus shape and were compressed in the Al walls. The mechanism for the confinement effects was discussed using shock wave theory.

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

    SciTech Connect (OSTI)

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

    1982-01-01T23:59:59.000Z

    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 ..mu..g/m/sup 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.

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

    DOE Patents [OSTI]

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

    2014-11-18T23:59:59.000Z

    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.

  6. Optical emission in magnetically confined laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Shen, X. K.; Lu, Y. F.; Gebre, T.; Ling, H.; Han, Y. X. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

    2006-09-01T23:59:59.000Z

    Magnetically confined laser-induced breakdown spectroscopy was investigated by studying the optical emission from laser-induced plasma plumes expanding across an external transverse magnetic field. KrF excimer laser pulses with a pulse duration of 23 ns and a wavelength of 248 nm were used to produce plasmas from Al, Cu, and Co targets. Various optical emission lines obtained from Al and Cu targets show an obvious enhancement in the intensity of optical emission when a magnetic field of {approx}0.8 T is applied, while the optical emission lines from Co targets show a decrease in the optical emission intensity. The enhancement factors of optical emission lines were measured to be around 2 for the Al and Mn (impurity) lines from Al targets, and 6-8 for Cu lines from Cu targets. Temporal evolution of the optical emission lines from the Al samples shows a maximum enhancement in emission intensity at time delays of 8-20 {mu}s after the incident laser pulse, while from the Cu targets it shows a continuous enhancement at time delays of 3-20 {mu}s after the pulse. The enhancement in the optical emission from the Al and Cu plasmas was presumably due to the increase in the effective plasma density as a result of magnetic confinement. The decrease in the emission intensity from the Co plasmas was suggested to be due to the decrease of effective plasma density as a result of the magnetic force.

  7. Titanium monoxide spectroscopy following laser-induced optical breakdown

    SciTech Connect (OSTI)

    Parigger, Christian G.; Woods, Alexander C.; Keszler, Anna; Nemes, Laszlo; Hornkohl, James O. [The University of Tennessee/UT Space Institute, Center for Laser Applications, 411 B.H. Goethert Parkway, Tullahoma, TN 37388-9700 (United States); Chemical Research Center of the Hungarian Academy of Sciences, Institute of Materials and Environmental Chemistry, Pusztaszeri ut 59-67, H-1025 Budapest (Hungary); Chemical Research Center of the Hungarian Academy of Sciences, Laser Spectroscopy Laboratory, Pusztaszeri ut 59-67, H-1025 Budapest (Hungary); Hornkohl Consulting, Tullahoma, TN 37388 (United States)

    2012-07-30T23:59:59.000Z

    This work investigates Titanium Monoxide (TiO) in ablation-plasma by employing laser-induced breakdown spectroscopy (LIBS) with 1 to 10 TW/cm{sup 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 {gamma} and B-X {gamma} Prime bands. Electric dipole line strengths for the A{sup 3}{Phi}-X{sup 3}{delta} and B{sup 3}{Pi}-X{sup 3}{delta} 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{sub 2}, CN, CH, N{sub 2}, NH, NO and OH.

  8. Laser-induced breakdown spectroscopy in industrial and security applications

    SciTech Connect (OSTI)

    Bol'shakov, Alexander A.; Yoo, Jong H.; Liu Chunyi; Plumer, John R.; Russo, Richard E.

    2010-05-01T23:59:59.000Z

    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 {approx}10 {mu}g/g to determination of halogens at 90 {mu}g/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.

  9. Elemental analysis of cotton by laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Schenk, Emily R.; Almirall, Jose R.

    2010-05-01T23:59:59.000Z

    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.

  10. Laser Induced Breakdown Spectroscopy and Applications Toward Thin Film Analysis

    E-Print Network [OSTI]

    Owens, Travis Nathan

    2011-01-01T23:59:59.000Z

    phase laser induced plasma diagnostics and mass removalS. S. Mao. Time-resolved plasma diagnostics and mass removal

  11. Plasma confinement by hemispherical cavity in laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Guo, L. B.; Li, C. M. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Hu, W.; Zhou, Y. S.; Zhang, B. Y.; Lu, Y. F. [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States); Cai, Z. X.; Zeng, X. Y. [School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2011-03-28T23:59:59.000Z

    An aluminum hemispherical cavity (diameter: 11.1 mm) was used to confine plasmas produced by a KrF excimer laser in air from a steel target with a low concentration manganese in laser-induced breakdown spectroscopy. A significant enhancement (factor >12) in the emission intensity of Mn lines was observed at a laser fluence of 7.8 J/cm{sup 2} when the plasma was confined by the hemispherical cavity, leading to an increase in plasma temperature about 3600 K. The maximum emission enhancement increased with increasing laser fluence. The spatial confinement mechanism was discussed using shock wave theory.

  12. Laser-induced breakdown spectroscopy at high temperatures in industrial boilers and furnaces.

    SciTech Connect (OSTI)

    Walsh, Peter M. (University of Alabama at Birmingham and Southern Research Institute, Birmingham, AL); Shaddix, Christopher R.; Sickafoose, Shane M.; Blevins, Linda Gail

    2003-02-01T23:59:59.000Z

    Laser-induced breakdown spectroscopy (LIBS) was applied (1) near the superheater of an electric power generation boiler burning biomass, coat, or both, (2) at the exit of a glass-melting furnace burning natural gas and oxygen, and (3) near the nose arches of two paper mill recovery boilers burning black liquor. Difficulties associated with the high temperatures and high particle loadings in these environments were surmounted by use of novel LIBS probes. Echelle and linear spectrometers coupled to intensified CCD cameras were used individually and sometimes simultaneously. Elements detected include Na, K, Ca, Mg, C, B, Si, Mn, Al, Fe, Rb, Cl, and Ti.

  13. Laser-induced breakdown spectroscopy for real time and online elemental analysis

    E-Print Network [OSTI]

    Rai, V N; Yueh, Fang-Yu; Singh, J P

    2014-01-01T23:59:59.000Z

    Laser-induced breakdown spectroscopy (LIBS) is a laser based diagnostics used to study atomic emission from the expanding plasma plume formed during the laser-matter interaction. It provides valuable information about the composition of the target material. LIBS has proved its potential application in the analysis of impurities, pollutants and toxic elements in various types of matrices of different samples (solid, liquid and gases), even those present under difficult and harsh environmental conditions. This article reviews some recent developments in the field, and its wide application in various fields of research and analysis.

  14. Laser-induced breakdown spectroscopy with laser irradiation resonant with vibrational transitions

    SciTech Connect (OSTI)

    Khachatrian, Ani; Dagdigian, Paul J.

    2010-05-01T23:59:59.000Z

    An investigation of laser-induced breakdown spectroscopy (LIBS) of polymers, both in bulk form and spin coated on Si wafers, with laser irradiation in the mid-infrared spectral region is presented. Of particular interest is whether the LIBS signals are enhanced when the laser wavelength is resonant with a fundamental vibrational transition of the polymer. Significant increases in the LIBS signals were observed for irradiation on hydride stretch fundamental transitions, and the magnitude of the enhancement showed a strong dependence on the mode excited. The role of the substrate was investigated by comparison of results for bulk and spin-coated samples. The polymers investigated were Nylon 12 and poly(vinyl alcohol-co-ethylene).

  15. Fiber optic laser-induced breakdown spectroscopy sensor for molten material analysis

    DOE Patents [OSTI]

    Zhang, Hansheng; Rai, Awadesh K.; Singh, Jagdish P.; Yueh, Fang-Yu

    2004-07-13T23:59:59.000Z

    A fiber optic laser-induced breakdown spectroscopy (LIBS) sensor, including a laser light source, a harmonic separator for directing the laser light, a dichroic mirror for reflecting the laser light, a coupling lens for coupling the laser light at an input of a multimode optical fiber, a connector for coupling the laser light from an output of the multimode optical fiber to an input of a high temperature holder, such as a holder made of stainless steel, and a detector portion for receiving emission signal and analyzing LIBS intensities. In one variation, the multimode optical fiber has silica core and silica cladding. The holder includes optical lenses for collimating and focusing the laser light in a molten alloy to produce a plasma, and for collecting and transmitting an emission signal to the multimode optical fiber.

  16. Laser-induced breakdown spectroscopy measurement in methane and biodiesel flames using an ungated detector

    SciTech Connect (OSTI)

    Eseller, Kemal E.; Yueh, Fang Y.; Singh, Jagdish P

    2008-11-01T23:59:59.000Z

    Laser-induced breakdown spectroscopy (LIBS) has been applied to measure the equivalence ratio of CH4/air flames using gated detection. In this work, we have developed an ungated, miniature LIBS-based sensor for studying CH4/air and biodiesel flames. We have used this sensor to characterize the biodiesel flame. LIBS spectra of biodiesel flames were recorded with different ethanol concentrations in the biodiesel and also at different axial locations within the flame. The sensor performance was evaluated with a CH4/air flame. LIBS signals of N, O, and H from a CH4/air flame were used to determine the equivalence ratio. A linear relationship between the intensity ratio of H and O lines and the calculated equivalence ratio were obtained with this sensor.

  17. Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser-induced breakdown spectroscopy

    E-Print Network [OSTI]

    Harilal, S. S.

    Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser of collinear double-pulse compared to single-pulse ultrafast laser induced breakdown spectroscopy. Our results showed that the significant signal enhancement noticed in the double pulse scheme is strongly correlated

  18. Investigation of historical metal objects using Laser Induced Breakdown Spectroscopy (LIBS) technique

    SciTech Connect (OSTI)

    Abdel-Kareem, O. [Conservation Department, Faculty of Archaeology, Cairo University (Egypt); Ghoneim, M. [Conservation Department, Faculty of Fine Arts, Minia University (Egypt); Harith, M. A. [National Institute of Laser Enhanced Science, Cairo University (Egypt)

    2011-09-22T23:59:59.000Z

    Analysis of metal objects is a necessary step for establishing an appropriate conservation treatment of an object or to follow up the application's result of the suggested treatments. The main considerations on selecting a method that can be used in investigation and analysis of metal objects are based on the diagnostic power, representative sampling, reproducibility, destructive nature/invasiveness of analysis and accessibility to the appropriate instrument. This study aims at evaluating the usefulness of the use of Laser Induced Breakdown Spectroscopy (LIBS) Technique for analysis of historical metal objects. In this study various historical metal objects collected from different museums and excavations in Egypt were investigated using (LIBS) technique. For evaluating usefulness of the suggested analytical protocol of this technique, the same investigated metal objects were investigated by other methods such as Scanning Electron Microscope with energy-dispersive x-ray analyzer (SEM-EDX) and X-ray Diffraction (XRD). This study confirms that Laser Induced Breakdown Spectroscopy (LIBS) Technique is considered very useful technique that can be used safely for investigating historical metal objects. LIBS analysis can quickly provide information on the qualitative and semi-quantitative elemental content of different metal objects and their characterization and classification. It is practically non-destructive technique with the critical advantage of being applicable in situ, thereby avoiding sampling and sample preparations. It is can be dependable, satisfactory and effective method for low cost study of archaeological and historical metals. But we have to take into consideration that the corrosion of metal leads to material alteration and possible loss of certain metals in the form of soluble salts. Certain corrosion products are known to leach out of the object and therefore, their low content does not necessarily reflect the composition of the metal at the time of the object manufacture. Another point should be taken into consideration that the heterogeneity of a metal alloy object that often result from poor mixing of the different metal alloy composition.There is a necessity to carry out further research to investigate and determine the most appropriate and effective approaches and methods for conservation of these metal objects.

  19. Analysis of indium zinc oxide thin films by laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Popescu, A. C. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. de Luminy, Marseille 13288 (France); National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov 077125 (Romania); Beldjilali, S. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. de Luminy, Marseille 13288 (France); LPPMCA, Universite des Sciences et de la Technologie d'Oran, BP 1505 El Mnaouer, Oran (Algeria); Socol, G.; Mihailescu, I. N. [National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov 077125 (Romania); Craciun, V. [National Institute for Lasers, Plasma and Radiation Physics, Magurele, Ilfov 077125 (Romania); MAIC, University of Florida, Gainesville, FL 32611 (United States); Hermann, J. [LP3, CNRS - Universite Aix-Marseille, 163 Ave. de Luminy, Marseille 13288 (France)

    2011-10-15T23:59:59.000Z

    We have performed spectroscopic analysis of the plasma generated by Nd:YAG ({lambda} = 266 nm) laser irradiation of thin indium zinc oxide films with variable In content deposited by combinatorial pulsed laser deposition on glass substrates. The samples were irradiated in 5 x 10{sup 4} Pa argon using laser pulses of 5 ns duration and 10 mJ energy. The plasma emission spectra were recorded with an Echelle spectrometer coupled to a gated detector with different delays with respect to the laser pulse. The relative concentrations of indium and zinc were evaluated by comparing the measured spectra to the spectral radiance computed for a plasma in local thermal equilibrium. Plasma temperature and electron density were deduced from the relative intensities and Stark broadening of spectral lines of atomic zinc. Analyses at different locations on the deposited thin films revealed that the In/(In + Zn) concentration ratio significantly varies over the sample surface, from 0.4 at the borders to about 0.5 in the center of the film. The results demonstrate that laser-induced breakdown spectroscopy allows for precise and fast characterization of thin films with variable composition.

  20. Temperature effect on laser-induced breakdown spectroscopy spectra of molten and solid salts

    SciTech Connect (OSTI)

    Cynthia Hanson; Supathorn Phongikaroon; Jill R. Scott

    2014-07-01T23:59:59.000Z

    Laser-induced breakdown spectroscopy (LIBS) has been investigated as a potential analytical tool to improve operations and safeguards for electrorefiners, such as those used in processing spent nuclear fuel. This study set out to better understand the effect of sample temperature and physical state on LIBS spectra of molten and solid salts by building calibration curves of cerium and assessing self-absorption, plasma temperature, electron density, and local thermal equilibrium (LTE). Samples were composed of a LiClKCl eutectic salt, an internal standard of MnCl2, and varying concentrations of CeCl3 (0.1, 0.3, 0.5, 0.8, and 1.0 wt.% Ce) under different temperatures (773, 723, 673, 623, and 573 K). Analysis of salts in their molten form is preferred as plasma plumes from molten samples experienced less self-absorption, less variability in plasma temperature, and higher clearance of the minimum electron density required for local thermal equilibrium. These differences are attributed to plasma dynamics as a result of phase changes. Spectral reproducibility was also better in the molten state due to sample homogeneity.

  1. Rapid Analysis of Ash Composition Using Laser-Induced Breakdown Spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Tyler L. Westover

    2013-01-01T23:59:59.000Z

    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.

  2. Elemental analysis by microwave-assisted laser-induced breakdown spectroscopy: Evaluation on ceramics

    E-Print Network [OSTI]

    Richardson, Martin C.

    ,2 These sources are usually flames or plasmas: arcs, sparks, plasma jets, inductively coupled plasma (ICP), high demonstrated the signal enhancement ability of their LAMPS (Laser-Assisted Microwave Plasma Spectroscopy utilizing interaction between microwave radiation and laser-induced plasma has been evaluated. Experimental

  3. Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

    SciTech Connect (OSTI)

    Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

    2010-12-13T23:59:59.000Z

    The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to quantitatively determine the major elemental abundance of the remaining samples. PLS analysis suggests that the major element compositions can be determined with root mean square errors ca. 5% (absolute) for SiO{sub 2}, Al{sub 2}O{sub 3}, Fe{sub 2}O{sub 3}(total), MgO, and CaO, and ca. 2% or less for TiO{sub 2}, Cr{sub 2}O{sub 3}, MnO, K{sub 2}O, and Na{sub 2}O. Finally, the Raman experiments have been conducted under supercritical CO{sub 2} involving single-mineral and mixed-mineral samples containing talc, olivine, pyroxenes, feldspars, anhydrite, barite, and siderite. The Raman data have shown that the individual minerals can easily be identified individually or in mixtures.

  4. Electron-ion relaxation time dependent signal enhancement in ultrafast double-pulse laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Harilal, S. S.; Diwakar, P. K.; Hassanein, A. [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)] [Center for Materials Under Extreme Environment, School of Nuclear Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)

    2013-07-22T23:59:59.000Z

    We investigated the emission properties of collinear double-pulse compared to single-pulse ultrafast laser induced breakdown spectroscopy. Our results showed that the significant signal enhancement noticed in the double pulse scheme is strongly correlated to the characteristic electron-ion relaxation time and hence to the inter-pulse delays. Spectroscopic excitation temperature analysis showed that the improvement in signal enhancement is caused by the delayed pulse efficient reheating of the pre-plume. The signal enhancement is also found to be related to the upper excitation energy of the selected lines, i.e., more enhancement noticed for lines originating from higher excitation energy levels, indicating reheating is the major mechanism behind the signal improvement.

  5. ,* Copper transport and accumulation in spruce stems (picea abies(L.) Karsten) revelaed by laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Krajcarova, Dr. Lucie [Czech Technical University; Novotny, Dr. Karel [Mendel University of Brno; Babula, Dr. Petr [Czech Technical University; Pravaznik, Dr Ivo [Czech Technical University; Kucerova, Dr. Petra [Czech Technical University; Vojtech, Dr. Adam [Czech Technical University; Martin, Madhavi Z [ORNL; Kizek, Dr. Rene [Czech Technical University; Kaiser, Jozef [ORNL

    2013-01-01T23:59:59.000Z

    Laser-Induced Breakdown Spectroscopy (LIBS) in double pulse configuration (DP LIBS) was used for scanning elemental spatial distribution in annual terminal stems of spruce (Picea abies (L.) Karsten). Cross sections of stems cultivated in Cu2+ solution of different concentrations were prepared and analyzed by DP LIBS. Raster scanning with 150 m spatial resolution was set and 2D (2-dimentional) maps of Cu and Ca distribution were created on the basis of the data obtained. Stem parts originating in the vicinity of the implementation of the cross sections were mineralized and subsequently Cu and Ca contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results provide quantitative information about overall concentration of the elements in places, where LIBS measurements were performed. The fluorescence pictures were created to compare LIBS distribution maps and the fluorescence intensity (or the increase in autofluorescence) was used for the comparison of ICP-MS quantitative results. Results from these three methods can be utilized for quantitative measurements of copper ions transport in different plant compartments in dependence on the concentration of cultivation medium and/or the time of cultivation.

  6. Methods for measurement of heterogeneous materials with laser-induced breakdown spectroscopy (LIBS)

    E-Print Network [OSTI]

    Effenberger, Andrew Jay

    2009-01-01T23:59:59.000Z

    2000. 15) Welz B, Atomic Absorption Spectrometry, ThirdFor elemental analyses atomic absorption spectroscopy iscommonly used (15). Atomic absorption spectroscopy works by

  7. Elemental content of enamel and dentin after bleaching of teeth (a comparative study between laser-induced breakdown spectroscopy and x-ray photoelectron spectroscopy)

    SciTech Connect (OSTI)

    Imam, H. [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt)] [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Ahmed, Doaa [Department of Restorative Sciences, Faculty of Dentistry, Alexandria University, Alexandria (Egypt)] [Department of Restorative Sciences, Faculty of Dentistry, Alexandria University, Alexandria (Egypt); Eldakrouri, Ashraf [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt) [National Institute of Laser Enhanced Sciences, NILES, Cairo University, Giza (Egypt); Department of Optometry and Vision Science, College of Applied Medical Science, King Saud University, Riyadh (Saudi Arabia)

    2013-06-21T23:59:59.000Z

    The elemental content of the superficial and inner enamel as well as that of dentin was analyzed using laser-induced breakdown spectroscopy (LIBS) and x-ray photoelectron spectroscopy (XPS) of bleached and unbleached tooth specimens. It is thus clear from the spectral analysis using both the LIBS and XPS technique that elemental changes (though insignificant within the scopes of this study) of variable intensities do occur on the surface of the enamel and extend deeper to reach dentin. The results of the LIBS revealed a slight reduction in the calcium levels in the bleached compared to the control specimens in all the different bleaching groups and in both enamel and dentin. The good correlation found between the LIBS and XPS results demonstrates the possibility of LIBS technique for detection of minor loss in calcium and phosphorus in enamel and dentin.

  8. Towards the clinical application of laser-induced breakdown spectroscopy for rapid pathogen diagnosis Qassem Mohaidat

    E-Print Network [OSTI]

    Rehse, Steven J.

    and Microbiology) Asst. Prof. Choong-Min Kang (WSU Dept. of Biological Sciences) Asst. Prof. Hossein Salimnia (WSU of Pathogenic Bacteria: A Spectroscopy Experiment at the Crossroads of Atomic Physics and Microbiology," S- resolution spectrometer, laser power supply, computer, and battery Hand-held probe contains laser, joystick

  9. Detection of chlorine with concentration of 0.18 kg/m{sup 3} in concrete by laser-induced breakdown spectroscopy

    SciTech Connect (OSTI)

    Sugiyama, K.; Fujii, T.; Matsumura, T.; Shiogama, Y.; Yamaguchi, M.; Nemoto, K.

    2010-05-01T23:59:59.000Z

    The chlorine concentration in concrete samples was measured by laser-induced breakdown spectroscopy (LIBS). One or two pulsed second harmonic Nd:YAG lasers ({lambda}=532 nm) were used for the generation of laser-induced breakdown, and an intensified CCD camera, spectrometer, and optical bundle fiber were used for spectral measurement. To maximize the spectral intensity of the chlorine fluorescence line at a wavelength of 837.59 nm, the time delay between laser irradiation and spectral measurement, the time delay between the two laser pulses in double-pulse measurement, and the gate width of the spectral measurement were optimized. The linear relationship between the spectral intensity of the chlorine fluorescence line and the chlorine concentration was verified for pressed samples with chlorine concentrations from 0.18 to 5.4 kg/m{sup 3}. The signal-to-noise ratio was higher than 2 for the sample with a chlorine concentration of 0.18 kg/m{sup 3} (0.008 wt. %). Thus, a chlorine concentration of 0.6 kg/m{sup 3}, at which the reinforcing bars in concrete structures start to corrode, can be detected. These results show that LIBS is effective for the quantitative measurement of chlorine concentration in concrete with high sensitivity.

  10. A Fundamental Study of Laser-Induced Breakdown Spectroscopy Using Fiber Optics for Remote Measurements Of Trace Metals

    SciTech Connect (OSTI)

    Scott Goode; S. Michael Angel

    2004-01-20T23:59:59.000Z

    Develop a fiber-optic imaging probe for microanalysis of solid samples; Design a time-resolved plasma imaging system to measure the development of the LIBS signal; Setup a laboratory system capable of timing two lasers independently, for optimizing and characterizing dual-pulse LIBS; Compare the development of laser-induced plasmas generated with a single laser pulse to the development of laser-induced plasmas generated with a pre-ablation spark prior to sample ablation; Examine the effect of sample matrix on the LIBS signals of elements in different sample matrices; Investigate the effect of excitation wavelength of the ablation beam in pre-ablation spark dual-pulse LIBS experiments; Determine the effect of the physical properties of the sample on the mass of materials ablated.

  11. Design of a laser-induced breakdown spectroscopy system for on-line quality analysis of pulverized coal in power plants

    SciTech Connect (OSTI)

    Yin, W.B.; Zhang, L.; Dong, L.; Ma, W.G.; Jia, S.T. [Shanxi Agricultural University, Taiyuan (China)

    2009-08-15T23:59:59.000Z

    It is vitally important for a power plant to determine the chemical composition of coal prior to combustion in order to obtain optimal boiler control. In this work, a fully software-controlled laser-induced breakdown spectroscopy (LIBS) system comprising a LIBS apparatus and sampling equipment has been designed for possible application to power plants for on-line quality analysis of pulverized coal. Special attention was given to the LIBS system, the data processing methods (especially the normalization with Bode Rule/DC Level) and the specific settings (the software-controlled triggering source, high-pressure gas cleaning device, sample preparation module, sampling module, etc.), which gave the best direct measurement for C, H, Si, Na, Mg, Fe, Al, and Ti with measurement errors less than 10% for pulverized coal. Therefore, the apparatus is accurate enough to be applied to industries for on-line monitoring of pulverized coal. The method of proximate analysis was also introduced and the experimental error of A(ad) (Ash, 'ad' is an abbreviation for 'air dried') was shown in the range of 2.29 to 13.47%. The programmable logic controller (PLC) controlled on-line coal sampling equipment, which is designed based upon aerodynamics, and is capable of performing multipoint sampling and sample-preparation operation.

  12. Procedure for calibration of a portable, real-time beryllium aerosol monitor based on laser-induced breakdown spectroscopy

    E-Print Network [OSTI]

    Killough, David Thomas

    2012-06-07T23:59:59.000Z

    Spectroscopy (LIPS), is an analytical method whereby atmospheric components and contaminants may be analyzed in real-time or near real-time directly in the workplace. A transportable beryllium air monitor system based on LIBS has been developed at the Los...

  13. E-Print Network 3.0 - all-fiber-coupled laser-induced breakdown...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    coupled laser-induced breakdown Search Powered by Explorit Topic List Advanced Search Sample search results for: all-fiber-coupled laser-induced breakdown Page: << < 1 2 3 4 5 > >>...

  14. Bulk measurement of copper and sodium content in CuIn(0.7)Ga(0.3)Se(2) (CIGS) solar cells with nanosecond pulse length laser induced breakdown spectroscopy (LIBS)

    E-Print Network [OSTI]

    Kowalczyk, Jeremy M D; DeAngelis, Alexander; Kaneshiro, Jess; Mallory, Stewart A; Chang, Yuancheng; Gaillard, Nicolas

    2013-01-01T23:59:59.000Z

    In this work, we show that laser induced breakdown spectroscopy (LIBS) with a nanosecond pulse laser can be used to measure the copper and sodium content of CuIn(0.7)Ga(0.3)Se(2) (CIGS) thin film solar cells on molybdenum. This method has four significant advantages over methods currently being employed: the method is inexpensive, measurements can be taken in times on the order of one second, without high vacuum, and at distances up to 5 meters or more. The final two points allow for in-line monitoring of device fabrication in laboratory or industrial environments. Specifically, we report a linear relationship between the copper and sodium spectral lines from LIBS and the atomic fraction of copper and sodium measured via secondary ion mass spectroscopy (SIMS), discuss the ablation process of this material with a nanosecond pulse laser compared to shorter pulse duration lasers, and examine the depth resolution of nanosecond pulse LIBS.

  15. Quantitative laser-induced breakdown spectroscopy data using peak area step-wise regression analysis: an alternative method for interpretation of Mars science laboratory results

    SciTech Connect (OSTI)

    Clegg, Samuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Dyar, Melinda D [MT HOLYOKE COLLEGE; Schafer, Martha W [LSU; Tucker, Jonathan M [MT HOLYOKE COLLEGE

    2008-01-01T23:59:59.000Z

    The ChemCam instrument on the Mars Science Laboratory (MSL) will include a laser-induced breakdown spectrometer (LIBS) to quantify major and minor elemental compositions. The traditional analytical chemistry approach to calibration curves for these data regresses a single diagnostic peak area against concentration for each element. This approach contrasts with a new multivariate method in which elemental concentrations are predicted by step-wise multiple regression analysis based on areas of a specific set of diagnostic peaks for each element. The method is tested on LIBS data from igneous and metamorphosed rocks. Between 4 and 13 partial regression coefficients are needed to describe each elemental abundance accurately (i.e., with a regression line of R{sup 2} > 0.9995 for the relationship between predicted and measured elemental concentration) for all major and minor elements studied. Validation plots suggest that the method is limited at present by the small data set, and will work best for prediction of concentration when a wide variety of compositions and rock types has been analyzed.

  16. Laser-induced plasma spectroscopy: principles, methods and applications

    SciTech Connect (OSTI)

    Lazic, Violeta; Colao, Francesco; Fantoni, Roberta; Spizzichino, Valeria [ENEA, FIS-LAS, V. E. Fermi 45, Frascati (RM) (Italy); Jovicevic, Sonja [Institute of Physics, 11080 Belgrade, Pregrevica 118 (Serbia and Montenegro)

    2006-12-01T23:59:59.000Z

    Principles of the Laser Induced Plasma Spectroscopy and its advances are reported. Methods for obtaining quantitative analyses are described, together with discussion of some applications and the specific problems.

  17. Preliminary Design of Laser - induced Breakd own Spectroscopy for Proto - MPEX

    SciTech Connect (OSTI)

    Shaw, Guinevere C [ORNL] [ORNL; Biewer, T.M. [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Martin, Madhavi Z [ORNL] [ORNL; Martin, Rodger Carl [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Laser-induced breakdown spectroscopy (LIBS) is a technique for measuring surface matter composition. LIBS is performed by focusing laser radiation onto a target surface, ablating the surface, forming a plasma, and analyzing the light produced. LIBS surface analysis is a possible diagnostic for characterizing plasma-facing materials in ITER. Oak Ridge National Laboratory (ORNL) has enabled the initial installation of a laser-induced breakdown spectroscopy diagnostic on the prototype Material-Plasma Exposure eXperiment (Proto-MPEX), which strives to mimic the conditions found at the surface of the ITER divertor. This paper will discuss the LIBS implementation on Proto-MPEX, preliminary design of the fiber optic LIBS collection probe, and the expected results.

  18. On the measurement of laser-induced plasma breakdown thresholds

    SciTech Connect (OSTI)

    Brieschenk, Stefan [Centre for Hypersonics, The University of Queensland, Brisbane 4072 (Australia)] [Centre for Hypersonics, The University of Queensland, Brisbane 4072 (Australia); Kleine, Harald; O'Byrne, Sean [The University of New South Wales Canberra, The Australian Defence Force Academy, Canberra 2600 (Australia)] [The University of New South Wales Canberra, The Australian Defence Force Academy, Canberra 2600 (Australia)

    2013-09-07T23:59:59.000Z

    The breakdown threshold of a gas exposed to intense laser-radiation is a function of gas and laser properties. Breakdown thresholds reported in the literature often vary greatly and these differences can partially be traced back to the method that is typically used to determine breakdown thresholds. This paper discusses the traditional method used to determine breakdown thresholds and the potential errors that can arise using this approach, and presents an alternative method which can yield more accurate data especially when determining breakdown thresholds as functions of gas pressure.

  19. Laser Induced Spectroscopy - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces and Interfaces Sample6, 2011 CERN 73-11LargeLaser EnablesLaser Induced

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

    SciTech Connect (OSTI)

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

    1993-12-01T23:59:59.000Z

    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.

  1. Aerosol measurements with laser-induced breakdown spectroscopy

    E-Print Network [OSTI]

    Lithgow, Gregg Arthur

    2007-01-01T23:59:59.000Z

    Lochte-Holtgreven, Plasma diagnostics. New York : AIP Press,Principles of plasma diagnostics. Cambridge ; New York :

  2. Laser Induced Breakdown Spectroscopy and Applications Toward Thin Film Analysis

    E-Print Network [OSTI]

    Owens, Travis Nathan

    2011-01-01T23:59:59.000Z

    extensively in dye-sensitized solar cells for their porositylayers for dye-sensitized solar cells [59]. A mortar and

  3. Laser Induced Breakdown Spectroscopy and Applications Toward Thin Film Analysis

    E-Print Network [OSTI]

    Owens, Travis Nathan

    2011-01-01T23:59:59.000Z

    on the surface. Ultrafast laser pulses are shorter than thethe advantages of ultrafast laser pulses for thin film LIBS,each time. While ultrafast laser pulses are effective in

  4. Aerosol measurements with laser-induced breakdown spectroscopy

    E-Print Network [OSTI]

    Lithgow, Gregg Arthur

    2007-01-01T23:59:59.000Z

    fused silica lenses to focus the plasma emission onto a UVideal lens focuses light from the plasma onto the tip of anboth focus the laser pulse and collect the plasma emission

  5. Laser Induced Breakdown Spectroscopy and Applications Toward Thin Film Analysis

    E-Print Network [OSTI]

    Owens, Travis Nathan

    2011-01-01T23:59:59.000Z

    1.5 Laserb) 60 shots, (c) 80 shots, and (d) 100 shots with 60mJ laserAutofocusing . . . . . . . . . . 2.4 Laser and Spectrometer

  6. Improved Laser Induced Breakdown Spectroscopy (LIBS) Elemental Composition

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300 219 255 135Detection System - Energy

  7. Optimally enhanced optical emission in laser-induced air plasma by femtosecond double-pulse

    SciTech Connect (OSTI)

    Chen, Anmin [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China) [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Li, Suyu; Li, Shuchang; Jiang, Yuanfei; Ding, Dajun [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China)] [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); Shao, Junfeng; Wang, Tingfeng [State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)] [State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Huang, Xuri [Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China)] [Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, Changchun 130012 (China); Jin, Mingxing [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China) [Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012 (China); State Key Laboratory of Laser Interaction with Matter, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China)

    2013-10-15T23:59:59.000Z

    In laser-induced breakdown spectroscopy, a femtosecond double-pulse laser was used to induce air plasma. The plasma spectroscopy was observed to lead to significant increase of the intensity and reproducibility of the optical emission signal compared to femtosecond single-pulse laser. In particular, the optical emission intensity can be optimized by adjusting the delay time of femtosecond double-pulse. An appropriate pulse-to-pulse delay was selected, that was typically about 50 ps. This effect can be especially advantageous in the context of femtosecond laser-induced breakdown spectroscopy, plasma channel, and so on.

  8. Schlieren Visualization Technique Applied to the Study of Laser-Induced Breakdown in Low Density Hypersonic Flow

    SciTech Connect (OSTI)

    Oliveira, A. C. [Laboratorio Associado de Combustao e Propulsao INPE, Caixa Postal 01 12630-000 Cachoeira Paulista, SP. (Brazil); Laboratory of Aerothermodynamics and Hypersonics, IEAv-CTA, Sao Jose dos Campos - SP 12228-840 (Brazil); Minucci, M. A. S.; Toro, P. G. P.; Chanes, J. B. Jr [Laboratory of Aerothermodynamics and Hypersonics, IEAv-CTA, Sao Jose dos Campos - SP 12228-840 (Brazil); Salvador, I. I. [Laboratorio Associado de Combustao e Propulsao INPE, Caixa Postal 01 12630-000 Cachoeira Paulista, SP (Brazil); Myrabo, L. N.; Nagamatsu, H. T. [Department of Mechanical, Aerospace, and Nuclear Engineering. Rensselaer Polytechnic Institute (RPI), Troy, NY (United States)

    2006-05-02T23:59:59.000Z

    Experimental results on the visualization of the time evolution of the laser-plasma induced breakdown produced in low density hypersonic flow using the Schlieren technique are presented. The plasma was generated by focusing the high power laser pulse of a CO2 TEA laser in the test section of the IEAv 0.3m Hypersonic Shock Tunnel. An ultra-high speed electronic tube camera was used to register the event. The photographs reveal the expansion of the shock wave produced by the laser generated hot plasma and the convection of the plasma kernel by the hypersonic flow. It is also observed the interaction between the plasma disturbed region and the shock established by the flow around an hemisphere-cylinder model. A strong change in the shock wave structure near the model was observed, corroborating the DEAS concept.

  9. Qualitative analysis of Pb liquid sample using laser-induced breakdown spectroscopy (LIBS)

    SciTech Connect (OSTI)

    Suyanto, Hery; Rupiasih, Ni Nyoman; Winardi, T. B. [Physics Department, Faculty of Mathematics and Natural Sciences, Udayana University. Kampus Bukit Jimbaran, Badung, Bali, Indonesia 80361 (Indonesia)] [Physics Department, Faculty of Mathematics and Natural Sciences, Udayana University. Kampus Bukit Jimbaran, Badung, Bali, Indonesia 80361 (Indonesia); Manurung, M. [Chemistry Dept, Faculty of Mathematics and Natural Sciences, Udayana University. Kampus Bukit Jimbaran, Badung, Bali, Indonesia 80361 (Indonesia)] [Chemistry Dept, Faculty of Mathematics and Natural Sciences, Udayana University. Kampus Bukit Jimbaran, Badung, Bali, Indonesia 80361 (Indonesia); Kurniawan, K. H. [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia)] [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia)

    2013-09-03T23:59:59.000Z

    Qualitative analysis of liquid sample containing 1,000 ppm of Pb was performed by using LIBS technique. In order to avoid splashing off of the liquid sample during laser irradiation, a sample pretreatment was done, namely the liquid sample was absorbed by using commercial available stomach medicine. Two kinds of absorbent materials were chosen in this experiment, first containing 125 mg activated carbon and second 600 mg activated attapulgite. These absorbent materials were used since carbon sample gives better absorption of infrared laser irradiation used in this experiment. In order to characterize the absorption process, three treatments were conducted in this experiment; first, without heating the sample but varying the absorption time before laser irradiation; second by varying the heating temperature after certain time of absorption process and third by varying the temperature only. The maximum emission intensity of Pb I 405.7 nm was found in the second treatment of heating the sample till 85C after 30 minutes absorption of the liquid sample in both absorbent materials.

  10. Indirect determination of the electric field in plasma discharges using laser-induced fluorescence spectroscopy

    SciTech Connect (OSTI)

    Vaudolon, J., E-mail: julien.vaudolon@cnrs-orleans.fr; Mazouffre, S., E-mail: stephane.mazouffre@cnrs-orleans.fr [CNRS - ICARE (Institut de Combustion Arothermique Ractivit et Environnement), 1 C Av. de la Recherche Scientifique, 45071 Orlans Cedex 2 (France)

    2014-09-15T23:59:59.000Z

    The evaluation of electric fields is of prime interest for the description of plasma characteristics. In this work, different methods for determining the electric field profile in low-pressure discharges using one- and two-dimensional Laser-Induced Fluorescence (LIF) measurements are presented and discussed. The energy conservation, fluid, and kinetic approaches appear to be well-suited for the electric field evaluation in this region of the plasma flow. However, the numerical complexity of a two-dimensional kinetic model is penalizing due to the limited signal-to-noise ratio that can be achieved, making the computation of the electric field subject to large error bars. The ionization contribution which appears in the fluid model makes it unattractive on an experimental viewpoint. The energy conservation and 1D1V kinetic approaches should therefore be preferred for the determination of the electric field when LIF data are used.

  11. Laser induced fluorescence and resonant two-photon ionization spectroscopy of jet-cooled 1-hydroxy-9,10-anthraquinone

    SciTech Connect (OSTI)

    Cho, Sung Haeng; Huh, Hyun; Kim, Hyung Min; Kim, Choong Ik; Kim, Nam Joon; Kim, Seong Keun [School of Chemistry, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2005-01-15T23:59:59.000Z

    We carried out laser induced fluorescence and resonance enhanced two-color two-photon ionization spectroscopy of jet-cooled 1-hydroxy-9,10-anthraquinone (1-HAQ). The 0-0 band transition to the lowest electronically excited state was found to be at 461.98 nm (21 646 cm-1). A well-resolved vibronic structure was observed up to 1100 cm-1 above the 0-0 band, followed by a rather broad absorption band in the higher frequency region. Dispersed fluorescence spectra were also obtained. Single vibronic level emissions from the 0-0 band showed Stokes-shifted emission spectra. The peak at 2940 cm-1 to the red of the origin in the emission spectra was assigned as the OH stretching vibration in the ground state, whose combination bands with the C=O bending and stretching vibrations were also seen in the emission spectra. In contrast to the excitation spectrum, no significant vibronic activity was found for low frequency fundamental vibrations of the ground state in the emission spectrum. The spectral features of the fluorescence excitation and emission spectra indicate that a significant change takes place in the intramolecular hydrogen bonding structure upon transition to the excited state, such as often seen in the excited state proton (or hydrogen) transfer. We suggest that the electronically excited state of interest has a double minimum potential of the 9,10-quinone and the 1,10-quinone forms, the latter of which, the proton-transferred form of 1-HAQ, is lower in energy. On the other hand, ab initio calculations at the B3LYP/6-31G(d,p) level predicted that the electronic ground state has a single minimum potential distorted along the reaction coordinate of tautomerization. The 9,10-quinone form of 1-HAQ is the lowest energy structure in the ground state, with the 1,10-quinone form lying {approx}5000 cm-1 above it. The intramolecular hydrogen bond of the 9,10-quinone was found to be unusually strong, with an estimated bond energy of {approx}13 kcal/mol ({approx}4500 cm-1), probably due to the resonance-assisted nature of the hydrogen bonding involved.

  12. E-Print Network 3.0 - abnormal breakdown characteristic Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    present the measurements and analysis of laser- induced breakdown processes in dry... -power microwave breakdown based on measured laser breakdown observations....

  13. Infrared laser induced plasma diagnostics of silver target

    SciTech Connect (OSTI)

    Ahmat, L., E-mail: lubnaphysics@yahoo.com; Nadeem, Ali [Laser Spectroscopy Laboratory, National Institute of Lasers and Optronics (NILOP), P.O. Nilore, Islamabad 45650 (Pakistan); Ahmed, I. [Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences (PIEAS), P.O. Nilore, Islamabad 45650 (Pakistan)

    2014-09-15T23:59:59.000Z

    In the present work, the optical emission spectra of silver (Ag) plasma have been recorded and analyzed using the laser induced breakdown spectroscopy technique. The emission line intensities and plasma parameters were investigated as a function of lens to sample distance, laser irradiance, and distance from the target surface. The electron number density (n{sub e}) and electron temperature (T{sub e}) were determined using the Stark broadened line profile and Boltzmann plot method, respectively. A gradual increase in the spectral line intensities and the plasma parameters, n{sub e} from 2.89??10{sup 17} to 3.92??10{sup 17?}cm{sup ?3} and T{sub e} from 4662 to 8967?K, was observed as the laser irradiance was increased 2.29??10{sup 10}1.06??10{sup 11} W cm{sup ?2}. The spatial variations in n{sub e} and T{sub e} were investigated from 0 to 5.25?mm from the target surface, yielding the electron number density from 4.78??10{sup 17} to 1.72??10{sup 17?}cm{sup ?3} and electron temperature as 98693789?K. In addition, the emission intensities and the plasma parameters of silver were investigated by varying the ambient pressure from 0.36 to 1000 mbars.

  14. Laboratory evaluation of laser-induced breakdown spectroscopy (LIBS) as a new in situ chemical sensing technique for the deep ocean

    E-Print Network [OSTI]

    Michel, Anna Pauline Miranda, 1976-

    2007-01-01T23:59:59.000Z

    Present-day expeditionary oceanography is beginning to shift from a focus on short-term ship and submersible deployments to an ocean observatory mode where long-term temporally-focused studies are feasible. As a result, a ...

  15. Femtosecond laser-induced modification of potassium-magnesium silicate glasses: An analysis of structural changes by near edge x-ray absorption spectroscopy

    SciTech Connect (OSTI)

    Seuthe, T.; Eberstein, M. [Fraunhofer-Institut fuer Keramische Technologien und Systeme (IKTS), Winterbergstrasse 28, 01277 Dresden (Germany); Hoefner, M.; Eichler, H. J.; Grehn, M. [Technische Universitaet Berlin, Institut fuer Optik und Atomare Physik, Strasse des 17. Juni 135, 10623 Berlin (Germany); Reinhardt, F. [Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin (Germany); Tsai, W. J. [ITRI South, Industrial Technology Research Institute, 8 Gongyan Rd., Liu-jia District, Tainan City 73445, Taiwan (China); Bonse, J. [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, 12205 Berlin (Germany)

    2012-05-28T23:59:59.000Z

    The effects of femtosecond laser pulse irradiation on the glass structure of alkaline silicate glasses were investigated by x-ray absorption near edge structure spectroscopy using the beamline of the Physikalisch-Technische Bundesanstalt at the electron synchrotron BESSY II in Berlin (Germany) by analyzing the magnesium K-edge absorption peak for different laser fluences. The application of fluences above the material modification threshold (2.1 J/cm{sup 2}) leads to a characteristic shift of {approx}1.0 eV in the K-edge revealing a reduced ({approx}3%) mean magnesium bond length to the ligated oxygen ions (Mg-O) along with a reduced average coordination number of the Mg ions.

  16. Laser Induced Chemical Liquid Phase Deposition (LCLD)

    SciTech Connect (OSTI)

    Nanai, Laszlo; Balint, Agneta M. [University of Szeged, JGYPK, Department of General and Environmental Physics H-6725 Szeged, Boldogasszony sgt. 6 (Hungary); West University of Timisoara, Faculty of Physics, Department of Physics, Bulv. V. Parvan 4, Timisoara 300223 (Romania)

    2012-08-17T23:59:59.000Z

    Laser induced chemical deposition (LCLD) of metals onto different substrates attracts growing attention during the last decade. Deposition of metals onto the surface of dielectrics and semiconductors with help of laser beam allows the creation of conducting metal of very complex architecture even in 3D. In the processes examined the deposition occurs from solutions containing metal ions and reducing agents. The deposition happens in the region of surface irradiated by laser beam (micro reactors). Physics -chemical reactions driven by laser beam will be discussed for different metal-substrate systems. The electrical, optical, mechanical properties of created interfaces will be demonstrated also including some practical-industrial applications.

  17. Modeling of Laser-Induced Metal Combustion

    SciTech Connect (OSTI)

    Boley, C D; Rubenchik, A M

    2008-02-20T23:59:59.000Z

    Experiments involving the interaction of a high-power laser beam with metal targets demonstrate that combustion plays an important role. This process depends on reactions within an oxide layer, together with oxygenation and removal of this layer by the wind. We present an analytical model of laser-induced combustion. The model predicts the threshold for initiation of combustion, the growth of the combustion layer with time, and the threshold for self-supported combustion. Solutions are compared with detailed numerical modeling as benchmarked by laboratory experiments.

  18. Speciation and spectroscopy of the uranyl and tetravalent plutonium nitrate systems: Fundamental studies and applications to used fuel reprocessing.

    E-Print Network [OSTI]

    Smith, Nicholas A

    2010-01-01T23:59:59.000Z

    ??This dissertation explores the use of UV-Visible spectroscopy and Time Resolved Laser Induced Fluorescence spectroscopy as near real time process monitors of uranium and plutonium (more)

  19. Classical cutoffs for laser-induced nonsequential double ionization

    SciTech Connect (OSTI)

    Milosevic, D.B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany); Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2003-12-01T23:59:59.000Z

    Classical cutoffs for the momenta of electrons ejected in laser-induced nonsequential double ionization are derived for the recollision-impact-ionization scenario. Such simple cutoff laws can aid in the interpretation of the observed electron spectra.

  20. Flame front tracking by laser induced fluorescence spectroscopy and advanced

    E-Print Network [OSTI]

    Hamarneh, Ghassan

    surface characteristics in turbulent premixed propane/air combustion," Combustion and Flame 120(4), 407 References and links 1. J. Warnatz, U. Maas, and R.W. Dibble, Combustion - physical and chemical fundamentals, "Characterization of flame front surfaces in turbulent premixed methane/air combustion," Combustion and Flame 101

  1. Laser-induced differential normalized fluorescence method for cancer diagnosis

    DOE Patents [OSTI]

    Vo-Dinh, T.; Panjehpour, M.; Overholt, B.F.

    1996-12-03T23:59:59.000Z

    An apparatus and method for cancer diagnosis are disclosed. The diagnostic method includes the steps of irradiating a tissue sample with monochromatic excitation light, producing a laser-induced fluorescence spectrum from emission radiation generated by interaction of the excitation light with the tissue sample, and dividing the intensity at each wavelength of the laser-induced fluorescence spectrum by the integrated area under the laser-induced fluorescence spectrum to produce a normalized spectrum. A mathematical difference between the normalized spectrum and an average value of a reference set of normalized spectra which correspond to normal tissues is calculated, which provides for amplifying small changes in weak signals from malignant tissues for improved analysis. The calculated differential normalized spectrum is correlated to a specific condition of a tissue sample. 5 figs.

  2. Laser-induced differential normalized fluorescence method for cancer diagnosis

    DOE Patents [OSTI]

    Vo-Dinh, Tuan (Knoxville, TN); Panjehpour, Masoud (Knoxville, TN); Overholt, Bergein F. (Knoxville, TN)

    1996-01-01T23:59:59.000Z

    An apparatus and method for cancer diagnosis are disclosed. The diagnostic method includes the steps of irradiating a tissue sample with monochromatic excitation light, producing a laser-induced fluorescence spectrum from emission radiation generated by interaction of the excitation light with the tissue sample, and dividing the intensity at each wavelength of the laser-induced fluorescence spectrum by the integrated area under the laser-induced fluorescence spectrum to produce a normalized spectrum. A mathematical difference between the normalized spectrum and an average value of a reference set of normalized spectra which correspond to normal tissues is calculated, which provides for amplifying small changes in weak signals from malignant tissues for improved analysis. The calculated differential normalized spectrum is correlated to a specific condition of a tissue sample.

  3. High resolution analysis of soil elements with laser-induced breakdown

    DOE Patents [OSTI]

    Ebinger, Michael H. (Santa Fe, NM); Harris, Ronny D. (Los Alamos, NM)

    2010-04-06T23:59:59.000Z

    The invention is a system and method of detecting a concentration of an element in a soil sample wherein an opening or slot is formed in a container that supports a soil sample that was extracted from the ground whereupon at least a length of the soil sample is exposed via the opening. At each of a plurality of points along the exposed length thereof, the soil sample is ablated whereupon a plasma is formed that emits light characteristic of the elemental composition of the ablated soil sample. Each instance of emitted light is separated according to its wavelength and for at least one of the wavelengths a corresponding data value related to the intensity of the light is determined. As a function of each data value a concentration of an element at the corresponding point along the length of the soil core sample is determined.

  4. Comparison and Validation of Compressible Flow Simulations of Laser-Induced Cavitation

    E-Print Network [OSTI]

    Comparison and Validation of Compressible Flow Simulations of Laser-Induced Cavitation Bubbles)). The validation is performed for the case of laser-induced cavitation bubbles collapsing in an infinite medium

  5. E-Print Network 3.0 - alleviates laser-induced choroidal Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    laser-induced choroidal Search Powered by Explorit Topic List Advanced Search Sample search results for: alleviates laser-induced choroidal Page: << < 1 2 3 4 5 > >> 1 SPIE...

  6. Laser induced electron acceleration in vacuum K. P. Singha)

    E-Print Network [OSTI]

    Singh, Kunwar Pal

    Laser induced electron acceleration in vacuum K. P. Singha) Department of Physics, Indian Institute acceleration by a plane polarized laser wave has been studied in vacuum. Relativistic equations of motion have been solved exactly for electron trajectory and energy as a function of laser intensity, phase

  7. Molecular Dynamics Simulations of Laser Induced Incandescence Dr. Adri van Duin

    E-Print Network [OSTI]

    Bjørnstad, Ottar Nordal

    Molecular Dynamics Simulations of Laser Induced Incandescence (LII) Dr. Adri van Duin Associate of Engineering. Laser Induced Incandescence (LII) is a popular method to estimate the properties of soot. Molecular Dynamics Simulations of Laser-Induced Incandescence of Soot Using an Extended ReaxFF Reactive

  8. Ultratrace analysis of transuranic actinides by laser-induced fluorescence

    DOE Patents [OSTI]

    Miller, S.M.

    1983-10-31T23:59:59.000Z

    Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

  9. AN ANALYTICAL AND QUANTITATIVE ANALYSIS OF THE LASER-INDUCED INCANDESCENCE OF SOOT

    E-Print Network [OSTI]

    Seitzman, Jerry M.

    AN ANALYTICAL AND QUANTITATIVE ANALYSIS OF THE LASER-INDUCED INCANDESCENCE OF SOOT A Thesis-INDUCED INCANDESCENCE OF SOOT Approved: _________________________ Jerry M. Seitzman, Chairman

  10. E-Print Network 3.0 - attenuates laser-induced choroidal Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A dynamic boundary condition that accounts for the laser induced pressure... of energy relaxation of individual molecules internally excited by photon absorption. The...

  11. Generation of laser-induced cavitation bubbles with a digital hologram

    E-Print Network [OSTI]

    Quinto-Su, P. A; Venugopalan, V.; Ohl, C.-D.

    2008-01-01T23:59:59.000Z

    C. D. Ohl, Controlled cavitation-cell interaction: trans-R. Dijkink and C. D. Ohl, Cavitation based micropump, Labobservations of laser- induced cavitation bubbles in water,

  12. Ultrafast dynamics of the laser-induced solid-to-liquid phase transition in aluminum

    E-Print Network [OSTI]

    Mazur, Eric

    Ultrafast dynamics of the laser-induced solid-to-liquid phase transition in aluminum A thesis dynamics of the laser-induced solid-to-liquid phase transition in aluminum Eric Mazur Maria Kandyla Abstract This dissertation reports the ultrafast dynamics of aluminum during the solid-to- liquid phase

  13. Luminescence from acoustic-driven laser-induced cavitation bubbles Claus-Dieter Ohl*

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    Luminescence from acoustic-driven laser-induced cavitation bubbles Claus-Dieter Ohl* Drittes and on the cavitation luminescence of a transient laser-induced bubble is investigated experimentally. The variation.60.Mq, 47.55.Bx, 47.55.Dz A vast concentration of energy occurs during the collapse of a cavitation

  14. LASER-INDUCED SHOCK WAVES IN CONDENSED MATTER: SOME TECHNIQUES AND APPLICATIONS

    E-Print Network [OSTI]

    Asimow, Paul D.

    LASER-INDUCED SHOCK WAVES IN CONDENSED MATTER: SOME TECHNIQUES AND APPLICATIONS S. N. LUOa,? , D. C, NV 89154, USA; c GPS Division, California Institute of Technology, Pasadena, CA 91125, USA Laser pressure physics. We briefly review some techniques in laser-induced shock waves, including direct laser

  15. Ultrafast laser induced periodic sub-wavelength aluminum surface structures and nanoparticles in air and liquids

    SciTech Connect (OSTI)

    Kuladeep, Rajamudili; Dar, Mudasir H.; Rao, D. Narayana, E-mail: dnrsp@uohyd.ac.in, E-mail: dnr-laserlab@yahoo.com [School of Physics, University of Hyderabad, Hyderabad 500046 (India); Deepak, K. L. N. [Department of Physics and Center for Research in Photonics, University of Ottawa, 150 Louis Pasteur, Ottawa K1N6N5, Ontario (Canada)

    2014-09-21T23:59:59.000Z

    In this communication, we demonstrate the generation of laser-induced periodic sub-wavelength surface structures (LIPSS) or ripples on a bulk aluminum (Al) and Al nanoparticles (NPs) by femtosecond (fs) laser direct writing technique. Laser irradiation was performed on Al surface at normal incidence in air and by immersing in ethanol (C{sub 2}H{sub 5}OH) and water (H{sub 2}O) using linearly polarized Ti:sapphire fs laser pulses of ?110 fs pulse duration and ?800?nm wavelength. Field emission scanning electron microscope is utilized for imaging surface morphology of laser written structures and it reveals that the spatial periodicity as well as the surface morphology of the LIPSS depends on the surrounding dielectric medium and also on the various laser irradiation parameters. The observed LIPSS have been classified as low spatial frequency LIPSS which are perpendicularly oriented to the laser polarization with a periodicity from 460 to 620?nm and high spatial frequency LIPSS which spectacles a periodicity less than 100?nm with the orientation parallel to the polarization of the incident laser beam. Fabricated colloidal solutions, which contain the Al NPs, were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). TEM results reveal the formation of internal cavities in Al NPs both in ethanol and water. Formation mechanism of LIPSS and cavities inside the nanoparticles are discussed in detail.

  16. Laser induced damage of fused silica polished optics due to a droplet forming organic contaminant

    SciTech Connect (OSTI)

    Bien-Aime, Karell; Neauport, Jerome; Tovena-Pecault, Isabelle; Fargin, Evelyne; Labrugere, Christine; Belin, Colette; Couzi, Michel

    2009-04-20T23:59:59.000Z

    We report on the effect of organic molecular contamination on single shot laser induced damage density at the wavelength of 351 nm, with a 3 ns pulse length. Specific contamination experiments were made with dioctylphthalate (DOP) in liquid or gaseous phase, on the surface of fused silica polished samples, bare or solgel coated. Systematic laser induced damage was observed only in the case of liquid phase contamination. Different chemical and morphological characterization methods were used to identify and understand the damage process. We demonstrate that the contaminant morphology, rather than its physicochemical nature, can be responsible for the decrease of laser induced damage threshold of optics.

  17. Finite element analysis of blister formation in laser-induced forward transfer

    E-Print Network [OSTI]

    Arnold, Craig B.

    , the large film thickness and small thermal diffusivity of the polymer minimize heat diffusion throughARTICLES Finite element analysis of blister formation in laser-induced forward transfer Nicholas T

  18. CO-CATALYTIC ABSORPTION LAYERS FOR CONTROLLED LASER-INDUCED CHEMICAL VAPOR DEPOSITION OF CARBON NANOTUBES

    E-Print Network [OSTI]

    Michaelis, F.B.; Weatherup, R.S.; Bayer, B.C.; Bock, M.C.D; Sugime, H.; Caneva, S.; Robertson, J.; Baumberg, J.J.; Hofmann, S.

    2014-02-24T23:59:59.000Z

    The concept of co-catalytic layer structures for controlled laser-induced chemical vapor deposition of carbon nanotubes is established, in which a thin Ta support layer chemically aids the initial Fe catalyst reduction. This enables a significant...

  19. Assessment of soot particle vaporization effects during laser-induced incandescence with

    E-Print Network [OSTI]

    Hahn, David W.

    Assessment of soot particle vaporization effects during laser-induced incandescence with time-induced incandescence (LII) has been successfully used for soot volume fraction and particle size measurements

  20. Ultrafast Laser Induced Thermo-Elasto-Visco-Plastodynamics in Single Crystalline Silicon

    E-Print Network [OSTI]

    Qi, Xuele

    2011-02-22T23:59:59.000Z

    pulse width in Laser Induced Stress Waves Thermometry (LISWT) for single crystalline silicon processing motivated the work. The model formulation developed is of a hyperbolic type capable of characterizing non-thermal melting and thermo...

  1. E-Print Network 3.0 - absorption laser-induced lyman- Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Powered by Explorit Topic List Advanced Search Sample search results for: absorption laser-induced lyman- Page: << < 1 2 3 4 5 > >> 1 6412 J. Phys. Chcm. 1993,97, 64126417 H +0...

  2. Airborne laser induced fluorescence imaging. Innovative technology summary report

    SciTech Connect (OSTI)

    NONE

    1999-06-01T23:59:59.000Z

    Laser-Induced Fluorescence (LIF) was demonstration as part of the Fernald Environmental Management Project (FEMP) Plant 1 Large Scale Demonstration and Deployment Project (LSDDP) sponsored by the US Department of Energy (DOE) Office of Science and Technology, Deactivation and Decommissioning Focus Area located at the Federal Energy Technology Center (FETC) in Morgantown, West Virginia. The demonstration took place on November 19, 1996. In order to allow the contaminated buildings undergoing deactivation and decommissioning (D and D) to be opened to the atmosphere, radiological surveys of floors, walls and ceilings must take place. After successful completion of the radiological clearance survey, demolition of the building can continue. Currently, this process is performed by collecting and analyzing swipe samples for radiological analysis. Two methods are used to analyze the swipe samples: hand-held frisker and laboratory analysis. For the purpose of this demonstration, the least expensive method, swipe samples analyzed by hand-held frisker, is the baseline technology. The objective of the technology demonstration was to determine if the baseline technology could be replaced using LIF.

  3. Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakersSpectroscopy Print In

  4. Laser-induced fluorescence of fused silica irradiated by ArF excimer laser

    SciTech Connect (OSTI)

    Zhang Haibo [Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China); Graduate University of Chinese Academy of Science, Beijing 100049 (China); Yuan Zhijun; Zhou Jun; Dong Jingxing; Wei Yunrong; Lou Qihong [Shanghai Key Laboratory of All Solid-state Laser and Applied Techniques, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800 (China)

    2011-07-01T23:59:59.000Z

    Laser-induced fluorescence (LIF) of high-purity fused silica irradiated by ArF excimer laser is studied experimentally. LIF bands of the fused silica centered at 281 nm, 478 nm, and 650 nm are observed simultaneously. Furthermore, the angular distribution of the three fluorescence peaks is examined. Microscopic image of the laser modified fused silica indicates that scattering of the generated fluorescence by laser-induced damage sites is the main reason for the angular distribution of LIF signals. Finally, the dependence of LIF signals intensities of the fused silica on laser power densities is presented. LIF signals show a squared power density dependence, which indicates that laser-induced defects are formed mainly via two-photon absorption processes.

  5. Laser-induced synthesis and decay of Tritium under exposure of solid targets in heavy water

    E-Print Network [OSTI]

    E. V. Barmina; P. G. Kuzmin; S. F. Timashev; G. A. Shafeev

    2013-06-03T23:59:59.000Z

    The processes of laser-assisted synthesis of Tritium nuclei and their laser-induced decay in cold plasma in the vicinity of solid targets (Au, Ti, Se, etc.) immersed into heavy water are experimentally realized at peak laser intensity of 10E10-10E13 Watts per square centimeter. Initial stages of Tritium synthesis and their laser-induced beta-decay are interpreted on the basis of non-elastic interaction of plasma electrons having kinetic energy of 5-10 eV with nuclei of Deuterium and Tritium, respectively.

  6. Laser-induced synthesis and decay of Tritium under exposure of solid targets in heavy water

    E-Print Network [OSTI]

    Barmina, E V; Timashev, S F; Shafeev, G A

    2013-01-01T23:59:59.000Z

    The processes of laser-assisted synthesis of Tritium nuclei and their laser-induced decay in cold plasma in the vicinity of solid targets (Au, Ti, Se, etc.) immersed into heavy water are experimentally realized at peak laser intensity of 10E10-10E13 Watts per square centimeter. Initial stages of Tritium synthesis and their laser-induced beta-decay are interpreted on the basis of non-elastic interaction of plasma electrons having kinetic energy of 5-10 eV with nuclei of Deuterium and Tritium, respectively.

  7. Multiscale analysis of the laser-induced damage threshold in optical coatings

    SciTech Connect (OSTI)

    Capoulade, Jeremie; Gallais, Laurent; Natoli, Jean-Yves; Commandre, Mireille

    2008-10-10T23:59:59.000Z

    We have investigated the influence of laser beam size on laser-induced damage threshold (LIDT) in the case of single- and multiple-shot irradiation. The study was performed on hafnia thin films deposited with various technologies (evaporation, sputtering, with or without ion assistance). LIDT measurements were carried out at 1064 nm and 12 ns with a spot size ranging from a few tens to a few hundreds of micrometers, in 1-on-1 and R-on-1 modes. These measurements were compared with simulations obtained with the statistical theory of laser-induced damage caused by initiating inclusions.

  8. PAPER www.rsc.org/loc | Lab on a Chip Laser-induced cavitation based micropump

    E-Print Network [OSTI]

    Ohl, Claus-Dieter

    PAPER www.rsc.org/loc | Lab on a Chip Laser-induced cavitation based micropump Rory Dijkinka as versatile and robust pumping techniques. Here, we present a cavitation based technique, which is able cavitation event is created by focusing a laser pulse in a conventional PDMS microfluidic chip close

  9. Transient phenomena in the dielectric breakdown of HfO{sub 2} optical films probed by ultrafast laser pulse pairs

    SciTech Connect (OSTI)

    Nguyen, Duy N.; Emmert, Luke A.; Rudolph, Wolfgang [Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Patel, Dinesh; Menoni, Carmen S. [Department of Electrical and Computer Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2010-11-08T23:59:59.000Z

    The laser induced breakdown threshold of HfO{sub 2} films is studied with single pairs of pulses of variable delay and 50 fs and 1 ps pulse duration. Two distinct transient regimes are observed that can be related to the relaxation of the electron density from the conduction band via an intermediate state to the valence band. The experimental results are in good agreement with a theoretical model that assumes occupation of mid gap states after the first pulse on a time scale of several tens of picoseconds and subsequent decay of this population via recombination with holes in the valence band on a time scale of several tens of milliseconds.

  10. Characterization of hydrocarbon and mixed layers in TEXTOR by laser induced ablation spectroscopy

    E-Print Network [OSTI]

    Giesen, Thomas

    : 134.95.83.67 The article was downloaded on 10/03/2012 at 13:13 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search the plasma discharge by intense laser radiation. The light emitted by particles entering the edge

  11. AFM CHARACTERIZATION OF RAMAN LASER INDUCED DAMAGE ON CDZNTECRYSTAL SURFACES

    SciTech Connect (OSTI)

    Teague, L.; Duff, M.

    2008-10-07T23:59:59.000Z

    High quality CdZnTe (or CZT) crystals have the potential for use in room temperature gamma-ray and X-ray spectrometers. Over the last decade, the methods for growing high quality CZT have improved the quality of the produced crystals however there are material features that can influence the performance of these materials as radiation detectors. The presence of structural heterogeneities within the crystals, such as twinning, pipes, grain boundaries (polycrystallinity), and secondary phases (SPs) can have an impact on the detector performance. There is considerable need for reliable and reproducible characterization methods for the measurement of crystal quality. With improvements in material characterization and synthesis, these crystals may become suitable for widespread use in gamma radiation detection. Characterization techniques currently utilized to test for quality and/or to predict performance of the crystal as a gamma-ray detector include infrared (IR) transmission imaging, synchrotron X-ray topography, photoluminescence spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM) and Raman spectroscopy. In some cases, damage caused by characterization methods can have deleterious effects on the crystal performance. The availability of non-destructive analysis techniques is essential to validate a crystal's quality and its ability to be used for either qualitative or quantitative gamma-ray or X-ray detection. The work presented herein discusses the damage that occurs during characterization of the CZT surface by a laser during Raman spectroscopy, even at minimal laser powers. Previous Raman studies have shown that the localized annealing from tightly focused, low powered lasers results in areas of higher Te concentration on the CZT surface. This type of laser damage on the surface resulted in decreased detector performance which was most likely due to increased leakage current caused by areas of higher Te concentration. In this study, AFM was used to characterize the extent of damage to the CZT crystal surface following exposure to a Raman laser. AFM data reveal localized surface damage and increased conductivity in the areas exposed to the Raman laser beam.

  12. AFM CHARACTERIZATION OF LASER INDUCED DAMAGE ON CDZNTE CRYSTAL SURFACES

    SciTech Connect (OSTI)

    Hawkins, S; Lucile Teague, L; Martine Duff, M; Eliel Villa-Aleman, E

    2008-06-10T23:59:59.000Z

    Semi-conducting CdZnTe (or CZT) crystals can be used in a variety of detector-type applications. CZT shows great promise for use as a gamma radiation spectrometer. However, its performance is adversely affected by point defects, structural and compositional heterogeneities within the crystals, such as twinning, pipes, grain boundaries (polycrystallinity), secondary phases and in some cases, damage caused by external forces. One example is damage that occurs during characterization of the surface by a laser during Raman spectroscopy. Even minimal laser power can cause Te enriched areas on the surface to appear. The Raman spectra resulting from measurements at moderate intensity laser power show large increases in peak intensity that is attributed to Te. Atomic Force Microscopy (AFM) was used to characterize the extent of damage to the CZT crystal surface following exposure to the Raman laser. AFM data reveal localized surface damage in the areas exposed to the Raman laser beam. The degree of surface damage to the crystal is dependent on the laser power, with the most observable damage occurring at high laser power. Moreover, intensity increases in the Te peaks of the Raman spectra are observed even at low laser power with little to no visible damage observed by AFM. AFM results also suggest that exposure to the same amount of laser power yields different amounts of surface damage depending on whether the exposed surface is the Te terminating face or the Cd terminating face of CZT.

  13. Application of a ratiometric laser induced fluorescence (LIF) thermometry for micro-scale temperature measurement for natural convection flows

    E-Print Network [OSTI]

    Lee, Heon Ju

    2004-11-15T23:59:59.000Z

    A ratiometric laser induced fluorescence (LIF) thermometry applied to micro-scale temperature measurement for natural convection flows. To eliminate incident light non-uniformity and imperfection of recording device, two fluorescence dyes are used...

  14. KrF- and ArF-excimer-laser-induced absorption in silica glasses produced by melting synthetic silica powder

    SciTech Connect (OSTI)

    Kuzuu, Nobu; Sasaki, Toshiya; Kojima, Tatsuya [Department of Applied Physics, University of Fukui, 3-9-1 Bunkyo, Fukui-shi, Fukui 910-8507 (Japan); Tanaka, Jun-ichiro; Nakamura, Takayuki; Horikoshi, Hideharu [Tosoh SGM Corp., 4555 Kaisei-cho, Shunan-shi, Yamaguchi 746-0006 (Japan)

    2013-07-07T23:59:59.000Z

    KrF- and ArF-excimer-laser-induced absorption of silica glasses produced by electric melting and flame fusion of synthetic silica powder were investigated. The growth of KrF-laser-induced absorption was more gradual than that of ArF-laser-induced absorption. Induced absorption spectra exhibited a peak at about 5.8 eV, of which the position and width differed slightly among samples and laser species. Widths of ArF-laser-induced absorption spectra were wider than those of KrF-laser-induced spectra. KrF-laser-induced absorption is reproducible by two Gaussian absorption bands peaking at 5.80 eV with full width at half maximum (FWHM) of 0.62 eV and at 6.50 eV with FWHM of 0.74 eV. For reproduction of ArF-laser-induced absorption, Gaussian bands at 5.41 eV with FWHM of 0.62 eV was necessary in addition to components used for reproducing KrF-laser-induced absorption. Based on the discussion of the change of defect structures evaluated from change of absorption components, we proposed that the precursor of the 5.8-eV band ascribed to E Prime center ({identical_to}Si{center_dot}) is {identical_to}Si-H HO-Si{identical_to} structures formed by the reaction between strained Si-O-Si bonds and interstitial H{sub 2} molecules during the irradiation.

  15. Use of fiber optic guided, laser induced acoustic waves for nde

    E-Print Network [OSTI]

    Duffer, Charles Edward

    1990-01-01T23:59:59.000Z

    the fiber ends. This heat was generated because as mentioned before the laser light only propagates in the core of the fiber. So a large percentage of the energy strikes cladding and surrounding material where it is partially absorbed as heat. The reason...USE OF FIBER OPTIC GUIDED, LASER INDUCED ACOUSTIC WAVES FOR NDE A Thesis by CHARLES EDWARD DUFFER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

  16. Femtosecond laser-induced asymmetric large scale waves on gold surfaces

    SciTech Connect (OSTI)

    Yong Hwang, Taek; Guo, Chunlei [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

    2012-07-09T23:59:59.000Z

    With femtosecond (fs) pulse irradiation, we investigate the morphological evolution of a unique type of fs laser-induced periodic surface structure, called nanostructure-covered large scale waves (NC-LSWs), covered by iterating stripe patterns of nanostructures and microstructures with a period of tens of microns. By monitoring the morphological profile of NC-LSWs following fs laser heating of Au, we show that the NC-LSWs are highly asymmetrically formed and propagate on a gold surface. We believe that the selective laser ablation of Au surface and the subsequent mass transfer of liquid Au following nonuniform energy deposition result in the asymmetric NC-LSW propagation on metals.

  17. Observation of femtosecond laser-induced nanostructure-covered large scale waves on metals

    SciTech Connect (OSTI)

    Hwang, Taek Yong; Guo Chunlei [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

    2011-04-15T23:59:59.000Z

    Following femtosecond (fs) laser pulse irradiation, we produce a type of periodic surface structure with a period tens of times greater than the laser wavelength and densely covered by an iterating pattern that consists of stripes of nanostructures and microscale cellular structures. The morphology of this large scale wave pattern crucially depends on laser fluence and the number of laser pulses, but not on the laser wavelength. Our study suggests that this large scale wave is initiated by fs laser induced surface unevenness followed by periodically distributed nonuniform surface heating from fs pulse irradiation.

  18. Dressed-state strong-field approximation for laser-induced molecular ionization

    SciTech Connect (OSTI)

    Becker, W. [Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany); Chen, J.; Chen, S. G. [Institute of Applied Physics and Computational Mathematics, P. O. Box 8009(28), 100088 Beijing (China); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2007-09-15T23:59:59.000Z

    In the customary formulation of the strong-field approximation (SFA) for laser-induced ionization, the initial bound state is taken as field-free. In the formulation of a length-gauge SFA for ionization of a molecule described by a two-center binding potential with sufficiently large internuclear separation, we argue that the initial state has to be dressed in order to account for the different scalar potentials at the various centers. We propose a 'dressed-state' SFA to this end.

  19. Simultaneous two-dimensional laser-induced-fluorescence measurements of argon ions

    SciTech Connect (OSTI)

    Hansen, A. K.; Galante, Matthew; McCarren, Dustin; Sears, Stephanie; Scime, E. E. [Department of Physics, West Virginia University, P.O. Box 6315, Morgantown, West Virginia 26506-6315 (United States)

    2010-10-15T23:59:59.000Z

    Recent laser upgrades on the Hot Helicon Experiment at West Virginia University have enabled multiplexed simultaneous measurements of the ion velocity distribution function at a single location, expanding our capabilities in laser-induced fluorescence diagnostics. The laser output is split into two beams, each modulated with an optical chopper and injected perpendicular and parallel to the magnetic field. Light from the crossing point of the beams is transported to a narrow-band photomultiplier tube filtered at the fluorescence wavelength and monitored by two lock-in amplifiers, each referenced to one of the two chopper frequencies.

  20. Femtosecond diffraction dynamics of laser-induced periodic surface structures on fused silica

    SciTech Connect (OSTI)

    Hoehm, S.; Rosenfeld, A. [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strasse 2A, D-12489 Berlin (Germany)] [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strasse 2A, D-12489 Berlin (Germany); Krueger, J.; Bonse, J. [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, D-12205 Berlin (Germany)] [BAM Bundesanstalt fuer Materialforschung und - pruefung, Unter den Eichen 87, D-12205 Berlin (Germany)

    2013-02-04T23:59:59.000Z

    The formation of laser-induced periodic surface structures (LIPSS) on fused silica upon irradiation with linearly polarized fs-laser pulses (50 fs pulse duration, 800 nm center wavelength) is studied experimentally using a transillumination femtosecond time-resolved (0.1 ps-1 ns) pump-probe diffraction approach. This allows to reveal the generation dynamics of near-wavelength-sized LIPSS showing a transient diffraction at specific spatial frequencies even before a corresponding permanent surface relief was observed. The results confirm that the ultrafast energy deposition to the materials surface plays a key role and triggers subsequent physical mechanisms such as carrier scattering into self-trapped excitons.

  1. Pump-probe imaging of laser-induced periodic surface structures after ultrafast irradiation of Si

    SciTech Connect (OSTI)

    Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Adams, David P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2013-09-30T23:59:59.000Z

    Ultrafast pump-probe microscopy has been used to investigate laser-induced periodic surface structure (LIPSS) formation on polished Si surfaces. A crater forms on the surface after irradiation by a 150 fs laser pulse, and a second, subsequent pulse forms LIPSS within the crater. Sequentially delayed images show that LIPSS with a periodicity slightly less than the fundamental laser wavelength of 780 nm appear on Si surfaces ?50 ps after arrival of the second pump laser pulse, well after the onset of melting. LIPSS are observed on the same timescale as material removal, suggesting that their formation involves material ejection.

  2. Cooperative effect of ultraviolet and near-infrared beams in laser-induced condensation

    SciTech Connect (OSTI)

    Matthews, M.; Henin, S.; Pomel, F.; Kasparian, J.; Wolf, J.-P. [Universit de Genve, GAP-Biophotonics, Chemin de Pinchat 22, 1211 Geneva 4 (Switzerland)] [Universit de Genve, GAP-Biophotonics, Chemin de Pinchat 22, 1211 Geneva 4 (Switzerland); Thberge, F.; Daigle, J.-F. [Defence R and D Canada Valcartier, 2459 de la Bravoure Blvd., Quebec (Qc) G3J 1X5 (Canada)] [Defence R and D Canada Valcartier, 2459 de la Bravoure Blvd., Quebec (Qc) G3J 1X5 (Canada); Lassonde, P.; Kieffer, J.-C. [INRS-EMT, 1650 Lionel Boulet Blvd., Varennes, Quebec (Qc) J3X1S2 (Canada)] [INRS-EMT, 1650 Lionel Boulet Blvd., Varennes, Quebec (Qc) J3X1S2 (Canada)

    2013-12-23T23:59:59.000Z

    We demonstrate the cooperative effect of near infrared (NIR) and ultraviolet (UV) beams on laser-induced condensation. Launching a UV laser after a NIR pulse yields up to a 5-fold increase in the production of nanoparticles (25300 nm) as compared to a single NIR beam. This cooperative effect exceeds the sum of those from the individual beams and occurs for delays up to 1 ?s. We attribute it to the UV photolysis of ozone created by the NIR pulses. The resulting OH radicals oxidize NO{sub 2} and volatile organic compounds, producing condensable species.

  3. RF breakdown effects in microwave power amplifiers

    E-Print Network [OSTI]

    Arumilli, Gautham Venkat

    2007-01-01T23:59:59.000Z

    Electrical stresses in the transistors of high-efficiency switching power amplifiers can lead to hot-electron-induced "breakdown" in these devices. This thesis explores issues related to breakdown in the Transcom TC2571 ...

  4. Resonant- and avalanche-ionization amplification of laser-induced plasma in air

    SciTech Connect (OSTI)

    Wu, Yue; Zhang, Zhili, E-mail: zzhang24@utk.edu [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Jiang, Naibo; Roy, Sukesh [Spectral Energies, LLC, 5100 Springfield St., Suite 301, Dayton, Ohio 45431 (United States); Gord, James R. [Air Force Research Laboratory, Aerospace Systems Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States)

    2014-10-14T23:59:59.000Z

    Amplification of laser-induced plasma in air is demonstrated utilizing resonant laser ionization and avalanche ionization. Molecular oxygen in air is ionized by a low-energy laser pulse employing (2 + 1) resonance-enhanced multi-photon ionization (REMPI) to generate seed electrons. Subsequent avalanche ionization of molecular oxygen and nitrogen significantly amplifies the laser-induced plasma. In this plasma-amplification effect, three-body attachments to molecular oxygen dominate the electron-generation and -loss processes, while either nitrogen or argon acts as the third body with low electron affinity. Contour maps of the electron density within the plasma obtained in O{sub 2}/N{sub 2} and O{sub 2}/Ar gas mixtures are provided to show relative degrees of plasma amplification with respect to gas pressure and to verify that the seed electrons generated by O{sub 2} 2 + 1 REMPI are selectively amplified by avalanche ionization of molecular nitrogen in a relatively low-pressure condition (?100?Torr). Such plasma amplification occurring in air could be useful in aerospace applications at high altitude.

  5. Laser-induced magnesium production from magnesium oxide using reducing agents

    SciTech Connect (OSTI)

    Mohamed, M. S.; Yabe, T.; Baasandash, C.; Sato, Y.; Mori, Y.; Shi-Hua, Liao; Sato, H.; Uchida, S. [Entropia Laser Initiative, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, Tokyo 152-8552 (Japan)

    2008-12-01T23:59:59.000Z

    Experiments for laser induced production of magnesium (Mg) from magnesium oxide (MgO) using reducing agents (R) were conducted. In these experiments, continuous wave CO{sub 2} focused laser is focused on a mixture of magnesium oxide and reducing agent. High power density of focused laser leads to high temperature and the reduction reaction resulting in Mg production. The resultant vapor is collected on a copper plate and analyzed in terms of magnesium deposition efficiency. Deposition efficiencies with various reducing agents such as Zr, C, and Si have been measured to be 60, 9.2, and 12.1 mg/kJ respectively. An excess addition of reducing agent over their corresponding reaction stoichiometric amounts is found to be optimum condition for the most of performed laser induced reactions. In addition, utilizing solar-pumped laser in Mg production with reducing agent will reduce CO{sub 2} emission and produce magnesium with high-energy efficiency and large throughput.

  6. Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural transformations: Molecular dynamics study

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural dynamics simulations of a 20 nm Au film irradiated with 200 fs laser pulses of different intensity in time-resolved x-ray and electron diffraction experiments. Three processes are found to be responsible

  7. Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium: a first-principles study

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Free electron properties of metals under ultrafast laser-induced electron-phonon nonequilibrium CEA-DIF, 91297 Arpajon, France (Dated: April 3, 2014) The electronic behavior of various solid metals modelled based on the free electron classical theory, the free electron number is a key parameter. However

  8. Effect of damping on the laser induced ultrafast switching in rare earth-transition metal alloys

    SciTech Connect (OSTI)

    Oniciuc, Eugen; Stoleriu, Laurentiu; Cimpoesu, Dorin; Stancu, Alexandru, E-mail: alstancu@uaic.ro [Faculty of Physics and CARPATH Center, Alexandru Ioan Cuza University, 700506 Iasi (Romania)

    2014-06-02T23:59:59.000Z

    In this paper, we present simulations of thermally induced magnetic switching in ferrimagnetic systems performed with a Landau-Lifshitz-Bloch (LLB) equation for damping constant in a wide range of values. We have systematically studied the GdFeCo ferrimagnet with various concentrations of Gd and compared for some values of parameters the LLB results with atomistic simulations. The agreement is remarkably good, which shows that the dynamics described by the ferrimagnetic LLB is a reasonable approximation of this complex physical phenomenon. As an important element, we show that the LLB is able to also describe the intermediate formation of a ferromagnetic state which seems to be essential to understand laser induced ultrafast switching. The study reveals the fundamental role of damping during the switching process.

  9. Polarization dependent formation of femtosecond laser-induced periodic surface structures near stepped features

    SciTech Connect (OSTI)

    Murphy, Ryan D. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, Ben [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Adams, David P. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Yalisove, Steven M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-06-09T23:59:59.000Z

    Laser-induced periodic surface structures (LIPSS) are formed near 110?nm-tall Au microstructured edges on Si substrates after single-pulse femtosecond irradiation with a 150 fs pulse centered near a 780 nm wavelength. We investigate the contributions of Fresnel diffraction from step-edges and surface plasmon polariton (SPP) excitation to LIPSS formation on Au and Si surfaces. For certain laser polarization vector orientations, LIPSS formation is dominated by SPP excitation; however, when SPP excitation is minimized, Fresnel diffraction dominates. The LIPSS orientation and period distributions are shown to depend on which mechanism is activated. These results support previous observations of the laser polarization vector influencing LIPSS formation on bulk surfaces.

  10. A laser-induced repetitive fast neutron source applied for gold activation analysis

    SciTech Connect (OSTI)

    Lee, Sungman; Park, Sangsoon; Lee, Kitae; Cha, Hyungki [Quantum Optics Division, Korea Atomic Energy Research Institute, Daejeon 305-600 (Korea, Republic of)

    2012-12-15T23:59:59.000Z

    A laser-induced repetitively operated fast neutron source was developed for applications in laser-driven nuclear physics research. The developed neutron source, which has a neutron yield of approximately 4 Multiplication-Sign 10{sup 5} n/pulse and can be operated up to a pulse repetition rate of 10 Hz, was applied for a gold activation analysis. Relatively strong delayed gamma spectra of the activated gold were measured at 333 keV and 355 keV, and proved the possibility of the neutron source for activation analyses. In addition, the nuclear reactions responsible for the measured gamma spectra of gold were elucidated by the 14 MeV fast neutrons resulting from the D(t,n)He{sup 4} nuclear reaction, for which the required tritium originated from the primary fusion reaction, D(d,p)T{sup 3}.

  11. Time-resolved measurement of single pulse femtosecond laser-induced periodic surface structure formation

    E-Print Network [OSTI]

    Kafka, K R P; Li, H; Yi, A; Cheng, J; Chowdhury, E A

    2015-01-01T23:59:59.000Z

    Time-resolved diffraction microscopy technique has been used to observe the formation of laser-induced periodic surface structures (LIPSS) from the interaction of a single femtosecond laser pulse (pump) with a nano-scale groove mechanically formed on a single-crystal Cu substrate. The interaction dynamics (0-1200 ps) was captured by diffracting a time-delayed, frequency-doubled pulse from nascent LIPSS formation induced by the pump with an infinity-conjugate microscopy setup. The LIPSS ripples are observed to form sequentially outward from the groove edge, with the first one forming after 50 ps. A 1-D analytical model of electron heating and surface plasmon polariton (SPP) excitation induced by the interaction of incoming laser pulse with the groove edge qualitatively explains the time-evloution of LIPSS formation.

  12. Laser-induced fluorescence measurements on plasma science experiments at PPPL

    SciTech Connect (OSTI)

    Koepke, Mark

    2011-12-20T23:59:59.000Z

    Collaborative research between WVU and PPPL was carried out at WVU for the purpose of incorporating the sophisticated diagnostic technique known as laser-induced fluorescence (LIF) in the Paul-Trap Simulation Experiment (PTSX) at PPPL. WVU assembled a LIF system at WVU, transported it to PPPL, helped make LIF experiments on the PTSX device, participated in PTSX science, and trained PPPL staff in LIF techniques. In summary, WVU refurbished a non-operational LIF system being loaned from University of Maryland to PPPL and, by doing so, provided PPPL with additional diagnostic capability for its PTSX device and other General Plasma Science experiments. WVU students, staff, and faculty will visit PPPL to collaborate on PTSX experiments in the future.

  13. Influence of cleaning process on the laser-induced damage threshold of substrates

    SciTech Connect (OSTI)

    Shen Zhengxiang; Ding Tao; Ye Xiaowen; Wang Xiaodong; Ma Bin; Cheng Xinbin; Liu Huasong; Ji Yiqin; Wang Zhanshan

    2011-03-20T23:59:59.000Z

    The cleaning process of optical substrates plays an important role during the manufacture of high-power laser coatings. Two kinds of substrates, fused silica and BK7 glass, and two cleaning processes, called process 1 and process 2 having different surfactant solutions and different ultrasonic cleaning parameters, are adopted to compare the influence of the ultrasonic cleaning technique on the substrates. The evaluation standards of the cleaning results include contaminant-removal efficiency, weak absorption, and laser-induced damage threshold of the substrates. For both fused silica and BK7, process 2 is more efficient than process 1. Because acid and alkaline solutions can increase the roughness of BK7, process 2 is unsuitable for BK7 glass cleaning. The parameters of the cleaning protocol should be changed depending on the material of the optical components and the type of contamination.

  14. E-Print Network 3.0 - andrzej bernacki tomasz Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    QD96 .A8 C74 2006 Laser Induced Breakdown Spectroscopy by Andrzej... .2 .R63 2005 Mathematics for Finance: An Introduction to Financial Engineering by Marek Capinski, Tomasz...

  15. Estimating the pressure of laser-induced plasma shockwave by stimulated Raman shift of lattice translational modes

    SciTech Connect (OSTI)

    Li Zhanlong [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China); College of Physics, Jilin University, Changchun 130012 (China); Shan Xiaoning; Li Zuowei; Zhou Mi; Men Zhiwei [College of Physics, Jilin University, Changchun 130012 (China); Cao Junsheng [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033 (China); Wang Yiding [College of Electronic Science and Engineering and Key Laboratory on Integrated Optoelectronics, Jilin University, Changchun 130012 (China); Sun Chenglin [State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012 (China)

    2012-07-09T23:59:59.000Z

    The current paper investigates stimulated Raman scattering (SRS) when laser-induced plasma is formed in heavy water by focusing an intense pulsed 532 nm Nd:YAG laser beam at room temperature. An unexpected low-frequency SRS line attributed to the lattice translational modes of ice-VII (D{sub 2}O) is observed. The pressure of the plasma shockwave is estimated using low-frequency SRS line shift.

  16. Morphologies of laser-induced damage in hafnia-silica multilayer mirror and polarizer coatings

    SciTech Connect (OSTI)

    Genin, F.Y.; Stolz, C.J.

    1996-08-01T23:59:59.000Z

    Hafnium-silica multilayer mirrors and polarizers were deposited by e-beam evaporation onto BK7 glass substrates. The mirrors and polarizers were coated for operation at 1053 nm at 45{degree} and at Brewster`s angle (56{degree}), respectively. They were tested with a single 3-ns laser pulse. Morphology of the laser-induced damage was characterized by optical and scanning electron microscopy. Four distinct damage morphologies were found: pits, flatbottom pits, scalds, and delaminates. The pits and flat bottom pits (<30{mu}m dia) were detected at lower fluences (as low as 5 J/cm{sup 2}). The pits seemed to result from ejection of nodular defects by causing local enhancement of the electric field. Scalds and delaminates could be observed at higher fluences (above 13 J/cm{sup 2}) and seemed to result from the formation of plasmas on the surface. These damage types often originated at pits and were less than 300 {mu}m diameter; their size increased almost linearly with fluence. Finally, effects of the damage on the beam (reflectivity degradation and phase modulations) were measured.

  17. Formation of laser-induced periodic surface structures on niobium by femtosecond laser irradiation

    SciTech Connect (OSTI)

    Pan, A.; Dias, A.; Gomez-Aranzadi, M.; Olaizola, S. M. [CIC microGUNE, Goiru Kalea 9 Polo Innovacin Garaia, 20500 Arrasate-Mondragn (Spain); CEIT-IK4 and Tecnun, University of Navarra, Manuel Lardizbal 15, 20018 San Sebastin (Spain); Rodriguez, A. [CIC microGUNE, Goiru Kalea 9 Polo Innovacin Garaia, 20500 Arrasate-Mondragn (Spain)

    2014-05-07T23:59:59.000Z

    The surface morphology of a Niobium sample, irradiated in air by a femtosecond laser with a wavelength of 800?nm and pulse duration of 100 fs, was examined. The period of the micro/nanostructures, parallel and perpendicularly oriented to the linearly polarized fs-laser beam, was studied by means of 2D Fast Fourier Transform analysis. The observed Laser-Induced Periodic Surface Structures (LIPSS) were classified as Low Spatial Frequency LIPSS (periods about 600?nm) and High Spatial Frequency LIPSS, showing a periodicity around 300?nm, both of them perpendicularly oriented to the polarization of the incident laser wave. Moreover, parallel high spatial frequency LIPSS were observed with periods around 100?nm located at the peripheral areas of the laser fingerprint and overwritten on the perpendicular periodic gratings. The results indicate that this method of micro/nanostructuring allows controlling the Niobium grating period by the number of pulses applied, so the scan speed and not the fluence is the key parameter of control. A discussion on the mechanism of the surface topology evolution was also introduced.

  18. Microwave pulse compression from a storage cavity with laser-induced switching

    DOE Patents [OSTI]

    Bolton, Paul R. (Menlo Park, CA)

    1992-01-01T23:59:59.000Z

    A laser-induced switch and a multiple cavity configuration are disclosed for producing high power microwave pulses. The microwave pulses are well controlled in wavelength and timing, with a quick rise time and a variable shape and power of the pulse. In addition, a method of reducing pre-pulse leakage to a low level is disclosed. Microwave energy is directed coherently to one or more cavities that stores the energy in a single mode, represented as a standing wave pattern. In order to switch the stored microwave energy out of the main cavity and into the branch waveguide, a laser-actuated switch is provided for the cavity. The switch includes a laser, associated optics for delivering the beam into the main cavity, and a switching gas positioned at an antinode in the main cavity. When actuated, the switching gas ionizes, creating a plasma, which becomes reflective to the microwave energy, changing the resonance of the cavity, and as a result the stored microwave energy is abruptly switched out of the cavity. The laser may directly pre-ionize the switching gas, or it may pump an impurity in the switching gas to an energy level which switches when a pre-selected cavity field is attained. Timing of switching the cavities is controlled by varying the pathlength of the actuating laser beam. For example, the pathlengths may be adjusted to output a single pulse of high power, or a series of quick lower power pulses.

  19. Femtosecond laser-induced periodic surface structure on the Ti-based nanolayered thin films

    SciTech Connect (OSTI)

    Petrovi?, Suzana M.; Gakovi?, B.; Peruko, D. [Institute of Nuclear ScienceVin?a, University of Belgrade, POB 522, 11001 Belgrade (Serbia)] [Institute of Nuclear ScienceVin?a, University of Belgrade, POB 522, 11001 Belgrade (Serbia); Stratakis, E. [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece) [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece); Department of Materials Science and Technology, University of Crete, 710 03 Heraklion, Crete (Greece); Bogdanovi?-Radovi?, I. [Ru?er Bokovi? Institute, P.O. Box 180, 10002 Zagreb (Croatia)] [Ru?er Bokovi? Institute, P.O. Box 180, 10002 Zagreb (Croatia); ?ekada, M. [Joef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia)] [Joef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Fotakis, C. [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece) [Institute of Electronic Structure and Laser, Foundation for Research and TechnologyHellas, P.O. Box 1527, Gr-711 10 Heraklion (Greece); Department of Physics, University of Crete, 714 09 Heraklion, Crete (Greece); Jelenkovi?, B. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)] [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

    2013-12-21T23:59:59.000Z

    Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.

  20. Analysis of oil flow mechanisms in internal combustion engines via high speed Laser Induced Fluorescence (LIF) spectroscopy

    E-Print Network [OSTI]

    Zanghi, Eric (Eric James)

    2014-01-01T23:59:59.000Z

    Automotive manufacturers have a significant challenge ahead of them with new more stringent regulations for exhaust emissions and fuel economy being implemented in the coming future. To make an impact on current emissions ...

  1. Ambient methods and apparatus for rapid laser trace constituent analysis

    DOE Patents [OSTI]

    Snyder, Stuart C. (Idaho Falls, ID); Partin, Judy K. (Idaho Falls, ID); Grandy, Jon D. (Idaho Falls, ID); Jeffery, Charles L. (Blackfoot, ID)

    2002-01-01T23:59:59.000Z

    A method and apparatus are disclosed for measuring trace amounts of constituents in samples by using laser induced breakdown spectroscopy and laser induced fluorescence under ambient conditions. The laser induced fluorescence is performed at a selected wavelength corresponding to an absorption state of a selected trace constituent. The intensity value of the emission decay signal which is generated by the trace constituent is compared to calibrated emission intensity decay values to determine the amount of trace constituent present.

  2. Two photon absorption laser induced fluorescence measurements of neutral density in a helicon plasma

    SciTech Connect (OSTI)

    Galante, M. E.; Magee, R. M.; Scime, E. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)] [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

    2014-05-15T23:59:59.000Z

    We have developed a new diagnostic based on two-photon absorption laser induced fluorescence (TALIF). We use a high intensity (5?MW/cm{sup 2}), narrow bandwidth (0.1?cm{sup ?1}) laser to probe the ground state of neutral hydrogen, deuterium and krypton with spatial resolution better than 0.2?cm, a time resolution of 10?ns, and a measurement cadence of 20?Hz. Here, we describe proof-of-principle measurements in a helicon plasma source that demonstrate the TALIF diagnostic is capable of measuring neutral densities spanning four orders of magnitude; comparable to the edge neutral gradients predicted in the DIII-D tokamak pedestal. The measurements are performed in hydrogen and deuterium plasmas and absolute calibration is accomplished through TALIF measurements in neutral krypton. The optical configuration employed is confocal, i.e., both light injection and collection are accomplished with a single lens through a single optical port in the vacuum vessel. The wavelength resolution of the diagnostic is sufficient to separate hydrogen and deuterium spectra and we present measurements from mixed hydrogen and deuterium plasmas that demonstrate isotopic abundance measurements are feasible. Time resolved measurements also allow us to explore the evolution of the neutral hydrogen density and temperature and effects of wall recycling. We find that the atomic neutral density grows rapidly at the initiation of the discharge, reaching the steady-state value within 1?ms. Additionally, we find that neutral hydrogen atoms are born with 0.08?eV temperatures, not 2?eV as is typically assumed.

  3. Humidity effects on wire insulation breakdown strength.

    SciTech Connect (OSTI)

    Appelhans, Leah

    2013-08-01T23:59:59.000Z

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  4. Laser-induced dehydration of graphite oxide coatings on polymer substrates

    SciTech Connect (OSTI)

    Longo, Angela, E-mail: angela.longo@cnr.it; Palomba, Mariano; Carotenuto, Gianfranco; Nicolais, Luigi [Institute for Composite and Biomedical Materials, National Research Council, Viale Kennedy, 54, Mostra d'Oltremare Padiglione 20, 80125 Napoli (Italy); Orabona, Emanuele; Maddalena, Pasqualino [Department of Physics, University of Naples, Federico II, via cintia, 80126, Naples, Italy and SPIN Institute, National Research Council, UOS Naples, via cintia, 80126, Naples (Italy); Ambrosio, Antonio [SPIN Institute, National Research Council, UOS Naples, via cintia, 80126, Naples (Italy)

    2014-05-15T23:59:59.000Z

    Nanosized graphite has been oxidized by the Hummers method to give high quality graphite oxide. This reaction is characterized by a very fast kinetic behavior and a high yield. The produced graphite oxide has been conveniently used to pattern graphene by using a standard photolithographic method, and the resulting systems have been characterized by optical microscopy (OM), scanning electron microscopy (SEM) and by Fourier transform infrared spectroscopy (FT-IR) and Visible-Near Infrared spectroscopy (Vis-NIR)

  5. Ultraviolet laser-induced poling inhibition produces bulk domains in MgO-doped lithium niobate crystals

    SciTech Connect (OSTI)

    Boes, Andreas, E-mail: s3363819@student.rmit.edu.au; Steigerwald, Hendrik; Sivan, Vijay; Mitchell, Arnan [School of Electrical and Computer Engineering, RMIT University, Melbourne, Victoria 3001 (Australia); ARC Center for Ultra-high Bandwidth Devices for Optical Systems (CUDOS), RMIT University, Melbourne, Victoria 3001 (Australia); Yudistira, Didit [School of Electrical and Computer Engineering, RMIT University, Melbourne, Victoria 3001 (Australia); Wade, Scott [Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia); Mailis, Sakellaris [Optoelectronics Research Centre, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Soergel, Elisabeth [Institute of Physics, University of Bonn, Wegelerstr. 8, 53115 Bonn (Germany)

    2014-09-01T23:59:59.000Z

    We report the realization of high-resolution bulk domains achieved using a shallow, structured, domain inverted surface template obtained by UV laser-induced poling inhibition in MgO-doped lithium niobate. The quality of the obtained bulk domains is compared to those of the template and their application for second harmonic generation is demonstrated. The present method enables domain structures with a period length as small as 3??m to be achieved. Furthermore, we propose a potential physical mechanism that leads to the transformation of the surface template into bulk domains.

  6. Formation of laser-induced periodic surface structures on fused silica upon two-color double-pulse irradiation

    SciTech Connect (OSTI)

    Hhm, S.; Herzlieb, M.; Rosenfeld, A. [Max-Born-Institut fr Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strae 2A, D-12489 Berlin (Germany)] [Max-Born-Institut fr Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Strae 2A, D-12489 Berlin (Germany); Krger, J.; Bonse, J. [BAM Bundesanstalt fr Materialforschung und prfung, Unter den Eichen 87, D-12205 Berlin (Germany)] [BAM Bundesanstalt fr Materialforschung und prfung, Unter den Eichen 87, D-12205 Berlin (Germany)

    2013-12-16T23:59:59.000Z

    The formation of laser-induced periodic surface structures (LIPSS) upon irradiation of fused silica with multiple irradiation sequences consisting of laser pulse pairs (50 fs single-pulse duration) of two different wavelengths (400 and 800 nm) is studied experimentally. Parallel polarized double-pulse sequences with a variable delay ?t between ?10 and +10 ps and between the individual fs-laser pulses were used to investigate the LIPSS periods versus ?t. These two-color experiments reveal the importance of the ultrafast energy deposition to the silica surface by the first laser pulse for LIPSS formation. The second laser pulse subsequently reinforces the previously seeded spatial LIPSS frequencies.

  7. Effect of defects on long-pulse laser-induced damage of two kinds of optical thin films

    SciTech Connect (OSTI)

    Wang Bin; Qin Yuan; Ni Xiaowu; Shen Zhonghua; Lu Jian

    2010-10-10T23:59:59.000Z

    In order to study the effect of defects on the laser-induced damage of different optical thin films, we carried out damage experiments on two kinds of thin films with a 1ms long-pulse laser. Surface-defect and subsurface-defect damage models were used to explain the damage morphology. The two-dimensional finite element method was applied to calculate the temperature and thermal-stress fields of these two films. The results show that damages of the two films are due to surface and subsurface defects, respectively. Furthermore, the different dominant defects for thin films of different structures are discussed.

  8. Gas breakdown in the T-7 tokamak

    SciTech Connect (OSTI)

    Denisov, V.F.; Ivanov, D.P.; Ivanov, N.V.; Kakurin, A.M.; Kislov, A.Y.; Kochin, V.A.; Mikhailichenko, V.A.; Khvostenko, P.P.; Khilil', V.V.

    1982-03-01T23:59:59.000Z

    Study of the initial stage of the discharge of the T-7 tokamak shows that when the magnetic field in the discharge chamber has a comparatively small transverse component (B/sub perpendicular/approx.10/sup -3/B/sub parallel/) the gas breakdown occurs in two stages. First, while the discharge current is low, the breakdown occurs along a helical magnetic line of force between upper and lower parts of a limiter in one cross section in the chamber. In the second stage, when the field of the current exceeds the transverse magnetic field, and a rotational transform arises, a toroidal electrodeless discharge occurs.

  9. Cost Codes and the Work Breakdown Structure

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1997-03-28T23:59:59.000Z

    The chapter discusses the purpose of the work breakdown structure (WBS) and code of account (COA) cost code system, shows the purpose and fundamental structure of both the WBS and the cost code system, and explains the interface between the two systems.

  10. The tunneling model of laser-induced ionization and its failure at low frequencies

    E-Print Network [OSTI]

    H. R. Reiss

    2014-05-11T23:59:59.000Z

    The tunneling model of ionization applies only to longitudinal fields: quasistatic electric fields that do not propagate. Laser fields are transverse: plane wave fields that possess the ability to propagate. Although there is an approximate connection between the effects of longitudinal and transverse fields in a useful range of frequencies, that equivalence fails completely at very low frequencies. Insight into this breakdown is given by an examination of radiation pressure, which is a unique transverse-field effect whose relative importance increases rapidly as the frequency declines. Radiation pressure can be ascribed to photon momentum, which does not exist for longitudinal fields. Two major consequences are that the near-universal acceptance of a static electric field as the zero frequency limit of a laser field is not correct; and that the numerical solution of the dipole-approximate Schr\\"{o}dinger equation for laser effects is inapplicable as the frequency declines. These problems occur because the magnetic component of the laser field is very important at low frequencies, and hence the dipole approximation is not valid. Some experiments already exist that demonstrate the failure of tunneling concepts at low frequencies.

  11. Laser-induced resonant transitions in the v=n-l-1=2 and 3 metastable cascades of antiprotonic $^{3}He atoms

    E-Print Network [OSTI]

    Torii, H A; Ishikawa, T; Maas, F E; Hayano, R S; Morita, N; Kumakura, M; Sugai, I; Ketzer, B; Daniel, H; Hartmann, F J; Pohl, R; Schmidt, R; Von Egidy, T; Horvth, D; Eades, John; Widmann, E; Yamazaki, T

    1996-01-01T23:59:59.000Z

    Laser-induced resonant transitions in metastable antiprotonic ^3He atoms have been found. The observed transitions at wavelengths 593.388 \\pm 0.001~nm and at 463.947 \\pm 0.002~nm have been respectively ascribed to the (n,l)~=~(38,34)\\,\\rightarrow\\,(37,33) and the (36 33)\\,\\rightarrow\\,(35,32) transitions.

  12. J. Chem. Soc., Perkin Trans. 2, 1997 1147 Laser-induced decompositions of 3,5-dimethyl-1,2,4-trioxolane

    E-Print Network [OSTI]

    Haas, Yehuda

    oligomerization occurring on the reactor walls. The multiple of the ArF laser induced photolytic products in the atmosphere is naturally of great interest, studies on their gas-phase thermal and photolytical decomposition radiation.4 We have recently studied the TEA CO2 laser-photosensitized (SF6) (homogeneous) decomposition

  13. Nanosecond-laser-induced damage in potassium titanyl phosphate: pure 532 nm pumping and frequency conversion situations

    SciTech Connect (OSTI)

    Wagner, Frank R.; Hildenbrand, Anne; Natoli, Jean-Yves; Commandre, Mireille

    2011-08-01T23:59:59.000Z

    Nanosecond-laser-induced damage measurements in the bulk of KTiOPO{sub 4} (KTP) crystals are reported using incident 532 nm light or using incident 1064 nm light, which pumps more or less efficient second harmonic generation. No damage threshold fatigue effect is observed with pure 532 nm irradiation. The damage threshold of Z-polarized light is higher than the one for X- or Y-polarized light. During frequency doubling, the damage threshold was found to be lower than for pure 1064 or 532 nm irradiation. More data to quantify the cooperative damage mechanism were generated by performing fluence ramp experiments with varying conditions and monitoring the conversion efficiency. All damage thresholds plotted against the conversion efficiency align close to a characteristic curve.

  14. Prevention of breakdown behind railgun projectiles

    DOE Patents [OSTI]

    Hawke, R.S.

    1992-10-13T23:59:59.000Z

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF[sub 6]. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs.

  15. Prevention of breakdown behind railgun projectiles

    DOE Patents [OSTI]

    Hawke, R.S.

    1992-09-01T23:59:59.000Z

    An electromagnetic railgun accelerator system, for accelerating projectiles by a plasma arc, introduces a breakdown inhibiting gas into the railgun chamber behind the accelerating projectile. The breakdown inhibiting gas, which absorbs electrons, is a halide or a halide compound such as fluorine or SF[sub 6]. The gas is introduced between the railgun rails after the projectile has passed through inlets in the rails or the projectile; by coating the rails or the projectile with a material which releases the gas after the projectile passes over it; by fabricating the rails or the projectile or insulators out of a material which releases the gas into the portions of the chamber through which the projectile has travelled. The projectile may have a cavity at its rear to control the release of ablation products. 12 figs.

  16. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    SciTech Connect (OSTI)

    Johnson, Rolland

    2014-09-21T23:59:59.000Z

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A 1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

  17. Spectroscopy and reactions of vibrationally excited transient molecules

    SciTech Connect (OSTI)

    Dai, H.L. [Univ. of Pennsylvania, Philadelphia (United States)

    1993-12-01T23:59:59.000Z

    Spectroscopy, energy transfer and reactions of vibrationally excited transient molecules are studied through a combination of laser-based excitation techniques and efficient detection of emission from the energized molecules with frequency and time resolution. Specifically, a Time-resolved Fourier Transform Emission Spectroscopy technique has been developed for detecting dispersed laser-induced fluorescence in the IR, visible and UV regions. The structure and spectroscopy of the excited vibrational levels in the electronic ground state, as well as energy relaxation and reactions induced by specific vibronic excitations of a transient molecule can be characterized from time-resolved dispersed fluorescence in the visible and UV region. IR emissions from highly vibrational excited levels, on the other hand, reveal the pathways and rates of collision induced vibrational energy transfer.

  18. Laser-induced damage investigation at 1064 nmin KTiOPO4 crystals and its analogy with RbTiOPO4

    SciTech Connect (OSTI)

    Hildenbrand, A.; Wagner, F. R.; Akhouayri, H.; Natoli, J.-Y.; Commandre, M.; Theodore, F.; Albrecht, H.

    2009-07-20T23:59:59.000Z

    Bulk laser-induced damage at 1064 nm has been investigated in KTiOPO4 (KTP) and RbTiOPO4 (RTP) crystals with a nanosecond pulsed Nd:YAG laser. Both crystals belong to the same family. Throughout this study, their comparison shows a very similar laser-damage behavior. The evolution of the damage resistance under a high number of shots per site (10,000 shots) reveals a fatigue effect of KTP and RTP crystals. In addition, S-on-1 damage probability curves have been measured in both crystals for all combinations of polarization and propagation direction aligned with the principal axes of the crystals. The results show an influence of the polarization on the laser-induced damage threshold (LIDT), with a significantly higher threshold along the z axis, whereas no effect of the propagation direction has been observed. This LIDT anisotropy is discussed with regard to the crystallographic structure.

  19. Laser-Induced Damage in Optical Materials 2001, Gregory J. Exarhos, Arthur H. Guenther, Keith L. Lewis, M. J. Soileau, Christopher J. Stolz, Editors, Proceedings of SPIE Vol. 4679 (2002)

    E-Print Network [OSTI]

    Glebov, Leon

    Laser-Induced Damage in Optical Materials 2001, Gregory J. Exarhos, Arthur H. Guenther, Keith L. Lewis, M. J. Soileau, Christopher J. Stolz, Editors, Proceedings of SPIE Vol. 4679 (2002) © 2002 SPIE

  20. Final Technical Report - Development of a tunable diode laser induced fluorescence diagnostic for the Princeton magnetic nozzle experiment: West Virginia University and Princeton Plasma Physics Laboratory

    SciTech Connect (OSTI)

    Earl Scime

    2006-11-07T23:59:59.000Z

    This project involves the construction of a compact, portable, laser induced fluorescence (LIF) diagnostic for measurements of neutral helium, neutral argon, and argon ion velocity space distributions in a high density, steady state, helicon source. The project is collaborative effort between the Princeton Plasma Physics Laboratory (PPPL) and the West Virginia University (WVU) helicon source group. A key feature of the diagnostic system will be the use of tunable diode lasers instead of the tunable dye lasers typically used in LIF experiments.

  1. Increasing the laser-induced damage threshold of single-crystal ZnGeP{sub 2}

    SciTech Connect (OSTI)

    Zawilski, Kevin T.; Setzler, Scott D.; Schunemann, Peter G.; Pollak, Thomas M. [BAE Systems, Advanced Systems and Technology, P.O. Box 868, MER15-1813, Nashua, New Hampshire 03061-0868 (United States)

    2006-11-15T23:59:59.000Z

    The laser-induced damage threshold (LIDT) of single-crystal zinc germanium phosphide (ZGP), ZnGeP{sub 2}, was increased to 2 J/cm{sup 2} at 2.05 {mu}m and a 10 kHz pulse rate frequency (double the previously measured value of 1 J/cm{sup 2}). This increased LIDT was achieved by improving the polishing of ZGP optical parametric oscillator crystals. Two different polishing techniques were evaluated. Surfaces were characterized using scanning white-light interferometry to determine rms surface roughness and sample flatness. The photon backscatter technique was used to determine the degree of surface and subsurface damage in the sample induced through the fabrication process. The effect of subsurface damage in the samples was studied by removing different amounts of material during polishing for otherwise identical samples. Statistical LIDT was measured using a high-average-power, repetitively Q-switched Tm,Ho:YLF 2.05 {mu}m pump laser. On average, lower surface roughness and photon backscatter measurements were a good indicator of ZGP samples exhibiting higher LIDT. The removal of more material during polishing significantly improved the LIDT of otherwise identical samples, indicating the importance of subsurface damage defects in the LIDT of ZGP.

  2. An Improved Method of Mitigating Laser Induced Surface Damage Growth in Fused Silica Using a Rastered, Pulsed CO2 Laser

    SciTech Connect (OSTI)

    Bass, I L; Guss, G M; Nostrand, M J; Wegner, P L

    2010-10-21T23:59:59.000Z

    A new method of mitigating (arresting) the growth of large (>200 m diameter and depth) laser induced surface damage on fused silica has been developed that successfully addresses several issues encountered with our previously-reported large site mitigation technique. As in the previous work, a tightly-focused 10.6 {micro}m CO{sub 2} laser spot is scanned over the damage site by galvanometer steering mirrors. In contrast to the previous work, the laser is pulsed instead of CW, with the pulse length and repetition frequency chosen to allow substantial cooling between pulses. This cooling has the important effect of reducing the heat-affected zone capable of supporting thermo-capillary flow from scale lengths on the order of the overall scan pattern to scale lengths on the order of the focused laser spot, thus preventing the formation of a raised rim around the final mitigation site and its consequent down-stream intensification. Other advantages of the new method include lower residual stresses, and improved damage threshold associated with reduced amounts of redeposited material. The raster patterns can be designed to produce specific shapes of the mitigation pit including cones and pyramids. Details of the new technique and its comparison with the previous technique will be presented.

  3. Time-resolved imaging of material response during laser-induced bulk damage in SiO2

    SciTech Connect (OSTI)

    Demos, S G; Negres, R A

    2008-10-24T23:59:59.000Z

    We report on time resolved imaging of the dynamic events taking place during laser-induced damage in the bulk of fused silica samples with nanosecond temporal resolution and one micron spatial resolution. These events include: shock/pressure wave formation and propagation, transient absorption, crack propagation and formation of residual stress fields. The work has been performed using a time-resolved microscope system that utilizes a probe pulse to acquire images at delay times covering the entire timeline of a damage event. Image information is enhanced using polarized illumination and simultaneously recording the two orthogonal polarization image components. For the case of fused silica, an electronic excitation is first observed accompanied by the onset of a pressure wave generation and propagation. Cracks are seen to form early in the process and reach their final size at about 25 ns into the damage event. In addition, changes that in part are attributed to transient absorption in the modified material are observed for delays up to about 200 microseconds.

  4. Temperature activated absorption during laser-induced damage: The evolution of laser-supported solid-state absorption fronts

    SciTech Connect (OSTI)

    Carr, C W; Bude, J D; Shen, N; Demange, P

    2010-10-26T23:59:59.000Z

    Previously we have shown that the size of laser induced damage sites in both KDP and SiO{sub 2} is largely governed by the duration of the laser pulse which creates them. Here we present a model based on experiment and simulation that accounts for this behavior. Specifically, we show that solid-state laser-supported absorption fronts are generated during a damage event and that these fronts propagate at constant velocities for laser intensities up to 4 GW/cm{sup 2}. It is the constant absorption front velocity that leads to the dependence of laser damage site size on pulse duration. We show that these absorption fronts are driven principally by the temperature-activated deep sub band-gap optical absorptivity, free electron transport, and thermal diffusion in defect-free silica for temperatures up to 15,000K and pressures < 15GPa. In addition to the practical application of selecting an optimal laser for pre-initiation of large aperture optics, this work serves as a platform for understanding general laser-matter interactions in dielectrics under a variety of conditions.

  5. Laser-induced damage of hafnia coatings as a function of pulse duration in the femtosecond to nanosecond range

    SciTech Connect (OSTI)

    Gallais, Laurent; Mangote, Benoit; Zerrad, Myriam; Commandre, Mireille; Melninkaitis, Andrius; Mirauskas, Julius; Jeskevic, Maksim; Sirutkaitis, Valdas

    2011-03-20T23:59:59.000Z

    Laser-damage thresholds and morphologies of hafnia single layers exposed under femtosecond, picosecond, and nanosecond single pulses (1030/1064nm) are reported. The samples were made with different deposition parameters in order to study how the damage behavior of the samples evolves with the pulse duration and how it is linked to the deposition process. In the femtosecond to picosecond regime, the scaling law of the laser-induced damage threshold as a function of pulse duration is in good agreement with the models of photo and avalanche ionization based on the rate equation for free electron generation. However, differences in the damage morphologies between samples are shown. No correlation between the nanosecond and femtosecond/picosecond laser-damage resistance of hafnia coatings could be established. We also report evidence of the transition in damage mechanisms for hafnia, from an ablation process linked to intrinsic properties of the material to a defect-induced process, that exists between a few picoseconds and a few tens of picoseconds.

  6. Investigations of laser-induced damages in fused silica optics using x-ray laser interferometric microscopy

    SciTech Connect (OSTI)

    Margarone, D.; Rus, B.; Kozlova, M.; Nejdl, J.; Mocek, T.; Homer, P.; Polan, J.; Stupka, M. [Department of X-ray Lasers/PALS Centre, Institute of Physics of the ASCR, 18221 Prague 8 (Czech Republic); Cassou, K.; Kazamias, S.; Lagron, J. C.; Ros, D. [LIXAM, Universite Paris-Sud, 91405 Orsay (France); Danson, C.; Hawkes, S. [Central Laser Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom)

    2010-05-15T23:59:59.000Z

    A novel x-ray laser (XRL) application, aimed at understanding the microscopic effects involved in formation of laser-induced damage in optical materials exposed to high-power sub-ns laser pulses, is presented. Standard fused silica substrates with permanent damage threshold below 20 J/cm{sup 2}, when irradiated by 438 nm laser pulses, were probed in situ by a neonlike zinc XRL at 21.2 nm. The probing beamline employed a double Lloyd's mirror x-ray interferometer, used in conjunction with an imaging mirror to achieve magnification of {approx}8. In conjunction with an array of in situ optical diagnostics, the main question addressed is whether the damage on the rear surface of the beamsplitter is transient or permanent. The second issue, examined by both the x-ray interferometric microscopy and the optical diagnostics, is whether a local rear-surface modification is associated with nonlinear effects such as self-focusing or filamentation of the damaging laser beam in the bulk.

  7. Laser-induced temperature jump/time-resolved infrared study of the fast events in protein folding

    SciTech Connect (OSTI)

    Woodruff, W.H.; Dyer, R.B.; Williams, S. [Los Alamos National Laboratory, NM (United States); Callender, H.; Gilmanshin, R. [CUNY, NY (United States)

    1996-10-01T23:59:59.000Z

    Laser-induced temperature jump followed by time-resolved infrared probe of reaction dynamics are used to study the temporal evolution of polypeptide structure during protein folding and unfolding. Reactions are initiated in times of 50 ps or longer by T-jumps of 10`s of degrees, obtained by laser excitation of water overtone absorbances. Observation of the Amide I transient absorbances reveal melting lifetimes of helices unconstrained by tertiary structure to be ca. 160 ns in a model 21-peptide and ca. 30 ns in {open_quotes}molten globule{close_quotes} apomyoglobin. No other processes are observed in these systems over the timescale 50 ps to 2 ms. Equilibrium data suggest the corresponding helix formation lifetimes to be ca. 16 and 1 ns, respectively. In {open_quotes}native{close_quotes} apomyoglobin two helix melting lifetimes are observed and we infer that a third occurs on a timescale inaccessible to our experiment (> 1 ms). The shorter observed lifetime, as in the molten globule, is ca. 30 ns. The longer lifetime is ca. 70 {mu}s. We suggest that the slower process is helix melting that is rate-limited by the unfolding of tertiary structure. Equilibrium data suggest a lifetime of ca. 1 {mu}s for the development of these tertiary folds.

  8. 2-dimensional ion velocity distributions measured by laser-induced fluorescence above a radio-frequency biased silicon wafer

    SciTech Connect (OSTI)

    Moore, Nathaniel B.; Gekelman, Walter; Pribyl, Patrick [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Zhang, Yiting; Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States)] [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States)

    2013-08-15T23:59:59.000Z

    The dynamics of ions traversing sheaths in low temperature plasmas are important to the formation of the ion energy distribution incident onto surfaces during microelectronics fabrication. Ion dynamics have been measured using laser-induced fluorescence (LIF) in the sheath above a 30 cm diameter, 2.2 MHz-biased silicon wafer in a commercial inductively coupled plasma processing reactor. The velocity distribution of argon ions was measured at thousands of positions above and radially along the surface of the wafer by utilizing a planar laser sheet from a pulsed, tunable dye laser. Velocities were measured both parallel and perpendicular to the wafer over an energy range of 0.4600 eV. The resulting fluorescence was recorded using a fast CCD camera, which provided resolution of 0.4 mm in space and 30 ns in time. Data were taken at eight different phases during the 2.2 MHz cycle. The ion velocity distributions (IVDs) in the sheath were found to be spatially non-uniform near the edge of the wafer and phase-dependent as a function of height. Several cm above the wafer the IVD is Maxwellian and independent of phase. Experimental results were compared with simulations. The experimental time-averaged ion energy distribution function as a function of height compare favorably with results from the computer model.

  9. Trends in Ln(III) Sorption to Quartz Assessed by Molecular Dynamics Simulations and Laser Induced Flourescence Studies

    SciTech Connect (OSTI)

    Kuta, Jadwiga; Wander, Matthew C F.; Wang, Zheming; Jiang, Siduo; Wall, Nathalie; Clark, Aurora E.

    2011-11-08T23:59:59.000Z

    Molecular dynamics simulations were performed to examine trends in trivalent lanthanide [Ln(III)] sorption to quartz surface SiOH0 and SiO- sites across the 4f period. Complementary laser induced fluorescence studies examined Eu(III) sorption to quartz at varying ionic strength such that the surface sorbed species could be extrapolated at zero ionic strength, the conditions under which the simulations are performed. This allowed for direct comparison of the data, enabling a molecular understanding of the surface sorbed species and the role of the ion surface charge density upon the interfacial reactivity. Thus, this combined theoretical and experimental approach aids in the prediction of the fate of trivalent radioactive contaminants at temporary and permanent nuclear waste storage sites. Potential of mean force molecular dynamics, as well as simulations of pre-sorbed Ln(III) species agrees with the spectroscopic study of Eu(III) sorption, indicating that strongly bound inner-sphere complexes are formed upon sorption to an SiO- site. The coordination shell of the ion contains 6-7 waters of hydration and it is predicted that surface OH groups dissociate from the quartz and bind within the inner coordination shell of Eu(III). Molecular simulations predict less-strongly bound inner2 sphere species in early lanthanides and more strongly bound species in late lanthanides, following trends in the ionic radius of the 4f ions. The participation of surface dissociated OHgroups within the inner coordination shell of the Ln(III) ion is, however, consistent across the series studied. Sorption to a fully protonated quartz surface is not predicted to be favorable by any Ln(III), except perhaps Lu.

  10. E-Print Network 3.0 - air breakdown mechanism Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Steven R. Raine... by aggregate hierarchy theory, breakdown occurs when sufficient mechanical stress has been applied to overcome... breakdown in soils is a function of the...

  11. Evaluation of XRF and LIBS technologies for on-line sorting of CCA-treated wood waste

    E-Print Network [OSTI]

    Florida, University of

    Evaluation of XRF and LIBS technologies for on-line sorting of CCA-treated wood waste Helena M technologies evaluated included X-ray fluorescence spectroscopy (XRF) and laser induced breakdown spectroscopy (LIBS). The XRF detector system utilized in this study was capable of rapidly detecting the presence

  12. Spectroscopy and Diffraction | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Techniques Electron spectroscopy Electron backscatter diffraction Atom probe tomography Ionmolecular beam spectroscopy 57Fe-Mssbauer spectroscopy Optical spectroscopy...

  13. Cone penetrometer fiber optic raman spectroscopy probe assembly

    DOE Patents [OSTI]

    Kyle, Kevin R. (Brentwood, CA); Brown, Steven B. (Livermore, CA)

    2000-01-01T23:59:59.000Z

    A chemically and mechanically robust optical Raman spectroscopy probe assembly that can be incorporated in a cone penetrometer (CPT) for subsurface deployment. This assembly consists of an optical Raman probe and a penetrometer compatible optical probe housing. The probe is intended for in-situ chemical analysis of chemical constituents in the surrounding environment. The probe is optically linked via fiber optics to the light source and the detection system at the surface. A built-in broadband light source provides a strobe method for direct measurement of sample optical density. A mechanically stable sapphire window is sealed directly into the side-wall of the housing using a metallic, chemically resistant, hermetic seal design. This window permits transmission of the interrogation light beam and the resultant signal. The spectroscopy probe assembly is capable of accepting Raman, Laser induced Fluorescence, reflectance, and other optical probes with collimated output for CPT deployment.

  14. Observation of double resonant laser induced transitions in the $v = n - l - 1 = 2$ metastable cascade of antiprotonic helium-4 atoms

    E-Print Network [OSTI]

    Hayano, R S; Tamura, H; Torii, H A; Hori, Masaki; Maas, F E; Morita, N; Kumakura, M; Sugai, I; Hartmann, F J; Daniel, H; Von Egidy, T; Ketzer, B; Pohl, R; Horvth, D; Eades, John; Widmann, E; Yamazaki, T

    1997-01-01T23:59:59.000Z

    A new laser-induced resonant transition in the $v=n-l-1=2$ metastable cascade of antiprotonic $^4$He atoms has been found by using a double resonance technique. This was done by setting the first laser to the already known 470.724 nm resonance ($(n,l)=(37,34)\\rightarrow (36,33)$), while the $(38,35)\\rightarrow (37,34)$ transition was searched for with the second laser. The resonant transition was found at wavelength of 529.622$\\pm$0.003 nm, showing excellent agreement with a recent prediction of Korobov.

  15. REAL-TIME IN SITU DETECTION OF ORGANIC CONTAMINANTS BY LASER-INDUCED FLUORESCENCE SYSTEM. Final tropical report (Task 1.3).

    SciTech Connect (OSTI)

    Daniel J. Stepan; James A. Sorensen; Jaroslav Solc

    1999-08-01T23:59:59.000Z

    This report summarizes the results of the field demonstration of a laser-induced fluorescence (LIF) method for characterization of brownfields and other contaminated sites. The technology was provided and demonstrated by Dakota Technologies, Inc. (DTI), of Fargo, North Dakota. LIF generates continuous data on the distribution of polycyclic aromatic hydrocarbons (PAHs) within the soil profile. The sensor used to record real-time data is deployed into the soil using a modified truck-mounted Geoprobe percussion soil probing device. The summary of observations described in the following text represents an independent evaluation of the performance, usefulness, and economics of the demonstrated technology for characterization at PAH-contaminated sites.

  16. Pattern formation and propagation during microwave breakdown

    SciTech Connect (OSTI)

    Chaudhury, Bhaskar [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Boeuf, Jean-Pierre [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); LAPLACE, CNRS, F-31062 Toulouse (France); Zhu, Guo Qiang [Laboratoire Plasma et Conversion d'Energie (LAPLACE), INPT, UPS, Universite de Toulouse, 118 route de Narbonne, F-31062 Toulouse Cedex 9 (France); Northwestern Polytechnique University, Xi'an 710072 (China)

    2010-12-15T23:59:59.000Z

    During microwave breakdown at atmospheric pressure, a sharp plasma front forms and propagates toward the microwave source at high velocities. Experiments show that the plasma front may exhibit a complex dynamical structure or pattern composed of plasma filaments aligned with the wave electric field and apparently moving toward the source. In this paper, we present a model of the pattern formation and propagation under conditions close to recent experiments. Maxwell's equations are solved together with plasma fluid equations in two dimensions to describe the space and time evolution of the wave field and plasma density. The simulation results are in excellent agreement with the experimental observations. The model provides a physical interpretation of the pattern formation and dynamics in terms of ionization-diffusion and absorption-reflection mechanisms. The simulations allow a good qualitative and quantitative understanding of different features such as plasma front velocity, spacing between filaments, maximum plasma density in the filaments, and influence of the discharge parameters on the development of well-defined filamentary plasma arrays or more diffuse plasma fronts.

  17. COST BREAKDOWN AWARD NO: START DATE: EXPIRATION DATE: FISCAL YEAR BREAKDOWN OF FUNDS

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites Proposed Route BTRICGEGR-N Goods PO 1PhotoemissionCOST BREAKDOWN

  18. Avalanches in breakdown and fracture processes Stefano Zapperi,1

    E-Print Network [OSTI]

    Stanley, H. Eugene

    Avalanches in breakdown and fracture processes Stefano Zapperi,1 Purusattam Ray,2 H. Eugene Stanley in a stressed solid was studied by Golubovic and co-workers 9 using Monte Carlo simulations. Recently

  19. Breakdown Anodization (BDA) for hierarchical structures of titanium oxide

    E-Print Network [OSTI]

    Choi, Soon Ju, S.M. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Breakdown Anodization (BDA) of titanium dioxide is a very promising, fast fabrication method to construct micro-scale and nano-scale structures on titanium surfaces. This method uses environmentally friendly electrolytes, ...

  20. Studies of electrical breakdown processes across vacuum gaps between metallic electrodes

    E-Print Network [OSTI]

    Gilson, Erik

    Studies of electrical breakdown processes across vacuum gaps between metallic electrodes L Keywords: Magnetic insulation Vacuum electrical breakdown Bacteria-induced electrical breakdown Accelerator a b s t r a c t An experimental program to elucidate the physical causes of electrical breakdown

  1. The development and deployment of a ground-based, laser-induced fluorescence instrument for the in situ detection of iodine monoxide radicals

    SciTech Connect (OSTI)

    Thurlow, M. E., E-mail: thurlow@huarp.harvard.edu; Hannun, R. A.; Lapson, L. B.; Anderson, J. G. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States)] [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); Co, D. T. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); Argonne-Northwestern Solar Energy Research Center and Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113 (United States); O'Brien, A. S. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Hanisco, T. F. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); NASA Goddard Space Flight Center, Code 614, Greenbelt, Maryland 20771 (United States)

    2014-04-15T23:59:59.000Z

    High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer. Of particular interest are the roles IO plays in the formation of new particles in coastal marine environments and in depletion episodes of ozone and mercury in the Arctic polar spring. This paper describes a ground-based instrument that measures IO at mixing ratios less than one part in 10{sup 12}. The IO radical is measured by detecting laser-induced fluorescence at wavelengths longer that 500 nm. Tunable visible light is used to pump the A{sup 2}?{sub 3/2} (v{sup ?} = 2) ? X{sup 2}?{sub 3/2} (v{sup ?} = 0) transition of IO near 445 nm. The laser light is produced by a solid-state, Nd:YAG-pumped Ti:Sapphire laser at 5 kHz repetition rate. The laser-induced fluorescence instrument performs reliably with very high signal-to-noise ratios (>10) achieved in short integration times (<1 min). The observations from a validation deployment to the Shoals Marine Lab on Appledore Island, ME are presented and are broadly consistent with in situ observations from European Coastal Sites. Mixing ratios ranged from the instrumental detection limit (<1 pptv) to 10 pptv. These data represent the first in situ point measurements of IO in North America.

  2. EMSL - spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectroscopy en Behavior of nanoceria in biologically-relevant environments. http:www.emsl.pnl.govemslwebpublicationsbehavior-nanoceria-biologically-relevant-environments

  3. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    SciTech Connect (OSTI)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01T23:59:59.000Z

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  4. Characterization of superconducting radiofrequency breakdown by two-mode excitation

    SciTech Connect (OSTI)

    Eremeev, Grigory V. [JLAB, Newport News, VA (United States); Palczewski, Ari D. [JLAB, Newport News, VA (United States)

    2014-01-01T23:59:59.000Z

    We show that thermal and magnetic contributions to the breakdown of superconductivity in radiofrequency (RF) fields can be separated by applying two RF modes simultaneously to a superconducting surface. We develop a simple model that illustrates how mode-mixing RF data can be related to properties of the superconductor. Within our model the data can be described by a single parameter, which can be derived either from RF or thermometry data. Our RF and thermometry data are in good agreement with the model. We propose to use mode-mixing technique to decouple thermal and magnetic effects on RF breakdown of superconductors.

  5. The effect of pulse duration on the growth rate of laser-induced damage sites at 351 nm on fused silica surfaces

    SciTech Connect (OSTI)

    Negres, R A; Norton, M A; Liao, Z M; Cross, D A; Bude, J D; Carr, C W

    2009-10-29T23:59:59.000Z

    Past work in the area of laser-induced damage growth has shown growth rates to be primarily dependent on the laser fluence and wavelength. More recent studies suggest that growth rate, similar to the damage initiation process, is affected by a number of additional parameters including pulse duration, pulse shape, site size, and internal structure. In this study, we focus on the effect of pulse duration on the growth rate of laser damage sites located on the exit surface of fused silica optics. Our results demonstrate, for the first time, a significant dependence of growth rate at 351 nm on pulse duration from 1 ns to 15 ns as {tau}{sup 0.3} for sites in the 50-100 {micro}m size range.

  6. Corrosion inhibitor storage and release property of TiO{sub 2} nanotube powder synthesized by rapid breakdown anodization method

    SciTech Connect (OSTI)

    Arunchandran, C.; Ramya, S.; George, R.P. [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)] [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Kamachi Mudali, U., E-mail: kamachi@igcar.gov.in [Corrosion Science and Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Display Omitted Highlights: ? TiO{sub 2} nanotube powders were synthesized by rapid breakdown anodization method. ? Benzotriazole was loaded into the TiO{sub 2} nanotube powders. ? Low pH induced release of benzotriazole from TiO{sub 2} nanotube powders was proved. -- Abstract: Titanium dioxide (TiO{sub 2}) is one of the most studied substances in material science due to its versatile properties and diverse applications. In this study titanium dioxide nanotube powder were synthesized by rapid breakdown anodization (RBA) method. The synthesis involved potentiostatic anodization of titanium foil in 0.1 M HClO{sub 4} electrolyte under an applied voltage of 20 V and rapid stirring. The morphology and the phase of titanium dioxide nanotube powder were studied using field emission scanning electron microscopy, laser Raman spectroscopy and high resolution transmission electron microscopy. Benzotriazole was chosen as model inhibitor to evaluate TiO{sub 2} nanotube powder's corrosion inhibitor loading and releasing properties. The storage and release properties of TiO{sub 2} nanotube powder were studied using UVvisible spectroscopy and thermogravimetric analysis.

  7. Studies of electrical breakdown processes across vacuum gaps between metallic electrodes

    E-Print Network [OSTI]

    Gilson, Erik

    Studies of electrical breakdown processes across vacuum gaps between metallic electrodes L Available online 3 June 2013 Keywords: Magnetic insulation Vacuum electrical breakdown Bacteria-induced electrical breakdown Accelerator a b s t r a c t An experimental program to elucidate the physical causes

  8. System for time-discretized vacuum ultraviolet spectroscopy of spark breakdown in air

    SciTech Connect (OSTI)

    Ryberg, D.; Fierro, A.; Dickens, J.; Neuber, A. [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering and Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-10-15T23:59:59.000Z

    A system for time-discretized spectroscopic measurements of the vacuum ultraviolet (VUV) emission from spark discharges in the 60-160 nm range has been developed for the study of early plasma-forming phenomena. The system induces a spark discharge in an environment close to atmospheric conditions created using a high speed puff value, but is otherwise kept at high vacuum to allow for the propagation of VUV light. Using a vertical slit placed 1.5 mm from the discharge the emission from a small cross section of the discharge is allowed to pass into the selection chamber consisting of a spherical grating, with 1200 grooves/mm, and an exit slit set to 100 ?m. Following the exit slit is a photomultiplier tube with a sodium salicylate scintillator that is used for the time discretized measurement of the VUV signal with a temporal resolution limit of 10 ns. Results from discharges studied in dry air, Nitrogen, SF{sub 6}, and Argon indicate the emission of light with wavelengths shorter than 120 nm where the photon energy begins to approach the regime of direct photoionization.

  9. Detecting excess ionizing radiation by electromagnetic breakdown of air

    SciTech Connect (OSTI)

    Granatstein, Victor L.; Nusinovich, Gregory S. [Center for Applied Electromagnetics, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, Maryland 20742 (United States)

    2010-09-15T23:59:59.000Z

    A scheme is proposed for detecting a concealed source of ionizing radiation by observing the occurrence of breakdown in atmospheric air by an electromagnetic wave whose electric field surpasses the breakdown field in a limited volume. The volume is chosen to be smaller than the reciprocal of the naturally occurring concentration of free electrons. The pulse duration of the electromagnetic wave must exceed the avalanche breakdown time (10-200 ns) and could profitably be as long as the statistical lag time in ambient air (typically, microseconds). Candidate pulsed electromagnetic sources over a wavelength range, 3 mm>{lambda}>10.6 {mu}m, are evaluated. Suitable candidate sources are found to be a 670 GHz gyrotron oscillator with 200 kW, 10 {mu}s output pulses and a Transversely Excited Atmospheric-Pressure (TEA) CO{sub 2} laser with 30 MW, 100 ns output pulses. A system based on 670 GHz gyrotron would have superior sensitivity. A system based on the TEA CO{sub 2} laser could have a longer range >100 m.

  10. Characterization of nonpolar lipids and steroids by using laser-induced acoustic desorption/chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization mass spectrometry

    SciTech Connect (OSTI)

    Jin, Z.; Daiya, S.; Kenttmaa, Hilkka I.

    2011-01-01T23:59:59.000Z

    Laser-induced acoustic desorption (LIAD) combined with ClMn(H{sub 2}O){sup +} chemical ionization (CI) was tested for the analysis of nonpolar lipids and selected steroids in a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR). The nonpolar lipids studied, cholesterol, 5?-cholestane, cholesta-3,5-diene, squalene, and ?-carotene, were found to solely form the desired water replacement product (adduct-H{sub 2}O) upon reaction with the ClMn(H{sub 2}O){sup +} ions. The steroids, androsterone, dehydroepiandrosterone (DHEA), estrone, estradiol, and estriol, also form abundant adduct-H{sub 2}O ions, but less abundant adduct-2H{sub 2}O ions were also observed. Neither (+)APCI nor (+)ESI can ionize the saturated hydrocarbon lipid, cholestane. APCI successfully ionizes the unsaturated hydrocarbon lipids to form exclusively the intact protonated analytes. However, it causes extensive fragmentation for cholesterol and the steroids. The worst case is cholesterol that does not produce any stable protonated molecules. On the other hand, ESI cannot ionize any of the hydrocarbon analytes, saturated or unsaturated. However, ESI can be used to protonate the oxygen-containing analytes with substantially less fragmentation than for APCI in all cases except for cholesterol and estrone. In conclusion, LIAD/ClMn(H{sub 2}O){sup +} chemical ionization is superior over APCI and ESI for the mass spectrometric characterization of underivatized nonpolar lipids and steroids.

  11. Detailed modeling and laser-induced fluorescence imaging of nitric oxide in a NH(i)-seeded non-premixed methane/air flame

    SciTech Connect (OSTI)

    Bell, John B.; Day, Marcus S.; Grcar, Joseph F.; Bessler, Wolfgang G.; Schulz, Christof; Glarborg, Peter; Jensen, Anker D.

    2001-12-14T23:59:59.000Z

    In this paper we study the formation of NO in laminar, nitrogen diluted methane diffusion flames that are seeded with ammonia in the fuel stream. We have performed numerical simulations with detailed chemistry as well as laser-induced fluorescence imaging measurements for a range of ammonia injection rates. For comparison with the experimental data, synthetic LIF images are calculated based on the numerical data accounting for temperature and fluorescence quenching effects. We demonstrate good agreement between measurements and computations. The LIF corrections inferred from the simulation are then used to calculate absolute NO mole fractions from the measured signal.The NO formation in both doped and undoped flames occurs in the flame sheet. In the undoped flame, four different mechanisms including thermal and prompt NO appear to contribute to NO formation. As the NH3 seeding level increases, fuel-NO becomes the dominant mechanism and N2 shifts from being a net reactant to being a net product. Nitric oxide in the undoped flame as well as in the core region of the doped flames are underpredicted by the model; we attribute this mainly to inaccuracies in the NO recycling chemistry on the fuel-rich side of the flame sheet.

  12. Laser induced fluorescence measurements of ion velocity and temperature of drift turbulence driven sheared plasma flow in a linear helicon plasma device

    SciTech Connect (OSTI)

    Chakraborty Thakur, S.; Fedorczak, N.; Manz, P.; Tynan, G. R.; Xu, M. [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego, California 92093 (United States); Center for Energy Research, University of California at San Diego, San Diego, California 92093 (United States); McCarren, D.; Scime, E. E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States); Lee, T. [Center for Energy Research, University of California at San Diego, San Diego, California 92093 (United States)

    2012-08-15T23:59:59.000Z

    Using laser induced fluorescence (LIF), radial profiles of azimuthal ion fluid velocity and ion temperature are measured in the controlled shear de-correlation experiment (CSDX) linear helicon plasma device. Ion velocities and temperatures are derived from the measured Doppler broadened velocity distribution functions of argon ions. The LIF system employs a portable, high power (>300 mW), narrowband ({approx}1 MHz) tunable diode laser-based system operating at 668.614 nm. Previous studies in CSDX have shown the existence of a radially sheared azimuthal flow as measured with time delay estimation methods and Mach probes. Here, we report the first LIF measurements of sheared plasma fluid flow in CSDX. Above a critical magnetic field, the ion fluid flow profile evolves from radially uniform to peaked on axis with a distinct reversed flow region at the boundary, indicating the development of a sheared azimuthal flow. Simultaneously, the ion temperature also evolves from a radially uniform profile to a profile with a gradient. Measurements in turbulent and coherent drift wave mode dominated plasmas are compared.

  13. Using Gold Nanoparticles as Artificial Defects in Thin Films: What Have We Learned About Laser-Induced Damage Driven by Localized Absorbers?

    SciTech Connect (OSTI)

    Papernov, S.; Schmid, A.W.

    2007-03-14T23:59:59.000Z

    There is general agreement that localized absorbing defects are a major factor affecting thin-film performance, and laser-induced damage in films designed for UV, nanosecond-scale, pulsed-laser applications is driven by nanoscale absorbers. Low number densities and size (few nanometer), however, prevent any characterization of these defects and, consequently, deterministic film improvement. This situation also hampers further development of localized defect-driven damage theory, since initial conditions for modeling remain uncertain. Recently, a new approach for studying laser interaction with thin-film nanoscale defects was implemented in which well-characterized, isolated artificial absorbing defects (gold nanoparticles) were introduced inside the thin film. This work is a review in which we discuss main findings from experiments with gold nanoparticles, such as delocalization of absorption during the laser pulse, importance of the defect boundary conditions (contact with the matrix), and competition of pure thermal and stress-driven mechanisms of damage-crater formation. These experimental results will be compared with theoretical results of damage-crater formation in such model thin films using both phenomenological modeling and detailed calculations of the kinetics of the damage process. An outlook on future thin-film-damage studies using model systems with artificial defects is also presented.

  14. Electrical breakdown of a bubble in a water-filled capillary

    SciTech Connect (OSTI)

    Bruggeman, P.J.; Leys, C.A.; Vierendeels, J. A. [Department of Applied Physics, Research Unit Plasma Technology (RUPT), Faculty of Engineering, Ghent University, Rozier 44, B-9000 Ghent (Belgium); Department of Flow, Heat and Combustion Mechanics, Faculty of Engineering, Ghent University, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium)

    2006-06-01T23:59:59.000Z

    In this Communication, the electrical breakdown of a static bubble in a water-filled capillary generated in a dc electrical field is studied. We present experimental results which indicate that the liquid layer between capillary and bubble wall can have an important influence on the breakdown mechanism of the bubble. The breakdown electrical field (atmospheric pressure) without a liquid layer in a (vapor) bubble is 18 kV/cm. When a liquid layer is present, the electrical breakdown of an air bubble is observed at electrical fields typically two times smaller. Local plasma formation is observed in this case possibly due to bubble deformation.

  15. E-Print Network 3.0 - axisymmetric vortex breakdown Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the breakdown of vortex rings in the cycle following t 300T. Downstream... A straight tube with a smooth axisymmetric constriction is an idealised representation of a stenosed...

  16. Isotope effects and Born-Oppenheimer breakdown in excited singlet states of the lithium dimer

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Isotope effects and Born-Oppenheimer breakdown in excited singlet states of the lithium dimer A of infrared electronic transitions involving the 1 1 g state of 7 Li2 has instigated an investigation of Born-Oppenheimer and the leading vibrational and/or rotational Born-Oppenheimer breakdown terms for the X 1 g , A 1 u , B 1 u

  17. Laser induced phosphorescence uranium analysis

    DOE Patents [OSTI]

    Bushaw, Bruce A. (Kennewick, WA)

    1986-01-01T23:59:59.000Z

    A method is described for measuring the uranium content of aqueous solutions wherein a uranyl phosphate complex is irradiated with a 5 nanosecond pulse of 425 nanometer laser light and resultant 520 nanometer emissions are observed for a period of 50 to 400 microseconds after the pulse. Plotting the natural logarithm of emission intensity as a function of time yields an intercept value which is proportional to uranium concentration.

  18. Laser induced phosphorescence uranium analysis

    DOE Patents [OSTI]

    Bushaw, B.A.

    1983-06-10T23:59:59.000Z

    A method is described for measuring the uranium content of aqueous solutions wherein a uranyl phosphate complex is irradiated with a 5 nanosecond pulse of 425 nanometer laser light and resultant 520 nanometer emissions are observed for a period of 50 to 400 microseconds after the pulse. Plotting the natural logarithm of emission intensity as a function of time yields an intercept value which is proportional to uranium concentration.

  19. Two-dimensional space-resolved emission spectroscopy of laser ablation plasma in water

    SciTech Connect (OSTI)

    Matsumoto, Ayumu; Tamura, Ayaka; Fukami, Kazuhiro; Ogata, Yukio H. [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan); Sakka, Tetsuo [Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510 (Japan)

    2013-02-07T23:59:59.000Z

    We developed a method for two-dimensional space-resolved emission spectroscopy of laser-induced plasma in water to investigate the spatial distribution of atomic species involved in the plasma. Using this method, the laser ablation plasma produced on a Cu target in 5 mM NaCl aqueous solution was examined. The emission spectrum varied considerably depending on the detecting position. The temperature and the atomic density ratio N{sub Na}/N{sub Cu} at various detecting positions were evaluated by fitting emission spectra to a theoretical model based on the Boltzmann distribution. We are successful in observing even a small difference between the distributions of the plasma parameters along the directions vertical and horizontal to the surface. The present approach gives direct information for sound understanding of the behavior of laser ablation plasma produced on a solid surface in water.

  20. DOE-Imaging grant FG02-06ER15829, entitled "Developing Laser-Induced Re-Collision Electron Self-Diffraction" Brief summary of accomplishments

    SciTech Connect (OSTI)

    Igor V. Litvinyuk, and Itzik Ben-Itzhak

    2012-04-01T23:59:59.000Z

    Our principal goal was the experimental demonstration of Laser-Induced Electron Diffraction (LIED). Key steps along the development of this experimental technique have been accomplished and reported in the publications listed in this brief report. We started with measuring 3D electron momenta spectra in aligned nitrogen and oxygen molecules. Chakra Maharjan (Ph.D. student of Lew Cocke) was a lead researcher on this project. Although Chakra succeeded in obtaining those spectra, we were scooped by the publication of identical results in Science by the NRC Ottawa group. Our results were never published as a refereed article, but became a part of Chakra's Ph.D. dissertation. That Science paper was the first experimental demonstration of Laser-Induced Electron Diffraction (LIED). Chakra also worked on wavelength dependence of 3D ATI spectra of atoms and molecules using tunable OPA pulses. Another Ph.D. student, Maia Magrakvelidze (her GRA was funded by the grant), started working on COLTRIMS experiments using OPA pulses (1800 nm wavelength). After some initial experiments it became apparent that COLTRIMS did not yield sufficient count rates of electrons in the high-energy part of the spectrum to see diffraction signatures with acceptable statistics (unfavorable scaling of the electron yield with laser wavelength was partly to blame). Nevertheless, Maia managed to use COLTRIMS and OPA to measure the angular dependence of the tunneling ionization rate in D{sub 2} molecules. Following the initial trial experiments, the decision was made to switch from COLTRIMS to VMI in order to increase the count rates by a factor of {approx}100, which may have given us a chance to see LIED. Research Associate Dr. Sankar De (his salary was funded by the grant), in collaboration with Matthias Kling's group (then at MPQ Garching), proceeded to design a special multi-electrode VMI spectrometer for capturing high-energy ATI electrons and to install it in place of COLTRIMS inside our experimental chamber. That apparatus was later used for the first demonstration of field-free orientation in CO using two-color laser pulses as well as for a series of other experiments, such as pump-probe studies of molecular dynamics with few-cycle laser pulses, control of electron localization in dissociating hydrogen molecules using two-color laser pulses, and ATI spectra of Xe ionized by two-color laser pulses. In parallel, Dipanwita Ray (Ph.D. student of Lew Cocke) worked on measuring angle-resolved ATI spectra of noble gases using a stereo-ATI phasemeter as a TOF electron spectrometer. She observed the angular diffraction structures in 3D ATI spectra of Ar, Kr and Xe, which were interpreted in terms of the Quantitative Rescattering theory newly developed by C.D. Lin. We also attempted to use a much more powerful OPA (five times more energy per pulse than the one we had at JRML) available at the Advanced Laser Light Source (ALLS) in Montreal to observe LIED. Two visits to ALLS by the PI, Igor Litvinyuk, and one visit by the PI's Ph.D. student (Irina Bocharova) were funded by the grant. Though we failed to observe LIED (the repetition rate of the ALLS OPA was too low at only 100 Hz), this international collaboration resulted in several publications on other related subjects, such as the wavelength dependence of laser Coulomb explosion of hydrogen, the wavelength dependence of non-sequential double ionization of neon and argon, the demonstration of charge-resonance enhanced ionization in CO{sub 2}, and the study of non-elastic scattering processes in H{sub 2}. Theoretical efforts to account for the hydrogen Coulomb explosion experiment resulted in another paper by Maia Magrakvelidze as lead author. Although for various reasons we failed to achieve our main goal of observing LIED, we salute the recent success in this endeavor by Lou DiMauro's group (with theoretical support from our KSU colleague C.D. Lin) published in Nature, which validates our approach.

  1. Optical instrumentation for on-line analysis of chemical processes

    SciTech Connect (OSTI)

    Hartford, A. Jr.; Cremers, D.A.; Loree, T.R.; Quigley, G.P.

    1983-01-01T23:59:59.000Z

    Optical diagnostics provide the capability for nonintrusive, on-line, real time analysis of chemical process streams. Several laser-based methods for monitoring fossil energy processes have been evaluated. Among the instrumentation techniques which appear quite promising are coherent anti-Stokes Raman spectroscopy (CARS), laser-induced breakdown spectroscopy (LIBS), and synchronous detection of laser-induced fluorescence (SDLIF). A CARS diagnostic was implemented on a coal gasifier and was successfully employed to measure species concentrations and temperatures within the process stream. The LIBS approach has been used to identify total trace impurities (e.g., Na, K, and S) within a gasifier. Recently, individual components in mixtures of aromatics hydrocarbons have been resolved via the synchronous detection of laser-induced fluorescence. 9 figures.

  2. Experiment for measurements of the gas breakdown statistics by ramp voltage pulses

    SciTech Connect (OSTI)

    Markovic, V. Lj.; Stamenkovic, S. N.; Gocic, S. R.; Petrovic, Z. Lj. [Department of Physics, University of Nis, P.O. Box 224, 18001 Nis (Serbia and Montenegro); Institute of Physics, P.O. Box 68, 11080 Belgrade (Serbia and Montenegro)

    2006-09-15T23:59:59.000Z

    In the first part of this article the electronic automatic system for the measurements of dynamic breakdown voltages U{sub b} with linearly rising (ramp) pulses is presented. It generates the sequence of ramp pulses with subvoltage level U{sub sub}{approx_equal}0 during the relaxation time {tau} of the tube, and the ramp pulses start from the static breakdown voltage U{sub s}, thus enabling the correct study of electrical breakdowns and relaxation in gases. In the second part the measurements in argon with and without a voltage during the off period of the pulse are analyzed. The influence of the subvoltage on the mean value of the breakdown voltage U{sub b} as a function of the rise rate k, on the statistical U{sub b} distributions and on the afterglow kinetics is also discussed.

  3. Collision and diffusion in microwave breakdown of nitrogen gas in and around microgaps

    SciTech Connect (OSTI)

    Campbell, J. D.; Lenters, G. T. [Grand Valley State University, Allendale, MI 49401 (United States)] [Grand Valley State University, Allendale, MI 49401 (United States); Bowman, A.; Remillard, S. K., E-mail: remillard@hope.edu [Hope College, Holland, MI 49423 (United States)

    2014-01-15T23:59:59.000Z

    The microwave induced breakdown of N{sub 2} gas in microgaps was modeled using the collision frequency between electrons and neutral molecules and the effective electric field concept. Low pressure breakdown at the threshold electric field occurs outside the gap, but at high pressures it is found to occur inside the microgap with a large threshold breakdown electric field corresponding to a very large electron oscillation amplitude. Three distinct pressure regimes are apparent in the microgap breakdown: a low pressure multipactor branch, a mid-pressure Paschen branch, both of which occur in the space outside the microgap, and a high pressure diffusion-drift branch, which occurs inside the microgap. The Paschen and diffusion-drift branches are divided by a sharp transition and each separately fits the collision frequency model. There is evidence that considerable electron loss to the microgap faces accompanies the diffusion-drift branch in microgaps.

  4. Charge transport and breakdown physics in liquid/solid insulation systems

    E-Print Network [OSTI]

    Jadidian, Jouya

    2013-01-01T23:59:59.000Z

    Liquid dielectrics provide superior electrical breakdown strength and heat transfer capability, especially when used in combination with liquid-immersed solid dielectrics. Over the past half-century, there has been extensive ...

  5. E-Print Network 3.0 - atria phosphatidylinositol breakdown Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    breakdown Page: << < 1 2 3 4 5 > >> 1 ISSN: 1524-4539 Copyright 2010 American Heart Association. All rights reserved. Print ISSN: 0009-7322. Online Summary: ,25 presented...

  6. Elucidating the mechanisms behind pre-breakdown phenomena in transformer oil systems

    E-Print Network [OSTI]

    Hwang, Jae-Won George, 1980-

    2010-01-01T23:59:59.000Z

    The widespread use of dielectric liquids for high voltage insulation and power apparatus cooling is due to their greater electrical breakdown strength and thermal conductivity than gaseous insulators. In addition, their ...

  7. Analysis of low-pressure dc breakdown in nitrogen between two spherical iron electrodes

    SciTech Connect (OSTI)

    Pejovic, Momcilo M.; Nesic, Nikola T.; Pejovic, Milic M. [Faculty of Electronic Engineering, University of Nis, P.O. Box 73, 18001 (Serbia and Montenegro)

    2006-02-15T23:59:59.000Z

    The influence of afterglow period {tau}, voltage increase rate k, and electrode gap d on breakdown voltage U{sub b} for a nitrogen-filled tube with spherical electrodes of diameter D>>d and p=6.5 mbar has been investigated. The data for the breakdown voltage were obtained for the case when there is a presence of N({sup 4}S) atoms, which release secondary electrons via recombination on the cathode. By fitting the experimental data of breakdown voltage mean values as a function of the voltage increase rate, the static breakdown voltages for afterglow periods of 15 and 100 s were estimated. The electrical field as a function of the electrode gap using breakdown voltage mean values was also determined. It is shown that experimental results of the breakdown voltage mean value as a function of pd in the interval of d from 0.82 to 1.62 mm can be very well described with Paschen's law, valid for the case of parallel-plate electrodes.

  8. Factors contributing to the breakdown of sodium beta-alumina

    SciTech Connect (OSTI)

    Buechele, A.C.

    1982-05-01T23:59:59.000Z

    Clarification of the breakdown process occurring during charge transfer in sodium beta alumina solid electrolytes was derived from: (1) studying the effects of molten sodium contact at 350/sup 0/C on single crystal sodium beta alumina and polycrystalline sodium beta alumina; (2) determination of critical current density by monitoring acoustic emissions accompanying crack growth in sodium/sodium beta alumina/sodium cells subjected to linear current ramping at 1 mA cm/sup -2/ sec/sup -1/; (3) failure analysis conducted on cycled electrolytes, some from commercial sodium/sulfur cells, which had been subjected to up to 703 Ahr cm/sup -2/ of charge transfer. Gray coloration developing in beta aluminas in contact with molten sodium was found to be a consequence of formation, through reduction by sodium, of oxygen vacancies charge compensated by electrons. Electronic conductivity of the electrolyte increases as a result. No second phase formation was detected. Colored electrolytes from sodium/sulfur cells show evidence of a newly recognized degradation mechanism in which fracture occurs when sodium is reduced and deposited internally under pressure as metal in regions where an electronic conductivity gradient exists. Heating colored beta aluminas in air produces reoxidation and bleaching. Kinetics and other properties of the coloration and bleaching processes were determined. Critical current density was found to bear an inverse relation to average electrolyte grain size. Evidence was found in the cycled electrolytes for a slow crack growth mechanism and a progressive mode of degradation advancing from the sulfur electrode interface. Implications of the findings for the construction and operation of sodium/sulfur battery systems are discussed.

  9. Comparison of femtosecond and nanosecond laser-induced damage in HfO{sub 2} single-layer film and HfO{sub 2}-SiO{sub 2} high reflector

    SciTech Connect (OSTI)

    Yuan Lei; Zhao Yuanan; Shang Guangqiang; Wang Chengren; He Hongbo; Shao Jianda; Fan Zhengxiu [Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China) and Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China) and Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2007-03-15T23:59:59.000Z

    HfO{sub 2} single layers, 800 nm high-reflective (HR) coating, and 1064 nm HR coating were prepared by electron-beam evaporation. The laser-induced damage thresholds (LIDTs) and damage morphologies of these samples were investigated with single-pulse femtosecond and nanosecond lasers. It is found that the LIDT of the HfO{sub 2} single layer is higher than the HfO{sub 2}-SiO{sub 2} HR coating in the femtosecond regime, while the situation is opposite in the nanosecond regime. Different damage mechanisms are applied to study this phenomenon. Damage morphologies of all samples due to different laser irradiations are displayed.

  10. In-situ characterization of femtosecond laser-induced crystallization in borosilicate glass using time-resolved surface third-harmonic generation

    SciTech Connect (OSTI)

    Liu, Weimin; Wang, Liang; Han, Fangyuan; Fang, Chong [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)] [Department of Chemistry, Oregon State University, Corvallis, Oregon 97331 (United States)

    2013-11-11T23:59:59.000Z

    Coherent phonon dynamics in condensed-phase medium are responsible for important material properties including thermal and electrical conductivities. We report a structural dynamics technique, time-resolved surface third-harmonic generation (TRSTHG) spectroscopy, to capture transient phonon propagation near the surface of polycrystalline CaF{sub 2} and amorphous borosilicate (BK7) glass. Our approach time-resolves the background-free, high-sensitivity third harmonic generation (THG) signal in between the two crossing near-IR pulses. Pronounced intensity quantum beats reveal the impulsively excited low-frequency Raman mode evolution on the femtosecond to picosecond timescale. After amplified laser irradiation, danburite-crystal-like structure units form at the glass surface. This versatile TRSTHG setup paves the way to mechanistically study and design advanced thermoelectrics and photovoltaics.

  11. Statistical analysis of the electrical breakdown time delay distributions in krypton

    SciTech Connect (OSTI)

    Maluckov, Cedomir A.; Karamarkovic, Jugoslav P.; Radovic, Miodrag K.; Pejovic, Momcilo M. [Technical Faculty in Bor, University of Belgrade, Vojske Jugoslavije 24, 19210 Bor (Serbia and Montenegro); Faculty of Civil Engineering and Architecture, University of Nis, Beogradska 14, 18000 Nis (Serbia and Montenegro); Faculty of Sciences and Mathematics, University of Nis, P.O. Box 224, 18001 Nis (Serbia and Montenegro); Faculty of Electronic Engineering, University of Nis, P.O. Box 73, 18001 Nis (Serbia and Montenegro)

    2006-08-15T23:59:59.000Z

    The statistical analysis of the experimentally observed electrical breakdown time delay distributions in the krypton-filled diode tube at 2.6 mbar is presented. The experimental distributions are obtained on the basis of 1000 successive and independent measurements. The theoretical electrical breakdown time delay distribution is evaluated as the convolution of the statistical time delay with exponential, and discharge formative time with Gaussian distribution. The distribution parameters are estimated by the stochastic modelling of the time delay distributions, and by comparing them with the experimental distributions for different relaxation times, voltages, and intensities of UV radiation. The transition of distribution shapes, from Gaussian-type to the exponential-like, is investigated by calculating the corresponding skewness and excess kurtosis parameters. It is shown that the mathematical model based on the convolution of two random variable distributions describes experimentally obtained time delay distributions and the separation of the total breakdown time delay to the statistical and formative time delay.

  12. The quantum mechanics of ion-enhanced field emission and how it influences microscale gas breakdown

    SciTech Connect (OSTI)

    Li, Yingjie [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Go, David B., E-mail: dgo@nd.edu [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2014-09-14T23:59:59.000Z

    The presence of a positive gas ion can enhance cold electron field emission by deforming the potential barrier and increasing the tunneling probability of electronsa process known as ion-enhanced field emission. In microscale gas discharges, ion-enhanced field emission produces additional emission from the cathode and effectively reduces the voltage required to breakdown a gaseous medium at the microscale (<10??m). In this work, we enhance classic field emission theory by determining the impact of a gaseous ion on electron tunneling and compute the effect of ion-enhanced field emission on the breakdown voltage. We reveal that the current density for ion-enhanced field emission retains the same scaling as vacuum cold field emission and that this leads to deviations from traditional breakdown theory at microscale dimensions.

  13. X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment

    SciTech Connect (OSTI)

    Marsh, Roark A.; /MIT /MIT /NIFS, Gifu /JAERI, Kyoto /LLNL, Livermore; Shapiro, Michael A.; Temkin, Richard J.; /MIT; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A.Dian; Tantawi, Sami G.; /SLAC

    2012-06-11T23:59:59.000Z

    In order to understand the performance of photonic band-gap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65 MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110 MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100 MV/m and a surface magnetic field of 890 kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14 MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  14. The effects of a jet on vortex breakdown over a sharp leading-edge delta wing

    E-Print Network [OSTI]

    Maynard, Ian Kenneth

    2012-06-07T23:59:59.000Z

    THE EFFECTS OF A JET ON VORTEX BREAKDOWN OVER A SHARP LEADING-EDGE DELTA WING A Thesis Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1985... Major Subject: Aerospace Engineering THE EFFECTS OF A JET ON VORTEX BREAKDOWN OVER A SHARP LEADING-EDGE DELTA WING A Thesis by IAN KENNETH MAYNARD Approved as to style and content by: Cyrus Ostowar (Chairman of Committee) Stan J Miley (M er...

  15. Time-dependent dielectric breakdown measurements of porous organosilicate glass using mercury and solid metal probes

    SciTech Connect (OSTI)

    Pei, Dongfei; Nichols, Michael T.; Shohet, J. Leon, E-mail: shohet@engr.wisc.edu [Plasma Processing and Technology Laboratory, Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, Sean W.; Clarke, James S. [Intel Corporation, Hillsboro, Oregon 97124 (United States); Nishi, Yoshio [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2014-09-01T23:59:59.000Z

    Time-dependent dielectric breakdown (TDDB) is one of the major concerns for low-k dielectric materials. During plasma processing, low-k dielectrics are subjected to vacuum ultraviolet photon radiation and charged-particle bombardment. To examine the change of TDDB properties, time-to-breakdown measurements are made to porous SiCOH before and after plasma exposure. Significant discrepancies between mercury and solid-metal probes are observed and have been shown to be attributed to mercury diffusion into the dielectric porosities.

  16. Photodissociation spectroscopy and dynamics of the vinoxy (CH{sub 2}CHO) radical

    SciTech Connect (OSTI)

    Osborn, D.L.; Choi, H.; Neumark, D.M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry]|[Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.

    1995-11-01T23:59:59.000Z

    The photodissociation spectroscopy and dynamics of the vinoxy (CH{sub 2}CHO) radical have been studied using fast beam photofragment translational spectroscopy. The photodissociation cross section over the B{sup 2}A{double_prime} {l_arrow} X{sup 2}A{double_prime} band is measured, and photofragment translational energy and angular distributions are obtained at several excitation energies. For CH{sub 2}CHO, predissociation is observed over the entire band, including several transitions near the band origin which were seen previously in laser-induced fluorescence experiments. Two dissociation channels are seen: CH{sub 3} + CO and H + CH{sub 2}CO. The CH{sub 3} + CO channel was investigated in considerable detail and appears to proceed via internal conversion to the CH{sub 2}CHO ground state followed by isomerization to CH{sub 3}CO and subsequent dissociation. The translational energy distributions for this channel suggest an isomerization barrier in the range of 2 eV with respect to CH{sub 3} + CO products.

  17. Dielectric breakdown model for conductor-loaded and insulator-loaded composite materials P. Bergero,1

    E-Print Network [OSTI]

    Peruani, Fernando

    Dielectric breakdown model for conductor-loaded and insulator-loaded composite materials P. Bergero strength is highly desirable, and in the past years composite materials such as resin matrix filled- tors, and composites containing carbon black and titanium dioxide have recently been tested

  18. Relating carrion breakdown rates to ambient resource level and community structure in four cave stream ecosystems

    E-Print Network [OSTI]

    Benstead, Jon

    into ecosystems vary in quantity and quality (e.g., plant litter vs carrion). Variability in detrital quantity and quality potentially affects consumer biomass and rates of organic matter (OM) breakdown. We used cave streams to test 2 linked hypotheses regarding the influence of total detrital inputs on consumer biomass

  19. Breakdown of Angular Momentum Selection Rules in High Pressure Optical Pumping Experiments

    SciTech Connect (OSTI)

    Lancor, B.; Wyllie, R.; Walker, T. G. [Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Babcock, E. [Juelich Centre for Neutron Science, Garching 85747 (Germany)

    2010-08-20T23:59:59.000Z

    We present measurements, by using two complementary methods, of the breakdown of atomic angular momentum selection rules in He-broadened Rb vapor. Atomic dark states are rendered weakly absorbing due to fine-structure mixing during Rb-He collisions. The effect substantially increases the photon demand for optical pumping of dense vapors.

  20. Wiedenhfer et al. Inter-Organizational Crisis Management Infrastructure for Electrical Power Breakdowns

    E-Print Network [OSTI]

    .pipek}@uni-siegen.de ABSTRACT Major electricity breakdowns like the Northeast Blackout (USA) in 2003 or the blackout in most on electricity, as was the case in 2003 in the Northeast Blackout, USA, or 2005 in Western Europe (Lorenz, 2010Wiedenhöfer et al. Inter-Organizational Crisis Management Infrastructure for Electrical Power

  1. Leakage current and dielectric breakdown behavior in annealed SiO2 aerogel films

    E-Print Network [OSTI]

    Jo, Moon-Ho

    Leakage current and dielectric breakdown behavior in annealed SiO2 aerogel films Moon-Ho Jo behavior in annealed SiO2 aerogel films for intermetal dielectric applications was investigated in a metal­insulator­semiconductor structure. SiO2 aerogel films with porosities of 70% exhibited Poole­Frenkel conduction both before

  2. Empirical Features of Spontaneous and Induced Traffic Breakdowns in Free Flow at Highway Bottlenecks

    E-Print Network [OSTI]

    Kerner, Boris S; Klenov, Sergey L; Rehborn, Hubert; Leibel, Michael

    2015-01-01T23:59:59.000Z

    Based on an empirical study of real field traffic data measured in 1996--2014 through road detectors installed on German freeways, we reveal physical features of empirical nuclei for spontaneous traffic breakdown in free flow at highway bottlenecks. It is shown that the source of a nucleus for traffic breakdown is the solely difference between empirical spontaneous and induced traffic breakdowns at a highway bottleneck. Microscopic traffic simulations with a stochastic traffic flow model in the framework of three-phase theory explain the empirical findings. It turns out that in the most cases, a nucleus for empirical spontaneous traffic breakdown occurs through an interaction of one of waves in free flow with an empirical permanent speed disturbance localized at a highway bottleneck. The wave is a localized structure in free flow, in which the total flow rate is larger and the speed averaged across the highway is smaller than outside the wave. The waves in free flow appear due to oscilations in the percentage...

  3. The onset of optical breakdown in KrF-laser-irradiated silica glass surfaces

    E-Print Network [OSTI]

    Dickinson, J. Thomas

    A synthetic fused silica obtained from Tosoh SGM Co., ESL-1000 (OH % 1200 wt. ppm), with a thick- ness of 2 mmThe onset of optical breakdown in KrF-laser-irradiated silica glass surfaces Y. Kawaguchia,* , A Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1

  4. Breakdown of 2mm symmetry in electron diffraction from multiwalled carbon nanotubes

    E-Print Network [OSTI]

    Qin, Lu-Chang

    Breakdown of 2mm symmetry in electron diffraction from multiwalled carbon nanotubes Zejian Liu of single-walled carbon nanotubes always have 2mm symmetry regardless if the nanotubes them- selves have such symmetry. We here show that, for the case of multiwalled carbon nanotubes, the 2mm symmetry can break down

  5. Logarithmic Fermi-liquid breakdown in NbFe2 M. Brando,1,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    temperature dependence of the Sommerfeld coefficient = C/T of the specific heat capacity, C, over nearly two temperature dependences of the resistivity and of the heat capacity over extended ranges in temperatureLogarithmic Fermi-liquid breakdown in NbFe2 M. Brando,1, W. J. Duncan,1 D. Moroni-Klementowicz,1 C

  6. Improving Device-level Electricity Consumption Breakdowns in Private Households Using ON/OFF Events

    E-Print Network [OSTI]

    recommen- dations on how to reduce the overall energy consumption of the household. In this paper, we build Descriptors H.4 [Information Systems Applications]: Miscellaneous 1. INTRODUCTION The energy sectorImproving Device-level Electricity Consumption Breakdowns in Private Households Using ON/OFF Events

  7. PART I. THERMAL BREAKDOWN CHARACTERISTICS OF MUNICIPAL SOLID WASTE COMPONENTS IN

    E-Print Network [OSTI]

    Columbia University

    Engineering Columbia University in the City of New York - 3 - waste is an area of deep concern both within and Environmental Engineering Columbia University in the City of New York - 2 - Thermal Breakdown Characteristics to the increasing use of and investment in waste- to-energy technologies in Asia, these two realms of knowledge

  8. Investigating the effective range of vacuum ultraviolet-mediated breakdown in high-power microwave metamaterials

    SciTech Connect (OSTI)

    Liu, Chien-Hao, E-mail: cliu82@wisc.edu; Neher, Joel D., E-mail: jdneher@wisc.edu; Booske, John H., E-mail: booske@engr.wisc.edu; Behdad, Nader, E-mail: behdad@wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 (United States)

    2014-10-14T23:59:59.000Z

    Metamaterials and periodic structures operating under high-power excitations are susceptible to breakdown. It was recently demonstrated that a localized breakdown created in a given region of a periodic structure can facilitate breakdown in other regions of the structure where the intensity of the incident electromagnetic fields may not be high enough to cause breakdown under normal circumstances. It was also demonstrated that this phenomenon is due to the generation of vacuum ultraviolet radiation at the location of the initial discharge, which propagates to the neighboring regions (e.g., other unit cells in a periodic structure) and facilitates the generation of a discharge at a lower incident power level. In this paper, we present the results of an experimental study conducted to determine the effective range of this physical phenomenon for periodic structures that operate in air and in pure nitrogen gas at atmospheric pressure levels. It is demonstrated that when breakdown is induced in a periodic structure using a high-power pulse with a frequency of 9.382 GHz, duration of 0.8??s, and peak power level of 25?kW, this phenomenon is highly likely to happen in radii of approximately 1617?mm from the location of the initial discharge under these test conditions. The results of this study are significant in designing metamaterials and periodic structures for high-power microwave applications as they suggest that a localized discharge created in such a periodic structure with a periodicity less than 1617?mm can spread over a large surface and result in a distributed discharge.

  9. Accurate Analytic Potential and Born-Oppenheimer Breakdown Functions for MgH and MgD from a Direct-Potential-Fit Data Analysis

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Accurate Analytic Potential and Born-Oppenheimer Breakdown Functions for MgH and MgD from a Direct-potential-fit analysis to yield improved analytic potential energy and Born-Oppenheimer breakdown functions allowed us also to determine the adiabatic Born- Oppenheimer breakdown effects in this molecule

  10. YAG laser-induced structural modification in transition metal ion containing 40K{sub 2}O-40Nb{sub 2}O{sub 5}-20SiO{sub 2} glasses

    SciTech Connect (OSTI)

    Venkataraman, B. Harihara [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan); Komatsu, Takayuki [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka-cho, Nagaoka 940-2188 (Japan)], E-mail: komatsu@mst.nagaokaut.ac.jp

    2008-10-02T23:59:59.000Z

    Glasses with the compositions of 40K{sub 2}O-40Nb{sub 2}O{sub 5}-20SiO{sub 2} (in mol%) containing different concentrations (0.01, 1 and 2 mol%) of NiO were prepared by a melt quenching technique. The glasses were irradiated with a continuous wave Nd:YAG laser with a wavelength of 1064 nm, and a metastable crystalline phase of KNbO{sub 3} was obtained. In 2 mol% NiO-doped glass, lines with a width of {approx}10 {mu}m are successfully patterned by laser irradiations with a power of 0.9 W and a scanning speed of 15 {mu}m/s. It is found from micro-Raman scattering spectra that the lines are composed of the metastable crystalline phase of KNbO{sub 3}. The crystallization mechanism in Nd:YAG laser-induced crystallization in the glasses is discussed in comparison with the usual crystallization in an electric furnace.

  11. Evidence of Magnetic Breakdown on the Defects With Thermally Suppressed Critical Field in High Gradient SRF Cavities

    SciTech Connect (OSTI)

    Eremeev, Grigory [JLAB; Palczewski, Ari [JLAB

    2013-09-01T23:59:59.000Z

    At SRF 2011 we presented the study of quenches in high gradient SRF cavities with dual mode excitation technique. The data differed from measurements done in 80's that indicated thermal breakdown nature of quenches in SRF cavities. In this contribution we present analysis of the data that indicates that our recent data for high gradient quenches is consistent with the magnetic breakdown on the defects with thermally suppressed critical field. From the parametric fits derived within the model we estimate the critical breakdown fields.

  12. Charmonium spectroscopy, 1987

    SciTech Connect (OSTI)

    Cahn, R.N.

    1987-07-30T23:59:59.000Z

    The state of charmonium spectroscopy is reviewed. All analyses proceed from a spin-dependent, non-relativistic Schroedinger equation. Many of the possible branching ratios for charm like states are investigated. 17 refs.

  13. Toward pure electronic spectroscopy

    E-Print Network [OSTI]

    Petrovi?, Vladimir, 1978-

    2009-01-01T23:59:59.000Z

    In this thesis is summarized the progress toward completing our understanding of the Rydberg system of CaF and developing Pure Electronic Spectroscopy. The Rydberg system of CaF possesses a paradigmatic character due to ...

  14. Electronic Spectroscopy & Dynamics

    SciTech Connect (OSTI)

    Mark Maroncelli, Nancy Ryan Gray

    2010-06-08T23:59:59.000Z

    The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

  15. Study of relaxation kinetics in argon afterglow by the breakdown time delay measurements

    SciTech Connect (OSTI)

    Markovic, V.Lj.; Gocic, S.R.; Stamenkovic, S.N.; Petrovic, Z.Lj. [Department of Physics, University of Nis, P.O. BOX 224, 18001 Nis (Serbia and Montenegro); Institute of Physics, P.O. BOX 68, Belgrade (Serbia and Montenegro)

    2005-07-15T23:59:59.000Z

    In this paper the afterglow kinetics in argon is studied by the breakdown time delay measurements as a function of relaxation time t{sub d}({tau}) ('memory curve'). Measurements were carried out at the pressure of 1.33 mbar in a gas tube with gold-plated copper cathode and approximate and exact numerical models are developed to follow metastable and charged particle decay. It was found that the early afterglow kinetics is governed by the charged particle decay up to hundreds of milliseconds, extending from ambipolar to the free diffusion limit. Quenching processes reduce the effective lifetime of metastable states several orders of magnitude below that relevant for the time scale of the observations if realistic abundances and processes are included in the model. Nitrogen atoms originating from impurities and recombining on the cathode surface can determine the breakdown time delay down to that defined by the level of cosmic rays and natural radioactivity.

  16. An approach to predict tarmat breakdown in Minagish Reservoir in Kuwait

    SciTech Connect (OSTI)

    Osman, M.E.

    1983-03-01T23:59:59.000Z

    Minagish Oolite reservoir, Minagish Field in Kuwait is characterized by tarmat presence at the oil-water contact. A water flooding project is planned for the reservoir. This paper discusses the possibility of tarmat break-down upon water injection below it. It was found that differential pressure at tarmat would be mainly due to water injection and that differential pressure due to oil production would be negligible. This paper suggests a technique to predict tarmat break-down time, response time at the nearest producer or observation well and the time at which water injection should be switched from below tarmat to above it. Also, the technique could be used to predict the differential pressure at tarmat anywhere in the reservoir.

  17. Electroneutrality Breakdown and Specific Ion Effects in Nanoconfined Aqueous Electrolytes Observed by NMR

    E-Print Network [OSTI]

    Luo, Zhi-Xiang; Ling, Yan-Chun; Kleinhammes, Alfred; Wu, Yue

    2015-01-01T23:59:59.000Z

    Ion distribution in aqueous electrolytes near the interface plays critical roles in electrochemical, biological and colloidal systems and is expected to be particularly significant inside nanoconfined regions. Electroneutrality of the total charge inside nanoconfined regions is commonly assumed a priori in solving ion distribution of aqueous electrolytes nanoconfined by uncharged hydrophobic surfaces with no direct experimental validation. Here, we use a quantitative nuclear magnetic resonance approach to investigate the properties of aqueous electrolytes nanoconfined in graphitic-like nanoporous carbon. Substantial electroneutrality breakdown in nanoconfined regions and very asymmetric responses of cations and anions to the charging of nanoconfining surfaces are observed. The electroneutrality breakdown is shown to depend strongly on the propensity of anions toward the water-carbon interface and such ion-specific response follows generally the anion ranking of the Hofmeister series. The experimental observat...

  18. Electroneutrality Breakdown and Specific Ion Effects in Nanoconfined Aqueous Electrolytes Observed by NMR

    E-Print Network [OSTI]

    Zhi-Xiang Luo; Yun-Zhao Xing; Yan-Chun Ling; Alfred Kleinhammes; Yue Wu

    2015-02-24T23:59:59.000Z

    Ion distribution in aqueous electrolytes near the interface plays critical roles in electrochemical, biological and colloidal systems and is expected to be particularly significant inside nanoconfined regions. Electroneutrality of the total charge inside nanoconfined regions is commonly assumed a priori in solving ion distribution of aqueous electrolytes nanoconfined by uncharged hydrophobic surfaces with no direct experimental validation. Here, we use a quantitative nuclear magnetic resonance approach to investigate the properties of aqueous electrolytes nanoconfined in graphitic-like nanoporous carbon. Substantial electroneutrality breakdown in nanoconfined regions and very asymmetric responses of cations and anions to the charging of nanoconfining surfaces are observed. The electroneutrality breakdown is shown to depend strongly on the propensity of anions toward the water-carbon interface and such ion-specific response follows generally the anion ranking of the Hofmeister series. The experimental observations are further supported by numerical evaluation using the generalized Poisson-Boltzmann equation

  19. Extension of thickness-dependent dielectric breakdown law on adiabatically compressed ferroelectric materials

    SciTech Connect (OSTI)

    Shkuratov, Sergey I. [Loki Incorporated, Rolla, Missouri 65409 (United States)] [Loki Incorporated, Rolla, Missouri 65409 (United States); Baird, Jason [Loki Incorporated, Rolla, Missouri 65409 (United States) [Loki Incorporated, Rolla, Missouri 65409 (United States); Department of Mining and Nuclear Engineering, Missouri University of Science and Technology, Rolla, Missouri 65409-0450 (United States); Talantsev, Evgueni F. [Pulsed Power LLC, Lubbock, Texas 79416 (United States)] [Pulsed Power LLC, Lubbock, Texas 79416 (United States)

    2013-02-04T23:59:59.000Z

    It is experimentally found that the E{sub b}(d) = {gamma} {center_dot} d{sup -{xi}} law describing the thickness-dependent breakdown electric field for solid dielectrics at ambient conditions can be extended for dielectrics in other thermodynamic states. It follows from the experimental results reported herein that the breakdown field, E{sub b}(d), of Pb(Zr{sub 0.95}Ti{sub 0.05})O{sub 3} (PZT 95/5) and Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} (PZT 52/48) ferroelectrics subjected to explosive adiabatic compression obeys the above-mentioned law in a wide range of voltages, up to 150 kV.

  20. Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-Gradient Accelerating Structures

    E-Print Network [OSTI]

    Tecker, F; Kelisani, M; Doebert, S; Grudiev, A; Quirante, J; Riddone, G; Syratchev, I; Wuensch, W; Kononenko, O; Solodko, A; Lebet, S

    2013-01-01T23:59:59.000Z

    RF breakdown is a key issue for the multi-TeV highluminosity e+e- Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam.

  1. A field programmable gate array-based time-resolved scaler for collinear laser spectroscopy with bunched radioactive potassium beams

    SciTech Connect (OSTI)

    Rossi, D. M., E-mail: rossi@nscl.msu.edu; Davis, M.; Ringle, R.; Rodriguez, J. A.; Ryder, C. A.; Schwarz, S.; Sumithrarachchi, C.; Zhao, S. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Minamisono, K., E-mail: minamiso@nscl.msu.edu; Barquest, B. R.; Bollen, G.; Hughes, M.; Strum, R.; Tarazona, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Cooper, K.; Hammerton, K.; Mantica, P. F.; Morrissey, D. J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)

    2014-09-15T23:59:59.000Z

    A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive {sup 37}K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 ?s bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 10{sup 5} in resonant photon detection measurements. The hyperfine structure of {sup 37}K and its isotope shift relative to the stable {sup 39}K were determined using 5 10{sup 4} s{sup ?1} {sup 37}K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A({sup 2}S{sub 1/2}) = 120.3(1.4) MHz, A({sup 2}P{sub 1/2}) = 15.2(1.1) MHz, and A({sup 2}P{sub 3/2}) = 1.4(8) MHz, and the isotope shift ??{sup 39,} {sup 37} = ?264(3) MHz are consistent with the previously determined values, where available.

  2. Optical Spectroscopy of Tungsten Carbide for Uncertainty Analysis in Electron Electric Dipole Moment Search

    E-Print Network [OSTI]

    Lee, J; Skripnikov, L V; Petrov, A N; Titov, A V; Mosyagin, N S; Leanhardt, A E

    2012-01-01T23:59:59.000Z

    We perform laser induced fluorescence(LIF) spectroscopy on a pulsed supersonic beam of tungsten carbide(WC) molecules, which has been proposed as a candidate molecular system for a permanent Electric Dipole Moment(EDM) search of the electron in its rovibrational ground state of the X3Delta1 state. In particular, [20.6]Omega=2, v'=4 <- X3Delta1,v"=0 transition at 485nm was used for the detection. The hyperfine structure and the Omega-doublet of the transition are measured, which are essential for estimating the size of the potential systematic uncertainties for electron EDM measurement. For further suppression of the systematic uncertainty, an alternative electron EDM measurement scheme utilizing the g factor crossing point of the Omega-doublet levels is discussed. On the other hand, flux and internal temperature of the molecular beam are characterized, which sets the limit on the statistical uncertainty of the electron EDM experiment. With the given results, the prospect of electron EDM experiment with the...

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

    SciTech Connect (OSTI)

    Garcia-Lechuga, M. [Departamento de Fsica Terica, Atmica y ptica, Universidad de Valladolid, 47011-Valladolid (Spain); Laser Processing Group, Instituto de ptica Daza de Valds, CSIC, 28006-Madrid (Spain); Fuentes, L. M. [Departamento de Fsica Aplicada, Universidad de Valladolid, 47011-Valladolid (Spain); Grtzmacher, K.; Prez, C., E-mail: concha@opt.uva.es; Rosa, M. I. de la [Departamento de Fsica Terica, Atmica y ptica, Universidad de Valladolid, 47011-Valladolid (Spain)

    2014-10-07T23:59:59.000Z

    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.

  4. Fourier Transform Infrared Spectroscopy

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    FTIR - 1 Fourier Transform Infrared Spectroscopy FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL FTIR DETERMINATION OF MTBE IN GASOLINE AND ETHANOL IN VODKA AND MOUTHWASH INTRODUCTION As a part has contained MTBE (methyl tert­butyl ether) as its primary oxygenate. However, there has been

  5. X-ray absorption spectroscopy

    E-Print Network [OSTI]

    Yano, Junko; Yachandra, Vittal K.

    2009-01-01T23:59:59.000Z

    009-9473-8 REVIEW X-ray absorption spectroscopy Junko Yano and application of X-ray absorption spectroscopy, bothX-ray absorption near-edge structure (XANES) and extended X-

  6. X-ray Absorption Spectroscopy

    E-Print Network [OSTI]

    Yano, Junko

    2010-01-01T23:59:59.000Z

    type: Review X-ray Absorption Spectroscopy Junko Yano andPhotosystem II; XAS, X-ray absorption spectroscopy; EXAFS,X-ray absorption fine structure; EPR, electron paramagnetic

  7. Dielectric breakdown properties of hot SF{sub 6}/He mixtures predicted from basic data

    SciTech Connect (OSTI)

    Wang, Weizong [Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094 (China) [Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing 100094 (China); State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an Shaanxi 710049 (China); Tu, Xin; Mei, Danhua [Department of Electrical Engineering and Electronics, The University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom)] [Department of Electrical Engineering and Electronics, The University of Liverpool, Brownlow Hill, Liverpool L69 3GJ (United Kingdom); Rong, Mingzhe [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an Shaanxi 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an Shaanxi 710049 (China)

    2013-11-15T23:59:59.000Z

    Sulfur hexafluoride (SF{sub 6}) gas has a quite high global warming potential and hence it is required that applying any substitute for SF{sub 6} gas. Much interest in the use of a mixture of helium and SF{sub 6} as arc quenching medium was investigated indicating a higher recovery performance of arc interruption than that of pure SF{sub 6}. It is known that the electrical breakdown in a circuit breaker after arc interruption occurs in a hot gas environment, with a complicated species composition because of the occurrence of dissociation and other reactions. The likelihood of breakdown relies on the electron interactions with all these species. The critical reduced electric field strength (the field at which breakdown can occur, relative to the number density) of hot SF{sub 6}/He mixtures related to the dielectric recovery phase of a high voltage circuit breaker is calculated in the temperature range from 300 K to 3500 K. The critically reduced electric field strength of these mixtures was obtained by balancing electron generation and loss mechanisms. These were evaluated using the electron energy distribution function derived from the Boltzmann transport equation under the two-term approximation. Good agreement was found between calculations for pure hot SF{sub 6} and pure hot He and experimental results and previous calculations. The addition of He to SF{sub 6} was found to decrease the critical reduced electric field strength in the whole temperature range due to a lack of electron impact attachment process for helium regardless its high ionization potential. This indicates that not the behaviour of dielectric strength but possibly the higher energy dissipation capability caused mainly by light mass and high specific heat as well as thermal conductivity of atomic helium contributes most to a higher dielectric recovery performance of arc interruption for SF{sub 6}/He mixtures.

  8. Nuclear reactivity control using laser induced polarization

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neturons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

  9. Nuclear reactivity control using laser induced polarization

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

  10. Laser-induced quantum pumping in graphene

    SciTech Connect (OSTI)

    San-Jose, Pablo [Instituto de Estructura de la Materia (IEM-CSIC), Serrano 123, 28006 Madrid (Spain); Prada, Elsa; Kohler, Sigmund [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain); Schomerus, Henning [Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)

    2012-10-08T23:59:59.000Z

    We investigate non-adiabatic electron pumping in graphene generated by laser irradiation with linear polarization parallel or perpendicular to the transport direction. Transport is dominated by the spatially asymmetric excitation of electrons from evanescent into propagating modes. For a laser with parallel polarization, the pumping response exhibits a subharmonic resonant enhancement which directly probes the Fermi energy; no such enhancement occurs for perpendicular polarization. The resonance mechanism relies on the chirality of charge carriers in graphene.

  11. Method for laser induced isotope enrichment

    DOE Patents [OSTI]

    Pronko, Peter P.; Vanrompay, Paul A.; Zhang, Zhiyu

    2004-09-07T23:59:59.000Z

    Methods for separating isotopes or chemical species of an element and causing enrichment of a desired isotope or chemical species of an element utilizing laser ablation plasmas to modify or fabricate a material containing such isotopes or chemical species are provided. This invention may be used for a wide variety of materials which contain elements having different isotopes or chemical species.

  12. LASER INDUCED FLUORESCENCE OF TRAPPED MOLECULAR IONS

    E-Print Network [OSTI]

    Grieman, Frederick Joseph.

    2010-01-01T23:59:59.000Z

    DC!. , -IOC C IS?. MSC JM^ CLA TAD MSOA DCA M5C CDF C I F CJMPX WAIT C CL. \\ TAD JSUB+2 SNA JNP DCN DCA DL-|>1 TAC - S U RD 1 NT TAD K10CA ECA MICC i s - MI or

  13. Laser induced thermophoresis and particulate deposition efficiency

    SciTech Connect (OSTI)

    Cipolla, J.; Morse, T.F.; Wang, C.Y.

    1983-07-01T23:59:59.000Z

    The interaction of laser radiation and an absorbing aerosol in a tube flow has been considered. The aerosol is produced by external heating of reactants as in the MCVD (Modified Chemical Vapor Deposition) process to produce submicron size particles in the manufacture of optical fiber preforms. These are subsequently deposited by thermophoretic forces on the inner wall of the tube as they are convected by a Poiseuille velocity profile. Axial laser radiation in the tube interacts with the absorbing particles, and the laser heating of the gas induces additional thermophoretic forces that markedly increase the efficiency of particulate deposition. A particle concentration dependent absorption coefficient that appears in the energy equation couples the energy equation to the equation of particle conservation, so that a non-linear set of coupled partial integrodifferential equations must be solved. Numerical solutions for aerosol particle trajectories, and thus deposition efficiencies, have been obtained. It is shown that laser enhanced thermophoresis markedly improves the deposition efficiency.

  14. Laser induced natural convection and thermophoresis

    SciTech Connect (OSTI)

    Wang, C.Y.; Cipolla, J.; Morse, T.F.

    1983-07-01T23:59:59.000Z

    The influence of axial laser volumetric heating and forced convection on the motion of aerosol particles in a vertical tube has been studied. The asymptotic case of constant wall temperature provides simple temperature and velocity profiles that determine the convection and thermophoretic motion of small aerosol particles. For the case in which the flow (in the absence of laser heating) is downward, the laser heating induces upward buoyant motion near the tube center. When the laser heating is taken to be constant (a small absorption limit), a velocity profile may be found that will minimize the distance over which particles are deposited on the wall. Such an observation may have some bearing on the manufacture of preforms from which optical fibers are drawn.

  15. Investigation of the statistical nature and structure of the electrical breakdown time delay in gas diodes filled with neon

    SciTech Connect (OSTI)

    Maluckov, Cedomir A. [Technical Faculty in Bor, University of Belgrade, Vojske Jugoslavije 24, 19210 Bor (Serbia and Montenegro); Karamarkovic, Jugoslav P. [Faculty of Civil Eng. and Architecture, University of Nis, Beogradska 14, 18000 Nis (Serbia); Radovic, Miodrag K. [Faculty of Sciences and Mathematics, University of Nis, P.O.B.224, 18001 Nis (Serbia)

    2006-12-01T23:59:59.000Z

    The electrical breakdown time delay in gas diodes filled by neon at the low pressures is investigated experimentally and theoretically. Experimental results are obtained measuring the characteristics of gas diodes filled by spectroscopically pure neon. In order to discard any systematic trend during the measurement procedure, checking of the measured values randomness preceded the statistical analysis of the experimental results. Novel theoretical model is established for interpretation of obtained experimental results on the breakdown time delay. The model is based on the assumptions of the exponential distribution of the statistical time delay and Gaussian distribution of the formative discharge time. Therefore, the density distribution of the breakdown time delay is assumed to be convolution of the statistical and formative time delay distributions. Parameters of the statistical and formative time delay, as stochastic variables, are modeled by the numerical Monte Carlo method. Numerical distributions are tested to the corresponding experimental distributions of the breakdown time delay by varying the distribution parameters. In addition, the asymmetry coefficient and skewness coefficient of the breakdown time delay distribution, and coefficients of the statistical and formative time delay distributions are analyzed. Numerically calculated time delay distributions fit well to the corresponding experimental distributions in gas diodes filled with neon at low pressures.

  16. Effect of high solenoidal magnetic fields on breakdown voltages of high vacuum 805 MHz cavities

    SciTech Connect (OSTI)

    Moretti, A.; Bross, A.; Geer, S.; Qian, Z.; /Fermilab; Norem, J.; /Argonne; Li, D.; Zisman, M.; /LBL, Berkeley; Torun, Y.; /IIT, Chicago; Rimmer, R.; /Jefferson Lab; Errede,; /Illinois U., Urbana

    2005-10-01T23:59:59.000Z

    There is an on going international collaboration studying the feasibility and cost of building a muon collider or neutrino factory [1,2]. An important aspect of this study is the full understanding of ionization cooling of muons by many orders of magnitude for the collider case. An important muon ionization cooling experiment, MICE [3], has been proposed to demonstrate and validate the technology that could be used for cooling. Ionization cooling is accomplished by passing a high-emittance muon beam alternately through regions of low Z material, such as liquid hydrogen, and very high accelerating RF Cavities within a multi-Tesla solenoidal field. To determine the effect of very large solenoidal magnetic fields on the generation of dark current, x-rays and on the breakdown voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station and a large warm bore 5 T solenoidal superconducting magnet containing a pill box type cavity with thin removable window apertures. This system allows dark current and breakdown studies of different window configurations and materials. The results of this study will be presented. The study has shown that the peak achievable accelerating gradient is reduced by a factor greater than 2 when solenoidal field of greater than 2 T are applied to the cavity.

  17. INVESTIGATION OF BREAKDOWN INDUCED SURFACE DAMAGE ON 805 MHZ PILLBOX CAVITY INTERIOR SURFACES

    SciTech Connect (OSTI)

    Jana, M.R.; Chung, M.; Leonova, M.; Moretti, A.; Tollestrup,A.; Yonehara, K.; Freemire, B.; Torun, Y.; Bowring, D.; Flanagan, G.

    2013-09-25T23:59:59.000Z

    The MuCool Test Area (MTA) at Fermilab is a facility to develop the technology required for ionization cooling for a future Muon Collider and/or Neutrino Factory. As part of this research program, we have tested two 805 MHz vacuum RF cavities in a multi-Tesla magnetic field to study the effects of the static magnetic field on the cavity operation. This study gives useful information on field emitters in the cavity, dark current, surface conditioning, breakdown mechanisms and material properties of the cavity. All these factors determine the maximum accelerating gradient in the cavity. This paper discusses the image processing technique for quantitative estimation of spark damage spot distribution on cavity interior surfaces. The distribution is compared with the electric field distribution predicted by a computer code calculation. The local spark density is proportional to probability of surface breakdown and shows a power law dependence on the maximum electric field (E). This E dependence is consistent with the dark current calculated from the Fowler-Nordheim equation.

  18. Pre-breakdown cavitation development in the dielectric fluid in the inhomogeneous, pulsed electric fields

    E-Print Network [OSTI]

    Mikhail N. Shneider; Mikhail Pekker

    2014-12-01T23:59:59.000Z

    We consider the development of pre-breakdown cavitation nanopores appearing in the dielectric fluid under the influence of the electrostrictive stresses in the inhomogeneous pulsed electric field. It is shown that three characteristic regions can be distinguished near the needle electrode. In the first region, where the electric field gradient is greatest, the cavitation nanopores, occurring during the voltage nanosecond pulse, may grow to the size at which an electron accelerated by the field inside the pores can acquire enough energy for excitation and ionization of the liquid on the opposite pore wall, i.e., the breakdown conditions are satisfied. In the second region, the negative pressure caused by the electrostriction is large enough for the cavitation initiation (which can be registered by optical methods), but, during the voltage pulse, the pores do not reach the size at which the potential difference across their borders becomes sufficient for ionization or excitation of water molecules. And, in the third, the development of cavitation is impossible, due to an insufficient level of the negative pressure: in this area, the spontaneously occurring micropores do not grow and collapse under the influence of surface tension forces. This paper discusses the expansion dynamics of the cavitation pores and their most probable shape.

  19. A Beale-Kato-Majda breakdown criterion for an Oldroyd-B fluid in the creeping flow regime

    E-Print Network [OSTI]

    Raz Kupferman; Claude Mangoubi; Edriss S. Titi

    2007-09-10T23:59:59.000Z

    We derive a criterion for the breakdown of solutions to the Oldroyd-B model in $\\R^3$ in the limit of zero Reynolds number (creeping flow). If the initial stress field is in the Sobolev space $H^m$, $m> 5/2$, then either a unique solution exists within this space indefinitely, or, at the time where the solution breaks down, the time integral of the $L^\\infty$-norm of the stress tensor must diverge. This result is analogous to the celebrated Beale-Kato-Majda breakdown criterion for the inviscid Eluer equations of incompressible fluids.

  20. (Resonance ionization spectroscopy)

    SciTech Connect (OSTI)

    Young, J.P.

    1990-10-11T23:59:59.000Z

    J. P. Young attended the Fifth International Symposium on Resonance Ionization Spectroscopy and presented an invited oral presentation on research he and coworkers had carried out in applying diode lasers to resonance ionization mass spectrometry. A summary of the conference is given along with an assessment of some of the presentations that the author found of interest. Young also visited Professor Marassi at the University of Camerino to present a seminar and discuss mutual interests in a new molten salt research project of the author. Some of the studies at Camerino are described. Ideas concerning the author's research that came from private discussions are also presented here.

  1. Spectroscopy and Diffraction | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System Highlights Power2014 EvaluateSpectroscopy and

  2. Spectroscopy of semiconductor materials

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakersSpectroscopy Print

  3. Dynamics of local micro-breakdown in the Geiger mode of avalanche photodiodes

    SciTech Connect (OSTI)

    Verhovtseva, A. V., E-mail: alevteena@gmail.com; Gergel, V. A. [Russian Academy of Sciences, Kotel'nikov Institute of Radio Engineering and Electronics (Russian Federation)], E-mail: gergel@mail.cplire.ru

    2009-07-15T23:59:59.000Z

    Mathematical modeling methods were used to study the dynamics of micro-breakdown development in structures of silicon avalanche photodiodes. The constructed model considers the locality of the avalanchexs multiplication region appearing during single photon absorption and the delay of the avalanchexs current spreading over the rear electrode of the diode. The calculations showed two different phases of transient process of the formation of the electrical signal, i.e., the rapid and slow ones due to current spreading and ordinary RC recharge, respectively. The load resistances required to implement the pulsed mode of operation of the structures of the avalanche photodiode were calculated for a series of actual diode capacitances and spreading resistances of the rear electrode.

  4. Femtosecond laser ablation of dielectric materials in the optical breakdown regime: Expansion of a transparent shell

    SciTech Connect (OSTI)

    Garcia-Lechuga, M.; Siegel, J., E-mail: j.siegel@io.cfmac.csic.es; Hernandez-Rueda, J.; Solis, J. [Laser Processing Group, Instituto de Optica, Serrano 121, 28006 Madrid (Spain)

    2014-09-15T23:59:59.000Z

    Phase transition pathways of matter upon ablation with ultrashort laser pulses have been considered to be understood long-since for metals and semiconductors. We provide evidence that also certain dielectrics follow the same pathway, even at high pulse energies triggering optical breakdown. Employing femtosecond microscopy, we observe a characteristic ring pattern within the ablating region that dynamically changes for increasing time delays between pump and probe pulse. These transient Newton rings are related to optical interference of the probe beam reflected at the front surface of the ablating layer with the reflection at the interface of the non-ablating substrate. Analysis of the ring structure shows that the ablation mechanism is initiated by a rarefaction wave leading within a few tens of picoseconds to the formation of a transparent thin shell of reduced density and refractive index, featuring optically sharp interfaces. The shell expands and eventually detaches from the solid material at delays of the order of 100 ps.

  5. Grain-scale thermoelastic stresses and spatiotemporal temperature gradients on airless bodies, implications for rock breakdown

    E-Print Network [OSTI]

    Molaro, Jamie L; Langer, Steve A

    2015-01-01T23:59:59.000Z

    Thermomechanical processes such as fatigue and shock have been suggested to cause and contribute to rock breakdown on Earth, and on other planetary bodies, particularly airless bodies in the inner solar system. In this study, we modeled grain-scale stresses induced by diurnal temperature variations on simple microstructures made of pyroxene and plagioclase on various solar system bodies. We found that a heterogeneous microstructure on the Moon experiences peak tensile stresses on the order of 100 MPa. The stresses induced are controlled by the coefficient of thermal expansion and Young's modulus of the mineral constituents, and the average stress within the microstructure is determined by relative volume of each mineral. Amplification of stresses occurs at surface-parallel boundaries between adjacent mineral grains and at the tips of pore spaces. We also found that microscopic spatial and temporal surface temperature gradients do not correlate with high stresses, making them inappropriate proxies for investig...

  6. Breakdown of the equivalence between gravitational mass and energy for a composite quantum body

    E-Print Network [OSTI]

    Andrei G. Lebed

    2014-04-14T23:59:59.000Z

    The simplest quantum composite body, a hydrogen atom, is considered in the presence of a weak external gravitational field. We define an operator for the passive gravitational mass of the atom in the post-Newtonian approximation of the general relativity and show that it does not commute with its energy operator. Nevertheless, the equivalence between the expectation values of the mass and energy is shown to survive at a macroscopic level for stationary quantum states. Breakdown of the equivalence between passive gravitational mass and energy at a microscopic level for stationary quantum states can be experimentally detected by studying unusual electromagnetic radiation, emitted by the atoms, supported by and moving in the Earth's gravitational field with constant velocity, using spacecraft or satellite

  7. Dead-Space Theory Predictions of Excess-Noise Factor, Breakdown Voltage, and Frequency Response for Thin Avalanche Photodiodes

    E-Print Network [OSTI]

    Teich, Malvin C.

    for Thin Avalanche Photodiodes Majeed M. Hayat°", Mohammad A. Sa1eh', Ohhyun Kwonc, Bahaa E. A. Sale width. Keywords: Avalanche photodiode, dead space, impact ionization, excess noise factor, avalanche breakdown down, frequency response. 1 Introduction It is well known that for avalanche photodiodes (APDs

  8. 670 IEEE ELECTRON DEVICE LETTERS, VOL. 33, NO. 5, MAY 2012 Breakdown-Voltage-Enhancement Technique for

    E-Print Network [OSTI]

    Ng, Wai Tung

    670 IEEE ELECTRON DEVICE LETTERS, VOL. 33, NO. 5, MAY 2012 Breakdown-Voltage-Enhancement Technique (FP), GaN power devices, leakage current. I. INTRODUCTION AlGaN/GaN high-electron-mobility transistors Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. E. Xu, J. Lee, N

  9. Towards a better understanding of dielectric barrier discharges in ferroelectrets: Paschen breakdown fields in micrometer sized voids

    SciTech Connect (OSTI)

    Harris, Scott, E-mail: harri4s@cmich.edu [Department of Physics and Science of Advanced Materials Program, Central Michigan University, Mount Pleasant, Michigan 48859 (United States); Applied Condensed-Matter Physics, Department of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm (Germany); Mellinger, Axel, E-mail: axel.mellinger@cmich.edu [Department of Physics and Science of Advanced Materials Program, Central Michigan University, Mount Pleasant, Michigan 48859 (United States)

    2014-04-28T23:59:59.000Z

    Charged cellular polypropylene foams (i.e., ferro- or piezoelectrets) demonstrate high piezoelectric activity upon being electrically charged. When an external electric field is applied, dielectric barrier discharges (DBDs) occur, resulting in a separation of charges which are subsequently deposited on dielectric surfaces of internal micrometer sized voids. This deposited space charge is responsible for the piezoelectric activity of the material. Previous studies have indicated charging fields larger than predicted by Townsend's model of Paschen breakdown applied to a multilayered electromechanical model; a discrepancy which prompted the present study. The actual breakdown fields for micrometer sized voids were determined by constructing single cell voids using polypropylene spacers with heights ranging from 8 to 75??m, sandwiched between two polypropylene dielectric barriers and glass slides with semi-transparent electrodes. Subsequently, a bipolar triangular charging waveform with a peak voltage of 6?kV was applied to the samples. The breakdown fields were determined by monitoring the emission of light due to the onset of DBDs using an electron multiplying CCD camera. The breakdown fields at absolute pressures from 101 to 251?kPa were found to be in good agreement with the standard Paschen curves. Additionally, the magnitude of the light emission was found to scale linearly with the amount of gas, i.e., the height of the voids. Emissions were homogeneous over the observed regions of the voids for voids with heights of 25??m or less and increasingly inhomogeneous for void heights greater than 40??m at high electric fields.

  10. Electrical and Sensing Properties of Single-Walled Carbon Nanotubes Network: Effect of Alignment and Selective Breakdown

    E-Print Network [OSTI]

    Full Paper Electrical and Sensing Properties of Single-Walled Carbon Nanotubes Network: Effect The electrical transport and NH3 sensing properties of randomly oriented and aligned SWNT networks were presented. Gated electrical breakdown was implemented to selectively remove metallic (m-) SWNTs, thereby reducing

  11. The role of boundary conditions in a simple model of incipient vortex breakdown F. Gallaire and J.-M. Chomaz

    E-Print Network [OSTI]

    Boyer, Edmond

    . In the labora- tory, it is preferentially studied in vortex tubes, where it is seen in many cases to give riseThe role of boundary conditions in a simple model of incipient vortex breakdown F. Gallaire and J of a hairpin vortex in a shear-thinning fluid governed by a power-law model Phys. Fluids 25, 101703 (2013); 10

  12. 518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Plasma Dynamics During Breakdown in

    E-Print Network [OSTI]

    Kushner, Mark

    , lamp, modeling, plasma. METAL halide arc lamps are widely used sources of in- door and large area plasma hydrodynamics model was used to investigate breakdown in metal halide lamp. Images depicting518 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 33, NO. 2, APRIL 2005 Plasma Dynamics During

  13. Metastable and charged particle decay in neon afterglow studied by the breakdown time delay measurements

    SciTech Connect (OSTI)

    Markovic, V. Lj.; Gocic, S. R.; Stamenkovic, S. N.; Petrovic, Z. Lj. [Department of Physics, University of Nis, P.O. Box 224, 18001 Nis (Serbia); Institute of Physics, P.O. Box 68, 11000 Belgrade (Serbia and Montenegro)

    2007-10-15T23:59:59.000Z

    Memory effect--the long time variation of the electrical breakdown time delay on the relaxation time t{sub d}({tau}) in neon--was explained by the Ne({sup 3}P{sub 2}) (1s{sub 5}) metastable state remaining from the preceding glow [Dj. A. Bosan, M. K. Radovic, and Dj. M. Krmpotic, J. Phys. D 19, 2343 (1986)]. However, the authors neglected the quenching processes that reduce the effective lifetime of metastable states several orders of magnitude below that of the memory effect observations. In this paper the time delay measurements were carried out in neon at the pressure of 6.6 mbar in a gas tube with gold-plated copper cathode, and the approximate and exact numerical models are developed in order to study the metastable and charged particle decay in afterglow. It was found that the metastable hypothesis completely failed to explain the afterglow kinetics, which is governed by the decay of molecular neon ions and molecular nitrogen ions produced in Ne{sub 2}{sup +} collisions with nitrogen impurities; i.e., Ne{sub 2}{sup +}+N{sub 2}{yields}N{sub 2}{sup +}+2Ne. Charged particle decay is followed up to hundreds of milliseconds in afterglow, from ambipolar to the free diffusion limit. After that, the late afterglow kinetics in neon can be explained by the nitrogen atoms recombining on the cathode surface and providing secondary electrons that determine the breakdown time delay down to the cosmic rays and natural radioactivity level.

  14. Method of Controlling Corona Effects and Breakdown Voltage of Small Air Gaps Stressed by Impulse Voltages

    E-Print Network [OSTI]

    Athanasios Maglaras; Trifon Kousiouris; Frangiskos Topalis; Dimitrios Katsaros; Leandros A. Maglaras; Konstantina Giannakopoulou

    2014-10-15T23:59:59.000Z

    This paper investigates the influence of a resistor on the dielectric behavior of an air gap. The resistor is connected in series with the air gap and the latter is stressed by impulse voltage. Air gap arrangements of different geometry with either the rod or the plate grounded are stressed with impulse voltages of both positive and negative polarity. The resistor is connected in series with the air gap in the return circuit connecting the gap with the impulse generator. The method followed involves the investigation of the graphs of the charging time concerning the air gaps capacitances, in connection to the value of the resistor, the geometry of the gap, the effect of grounding and the polarity effect. It is determined that the charging time of the air gap increases, as the value of the resistor increases. It is also determined that the peak voltage value of the fully charged air gap decreases as the value of the resistor increases. The results of the mathematical and simulation analysis are compared with the results of the oscillograms taken from experimental work. In addition and consequently to the above results it is concluded from the experimental work that the in series connection of the resistor in the circuit has significant influence on corona pulses (partial discharges) occurring in the gap and on the breakdown voltage of the gap. A new method of controlling the corona effects and consequently the breakdown voltage of small air gaps stressed by impulse voltage of short duration in connection to the ground effect and the polarity effect has arisen. Furthermore through mathematical analysis of the charging graphs obtained from simulation and experimental oscillograms there was a calculation of the values of the capacitance of the air gaps in relation to their geometry and the results were compared to the values calculated with mathematical analysis.

  15. IONIZATION IN ATMOSPHERES OF BROWN DWARFS AND EXTRASOLAR PLANETS. III. BREAKDOWN CONDITIONS FOR MINERAL CLOUDS

    SciTech Connect (OSTI)

    Helling, Ch.; Jardine, M.; Stark, C. [SUPA, School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS (United Kingdom); Diver, D., E-mail: ch@leap2010.eu [SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2013-04-20T23:59:59.000Z

    Electric discharges were detected directly in the cloudy atmospheres of Earth, Jupiter, and Saturn, are debatable for Venus, and indirectly inferred for Neptune and Uranus in our solar system. Sprites (and other types of transient luminous events) have been detected only on Earth, and are theoretically predicted for Jupiter, Saturn, and Venus. Cloud formation is a common phenomenon in ultra-cool atmospheres such as in brown dwarf and extrasolar planetary atmospheres. Cloud particles can be expected to carry considerable charges which may trigger discharge events via small-scale processes between individual cloud particles (intra-cloud discharges) or large-scale processes between clouds (inter-cloud discharges). We investigate electrostatic breakdown characteristics, like critical field strengths and critical charge densities per surface, to demonstrate under which conditions mineral clouds undergo electric discharge events which may trigger or be responsible for sporadic X-ray emission. We apply results from our kinetic dust cloud formation model that is part of the DRIFT-PHOENIX model atmosphere simulations. We present a first investigation of the dependence of the breakdown conditions in brown dwarf and giant gas exoplanets on the local gas-phase chemistry, the effective temperature, and primordial gas-phase metallicity. Our results suggest that different intra-cloud discharge processes dominate at different heights inside mineral clouds: local coronal (point discharges) and small-scale sparks at the bottom region of the cloud where the gas density is high, and flow discharges and large-scale sparks near, and maybe above, the cloud top. The comparison of the thermal degree of ionization and the number density of cloud particles allows us to suggest the efficiency with which discharges will occur in planetary atmospheres.

  16. Breakdown of time-temperature superposition in a bead-spring polymer melt near the glass transition temperature

    E-Print Network [OSTI]

    Tamio Yamazaki

    2014-10-06T23:59:59.000Z

    The breakdown of the time-temperature superposition (TTS) near its glass transition temperature (Tg) in simple bead-spring polymer melts with and without the chain angle potential was numerically investigated. The stress relaxation modulus at different temperatures G(t,T) was calculated by the Green-Kubo relation. The TTS of G(t,T) of bead-spring polymer melts worked well at temperatures sufficiently higher than its Tg. However, when the system temperature is approaching the glass transition regime, the breakdown of TTS is observed. At temperatures near the Tg, the temperature dependence of the shift factor aTB, which is defined at the time scale between the bond relaxation and the chain relaxation regimes of a G(t)-function, is significantly stronger than ones aTA defined by the time scale of the chain relaxation modes. In direct relation to the breakdown of TTS of G(t,T), the decoupling of Stokes-Einstein law of diffusion-viscosity relation also appears in the glass transition regime. The analysis of the van Hove function Gs(r,t) and non-gaussian parameter, a2(t), of the bead motions strongly suggest that the TTS breakdown is concerned with the dynamic heterogeneity. The effect of the chain stiffness on the temperature dependence of the shift factors was also investigated in this study. The stiffer chains melt has a stronger temperature dependence of the shift factors than the ones of the flexible chains melt. However, regardless of the chain stiffness, the stress relaxation modulus functions of the bead-spring polymer melts will begin to breakdown the TTS at a similar Tg-normalized temperature around T/Tg ~ 1.2.

  17. Rapid breakdown anodization technique for the synthesis of high aspect ratio and high surface area anatase TiO{sub 2} nanotube powders

    SciTech Connect (OSTI)

    Antony, Rajini P. [Thin Films and Coatings Section, Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Mathews, Tom, E-mail: tom@igcar.gov.i [Thin Films and Coatings Section, Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Dasgupta, Arup [Physical Metallurgy Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Dash, S.; Tyagi, A.K. [Thin Films and Coatings Section, Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Raj, Baldev [Thin Films and Coatings Section, Surface and Nanoscience Division, Materials Science Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India); Physical Metallurgy Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, Tamil Nadu (India)

    2011-03-15T23:59:59.000Z

    Clusters of high aspect ratio, high surface area anatase-TiO{sub 2} nanotubes with a typical nanotube outer diameter of about 18 nm, wall thickness of approximately 5 nm and length of 5-10 {mu}m were synthesized, in powder form, by breakdown anodization of Ti foils in 0.1 M perchloric acid, at 10 V (299 K) and 20 V ({approx}275 and 299 K). The surface area, morphology, structure and band gap were determined from Brunauer Emmet Teller method, field emmission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman, photoluminescence and diffuse reflectance spectroscopic studies. The tubular morphology and anatase phase were found to be stable up to 773 K and above 773 K anatase phase gradually transformed to rutile phase with disintegration of tubular morphology. At 973 K, complete transformation to rutile phase and disintegration of tubular morphology were observed. The band gap of the as prepared and the annealed samples varied from 3.07 to 2.95 eV with increase in annealing temperature as inferred from photoluminescence and diffuse reflectance studies. -- Graphical abstract: Display Omitted Research highlights: {yields} High aspect ratio anatase-titania nanotube powders were synthesized electrochemically. {yields} The surface area of the nanotubes were much higher than those reported. {yields} The annealing temperature limit for maintaining tubular morphology was established. {yields} The photoluminiscence spectroscopy reflected the presence of defects, annealing of defects and phase transformation. {yields} The nanotubes were of {approx}5 nm wall thickness as revealed by TEM studies.

  18. The light meson spectroscopy program

    SciTech Connect (OSTI)

    Smith, Elton S. [JLAB

    2014-06-01T23:59:59.000Z

    Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

  19. Solar Spectroscopy at ARIES

    E-Print Network [OSTI]

    K. Sinha

    2006-10-10T23:59:59.000Z

    Identification of Fraunhofer lines with the known atomic and molecular absorbers and predictions leading to such an effort has been a challenging area of study crowned with occasional success. Such studies have also lead, amongst other things to (i) a determination of abundances of elements and that of their isotopes (ii) valuable information on model atmospheres and (iii) use of Sun as a laboratory source. We summarize and review here the work done in the last four decades in the area of solar spectroscopy at Aryabhatta Research Institute of observational sciencES (ARIES in short) with a view to pick up new and interesting areas for future investigations in the light of the tremendous progress made elsewhere in observations of the sun and in the laboratory studies.

  20. Time of flight emission spectroscopy of laser produced nickel plasma: Short-pulse and ultrafast excitations

    SciTech Connect (OSTI)

    Smijesh, N.; Chandrasekharan, K. [Laser and Nonlinear Optics Laboratory, Department of Physics, National Institute of Technology Calicut, Calicut 673601 (India); Joshi, Jagdish C.; Philip, Reji, E-mail: reji@rri.res.in [Ultrafast and Nonlinear Optics Lab, Light and Matter Physics Group, Raman Research Institute, Bangalore 560080 (India)

    2014-07-07T23:59:59.000Z

    We report the experimental investigation and comparison of the temporal features of short-pulse (7?ns) and ultrafast (100 fs) laser produced plasmas generated from a solid nickel target, expanding into a nitrogen background. When the ambient pressure is varied in a large range of 10{sup ?6?}Torr to 10{sup 2?}Torr, the plume intensity is found to increase rapidly as the pressure crosses 1?Torr. Time of flight (TOF) spectroscopy of emission from neutral nickel (Ni I) at 361.9?nm (3d{sup 9}({sup 2}D) 4p ? 3d{sup 9}({sup 2}D) 4s transition) reveals two peaks (fast and slow species) in short-pulse excitation and a single peak in ultrafast excitation. The fast and slow peaks represent recombined neutrals and un-ionized neutrals, respectively. TOF emission from singly ionized nickel (Ni II) studied using the 428.5?nm (3p{sup 6}3d{sup 8}({sup 3}P) 4s? 3p{sup 6}3d{sup 9} 4s) transition shows only a single peak for either excitation. Velocities of the neutral and ionic species are determined from TOF measurements carried out at different positions (i.e., at distances of 2?mm and 4?mm, respectively, from the target surface) on the plume axis. Measured velocities indicate acceleration of neutrals and ions, which is caused by the Coulomb pull of the electrons enveloping the plume front in the case of ultrafast excitation. Both Coulomb pull and laser-plasma interaction contribute to the acceleration in the case of short-pulse excitation. These investigations provide new information on the pressure dependent temporal behavior of nickel plasmas produced by short-pulse and ultrafast laser pulses, which have potential uses in applications such as pulsed laser deposition and laser-induced nanoparticle generation.

  1. Sum Frequency Generation for Surface Vibrational Spectroscopy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Sum Frequency Generation for Surface Vibrational Spectroscopy Sum Frequency Generation for Surface Vibrational Spectroscopy This customized SFG-VS spectrometer incorporates unique...

  2. High altitude atmospheric discharges according to the runaway air breakdown mechanism

    SciTech Connect (OSTI)

    Symbalisty, E.; Roussel-Dupre, R.; Yukhimuk, V.; Taranenko, Y.

    1997-04-01T23:59:59.000Z

    High altitude optical transients - red sprites, blue jets, and elves - are modeled in the context of the relativistic electron runaway air breakdown mechanism. These emissions are usually associated with large mesoscale convective systems (hereafter MCS). In thunderstorms cloud electrification proceeds over a time scale long enough to permit the conducting atmosphere above the cloud to polarize and short out the thunderstorm electric field. When a lightning strike rapidly neutralizes a cloud charge layer runaway driving fields can develop in the stratosphere and mesosphere. According to present simulations of the full runaway process the variety of observed optical emissions are due to the nature of the normal lightning event in the MCS that kick starts the runaway avalanche. In this paper the authors describe some details of the model, present the results of the evolution of the primary electron population, and summarize the initial conditions necessary for different types of discharges. Two companion papers present (a) the predicted optical, gamma ray, and radio emissions caused by these electrical discharges, and (b) the time evolution of the secondary electron population and its implications in terms of observables.

  3. Ring resonant cavities for spectroscopy

    DOE Patents [OSTI]

    Zare, R.N.; Martin, J.; Paldus, B.A.; Xie, J.

    1999-06-15T23:59:59.000Z

    Ring-shaped resonant cavities for spectroscopy allow a reduction in optical feedback to the light source, and provide information on the interaction of both s- and p-polarized light with samples. A laser light source is locked to a single cavity mode. An intracavity acousto-optic modulator may be used to couple light into the cavity. The cavity geometry is particularly useful for Cavity Ring-Down Spectroscopy (CRDS). 6 figs.

  4. Transient Absorption Spectroscopy with Isolated Attosecond Pulses

    E-Print Network [OSTI]

    Bell, Marie Justine

    2013-01-01T23:59:59.000Z

    viii Attosecond transient absorption instrument. . . . . .5.2.2 AbsorptionTransient absorption spectroscopy . . . . . . . . . . . .

  5. Measurements of the volt-ampere characteristics and the breakdown voltages of direct-current helium and hydrogen discharges in microgaps

    SciTech Connect (OSTI)

    Klas, M.; Matej?ik, . [Department of Experimental Physics, Comenius University, Mlynskadolina F2, 84248 Bratislava (Slovakia); Radjenovi?, B.; Radmilovi?-Radjenovi?, M. [Institute of Physics, University of Belgrade, P.O. Box 57, 11080 Belgrade (Serbia)

    2014-10-15T23:59:59.000Z

    The discharge phenomena for micro meter gap sizes include many interesting problems from engineering and physical perspectives. In this paper, the authors deal with the experimental and theoretical results of the breakdown voltage and current-voltage characteristics of the direct-current helium and hydrogen discharges. The measurements were performed at a constant pressure of around one atmosphere, while varying the gap size between two parallel plane tungsten electrodes between 1??m and 100??m. From the measured breakdown voltage curves, the effective yields and the ionization coefficients were derived for both gases. Present data for the ionization coefficients correlate with the data obtained for the breakdown voltage curves measured for fixed 100??m interelectrode separation. The current-voltage characteristics were plotted for the various gap sizes illustrating the role of the field emission effects in the microgaps. Based on the Fowler-Nordheim theory, the enhancement factors were determined. The gap spacing dependence of the field emission current can be explained by the introduction of two ideas, the first being a space charge effect by emitted electrons, and the second a change in the breakdown mechanism. Experimental results, presented here, demonstrate that Townsend phenomenology breaks down when field emission becomes the key mechanism affecting the breakdown and deforming the left hand side of the breakdown voltage curves.

  6. TIME-RESOLVED VIBRATIONAL SPECTROSCOPY

    SciTech Connect (OSTI)

    Andrei Tokmakoff, MIT (Conference Chair) [Conference Chair; Paul Champion, Northeastern University; Edwin J. Heilweil, NIST; Keith A. Nelson, MIT; Larry Ziegler, Boston University

    2009-05-14T23:59:59.000Z

    This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOEâ??s Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all five of DOEâ??s grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  7. Scientific innovation and resonance ionization spectroscopy

    SciTech Connect (OSTI)

    Richmond, C.R.

    1981-01-01T23:59:59.000Z

    An account is presented of the development and appliations of resonance ionization spectroscopy and one atom detection.

  8. The surface structure of ?-uranophane and its interaction with Eu(III) An integrated computational and fluorescence spectroscopy study

    SciTech Connect (OSTI)

    Kuta, Jadwiga; Wang, Zheming; Wisuri, Katy; Wander, Matthew C F.; Wall, Nathalie; Clark, Aurora E.

    2013-02-15T23:59:59.000Z

    Uranophane is a rare U(VI) secondary silicate mineral formed in nature by the oxidation of the primary mineral uraninite. It is also relevant to the long-term geochemistry of nuclear waste repositories, where it can be formed under oxidizing conditions and has the potential to act as a secondary barrier to the migration of radionuclides through mineral sorption reactions. A combination of classical molecular dynamics and ab-initio density functional theory (DFT) has been employed to investigate the uranophane|water interface as well as the interfacial reactivity of the U(VI) silicate toward acidic conditions and radionuclide ion sorption. The sorption simulations have been complemented by experimental sorption studies and laser induced fluorescence spectroscopy to help identify the molecular structure of the surface sorbed species. Experimental distances and essential coordination numbers are properly captured by the simulation results within bulk uranophane, while interfacial water is found to orient primarily with the hydrogen-atoms directed towards the negatively charged surface. Sorption sites for water are observed to belong to 3 different groups: (1) those involving uranyl oxygen, (2) involving uranyl and silica hydroxyl oxygen atoms, and (3) involving hydroxyl hydrogen. The pKa of the surface -OH groups have been calculated using a variety of models, including a bond valence approach and utilization of the energetics of deprotonation within DFT. Under basic conditions, deprotonation of the Si-OH groups is likely responsible for uranophane dissolution. Finally, the stability and structure of surface sorbed Eu3+ has been examined, with a stable inner-sphere species being observed.

  9. Stark spectroscopy on rare gas atoms

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Stark spectroscopy on rare gas atoms PROEFSCHRIFT ter verkrijging van de graad van doctor aan de-DATA LIBRARY TECHNISCHE UNIVERSITEIT EINDHOVEN Jiang, Tao Stark spectroscopy on rare gas atoms / by Tao Jiang / gasontladingen Subject headings : plasma diagnostics / Stark effect / optogalvanic spectroscopy / atomic emission

  10. X-Ray Absorption Spectroscopy of Metallobiomolecules

    E-Print Network [OSTI]

    Scott, Robert A.

    2/9/07 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 9, 07] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

  11. X-Ray Absorption Spectroscopy of Metallobiomolecules

    E-Print Network [OSTI]

    Scott, Robert A.

    9/6/09 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 6, 09] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

  12. 2014 Journal Articles

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Optics Demos, SG., et al., "Dynamics of the plume containing nanometric-sized particles ejected into the atmospheric air following laser-induced breakdown on the exit surface of a...

  13. Spectroscopy with Multichannel Correlation Radiometers

    E-Print Network [OSTI]

    A. I. Harris

    2005-04-20T23:59:59.000Z

    Correlation radiometers make true differential measurements in power with high accuracy and small systematic errors. This receiver architecture has been used in radio astronomy for measurements of continuum radiation for over 50 years; this article examines spectroscopy over broad bandwidths using correlation techniques. After general discussions of correlation and the choice of hybrid phase, experimental results from tests with a simple laboratory multi-channel correlation radiometer are shown. Analysis of the effect of the input hybrid's phase shows that a 90 degree hybrid is likely to be the best general choice for radio astronomy, depending on its amplitude match and phase flatness with frequency. The laboratory results verify that the combination of the correlation architecture and an analog lag correlator is an excellent method for spectroscopy over very wide bandwidths.

  14. Quantitative tunneling spectroscopy of nanocrystals

    SciTech Connect (OSTI)

    First, Phillip N; Whetten, Robert L; Schaaff, T Gregory

    2007-05-25T23:59:59.000Z

    The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene" refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronics

  15. Resonance emission spectroscopy of predissociating SO2 C~ ,,1 1 Coupling with a repulsive 1

    E-Print Network [OSTI]

    Butler, Laurie J.

    absorption and fluorescence excitation spectra of the C~ X~ transition under bulb conditions at room temperature and showed clearly that the fluorescence intensity drops abruptly for ex- citation wavelengths. They observed the laser-induced fluores- cence LIF spectrum of jet-cooled SO2 and reported the pre- dissociation

  16. Light Hadron Spectroscopy and Charmonium

    E-Print Network [OSTI]

    Frederick A. Harris

    2008-10-17T23:59:59.000Z

    During the last few years there has been a renaissance in charm and charmonium spectroscopy with higher precision measurements at the $\\psi^{'}$ and $\\psi(3770)$ coming from BESII and CLEOc and many new discoveries coming from B-factories. In this paper, I review some new results on "classical" charmonium and $e^+ e^- \\to$ hadrons using B-factory Initial State Radiation and two photon events.

  17. Spectroscopy of barium atoms in liquid and solid helium matrices

    SciTech Connect (OSTI)

    Lebedev, V.; Moroshkin, P.; Weis, A. [Departement de Physique, Universite de Fribourg, Chemin du Musee 3, CH-1700 Fribourg (Switzerland)

    2011-08-15T23:59:59.000Z

    We present an exhaustive overview of optical absorption and laser-induced fluorescence lines of Ba atoms in liquid and solid helium matrices in visible and near-infrared spectral ranges. Due to the increased density of isolated atoms, we have found a large number of spectral lines that were not observed in condensed helium matrices before. We have also measured the lifetimes of metastable states. The lowest {sup 3}D{sub 1} metastable state has lifetime of 2.6 s and can be used as an intermediate state in two-step excitations of high-lying states. Various matrix-induced radiationless population transfer channels have been identified.

  18. Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest RegionatSearchScheduled System Highlights Power2014 Evaluate

  19. Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future |CarlosSpeakers

  20. 1204 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 34, NO. 9, SEPTEMBER 1999 Breakdown in Millimeter-Wave Power InP

    E-Print Network [OSTI]

    del Alamo, Jess A.

    1204 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 34, NO. 9, SEPTEMBER 1999 Breakdown in Millimeter-Wave Power InP HEMT's: A Comparison with GaAs PHEMT's J. A. del Alamo and M. H. Somerville Abstract's) deliver lower output power than GaAs pseudomorphic HEMT's (PHEMT's) throughout most of the millimeter

  1. Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I. Gonin2, S. Schreiber1

    E-Print Network [OSTI]

    Experimental observation of breakdowns in the Fermilab RF Gun G4 J.-P. Carneiro1, D. Edwards2, I Fermilab has developed and delivered to DESY Hamburg two RF guns for the operation of the phase I at the A0 photo-injector at Fermilab since January 1999 where it has been successfully conditioned at 1 Hz

  2. Final Report: Investigation of Catalytic Pathways for Lignin Breakdown into Monomers and Fuels

    SciTech Connect (OSTI)

    Gluckstein, Jeffrey A [ORNL; Hu, Michael Z. [ORNL; Kidder, Michelle [ORNL; McFarlane, Joanna [ORNL; Narula, Chaitanya Kumar [ORNL; Sturgeon, Matthew R [ORNL

    2010-12-01T23:59:59.000Z

    Lignin is a biopolymer that comprises up to 35% of woody biomass by dry weight. It is currently underutilized compared to cellulose and hemicellulose, the other two primary components of woody biomass. Lignin has an irregular structure of methoxylated aromatic groups linked by a suite of ether and alkyl bonds which makes it difficult to degrade selectively. However, the aromatic components of lignin also make it promising as a base material for the production of aromatic fuel additives and cyclic chemical feed stocks such as styrene, benzene, and cyclohexanol. Our laboratory research focused on three methods to selectively cleave and deoxygenate purified lignin under mild conditions: acidolysis, hydrogenation and electrocatalysis. (1) Acidolysis was undertaken in CH2Cl2 at room temperature. (2) Hydrogenation was carried out by dissolving lignin and a rhodium catalyst in 1:1 water:methoxyethanol under a 1 atm H2 environment. (3) Electrocatalysis of lignin involved reacting electrically generated hydrogen atoms at a catalytic palladium cathode with lignin dissolved in a solution of aqueous methanol. In all of the experiments, the lignin degradation products were identified and quantified by gas chromatography mass spectroscopy and flame ionization detection. Yields were low, but this may have reflected the difficulty in recovering the various fractions after conversion. The homogeneous hydrogenation of lignin showed fragmentation into monomers, while the electrocatalytic hydrogenation showed production of polyaromatic hydrocarbons and substituted benzenes. In addition to the experiments, promising pathways for the conversion of lignin were assessed. Three conversion methods were compared based on their material and energy inputs and proposed improvements using better catalyst and process technology. A variety of areas were noted as needing further experimental and theoretical effort to increase the feasibility of lignin conversion to fuels.

  3. Raman spectroscopy of shocked water

    SciTech Connect (OSTI)

    Holmes, N.C.; Mitchell, A.C.; Nellis, W.J.; Graham, W.B.; Walrafen, G.E.

    1983-07-01T23:59:59.000Z

    Raman scattering has been used extensively to study the vibrational and rotational properties of molecules under a variety of conditions. Here, interest is in the behavior of water molecules shocked to high pressures and temperatures. Behind the shock front the water molecules undergo changes in bonding and the molecules may become ionized. Raman spectroscopy can be used to determine the molecular species behind the shock front. In addition, changes in Raman spectra can yield information regarding inter- and intramolecular potentials and the temperature behind the shock front.

  4. Simultaneous beta and gamma spectroscopy

    DOE Patents [OSTI]

    Farsoni, Abdollah T. (Corvallis, OR); Hamby, David M. (Corvallis, OR)

    2010-03-23T23:59:59.000Z

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  5. VARIOUS APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY

    E-Print Network [OSTI]

    Koizumi, Hideaki

    2011-01-01T23:59:59.000Z

    APPLICATIONS OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPYthe Zeeman effect to atomic absorption spectroscopy has beenthe Zeeman effect on atomic absorption spectrometry has been

  6. An electron paramagnetic resonance spectroscopy investigation...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    channel is sufficiently small. The results of an electron paramagnetic resonance (EPR) spectroscopy study of Mn and Cu adsorption on the zeolite minerals zeolite Y (large...

  7. Combining Feedback Absorption Spectroscopy, Amplified Resonance...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    On-Board Measurement of Ammonia and Nitrous Oxide Using Feedback Absorption Laser Spectroscopy Combined with Amplified Resonance and Low Pressure Sampling Cummins...

  8. Optical sensing based on wavelength modulation spectroscopy

    DOE Patents [OSTI]

    Buckley, Steven G. (Redmond, WA); Gharavi, Mohammadreza (Tehran, IR); Borchers; Marco (Berlin, DE)

    2011-06-28T23:59:59.000Z

    Techniques, apparatus and systems for using Wavelength Modulation Spectroscopy measurements to optically monitor gas media such as gases in gas combustion chambers.

  9. E-Print Network 3.0 - analytical atomic spectroscopy Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission spectroscopy Atomic fluorescence...

  10. E-Print Network 3.0 - atomic spectroscopy technologies Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission spectroscopy Atomic fluorescence...

  11. Gas-Phase Spectroscopy of Biomolecular

    E-Print Network [OSTI]

    de Vries, Mattanjah S.

    Gas-Phase Spectroscopy of Biomolecular Building Blocks Mattanjah S. de Vries1 and Pavel Hobza2 1, REMPI, computational chemistry, spectral hole burning, jet cooling Abstract Gas-phase spectroscopy lends. In recent years, we have seen enormous progress in the study of biomolecular building blocks in the gas

  12. X-ray Spectroscopy of Cool Stars

    E-Print Network [OSTI]

    M. Guedel

    2006-09-11T23:59:59.000Z

    High-resolution X-ray spectroscopy has addressed not only various topics in coronal physics of stars, but has also uncovered important features relevant for our understanding of stellar evolution and the stellar environment. I summarize recent progress in coronal X-ray spectroscopy and in particular also discuss new results from studies of X-rays from pre-main sequence stars.

  13. 3D Spectroscopy and the Virtual Observatory

    E-Print Network [OSTI]

    Bryan W. Miller

    2007-08-15T23:59:59.000Z

    Integral field, or 3D, spectroscopy is the technique of obtaining spectral information over a two-dimensional, hopefully contiguous, field of view. While there is some form of astronomical 3D spectroscopy at all wavelengths, there has been a rapid increase in interest in optical and near-infrared 3D spectroscopy. This has resulted in the deployment of a large variety of integral-field spectrographs on most of the large optical/infrared telescopes. The amount of IFU data available in observatory archives is large and growing rapidly. The complications of treating IFU data as both imaging and spectroscopy make it a special challenge for the virtual observatory. This article describes the various techniques of optical and near-infrared spectroscopy and some of the general needs and issues related to the handling of 3D data by the virtual observatory.

  14. Effects of Combustion-Induced Vortex Breakdown on Flashback Limits of Syngas-Fueled Gas Turbine Combustors

    SciTech Connect (OSTI)

    Ahsan Choudhuri

    2011-03-31T23:59:59.000Z

    Turbine combustors of advanced power systems have goals to achieve very low pollutants emissions, fuel variability, and fuel flexibility. Future generation gas turbine combustors should tolerate fuel compositions ranging from natural gas to a broad range of syngas without sacrificing operational advantages and low emission characteristics. Additionally, current designs of advanced turbine combustors use various degrees of swirl and lean premixing for stabilizing flames and controlling high temperature NOx formation zones. However, issues of fuel variability and NOx control through premixing also bring a number of concerns, especially combustor flashback and flame blowout. Flashback is a combustion condition at which the flame propagates upstream against the gas stream into the burner tube. Flashback is a critical issue for premixed combustor designs, because it not only causes serious hardware damages but also increases pollutant emissions. In swirl stabilized lean premixed turbine combustors onset of flashback may occur due to (i) boundary layer flame propagation (critical velocity gradient), (ii) turbulent flame propagation in core flow, (iii) combustion instabilities, and (iv) upstream flame propagation induced by combustion induced vortex breakdown (CIVB). Flashback due to first two foregoing mechanisms is a topic of classical interest and has been studied extensively. Generally, analytical theories and experimental determinations of laminar and turbulent burning velocities model these mechanisms with sufficient precision for design usages. However, the swirling flow complicates the flashback processes in premixed combustions and the first two mechanisms inadequately describe the flashback propensity of most practical combustor designs. The presence of hydrogen in syngas significantly increases the potential for flashback. Due to high laminar burning velocity and low lean flammability limit, hydrogen tends to shift the combustor operating conditions towards flashback regime. Even a small amount of hydrogen in a fuel blend triggers the onset of flashback by altering the kinetics and thermophysical characteristics of the mixture. Additionally, the presence of hydrogen in the fuel mixture modifies the response of the flame to the global effects of stretch and preferential diffusion. Despite its immense importance in fuel flexible combustor design, little is known about the magnitude of fuel effects on CIVB induced flashback mechanism. Hence, this project investigates the effects of syngas compositions on flashback resulting from combustion induced vortex breakdown. The project uses controlled experiments and parametric modeling to understand the velocity field and flame interaction leading to CIVB driven flashback.

  15. Silicon Photonics for chemical sensing and spectroscopy, diagnosis and therapy

    E-Print Network [OSTI]

    Hon, Kam Yan

    2012-01-01T23:59:59.000Z

    5.5. Single-shot atomic absorption spectroscopy of rubidium26] time-wavelength atomic absorption spectroscopy of the D5.5. Single-shot atomic absorption spectroscopy of rubidium

  16. X-ray Absorption Spectroscopy of Biologically Relevant Systems

    E-Print Network [OSTI]

    Uejio, Janel Sunayo

    2010-01-01T23:59:59.000Z

    308, Messer, B. M. X-ray Absorption Spectroscopy of AqueousSarcosine via X-ray Absorption Spectroscopy 5.1 Introductionwith Carboxylate by X-Ray Absorption Spectroscopy of Liquid

  17. In-situ Transmission Electron Microscopy and Spectroscopy Studies...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transmission Electron Microscopy and Spectroscopy Studies of Interfaces in Li-ion Batteries: Challenges and In-situ Transmission Electron Microscopy and Spectroscopy Studies of...

  18. Self-corrected Sensors Based On Atomic Absorption Spectroscopy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    corrected Sensors Based On Atomic Absorption Spectroscopy For Atom Flux Measurements In Molecular Beam Epitaxy. Self-corrected Sensors Based On Atomic Absorption Spectroscopy For...

  19. Infrared Spectroscopy and Optical Constants of Porous Amorphous...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Infrared Spectroscopy and Optical Constants of Porous Amorphous Solid Water. Abstract: Reflection-absorption...

  20. Applications of pulsed EPR spectroscopy to structural studies...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    pulsed EPR spectroscopy to structural studies of sulfite oxidizing enzymes. Applications of pulsed EPR spectroscopy to structural studies of sulfite oxidizing enzymes. Abstract:...

  1. High Resolution and Low-Temperature Photoelectron Spectroscopy...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    High Resolution and Low-Temperature Photoelectron Spectroscopy of an Oxygen-Linked Fullerene Dimer Dianion: C120O2-. High Resolution and Low-Temperature Photoelectron Spectroscopy...

  2. Infrared near-field spectroscopy of trace explosives using an...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectroscopy of trace explosives using an external cavity quantum cascade laser. Infrared near-field spectroscopy of trace explosives using an external cavity quantum...

  3. The Spectroscopy of Neutron-Rich sdf-Shell Nuclei Using the CLARA-PRISMA Setup

    SciTech Connect (OSTI)

    Liang, X.; Hodsdon, A.; Chapman, R.; Burns, M.; Keyes, K.; Ollier, J.; Papenberg, A.; Spohr, K. [School of Engineering and Science, University of Paisley, Paisley, PA1 2BE (United Kingdom); Azaiez, F.; Ibrahim, F.; Stanoiu, M. [IPN, IN2P3-CNRS, F-91406 Orsay Cedex (France); Universite Paris-Sud, F-91406 Orsay Cedex (France); Haas, F.; Caurier, E.; Curien, D.; Nowacki, F.; Salsac, M.-D. [IPHC, UMR 7500, CNRS-IN2P3, 67037 Strasbourg Cedex 2 (France); Universite Louis Pasteur, 67037 Strasbourg Cedex 2 (France); Bazzacco, D.; Beghini, S.; Farnea, E.; Menegazzo, R. [Dipartimento di Fisica, Universita di Padova, I-35131 Padova (Italy); INFN-Sezione di Padova, Universita' di Padova, I-35131 Padova (Italy)] (and others)

    2006-08-14T23:59:59.000Z

    Since the discovery of the breakdown of shell effects in very neutron-rich N=20 and 28 nuclei, studies of the properties of nuclei far from stability have been of intense interest since they provide a unique opportunity to increase our understanding of nuclear interactions in extreme conditions and often challenge our theoretical models.Deep-inelastic processes can be used to populated high spin states of neutron-rich nuclei. In the deep-inelastic processes, an equilibration in N/Z between the target and projectile nuclei is achieved. For most heavy neutron-rich target nuclei, the N/Z ratio is 1.5 - 1.6, while for the possible neutron-rich sdf-shell projectile it is about 1.2. Thus by using deep-inelastic processes one can populate neutron-rich nuclei around N=20 and N=28.New results for the spectroscopy of neutron-rich N=22 36Si and 37P are presented here.

  4. Optical breakdown threshold in nanosecond high repetition second harmonic generation by periodically poled Mg-doped LiTaO{sub 3} crystal

    SciTech Connect (OSTI)

    Louchev, Oleg A.; Wada, Satoshi [Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)] [Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hatano, Hideki; Kitamura, Kenji [Division of Environment and Energy Materials, National Institute for Materials Science (NIMS) 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)] [Division of Environment and Energy Materials, National Institute for Materials Science (NIMS) 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2013-08-26T23:59:59.000Z

    Our study shows that a local temperature increase of ?1 K in the crystal lattice caused by second harmonic generation (SHG) and two-photon absorption of 532 nm radiation at the rear of periodically poled stoichiometric LiTaO{sub 3} crystal by changing spontaneous polarization induces a pyroelectric field ?10 kV/cm, accelerating free electrons to an energy of ?10 eV, followed by optical breakdown and crystal damage. Theoretical analysis leads to an explicit expression for the threshold laser fluence of optical breakdown giving ?1.2 J/cm{sup 2} for 1064 nm input radiation in 6.8 kHz pulsed SHG operation, agreeing well with the experimentally found value ?1.32 J/cm{sup 2}.

  5. Laser-induced metallic nanograined thin films processing

    SciTech Connect (OSTI)

    Tosa, Nicoleta, E-mail: nicoleta.tosa@itim-cj.ro, E-mail: florin.toadere@itim-cj.ro; Toadere, Florin, E-mail: nicoleta.tosa@itim-cj.ro, E-mail: florin.toadere@itim-cj.ro; Hojbota, Calin, E-mail: nicoleta.tosa@itim-cj.ro, E-mail: florin.toadere@itim-cj.ro; Tosa, Valer, E-mail: nicoleta.tosa@itim-cj.ro, E-mail: florin.toadere@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath., 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath., 400293 Cluj-Napoca (Romania)

    2013-11-13T23:59:59.000Z

    A direct laser writing method for designing metallic nanograined thin films is presented. This method takes advantage of photon conversion within a chemical process localized at the focal point. A computer controlled positioning system allows the control of experimental parameters and spatial resolution of the pattern. Spectroscopic investigations reveal variable attenuation of the optical properties in UV-visible range and a spectral imaging processing algorithm simulated the functionality of these films in visible light. This could be an important step for obtaining neutral density attenuators.

  6. COMPETING REACTION CHANNELS IN IR LASER INDUCED UNIMOLECULAR REACTIONS

    E-Print Network [OSTI]

    Berman, M.R.

    2010-01-01T23:59:59.000Z

    M. R. Berman, P. B. Comita, C. B. Moore, and R. G. Bergman,of a collaboration with Paul Comita and Bob Bergman. ourused were prepared by Paul Comita. corporation in these

  7. Laser induced stress wave thermometry applied to silicon wafer processing

    E-Print Network [OSTI]

    Rabroker, George Andrew

    2000-01-01T23:59:59.000Z

    The research presented in this work employs laser-based generation and detection of ultrasound in anisotropic plate structures. Ultrasound generation is achieved in the thermoelastic region by a Q-switched Nd:YAG laser. Acoustic detection...

  8. Measurements of elastic modulus using laser-induced surface waves

    SciTech Connect (OSTI)

    Chang, D.J.; Amimoto, S.T.; Gross, R.W.F. [Aerospace Corporation, Los Angeles, CA (United States); Glenn, T. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1995-12-31T23:59:59.000Z

    In general, the mechanical testing methods that are utilized for alloys and polymers, e.g., dogbone, rheovibron, etc., are not applicable to thin film structures. We wish to report noncontacting measurements of the surface acoustic wave (SAW) velocity and the elastic modulus applicable to thin films of moderate thickness. An accompanying paper extends this technique to smaller film dimensions. A 15 ns pulsed YAG laser was used as the energy source to thermoelastically excite surface waves. The propagation of the waves was then observed by a second, independent He-Ne laser at a distance from the excitation spot. using the knife edge/beam deflection technique. A cylindrical lens was used to reduce the energy loading of the YAG laser on the sample to avoid damaging the surface of the specimen. The Rayleigh wave velocity is calculated from measurements of the arrival time of the surface wave as a function of distance from the ND:YAG laser spot. The shear modulus, G, can be determined from the measured speed of the surface waves, V, the specimen density, p, and Poisson`s ratio, v, according to the following relationship: V = R(v){sm_bullet}(G/p){sup {1/2}} where R(v), expressed as (0.862 + 1.14v)/(l + v), is the ratio of the Rayleigh wave velocity to the shear wave velocity and ranges from 0.86 to 0.95 Table below lists the measured surface wave velocities and the calculated shear modulus for our experimental results and the published values. Excellent agreement is observed. The depth of the SAW is approximately equal to the SAW wavelength which is approximately the laser spot size. Typically 30 {mu}m spot sizes can be readily achieved. In conclusion, SAW velocities and the modulus of elasticity of various materials have been measured. We have demonstrated that this non-contacting method can be used to characterize moderately thin films.

  9. DNA fragment sizing and sorting by laser-induced fluorescence

    DOE Patents [OSTI]

    Hammond, Mark L. (Angier, NC); Jett, James H. (Los Alamos, NM); Keller, Richard A. (Los Alamos, NM); Marrone, Babetta L. (Los Alamos, NM); Martin, John C. (Los Alamos, NM)

    1996-01-01T23:59:59.000Z

    A method is provided for sizing DNA fragments using high speed detection systems, such as flow cytometry to determine unique characteristics of DNA pieces from a sample. In one characterization the DNA piece is fragmented at preselected sites to produce a plurality of DNA fragments. The DNA piece or the resulting DNA fragments are treated with a dye effective to stain stoichiometrically the DNA piece or the DNA fragments. The fluorescence from the dye in the stained fragments is then examined to generate an output functionally related to the number of nucleotides in each one of the DNA fragments. In one embodiment, the intensity of the fluorescence emissions from each fragment is linearly related to the fragment length. The distribution of DNA fragment sizes forms a characterization of the DNA piece for use in forensic and research applications.

  10. Laser-induced Damage in Optical Materials: 2004

    SciTech Connect (OSTI)

    Exarhos, Gregory J.; Guenther, Arthur H.; Kaiser, Norbert; Lewis, Keith L.; Soileau, M. J.; Stolz, Christopher J.

    2005-03-01T23:59:59.000Z

    This volume contains papers presented at the 35th Annual Symposium on Optical Materials for High-Power Lasers, held at the National Institute of Standards and Technology in Boulder, Colorado, 22-24 September 2003. The symposium was attended by 125 participants from China, India, Russia, France, Germany, Japan, the United States, and the United Kingdom. A meeting summary and some 75 reviewed papers appear. The book is divided into sections devoted to the following topics: thin films, surfaces and mirrors, fundamental mechanisms, materials and measurements, and finally, understanding optical damage with ultrashort laser pulses. Topics of interest to the high-peak-power and high-average-power laser communities in addition to damage issues related to various research efforts and commercial laser applications are discussed. Also discussed are improved scaling relations as a function of pulse duration in the femtosecond range, beam footprint size, and irradiation of optical materials with wavelengths down to the x-ray region. New sources at shorter wavelengths continue to be developed, and a corresponding shift in emphasis to short-wavelength and repetitively pulsed damage problems can be seen in some of these papers. Fabrication and test procedures are discussed particularly in the area of thin films. New materials and the implication of defects on the damage process are emphasized in addition to new reports of conditioning effects and damage repair or damage mitigation.

  11. Aerosol beam-focus laser-induced plasma spectrometer device

    DOE Patents [OSTI]

    Cheng, Meng-Dawn (Oak Ridge, TN)

    2002-01-01T23:59:59.000Z

    An apparatus for detecting elements in an aerosol includes an aerosol beam focuser for concentrating aerosol into an aerosol beam; a laser for directing a laser beam into the aerosol beam to form a plasma; a detection device that detects a wavelength of a light emission caused by the formation of the plasma. The detection device can be a spectrometer having at least one grating and a gated intensified charge-coupled device. The apparatus may also include a processor that correlates the wavelength of the light emission caused by the formation of the plasma with an identity of an element that corresponds to the wavelength. Furthermore, the apparatus can also include an aerosol generator for forming an aerosol beam from bulk materials. A method for detecting elements in an aerosol is also disclosed.

  12. Nuclear activation technique for analysis of laser induced energetic protons

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . For that purpose, we have developed a method in which the particles induce nuclear reactions in a stack of copper for medical applications [6]). In addition, nuclear reaction yields and nuclear decay rates might be studied radioactive nuclei. In a stack of samples, each foil acts as a low energy proton filter for the following ones

  13. Laser-induced nonresonant nuclear excitation in muonic atoms

    E-Print Network [OSTI]

    A. Shahbaz; C. Mller; T. J. Buervenich; C. H. Keitel

    2008-12-13T23:59:59.000Z

    Coherent nuclear excitation in strongly laser-driven muonic atoms is calculated. The nuclear transition is caused by the time-dependent Coulomb field of the oscillating charge density of the bound muon. A closed-form analytical expression for electric multipole transitions is derived and applied to various isotopes; the excitation probabilities are in general very small. We compare the process with other nuclear excitation mechanisms through coupling with atomic shells and discuss the prospects to observe it in experiment.

  14. Laser induced rotation of trapped chiral and achiral nematic droplets

    E-Print Network [OSTI]

    Marjan Mosallaeipour; Yashodhan Hatwalne; N. V. Madhusudana; Sharath Ananthamurthy

    2010-02-05T23:59:59.000Z

    We study the response of optically trapped achiral and chiralised nematic liquid crystal droplets to linear as well as circular polarised light. We find that there is internal dissipation in rotating achiral nematic droplets trapped in glycerine. We also demonstrate that some chiralised droplets rotate under linearly polarised light. The best fit to our data on chiralised droplets indicates that rotational frequency of these droplets with radius R is approximately proportional to1/R^2, rather than to 1/R^3.

  15. " A Heterodyne Laser-induced Fluorescence Technique to Determine

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLasDelivered‰PNG IHDR€ÍSolar Energy SystemsFebruary 7-8,March 8,8)Normal 27Simultaneously the

  16. Sandia National Laboratories: two-photon laser-induced fluorescence

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbineredox-activeNational SolartSSLPVinteraction DOEtwo-photon

  17. PAC spectroscopy of electronic ceramics

    SciTech Connect (OSTI)

    Gardner, J.A.; Wang, Ruiping; Schwenker, R. [Oregon Univ., Eugene, OR (United States). Dept. of Physics; Evenson, W.E. [Brigham Young Univ., Provo, UT (United States). Dept. of Physics and Astronomy; Rasera, R.L. [Maryland Univ., Catonsville, MD (United States). Dept. of Physics; Sommers, J.A. [Teledyne-Wah Chang, Albany, OR (United States)

    1991-12-31T23:59:59.000Z

    Dilute indium dopants in cerium oxides and YBa{sub 2}Cu{sub 3}O{sub x} have been studied by{sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. By controlling oxygen vacancy concentration in the cerium oxides through doping or high-temperature vacuum annealing, we have found that indium always forms a defect complex unless the sample is doped to reduce greatly the oxygen vacancy concentration. Three different vacancy-associated complexes are found with concentrations that depend on doping and oxygen stoichiometry. Another defect complex occurs in samples having negligible vacancy concentration. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent. In YBa{sub 2}Cu{sub 3}O{sub x} the indium substitutes preferentially at the Y site but has measurable probability of substitution in at least one of the two copper sites. A symmetry change near 650 {degree}C is consistent with the well-documented orthorhombic/tetragonal transition for samples in air or oxygen.

  18. PAC spectroscopy of electronic ceramics

    SciTech Connect (OSTI)

    Gardner, J.A.; Wang, Ruiping; Schwenker, R. (Oregon Univ., Eugene, OR (United States). Dept. of Physics); Evenson, W.E. (Brigham Young Univ., Provo, UT (United States). Dept. of Physics and Astronomy); Rasera, R.L. (Maryland Univ., Catonsville, MD (United States). Dept. of Physics); Sommers, J.A. (Teledyne-Wah Chang, Albany, OR (United States))

    1991-01-01T23:59:59.000Z

    Dilute indium dopants in cerium oxides and YBa{sub 2}Cu{sub 3}O{sub x} have been studied by{sup 111}In/Cd Perturbed Angular Correlation (PAC) spectroscopy. By controlling oxygen vacancy concentration in the cerium oxides through doping or high-temperature vacuum annealing, we have found that indium always forms a defect complex unless the sample is doped to reduce greatly the oxygen vacancy concentration. Three different vacancy-associated complexes are found with concentrations that depend on doping and oxygen stoichiometry. Another defect complex occurs in samples having negligible vacancy concentration. At low temperatures, evidence is found of interaction with an electronic hole trapped by {sup 111}Cd after the radioactive decay of the {sup 111}In parent. In YBa{sub 2}Cu{sub 3}O{sub x} the indium substitutes preferentially at the Y site but has measurable probability of substitution in at least one of the two copper sites. A symmetry change near 650 {degree}C is consistent with the well-documented orthorhombic/tetragonal transition for samples in air or oxygen.

  19. Laser photoelectron spectroscopy of ions

    SciTech Connect (OSTI)

    Ellison, G.B.

    1992-01-16T23:59:59.000Z

    This enterprise uses photoelectron spectroscopy to study the properties of negative ions and radicals. The essence of our experiment is to cross a 0.6 keV mass-selected ion beam (M{sup {minus}}) with the output of a CW laser, {Dirac h}{omega}{sub o}. The resultant detached photoelectrons with kinetic energy, KE, are energy analyzed by means of a set of electrostatic hemispherical analyzers. Analysis of the photoelectron spectra enables us to extract molecular electron affinities, vibrational frequencies and electronic splittings of the final radical, M, as well as the relative molecular geometries of ions (M{sup {minus}}) and radicals (M). We have scrutinized the two simplest nitrenes: methylnitrene (CH{sub 3}N) and phenylnitrene (C{sub 6}H{sub 5}N). By preparing the corresponding anions, CH{sub 3}N{sup {minus}} and C{sub 6}H{sub 5}N{sup {minus}}, we have studied these nitrene biradicals. Singlet methylnitrene is especially interesting since it is formally a transition state.''

  20. Nonresonant ionization of oxygen molecules by femtosecond pulses: Plasma dynamics studied by time-resolved terahertz spectroscopy

    E-Print Network [OSTI]

    Apkarian, V. Ara

    contribution to laser plasmas generated in air,26 ionized oxygen O2 + plays an important role in the upperNonresonant ionization of oxygen molecules by femtosecond pulses: Plasma dynamics studied by time for exploring laser-induced ionization and plasma formation in gases. Plasma was produced in gaseous oxygen

  1. Metamaterial-Enhanced Nonlinear Terahertz Spectroscopy

    E-Print Network [OSTI]

    Hwang, Harold Young

    We demonstrate large nonlinear terahertz responses in the gaps of metamaterial split ring resonators in several materials and use nonlinear THz transmission and THz-pump/THz-probe spectroscopy to study the nonlinear responses ...

  2. Negative Ion Photoelectron Spectroscopy Confirms the Prediction...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Confirms the Prediction that (CO)5 and (CO)6 Each Has a Singlet Ground State. Negative Ion Photoelectron Spectroscopy Confirms the Prediction that (CO)5 and (CO)6 Each Has a...

  3. Applying near-infrared spectroscopy (nirs)

    E-Print Network [OSTI]

    Wruck, Eric Michael

    2005-08-29T23:59:59.000Z

    investigated. A recently developed optical imaging technique called near-infrared spectroscopy (NIRS) shows promise for being an acceptable alternative to invasive imaging techniques. NIRS measures correlates of neural activity by assessing hemoglobin...

  4. Developments and advances in nonlinear terahertz spectroscopy

    E-Print Network [OSTI]

    Brandt, Nathaniel Curran

    2014-01-01T23:59:59.000Z

    Nonlinear terahertz (THz) spectroscopy is a rapidly developing field, which is concerned with driving and observing nonlinear material responses in the THz range of the electromagnetic spectrum. In this thesis, I present ...

  5. A superconducting dipole magnet for laser spectroscopy

    E-Print Network [OSTI]

    Wagenhauser, Kenneth Edward

    1990-01-01T23:59:59.000Z

    A SUPERCONDUCTING DIPOLE MAGNET FOR LASER SPECTROSCOPY A Thesis by KENNETH EDWARD WAGENHAUSER Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requhements for the degree of MASTER OF SCIENCE... May 1990 Major subject: Physics A SUPERCONDUCTING DIPOLE MAGNET FOR LASER SPECTROSCOPY A thesis by KENNETH EDWARD WAGENHAUSER Approved to as to style and content by: Hans A. Schuessler (Chair of Committee) David H. Russell (Member) Glenn A...

  6. Spectroscopy of Mn atoms isolated in solid {sup 4}He

    SciTech Connect (OSTI)

    Moroshkin, P., E-mail: petr.moroshkin@riken.jp; Lebedev, V.; Weis, A. [Department of Physics, University of Fribourg, Chemin du Muse 3, 1700 Fribourg (Switzerland)

    2014-06-07T23:59:59.000Z

    We present an experimental study of the laser-induced luminescence spectra of Mn atoms in solid helium matrices. We observe transitions of the valence electron and of inner-shell electrons. We find that the Mn-He interaction perturbs the inner-shell transitions to a lesser extent than the valence-electron transitions. The observed lineshapes of the inner-shell transitions of Mn are similar to those of an inner-shell transition in Ba studied earlier. At the same time, they are more strongly perturbed than the corresponding transitions in Au and Cu under the same conditions. We suggest a qualitative explanation of these observations based on the atomic bubble model. Our results also suggest that the inner-shell transitions of Mn in solid He are more strongly perturbed than the same lines of Mn isolated in solid Ar or Kr matrices.

  7. Biofuel breakdown | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I.ProgramBig SolBiofilm assembly Biofilm

  8. Nuclear-spectroscopy problems studied with neutrons

    SciTech Connect (OSTI)

    Raman, S.

    1982-01-01T23:59:59.000Z

    Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions have been obtained that are not ony interesting per se but are also grist for old and new theory mills. The above technical advances have opened up new opportunities for further discoveries.

  9. Imaging laser analysis of building materials - practical examples

    SciTech Connect (OSTI)

    Wilsch, G.; Schaurich, D.; Wiggenhauser, H. [BAM, Federal Institute for Materials Research and Testing, Berlin (Germany)

    2011-06-23T23:59:59.000Z

    The Laser induced Breakdown Spectroscopy (LIBS) is supplement and extension of standard chemical methods and SEM- or Micro-RFA-applications for the evaluation of building materials. As a laboratory method LIBS is used to gain color coded images representing composition, distribution of characteristic ions and/or ingress characteristic of damaging substances. To create a depth profile of element concentration a core has to be taken and split along the core axis. LIBS was proven to be able to detect all important elements in concrete, e. g. Chlorine, Sodium or Sulfur, which are responsible for certain degradation mechanisms and also light elements like lithium or hydrogen. Practical examples are given and a mobile system for on-site measurements is presented.

  10. Feedstock Quality Factor Calibration and Data Model Development

    SciTech Connect (OSTI)

    Richard D. Boardman; Tyler L. Westover; Garold L. Gresham

    2010-05-01T23:59:59.000Z

    The goal of the feedstock assembly operation is to deliver uniform, quality-assured feedstock materials that will enhance downstream system performance by avoiding problems in the conversion equipment. In order to achieve this goal, there is a need for rapid screening tools and methodologies for assessing the thermochemical quality characteristics of biomass feedstock through the assembly process. Laser-induced breakdown spectroscopy (LIBS) has been identified as potential technique that could allow rapid elemental analyses of the inorganic content of biomass feedstocks; and consequently, would complement the carbohydrate data provided by near-infrared spectrometry (NIRS). These constituents, including Si, K, Ca, Na, S, P, Cl, Mg, Fe and Al, create a number of downstream problems in thermochemical processes. In particular, they reduce the energy content of the feedstock, influence reaction pathways, contribute to fouling and corrosion within systems, poison catalysts, and impact waste streams.

  11. Monitoring changes in soil carbon resulting from intensive production, a non-traditional agricultural methodology.

    SciTech Connect (OSTI)

    Dwyer, Brian P.

    2013-03-01T23:59:59.000Z

    New Mexico State University and a group of New Mexico farmers are evaluating an innovative agricultural technique they call Intensive Production (IP). In contrast to conventional agricultural practice, IP uses intercropping, green fallowing, application of soil amendments and soil microbial inocula to sequester carbon as plant biomass, resulting in improved soil quality. Sandia National Laboratories role was to identify a non-invasive, cost effective technology to monitor soil carbon changes. A technological review indicated that Laser Induced Breakdown Spectroscopy (LIBS) best met the farmers' objectives. Sandia partnered with Los Alamos National Laboratory (LANL) to analyze farmers' test plots using a portable LIBS developed at LANL. Real-time LIBS field sample analysis was conducted and grab samples were collected for laboratory comparison. The field and laboratory results correlated well implying the strong potential for LIBS as an economical field scale analytical tool for analysis of elements such as carbon, nitrogen, and phosphate.

  12. Spectroscopy of element 115 decay chains

    SciTech Connect (OSTI)

    Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

    2013-01-01T23:59:59.000Z

    A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

  13. E-Print Network 3.0 - alpha spectroscopy system Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectroscopy... Method: high resolution (R2 104) spectroscopy of single ZL Fraunhofer line 12;Zodiacal light... spectroscopy Zodiacal light pictures 12;Zodiacal...

  14. SPECIES DETERMINATION OF ORGANOMETALLIC COMPOUNDS USING ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY WITH LIQUID CHROMATOGRAPHY

    E-Print Network [OSTI]

    Koizumi, H.

    2011-01-01T23:59:59.000Z

    Compounds Using Zeeman Atomic Absorption Spectroscopy WithCompounds Using Zeeman ,Atomic Absorption Spectroscopy withcapabilities of Zeeman atomic absorption spectroscopy (ZAA)

  15. X-RAY ABSORPTION SPECTROSCOPY FOR THE CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS

    E-Print Network [OSTI]

    Jaklevic, J. M.

    2011-01-01T23:59:59.000Z

    November 11-16 9 1979 X-RAY ABSORPTION SPECTROSCOPY FOR THEUniversity of California. ABSORPTION SPECTROSCOPY FOR THEand x-ray emission and absorption spectroscopy. The first

  16. Study of the dielectric breakdown properties of hot SF{sub 6}CF{sub 4} mixtures at 0.011.6 MPa

    SciTech Connect (OSTI)

    Li, Xingwen; Zhao, Hu; Jia, Shenli [State Key Laboratory of Electrical Insulation and Power Equipment, Xian Jiaotong University, No. 28 XianNing West Road, Xian, Shaanxi Province 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xian Jiaotong University, No. 28 XianNing West Road, Xian, Shaanxi Province 710049 (China); Murphy, Anthony B. [CSIRO Materials Science and Engineering, PO Box 218, Lindfield, NSW 2070 (Australia)] [CSIRO Materials Science and Engineering, PO Box 218, Lindfield, NSW 2070 (Australia)

    2013-08-07T23:59:59.000Z

    The dielectric breakdown properties of SF{sub 6}CF{sub 4} mixtures were investigated at different ratios of SF{sub 6}, 0.011.6 MPa, and gas temperatures up to 3000 K. Initially, the equilibrium compositions of SF{sub 6}CF{sub 4} mixtures were calculated by minimizing the Gibbs free energy under the assumptions of local thermodynamic and chemical equilibrium. Then the electron energy distribution function was obtained based on those data by solving the Boltzmann equation under the zero-dimensional two-term spherical harmonic approximation. Finally, the critical reduced electric field strength (E/N){sub cr} of SF{sub 6}CF{sub 4} mixtures, which is defined as the value for which total ionization reaction is equal to total attachment reaction, were determined and analyzed. The results confirm the superior breakdown properties of pure SF{sub 6} at relatively low gas temperatures. However, for higher gas temperatures (i.e., T > 2200 K at 0.4 MPa), the (E/N){sub cr} in SF{sub 6}CF{sub 4} mixtures are obviously higher than that in pure SF{sub 6} and the values of (E/N){sub cr} increase with the reduction of the ratio of SF{sub 6}.

  17. Laser spectroscopy and dynamics of transient species

    SciTech Connect (OSTI)

    Clouthier, D.J. [Univ. of Kentucky, Lexington (United States)

    1993-12-01T23:59:59.000Z

    The goal of this program is to study the vibrational and electronic spectra and excited state dynamics of a number of transient sulfur and oxygen species. A variety of supersonic jet techniques, as well as high resolution FT-IR and intracavity dye laser spectroscopy, have been applied to these studies.

  18. Inelastic Tunneling Spectroscopy in Unconventional Superconductors

    E-Print Network [OSTI]

    Inelastic Tunneling Spectroscopy in Unconventional Superconductors Molecular Vibration and Single Superconductors ­ p.1/13 #12;Old Results R.C. Jaklevic and J. Lambe, Phys. Rev. Lett. 17, 1139-1140 (1966 in Unconventional Superconductors ­ p.2/13 #12;STM observation of local inelastic mode B.C. Stipe, M.A Rezaei, and W

  19. Photoassociative molecular spectroscopy for atomic radiative lifetimes.

    E-Print Network [OSTI]

    Boyer, Edmond

    very far apart, in so-called long- range molecular states, their mutual interaction is ruled by plain atomic properties. The high- resolution spectroscopic study of some molecular excited states populated by photoassociation of cold atoms (photoassociative spectroscopy) gives a good illustration of this property

  20. Multichannel photodiode detector for ultrafast optical spectroscopy

    E-Print Network [OSTI]

    Mertelj, T; Borzda, T; Vaskivskyi, I; Pogrebna, A; Mihailovic, D

    2014-01-01T23:59:59.000Z

    Construction and characterization of a multichannel photodiode detector based on commercially available components with high signal to noise of $\\sim10^{6}$ and a rapid frame rate, suitable for time resolved femtosecond spectroscopy with high repetition femtosecond sources, is presented.

  1. Spectroscopy and decays of charm and bottom

    SciTech Connect (OSTI)

    Butler, J.N.

    1997-10-01T23:59:59.000Z

    After a brief review of the quark model, we discuss our present knowledge of the spectroscopy of charm and bottom mesons and baryons. We go on to review the lifetimes, semileptonic, and purely leptonic decays of these particles. We conclude with a brief discussion B and D mixing and rare decays.

  2. A New Spin on Photoemission Spectroscopy

    SciTech Connect (OSTI)

    Advanced Light Source; Jozwiak, Chris

    2008-12-18T23:59:59.000Z

    The electronic spin degree of freedom is of general fundamental importance to all matter. Understanding its complex roles and behavior in the solid state, particularly in highly correlated and magnetic materials, has grown increasingly desirable as technology demands advanced devices and materials based on ever stricter comprehension and control of the electron spin. However, direct and efficient spin dependent probes of electronic structure are currently lacking. Angle Resolved Photoemission Spectroscopy (ARPES) has become one of the most successful experimental tools for elucidating solid state electronic structures, bolstered bycontinual breakthroughs in efficient instrumentation. In contrast, spin-resolved photoemission spectroscopy has lagged behind due to a lack of similar instrumental advances. The power of photoemission spectroscopy and the pertinence of electronic spin in the current research climate combine to make breakthroughs in Spin and Angle Resolved Photoemission Spectroscopy (SARPES) a high priority . This thesis details the development of a unique instrument for efficient SARPES and represents a radical departure from conventional methods. A custom designed spin polarimeter based on low energy exchange scattering is developed, with projected efficiency gains of two orders of magnitude over current state-of-the-art polarimeters. For energy analysis, the popular hemispherical analyzer is eschewed for a custom Time-of-Flight (TOF) analyzer offering an additional order of magnitude gain in efficiency. The combined instrument signifies the breakthrough needed to perform the high resolution SARPES experiments necessary for untangling the complex spin-dependent electronic structures central to today?s condensed matter physics.

  3. Baryon spectroscopy with CLAS at Jefferson Lab

    SciTech Connect (OSTI)

    Eugene Pasyuk, CLAS Collaboration

    2012-04-01T23:59:59.000Z

    A substantial part of the experimental efforts at the experimental Hall-B of Jefferson Laboratory is dedicated to this studies of light baryon spectroscopy. In this report a general overview of the experimental capabilities in the Experimental Hall-B will be presented together with preliminary results of recent double polarization measurements and finally overall status of the program.

  4. Results and Frontiers in Lattice Baryon Spectroscopy

    SciTech Connect (OSTI)

    Bulava, John; Morningstar, Colin [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Edwards, Robert; Richards, David [Thomas Jefferson National Accelerator Facility, Newport News, VA 23606 (United States); Fleming, George [Yale University New Haven, CT 06520 (United States); Juge, K. Jimmy [Department of Physics, University of the Pacific, Stockton, CA 95211 (United States); Lichtl, Adam C. [RBRC, Brookhaven National Laboratory, Upton, NY 11973 (United States); Mathur, Nilmani [Tata Institute of Fundamental Research, Mumbai 40005 (India); Wallace, Stephen J. [University of Maryland, College Park, MD 20742 (United States)

    2007-10-26T23:59:59.000Z

    The Lattice Hadron Physics Collaboration (LHPC) baryon spectroscopy effort is reviewed. To date the LHPC has performed exploratory Lattice QCD calculations of the low-lying spectrum of Nucleon and Delta baryons. These calculations demonstrate the effectiveness of our method by obtaining the masses of an unprecedented number of excited states with definite quantum numbers. Future work of the project is outlined.

  5. Multivariate Optical Computation for Predictive Spectroscopy

    E-Print Network [OSTI]

    Myrick, Michael Lenn

    Multivariate Optical Computation for Predictive Spectroscopy Matthew P. Nelson, Jeffrey F. Aust, J Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6 A novel optical approach to predicting chemical into the structure of a set of paired optical filters. Light passing through the paired filters produces an analog

  6. Theoretical and experimental investigation of polarization spectroscopy

    E-Print Network [OSTI]

    Hanna, Sherif Fayez

    2001-01-01T23:59:59.000Z

    , Sweden. Polarization spectroscopy saturation curves in the co-propagating beam geometry from the excitation of OH A []?-X[] (0,0) at the Q?(8) line for sub-atmospheric pressures have been fitted to the proposed model. The model proposed in this work...

  7. In-flight decay spectroscopy of exotic light nuclei

    SciTech Connect (OSTI)

    Charity, R. J. [Department of Chemistry, Washington University, St. Louis, Mo 63130 (United States)

    2012-11-20T23:59:59.000Z

    In-flight-decay spectroscopy is discussed, including its advantages and disadvantages. In particular the use of in-flight-decay spectroscopy for the study of two-proton decay along isobaric multiplets in highlighted.

  8. Depth-resolved cathodoluminescence spectroscopy of silicon supersaturated with sulfur

    E-Print Network [OSTI]

    Fabbri, Filippo

    We investigate the luminescence of Si supersaturated with S (Si:S) using depth-resolved cathodoluminescence spectroscopy and secondary ion mass spectroscopy as the S concentration is varied over 2 orders of magnitude ...

  9. EVALUATION OF TWO-BEAM SPECTROSCOPY AS A PLASMA DIAGNOSTIC.

    E-Print Network [OSTI]

    Billard, Barton Dawes

    2010-01-01T23:59:59.000Z

    BEAM SPECTROSCOPY AS A PLASMA DIAGNOSTIC Barton. Dawes B i lSpectroscopy as a Plasma Diagnostic Barton Dawes Billardis thus a non-perturbing plasma diagnostic which is shown to

  10. Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Azimuth-Resolved Infrared Spectroscopy of Water on TiO2(110): Anisotropy and the Hydrogen-Bonding Network. Polarization- and Azimuth-Resolved Infrared Spectroscopy of Water on...

  11. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Wednesday, 29 October 2008 00:00 Graphene-a single layer...

  12. X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for You X-Ray Photoelectron Spectroscopy (XPS) Applied to Soot & What It Can Do for You Presentation given at DEER...

  13. Core-level Spectroscopies with FEFF9 and OCEAN

    E-Print Network [OSTI]

    Botti, Silvana

    Core-level Spectroscopies with FEFF9 and OCEAN J. J. Rehr1,4 K. Gilmore,2,4 J. Kas,1 J. Vinson,3 E European Theoretical Spectroscopy Facility Supported by DOE BES Soleil Theory Day Synchrotron SOLEIL, Grand Amphi 6/5/2014 #12;Core-level Spectroscopies with FEFF9 and OCEAN · GOAL: ab initio theory · Accuracy

  14. FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS)

    E-Print Network [OSTI]

    Ohta, Shigemi

    FRONTIER SYNCHROTRON INFRARED SPECTROSCOPY BEAMLINE UNDER EXTREME CONDITIONS (FIS) Proposal Team: L INFORMATION · TECHNIQUE(S): Fourier transform infrared spectroscopy; Raman and visible spectroscopy; Diamond techniques combined with DACs; Laser heating techniques combined with DACs. · SOURCE: Large-gap (90 mm

  15. E-Print Network 3.0 - absorption spectroscopy measurements Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Auger electron ... Source: Yucca Mountain Project, US...

  16. E-Print Network 3.0 - atomic spectroscopy study Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... spectroscopy Atomic emission ... Source: Yucca Mountain Project,...

  17. E-Print Network 3.0 - absorption edge spectroscopy Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Domain Spectroscopy From... Industrial applications: spectroscopy, imaging and security Terahertz: Research and Applications 12... of Photonic THz Radiation transmission &...

  18. Meson Spectroscopy At Jlab At 12 Gev

    SciTech Connect (OSTI)

    Fegan, Stuart [INFN-GENOVA

    2014-12-01T23:59:59.000Z

    The 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab will enable a new generation of experiments in hadronic nuclear physics, seeking to address fundamental questions in our understanding of QCD. The existence of exotic states, suggested by both quark models and lattice calculations, would allow gluonic degrees of freedom to be explored, and may help explain the role played by gluons in the QCD interaction. This article will review the meson spectroscopy program being planned at the lab following the 12 GeV upgrade, utilising real and quasi-real photon beams in two of the lab's four experimental halls, whose distinct capabilities will enable an extensive set of spectroscopy experiments to be performed at the same facility.

  19. Charge exchange recombination spectroscopy on fusion devices

    SciTech Connect (OSTI)

    Duval, B. P. [Centre de Recherches en Physique des Plasmas, EPFL, Lausanne (Switzerland)

    2012-05-25T23:59:59.000Z

    For fusion, obtaining reliable measurements of basic plasma parameters like ion and electron densities and temperatures is a primary goal. For theory, measurements are needed as a function of time and space to understand plasma transport and confinement with the ultimate goal of achieving economic nuclear fusion power. Electron profile measurements and plasma spectroscopy for the plasma ions are introduced. With the advent of Neutral Beam auxiliary plasma heating, Charge Exchange Recombination Spectroscopy provides accurate and time resolved measurements of the ions in large volume fusion devices. In acknowledgement of Nicol Peacock's role in the development of these techniques, still at the forefront of plasma fusion research, this paper describes the evolution of this diagnostic method.

  20. Standoff spectroscopy using a conditioned target

    DOE Patents [OSTI]

    Van Neste, Charles W. (Kingston, TN); Morales-Rodriguez, Marissa E. (Knoxville, TN); Senesac, Lawrence R. (Knoxville, TN); Thundat, Thomas G. (Knoxville, TN)

    2011-12-20T23:59:59.000Z

    A system and method are disclosed for standoff spectroscopy of molecules (e.g. from a residue) on a surface from a distance. A source emits radiation that modifies or conditions the residue, such as through photodecomposition. A spectral generating source measures a spectrum of the residue before and after the residue is exposed to the radiation from that source. The two spectra are compared to produce a distinct identification of the residues on the surface or identify certain properties of the residue.

  1. Spin noise spectroscopy of ZnO

    SciTech Connect (OSTI)

    Horn, H.; Berski, F.; Hbner, J.; Oestreich, M. [Institute for Solid State Physics, Leibniz Universitt Hannover, Appelstr. 2, 30167 Hannover (Germany); Balocchi, A.; Marie, X. [INSA-CNRS-UPS, LPCNO, Universit de Toulouse, 135 Av. de Rangueil, 31077 Toulouse (France); Mansur-Al-Suleiman, M.; Bakin, A.; Waag, A. [Institute of Semiconductor Technology, Technische Universitt Braunschweig, Hans-Sommer-Strae 66, 38106 Braunschweig (Germany)

    2013-12-04T23:59:59.000Z

    We investigate the thermal equilibrium dynamics of electron spins bound to donors in nanoporous ZnO by optical spin noise spectroscopy. The spin noise spectra reveal two noise contributions: A weak spin noise signal from undisturbed localized donor electrons with a dephasing time of 24 ns due to hyperfine interaction and a strong spin noise signal with a spin dephasing time of 5 ns which we attribute to localized donor electrons which interact with lattice defects.

  2. New Spectroscopy at BaBar

    SciTech Connect (OSTI)

    Mazzoni, M.A.; /INFN, Rome

    2007-04-18T23:59:59.000Z

    The Babar experiment at the SLAC B factory has accumulated a high luminosity that offers the possibility of systematic studies of quarkonium spectroscopy and of investigating rare new phenomena. Recent results in this field are presented. In recent times spectroscopy has become exciting again, after the discovery of new states that are not easily explained by conventional models. States such as the X(3872) and the Y(4260) could be new excited charmonium states, but require precise measurements for positive identification. The BaBar experiment [1] is installed at the asymmetric storage ring PEP-II. 90% of the data accumulated by BaBar are taken at the Y(4S) (10.58 GeV) and 10% just below (10.54 GeV). The BaBar detector includes a 5-layer, double-sided silicon vertex tracker and a 40-layer drift chamber in a 1.5 T solenoidal magnetic field, which detect charged particles and measures their momenta and ionization energy losses. Photons, electrons, and neutral hadrons are detected with a CsI(Tl)-crystal electromagnetic calorimeter. An internally reflecting ring-imaging Cherenkov is also used for particle id. Penetrating muon and neutral hadrons are identified by an array of resistive-plate chambers embedded in the steel of the flux return. The detector allows good track and vertex resolution, good particle id and good photon detection so it is especially suited for spectroscopy studies.

  3. Work Breakdown Structure and Plant/Equipment Designation System Numbering Scheme for the High Temperature Gas- Cooled Reactor (HTGR) Component Test Capability (CTC)

    SciTech Connect (OSTI)

    Jeffrey D Bryan

    2009-09-01T23:59:59.000Z

    This white paper investigates the potential integration of the CTC work breakdown structure numbering scheme with a plant/equipment numbering system (PNS), or alternatively referred to in industry as a reference designation system (RDS). Ideally, the goal of such integration would be a single, common referencing system for the life cycle of the CTC that supports all the various processes (e.g., information, execution, and control) that necessitate plant and equipment numbers be assigned. This white paper focuses on discovering the full scope of Idaho National Laboratory (INL) processes to which this goal might be applied as well as the factors likely to affect decisions about implementation. Later, a procedure for assigning these numbers will be developed using this white paper as a starting point and that reflects the resolved scope and outcome of associated decisions.

  4. Excitation in low-current discharges and breakdown in He at low pressures and very high electric field to gas density ratios E/N

    SciTech Connect (OSTI)

    Jelenkovic, B.M.; Phelps, A.V. [JILA, University of Colorado and National Institute of Standards and Technology, Boulder, Colorado 80309-0440 (United States); Institute of Physics, P.O. Box 75, Belgrade (Serbia and Montenegro); JILA, University of Colorado and National Institute of Standards and Technology, Boulder, Colorado 80309-0440 (United States)

    2005-01-01T23:59:59.000Z

    We investigate optical emission from low-current discharges in He at very high electric field to gas density ratios E/N between parallel plate electrodes. We also determine the electrical breakdown and the voltage-current behavior at low currents. The E/N are 300 Td to 9 kTd (1 Td=10{sup -21} V m{sup 2}) at pressures times electrode separations p{sub 0}d from 3 to 0.9 Torr cm. Absolute optical emission probabilities versus distance are determined for the 501.6 nm line (3 {sup 1}P{yields}2 {sup 1}S) and for the 587.6 nm line (3 {sup 3}D{yields}2 {sup 3}P) by reference to Boltzmann calculations at our lowest E/N and to published pressure dependent electron beam experiments. At E/N below 1 kTd, the emission follows the exponential growth of the electron density, while at above 7 kTd heavy particle excitation is evident near the cathode. Collisional transfer of excitation from the singlet to the triplet system dominates the 587.6 nm excitation. Comparisons of models with experiments show the importance of excitation and of electron production at the cathode by fast He atoms produced by charge transfer collisions of He{sup +} with He. The breakdown voltage versus p{sub 0}d is multivalued for p{sub 0}d{approx}1.5 Torr cm. At currents below 100 {mu}A and our lower E/N, the discharge voltage decreases linearly with current as expected for an increasing electron yield with ion energy and E/N at the cathode.

  5. Issues in Light Meson Spectroscopy: The Case for Meson Spectroscopy at Cebaf

    E-Print Network [OSTI]

    Stephen Godfrey

    1994-06-10T23:59:59.000Z

    I review some outstanding issues in meson spectroscopy. The most important qualitative issue is whether hadrons with explicit gluonic degrees of freedom exist. To answer this question requires a much better understanding of conventional $q\\bar{q}$ mesons. I therefore begin by examining the status of conventional meson spectroscopy and how the situation can be improved. The expected properties of gluonic excitations are discussed with particular emphasis on hybrids to give guidance to experimental searches. Multiquark systems are commented upon as they are likely to be important in the mass region under study and will have to be understood better. In the final section I discuss the opportunities that CEBAF can offer for the study of meson spectroscopy.

  6. Dielectric breakdown properties of hot SF{sub 6}-CO{sub 2} mixtures at temperatures of 3003500?K and pressures of 0.011.0?MPa

    SciTech Connect (OSTI)

    Zhong, Linlin; Yang, Aijun; Wang, Xiaohua, E-mail: xhw@mail.xjtu.edu.cn; Liu, Dingxin; Wu, Yi; Rong, Mingzhe, E-mail: mzrong@mail.xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China)] [State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Xi'an 710049 (China)

    2014-05-15T23:59:59.000Z

    Recently, much attention has been paid to SF{sub 6}-CO{sub 2} mixtures as one of substitutes for pure SF{sub 6} gas. In this paper, the dielectric breakdown properties of hot SF{sub 6}-CO{sub 2} mixtures are investigated at temperatures of 3003500?K and pressures of 0.011.0?MPa. Under the assumptions of local thermodynamic equilibrium and local chemical equilibrium, the equilibrium compositions of hot SF{sub 6}-CO{sub 2} mixtures with different CO{sub 2} proportions are obtained based on Gibbs free energy minimization. The cross sections for interactions between electrons and neutral species are presented. Some unknown ionization cross sections are determined theoretically using DeutschMrk (DM) formalism based on quantum chemistry. Two-term Boltzmann equation is adopted to calculate the electron energy distribution function, reduced ionization coefficient, reduced attachment coefficient, and reduced effective ionization coefficient. Then the reduced critical electric field strength of mixtures, corresponding to dielectric breakdown performances, is determined when the generation and loss of electrons are balanced. Finally, the influences of temperature, pressure, and CO{sub 2} proportion on the reduced critical electric field strength are studied. It is found that a large percentage of CO{sub 2} can obviously reduce concentrations of high-energy electrons. At temperatures above 1750?K, an addition of CO{sub 2} to SF{sub 6} gas can enhance dielectric breakdown performances. However, at low temperatures, too much CO{sub 2} added into mixtures can reduce dielectric breakdown abilities. In addition, increasing gas pressure can improve dielectric breakdown performances. But the influence will be no more significant if pressure is over 0.8?MPa.

  7. Estimating radiological background using imaging spectroscopy

    SciTech Connect (OSTI)

    Bernacki, Bruce E.; Schweppe, John E.; Stave, Sean C.; Jordan, David V.; Kulisek, Jonathan A.; Stewart, Trevor N.; Seifert, Carolyn E.

    2014-06-13T23:59:59.000Z

    Optical imaging spectroscopy is investigated as a method to estimate radiological background by spectral identification of soils, sediments, rocks, minerals and building materials derived from natural materials and assigning tabulated radiological emission values to these materials. Radiological airborne surveys are undertaken by local, state and federal agencies to identify the presence of radiological materials out of regulatory compliance. Detection performance in such surveys is determined by (among other factors) the uncertainty in the radiation background; increased knowledge of the expected radiation background will improve the ability to detect low-activity radiological materials. Radiological background due to naturally occurring radiological materials (NORM) can be estimated by reference to previous survey results, use of global 40K, 238U, and 232Th (KUT) values, reference to existing USGS radiation background maps, or by a moving average of the data as it is acquired. Each of these methods has its drawbacks: previous survey results may not include recent changes, the global average provides only a zero-order estimate, the USGS background radiation map resolutions are coarse and are accurate only to 1 km 25 km sampling intervals depending on locale, and a moving average may essentially low pass filter the data to obscure small changes in radiation counts. Imaging spectroscopy from airborne or spaceborne platforms can offer higher resolution identification of materials and background, as well as provide imaging context information. AVIRIS hyperspectral image data is analyzed using commercial exploitation software to determine the usefulness of imaging spectroscopy to identify qualitative radiological background emissions when compared to airborne radiological survey data.

  8. Construction and Commissioning of a Collinear Laser Spectroscopy Setup at TRIGA Mainz and Laser Spectroscopy of Magnesium Isotopes at ISOLDE (CERN)

    E-Print Network [OSTI]

    Kraemer, Joerg

    Construction and Commissioning of a Collinear Laser Spectroscopy Setup at TRIGA Mainz and Laser Spectroscopy of Magnesium Isotopes at ISOLDE (CERN)

  9. (Resonance ionization spectroscopy and its applications)

    SciTech Connect (OSTI)

    Payne, M.G.

    1990-10-05T23:59:59.000Z

    The field of Resonance Ionization Spectroscopy grew out of work done in the Photophysics Group at Oak Ridge National Laboratory. As one of the original developers of this field the traveler has continued to attend this meeting on a regular basis. The traveler was originally asked to present an invited talk and to present part of a short course offered to graduate students attending the conference. Subsequently, the traveler was also asked to chair a session and to be a judge of the students papers entered in a contest for a $1000 first prize.

  10. Spectroscopy and Thermodynamics of MSW Black Hole

    E-Print Network [OSTI]

    Sebastian, Saneesh

    2013-01-01T23:59:59.000Z

    We study the thermodynamics and spectroscopy of a 2+1 dimensional black hole pro- posed by Mandal et. al1 . We put the background space time in Kruskal like co-ordinate and find period with respect to Euclidean time. Different thermodynamic quantities like entropy, specific heat, temperature etc are obtained. The adiabatic invariant for the black hole is found out and quantized using Bohr-Sommerfeld quantization rule. The study shows that the area spectrum of MSW black hole is equally spaced and the value of spacing is found to be h bar

  11. Spectroscopy and Thermodynamics of MSW Black Hole

    E-Print Network [OSTI]

    Saneesh Sebastian; V. C. Kuriakose

    2013-09-02T23:59:59.000Z

    We study the thermodynamics and spectroscopy of a 2+1 dimensional black hole pro- posed by Mandal et. al1 . We put the background space time in Kruskal like co-ordinate and find period with respect to Euclidean time. Different thermodynamic quantities like entropy, specific heat, temperature etc are obtained. The adiabatic invariant for the black hole is found out and quantized using Bohr-Sommerfeld quantization rule. The study shows that the area spectrum of MSW black hole is equally spaced and the value of spacing is found to be h bar

  12. Cavity-locked ring down spectroscopy

    DOE Patents [OSTI]

    Zare, Richard N. (Stanford, CA); Paldus, Barbara A. (Stanford, CA); Harb, Charles C. (Palo Alto, CA); Spence, Thomas (Union City, CA)

    2000-01-01T23:59:59.000Z

    Distinct locking and sampling light beams are used in a cavity ring-down spectroscopy (CRDS) system to perform multiple ring-down measurements while the laser and ring-down cavity are continuously locked. The sampling and locking light beams have different frequencies, to ensure that the sampling and locking light are decoupled within the cavity. Preferably, the ring-down cavity is ring-shaped, the sampling light is s-polarized, and the locking light is p-polarized. Transmitted sampling light is used for ring-down measurements, while reflected locking light is used for locking in a Pound-Drever scheme.

  13. Fractal properties applied to hadron spectroscopy

    E-Print Network [OSTI]

    Boris Tatischeff

    2011-05-05T23:59:59.000Z

    A contribution is presented to the study of hadron spectroscopy through the use of fractals and discrete scale invariance implying log-periodic corrections to continuous scaling. The masses of mesons and baryons, reported by the Particle Data Group (PDG), are properly fitted with help of the equation derived from the discrete-scale invariance (DSI) model. The same property is observed for the mass ratios between different particle species. This is also the case for total widths of several hadronic species. Each fitted parameter, as a function of the hadronic masses, displays the same distribution for all hadronic species. Several masses of still unobserved mesons and baryons are tentatively predicted.

  14. Ultrafast Spectroscopy of Warm Dense Matter

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layeredof2014 EIA Energy40081AEnergyUltrafastUltrafast Spectroscopy

  15. Theoretical standards in x-ray spectroscopies

    SciTech Connect (OSTI)

    Not Available

    1992-01-01T23:59:59.000Z

    We propose to extend our state-of-the-art, ab initio XAFS (X-ray absorption fine structure) codes, FEFF. Our current work has been highly successful in achieving accurate, user-friendly XAFS standards, exceeding the performance of both tabulated standards and other codes by a considerable margin. We now propose to add the capability to treat more complex materials. This includes multiple-scattering, polarization dependence, an approximate treatment of XANES (x-ray absorption near edge structure), and other improvements. We also plan to adapt FEFF to other spectroscopies, e.g. photoelectron diffraction (PD) and diffraction anomalous fine structure (DAFS).

  16. Study of clusters using negative ion photodetachment spectroscopy

    SciTech Connect (OSTI)

    Zhao, Yuexing

    1995-12-01T23:59:59.000Z

    The weak van der Waals interaction between an open-shell halogen atom and a closed-shell atom or molecule has been investigated using zero electron kinetic energy (ZEKE) spectroscopy. This technique is also applied to study the low-lying electronic states in GaAs and GaAs{sup {minus}}. In addition, the spectroscopy and electron detachment dynamics of several small carbon cluster anions are studied using resonant multiphoton detachment spectroscopy.

  17. IR Spectroscopy Spectroscopy: Branch of science in which light or other electromagnetic radiation

    E-Print Network [OSTI]

    Sherrill, David

    is resolved into its component wavelengths to produce spectra, which are graphs of intensity vs. wavelength or frequency of radiation. Current usage broadens this definition to include some methods that don't involve the energy difference of 2 quantum levels of the sample of matter. hE = IR Spectroscopy Tool for examining

  18. Theory and Applications of NMR Spectroscopy Arthur S. Edison

    E-Print Network [OSTI]

    Collins, Gary S.

    . Prerequisites: Graduate student or advanced undergraduate status, physical chemistry, organic chemistry Spectroscopy Week 1: Introduction to the basics: Bloch equations References: Most NMR books. These notes were

  19. Graphene and its derivatives : fabrication and Raman spectroscopy study.

    E-Print Network [OSTI]

    Cong, Chunxiao.

    2012-01-01T23:59:59.000Z

    ??This thesis presents results on fabrication and Raman spectroscopy studies of graphene and its derivates. The works can be divided into two parts as follows. (more)

  20. E-Print Network 3.0 - absorption spectroscopy characterization...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Restoration Technologies 87 Terahertz Time-Domain Spectroscopy Study of Silica Aerogels and Adsorbed Molecular Jiangquan Zhang and D. Grischkowsky* Summary: absorption...

  1. Wave functions and their use in spectroscopy and phenomenology

    E-Print Network [OSTI]

    T. DeGrand; M. Hecht

    1992-10-08T23:59:59.000Z

    We describe the calculation of Coulomb gauge wave functions for light quark systems, and their use as interpolating fields for excited state spectroscopy.

  2. annihilation spectroscopy applied: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the mid-IR spectral Society for Applied Spectroscopy accelerated paper Negligible Sample Heating from Synchrotron Infrared, they could cause damage to biological molecules due to...

  3. applying gamma spectroscopy: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the mid-IR spectral Society for Applied Spectroscopy accelerated paper Negligible Sample Heating from Synchrotron Infrared, they could cause damage to biological molecules due to...

  4. First Principles Calculations and NMR Spectroscopy of Electrode...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Calculations and NMR Spectroscopy of Electrode Materials 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

  5. Natural Abundance 43Ca NMR Spectroscopy of Tobermorite and Jennite...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    which has limited our ability to understand the structure of, for example, Casilicate hydrate (CSH). 43Ca nuclear magnetic resonance (NMR) spectroscopy has...

  6. Single Molecule Spectroscopy of Electron Transfer

    SciTech Connect (OSTI)

    Michael Holman; Ling Zang; Ruchuan Liu; David M. Adams

    2009-10-20T23:59:59.000Z

    The objectives of this research are threefold: (1) to develop methods for the study electron transfer processes at the single molecule level, (2) to develop a series of modifiable and structurally well defined molecular and nanoparticle systems suitable for detailed single molecule/particle and bulk spectroscopic investigation, (3) to relate experiment to theory in order to elucidate the dependence of electron transfer processes on molecular and electronic structure, coupling and reorganization energies. We have begun the systematic development of single molecule spectroscopy (SMS) of electron transfer and summaries of recent studies are shown. There is a tremendous need for experiments designed to probe the discrete electronic and molecular dynamic fluctuations of single molecules near electrodes and at nanoparticle surfaces. Single molecule spectroscopy (SMS) has emerged as a powerful method to measure properties of individual molecules which would normally be obscured in ensemble-averaged measurement. Fluctuations in the fluorescence time trajectories contain detailed molecular level statistical and dynamical information of the system. The full distribution of a molecular property is revealed in the stochastic fluctuations, giving information about the range of possible behaviors that lead to the ensemble average. In the case of electron transfer, this level of understanding is particularly important to the field of molecular and nanoscale electronics: from a device-design standpoint, understanding and controlling this picture of the overall range of possible behaviors will likely prove to be as important as designing ia the ideal behavior of any given molecule.

  7. High-harmonic spectroscopy of molecular isomers

    SciTech Connect (OSTI)

    Wong, M. C. H.; Brichta, J.-P.; Bhardwaj, V. R. [Department of Physics, University of Ottawa, 150 Louis-Pasteur, Ottawa, Ontario, K1N 6N5 (Canada); Spanner, M.; Patchkovskii, S. [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, K1A 0R6 (Canada)

    2011-11-15T23:59:59.000Z

    We demonstrate that high-order-harmonic generation (HHG) spectroscopy can be used to probe stereoisomers of randomly oriented 1,2-dichloroethylene (C{sub 2}H{sub 2}Cl{sub 2}) and 2-butene (C{sub 4}H{sub 8}). The high-harmonic spectra of these isomers are distinguishable over a range of laser intensities and wavelengths. Time-dependent numerical calculations of angle-dependent ionization yields for 1,2-dichloroethylene suggest that the harmonic spectra of molecular isomers reflect differences in their strong-field ionization. The subcycle ionization yields for the cis isomer are an order of magnitude higher than those for the trans isomer. The sensitivity in discrimination of the harmonic spectra of cis- and trans- isomers is greater than 8 and 5 for 1,2-dichloroethylene and 2-butene, respectively. We show that HHG spectroscopy cannot differentiate the harmonic spectra of the two enantiomers of the chiral molecule propylene oxide (C{sub 3}H{sub 6}O).

  8. High fidelity nanohole enhanced Raman spectroscopy.

    SciTech Connect (OSTI)

    Bahns, J. T.; Guo, Q.; Gray, S. K.; Jaeger, H. M.; Chen, L.; Montgomery, J. M.; Univ. of Chicago

    2009-01-01T23:59:59.000Z

    Surface enhanced Raman spectroscopy (SERS) is a sensitive technique that can even detect single molecules. However, in many SERS applications, the strongly inhomogeneous distribution of intense local fields makes it very difficult for a quantitive assessment of the fidelity, or reproducibility of the signal, which limits the application of SERS. Herein, we report the development of exceptionally high-fidelity hole-enhanced Raman spectroscopy (HERS) from ordered, 2D hexagonal nanohole arrays. We take the fidelity f to be a measure of the percent deviation of the Raman peaks from measurement to measurement. Overall, area averaged fidelities for 12 gold array samples ranged from f {approx} 2-15% for HERS using aqueous R6G molecules. Furthermore, intensity modulations of the enhanced Raman spectra were measured for the first time as a function of polarization angle. The best of these measurements, which focus on static laser spots on the sample, could be consistent with even higher fidelities than the area-averaged results. Nanohole arrays in silver provided supporting polarization measurements and a more complete enhanced Raman fingerprint for phenylalanine molecules. We also carried out finite-difference time-domain calculations to assist in the interpretation of the experiments, identifying the polarization dependence as possibly arising from hole-hole interactions. Our results represent a step toward making quantitative and reproducible enhanced Raman measurements possible and also open new avenues for a large-scale source of highly uniform hot spots.

  9. Rotational Spectroscopy of PAHs: Acenaphthene, Acenaphthylene and Fluorene

    E-Print Network [OSTI]

    Thorwirth, S; Gottlieb, C A; McCarthy, M C; Thaddeus, P

    2005-01-01T23:59:59.000Z

    Pure rotational spectra of three polycyclic aromatic hydrocarbons - acenaphthene, acenaphthylene and fluorene - have been obtained by Fourier transform microwave spectroscopy of a molecular beam and subsequently by millimeter wave absorption spectroscopy for acenaphthene and fluorene. The data presented here will be useful for deep radio astronomical searches for PAHs employing large radio telecopes.

  10. Rotational Spectroscopy of PAHs: Acenaphthene, Acenaphthylene and Fluorene

    E-Print Network [OSTI]

    S. Thorwirth; P. Theule; C. A. Gottlieb; M. C. McCarthy; P. Thaddeus

    2005-09-23T23:59:59.000Z

    Pure rotational spectra of three polycyclic aromatic hydrocarbons - acenaphthene, acenaphthylene and fluorene - have been obtained by Fourier transform microwave spectroscopy of a molecular beam and subsequently by millimeter wave absorption spectroscopy for acenaphthene and fluorene. The data presented here will be useful for deep radio astronomical searches for PAHs employing large radio telecopes.

  11. Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes

    E-Print Network [OSTI]

    Dekker, Cees

    Scanning tunneling spectroscopy of suspended single-wall carbon nanotubes B. J. LeRoy,a) S. G-wall carbon nanotubes that are freely suspended over a trench. The nanotubes were grown by chemical vapor on the freestanding portions of the nanotubes. Spatially resolved spectroscopy on the suspended portion of both

  12. Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells

    E-Print Network [OSTI]

    Schiff, Eric A.

    Infrared modulation spectroscopy of interfaces in amorphous silicon solar cells Kai Zhu a,1 , E Solar, Toano, VA 23168, USA Abstract We report infrared depletion modulation spectra for near an infrared modulation spectroscopy technique that probes the optical spectra of dopants and defects

  13. production under ionizing radiation in aluminoborosilicate glasses by EPR spectroscopy.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Ti3+ production under ionizing radiation in aluminoborosilicate glasses by EPR spectroscopy. P irradiation of Ti4+ ions in aluminoborosilicate glasses have been studied by EPR spectroscopy at 20 K of the Ti3+ ion EPR spectra has shown three different Ti3+ environment attributed to one [VI] Ti3+ and two

  14. Near-infrared spectroscopy of HD the barrier to linearity

    E-Print Network [OSTI]

    Oka, Takeshi

    Near-infrared spectroscopy of HD 3 above the barrier to linearity BY JENNIFER L. GOTTFRIED, transitions of HC 3 above the barrier to linearity have been observed. A highly sensitive near-infrared-adiabatic and radiative corrections is revealed. Keywords: HD 3 ; near-infrared spectroscopy; barrier to linearity 1

  15. Optical Spectroscopy of Hydrogenic Atoms MIT Department of Physics

    E-Print Network [OSTI]

    Seager, Sara

    Optical Spectroscopy of Hydrogenic Atoms MIT Department of Physics (Dated: September 1, 2013) This experiment is an exercise in optical spectroscopy in a study of the spectra of "hydrogenic" atoms, i.e. atoms with one "optical" electron outside a closed shell of other electrons. Measurements include finding

  16. Deflecting light into resonant cavities for spectroscopy

    DOE Patents [OSTI]

    Zare, Richard N. (Stanford, CA); Martin, Juergen (Harxheim, DE); Paldus, Barbara A. (Stanford, CA)

    1998-01-01T23:59:59.000Z

    Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available.

  17. Pressurised xenon as scintillator for gamma spectroscopy

    E-Print Network [OSTI]

    Resnati, F

    2013-01-01T23:59:59.000Z

    Detectors based on liquid or gas xenon have been used and are in use for a number of applications, in particular for the detection of gamma rays. Xenon is a well-suited medium for gamma spectroscopy thanks to its high atomic number and, consequently, large cross-section for photo-electric absorption. This paper presents experimental studies of high pressure xenon as a scintillator, with the aim of developing a gamma ray detector for the detection of Special Nuclear Materials (SNM). The first goal was to study the dependence of the light yield and of the energy resolution on the thermodynamic conditions. We present preliminary results from an optimised version of the detector.

  18. Deflecting light into resonant cavities for spectroscopy

    DOE Patents [OSTI]

    Zare, R.N.; Martin, J.; Paldus, B.A.

    1998-09-29T23:59:59.000Z

    Light is coupled into a cavity ring down spectroscopy (CRDS) resonant cavity using an acousto-optic modulator. The AOM allows in-coupling efficiencies in excess of 40%, which is two to three orders of magnitude higher than in conventional systems using a cavity mirror for in-coupling. The AOM shutoff time is shorter than the roundtrip time of the cavity. The higher light intensities lead to a reduction in shot noise, and allow the use of relatively insensitive but fast-responding detectors such as photovoltaic detectors. Other deflection devices such as electro-optic modulators or elements used in conventional Q-switching may be used instead of the AOM. The method is particularly useful in the mid-infrared, far-infrared, and ultraviolet wavelength ranges, for which moderately reflecting input mirrors are not widely available. 5 figs.

  19. Anion photoelectron spectroscopy of radicals and clusters

    SciTech Connect (OSTI)

    Travis, Taylor R.

    1999-12-16T23:59:59.000Z

    Anion photoelectron spectroscopy is used to study free radicals and clusters. The low-lying {sup 2}{Sigma} and {sup 2}{Pi} states of C{sub 2n}H (n = 1--4) have been studied. The anion photoelectron spectra yielded electron affinities, term values, and vibrational frequencies for these combustion and astrophysically relevant species. Photoelectron angular distributions allowed the author to correctly assign the electronic symmetry of the ground and first excited states and to assess the degree of vibronic coupling in C{sub 2}H and C{sub 4}H. Other radicals studied include NCN and I{sub 3}. The author was able to observe the low-lying singlet and triplet states of NCN for the first time. Measurement of the electron affinity of I{sub 3} revealed that it has a bound ground state and attachment of an argon atom to this moiety enabled him to resolve the symmetric stretching progression.

  20. Remote adjustable focus Raman spectroscopy probe

    DOE Patents [OSTI]

    Schmucker, John E. (Hurt, VA); Blasi, Raymond J. (Harrison City, PA); Archer, William B. (Bethel Park, PA)

    1999-01-01T23:59:59.000Z

    A remote adjustable focus Raman spectroscopy probe allows for analyzing Raman scattered light from a point of interest external probe. An environmental barrier including at least one window separates the probe from the point of interest. An optical tube is disposed adjacent to the environmental barrier and includes a long working length compound lens objective next to the window. A beam splitter and a mirror are at the other end. A mechanical means is used to translated the prove body in the X, Y, and Z directions resulting in a variable focus optical apparatus. Laser light is reflected by the beam splitter and directed toward the compound lens objective, then through the window and focused on the point of interest. Raman scattered light is then collected by the compound lens objective and directed through the beam splitter to a mirror. A device for analyzing the light, such as a monochrometer, is coupled to the mirror.

  1. New Results on Baryon Spectroscopy from MAMI

    SciTech Connect (OSTI)

    Schumann, Sven [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet, Mainz (Germany)

    2010-08-05T23:59:59.000Z

    An overview of the MAMI-C electron accelerator facility (E{sub 0} = 1.6 GeV) and the experimental setups of the A1 and A2 collaborations for electro- and photoproduction reactions is given. Several experimental results and their interpretations for baryon spectroscopy are discussed. The topics presented here are the beam-helicity asymmetry I{center_dot} for {pi}{pi} photoproduction in the second resonance region, the photoproduction of {pi}{sup 0{eta}} up to beam energies of {omega} = 1.4 GeV as a way to study the {Delta}(1700)D{sub 33} baryon, and polarisation observables in h electro- and photoproduction in order to investigate an unexpected s-d-wave phase shift and its possible implications for the nature of the S{sub 11}(1535) resonance.

  2. Development of the charge exchange recombination spectroscopy and the beam emission spectroscopy on the EAST tokamak

    SciTech Connect (OSTI)

    Li, Y. Y.; Fu, J.; Lyu, B., E-mail: blu@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Du, X. W.; Li, C. Y.; Yu, Y.; Wang, Q. P. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Y.; Yin, X. H.; Ye, M. Y.; Wan, B. N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hellermann, M. von [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM, Trilateral Euregio Cluster, 3430BE Nieuwegein (Netherlands); Shi, Y. J. [School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026 (China); WCI for Fusion Theory, National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon 305-333 (Korea, Republic of)

    2014-11-15T23:59:59.000Z

    Charge eXchange Recombination Spectroscopy (CXRS) and Beam Emission Spectroscopy (BES) diagnostics based on a heating neutral beam have recently been installed on EAST to provide local measurements of ion temperature, velocity, and density. The system design features common light collection optics for CXRS and BES, background channels for the toroidal views, multi-chord viewing sightlines, and high throughput lens-based spectrometers with good signal to noise ratio for high time resolution measurements. Additionally, two spectrometers each has a tunable grating to observe any wavelength of interest are used for the CXRS and one utilizes a fixed-wavelength grating to achieve higher diffraction efficiency for the BES system. A real-time wavelength correction is implemented to achieve a high-accuracy wavelength calibration. Alignment and calibration are performed. Initial performance test results are presented.

  3. Coherent States of Accelerated Relativistic Quantum Particles, Vacuum Radiation and the Spontaneous Breakdown of the Conformal SU(2,2) Symmetry

    E-Print Network [OSTI]

    M. Calixto; E. Perez-Romero; V. Aldaya

    2010-12-21T23:59:59.000Z

    We give a quantum mechanical description of accelerated relativistic particles in the framework of Coherent States (CS) of the (3+1)-dimensional conformal group SU(2,2), with the role of accelerations played by special conformal transformations and with the role of (proper) time translations played by dilations. The accelerated ground state $\\tilde\\phi_0$ of first quantization is a CS of the conformal group. We compute the distribution function giving the occupation number of each energy level in $\\tilde\\phi_0$ and, with it, the partition function Z, mean energy E and entropy S, which resemble that of an "Einstein Solid". An effective temperature T can be assigned to this "accelerated ensemble" through the thermodynamic expression dE/dS, which leads to a (non linear) relation between acceleration and temperature different from Unruh's (linear) formula. Then we construct the corresponding conformal-SU(2,2)-invariant second quantized theory and its spontaneous breakdown when selecting Poincar\\'e-invariant degenerated \\theta-vacua (namely, coherent states of conformal zero modes). Special conformal transformations (accelerations) destabilize the Poincar\\'e vacuum and make it to radiate.

  4. The Gender Breakdown of the Applicant Pool for Tenure-Track Faculty Positions at a Sample of North American Research Astronomy Programs

    E-Print Network [OSTI]

    Thompson, Todd A

    2015-01-01T23:59:59.000Z

    The demographics of the field of Astronomy, and the gender balance in particular, is an important active area of investigation. A piece of information missing from the discussion is the gender breakdown of the applicant pool for faculty positions. For a sample of 35 tenure-track faculty positions at 25 research universities advertised over the last few years in astronomy and astrophysics, I find that the ratio of female applicants to the total number of applicants is ~0.2, with little dispersion and with no strong dependence on the total number of applicants. Some discussion is provided in the context of the fraction of women at the graduate student, postdoctoral researcher, and assistant professor levels, but strong conclusions are not possible given the limitations of the study. Current and future faculty search committees will likely be interested to compare their numbers to this distribution to decide whether or not they could be doing more to attract an applicant pool that is representative of the commun...

  5. On the global uniqueness for the Einstein-Maxwell-scalar field system with a cosmological constant. Part 1: Well posedness and breakdown criterion

    E-Print Network [OSTI]

    Joo L. Costa; Pedro M. Giro; Jos Natrio; Jorge Drumond Silva

    2014-10-23T23:59:59.000Z

    This paper is the first part of a trilogy dedicated to the following problem: given spherically symmetric characteristic initial data for the Einstein-Maxwell-scalar field system with a cosmological constant $\\Lambda$, with the data on the outgoing initial null hypersurface given by a subextremal Reissner-Nordstrom black hole event horizon, study the future extendibility of the corresponding maximal globally hyperbolic development (MGHD) as a "suitably regular" Lorentzian manifold. In this first part we establish well posedness of the Einstein equations for characteristic data satisfying the minimal regularity conditions leading to classical solutions. We also identify the appropriate notion of maximal solution, from which the construction of the corresponding MGHD follows, and determine breakdown criteria. This is the unavoidable starting point of the analysis; our main results will depend on the detailed understanding of these fundamentals. In the second part of this series we study the stability of the radius function at the Cauchy horizon. In the third and final paper we show that, depending on the decay rate of the initial data, mass inflation may or may not occur; in fact, it is even possible to have (non-isometric) extensions of the spacetime across the Cauchy horizon as classical solutions of the Einstein equations.

  6. Inner surface flash-over of insulator of low-inductance high-voltage self-breakdown gas switch and its application

    SciTech Connect (OSTI)

    Zhang, Hong-bo, E-mail: walkman67@163.com; Liu, Jin-liang [College of Opto-electronic Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)] [College of Opto-electronic Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)

    2014-04-15T23:59:59.000Z

    In this paper, the inner surface flash-over of high-voltage self-breakdown switch, which is used as a main switch of pulse modulator, is analyzed in theory by employing the method of distributed element equivalent circuit. Moreover, the field distortion of the switch is simulated by using software. The results of theoretical analysis and simulation by software show that the inner surface flash-over usually starts at the junction points among the stainless steel, insulator, and insulation gas in the switch. A switch with improved structure is designed and fabricated according to the theoretical analysis and simulation results. Several methods to avoid inner surface flash-over are used to improve the structure of switch. In experiment, the inductance of the switch is no more than 100 nH, the working voltage of the switch is about 600 kV, and the output voltage and current of the accelerator is about 500 kV and 50 kA, respectively. And the zero-to-peak rise time of output voltage at matched load is less than 30 ns due to the small inductance of switch. The original switch was broken-down after dozens of experiments, and the improved switch has been worked more than 200 times stably.

  7. images/logoetsf Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes and Graphene Perspectives

    E-Print Network [OSTI]

    Botti, Silvana

    images/logoetsf Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes and Graphene excitations Francesco Sottile #12;Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes excitations Francesco Sottile #12;Introduction Electron Energy Loss Spectroscopy Applications: Nanotubes

  8. Harmonic wavelet analysis of modulated tunable diode laser absorption spectroscopy signals

    E-Print Network [OSTI]

    Cheng, Harry H.

    of the direct absorption characteristics of atomic or molecular absorption lines. This is accomplishedHarmonic wavelet analysis of modulated tunable diode laser absorption spectroscopy signals Hong analyses of tunable diode laser absorption spectroscopy signals were performed. The absorption spectroscopy

  9. Spectroscopic investigations of intersystem crossing and triplet state structure in acetylene

    E-Print Network [OSTI]

    Thom, Ryan L. (Ryan Louis), 1978-

    2006-01-01T23:59:59.000Z

    A multispectral study employing both Ultraviolet Laser Induced Fluorescence (UV-LIF) and Surface Electron Ejection by Laser Excited Metastables (SEELEM) spectroscopies has yielded a complete characterization of singlet-triplet ...

  10. Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum cascade laser

    E-Print Network [OSTI]

    Faraday rotation spectroscopy of nitrogen dioxide based on a widely tunable external cavity quantum: Faraday Rotation Spectroscopy, external-cavity quantum cascade laser, nitrogen dioxide, trace

  11. Spectroscopy of Photovoltaic Materials: Charge-Transfer Complexes and Titanium Dioxide

    E-Print Network [OSTI]

    Dillon, Robert

    2013-01-01T23:59:59.000Z

    RIVERSIDE Spectroscopy of Photovoltaic Materials: Charge-DISSERTATION Spectroscopy of Photovoltaic Materials: Charge-function of photovoltaic (PV) and photocatalytic (PC)

  12. E-Print Network 3.0 - applications spectroscopie du Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    DivisionOptical Spectroscopy DivisionOptical Spectroscopy ... Source: McCombe, Bruce D. - Department of Physics, State University of New York at Buffalo Collection:...

  13. Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Soft X-Ray Microscopy and Spectroscopy at the Molecular Environmental Science Beamline at the Advanced Light Source. Soft X-Ray Microscopy and Spectroscopy at the Molecular...

  14. E-Print Network 3.0 - absorption spectroscopy techniques Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    A partial sampling of these techniques includes: Absorption spectroscopy Atomic absorption... 109 3.4 Spectroscopic Sensors Spectroscopy is the scientific study of...

  15. E-Print Network 3.0 - atomic spectroscopy programacion Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Name Summary: of an unknown metal ion in a biomolecule Atomic absorption spectroscopy or ICP spectroscopy (b) the presence... coordinated to...

  16. E-Print Network 3.0 - atomic spectroscopy sympsoium Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Name Summary: of an unknown metal ion in a biomolecule Atomic absorption spectroscopy or ICP spectroscopy (b) the presence... coordinated to...

  17. INFRARED ABSORPTION SPECTROSCOPY OF CARBON MONOXIDE ON NICKEL FILMS: A LOW TEMPERATURE THERMAL DETECTION TECHNIQUE

    E-Print Network [OSTI]

    Bailey, Robert Brian

    2011-01-01T23:59:59.000Z

    A. B. Optical System Absorption Signal C. Small SignalNoise . Sensitivity of Absorption Spectroscopy EXPERIMENTSINFRARED ABSORPTION SPECTROSCOPY OF CARBON MONOXIDE ON

  18. E-Print Network 3.0 - absorption spectroscopy diagnostics Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Domain Spectroscopy From... Industrial applications: spectroscopy, imaging and security Terahertz: Research and Applications 12... in a volume Measuring of moisture in a volume...

  19. E-Print Network 3.0 - astronomical infrared spectroscopy Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectroscopy. Projects: Principal Investigator, NSF ATI grant for development... of near infrared laser frequency comb for precision NIR spectroscopy and RV planet finding...

  20. E-Print Network 3.0 - anharmonic vibrational spectroscopy Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectroscopy Page: << < 1 2 3 4 5 > >> 1 Chem 791 Molecular Spectroscopy Spring 2008 Chemistry 791 Summary: branches. - Anharmonicity: electrical; mechanical. Violation of v 1...

  1. Validating the Melusine Gamma Spectroscopy Tool

    SciTech Connect (OSTI)

    Erikson, Luke E.; Keillor, Martin E.; Stavenger, Timothy J.

    2013-11-26T23:59:59.000Z

    This technical report describes testing to evaluate the gamma spectroscopy tool, Melusine, under development by Pacific Northwest National Laboratory. The goal was to verify that the software can successfully be used to provide accurate results and statistical uncertainties for the detection of isotopes of interest and their activities. Of special interest were spectra similar to those produced by radionuclide stations that contribute to the Comprehensive Nuclear Test Ban Treaty Organizations International Monitoring System. Two data sets were used to test Melusines capabilities. The first was the result of a multi-lab calibration effort based on neutron activations produced at the University of California at Davis. The second was taken from the Proficiency Test Exercises conducted by the CTBTO directly in 2005. In 37 of 42 cases, Melusine produced results in agreement with the best answer presently available, in most cases with calculated uncertainties comparable to or better than competing analyses. In fact, Melusine technically provided one more result than CTBTOs PTE analyses that agreed with the book answer (Monte Carlo simulation). Despite these promising results, the Melusine software is still under development. Effort is especially needed to simplify its analysis process, improve stability, and provide user documentation. Some significant analysis tasks require further vetting, such as those to address summing effects. However, our test results indicate that Melusines calculations as presently implemented are sound and can be used to reliably analyze spectra from the CTBTOs radionuclide stations.

  2. NAIS: Nuclear activation-based imaging spectroscopy

    SciTech Connect (OSTI)

    Gnther, M. M.; Britz, A.; Harres, K.; Hoffmeister, G.; Nrnberg, F.; Otten, A.; Pelka, A.; Roth, M. [Institut fr Kernphysik, Schlossgartenstr. 9, Technische Universitt Darmstadt, D-64289 Darmstadt (Germany)] [Institut fr Kernphysik, Schlossgartenstr. 9, Technische Universitt Darmstadt, D-64289 Darmstadt (Germany); Clarke, R. J. [Central Laser Facility, Rutherford Appelton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom)] [Central Laser Facility, Rutherford Appelton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Vogt, K. [GSI Helmholtzzentrum fr Schwerionenforschung GmbH, D-64291 Darmstadt (Germany)] [GSI Helmholtzzentrum fr Schwerionenforschung GmbH, D-64291 Darmstadt (Germany)

    2013-07-15T23:59:59.000Z

    In recent years, the development of high power laser systems led to focussed intensities of more than 10{sup 22} W/cm{sup 2} at high pulse energies. Furthermore, both, the advanced high power lasers and the development of sophisticated laser particle acceleration mechanisms facilitate the generation of high energetic particle beams at high fluxes. The challenge of imaging detector systems is to acquire the properties of the high flux beam spatially and spectrally resolved. The limitations of most detector systems are saturation effects. These conventional detectors are based on scintillators, semiconductors, or radiation sensitive films. We present a nuclear activation-based imaging spectroscopy method, which is called NAIS, for the characterization of laser accelerated proton beams. The offline detector system is a combination of stacked metal foils and imaging plates (IP). After the irradiation of the stacked foils they become activated by nuclear reactions, emitting gamma decay radiation. In the next step, an autoradiography of the activated foils using IPs and an analysis routine lead to a spectrally and spatially resolved beam profile. In addition, we present an absolute calibration method for IPs.

  3. Investigation of Zeolite Nucleation and Growth Using NMR Spectroscopy

    E-Print Network [OSTI]

    Rivas Cardona, Alejandra

    2012-02-14T23:59:59.000Z

    and control of the zeolite properties. The primary objective of this dissertation is to determine the strength of organicinorganic interactions (i.e., the adsorption Gibbs energy) in transparent synthesis mixtures using PFG NMR spectroscopy, in order...

  4. Testing Spin-Statistics Connection by Highly Sensitive Spectroscopy

    E-Print Network [OSTI]

    Shy,Jow-Tsong

    Testing Spin-Statistics Connection by Highly Sensitive Spectroscopy of CO2 Y.-H. Lien ,Y.-L. Hsu ,Y #12;Experimental Scheme Searching for the very weak or even nonexistent J=(2n+1) transitions 2 µm 0000

  5. Hyperfine Studies of Lithium Vapor using Saturated Absorption Spectroscopy

    E-Print Network [OSTI]

    Cronin, Alex D.

    the frequency of a laser with respect to an atomic spectral feature.[20] As such, saturated absorptionHyperfine Studies of Lithium Vapor using Saturated Absorption Spectroscopy? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.3 Broadening Mechanisms . . . . . . . . . . . . . . . . . . . . . 15 3.4 Saturated Absorption

  6. Detection of Physiologically Relevant Alcohol Concentrations Using Raman Spectroscopy

    E-Print Network [OSTI]

    McKay, Joshua L.

    2006-08-16T23:59:59.000Z

    This is the first step in a series of studies to test the feasibility of using Raman Spectroscopy (RS) to non-invasively detect physiologically relevant blood alcohol concentrations. Blood tests, urine tests, and the breathalyzer are currently...

  7. angled-resolved photoelectron spectroscopy: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

  8. angle-resolved photoelectron spectroscopies: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

  9. angle-resolved photoelectron spectroscopy: Topics by E-print...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    profile and nitrogen chemical bonding states,6-9,11,13,17,18 secondary ion mass spectrometry SIMS ,14 Auger electron spectroscopy,19,20 nuclear reaction analysis NRA ,21 medium...

  10. Surface enhanced Raman spectroscopy on a flat graphene surface

    E-Print Network [OSTI]

    Xu, Weigao

    Surface enhanced Raman spectroscopy (SERS) is an attractive analytical technique, which enables single-molecule sensitive detection and provides its special chemical fingerprints. During the past decades, researchers have ...

  11. Early diagnosis of cancer using light scattering spectroscopy

    E-Print Network [OSTI]

    Backman, Vadim, 1973-

    2001-01-01T23:59:59.000Z

    This thesis presents a novel optical technique, light scattering spectroscopy (LSS), developed for quantitative characterization of tissue morphology as well as in vivo detection and diagnosis of the diseases associated ...

  12. Thermal unfolding dynamics of proteins probed by nonlinear infrared spectroscopy

    E-Print Network [OSTI]

    Chung, Hoi Sung

    2007-01-01T23:59:59.000Z

    This thesis presents spectroscopic approaches to study the thermal unfolding dynamics of proteins. The spectroscopic tool is nonlinear infrared (IR) spectroscopy of the protein amide I band. Among various nonlinear IR ...

  13. Quantitative biological Raman spectroscopy for non-invasive blood analysis

    E-Print Network [OSTI]

    Shih, Wei-Chuan

    2007-01-01T23:59:59.000Z

    The long term goal of this project is the measurement of clinically-relevant analytes in the blood tissue matrix of human subjects using near-infrared Raman spectroscopy, with the shorter term research directed towards ...

  14. Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dirac Charge Dynamcs in Graphene by Infrared Spectroscopy Print Graphene-a single layer of carbon atoms arranged in a honeycomb lattice-has very high conductivity that can be tuned...

  15. Photoinduced phase transitions studied by femtosecond single-shot spectroscopy

    E-Print Network [OSTI]

    Shin, Taeho

    2010-01-01T23:59:59.000Z

    Single-shot femtosecond spectroscopy has been developed and employed for the study of phase transitions of solid-state materials. Using two crossed echelons, a two dimensional spatial delay gradient was generated across a ...

  16. absorption spectroscopy study: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 On Automatic Absorption Detection for Imaging Spectroscopy: A Comparative Study Computer Technologies and...

  17. Photoelectron Spectroscopy of Doubly and Singly Charged Group...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Doubly and Singly Charged Group VIB Dimetalate Anions: M2O72-, MM'072-, and M207- (M, M'Cr, Mo, W Photoelectron Spectroscopy of Doubly and Singly Charged Group VIB Dimetalate...

  18. Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Free Multiply Charged Keggin Anions ?-PM12O403- (M Mo, W) in the Gas Phase. Photoelectron Spectroscopy of Free Multiply Charged Keggin Anions ?-PM12O403- (M Mo,...

  19. CODED SPECTROSCOPY FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA

    E-Print Network [OSTI]

    ABSTRACT CODED SPECTROSCOPY FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA by Scott Thomas Mc FOR ETHANOL DETECTION IN DIFFUSE, FLUORESCENT MEDIA by Scott Thomas McCain Department of Electrical

  20. Femtosecond time-resolved spectroscopy of coherent oscillations in nanomaterials

    E-Print Network [OSTI]

    Jerebtsov, Serguei Nikolaevich

    2009-05-15T23:59:59.000Z

    FEMTOSECOND TIME-RESOLVED SPECTROSCOPY OF COHERENT OSCILLATIONS IN NANOMATERIALS A Dissertation by SERGUEI JEREBTSOV Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY May 2007 Major Subject: Physics FEMTOSECOND TIME-RESOLVED SPECTROSCOPY OF COHERENT OSCILLATIONS IN NANOMATERIALS A Dissertation by SERGUEI JEREBTSOV Submitted to the Office of Graduate Studies of Texas A&M University in partial...

  1. Optical-acoustic effect in laser optics investigations N. E. Aver'anov (1), Yu. A. Baloshin (1), K. F. Bukhanov (1), I. V. Pavlishin (1),

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -induced damage such as evaporation of heat insulated defects, melting and optical breakdown off irradiated to laser induced damage greatly depends on an ability to absorb the laser radiation because at intense of an optical material, that is its damage. In laser optics, among well known methods of light absorption

  2. Chemical Shifts in X-ray and Photo-Electron Spectroscopy: A Historical review

    E-Print Network [OSTI]

    Lindgren, Ingvar

    Chemical Shifts in X-ray and Photo-Electron Spectroscopy: A Historical review Ingvar Lindgren 1 Introduction 2 2 Chemical shift in X-ray spectroscopy 2 2.1 Discovery of the chemical shift in X-ray spectroscopy . . . . . . . . . . . . . 3 2.2 Interpretation of the chemical shift in X-ray spectroscopy

  3. THE DEEP SWIRE FIELD. III. WIYN SPECTROSCOPY

    SciTech Connect (OSTI)

    Owen, Frazer N. [National Radio Astronomy Observatory , P.O. Box O, Socorro, NM 87801 (United States); Morrison, G. E. [Institute for Astronomy, University of Hawaii, Honolulu, 96822 (United States)], E-mail: fowen@nrao.edu

    2009-06-15T23:59:59.000Z

    We present the results of spectroscopy using HYDRA on the WIYN 3.5 m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24 {mu}m. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to active galactic nuclei and star formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z < 0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10{sup h}46{sup m}00{sup s}, 59{sup 0}01'00'' (J2000). Optical sources for spectroscopic observation were selected from an r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20 cm detections, 24 m detections, galaxies with r < 20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice, almost all the galaxies with r < 19 were observed including all of the radio sources and most of the 24 {mu}m sources with r < 20 and a sample of radio sources which had fainter optical counterparts on the r-band image.

  4. Magnetic spectroscopy and microscopy of functional materials

    SciTech Connect (OSTI)

    Jenkins, C.A.

    2011-01-28T23:59:59.000Z

    Heusler intermetallics Mn{sub 2}Y Ga and X{sub 2}MnGa (X; Y =Fe, Co, Ni) undergo tetragonal magnetostructural transitions that can result in half metallicity, magnetic shape memory, or the magnetocaloric effect. Understanding the magnetism and magnetic behavior in functional materials is often the most direct route to being able to optimize current materials for todays applications and to design novel ones for tomorrow. Synchrotron soft x-ray magnetic spectromicroscopy techniques are well suited to explore the the competing effects from the magnetization and the lattice parameters in these materials as they provide detailed element-, valence-, and site-specifc information on the coupling of crystallographic ordering and electronic structure as well as external parameters like temperature and pressure on the bonding and exchange. Fundamental work preparing the model systems of spintronic, multiferroic, and energy-related compositions is presented for context. The methodology of synchrotron spectroscopy is presented and applied to not only magnetic characterization but also of developing a systematic screening method for future examples of materials exhibiting any of the above effects. The chapter progression is as follows: an introduction to the concepts and materials under consideration (Chapter 1); an overview of sample preparation techniques and results, and the kinds of characterization methods employed (Chapter 2); spectro- and microscopic explorations of X{sub 2}MnGa/Ge (Chapter 3); spectroscopic investigations of the composition series Mn{sub 2}Y Ga to the logical Mn{sub 3}Ga endpoint (Chapter 4); and a summary and overview of upcoming work (Chapter 5). Appendices include the results of a Think Tank for the Graduate School of Excellence MAINZ (Appendix A) and details of an imaging project now in progress on magnetic reversal and domain wall observation in the classical Heusler material Co{sub 2}FeSi (Appendix B).

  5. 2012 ELECTRONIC SPECTROSCOPY & DYNAMICS GORDON RESEARCH CONFERENCE, JULY 22-27, 2012

    SciTech Connect (OSTI)

    Kohler, Bern

    2012-07-27T23:59:59.000Z

    Topics covered in this GRC include high-resolution spectroscopy, coherent electronic energy transport in biology, excited state theory and dynamics, excitonics, electronic spectroscopy of cold and ultracold molecules, and the spectroscopy of nanostructures. Several sessions will highlight innovative techniques such as time-resolved x-ray spectroscopy, frequency combs, and liquid microjet photoelectron spectroscopy that have forged stimulating new connections between gas-phase and condensed-phase work.

  6. Ion dip spectroscopy of cold molecules and ions. Progress report

    SciTech Connect (OSTI)

    Wessel, J.E.

    1988-08-23T23:59:59.000Z

    During the past year, the main emphasis in this research program has been on multiphoton ionization spectroscopy of aromatic clusters. This is being pursued in addition to continuing work in areas of ion dip spectroscopy and ion fragmentation spectroscopy. The program has the overall objective of developing improved ultrasensitive molecular detection methods based on multiphoton laser spectroscopy. Photoionization techniques are employed due to their extreme sensitivity combined with mass selectivity. The combination of these two features has led to the current capability to study molecular clusters of specific sizes with high spectral resolution. Clusters are formed in abundance in a supersonic expansion, where they are excited and ionized by an ultraviolet laser beam. The studies reported here are principally based on simple resonant excitation of clusters, followed by one-photon ionization. For the naphthalene clusters, a single laser wavelength suffices for both excitation steps. Additional investigations have been carried out to measure excited state cluster ionization spectra and cluster ion fragmentation spectra. Results from these measurements are not yet sufficiently advanced to report in detail, however the preliminary data support the importance of recently proposed new fundamental ionization mechanisms in clusters. This brief report summarizes results described in more detail in the preprint titled: Resonant two-photon ionization spectroscopy of naphthalene clusters and the preprint titled: Resonance interactions in naphthalene clusters. It also briefly describes preliminary undisclosed results of current investigations.

  7. 2010 GRC VIBRATIONAL SPECTROSCOPY AUGUST 1 - AUGUST 6, 2010

    SciTech Connect (OSTI)

    Brooks Pate

    2010-08-06T23:59:59.000Z

    The Vibrational Spectroscopy conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear and multidimensional spectroscopies. The conference highlights the application of these techniques in chemistry, materials, biology, and medicine. The theory of molecular vibrational motion and its connection to spectroscopic signatures and chemical reaction dynamics is the third major theme of the meeting. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules and nanomaterials.

  8. Infrared absorption spectroscopy and chemical kinetics of free radicals

    SciTech Connect (OSTI)

    Curl, R.F.; Glass, G.P. [Rice Univ., Houston, TX (United States)

    1993-12-01T23:59:59.000Z

    This research is directed at the detection, monitoring, and study of chemical kinetic behavior by infrared absorption spectroscopy of small free radical species thought to be important intermediates in combustion. During the last year, infrared kinetic spectroscopy using excimer laser flash photolysis and color-center laser probing has been employed to study the high resolution spectrum of HCCN, the rate constant of the reaction between ethynyl (C{sub 2}H) radical and H{sub 2} in the temperature region between 295 and 875 K, and the recombination rate of propargyl (CH{sub 2}CCH) at room temperature.

  9. Spectroscopy and Decay of $B$ Hadrons at the Tevatron

    SciTech Connect (OSTI)

    Paulini, Manfred

    2007-02-01T23:59:59.000Z

    The authors review recent results on heavy quark physics focusing on Run II measurements of B hadron spectroscopy and decay at the Tevatron. A wealth of new B physics measurements from CDF and D0 has been available. These include the spectroscopy of excited B states (B**, B**{sub s}) and the observation of the {Sigma}{sub b} baryon. The discussion of the decays of B hadrons and measurements of branching fractions focuses on charmless two-body decays of B {yields} h{sup +}h{sup -}. They report several new B{sub s}{sup 0} and {Lambda}{sub b}{sup 0} decay channels.

  10. Multiplexed absorption tomography with calibration-free wavelength modulation spectroscopy

    SciTech Connect (OSTI)

    Cai, Weiwei; Kaminski, Clemens F., E-mail: cfk23@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB2 3RA (United Kingdom)

    2014-04-14T23:59:59.000Z

    We propose a multiplexed absorption tomography technique, which uses calibration-free wavelength modulation spectroscopy with tunable semiconductor lasers for the simultaneous imaging of temperature and species concentration in harsh combustion environments. Compared with the commonly used direct absorption spectroscopy (DAS) counterpart, the present variant enjoys better signal-to-noise ratios and requires no baseline fitting, a particularly desirable feature for high-pressure applications, where adjacent absorption features overlap and interfere severely. We present proof-of-concept numerical demonstrations of the technique using realistic phantom models of harsh combustion environments and prove that the proposed techniques outperform currently available tomography techniques based on DAS.

  11. Development of Advanced Electrochemical Emission Spectroscopy for Monitoring Corrosion in Simulated DOE Liquid Waste

    SciTech Connect (OSTI)

    Digby D. Macdonald; Brian M. Marx; Sejin Ahn; Julio de Ruiz; Balaji Soundararaja; Morgan Smith; and Wendy Coulson

    2008-01-15T23:59:59.000Z

    Various forms of general and localized corrosion represent principal threats to the integrity of DOE liquid waste storage tanks. These tanks, which are of a single wall or double wall design, depending upon their age, are fabricated from welded carbon steel and contain a complex waste-form comprised of NaOH and NaNO{sub 3}, along with trace amounts of phosphate, sulfate, carbonate, and chloride. Because waste leakage can have a profound environmental impact, considerable interest exists in predicting the accumulation of corrosion damage, so as to more effectively schedule maintenance and repair. The different tasks that are being carried out under the current program are as follows: (1) Theoretical and experimental assessment of general corrosion of iron/steel in borate buffer solutions by using electrochemical impedance spectroscopy (EIS), ellipsometry and XPS techniques; (2) Development of a damage function analysis (DFA) which would help in predicting the accumulation of damage due to pitting corrosion in an environment prototypical of DOE liquid waste systems; (3) Experimental measurement of crack growth rate, acoustic emission signals and coupling currents for fracture in carbon and low alloy steels as functions of mechanical (stress intensity), chemical (conductivity), electrochemical (corrosion potential, ECP), and microstructural (grain size, precipitate size, etc) variables in a systematic manner, with particular attention being focused on the structure of the noise in the current and its correlation with the acoustic emissions; (4) Development of fracture mechanisms for carbon and low alloy steels that are consistent with the crack growth rate, coupling current data and acoustic emissions; (5) Inserting advanced crack growth rate models for SCC into existing deterministic codes for predicting the evolution of corrosion damage in DOE liquid waste storage tanks; (6) Computer simulation of the anodic and cathodic activity on the surface of the steel samples in order to exactly predict the corrosion mechanisms; (7) Wavelet analysis of EC noise data from steel samples undergoing corrosion in an environment similar to that of the high level waste storage containers, to extract data pertaining to general, pitting and stress corrosion processes, from the overall data. The Point Defect Model (PDM) is directly applied as the theoretical assessment method for describing the passive film formed on iron/steels. The PDM is used to describe general corrosion in the passive region of iron. In addition, previous work suggests that pit formation is due to the coalescence of cation vacancies at the metal/film interface which would make it possible to use the PDM parameters to predict the onset of pitting. This previous work suggests that once the critical vacancy density is reached, the film ruptures to form a pit. Based upon the kinetic parameters derived for the general corrosion case, two parameters relating to the cation vacancy formation and annihilation can be calculated. These two parameters can then be applied to predict the transition from general to pitting corrosion for iron/mild steels. If cation vacancy coalescence is shown to lead to pitting, it can have a profound effect on the direction of future studies involving the onset of pitting corrosion. The work has yielded a number of important findings, including an unequivocal demonstration of the role of chloride ion in passivity breakdown on nickel in terms of cation vacancy generation within the passive film, the first detection and characterization of individual micro fracture events in stress corrosion cracking, and the determination of kinetic parameters for the generation and annihilation of point defects in the passive film on iron. The existence of coupling between the internal crack environment and the external cathodic environment, as predicted by the coupled environment fracture model (CEFM), has also been indisputably established for the AISI 4340/NaOH system. It is evident from the studies that analysis of coupling current noise is a very sensitive tool f

  12. Nanoscience on the Timescale of Electrons Ultrafast Spectroscopy of Nanomaterials

    E-Print Network [OSTI]

    Kambhampati, Patanjali

    Nanoscience on the Timescale of Electrons Ultrafast Spectroscopy of Nanomaterials Pat Kambhampati with it??? ·How does it actually work??? #12;Nanoscience on the Ultrafast Timescale Pat Kambhampati, Mc? #12;Nanoscience on the Ultrafast Timescale Pat Kambhampati, McGill Chemistry Nanomaterial based

  13. Vibrational Raman Spectroscopy of High-temperature Superconductors

    E-Print Network [OSTI]

    Nabben, Reinhard

    Vibrational Raman Spectroscopy of High-temperature Superconductors C. Thomsen and G. Kaczmarczyk-temperature Superconductors C. Thomsen and G. Kaczmarczyk Technical University of Berlin, Berlin, Germany 1 INTRODUCTION Raman after the discovery of high- critical-temperature Tc superconductors:2 while reports on Raman scattering

  14. Charm and Charmonium Spectroscopy in BaBar

    SciTech Connect (OSTI)

    Negrini, M.; /Ferrara U.

    2008-02-06T23:59:59.000Z

    The BABAR experiment at the PEP-II B-factory offers excellent opportunities in charm and charmonium spectroscopy. The recent observation of new states in the D{sub s} and in the charmonium mass regions revived the interest in this field. Recent BABAR results are presented.

  15. Journal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220237

    E-Print Network [OSTI]

    Pilon, Laurent

    discontinuities associated with the propagation of a radiation front in transient radiation transport. r 2005 q heat flux s geometric path length S source term in the radiative transfer equation t time tc timeJournal of Quantitative Spectroscopy & Radiative Transfer 98 (2006) 220­237 Modified method

  16. Journal of Quantitative Spectroscopy & Radiative Transfer 91 (2005) 2746

    E-Print Network [OSTI]

    Dufresne, Jean-Louis

    used in the field of transport phenomena simulation, and more specifically in the field of radiative (application of the reciprocity principle to the integral form of the radiative transfer equation), and to netJournal of Quantitative Spectroscopy & Radiative Transfer 91 (2005) 27­46 A boundary-based net

  17. Instrumentation for Far-infrared Spectroscopy Peter R. Griffiths1

    E-Print Network [OSTI]

    Homes, Christopher C.

    at one end with an infrared transparent window (A) through which radiation reaches a thin absorbing film- and Far-Infrared Spectroscopy Window Incident radiation A B Absorbing film Pneumatic chamber Ballasting passes through the window onto a blackened film, causing the pressure of the gas in the pneumatic chamber

  18. Absorption spectroscopy of individual single-walled carbon nanotubes

    E-Print Network [OSTI]

    Boyer, Edmond

    Absorption spectroscopy of individual single-walled carbon nanotubes Stéphane Berciaud,a Laurent-walled carbon nanotubes (SWNTs) lead to heterogeneous samples containing mixtures of metallic and semiconducting species with a variety of lengths and defects. Optical detection at the single nanotube level should thus

  19. Carbon nanotubes adhesion and nanomechanical behavior from peeling force spectroscopy

    E-Print Network [OSTI]

    Boyer, Edmond

    Carbon nanotubes adhesion and nanomechanical behavior from peeling force spectroscopy Julien December 17, 2010 Abstract Applications based on Single Walled Carbon Nanotube (SWNT) are good example such as adhesion energy per unit length, curvature and bending rigidity of the nanotube. A complete picture

  20. Laser Locking with Doppler-free Saturated Absorption Spectroscopy

    E-Print Network [OSTI]

    Novikova, Irina

    there are many ways to stabilize the frequency of a laser, atomic absorption lines are particularly accurate are made, it becomes possible to resolve the saturated absorption lines that correspond to specific atomic absorption spectroscopy. This affects the number of atoms in the ground state and excited state

  1. Transient x-ray absorption spectroscopy of hydrated halogen atom

    E-Print Network [OSTI]

    Elles, Christopher G.; Shkrob, Ilya A.; Crowell, Robert A.; Arms, Dohn A.; Landahl, Eric C.

    2008-02-11T23:59:59.000Z

    Time-resolved x-ray absorption spectroscopy has been used to observe the transient species generated by one-photon detachment of an electron from aqueous bromide. The K-edge spectrum of the short-lived Br(0) atom exhibits a resonant 1s-4p transition...

  2. ENERGY LEVEL SPECTROSCOPY OF A BOUND VORTEX-ANTIVORTEX PAIR

    E-Print Network [OSTI]

    Wallraff, Andreas

    vortex- antivortex (VAV) state in an annular Josephson junction. The bound VAV pair is formed microwave spectroscopy. Keywords: Macroscopic quantum effects, long Josephson junctions, vortex­9]. Most of the studied systems, such as dc-biased Josephson junctions (JJ), supercon- ducting quantum

  3. Use of gamma spectroscopy for neutronic analysis of LMFBR Blankets

    E-Print Network [OSTI]

    Kang, Ch?ang-sun

    It was the purpose of the present investigation to extend and apply Ge(Li) gamma-ray spectroscopy to the study of fast reactor blankets. The focal point for this research was the Blanket Test Facility at the MITR and Blanket ...

  4. Application of nanoporous silicon substrates for terahertz spectroscopy

    E-Print Network [OSTI]

    Murphy, Thomas E.

    molecule," Spectrochim. Acta 61, 2741­2746 (2005). 4. M. Kutteruf, C. Brown, L. Iwaki, M. Campbell, T 1. M. van Exter, C. Fattinger, and D. Grischkowsky, "Terahertz time-domain spectroscopy of water acid molecule," J. Raman Spectrosc. 14, 347­352 (1983). 7. E. J. Heilweil and D. F. Plusquellic

  5. Proton Ordering of Cubic Ice Ic: Spectroscopy and Computer Simulations

    E-Print Network [OSTI]

    Dellago, Christoph

    by producing rotational Bjerrum L-defects.1 Ambient-pressure hexagonal ice, ice Ih, shows the lowest produced from ice Ih using hydroxide doping, for example, by freezing a 0.1 M KOH solution. Because ice IhProton Ordering of Cubic Ice Ic: Spectroscopy and Computer Simulations Philipp Geiger, Christoph

  6. Human brain cancer studied by resonance Raman spectroscopy

    E-Print Network [OSTI]

    Sun, Yi

    Human brain cancer studied by resonance Raman spectroscopy Yan Zhou Cheng-Hui Liu Yi Sun Yang Pu://biomedicaloptics.spiedigitallibrary.org/ on 11/16/2012 Terms of Use: http://spiedl.org/terms #12;Human brain cancer studied by resonance Raman of human brain tissues are examined using a confocal micro-Raman system with 532-nm excitation in vitro

  7. Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy

    E-Print Network [OSTI]

    Horn, Matthias

    Postdoc Position in Microfluidics and Single Cell Raman Spectroscopy Department of Microbial and Environmental Microfluidics Group (http://web.mit.edu/romanstocker) Department of Civil & Environmental (junior or senior) with strong expertise in microfluidics and an interest in applying it to microbial

  8. TIME-RESOLVED TERAHERTZ TRANSMISSION SPECTROSCOPY OF DIELECTRICS

    E-Print Network [OSTI]

    Ku?el, Petr

    semiconductor surfaces in bulk semiconductor wafers[5,6,7], etc. The detection techniques which are based in fact constitutes a bridge between the classical IR spectroscopy domain and the frequencies accessible polar excitations in optical materials like sapphire and quartz[15], in semiconductors (Ge, GaAs, Si

  9. Laser photothermal spectroscopy of light-induced absorption

    SciTech Connect (OSTI)

    Skvortsov, L A [Institute of Cryptography, Communications and Informatics, Moscow (Russian Federation)

    2013-01-31T23:59:59.000Z

    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)

  10. New Frontiers in Solar Physics: Broadband Imaging Spectroscopy with the

    E-Print Network [OSTI]

    , the solar panel of the AASC recommended an integrated suite of instrumentation designed to meetNew Frontiers in Solar Physics: Broadband Imaging Spectroscopy with the Frequency Agile Solar and other astrophysical objects and processes. Outstanding problems in solar physics include the magnetic

  11. Photoelectron spectroscopy of solvated electrons in alcohol and acetonitrile microjets

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Photoelectron spectroscopy of solvated electrons in alcohol and acetonitrile microjets Alexander T in methanol, ethanol, and acetonitrile microjets are reported. Solvated electrons are generated. Two features are observed in acetonitrile at 2.61 ? 0.11 eV and 3.67 ? 0.15 eV, attributed

  12. Skin cancer detection by oblique-incidence diffuse reflectance spectroscopy

    E-Print Network [OSTI]

    Smith, Elizabeth Brooks

    2009-05-15T23:59:59.000Z

    Skin cancer is the most common form of cancer and it is on the rise. If skin cancer is diagnosed early enough, the survival rate is close to 90%. Oblique-incidence diffuse reflectance (OIR) spectroscopy offers a technology that may be used...

  13. Laser and Spectroscopy Facility Center For Microanalysis of Materials

    E-Print Network [OSTI]

    Braun, Paul

    Laser and Spectroscopy Facility Center For Microanalysis of Materials Frederick Seitz Materials Research Laboratory Form revised 03 November 2009 Precautions for the safe use of lasers 1. NEVER LOOK DIRECTLY INTO ANY LASER BEAM, REGARDLESS OF POWER. 2. The lab door safety lamp "LASER in USE" must

  14. Time resolved ultraviolet absorption spectroscopy of pulsed fluorocarbon plasmas

    E-Print Network [OSTI]

    Gleason, Karen K.

    Time resolved ultraviolet absorption spectroscopy of pulsed fluorocarbon plasmas Brett A. Cruden.1063/1.1334936 I. INTRODUCTION The study of fluorocarbon plasmas is of great interest for their applications in silicon dioxide etching.1,2 Recently, at- tention has been paid to using fluorocarbon plasmas to pro- duce

  15. X-Ray Photoelectron Spectroscopy XPS Mark Engelhard

    E-Print Network [OSTI]

    X-Ray Photoelectron Spectroscopy XPS Mark Engelhard 1 #12;EMSL XPS Instrumentation 2 Physical Electronics Quantera XPS High Energy Resolution Focused X-ray Beam Capability Catalysis reaction and processing chamber with inert atmosphere glove box connected to a PHI Quantera Scanning X-ray Microprobe

  16. absorption spectroscopy xas: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    absorption spectroscopy xas First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Time Resolved X-Ray...

  17. absorption spectroscopy studies: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    absorption spectroscopy studies First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 On Automatic Absorption...

  18. Journal of Quantitative Spectroscopy & Radiative Transfer 99 (2006) 341348

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    structure on non-LTE, non-diffusive radiation transport and X-ray production is discussed. r 2005 Elsevier Ltd. All rights reserved. Keywords: Z-pinch plasma; K-shell X-ray production and spectroscopy; Opacity tungsten wires [2]. Strong j B forces implode the wire array, which generates nearly 2 MJ of X-rays in o

  19. E-Print Network 3.0 - auger spectroscopy studies Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectroscopy Analytical technique used in the study of surfaces... V and 15mA emission (3-5 times,20min interval) Flash heating the sample for 2 min. Auger Spectroscopy......

  20. Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye-Sensitized TiO2 Nanoparticles. Tip-Enhanced Near-Field Raman Spectroscopy Probing Single Dye-Sensitized TiO2...

  1. E-Print Network 3.0 - andreev reflection spectroscopy Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1 Andreev-level spectroscopy and Josephson-current switching in a three-terminal Josephson junction Summary: Andreev-level spectroscopy and Josephson-current switching in a...

  2. E-Print Network 3.0 - absorption spectroscopy Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    .619 nm Calculate the energy of the photon: h 1.633 aJ Absorption Spectroscopy In absorption... Atomic Spectroscopy Planck's constant: h 6.62608 10 34- joule sec: Speed of...

  3. E-Print Network 3.0 - atomic emission spectroscopy Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Spectroscopy of an Atomic Nucleus: The Thorium-229 Nuclear Clock Dr... spectroscopy of an atomic nucleus. Host: Mansoor Sheik-Bahae 12;... of 7.6 0.5 eV. This makes it...

  4. E-Print Network 3.0 - absorption spectroscopy q-xas Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    .619 nm Calculate the energy of the photon: h 1.633 aJ Absorption Spectroscopy In absorption... Atomic Spectroscopy Planck's constant: h 6.62608 10 34- joule sec: Speed of...

  5. USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE MEASUREMENT OF MERCURY IN OIL SHALE GASES

    E-Print Network [OSTI]

    Girvin, D.G.

    2011-01-01T23:59:59.000Z

    Isotope Zeeman Atomic Absorption; A new approach to chemical6782 Use of Zeeman Atomic Absorption Spectroscopy for theb:l r I USE OF ZEEMAN ATOMIC ABSORPTION SPECTROSCOPY FOR THE

  6. Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design

    E-Print Network [OSTI]

    , Gamma Spectrometry, uranium enrichment #12;PAPER Measurement of uranium enrichment by gamma spectroscopy: result of an experimental design Gamma spectroscopy is commonly used in nuclear safeguards to measure uranium enrichment. An experimental

  7. Thermal infrared emission spectroscopy of titanium-enriched V. E. Hamilton

    E-Print Network [OSTI]

    Hamilton, Victoria E.

    Thermal infrared emission spectroscopy of titanium-enriched pyroxenes V. E. Hamilton Hawai, Angra dos Reis, remote sensing Citation: Hamilton, V. E., Thermal infrared emission spectroscopy [Lyon, 1962], and emission [Hamilton, 1998, 2000] spectroscopic studies. These studies have documented

  8. E-Print Network 3.0 - angular correlation spectroscopy Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    80 Level-crossing spectroscopy of the 7, 9, and 10D states of Cs in an external electric field Summary: 's angular momentum. Keywords: Level-crossing spectroscopy, alignment...

  9. X-ray Absorption Spectroscopy Study of Prototype Chemical Systems: Theory vs. Experiment

    E-Print Network [OSTI]

    Schwartz, Craig Philip

    2010-01-01T23:59:59.000Z

    acids by Near Edge X-ray Absorption Fine Structure (NEXAFS)X-ray Absorption Spectroscopy Study of Prototype ChemicalGlaeser Spring 2010 X-ray Absorption Spectroscopy Study of

  10. X-ray absorption spectroscopy at the Ni-K edge in Stackhousia tryonii Bailey hyperaccumulator

    E-Print Network [OSTI]

    Kachenko, A.

    2009-01-01T23:59:59.000Z

    X-ray absorption spectroscopy at the NiK edge inin vivo by micro x-ray absorption spectroscopy (XAS) at theNiK edge. Both x-ray absorption near edge structure and

  11. Questioning the questions that have been asked about the infant brain using near-infrared spectroscopy

    E-Print Network [OSTI]

    Aslin, Richard N.

    Questioning the questions that have been asked about the infant brain using near-infrared, University of Rochester, Rochester, NY, USA Near-infrared spectroscopy (NIRS) is a noninvasive diffuse; Near-infrared spectroscopy. "Sheddinglight"onascientificquestiontookonnew meaning when

  12. Development of multimodal spectroscopy for the detection of vulnerable atherosclerotic plaques

    E-Print Network [OSTI]

    ?epanovi?, Obrad R., 1980-

    2008-01-01T23:59:59.000Z

    The combination of reflectance, fluorescence, and Raman spectroscopy - which is termed multimodal spectroscopy (MMS) - provides complementary and depth-sensitive information about tissue composition. As such, MMS can provide ...

  13. Development of High-Throughput Microfluidic Impedance Spectroscopy Platform for Analyzing Microdroplets in Droplet Microfluidic System

    E-Print Network [OSTI]

    Sobahi, Nebras MohammedKamal A.

    2014-07-22T23:59:59.000Z

    This thesis presents the development of a high-throughput microfluidic impedance spectroscopy platform for electrically detecting analyzing impedance measurements of non-contact and label free microdroplets. This microfluidic impedance spectroscopy...

  14. Protein Characterisation by Synchrotron Radiation Circular Dichroism (SRCD) Spectroscopy

    SciTech Connect (OSTI)

    Wallace, B.

    2009-01-01T23:59:59.000Z

    Circular dichroism (CD) spectroscopy is a well-established technique for the study of proteins. Synchrotron radiation circular dichroism (SRCD) spectroscopy extends the utility of conventional CD spectroscopy (i.e. using laboratory-based instruments) because the high light flux from a synchrotron enables collection of data to lower wavelengths, detection of spectra with higher signal-to-noise levels and measurements in the presence of strongly absorbing non-chiral components such as salts, buffers, lipids and detergents. This review describes developments in instrumentation, methodologies and bioinformatics that have enabled new applications of the SRCD technique for the study of proteins. It includes examples of the use of SRCD spectroscopy for providing static and dynamic structural information on molecules, including determinations of secondary structures of intact proteins and domains, assessment of protein stability, detection of conformational changes associated with ligand and drug binding, monitoring of environmental effects, examination of the processes of protein folding and membrane insertion, comparisons of mutant and modified proteins, identification of intermolecular interactions and complex formation, determination of the dispositions of proteins in membranes, identification of natively disordered proteins and their binding partners and examination of the carbohydrate components of glycoproteins. It also discusses how SRCD can be used in conjunction with macromolecular crystallography and other biophysical techniques to provide a more complete picture of protein structures and functions, including how proteins interact with other macromolecules and ligands. This review also includes a discussion of potential new applications in structural and functional genomics using SRCD spectroscopy and future instrumentation and bioinformatics developments that will enable such studies. Finally, the appendix describes a number of computational/bioinformatics resources for secondary structure analyses that take advantage of the improved data quality available from SRCD. In summary, this review discusses how SRCD can be used for a wide range of structural and functional studies of proteins.

  15. E-Print Network 3.0 - ablation mass spectroscopy Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    implants into rat livers after radiofrequency ablation were quantified by atomic absorption spectroscopy... Local carboplatin delivery and tissue distribution in...

  16. E-Print Network 3.0 - atomic fluorescence spectroscopy Sample...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    total reflectance... increasing. A partial sampling of these techniques includes: Absorption spectroscopy Atomic ... Source: Yucca Mountain Project, US EPA Collection:...

  17. Ion dip spectroscopy of cold molecules and ions. Progress report and renewal proposal

    SciTech Connect (OSTI)

    Wessel, J.

    1987-08-13T23:59:59.000Z

    A research program is underway with the objective of developing techniques of high resolution multiphoton spectroscopy for selective, ultrasensitive molecular detection. Methods under study include various forms of ion dip spectroscopy and new methods of ion fragmentation spectroscopy. The studies are providing a new understanding of the fundamental spectroscopy and photophysics of large molecular ions. Dimer and cluster ions of polynuclear aromatics and related species are also being investigated, with potential detection applications.

  18. Determination of Tellurium by Atomic-absorption Spectroscopy with Electrothermal Atomisation

    E-Print Network [OSTI]

    Canberra, University of

    305 Determination of Tellurium by Atomic-absorption Spectroscopy with Electrothermal Atomisation at sub-microgram levels by atomic-absorption spectroscopy ,,'ith electrothermal atomisation after the e generation -atomic-absorption spectroscopy. The prior con- version of tellurium into hydrogen telluride

  19. Infrared Spectroscopy of the Microhydrated Nitrate Ions NO3 Daniel J. Goebbert,,

    E-Print Network [OSTI]

    Neumark, Daniel M.

    Infrared Spectroscopy of the Microhydrated Nitrate Ions NO3 - (H2O)1-6 Daniel J. Goebbert ReceiVed: April 15, 2009 We present infrared photodissociation spectra of the microhydrated nitrate ions the infrared spectroscopy of NO3 - (H2O)n clusters, n ) 1-6. The gas-phase vibrational spectroscopy of NO3

  20. Coded Aperture Raman Spectroscopy for Quantitative Measurements of Ethanol in a Tissue Phantom

    E-Print Network [OSTI]

    Pitsianis, Nikos P.

    - mard transform spectroscopy'' (HTS).9 Initially, HTS systems were designed to use multiplexing tissue phantom. With 60 mW of excitation power at 808 nm, leave-one-out and blind cross spectroscopy; Multiplexing; Chemometrics. INTRODUCTION Raman spectroscopy is a powerful diagnostic tool