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Sample records for high-resolution cathodoluminescence spectroscopy

  1. High resolution cathodoluminescence spectroscopy of carbonate cementation in Khurmala Formation (Paleocene-L. Eocene) from Iraqi Kurdistan Region, Northern Iraq

    NASA Astrophysics Data System (ADS)

    Omer, Muhamed F.; Omer, Dilshad; Zebari, Bahroz Gh.

    2014-12-01

    A combination of high resolution cathodoluminsecnce-spectroscopy (HRS-CL) with spatial electron microprobe analysis and optical microscopy is used to determine paragenesis and history of cementation in the limestones and dolostones of Khurmala Formation which is exposed in many parts of Northern Iraq. Khurmala Formation was subjected to different diagenetic processes such as micritization, compaction, dissolution, neomorphism, pyritization and cementation that occurred during marine to shallow burial stages and culminated during intermediate to deep burial later stages. Five dolomite textures are recognized and classified according to crystal size distribution and crystal-boundary shape. Dolomitization is closely associated with the development of secondary porosity that pre-and postdates dissolution and corrosion; meanwhile such porosity was not noticed in the associated limestones. Microprobe analysis revealed three types of cement, calcite, dolomite and ankerite which range in their luminescence from dull to bright. Cathodoluminescence study indicated four main texture generations. These are (1) unzoned microdolomite of planar and subhedral shape, with syntaxial rim cement of echinoderm that show dull to red luminescence, (2) equant calcite cements filling interparticle pores which shows dull luminescence and weak zonal growth, (3.1) homogenous intrinsic blue stoichiometric calcite with dull luminescence and without activators, (3.2) coarse blocky calcite cement with strong oscillatory zoning and bright orange luminescence which postdates other calcite cements, (4) ankerite cement with red to orange, non-luminescence growth zonation which is the last formed cement.

  2. High Resolution Laboratory Spectroscopy

    NASA Astrophysics Data System (ADS)

    Brünken, S.; Schlemmer, S.

    2016-05-01

    In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA. Among these is the development of broadband techniques for the study of complex organic molecules, like fast scanning conventional absorption spectroscopy based on multiplier chains, chirped pulse instrumentation, or the use of synchrotron facilities. Of similar importance is the extension of the accessible frequency range to THz frequencies, where many light hydrides have their ground state rotational transitions. Another key experimental challenge is the production of sufficiently high number densities of refractory and transient species in the laboratory, where discharges have proven to be efficient sources that can also be coupled to molecular jets. For ionic molecular species sensitive action spectroscopic schemes have recently been developed to overcome some of the limitations of conventional absorption spectroscopy. Throughout this review examples demonstrating the strong interplay between laboratory and observational studies will be given.

  3. Development of high-resolution cathodoluminescence system for STEM and application to plasmonic nanostructures.

    PubMed

    Yamamoto, Naoki

    2016-08-01

    A high-resolution cathodoluminescence (CL) system for scanning transmission electron microscope (STEM) has been developed by employing a field emission gun and a spherical aberration corrector, which realizes a probe size of 1 nm even at an accelerating voltage of 80 kV and beam current of the order of 1 nA. Angle resolved measurement of light emission from a sample in the STEM is possible by combining a parabolic mirror and position-controlled pinhole. CL spectra are successively acquired by a highly sensitive charge-coupled device while scanning the incident electron beam or pinhole, which enables various detection modes, i.e. (i) angle resolved spectral pattern, (ii) beam scan spectral image and (iii) photon map. In order to calibrate the acquired spectrum, the correction function is created from the comparison between the observed and theoretical spectra of the transition radiation. Furthermore, the modification of polarization by the parabolic mirror is discussed. Some examples of the applications of the STEM-CL system to plasmonics are presented to demonstrate the unique measurement features of the CL system, i.e. (i) multipole modes in silver nanoparticles, (ii) surface plasmon polariton modes in a 2D plasmonic crystal and (iii) localized surface plasmon modes in a gold bow tie nano-antenna. PMID:27473259

  4. Star formation seen with high resolution spectroscopy.

    NASA Astrophysics Data System (ADS)

    Winnewisser, G.

    1990-03-01

    More than 90 anorganic and organic molecules have been detected by high resolution spectroscopy in interstellar molecular clouds or in the envelopes of stars. The detected wavelengths of the lines - predominantly located in the millimeter- and submillimeter wavelength region - unequivocally identify the molecules and give precise knowledge of the physical and chemical conditions of molecular clouds from which the radiation emanates. The line intensities and line profiles contain information about the densities, temperatures and dynamics prevailing in molecular clouds.

  5. Nanoscale optical tomography with cathodoluminescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Atre, Ashwin C.; Brenny, Benjamin J. M.; Coenen, Toon; García-Etxarri, Aitzol; Polman, Albert; Dionne, Jennifer A.

    2015-05-01

    Tomography has enabled the characterization of the Earth's interior, visualization of the inner workings of the human brain, and three-dimensional reconstruction of matter at the atomic scale. However, tomographic techniques that rely on optical excitation or detection are generally limited in their resolution by diffraction. Here, we introduce a tomographic technique—cathodoluminescence spectroscopic tomography—to probe optical properties in three dimensions with nanometre-scale spatial and spectral resolution. We first obtain two-dimensional cathodoluminescence maps of a three-dimensional nanostructure at various orientations. We then use the method of filtered back-projection to reconstruct the cathodoluminescence intensity at each wavelength. The resulting tomograms allow us to locate regions of efficient cathodoluminescence in three dimensions across visible and near-infrared wavelengths, with contributions from material luminescence and radiative decay of electromagnetic eigenmodes. The experimental signal can be further correlated with the radiative local density of optical states in particular regions of the reconstruction. We demonstrate how cathodoluminescence tomography can be used to achieve nanoscale three-dimensional visualization of light-matter interactions by reconstructing a three-dimensional metal-dielectric nanoresonator.

  6. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Benner, D. Chris; Venkataraman, Malathy Devi

    2000-01-01

    The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as carbon dioxide, water vapor, ozone, methane, and carbon monoxide, to name a few. Measurements were made using the NASA Langley Tunable Diode Laser Spectrometer System (TDL) and several Fourier Transform Spectrometer Systems (FTS) around the globe. The results from these studies made remarkable improvements in the line positions and intensities for several molecules, particularly ozone and carbon dioxide in the 2 to 17-micrometer spectral region. Measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced line shift coefficients for infrared transitions of ozone, methane, and water vapor were also performed. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon-and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields.

  7. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Venkataraman, Malathy Devi

    2003-01-01

    Spectroscopic parameters (such as line position, intensity, broadening and shifting coefficients and their temperature dependences, line mixing coefficients etc.) for various molecular species of atmospheric interest are determined. In order to achieve these results, infrared spectra of several molecular bands are obtained using high-resolution recording instruments such as tunable diode laser spectrometer and Fourier transform spectrometers. Using sophisticated analysis routines (Multispectrum nonlinear least squares technique) these high-resolution infrared spectra are processed to determine the various spectral line parameters that are cited above. Spectra were taken using the McMath-Pierce Fourier transform spectrometer (FTS) at the National Solar Observatory on Kitt Peak, Arizona as well as the Bruker FTS at the Pacific Northwest National Laboratory (PNNL) at Richland, Washington. Most of the spectra are acquired not only at room temperature, but also at several different cold temperatures. This procedure is necessary to study the variation of the spectral line parameters as a function of temperature in order to simulate the Earth's and other planetary atmospheric environments. Depending upon the strength or weakness of the various bands recorded and analyzed, the length(s) of the absorption cells in which the gas samples under study are kept varied from a few centimeters up to several meters and the sample temperatures varied from approximately +30 C to -63 C. Research on several infrared bands of various molecular species and their isotopomers are undertaken. Those studies are briefly described.

  8. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Benner, D. Chris; Venkataraman, Malathy Devi

    2000-01-01

    The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as carbon dioxide, water vapor, ozone, methane, and carbon monoxide, to name a few. Measurements were made using the NASA Langley Tunable Diode Laser Spectrometer System (TDL) and several Fourier Transform Spectrometer Systems (FTS) around the globe. The results from these studies made remarkable improvements in the line positions and intensities for several molecules, particularly ozone and carbon dioxide in the 2 to 17-micrometer spectral region. Measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced line shift coefficients for infrared transitions of ozone, methane, and water vapor were also performed. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon- and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields.

  9. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Venkataraman, Malathy Devi

    2006-01-01

    The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as H2O (water vapor), O3 (ozone), HCN (hydrogen cyanide), CH4 (methane), NO2 (nitrogen dioxide) and CO (carbon monoxide). The data required for the analyses were obtained from two different Fourier Transform Spectrometers (FTS); one of which is located at the National Solar Observatory (NSO) on Kitt Peak, Arizona and the other instrument is located at the Pacific Northwest National Laboratories (PNNL) at Richland, Washington. The data were analyzed using a modified multispectrum nonlinear least squares fitting algorithm developed by Dr. D. Chris Benner of the College of William and Mary. The results from these studies made significant improvements in the line positons and intensities for these molecules. The measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced shift coefficients for hundreds of infrared transitions of HCN, CO3 CH4 and H2O were also performed during this period. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research Satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon- and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields. The research conducted during the period 2003-2006 has resulted in publications given in this paper. In addition to Journal publications, several oral and poster presentations were given at various Scientific conferences within the United States

  10. Applications of high resolution inverse Raman spectroscopy

    SciTech Connect

    Owyoung, A.; Esherick, P.

    1980-01-01

    The use of high-power, narrow-band lasers has significantly improved the resolving power and sensitivity of inverse Raman spectroscopy of gases. In this paper we shall describe this technique, illustrate its capabilities by showing some Q-branch spectra of heavy spherical tops, and survey some possible future applications.

  11. High-resolution flurescence spectroscopy in immunoanalysis

    SciTech Connect

    Grubor, Nenad M.

    2005-05-01

    The work presented in this dissertation combines highly sensitive and selective fluorescence line-narrowing spectroscopy (FLNS) detection with various modes of immunoanalytical techniques. It has been shown that FLNS is capable of directly probing molecules immunocomplexed with antibodies, eliminating analytical ambiguities that may arise from interferences that accompany traditional immunochemical techniques. Moreover, the utilization of highly cross-reactive antibodies for highly specific analyte determination has been demonstrated. Finally, they demonstrate the first example of the spectral resolution of diastereomeric analytes based on their interaction with a cross-reactive antibody.

  12. High resolution X-ray spectroscopy using microcalorimeters

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.; Holt, S. S.; Madejski, G. M.; Moseley, S. H.; Schoelkopf, R. J.; Szymkowiak, A. E.

    1988-01-01

    The use of microcalorimeters for high-resolution, high quantum efficiency, nondispersive X-ray spectroscopy has been demonstrated over the past few years. In this paper, the principles of X-ray calorimetry are reviewed, and the results of ongoing X-ray tests using microcalorimetry are summarized. An approach to building an X-ray calorimeter spectrometer is discussed.

  13. An Introduction to High Resolution Coherent Multidimensional Spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, Peter C.; Wells, Thresa A.; House, Zuri R.; Strangfeld, Benjamin R.

    2013-06-01

    High resolution coherent multidimensional spectroscopy is a technique that can be used to analyze and assign peaks for molecules that have resisted spectral analysis. Molecules that yield heavily congested and seemingly patternless spectra using conventional methods can yield 2D spectra that have recognizable patterns. The off-diagonal region of the coherent 2D plot shows only cross-peaks that are related by rotational selection rules. The resulting patterns facilitate peak assignment if they are sufficiently resolved. For systems that are not well-resolved, coherent 3D spectra may be generated to further improve resolution and provide selectivity. This presentation will provide an introduction to high resolution coherent 2D and 3D spectroscopies.

  14. Single-sided sensor for high-resolution NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Perlo, J.; Casanova, F.; Blümich, B.

    2006-06-01

    The unavoidable spatial inhomogeneity of the static magnetic field generated by open sensors has precluded their use for high-resolution NMR spectroscopy. In fact, this application was deemed impossible because these field variations are usually orders of magnitude larger than those created by the microscopic structure of the molecules to be detected. Recently, chemical shift resolved NMR spectra were observed for the first time outside a portable single-sided magnet by implementing a method that exploits inhomogeneities in the rf field designed to reproduce variations of the static magnetic field [J. Perlo, V. Demas, F. Casanova, C.A. Meriles, J. Reimer, A. Pines, B. Blümich, High-resolution spectroscopy with a portable single-sided sensor, Science 308 (2005) 1279]. In this communication, we describe in detail the magnet system built from permanent magnets as well as the rf coil geometry used to compensate the static field variations.

  15. Adaptive optics high resolution spectroscopy: present status and future direction

    SciTech Connect

    Alcock, C; Angel, R; Ciarlo, D; Fugate, R O; Ge, J; Kuzmenko, P; Lloyd-Hart, M; Macintosh, B; Najita, J; Woolf, N

    1999-07-27

    High resolution spectroscopy experiments with visible adaptive optics (AO) telescopes at Starfire Optical Range and Mt. Wilson have demonstrated that spectral resolution can be routinely improved by a factor of - 10 over the seeing-limited case with no extra light losses at visible wavelengths. With large CCDs now available, a very wide wavelength range can be covered in a single exposure. In the near future, most large ground-based telescopes will be equipped with powerful A0 systems. Most of these systems are aimed primarily at diffraction-limited operation in the near IR. An exciting new opportunity will thus open up for high resolution IR spectroscopy. Immersion echelle gratings with much coarser grooves being developed by us at LLNL will play a critical role in achieving high spectral resolution with a compact and low cost IR cryogenically cooled spectrograph and simultaneous large wavelength coverage on relatively small IR detectors. We have constructed a new A0 optimized spectrograph at Steward Observatory to provide R = 200,000 in the optical, which is being commissioned at the Starfire Optical Range 3.5m telescope. We have completed the optical design of the LLNL IR Immersion Spectrograph (LISPEC) to take advantage of improved silicon etching technology. Key words: adaptive optics, spectroscopy, high resolution, immersion gratings

  16. High Resolution Coherent 3d Spectroscopy of Bromine

    NASA Astrophysics Data System (ADS)

    Strangfeld, Benjamin R.; Wells, Thresa A.; House, Zuri R.; Chen, Peter C.

    2013-06-01

    The high resolution gas phase electronic spectrum of bromine is rather congested due to many overlapping vibrational and rotational transitions with similar transition frequencies, and also due to isotopomeric effects. Expansion into the second dimension will remove some of this congestion; however through the implementation of High Resolution Coherent 3D Spectroscopy, the density of peaks is further reduced by at least two orders of magnitude. This allows for the selective examination of a small number of spatially resolved multidimensional bands, separated by vibrational quantum number and by isotopomer, which facilitates the fitting of many rovibrational peaks in bromine. The ability to derive information about the molecular constants for the electronic states involved will be discussed.

  17. High resolution coherent three dimensional spectroscopy of NO2.

    PubMed

    Wells, Thresa A; Muthike, Angelar K; Robinson, Jessica E; Chen, Peter C

    2015-06-01

    Expansion from coherent 2D spectroscopy to coherent 3D spectroscopy can provide significant advantages when studying molecules that have heavily perturbed energy levels. This paper illustrates such advantages by demonstrating how high resolution coherent 3D (HRC3D) spectroscopy can be used to study a portion of the visible spectrum of nitrogen dioxide. High resolution coherent 2D spectra usually contain rotational and vibrational patterns that are easy to analyze, but severe congestion and complexity preclude its effective use for many parts of the NO2 spectrum. HRC3D spectroscopy appears to be much more effective; multidimensional rotational and vibrational patterns produced by this new technique are easy to identify even in the presence of strong perturbations. A method for assigning peaks, which is based upon analyzing the resulting multidimensional patterns, has been developed. The higher level of multidimensionality is useful for reducing uncertainty in peak assignments, improving spectral resolution, providing simultaneous information on multiple levels and states, and predicting, verifying, and categorizing peaks. PMID:26049446

  18. A high-resolution Fourier Transform Spectrometer for planetary spectroscopy

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Sinton, W. M.

    1973-01-01

    The employment of a high-resolution Fourier Transform Spectrometer (FTS) is described for planetary and other astronomical spectroscopy in conjunction with the 88-inch telescope at Mauna Kea Observatory. The FTS system is designed for a broad range of uses, including double-beam laboratory spectroscopy, infrared gas chromatography, and nuclear magnetic resonance spectroscopy. The data system is well-suited to astronomical applications because of its great speed in acquiring and transforming data, and because of the enormous storage capability of the magnetic tape unit supplied with the system. The basic instrument is outlined 2nd some of the initial results from the first attempted use on the Mauna Kea 88-inch telescope are reported.

  19. High-Resolution Infrared Spectroscopy with Synchrotron Sources

    SciTech Connect

    McKellar, A.

    2010-01-01

    Most applications of synchrotron radiation lie in the ultraviolet and X-ray region, but it also serves as a valuable continuum source of infrared (IR) light which is much brighter (i.e. more highly directional) than that from normal thermal sources. The synchrotron brightness advantage was originally exploited for high spatial resolution spectroscopy of condensed-phase samples. But it is also valuable for high spectral resolution of gas-phase samples, particularly in the difficult far-IR (terahertz) range (1/{lambda} {approx} 10-1000 cm{sup -1}). Essentially, the synchrotron replaces the usual thermal source in a Fourier transform IR spectrometer, giving a increase of up to two (or even more) orders of magnitude in signal at very high-resolution. Following up on pioneering work in Sweden (MAX-lab) and France (LURE), a number of new facilities have recently been constructed for high-resolution gas-phase IR spectroscopy. In the present paper, this new field is reviewed. The advantages and difficulties associated with synchrotron IR spectroscopy are outlined, current and new facilities are described, and past, present, and future spectroscopic results are summarized.

  20. High resolution ultrasonic spectroscopy system for nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Chen, C. H.

    1991-01-01

    With increased demand for high resolution ultrasonic evaluation, computer based systems or work stations become essential. The ultrasonic spectroscopy method of nondestructive evaluation (NDE) was used to develop a high resolution ultrasonic inspection system supported by modern signal processing, pattern recognition, and neural network technologies. The basic system which was completed consists of a 386/20 MHz PC (IBM AT compatible), a pulser/receiver, a digital oscilloscope with serial and parallel communications to the computer, an immersion tank with motor control of X-Y axis movement, and the supporting software package, IUNDE, for interactive ultrasonic evaluation. Although the hardware components are commercially available, the software development is entirely original. By integrating signal processing, pattern recognition, maximum entropy spectral analysis, and artificial neural network functions into the system, many NDE tasks can be performed. The high resolution graphics capability provides visualization of complex NDE problems. The phase 3 efforts involve intensive marketing of the software package and collaborative work with industrial sectors.

  1. High resolution X-ray spectroscopy of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Krolik, Julian H.

    1990-01-01

    After a brief review of the principal problems of AGN research, selected potential high-resolution observations are discussed with a view toward assessing their scientific value and the degree of resolution they will require. Two classes of observations pertaining directly to AGNs are discussed. Fe K-alpha spectroscopy relevant to the dynamical and thermal character of the emission line zones; and measurement of resonance line absorption by highly-ionized species in BL Lac objects, which should provide information about entrainment of interstellar material by relativistic jets. A third class of potentially important observations uses AGNs as background light sources in order to directly measure the distance to clusters of galaxies.

  2. Techniques in molecular spectroscopy: from broad bandwidth to high resolution

    NASA Astrophysics Data System (ADS)

    Cossel, Kevin C.

    This thesis presents a range of different experiments all seeking to extended the capabilities of molecular spectroscopy and enable new applications. The new technique of cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) provides a unique combination of broad bandwidth, high resolution, and high sensitivity that can be useful for a wide range of applications. Previous demonstrations of CE-DFCS were confined to the visible or near-infrared and operated over a limited bandwidth: for many applications it is desirable to increase the spectral coverage and to extend to the mid-infrared where strong, fundamental vibrational modes of molecules occur. There are several key requirements for CE-DFCS: a frequency comb source that provides broad bandwidth and high resolution, an optical cavity for high sensitivity, and a detection system capable of multiplex detection of the comb spectrum transmitted through the cavity. We first discuss comb sources with emphasis on the coherence properties of spectral broadening in nonlinear fiber and the development of a high-power frequency comb source in the mid-infrared based on an optical-parametric oscillator (OPO). To take advantage of this new mid-infrared comb source for spectroscopy, we also discuss the development of a rapid-scan Fourier-transform spectrometer (FTS). We then discuss the first demonstration of CE-DFCS with spectrally broadened light from a highly nonlinear fiber with the application to measurements of impurities in semiconductor manufacturing gases. We also cover our efforts towards extending CE-DFCS to the mid-infrared using the mid-infrared OPO and FTS to measure ppb levels of various gases important for breath analysis and atmospheric chemistry and highlight some future applications of this system. In addition to the study of neutral molecules, broad-bandwidth and high-resolution spectra of molecular ions are useful for astrochemistry where many of the observed molecules are ionic, for studying

  3. Metallicity determination of M dwarfs. High-resolution infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Lindgren, Sara; Heiter, Ulrike; Seifahrt, Andreas

    2016-02-01

    Context. Several new techniques to determine the metallicity of M dwarfs with better precision have been developed over the last decades. However, most of these studies were based on empirical methods. In order to enable detailed abundance analysis, standard methods established for warmer solar-like stars, i.e. model-dependent methods using fitting of synthetic spectra, still need to be used. Aims: In this work we continue the reliability confirmation and development of metallicity determinations of M dwarfs using high-resolution infrared spectra. The reliability was confirmed through analysis of M dwarfs in four binary systems with FGK dwarf companions and by comparison with previous optical studies of the FGK dwarfs. Methods: The metallicity determination was based on spectra taken in the J band (1.1-1.4 μm) with the CRIRES spectrograph. In this part of the infrared, the density of stellar molecular lines is limited, reducing the amount of blends with atomic lines enabling an accurate continuum placement. Lines of several atomic species were used to determine the stellar metallicity. Results: All binaries show excellent agreement between the derived metallicity of the M dwarf and its binary companion. Our results are also in good agreement with values found in the literature. Furthermore, we propose an alternative way to determine the effective temperature of M dwarfs of spectral types later than M2 through synthetic spectral fitting of the FeH lines in our observed spectra. Conclusions: We have confirmed that a reliable metallicity determination of M dwarfs can be achieved using high-resolution infrared spectroscopy. We also note that metallicites obtained with photometric metallicity calibrations available for M dwarfs only partly agree with the results we obtain from high-resolution spectroscopy. Based on data obtained at ESO-VLT, Paranal Observatory, Chile, Program ID 082.D-0838(A) and 084.D-1042(A).

  4. High Resolution Laboratory Spectroscopy: Unraveling the Secrets of Interstellar Chemistry

    NASA Astrophysics Data System (ADS)

    Ziurys, Lucy M.

    2008-05-01

    At present, over 140 different chemical compounds have been identified in interstellar and circumstellar gas. Such observations have offered a unique avenue by which to probe the cold, dense regions in our Galaxy and in external galaxies. Because these molecules are primarily present in colder material, they are usually studied at high spectral resolutions (1 part in 106-107) via their pure rotational transitions, which typically occur at millimeter and sub-millimeter wavelengths. Such studies cannot be carried out, however, without the input of high resolution laboratory spectroscopy. Such measurements provide the "fingerprint” spectral pattern critical for accurate astronomical identifications. Because of the complexity of current interstellar spectra and the propensity of unidentified features, precise laboratory data are essential. Current methods employed in the laboratory for high resolution measurements include millimeter/sub-mm direct absorption, velocity modulation, and Fourier transform microwave spectroscopy (FTMW). Each of these experimental techniques has certain unique advantages, which will be discussed. Also of importance are the synthetic methods utilized to create the radicals, ions, and other transient species typically found in interstellar space. Such molecules are generated in DC and AC glow discharges, pulsed supersonic jet expansions, and using Broida-type ovens. In addition, spectral analyses can be quite complex, in particular if there are low lying excited torsional or electronic states, or if molecular inversion is present. Recent laboratory results for potential interstellar species will also be presented, in particular those for negative ions, phosphorus-bearing radicals, and organic "prebiotic” species.

  5. High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy.

    PubMed

    Czarnocki, Cyprian; Kerfoot, Mark L; Casara, Joshua; Jacobs, Andrew R; Jennings, Cameron; Scheibner, Michael

    2016-01-01

    High resolution optical spectroscopy methods are demanding in terms of either technology, equipment, complexity, time or a combination of these. Here we demonstrate an optical spectroscopy method that is capable of resolving spectral features beyond that of the spin fine structure and homogeneous linewidth of single quantum dots (QDs) using a standard, easy-to-use spectrometer setup. This method incorporates both laser and photoluminescence spectroscopy, combining the advantage of laser line-width limited resolution with multi-channel photoluminescence detection. Such a scheme allows for considerable improvement of resolution over that of a common single-stage spectrometer. The method uses phonons to assist in the measurement of the photoluminescence of a single quantum dot after resonant excitation of its ground state transition. The phonon's energy difference allows one to separate and filter out the laser light exciting the quantum dot. An advantageous feature of this method is its straight forward integration into standard spectroscopy setups, which are accessible to most researchers. PMID:27405015

  6. Recent Results in Quantum Chemical Kinetics from High Resolution Spectroscopy

    SciTech Connect

    Quack, Martin

    2007-12-26

    We outline the approach of our group to derive intramolecular kinetic primary processes from high resolution spectroscopy. We then review recent results on intramolecular vibrational redistribution (IVR) and on tunneling processes. Examples are the quantum dynamics of the C-H-chromophore in organic molecules, hydrogen bond dynamics in (HF){sub 2} and stereomutation dynamics in H{sub 2}O{sub 2} and related chiral molecules. We finally discuss the time scales for these and further processes which range from 10 fs to more than seconds in terms of successive symmetry breakings, leading to the question of nuclear spin symmetry and parity violation as well as the question of CPT symmetry.

  7. High Resolution Absorption Spectroscopy using Externally Dispersed Interferometry

    SciTech Connect

    Edelstein, J; Erskine, D J

    2005-07-06

    We describe the use of Externally Dispersed Interferometry (EDI) for high-resolution absorption spectroscopy. By adding a small fixed-delay interferometer to a dispersive spectrograph, a precise fiducial grid in wavelength is created over the entire spectrograph bandwidth. The fiducial grid interacts with narrow spectral features in the input spectrum to create a moire pattern. EDI uses the moire pattern to obtain new information about the spectra that is otherwise unavailable, thereby improving spectrograph performance. We describe the theory and practice of EDI instruments and demonstrate improvements in the spectral resolution of conventional spectrographs by a factor of 2 to 6. The improvement of spectral resolution offered by EDI can benefit space instruments by reducing spectrograph size or increasing instantaneous bandwidth.

  8. High Resolution K-Band Spectroscopy of Selected M Dwarfs

    NASA Astrophysics Data System (ADS)

    Nakajima, Tadashi

    2013-06-01

    We propose to obtain high-resolution K-band spectra of selected M dwarfs to study stellar properties such as effective temperature and metallicity. M dwarfs are under scrutiny as potential planet hosts. They have sufficiently low masses and small radii that exoplanets induce considerably larger reflex velocities and transit depths than an identical planet would around larger, more massive hosts. The low temperatures of M dwarfs imply short-period planets are in the habitable zone. However, due to the cool atmosphere, the characterization of M dwarfs at visible wavelengths has been rather difficult and the previously known stellar parameters have been rather crude. Recently a new method to use medium resolution K-band spectroscopy to determine the effective temperature and metallicity was devised. The purposes of this proposal is to examine the validity of the new method with a spectral resolution one order of magnitude higher and, if possible, to find a better method to determine the stellar properties.

  9. Pluto's atmosphere in 2015 from high-resolution spectroscopy

    NASA Astrophysics Data System (ADS)

    Roe, Henry G.; Cook, Jason C.; Mace, Gregory N.; Holler, Bryan J.; Young, Leslie A.; McLane, Jacob N.; Jaffe, Daniel T.

    2015-11-01

    Pluto's thin N2/CH4 atmosphere is in vapor-pressure equilibrium with ices on its surface. The atmosphere evolves seasonally with the varying insolation pattern on Pluto's heterogenous surface, perhaps even largely freezing out to the surface during the coldest portion of Pluto's year. We use high-resolution (R≈25,000-50,000) near-infrared spectroscopy to resolve atmospheric methane absorption lines from Pluto's continuum spectra, as well as separate Pluto's atmospheric lines from the telluric spectrum. In addition to measuring the abundance and temperature of Pluto's atmospheric CH4, with broad wavelength coverage we are able to search for the inevitable products of N2/CH4 photochemistry. In 2015 we are undertaking an intensive campaign using NIRSPEC at Keck Observatory and IGRINS (Immersion Grating INfrared Spectrometer) at McDonald Observatory to coincide with the New Horizons Pluto encounter. We will report initial results from this 2015 campaign and compare the state of Pluto's atmosphere at the time of the New Horizons encounter with earlier years.

  10. High-resolution NMR spectroscopy under the fume hood.

    PubMed

    Küster, Simon K; Danieli, Ernesto; Blümich, Bernhard; Casanova, Federico

    2011-08-01

    This work reports the possibility to acquire high-resolution (1)H NMR spectra with a fist-sized NMR magnet directly installed under the fume hood. The small NMR sensor based on permanent magnets was used to monitor the trimerization of propionaldehyde catalyzed by indium trichloride in real time by continuously circulating the reaction mixture through the magnet bore in a closed loop with the help of a peristaltic pump. Thanks to the chemical selectivity of NMR spectroscopy the progress of the reaction can be monitored on-line by determining the concentrations of both reactant and product from the area under their respective lines in the NMR spectra as a function of time. This in situ measurement demonstrates that NMR probes can be used in chemistry laboratories, e.g. for reaction optimization, or installed at specific points of interest along industrial process lines. Therefore, it will open the door for the implementation of feedback control based on spectroscopic NMR data. PMID:21698335

  11. Optical multichannel analyzer techniques for high resolution optical spectroscopy

    SciTech Connect

    Chao, J.L.

    1980-06-01

    The development of optical multichannel analyzer techniques for UV/VIS spectroscopy is presented. The research focuses on the development of spectroscopic techniques for measuring high resolution spectral lineshape functions from the exciton phosphorescence in H/sub 2/-1,2,4,5-tetrachlorobenzene. It is found that the temperature dependent frequency shifts and widths confirm a theoretical model based on an exchange theory. The exchange of low energy phonon modes which couple with excited state exciton transitions is shown to display the proper temperature dependent behavior. In addition to the techniques for using the optical multichannel analyzer (OMA) to perform low light level target integration, the use of the OMA for capturing spectral information in transient pulsed laser applications is discussed. An OMP data acquisition system developed for real-time signal processng is described. Both hardware and software interfacing considerations for control and data acquisition by a microcomputer are described. The OMA detector is described in terms of the principles behind its photoelectron detection capabilities and its design is compared with other optoelectronic devices.

  12. Improvement of sensitivity in high-resolution Rutherford backscattering spectroscopy

    SciTech Connect

    Hashimoto, H.; Nakajima, K.; Suzuki, M.; Kimura, K.; Sasakawa, K.

    2011-06-15

    The sensitivity (limit of detection) of high-resolution Rutherford backscattering spectroscopy (HRBS) is mainly determined by the background noise of the spectrometer. There are two major origins of the background noise in HRBS, one is the stray ions scattered from the inner wall of the vacuum chamber of the spectrometer and the other is the dark noise of the microchannel plate (MCP) detector which is commonly used as a focal plane detector of the spectrometer in HRBS. In order to reject the stray ions, several barriers are installed inside the spectrometer and a thin Mylar foil is mounted in front of the detector. The dark noise of the MCP detector is rejected by the coincidence measurement with the secondary electrons emitted from the Mylar foil upon the ion passage. After these improvements, the background noise is reduced by a factor of 200 at a maximum. The detection limit can be improved down to 10 ppm for As in Si at a measurement time of 1 h under ideal conditions.

  13. High-Resolution Spectroscopy of the Lunar Sodium Exosphere

    NASA Technical Reports Server (NTRS)

    Mierkiewicz, E. J.; Oliversen, R. J.; Roesler, F. L.; Lupie, O. L.

    2014-01-01

    We have applied high-resolution Fabry-Perot spectroscopy to the study of the lunar sodium exosphere for the study of exospheric effective temperature and velocity variations. Observing from the National Solar Observatory McMath-Pierce Telescope, we used a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,000 to measure line widths and Doppler shifts of the sodium D2 (5889.95 Å) emission line. Our field of view was 360 km, and measurements were made in equatorial and polar regions from 500 km to 3500 km off the limb. Data were obtained from full moon to 3 days following full moon (waning phase) in March 2009. Measured Doppler line widths within 1100 km of the sunlit east and south lunar limbs for observations between 5 and 40 deg lunar phase imply effective temperatures ranging between 3260 +/- 190 and 1000 +/- 135 K. Preliminary line center analysis indicates velocity displacements between different locations off the lunar limb ranging between 100 and 600 m/s from the lunar rest velocity with a precision of +/-20 to +/-50 m/s depending on brightness. Based on the success of these exploratory observations, an extensive program has been initiated that is expected to constrain lunar atmospheric and surface-process modeling and help quantify source and escape mechanisms.

  14. Johann Spectrometer for High Resolution X-ray Spectroscopy

    SciTech Connect

    Machek, Pavel; Froeba, Michael; Welter, Edmund; Caliebe, Wolfgang; Brueggmann, Ulf; Draeger, Guenter

    2007-01-19

    A newly designed vacuum Johann spectrometer with a large focusing analyzer crystal for inelastic x-ray scattering and high resolution fluorescence spectroscopy has been installed at the DORIS III storage ring. Spherically bent crystals with a maximum diameter of 125 mm, and cylindrically bent crystals are employed as dispersive optical elements. Standard radius of curvature of the crystals is 1000 mm, however, the design of the mechanical components also facilitates measurements with smaller and larger bending radii. Up to four crystals are mounted on a revolving crystal changer which enables crystal changes without breaking the vacuum. The spectrometer works at fixed Bragg angle. It is preferably designed for the measurements in non-scanning mode with a broad beam spot, and offers a large flexibility to set the sample to the optimum position inside the Rowland circle. A deep depletion CCD camera is employed as a position sensitive detector to collect the energy-analyzed photons on the circumference of the Rowland circle. The vacuum in the spectrometer tank is typically 10-6 mbar. The sample chamber is separated from the tank either by 25 {mu}m thick Kapton windows, which allows samples to be measured under ambient conditions, or by two gate valves. The spectrometer is currently installed at wiggler beamline W1 whose working range is 4-10.5 keV with typical flux at the sample of 5x1010photons/s/mm2. The capabilities of the spectrometer are illustrated by resonant inelastic experiments on 3d transition metals and rare earth compounds, and by chemical shift measurements on chromium compounds.

  15. Johann Spectrometer for High Resolution X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Machek, Pavel; Welter, Edmund; Caliebe, Wolfgang; Brüggmann, Ulf; Dräger, Günter; Fröba, Michael

    2007-01-01

    A newly designed vacuum Johann spectrometer with a large focusing analyzer crystal for inelastic x-ray scattering and high resolution fluorescence spectroscopy has been installed at the DORIS III storage ring. Spherically bent crystals with a maximum diameter of 125 mm, and cylindrically bent crystals are employed as dispersive optical elements. Standard radius of curvature of the crystals is 1000 mm, however, the design of the mechanical components also facilitates measurements with smaller and larger bending radii. Up to four crystals are mounted on a revolving crystal changer which enables crystal changes without breaking the vacuum. The spectrometer works at fixed Bragg angle. It is preferably designed for the measurements in non-scanning mode with a broad beam spot, and offers a large flexibility to set the sample to the optimum position inside the Rowland circle. A deep depletion CCD camera is employed as a position sensitive detector to collect the energy-analyzed photons on the circumference of the Rowland circle. The vacuum in the spectrometer tank is typically 10-6 mbar. The sample chamber is separated from the tank either by 25 μm thick Kapton windows, which allows samples to be measured under ambient conditions, or by two gate valves. The spectrometer is currently installed at wiggler beamline W1 whose working range is 4-10.5 keV with typical flux at the sample of 5×1010photons/s/mm2. The capabilities of the spectrometer are illustrated by resonant inelastic experiments on 3d transition metals and rare earth compounds, and by chemical shift measurements on chromium compounds.

  16. High-resolution tunnelling spectroscopy of a graphene quartet.

    PubMed

    Song, Young Jae; Otte, Alexander F; Kuk, Young; Hu, Yike; Torrance, David B; First, Phillip N; de Heer, Walt A; Min, Hongki; Adam, Shaffique; Stiles, Mark D; MacDonald, Allan H; Stroscio, Joseph A

    2010-09-01

    Electrons in a single sheet of graphene behave quite differently from those in traditional two-dimensional electron systems. Like massless relativistic particles, they have linear dispersion and chiral eigenstates. Furthermore, two sets of electrons centred at different points in reciprocal space ('valleys') have this dispersion, giving rise to valley degeneracy. The symmetry between valleys, together with spin symmetry, leads to a fourfold quartet degeneracy of the Landau levels, observed as peaks in the density of states produced by an applied magnetic field. Recent electron transport measurements have observed the lifting of the fourfold degeneracy in very large applied magnetic fields, separating the quartet into integer and, more recently, fractional levels. The exact nature of the broken-symmetry states that form within the Landau levels and lift these degeneracies is unclear at present and is a topic of intense theoretical debate. Here we study the detailed features of the four quantum states that make up a degenerate graphene Landau level. We use high-resolution scanning tunnelling spectroscopy at temperatures as low as 10 mK in an applied magnetic field to study the top layer of multilayer epitaxial graphene. When the Fermi level lies inside the fourfold Landau manifold, significant electron correlation effects result in an enhanced valley splitting for even filling factors, and an enhanced electron spin splitting for odd filling factors. Most unexpectedly, we observe states with Landau level filling factors of 7/2, 9/2 and 11/2, suggestive of new many-body states in graphene. PMID:20829790

  17. Characterizing The Nearest Young Moving Groups Through High Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    McCarthy, Kyle; Wilhelm, Ronald J.

    2015-01-01

    We present a detailed method for characterizing the nearest young moving groups via high resolution spectroscopy. This method has three diagnostics which classify a moving group: (1) Chemical Homogeneity, (2) Kinematic Traceback, and (3) Isochrone Fitting. We have applied this technique on 10 F- and G-type stars from the AB Doradus Moving Group (ABD) and found 8 stars share similar metal abundances with an average abundance for ABD of <[M/H]> = -0.03 ± 0.06; of the two outliers, one is metal rich and the other metal poor. Seven stars follow a common traceback and share a common origin around 125 Myr. One of the outlying traceback stars diverges around 90-100 Myr, and is the same star which is metal rich. Eight stars fall along the same isochrone of 100 Myr, which is synonymous with the main sequence. We further evaluated this technique on 5 members of the newly discovered Octans-Near Moving Group (ONMG). Two of these were listed as possible members with the other three being probable members. There is a large spread in the metal abundance with <[M/H]> = -0.17 ± 0.1 and no core group of stars that define the cluster in abundance space. ONMG is also enigmatic because several age indicators (e.g. lithium abundance, surface gravities, activity) indicate a much younger cluster; however, the traceback age shows these stars were closest around 150 Myr (though this age should be taken very lightly) and 4 of the 5 stars fall on the main sequence. We therefore conclude that while these stars do share present day velocities and positions, the group is not well defined in abundance, origin, or age, and should be concidered with caution.

  18. High-resolution isotopic records ( δ 18O and δ 13C) and cathodoluminescence study of lucinid shells from methane seeps of the Eastern Mediterranean

    NASA Astrophysics Data System (ADS)

    Lietard, Cécile; Pierre, Catherine

    2008-08-01

    We present high-resolution isotopic records and cathodoluminescence studies of recently dead and live bivalve specimens from cold seeps, in an attempt to reconstruct environmental conditions during organism growth, and thereby the possible variability of fluid-venting activity at the seafloor. Shells of the burrowing lucinid Myrtea aff. amorpha were collected at three localities near actively venting methane seeps in the Eastern Mediterranean deep sea, using the Nautile submersible during two French oceanographic cruises: from the Kazan mud volcano, in the vicinity of the Anaximander mounts (MEDINAUT cruise, 1998), and from the central pockmark province and the Amon mud volcano of the Nile deep-sea fan (NAUTINIL cruise, 2003). The oxygen and carbon isotope compositions of 18 shells from the various localities, and also from different sites at the same locality show a rather strong scatter (1.8 < δ 18O‰ < 3.4; -10.2 < δ 13C‰ < 2.2), and values lower than those expected for carbonate precipitated at equilibrium with present-day bottom waters. This means that warm methane-rich fluids were mixed with bottom seawater during precipitation of shell carbonates. We have tried to determine ontogenetic age of two shells by using cathodoluminescence as a sclerochronological proxy, because the direct counting of carbonate increments was not possible in these specimens. There is a relatively good correspondence between cathodoluminescence trends and oxygen isotope profiles that might support the link between manganese incorporation during growth and temperature. Eight specimens of lucinid shells were selected for high-resolution isotopic profiling. A few shells exhibit decreasing δ 18O and δ 13C values from the umbo to the actively growing ventral shell margin, which can be attributed to the commonly observed physiologically controlled deceleration of growth with increasing organism age, this metabolic effect corresponding to the increase of incorporation of respiratory

  19. High Resolution Coherent Three-Dimensional Spectroscopy of Iodine

    NASA Astrophysics Data System (ADS)

    House, Zuri R.; Wells, Thresa A.; Chen, Peter C.; Strangfeld, Benjamin R.

    2013-06-01

    The heavy congestion found in many one-dimensional spectra can make it difficult to study many transitions. A new coherent three-dimensional spectroscopic technique has been developed to eliminate the kind of congestion commonly seen in high resolution electronic spectra. The molecule used for this test was Iodine. A well-characterized transition (X to B) was used to determine which four wave mixing process or processes were responsible for the peaks in the resulting multidimensional spectrum. The resolution of several peaks that overlap in a coherent 2D spectrum can be accomplished by using a higher dimensional (3D) spectroscopic method. This talk will discuss strategies for finding spectroscopic constants using this high resolution coherent 3D spectroscopic method.

  20. High Resolution Thz and FIR Spectroscopy of SOCl_2

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, M. A.; Cuisset, A.; Sadovskii, D. A.; Mouret, G.; Hindle, F.; Pirali, O.

    2013-06-01

    Thionyl chloride (SOCl_2) is an extremely powerful oxidant widely used in industrial processes and playing a role in the chemistry of the atmosphere. In addition, it has a molecular configuration similar to that of phosgene (COCl_2), and is therefore of particular interest for security and defense applications. Low resolution vibrational spectra of gas phase SOCl_2 as well as high resolution pure rotational transitions up to 25 GHz have previously been investigated. To date no high resolution data are reported at frequencies higher than 25 GHz. We have investigated the THz absorption spectrum of SOCl_2 in the spectral region 70-650 GHz using a frequency multiplier chain coupled to a 1 m long single path cell containing a pressure of about 15 μbar. At the time of the writing, about 8000 pure rotational transitions of SO^{35}Cl_2 with highest J and K_a values of 110 and 50 respectively have been assigned on the spectrum. We have also recorded the high resolution FIR spectra of SOCl_2 in the spectral range 50-700 wn using synchrotron radiation at the AILES beamline of SOLEIL facility. A White-type cell aligned with an absorption path length of 150 m has been used to record, at a resolution of 0.001 wn, two spectra at pressures of 5 and 56 μbar of SOCl_2. On these spectra all FIR modes of SOCl_2 are observed (ν_2 to ν_6) and present a resolved rotational structure. Their analysis is in progress. T. J. Johnson et al., J. Phys. Chem. A 107, 6183 (2003) D. E. Martz and R. T. Lagemann, J. Chem. Phys. 22,1193 (1954) H. S. P. Müller and M. C. L. Gerry, J. Chem. Soc. Faraday Trans. 90, 3473 (1994)

  1. High-Resolution Spectroscopy of Some Very Inactive Southern Stars

    NASA Astrophysics Data System (ADS)

    Villarreal, A.; King, J. R.; Soderblom, D. R.; Henry, T. J.

    2001-12-01

    We have obtained high-resolution echelle spectra of a few dozen solar-type stars that an earlier low resolution Ca II H & K survey suggested have modest evels of chromospheric activity. We present Hα -based chromospheric activity measures, binarity information, and Li abundances of the sample. As expected, our spectra: confirm the low levels of chromospheric activity; suggest that these objects are apparently single; indicate the stars have small projected rotational velocities; and yield low photospheric abundances of Li. This work was supported by NSF grant AST-0086576 to JRK.

  2. MAGELLAN: High resolution spectroscopy at FUV and EUV wavelengths

    NASA Technical Reports Server (NTRS)

    Grewing, M.; Alighieri, S. D.; Burton, W.; Coleman, C. I.; Hoekstra, R.; Jamar, C.; Labeque, A.; Laurent, C.; Vidal-Madjar, A.; Rafanelli, P.

    1982-01-01

    The aim of ESA's MAGELLAN mission is to provide high resolution spectra of celestial sources down to sixteenth magnitude over the extreme ultraviolet wavelength range (between 50 and 140 nm). This range extends from studies of interstellar matter in the disc and halo of this and other galaxies, to stellar envelopes, hot and evolved stars, clusters, intergalactic matter, nuclei of galaxies, quasars, and, finally, planets and satellites. The instrument has a nonconventional optical design using only one reflecting surface; a high groove density concave grating collects the star light, diffracts it and focuses its spectrum into a bidimensional windowless detector operated in a photon counting mode. The slitless configuration provides the spectra of all the sources (point like and extended) in the field of view of the grating. This field of view is limited by a grid collimator to reduce the diffuse background, the stray light and the probability of overlapping spectra in crowded fields.

  3. High resolution spectroscopy from low altitude satellites. [gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Nakano, G. H.; Imhof, W. L.

    1978-01-01

    The P 78 1 satellite to be placed in a synchronous polar orbit at an altitude of 550-660 km will carry two identical high resolution spectrometers each consisting of a single (approximately 85 cc) intrinsic germanium IGE detector. The payload also includes a pair of phoswitch scintillators, an array of CdTe detectors and several particle detectors, all of which are mounted on the wheel of the satellite. The intrinsic high purity IGE detectors receive cooling from two Stirling cycle refrigerators and facilitate the assembly of large and complex detector arrays planned for the next generation of high sensitivity instruments such as those planned for the gamma ray observatory. The major subsystems of the spectrometer are discussed as well as its capabilities.

  4. Quadrature phase interferometer for high resolution force spectroscopy.

    PubMed

    Paolino, Pierdomenico; Aguilar Sandoval, Felipe A; Bellon, Ludovic

    2013-09-01

    In this article, we present a deflection measurement setup for Atomic Force Microscopy (AFM). It is based on a quadrature phase differential interferometer: we measure the optical path difference between a laser beam reflecting above the cantilever tip and a reference beam reflecting on the static base of the sensor. A design with very low environmental susceptibility and another allowing calibrated measurements on a wide spectral range are described. Both enable a very high resolution (down to 2.5×10(-15) m/√Hz), illustrated by thermal noise measurements on AFM cantilevers. They present an excellent long-term stability and a constant sensitivity independent of the optical phase of the interferometer. A quick review shows that our precision is equaling or out-performing the best results reported in the literature, but for a much larger deflection range, up to a few μm. PMID:24089852

  5. Quadrature phase interferometer for high resolution force spectroscopy

    NASA Astrophysics Data System (ADS)

    Paolino, Pierdomenico; Aguilar Sandoval, Felipe A.; Bellon, Ludovic

    2013-09-01

    In this article, we present a deflection measurement setup for Atomic Force Microscopy (AFM). It is based on a quadrature phase differential interferometer: we measure the optical path difference between a laser beam reflecting above the cantilever tip and a reference beam reflecting on the static base of the sensor. A design with very low environmental susceptibility and another allowing calibrated measurements on a wide spectral range are described. Both enable a very high resolution (down to 2.5 × 10^{-15} m/sqrtHz), illustrated by thermal noise measurements on AFM cantilevers. They present an excellent long-term stability and a constant sensitivity independent of the optical phase of the interferometer. A quick review shows that our precision is equaling or out-performing the best results reported in the literature, but for a much larger deflection range, up to a few μm.

  6. High-resolution near-infrared spectroscopy of water dimer

    NASA Technical Reports Server (NTRS)

    Huang, Z. S.; Miller, R. E.

    1989-01-01

    High-resolution near-infrared spectra are reported for all of the O-H stretch vibrational bands of the water dimer. The four O-H vibrations are characterized as essentially independent proton-donor or proton-acceptor motions. In addition to the rotational and vibrational information contained in these spectra, details are obtained concerning the internal tunneling dynamics in both the ground and excited vibrational states. These results show that, for tunneling motions which involve the interchange of the proton donor and acceptor molecules, the associated frequencies decrease substantially due to vibrational excitation. The predissociation lifetimes for the various states of the dimer are determined from linewidth measurements. These results clearly show that the predissociation dynamics is strongly dependent on the tunneling states, as well as the Ka quantum number, indicating that the internal tunneling dynamics plays an important role in determining the dissociation rate in this complex.

  7. Quadrature phase interferometer for high resolution force spectroscopy

    SciTech Connect

    Paolino, Pierdomenico; Aguilar Sandoval, Felipe A.; Bellon, Ludovic

    2013-09-15

    In this article, we present a deflection measurement setup for Atomic Force Microscopy (AFM). It is based on a quadrature phase differential interferometer: we measure the optical path difference between a laser beam reflecting above the cantilever tip and a reference beam reflecting on the static base of the sensor. A design with very low environmental susceptibility and another allowing calibrated measurements on a wide spectral range are described. Both enable a very high resolution (down to 2.5×10{sup −15} m/√(Hz)), illustrated by thermal noise measurements on AFM cantilevers. They present an excellent long-term stability and a constant sensitivity independent of the optical phase of the interferometer. A quick review shows that our precision is equaling or out-performing the best results reported in the literature, but for a much larger deflection range, up to a few μm.

  8. High-resolution spectroscopy of a giant solar filament

    NASA Astrophysics Data System (ADS)

    Kuckein, Christoph; Denker, Carsten; Verma, Meetu

    2014-01-01

    High-resolution spectra of a giant solar quiescent filament were taken with the Echelle spectrograph at the Vacuum Tower Telescope (VTT; Tenerife, Spain). A mosaic of various spectroheliograms (Hα, Hα+/-0.5 Å and Na D2) were chosen to examine the filament at different heights in the solar atmosphere. In addition, full-disk images (He i 10830 Å and Ca ii K) of the Chromspheric Telescope and full-disk magnetograms of the Helioseismic and Magnetic Imager were used to complement the spectra. Preliminary results are shown of this filament, which had extremely large linear dimensions (~740'') and was observed in November 2011 while it traversed the northern solar hemisphere.

  9. CARMENES science preparation. High-resolution spectroscopy of M dwarfs

    NASA Astrophysics Data System (ADS)

    Montes, D.; Caballero, J. A.; Jeffers, S.; Alonso-Floriano, F. J.; Mundt, R.; CARMENES Consortium

    2015-05-01

    To ensure an efficient use of CARMENES observing time, and the highest chances of success, it is necessary first to select the most promising targets. To achieve this, we are observing 500 M dwarfs at high-resolution (R = 30,000-48,000), from which we determine the projected rotational velocity vsin{i} with an accuracy better than 0.5-0.2 km/s and radial-velocity stability better than 0.2-0.1 km/s. Our aim is to have at least two spectra at different epochs of the final 300 CARMENES targets. Our observations with FEROS at ESO/MPG 2.2 m La Silla, CAFE at 2.2 m Calar Alto and HRS at Hobby Eberly Telescope allow us to identify single- and double-line spectroscopic binaries and, especially, fast rotators, which should be discarded from the target list for exoplanet searches. Here we present preliminary results.

  10. High Resolution Spectroscopy of Two FK Comae Stars

    NASA Astrophysics Data System (ADS)

    Linsky, Jeffrey L.

    The FK Comae stars are a class of extremely rapidly rotating G-K giants that exhibit among the brightest UV and X-ray emission seen in late type stars. Previous IUE and optical observations have indicated that the activity (the extreme surface fluxes) in FK Comae may be qualitatively different from that in "normal" late type stars, and that the other four members of the class are far less bizarre than FK Comae itself. A definitive method for determining the structure of the outer atmospheres of these stars, and deciding whether the heating mechanism is normal chromospheric heating or accretion heating is by analysis of high resolution SWP spectra. We propose, in collaboration with S. Rucinski, to obtain 16-20 hour collaborative NASA-ESA SWP-HI spectra of FK Comae, which exhibits Hot and MgII line widths of ˜500 kms^-1, and HD 36705, which appears to be a far less bizarre member of this class. These observations would be the first high dispersion SWP spectra ever obtained of FK Comae stars.

  11. Exploring conical intersections through high resolution photofragment translational spectroscopy

    NASA Astrophysics Data System (ADS)

    Ashfold, Michael

    2007-03-01

    High resolution measurements of the kinetic energies of H atom fragments formed during UV photolysis of gas phase imidazole, [1,2] pyrrole, [3] phenol [4] and thiophenol molecules show that: (i) X-H (X = N, O, S) bond fission is an important non-radiative decay process from the ^1πσ* excited states in each of these molecules, and (ii) that the respective co-fragments (imidazolyl, pyrrolyl, phenoxyl and thiophenoxyl) are formed in very limited sub-sets of their available vibrational states. Identification of these product states yields uniquely detailed insights into the vibronic couplings involved in the photo-induced evolution from parent molecule to ultimate fragments. [1] M.N.R. Ashfold, B. Cronin, A.L. Devine, R.N. Dixon and M.G.D. Nix, Science (2006), 312, 1637. [2] A.L. Devine, B. Cronin, M.G.D. Nix and M.N.R. Ashfold, J. Chem. Phys. (in press). [3] B. Cronin, M.G.D. Nix, R.H. Qadiri and M.N.R. Ashfold, Phys. Chem. Chem. Phys. (2004), 6, 5031. [4] M.G.D. Nix, A.L. Devine, B. Cronin, R.N. Dixon and M.N.R. Ashfold, J. Chem. Phys. (2006), 125, 133318.

  12. High resolution {gamma}-ray spectroscopy: The first 85 years

    SciTech Connect

    Deslattes, R.D.

    2000-02-01

    This opening review attempts to follow the main trends in crystal diffraction spectrometry of nuclear {gamma} rays from its 1914 beginning in Rutherford's laboratory to the ultra-high resolution instrumentation realized in the current generation of spectrometers at the Institute Laue Langeven (ILL). The authors perspective is that of an instrumentalist hoping to convey a sense of intellectual debt to a number of predecessors, each of whom realized a certain elegance in making the tools that have enabled much good science, including that to which the remainder of this workshop is dedicated. This overview follows some of the main ideas along a trajectory toward higher resolution at higher energies, thereby enabling not only the disentangling of dense spectra, but also allowing detailed study of aspects of spectral profiles sensitive to excited state lifetimes and interatomic potentials. The parallel evolution toward increasing efficiency while preserving needed resolution is also an interesting story of artful compromise that should not be neglected. Finally, it is the robustness of the measurement chain connecting {gamma}-ray wavelengths with optical wave-lengths associated with the Rydberg constant that only recently has allowed {gamma}-ray data to contribute to determine of particle masses and fundamental constants, as will be described in more detail in other papers from this workshop.

  13. High Resolution FIR and IR Spectroscopy of Methanol Isotopologues

    SciTech Connect

    Lees, R. M.; Xu, Li-Hong; Appadoo, D. R. T.; Billinghurst, B.

    2010-02-03

    New astronomical facilities such as HIFI on the Herschel Space Observatory, the SOFIA airborne IR telescope and the ALMA sub-mm telescope array will yield spectra from interstellar and protostellar sources with vastly increased sensitivity and frequency coverage. This creates the need for major enhancements to laboratory databases for the more prominent interstellar 'weed' species in order to model and account for their lines in observed spectra in the search for new and more exotic interstellar molecular 'flowers'. With its large-amplitude internal torsional motion, methanol has particularly rich spectra throughout the FIR and IR regions and, being very widely distributed throughout the galaxy, is perhaps the most notorious interstellar weed. Thus, we have recorded new spectra for a variety of methanol isotopic species on the high-resolution FTIR spectrometer on the CLS FIR beamline. The aim is to extend quantum number coverage of the data, improve our understanding of the energy level structure, and provide the astronomical community with better databases and models of the spectral patterns with greater predictive power for a range of astrophysical conditions.

  14. High resolution photoelectron spectroscopy of clusters of Group V elements

    SciTech Connect

    Wang, Lai-sheng; Niu, B.; Lee, Y.T.; Shirley, D.A.

    1989-07-01

    High resolution HeI (580{angstrom}) photoelectron spectra of As{sub 2}, As{sub 4}, and P{sub 4} were obtained with a newly-built high temperature molecular beam source. Vibrational structure was resolved in the photoelectron spectra of the three cluster species. The Jahn-Teller effect is discussed for the {sup 2}E and {sup 2}T{sub 2} states of P{sub 4}{sup +} and As{sub 4}{sup +}. As a result of the Jahn-Teller effect, the {sup 2}E state splits into two bands, and the {sup 2}T{sub 2} state splits into three bands, in combination with the spin-orbit effect. It was observed that the {nu}{sub 2} normal vibrational mode was involved in the vibronic interaction of the {sup 2}E state, while both the {nu}{sub 2} and {nu}{sub 3} modes were active in the {sup 2}T{sub 2} state. 26 refs., 5 figs., 3 tabs.

  15. High Resolution X-Ray Spectroscopy Using Microcalorimeters

    NASA Technical Reports Server (NTRS)

    Kelley, R. L.

    1997-01-01

    During the past 13 years high resolution X ray spectrometers have been developed that use cryogenically cooled microcalorimeters. These devices have inherently high signal-to-noise by operating at temperatures below 0.1 K and can achieve an energy resolution of < 10 eV over the 0.1-10 keV band. Existing devices use doped semiconductor thermometers and typically employ HgTe absorbers. The energy resolution depends on achieving a low heat capacity for the device. For soft X ray applications a relatively thin absorber (approximately 1 micrometer) may be used and an energy resolution of approximately 7 eV has been achieved. For applications up to approximately 10 keV an absorber thickness of approximately 10 micrometer is required and the energy resolution is typically approximately 12 eV. Improvements to the energy resolution in this energy band could be achieved if the problems of thermalizing X rays in low heat capacity superconductors can be overcome. The recent work on transition edge thermometers by Irwin et nl. looks particularly promising because of the higher sensitivity achievable from a sharp superconducting transition. The relatively low impedance of such a device permits the use of a low noise SQUID amplifier for readout. This would also significantly reduce the cryogen heat load compared with JFETs required by higher impedance semiconductor thermometers.

  16. High-Resolution Laser Spectroscopy on the Negative Osmium Ion

    SciTech Connect

    Warring, U.; Amoretti, M.; Canali, C.; Fischer, A.; Heyne, R.; Meier, J. O.; Morhard, Ch.; Kellerbauer, A.

    2009-01-30

    We have applied a combination of laser excitation and electric-field detachment to negative atomic ions for the first time, resulting in an enhancement of the excited-state detection efficiency for spectroscopy by at least 2 orders of magnitude. Applying the new method, a measurement of the bound-bound electric-dipole transition frequency in {sup 192}Os{sup -} was performed using collinear spectroscopy with a narrow-bandwidth cw laser. The transition frequency was found to be 257.831 190(35) THz [wavelength 1162.747 06(16) nm, wave number 8600.3227(12) cm{sup -1}], in agreement with the only prior measurement, but with more than 100-fold higher precision.

  17. Giant quiescent solar filament observed with high-resolution spectroscopy

    NASA Astrophysics Data System (ADS)

    Kuckein, C.; Verma, M.; Denker, C.

    2016-05-01

    Aims: An extremely large filament was studied in various layers of the solar atmosphere. The inferred physical parameters and the morphological aspects are compared with smaller quiescent filaments. Methods: A giant quiet-Sun filament was observed with the high-resolution Echelle spectrograph at the Vacuum Tower Telescope at Observatorio del Teide, Tenerife, Spain, on 2011 November 15. A mosaic of spectra (ten maps of 100″ × 182″) was recorded simultaneously in the chromospheric absorption lines Hα and Na i D2. Physical parameters of the filament plasma were derived using cloud model (CM) inversions and line core fits. The spectra were complemented with full-disk filtergrams (He i λ10830 Å, Hα, and Ca ii K) of the Chromospheric Telescope (ChroTel) and full-disk magnetograms of the Helioseismic and Magnetic Imager (HMI). Results: The filament had extremely large linear dimensions (~817 arcsec), which corresponds to about 658 Mm along a great circle on the solar surface. A total amount of 175119 Hα contrast profiles were inverted using the CM approach. The inferred mean line-of-sight (LOS) velocity, Doppler width, and source function were similar to previous works of smaller quiescent filaments. However, the derived optical thickness was higher. LOS velocity trends inferred from the Hα line core fits were in accord but weaker than those obtained with CM inversions. Signatures of counter-streaming flows were detected in the filament. The largest brightening conglomerates in the line core of Na i D2 coincided well with small-scale magnetic fields as seen by HMI. Mixed magnetic polarities were detected close to the ends of barbs. The computation of photospheric horizontal flows based on HMI magnetograms revealed flow kernels with a size of 5-8 Mm and velocities of 0.30-0.45 km s-1 at the ends of the filament. Conclusions: The physical properties of extremely large filaments are similar to their smaller counterparts, except for the optical thickness, which in

  18. Molecular Chirality: Enantiomer Differentiation by High-Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hirota, Eizi

    2014-06-01

    I have demonstrated that triple resonance performed on a three-rotational-level system of a chiral molecule of C1 symmetry exhibits signals opposite in phase for different enantiomers, thereby making enantiomer differentiation possible by microwave spectroscopy This prediction was realized by Patterson et al. on 1,2-propanediol and 1,3-butanediol. We thus now add a powerful method: microwave spectroscopy to the study of chiral molecules, for which hitherto only the measurement of optical rotation has been employed. Although microwave spectroscopy is applied to molecules in the gaseous phase, it is unprecedentedly superior to the traditional method: polarimeter in resolution, accuracy, sensitivity, and so on, and I anticipate a new fascinating research area to be opened in the field of molecular chirality. More versatile and efficient systems should be invented and developed for microwave spectroscopy, in order to cope well with new applications expected for this method For C2 and Cn (n ≥ 3)chiral molecules, the three-rotational-level systems treated above for C1 molecules are no more available within one vibronic state. It should, however, be pointed out that, if we take into account an excited vibronic state in addition to the ground state, for example, we may encounter many three-level systems. Namely, either one rotational transition in the ground state is combined with two vibronic transitions, or such a rotational transition in an excited state may be connected through two vibronic transitions to a rotational level in the ground state manifold. The racemization obviously plays a crucial role in the study of molecular chirality. However, like many other terms employed in chemistry, this important process has been "defined" only in a vague way, in other words, it includes many kinds of processes, which are not well classified on a molecular basis. I shall mention an attempt to obviate these shortcomings in the definition of racemization and also to clarify the

  19. High-Resolution Waveguide THz Spectroscopy of Biological Molecules☆

    PubMed Central

    Laman, N.; Harsha, S. Sree; Grischkowsky, D.; Melinger, Joseph S.

    2008-01-01

    Abstract Low-frequency vibrational modes of biological molecules consist of intramolecular modes, which are dependent on the molecule as a whole, as well as intermolecular modes, which arise from hydrogen-bonding interactions and van der Waals forces. Vibrational modes thus contain important information about conformation dynamics of biological molecules, and can also be used for identification purposes. However, conventional Fourier transform infrared spectroscopy and terahertz time-domain spectroscopy (THz-TDS) often result in broad, overlapping features that are difficult to distinguish. The technique of waveguide THz-TDS has been recently developed, resulting in sharper features. For this technique, an ordered polycrystalline film of the molecule is formed on a metal sample plate. This plate is incorporated into a metal parallel-plate waveguide and probed via waveguide THz-TDS. The planar order of the film reduces the inhomogeneous broadening, and cooling of the samples to 77K reduces the homogenous broadening. This combination results in the line-narrowing of THz vibrational modes, in some cases to an unprecedented degree. Here, this technique has been demonstrated with seven small biological molecules, thymine, deoxycytidine, adenosine, D-glucose, tryptophan, glycine, and L-alanine. The successful demonstration of this technique shows the possibilities and promise for future studies of internal vibrational modes of large biological molecules. PMID:17933879

  20. Mobile sensor for high resolution NMR spectroscopy and imaging

    NASA Astrophysics Data System (ADS)

    Danieli, Ernesto; Mauler, Jörg; Perlo, Juan; Blümich, Bernhard; Casanova, Federico

    2009-05-01

    In this work we describe the construction of a mobile NMR tomograph with a highly homogeneous magnetic field. Fast MRI techniques as well as NMR spectroscopy measurements were carried out. The magnet is based on a Halbach array built from identical permanent magnet blocks generating a magnetic field of 0.22 T. To shim the field inhomogeneities inherent to magnet arrays constructed from these materials, a shim strategy based on the use of movable magnet blocks is employed. With this approach a reduction of the line-width from ˜20 kHz to less than 0.1 kHz was achieved, that is by more than two orders of magnitude, in a volume of 21 cm 3. Implementing a RARE sequence, 3D images of different objects placed in this volume were obtained in short experimental times. Moreover, by reducing the sample size to 1 cm 3, sub ppm resolution is obtained in 1H NMR spectra.

  1. High resolution ion Doppler spectroscopy at Prairie View Rotamak

    SciTech Connect

    Houshmandyar, Saeid; Yang Xiaokang; Magee, Richard

    2012-10-15

    A fast ion Doppler spectroscopy (IDS) diagnostic system is installed on the Prairie View Rotamak to measure ion temperature and plasma flow. The diagnostic employs a single channel photomultiplier tube and a Jarrell-Ash 50 monochromator with a diffraction grating line density of 1180 lines/mm, which allows for first order spectra of 200-600 nm. The motorized gear of the monochromator allows spectral resolution of 0.01 nm. Equal IDS measurements are observed for various impurity emission lines of which carbon lines exhibit stronger intensities. Furthermore, the diagnostics is examined in an experiment where plasma experiences sudden disruption and quick recovery. In this case, the IDS measurements show {approx}130% increase in ion temperature. Flow measurements are shown to be consistent with plasma rotation.

  2. High resolution gamma-ray spectroscopy at GANIL

    SciTech Connect

    France, G. de

    2014-11-11

    Gamma-ray spectroscopy is intensively used at GANIL to measure low lying states in exotic nuclei on the neutron-rich as well as on the neutron-deficient side of the nuclear chart. On the neutron deficient border, gamma-rays have been observed for the first time in {sup 92}Pd. The level scheme which could be established points to the role of isoscalar pairing. On the neutron rich side, the lifetime of excited states in nuclei around {sup 68}Ni have been been measured using the plunger technique. This allows us to study the evolution of collectivity in a broad range of nuclei. In 2014 GANIL will host the AGATA array for a campaign of at least 2 years. This array is based on the gamma-ray tracking technique, which allows an impressive gain in resolving power.

  3. High resolution FTIR spectroscopy of the ClO radical

    NASA Technical Reports Server (NTRS)

    Lang, Valerie; Sander, Stanley P.; Friedl, Randy

    1988-01-01

    The chlorine monoxide radical, ClO, plays a significant role in the catalytic destruction of ozone in the Earth's stratosphere. Because of its atmospheric importance, ClO has been the subject of numerous observational attempts. In order to deduce ClO concentrations from stratospheric infrared measurements, the infrared spectroscopy of ClO must be well characterized. Approximately 830 individual lines were measured form ClO imfrared spectra with the ClO concentration between 1 x 10 to the 13th power and 6 x 10 to the 13th power molecules per cu cu. The lines were then averaged and fit to a function of m (where m = O, -J or J+1 for the Q,P and R branches respectively) to obtain the band strength, S sub v and the first Herman-Wallis coefficient, alpha. The total S sub v for the two main isotopmers was 13.11 plus or minus 1 cm(-2) atm(-1) while alpha was 0.00412 plus or minus .00062.

  4. Ultra high resolution molecular beam cars spectroscopy with application to planetary atmospheric molecules

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1982-01-01

    The measurement of high resolution pulsed and continuous wave (CW) coherent anti-Stokes Raman spectroscopy (CARS) measurements in pulsed and steady state supersonic expansions were demonstrated. Pulsed molecular beam sources were characterized, and saturation of a Raman transition and, for the first time, the Raman spectrum of a complex molecular cluster were observed. The observation of CW CARS spectra in a molecular expansion and the effects of transit time broadening is described. Supersonic expansion is established as a viable technique for high resolution Raman spectroscopy of cold molecules with resolutions of 100 MH2.

  5. Low Temperature Cathodoluminescence Spectroscopy of Amorphous Aluminum Nitride Nanoparticles doped with Erbium, synthesized using Inert Gas Condensation Technique

    NASA Astrophysics Data System (ADS)

    Pandya, Sneha; Wang, Jingzhou; Wojciech, Jadwisienczak; Kordesch, Martin

    2015-03-01

    Free standing Aluminum Nitride Nanoparticles (NPs) doped in situwith Erbium (AlN:Er), ranging from 3-30nm in size, were synthesized using a vapor phase deposition technique known as Inert Gas Condensation (IGC). Amorphous behavior of these NPs was inferred from the wide-angle X-ray spectroscopy studies. Raman spectra analysis for these AlN:Er NPs showed characteristic peaks for A1(TO) and E2(high) phonon modes of AlN. Detailed structural characterization of these Er doped AlN NPs will be carried out using a High-Resolution TEM, results of which will be included in my talk. Low temperature Cathodoluminescence (CL) measurements were carried out for these a-AlN:Er NPs. The corresponding Er+3 ion emission peaks were compared to the CL emission spectra obtained for a-AlN:Er thin films, and for commercially obtained Erbium-Oxide NPs. These spectroscopic results will be discussed in detail. I will also present the CL results obtained for in-air and in-nitrogen atmosphere annealed a-AlN:Er NPs. In addition to this, I will illustrate how these Er doped NPs can be used as nano-scale temperature sensors. The SNOM help provided by Prof. Hugh Richardson is gratefully acknowledged.

  6. High-Resolution Solid-State NMR Spectroscopy: Characterization of Polymorphism in Cimetidine, a Pharmaceutical Compound

    ERIC Educational Resources Information Center

    Pacilio, Julia E.; Tokarski, John T.; Quiñones, Rosalynn; Iuliucci, Robbie J.

    2014-01-01

    High-resolution solid-state NMR (SSNMR) spectroscopy has many advantages as a tool to characterize solid-phase material that finds applications in polymer chemistry, nanotechnology, materials science, biomolecular structure determination, and others, including the pharmaceutical industry. The technology associated with achieving high resolution…

  7. Application of high-resolution laser spectroscopy to the monitoring of vapor-phase metals

    SciTech Connect

    Lipert, R.J.; Wang, Z.M.; Schuler, R.; Edelson, M.C.

    1992-10-01

    Research conducted in the Ames Laboratory Nuclear Safeguards and Security Program is reviewed. Progress in applying high-resolution laser spectroscopy to the monitoring of vapor-phase metals is described. The spectroscopic techniques employed include fluorescence excitation in an atomic beam, laser atomic absorption in a heat-pipe oven and atomic beam, Doppler-free saturated absorption in a heat-pipe oven, and Doppler-free polarization spectroscopy for the stabilization of the laser wavelength.

  8. Very high resolution UV and X-ray spectroscopy and imagery of solar active regions

    NASA Technical Reports Server (NTRS)

    Bruner, M.; Brown, W. A.; Haisch, B. M.

    1987-01-01

    A scientific investigation of the physics of the solar atmosphere, which uses the techniques of high resolution soft X-ray spectroscopy and high resolution UV imagery, is described. The experiments were conducted during a series of three sounding rocket flights. All three flights yielded excellent images in the UV range, showing unprecedented spatial resolution. The second flight recorded the X-ray spectrum of a solar flare, and the third that of an active region. A normal incidence multi-layer mirror was used during the third flight to make the first astronomical X-ray observations using this new technique.

  9. [Measurement of OH radicals in flame with high resolution differential optical absorption spectroscopy].

    PubMed

    Liu, Yu; Liu, Wen-Qing; Kan, Rui-Feng; Si, Fu-Qi; Xu, Zhen-Yu; Hu, Ren-Zhi; Xie, Pin-Hua

    2011-10-01

    The present paper describes a new developed high resolution differential optical absorption spectroscopy instrument used for the measurement of OH radicals in flame. The instrument consists of a Xenon lamp for light source; a double pass high resolution echelle spectrometer with a resolution of 3.3 pm; a multiple-reflection cell of 20 meter base length, in which the light reflects in the cell for 176 times, so the whole path length of light can achieve 3 520 meters. The OH radicals'6 absorption lines around 308 nm were simultaneously observed in the experiment. By using high resolution DOAS technology, the OH radicals in candles, kerosene lamp, and alcohol burner flames were monitored, and their concentrations were also inverted. PMID:22250529

  10. High-resolution heteronuclear correlation spectroscopy based on spatial encoding and coherence transfer in inhomogeneous fields

    NASA Astrophysics Data System (ADS)

    Wang, Kaiyu; Zhang, Zhiyong; Chen, Hao; Cai, Shuhui; Chen, Zhong

    2015-11-01

    Two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy has been proven to be a powerful technique for chemical, biological, and medical studies. Heteronuclear single quantum correlation (HSQC) and heteronuclear multiple bond correlation (HMBC) are two frequently used 2D NMR methods. In combination with spatially encoded techniques, a heteronuclear 2D NMR spectrum can be acquired in several seconds and may be applied to monitoring chemical reactions. However, it is difficult to obtain high-resolution NMR spectra in inhomogeneous fields. Inspired by the idea of tracing the difference of precession frequencies between two different spins to yield high-resolution spectra, we propose a method with correlation acquisition option and J-resolved-like acquisition option to ultrafast obtain high-resolution HSQC/HMBC spectra and heteronuclear J-resolved-like spectra in inhomogeneous fields.

  11. High-resolution inverse Raman and resonant-wave-mixing spectroscopy

    SciTech Connect

    Rahn, L.A.

    1993-12-01

    These research activities consist of high-resolution inverse Raman spectroscopy (IRS) and resonant wave-mixing spectroscopy to support the development of nonlinear-optical techniques for temperature and concentration measurements in combustion research. Objectives of this work include development of spectral models of important molecular species needed to perform coherent anti-Stokes Raman spectroscopy (CARS) measurements and the investigation of new nonlinear-optical processes as potential diagnostic techniques. Some of the techniques being investigated include frequency-degenerate and nearly frequency-degenerate resonant four-wave-mixing (DFWM and NDFWM), and resonant multi-wave mixing (RMWM).

  12. High resolution X-ray spectroscopy of astrophysical sources: current and future

    NASA Astrophysics Data System (ADS)

    Paerels, Frits

    High resolution spectroscopy of cosmic X-ray sources has become a well-established technique over the last decade, with the wide variety of investigations performed with the diffraction grating spectrometers on Chandra and XMM-Newton. I will review some of the common themes that have emerged from these studies, which comprises observations of "sources" as varied as the intergalactic medium and the atmospheres of hot neutron stars. With the microcalorimeter spectrometer array on Astro-H, we will be making two more big steps: true imaging spectroscopy, and extension of the high resolution to the Fe K band. I will outline some of the issues we will encounter, against the background of possible discoveries we may make.

  13. High-Resolution 3D Structure Determination of Kaliotoxin by Solid-State NMR Spectroscopy

    PubMed Central

    Korukottu, Jegannath; Schneider, Robert; Vijayan, Vinesh; Lange, Adam; Pongs, Olaf; Becker, Stefan; Baldus, Marc; Zweckstetter, Markus

    2008-01-01

    High-resolution solid-state NMR spectroscopy can provide structural information of proteins that cannot be studied by X-ray crystallography or solution NMR spectroscopy. Here we demonstrate that it is possible to determine a protein structure by solid-state NMR to a resolution comparable to that by solution NMR. Using an iterative assignment and structure calculation protocol, a large number of distance restraints was extracted from 1H/1H mixing experiments recorded on a single uniformly labeled sample under magic angle spinning conditions. The calculated structure has a coordinate precision of 0.6 Å and 1.3 Å for the backbone and side chain heavy atoms, respectively, and deviates from the structure observed in solution. The approach is expected to be applicable to larger systems enabling the determination of high-resolution structures of amyloid or membrane proteins. PMID:18523586

  14. Update of High Resolution (e,e'K^+) Hypernuclear Spectroscopy at Jefferson Lab's Hall A

    SciTech Connect

    Cusanno, F; Bydzovsky, P; Chang, C C; Cisbani, E; De Jager, C W; De Leo, R; Frullani, S; Garibaldi, F; Higinbotham, D W; Iodice, M; LeRose, J J; Markowitz, P; Marrone, S; Sotona, M; Urciuoli, G M

    2010-03-01

    Updated results of the experiment E94-107 hypernuclear spectroscopy in Hall A of the Thomas Jefferson National Accelerator Facility (Jefferson Lab), are presented. The experiment provides high resolution spectra of excitation energy for 12B_\\Lambda, 16N_\\Lambda, and 9Li_\\Lambda hypernuclei obtained by electroproduction of strangeness. A new theoretical calculation for 12B_\\Lambda, final results for 16N_\\Lambda, and discussion of the preliminary results of 9Li_\\Lambda are reported.

  15. Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species

    SciTech Connect

    Hall G. E.; Goncharov, V.

    2012-05-29

    This research is carried out as part of the Gas-Phase Molecular Dynamics program in the Chemistry Department at Brookhaven National Laboratory. Chemical intermediates in the elementary gas-phase reactions involved in combustion chemistry are investigated by high resolution spectroscopic tools. Production, reaction, and energy transfer processes are investigated by transient, double resonance, polarization and saturation spectroscopies, with an emphasis on technique development and connection with theory, as well as specific molecular properties.

  16. Beamline 9.0.1 - a high-resolution undulator beamline for gas-phase spectroscopy

    SciTech Connect

    Bozek, J.D.; Heimann, P.A.; Mossessian, D.

    1997-04-01

    Beamline 9.0.1 at the Advanced Light Source is an undulator beamline with a Spherical Grating Monochromator (SGM) which provides very high resolution and flux over the photon energy range 20-320eV. The beamline has been used primarily by the atomic and molecular science community to conduct spectroscopy experiments using electron, ion and fluorescence photon detection. A description of the beamline and its performance will be provided in this abstract.

  17. Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species

    SciTech Connect

    Hall, G.E.

    2011-05-31

    This research is carried out as part of the Gas-Phase Molecular Dynamics program in the Chemistry Department at Brookhaven National Laboratory. Chemical intermediates in the elementary gas-phase reactions involved in combustion chemistry are investigated by high resolution spectroscopic tools. Production, reaction, and energy transfer processes are investigated by transient, double resonance, polarization and saturation spectroscopies, with an emphasis on technique development and connection with theory, as well as specific molecular properties.

  18. High-resolution extreme-ultraviolet spectroscopy of potassium using anti-Stokes radiation

    NASA Technical Reports Server (NTRS)

    Rothenberg, J. E.; Young, J. F.; Harris, S. E.

    1981-01-01

    The use of a new extreme-ultraviolet radiation source based on spontaneous anti-Stokes scattering for high-resolution absorption spectroscopy of transition originating from the 3p6 shell of potassium is reported. The region from 546.6 to 536.8 A is scanned at a resolution of about 1.2 Kayser. Within this region, four previously unreported lines are observed.

  19. High-resolution heteronuclear multi-dimensional NMR spectroscopy in magnetic fields with unknown spatial variations

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiyong; Huang, Yuqing; Smith, Pieter E. S.; Wang, Kaiyu; Cai, Shuhui; Chen, Zhong

    2014-05-01

    Heteronuclear NMR spectroscopy is an extremely powerful tool for determining the structures of organic molecules and is of particular significance in the structural analysis of proteins. In order to leverage the method’s potential for structural investigations, obtaining high-resolution NMR spectra is essential and this is generally accomplished by using very homogeneous magnetic fields. However, there are several situations where magnetic field distortions and thus line broadening is unavoidable, for example, the samples under investigation may be inherently heterogeneous, and the magnet’s homogeneity may be poor. This line broadening can hinder resonance assignment or even render it impossible. We put forth a new class of pulse sequences for obtaining high-resolution heteronuclear spectra in magnetic fields with unknown spatial variations based on distant dipolar field modulations. This strategy’s capabilities are demonstrated with the acquisition of high-resolution 2D gHSQC and gHMBC spectra. These sequences’ performances are evaluated on the basis of their sensitivities and acquisition efficiencies. Moreover, we show that by encoding and decoding NMR observables spatially, as is done in ultrafast NMR, an extra dimension containing J-coupling information can be obtained without increasing the time necessary to acquire a heteronuclear correlation spectrum. Since the new sequences relax magnetic field homogeneity constraints imposed upon high-resolution NMR, they may be applied in portable NMR sensors and studies of heterogeneous chemical and biological materials.

  20. Broadband High-Resolution Spectroscopy with Fabry-Perot Quantum Cascade Lasers

    NASA Astrophysics Data System (ADS)

    Wang, Yin; Wysocki, Gerard

    2014-06-01

    Simultaneous spectroscopic detection of large molecules with broad ro-vibrational spectra, and small molecules with well-resolved narrow spectral lines requires both broadband optical frequency coverage (>50 wn) and high resolution (<0.01 wn) to perform accurate spectral measurements. With the advent of room temperature, high power, continuous wave quantum cascade lasers (QCLs), high resolution mid-IR spectrometers for field applications became feasible. So far to address the broadband spectral coverage, external cavity (EC) QCLs with >100 wn tuning ranges have been spectroscopic sources of choice in the mid-IR; however EC-QCLs are rather complex opto-mechanical systems, which are vibration-sensitive, and construction of robust transportable systems is difficult. In this work we present a new method of performing broadband mid-IR spectroscopy using two free-running Fabry-Perot (FP) QCLs to perform multi-heterodyne down-conversion of optical signals to RF domain. The sample transmission spectrum probed by one multi-mode FP-QCL is down-converted to the RF domain through an optical multi-heterodyne process using a second FP-QCL as the local oscillator. Both a broadband multi-mode spectral measurement as well as high-resolution ( 15 MHz or 0.0005 wn) absorption spectroscopy of NH3 and N2O are demonstrated and show potential for all-solid-state FP-laser-based spectrometers for chemical sensing. Y. Wang, M. G. Soskind, W. Wang, and G. Wysocki, "High-resolution multi-heterodyne spectroscopy based on Fabry-Perot quantum cascade lasers," Appl Phys Lett 104, 0311141-0311145 (2014)

  1. High resolution transmission spectroscopy as a diagnostic for Jovian exoplanet atmospheres: constraints from theoretical models

    SciTech Connect

    Kempton, Eliza M.-R.; Perna, Rosalba; Heng, Kevin

    2014-11-01

    We present high resolution transmission spectra of giant planet atmospheres from a coupled three-dimensional (3D) atmospheric dynamics and transmission spectrum model that includes Doppler shifts which arise from winds and planetary motion. We model Jovian planets covering more than two orders of magnitude in incident flux, corresponding to planets with 0.9-55 day orbital periods around solar-type stars. The results of our 3D dynamical models reveal certain aspects of high resolution transmission spectra that are not present in simple one-dimensional (1D) models. We find that the hottest planets experience strong substellar to anti-stellar (SSAS) winds, resulting in transmission spectra with net blueshifts of up to 3 km s{sup –1}, whereas less irradiated planets show almost no net Doppler shifts. We find only minor differences between transmission spectra for atmospheres with temperature inversions and those without. Compared to 1D models, peak line strengths are significantly reduced for the hottest atmospheres owing to Doppler broadening from a combination of rotation (which is faster for close-in planets under the assumption of tidal locking) and atmospheric winds. Finally, high resolution transmission spectra may be useful in studying the atmospheres of exoplanets with optically thick clouds since line cores for very strong transitions should remain optically thick to very high altitude. High resolution transmission spectra are an excellent observational test for the validity of 3D atmospheric dynamics models, because they provide a direct probe of wind structures and heat circulation. Ground-based exoplanet spectroscopy is currently on the verge of being able to verify some of our modeling predictions, most notably the dependence of SSAS winds on insolation. We caution that interpretation of high resolution transmission spectra based on 1D atmospheric models may be inadequate, as 3D atmospheric motions can produce a noticeable effect on the absorption

  2. High Resolution Transmission Spectroscopy as a Diagnostic for Jovian Exoplanet Atmospheres: Constraints from Theoretical Models

    NASA Astrophysics Data System (ADS)

    Kempton, Eliza M.-R.; Perna, Rosalba; Heng, Kevin

    2014-11-01

    We present high resolution transmission spectra of giant planet atmospheres from a coupled three-dimensional (3D) atmospheric dynamics and transmission spectrum model that includes Doppler shifts which arise from winds and planetary motion. We model Jovian planets covering more than two orders of magnitude in incident flux, corresponding to planets with 0.9-55 day orbital periods around solar-type stars. The results of our 3D dynamical models reveal certain aspects of high resolution transmission spectra that are not present in simple one-dimensional (1D) models. We find that the hottest planets experience strong substellar to anti-stellar (SSAS) winds, resulting in transmission spectra with net blueshifts of up to 3 km s-1, whereas less irradiated planets show almost no net Doppler shifts. We find only minor differences between transmission spectra for atmospheres with temperature inversions and those without. Compared to 1D models, peak line strengths are significantly reduced for the hottest atmospheres owing to Doppler broadening from a combination of rotation (which is faster for close-in planets under the assumption of tidal locking) and atmospheric winds. Finally, high resolution transmission spectra may be useful in studying the atmospheres of exoplanets with optically thick clouds since line cores for very strong transitions should remain optically thick to very high altitude. High resolution transmission spectra are an excellent observational test for the validity of 3D atmospheric dynamics models, because they provide a direct probe of wind structures and heat circulation. Ground-based exoplanet spectroscopy is currently on the verge of being able to verify some of our modeling predictions, most notably the dependence of SSAS winds on insolation. We caution that interpretation of high resolution transmission spectra based on 1D atmospheric models may be inadequate, as 3D atmospheric motions can produce a noticeable effect on the absorption signatures.

  3. Protected Plasmonic Nanostructures for High Resolution Chemical Imaging using Tip Enhanced Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Butt, Rebecca; Barrios, Carlos; Malkovskiy, Andrey; Kisliuk, Alexander; Sokolov, Alexei; Foster, Mark

    2009-03-01

    Tip enhanced Raman spectroscopy (TERS), an emerging technique that combines optical microscopy and scanning probe microscopy, provides the sensitivity and selectivity necessary for high-resolution chemical imaging of polymer surfaces. An unprecedented 20 nm lateral resolution for the chemical imaging has been achieved. Unfortunately, the fragile plasmonic structures used to enhance the electric field are prone to mechanical, chemical, and thermal degradation. Developing robust noble metal nanostructures with stable plasmonic resonance is essential to reliable high resolution chemical imaging. Covering the metal layer with organic and inorganic ultrathin coatings is being investigated to extend the plasmonic activity of the engineered nanostructures. Addition of an ultrathin aluminum oxide (Al2O3) coating to a silver-coated scanning probe microscopy tip for TERS significantly improves plasmonic structure stability without sacrificing the initial TERS efficiency. This ultrathin coating provides wear resistance and stops chemical degradation responsible for the loss of signal enhancement.

  4. Fast acquisition of high-resolution 2D NMR spectroscopy in inhomogeneous magnetic fields

    NASA Astrophysics Data System (ADS)

    Lin, Liangjie; Wei, Zhiliang; Zeng, Qing; Yang, Jian; Lin, Yanqin; Chen, Zhong

    2016-05-01

    High-resolution nuclear magnetic resonance (NMR) spectroscopy plays an important role in chemical and biological analyses. In this study, we combine the J-coupling coherence transfer module with the echo-train acquisition technique for fast acquisition of high-resolution 2D NMR spectra in magnetic fields with unknown spatial variations. The proposed method shows satisfactory performance on a 5 mM ethyl 3-bromopropionate sample, under a 5-kHz (10 ppm at 11.7 T) B0 inhomogeneous field, as well as under varying degrees of pulse-flip-angle deviations. Moreover, a simulative ex situ NMR measurement is also conducted to show the effectiveness of the proposed pulse sequence.

  5. HERMES at Mercator, competitive high-resolution spectroscopy with a small telescope

    NASA Astrophysics Data System (ADS)

    Raskin , G.; Van Winckel, H.

    2014-01-01

    HERMES, a fibre-fed high-resolution (R = 85 000) échelle spectrograph with good stability and excellent throughput, is the work-horse instrument of the 1.2-m Mercator telescope on La Palma. HERMES targets building up time series of high-quality data of variable stellar phenomena, mainly for asteroseismology and binary-evolution research. In this paper we present the HERMES project and discuss the instrument design, performance, and a future upgrade. We also present some results of the first four years of HERMES observations. We illustrate the value of small telescopes, equipped with efficient instrumentation, for high-resolution spectroscopy. Based on observations made with the Mercator Telescope, operated on the island of La Palma by the Flemish Community, at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

  6. High resolution coherent three dimensional spectroscopy of NO{sub 2}

    SciTech Connect

    Wells, Thresa A.; Muthike, Angelar K.; Robinson, Jessica E.; Chen, Peter C.

    2015-06-07

    Expansion from coherent 2D spectroscopy to coherent 3D spectroscopy can provide significant advantages when studying molecules that have heavily perturbed energy levels. This paper illustrates such advantages by demonstrating how high resolution coherent 3D (HRC3D) spectroscopy can be used to study a portion of the visible spectrum of nitrogen dioxide. High resolution coherent 2D spectra usually contain rotational and vibrational patterns that are easy to analyze, but severe congestion and complexity preclude its effective use for many parts of the NO{sub 2} spectrum. HRC3D spectroscopy appears to be much more effective; multidimensional rotational and vibrational patterns produced by this new technique are easy to identify even in the presence of strong perturbations. A method for assigning peaks, which is based upon analyzing the resulting multidimensional patterns, has been developed. The higher level of multidimensionality is useful for reducing uncertainty in peak assignments, improving spectral resolution, providing simultaneous information on multiple levels and states, and predicting, verifying, and categorizing peaks.

  7. Synchrotron-Based High Resolution Spectroscopy of N-Bearing Pahs

    NASA Astrophysics Data System (ADS)

    Gruet, Sébastien; Pirali, Olivier; Goubet, Manuel; Brechignac, Philippe

    2014-06-01

    For thirty years, the Polycyclic Aromatic Hydrocarbons (PAHs) have been suspected to give rise to the numerous Unidentified Infrared Bands (UIBs) observed in most astrophysical objects. Pure carbon molecules as well as derivatives with nitrogen atom(s) incorporated into the carbon skeleton have been considered. These N-bearing molecules are interesting candidates for astronomical research since they possess a larger permanent dipole moment than purely carbon-based PAHs. Most of the data reported in the literature deal with rotationally unresolved data. During the last decade, high-resolution microwave spectroscopy initiated high resolution studies of this broad family of molecules. Recent advances in laboratory techniques permitted to provide interesting new results to rotationally resolve the IR/Far-IR vibrational bands of these relatively large C-bearing molecules, in particular, making use of synchrotron radiation as the IR continuum source of high resolution Fourier transform (FT) spectrometers. We will present an overview of the synchrotron-based high resolution FTIR spectroscopy of 5 aza-derivatives of naphthalene (isoquinoline, quinoline, quinoxaline, quinazoline, [1,5] naphthyridine) using a room temperature long path absorption cell at the French facility SOLEIL. In support to the rovibrational analysis of these FIR spectra, very accurate anharmonic DFT calculations were performed. A. Leger, J. L. Puget, Astron. Astrophys. 137, L5-L8 (1984) L. J. Allamandola et al. Astrophys. J. 290, L25-L28 (1985). Z. Kisiel et al. J. Mol. Spectrosc. 217, 115 (2003) S. Thorwirth et al. Astrophys. J. 662, 1309 (2007) D. McNaughton et al. J. Chem. Phys. 124, 154305 (2011). S. Albert et al. Faraday Discuss. 150, 71-99 (2011) B. E. Brumfield et al. Phys. Chem. Lett. 3, 1985-1988 (2012) O. Pirali et al. Phys. Chem. Chem. Phys. 15, 10141 (2013) M. Goubet, O. Pirali, J. Chem. Phys., 140, 044322 (2014).

  8. Optical Properties of Wurtzite Semiconductors Studied Using Cathodoluminescence Imaging and Spectroscopy

    NASA Astrophysics Data System (ADS)

    Juday, Reid

    The work contained in this dissertation is focused on the optical properties of direct band gap semiconductors which crystallize in a wurtzite structure: more specifically, the III-nitrides and ZnO. By using cathodoluminescence spectroscopy, many of their properties have been investigated, including band gaps, defect energy levels, carrier lifetimes, strain states, exciton binding energies, and effects of electron irradiation on luminescence. Part of this work is focused on p-type Mg-doped GaN and InGaN. These materials are extremely important for the fabrication of visible light emitting diodes and diode lasers and their complex nature is currently not entirely understood. The luminescence of Mg-doped GaN films has been correlated with electrical and structural measurements in order to understand the behavior of hydrogen in the material. Deeply-bound excitons emitting near 3.37 and 3.42 eV are observed in films with a significant hydrogen concentration during cathodoluminescence at liquid helium temperatures. These radiative transitions are unstable during electron irradiation. Our observations suggest a hydrogen-related nature, as opposed to a previous assignment of stacking fault luminescence. The intensity of the 3.37 eV transition can be correlated with the electrical activation of the Mg acceptors. Next, the acceptor energy level of Mg in InGaN is shown to decrease significantly with an increase in the indium composition. This also corresponds to a decrease in the resistivity of these films. In addition, the hole concentration in multiple quantum well light emitting diode structures is much more uniform in the active region when Mg-doped InGaN (instead of Mg-doped GaN) is used. These results will help improve the efficiency of light emitting diodes, especially in the green/yellow color range. Also, the improved hole transport may prove to be important for the development of photovoltaic devices. Cathodoluminescence studies have also been performed on

  9. High-resolution pulsed-field ionization photoelectron spectroscopy using multi-bunch synchrotron radiation

    SciTech Connect

    Hsu, C.W.; Evans, M.; Ng, C.Y.; Heimann, P.

    1997-04-01

    BL9.0.2.2 is the newly constructed experimental End Station 2 at the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source (ALS). It is dedicated to the high resolution photoionization study of molecules of interest to atmospheric and combustion chemistry. This End Station is equipped with a high resolution scanning monochromator, which has been demonstrated to have a world record resolution of E/{delta}E=70,000. Taking the advantage of the high resolution ALS light, the authors have improved the energy resolution in threshold photoelectron spectroscopy (TPES) to 0.8 meV. The TPES is a popular technique for photoionization experiments at all synchrotron radiation facilities due to its high energy resolution as compared to that of traditional photoelectron spectroscopy (PES). TPES achieves higher energy resolution by preferentially detecting near zero kinetic energy photoelectrons resulting from threshold photoionization. However, the spectra obtained from the TPES technique generally are complicated by the simultaneous detection of electrons with nonzero kinetic energy, which are not fully discriminated against. On the other hand, the spectra obtained from pulsed field ionization photoelectron spectroscopy (PFI-PES) are completely free of the contamination from kinetic electrons. The PFI-PE technique basically involves the detection of the photoelectrons from field ionization of the very high-n Rydberg states, a few cm{sup {minus}1} below the ionization energy (IE), by applying a delayed pulsed electric field. Within a delay of a few microseconds, all the prompt electrons formed from direct ionization will escape from the photoionization region and will not be collected. The authors have recently overcome problems with energy resolution of an electron time-of-flight technique, and incorporated the PFI-PE technique with multi-bunch VUV synchrotron radiation.

  10. High-Resolution Kaonic-Atom X-ray Spectroscopy with Transition-Edge-Sensor Microcalorimeters

    NASA Astrophysics Data System (ADS)

    Okada, S.; Bennett, D. A.; Doriese, W. B.; Fowler, J. W.; Irwin, K. D.; Ishimoto, S.; Sato, M.; Schmidt, D. R.; Swetz, D. S.; Tatsuno, H.; Ullom, J. N.; Yamada, S.

    2014-09-01

    We are preparing for an ultra-high resolution X-ray spectroscopy of kaonic atoms using an X-ray spectrometer based on an array of superconducting transition-edge-sensor microcalorimeters developed by NIST. The instrument has excellent energy resolutions of 2-3 eV (FWHM) at 6 keV and a large collecting area of about 20 mm. This will open new door to investigate kaon-nucleus strong interaction and provide new accurate charged-kaon mass value.

  11. High-resolution magic-angle-spinning NMR spectroscopy of intact tissue.

    PubMed

    Giskeødegård, Guro F; Cao, Maria D; Bathen, Tone F

    2015-01-01

    High-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy is a nondestructive technique that is used to obtain the metabolite profile of a tissue sample. This method requires minimal sample preparation. However, it is important to handle the sample with care and keep it frozen during preparation to minimize degradation. Here, we describe a typical protocol for HR-MAS analysis of intact tissue. We also include examples of typical pulse sequence programs and quantification methods that are used today. PMID:25677145

  12. Determination of Ionization Potential of Calcium by High-Resolution Resonance Ionization Spectroscopy

    NASA Astrophysics Data System (ADS)

    Miyabe, Masabumi; Geppert, Christopher; Kato, Masaaki; Oba, Masaki; Wakaida, Ikuo; Watanabe, Kazuo; Wendt, Klaus D. A.

    2006-03-01

    High-resolution resonance ionization spectroscopy has been utilized to determine a precise ionization potential of Ca. Three-step resonance excitation with single-mode extended-cavity diode lasers populates long and unperturbed Rydberg series of 4snp (1P1) and 4snf (1F3) states in the range of n=20--150. Using an extended Ritz formula for quantum defects, the series convergence limit has been determined to be 49305.9240(20) cm-1 with the accuracy improved one order of magnitude higher than previously reported ones.

  13. High-Resolution Spectroscopy with the Chandra X-ray Observatory

    ScienceCinema

    Canizares, Claude R. [MIT, Cambridge, Massachusetts, United States

    2010-01-08

    The capabilities of the Chandra X-ray Observatory and XMM-Newton for high-resolution spectroscopy have brought tradition plasma diagnostic techniques to the study of cosmic plasma. Observations have probed nearly every class of astronomical object, from young proto-starts through massive O starts and black hole binaries, supernova remnants, active galactic nuclei, and the intergalactic medium. Many of these sources show remarkable rich spectra that reveal new physical information, such as emission measure distributions, elemental abundances, accretion disk and wind signatures, and time variability. This talk will present an overview of the Chandra instrumentaton and selected examples of spectral observations of astrophysical and cosmological importance.

  14. High resolution photoelectron spectroscopy and femtosecond intramolecular dynamics using supersonic molecular beams

    SciTech Connect

    Niu, B.

    1992-09-01

    High resolution He I[alpha] photoelectron spectroscopy of formaldehyde and ketene and their deuterated compounds, are reported. The combination of a (H2CO) double-pass high-resolution electron-energy analyzer and effective rotational cooling of the sample by supersonic expansion enable the spectroscopy of these molecular cations. The vibrational autocorrelation functions are calculated from the high-resolution photoelectron spectra, shedding light on the ultrafast intramolecular dynamics of the molecular cations. This study reveals much more vibrational structural detail in the first electronic excited state of H2CO cations. The first electronic excited state of H2CO cations may have nonplanar equilibrium geometry. Strong isotope effects on vibronic (vibrational) coupling are observed in the second electronic excited state of H2CO. Vibrational autocorrelation functions are calculated for all four observed electronic states of H2CO. The correlation function of the first electronic excited state of H2CO shows a slow decay rate on the femtosecond time scale. The ultrafast decay of the H2CO cations in the third electronic excited state implies that dissociation and intramolecular processes are the main decay pathways. The present spectra of the ground states of ketene cations have more fine structure than before. The AIEs of the first and fifth excited states are determined unambiguously more accurately. The doublet-like fine structures present in the lint excited state of ketene implies the excitation of a soft'' mode not observed before. The vibrational autocorrelation functions are calculated for 4 of the 6 observed electronic states. The dynamics of the ground states of the cations are characterized by a wave packet oscillating with small amplitude around the minimum on the upper PES. The decay dynamics of the first and the fifth excited states of ketene are characterized by ultra-fast intramolecular processes like predissociation.

  15. High resolution photoelectron spectroscopy and femtosecond intramolecular dynamics using supersonic molecular beams

    SciTech Connect

    Niu, B.

    1992-09-01

    High resolution He I{alpha} photoelectron spectroscopy of formaldehyde and ketene and their deuterated compounds, are reported. The combination of a (H2CO) double-pass high-resolution electron-energy analyzer and effective rotational cooling of the sample by supersonic expansion enable the spectroscopy of these molecular cations. The vibrational autocorrelation functions are calculated from the high-resolution photoelectron spectra, shedding light on the ultrafast intramolecular dynamics of the molecular cations. This study reveals much more vibrational structural detail in the first electronic excited state of H2CO cations. The first electronic excited state of H2CO cations may have nonplanar equilibrium geometry. Strong isotope effects on vibronic (vibrational) coupling are observed in the second electronic excited state of H2CO. Vibrational autocorrelation functions are calculated for all four observed electronic states of H2CO. The correlation function of the first electronic excited state of H2CO shows a slow decay rate on the femtosecond time scale. The ultrafast decay of the H2CO cations in the third electronic excited state implies that dissociation and intramolecular processes are the main decay pathways. The present spectra of the ground states of ketene cations have more fine structure than before. The AIEs of the first and fifth excited states are determined unambiguously more accurately. The doublet-like fine structures present in the lint excited state of ketene implies the excitation of a ``soft`` mode not observed before. The vibrational autocorrelation functions are calculated for 4 of the 6 observed electronic states. The dynamics of the ground states of the cations are characterized by a wave packet oscillating with small amplitude around the minimum on the upper PES. The decay dynamics of the first and the fifth excited states of ketene are characterized by ultra-fast intramolecular processes like predissociation.

  16. High-Resolution Structure of the Photosynthetic Mn4Ca Catalyst from X-ray Spectroscopy

    SciTech Connect

    Yachandra, Vittal; Yano, Junko; Kern, Jan; Pushkar, Yulia; Sauer, Kenneth; Glatzel, Pieter; Bergmann, Uwe; Messinger, Johannes; Zouni, Athina; Yachandra, Vittal K.

    2007-08-01

    The application of high-resolution X-ray spectroscopy methods to study the photosynthetic water oxidizing complex, which contains a unique hetero-nuclear catalytic Mn4Ca cluster, are described. Issues of X-ray damage especially at the metal sites in the Mn4Ca cluster are discussed. The structure of the Mn4Ca catalyst at high-resolution which has so far eluded attempts of determination by X-ray diffraction, EXAFS and other spectroscopic techniques has been addressed using polarized EXAFS techniques applied to oriented PS II membrane preparations and PS II single crystals. A review of how the resolution of traditional EXAFS techniques can be improved, using methods such as range-extended EXAFS is presented, and the changes that occur in the structure of the cluster as it advances through the catalytic cycle are described. X-ray absorption and emission techniques (XANES and K? emission) have been used earlier to determine the oxidation states of the Mn4Ca cluster, and in this report we review the use of X-ray resonant Raman spectroscopy to understand the electronic structure of the Mn4Ca cluster as it cycles through the intermediate S-states.

  17. High resolution Halpha spectroscopy and R-band photometry of Swift J1357.2-0933

    NASA Astrophysics Data System (ADS)

    Casares, Jorge; Torres, Manuel A. P.; Negueruela, Ignacio; Gonzalez-Fernandez, Carlos; Corral-Santana, Jesus M.; Zurita, Cristina; Llano, Sergio Rodriguez

    2011-03-01

    We report on high resolution Halpha spectroscopy and time-resolved photometry of the optical counterpart to the X-ray transient Swift J1357.2-0933 in outburst (Krimm et al. ATEL #3138). SPECTROSCOPY: Six 30-33 min spectra were obtained on the nights of 2011 Feb 25-27 using the IDS Spectrograph on the 2.5m Isaac Newton Telescope (INT) at the Observatorio del Roque de Los Muchachos. The observations were performed with the H1800V grating and a slit width 1.6 arcsec to yield a spectral coverage of 6270-7000 Angs with a 30 km/s FWHM spectral resolution at Halpha..

  18. Automatic pole-zero/zero-pole digital compensator for high-resolution spectroscopy: Design and experiments

    SciTech Connect

    Geraci, A.; Pullia, A.; Ripamonti, G.

    1999-08-01

    In a high-resolution spectroscopy system the relatively long exponential decay due to the charge preamplifier is customarily canceled in an analogue fashion by means of a PZ (Pole-Zero) stage. The accurateness of such a compensation has a big impact on the energy resolution because it strongly affects the baseline-stability problems. The authors have automatically and on-line performed such a compensation in a digital way, while maintaining a spectroscopy performance and keeping at minimum both the ADC sampling frequency (thus power consumption) and its resolution (thus cost). This is done through an IIR filter, implemented within a FPGA by a DSP. The so-compensated waveform has, in excellent approximation, an all-pole shape. Starting from such a signal, the minimum-noise filters for energy and/or time measurements are then promptly synthesized and implemented for real time operation through the same DSP.

  19. Forensic examination of electrical tapes using high resolution magic angle spinning ¹H NMR spectroscopy.

    PubMed

    Schoenberger, Torsten; Simmross, Ulrich; Poppe, Christian

    2016-01-01

    The application of high resolution magic angle spinning (HR-MAS) (1)H NMR spectroscopy is ideally suited for the differentiation of plastics. In addition to the actual material composition, the different types of polymer architectures and tacticity provide characteristic signals in the fingerprint of the (1)H NMR spectra. The method facilitates forensic comparison, as even small amounts of insoluble but swellable plastic particles are utilized. The performance of HR-MAS NMR can be verified against other methods that were recently addressed in various articles about forensic tape comparison. In this study samples of the 90 electrical tapes already referenced by the FBI laboratory were used. The discrimination power of HR-MAS is demonstrated by the fact that more tape groups can be distinguished by NMR spectroscopy than by using the combined evaluation of several commonly used analytical techniques. An additional advantage of this robust and quick method is the very simple sample preparation. PMID:26558760

  20. A tunable low-energy photon source for high-resolution angle-resolved photoemission spectroscopy

    SciTech Connect

    Harter, John W.; Monkman, Eric J.; Shai, Daniel E.; Nie Yuefeng; Uchida, Masaki; Burganov, Bulat; Chatterjee, Shouvik; King, Philip D. C.; Shen, Kyle M.

    2012-11-15

    We describe a tunable low-energy photon source consisting of a laser-driven xenon plasma lamp coupled to a Czerny-Turner monochromator. The combined tunability, brightness, and narrow spectral bandwidth make this light source useful in laboratory-based high-resolution photoemission spectroscopy experiments. The source supplies photons with energies up to {approx}7 eV, delivering under typical conditions >10{sup 12} ph/s within a 10 meV spectral bandwidth, which is comparable to helium plasma lamps and many synchrotron beamlines. We first describe the lamp and monochromator system and then characterize its output, with attention to those parameters which are of interest for photoemission experiments. Finally, we present angle-resolved photoemission spectroscopy data using the light source and compare its performance to a conventional helium plasma lamp.

  1. High-resolution laser spectroscopy with the Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at CERN-ISOLDE

    NASA Astrophysics Data System (ADS)

    Cocolios, T. E.; de Groote, R. P.; Billowes, J.; Bissell, M. L.; Budinčević, I.; Day Goodacre, T.; Farooq-Smith, G. J.; Fedosseev, V. N.; Flanagan, K. T.; Franchoo, S.; Garcia Ruiz, R. F.; Gins, W.; Heylen, H.; Kron, T.; Li, R.; Lynch, K. M.; Marsh, B. A.; Neyens, G.; Rossel, R. E.; Rothe, S.; Smith, A. J.; Stroke, H. H.; Wendt, K. D. A.; Wilkins, S. G.; Yang, X.

    2016-06-01

    The Collinear Resonance Ionisation Spectroscopy (CRIS) experiment at CERN has achieved high-resolution resonance ionisation laser spectroscopy with a full width at half maximum linewidth of 20(1) MHz for 219,221 Fr, and has measured isotopes as short lived as 5 ms with 214 Fr. This development allows for greater precision in the study of hyperfine structures and isotope shifts, as well as a higher selectivity of single-isotope, even single-isomer, beams. These achievements are linked with the development of a new laser laboratory and new data-acquisition systems.

  2. High-Resolution Electron Energy-Loss Spectroscopy (HREELS) Using a Monochromated TEM/STEM

    NASA Technical Reports Server (NTRS)

    Sai, Z. R.; Bradley, J. P.; Erni, R.; Browning, N.

    2005-01-01

    A 200 keV FEI TF20 XT monochromated (scanning) transmission electron microscope funded by NASA's SRLIDAP program is undergoing installation at Lawrence Livermore National Laboratory. Instrument specifications in STEM mode are Cs =1.0 mm, Cc =1.2 mm, image resolution =0.18 nm, and in TEM mode Cs =1.3 mm, Cc =1.3 mm, information limit =0.14 nm. Key features of the instrument are a voltage-stabilized high tension (HT) supply, a monochromator, a high-resolution electron energy-loss spectrometer/energy filter, a high-resolution annular darkfield detector, and a solid-state x-ray energy-dispersive spectrometer. The high-tension tank contains additional sections for 60Hz and high frequency filtering, resulting in an operating voltage of 200 kV plus or minus 0.005V, a greater than 10-fold improvement over earlier systems. The monochromator is a single Wien filter design. The energy filter is a Gatan model 866 Tridiem-ERS high resolution GIF spec d for less than or equal to 0.15 eV energy resolution with 29 pA of current in a 2 nm diameter probe. 0.13 eV has already been achieved during early installation. The x-ray detector (EDAX/Genesis 4000) has a take-off angle of 20 degrees, an active area of 30 square millimeters, and a solid angle of 0.3 steradians. The higher solid angle is possible because the objective pole-piece allows the detector to be positioned as close as 9.47 mm from the specimen. The voltage-stabilized HT supply, monochromator and GIF enable high-resolution electron energy-loss spectroscopy (HREELS) with energy resolution comparable to synchrotron XANES, but with approximately 100X better spatial resolution. The region between 0 and 100 eV is called the low-loss or valence electron energy-loss spectroscopy (VEELS) region where features due to collective plasma oscillations and single electron transitions of valence electrons are observed. Most of the low-loss VEELS features we are detecting are being observed for the first time in IDPs. A major focus of

  3. Potential of Cathodoluminescence Microscopy and Spectroscopy for the Detection of Prokaryotic Cells on Minerals

    NASA Astrophysics Data System (ADS)

    Rommevaux-Jestin, Céline; Ménez, Bénédicte

    2010-11-01

    Detecting mineral-hosted ecosystems to assess the extent and functioning of the biosphere from the surface to deep Earth requires appropriate techniques that provide, beyond the morphological criteria, indubitable clues of the presence of prokaryotic cells. Here, we evaluate the capability of cathodoluminescence microscopy and spectroscopy, implemented on a scanning electron microscope, to identify prokaryotes on mineral surfaces. For this purpose, we used, as a first step, a simple model of either unstained or stained cultivable cells (Escherichia coli, Deinococcus radiodurans) deposited on minerals that are common in the oceanic crust (basaltic glass, amphibole, pyroxene, and magnetite). Our results demonstrate that the detection of cells is possible at the micrometric level on the investigated minerals through the intrinsic fluorescence of their constituting macromolecules (aromatic amino and nucleic acids, coenzymes). This allows us to distinguish biomorph inorganic phases from cells. This easily implemented technique permits an exploration of colonized rock samples. In addition, the range of spectrometric techniques available on a scanning electron microscope can provide additional information on the nature and chemistry of the associated mineral phases, which would lead to a simultaneous characterization of cells, their microhabitats, and a better understanding of their potential relationships.

  4. Microscopy and Cathodoluminescence Spectroscopy Characterization of Quartz Exhibiting Different Alkali-Silica Reaction Potential.

    PubMed

    Kuchařová, Aneta; Götze, Jens; Šachlová, Šárka; Pertold, Zdeněk; Přikryl, Richard

    2016-02-01

    Different quartz types from several localities in the Czech Republic and Sweden were examined by polarizing microscopy combined with cathodoluminescence (CL) microscopy, spectroscopy, and petrographic image analysis, and tested by use of an accelerated mortar bar test (following ASTM C1260). The highest alkali-silica reaction potential was indicated by very fine-grained chert, containing significant amounts of fine-grained to cryptocrystalline matrix. The chert exhibited a dark red CL emission band at ~640 nm with a low intensity. Fine-grained orthoquartzites, as well as fine-grained metamorphic vein quartz, separated from phyllite exhibited medium expansion values. The orthoquartzites showed various CL of quartz grains, from blue through violet, red, and brown. Two CL spectral bands at ~450 and ~630 nm, with various intensities, were detected. The quartz from phyllite displayed an inhomogeneous dark red CL with two CL spectral bands of low intensities at ~460 and ~640 nm. The massive coarse-grained pegmatite quartz from pegmatite was assessed to be nonreactive and displayed a typical short-lived blue CL (~480 nm). The higher reactivity of the fine-grained hydrothermal quartz may be connected with high concentrations of defect centers, and probably with amorphized micro-regions in the quartz, respectively; indicated by a yellow CL emission (~570 nm). PMID:26790877

  5. The role of transition radiation in cathodoluminescence imaging and spectroscopy of thin-foils.

    PubMed

    Mendis, B G; Howkins, A; Stowe, D; Major, J D; Durose, K

    2016-08-01

    There is renewed interest in cathodoluminescence (CL) in the transmission electron microscope, since it can be combined with low energy loss spectroscopy measurements and can also be used to probe defects, such as grain boundaries and dislocations, at high spatial resolution. Transition radiation (TR), which is emitted when the incident electron crosses the vacuum-specimen interface, is however an important artefact that has received very little attention. The importance of TR is demonstrated on a wedge shaped CdTe specimen of varying thickness. For small specimen thicknesses (<250nm) grain boundaries are not visible in the panchromatic CL image. Grain boundary contrast is produced by electron-hole recombination within the foil, and a large fraction of that light is lost to multiple-beam interference, so that thicker specimens are required before the grain boundary signal is above the TR background. This is undesirable for high spatial resolution. Furthermore, the CL spectrum contains additional features due to TR which are not part of the 'bulk' specimen. Strategies to minimise the effects of TR are also discussed. PMID:27163963

  6. Potential of cathodoluminescence microscopy and spectroscopy for the detection of prokaryotic cells on minerals.

    PubMed

    Rommevaux-Jestin, Céline; Ménez, Bénédicte

    2010-11-01

    Detecting mineral-hosted ecosystems to assess the extent and functioning of the biosphere from the surface to deep Earth requires appropriate techniques that provide, beyond the morphological criteria, indubitable clues of the presence of prokaryotic cells. Here, we evaluate the capability of cathodoluminescence microscopy and spectroscopy, implemented on a scanning electron microscope, to identify prokaryotes on mineral surfaces. For this purpose, we used, as a first step, a simple model of either unstained or stained cultivable cells (Escherichia coli, Deinococcus radiodurans) deposited on minerals that are common in the oceanic crust (basaltic glass, amphibole, pyroxene, and magnetite). Our results demonstrate that the detection of cells is possible at the micrometric level on the investigated minerals through the intrinsic fluorescence of their constituting macromolecules (aromatic amino and nucleic acids, coenzymes). This allows us to distinguish biomorph inorganic phases from cells. This easily implemented technique permits an exploration of colonized rock samples. In addition, the range of spectrometric techniques available on a scanning electron microscope can provide additional information on the nature and chemistry of the associated mineral phases, which would lead to a simultaneous characterization of cells, their microhabitats, and a better understanding of their potential relationships. PMID:21118024

  7. In situ high-resolution X-ray photoelectron spectroscopy - Fundamental insights in surface reactions

    NASA Astrophysics Data System (ADS)

    Papp, Christian; Steinrück, Hans-Peter

    2013-11-01

    Since the advent of third generation synchrotron light sources optimized for providing soft X-rays up to 2 keV, X-ray photoelectron spectroscopy (XPS) has been developed to be an outstanding tool to study surface properties and surface reactions at an unprecedented level. The high resolution allows identifying various surface species, and for small molecules even the vibrational fine structure can be resolved in the XP spectra. The high photon flux reduces the required measuring time per spectrum to the domain of a few seconds or even less, which enables to follow surface processes in situ. Moreover, it also provides access to very small coverages down to below 0.1% of a monolayer, enabling the investigation of minority species or processes at defect sites. The photon energy can be adjusted according to the requirement of a particular experiment, i.e., to maximize or minimize the surface sensitivity or the photoionization cross-section of the substrate or the adsorbate. For a few instruments worldwide, a next step forward was taken by combining in situ high-resolution spectrometers with supersonic molecular beams. These beams allow to control and vary the kinetic and internal energies of the incident molecules and provide a local pressure of up to ~10-5 mbar, which can be switched on and off in a controllable way, thus offering a well-defined time structure to study adsorption or reaction processes.

  8. High-resolution X-ray spectroscopy of four active galaxies - Probing the intercloud medium

    NASA Technical Reports Server (NTRS)

    Lum, Kenneth S. K.; Canizares, Claude R.; Markert, Thomas H.; Arnaud, Keith A.

    1990-01-01

    The focal plane crystal spectrometer (FPCS) on the Einstein Observatory has been used to perform a high-resolution spectroscopic search for oxygen X-ray line emission from four active galaxies: Fairall 9, Mrk 421, Mrk 501, and PKS 0548 - 322. Specifically, O VIII Ly-alpha and Ly-beta, whose unredshifted energies are 653 and 775 eV, respectively, were sought. No narrow-line emission was detected within the energy bands searched. Upper limits are calculated on the line flux from these sources of 30 eV equivalent width and use a photoionization model to place corresponding upper limits on the densities of diffuse gas surrounding the active nuclei. The upper limits on gas density range from about 0.02-50/cu cm and probe various radial distances from the central source. This is the first time high-resolution X-ray spectroscopy has been used to place constraints on the intercloud medium in active galaxies.

  9. Continuous wave terahertz wave spectrometer based on diode laser pumping: potential applications in high resolution spectroscopy.

    PubMed

    Tanabe, Tadao; Ragam, Srinivasa; Oyama, Yutaka

    2009-11-01

    We constructed a high resolution terahertz (THz) spectroscopic system with an automatic scanning control using a continuous wave (cw) THz wave generator based on difference frequency generation method by excitation of phonon-polariton mode in GaP. The pump and signals lasers were compact, tunable external cavity laser, and distributed feedback (DFB) lasers, respectively. The generated THz waves were tuned automatically by changing the temperature of the DFB laser using a system control. We present the water vapor transmission characteristics of the THz wave and also absorption spectrum of a white polyethylene in the frequency range of 1.97-2.45 THz. The spectroscopic measurements performed at an output power level of 2 nW, which was obtained with a 15-mm-long GaP crystal at 2 THz. The advantage of this cw THz spectrometer is wide frequency tuning range (0.7-4.42 THz) with an estimated linewidth of full width at quarter maximum <8 MHz and this system has a potential application in high resolution spectroscopy. PMID:19947715

  10. Diamond-machined ZnSe immersion grating for NIR high-resolution spectroscopy

    SciTech Connect

    Ikeda, Y; Kobayashi, N; Kuzmenko, P J; Little, S L; Yasui, C; Kondo, S; Minami, A; Motohara, K

    2008-07-25

    ZnSe immersion gratings (n {approx} 2.45) provide the possibility of high-resolution spectroscopy for the near-infrared (NIR) region. Since ZnSe has a lower internal attenuation than other NIR materials, it is most suitable for immersion grating, particularly in short NIR region (0.8-1.4 {micro}m). We are developing an extremely high-resolution spectrograph with {lambda}/{Delta}{lambda} = 100,000, WINERED, customized for the short NIR region, using ZnSe (or ZnS) immersion grating. However, it had been very difficult to make fine grooves on ZnSe substrate with a small pitch of less than 50 {micro}m because ZnSe is a soft/brittle material. We have overcome this problem and successfully machined sharp grooves with fine pitch on ZnSe substrates by nano precision fly-cutting technique at LLNL. The optical testing of the sample grating with HeNe laser shows an excellent performance: the relative efficiency more than 87.4 % at 0.633 {micro}m for a classical grating configuration. The diffraction efficiency when used as an immersion grating is estimated to be more than 65 % at 1 {micro}m. Following this progress, we are about to start machining a grating on a large ZnSe prism with an entrance aperture of 23mm x 50mm and the blaze angle of 70{sup o}.

  11. High-resolution magic-angle spinning (13)C spectroscopy of brain tissue at natural abundance.

    PubMed

    Yang, Yongxia; Chen, Lei; Gao, Hongchang; Zeng, Danlin; Yue, Yong; Liu, Maili; Lei, Hao; Deng, Feng; Ye, Chaohui

    2006-03-01

    High-resolution magic-angle spinning (MAS) (1)H and (13)C magnetic resonance spectroscopy (MRS) has recently been applied to study the metabolism in intact biological tissue samples. Because of the low natural abundance and the low gyromagnetic ratio of the (13)C nuclei, signal enhancement techniques such as cross-polarization (CP) and distortionless enhancement by polarization transfer (DEPT) are often employed in MAS (13)C MRS to improve the detection sensitivity. In this study, several sensitivity enhancement techniques commonly used in liquid- and solid-state NMR, including CP, DEPT and nuclear Overhauser enhancement (NOE), were combined with MAS to acquire high-resolution (13)C spectra on intact rat brain tissue at natural abundance, and were compared for their performances. The results showed that different signal enhancement techniques are sensitive to different classes of molecules/metabolites, depending on their molecular weights and mobility. DEPT was found to enhance the signals of low-molecular weight metabolites exclusively, while the signals of lipids, which often are associated with membranes and have relatively lower mobility, were highly sensitive to CP enhancement. PMID:16477685

  12. Alkyl-terminated Si(111) surfaces: A high-resolution, core level photoelectron spectroscopy study

    SciTech Connect

    Terry, J.; Linford, M.R.; Wigren, C.; Cao, R.; Pianetta, P.; Chidsey, C.E.

    1999-01-01

    The bonding of alkyl monolayers to Si(111) surfaces has been studied with high-resolution core level photoelectron spectroscopy (PES). Two very different wet-chemical methods have been used to prepare the alkyl monolayers: (i) Olefin insertion into the H{endash}Si bond of the H{endash}Si(111) surface, and (ii) replacement of Cl on the Cl{endash}Si(111) surface by an alkyl group from an alkyllithium reagent. In both cases, PES has revealed a C 1s component shifted to lower binding energy and a Si 2p component shifted to higher binding energy. Both components are attributed to the presence of a C{endash}Si bond at the interface. Along with photoelectron diffraction data [Appl. Phys. Lett. {bold 71}, 1056, (1997)], these data are used to show that these two synthetic methods can be used to functionalize the Si(111) surface. {copyright} {ital 1999 American Institute of Physics.}

  13. Superconducting Detector System for High-Resolution Energy-Dispersive Soft X-Ray Spectroscopy

    SciTech Connect

    Friedrich, S; Niedermayr, T; Drury, O; Funk, T; Frank, M; Labov, S E; Cramer, S

    2001-02-21

    Synchrotron-based soft x-ray spectroscopy is often limited by detector performance. Grating spectrometers have the resolution, but lack the efficiency for the analysis of dilute samples. Semiconducting Si(Li) or Ge detectors are efficient, but often lack the resolution to separate weak signals from strong nearby lines in multi-element samples. Superconducting tunnel junctions (STJs) operated at temperatures below 1 K can be used as high-resolution high-efficiency x-ray detectors. They combine high energy resolution around 10 eV FWHM with the broad band efficiency of energy-dispersive detectors. We have designed a two-stage adiabatic demagnetization refrigerator (ADR) to operate STJ detectors in x-ray fluorescence measurements at beam line 4 of the ALS. We demonstrate the capabilities of such a detector system for fluorescence analysis of dilute metal sites in proteins and inorganic model compounds.

  14. High-resolution photoelectron spectroscopy analysis of sulfidation of brass at the rubber/brass interface

    NASA Astrophysics Data System (ADS)

    Ozawa, Kenichi; Kakubo, Takashi; Shimizu, Katsunori; Amino, Naoya; Mase, Kazuhiko; Komatsu, Takayuki

    2013-01-01

    High resolution photoelectron spectroscopy is utilized to investigate the chemical composition at the rubber/brass interface to elucidate the origin of strong adhesion as well as the degradation between rubber and brass. Special attention has been given to copper sulfides formed at the interface during the vulcanization reaction at 170 °C. At least five sulfur-containing species are identified in the adhesive interlayer including crystalline CuS and amorphous CuxS (x ≃ 2). These copper sulfide species are not uniformly distributed within the layer, but there exits the concentration gradation; the concentration of CuxS is high in the region on the rubber side and is diminished in the deeper region, while vice versa for that of CuS. Degradation of the interface adhesive strength by prolonged vulcanization arises from the decrease in the CuxS/CuS ratio accompanying desulfurization of the adhesive layer.

  15. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    PubMed

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter. PMID:23507905

  16. Past, Present and Future Prospects of High Resolution X-ray Spectroscopy of Clusters of Galaxies

    NASA Astrophysics Data System (ADS)

    Kaastra, J.

    2006-08-01

    The first high resolution X-ray spectra of clusters of galaxies have revolutionised the study of cooling flows. These excellent data have been obtained with an instrument (the RGS of XMM-Newton) that has not been optimised for spectroscopy of extended sources. I will present a few recent examples of what can be achieved further with the RGS in combination with the imaging EPIC cameras for the study of chemical enrichment of clusters. The new generation of high spectral resolution imaging TES arrays that is currently being studied for a variety of possible future X-ray observatories (such as XEUS, Constellation-X, DIOS, Estremo and NEW) offer exciting new opportunities to study the physics of clusters of galaxies. I will present examples of how these new instruments will achieve this.

  17. Recent results on high resolution hypernuclear spectroscopy by electroproduction at Jefferson Lab, Hall A

    SciTech Connect

    F. Garibaldi; H. Breuer; P. Brindza; P. Bydzovski; G. Chang; E. Cisbani; S. Colilli; F. Cusanno; R. De Leo; G. De Cataldo; K. De Jager; R. Feuerbach; E. Folts; R. Fratoni; S. Frullani; F. Giuliani; M. Gricia; D. Higinbotham; M. Iodice; B. Kross; L. Lagamba; J.J.Le Rose; M. Lucentini; P. Markowitz; S. Marrone; R. Michaels; E. Nappi; Y. Qiang; B. Reitz; F. Santavenere; J. Segal; M. Sotona; G.M.Urciuoli; P. Veneroni; B.Wojtsekhowski; C. Zorn

    2005-12-01

    The first ''systematic'' study of 1 p shell hypernuclei with electromagnetic probes has started in Hall A at Jefferson Lab [?]. The aim is to perform hypernuclear high resolution spectroscopy by the electroproduction of strangeness on four 1p-shell targets: 12C, 9Be, 16O, 7Li. The first part of the experiment on 12C and 9Be has been performed in 2004, the second part (16O and 7Li) is scheduled for June 2005. To overcome the major experimental difficulties, namely the low counting rate and the challenging Particle IDentification (PID), two septum magnets and a Ring Imaging CHerenkov (RICH) detector had to be added to the existing apparatus. After underlining the particular role the electroproduction reaction plays in hypernuclear physics we describe the challenging modifications of the Hall A apparatus. Preliminary results on 12C and 9Be are presented.

  18. Oxidation of diamond films by atomic oxygen: High resolution electron energy loss spectroscopy studies

    NASA Astrophysics Data System (ADS)

    Shpilman, Z.; Gouzman, I.; Grossman, E.; Akhvlediani, R.; Hoffman, A.

    2007-12-01

    Diamond surface oxidation by atomic oxygen, annealing up to ˜700°C, and in situ exposure to thermally activated hydrogen were studied by high resolution electron energy loss spectroscopy (HREELS). After atomic oxygen (AO) exposure, HREELS revealed peaks associated with CHx groups, carbonyl, ether, and peroxide-type species and strong quenching of the diamond optical phonon and its overtones. Upon annealing of the oxidized surfaces, the diamond optical phonon overtones at 300 and 450meV emerge and carbonyl and peroxide species gradually desorb. The diamond surface was not completely regenerated after annealing to ˜700°C and in situ exposure to thermally activated hydrogen, probably due to the irreversible deterioration of the surface by AO.

  19. High Resolution Spectroscopy of Naphthalene Calibrated by AN Optical Frequency Comb

    NASA Astrophysics Data System (ADS)

    Nishiyama, Akiko; Nakashima, Kazuki; Matsuba, Ayumi; Misono, Masatoshi

    2015-06-01

    In high-resolution molecular spectroscopy, the precise measure of the optical frequency is crucial to evaluate minute shifts and splittings of the energy levels. On the other hand, in such spectroscopy, thousands of spectral lines distributed over several wavenumbers have to be measured by a continuously scanning cw laser. Therefore, the continuously changing optical frequency of the scanning laser has to be determined with enough precision. To satisfy these contradictory requirements, we have been developed two types of high-resolution spectroscopic systems employing an optical frequency comb. One of the systems employs RF band-pass filters to generate equally spaced frequency markers for optical frequency calibration, and is appropriate for wide wavelength-range measurement with relatively high scanning rate.^a In the other system, the beat frequency between the optical frequency comb and the scanning laser is controlled by an acousto-optic frequency shifter. This system is suitable for more precise measurement, and enables detailed analyses of frequency characteristics of scanning laser.^b In the present study, we observe Doppler-free two-photon absorption spectra of A^1B1u (v_4 = 1) ← X^1A_g (v = 0) transition of naphthalene around 298 nm. The spectral lines are rotationally resolved and the resolution is about 100 kHz. For ^qQ transition, the rotational lines are assigned, and molecular constants in the excited state are determined. In addition, we analyze the origin of the measured linewidth and Coriolis interactions between energy levels. To determine molecular constants more precisely, we proceed to measure and analyze spectra of other transitions, such as ^sS transitions. ^a A. Nishiyama, D. Ishikawa, and M. Misono, J. Opt. Soc. Am. B 30, 2107 (2013). ^b A. Nishiyama, A. Matsuba, and M. Misono, Opt. Lett. 39, 4923 (2014).

  20. a Thz Photomixing Synthesizer Based on a Fiber Frequency Comb for High Resolution Rotational Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hindle, Francis; Mouret, Gael; Cuisset, Arnaud; Yang, Chun; Eliet, Sophie; Bocquet, Robin

    2010-06-01

    To date the principal application for photomixing sources has been for high resolution spectroscopy of gases due to the large tuning range and spectral purity. New Developments of the Opto-Electronic THz Spectrometer have been performed in order to obtain a powerful tool for High-Resolution Spectroscopy. The combination of two extended cavity laser diodes and fast charge carrier lifetime semiconductor materials has allowed a continuous-wave THz spectrometer to be constructed based on optical heterodyning. Unlike many THz sources, this instrument gives access to all frequencies in the range 0.3 to 3.5 THz with a resolution of 1 MHz. The main spectroscopic applications of this spectrometer were dedicated to line profile analysis of rotational transitions referenced in the spectroscopic databases. One limitation of the THz spectrometer was accuracy with which the generated frequency is known. Recently, this obstacle has been circled with the construction of a photomixing spectrometer where the two pump lasers are phase locked to two modes of a repetition rate stabilized frequency doubled fiber laser frequency comb. In order to achieve a tuning range in excess to 100 MHz a third cw laser was required in the new configuration of the THz spectrometer. To assess the performances of this instrument, the frequencies of the pure rotational transitions of OCS molecules have been measured between 0,8 to 1,2 THz. A rms inferior to 100 kHz, deduced from the frequencies measured, demonstrates that the THz photomixing synthesizer is now able to be competitive with microwave and submillimeter techniques. S. Matton, F. Rohart, R. Bocquet, D. Bigourd, A. Cuisset, F. Hindle, G. Mouret, J. Mol. Spectrosc., 2006, 239: 182. C. Yang, J. Buldyreva, I. E. Gordon, F. Rohart, A. Cuisset, G. Mouret, R. Bocquet, F. Hindle, J. Quant. Spectrosc. Radiat. Transfer, 2008, 109: 2857. G. Mouret, F. Hindle, A. Cuisset, C. Yang, R. Bocquet, M. Lours, D. Rovera, Opt. Express, 2009, 17: 22031.

  1. Partial-Homogeneity-Based Two-Dimensional High-Resolution Nuclear Magnetic Resonance Spectroscopy under Inhomogeneous Magnetic Fields.

    PubMed

    Qiu, Wenqi; Wei, Zhiliang; Ding, Nan; Yang, Yu; Ye, Qimiao; Lin, Yulan; Chen, Zhong

    2016-05-18

    High-resolution multidimensional nuclear magnetic resonance (NMR) spectroscopy serves as an irreplaceable and versatile tool in various chemical investigations. In this study, a method based on the concept of partial homogeneity is developed to offer two-dimensional (2D) high-resolution NMR spectra under inhomogeneous fields. Oscillating gradients are exerted to encode the high-resolution information, and a field-inhomogeneity correction algorithm based on pattern recognition is designed to recover high-resolution spectra. Under fields where inhomogeneity primarily distributes along a single orientation, the proposed method will improve performances of 2D NMR spectroscopy without increasing the experimental duration or significant loss in sensitivity, and thus may open important perspectives for studies of inhomogeneous chemical systems. PMID:26891886

  2. High-resolution atomic force microscopy and spectroscopy of native membrane proteins

    NASA Astrophysics Data System (ADS)

    Bippes, Christian A.; Muller, Daniel J.

    2011-08-01

    Membranes confining cells and cellular compartments are essential for life. Membrane proteins are molecular machines that equip cell membranes with highly sophisticated functionality. Examples of such functions are signaling, ion pumping, energy conversion, molecular transport, specific ligand binding, cell adhesion and protein trafficking. However, it is not well understood how most membrane proteins work and how the living cell regulates their function. We review how atomic force microscopy (AFM) can be applied for structural and functional investigations of native membrane proteins. High-resolution time-lapse AFM imaging records membrane proteins at work, their oligomeric state and their dynamic assembly. The AFM stylus resembles a multifunctional toolbox that allows the measurement of several chemical and physical parameters at the nanoscale. In the single-molecule force spectroscopy (SMFS) mode, AFM quantifies and localizes interactions in membrane proteins that stabilize their folding and modulate their functional state. Dynamic SMFS discloses fascinating insights into the free energy landscape of membrane proteins. Single-cell force spectroscopy quantifies the interactions of live cells with their environment to single-receptor resolution. In the future, technological progress in AFM-based approaches will enable us to study the physical nature of biological interactions in more detail and decipher how cells control basic processes.

  3. Millimeter and Sub-millimeter High Resolution Spectroscopy: New Frontiers with ALMA

    NASA Astrophysics Data System (ADS)

    Ziurys, Lucy M.

    2016-06-01

    It is becoming increasingly clear that new laboratory data will be critical for the next decade of observations with the Atacama Large Millimeter Array (ALMA). The high spatial resolution offered by ALMA will probe new regions of molecular complexity, including the inner envelopes of evolved stars, regions dominated by UV radiation, and the densest cores of molecular clouds. New molecular lines will be discovered in the wide wavelength range covered by the ALMA bands, and high resolution, gas-phase spectroscopy are needed to provide crucial “rest frequencies.” In particular, highly accurate methods that measure millimeter and sub-millimeter rotational transitions, such as direct absorption and Fourier transform mm-wave techniques, are important, especially when coupled to exotic molecular production schemes. Recent ALMA studies of SH+ and larger organic species have already demonstrated the need for laboratory measurements. New laboratory work will likely be required for circumstellar refractory molecules, radicals and ions generated near photon-dominated regions (PDRs), and large, organic-type species. This talk will give an overview of current contributions of laboratory spectroscopy to ALMA observations, summarize relevant spectroscopic techniques, and provide input into future prospects and directions.

  4. Exploring the High-Resolution Spectroscopy of Molecules that can Affect the Quality of your Life

    NASA Astrophysics Data System (ADS)

    Miller, Terry A.

    2014-06-01

    Few things affect your quality of life more than the air you breathe and the temperature of your immediate environment. Since more than 80% of the energy used in the industrialized world today is still derived from fossil fuels, these two quantities are not unrelated. Most organic molecules injected into the troposphere are degraded via oxidative processes involving free radical intermediates, and many of these intermediates are the same as the ones involved in the combustion of fossil fuels. Key oxidizing intermediates are hydroxyl, OH (day), and nitrate, NO_3 (night), and early intermediates of oxidized organic compounds include the alkoxy (RO) and peroxy (RO_2) families of radicals. Recently we have explored the spectroscopy of RO, RO_2, and NO_3 radicals both for diagnostic purposes and to characterize their molecular properties and benchmark quantum chemistry calculations. We have utilized moderate resolution cavity ringdown spectroscopy (CRDS) to study ambient temperature radicals and high resolution CRDS and laser induced fluorescence (LIF) to study jet-cooled radicals. Peroxy radicals and NO_3 have weak tilde{A}-tilde{X} electronic transitions in the near infrared which we have studied with CRDS. Comparable LIF measurements have been made for the alkoxy species in the UV. Both vibrational and rotational resolution of the electronic spectra is observed. Data obtained from the spectral observations provide information about both the geometric and electronic structure of these radicals as well as their dynamics and also provide the capability for unambiguous diagnostics of their concentrations and reactions.

  5. Far Infrared High Resolution Synchrotron FTIR Spectroscopy of the Low Frequency Bending Modes of Dmso

    NASA Astrophysics Data System (ADS)

    Cuisset, Arnaud; Smirnova, Irina; Bocquet, Robin; Hindle, Francis; Mouret, Gael; Sadovskii, Dmitrii A.; Pirali, Olivier; Roy, Pascale

    2010-06-01

    In addition to its importance for industrial and environmental studies, the monitoring of DiMethylSulfOxyde (DMSO, (CH_3)_2SO) concentrations is of considerable interest for civil protection. The existing high resolution gas phase spectroscopic data of DMSO only concerned the pure rotational transitions in the ground state. In the Far-IR domain, the low-frequency rovibrational transitions have never previously resolved. The high brightness of the AILES beamline of the synchrotron SOLEIL and the instrumental sensitivity provided by the multipass cell allowed to measure for the first time these transitions. 1581 A-type and C-type transitions in the ν11 band have been assigned and 25 molecular constants of Watson's s-form hamiltonian developed to degree 8 have been fitted within the experimental accuracy. The use of then synchrotron radiation has opened many possibilities for new spectroscopic studies. Together with several other recent studies, our successful measurement and analysis of DMSO convincingly demonstrates the potential of the AILES beamline for high resolution FIR spectroscopy. Thus our present work is just at the beginning of unraveling the rovibrational structure of low frequency bending and torsional vibrational states of DMSO and yielding important comprehensive structural and spectroscopic information on this molecule. L. Margules, R. A. Motienko, E. A. Alekseev, J. Demaison, J. Molec. Spectrosc., 260(23),2009 V. Typke, M. Dakkouri, J. Molec. Struct., 599(177),2001 A. Cuisset, L. Nanobashvili, I. Smirnova, R. Bocquet, F. Hindle, G. Mouret, O. Pirali, P. Roy, D. Sadovskii, Chem. Phys. Lett., accepted for publication

  6. M31 GLOBULAR CLUSTER ABUNDANCES FROM HIGH-RESOLUTION, INTEGRATED-LIGHT SPECTROSCOPY

    SciTech Connect

    Colucci, Janet E.; McWilliam, Andrew; Cohen, Judith G. E-mail: sacamero@umich.ed E-mail: andy@ociw.ed

    2009-10-10

    We report the first detailed chemical abundances for five globular clusters (GCs) in M31 from high-resolution (R approx 25,000) spectroscopy of their integrated light (IL). These GCs are the first in a larger set of clusters observed as part of an ongoing project to study the formation history of M31 and its GC population. The data presented here were obtained with the HIRES echelle spectrograph on the Keck I telescope and are analyzed using a new IL spectra analysis method that we have developed. In these clusters, we measure abundances for Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, and Ba, ages >=10 Gyr, and a range in [Fe/H] of -0.9 to -2.2. As is typical of Milky Way GCs, we find these M31 GCs to be enhanced in the alpha-elements Ca, Si, and Ti relative to Fe. We also find [Mg/Fe] to be low relative to other [alpha/Fe], and [Al/Fe] to be enhanced in the IL abundances. These results imply that abundances of Mg, Al (and likely O, Na) recovered from IL do display the inter- and intra-cluster abundance variations seen in individual Milky Way GC stars, and that special care should be taken in the future in interpreting low- or high-resolution IL abundances of GCs that are based on Mg-dominated absorption features. Fe-peak and the neutron-capture elements Ba and Y also follow Milky Way abundance trends. We also present high-precision velocity dispersion measurements for all five M31 GCs, as well as independent constraints on the reddening toward the clusters from our analysis.

  7. High resolution x-ray fluorescence spectroscopy - a new technique for site- and spin-selectivity

    SciTech Connect

    Wang, Xin

    1996-12-01

    X-ray spectroscopy has long been used to elucidate electronic and structural information of molecules. One of the weaknesses of x-ray absorption is its sensitivity to all of the atoms of a particular element in a sample. Through out this thesis, a new technique for enhancing the site- and spin-selectivity of the x-ray absorption has been developed. By high resolution fluorescence detection, the chemical sensitivity of K emission spectra can be used to identify oxidation and spin states; it can also be used to facilitate site-selective X-ray Absorption Near Edge Structure (XANES) and site-selective Extended X-ray Absorption Fine Structure (EXAFS). The spin polarization in K fluorescence could be used to generate spin selective XANES or spin-polarized EXAFS, which provides a new measure of the spin density, or the nature of magnetic neighboring atoms. Finally, dramatic line-sharpening effects by the combination of absorption and emission processes allow observation of structure that is normally unobservable. All these unique characters can enormously simplify a complex x-ray spectrum. Applications of this novel technique have generated information from various transition-metal model compounds to metalloproteins. The absorption and emission spectra by high resolution fluorescence detection are interdependent. The ligand field multiplet model has been used for the analysis of K{alpha} and K{beta} emission spectra. First demonstration on different chemical states of Fe compounds has shown the applicability of site selectivity and spin polarization. Different interatomic distances of the same element in different chemical forms have been detected using site-selective EXAFS.

  8. What can we Expect of High-Resolution Spectroscopies on Carbohydrates?

    NASA Astrophysics Data System (ADS)

    Cocinero, Emilio J.; Ecija, Patricia; Uriarte, Iciar; Usabiaga, Imanol; Fernández, José A.; Basterretxea, Francisco J.; Lesarri, Alberto; Davis, Benjamin G.

    2015-06-01

    Carbohydrates are one of the most multifaceted building blocks, performing numerous roles in living organisms. We present several structural investigations on carbohydrates exploiting an experimental strategy which combines microwave (MW) and laser spectroscopies in high-resolution. Laser spectroscopy offers high sensitivity coupled to mass and conformer selectivity, making it ideal for polysaccharides studies. On the other hand, microwave spectroscopy provides much higher resolution and direct access to molecular structure of monosaccharides. This combined approach provides not only accurate chemical insight on conformation, structure and molecular properties, but also benchmarking standards guiding the development of theoretical calculations. In order to illustrate the possibilities of a combined MW-laser approach we present results on the conformational landscape and structural properties of several monosaccharides and oligosaccharides including microsolvation and molecular recognition processes of carbohydrates. E.J. Cocinero, A. Lesarri, P. écija, F.J. Basterretxea, J.-U. Grabow, J.A. Fernández and F. Casta {n}o Angew. Chem. Int. Ed. 51, 3119-3124, 2012. E.J. Cocinero, A. Lesarri, P. écija, Á. Cimas, B.G. Davis, F.J. Basterretxea, J.A. Fernández and F. Casta {n}o J. Am. Chem. Soc. 135, 2845-2852, 2013. E.J. Cocinero, P. Çarçabal, T.D. Vaden, J.P. Simons and B.G. Davis Nature 469, 76-80, 2011. C.S. Barry, E.J. Cocinero, P. Çarçabal, D.P. Gamblin, E.C. Stanca-Kaposta, S. M. Fernández-Alonso, S. Rudić, J.P. Simons and B.G. Davis J. Am. Chem. Soc. 135, 16895-16903, 2013.

  9. Correlating high-resolution magic angle spinning NMR spectroscopy and gene analysis in osteoarthritic cartilage.

    PubMed

    Tufts, Lauren; Shet Vishnudas, Keerthi; Fu, Eunice; Kurhanewicz, John; Ries, Michael; Alliston, Tamara; Li, Xiaojuan

    2015-05-01

    Osteoarthritis (OA) is a common multifactorial and heterogeneous degenerative joint disease, and biochemical changes in cartilage matrix occur during the early stages of OA before morphological changes occur. Thus, it is desired to measure regional biochemical changes in the joint. High-resolution magic angle spinning (HRMAS) NMR spectroscopy is a powerful method of observing cartilaginous biochemical changes ex vivo, including the concentrations of alanine and N-acetyl, which are markers of collagen and total proteoglycan content, respectively. Previous studies have observed significant changes in chondrocyte metabolism of OA cartilage via the altered gene expression profiles of ACAN, COL2A1 and MMP13, which encode aggrecan, type II collagen and matrix metalloproteinase 13 (a protein crucial in the degradation of type II collagen), respectively. Employing HRMAS, this study aimed to elucidate potential relationships between N-acetyl and/or alanine and ACAN, COL2A1 and/or MMP13 expression profiles in OA cartilage. Thirty samples from the condyles of five subjects undergoing total knee arthroplasty to treat OA were collected. HRMAS spectra were obtained at 11.7 T for each sample. RNA was subsequently extracted to determine gene expression profiles. A significant negative correlation between N-acetyl metabolite and ACAN gene expression levels was observed; this provides further evidence of N-acetyl as a biomarker of cartilage degeneration. The alanine doublet was distinguished in the spectra of 15 of the 30 specimens of this study. Alanine can only be detected with HRMAS NMR spectroscopy when the collagen framework has been degraded such that alanine is sufficiently mobile to form a distinguished peak in the spectrum. Thus, HRMAS NMR spectroscopy may provide unique localized measurements of collagenous degeneration in OA cartilage. The identification of imaging markers that could provide a link between OA pathology and chondrocyte metabolism will facilitate the

  10. The Astro-H Mission and High Resolution X-ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kelley, Richard L.; Mitsuda, K.; Awaki, H.; Fujimoto, R.; den Herder, J. W.; Ishida, M.; Kilbourne, C. A.; Kunieda, H.; Maeda, Y.; McCammon, D.; Ohashi, T.; Okajima, T.; Porter, F.; Serlemitsos, P.; Soong, Y.; Szymkowiak, A. E.; Takahashi, T.; Takei, Y.; Tashiro, M.; Tawara, Y.; Yamasaki, N. Y.; Astro-H Collaboration

    2010-03-01

    The Japan Aerospace Exploration Agency's Institute of Space and Aeronautical Science (JAXA/ISAS) is developing a major new high-energy astrophysics observatory. Astro-H will provide broadband, high-resolution spectroscopy and imaging over the 0.3-600 keV band using four co-aligned instruments operated simultaneously. The mission will have major US participation supported by NASA as well as contributions from Europe and Canada. For high-resolution x-ray spectroscopy, the soft x-ray spectrometer (SXS) will feature an x-ray calorimeter spectrometer and x-ray mirror. The instrument will cover the energy range 0.3-12 keV and is expected to have an energy resolution better than 5 eV (FWHM) with a collecting area of over 200 cm2 at 6 keV. The cooling system will have both cryogenic and mechanical coolers for up to five years of operation. The SXS is a joint collaboration between NASA/GSFC, ISAS/JAXA and SRON, and the NASA participation was selected as an Explorers Mission of Opportunity in June 2008. As part of this investigation, a fully supported US guest observer program was also proposed and is under review by NASA. Other instruments on Astro-H include a soft x-ray imager (SXI) consisting of a large area CCD camera with 35 arcmin field-of-view and a hard x-ray imager (HXI) that uses focusing x-ray optics combined with both double-sided silicon strip detectors and CdTe array. The 12-m focal length optical system will provide an effective area of 300 cm2 at 30 keV, and high sensitivity from 10-80 keV using multilayer x-ray mirrors with 2-4 arcmin imaging. The soft gamma detector (SGD) is a non-focusing instrument based on a new, narrow-field-of-view Compton telescope with an energy range of 10-600 keV and sensitivity at 300 keV that is more than 10 times higher than Suzaku. Astro-H is planned for launch in 2014 aboard a JAXA HII-A rocket.

  11. High-Resolution Spectroscopy of Mars: Recent Results and Implications for Atmospheric Evolution

    NASA Technical Reports Server (NTRS)

    Krasnopolsky, V. A.; Owen, T. C.; Maillard, J. P.

    1999-01-01

    It is believed that Earth, Venus, and Mars were formed by the same rocky and icy planetesimals, which resembled meteorites and comets in their composition, respectively. These planets are thus expected to have initially had the same chemical and isotope composition. Scaling the mass of the terrestrial ocean by the planetary mass ratio, the expected initial H2O abundance on Mars is a layer of about 1 km thick. Scaling the abundance of CO2 on Venus, the expected initial CO2 abundance on Mars is 15 bars. Evidently, significant parts of the initial H2O and CO2 abundances have been lost. Intense meteorite impact erosion and hydrodynamic escape of hydrogen (which could drag to escape more heavy species) were dominant loss processes in the first 0.8 Byr. Later, atmospheric sputtering by O+ ions resulted in the dissociation of CO2 and massive losses of O, C, and H. Formation of carbonates also reduced CO2 to its present abundance which currently exists in the atmosphere, on the polar caps, and is absorbed by regolith. Water loss is currently due to thermal escape of H and nonthermal escape of O, both formed by photodissociation of H2O. All loss processes resulted in fractionation of the H, O, and C isotopes. Therefore, the current isotope ratios in H2O and CO2 are clues to the history of volatiles on Mars. There are three tools to study H2O and CO2 isotopes in the martian atmosphere: (i) mass spectrometry from landing probes, (ii) analyses of Mars' gases trapped in the SNC meteorites which were ejected from Mars, and (iii) high-resolution spectroscopy of the H2O andCO2 bands. Method (i) is the best but is the most expensive. Mass spectrometers to be used should be designed for high-precision isotope measurements. Method (ii) makes it possible to reach an uncertainty +/- 0.1%. However, the obtained results are affected by some uncontrolled interactions: isotope fractionations of (1) trapped gases and (2) those released in pyrolysis, (3) contribution of the impactor, isotope

  12. Advances in Computational High-Resolution Mechanical Spectroscopy HRMSPart I: Logarithmic Decrement

    NASA Astrophysics Data System (ADS)

    Majewski, M.; Piłat, A.; Magalas, L. B.

    2012-02-01

    The comparison between different methods used to compute the logarithmic decrement in high-resolution mechanical spectroscopy (HRMS) is analyzed. The performance of parametric OMI method (Optimization in Multiple Intervals) and interpolated discrete Fourier transform (IpDFT) methods are investigated as a function of the sampling frequency used to digitize free decaying oscillations in low-frequency resonant mechanical spectrometers. It is clearly demonstrated that a new Yoshida-Magalas (YM) method is the most powerful IpDFT-based method which outperforms the standard Yoshida (Y) method and other DFT-based methods. Four IpDFT methods and the OMI method are carefully analyzed as a function of the sampling frequency. The results presented in this work clearly show that the relative error in the estimation of the logarithmic decrement depends both on the length of free decaying signal and on the sampling frequency. The effect of the sampling frequency was not yet reported in the literature. The performance of different methods used in the computations of the logarithmic decrement can be listed in the following order: (1) the OMI, (2) the Yoshida-Magalas YM, (3) the Yoshida-Magalas YMC, and finally (4) the Yoshida Y.

  13. On the accuracy of CO line positions for high resolution IR stellar spectroscopy

    NASA Technical Reports Server (NTRS)

    Sauval, A. J.; Farrenq, R.; Guelachvili, G.; Grevesse, N.; Farmer, C. B.; Norton, R. H.

    1992-01-01

    The paper demonstrates the high accuracy of line positions derived from improved sets of Dunham coefficients for the four more abundant isotopic species of carbon monoxide - (C-12)(O-16), (C-13)(O-16), (C-12)(O-18), and (C-12)(O-17) - which are present in the sun and in cool stellar atmospheres. These new spectroscopic constants make it possible to predict very accurate positions of CO lines at any J-values, especially at very high rotational excitation (up to J around 135). Earlier proposed identifications of CO lines at large J-values are checked, and some incorrect identifications in sunspot spectra are found. The present accurate line positions are also compared with predictions from other available sets of molecular constants. It is concluded that the present improved sets of molecular constants are the most appropriate to all problems of high-resolution stellar and solar spectroscopy at any J- and v-values, particularly for synthetic spectra of cool stars.

  14. High-Resolution Spectroscopy of Winds Associated with T Tauri Stars

    NASA Astrophysics Data System (ADS)

    Iguchi, Naoto; Itoh, Yoichi

    2016-02-01

    We carried out optical high-resolution spectroscopy of T Tauri stars using the Subaru Telescope. Using archived data from the Keck Telescope and the Very Large Telescope, we detected forbidden lines of [S II] at 4069 Å, in addition to those of [O I] at 5577 Å and 6300 Å, for 13 T Tauri stars. We consider that low-velocity components of these forbidden lines emanate from the wind associated with T Tauri stars. Using two flux ratios of the three lines, we simultaneously determined the hydrogen density and temperature of the winds. The winds of T Tauri stars have a hydrogen density of 2.5 × 106 cm-3 - 2.5 × 109 cm-3 and a temperature of 10800 -18 000 K. The mass loss rates by the wind are estimated to lie in the range from 2.0 × 10-10 M⊙ yr-1 to 1.4 × 10-9 M⊙ yr-1. The mass loss rates are found to increase with increasing mass accretion rates. The ratio of the mass loss rate to the mass accretion rate is 0.001-0.1 for classical T Tauri stars and 0.1-1 for transitional disk objects.

  15. Practical high resolution detection method for laser-induced breakdown spectroscopy

    SciTech Connect

    Andrew J. Effenberger Jr; Jill R. Scott

    2012-02-01

    A Fabry-Perot etalon was coupled to a Czerny-Turner spectrometer to acquire high-resolution measurements in laser-induced breakdown spectroscopy (LIBS). The spectrometer was built using an inexpensive etalon coupled to a standard 0.5-m imaging spectrometer. The Hg emission doublet at 313.2 nm was used to evaluate instrument performance because it has a splitting of 29 pm. The 313.2 nm doublet was chosen due to the similar splitting seen in isotope splitting from uranium at 424.437 nm, which is 25 pm. The Hg doublet was easily resolved from a continuous source Hg-lamp with a 2 s acquisition. The doublet was also resolved in LIBS spectra of cinnabar (HgS) from the accumulation of 600 laser shots at rate of 10 Hz, or 1 min, under a helium atmosphere. In addition to observed spitting of the 313.2 nm Hg doublet, the FWHM of the 313.1844 nm line from the doublet is reported at varying He atmospheric pressures. The high performance, low cost, and compact footprint makes this system highly competitive with 2-m double pass Czerny-Turner spectrometers.

  16. High resolution electron microscopy and spectroscopy of ferritin in thin window liquid cells

    NASA Astrophysics Data System (ADS)

    Wang, Canhui; Qiao, Qiao; Shokuhfar, Tolou; Klie, Robert

    2014-03-01

    In-situ transmission electron microscopy (TEM) has seen a dramatic increase in interest in recent years with the commercial development of liquid and gas stages. High-resolution TEM characterization of samples in a liquid environment remains limited by radiation damage and loss of resolution due to the thick window-layers required by the in-situ stages. We introduce thin-window static-liquid cells that enable sample imaging with atomic resolution and electron energy-loss (EEL) spectroscopy with 1.3 nm resolution. Using this approach, atomic and electronic structures of biological samples such as ferritin is studied via in-situ transmission electron microscopy experiments. Ferritin in solution is encapsulated using the static liquid cells with reduced window thickness. The integrity of the thin window liquid cell is maintained by controlling the electron dose rate. Radiation damage of samples, such as liquid water and protein, is quantitatively studied to allow precision control of radiation damage level within the liquid cells. Biochemical reactions, such as valence change of the iron in a functioning ferritin, is observed and will be quantified. Relevant biochemical activity: the release and uptake of Fe atoms through the channels of ferritin protein shell is also imaged at atomic resolution. This work is funded by Michigan Technological University. The UIC JEOL JEM-ARM200CF is supported by an MRI-R2 grant from the National Science Foundation (Grant No. DMR-0959470).

  17. Quantitative neuropathology by high resolution magic angle spinning proton magnetic resonance spectroscopy

    PubMed Central

    Cheng, L. L.; Ma, M. J.; Becerra, L.; Ptak, T.; Tracey, I.; Lackner, A.; González, R. G.

    1997-01-01

    We describe a method that directly relates tissue neuropathological analysis to medical imaging. Presently, only indirect and often tenuous relationships are made between imaging (such as MRI or x-ray computed tomography) and neuropathology. We present a biochemistry-based, quantitative neuropathological method that can help to precisely quantify information provided by in vivo proton magnetic resonance spectroscopy (1HMRS), an emerging medical imaging technique. This method, high resolution magic angle spinning (HRMAS) 1HMRS, is rapid and requires only small amounts of unprocessed samples. Unlike chemical extraction or other forms of tissue processing, this method analyzes tissue directly, thus minimizing artifacts. We demonstrate the utility of this method by assessing neuronal damage using multiple tissue samples from differently affected brain regions in a case of Pick disease, a human neurodegenerative disorder. Among different regions, we found an excellent correlation between neuronal loss shown by traditional neurohistopathology and decrease of the neuronal marker N-acetylaspartate measured by HRMAS 1HMRS. This result demonstrates for the first time, to our knowledge, a direct, quantitative link between a decrease in N-acetylaspartate and neuronal loss in a human neurodegenerative disease. As a quantitative method, HRMAS 1HMRS has potential applications in experimental and clinical neuropathologic investigations. It should also provide a rational basis for the interpretation of in vivo 1HMRS studies of human neurological disorders. PMID:9177231

  18. Determination of reference ultrasound parameters for model and hydrofluoroalkane propellants using high-resolution ultrasonic spectroscopy.

    PubMed

    Hoe, Susan; Young, Paul M; Rogueda, Philippe; Traini, Daniela

    2008-01-01

    The aim of this research was to determine the reference ultrasonic velocity (v) and attenuation coefficient (alpha) for 2H, 3H-perfluoropentane (HPFP), 1,1,1,2-tetrafluoroethane (HFA-134a) and 1,1,1,2,3,3,3-tetrafluoroethane (HFA-227) propellants, for the future purpose of characterising pressurised metered dose inhaler (pMDI) formulations using high-resolution ultrasonic spectroscopy (HRUS). Perfluoroheptane (PFH) was used as a reference material for HPFP. With its velocity and attenuation coefficient determined at 25 degrees C, HPFP was subsequently used as a reference for HFA-134a and HFA-227. It was found that there is a linear decline in ultrasonic velocity with an increase in temperature. As with HPFP, the ultrasonic velocity of HFA-134a and HFA-227 were successfully calculated at 25 degrees C. However, the difference in density and viscosity between reference and sample prevented accurate determination of reference attenuation coefficient for the hydrofluoroalkanes. With ultrasonic velocity alone, dispersion concentration and stability monitoring for experimental pMDI formulations is possible using HRUS. However, at this point in time measurement of particle size is not feasible. PMID:18459053

  19. High-resolution photoluminescence spectroscopy of Sn-doped ZnO single crystals

    DOE PAGESBeta

    Kumar, E. Senthil; Mohammadbeigi, F.; Boatner, Lynn A.; Watkins, S. P.

    2016-01-01

    Here, Group IV donors in ZnO are poorly understood, despite evidence that they are effective n-dopants. We present high-resolution photoluminescence spectroscopy studies of unintentionally doped and Sn doped ZnO single crystals grown by the chemical vapor transport method. Doped samples showed greatly increased emission from the I10 bound exciton transition which was recently proven to be related to the incorporation of Sn impurities based on radio-isotope studies. PL linewidths are exceptionally sharp for these samples, enabling clear identification of several donor species. Temperature dependent PL measurements of the I10 line emission energy and intensity dependence reveal a behavior similar tomore » other shallow donors in ZnO. Ionized donor bound exciton and two electron satellite transitions of the I10 transition are unambiguously identified and yield a donor binding energy of 71 meV. In contrast to recent reports of Ge-related donors in ZnO, the spectroscopic binding energy for the Sn-related donor bound exciton follows a linear relationship with donor binding energy (Haynes rule), confirming the shallow nature of this defect center, which we attribute to a SnZn double donor compensated by an unknown single acceptor.« less

  20. High resolution electron energy loss spectroscopy with two-dimensional energy and momentum mapping.

    PubMed

    Zhu, Xuetao; Cao, Yanwei; Zhang, Shuyuan; Jia, Xun; Guo, Qinlin; Yang, Fang; Zhu, Linfan; Zhang, Jiandi; Plummer, E W; Guo, Jiandong

    2015-08-01

    High resolution electron energy loss spectroscopy (HREELS) is a powerful technique to probe vibrational and electronic excitations at surfaces. The dispersion relation of surface excitations, i.e., energy as a function of momentum, has in the past, been obtained by measuring the energy loss at a fixed angle (momentum) and then rotating sample, monochromator, or analyzer. Here, we introduce a new strategy for HREELS, utilizing a specially designed lens system with a double-cylindrical Ibach-type monochromator combined with a commercial VG Scienta hemispherical electron energy analyzer, which can simultaneously measure the energy and momentum of the scattered electrons. The new system possesses high angular resolution (<0.1°), detecting efficiency and sampling density. The capabilities of this system are demonstrated using Bi2Sr2CaCu2O(8+δ). The time required to obtain a complete dispersion spectrum is at least one order of magnitude shorter than conventional spectrometers, with improved momentum resolution and no loss in energy resolution. PMID:26329206

  1. High-resolution X-ray spectroscopy: the coming-of-age

    NASA Astrophysics Data System (ADS)

    Kaastra, J.

    2016-06-01

    Since the launch of Chandra and XMM-Newton, high-resolution X-ray spectra of cosmic sources of all kinds have become available. These spectra have resulted in major scientific breakthroughs. However, due to the techniques used, in general high-quality spectra can only be obtained for the brightest few sources of each class. Moreover, except for the most compact extended sources, like cool core clusters, grating spectra are limited to point sources. ASTRO-H makes another major step forward, in yielding for the first time high-quality spectra of extended sources, and improved spectral sensitivity in the Fe-K band. With the launch of Athena, X-ray spectroscopy will become mature. It allows us to extend the investigations from the few handful of brightest sources of each category to a large number of sources far away in space and time, or to get high time-resolution, high-spectral resolution spectra of bright time variable sources.

  2. Spectral characteristics of chlorites and Mg-serpentines using high- resolution reflectance spectroscopy

    USGS Publications Warehouse

    King, T.V.V.; Clark, R.N.

    1989-01-01

    The present laboratory study using high-resolution reflectance spectroscopy (0.25-2.7 ??m) focuses on two primary phyllosilicate groups, serpentines and chlorites. The results show that it is possible to spectrally distinguish between isochemical end-members of the Mg-rich serpentine group (chrysotile, antigorite, and lizardite) and to recognize spectral variations in chlorites as a function of Fe/Mg ratio (~8-38 wt% Fe). The position and relative strength of the 1.4-??m absorption feature in the trioctahedral chlorites appear to be correlated to the total iron content and/or the Mg/Si ratio and the loss on ignition values of the sample. Spectral differences in the 2.3-??m wavelength region can be attributed to differences in lattice environments and are characteristic for specific trioctahedral chlorites. The 1.4-??m feature in the isochemical Mg-rich serpentines (total iron content ~1.5-7.0 wt%) show marked spectral differences, apparently due to structural differences. -Authors

  3. High-resolution photoluminescence spectroscopy of Sn-doped ZnO single crystals

    SciTech Connect

    Kumar, E. Senthil; Mohammadbeigi, F.; Boatner, Lynn A.; Watkins, S. P.

    2016-01-01

    Here, Group IV donors in ZnO are poorly understood, despite evidence that they are effective n-dopants. We present high-resolution photoluminescence spectroscopy studies of unintentionally doped and Sn doped ZnO single crystals grown by the chemical vapor transport method. Doped samples showed greatly increased emission from the I10 bound exciton transition which was recently proven to be related to the incorporation of Sn impurities based on radio-isotope studies. PL linewidths are exceptionally sharp for these samples, enabling clear identification of several donor species. Temperature dependent PL measurements of the I10 line emission energy and intensity dependence reveal a behavior similar to other shallow donors in ZnO. Ionized donor bound exciton and two electron satellite transitions of the I10 transition are unambiguously identified and yield a donor binding energy of 71 meV. In contrast to recent reports of Ge-related donors in ZnO, the spectroscopic binding energy for the Sn-related donor bound exciton follows a linear relationship with donor binding energy (Haynes rule), confirming the shallow nature of this defect center, which we attribute to a SnZn double donor compensated by an unknown single acceptor.

  4. High-resolution spectroscopy on the laser-cooling candidate La^{-}.

    PubMed

    Jordan, E; Cerchiari, G; Fritzsche, S; Kellerbauer, A

    2015-09-11

    The bound-bound transition from the 5d^{2}6s^{2} ^{3}F_{2}^{e} ground state to the 5d6s^{2}6p ^{3}D_{1}^{o} excited state in negative lanthanum has been proposed as a candidate for laser cooling, which has not yet been achieved for negative ions. Anion laser cooling holds the potential to allow the production of ultracold ensembles of any negatively charged species. We have studied the aforementioned transition in a beam of negative La ions by high-resolution laser spectroscopy. The center-of-gravity frequency was measured to be 96.592 80(10) THz. Seven of the nine expected hyperfine structure transitions were resolved. The observed peaks were unambiguously assigned to the predicted hyperfine transitions by a fit, confirmed by multiconfigurational self-consistent field calculations. From the determined hyperfine structure we conclude that La^{-} is a promising laser cooling candidate. Using this transition, only three laser beams would be required to repump all hyperfine levels of the ground state. PMID:26406825

  5. High-resolution x-ray absorption spectroscopy studies of metal compounds in neurodegenerative brain tissue

    SciTech Connect

    Collingwood, J.F.; Mikhaylova, A.; Davidson, M.R.; Batich, C.; Streit, W.J.; Eskin, T.; Terry, J.; Barrea, R.; Underhill, R.S.; Dobson, J.

    2008-06-16

    Fluorescence mapping and microfocus X-ray absorption spectroscopy are used to detect, locate and identify iron biominerals and other inorganic metal accumulations in neurodegenerative brain tissue at sub-cellular resolution (< 5 microns). Recent progress in developing the technique is reviewed. Synchrotron X-rays are used to map tissue sections for metals of interest, and XANES and XAFS are used to characterize anomalous concentrations of the metals in-situ so that they can be correlated with tissue structures and disease pathology. Iron anomalies associated with biogenic magnetite, ferritin and haemoglobin are located and identified in an avian tissue model with a pixel resolution {approx} 5 microns. Subsequent studies include brain tissue sections from transgenic Huntington's mice, and the first high-resolution mapping and identification of iron biominerals in human Alzheimer's and control autopsy brain tissue. Technical developments include use of microfocus diffraction to obtain structural information about biominerals in-situ, and depositing sample location grids by lithography for the location of anomalies by conventional microscopy. The combined techniques provide a breakthrough in the study of both intra- and extra-cellular iron compounds and related metals in tissue. The information to be gained from this approach has implications for future diagnosis and treatment of neurodegeneration, and for our understanding of the mechanisms involved.

  6. High resolution electron energy loss spectroscopy with two-dimensional energy and momentum mapping

    SciTech Connect

    Zhu, Xuetao; Cao, Yanwei; Zhang, Shuyuan; Jia, Xun; Guo, Qinlin; Yang, Fang; Zhu, Linfan; Zhang, Jiandi; Plummer, E. W.; Guo, Jiandong

    2015-08-15

    High resolution electron energy loss spectroscopy (HREELS) is a powerful technique to probe vibrational and electronic excitations at surfaces. The dispersion relation of surface excitations, i.e., energy as a function of momentum, has in the past, been obtained by measuring the energy loss at a fixed angle (momentum) and then rotating sample, monochromator, or analyzer. Here, we introduce a new strategy for HREELS, utilizing a specially designed lens system with a double-cylindrical Ibach-type monochromator combined with a commercial VG Scienta hemispherical electron energy analyzer, which can simultaneously measure the energy and momentum of the scattered electrons. The new system possesses high angular resolution (<0.1°), detecting efficiency and sampling density. The capabilities of this system are demonstrated using Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+δ}. The time required to obtain a complete dispersion spectrum is at least one order of magnitude shorter than conventional spectrometers, with improved momentum resolution and no loss in energy resolution.

  7. Earle K. Plyler Prize Talk: Using High Resolution Electronic Spectroscopy to Probe Reactive Chemical Intermediates

    NASA Astrophysics Data System (ADS)

    Miller, Terry

    2009-03-01

    Gas phase chemical reactions, such as occur in atmospheric chemistry, combustion, plasma processing, etc. are of great importance to our economy and society. These reactions are typically very complex involving up to 1000's of elementary steps with a corresponding number of reactive chemical intermediates. Spectrospic diagnostics, based upon well analyzed and well understood spectra of the intermediates, are crucial for monitoring such reactions and unraveling their mechanisms. These spectral analyses often benefit from the guidance provided by quantum chemical calculations and conversely the molecular parameters, experimentally determined from the spectra, serve as ``gold standards'' for benchmarking such calculations. Such standards are especially valuable for reactive intermediates whose electronic or geometric structure is particularly complex because of electron-spin interactions, Jahn-Teller effects or other vibronic interactions, hindered internal motions, large molecular size and weight, etc. The organic alkoxy, RO., and peroxy, RO2., (R=alkyl group) free radicals are excellent examples of such species. The talk will focus on our recent characterization of these radicals via their ``high-resolution,'' mostly rotationally resolved, electronic spectra utilizing the techniques of laser induced fluorescence, stimulated emission pumping, and cavity ringdown spectroscopy. Selected spectra, their analysis, and the molecular information resulting therefrom will be discussed.

  8. High resolution X-ray spectroscopy of SN 1987 A: monitoring with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Sturm, R.; Haberl, F.; Aschenbach, B.; Hasinger, G.

    2010-06-01

    Context. The ongoing propagation of the supernova blast wave of SN 1987 A through its inner circumstellar ring has caused a drastic increase in X-ray luminosity in the past few years, which has allowed detailed high resolution X-ray spectroscopy to be performed with the Reflection Grating Spectrometer. Aims: We report the results of our XMM-Newton monitoring of SN 1987 A, which may be used to follow the detailed evolution of the arising supernova remnant. Methods: The fluxes and broadening of the numerous emission lines measured in the dispersed spectra provide information about the evolution of the X-ray emitting plasma and its dynamics. These were analyzed in combination with the EPIC-pn spectra, which allow a precise determination of the higher temperature plasma. We modeled individual emission lines and fitted plasma emission models. Results: For observations between 2003 and 2007 in particular, we detect significant evolution in the plasma parameters and a deceleration of the radial velocity in the lower temperature plasma regions. We detected (at 3σ-level) an iron K feature in the coadded EPIC-pn spectra. Conclusions: By comparing with Chandra grating observations in 2004, we observe a clear temporal coherence of the spectral evolution and the sudden deceleration of the expansion velocity detectable in X-ray images ~6100 days after the explosion.

  9. High-efficiency blazed transmission gratings for high-resolution soft x-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Bruccoleri, Alexander R.; Schattenburg, Mark L.

    2015-09-01

    High-resolution spectroscopy of astrophysical sources is the key to gaining a quantitative understanding of the history, dynamics, and current conditions of the cosmos. A large-area (> 1,000 cm2), high resolving power (R = λ/Δλ> 3000) soft x-ray grating spectrometer (XGS) that covers the lines of C, N, O, Ne and Fe ions is the ideal tool to address a number of high-priority science questions from the 2010 Decadal Survey, such as the connection between super-massive black holes and large-scale structure via cosmic feedback, the evolution of large- scale structure, the behavior of matter at high densities, and the conditions close to black holes. While no grating missions or instruments are currently approved, an XGS aboard a potential future X-ray Surveyor could easily surpass the above performance metrics. To improve the chances for future soft x-ray grating spectroscopy missions or instruments, grating technology has to progress and advance to higher Technology Readiness Levels (TRLs). To that end we have developed Critical-Angle Transmission (CAT) gratings that combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, high transparency at higher energies). A CAT grating-based spectrometer can provide performance 1-2 orders of magnitude better than current grating instruments on Chandra and Newton-XMM with minimal resource requirements. At present we have fabricated large-area freestanding CAT gratings with narrow integrated support structures from silicon-on- insulator wafers using advanced lithography and a combination of deep reactive-ion and wet etching. Our latest x-ray test results show record high absolute diffraction efficiencies in blazed orders in excess of 30% with room for improvement.

  10. High-efficiency blazed transmission gratings for high-resolution soft x-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Bruccoleri, Alexander R.; Schattenburg, Mark L.

    2015-01-01

    High-resolution spectroscopy of astrophysical sources is the key to gaining a quantitative understanding of the history, dynamics, and current conditions of the cosmos. A large-area (> 1,000 cm2), high resolving power (R = λ/Δλ > 3,000) soft x-ray spectrometer that covers the lines of C, N, O, Ne and Fe ions is the ideal tool to address a number of high-priority sciences questions from the 2010 Decadal Survey, such as the connection between super-massive black holes and large-scale structure via cosmic feedback, the evolution of large-scale structure, the behavior of matter at high densities, and the conditions close to black holes. Numerous mission concepts that meet these requirements have been studied and proposed over the last few years, including grating instruments for the International X-ray Observatory. Nevertheless, no grating missions are currently approved. To improve the chances for future soft x-ray grating spectroscopy missions, grating technology has to progress and be advanced to higher TRLs. We have developed Critical-Angle Transmission (CAT) gratings that combine the advantages of blazed reflection gratings (high efficiency, use of higher diffraction orders) with those of conventional transmission gratings (low mass, relaxed alignment tolerances and temperature requirements, transparent at higher energies). A CAT grating-based spectrometer can provide performance 1-2 orders of magnitude better than current grating instruments on Chandra and Newton-XMM with minimal resource requirements. We have fabricated large-area free-standing CAT gratings with minimal integrated support structures from silicon-on-insulator wafers using advanced lithography and a combination of deep reactive-ion and wet etching, and will present our latest x-ray test results showing record high diffraction efficiencies in blazed orders.

  11. High Resolution Imaging Spectroscopy for Characterizing Soil Properties over Large Areas

    NASA Astrophysics Data System (ADS)

    Dutta, D.; Kumar, P.

    2014-12-01

    Quantitative mapping of high resolution surface soil texture (percentage sand, silt and clay), soil organic matter and chemical constituents are important for understanding infiltration, runoff and other surficial hydrologic processes at different scales. The Visible Near Infrared Analysis (VNIRA) method, which is a combination of imaging spectroscopy and laboratory chemical analysis with an underlying statistical model, has been established for the quantification of soil properties from imaging spectrometer data. In this study we characterize the feasibility of quantifying soil properties over large areas with the aim that these methods may be extended to space-borne sensors such as HyspIRI. Hyperspectral Infrared Imager (HyspIRI) is a space-borne NASA mission concept having 10nm contiguous bands in the VSWIR region (380nm to 2500nm) of the electromagnetic spectra. High resolution (7.6m) Airborne Visible Infrared Imaging Spectrometer (AVIRIS) data collected by NASA immediately after the massive 2011 Mississippi River floods at the Birds Point New Madrid (BPNM) floodway, coupled with in situ samples obtained at the time of the flight, is used to generate HyspIRI like data at 60m resolution. The VNIRA method is applied in a data-mining framework for quantification of the different soil textural properties and chemical constituents. The empirical models are further used for creating quantitative maps of the soil properties for the entire BPNM floodway. These maps are compared with the fine resolution AVIRIS maps of the same area for the different legacy landscape features and spatial correlations with the underlying topography immediately disturbed by the flooding event. The scales of variation in the soil constituents captured by the fine resolution data are also compared to the scales of variation captured by coarser resolution data. This study further explores the issues of applicability, challenges (such as the sensitivity of NDVI from mixed neighborhood pixels

  12. Ge-diode detector combined with crystal-diffraction spectrometer permits high-resolution gamma ray spectroscopy

    NASA Technical Reports Server (NTRS)

    Namenson, A. I.; Smither, R. K.

    1969-01-01

    Crystal-diffraction spectrometer, combined with a lithium-drifted Ge-diode detector, performs high-resolution gamma ray spectroscopy on the complicated neutron-capture gamma ray spectra. The system is most useful in the 1-3 MeV energy range and improves the signal to background ratio.

  13. IGRINS Near-IR High-resolution Spectroscopy of Multiple Jets around LkHα 234

    NASA Astrophysics Data System (ADS)

    Oh, Heeyoung; Pyo, Tae-Soo; Yuk, In-Soo; Park, Byeong-Gon; Park, Chan; Chun, Moo-Young; Pak, Soojong; Kim, Kang-Min; Sok Oh, Jae; Jeong, Ueejeong; Yu, Young Sam; Lee, Jae-Joon; Kim, Hwihyun; Hwang, Narae; Kaplan, Kyle; Pavel, Michael; Mace, Gregory; Lee, Hye-In; Nguyen Le, Huynh Anh; Lee, Sungho; Jaffe, Daniel T.

    2016-02-01

    We present the results of high-resolution near-IR spectroscopy toward the multiple outflows around the Herbig Be star LkHα 234 using the Immersion Grating Infrared Spectrograph. Previous studies indicate that the region around LkHα 234 is complex, with several embedded young stellar objects and the outflows associated with them. In simultaneous H- and K-band spectra from HH 167, we detected 5 [Fe ii] and 14 H2 emission lines. We revealed a new [Fe ii] jet driven by radio continuum source VLA 3B. Position-velocity diagrams of the H2 1-0 S(1) λ2.122 μm line show multiple velocity peaks. The kinematics may be explained by a geometrical bow shock model. We detected a component of H2 emission at the systemic velocity (VLSR = -10.2 km s-1) along the whole slit in all slit positions, which may arise from the ambient photodissociation region. Low-velocity gas dominates the molecular hydrogen emission from knots A and B in HH 167, which is close to the systemic velocity; [Fe ii] emission lines are detected farther from the systemic velocity, at VLSR = -100--130 km s-1. We infer that the H2 emission arises from shocked gas entrained by a high-velocity outflow. Population diagrams of H2 lines imply that the gas is thermalized at a temperature of 2500-3000 K and the emission results from shock excitation. This paper includes data taken at The McDonald Observatory of The University of Texas at Austin.

  14. Fluorescence Spectroscopy as a Rapid, High-Resolution Tool for Detecting Biomolecules in Glacial Ice

    NASA Astrophysics Data System (ADS)

    Rohde, R. A.; Price, P. B.; Bramall, N.; Bay, R.

    2007-12-01

    We have developed new instruments utilizing the intrinsic fluorescence of specific biomolecules as a sensitive, non-destructive tool for detecting microorganisms. Using a 224-nm excitation, we detect protein-bound tryptophan (an amino acid present in all cells) at a detection threshold of approximately 1 cell per laser excitation volume and a duty cycle of 100 ms per measurement. Tryptophan is easily distinguished from inorganic backgrounds due to its characteristic spectral shape and ~300 times higher intensity per unit volume than typical inorganic compounds. A different excitation was also used to detect coenzyme F420, a characteristic marker for viable methanogenic cells. At the National Ice Core Laboratory, systematic scans of a 1 meter core sections took about 15 minutes and generated ~5000 measurements per meter. The high-resolution of this work revealed strong variability of microbial content on a scale of cm within individual cores, which suggests that microbial deposition at polar sites is strongly influenced by meteorological events (e.g. storms) on subannual and interannual scales. In addition, high levels of microbes are found to correlate with anomalously high concentrations of metabolic gases (e.g. methane, nitrous oxide, and 18O/16O of O2), suggesting that many of the isolated "gas artifacts" identified in deep ice cores are the accumulated waste products of in situ metabolism. This means that fluorescence spectroscopy may be a useful tool for identifying regions where high microbial concentrations have contaminated gas records. The existing instrumentation is suitcase portable and could be easily deployed in a variety of environments. Future versions of these instruments may be practical for continuous, rapid scans of entire cores, as an on-site deployable technique for characterizing microbial abundances in ice, and for searching for as few as 1 microbe per cm3 in ice-bound planets. This work was supported by NSF grant ANT-0440609.

  15. Long-term High-Resolution Spectroscopy of γ Cas, ζ Tau, and π Aqr

    NASA Astrophysics Data System (ADS)

    Bjorkman, K. S.; Miroshnichenko, A. S.; Krugov, V. D.

    2000-05-01

    High-resolution spectroscopic data (λ λ 5285-6595 Angstroms) for three bright classical Be stars with unusual Hα profiles (γ Cas, ζ Tau, and π Aqr) have been obtained during the time period 1993-2000 at the Ritter Observatory of the University of Toledo. The data for γ Cas are supplemented by medium-resolution spectroscopy taken at the Terskol station of the Main Astronomical Observatory of the Ukranian Academy of Sciences. The stars show the presence of an additional variable (central) emission peak in the Hα line, which has a double-peaked profile in most stars of this type. Long-term radial velocity (RV) variations of H I, He I, Si II, and Fe II lines are detected in γ Cas and ζ Tau. The RV of the central peak of Hα in ζ Tau seem to follow the binary orbital motion (period 132.9 days) on top of the long-term variations (period 1420 days). In γ Cas this peak shows a constant trend towards negative velocities since 1993, which is opposite to the behavior of other emission lines. Short-term RV variations of the Hα emission peak with a period 84 days are found in π Aqr during its weak-disk phase (since 1996). This work has been supported in part by NASA grant NAG5-8054 to the Univ. of Toledo, and by a Cottrell Scholars Award to KSB from the Research Corporation. Support for Ritter Observatory has been provided in part by NSF grant AST-9024802, and in part by a grant from the Fund for Astrophysical Research.

  16. Imaging and high-resolution spectroscopy of the Planetary Nebula NGC 3242

    NASA Astrophysics Data System (ADS)

    Gómez-Muñoz, Marco Antonio; Wendolyn Blanco Cárdenas, Mónica; Vázquez, Roberto; Zavala, Saúl A.; Guillén, Pedro F.; Ayala, Sandra A.

    2015-08-01

    We present a high-resolution imaging and high-dispersion spectroscopy study of the complex morphological and kinematical structure of the planetary nebula NGC 3242. We analyze narrowband Hα, [O III] and [N II] images, addressing important morphological features: in the [O III] image we found one knot oriented to PA=-4°, in the [N II] image, three knots oriented at PA1=155°, PA2=+157°, and PA3=-45.5°, and in the Hα image, two bubbles in the internal region, one of them oriented toward SE and the other toward NW. Additionally we used the unsharp-masking technique and found faint structures in the halo that have not been studied before. These structures are presented in two pairs of arcs, one pair oriented toward PA=-35° and the other toward PA=140°. NGC 3242 is a morphologically rich PN with bubbles, asymmetrical outflows, and some knots in a double-shell nebular structure. Ground-based long-slit echelle spectra were obtained crossing NGC 3242 at twelve different positions to precisely determine kinematical features in the structure of the nebula. We obtain a systemic velocity of VLSR=-6.6 km/s. We have used the software SHAPE (Steffen et al. 2011, IEEE Trans. Vis. Comput. Graphics, 17, 454), to reconstruct a 3D model of NGC 3242 which fits all our observational data. Preliminary results (deprojected velocities and kinematical ages) of all these structures will be presented.This project has been supported by grant PAPIIT-DGAPA-UNAM IN107914. MWB is in grateful receipt of a DGAPA-UNAM postdoctoral scholarship. MAG acknowledges CONACYT for his graduate scholarship.

  17. High-Resolution Spectroscopy of Stratospheric Ethane Following the Jupiter Impact of 2009

    NASA Technical Reports Server (NTRS)

    Fast, Kelly; Kostiuk, Theodor; Livengood, Timothy A.; Hewagama, Tilak; Amen, John

    2010-01-01

    We report on high-resolution infrared spectroscopy of ethane (C2H6) performed at the latitude of an impact site on Jupiter discovered on 19 July 2009 by A. Wesley from a location in Murrumbateman, Australia. The observations used the NASA Goddard Space Flight Center's Heterodyne Instrument for Planetary Wind and Composition (HIPWAC) at the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii. HIPWAC is a mid-infrared (9-12 microns) heterodyne spectrometer operating at the highest limit of spectral resolving power (lambda\\Delta\\lambda > l06), providing information on atmospheric constituent abundance and temperature through fully resolved tine shapes. Ethane is a stable trace product of methane photochemistry that is nearly uniformly mixed in Jupiter's stratosphere, providing an effective probe of that altitude region. Ethane emission line profiles near 11,74 microns in the Ug band were measured in Jupiter's stratosphere at 25 MHz (11.00083/cm) resolution. A sequence of spectra of ethane acquired over a range of longitude at the impact latitude (56S planetocentric) probes constituent abundance and temperature profile, both on and off the impact region. Near the site of the impact, ethane emission increased above levels measured well outside the impact region. Radiative transfer analysis indicates increased ethane mole fraction (30% greater). Variation in the measured continuum level and line intensities within 75deg of the impact longitude indicate the presence of an opacity source (haze) at altitudes near and above the tropopause and as high as the 10-mbar level near the impact site. The indication of possible haze opacity up to the 10-mbar level in the atmosphere is consistent with measurements made by HIPWAC's predecessor as part of the IRTF Shoemaker Levy-9 campaign in 1994.

  18. High Resolution Far Infrared Fourier Transform Spectroscopy of the NH_2 Radical.

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, M. A.; Pirali, O.; Balcon, D.; Vervloet, M.

    2011-06-01

    First identified toward Sgr B2, the NH_2 radical has recently been detected in the interstellar medium by the HIFI instrument on board of Herschel. Despite the fact that this radical has not been detected in brown dwarfs and exoplanets yet, it is already included in physical and chemical models of those environments (temperature higher than 2000 K expected in several objects). Its detection in those objects will depend on the existence of a reliable high temperature and high resolution spectroscopic database on the NH_2 radical.The absorption spectrum of NH_2 has been recorded between 15 and 700 Cm-1 at the highest resolution available using the Bruker IFS125HR Fourier transform interferometer connected to the far infrared AILES beamline at SOLEIL (R=0.001 Cm-1). The radical was produced by an electrical discharge (DC) through a continuous flow of NH_3 and He using the White-type discharge cell developped on the beamline (optical path: 24m). Thanks to the brilliance of the synchrotron radiation, more than 700 pure rotational transitions of NH_2 have been identified with high N values (NMax=25) in its fundamental and first excited vibrational modes. By comparison to the previous FT spectroscopic study on that radical in the FIR spectral range, asymmetric splitting as well as fine and hyperfine structure have been resolved for several transitions. E. F. Van Dishoeck, D. J. Jansen, P. Schilke, T. G. Phillips The Astrophysical Journal 416, L83-L86 (1993) C. M. Persson, J. H. Black, J. Cernicharo et al. Astronomy and Astrophysics 521, L45 (2010) K. Lodders and B. Fegley, Jr Icarus 155, 393-424 (2002) I. Morino and K. Kawaguchi Journal of Molecular Spectroscopy 182, 428-438 (1997)

  19. Development of an Apparatus for High-Resolution Auger Photoelectron Coincidence Spectroscopy (APECS) and Electron Ion Coincidence (EICO) Spectroscopy

    NASA Astrophysics Data System (ADS)

    Kakiuchi, Takuhiro; Hashimoto, Shogo; Fujita, Narihiko; Mase, Kazuhiko; Tanaka, Masatoshi; Okusawa, Makoto

    We have developed an electron electron ion coincidence (EEICO) apparatus for high-resolution Auger photoelectron coincidence spectroscopy (APECS) and electron ion coincidence (EICO) spectroscopy. It consists of a coaxially symmetric mirror electron energy analyzer (ASMA), a miniature double-pass cylindrical mirror electron energy analyzer (DP-CMA), a miniature time-of-flight ion mass spectrometer (TOF-MS), a magnetic shield, an xyz stage, a tilt-adjustment mechanism, and a conflat flange with an outer diameter of 203 mm. A sample surface was irradiated by synchrotron radiation, and emitted electrons were energy-analyzed and detected by the ASMA and the DP-CMA, while desorbed ions were mass-analyzed and detected by the TOF-MS. The performance of the new EEICO analyzer was evaluated by measuring Si 2p photoelectron spectra of clean Si(001)-2×1 and Si(111)-7×7, and by measuring Si-L23VV-Si-2p Auger photoelectron coincidence spectra (Si-L23VV-Si-2p APECS) of clean Si(001)-2×1.

  20. Site-selective high-resolution X-ray absorption spectroscopy and high-resolution X-ray emission spectroscopy of cobalt nanoparticles.

    PubMed

    Kühn, Timna-Josua; Hormes, Josef; Matoussevitch, Nina; Bönnemann, Helmut; Glatzel, Pieter

    2014-08-18

    The special (macroscopic) properties of nanoparticles are mainly due to their large surface-to-volume ratio. Thus, the separate characterization of geometric and electronic properties of surface and bulk would be favorable for a better understanding of the properties of nanoparticles. Because of the chemical sensitivity of X-ray fluorescence lines, in particular those involving higher lying electronic states, high-resolution fluorescence-detected X-ray absorption spectra (HRFD-XAS) offer these opportunities. In this study, three types of wet-chemically synthesized Co nanoparticles, ∼6 nm in diameter with varying thicknesses of a protective shell, were investigated at the ID26 beamline of the European Synchrotron Radiation Facility. HRFD-XAS spectra at the Co K-edge, that is, X-ray absorption near-edge structure (HRFD-XANES) and extended X-ray absorption fine structure (HRFD-EXAFS) spectra, were recorded via detection of the Kβ1,3 fluorescence at specific energies. As these spectra are only partly site-selective due to a strong overlap of the emission lines, a numerical procedure was applied based on a least-squares fitting procedure, realized by singular value decomposition. The detailed analysis of the obtained site-selective spectra, regarding chemical composition and crystallographic phase, using measured and simulated FEFF9-based reference spectra, showed that the metallic core had mainly hexagonal close-packed structure with lattice constants matching bulk Co; the spectra for the shell could be satisfactorily fitted by a mixture of CoO and CoCO3; however, with an obvious need for at least a third compound. To obtain additional information about ligands attached to Co, valence-to-core X-ray emission spectra (VTC-XES) using the Kβ2,5 and the satellite structure Kβ″ and VTC-XANES spectra thereof were also recorded, by which the former results are confirmed. Further on, FEFF simulations indicate that a Co-N compound is a very likely candidate for the third

  1. High-resolution spectroscopy for Cepheids distance determination. IV. Time series of Hα line profiles

    NASA Astrophysics Data System (ADS)

    Nardetto, N.; Groh, J. H.; Kraus, S.; Millour, F.; Gillet, D.

    2008-10-01

    Context: In recent years, infrared interferometry has revealed the presence of faint dusty circumstellar envelopes (CSE) around Cepheids. However the size, shape, chemical nature, and the interaction of the CSE with the star itself are still under investigation. The presence of a CSE might have an effect on the angular diameter estimates used in the interferometric Baade-Wesselink and surface-brightness methods of determining the distance of Cepheids. Aims: By studying Hα profiles as a function of the period, we investigate the permanent mass loss and the CSE around Cepheids. Our high spectral- and time-resolution data, combined with a very good S/N, will be useful in constraining future hydrodynamical models of Cepheids atmosphere and their close environment. Methods: We present HARPS (High Accuracy Radial velocity Planetary Search project developed by the European Southern Observatory.) high-resolution spectroscopy (R = 120 000) of eight galactic Cepheids: R Tra, S Cru, Y Sgr, β Dor, zeta Gem, RZ Vel, ell Car, and RS Pup, providing a good period sampling (P = 3.39 d to P = 41.52 d). The Hα line profiles are described for all stars using a 2D (wavelength versus pulsation phase) representation. For each star, an average spectral line profile is derived, together with its first moment (γ-velocity) and its asymmetry (γ-asymmetry). Results: Short-period Cepheids show Hα line profiles following the pulsating envelope of the star, while long-period Cepheids show very complex line profiles and, in particular, large asymmetries. We find a new relationship between the period of Cepheids and their γ-velocities and -asymmetries. These results may be related to the dynamical structure of the atmosphere and to a permanent mass loss of Cepheids. In particular, we confirm for ell Car a dominant absorption component whose velocity is constant and nearly of zero km s-1 in the stellar rest frame. This component is attributed to the presence of circumstellar envelope

  2. Investigation of Exploding Wire Plasmas Using High Resolution Point Projection X-ray Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Knapp, Patrick

    2011-10-01

    We have determined the properties of plasma around and between two exploding wires using high-resolution x-ray absorption spectroscopy. Plasma densities and temperatures ranging from 1020 cm-3 and a few eV to 1017 cm-3 and 30 eV have been measured in experiments at Cornell University with two 25 μm aluminum (Al) wires spaced 1 mm apart driven by ~ 100 kA peak current pulses with 50 - 100 ns rise time. The wire plasma was backlit by the 1 . 4 - 1 . 6 keV continuum radiation produced by a Mo wire X-pinch. The spectrometer employed two spherically bent quartz crystals to record the absorption and backlighter spectra simultaneously. The transition between the dense Al wire core and the coronal plasma is seen as a transition from cold K-edge absorption to Mg-, Na- and finally Ne-like absorption at the boundary. In the plasma that accumulates between the wires, ionization states up to Be-Like Al have been seen. The spectrometer geometry and ~ 2 μm X-pinch source size provide 0 . 3 eV spectral resolution and 20 μm spatial resolution, enabling us to see 1 --> 2 satellite transitions as separate lines as well as O-, F- and N-like 1 --> 3 transitions that have not been seen before. A step wedge was used to calibrate the transmission, enabling density to be measured within 50 % and temperature to be measured within 25 % . A genetic algorithm was developed to fit synthetic spectra calculated using the collisional-radiative code SCRAM to the experimental spectra. In order to obtain agreement it was necessary to assume 3 plasma regions with variable thicknesses, thereby allowing the inferred plasma conditions to vary along the absorption path. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the National Nuclear Security Administration under DE-AC04-94AL85000 This research was carried out at Cornell University sponsored by the NNSA Stewardship Science Academic Alliances program under DOE agreement DE-FC03-02NA00057.

  3. The Wesleyan Hobby-Eberly High-Resolution Exoplanetary Atmospheric Transmission Spectroscopy Survey: Latest Results

    NASA Astrophysics Data System (ADS)

    Jensen, Adam G.; Redfield, S.; Cochran, W. D.; Endl, M.; Koesterke, L.; Barman, T. S.

    2013-01-01

    The Wesleyan Hobby-Eberly High-Resolution Exoplanetary Atmospheric Transmission Spectroscopy Survey (W[HE]2ATS2) has used the 9.2m Hobby-Eberly Telescope (HET) at McDonald Observatory to make observations of the transmission spectra of hot Jupiter atmospheres at high spectral resolution ( 60,000). This program has made the first ground-based detection of neutral sodium in an exoplanetary atmosphere (Redfield et al. 2008) and the first detection of exoplanetary Hα (Jensen et al. 2012). A primary goal of exoplanet characterization science is to press toward smaller, Earth-like atmospheres. Though such Earth-like atmospheres are largely beyond the reach of current instrumentation, the W[HE]2ATS2 program has obtained data on a hot Neptune-class planet and a highly irradiated hot Jupiter. The purpose of studying a hot Neptune is to explore a planet with a lower surface gravity and possibly a different atmospheric molecular weight and scale height. The goal of observing the irradiated hot Jupiter is to explore the effects of star-planet interactions on exoplanetary atmospheres. Though such a planet is not a precise analogy to Super-Earths or Earth-like planets, there is a great deal of interest in planets around relatively active M dwarf stars, where the habitable zone is much closer to the star and the star-planet interaction may have a great effect on the planet’s atmosphere. Here we present our initial results for our newest data, where we search for resonance absorption lines of alkali metals such as sodium and potassium, and nonthermally excited material such as n=2 hydrogen detected through Hα absorption. We also discuss directions for future work with the HET and the W[HE]2ATS2 program. This work is supported by the National Science Foundation through an Astronomy and Astrophysics Research Grant (AST-0903573). The Hobby-Eberly Telescope is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig

  4. High-Resolution Vibration-Rotation Spectroscopy of CO[subscript 2]: Understanding the Boltzmann Distribution

    ERIC Educational Resources Information Center

    Castle, Karen J.

    2007-01-01

    In this undergraduate physical chemistry laboratory experiment, students acquire a high-resolution infrared absorption spectrum of carbon dioxide and use their data to show that the rotational-vibrational state populations follow a Boltzmann distribution. Data are acquired with a mid-infrared laser source and infrared detector. Appropriate…

  5. Investigating Protostellar Carbon Reservoirs with High-Resolution Spectroscopy Toward Massive Young Stellar Objects

    NASA Astrophysics Data System (ADS)

    Smith, R. L.; Blake, G. A.; Boogert, A. C. A.; Pontoppidan, K. M.; Lockwood, A. C.

    2014-09-01

    High-resolution CO spectra toward massive YSOs reveal less dispersion in [12C16O]/[13C16O] gas compared to low-mass YSOs, while these ratios may be similarly affected by CO ice. Our new data suggest that CO2 may not originate from a CO reservoir.

  6. Coordination defects in bismuth-modified arsenic selenide glasses: High-resolution x-ray photoelectron spectroscopy measurements

    SciTech Connect

    Golovchak, Roman; Shpotyuk, Oleh

    2008-05-01

    The possibility of coordination defects formation in Bi-modified chalcogenide glasses is examined by high-resolution x-ray photoelectron spectroscopy. The results provide evidence for the formation of positively charged fourfold coordinated defects on As and Bi sites in glasses with low Bi concentration. At high Bi concentration, mixed As{sub 2}Se{sub 3}-Bi{sub 2}Se{sub 3} nanocrystallites are formed in the investigated Se-rich As-Se glasses.

  7. Sensitivity enhancement in high resolution stimulated Raman spectroscopy of gases with hollow-core photonic crystal fibers.

    PubMed

    Doménech, José Luis; Cueto, Maite

    2013-10-15

    We show the first experimental evidence of the sensitivity enhancement that can be achieved in high resolution stimulated Raman spectroscopy of gases using hollow-core photonic crystal fibers (HCPCFs). Using low power cw lasers and a HCPCF containing the gas, we have observed more than four orders of magnitude enhancement of sensitivity when compared with the cw single focus regime, and a similar sensitivity to that achieved in the more sensitive quasi-cw setups with multipass cells. PMID:24321926

  8. High resolution mass spectroscopy for the characterization of complex, fossil organic mixtures

    SciTech Connect

    Winans, R.E.; Haas, G.W.; Kim, Y.L.; Hunt, J.E.

    1995-12-31

    The nature of molecules with heteroatom functionality in the Argonne Premium Coal Samples and petroleum samples is being explored using high resolution mass spectrometry (HRMS). Both desorption electron impact and desorption chemical ionization (DCI) are used to sample the mixtures. Structural information is obtained from tandem MS experiments using high resolution to select the ions to fragment. The first DCI HRMS spectra of complex mixtures will be shown. Quantitative aspects and the method for obtaining precise mass measurements in chemical ionization will be discussed. Molecular weight distribution determined by DCI are similar to those determined by laser desorption and field ionization mass spectrometry with very little ion intensity observed at greater than 1000 Daltons. Results will be correlated with other techniques such as NMR, XPS, and XANES.

  9. High-resolution multiple quantum MAS NMR spectroscopy of half-integer quadrupolar nuclei

    NASA Astrophysics Data System (ADS)

    Wu, Gang; Rovnyank, David; Sun, Boqin; Griffin, Robert G.

    1996-02-01

    We demonstrate the utility of a two-pulse sequence in obtaining high-resolution solid state NMR spectra of half-integer quadrupolar nuclei with magic-angle-spinning (MAS). The experiment, which utilizes multiple/single-quantum correlation, was first described in a different form by Frydman and Harwood [J. Am. Chem. Soc. 117 (1995) 5367] and yields high-resolution isotropic NMR spectra where shifts are determined by the sum of resonance offset (chemical shift) and second-order quadrupolar effects. The two-pulse sequence described here is shown to provide a higher and more uniform excitation of multiple-quantum coherence than the three-pulse sequence used previously.

  10. High-resolution Infrared Spectroscopy of Starspots on RS CVn Stars

    NASA Astrophysics Data System (ADS)

    O'Neal, D.; Neff, J. E.; Saar, S. H.

    1997-12-01

    We present results from a study of magnetically active stars using the PHOENIX infrared spectrograph at KPNO. We constrain starspot coverages on RS CVn stars using high-resolution observations of two temperature-sensitive OH lines near 1.563mu m (6397 cm(-1) ). The use of these features holds two advantages over the TiO bands that we have used previously: the OH lines are visible in spots up to ~ 4500 K; and spots are much brighter, relative to the unspotted photosphere, in the infrared than in the visible. These properties also make these OH lines excellent candidates for the first Doppler imaging study to use high-resolution observations of infrared spectral features. Using the OH lines, we also search for previously unknown secondary stars in ``single-lined'' RS CVn binary systems, including II Pegasi (HD 224085).

  11. Differential high-resolution stimulated CW Raman spectroscopy of hydrogen in a hollow-core fiber.

    PubMed

    Westergaard, Philip G; Lassen, Mikael; Petersen, Jan C

    2015-06-15

    We demonstrate sensitive high-resolution stimulated Raman measurements of hydrogen using a hollow-core photonic crystal fiber (HC-PCF). The Raman transition is pumped by a narrow linewidth (< 50 kHz) 1064 nm continuous-wave (CW) fiber laser. The probe light is produced by a homebuilt CW optical parametric oscillator (OPO), tunable from around 800 nm to 1300 nm (linewidth ∼ 5 MHz). These narrow linewidth lasers allow for an excellent spectral resolution of approximately 10(-4) cm(-1). The setup employs a differential measurement technique for noise rejection in the probe beam, which also eliminates background signals from the fiber. With the high sensitivity obtained, Raman signals were observed with only a few mW of optical power in both the pump and probe beams. This demonstration allows for high resolution Raman identification of molecules and quantification of Raman signal strengths. PMID:26193604

  12. High temperature and high resolution uv photoelectron spectroscopy using supersonic molecular beams

    SciTech Connect

    Wang, Lai-Sheng; Reutt-Robey, J.E.; Niu, B.; Lee, Y.T.; Shirley, D.A.; Maryland Univ., College Park, MD . Dept. of Chemistry and Biochemistry; Lawrence Berkeley Lab., CA )

    1989-07-01

    A high temperature molecular beam source with electron bombardment heating has been built for high resolution photoelectron spectroscopic studies of high temperature species and clusters. This source has the advantages of: producing an intense, continuous, seeded molecular beam, eliminating the interference of the heating mechanism from the photoelectron measurement. Coupling the source with our hemispherical electron energy analyzer, we can obtain very high resolution HeI{alpha} (584{angstrom}) photoelectron spectra of high temperature species. Vibrationally-resolved photoelectron spectra of PbSe, As{sub 2}, As{sub 4}, and ZnCl{sub 2} are shown to demonstrate the performance of the new source. 25 refs., 8 figs., 1 tab.

  13. High resolution X- and gamma-ray spectroscopy of cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Lin, R. P.

    1983-01-01

    A high resolution X-ray spectrometer and large area phoswich detector were designed and co-aligned in a common elevation mounting in order to measure solar and cosmic X-ray and gamma ray emission in the 13 to 600 KeV energy range from a balloon. The instrument is described and results obtained for the Crab Nebula, the supernova remnant Cas A, and the Sun are discussed and analyzed.

  14. New High Resolution Spectroscopy Studies of Methyl Nitrite CH_3ONO

    NASA Astrophysics Data System (ADS)

    Sironneau, V.; Chelin, P.; Tchana, F. Kwabia; Kleiner, I.; Orphal, J.; Pirali, O.; Guillemin, J.-C.; Margules, L.; Motiyenko, R.; Cooke, S.; Youngblood, W. J.; Agnew, A.; Dewberry, C. T.

    2010-06-01

    Methyl nitrite CH3ONO is an important species in atmospheric chemistry involved in photochemical oxidation of volatile organic compounds. The cis conformer (more stable by about 298 cm-1) has a high internal rotation potential barrier for the methyl group (731 cm-1) whereas for the trans conformer the barrier to internal rotation is extremely low (10 cm-1), leading to large internal rotation splittings. Only one high resolution infrared study was performed prior to this study. For the first time, high-resolution spectrum of CH3ONO was recorded in the far infrared region (30-500 cm-1) using the synchrotron SOLEIL far-infrared beamline (AILES) and a Fourier transform (FT) spectrometer. Some 987 lines were assigned for the cis isomer up to J=65 and combined with 66 previously recorded microwave lines. In addition, high-resolution spectrum of the ν9 band of the cis isomer around 627.9 cm-1 was also recorded using the FT spectrometer at LISA. New microwave data is currently recorded to improve the knowledge of both the cis and trans ground state parameters. P. N. Gosh, A. Bauder and Hs. H. Gunthard, Chem. Phys. 53, 39-60 (1980) P. H. Turner, M. J. Corkill, and A. P. Cox, J. Chem. Phys. 83, 1473-1482 1979) L. M. Goss, C. D. Mortensen and T. A. Blake, J. Mol. Spectrosc., 225, 182-188 (2004)

  15. Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy

    NASA Astrophysics Data System (ADS)

    de Groote, R. P.; Budinčević, I.; Billowes, J.; Bissell, M. L.; Cocolios, T. E.; Farooq-Smith, G. J.; Fedosseev, V. N.; Flanagan, K. T.; Franchoo, S.; Garcia Ruiz, R. F.; Heylen, H.; Li, R.; Lynch, K. M.; Marsh, B. A.; Neyens, G.; Rossel, R. E.; Rothe, S.; Stroke, H. H.; Wendt, K. D. A.; Wilkins, S. G.; Yang, X.

    2015-09-01

    New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t1 /2=22.0 (5 ) ms ] 219Fr Qs=-1.21 (2 ) eb , which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in two-step resonance ionization. Exotic nuclei produced at rates of a few hundred ions/s can now be studied with high resolution, allowing detailed studies of the anchor points for nuclear theories.

  16. Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy.

    PubMed

    de Groote, R P; Budinčević, I; Billowes, J; Bissell, M L; Cocolios, T E; Farooq-Smith, G J; Fedosseev, V N; Flanagan, K T; Franchoo, S; Garcia Ruiz, R F; Heylen, H; Li, R; Lynch, K M; Marsh, B A; Neyens, G; Rossel, R E; Rothe, S; Stroke, H H; Wendt, K D A; Wilkins, S G; Yang, X

    2015-09-25

    New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t_{1/2}=22.0(5) ms] ^{219}Fr Q_{s}=-1.21(2) eb, which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in two-step resonance ionization. Exotic nuclei produced at rates of a few hundred ions/s can now be studied with high resolution, allowing detailed studies of the anchor points for nuclear theories. PMID:26451548

  17. Coherent Vibrational Dynamics and High-Resolution Nonlinear Spectroscopy: A Comparison with the Air/DMSO Liquid Interface

    SciTech Connect

    Velarde Ruiz Esparza, Luis A.; Lu, Zhou; Wang, Hongfei

    2013-12-27

    In this report we present a comparative study on the C-H stretching vibrations at air/DMSO (dimethyl sulfoxide) interface with both the free-induction decay (FID) coherent vibrational dynamics and sub-wavenumber high resolution sum-frequency generation vibrational spectroscopy measurements. In principle the frequency-domain and time-domain spectroscopic measurements should generate identical information for a given molecular system. However, when the molecular systems are with several coupled or overlapping vibrational modes, to obtain detailed spectroscopic and coherent dynamics information is not as straightforward and rather difficult from either the time-domain or the frequency domain measurements. For the case of air/DMSO interface that is with moderately complex vibrational spectra, we show that the frequency-domain measurement with sub-wavenumber high-resolution SFGVS is probably more advantageous than the time-domain measurement in obtaining quantitative understanding of the structure and coherent dynamics of the molecular interface.

  18. HIGH-RESOLUTION XMM-NEWTON SPECTROSCOPY OF THE COOLING FLOW CLUSTER A3112

    SciTech Connect

    Bulbul, G. Esra; Smith, Randall K.; Foster, Adam; Cottam, Jean; Loewenstein, Michael; Mushotzky, Richard; Shafer, Richard

    2012-03-01

    We examine high signal-to-noise XMM-Newton European Photon Imaging Camera (EPIC) and Reflection Grating Spectrometer (RGS) observations to determine the physical characteristics of the gas in the cool core and outskirts of the nearby rich cluster A3112. The XMM-Newton Extended Source Analysis Software data reduction and background modeling methods were used to analyze the XMM-Newton EPIC data. From the EPIC data, we find that the iron and silicon abundance gradients show significant increase toward the center of the cluster while the oxygen abundance profile is centrally peaked but has a shallower distribution than that of iron. The X-ray mass modeling is based on the temperature and deprojected density distributions of the intracluster medium determined from EPIC observations. The total mass of A3112 obeys the M-T scaling relations found using XMM-Newton and Chandra observations of massive clusters at r{sub 500}. The gas mass fraction f{sub gas} = 0.149{sup +0.036}{sub -0.032} at r{sub 500} is consistent with the seven-year Wilkinson Microwave Anisotropy Probe results. The comparisons of line fluxes and flux limits on the Fe XVII and Fe XVIII lines obtained from high-resolution RGS spectra indicate that there is no spectral evidence for cooler gas associated with the cluster with temperature below 1.0 keV in the central <38'' ({approx}52 kpc) region of A3112. High-resolution RGS spectra also yield an upper limit to the turbulent motions in the compact core of A3112 (206 km s{sup -1}). We find that the contribution of turbulence to total energy is less than 6%. This upper limit is consistent with the energy contribution measured in recent high-resolution simulations of relaxed galaxy clusters.

  19. High Resolution UV Emission Spectroscopy of Molecules Excited by Electron Impact

    NASA Technical Reports Server (NTRS)

    James, G. K.; Ajello, J. M.; Beegle, L.; Ciocca, M.; Dziczek, D.; Kanik, I.; Noren, C.; Jonin, C.; Hansen, D.

    1999-01-01

    Photodissociation via discrete line absorption into predissociating Rydberg and valence states is the dominant destruction mechanism of CO and other molecules in the interstellar medium and molecular clouds. Accurate values for the rovibronic oscillator strengths of these transitions and predissociation yields of the excited states are required for input into the photochemical models that attempt to reproduce observed abundances. We report here on our latest experimental results of the electron collisional properties of CO and N2 obtained using the 3-meter high resolution single-scattering spectroscopic facility at JPL.

  20. High-resolution spectroscopy with the multi-anode microchannel array detector systems

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.; Joseph, C. L.; Wolf, S. C.

    1982-01-01

    The results of a series of high-resolution spectroscopic observations undertaken with a linear (1 x 1024)-pixel visible-light Multi-Anode Microchannel Array (MAMA) detector on the Coudespectrograph of the 2.2-meter telescope at the Mauna Kea Observatory and on the vacuum spectrograph of the McMath Solar telescope at the Kitt Peak National Observatory are described. In addition, the two-dimensional MAMA detector systems with (16 x 1024)-pixel, (24 x 1024)-pixel, and (256 x 1024)-pixel formats which are now being readied for use in a series of ground-based, balloon, and sounding-rocket observing programs are briefly described.

  1. High resolution spectroscopy of the new FU Orionis object BBW 76

    NASA Astrophysics Data System (ADS)

    Eisloeffel, J.; Hessman, F. V.; Mundt, R.

    1990-06-01

    High-resolution spectra of the new FU Orionis object BBW 76 are presented. Although the photometric outburst of this FU Orionis object could not be observed, its spectral characteristics clearly identify it as belonging to this class. BBW 76 shows Balmer line profiles typical for FU Orionis stars. Its absorption line spectrum and, in particular, the line widths are strikingly similar to that of FU Ori. Other similarities to FU Ori are the presence of an arclike nebula, and the FIR luminosities and color temperatures.

  2. Spatially resolved high resolution x-ray spectroscopy for magnetically confined fusion plasmas (invited)

    SciTech Connect

    Ince-Cushman, A.; Rice, J. E.; Reinke, M. L.; Podpaly, Y.; Marmar, E. S.; Bitter, M.; Hill, K. W.; Scott, S.; Gu, M. F.; Eikenberry, E.; Broennimann, Ch.; Lee, S. G.

    2008-10-15

    The use of high resolution x-ray crystal spectrometers to diagnose fusion plasmas has been limited by the poor spatial localization associated with chord integrated measurements. Taking advantage of a new x-ray imaging spectrometer concept [M. Bitter et al., Rev. Sci. Instrum. 75, 3660 (2004)], and improvements in x-ray detector technology [Ch. Broennimann et al., J. Synchrotron Radiat. 13, 120 (2006)], a spatially resolving high resolution x-ray spectrometer has been built and installed on the Alcator C-Mod tokamak. This instrument utilizes a spherically bent quartz crystal and a set of two dimensional x-ray detectors arranged in the Johann configuration [H. H. Johann, Z. Phys. 69, 185 (1931)] to image the entire plasma cross section with a spatial resolution of about 1 cm. The spectrometer was designed to measure line emission from H-like and He-like argon in the wavelength range 3.7 and 4.0 A with a resolving power of approximately 10 000 at frame rates up to 200 Hz. Using spectral tomographic techniques [I. Condrea, Phys. Plasmas 11, 2427 (2004)] the line integrated spectra can be inverted to infer profiles of impurity emissivity, velocity, and temperature. From these quantities it is then possible to calculate impurity density and electron temperature profiles. An overview of the instrument, analysis techniques, and example profiles are presented.

  3. Synthesis, High-Resolution Infrared Spectroscopy, and Vibrational Structure of Cubane, C8H8.

    PubMed

    Boudon, V; Lamy, M; Dugue-Boyé, F; Pirali, O; Gruet, S; D'Accolti, L; Fusco, C; Annese, C; Alikhani, M E

    2016-06-30

    Carbon-cage molecules have generated a considerable interest from both experimental and theoretical points of view. We recently performed a high-resolution study of adamantane (C10H16), the smallest hydrocarbon cage belonging to the diamandoid family ( Pirali , O. ; et al. J. Chem. Phys. 2012 , 136 , 024310 ). There exist another family of hydrocarbon cages with additional interesting chemical properties: the so-called platonic hydrocarbons that comprise dodecahedrane (C20H20) and cubane (C8H8). Both possess C-C bond angles that deviate from the tetrahedral angle (109.8°) of the sp(3) hybridized form of carbon. This generates a considerable strain in the molecule. We report a new wide-range high-resolution study of the infrared spectrum of cubane. The sample was synthesized in Bari upon decarboxylation of 1,4-cubanedicarboxylic acid thanks to the improved synthesis of literature. Several spectra have been recorded at the AILES beamline of the SOLEIL synchrotron facility. They cover the 600-3200 cm(-1) region. Besides the three infrared-active fundamentals (ν10, ν11, and ν12), we could record many combination bands, all of them displaying a well-resolved octahedral rotational structure. We present here a preliminary analysis of some of the recorded bands, performed thanks the SPVIEW and XTDS software, based on the tensorial formalism developed in the Dijon group. A comparison with ab initio calculations, allowing to identify some combination bands, is also presented. PMID:27267150

  4. High-resolution subtyping of Staphylococcus aureus strains by means of Fourier-transform infrared spectroscopy.

    PubMed

    Johler, Sophia; Stephan, Roger; Althaus, Denise; Ehling-Schulz, Monika; Grunert, Tom

    2016-05-01

    Staphylococcus aureus causes a variety of serious illnesses in humans and animals. Subtyping of S. aureus isolates plays a crucial role in epidemiological investigations. Metabolic fingerprinting by Fourier-transform infrared (FTIR) spectroscopy is commonly used to identify microbes at species as well as subspecies level. In this study, we aimed to assess the suitability of FTIR spectroscopy as a tool for S. aureus subtyping. To this end, we compared the subtyping performance of FTIR spectroscopy to other subtyping methods such as pulsed field gel electrophoresis (PFGE) and spa typing in a blinded experimental setup and investigated the ability of FTIR spectroscopy for identifying S. aureus clonal complexes (CC). A total of 70 S. aureus strains from human, animal, and food sources were selected, for which clonal complexes and a unique virulence and resistance gene pattern had been determined by DNA microarray analysis. FTIR spectral analysis resulted in high discriminatory power similar as obtained by spa typing and PFGE. High directional concordance was found between FTIR spectroscopy based subtypes and capsular polysaccharide expression detected by FTIR spectroscopy and the cap specific locus, reflecting strain specific expression of capsular polysaccharides and/or other surface glycopolymers, such as wall teichoic acid, peptidoglycane, and lipoteichoic acid. Supervised chemometrics showed only limited possibilities for differentiation of S. aureus CC by FTIR spectroscopy with the exception of CC45 and CC705. In conclusion, FTIR spectroscopy represents a valuable tool for S. aureus subtyping, which complements current molecular and proteomic strain typing. PMID:27021524

  5. High-Resolution Infrared Spectroscopy of Cubane, C_8H_8

    NASA Astrophysics Data System (ADS)

    Boudon, Vincent; Pirali, Olivier; Gruet, Sébastien; D'accolti, Lucia; Fusco, Caterina; Annese, Cosimo

    2014-06-01

    Carbon-cage molecules have generated a considerable interest from both experimental and theoretical point of views. We recently performed a high-resolution study of adamantane (C10H16), the smallest hydrocarbon cage belonging to the diamandoid family. There exist another family of hydrocarbon cages with additional interesting chemical properties: the so-called Platonic hydrocarbons that comprise dodecahedrane (C20H20) and cubane (C_8H_8). Both possess C-C bond angles that deviate from the tetrahedral angle (109.8°) of the sp^3 hybridized form of carbon. This generates a considerable strain in the molecule. Cubane itself has the highest density of all hydrocarbons (1.29 g/cm^3). This makes it able to store larges amounts of energy, although the molecule is fully stable. Up to now, only one high-resolution study of cubane has been performed on a few bands [2]. We report here a new wide-range high-resolution study of the infrared spectrum of cubane. The sample was synthesized in Bari upon decarboxylation of 1,4-cubanedicarboxylic acid thanks to the improved synthesis of literature [3]; its {}1H and 13C NMR, FTIR, and mass spectrometry agreed with reported data [4]. Several spectra have been recorded at the AILES beamline of the SOLEIL French synchrotron facility. They cover the 800 to 3100 cm-1 region. Besides the three infrared-active fundamentals (ν10, ν11 and ν12), we could record many combination bands, all of them displaying a well-resolved octahedral rotational structure. We present here a preliminary analysis of some of the recorded bands, performed thanks the SPVIEW and XTDS software, based on the tensrorial formalism developed in the Dijon group [5]. [1] O. Pirali, V. Boudon, J. Oomens, M. Vervloet, J. Chem. Phys., 136, 024310 (2012). [2] A. S. Pine, A. G. Maki, A. G. Robiette, B. J. Krohn, J. K. G. Watson, Th. Urbanek, J. Am. Chem. Soc., 106, 891-897 (1984). [3] P. E. Eaton, N. Nordari, J. Tsanaktsidis, P. S. Upadhyaya, Synthesis, 1, 501, (1995). [4] E

  6. High resolution infrared spectroscopy: Some new approaches and applications to planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Mumma, M. J.

    1978-01-01

    The principles of spectral line formation and of techniques for retrieval of atmospheric temperature and constituent profiles are discussed. Applications to the atmospheres of Earth, Mars, Venus, and Jupiter are illustrated by results obtained with Fourier transform and infrared heterodyne spectrometers at resolving powers (lambda/delta hyperon lambda of approximately 10,000 and approximately 10 to the seventh power), respectively, showing the high complementarity of spectroscopy at these two widely different resolving powers. The principles of heterodyne spectroscopy are presented and its applications to atmospheric probing and to laboratory spectroscopy are discussed. Direct absorption spectroscopy with tuneable semiconductor lasers is discussed in terms of precision frequency-and line strength-measurements, showing substantial advances in laboratory infrared spectroscopy.

  7. CARMENES at PPVI. High-Resolution Spectroscopy of M Dwarfs with FEROS, CAFE and HRS

    NASA Astrophysics Data System (ADS)

    Alonso-Floriano, F. J.; Montes, D.; Jeffers, S.; Caballero, J. A.; Zechmeister, M.; Mundt, R.; Reiners, A.; Amado, P. J.; Casal, E.; Cortés-Contreras, M.; Modroño, Z.; Ribas, I.; Rodríguez-López, C.; Quirrenbach, A.

    2013-07-01

    To ensure an efficient use of CARMENES observing time, and the highest chances of success, it is necessary first to select the most promising targets. To achieve this, we are observing ~500 M dwarfs at high-resolution (R = 30,000-48,000), from which we determine the projected rotational velocity vsini with an accuracy better than 0.5-0.2 km/s and radial-velocity stability better than 0.2-0.1 km/s. Our aim is to have at least two spectra at different epochs of the final 300 CARMENES targets. Our observations with FEROS at ESO/MPG 2.2m La Silla , CAFE at 2.2m Calar Alto and HRS at Hobby Eberly Telescope allow us to identify single- and double-line spectroscopic binaries and, especially, fast rotators, which should be discarded from the target list for exoplanet searches. Here we present preliminary results.

  8. High Resolution Near-IR Spectroscopy of Protostars With Large Telescopes

    NASA Technical Reports Server (NTRS)

    Greene, Tom; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    It is now possible to measure absorption spectra of Class I protostars using D greater than or = 8m telescopes equipped with sensitive cryogenic IR spectrographs. Our latest high-resolution (R approx. 20,000) Keck data reveal that Class I protostars are indeed low-mass stars with dwarf-like features. However, they differ from T Tauri stars in that Class I protostars have much higher IR veilings (tau(sub k) greater than or = 1 - 3+) and they are rotating quickly, v sin i greater than 20 km/s. Interestingly, the vast majority of protostellar absorption spectra show stellar - not disk - absorption features. A preliminary H-R diagram suggests that protostellar photospheres may have different physical structures than T Tauri stars, perhaps due to their higher accretion rates.

  9. High-Resolution Threshold Photoionization and Photoelectron Spectroscopy of Propene and 2-BUTYNE

    NASA Astrophysics Data System (ADS)

    Michaud, Julie M.; Vasilatou, Konstantina; Merkt, Frédéric

    2009-06-01

    The high-resolution photoionization and pulsed-field ionization zero-kinetic energy (PFI-ZEKE) photoelectron spectra of propene and 2-butyne and their perdeuterated isotopologues have been recorded in the vicinity of the first adiabatic ionization energy following single-photon excitation from the neutral ground state using a narrowband vacuum ultraviolet laser system. The spectral resolution of better than 0.1 cm^{-1} achieved in these spectra has enabled us to partially resolve the rotational structure of the photoelectron spectra and to obtain information on the internal rotation/torsional vibration of the methyl groups in the cationic ground state. The intensity distributions observed in the photoelectron spectra will be discussed in terms of rovibronic photoionization selection rules and Franck-Condon factors for transitions between the neutral and ionized molecules.

  10. High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning

    SciTech Connect

    Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander

    2005-01-27

    High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.

  11. High-resolution photoassociation spectroscopy of the 6Li2 A(11Σu+) state

    NASA Astrophysics Data System (ADS)

    Gunton, Will; Semczuk, Mariusz; Dattani, Nikesh S.; Madison, Kirk W.

    2013-12-01

    We present spectroscopic measurements of seven vibrational levels v=29-35 of the A(11Σu+) excited state of Li2 molecules by the photoassociation of a degenerate Fermi gas of 6Li atoms. The absolute uncertainty of our measurements is ±0.00002 cm-1 (±600 kHz) and we use these new data to further refine an analytic potential for this state. This work provides high accuracy photoassociation resonance locations essential for the eventual high-resolution mapping of the X(11Σg+) state enabling further improvements to the s-wave scattering length determination of Li and enabling the eventual creation of ultracold ground-state 6Li2 molecules.

  12. High-resolution spectroscopy and mode identification in non-radially pulsating stars

    NASA Astrophysics Data System (ADS)

    Pollard, K. R.; Wright, D. J.; Zima, W.; Cottrell, P. L.; De Cat, P.

    2008-12-01

    We have obtained high-resolution spectroscopic data of a sample of non-radially pulsating stars with the HERCULES spectrograph on the 1.0-m telescope at the Mt John University Observatory in New Zealand. We have developed and used a new technique which cross- correlates stellar spectra with scaled delta function templates to obtain high signal-to-noise representative spectral line profiles for further analysis. Using these profiles, and employing the Fourier Parameter Fit method, we have been able to place constraints on the degree, ℓ, and azimuthal order, m, of the non-radial pulsation modes in one β Cephei star, V2052 Oph and two γ Doradus stars, QW Pup and HD 139095.

  13. High-resolution spectroscopy used to measure inertial confinement fusion neutron spectra on Omega (invited).

    PubMed

    Forrest, C J; Radha, P B; Glebov, V Yu; Goncharov, V N; Knauer, J P; Pruyne, A; Romanofsky, M; Sangster, T C; Shoup, M J; Stoeckl, C; Casey, D T; Gatu-Johnson, M; Gardner, S

    2012-10-01

    The areal density (ρR) of cryogenic DT implosions on Omega is inferred by measuring the spectrum of neutrons that elastically scatter off the dense deuterium (D) and tritium (T) fuel. Neutron time-of-flight (nTOF) techniques are used to measure the energy spectrum with high resolution. High signal-to-background data has been recorded on cryogenic DT implosions using a well-collimated 13.4-m line of sight and an nTOF detector with an advanced liquid scintillator compound. An innovative method to analyze the elastically scattered neutron spectra was developed using well-known cross sections of the DT nuclear reactions. The estimated areal densities are consistent with alternative ρR measurements and 1-D simulations. PMID:23126921

  14. High-resolution NMR spectroscopy of encapsulated proteins dissolved in low-viscosity fluids.

    PubMed

    Nucci, Nathaniel V; Valentine, Kathleen G; Wand, A Joshua

    2014-04-01

    High-resolution multi-dimensional solution NMR is unique as a biophysical and biochemical tool in its ability to examine both the structure and dynamics of macromolecules at atomic resolution. Conventional solution NMR approaches, however, are largely limited to examinations of relatively small (<25kDa) molecules, mostly due to the spectroscopic consequences of slow rotational diffusion. Encapsulation of macromolecules within the protective nanoscale aqueous interior of reverse micelles dissolved in low viscosity fluids has been developed as a means through which the 'slow tumbling problem' can be overcome. This approach has been successfully applied to diverse proteins and nucleic acids ranging up to 100kDa, considerably widening the range of biological macromolecules to which conventional solution NMR methodologies may be applied. Recent advances in methodology have significantly broadened the utility of this approach in structural biology and molecular biophysics. PMID:24656086

  15. High resolution FTIR spectroscopy of 1,1,1,2-tetrafluoroethane: ν6

    NASA Astrophysics Data System (ADS)

    Thompson, Christopher D.; Robertson, Evan G.; Evans, Corey J.; McNaughton, Don

    2003-03-01

    High resolution FTIR spectra of 1,1,1,2-tetrafluoromethane (R134a) were recorded using both an enclosive flow cell and a supersonic jet expansion. The temperature in the collisionally cooled enclosive flow was approximately 150 K, whilst in the jet a rotational temperature of 65 K was achieved. A rovibrational analysis was performed for ν6, an a/b hybrid band at 1104.5 cm-1. Least squares fits were used to derive effective rotational and centrifugal distortion constants for ν6 using a total of 799 assigned transitions with quantum numbers up to Ka=21 and J=32. A second fit is presented considering the Coriolis interactions with two dark state combination bands perturbing the rotational structure of the fundamental, fitting a total of 1118 lines and with quantum numbers up to Ka=21 and J=42.

  16. High resolution gamma-ray spectroscopy applied to bulk sample analysis

    SciTech Connect

    Kosanke, K.L.; Koch, C.D.; Wilson, R.D.

    1980-01-01

    A high resolution Ge(Li) gamma-ray spectrometer has been installed and made operational for use in routine bulk sample analysis by the Bendix Field Engineering Corporation (BFEC) geochemical analysis department. The Ge(Li) spectrometer provides bulk sample analyses for potassium, uranium, and thorium that are superior to those obtained by the BFEC sodium iodide spectrometer. The near term analysis scheme permits a direct assay for uranium that corrects for bulk sample self-absorption effects and is independent of the uranium/radium disequilibrium condition of the sample. A more complete analysis scheme has been developed that fully utilizes the gamma-ray data provided by the Ge(Li) spectrometer and that more properly accounts for the sample self-absorption effect. This new analysis scheme should be implemented on the BFEC Ge(Li) spectrometer at the earliest date.

  17. High-resolution spectroscopy of jet-cooled CH{sub 5}{sup +}: Progress

    SciTech Connect

    Savage, C.; Dong, F.; Nesbitt, D. J.

    2015-01-22

    Protonated methane (CH{sub 5}{sup +}) is thought to be a highly abundant molecular ion in interstellar medium, as well as a potentially bright μwave- mm wave emitter that could serve as a tracer for methane. This paper describes progress and first successful efforts to obtain a high resolution, supersonically cooled spectrum of CH{sub 5}{sup +} in the 2900-3100 cm{sup −1} region, formed in a slit supersonic discharge at low jet temperatures and with sub-Doppler resolution. Short term precision in frequency measurement (< 5 MHz on an hour time scale) is obtained from a thermally controlled optical transfer cavity servoloop locked onto a frequency stabilized HeNe laser. Long term precision (< 20 MHz day-to-day) due to pressure, temperature and humidity dependent index of refraction effects in the optical transfer cavity is also present and discussed.

  18. High-resolution photoassociation spectroscopy of ultracold ytterbium atoms by using the intercombination transition.

    PubMed

    Tojo, Satoshi; Kitagawa, Masaaki; Enomoto, Katsunari; Kato, Yutaka; Takasu, Yosuke; Kumakura, Mitsutaka; Takahashi, Yoshiro

    2006-04-21

    We observed high-resolution photoassociation spectra of laser-cooled ytterbium (Yb) atoms in the spin-forbidden 1S0 - 3P1 intercombination line. The rovibrational levels in the 0u+ state were measured for red detunings of the photoassociation laser ranging from 2.9 MHz to 1.97 GHz with respect to the atomic resonance. The rotational splitting of the vibrational levels near the dissociation limit were fully resolved due to the sub-MHz linewidth of the spectra in contrast to previous measurements using the spin-allowed singlet transition. In addition, from a comparison between the spectra of 174Yb and those of 176Yb, a d-wave shape resonance for 174Yb is strongly suggested. PMID:16712155

  19. High-resolution NMR spectroscopy of encapsulated proteins dissolved in low-viscosity fluids

    NASA Astrophysics Data System (ADS)

    Nucci, Nathaniel V.; Valentine, Kathleen G.; Wand, A. Joshua

    2014-04-01

    High-resolution multi-dimensional solution NMR is unique as a biophysical and biochemical tool in its ability to examine both the structure and dynamics of macromolecules at atomic resolution. Conventional solution NMR approaches, however, are largely limited to examinations of relatively small (<25 kDa) molecules, mostly due to the spectroscopic consequences of slow rotational diffusion. Encapsulation of macromolecules within the protective nanoscale aqueous interior of reverse micelles dissolved in low viscosity fluids has been developed as a means through which the ‘slow tumbling problem' can be overcome. This approach has been successfully applied to diverse proteins and nucleic acids ranging up to 100 kDa, considerably widening the range of biological macromolecules to which conventional solution NMR methodologies may be applied. Recent advances in methodology have significantly broadened the utility of this approach in structural biology and molecular biophysics.

  20. High-resolution spectroscopy used to measure inertial confinement fusion neutron spectra on Omega (invited)

    SciTech Connect

    Forrest, C. J.; Radha, P. B.; Glebov, V. Yu.; Goncharov, V. N.; Knauer, J. P.; Pruyne, A.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J. III; Stoeckl, C.; Casey, D. T.; Gatu-Johnson, M.; Gardner, S.

    2012-10-15

    The areal density ({rho}R) of cryogenic DT implosions on Omega is inferred by measuring the spectrum of neutrons that elastically scatter off the dense deuterium (D) and tritium (T) fuel. Neutron time-of-flight (nTOF) techniques are used to measure the energy spectrum with high resolution. High signal-to-background data has been recorded on cryogenic DT implosions using a well-collimated 13.4-m line of sight and an nTOF detector with an advanced liquid scintillator compound. An innovative method to analyze the elastically scattered neutron spectra was developed using well-known cross sections of the DT nuclear reactions. The estimated areal densities are consistent with alternative {rho}R measurements and 1-D simulations.

  1. High-resolution Inductively Coupled Plasma--Atomic Emission Spectroscopy applied to problems in Nuclear Waste Management

    SciTech Connect

    Edelson, M.C.; Winge, R.K.; Eckels, D.E. ); Douglas, J.G. )

    1990-01-01

    High-resolution Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) is a variant of the more conventional ICP-AES that is widely used for environmental monitoring. The relevance of high-resolution capabilities of three such analytical problems are discussed herein. (1) Pu in very complex, radioactive matrices can be determined with good accuracy without the need for prior chemical separations. Isotopically resolved spectra from actinides in fuel dissolver solutions can be obtained after a simple ion-exchange step. (2) High-resolution methods permit the simultaneous determination of fission products and actinides in simulated high-level nuclear waste solutions. Such measurements can be useful for both safeguards and waste processing. (3) The ICP-AES technique, with a photodiode array detector, can be used to determine the composition of nuclear waste glasses. Such measurements can assist the glass producer as well as providing predictors of nuclear waste form performance in a repository. 16 refs., 5 figs., 4 tabs.

  2. An atomic beam of 6Li — 7Li for high resolution spectroscopy from matrix isolation sublimation

    NASA Astrophysics Data System (ADS)

    Oliveira, A. N.; Sacramento, R. L.; Silva, B. A.; Uhlmann, F. O.; Wolff, W.; Cesar, C. L.

    2016-07-01

    We propose the Matrix Isolation Sublimation (MlSu) technique for generating cold lithium atoms for the measurement of the 6Li - 7Li isotope shift in D1 and D2 transitions. The technique is capable of generating cold 6Li and 7Li beams at 4 K with forward velocity of 125 m/s. Using this beam we offer a distinguished source of lithium atoms for transitions measurements, adding a new possibility to make high resolution spectroscopy towards improving the experimental checks of the theory.

  3. High Resolution X-Ray Absorption Spectroscopy: Distribution of Matter in and around Galaxies

    NASA Astrophysics Data System (ADS)

    Schulz, Norbert; MIT/CAT Team

    2015-10-01

    The chemical evolution of the Universe embraces aspects that reachdeep into modern astrophysics and cosmology. We want to know how present and past matter is affected by various levels and types of nucleo-synthesis and stellar evolution. Three major categories were be identified: 1. The study of pre-mordial star formation including periods of super-massive black hole formation, 2. The embedded evolution of the intergalactic medium IGM, 3. The status and evolution of stars and the interstellar medium ISM in galaxies. Today a fourth category relates to our understanding of dark matter in relationwith these three categories. The X-ray band is particularly sensitive to K- and L-shell absorption and scattering from high abundant elements like C, N, O, Ne, Mg, Si, S,Ar, Ca, Fe, and Ni. Like the Lyman alpha forest in the optical band, absorbers in the IGM produce an X-ray line forest along the line of sight in the X-rayspectrum of a background quasar. Similary bright X-ray sources within galaxies and the Milky Way produce a continuum, which is being absorbed by elements invarious phases of the ISM. High resolution X-ray absorption surveys are possible with technologies ready for flight within decade. == high efficiency X-ray optics with optical performance 3== high resolution X-ray gratings with R 3000 for E 1.5 keV== X-ray micro-calorimeters with R 2000 for E 1.5 keV. The vision for the next decade needs to lead to means and strategies which allows us to perform such absorption surveys as effectively as surveys are now or in very near future quite common in astronomy pursued in other wave length bands such as optical, IR, and sub-mm.

  4. Signatures of Fano interferences in the electron energy loss spectroscopy and cathodoluminescence of symmetry-broken nanorod dimers.

    PubMed

    Bigelow, Nicholas W; Vaschillo, Alex; Camden, Jon P; Masiello, David J

    2013-05-28

    Through numerical simulation, we predict the existence of the Fano interference effect in the electron energy loss spectroscopy (EELS) and cathodoluminescence (CL) of symmetry-broken nanorod dimers that are heterogeneous in material composition and asymmetric in length. The differing selection rules of the electron probe in comparison to the photon of a plane wave allow for the simultaneous excitation of both optically bright and dark plasmons of each monomer unit, suggesting that Fano resonances will not arise in EELS and CL. Yet, interferences are manifested in the dimer's scattered near- and far-fields and are evident in EELS and CL due to the rapid π-phase offset in the polarizations between super-radiant and subradiant hybridized plasmon modes of the dimer as a function of the energy loss suffered by the impinging electron. Depending upon the location of the electron beam, we demonstrate the conditions under which Fano interferences will be present in both optical and electron spectroscopies (EELS and CL) as well as a new class of Fano interferences that are uniquely electron-driven and are absent in the optical response. Among other things, the knowledge gained from this work bears impact upon the design of some of the world's most sensitive sensors, which are currently based upon Fano resonances. PMID:23594310

  5. Static FBG strain sensor with high resolution and large dynamic range by dual-comb spectroscopy.

    PubMed

    Kuse, Naoya; Ozawa, Akira; Kobayashi, Yohei

    2013-05-01

    We demonstrate a fiber Bragg grating (FBG) strain sensor with optical frequency combs. To precisely characterize the optical response of the FBG when strain is applied, dual-comb spectroscopy is used. Highly sensitive dual-comb spectroscopy of the FBG enabled strain measurements with a resolution of 34 nε. The optical spectral bandwidth of the measurement exceeds 1 THz. Compared with conventional FBG strain sensor using a continuous-wave laser that requires rather slow frequency scanning with a limited range, the dynamic range and multiplexing capability are significantly improved by using broadband dual-comb spectroscopy. PMID:23669971

  6. High resolution Raman spectroscopy of complexes and clusters in molecular beams. Performance report

    SciTech Connect

    Felker, P.M.

    1991-12-31

    The DOE-sponsored project in this laboratory has two facets. The first is the development of methods of nonlinear Raman spectroscopy for application in studies of sparse samples. The second is the application of such methods to structural and dynamical studies of species in supersonic molecular beams. The progress we have made in both of these areas is described in this paper. The report is divided into five remaining sections. The first pertains to theoretical and experimental developments in Fourier transform stimulated emission spectroscopy and Fourier transform hole-burning spectroscopy. The second deals with progress in the development of ionization-detected stimulated Raman spectroscopies (IDSRS). The third describes results from the application of IDSRS methods to studies of jet-cooled benzene clusters. The fourth describes IDSRS results from studies of hydrogen-bonded complexes containing phenols. The fifth relates to studies of carbazole-(Ar){sub n} clusters.

  7. High resolution Raman spectroscopy of complexes and clusters in molecular beams

    SciTech Connect

    Felker, P.M.

    1991-01-01

    The DOE-sponsored project in this laboratory has two facets. The first is the development of methods of nonlinear Raman spectroscopy for application in studies of sparse samples. The second is the application of such methods to structural and dynamical studies of species in supersonic molecular beams. The progress we have made in both of these areas is described in this paper. The report is divided into five remaining sections. The first pertains to theoretical and experimental developments in Fourier transform stimulated emission spectroscopy and Fourier transform hole-burning spectroscopy. The second deals with progress in the development of ionization-detected stimulated Raman spectroscopies (IDSRS). The third describes results from the application of IDSRS methods to studies of jet-cooled benzene clusters. The fourth describes IDSRS results from studies of hydrogen-bonded complexes containing phenols. The fifth relates to studies of carbazole-(Ar){sub n} clusters.

  8. Quantitative high-resolution on-line NMR spectroscopy in reaction and process monitoring.

    PubMed

    Maiwald, Michael; Fischer, Holger H; Kim, Young-Kyu; Albert, Klaus; Hasse, Hans

    2004-02-01

    On-line nuclear magnetic resonance spectroscopy (on-line NMR) is a powerful technique for reaction and process monitoring. Different set-ups for direct coupling of reaction and separation equipment with on-line NMR spectroscopy are described. NMR spectroscopy can be used to obtain both qualitative and quantitative information from complex reacting multicomponent mixtures for equilibrium or reaction kinetic studies. Commercial NMR probes can be used at pressures up to 35 MPa and temperatures up to 400 K. Applications are presented for studies of equilibria and kinetics of complex formaldehyde-containing mixtures as well as homogeneously and heterogeneously catalyzed esterification kinetics. Direct coupling of a thin-film evaporator is described as an example for the benefits of on-line NMR spectroscopy in process monitoring. PMID:14729025

  9. Cassini UVIS Solar Zenith Angle Studies of Titan Dayglow Based on N2 High Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ajello, Joseph; West, Robert; Holsclaw, Greg; Royer, Emilie; Heays, Alan; Bradley, Todd; Stevens, Michael

    2014-11-01

    The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed photon emissions of Titan’s day and night limb-airglow on multiple occasions, including during an eclipse observation. On one occasion the UVIS made a Solar Zenith Angle (SZA) study of the Titan limb dayglow (2011 DOY 171) from about 70 to 95 degrees SZA. The UV intensity variation observations of the N2 photoelectron excited spectral features from the EUV (563-118.2 nm) and FUV (111.5-191.2nm) sub-systems followed a Chapman function. For other observations at night on the limb, the emission features are much weaker in intensity. Beyond 120 deg SZA, when the upper atmosphere of Titan below 1200 km is in total XUV darkness, there is an indication of weak and sporadic night side UV airglow emission excited by magnetosphere plasma collisions with ambient thermosphere gas, with similar N2 excited features as above in the daylight or twilight glow over an extended altitude range. We have analyzed the UVIS airglow spectra with models based on high resolution laboratory electron impact induced fluorescence spectra. We have measured high-resolution (FWHM = 0.2 Å) extreme-ultraviolet (EUV, 800-1350 Å) laboratory emission spectra of molecular nitrogen excited by electron impact at 20 and 100 eV. Molecular emission was observed to vibrationally-excited ground state levels as high as v''=17, from the a 1Πg , b 1Πu, and b‧ 1Σu+ excited valence states and the Rydberg series c‧n+1 1Σu+, cn 1Πu and o 1Πu for n between 3 and 9. A total of 491 emission features were observed from N2 electronic-vibrational transitions and atomic N I and N II multiplets. Their emission cross sections were measured.The blended molecular emission bands were disentangled with the aid of a model which solves the coupled-Schroedinger equation

  10. High Resolution Spectroscopy in the Non-thermal Infrared: Use of an Existing Coude System

    NASA Astrophysics Data System (ADS)

    Basri, Gibor; Marcy, Geoffrey W.

    1993-05-01

    We describe a recent effort to use a NICMOS 3 chip as the detector on the 160" coude spectrograph camera at Lick Observatory. This new instrument (IRCS) has a useful spectral range of 1-2mu with spectral coverage in one exposure of about 25 Angstroms, and resolutions up to 75000. We have successfully obtained astronomical observations with essentially no modification of the (uncooled) spectrograph, using an existing grating blazed at 1.22mu , and a dewar without optics (but containing a filter) easily mounted at the position of the old photographic plates. The throughput of the system is very high. Its sensitivity is primarily limited by the background from the warm spectrograph. Using filters with 0.1mu bandwidth, the expected background is negligible below 1.5mu , but limits exposures to one minute near 2mu . With an optimized dewar, one can remain photon (rather than background) limited down to 10th magnitude even at 2mu . Our current system (using a test dewar and engineering grade chip) has been tested at 1.6mu . We have operated with and without an image slicer. We show spectra and discuss the current successes and problems. Our first application is to study the Zeeman--sensitive line at 1.56mu at high resolution. We expect to be able to achieve S/N of 200:1 in 10 minutes on 6th magnitude stars now, and eventually 100:1 in one hour on 10th magnitude stars using the 3-m telescope. This opens the possibility of measuring magnetic fields for large numbers of RS CVN and dM(e) stars (in addition to many G,K dwarfs), and even perhaps a few pre-main sequence stars. There is a lot of potential for science in the 1-2mu range at high resolution, which cannot be done as easily with any other type of instrument. This includes: (1) molecular lines in giants and winds, (2) lines from the ISM for abundances and kinematics, (3) detailed atmospheric analysis of embedded stars (and disks?).

  11. On-chip near-infrared spectroscopy of CO2 using high resolution plasmonic filter array

    NASA Astrophysics Data System (ADS)

    Chong, Xinyuan; Li, Erwen; Squire, Kenneth; Wang, Alan X.

    2016-05-01

    We report an ultra-compact, cost-effective on-chip near-infrared spectroscopy system for CO2 sensing using narrow-band optical filter array based on plasmonic gratings with a waveguide layer. By varying the periodicity of the gratings, the transmission spectra of the filters can be continuously tuned to cover the 2.0 μm sensing window with high spectral resolution around 10 nm. Our experimental results show that the on-chip spectroscopy system can resolve the two symmetric vibrational bands of CO2 at 2.0 μm wavelength, which proves its potential to replace the expensive commercial IR spectroscopy system for on-site gas sensing.

  12. High-Resolution Spectroscopy of C3 around 3 μm

    NASA Astrophysics Data System (ADS)

    Krieg, J.; Lutter, V.; Endres, C. P.; Keppeler, I. H.; Jensen, P.; Harding, M. E.; Vazquez, J.; Schlemmer, S.; Giesen, T. F.; Thorwirth, S.

    2013-03-01

    We report on the detection of the (1001)-(0000) vibrational band of gas-phase C3 and the two of its mono 13C substituted isotopologs in the infrared region around 3200 cm-1. Additionally, the associated hot band (1111)-(0110) has been assigned for the parent isotopolog. Spectra have been recorded using a supersonic jet spectrometer with a laser ablation source in combination with a continuous-wave optical parametric oscillator as radiation source. High-level quantum-chemical ab initio calculations have been performed and used to assist the assignment. A combined fit for the vibrational states of C3 found in this study has been done together with previously reported high-resolution data to increase the accuracy of the molecular parameters, especially for the ground state. The vibrational energies are 3260.126, 3205.593, and 3224.751 cm-1 for the (1001) state of C3, 12C13C12C, and 13C12C12C, respectively. The (1111) state of C3 has been found to be at 3330.509 cm-1.

  13. Lineshape spectroscopy with a very high resolution, very high signal-to-noise crystal spectrometer.

    PubMed

    Beiersdorfer, P; Magee, E W; Brown, G V; Chen, H; Emig, J; Hell, N; Bitter, M; Hill, K W; Allan, P; Brown, C R D; Hill, M P; Hoarty, D J; Hobbs, L M R; James, S F

    2016-06-01

    We have developed a high-resolution x-ray spectrometer for measuring the shapes of spectral lines produced from laser-irradiated targets on the Orion laser facility. The instrument utilizes a spherically bent crystal geometry to spatially focus and spectrally analyze photons from foil or microdot targets. The high photon collection efficiency resulting from its imaging properties allows the instrument to be mounted outside the Orion chamber, where it is far less sensitive to particles, hard x-rays, or electromagnetic pulses than instruments housed close to the target chamber center in ten-inch manipulators. Moreover, Bragg angles above 50° are possible, which provide greatly improved spectral resolution compared to radially viewing, near grazing-incidence crystal spectrometers. These properties make the new instrument an ideal lineshape diagnostic for determining plasma temperature and density. We describe its calibration on the Livermore electron beam ion trap facility and present spectral data of the K-shell emission from highly charged sulfur produced by long-pulse as well as short-pulse beams on the Orion laser in the United Kingdom. PMID:27370448

  14. High-resolution rovibrational spectroscopy of carbon monoxide isotopologues isolated in solid parahydrogen.

    PubMed

    Fajardo, Mario E

    2013-12-19

    We report high-resolution infrared absorption spectra of six different CO isotopologues isolated in cryogenic parahydrogen (pH2) solids. These data provide a stringent test for theories of nearly free molecular rotors in crystalline solids, such as crystal field theory, rotation-translation coupling theory, and the pseudorotating cage model. A gas-phase molecule rotates about its center-of-mass (C.M.); a trapped molecule instead rotates about its "center of interaction" (C.I.) with the trapping cage, which may differ from the C.M. for heteronuclear diatomics like CO. Isotopic manipulation of CO allows the systematic variation of the C.M. relative to the C.I. We report remarkably good straight line correlation plots between the observed matrix effects and C.M. locations. Extrapolation of these lines to the limit of vanishing matrix effects yields an "experimental prediction" of the C.I. in excellent (fortuitous?) agreement with the C.I. calculated using a linear pH2-CO-pH2 toy model. PMID:24102285

  15. Applications of High Resolution Laser Induced Breakdown Spectroscopy for Environmental and Biological Samples

    SciTech Connect

    Martin, Madhavi Z; Labbe, Nicole; Wagner, Rebekah J.

    2013-01-01

    This chapter details the application of LIBS in a number of environmental areas of research such as carbon sequestration and climate change. LIBS has also been shown to be useful in other high resolution environmental applications for example, elemental mapping and detection of metals in plant materials. LIBS has also been used in phytoremediation applications. Other biological research involves a detailed understanding of wood chemistry response to precipitation variations and also to forest fires. A cross-section of Mountain pine (pinceae Pinus pungen Lamb.) was scanned using a translational stage to determine the differences in the chemical features both before and after a fire event. Consequently, by monitoring the elemental composition pattern of a tree and by looking for abrupt changes, one can reconstruct the disturbance history of a tree and a forest. Lastly we have shown that multivariate analysis of the LIBS data is necessary to standardize the analysis and correlate to other standard laboratory techniques. LIBS along with multivariate statistical analysis makes it a very powerful technology that can be transferred from laboratory to field applications with ease.

  16. ISIS: An Interactive Spectral Interpretation System for High Resolution X-Ray Spectroscopy

    NASA Astrophysics Data System (ADS)

    Houck, J. C.; Denicola, L. A.

    The Interactive Spectral Interpretation System (ISIS) is designed to facilitate the interpretation and analysis of high resolution X-ray spectra like those obtained using the grating spectrographs on Chandra and XMM and the microcalorimeter on Astro-E. It is being developed as an interactive tool for studying the physics of X-ray spectrum formation, supporting measurement and identification of spectral features, and interaction with a database of atomic structure parameters and plasma emission models. The current version uses the atomic data and collisional ionization equilibrium models in the Astrophysical Plasma Emission Database (APED) of Brickhouse et.al., and also provides access to earlier plasma emission models including Raymond-Smith and MEKAL. Although the current version focuses on collisional ionization equilibrium plasmas, the system is designed to allow use of other databases to provide better support for studies of non-equilibrium and photoionized plasmas. To maximize portability between Unix operating systems, ISIS is being written entirely in ANSI C using free-software components (CFITSIO, PGPLOT and S-Lang).

  17. New results in high-resolution X-ray fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Žitnik, Matjaž; Kavčič, Matjaž; Bučar, Klemen; Mihelič, Andrej; Bohinc, Rok

    2014-04-01

    We present some recent results dealing with resonant inelastic X-ray scattering (RIXS) on atomic targets in the 3-5 keV enegy region. In this so-called tender spectral region, the K-shell fluorescence branching ratios become reasonably large, but a full vacuum enclosure is still preferable to avoid detection efficiency loss due to the sizeable arms of high resolution crystal spectrometers. By squeezing energy resolution in the fluorescence decay channel, one may improve the spectral resolution of photoabsorption, enable separation of multielectron excitation and relaxation channels, and completely eliminate the need to scan across the selected energy range of the photon probe in order to acquire the photoabsorption spectrum. On the other hand, the spectra may be untrivially modified by effects such as interference of absorption-emission paths or structured relaxation modes, and a more elaborated modelling is needed to understand the emitted signal. We illustrate these aspects by presenting four cases: the reconstruction of Ar KM and Ar KL absorption edges from a series of highly resolved emission spectra recorded at different probe energies, the reconstruction of the Xe L3 edge from a single X-ray emission spectrum, and the analysis of the radiative Ar K-MM Auger decay preceeded by the resonant or nonresonant photon absorption.

  18. 5f-electron states in uranium dioxide investigated using high-resolution neutron spectroscopy

    NASA Astrophysics Data System (ADS)

    Amoretti, G.; Blaise, A.; Caciuffo, R.; Fournier, J. M.; Hutchings, M. T.; Osborn, R.; Taylor, A. D.

    1989-07-01

    High-resolution, high-energy-transfer, inelastic neutron scattering has been used to explore the crystal-field (CF) excitations in UO2. As all the dipole-allowed transitions within the free-ion ground manifold have been identified, the observations provide a complete determination of the crystal-field potential and 5f-electron eigenstates. The fourth- and sixth-degree CF parameters are V4=-123 meV and V6=26.5 meV. In spite of the strength of the CF, the ground state is accurately given by the intermediate-coupling approximation with little modification by J-mixing effects. In the antiferromagnetic phase below TN=30.8 K, a splitting of the cubic CF levels, due to the combined effects of the molecular field and the distortion of the oxygen-ligand cage surrounding the U4+ ions, has been observed. Detailed CF calculations are presented both for the case of a double-k magnetic structure with a monoclinic distortion of the oxygen sublattice, and for a combined triple-k distortion and magnetic order. The observed splittings are shown to be more consistent with the triple-k model.

  19. High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons: The Realm of Anharmonicity

    NASA Technical Reports Server (NTRS)

    Maltseva, Elena; Petrignani, Annemieke; Candian, Alessandra; Mackie, Cameron J.; Huang, Xinchuan; Lee, Timothy J.; Tielens, Alexander G. G. M.; Oomens, Jos; Buma, Wybren Jan

    2016-01-01

    We report on an experimental and theoretical investigation of the importance of anharmonicity in the 3 micrometers CH stretching region of Polycyclic Aromatic Hydrocarbon (PAH) molecules. We present mass-resolved, high-resolution spectra of the gas-phase cold ((is) approximately 4K) linear PAH molecules naphthalene, anthracene, and tetracene. The measured IR spectra show a surprisingly high number of strong vibrational bands. For naphthalene, the observed bands are well separated and limited by the rotational contour, revealing the band symmetries. Comparisons are made to the harmonic and anharmonic approaches of the widely used Gaussian software. We also present calculated spectra of these acenes using the computational program SPECTRO, providing anharmonic predictions enhanced with a Fermi-resonance treatment that utilizes intensity redistribution. We demonstrate that the anharmonicity of the investigated acenes is strong, dominated by Fermi resonances between the fundamental and double combination modes, with triple combination bands as possible candidates to resolve remaining discrepancies. The anharmonic spectra as calculated with SPECTRO lead to predictions of the main modes that fall within 0.5% of the experimental frequencies. The implications for the Aromatic Infrared Bands, specifically the 3-m band are discussed.

  20. Lineshape spectroscopy with a very high resolution, very high signal-to-noise crystal spectrometer

    NASA Astrophysics Data System (ADS)

    Beiersdorfer, P.; Magee, E. W.; Brown, G. V.; Chen, H.; Emig, J.; Hell, N.; Bitter, M.; Hill, K. W.; Allan, P.; Brown, C. R. D.; Hill, M. P.; Hoarty, D. J.; Hobbs, L. M. R.; James, S. F.

    2016-06-01

    We have developed a high-resolution x-ray spectrometer for measuring the shapes of spectral lines produced from laser-irradiated targets on the Orion laser facility. The instrument utilizes a spherically bent crystal geometry to spatially focus and spectrally analyze photons from foil or microdot targets. The high photon collection efficiency resulting from its imaging properties allows the instrument to be mounted outside the Orion chamber, where it is far less sensitive to particles, hard x-rays, or electromagnetic pulses than instruments housed close to the target chamber center in ten-inch manipulators. Moreover, Bragg angles above 50° are possible, which provide greatly improved spectral resolution compared to radially viewing, near grazing-incidence crystal spectrometers. These properties make the new instrument an ideal lineshape diagnostic for determining plasma temperature and density. We describe its calibration on the Livermore electron beam ion trap facility and present spectral data of the K-shell emission from highly charged sulfur produced by long-pulse as well as short-pulse beams on the Orion laser in the United Kingdom.

  1. Applications of High Resolution Laser: Induced Breakdown Spectroscopy for Environmental and Biological Samples

    NASA Astrophysics Data System (ADS)

    Martin, Madhavi Z.; Labbe, Nicole; Wagner, Rebekah J.

    This chapter details the application of LIBS in a number of environmental areas of research such as carbon sequestration and climate change. LIBS has also been shown to be useful in other high resolution environmental applications for example, elemental mapping and detection of metals in plant materials. LIBS has also been used in phytoremediation applications. Other biological research involves a detailed understanding of wood chemistry response to precipitation variations and also to forest fires. A cross-section of Mountain pine (pinceae Pinus pungen Lamb.) was scanned using a translational stage to determine the differences in the chemical features both before and after a fire event. Consequently, by monitoring the elemental composition pattern of a tree and by looking for abrupt changes, one can reconstruct the disturbance history of a tree and a forest. Lastly we have shown that multivariate analysis of the LIBS data is necessary to standardize the analysis and correlate to other standard laboratory techniques. LIBS along with multivariate statistical analysis makes it a very powerful technology that can be transferred from laboratory to field applications with ease.

  2. High-resolution electron momentum spectroscopy of valence satellites of carbon disulfide

    NASA Astrophysics Data System (ADS)

    Huang, Chengwu; Shan, Xu; Zhang, Zhe; Wang, Enliang; Li, Zhongjun; Chen, XiangJun

    2010-09-01

    The binding energy spectrum of carbon disulphide (CS2) in the energy range of 9-23 eV has been measured by a high-resolution (e,2e) spectrometer employing asymmetric noncoplanar kinematics at an impact energy of 2500 eV plus the binding energy. Taking the advantage of the high energy resolution of 0.54 eV, four main peaks and five satellites in the outer-valence region are resolved. The assignments and pole strengths for these satellite states are achieved by comparing the experimental electron momentum profiles with the corresponding theoretical ones calculated using Hartree-Fock and density functional theory methods. The results are also compared in detail with the recent SAC-CI general-R calculations. General agreement is satisfactory, while the present experiment suggests cooperative contributions from Π2u, Σg+2 states to satellite 2 and Σg+2, Π2g states to satellite 3. Besides, relatively low pole strength for X Π2g state is obtained which contradicts all the theoretical calculations [2ph-TDA, ADC(3), SAC-CI general-R, ADC(4)] so far.

  3. Spectroscopy of 9B via high-resolution ejectile-tagged recoil break-up

    NASA Astrophysics Data System (ADS)

    Wheldon, C.; Kokalova, Tz.; Freer, M.; Walshe, J.; Hertenberger, R.; Wirth, H.-F.; Ashwood, N. I.; Barr, M.; Curtis, N.; Faestermann, Th.; Lutter, R.; Malcolm, J. D.; Marín-Lámbarri, D. J.

    2015-02-01

    An experiment has been carried out using the 9Be(3He ,t )B9* reaction at a beam energy of 33 MeV. A large acceptance silicon-strip array was used to detect the B9* break-up in coincidence with the triton ejectiles in the high-resolution Munich-Q3D spectrograph. The excitation energy regime <3 MeV has been explored and the spectrum resulting from proton decaying states, isolated and characterized. Additional resonance strength is observed at 1.86 MeV ±70 keV(stat) ±35 keV(syst), in agreement with two other recent measurements at higher energies and different angles. The consequences for the "missing" ½+ first excited state are discussed. Additionally, the branching ratios for the 2.36 MeV 5/2 - state have been measured as Γα 0/Γ =0.98 ±0.12 and Γp 0/Γ =0.016 ±0.008 , in close agreement with earlier work.

  4. High Resolution FTIR Spectroscopy of DCCCl: Anharmonic Resonances in the nu(1) and nu(2) Bands.

    PubMed

    Wang, DongBing; Imajo, Takashi; Tanaka, Keiichi; Tanaka, Takehiko; Bürger, Hans

    2001-05-01

    High-resolution infrared spectra of the nu(1) and nu(2) bands of DCCCl were observed using Bruker IFS 120HR Fourier transform spectrometers at resolutions of 0.0044 and 0.0035 cm(-1), respectively. For the DCC(35)Cl isotopomer, the nu(1) as well as the nu(2) band was found to be heavily perturbed. Detailed analyses revealed that the nu(1) state is in resonance with the l=0 substate of the nu(3)+4nu(4) state and that the nu(2) state is in resonance with the l=0 substate of the nu(3)+4nu(5) state. The rotational constants played a key role in identifying the perturbing states. In contrast, for the DCC(37)Cl isotopomer, the rotational structures of the nu(1) and nu(2) states are almost regular but slightly perturbed by interactions with the nu(3)+4nu(4) and nu(3)+4nu(5) states, respectively. The constants of resonances as well as the molecular constants for the nu(1), nu(2), nu(3)+4nu(4) and nu(3)+4nu(5) states were determined. Copyright 2001 Academic Press. PMID:11336523

  5. High Resolution FTIR Spectroscopy of DCCCl: Anharmonic Resonances in the ν 1 and ν 2 Bands

    NASA Astrophysics Data System (ADS)

    Wang, DongBing; Imajo, Takashi; Tanaka, Keiichi; Tanaka, Takehiko; Bürger, Hans

    2001-05-01

    High-resolution infrared spectra of the ν1 and ν2 bands of DCCCl were observed using Bruker IFS 120HR Fourier transform spectrometers at resolutions of 0.0044 and 0.0035 cm-1, respectively. For the DCC35Cl isotopomer, the ν1 as well as the ν2 band was found to be heavily perturbed. Detailed analyses revealed that the ν1 state is in resonance with the l=0 substate of the ν3+4ν4 state and that the ν2 state is in resonance with the l=0 substate of the ν3+4ν5 state. The rotational constants played a key role in identifying the perturbing states. In contrast, for the DCC37Cl isotopomer, the rotational structures of the ν1 and ν2 states are almost regular but slightly perturbed by interactions with the ν3+4ν4 and ν3+4ν5 states, respectively. The constants of resonances as well as the molecular constants for the ν1, ν2, ν3+4ν4 and ν3+4ν5 states were determined.

  6. HIGH-RESOLUTION SPECTROSCOPY OF FEIGE 24 IN THE EXTREME-ULTRAVIOLET

    SciTech Connect

    Kowalski, M. P.; Wood, K. S.; Yentis, D. J.; Berendse, F. B.; Cruddace, R. G.; Barstow, M. A.; Lapington, J. S.; Fritz, G. G.; Barbee, T. W. Jr E-mail: kent.wood@nrl.navy.mil E-mail: raymond.cruddace@nrl.navy.mil E-mail: jsl12@star.le.ac.uk E-mail: barbee2@llnl.gov

    2011-04-01

    We report the first high-resolution (R = 4000) spectroscopic observation of the binary DA white dwarf Feige 24 in the extreme-ultraviolet band 220-250 A. A stellar atmosphere model assuming a homogeneous element distribution yields a best fit to the data that excludes a significant abundance of photospheric helium. The upper limit on the photospheric helium abundance is 2.5 x 10{sup -6} (90% confidence), equivalent to a lower limit of 1.2 x 10{sup -13} M{sub sun} on the overlying layer of hydrogen. An ionized interstellar He component (3.9 x 10{sup 17} cm{sup -2}) is clearly present along the line of sight, which implies an He ionization fraction of 0.72, considerably higher than is typical of the local interstellar medium. However, some of this material may be associated with circumstellar gas, which has been detected by analysis of the C IV absorption line doublet in a Hubble Space Telescope/Space Telescope Imaging Spectrograph spectrum.

  7. High-resolution photoelectron imaging spectroscopy of cryogenically cooled Fe4O- and Fe5O-

    NASA Astrophysics Data System (ADS)

    Weichman, Marissa L.; DeVine, Jessalyn A.; Neumark, Daniel M.

    2016-08-01

    We report high-resolution photodetachment spectra of the cryogenically cooled iron monoxide clusters Fe4O- and Fe5O- obtained with slow photoelectron velocity-map imaging (cryo-SEVI). Well-resolved vibrational progressions are observed in both sets of spectra, and transitions to low-lying excited states of both species are seen. In order to identify the structural isomers, electronic states, and vibrational modes that contribute to the cryo-SEVI spectra of these clusters, experimental results are compared with density functional theory calculations and Franck-Condon simulations. The main bands observed in the SEVI spectra are assigned to the 15A2←16B2 photodetachment transition of Fe4O- and the 17A'←18A″ photodetachment transition of Fe5O-. We report electron affinities of 1.6980(3) eV for Fe4O and 1.8616(3) eV for Fe5O, although there is some uncertainty as to whether the 15A2 state is the true ground state of Fe4O. The iron atoms have a distorted tetrahedral geometry in Fe4O0/- and a distorted trigonal-bipyramidal arrangement in Fe5O0/-. For both neutral and anionic species, the oxygen atom preferably binds in a μ2-oxo configuration along the cluster edge. This finding is in contrast to prior predictions that Fe5O0/- exhibits a μ3 face-bound structure.

  8. HIGH-RESOLUTION INFRARED IMAGING AND SPECTROSCOPY OF THE Z CANIS MAJORIS SYSTEM DURING QUIESCENCE AND OUTBURST

    SciTech Connect

    Hinkley, Sasha; Hillenbrand, Lynne; Crepp, Justin R.; Oppenheimer, Ben R.; Zimmerman, Neil; Brenner, Douglas; Rice, Emily L.; Pueyo, Laurent; Vasisht, Gautam; Roberts, Jennifer E.; Roberts, Lewis C. Jr.; Burruss, Rick; Wallace, J. Kent; Cady, Eric; Zhai, Chengxing; Kraus, Adam L.; Ireland, Michael J.; Beichman, Charles; Dekany, Richard; Parry, Ian R.; and others

    2013-01-20

    We present adaptive optics photometry and spectra in the JHKL bands along with high spectral resolution K-band spectroscopy for each component of the Z Canis Majoris system. Our high angular resolution photometry of this very young ({approx}<1 Myr) binary, comprised of an FU Ori object and a Herbig Ae/Be star, was gathered shortly after the 2008 outburst while our high-resolution spectroscopy was gathered during a quiescent phase. Our photometry conclusively determines that the outburst was due solely to the embedded Herbig Ae/Be member, supporting results from earlier works, and that the optically visible FU Ori component decreased slightly ({approx}30%) in luminosity during the same period, consistent with previous works on the variability of FU Ori type systems. Further, our high-resolution K-band spectra definitively demonstrate that the 2.294 {mu}m CO absorption feature seen in composite spectra of the system is due solely to the FU Ori component, while a prominent CO emission feature at the same wavelength, long suspected to be associated with the innermost regions of a circumstellar accretion disk, can be assigned to the Herbig Ae/Be member. These findings clarify previous analyses of the origin of the CO emission in this complex system.

  9. Mid-infrared high-resolution absorption spectroscopy by use of a semimonolithic entangled-cavity optical parametric oscillator.

    PubMed

    Desormeaux, A; Lefebvre, M; Rosencher, E; Huignard, J P

    2004-12-15

    By recording low-pressure absorption lines of N2O around 3.9 microm, we fully qualify a pulsed entangled-cavity doubly resonant optical parametric oscillator as a power tool for high-resolution spectroscopy. This compact source runs at a high repetition rate (>10 kHz) with a low threshold of oscillation (<8 microJ), is mode-hop-free tunable over 5 cm(-1), and displays single-frequency Fourier-transformed-limited operation (linewidth <0.005 cm(-1)). A high potential for nonlinear spectroscopy is also expected given the high peak power (70 W) and the good quality (M2 < 2) of the output beam. PMID:15645813

  10. High-resolution VUV spectroscopy: New results from the Advanced Light Source

    SciTech Connect

    Schlachter, F.; Bozek, J.

    1996-06-01

    Third-generation synchrotron light sources are providing photon beams of unprecedented brightness for researchers in atomic and molecular physics. Beamline 9.0.1, an undulator beamline at the Advanced Light Source (ALS), produces a beam in the vacuum-ultraviolet (VUV) region of the spectrum with exceptional flux and spectral resolution. Exciting new results from experiments in atomic and molecular VUV spectroscopy of doubly excited autoionizing states of helium, hollow lithium, and photoelectron spectroscopy of small molecules using Beamline 9.0.1 at the ALS are reported.

  11. High-resolution terahertz spectroscopy with a single tunable frequency comb.

    PubMed

    Skryl, A S; Pavelyev, D G; Tretyakov, M Y; Bakunov, M I

    2014-12-29

    We report an improvement of three orders of magnitude in the spectral resolution of a recently proposed single-comb terahertz spectroscopy [Opt. Lett.39, 5669 (2014)]. The improvement is achieved by using a femtosecond optical pulse train with a tunable repetition rate. Terahertz comb with tunable spectral line spacing generated by the train is detected via nonlinear mixing with a harmonic of a CW signal from a microwave frequency synthesizer. By applying this technique to the low-pressure gas spectroscopy, we achieved a 100 kHz spectral resolution in measuring separate absorption lines of the rotational manifold of fluoroform (CF3H). PMID:25607192

  12. High resolution spectroscopy of six SOCl2 isotopologues from the microwave to the far-infrared

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, M. A.; Roucou, A.; Brown, G. G.; Thorwirth, S.; Pirali, O.; Mouret, G.; Hindle, F.; McCarthy, M. C.; Cuisset, A.

    2016-02-01

    Despite its potential role as an atmospheric pollutant, thionyl chloride, SOCl2, remains poorly characterized in the gas phase. In this study, the pure rotational and ro-vibrational spectra of six isotopologues of this molecule, all detected in natural abundance, have been extensively studied from the cm-wave band to the far-infrared region by means of three complementary techniques: chirped-pulse Fourier transform microwave spectroscopy, sub-millimeter-wave spectroscopy using frequency multiplier chain, and synchrotron-based far-infrared spectroscopy. Owing to the complex line pattern which results from two nuclei with non-zero spins, new, high-level quantum-chemical calculations of the hyperfine structure played a crucial role in the spectroscopic analysis. From the combined experimental and theoretical work, an accurate semi-experimental equilibrium structure (reSE) of SOCl2 has been derived. With the present data, spectroscopy-based methods can now be applied with confidence to detect and monitor this species, either by remote sensing or in situ.

  13. USING HIGH-RESOLUTION SOLUTION-STATE NMR SPECTROSCOPY TO INVESTIGATE PMDI REACTIONS WITH WOOD

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solution-state NMR spectroscopy provides a powerful tool for understanding the formation of chemical bonds between wood components and adhesives. Finely ground cell wall (CW) material fully dissolves in a solvent system containing dimethylsulfoxide (DMSO-d6) and N-methyl¬imidazole (NMI-d6), keeping ...

  14. High-resolution infrared spectroscopy and ab initio studies of the cyclopropane-carbon dioxide interaction.

    PubMed

    Su, Zheng; Tam, Wai Shun; Xu, Yunjie

    2006-01-14

    A jet-cooled high-resolution infrared spectrum of the cyclopropane-carbon dioxide complex was detected for the first time, using a rapid scan infrared spectrometer with an astigmatic multipass sample cell. The spectrum was recorded in the vicinity of the CO2 asymmetric stretching band (nu3) and exhibits a b-dipole selection rule. Altogether, over 200 lines were observed, assigned, and fitted to Watson's S-reduction Hamiltonian. Rotational and quartic distortion constants were obtained. The band origin was located at 2347.6263(2) cm(-1), redshifted by 1.5230(2) cm(-1) from the corresponding frequency of the CO2 monomer. The experimentally determined structure shows that CO2 lies next to a C-C bond edge and is perpendicular to the C3 ring, indicating that the interaction is characterized by the bonding between the carbon atom of CO2 and the pseudo-pi system of cyclopropane. The intermolecular distance between the carbon atom of CO2 and the center of mass of cyclopropane was determined to be 3.667(2) A. Complete ab initio geometry optimizations and harmonic frequency calculations were carried out at the level of second-order Moller-Plesset perturbation theory with four different basis sets: cc-pVDZ, 6-311++G(d,p), aug-cc-pVDZ, and aug-cc-pVTZ. The lowest-energy structure identified with the three larger basis sets is in accord with the experimental finding. In addition, a transition state was identified and the tunneling barrier height was computed. PMID:16422587

  15. High-Resolution Spectroscopy of Long-Range Molecular States of 85Rb_2

    NASA Astrophysics Data System (ADS)

    Carollo, Ryan; Eyler, Edward E.; Bruneau, Yoann; Gould, Phillip; Stwalley, W. C.

    2015-06-01

    We present analysis of low-n long-range molecular Rydberg states in 85Rb_2, based on high-resolution spectra. The weakly bound states are accessed by bound-bound transitions from high-v levels of the a ^3 σ _u^+ state, which are prepared by photoassociation of laser-cooled atoms. Single-photon transitions to target states near the 5s + 7p asymptote are excited by a frequency-doubled pulse-amplified CW laser with a narrow linewidth, under 200 MHz. The long-range portion of the bonding potential is dominated by the elastic scattering interaction of the Rydberg electron of a perturbed 7p atom and a nearby ground-state atom, in much the same manner as trilobite states. We use time of flight to selectively measure molecular ions, which are formed via autoionization. This technique gives a two orders-of-magnitude improvement in linewidth over our previous work, reported in Ref. [1]. We also present calculations of a proposed scheme for STIRAP transfer from the current v''=35 level of the a ^3 σ _u^+ state to the v''=39 level. The long-range states accessible to us are defined in large part by the Franck-Condon factors, which are dominated by the outer lobe of the wavefunction. Thus, choosing a v'' sets R, and determines the Franck-Condon window. The proposed v'' = 39 level has a classical outer turning point at ˜ 72 a_0, and will provide access to higher-n states with longer-range wells. This work is supported by the NSF and AFOSR. [1] M. A. Bellos et al., Phys. Rev. Lett. 111, 053001 (2013)

  16. HIGH-RESOLUTION FOURIER TRANSFORM SPECTROSCOPY OF LANTHANUM IN Ar DISCHARGE IN THE NEAR-INFRARED

    SciTech Connect

    Güzelçimen, F.; Başar, Gö.; Tamanis, M.; Kruzins, A.; Ferber, R.; Windholz, L.; Kröger, S. E-mail: sophie.kroeger@htw-berlin.de

    2013-10-01

    A high-resolution spectrum of lanthanum has been recorded by a Fourier Transform spectrometer in the wavelength range from 833 nm to 1666 nm (6000 cm{sup –1} to 12,000 cm{sup –1}) using as light source a hollow cathode lamp operated with argon as the discharge carrier gas. In total, 2386 spectral lines were detected in this region, of which 555 lines could be classified as La I transitions and 10 lines as La II transitions. All La II transitions and 534 of these La I transitions were classified for the first time, and 6 of the La II transitions and 433 of the classified La I transitions appear to be new lines, which could not be found in the literature. The corresponding energy level data of classified lines are given. Additionally, 430 lines are assigned as Ar I lines and 394 as Ar II lines, of which 179 and 77, respectively, were classified for the first time. All 77 classified Ar II transitions as well as 159 of the classified Ar I transitions are new lines. Furthermore, the wavenumbers of 997 unclassified spectral lines were determined, 235 of which could be assigned as La lines, because of their hyperfine pattern. The remaining 762 lines may be either unclassified Ar lines or unresolved and unclassified La lines with only one symmetrical peak with an FWHM in the same order of magnitude as the Ar lines. The accuracy of the wavenumber for the classified lines with signal-to-noise-ratio higher than four is better than 0.006 cm{sup –1} which corresponds to an accuracy of 0.0004 nm at 830 nm and 0.0017 nm at 1660 nm, respectively.

  17. Understanding AGB evolution in Galactic bulge stars from high-resolution infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Uttenthaler, S.; Blommaert, J. A. D. L.; Wood, P. R.; Lebzelter, T.; Aringer, B.; Schultheis, M.; Ryde, N.

    2015-08-01

    An analysis of high-resolution near-infrared spectra of a sample of 45 asymptotic giant branch (AGB) stars towards the Galactic bulge is presented. The sample consists of two subsamples, a larger one in the inner and intermediate bulge, and a smaller one in the outer bulge. The data are analysed with the help of hydrostatic model atmospheres and spectral synthesis. We derive the radial velocity of all stars, and the atmospheric chemical mix ([Fe/H], C/O, 12C/13C, Al, Si, Ti, and Y) where possible. Our ability to model the spectra is mainly limited by the (in)completeness of atomic and molecular line lists, at least for temperatures down to Teff ≈ 3100 K. We find that the subsample in the inner and intermediate bulge is quite homogeneous, with a slightly subsolar mean metallicity and only few stars with supersolar metallicity, in agreement with previous studies of non-variable M-type giants in the bulge. All sample stars are oxygen-rich, C/O < 1.0. The C/O and carbon isotopic ratios suggest that third dredge-up (3DUP) is absent among the sample stars, except for two stars in the outer bulge that are known to contain technetium. These stars are also more metal-poor than the stars in the intermediate or inner bulge. Current stellar masses are determined from linear pulsation models. The masses, metallicities and 3DUP behaviour are compared to AGB evolutionary models. We conclude that these models are partly in conflict with our observations. Furthermore, we conclude that the stars in the inner and intermediate bulge belong to a more metal-rich population that follows bar-like kinematics, whereas the stars in the outer bulge belong to the metal-poor, spheroidal bulge population.

  18. SUBARU HIGH-RESOLUTION SPECTROSCOPY OF STAR G IN THE TYCHO SUPERNOVA REMNANT

    SciTech Connect

    Kerzendorf, Wolfgang E.; Schmidt, Brian P.; Yong, David; Asplund, M.; Nomoto, Ken'ichi; Podsiadlowski, Ph.; Frebel, Anna; Fesen, Robert A. E-mail: brian@mso.anu.edu.au E-mail: nomoto@astron.s.u-tokyo.ac.jp E-mail: anna@astro.as.utexas.edu

    2009-08-20

    It is widely believed that Type Ia supernovae (SNe Ia) originate in binary systems where a white dwarf accretes material from a companion star until its mass approaches the Chandrasekhar mass and carbon is ignited in the white dwarf's core. This scenario predicts that the donor star should survive the supernova (SNe) explosion, providing an opportunity to understand the progenitors of SNe Ia. In this paper, we argue that rotation is a generic signature expected of most nongiant donor stars that is easily measurable. Ruiz-Lapuente et al. examined stars in the center of the remnant of SN 1572 (Tycho SN) and showed evidence that a subgiant star (Star G by their naming convention) near the remnant's center was the system's donor star. We present high-resolution (R {approx_equal} 40, 000) spectra taken with the High Dispersion Spectrograph on Subaru of this candidate donor star and measure the star's radial velocity as 79 {+-} 2 km s{sup -1} with respect to the local standard of rest and put an upper limit on the star's rotation of 7.5 km s{sup -1}. In addition, by comparing images that were taken in 1970 and 2004, we measure the proper motion of Star G to be {mu} {sub l} = -1.6 {+-} 2.1 mas yr{sup -1} and {mu} {sub b} = -2.7 {+-} 1.6 mas yr{sup -1}. We demonstrate that all of the measured properties of Star G presented in this paper are consistent with those of a star in the direction of Tycho SN that is not associated with the SN event. However, we discuss an unlikely, but still viable scenario for Star G to be the donor star, and suggest further observations that might be able to confirm or refute it.

  19. High Resolution Emission Spectroscopy of the Vibration-Rotation Bands of Hbo and Hbs.

    NASA Astrophysics Data System (ADS)

    Li, G.; Ram, R. S.; Hargreaves, R. J.; Bernath, P. F.; Li, H.

    2012-06-01

    The vibration-rotation spectra of HBO and HBS have been investigated at high resolution using a Fourier transform spectrometer. The HBO molecules were produced in a high temperature furnace from the reaction of H2O vapor with boron by heating a mixture of crystalline boron and boron oxide (B2O3) at a temperature ˜1350°C. The spectra were recorded in the 1100-2200 cm-1 and 1700-4000 cm-1 wavenumber regions covering the ν3 and ν1 fundamentals, respectively. In total 24 vibrational bands involving 30 vibrational levels of H11BO and 12 bands involving 18 levels of H10BO have been rotationally analyzed. After combining the existing microwave and infrared measurements, the absolute term values have been determined for a number of vibrationally-excited states of H11BO and H10BO. The HBS molecules were formed by the reaction of CS2 and water vapor with crystalline boron at a temperature ˜1300°C. The spectra were recorded in the 850-1500 cm-1 and 1750-4000 cm-1 wavenumber regions covering the ν3 and ν1 frequency regions. In total 29 vibrational bands involving 33 vibrationally-excited levels of H11BS and 9 bands involving 12 vibrational levels of H10BS have been analyzed. The fitted spectroscopic parameters agree very well with the results of our {ab initio} calculations. {L}-resonance interactions observed between the 0200 (Σ) and 0220 (Δ) levels of HBO and HBS were analyzed using a 2×2 matrix to yield deperturbed constants.

  20. Mapping the Local Interstellar Medium Using High-Resolution UV Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Malamut, Craig; Redfield, S.; Linsky, J.

    2013-01-01

    Observations using the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope have provided high-resolution near ultraviolet spectra showing MgII, FeII and MnII absorption in the local interstellar medium (LISM). The sample includes sight lines towards over 30 stars within 100 parsecs and across a wide range of spectral types. Observations span the entire sky, probing previously unobserved regions of the LISM. The heavy ions studied in this survey produce narrow absorption features that make possible the identification of multiple interstellar components. Our simultaneous fits of the MgII, FeII, and MnII doublets reveal anywhere from one to six individual absorption components in a particular sight line, where the number of absorbers roughly correlates with the length of the sight line. The simultaneous fitting procedure reduces the systematic errors involved in continuum placement and number of absorbers. Already, sight lines show evidence of previously unidentified clouds within the Local Bubble. These measurements will be added to a growing data set of 81 near UV sight lines. The increase in the number of sight lines will test and improve a three dimensional kinematic model of the local interstellar medium. With an improved understanding of the LISM's kinematical structure, it will be possible to distinguish blended components within the absorption features of lighter ions. Specifically, the MAST Archive contains FUV observations of interstellar absorption by low mass ions (DI, CII, NI, OI) along the the same sight lines. The combination of these data will constrain properties of the LISM such as temperature, turbulence, ionization, abundances and depletions. We acknowledge support for this project through NASA HST Grant GO-11568 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555, and a student research fellowship from the

  1. Jupiter’s tropospheric composition and cloud structure from high-resolution ground-based spectroscopy

    NASA Astrophysics Data System (ADS)

    Giles, Rohini Sara; Fletcher, Leigh N.; Irwin, Patrick G. J.

    2015-11-01

    The CRIRES instrument on the Very Large Telescope was used to make high-resolution (R=100,000) observations of Jupiter in the 4.5-5.2 μm spectral range. At these wavelengths, Jupiter’s atmosphere is optically thin and the spectra are sensitive to the 4-8 bar region. This enabled us to spectrally resolve the line shapes of four minor species in Jupiter’s troposphere: CH3D, GeH4, AsH3 and PH3. The slit was aligned north-south along Jupiter’s central meridian, allowing us to search for latitudinal variability in these line shapes. The spectra were analysed using the NEMESIS radiative transfer code and retrieval algorithm.The CH3D line shape is narrower in the cool zones than in the warm belts. CH3D is chemically stable and does not condense in Jupiter’s atmosphere, so this difference cannot be due to variations in the CH3D abundance. Instead, it can be modelled as variations in the opacity of a deep cloud located at around 4 bar. This deep cloud is opaque in the zones and transparent in the belts.We also observe variability in the GeH4 line shape, with stronger absorption features in the belts than in the zones. As a disequilibrium species, GeH4 is expected to vary with latitude, but we found that the variations in the line shape could be entirely explained by the variations in the cloud structure.In contrast, there is clear evidence for spatial variability in the remaining two molecular species, AsH3 and PH3. Their absorption features are weak near the equator and significantly stronger at high latitudes. A full latitudinal retrieval leads to a broadly symmetric profile for both species, with a minimum at the equator and an enhancement towards the poles.

  2. HIGH-RESOLUTION, DIFFERENTIAL, NEAR-INFRARED TRANSMISSION SPECTROSCOPY OF GJ 1214b

    SciTech Connect

    Crossfield, I. J. M.; Hansen, Brad M. S.; Barman, Travis

    2011-08-01

    The nearby star GJ 1214 hosts a planet intermediate in radius and mass between Earth and Neptune, resulting in some uncertainty as to its nature. We have observed this planet, GJ 1214b, during transit with the high-resolution, near-infrared NIRSPEC spectrograph on the Keck II telescope, in order to characterize the planet's atmosphere. By cross-correlating the spectral changes through transit with a suite of theoretical atmosphere models, we search for variations associated with absorption in the planet atmosphere. Our observations are sufficient to rule out tested model atmospheres with wavelength-dependent transit depth variations {approx}> 5 x 10{sup -4} over the wavelength range 2.1-2.4 {mu}m. Our sensitivity is limited by variable slit loss and telluric transmission effects. We find no positive signatures but successfully rule out a number of plausible atmospheric models, including the default assumption of a gaseous, H-dominated atmosphere in chemical equilibrium. Such an atmosphere can be made consistent if the absorption due to methane is reduced. Clouds can also render such an atmosphere consistent with our observations, but only if they lie higher in the atmosphere than indicated by recent optical and infrared measurements. When taken in concert with other observational constraints, our results support a model in which the atmosphere of GJ 1214b contains significant H and He, but where CH{sub 4} is depleted. If this depletion is the result of photochemical processes, it may also produce a haze that suppresses spectral features in the optical.

  3. High-resolution optical spectroscopy using multimode interference in a compact tapered fibre

    NASA Astrophysics Data System (ADS)

    Wan, Noel H.; Meng, Fan; Schröder, Tim; Shiue, Ren-Jye; Chen, Edward H.; Englund, Dirk

    2015-07-01

    Optical spectroscopy is a fundamental tool in numerous areas of science and technology. Much effort has focused on miniaturizing spectrometers, but thus far at the cost of spectral resolution and broad operating range. Here we describe a compact spectrometer that achieves both high spectral resolution and broad bandwidth. The device relies on imaging multimode interference from leaky modes along a multimode tapered optical fibre, resulting in spectrally distinguishable spatial patterns over a wide range of wavelengths from 500 to 1,600 nm. This tapered fibre multimode interference spectrometer achieves a spectral resolution down to 40 pm in the visible spectrum and 10 pm in the near-infrared spectrum (corresponding to resolving powers of 104-105). Multimode interference spectroscopy is suitable in a variety of device geometries, including planar waveguides in a broad range of transparent materials.

  4. Rapid probe of the nicotine spectra by high-resolution rotational spectroscopy.

    PubMed

    Grabow, Jens-Uwe; Mata, S; Alonso, José L; Peña, I; Blanco, S; López, Juan C; Cabezas, C

    2011-12-21

    Nicotine has been investigated in the gas phase and two conformational forms were characterized through their rotational spectra. Two spectroscopic techniques have been used to obtain the spectra: a new design of broadband Fourier transform microwave (FTMW) spectroscopy with an in-phase/quadrature-phase-modulation passage-acquired-coherence technique (IMPACT) and narrowband FTMW spectroscopy with coaxially oriented beam-resonator arrangement (COBRA). The rotational, centrifugal distortion and hyperfine quadrupole coupling constants of two conformers of nicotine have been determined and found to be in N-methyl trans configurations with the pyridine and pyrrolidine rings perpendicular to one another. The quadrupole hyperfine structure originated by two (14)N nuclei has been completely resolved for both conformers and used for their unambiguous identification. PMID:22020263

  5. Estimating photosynthesis with high resolution field spectroscopy in a Mediterranean grassland under different nutrient availability

    NASA Astrophysics Data System (ADS)

    Perez-Priego, O.; Guan, J.; Fava, F.; Rossini, M.; Wutzler, T.; Moreno, G.; Carrara, A.; Kolle, O.; Schrumpf, M.; Reichstein, M.; Migliavacca, M.

    2014-12-01

    Recent studies have shown how human induced N:P imbalances are affecting essential processes (e.g. photosynthesis, plant growth rate) that lead to important changes in ecosystem structure and function. In this regard, the accuracy of the approaches based on remotely-sensed data for monitoring and modeling gross primary production (GPP) relies on the ability of vegetation indices (VIs) to track the dynamics of vegetation physiological and biophysical properties/variables. Promising results have been recently obtained when Chlorophyll-sensitive VIs and Chlorophyll fluorescence are combined with structural indices in the framework of the Monteith's light use efficiency (LUE) model. However, further ground-based experiments are required to validate LUE model performances, and their capability to be generalized under different nutrient availability conditions. In this study, the overall objective was to investigate the sensitivity of VIs to track short- and long-term GPP variations in a Mediterranean grassland under different N and P fertilization treatments. Spectral VIs were acquired manually using high resolution spectrometers (HR4000, OceanOptics, USA) along a phenological cycle. The VIs examined included photochemical reflectance index (PRI), MERIS terrestrial-chlorophyll index (MTCI) and normalized difference vegetation index (NDVI). Solar-induced chlorophyll fluorescence calculated at the oxygen absorption band O2-A (F760) using spectral fitting methods was also used. Simultaneously, measurements of GPP and environmental variables were conducted using a transient-state canopy chamber. Overall, GPP, F760 and VIs showed a clear seasonal time-trend in all treatments, which was driven by the phenological development of the grassland. Results showed significant differences (p<0.05) in midday GPP values between N and without N addition plots, in particular at the peak of the growing season during the flowering stage and at the end of the season during senescence. While

  6. High Resolution Spectroscopy Using a Tunable Thz Synthesizer Based on Photomixing

    NASA Astrophysics Data System (ADS)

    Cuisset, Arnaud; Hindle, Francis; Mouret, Gael; Eliet, Sophie; Guinet, Mickael; Bocquet, Robin

    2011-06-01

    Optical heterodyning, also know as photomixing is an attractive solution as a single device able to cover the entire frequency range from 300 GHz to 3 THz. As the THz frequency is extracted from the difference frequency of two lasers, the accuracy with which the generated frequency is known is directly determined by the frequency accuracy of the lasers. In order to fully characterize the spectral fingerprint of a given molecule an accuracy approximately one order of magnitude finer than the Doppler linewidth is required, around 100 kHz for smaller polar compounds. To generate accurate cw-THz the frequency spacing of the modes of a Frequency Comb (FC) has been employed to constrain the emission frequency of a photomixing source.footnote{G. Mouret, F. Hindle, A. Cuisset, C. Yang, R. Bocquet, M. Lours, D. Rovera, Opt. Express, 2009, 17: 22031.} Two phase locked loops are implemented coherently locking the two cw-lasers (CW1 and CW2) to different modes of the FC. Although this solution allows accurate generation of narrowband THz the continuous tuning of the frequency presents some obstacles. To overcome these difficulties a system architecture with a third cw-laser (CW3) phase locked to CW2 has been implemented. The beatnote between CW2 and CW3 is free from the FC modes therefore the PLL frequency can be freely scanned over its entire operating range, in our case around 200 MHz. The most of polar compounds may be studied at high resolution in the THz domain with this synthesizer. Three different examples of THz analysis with atmospherical and astrophysical interests will be presented: The ground and vibrationnally excited states of H_2CO revisited in the 0.5-2 THz frequency region The rotational dependences of the broadening coefficients of CH_3Cl studied at high J and K values The molecular discrimination of a complex mixture containing methanol and ethanol. F. Hindle, A. Cuisset, G. Mouret, R. Bocquet Comptes Rendus Physique, 2008, 9: 262-275.

  7. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy

    PubMed Central

    Mun, Je-Ho; Lee, Heonho; Yoon, Dahye; Kim, Byung-Soo; Kim, Moon-Bum; Kim, Shukmann

    2016-01-01

    High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy is a useful tool for investigating the metabolism of various cancers. Basal cell carcinoma (BCC) is the most common skin cancer. However, to our knowledge, data on metabolic profiling of BCC have not been reported in the literature. The objective of the present study was to investigate the metabolic profiling of cutaneous BCC using HR-MAS 1H NMR spectroscopy. HR-MAS 1H NMR spectroscopy was used to analyze the metabolite profile and metabolite intensity of histopathologically confirmed BCC tissues and normal skin tissue (NST) samples. The metabolic intensity normalized to the total spectral intensities in BCC and NST was compared, and multivariate analysis was performed with orthogonal partial least-squares discriminant analysis (OPLS-DA). P values < 0.05 were considered statistically significant. Univariate analysis revealed 9 metabolites that showed statistically significant difference between BCC and NST. In multivariate analysis, the OPLS-DA models built with the HR-MAS NMR metabolic profiles revealed a clear separation of BCC from NST. The receiver operating characteristic curve generated from the results revealed an excellent discrimination of BCC from NST with an area under the curve (AUC) value of 0.961. The present study demonstrated that the metabolite profile and metabolite intensity differ between BCC and NST, and that HR-MAS 1H NMR spectroscopy can be a valuable tool in the diagnosis of BCC. PMID:26934749

  8. Activators of photoluminescence in calcite: evidence from high-resolution, laser-excited luminescence spectroscopy

    USGS Publications Warehouse

    Pedone, V.A.; Cercone, K.R.; Burruss, R.C.

    1990-01-01

    Laser-excited luminescence spectroscopy of a red-algal, biogenic calcite and a synthetic Mn-calcite can make the distinction between organic and trace-element activators of photoluminescence. Organic-activated photoluminescence in biogenic calcite is characterized by significant peak shifts and increasing intensity with shorter-wavelength excitation and by significant decreases in intensity after heating to ??? 400??C. In contrast, Mn-activated photoluminescence shows no peak shift, greatest intensity under green excitation and limited changes after heating. Examination of samples with a high-sensitivity spectrometer using several wavelengths of exciting light is necessary for identification of photoluminescence activators. ?? 1990.

  9. High-resolution photodetachment spectroscopy from the lowest threshold of O{sup -}

    SciTech Connect

    Joiner, Anne; Mohr, Robert H.; Yukich, J. N.

    2011-03-15

    We conducted photodetachment spectroscopy near the lowest detachment threshold from O{sup -} in a 1-T field with sufficient resolution to observe a magnetic field structure similar to that observed in experiments conducted at the threshold of the electron affinity. These observations included not only cyclotron structure but also, to a smaller degree, individual Zeeman thresholds. The experiment was conducted in a Penning ion trap and with a single-mode, tunable, amplified diode laser. Finally, analysis of our results yielded a measurement of the lowest threshold energy.

  10. Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy

    PubMed Central

    Hindle, Francis; Yang, Chun; Mouret, Gael; Cuisset, Arnaud; Bocquet, Robin; Lampin, Jean-François; Blary, Karine; Peytavit, Emilien; Akalin, Tahsin; Ducournau, Guillaume

    2009-01-01

    A review is provided of sources and detectors that can be employed in the THz range before the description of an opto-electronic source of monochromatic THz radiation. The realized spectrometer has been applied to gas phase spectroscopy. Air-broadening coefficients of HCN are determined and the insensitivity of this technique to aerosols is demonstrated by the analysis of cigarette smoke. A multiple pass sample cell has been used to obtain a sensitivity improvement allowing transitions of the volatile organic compounds to be observed. A solution to the frequency metrology is presented and promises to yield accurate molecular line center measurements. PMID:22291552