Science.gov

Sample records for double focusing spectrometers

  1. Comparative performance of double-focus and quadrupole mass spectrometers

    NASA Technical Reports Server (NTRS)

    Wilson, S. K.

    1972-01-01

    Light-weight flight type double focus and quadruple mass spectrometer models were compared. Data cover size, weight, and power sensitivity required to achieve same resolution sensitivity at given mass number. Comparison was made using mathematical relationships. Analysis was confined to equal ion source area sensitivity variations not more than 40% over mass range.

  2. Double focusing ion mass spectrometer of cylindrical symmetry

    NASA Technical Reports Server (NTRS)

    Coplan, M. A.; Moore, J. H.; Hoffman, R. A.

    1984-01-01

    A mass spectrometer consisting of an electric sector followed by a magnetic sector is described. The geometry is a cylindrically symmetric generalization of the Mattauch-Herzog spectrometer (1934). With its large annular entrance aperture and a position-sensitive detector, the instrument provides a large geometric factor and 100-percent duty factor, making it appropriate for spacecraft experiments.

  3. Facility Overview and Double-Focusing Thermal Triple-Axis Spectrometer at the NCNR

    NASA Astrophysics Data System (ADS)

    Lynn, Jeffrey

    2012-02-01

    We will briefly overview the neutron scattering instrumentation at the NCNR, but will focus the talk on the capabilities of the new thermal triple-axis spectrometer is located at the BT-7 beam port [1]. This spectrometer takes full advantage of the large 165 mm diameter reactor beam to tailor the dual 20x20 cm^2 double-focusing monochromator system to provide monochromatic fluxes exceeding 10^8 n/cm^2/s onto the sample. The two monochromators installed are PG(002) and Cu(220), which provide incident energies for 5 meV to above 500 meV. The computer controlled analyzer system offers six standard modes of operation, including a diffraction detector, a position-sensitive detector (PSD) in diffraction mode, horizontal energy focusing analyzer with detector, a Q-E mode employing a flat analyzer and PSD, a constant-E mode with the analyzer crystal system and PSD, and a conventional mode with a selection of S"oller collimators and detector. Additional configurations for specific measurement needs are also available. The capabilities and performance will be discussed and examples of published data presented. [4pt] [1] J. W. Lynn, Y. Chen, S. Chang, Y. Zhao, S. Chi, W. Ratcliff, II, B. G. Ueland, and R. W. Erwin, J. Research NIST 117 (in press).

  4. Double-Focusing Thermal Triple-Axis Spectrometer at the NCNR

    PubMed Central

    Lynn, J. W.; Chen, Y.; Chang, S.; Zhao, Y.; Chi, S.; Ratcliff, W.; Ueland, B. G.; Erwin, R. W.

    2012-01-01

    The new thermal triple-axis spectrometer at the NIST Center for Neutron Research (NCNR) is located at the BT-7 beam port. The 165 mm diameter reactor beam is equipped with a selection of Söller collimators, beam-limiters, and a pyrolytic graphite (PG) filter to tailor the beam for the dual 20×20 cm2 double-focusing monochromator system that provides monochromatic fluxes exceeding 108 n/cm2/s onto the sample. The two monochromators installed are PG(002) and Cu(220), which provide incident energies from 5 meV to above 500 meV. The computer controlled analyzer system offers six standard modes of operation, including a diffraction detector, a position-sensitive detector (PSD) in diffraction mode, horizontal energy focusing analyzer with detector, a Q-E mode employing a flat analyzer and PSD, a constant-E mode with the analyzer crystal system and PSD, and a conventional mode with a selection of Söller collimators and detector. Additional configurations for specific measurement needs are also available. This paper discusses the capabilities and performance for this new state-of-the-art neutron spectrometer. PMID:26900514

  5. Studies on reducing the scale of a double focusing mass spectrometer

    SciTech Connect

    Chambers, D.M.; Gregg, H.R.; Andresen, B.D.

    1993-05-01

    Several groups have developed miniaturized sector mass spectrometers with the goal of remote sensing in confined spaces or portability. However, these achievements have been overshadowed by more successful development of man-portable quadrupole and ion trap mass spectrometers. Despite these accomplishments the development of a reduced-scale sector mass spectrometer remains attractive as a potentially low-cost, robust instrument requiring very simple electronics and low power. Previous studies on miniaturizing sector instruments include the use of a Mattauch-Herzog design for a portable mass spectrograph weighing less than 10 kg. Other work has included the use of a Nier-Johnson design in spacecraft-mountable gas chromatography mass spectrometers for the Viking spacecraft as well as miniature sector-based MS/MS instrument. Although theory for designing an optimized system with high resolution and mass accuracy is well understood, such specifications have not yet been achieved in a miniaturized instrument. To proceed further toward the development of a miniaturized sector mass spectrometer, experiments were conducted to understand and optimize a practical, yet nonideal instrument configuration. The sector mass spectrometer studied in this work is similar to the ones developed for the Viking project, but was further modified to be low cost, simple and robust. Characteristics of this instrument that highlight its simplicity include the use of a modified Varian leak detector ion source, source ion optics that use one extraction voltage, and an unshunted fixed nonhomogeneous magnetic sector. The effects of these design simplifications on ion trajectory were studied by manipulating the ion beam along with the magnetic sector position. This latter feature served as an aid to study ion focusing amidst fringing fields as well as nonhomogeneous forces and permitted empirical realignment of the instrument.

  6. DOE/University instrumentation program grant for funding of the high field, high mass, double focusing, high resolution mass spectrometer

    SciTech Connect

    Not Available

    1987-06-01

    This document discusses the research efforts accomplished using the double focusing, high field, high resolution mass spectrometer, Model JMS HX-100HF (JEOL). Installation of this instrument was accomplished during March of 1986 and operation of the instrument for purposes of application to biological and biochemical problems started during the month of April 1986. areas of research include post-translational modifications of rubisco, biosynthesis of abscisic acid, environmental control of plant development, plant cell wall protein, structural studies of thioltransferase and hexokinase and analogs of peptide harmones and neurotransmitters. 1 fig.

  7. A novel double-focusing time-of-flight mass spectrometer for absolute recoil ion cross sections measurements.

    PubMed

    Sigaud, L; de Jesus, V L B; Ferreira, Natalia; Montenegro, E C

    2016-08-01

    In this work, the inclusion of an Einzel-like lens inside the time-of-flight drift tube of a standard mass spectrometer coupled to a gas cell-to study ionization of atoms and molecules by electron impact-is described. Both this lens and a conical collimator are responsible for further focalization of the ions and charged molecular fragments inside the spectrometer, allowing a much better resolution at the time-of-flight spectra, leading to a separation of a single mass-to-charge unit up to 100 a.m.u. The procedure to obtain the overall absolute efficiency of the spectrometer and micro-channel plate detector is also discussed. PMID:27587105

  8. Development of Tandem, Double-Focusing, Electron Impact, Gas Source Mass Spectrometer for Measurement of Rare Double-Substituted Isotoplogues in Geochemistry

    SciTech Connect

    Young, Edward D.

    2015-07-30

    This project culminated in construction and delivery of the world’s first large-radius gas-source isotope ratio mass spectrometer that permits unparalleled analyses of the stable isotopic composition of methane gas. The instrument, referred to as the “Panorama” and installed at UCLA in March 2015, can now be used to determine the relative abundances of rare isotopic species of methane that serve as tracers of temperature of formation and/or subsequent processing of gas. With this technology we can begin to delineate different sources and sinks of methane isotopically in ways not possible until now.

  9. The high sensitivity double beta spectrometer TGV

    NASA Astrophysics Data System (ADS)

    Briancon, Ch.; Brudanin, V. B.; Egorov, V. G.; Janout, Z.; Koníček, J.; Kovalík, A.; Kovalenko, V. E.; Kubašta, J.; Pospíšil, S.; Revenko, A. V.; Rukhadze, N. I.; Salamatin, A. V.; Sandukovsky, V. G.; Štekl, I.; Timkin, V. V.; Tsupko-Sitnikov, V. V.; Vorobel, V.; Vylov, Ts.

    1996-02-01

    A high sensitivity double beta spectrometer TGV (Telescope Germanium Vertical) has been developed. It is based on 16 HPGe detectors of volume 1200 × 6 mm 3 each in the same cryostat. The TGV spectrometer was proposed for the study of ultrarare nuclear processes (e.g. 2νββ, 0νββ, 2νEC/EC). Details of the TGV spectrometer construction are described, the principles of background suppression, the results of Monte Carlo simulations and the results of test background measurements (in Dubna and Modane underground laboratory) are provided.

  10. First results from the new double velocity-double energy spectrometer VERDI

    NASA Astrophysics Data System (ADS)

    Frégeau, M. O.; Oberstedt, S.; Gamboni, Th.; Geerts, W.; Hambsch, F.-J.; Vidali, M.

    2016-05-01

    The VERDI spectrometer (VElocity foR Direct mass Identification) is a two arm time-of-flight spectrometer built at the European Commission Joint Research Centre IRMM. It determines fragment masses and kinetic energy distributions produced in nuclear fission by means of the double velocity and double energy (2v-2E) method. The simultaneous measurement of pre- and post neutron fragment characteristics allows studying the share of excitation energy between the two fragments. In particular, the evolution of fission modes and neutron multiplicity may be studied as a function of the available excitation energy. Both topics are of great importance for the development of models used in the evaluation of nuclear data, and also have important implications for the fundamental understanding of the fission process. The development of VERDI focus on maximum geometrical efficiency while striving for highest possible mass resolution. An innovative transmission start detector, using electrons ejected from the target itself, was developed. Stop signal and kinetic energy of both fragments are provided by two arrays of silicon detectors. The present design provides about 200 times higher geometrical efficiency than that of the famous COSI FAN TUTTE spectrometer [Nuclear Instruments and Methods in Physics Research 219 (1984) 569]. We report about a commissioning experiment of the VERDI spectrometer, present first results from a 2v-2E measurement of 252Cf spontaneous fission and discuss the potential of this instrument to contribute to the investigation prompt fission neutron characteristics as a function of fission fragment properties.

  11. The low background spectrometer TGV II for double beta decay measurements

    NASA Astrophysics Data System (ADS)

    Beneš, P.; Čermák, P.; Gusev, K. N.; Klimenko, A. A.; Kovalenko, V. E.; Kovalík, A.; Rukhadze, N. I.; Salamatin, A. V.; Šimkovic, F.; Štekl, I.; Timkin, V. V.; Vylov, Ts.

    2006-12-01

    The low-background multi-HPGe spectrometer TGV II installed in the Modane Underground Laboratory (France) is described in detail and the results of the background measurements are reported. The spectrometer is focused on the double beta decay measurements with two isotopes— 106Cd ( 2νEC/EC mode) and 48Ca ( ββ mode). A basic summary of the physics of ββ decay (especially EC/EC mode) is also given.

  12. The Los Alamos National Laboratory precision double crystal spectrometer

    SciTech Connect

    Morgan, D.V.; Stevens, C.J.; Liefield, R.J.

    1994-03-01

    This report discusses the following topics on the LANL precision double crystal X-ray spectrometer: Motivation for construction of the instrument; a brief history of the instrument; mechanical systems; motion control systems; computer control system; vacuum system; alignment program; scan programs; observations of the copper K{alpha} lines; and characteristics and specifications.

  13. Miniature Focusing Time-of-Flight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Kanik, Isik; Srivastava, Santosh

    2005-01-01

    An improved miniature time-of-flight mass spectrometer has been developed in a continuing effort to minimize the sizes, weights, power demands, and costs of mass spectrometers for such diverse applications as measurement of concentrations of pollutants in the atmosphere, detecting poisonous gases in mines, and analyzing exhaust gases of automobiles. Advantageous characteristics of this mass spectrometer include the following: It is simple and rugged. Relative to prior mass spectrometers, it is inexpensive to build. There is no need for precise alignment of its components. Its mass range is practically unlimited Relative to prior mass spectrometers, it offers high sensitivity (ability to measure relative concentrations as small as parts per billion). Its resolution is one dalton (one atomic mass unit). An entire mass spectrum is recorded in a single pulse. (In a conventional mass spectrometer, a spectrum is recorded mass by mass.) The data-acquisition process takes only seconds. It is a lightweight, low-power, portable instrument. Although time-of-flight mass spectrometers (TOF-MSs) have been miniaturized previously, their performances have not been completely satisfactory. An inherent adverse effect of miniaturization of a TOF-MS is a loss of resolution caused by reduction of the length of its flight tube. In the present improved TOF-MS, the adverse effect of shortening the flight tube is counteracted by (1) using charged-particle optics to constrain ion trajectories to the flight-tube axis while (2) reducing ion velocities to increase ion flight times. In the present improved TOF-MS, a stream of gas is generated by use of a hypodermic needle. The stream of gas is crossed by an energy-selected, pulsed beam of electrons (see Figure 1). The ions generated by impingement of the electrons on the gas atoms are then focused by three cylindrical electrostatic lenses, which constitute a segmented flight tube. After traveling along the flight tube, the ions enter a charged

  14. Inverse photoelectron spectrometer with magnetically focused electron gun

    NASA Technical Reports Server (NTRS)

    Krainsky, Isay L.

    1991-01-01

    An inverse photoelectron spectrometer is described which is based on the design of a magnetically focused low energy electron gun. The magnetic lens extends its field over a relatively large segment of the electron trajectory, which could provide a better focusing effect on a high-current-density low-velocity electron beam, providing the magnetic field in the vicinity of the target is reduced sufficiently to preserve the collinearity of the beam. In order to prove the concept, ray tracing is conducted using the Herrmannsfeldt program for solving electron trajectories in electrostatic and magnetostatic focusing systems. The program allows the calculation of the angles of the electron trajectories with the z axis, at the target location. The results of the ray-tracing procedure conducted for this gun are discussed. Some of the advantages of the magnetic focusing are also discussed.

  15. Double passing the Kitt Peak 1-m Fourier transform spectrometer

    NASA Technical Reports Server (NTRS)

    Jennings, D. E.; Hubbard, R.; Brault, J. W.

    1985-01-01

    Attention is given to a simple technique for performing the conversion of the Kitt Peak 1-m Fourier transform spectrometer's dual input/output optical configuration to a double pass configuration that improves spectral resolution by a factor of 2. The modification is made by placing a flat mirror in the output beam from each cat's eye, retroreflecting the beams back through the cat's eyes to the first beam splitter. A single detector is placed at the second input port, which then becomes the instrument's output.

  16. Conical focusing crystal spectrometers for cosmic X-ray astronomy

    NASA Technical Reports Server (NTRS)

    Woodgate, B. E.; Lowinger, T.; Schneider, M.

    1973-01-01

    A crystal spectrometer for rocket and satellite experiments is described. Parallel X rays from a stellar object are reflected at constant angle by Bragg crystals arranged around the sector of a cone so that a single wavelength is brought to a focus onto the axis of the cone. The aberrations produced when this array is tilted to change the wavelength are considered. It is shown that these are minimized by moving cone and detector in a nearly theta to two-theta motion and by using a small-angle sector. In a specific design for a satellite instrument using LiF crystal to observe a spectral region including the iron lines at 1.9 A, a spectral resolution of 3 mA over a spectral range of 1.6-2.1 A can be obtained, with the cosmic-ray background rate, and hence the time to detect a weak line decreased by a factor 80 compared to a flat crystal spectrometer. Examples of performance for a low energy rocket experiment are also given.

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

    DOEpatents

    Cheng, Meng-Dawn

    2002-01-01

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

  18. PHEBUS: A double ultraviolet spectrometer to observe Mercury's exosphere

    NASA Astrophysics Data System (ADS)

    Chassefière, E.; Maria, J.-L.; Goutail, J.-P.; Quémerais, E.; Leblanc, F.; Okano, S.; Yoshikawa, I.; Korablev, O.; Gnedykh, V.; Naletto, G.; Nicolosi, P.; Pelizzo, M.-G.; Correia, J.-J.; Gallet, S.; Hourtoule, C.; Mine, P.-O.; Montaron, C.; Rouanet, N.; Rigal, J.-B.; Muramaki, G.; Yoshioka, K.; Kozlov, O.; Kottsov, V.; Moisseev, P.; Semena, N.; Bertaux, J.-L.; Capria, M.-Th.; Clarke, J.; Cremonese, G.; Delcourt, D.; Doressoundiram, A.; Erard, S.; Gladstone, R.; Grande, M.; Hunten, D.; Ip, W.; Izmodenov, V.; Jambon, A.; Johnson, R.; Kallio, E.; Killen, R.; Lallement, R.; Luhmann, J.; Mendillo, M.; Milillo, A.; Palme, H.; Potter, A.; Sasaki, S.; Slater, D.; Sprague, A.; Stern, A.; Yan, N.

    2010-01-01

    Probing of Hermean exosphere by ultraviolet spectroscopy (PHEBUS) is a double spectrometer for the Extreme Ultraviolet range (55-155 nm) and the Far Ultraviolet range (145-315 nm) devoted to the characterization of Mercury's exosphere composition and dynamics, and surface-exosphere connections. This French-led instrument is implemented in a cooperative scheme involving Japan (detectors), Russia (scanner) and Italy (ground calibration). PHEBUS will address the following main scientific objectives relative to Mercury's exosphere: determination of the composition and the vertical structure of the exosphere; characterization of the exospheric dynamics: day to night circulation, transport between active and inactive regions; study of surface release processes; identification and characterization of the sources of exospheric constituents; detection and characterization of ionized species and their relation with the neutral atmosphere; space and time monitoring of exosphere/magnetosphere exchange and transport processes; study and quantification of escape, global scale source/sink balance and geochemical cycles synergistically with other experiments of BepiColombo (Mercury Sodium Atmospheric Spectral Imager (MSASI), Mercury Plasma Particle Experiment (MPPE) on Mercury Magnetospheric Orbiter (MMO); Mercury imaging X-ray spectrometer (MIXS), Search for exosphere refilling and emitted neutral abundance (SERENA) on Mercury Planetary Orbiter (MPO)). Two gratings and two detectors are used according to a specific, compact design. The spectrum detection is based on the photon counting method and is realized using micro-channel plate (MCP) detectors with Resistive Anode Encoder (RAE). Typical photocathodes are CsI or KBr for the extreme ultra-violet (EUV) range, CsTe for the far ultra-violet (FUV) range. Extra visible lines are monitored using a photo-multiplier (PM) that is also used in photon counting mode. In order to prevent sensitivity losses which are critical in UV ranges

  19. A second-order focusing electrostatic toroidal electron spectrometer with 2pi radian collection.

    PubMed

    Khursheed, Anjam; Hoang, Hung Quang

    2008-12-01

    This paper presents a toroidal electron energy spectrometer designed to capture electrons in the full 2pi azimuthal angular direction while at the same time having second-order focusing optics. Simulation results based upon direct ray tracing predict that the relative energy resolution of the spectrometer will be 0.146% and 0.0188% at input angular spreads of +/- 6 degrees and +/- 3 degrees, respectively, comparable to the theoretically best resolution of the cylindrical mirror analyzer (CMA), and an order of magnitude better than existing toroidal spectrometers. Also predicted for the spectrometer is a parallel energy acquisition mode of operation, where the energy bandwidth is expected to be > +/- 10% (20% total) of the pass energy. The spectrometer is designed to allow for retardation of the pass energy without the need to incorporate auxiliary lenses. PMID:18952374

  20. [The alignment of the optical system for 216 coude focus echelle spectrometer].

    PubMed

    Zhu, Y; Pan, J

    1997-04-01

    This paper gives a brief introduction about the structure of the echelle spectrometer which was installed at coude focus of the chinese 2. 16 meter astronomical telescope. According to the design requirment of this echelle spectrometer, the main points and steps of alignment of optical system are analysed. Authors work out a practical alignment scheme in which the fewest auxiliary tools are used. PMID:15810402

  1. Design and Fabrication of Double-Focused Ultrasound Transducers to Achieve Tight Focusing.

    PubMed

    Jang, Jihun; Chang, Jin Ho

    2016-01-01

    Beauty treatment for skin requires a high-intensity focused ultrasound (HIFU) transducer to generate coagulative necrosis in a small focal volume (e.g., 1 mm³) placed at a shallow depth (3-4.5 mm from the skin surface). For this, it is desirable to make the F-number as small as possible under the largest possible aperture in order to generate ultrasound energy high enough to induce tissue coagulation in such a small focal volume. However, satisfying both conditions at the same time is demanding. To meet the requirements, this paper, therefore, proposes a double-focusing technique, in which the aperture of an ultrasound transducer is spherically shaped for initial focusing and an acoustic lens is used to finally focus ultrasound on a target depth of treatment; it is possible to achieve the F-number of unity or less while keeping the aperture of a transducer as large as possible. In accordance with the proposed method, we designed and fabricated a 7-MHz double-focused ultrasound transducer. The experimental results demonstrated that the fabricated double-focused transducer had a focal length of 10.2 mm reduced from an initial focal length of 15.2 mm and, thus, the F-number changed from 1.52 to 1.02. Based on the results, we concluded that the proposed double-focusing method is suitable to decrease F-number while maintaining a large aperture size. PMID:27509500

  2. A portable direct view configuration prism spectrometer using a double Amici prism

    NASA Astrophysics Data System (ADS)

    Sun, Lanjun; Zhang, Yanchao; Tian, Zhaoshuo; Ren, Xiuyun; Fu, Shiyou

    2015-10-01

    In this paper, we present a prism spectrometer that exploits a double Amici prism dispersion structure. The system consists of a slit, a collimating lens, a double Amici prism, an imaging lens and a CCD. The incident light enter into slit, and then is paralleled by a collimating lens to the double Amici prism. The double Amici prism is used to realize spectral dispersion. The dispersed light is collected by an imaging lens and image on the photosensitive surface of the CCD. The dispersion resolution is theoretical analyzed from the ray tracing point of view. In addition, the imaging position on CCD element at different wavelength is presented according to nonlinear curve of dispersion. The designed prism spectrometer can obtain a high light throughput and less optical distortion spectrum in the spectral range of 370-700nm. In experiment, we measured the spectral resolution of the designed prism spectrometer at five wavelength used a grating monochromator. The designed in-line, direct view configuration prism spectrometer owns the advantages of high light throughput, less optical distortions, compact structure, small volume and easy operation, which has important role in application of laser spectral measurement especially laser remote sensing spectral detection.

  3. Spectrometer for hard X-ray free-electron laser based on diffraction focusing.

    PubMed

    Kohn, V G; Gorobtsov, O Y; Vartanyants, I A

    2013-03-01

    X-ray free-electron lasers (XFELs) generate sequences of ultra-short spatially coherent pulses of X-ray radiation. A diffraction focusing spectrometer (DFS), which is able to measure the whole energy spectrum of the radiation of a single XFEL pulse with an energy resolution of ΔE/E 2 × 10(-6), is proposed. This is much better than for most modern X-ray spectrometers. Such resolution allows one to resolve the fine spectral structure of the XFEL pulse. The effect of diffraction focusing occurs in a single-crystal plate due to dynamical scattering, and is similar to focusing in a Pendry lens made from a metamaterial with a negative refraction index. Such a spectrometer is easier to operate than those based on bent crystals. It is shown that the DFS can be used in a wide energy range from 5 keV to 20 keV. PMID:23412482

  4. Time-Resolved Spectra of Dense Plasma Focus Using Spectrometer, Streak Camera, CCD Combination

    SciTech Connect

    F. J. Goldin, B. T. Meehan, E. C. Hagen, P. R. Wilkins

    2010-10-01

    A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny–Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

  5. Time-resolved spectra of dense plasma focus using spectrometer, streak camera, and CCD combination

    SciTech Connect

    Goldin, F. J.; Meehan, B. T.; Hagen, E. C.; Wilkins, P. R.

    2010-10-15

    A time-resolving spectrographic instrument has been assembled with the primary components of a spectrometer, image-converting streak camera, and CCD recording camera, for the primary purpose of diagnosing highly dynamic plasmas. A collection lens defines the sampled region and couples light from the plasma into a step index, multimode fiber which leads to the spectrometer. The output spectrum is focused onto the photocathode of the streak camera, the output of which is proximity-coupled to the CCD. The spectrometer configuration is essentially Czerny-Turner, but off-the-shelf Nikon refraction lenses, rather than mirrors, are used for practicality and flexibility. Only recently assembled, the instrument requires significant refinement, but has now taken data on both bridge wire and dense plasma focus experiments.

  6. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer.

    PubMed

    Blase, Ryan C; Miller, Greg; Westlake, Joseph; Brockwell, Tim; Ostrom, Nathaniel; Ostrom, Peggy H; Waite, J Hunter

    2015-10-01

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a "perfect focus" mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.(3)) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups. PMID:26520982

  7. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer

    NASA Astrophysics Data System (ADS)

    Blase, Ryan C.; Miller, Greg; Westlake, Joseph; Brockwell, Tim; Ostrom, Nathaniel; Ostrom, Peggy H.; Waite, J. Hunter

    2015-10-01

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a "perfect focus" mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (˜10.7 in.3) and weight (˜2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.

  8. Developing a Sagittally Focusing Double-Multilayer Monochromator

    NASA Astrophysics Data System (ADS)

    Wang, Yujie; Narayanan, Suresh; Liu, Jinyuan; Shu, Deming; Wang, Jin

    2007-01-01

    We report the development of a sagittally focusing double multilayer monochromator to produce a spatially extended, wide-bandpass x-ray beam from intense synchrotron bending-magnet source at the Advanced Photon Source for ultrafast x-radiography and -tomography applications. This monochromator consists of the two W/B4C multilayers with a 25-Å periodicity coated on Si single-crystal substrates. The second crystal is mounted on a saggitally focusing bender which can; dynamically change the bending radius of the crystal in order to focus the beam to various points along the beamline. With this new apparatus, it becomes possible to adjust the x-ray beam size to best match the area detector size and the object size to facilitate a more efficient data collection using ultrafast x-radiography and -tomography.

  9. A compact E × B filter: A multi-collector cycloidal focusing mass spectrometer

    SciTech Connect

    Blase, Ryan C. Miller, Greg; Brockwell, Tim; Waite, J. Hunter; Westlake, Joseph; Ostrom, Nathaniel; Ostrom, Peggy H.

    2015-10-15

    A compact E × B mass spectrometer is presented. The mass spectrometer presented is termed a “perfect focus” mass spectrometer as the resolution of the device is independent of both the initial direction and energy of the ions (spatial and energy independent). The mass spectrometer is small in size (∼10.7 in.{sup 3}) and weight (∼2 kg), making it an attractive candidate for portability when using small, permanent magnets. A multi-collector Faraday cup design allows for the detection of multiple ion beams in discrete collectors simultaneously; providing the opportunity for isotope ratio monitoring. The mass resolution of the device is around 400 through narrow collector slits and the sensitivity of the device follows expected theoretical calculations of the ion current produced in the electron impact ion source. Example mass spectra obtained from the cycloidal focusing mass spectrometer are presented as well as information on mass discrimination based on instrumental parameters and isotope ratio monitoring of certain ion signals in separate Faraday cups.

  10. High Resolution Double-Focusing Isotope Ratio Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Radke, J.; Deerberg, M.; Hilkert, A.; Schlüter, H.-J.; Schwieters, J.

    2012-04-01

    In recent years isotope ratio mass spectrometry has extended to the capability of quantifying very small isotope signatures related with low abundances and simultaneously detecting molecular masses such as isotopomers and isotopologues containing clumped isotopes. Some of those applications are limited by molecular interferences like different gas molecules with the same nominal mass, e.g. Ar/O2, adducts of the same molecule or of different molecules, and very small isotope abundances. The Thermo Scientific MAT 253 ULTRA is the next generation of high precision gas isotope ratio mass spectrometry, which combines a 10 KV gas ionization source (Thermo Scientific MAT 253) with a double focusing multi-collector mass analyzer (Thermo Scientific Neptune) and reduces those limitations by measuring isotope ratios on a larger dynamic range with high precision. Small ion beam requirements and high sensitivity are achieved by signal-to-noise improvements through enhanced ion beam amplification in faraday cups and ion counters. Interfering backgrounds, e.g. interfering isotopologues or isobaric ions of contaminants, are dramatically decreased by a dynamic range increase combined with high evacuation leading to undisturbed ion transmission through the double-focusing analyser. Furthermore, automated gain calibration for mathematical baseline corrections, switchable detector arrays, ion source control, analyser focusing and full data export is controlled under Isodat data control. New reference/sample strategies are under investigation besides incorporation of the continuous-flow technique and its versatile inlet devices. We are presenting first results and applications of the MAT 253 Ultra.

  11. Ultra-high-vacuum double-axis goniometer for use with an electron spectrometer

    SciTech Connect

    Shleifer, M.; Williams, G.P.

    1981-01-01

    A double-axis goniometer designed for moving and indexing an electon spectrometer for angle-resolved photoemission studies is described. A feature of the design is that the two rotations operate independently and either can be carried out with the analyzer at any position. The goniometer is designed to be installed in a 14'' spool piece which makes it possible to add it to an existing 14'' uhv system.

  12. The LBT double prime focus camera control software

    NASA Astrophysics Data System (ADS)

    Di Paola, Andrea; Baruffolo, Andrea; Gallozzi, Stefano; Pedichini, Fernando; Speziali, Roberto

    2004-09-01

    The LBT double prime focus camera (LBC) is composed of twin CCD mosaic imagers. The instrument is designed to match the double channel structure of the LBT telescope and to exploit parallel observing mode by optimizing one camera at blue and the other at red side of the visible spectrum. Because of these facts, the LBC activity will likely consist of simultaneous multi-wavelength observation of specific targets, with both channels working at the same time to acquire and download images at different rates. The LBC Control Software is responsible for coordinating these activities by managing scientific sensors and all the ancillary devices such as rotators, filter wheels, optical correctors focusing, house-keeping information, tracking and Active Optics wavefront sensors. The result is obtained using four dedicated PCs to control the four CCD controllers and one dual processor PC to manage all the other aspects including instrument operator interface. The general architecture of the LBC Control Software is described as well as solutions and details about its implementation.

  13. Performances of a method for reconstructing the energy of neutrons detected by a double scattering spectrometer

    SciTech Connect

    Agnello, M.; Botta, E.; Bressani, T.; Calvo, D.; Gianotti, P.; Iazzi, F.; Lamberti, C.; Minetti, B. ); Balocco, E. )

    1992-10-01

    This paper reports on a neutron spectrometer based on the double scattering technique which has been designed and built at the Laboratorio Tecnologico of INFN - Turin (Italy) for Cold Fusion experiments. The operating principle for the reconstruction of the energy can be applied to various fields (neutron emission from sources, fission and fusion) and is described together with the performed tests: a resolution of less than 560 KeV FWHM has been obtained for neutrons of 2.45 MeV, in a typical running configuration.

  14. New search for double electron capture in 106Cd decay with the TGV-2 spectrometer

    NASA Astrophysics Data System (ADS)

    Briançon, Ch.; Brudanin, V. B.; Egorov, V. G.; Jose, J. M.; Klimenko, A. A.; Kovalik, A.; Rosov, S. V.; Rukhadze, E. N.; Rukhadze, N. I.; Salamatin, A. V.; Timkin, V. V.; Fajt, L.; Hodak, R.; Šimkovic, F.; Shitov, Yu. A.; Špavorova, M.; Štekl, I.; Yakushev, E. A.

    2015-09-01

    A new experiment devoted to searches for double electron capture in 106Cd decay is being performed at the Modane underground laboratory (4800 mwe) with the 32-detector TGV-2 spectrometer. The limit T 1/2(2 νEC/EC) > 2.0×1020 yr at a 90%confidence level (C.L.) was obtained from a preliminary analysis of data obtained over 2250 h of measurements with about 23.2 g sample enriched in the isotope 106Cd to 99.57%. The limits T 1/2(KL, 2741 keV) > 0.9 × 1020 yr and T 1/2(KK, 2718 keV) ≫ 1.4 × 1020 yr at a 90% C.L. on the neutrinoless decay of 106Cd were obtained from measurements performed with the Obelix low-background spectrometer from high-purity germanium (HPGe spectrometer) for a sample of mass about 23.2 g enriched in the isotope 106Cd.

  15. New search for double electron capture in {sup 106}Cd decay with the TGV-2 spectrometer

    SciTech Connect

    Briançon, Ch.; Brudanin, V. B.; Egorov, V. G.; Jose, J. M.; Klimenko, A. A.; Kovalik, A.; Rosov, S. V.; Rukhadze, E. N.; Rukhadze, N. I. Salamatin, A. V.; Timkin, V. V.; Fajt, L.; Hodak, R.; Šimkovic, F.; Shitov, Yu. A.; Špavorova, M.; Štekl, I.; Yakushev, E. A.

    2015-09-15

    A new experiment devoted to searches for double electron capture in {sup 106}Cd decay is being performed at the Modane underground laboratory (4800 mwe) with the 32-detector TGV-2 spectrometer. The limit T{sub 1/2}(2νEC/EC) > 2.0×10{sup 20} yr at a 90%confidence level (C.L.) was obtained from a preliminary analysis of data obtained over 2250 h of measurements with about 23.2 g sample enriched in the isotope {sup 106}Cd to 99.57%. The limits T{sub 1/2}(KL, 2741 keV) > 0.9 × 10{sup 20} yr and T{sub 1/2}(KK, 2718 keV) ≫ 1.4 × 10{sup 20} yr at a 90% C.L. on the neutrinoless decay of {sup 106}Cd were obtained from measurements performed with the Obelix low-background spectrometer from high-purity germanium (HPGe spectrometer) for a sample of mass about 23.2 g enriched in the isotope {sup 106}Cd.

  16. An Improvement on Space Focusing Resolution in Two-Field Time-of-Flight Mass Spectrometers

    SciTech Connect

    Yildirim, M.; Aydin, R.; Akin, U.; Kilic, H. S.; Sise, O.; Ulu, M.; Dogan, M.

    2007-04-23

    Time-of-Flight Mass Spectrometer (TOFMS) is a sophisticated device for the mass selective analysis of a variety of samples. The main limitation on TOFMS technique is the obtainable resolution where the two main limiting factors are the initial space and energy spread of particles created in ionization region. Similar charged particles starting at different points will reach the detector at different times. So, this problem makes space focusing is very important subject. We have presented principles of two-fields TOFMS with second-order space focusing both using analytical methods and ray-tracing simulation. This work aims understanding of ion optical system clearly and gives hint of expectation for future developments.

  17. DELICIOUS III: A multipurpose double imaging particle coincidence spectrometer for gas phase vacuum ultraviolet photodynamics studies

    NASA Astrophysics Data System (ADS)

    Garcia, G. A.; Cunha de Miranda, B. K.; Tia, M.; Daly, S.; Nahon, L.

    2013-05-01

    We present a versatile double imaging particle coincidence spectrometer operating in fully continuous mode, named DELICIOUS III, which combines a velocity map imaging device and a modified Wiley-McLaren time of flight momentum imaging analyzer for photoelectrons and photoions, respectively. The spectrometer is installed in a permanent endstation on the DESIRS vacuum ultraviolet (VUV) beamline at the French National Synchrotron Radiation Facility SOLEIL, and is dedicated to gas phase VUV spectroscopy, photoionization, and molecular dynamics studies. DELICIOUS III is capable of recording mass-selected threshold photoelectron photoion coincidence spectra with a sub-meV resolution, and the addition of a magnifying lens inside the electron drift tube provides a sizeable improvement of the electron threshold/ion mass resolution compromise. In fast electron mode the ultimate kinetic energy resolution has been measured at ΔE/E = 4%. The ion spectrometer offers a mass resolution—full separation of adjacent masses—of 250 amu for moderate extraction fields and the addition of an electrostatic lens in the second acceleration region allows measuring the full 3D velocity vector for a given mass with an ultimate energy resolution of ΔE/E = 15%, without sacrificing the mass resolution. Hence, photoelectron images are correlated both to the mass and to the ion kinetic energy and recoil direction, to access the electron spectroscopy of size-selected species, to study the photodissociation processes of state-selected cations in detail, or to measure in certain cases photoelectron angular distributions in the ion recoil frame. The performances of DELICIOUS III are explored through several examples including the photoionization of N2, NO, and CF3.

  18. Characterization of the Ion Beam Focusing in a Mass Spectrometer using an IonCCD™ Detector

    SciTech Connect

    Johnson, Grant E.; Hadjar, Omar; Laskin, Julia

    2011-07-26

    A position sensitive pixel-based detector array, referred to as the IonCCDTM, has been employed to characterize the ion optics and ion beam focusing in a custom built mass spectrometer designed for soft and reactive landing of mass-selected ions onto surfaces. The IonCCDTM was placed at several stages along the path of the ion beam to determine the focusing capabilities of the various ion optics which include an electrodynamic ion funnel, two radiofrequency (RF) only collision quadrupoles, a mass resolving quadrupole, a quadrupole bender, and two Einzel lens assemblies. The focusing capabilities of the RF-only collision quadrupoles and Einzel lenses are demonstrated by large decreases in the diameter of the ion beam. In contrast, the mass resolving quadrupole is shown to significantly defocus the mass-selected ion beam resulting in an expansion of the measured ion beam diameter. Combined with SIMION simulations we demonstrate that the IonCCDTM can identify minor errors in the alignment of charged-particle optics that result in erratic trajectories and significant deflections of the ion beam.. This information can be used to improve the design assembly and maintenance of custom-built mass spectrometry instrumentation.

  19. Characterization of the ion beam focusing in a mass spectrometer using an IonCCD™ detector.

    PubMed

    Johnson, Grant E; Hadjar, Omar; Laskin, Julia

    2011-08-01

    A position sensitive pixel-based detector array, referred to as the IonCCD, has been employed to characterize the ion optics and ion beam focusing in a custom built mass spectrometer designed for soft and reactive landing of mass-selected ions onto surfaces. The IonCCD was placed at several stages along the path of the ion beam to determine the focusing capabilities of the various ion optics, which include an electrodynamic ion funnel, two radiofrequency (rf)-only collision quadrupoles, a mass resolving quadrupole, a quadrupole bender, and two einzel lens assemblies. The focusing capabilities of the rf-only collision quadrupoles and einzel lenses are demonstrated by large decreases in the diameter of the ion beam. In contrast, the mass resolving quadrupole is shown to significantly defocus the mass-selected ion beam resulting in an expansion of the measured ion beam diameter. Combined with SIMION simulations, we demonstrate that the IonCCD can identify minor errors in the alignment of charged-particle optics that result in erratic trajectories and significant deflections of the ion beam. This information may be used to facilitate the design, assembly, and maintenance of custom-built mass spectrometry instrumentation. PMID:21953193

  20. Double emulsion formation through hierarchical flow-focusing microchannel

    NASA Astrophysics Data System (ADS)

    Azarmanesh, Milad; Farhadi, Mousa; Azizian, Pooya

    2016-03-01

    A microfluidic device is presented for creating double emulsions, controlling their sizes and also manipulating encapsulation processes. As a result of three immiscible liquids' interaction using dripping instability, double emulsions can be produced elegantly. Effects of dimensionless numbers are investigated which are Weber number of the inner phase (Wein), Capillary number of the inner droplet (Cain), and Capillary number of the outer droplet (Caout). They affect the formation process, inner and outer droplet size, and separation frequency. Direct numerical simulation of governing equations was done using volume of fluid method and adaptive mesh refinement technique. Two kinds of double emulsion formation, the two-step and the one-step, were simulated in which the thickness of the sheath of double emulsions can be adjusted. Altering each dimensionless number will change detachment location, outer droplet size and droplet formation period. Moreover, the decussate regime of the double-emulsion/empty-droplet is observed in low Wein. This phenomenon can be obtained by adjusting the Wein in which the maximum size of the sheath is discovered. Also, the results show that Cain has significant influence on the outer droplet size in the two-step process, while Caout affects the sheath in the one-step formation considerably.

  1. Developments in high-density Cobra fiber positioners for the Subaru Telescope's Prime Focus Spectrometer

    NASA Astrophysics Data System (ADS)

    Fisher, Charles D.; Braun, David F.; Kaluzny, Joel V.; Seiffert, Michael D.; Dekany, Richard G.; Ellis, Richard S.; Smith, Roger M.

    2012-09-01

    The Prime Focus Spectrograph (PFS) is a fiber fed multi-object spectrometer for the Subaru Telescope that will conduct a variety of targeted surveys for studies of dark energy, galaxy evolution, and galactic archaeology. The key to the instrument is a high density array of fiber positioners placed at the prime focus of the Subaru Telescope. The system, nicknamed “Cobra”, will be capable of rapidly reconfiguring the array of 2394 optical fibers to the image positions of astronomical targets in the focal plane with high accuracy. The system uses 2394 individual “SCARA robot” mechanisms that are 7.7mm in diameter and use 2 piezo-electric rotary motors to individually position each of the optical fibers within its patrol region. Testing demonstrates that the Cobra positioner can be moved to within 5μm of an astronomical target in 6 move iterations with a success rate of 95%. The Cobra system is a key aspect of PFS that will enable its unprecedented combination of high-multiplex factor and observing efficiency on the Subaru telescope. The requirements, design, and prototyping efforts for the fiber positioner system for the PFS are described here as are the plans for modular construction, assembly, integration, functional testing, and performance validation.

  2. Developing engineering model Cobra fiber positioners for the Subaru Telescope's prime focus spectrometer

    NASA Astrophysics Data System (ADS)

    Fisher, Charles; Morantz, Chaz; Braun, David; Seiffert, Michael; Aghazarian, Hrand; Partos, Eamon; King, Matthew; Hovland, Larry E.; Schwochert, Mark; Kaluzny, Joel; Capocasale, Christopher; Houck, Andrew; Gross, Johannes; Reiley, Daniel; Mao, Peter; Riddle, Reed; Bui, Khanh; Henderson, David; Haran, Todd; Culhane, Robert; Piazza, Daniele; Walkama, Eric

    2014-07-01

    The Cobra fiber positioner is being developed by the California Institute of Technology (CIT) and the Jet Propulsion Laboratory (JPL) for the Prime Focus Spectrograph (PFS) instrument that will be installed at the Subaru Telescope on Mauna Kea, Hawaii. PFS is a fiber fed multi-object spectrometer that uses an array of Cobra fiber positioners to rapidly reconfigure 2394 optical fibers at the prime focus of the Subaru Telescope that are capable of positioning a fiber to within 5μm of a specified target location. A single Cobra fiber positioner measures 7.7mm in diameter and is 115mm tall. The Cobra fiber positioner uses two piezo-electric rotary motors to move a fiber optic anywhere in a 9.5mm diameter patrol area. In preparation for full-scale production of 2550 Cobra positioners an Engineering Model (EM) version was developed, built and tested to validate the design, reduce manufacturing costs, and improve system reliability. The EM leveraged the previously developed prototype versions of the Cobra fiber positioner. The requirements, design, assembly techniques, development testing, design qualification and performance evaluation of EM Cobra fiber positioners are described here. Also discussed is the use of the EM build and test campaign to validate the plans for full-scale production of 2550 Cobra fiber positioners scheduled to begin in late-2014.

  3. Development in High-Density Cobra Fiber Positioners for the Subaru Telescope's Prime Focus Spectrometer

    NASA Technical Reports Server (NTRS)

    Fisher, Charles D.; Braun, David F.; Kaluzny, Joel V.; Seiffert, Mic D.; Dekany, Richard G.; Ellis, Richard S.; Smith, Roger S.

    2012-01-01

    The Prime Focus Spectrograph (PFS) is a fiber fed multi-object spectrometer for the Subaru Telescope that will conduct a variety of targeted surveys for studies of dark energy, galaxy evolution, and galactic archaeology. The key to the instrument is a high density array of fiber positioners placed at the prime focus of the Subaru Telescope. The system, nicknamed "Cobra", will be capable of rapidly reconfiguring the array of 2394 optical fibers to the image positions of astronomical targets in the focal plane with high accuracy. The system uses 2394 individual "SCARA robot" mechanisms that are 7.7mm in diameter and use 2 piezo-electric rotary motors to individually position each of the optical fibers within its patrol region. Testing demonstrates that the Cobra positioner can be moved to within 5 micrometers of an astronomical target in 6 move iterations with a success rate of 95%. The Cobra system is a key aspect of PFS that will enable its unprecedented combination of high-multiplex factor and observing efficiency on the Subaru telescope. The requirements, design, and prototyping efforts for the fiber positioner system for the PFS are described here as are the plans for modular construction, assembly, integration, functional testing, and performance validation.

  4. Periodic magnetic field as a polarized and focusing thermal neutron spectrometer and monochromator

    SciTech Connect

    Cremer, J. T.; Williams, D. L.; Fuller, M. J.; Gary, C. K.; Piestrup, M. A.; Pantell, R. H.; Feinstein, J.; Flocchini, R. G.; Boussoufi, M.; Egbert, H. P.; Kloh, M. D.; Walker, R. B.

    2010-01-15

    A novel periodic magnetic field (PMF) optic is shown to act as a prism, lens, and polarizer for neutrons and particles with a magnetic dipole moment. The PMF has a two-dimensional field in the axial direction of neutron propagation. The PMF alternating magnetic field polarity provides strong gradients that cause separation of neutrons by wavelength axially and by spin state transversely. The spin-up neutrons exit the PMF with their magnetic spins aligned parallel to the PMF magnetic field, and are deflected upward and line focus at a fixed vertical height, proportional to the PMF period, at a downstream focal distance that increases with neutron energy. The PMF has no attenuation by absorption or scatter, as with material prisms or crystal monochromators. Embodiments of the PMF include neutron spectrometer or monochromator, and applications include neutron small angle scattering, crystallography, residual stress analysis, cross section measurements, and reflectometry. Presented are theory, experimental results, computer simulation, applications of the PMF, and comparison of its performance to Stern-Gerlach gradient devices and compound material and magnetic refractive prisms.

  5. Evaluation of Engineering Double-Degree Programs in Sweden: Results of the Lund Focus Groups

    ERIC Educational Resources Information Center

    Culver, Steven M.; Warfvinge, Per; Grossmann, Christina; Puri, Ishwar K.

    2011-01-01

    This study describes the results of focus groups at Lund University, Sweden, intended to gather the perceptions of stakeholder groups associated with double-degree programs at the graduate level in engineering: students currently enrolled in double-degree programs, faculty teaching in those programs, and alumni who have recently graduated from…

  6. On the Alignment and Focusing of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)

    NASA Technical Reports Server (NTRS)

    Champey, Patrick; Winebarger, Amy; Kobayashi, Ken; Savage, Sabrina; Cirtain, Jonathan; Cheimets, Peter; Hertz, Edward; Golub, Leon; Ramsey, Brian; McCracken, Jeff

    2016-01-01

    The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument that is designed to observe soft X-ray emissions from 24 - 6.0 A (0.5 - 2.0 keV energies) in the solar atmosphere. For the rst time, high-temperature, low-emission plasma will be observed directly with 5 arcsecond spatial resolution and 22 mA spectral resolution. The unique optical design consists of a Wolter - I telescope and a 3-optic grazing- incidence spectrometer. The spectrometer utilizes a nite conjugate mirror pair and a blazed planar, varied line spaced grating, which is directly printed on a silicon substrate using e-beam lithography. The grating design is being nalized and the grating will be fabricated by the Massachusetts Institute of Technology (MIT) and Izentis LLC. Marshall Space Flight Center (MSFC) is producing the nickel replicated telescope and spectrometer mirrors using the same facilities and techniques as those developed for the ART-XC and FOXSI mirrors. The Smithsonian Astrophysical Observatory (SAO) will mount and align the optical sub-assemblies based on previous experience with similar instruments, such as the Hinode X-Ray Telescope (XRT). The telescope and spectrometer assembly will be aligned in visible light through the implementation of a theodolite and reference mirrors, in addition to the centroid detector assembly (CDA) { a device designed to align the AXAF-I nested mirrors. Focusing of the telescope and spectrometer will be achieved using the X-ray source in the Stray Light Facility (SLF) at MSFC. We present results from an alignment sensitivity analysis performed on the on the system and we also discuss the method for aligning and focusing MaGIXS.

  7. Design of a double Penning-trap mass spectrometer for high-precision mass measurements

    NASA Astrophysics Data System (ADS)

    Ratnayake, Ishara; Bryce, Richard; Hawks, Paul; Hunt, Curtis; Redshaw, Matthew

    2014-05-01

    The mass of an atom plays an important role in various fields throughout science. As such, there is a need for precise mass determinations on a wide range of isotopes. At Central Michigan University we are developing a Penning trap to focus on ultra-high precision measurements of long-lived radioactive isotopes and isotopes that have low natural abundances. The Penning trap we are constructing will consist of a double precision measurement trap structure for simultaneous cyclotron frequency comparisons to eliminate the effect of magnetic field fluctuations. An additional, cylindrical Penning trap will be used to capture ions from external ion sources, eliminate contaminant ions and transfer the ions of interest to the precision traps. In this poster we will present the design of the Penning trap system, and report on the current status of the project. This work supported in part by NSF award no. 1307233.

  8. Double Emulsion Generation Using a Polydimethylsiloxane (PDMS) Co-axial Flow Focus Device.

    PubMed

    Cole, Russell H; Tran, Tuan M; Abate, Adam R

    2015-01-01

    Double emulsions are useful in a number of biological and industrial applications in which it is important to have an aqueous carrier fluid. This paper presents a polydimethylsiloxane (PDMS) microfluidic device capable of generating water/oil/water double emulsions using a coaxial flow focusing geometry that can be fabricated entirely using soft lithography. Similar to emulsion devices using glass capillaries, double emulsions can be formed in channels with uniform wettability and with dimensions much smaller than the channel sizes. Three dimensional flow focusing geometry is achieved by casting a pair of PDMS slabs using two layer soft lithography, then mating the slabs together in a clamshell configuration. Complementary locking features molded into the PDMS slabs enable the accurate registration of features on each of the slab surfaces. Device testing demonstrates formation of double emulsions from 14 µm to 50 µm in diameter while using large channels that are robust against fouling and clogging. PMID:26780079

  9. Measurement of DT and DD components in neutron spectrum with a double-crystal time-of-flight spectrometer

    NASA Astrophysics Data System (ADS)

    Okada, K.; Kondo, K.; Ochiai, K.; Sato, S.; Nishitani, T.; Konno, C.; Okamoto, A.; Kitajima, S.; Sasao, M.

    2008-03-01

    To investigate the deuteron and triton density ratio in core plasmas, a new methodology with measurement of tritium (DT) and deuterium (DD) neutron count rate ratio using a double-crystal time-of-flight (TOF) spectrometer is proposed. Multi-discriminator electronic circuits for the first and second detectors are used in addition to the TOF technique. The optimum arrangement of the detectors and discrimination window were examined considering the relations between the geometrical arrangement and deposited energy using a Monte Carlo Code, PHITS (Particle and Heavy Ion Transport Code System). An experiment to verify the calculations was performed using DD neutrons from an accelerator.

  10. On the use of a toroidal mirror to focus neutrons at the ILL neutron spin echo spectrometer IN15

    SciTech Connect

    Hayes, C.; Alefeld, B.; Copley, J.R.D.

    1997-09-01

    The IN15 neutron spin echo spectrometer at the Institut Laue-Langevin (Grenoble) has been designed to accomodate a toroidal focusing mirror. This mirror will be used to increase the intensity at the sample position for measurements at long neutron wavelengths and to perform measurements in the low q-range (10{sup -3} {angstrom}{sup -1}). This paper summarizes the results of ray-tracing simulations for the toroidal mirror system. These calculations were performed in order to assess the effects of the neutron wavelength, gravitational fall, wavelength resolution and spherical aberrations on the quality of the focused beam. The gain in flux that can be expected from the focusing geometry is estimated. The recent installation and characterisation of the mirror is also briefly described.

  11. Double momentum spectrometer for ion-electron vector correlations in dissociative photoionization

    SciTech Connect

    Bomme, C.; Guillemin, R.; Marin, T.; Journel, L.; Marchenko, T.; Pilette, B.; Avila, A.; Ringuenet, H.; Kushawaha, R. K.; Simon, M.; Dowek, D.; Trcera, N.

    2013-10-15

    We have developed a new momentum spectrometer dedicated to momentum vector correlations in the context of deep core photoionization of atomic and molecular species in the gas phase. In this article, we describe the design and operation of the experimental setup. The capabilities of the apparatus are illustrated with a set of measurements done on the sulphur core 1s photoionization of gas-phase CS{sub 2}.

  12. Deformation of double emulsions under conditions of flow cytometry hydrodynamic focusing.

    PubMed

    Ma, Shaohua; Huck, Wilhelm T S; Balabani, Stavroula

    2015-11-21

    Water-in-oil-in-water (w/o/w) microfluidics double emulsions offer a new route to compartmentalise reagents into isolated aqueous microenvironments while maintaining an aqueous carrier fluid phase; this enables compatibility with commercial flow cytometry systems such as fluorescence-activated cell sorting (FACS). Double emulsion (inner core) deformation under hydrodynamic focusing conditions that mimic the environment double emulsions experience in flow cytometry applications is of particular importance for droplet stability and cell viability. This paper reports on an experimental study of the dynamic deformation of aqueous cores of w/o/w double emulsions under hydrodynamic focusing, with the sheath flow directed at 45° to the sample flow. A number of factors affecting the inner core deformation and recovery were examined. Deformation was found to depend significantly on the core or shell viscosity, the droplet-to-sheath flow velocity ratio, and core and shell sizes. Core deformation was found to depend more on the type of surfactant rather concentration with high molecular weight surfactant exhibiting a negligible effect on deformation whereas low molecular weight surfactant enhancing deformation at low concentrations due to their lateral mobility at the interface. PMID:26394745

  13. Double tungsten coil atomic absorption spectrometer based on an acousto-optic tunable filter

    NASA Astrophysics Data System (ADS)

    Jora, M. Z.; Nóbrega, J. A.; Rohwedder, J. J. R.; Pasquini, C.

    2015-01-01

    An atomic absorption spectrometer based on a quartz acousto-optic tunable filter (AOTF) monochromator operating in the 271-453 nm range, is described. The instrument was tailored to study the formation and evolution of electrothermal atomic cloud induced either by one or two tungsten coils. The spectrometer also includes a fast response programmable photomultiplier module for data acquisition, and a power supply capable of driving two parallel tungsten coils independently. The atomization cell herein described was manufactured in PTFE and presents a new design with reduced size. Synchronization between the instant of power delivering to start the atomization process and the detection was achieved, allowing for monitoring the atomization and thermal events synchronously and in real time. Absorption signals can be sampled at a rate of a few milliseconds, compatible with the fast phenomena that occur with electrothermal metallic atomizers. The instrument performance was preliminarily evaluated by monitoring the absorption of radiation of atomic clouds produced by standard solutions containing chromium or lead. Its quantitative performance was evaluated by using Cr aqueous solutions, resulting in detection limits as low as 0.24 μg L- 1, and a relative standard deviation of 3%.

  14. Tight focusing of a double-ring-shaped, azimuthally polarized beam through a dielectric interface.

    PubMed

    Shu, Jianhua; Chen, Ziyang; Pu, Jixiong; Liu, Yongxin

    2014-06-01

    We investigate the tight focusing properties of a double-ring-shaped, azimuthally polarized vector beam (DRS-APVB) by use of vectorial Debye theory. It is shown that a dark channel with an ultralong depth of focus (~106λ) and subwavelength focal holes (~0.5λ) can be generated by focusing a DRS-APVB through a dielectric interface with an annular high-numerical aperture (NA) objective lens. The influence of the NA of the objective, the relative refractive indices of two dielectric media, and the probe depth of the system on the focusing properties of the dark channel has been studied in detail. Such a non-diffracting dark channel could find potential applications in atom optical experiments, such as with atomic lenses, atom traps, and atom switches. PMID:24977354

  15. Acoustic radiation force on a double-layer microsphere by a Gaussian focused beam

    SciTech Connect

    Wu, Rongrong; Cheng, Kaixuan; Liu, Jiehui; Mao, Yiwei; Gong, Xiufen; Liu, Xiaozhou

    2014-10-14

    A new model for calculating the radiation force on double-layer microsphere is proposed based on the ray acoustics approach. The axial acoustic radiation force resulting from a focused Gaussian beam incident on spherical shells immersed in water is examined theoretically in relation to its thickness and the contents of its double-layer. The attenuation both in the water and inside the sphere is considered in this method, which cannot be ignored while the high frequency ultrasonic is used. Results of numerical calculations are presented for fat and low density polyethylene materials, with the hollow region filled with animal oil, water, or air. These results show how the acoustic impedance and the sound velocity of both layers, together with the thickness of the shell, affect the acoustic radiation force.

  16. Acoustic radiation force on a double-layer microsphere by a Gaussian focused beam

    NASA Astrophysics Data System (ADS)

    Wu, Rongrong; Cheng, Kaixuan; Liu, Xiaozhou; Liu, Jiehui; Mao, Yiwei; Gong, Xiufen

    2014-10-01

    A new model for calculating the radiation force on double-layer microsphere is proposed based on the ray acoustics approach. The axial acoustic radiation force resulting from a focused Gaussian beam incident on spherical shells immersed in water is examined theoretically in relation to its thickness and the contents of its double-layer. The attenuation both in the water and inside the sphere is considered in this method, which cannot be ignored while the high frequency ultrasonic is used. Results of numerical calculations are presented for fat and low density polyethylene materials, with the hollow region filled with animal oil, water, or air. These results show how the acoustic impedance and the sound velocity of both layers, together with the thickness of the shell, affect the acoustic radiation force.

  17. A range-based method to calibrate a magnetic spectrometer measuring the energy spectrum of the backward electron beam of a plasma focus

    SciTech Connect

    Ceccolini, E.; Mostacci, D.; Sumini, M.; Rocchi, F.; Tartari, A.

    2011-08-15

    The electron beam emitted from the back of plasma focus devices is being studied as a radiation source for intraoperative radiation therapy applications. A plasma focus device is being developed for this purpose, and there is a need for characterizing its electron beam, particularly, insofar as the energy spectrum is concerned. The instrument used is a magnetic spectrometer. To calibrate this spectrometer, a procedure relying on the energy-range relation in Mylar has been devised and applied. By measuring the transmission through increasing thicknesses of the material, electron energies could be assessed and compared to the spectrometer readings. Thus, the original calibration of the instrument has been extended to higher energies and also to better accuracy. Methods and results are presented.

  18. A range-based method to calibrate a magnetic spectrometer measuring the energy spectrum of the backward electron beam of a plasma focus

    NASA Astrophysics Data System (ADS)

    Ceccolini, E.; Rocchi, F.; Mostacci, D.; Sumini, M.; Tartari, A.

    2011-08-01

    The electron beam emitted from the back of plasma focus devices is being studied as a radiation source for intraoperative radiation therapy applications. A plasma focus device is being developed for this purpose, and there is a need for characterizing its electron beam, particularly, insofar as the energy spectrum is concerned. The instrument used is a magnetic spectrometer. To calibrate this spectrometer, a procedure relying on the energy-range relation in Mylar® has been devised and applied. By measuring the transmission through increasing thicknesses of the material, electron energies could be assessed and compared to the spectrometer readings. Thus, the original calibration of the instrument has been extended to higher energies and also to better accuracy. Methods and results are presented.

  19. Correction and analysis of noise in Hadamard transform spectrometer with digital micro-mirror device and double sub-gratings

    NASA Astrophysics Data System (ADS)

    Quan, Xiangqian; Liu, Hua; Lu, Zhenwu; Chen, Xiangzi; Wang, Xiaoduo; Xu, Jialin; Gao, Qun

    2016-01-01

    In order to correct spectra anomaly in Hadamard transform (HT) spectrometer with digital micro-mirror device (DMD) and double sub-gratings (DSG) which was proposed by our research team, the analysis of noise is carried out from two aspects, one noise is the intensity noise caused by the instability of light source, detector, substance concentration, electrical system, etc. The other noise is the spectral response noise caused by the diffraction efficiency of DMD and DSG. Consequently, the effects of these noises on Hadamard transform encoding matrix equation are determined and the decoding matrix equations are derived. As a result, the method of inserting testing masks is proposed to correct the intensity noise and the method of correcting spectra by spectral response function is presented to correct the spectral response noise. The simulation results show that the Pearson correlation coefficient (PCC) between detected spectra and original spectra is enhanced gradually from 0.9108 to 0.9997 and the experimental results also demonstrate those two methods are valid, concise and significant.

  20. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    NASA Astrophysics Data System (ADS)

    Kayser, Y.; Błachucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-04-01

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO2 optical fibers.

  1. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube.

    PubMed

    Kayser, Y; Błachucki, W; Dousse, J-Cl; Hoszowska, J; Neff, M; Romano, V

    2014-04-01

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO2 optical fibers. PMID:24784587

  2. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    SciTech Connect

    Kayser, Y.; Błachucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-04-15

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO{sub 2} optical fibers.

  3. Compact focusing spectrometer: Visible (1 eV) to hard x-rays (200 keV)

    NASA Astrophysics Data System (ADS)

    Baronova, E. O.; Stepanenko, A. M.; Pereira, N. R.

    2014-11-01

    A low-cost spectrometer that covers a wide range of photon energies can be useful to teach spectroscopy, and for simple, rapid measurements of the photon spectrum produced by small plasma devices. The spectrometer here achieves its wide range, nominally from 1 eV to 200 keV, with a series of spherically and cylindrically bent gratings or crystals that all have the same shape and the same radius of curvature; they are complemented by matching apertures and diagnostics on the Rowland circle that serves as the circular part of the spectrometer's vacuum vessel. Spectral lines are easily identified with software that finds their positions from the dispersion of each diffractive element and the known energies of the lines.

  4. Evaluation of Small Mass Spectrometer Systems

    NASA Technical Reports Server (NTRS)

    Arkin, C. Richard; Griffin, Timothy P.; Ottens, Andrew K.; Diaz, Jorge A.; Follistein, Duke W.; Adams, Fredrick W.; Helms, William R.; Voska, N. (Technical Monitor)

    2002-01-01

    Various mass analyzer systems were evaluated. Several systems show promise, including the Stanford Research Systems RGA-100, Inficon XPR-2, the University of Florida's Ion Trap, and the Compact Double Focus Mass Spectrometer. Areas that need improvement are the response time, recovery time, system volume, and system weight. Future work will investigate techniques to improve systems and will evaluate engineering challenges.

  5. Performance of a focused cavity aerosol spectrometer for measurements in the stratosphere of particle size in the 0.06-2.0-micrometer-diameter range

    NASA Technical Reports Server (NTRS)

    Jonsson, H. H.; Wilson, J. C.; Brock, C. A.; Knollenberg, R. G.; Newton, R.; Dye, J. E.; Baumgardner, D.; Borrmann, S.; Ferry, G. V.; Pueschel, R.

    1995-01-01

    A focused cavity aerosol spectrometer aboard a NASA ER-2 high-altitude aircraft provided high-resolution measurements of the size of the stratospheric particles in the 0.06-2.0-micrometer-diameter range in flights following the eruption of Mount Pinatubo in 1991. Effects of anisokinetic sampling and evaporation in the sampling system were accounted for by means adapted and specifically developed for this instrument. Calibrations with monodisperse aerosol particles provided the instrument's response matrix, which upon inversion during data reduction yielded the particle size distributions. The resultant dataset is internally consistent and generally shows agreement to within a factor of 2 with comparable measurements simultaneously obtained by a condensation nuclei counter, a forward-scattering spectrometer probe, and aerosol particle impactors, as well as with nearby extinction profiles obtained by satellite measurements and with lidar measurements of backscatter.

  6. Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST

    SciTech Connect

    Peng, X. Y.; Chen, Z. J.; Zhang, X.; Hu, Z. M.; Du, T. F.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S.; Gorini, G.; Nocente, M.; Tardocchi, M.; Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N.

    2014-11-15

    The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/E{sub p}) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed.

  7. Light output function and assembly of the time-of-flight enhanced diagnostics neutron spectrometer plastic scintillators for background reduction by double kinematic selection at EAST.

    PubMed

    Peng, X Y; Chen, Z J; Zhang, X; Hu, Z M; Du, T F; Cui, Z Q; Xie, X F; Ge, L J; Yuan, X; Gorini, G; Nocente, M; Tardocchi, M; Hu, L Q; Zhong, G Q; Lin, S Y; Wan, B N; Li, X Q; Zhang, G H; Chen, J X; Fan, T S

    2014-11-01

    The 2.5 MeV neutron spectrometer TOFED (Time-Of-Flight Enhanced Diagnostics) has been constructed to perform advanced neutron emission spectroscopy diagnosis of deuterium plasmas on EAST. The instrument has a double-ring structure which, in combination with pulse shape digitization, allows for a dual kinematic selection in the time-of-flight/recoil proton energy (tof/Ep) space, thus improving the spectrometer capability to resolve fast ion signatures in the neutron spectrum, in principle up to a factor ≈100. The identification and separation of features from the energetic ions in the neutron spectrum depends on the detailed knowledge of the instrument response function, both in terms of the light output function of the scintillators and the effect of undesired multiple neutron scatterings in the instrument. This work presents the determination of the light output function of the TOFED plastic scintillator detectors and their geometrical assembly. Results from dedicated experiments with γ-ray sources and quasi-monoenergetic neutron beams are presented. Implications on the instrument capability to perform background suppression based on double kinematic selection are discussed. PMID:25430291

  8. The GRAVITY spectrometers: optical qualification

    NASA Astrophysics Data System (ADS)

    Yazici, Senol; Straubmeier, Christian; Wiest, Michael; Wank, Imke; Fischer, Sebastian; Horrobin, Matthew; Eisenhauer, Frank; Perrin, Guy; Perraut, Karine; Brandner, Wolfgang; Amorim, Antonio; Schöller, Markus; Eckart, Andreas

    2014-07-01

    GRAVITY1 is a 2nd generation Very Large Telescope Interferometer (VLTI) operated in the astronomical K-band. In the Beam Combiner Instrument2 (BCI) four Fiber Couplers3 (FC) will feed the light coming from each telescope into two fibers, a reference channel for the fringe tracking spectrometer4 (FT) and a science channel for the science spectrometer4 (SC). The differential Optical Path Difference (dOPD) between the two channels will be corrected using a novel metrology concept.5 The metrology laser will keep control of the dOPD of the two channels. It is injected into the spectrometers and detected at the telescope level. Piezo-actuated fiber stretchers correct the dOPD accordingly. Fiber-fed Integrated Optics6 (IO) combine coherently the light of all six baselines and feed both spectrometers. Assisted by Infrared Wavefront Sensors7 (IWS) at each Unit Telescope (UT) and correcting the path difference between the channels with an accuracy of up to 5 nm, GRAVITY will push the limits of astrometrical accuracy to the order of 10 μas and provide phase-referenced interferometric imaging with a resolution of 4 mas. The University of Cologne developed, constructed and tested both spectrometers of the camera system. Both units are designed for the near infrared (1.95 - 2.45 μm) and are operated in a cryogenic environment. The Fringe Tracker is optimized for highest transmission with fixed spectral resolution (R = 22) realized by a double-prism.8 The Science spectrometer is more diverse and allows to choose from three different spectral resolutions8 (R = [22, 500, 4000]), where the lowest resolution is achieved with a prism and the higher resolutions are realized with grisms. A Wollaston prism in each spectrometer allows for polarimetric splitting of the light. The goal for the spectrometers is to concentrate at least 90% of the ux in 2 × 2 pixel (36 × 36 μm2) for the Science channel and in 1 pixel (24 × 24 μm) in the Fringe Tracking channel. In Section 1, we present

  9. Optimizing a neutron-beam focusing device for the direct geometry time-of-flight spectrometer TOFTOF at the FRM II reactor source

    NASA Astrophysics Data System (ADS)

    Rasmussen, N. G.; Simeoni, G. G.; Lefmann, K.

    2016-04-01

    A dedicated beam-focusing device has been designed for the direct geometry thermal-cold neutron time-of-flight spectrometer TOFTOF at the neutron facility FRM II (Garching, Germany). The prototype, based on the compressed Archimedes' mirror concept, benefits from the adaptive-optics technology (adjustable supermirror curvature) and the compact size (only 0.5 m long). We have simulated the neutron transport across the entire guide system. We present a detailed computer characterization of the existing device, along with the study of the factors mostly influencing the future improvement. We have optimized the simulated prototype as a function of the neutron wavelength, accounting also for all relevant features of a real instrument like the non-reflecting side edges. The results confirm the "chromatic" displacement of the focal point (flux density maximum) at fixed supermirror curvature, and the ability of a variable curvature to keep the focal point at the sample position. Our simulations are in excellent agreement with theoretical predictions and the experimentally measured beam profile. With respect to the possibility of a further upgrade, we find that supermirror coatings with m-values higher than 3.5 would have only marginal influence on the optimal behaviour, whereas comparable spectrometers could take advantage of longer focusing segments, with particular impact for the thermal region of the neutron spectrum.

  10. Guiding and focusing of fast electron beams produced by ultra-intense laser pulse using a double cone funnel target

    SciTech Connect

    Zhang, Wen-shuai; Cai, Hong-bo; Zhu, Shao-ping

    2015-10-15

    A novel double cone funnel target design aiming at efficiently guiding and focusing fast electron beams produced in high intensity (>10{sup 19 }W/cm{sup 2}) laser-solid interactions is investigated via two-dimensional particle-in-cell simulations. The forward-going fast electron beams are shown to be directed and focused to a smaller size in comparison with the incident laser spot size. This plasma funnel attached on the cone target guides and focuses electrons in a manner akin to the control of liquid by a plastic funnel. Such device has the potential to add substantial design flexibility and prevent inefficiencies for important applications such as fast ignition. Two reasons account for the collimation of fast electron beams. First, the sheath electric fields and quasistatic magnetic fields inside the vacuum gap of the double cone provide confinement of the fast electrons in the laser-plasma interaction region. Second, the interface magnetic fields inside the beam collimator further guide and focus the fast electrons during the transport. The application of this technique to cone-guided fast ignition is considered, and it is shown that it can enhance the laser energy deposition in the compressed fuel plasma by a factor of 2 in comparison with the single cone target case.

  11. Guiding and focusing of fast electron beams produced by ultra-intense laser pulse using a double cone funnel target

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-shuai; Cai, Hong-bo; Zhu, Shao-ping

    2015-10-01

    A novel double cone funnel target design aiming at efficiently guiding and focusing fast electron beams produced in high intensity (>1019 W/cm2) laser-solid interactions is investigated via two-dimensional particle-in-cell simulations. The forward-going fast electron beams are shown to be directed and focused to a smaller size in comparison with the incident laser spot size. This plasma funnel attached on the cone target guides and focuses electrons in a manner akin to the control of liquid by a plastic funnel. Such device has the potential to add substantial design flexibility and prevent inefficiencies for important applications such as fast ignition. Two reasons account for the collimation of fast electron beams. First, the sheath electric fields and quasistatic magnetic fields inside the vacuum gap of the double cone provide confinement of the fast electrons in the laser-plasma interaction region. Second, the interface magnetic fields inside the beam collimator further guide and focus the fast electrons during the transport. The application of this technique to cone-guided fast ignition is considered, and it is shown that it can enhance the laser energy deposition in the compressed fuel plasma by a factor of 2 in comparison with the single cone target case.

  12. A new double FFT-based filter to reduce the effect of 1/f noise spectrum in a tunable diode laser spectrometer (TDLS)

    NASA Astrophysics Data System (ADS)

    Mahdi, Samira; Chen, Youhua; Anderson, Gary

    2013-05-01

    A Tunable diode laser spectrometer (TDLS) system has been designed to scan the near-surface atmosphere for ammonia gas over a wide range of distances (10 m to 1 Km). Since the system is designed for space applications, it needs to be small, lightweight, and low power, which dictates the use of relatively low frequency measurement scans. The spectrometer uses a diode laser, which is subject to a large 1/f noise component at these low frequencies. In this work, digital signal processing techniques are used to maximize the measurement sensitivity of a low frequency TDLS system depending on Double Fast Fourier Transform (DFFT-BF) based- filter. Simulations of the 1/f noise spectrum and ammonia gas absorption peak were performed using a sinusoidal waveform to drive the diode laser. A DFFT-BF-BF method is proposed that reduces the average of the error in the gas readings to nearly 50 percent. Because, this method decreases the effect of 1/f noise while keeping the measurement signal relatively constant.

  13. Efficient proton acceleration and focusing by an ultraintense laser interacting with a parabolic double concave target with an extended rear

    SciTech Connect

    Bake, Muhammad Ali; Xie, Bai-Song; Aimidula, Aimierding; Wang, Hong-Yu

    2013-07-15

    A new scheme for acceleration and focusing of protons via an improved parabolic double concave target irradiated by an ultraintense laser pulse is proposed. When an intense laser pulse illuminates a concave target, the hot electrons are concentrated on the focal region of the rear cavity and they form a strong space-charge-separation field, which accelerates the protons. For a simple concave target, the proton energy spectrum becomes very broad outside the rear cavity because of transverse divergence of the electromagnetic fields. However, particle-in-cell simulations show that, when the concave target has an extended rear, the hot electrons along the wall surface induce a transverse focusing sheath field, resulting in a clear enhancement of proton focusing, which makes the lower proton energy spread, while, leads to a little reduction of the proton bunch peak energy.

  14. Efficient proton acceleration and focusing by an ultraintense laser interacting with a parabolic double concave target with an extended rear

    NASA Astrophysics Data System (ADS)

    Bake, Muhammad Ali; Xie, Bai-Song; Aimidula, Aimierding; Wang, Hong-Yu

    2013-07-01

    A new scheme for acceleration and focusing of protons via an improved parabolic double concave target irradiated by an ultraintense laser pulse is proposed. When an intense laser pulse illuminates a concave target, the hot electrons are concentrated on the focal region of the rear cavity and they form a strong space-charge-separation field, which accelerates the protons. For a simple concave target, the proton energy spectrum becomes very broad outside the rear cavity because of transverse divergence of the electromagnetic fields. However, particle-in-cell simulations show that, when the concave target has an extended rear, the hot electrons along the wall surface induce a transverse focusing sheath field, resulting in a clear enhancement of proton focusing, which makes the lower proton energy spread, while, leads to a little reduction of the proton bunch peak energy.

  15. Advancement of atmospheric-vacuum interfaces for mass spectrometers with a focus on increasing gas throughput for improving sensitivity.

    PubMed

    Prasad, Satendra; Wouters, Eloy R; Dunyach, Jean-Jacques

    2015-08-18

    Ion sampling from an electrospray ionization (ESI) source was improved by increasing gas conductance of the MS inlet by 4.3-fold. Converting the gas throughput (Q) into sensitivity improvement was dependent on ion desolvation and handling of the gas load. Desolvation was addressed by using a novel slot shaped inlet that exhibited desolvation properties identical to the 0.58 mm i.d capillary. An assay tailored for "small molecules" at high chromatographic flow rate (500 μL/min) yielded a compound dependent 6.5 to 14-fold signal gain while analysis at nano chromatographic flow rate (300 nL/min) showed 2 to 3.5-fold improvement for doubly charged peptides. Improvement exceeding the Q (4.3-fold) at high chromatographic flow rate was explained by superior sampling of the spatially dispersed ion spray when using the slot shaped capillary. Sensitivity improvement across a wide range of chromatographic flow rate confirmed no compromise in ion desolvation with the increase in Q. Another improvement included less overflow of gas into the mass analyzer from the foreline region owing to the slot shape of the capillary. By doubling the roughing pump capacity and operating the electrodynamic ion funnel (EDIF) at ∼4 Torr, a single pumping stage was sufficient to handle the gas load. The transport of solvent clusters from the LC effluent into the mass analyzer was prevented by a "wavy shaped" transfer quadrupole and was compared with a benchmark approach that delivered ions orthogonally into a differentially pumped dual EDIF at comparable gas Q. PMID:26192074

  16. Intuitive analysis of space-time focusing with double-ABCD calculation

    PubMed Central

    Durfee, Charles G.; Greco, Michael; Block, Erica; Vitek, Dawn; Squier, Jeff A.

    2012-01-01

    We analyze the structure of space-time focusing of spatially-chirped pulses using a technique where each frequency component of the beam follows its own Gaussian beamlet that in turn travels as a ray through the system. The approach leads to analytic expressions for the axially-varying pulse duration, pulse-front tilt, and the longitudinal intensity profile. We find that an important contribution to the intensity localization obtained with spatial-chirp focusing arises from the evolution of the geometric phase of the beamlets. PMID:22714487

  17. Intuitive analysis of space-time focusing with double-ABCD calculation.

    PubMed

    Durfee, Charles G; Greco, Michael; Block, Erica; Vitek, Dawn; Squier, Jeff A

    2012-06-18

    We analyze the structure of space-time focusing of spatially-chirped pulses using a technique where each frequency component of the beam follows its own Gaussian beamlet that in turn travels as a ray through the system. The approach leads to analytic expressions for the axially-varying pulse duration, pulse-front tilt, and the longitudinal intensity profile. We find that an important contribution to the intensity localization obtained with spatial-chirp focusing arises from the evolution of the geometric phase of the beamlets. PMID:22714487

  18. Detection of Nitro-Based and Peroxide-Based Explosives by Fast Polarity-Switchable Ion Mobility Spectrometer with Ion Focusing in Vicinity of Faraday Detector

    PubMed Central

    Zhou, Qinghua; Peng, Liying; Jiang, Dandan; Wang, Xin; Wang, Haiyan; Li, Haiyang

    2015-01-01

    Ion mobility spectrometer (IMS) has been widely deployed for on-site detection of explosives. The common nitro-based explosives are usually detected by negative IMS while the emerging peroxide-based explosives are better detected by positive IMS. In this study, a fast polarity-switchable IMS was constructed to detect these two explosive species in a single measurement. As the large traditional Faraday detector would cause a trailing reactant ion peak (RIP), a Faraday detector with ion focusing in vicinity was developed by reducing the detector radius to 3.3 mm and increasing the voltage difference between aperture grid and its front guard ring to 591 V, which could remove trailing peaks from RIP without loss of signal intensity. This fast polarity-switchable IMS with ion focusing in vicinity of Faraday detector was employed to detect a mixture of 10 ng 2,4,6-trinitrotoluene (TNT) and 50 ng hexamethylene triperoxide diamine (HMTD) by polarity-switching, and the result suggested that [TNT-H]− and [HMTD+H]+ could be detected in a single measurement. Furthermore, the removal of trailing peaks from RIP by the Faraday detector with ion focusing in vicinity also promised the accurate identification of KClO4, KNO3 and S in common inorganic explosives, whose product ion peaks were fairly adjacent to RIP. PMID:26021282

  19. Testing the performance of a VUV photoionization source on a double focussing mass spectrometer using alkanes and thiophenes

    NASA Astrophysics Data System (ADS)

    Bobeldijk, M.; Kistemaker, P. G.; Boon, J. J.

    1991-12-01

    The performance of a newly developed photoionization source in combination with a high resolution mass spectrometer is tested. The total ion currents for several linear alkanes (n-pentane to n-decane) and for some thiophenes (2-methylthiophene, 2,5-dimethylthiophene and 2-ethylthiophene) are measured at three fixed wavelengths: the Kr I (10.03 eV and 10.64 eV), Ar I (11.62 eV and 11.83 eV) and Ne I (16.67 eV and 16.85 eV) resonance lines. These total ion currents are compared with the data for the alkanes and thiophenes obtained with low energy (10.6 eV, 11.8 eV and 16.7eV) electron impact ionization on the same mass spectrometer. The loss in ion intensity at several positions throughout this instrument is determined for the photo-ionization source and for the electron impact ionization source. One out of every 1500 ions created in the photoionization source is measured by the detector. For the electron impact ionization source, one out of 180 ions is measured. The introduction of a five-element "Heddle" lens for the transfer of the ions from the photoion source to the mass analyser resulted in an approximately 1.5 fold loss in ion current. From the measured total ion intensities, the photoionization and electron impact ionization cross-sections at energies of 10.6 eV, 11.8 eV and 16.7 eV are calculated. The photoionization cross-section values of the linear alkanes are found to be in the range of 2.5 Mbarn to 355 Mbarn, and the electron impact ionization cross-section values are between 40 Mbarn and 735 Mbarn. The photoionization cross-section values of the thiophenes range from 4 Mbarn to 31 Mbarn, and the electron impact ionization cross-section values from 81 Mbarn to 760 Mbarn.

  20. A new double imaging velocity focusing coincidence experiment: i{sup 2}PEPICO

    SciTech Connect

    Bodi, Andras; Hemberger, Patrick; Gerber, Thomas; Sztaray, Balint

    2012-08-15

    The vacuum ultraviolet (VUV) beamline of the Swiss Light Source has been upgraded after two years of operation. A new, turntable-type monochromator was constructed at the Paul Scherrer Institut, which allows for fast yaw-alignment as well as quick grating change and exchange. In addition to the original imaging photoelectron photoion coincidence endstation (iPEPICO), a second, complementary double imaging setup (i{sup 2}PEPICO) has been built. Volatile samples can be introduced at room temperature or in a molecular beam, a pyrolysis source allows for radical production, and non-volatile solids can be evaporated in a heated cell. Monochromatic VUV radiation ionizes the sample and both photoelectrons and photoions are velocity map imaged onto two fast position sensitive detectors and detected in delayed coincidence. High intensity synchrotron radiation leads to ionization rates above 10{sup 5} s{sup -1}. New data acquisition and processing approaches are discussed for recording coincidence processes at high rates. The setup is capable of resolving pulsed molecular beam profiles and the synchrotron time structure temporally. The latter is shown by photoelectron autocorrelation, which displays both the 1.04 MHz ring clock frequency as well as resolving the micro-pulses with a separation of 2 ns. Kinetic energy release analysis on the dissociative photoionization of CF{sub 4} indicates a dissociation mechanism change in the Franck-Condon allowed energy range of the first ion state.

  1. High-pressure generation using double stage micro-paired diamond anvils shaped by focused ion beam

    SciTech Connect

    Sakai, Takeshi Ohfuji, Hiroaki; Yagi, Takehiko; Irifune, Tetsuo; Ohishi, Yasuo; Hirao, Naohisa; Suzuki, Yuya; Kuroda, Yasushi; Asakawa, Takayuki; Kanemura, Takashi

    2015-03-15

    Micron-sized diamond anvils with a 3 μm culet were successfully processed using a focused ion beam (FIB) system and the generation of high pressures was confirmed using the double stage diamond anvil cell technique. The difficulty of aligning two second-stage micro-anvils was solved via the paired micro-anvil method. Micro-manufacturing using a FIB system enables us to control anvil shape, process any materials, including nano-polycrystalline diamond and single crystal diamond, and assemble the sample exactly in a very small space between the second-stage anvils. This method is highly reproducible. High pressures over 300 GPa were achieved, and the pressure distribution around the micro-anvil culet was evaluated by using a well-focused synchrotron micro-X-ray beam.

  2. High-pressure generation using double stage micro-paired diamond anvils shaped by focused ion beam

    NASA Astrophysics Data System (ADS)

    Sakai, Takeshi; Yagi, Takehiko; Ohfuji, Hiroaki; Irifune, Tetsuo; Ohishi, Yasuo; Hirao, Naohisa; Suzuki, Yuya; Kuroda, Yasushi; Asakawa, Takayuki; Kanemura, Takashi

    2015-03-01

    Micron-sized diamond anvils with a 3 μm culet were successfully processed using a focused ion beam (FIB) system and the generation of high pressures was confirmed using the double stage diamond anvil cell technique. The difficulty of aligning two second-stage micro-anvils was solved via the paired micro-anvil method. Micro-manufacturing using a FIB system enables us to control anvil shape, process any materials, including nano-polycrystalline diamond and single crystal diamond, and assemble the sample exactly in a very small space between the second-stage anvils. This method is highly reproducible. High pressures over 300 GPa were achieved, and the pressure distribution around the micro-anvil culet was evaluated by using a well-focused synchrotron micro-X-ray beam.

  3. High Precision, Absolute Total Column Ozone Measurements from the Pandora Spectrometer System: Comparisons with Data from a Brewer Double Monochromator and Aura OMI

    NASA Technical Reports Server (NTRS)

    Tzortziou, Maria A.; Herman, Jay R.; Cede, Alexander; Abuhassan, Nader

    2012-01-01

    We present new, high precision, high temporal resolution measurements of total column ozone (TCO) amounts derived from ground-based direct-sun irradiance measurements using our recently deployed Pandora single-grating spectrometers. Pandora's small size and portability allow deployment at multiple sites within an urban air-shed and development of a ground-based monitoring network for studying small-scale atmospheric dynamics, spatial heterogeneities in trace gas distribution, local pollution conditions, photochemical processes and interdependencies of ozone and its major precursors. Results are shown for four mid- to high-latitude sites where different Pandora instruments were used. Comparisons with a well calibrated double-grating Brewer spectrometer over a period of more than a year in Greenbelt MD showed excellent agreement and a small bias of approximately 2 DU (or, 0.6%). This was constant with slant column ozone amount over the full range of observed solar zenith angles (15-80), indicating adequate Pandora stray light correction. A small (1-2%) seasonal difference was found, consistent with sensitivity studies showing that the Pandora spectral fitting TCO retrieval has a temperature dependence of 1% per 3K, with an underestimation in temperature (e.g., during summer) resulting in an underestimation of TCO. Pandora agreed well with Aura-OMI (Ozone Measuring Instrument) satellite data, with average residuals of <1% at the different sites when the OMI view was within 50 km from the Pandora location and OMI-measured cloud fraction was <0.2. The frequent and continuous measurements by Pandora revealed significant short-term (hourly) temporal changes in TCO, not possible to capture by sun-synchronous satellites, such as OMI, alone.

  4. Spherical grating spectrometers

    NASA Astrophysics Data System (ADS)

    O'Donoghue, Darragh; Clemens, J. Christopher

    2014-07-01

    We describe designs for spectrometers employing convex dispersers. The Offner spectrometer was the first such instrument; it has almost exclusively been employed on satellite platforms, and has had little impact on ground-based instruments. We have learned how to fabricate curved Volume Phase Holographic (VPH) gratings and, in contrast to the planar gratings of traditional spectrometers, describe how such devices can be used in optical/infrared spectrometers designed specifically for curved diffraction gratings. Volume Phase Holographic gratings are highly efficient compared to conventional surface relief gratings; they have become the disperser of choice in optical / NIR spectrometers. The advantage of spectrometers with curved VPH dispersers is the very small number of optical elements used (the simplest comprising a grating and a spherical mirror), as well as illumination of mirrors off axis, resulting in greater efficiency and reduction in size. We describe a "Half Offner" spectrometer, an even simpler version of the Offner spectrometer. We present an entirely novel design, the Spherical Transmission Grating Spectrometer (STGS), and discuss exemplary applications, including a design for a double-beam spectrometer without any requirement for a dichroic. This paradigm change in spectrometer design offers an alternative to all-refractive astronomical spectrometer designs, using expensive, fragile lens elements fabricated from CaF2 or even more exotic materials. The unobscured mirror layout avoids a major drawback of the previous generation of catadioptric spectrometer designs. We describe laboratory measurements of the efficiency and image quality of a curved VPH grating in a STGS design, demonstrating, simultaneously, efficiency comparable to planar VPH gratings along with good image quality. The stage is now set for construction of a prototype instrument with impressive performance.

  5. Energy- and time-resolved measurements of fast ions emitted from plasma-focus discharges by means of a Thomson spectrometer

    NASA Astrophysics Data System (ADS)

    Kwiatkowski, R.; Czaus, K.; Paduch, M.; Sadowski, M. J.; Skladnik-Sadowska, E.; Zaloga, D. R.; Zielinska, E.; Żebrowski, J.

    2015-09-01

    The paper presents results of time-resolved measurements of fast deuterons emitted from high-current discharges of the Plasma-Focus (PF) type. The measurements were performed in a modified PF-1000U facility which is operated at the IFPiLM in Warsaw, Poland. The device was equipped with a fast-acting gas valve placed inside the inner electrode and oriented along the z-axis. The valve could inject a small volume of a chosen gas in front of this electrode. The PF discharges were initiated at the initial deuterium pressure equal to 1.6 or 2 hPa, with or without the use of the gas-puffing. Such discharges emitted intense beams of accelerated primary ions and X-ray pulses as well as products of nuclear fusion reactions. The reported measurements of the fast ion beams were performed by means of a Thomson-type spectrometer located at a chosen distance at the z-axis and equipped with miniature scintillation detectors. These detectors were placed in different points upon the deuteron parabola which corresponded to determined energy values. The detectors configuration allowed us to determine instants of the ion emission (using a TOF technique) and to compare them with instants of the X-ray emission. The collected data provided important information about emission characteristics of the modified PF-1000U facility.

  6. Reproducibility of optical quality parameters measured at objective and subjective best focuses in a double-pass system

    PubMed Central

    Hu, Ai-Lian; Qiao, Li-Ya; Zhang, Ye; Cai, Xiao-Gu; Li, Lei; Wan, Xiu-Hua

    2015-01-01

    AIM To evaluate intra-session repeatability and reproducibility of optical quality parameters measured at objective and subjective best focuses in a double-pass system. METHODS Thirty Chinese healthy adults (19 to 40 years old) meeting our inclusion criterion were enrolled in the study. After a basic eye examination, two methods of optical quality measurement, based on subjective and objective best focuses were performed using the Optical Quality Analysis System (OQAS) with an artificial pupil diameter of 4.0 mm. RESULTS With each method, three consecutive measurements of the following parameters: the modulation transfer function cutoff frequency (MTFcutoff), the Strehl2D ratio, the OQAS values (OVs) at contrasts of 100%, 20%, 9% and the objective scatter index (OSI) were performed by an experienced examiner. The repeatability of each method was evaluated by the repeatability limit (RL) and the coefficient of repeatability (COR). Reproducibility of the two methods was evaluated by intra-class correlation coefficient (ICC) and the 95% limits of agreement (Bland and Altman analysis). Thirty subjects, seven females and twenty three males, of whom 15 right eyes and 15 left eyes were selected randomly for recruitment in the study. The RLs (percentage) for the six parameters measured at objective focus and subjective focus ranged from 8.44% to 15.13% and 10.85% to 16.26%, respectively. The CORs for the two measurement methods ranged from 8.27% to 14.83% and 10.63% to 15.93%, respectively. With regard to reproducibility, the ICCs for the six parameters of OQAS ranged from 0.024 to 0.276. The 95% limits of agreement obtained for the six parameters (in comparison of the two methods) ranged from -0.57 to 42.18 (MTFcutoff), -0.01 to 0.23 (Strehl2D ratio), -0.02 to 1.40 (OV100%), -0.10 to 1.75 (OV20%), -0.14 to 1.80 (OV9%) and -1.46 to 0.18 (OSI). CONCLUSION Measurements provided by OQAS with either method showed a good repeatability. However, the results obtained from the two

  7. Monolithic spectrometer

    DOEpatents

    Rajic, S.; Egert, C.M.; Kahl, W.K.; Snyder, W.B. Jr.; Evans, B.M. III; Marlar, T.A.; Cunningham, J.P.

    1998-05-19

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays. 6 figs.

  8. Monolithic spectrometer

    DOEpatents

    Rajic, Slobodan; Egert, Charles M.; Kahl, William K.; Snyder, Jr., William B.; Evans, III, Boyd M.; Marlar, Troy A.; Cunningham, Joseph P.

    1998-01-01

    A monolithic spectrometer is disclosed for use in spectroscopy. The spectrometer is a single body of translucent material with positioned surfaces for the transmission, reflection and spectral analysis of light rays.

  9. Nuclear structure analysis using the Orange Spectrometer

    SciTech Connect

    Regis, J.-M.; Pascovici, Gh.; Christen, S.; Meersschout, T.; Bernards, C.; Fransen, Ch.; Dewald, A.; Braun, N.; Heinze, S.; Thiel, S.; Jolie, J.; Materna, Th.

    2009-01-28

    Recently, an Orange spectrometer, a focusing iron-free magnetic spectrometer, has been installed at a beam line of the 10 MV Tandem accelerator of the IKP of the University of Cologne. The high efficiency of 15% of 4{pi} for the detection of conversion electrons and the energy resolution of 1% makes the Orange spectrometer a powerful instrument. From the conversion electron spectrum, transition multipolarities can be determined using the so called K to L ratio. In combination with an array of germanium and lanthanum bromide detectors, e{sup -}-{gamma}-coincidences can be performed to investigate the level scheme. Moreover, the very fast lanthanum bromide scintillator with an energy resolution of 3% allows e{sup -}-{gamma} lifetime measurements down to 0.3 ns. A second Orange spectrometer can be added to build the Double Orange Spectrometer for e{sup -}-e{sup -}-coincidences. It is indispensable for lifetime measurements of low intensity or nearby lying transitions as often occur in odd-A and odd-odd nuclei. The capabilities are illustrated with several examples.

  10. A double-focus collimator system for full PAT performance testing of inter-satellite laser communication terminals

    NASA Astrophysics Data System (ADS)

    Wang, Lijuan; Luan, Zhu; Sun, Jianfeng; Zhou, Yu; Liu, De'an; Liu, Liren

    2006-08-01

    A laser collimator is necessary for the testing and verification of the PAT performance of inter-satellite laser communication terminals. However, the terminals mostly have a large field of view for the acquisition and a high angular accuracy for the fine tracking needed to be examined. A single collimator has the conflict to reach at both a large field of view and a fine resolution. To compromise, a double-focus laser collimator is proposed. The collimator is mainly composed of a primary lens, a beam splitter, a secondary lens and some reflectors. The primary lens with a 9.9m focal length directly forms the long focal length arm of the collimator. The combination of the primary lens and the secondary lens has a new focal length of 1.3m and constructs the short focal length arm of the collimator. With two CMOS imaging sensors, the collimator can realize a 1.1mrad field of view with a <1μrad resolution in the focal plane of the long focal length arm and a 8.3mrad field of view with a 8.2μrad resolution in the focal plane of the short focal length arm. In combination with a coarse beam scanner (+/-15°) and a fine beam scanner (1mrad) to simulate the mutual angular movement between two satellites, the united system is capable to test the full PAT performance of inter-satellite laser communication terminals. The optical layouts of the collimator and two detecting units are illustrated. The optical design of the collimator is detailed. The mechanical design of the collimator is given.

  11. Automated mass spectrometer analysis system

    NASA Technical Reports Server (NTRS)

    Kuppermann, Aron (Inventor); Dreyer, William J. (Inventor); Giffin, Charles E. (Inventor); Boettger, Heinz G. (Inventor)

    1982-01-01

    An automated mass spectrometer analysis system is disclosed, in which samples are automatically processed in a sample processor and converted into volatilizable samples, or their characteristic volatilizable derivatives. Each volatilizable sample is sequentially volatilized and analyzed in a double focusing mass spectrometer, whose output is in the form of separate ion beams all of which are simultaneously focused in a focal plane. Each ion beam is indicative of a different sample component or different fragments of one or more sample components and the beam intensity is related to the relative abundance of the sample component. The system includes an electro-optical ion detector which automatically and simultaneously converts the ion beams, first into electron beams which in turn produce a related image which is transferred to the target of a vilicon unit. The latter converts the images into electrical signals which are supplied to a data processor, whose output is a list of the components of the analyzed sample and their abundances. The system is under the control of a master control unit, which in addition to monitoring and controlling various power sources, controls the automatic operation of the system under expected and some unexpected conditions and further protects various critical parts of the system from damage due to particularly abnormal conditions.

  12. Automated mass spectrometer analysis system

    NASA Technical Reports Server (NTRS)

    Boettger, Heinz G. (Inventor); Giffin, Charles E. (Inventor); Dreyer, William J. (Inventor); Kuppermann, Aron (Inventor)

    1978-01-01

    An automated mass spectrometer analysis system is disclosed, in which samples are automatically processed in a sample processor and converted into volatilizable samples, or their characteristic volatilizable derivatives. Each volatizable sample is sequentially volatilized and analyzed in a double focusing mass spectrometer, whose output is in the form of separate ion beams all of which are simultaneously focused in a focal plane. Each ion beam is indicative of a different sample component or different fragments of one or more sample components and the beam intensity is related to the relative abundance of the sample component. The system includes an electro-optical ion detector which automatically and simultaneously converts the ion beams, first into electron beams which in turn produce a related image which is transferred to the target of a vidicon unit. The latter converts the images into electrical signals which are supplied to a data processor, whose output is a list of the components of the analyzed sample and their abundances. The system is under the control of a master control unit, which in addition to monitoring and controlling various power sources, controls the automatic operation of the system under expected and some unexpected conditions and further protects various critical parts of the system from damage due to particularly abnormal conditions.

  13. Correlation spectrometer

    DOEpatents

    Sinclair, Michael B.; Pfeifer, Kent B.; Flemming, Jeb H.; Jones, Gary D.; Tigges, Chris P.

    2010-04-13

    A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.

  14. DETERMINING ION COMPOSITIONS USING AN ACCURATE MASS, TRIPLE QUADRUPOLE MASS SPECTROMETER

    EPA Science Inventory

    For the past decade, we have used double focusing mass spectrometers to determine
    compositions of ions observed in mass spectra produced from compounds introduced by GC
    based on measured exact masses of the ions and their +1 and +2 isotopic profiles arising from atoms of ...

  15. Multidimensional spectrometer

    SciTech Connect

    Zanni, Martin Thomas; Damrauer, Niels H.

    2010-07-20

    A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

  16. Determination of technetium-99, neptunium-237 and isotopes of thorium in uranyl nitrate solutions from a reprocessing plant, using double-focusing ICP-MS

    SciTech Connect

    Mitterrand, B.; Leprovost, P.; Delaunay, J.; Vian, A.M.

    1998-12-31

    The determination of some radionuclides in uranyl nitrate solutions from a reprocessing plant through chemical or radiochemical methods may be tedious, with poor precision. Quadrupole ICP-MS and, more recently, double-focusing ICP-MS, with high resolution capabilities, have proved to be very efficient tools for such determinations. These improvements will be illustrated by the examples of Technetium-99, Neptunium-237 and Thorium.

  17. SCINTILLATION SPECTROMETER

    DOEpatents

    Bell, P.R.; Francis, J.E.

    1960-06-21

    A portable scintillation spectrometer is described which is especially useful in radio-biological studies for determining the uptake and distribution of gamma -emitting substances in tissue. The spectrometer includes a collimator having a plurality of apertures that are hexagonal in cross section. Two crystals are provided: one is activated to respond to incident rays from the collimator; the other is not activated and shields the first from external radiation.

  18. [Design of Dual-Beam Spectrometer in Spectrophotometer for Colorimetry].

    PubMed

    Liu, Yi-xuan; Yan, Chang-xiang

    2015-07-01

    Spectrophotometers for colorimetry are usually composed of two independent and identical spectrometers. In order to reduce the volume of spectrophotometer for colorimetry, a design method of double-beam spectrometer is put forward. A traditional spectrometer is modified so that a new spectrometer can realize the function of double spectrometers, which is especially suitable for portable instruments. One slit is replaced by the double-slit, than two beams of spectrum can be detected. The working principle and design requirement of double-beam spectrometer are described. A spectrometer of portable spectrophotometer is designed by this method. A toroidal imaging mirror is used for the Czerny-Turner double-beam spectrometer in this paper, which can better correct astigmatism, and prevent the dual-beam spectral crosstalk. The results demonstrate that the double-beam spectrometer designed by this method meets the design specifications, with the spectral resolution less than 10 nm, the spectral length of 9.12 mm, and the volume of 57 mm x 54 mm x 23 mm, and without the dual-beam spectral overlap in the detector either. Comparing with a traditional spectrophotometer, the modified spectrophotometer uses a set of double-beam spectrometer instead of two sets of spectrometers, which can greatly reduce the volume. This design method can be specially applied in portable spectrophotometers, also can be widely applied in other double-beam spectrophotometers, which offers a new idea for the design of dual-beam spectrophotometers. PMID:26717779

  19. Multiple order common path spectrometer

    NASA Technical Reports Server (NTRS)

    Newbury, Amy B. (Inventor)

    2010-01-01

    The present invention relates to a dispersive spectrometer. The spectrometer allows detection of multiple orders of light on a single focal plane array by splitting the orders spatially using a dichroic assembly. A conventional dispersion mechanism such as a defraction grating disperses the light spectrally. As a result, multiple wavelength orders can be imaged on a single focal plane array of limited spectral extent, doubling (or more) the number of spectral channels as compared to a conventional spectrometer. In addition, this is achieved in a common path device.

  20. Determination of 90Sr / 238U ratio by double isotope dilution inductively coupled plasma mass spectrometer with multiple collection in spent nuclear fuel samples with in situ 90Sr / 90Zr separation in a collision-reaction cell

    NASA Astrophysics Data System (ADS)

    Isnard, H.; Aubert, M.; Blanchet, P.; Brennetot, R.; Chartier, F.; Geertsen, V.; Manuguerra, F.

    2006-02-01

    Strontium-90 is one of the most important fission products generated in nuclear industry. In the research field concerning nuclear waste disposal in deep geological environment, it is necessary to quantify accurately and precisely its concentration (or the 90Sr / 238U atomic ratio) in irradiated fuels. To obtain accurate analysis of radioactive 90Sr, mass spectrometry associated with isotope dilution is the most appropriated method. But, in nuclear fuel samples the interference with 90Zr must be previously eliminated. An inductively coupled plasma mass spectrometer with multiple collection, equipped with an hexapole collision cell, has been used to eliminate the 90Sr / 90Zr interference by addition of oxygen in the collision cell as a reactant gas. Zr + ions are converted into ZrO +, whereas Sr + ions are not reactive. A mixed solution, prepared from a solution of enriched 84Sr and a solution of enriched 235U was then used to quantify the 90Sr / 238U ratio in spent fuel sample solutions using the double isotope dilution method. This paper shows the results, the reproducibility and the uncertainties that can be obtained with this method to quantify the 90Sr / 238U atomic ratio in an UOX (uranium oxide) and a MOX (mixed oxide) spent fuel samples using the collision cell of an inductively coupled plasma mass spectrometer with multiple collection to perform the 90Sr / 90Zr separation. A comparison with the results obtained by inductively coupled plasma mass spectrometer with multiple collection after a chemical separation of strontium from zirconium using a Sr spec resin (Eichrom) has been performed. Finally, to validate the analytical procedure developed, measurements of the same samples have been performed by thermal ionization mass spectrometry, used as an independent technique, after chemical separation of Sr.

  1. Mass spectrometers with energy focusing: Combinations of magnetic and electric sector fields whose mean planes of deflection are tilted with respect to each other

    NASA Astrophysics Data System (ADS)

    Waldrich, H.; Ewald, H.

    1988-01-01

    First a combination of two sector fields is considered, for instance a homogeneous magnetic field followed by an electric cylinder condenser. The mean planes of deflection of the fields are tilted with respect to each other by an oblique angle. Such a combination has astigmatic focusing properties for paraxial rays of ions of certain mass and energy coming from an object point assumed at a certain distance before the first field on the incoming central ray. At different distances from the field combination are formed. calculated in first order, two real or virtual straight astigmatic focusing lines which are perpendicular to each other and to the outgoing central ray. By proper assumptions of the dimensions of the combination it can be arranged that its first order energy dispersion and one real of its astigmatic focusing lines have exactly the same direction. Then by addition of a third sector field (again a homogeneous magnetic field) it can be achieved that the astigmatic focusing will be changed into a stigmatic one while at the same time the energy dispersion can be reduced to small values. The mass dispersion of this three field combination in the given numerical example is about perpendicular to the direction of the energy dispersion.

  2. Understanding the Impact of Field-Emitter Characteristics on Electron Beam Focusing in the VAPoR Time-of-Fight Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Southard, Adrian E.; Getty, Stephanie A.; Costen, Nicholas P.; Hidrobo, Gregory B.; Glavin, Daniel P.

    2013-01-01

    Simulations of field emission of electrons from an electron gun are used to determine the angular distribution of the emitted electron beam and the percentage of charge transmitted through the grid. The simulations are a first step towards understanding the spherical aberration present after focusing the electron beam. The effect of offset of the cathode with respect to the grid and the separation between cathode and grid on the angular distributions of emitted electrons and transmission of the grid are explored.

  3. Double conical crystal x-ray spectrometer for high resolution ultrafast x-ray absorption near-edge spectroscopy of Al K edge

    NASA Astrophysics Data System (ADS)

    Levy, A.; Dorchies, F.; Fourment, C.; Harmand, M.; Hulin, S.; Santos, J. J.; Descamps, D.; Petit, S.; Bouillaud, R.

    2010-06-01

    An x-ray spectrometer devoted to dynamical studies of transient systems using the x-ray absorption fine spectroscopy technique is presented in this article. Using an ultrafast laser-induced x-ray source, this optical device based on a set of two potassium acid phthalate conical crystals allows the extraction of x-ray absorption near-edge spectroscopy structures following the Al absorption K edge. The proposed experimental protocol leads to a measurement of the absorption spectra free from any crystal reflectivity defaults and shot-to-shot x-ray spectral fluctuation. According to the detailed analysis of the experimental results, a spectral resolution of 0.7 eV rms and relative fluctuation lower than 1% rms are achieved, demonstrated to be limited by the statistics of photon counting on the x-ray detector.

  4. Multiaperture Spectrometer

    NASA Technical Reports Server (NTRS)

    Schindler, Rudolf A.; Pagano, Robert J.; O'Callaghan, Fred G.

    1991-01-01

    Proposed multiaperture spectrometer containing single grating provides high spectral resolution over broad spectrum. Produces parallel line images, each of which highly spectrally resolved display of intensity vs. wavelength in wavelength band of one of orders of spectrum produced by grating. Advantages; convenient two-dimensional spectral image, fewer components, and greater efficiency.

  5. Spectrometer gun

    DOEpatents

    Waechter, David A.; Wolf, Michael A.; Umbarger, C. John

    1985-01-01

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  6. Spectrometer gun

    DOEpatents

    Waechter, D.A.; Wolf, M.A.; Umbarger, C.J.

    1981-11-03

    A hand-holdable, battery-operated, microprocessor-based spectrometer gun is described that includes a low-power matrix display and sufficient memory to permit both real-time observation and extended analysis of detected radiation pulses. Universality of the incorporated signal processing circuitry permits operation with various detectors having differing pulse detection and sensitivity parameters.

  7. Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies.

    PubMed

    Franck, John M; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R; Freed, Jack H

    2015-06-01

    The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

  8. Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

    PubMed Central

    Franck, John M.; Dzikovski, Boris; Freed, Jack H.

    2015-01-01

    The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

  9. Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

    SciTech Connect

    Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H.

    2015-06-07

    The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

  10. Focus: Two-dimensional electron-electron double resonance and molecular motions: The challenge of higher frequencies

    NASA Astrophysics Data System (ADS)

    Franck, John M.; Chandrasekaran, Siddarth; Dzikovski, Boris; Dunnam, Curt R.; Freed, Jack H.

    2015-06-01

    The development, applications, and current challenges of the pulsed ESR technique of two-dimensional Electron-Electron Double Resonance (2D ELDOR) are described. This is a three-pulse technique akin to 2D Exchange Nuclear Magnetic Resonance, but involving electron spins, usually in the form of spin-probes or spin-labels. As a result, it required the extension to much higher frequencies, i.e., microwaves, and much faster time scales, with π/2 pulses in the 2-3 ns range. It has proven very useful for studying molecular dynamics in complex fluids, and spectral results can be explained by fitting theoretical models (also described) that provide a detailed analysis of the molecular dynamics and structure. We discuss concepts that also appear in other forms of 2D spectroscopy but emphasize the unique advantages and difficulties that are intrinsic to ESR. Advantages include the ability to tune the resonance frequency, in order to probe different motional ranges, while challenges include the high ratio of the detection dead time vs. the relaxation times. We review several important 2D ELDOR studies of molecular dynamics. (1) The results from a spin probe dissolved in a liquid crystal are followed throughout the isotropic → nematic → liquid-like smectic → solid-like smectic → crystalline phases as the temperature is reduced and are interpreted in terms of the slowly relaxing local structure model. Here, the labeled molecule is undergoing overall motion in the macroscopically aligned sample, as well as responding to local site fluctuations. (2) Several examples involving model phospholipid membranes are provided, including the dynamic structural characterization of the boundary lipid that coats a transmembrane peptide dimer. Additionally, subtle differences can be elicited for the phospholipid membrane phases: liquid disordered, liquid ordered, and gel, and the subtle effects upon the membrane, of antigen cross-linking of receptors on the surface of plasma membrane

  11. A monolithically three-dimensional flow-focusing device for formation of single/double emulsions in closed/open microfluidic systems

    NASA Astrophysics Data System (ADS)

    Huang, Shih-Hao; Tan, Wei-Heong; Tseng, Fan-Gang; Takeuchi, Shoji

    2006-11-01

    This paper proposes a design concept and fabrication method of a planar three-dimensional (3D) microfluidic flow-focusing device (MFFD) that can produce monodisperse single/double emulsions in a closed/open microfluidic system. The device consists of three layers of SU-8 resist structures to form coaxial embedded orifices at the center of the microchannel with dimensions ranging from 50 µm to 200 µm by means of the black photoresist shadow method. Two or three immiscible fluids can be focused through the coaxial orifices, producing monodispersed droplets with a coefficient of variance (CV) of less than 4.1%. At the orifice, the inner liquid thread stays confined to the central axis of the microchannel, surrounded by the continuous phase. As the dispensed phase (inner fluid thread) does not wet channel walls, our proposed 3D MFFD can produce single emulsions for both water-in-oil (W/O) and oil-in-water (O/W) droplets utilizing the same device. The droplet diameter ranges from 50 µm to 300 µm. Also, double emulsions containing one to several internal droplets were successfully produced in the closed channel configuration. In addition, we demonstrated for the first time the feasibility of forming W/O droplets and polymer particles in an open channel configuration by withdrawing the fluid from the outlet channel. W/O droplets and polymer particles, smaller than 10 µm and 40 µm, respectively, were successfully produced. In contrast to the closed channel configuration where the droplet size decreases with an increasing flow rate, in an open channel configuration, the droplet size increases with an increasing withdrawal rate. The unique fabrication of the monolithic 3D MFFD device utilizing SU-8 resist overcomes problems regarding orifice sizes/shapes, alignment and assembly for current axisymmetric flow-focusing devices (AFFD) based on capillary microtubes, and provides flexibility for the future development of an integrated miniaturized lab-on-a-chip microsystem.

  12. The Spectrometer

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    2012-01-01

    In the fall of 1999 I was shown an Ocean Optics spectrometer-in-the-computer at St. Patricks College at Maynooth, Ireland, and thought that I had seen heaven. Of course, it could not resolve the sodium D-lines (I had done that many years before with a homemade wire diffraction grating), and I began to realize that inside was some familiar old…

  13. Rapid, one-step fabrication and loading of nanoscale 1,2-distearoyl-sn-glycero-3-phosphocholine liposomes in a simple, double flow-focusing microfluidic device

    PubMed Central

    Tien Sing Young, Ryan V.; Tabrizian, Maryam

    2015-01-01

    Liposomes are currently well-established as biocompatible delivery vehicles for numerous compounds. However, conventional manufacturing tends to rely on time-consuming processes, costly equipment, unstable reaction parameters, and numerous pre- and post-processing steps. Herein, we demonstrate a microscope-slide-sized alternative: a double flow-focusing microfluidic geometry capable of sub-hour synthesis and controlled loading of tunable liposomes. Using phospholipid 1,2-distearoyl-sn-glycero-3-phosphocholine as the bilayer constituent, the effect of varying the dissolved lipid concentration and flow rate ratio on synthesized liposome diameters was investigated and the encapsulation of fluorescent hydrophobic drug model ergost-5,7,9(11),22-tetraen-3β-ol was performed to ascertain the potential of this device as a loading platform. PMID:26180573

  14. Compact reflective imaging spectrometer utilizing immersed gratings

    DOEpatents

    Chrisp, Michael P.

    2006-05-09

    A compact imaging spectrometer comprising an entrance slit for directing light, a first mirror that receives said light and reflects said light, an immersive diffraction grating that diffracts said light, a second mirror that focuses said light, and a detector array that receives said focused light. The compact imaging spectrometer can be utilized for remote sensing imaging spectrometers where size and weight are of primary importance.

  15. MASS SPECTROMETER

    DOEpatents

    White, F.A.

    1960-08-23

    A mass spectrometer is designed with a first adjustable magnetic field for resolving an ion beam into beams of selected masses, a second adjustable magnetic field for further resolving the ion beam from the first field into beams of selected masses, a thin foil disposed in the path of the beam between the first and second magnets to dissociate molecular ions incident thereon, an electrostatic field for further resolving the ion beam from the second field into beams of selected masses, and a detector disposed adjacent to the electrostatic field to receive the ion beam.

  16. In Situ Determination of Trace Elements in Fish Otoliths by Laser Ablation Double Focusing Sector Field Inductively Coupled Plasma Mass Spectrometry Using a Solution Standard Addition Calibration Method

    NASA Astrophysics Data System (ADS)

    Chen, Z.; Jones, C. M.

    2002-05-01

    Microchemistry of fish otoliths (fish ear bones) is a very useful tool for monitoring aquatic environments and fish migration. However, determination of the elemental composition in fish otolith by ICP-MS has been limited to either analysis of dissolved sample solution or measurement of limited number of trace elements by laser ablation (LA)- ICP-MS due to low sensitivity, lack of available calibration standards, and complexity of polyatomic molecular interference. In this study, a method was developed for in situ determination of trace elements in fish otoliths by laser ablation double focusing sector field ultra high sensitivity Finnigan Element 2 ICP-MS using a solution standard addition calibration method. Due to the lack of matrix-match solid calibration standards, sixteen trace elements (Na, Mg, P, Cr, Mn, Fe, Ni, Cu, Rb, Sr, Y, Cd, La, Ba, Pb and U) were determined using a solution standard calibration with Ca as an internal standard. Flexibility, easy preparation and stable signals are the advantages of using solution calibration standards. In order to resolve polyatomic molecular interferences, medium resolution (M/delta M > 4000) was used for some elements (Na, Mg, P, Cr, Mn, Fe, Ni, and Cu). Both external calibration and standard addition quantification strategies are compared and discussed. Precision, accuracy, and limits of detection are presented.

  17. Astronomical Fourier spectrometer.

    PubMed

    Connes, P; Michel, G

    1975-09-01

    A high resolution near ir Fourier spectrometer with the same general design as previously described laboratory instruments has been built for astronomical observations at a coudé focus. Present spectral range is 0.8-3.5 microm with PbS and Ge detectors and maximum path difference 1 m. The servo system can accommodate various recording modes: stepping or continuous scan, path difference modulation, sky chopping. A real time computer is incorporated into the system, which has been set up at the Hale 500-cm telescope on Mount Palomar. Samples of the results are given. PMID:20154966

  18. COMPARISON OF TIME-OF-FLIGHT AND DOUBLE FOCUSING MASS SPECTROMETRY FOR REACHING TENTATIVE IDENTIFICATIONS FOR UNANTICIPATED COMPOUNDS ADDED TO DRINKING WATER BY TERRORISTS

    EPA Science Inventory

    Local monitoring of post-treatment drinking water using bench-top mass spectrometers could identify target compounds in a mass spectral library. However, a terrorist might seek to incite greater hysteria by injecting or infusing a mixture of unanticipated compounds of unknown tox...

  19. Methods Development for In Situ Laser-Ablation Pb and Sr Isotopic Analyses Using a Double-Focusing Single-Collector ICPMS

    NASA Astrophysics Data System (ADS)

    Pietruszka, A. J.; Neymark, L. A.

    2014-12-01

    Laser-ablation (LA) ICPMS isotopic analyses of Pb and Sr in geological materials have mostly used multi-collector instruments equipped with Faraday-type detectors (e.g., [1-3]). The main limitation of this approach is that samples with relatively high concentrations of Pb and Sr are typically required. Here we present the development of analytical methods for the accurate and precise in situ measurement of Pb and Sr isotope ratios in relatively low-concentration samples using a laser ablation system (193-nm excimer laser) with a double-focusing single-collector (SC) ICPMS (Nu AttoMTM). Our methods build on published techniques [4-6] that used different LA-SC-ICPMS instrumentation to demonstrate the benefits of fast-scanning ion-counting measurements combined with flat-top peaks. We have paid special attention to the characterization and correction of instrumental artifacts using solutions of the NIST SRM981 Pb and SRM987 Sr standards in "wet plasma" mode. For Pb, this includes correcting for the interference of 204Hg on 204Pb, characterizing the effects of tails from thallium (at masses 203 and 205) on the Pb peaks, evaluating the stability of the instrumental mass bias, and maintaining linearity of the detector response over the full dynamic range. For Sr, this includes correcting for the interference of 86Kr on 86Sr and 87Rb on 87Sr, verifying the accuracy of an internal correction for instrumental mass bias, and calibrating the ion optics scanning parameters. LA-SC-ICPMS results for Pb and Sr isotopic measurements of international glass standards and newly developed in-house mineral and glass reference materials will be presented. [1] Davidson et al. (2001) EPSL 184, 427-442. [2] Ramos et al. (2004) Chem. Geol. 211, 135-158. [3] Simon et al. (2007) GCA 71, 2014-2035. [4] Jochum et al. (2005) IJMS 242, 281-289. [5] Jochum et al. (2006) JAAS 21, 666-675. [6] Jochum et al. (2009) JAAS 24, 1237-1243.

  20. Spectrometers for Beta Decay Electrons

    NASA Astrophysics Data System (ADS)

    Jiang, Yong; Hirshfield, Jay

    2015-04-01

    Inspired by the neutrino mass direct measurement experiment Project 8, precision spectrometers are proposed to simultaneously measure energy and momentum of beta-decay electrons produced in rare nuclear events with improved energy resolution. For detecting single beta decay electrons near the end-point from a gaseous source such as tritium, one type of spectrometer is proposed to utilize stimulated cyclotron resonance interaction of microwaves with electrons in a waveguide immersed in a magnetic mirror. In the external RF fields, on-resonance electrons will satisfy both the cyclotron resonance condition and waveguide dispersion relationship. By correlating the resonances at two waveguide modes, one can associate the frequencies with both the energy and longitudinal momentum of an on-resonance electron to account for the Doppler shifts. For detecting neutrino-less double-beta decay, another spectrometer is proposed with thin foil of double-beta-allowed material immersed in a magnetic field, and RF antenna array for detection of synchrotron radiation from electrons. It utilizes the correlation between the antenna signals including higher harmonics of radiation to reconstruct the total energy distribution.

  1. First insights on the organic species from the high resolution mass spectrometer ROSINA DFMS on-board the Rosetta spacecraft

    NASA Astrophysics Data System (ADS)

    Le Roy, L.; Altwegg, K.; Berthelier, J. J.; Calmonte, U.; Dhooghe, F.; Fiethe, B.; Fuselier, S.; Gombosi, T. I.; Rubin, M.; Tzou, C. Y.

    2014-12-01

    Starting in August 2014, the ROSINA experiment will characterize the composition and dynamics of 67P/Churyumov-Gerasimenko's coma. ROSINA consists of a suite of three instruments: a pressure sensor (COPS: COmetary Pressure Sensor) and two mass spectrometers: the Reflectron Time of Flight mass spectrometer (RTOF) and the Double Focusing Mass Spectrometer (DFMS). Here we will focus on the first results obtained by DFMS, the high-resolution mass spectrometer of ROSINA. DFMS is a traditional magnetic mass spectrometer that combines an electrostatic analyzer for energy analysis with a magnet for momentum analysis. To date, DFMS is the highest mass resolution mass spectrometer in space, with resolution (m/Δm = 3000 at 1% of the peak height at 28 amu/q). It will be able to resolve CO from N2 at m/z= 28 amu/q or 12CH and 13C at m/z= 13 amu/q. We will present the first results of DFMS: the detection of organic species and their implication for the origin of cometary material.

  2. Tropospheric Emission Spectrometer and Airborne Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Glavich, T.; Beer, R.

    1996-01-01

    The Tropospheric Emission Spectrometer (TES) is an instrument being developed for the NASA Earth Observing System Chemistry Platform. TES will measure the distribution of ozone and its precursors in the lower atmosphere. The Airborne Emission Spectrometer (AES) is an aircraft precursor to TES. Applicable descriptions are given of instrument design, technology challenges, implementation and operations for both.

  3. Compact Infrared Spectrometers

    NASA Technical Reports Server (NTRS)

    Mouroulis, Pantazis

    2009-01-01

    Concentric spectrometer forms are advantageous for constructing a variety of systems spanning the entire visible to infrared range. Spectrometer examples are given, including broadband or high resolution forms. Some issues associated with the Dyson catadioptric type are also discussed.

  4. Particle Spectrometers for FRIB

    NASA Astrophysics Data System (ADS)

    Amthor, A. M.

    2014-09-01

    FRIB promises to dramatically expand the variety of nuclear systems available for direct experimental study by providing rates of many rare isotopes orders of magnitude higher than those currently available. A new generation of experimental systems, including new particle spectrometers will be critical to our ability to take full advantage of the scientific opportunities offered by FRIB. The High-Rigidity Spectrometer (HRS) will allow for experiments with the most neutron-rich and short-lived isotopes produced by in-flight fragmentation at FRIB. The bending capability of the HRS (8 Tm) matches to the rigidity for which rare isotopes are produced at the highest intensity in the FRIB fragment separator. The experimental program will be focused on nuclear structure and astrophysics, and allow for the use of other cutting-edge detection systems for gamma, neutron, and charged-particle detection. Stopped and reaccelerated beam studies will be an important compliment to in-flight techniques at FRIB, providing world-unique, high quality, intense rare isotope beams at low energies up to and beyond the Coulomb barrier--with the completion of ReA12--and serving many of the science goals of the broader facility, from nuclear structure and astrophysics to applications. Two specialized recoil spectrometers are being developed for studies with reaccelerated beams. SECAR, the Separator for Capture Reactions, will be built following ReA3, coupled to a windowless gas jet target, JENSA, and will focus on radiative capture reactions for astrophysics, particularly those needed to improve our understanding of novae and X-ray bursts. A recoil separator following ReA12 is proposed to address a variety of physics cases based on fusion-evaporation, Coulomb excitation, transfer, and deep-inelastic reactions by providing a large angular, momentum and charge state acceptance; a high mass resolving power; and the flexibility to couple to a variety of auxiliary detector systems. Two designs

  5. Effects of Focus and De?niteness on Children's Word Order: Evidence from German Five-Year-Olds' Reproductions of Double Object Constructions

    ERIC Educational Resources Information Center

    Höhle, Barbara; Hörnig, Robin; Weskott, Thomas; Knauf, Selene; Krüger, Agnes

    2014-01-01

    Two experiments tested how faithfully German children aged 4;5 to 5;6 reproduce ditransitive sentences that are unmarked or marked with respect to word order and focus (Exp1) or definiteness (Exp2). Adopting an optimality theory (OT) approach, it is assumed that in the German adult grammar word order is ranked lower than focus and definiteness.…

  6. Fourier-Transform Infrared Spectrometer

    NASA Technical Reports Server (NTRS)

    Schindler, R. A.

    1986-01-01

    Fourier-transform spectrometer provides approximately hundredfold increase in luminosity at detector plane over that achievable with older instruments of this type. Used to analyze such weak sources as pollutants and other low-concentration substances in atmosphere. Interferometer creates fringe patterns on two distinct arrays of light detectors, which observe different wavelength bands. Objective lens focuses scene on image plane, which contains optical chopper. To make instrument less susceptible to variations in scene under observation, field and detector lenses focus entrance aperture, rather that image, onto detector array.

  7. Calibration of the γ-H2AX DNA Double Strand Break Focus Assay for Internal Radiation Exposure of Blood Lymphocytes

    PubMed Central

    Eberlein, Uta; Peper, Michel; Fernández, Maria; Lassmann, Michael; Scherthan, Harry

    2015-01-01

    DNA double strand break (DSB) formation induced by ionizing radiation exposure is indicated by the DSB biomarkers γ-H2AX and 53BP1. Knowledge about DSB foci formation in-vitro after internal irradiation of whole blood samples with radionuclides in solution will help us to gain detailed insights about dose-response relationships in patients after molecular radiotherapy (MRT). Therefore, we studied the induction of radiation-induced co-localizing γ-H2AX and 53BP1 foci as surrogate markers for DSBs in-vitro, and correlated the obtained foci per cell values with the in-vitro absorbed doses to the blood for the two most frequently used radionuclides in MRT (I-131 and Lu-177). This approach led to an in-vitro calibration curve. Overall, 55 blood samples of three healthy volunteers were analyzed. For each experiment several vials containing a mixture of whole blood and radioactive solutions with different concentrations of isotonic NaCl-diluted radionuclides with known activities were prepared. Leukocytes were recovered by density centrifugation after incubation and constant blending for 1 h at 37°C. After ethanol fixation they were subjected to two-color immunofluorescence staining and the average frequencies of the co-localizing γ-H2AX and 53BP1 foci/nucleus were determined using a fluorescence microscope equipped with a red/green double band pass filter. The exact activity was determined in parallel in each blood sample by calibrated germanium detector measurements. The absorbed dose rates to the blood per nuclear disintegrations occurring in 1 ml of blood were calculated for both isotopes by a Monte Carlo simulation. The measured blood doses in our samples ranged from 6 to 95 mGy. A linear relationship was found between the number of DSB-marking foci/nucleus and the absorbed dose to the blood for both radionuclides studied. There were only minor nuclide-specific intra- and inter-subject deviations. PMID:25853575

  8. Calibration of the γ-H2AX DNA double strand break focus assay for internal radiation exposure of blood lymphocytes.

    PubMed

    Eberlein, Uta; Peper, Michel; Fernández, Maria; Lassmann, Michael; Scherthan, Harry

    2015-01-01

    DNA double strand break (DSB) formation induced by ionizing radiation exposure is indicated by the DSB biomarkers γ-H2AX and 53BP1. Knowledge about DSB foci formation in-vitro after internal irradiation of whole blood samples with radionuclides in solution will help us to gain detailed insights about dose-response relationships in patients after molecular radiotherapy (MRT). Therefore, we studied the induction of radiation-induced co-localizing γ-H2AX and 53BP1 foci as surrogate markers for DSBs in-vitro, and correlated the obtained foci per cell values with the in-vitro absorbed doses to the blood for the two most frequently used radionuclides in MRT (I-131 and Lu-177). This approach led to an in-vitro calibration curve. Overall, 55 blood samples of three healthy volunteers were analyzed. For each experiment several vials containing a mixture of whole blood and radioactive solutions with different concentrations of isotonic NaCl-diluted radionuclides with known activities were prepared. Leukocytes were recovered by density centrifugation after incubation and constant blending for 1 h at 37°C. After ethanol fixation they were subjected to two-color immunofluorescence staining and the average frequencies of the co-localizing γ-H2AX and 53BP1 foci/nucleus were determined using a fluorescence microscope equipped with a red/green double band pass filter. The exact activity was determined in parallel in each blood sample by calibrated germanium detector measurements. The absorbed dose rates to the blood per nuclear disintegrations occurring in 1 ml of blood were calculated for both isotopes by a Monte Carlo simulation. The measured blood doses in our samples ranged from 6 to 95 mGy. A linear relationship was found between the number of DSB-marking foci/nucleus and the absorbed dose to the blood for both radionuclides studied. There were only minor nuclide-specific intra- and inter-subject deviations. PMID:25853575

  9. The upgrade of the cold neutron three-axis spectrometer IN12 at the ILL

    NASA Astrophysics Data System (ADS)

    Schmalzl, K.; Schmidt, W.; Raymond, S.; Feilbach, H.; Mounier, C.; Vettard, B.; Brückel, T.

    2016-05-01

    After nearly 40 years of successful operation the cold three-axis spectrometer IN12 at the Institut Laue-Langevin, Grenoble, France, has been relocated to a new position and the primary spectrometer has been upgraded. Latest modern optical components are employed. A new guide in combination with a virtual source concept and a double focusing monochromator guarantee highest flux. With its high unpolarized and polarized neutron flux IN12 allows for demanding experiments. A velocity selector in the guide ensures a clean beam and a very low background. A gain in flux of about an order of magnitude at the sample position has been achieved compared to the previous instrument and IN12's wavelength range now extends far into the warmish region.

  10. X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources

    SciTech Connect

    Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von

    1999-05-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.

  11. Supplementation of xylitol-containing chewing gum with probiotics: a double blind, randomised pilot study focusing on saliva flow and saliva properties.

    PubMed

    Gueimonde, Laura; Vesterlund, Satu; García-Pola, María J; Gueimonde, Miguel; Söderling, Eva; Salminen, Seppo

    2016-03-01

    The aim of this study was to investigate the impact of daily chewing, for 12 weeks, of 2 different probiotic gums compared with placebo on saliva flow rate, saliva IgA levels and saliva pH. The intervention study included 54 adult volunteers with hyposalivation in a double-blind, randomised and placebo-controlled design with three parallel groups. Volunteers were randomly assigned to 3 different groups: subjects in group A (n = 19) were given placebo chewing gum, group B (n = 17) received Bifidobacterium animalis ssp. lactis Bb12 (ATCC 27536) and group C (n = 18) received Lactobacillus rhamnosus LGG (ATCC 53103), Bifidobacterium longum 46 (DSM 14583) and Bifidobacterium longum 2C (DSM 14579) gums, during 3 months. Two volunteers from group B left the study for personal reasons leaving 19, 15 and 18 volunteers, respectively, for analyses. Clinical examinations, personal interviews, sialometries and saliva sampling were conducted at baseline and after 1, 2, 3 and 4 months. No statistically significant differences were found between probiotic and placebo groups for any of the parameters analysed. No side effects of probiotic or placebo chewing gums were observed. Chewing gum, with and without probiotics, had a positive impact on salivary flow rate and saliva pH and IgA levels. PMID:26913493

  12. The Quadrupole Mass Spectrometer

    ERIC Educational Resources Information Center

    Matheson, E.; Harris, T. J.

    1969-01-01

    Describes the construction and operation of a quadrupole mass spectrometer for experiments in an advanced-teaching laboratory. Discusses the theory of operation of the spectrometer and the factors affecting the resolution. Some examples of mass spectra obtained with this instrument are presented and discussed. (LC)

  13. Differential Moessbauer spectrometer

    SciTech Connect

    Kurinyi, Yu.A.; Grotov, Yu.D.

    1988-07-01

    A spectrometer is described that permits hardware differentiation of spectra with respect to the energy of gamma radiation, specimen temperature, etc. Differentiation is performed by secondary modulation of source motion with subsequent phase-sensitive detection at the harmonics. The spectrometer is CAMAC-compatible and permits simultaneous measurement of the first four harmonics.

  14. Photo ion spectrometer

    DOEpatents

    Gruen, Dieter M.; Young, Charles E.; Pellin, Michael J.

    1989-01-01

    A method and apparatus for extracting for quantitative analysis ions of selected atomic components of a sample. A lens system is configured to provide a slowly diminishing field region for a volume containing the selected atomic components, enabling accurate energy analysis of ions generated in the slowly diminishing field region. The lens system also enables focusing on a sample of a charged particle beam, such as an ion beam, along a path length perpendicular to the sample and extraction of the charged particles along a path length also perpendicular to the sample. Improvement of signal to noise ratio is achieved by laser excitation of ions to selected autoionization states before carrying out quantitative analysis. Accurate energy analysis of energetic charged particles is assured by using a preselected resistive thick film configuration disposed on an insulator substrate for generating predetermined electric field boundary conditions to achieve for analysis the required electric field potential. The spectrometer also is applicable in the fields of SIMS, ISS and electron spectroscopy.

  15. Photo ion spectrometer

    DOEpatents

    Gruen, D.M.; Young, C.E.; Pellin, M.J.

    1989-08-08

    A method and apparatus are described for extracting for quantitative analysis ions of selected atomic components of a sample. A lens system is configured to provide a slowly diminishing field region for a volume containing the selected atomic components, enabling accurate energy analysis of ions generated in the slowly diminishing field region. The lens system also enables focusing on a sample of a charged particle beam, such as an ion beam, along a path length perpendicular to the sample and extraction of the charged particles along a path length also perpendicular to the sample. Improvement of signal to noise ratio is achieved by laser excitation of ions to selected auto-ionization states before carrying out quantitative analysis. Accurate energy analysis of energetic charged particles is assured by using a preselected resistive thick film configuration disposed on an insulator substrate for generating predetermined electric field boundary conditions to achieve for analysis the required electric field potential. The spectrometer also is applicable in the fields of SIMS, ISS and electron spectroscopy. 8 figs.

  16. Double screening

    NASA Astrophysics Data System (ADS)

    Gratia, Pierre; Hu, Wayne; Joyce, Austin; Ribeiro, Raquel H.

    2016-06-01

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  17. Mass spectrometer experiments for the European space probe Giotto

    NASA Astrophysics Data System (ADS)

    Neumann, G.

    The Particulate Impact Analyzer (PIA) and Neutral Mass Spectrometer (NMS) experiments to be carried on board the Giotto cometary probe are presented. The NMS is designed to determine the chemical composition of gases and ions in the coma of Halley's Comet based on the ue of two spectrometers: an electrostatic parallel-plate analyzer, and a similar analyzer coupled with a magnetic analyzer with double-focusing geometry. The sensor structure consists of a monolithic multi-rib milled body with integral fixation points, with provisions for electromagnetic and thermal isolation, and dust protection. The PIA is intended for the measurement of the physical and chemical characteristics of cometary dust particles. It is based on an instrument comprising an entrance baffle and shutter unit, a target unit at which the dust is ionized, a light flash detector marking the flash of ionization, an acceleration grid sending the ions into the time-of-flight unit, and a multiplier unit for recording the time of flight spectrum. A microprocessor-based electronics system housed in a separate case next to the sensor performs tasks of power supply, signal processing, data processing and flow control.

  18. Delta-Doped CCDs as Detector Arrays in Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Nikzad, Shouleh; Jones, Todd; Jewell, April; Sinha, Mahadeva

    2007-01-01

    In a conventional mass spectrometer, charged particles (ions) are dispersed through a magnetic sector onto an MCP at an output (focal) plane. In the MCP, the impinging charged particles excite electron cascades that afford signal gain. Electrons leaving the MCP can be read out by any of a variety of means; most commonly, they are post-accelerated onto a solid-state detector array, wherein the electron pulses are converted to photons, which, in turn, are converted to measurable electric-current pulses by photodetectors. Each step in the conversion from the impinging charged particles to the output 26 NASA Tech Briefs, February 2007 current pulses reduces spatial resolution and increases noise, thereby reducing the overall sensitivity and performance of the mass spectrometer. Hence, it would be preferable to make a direct measurement of the spatial distribution of charged particles impinging on the focal plane. The utility of delta-doped CCDs as detectors of charged particles was reported in two articles in NASA Tech Briefs, Vol. 22, No. 7 (July 1998): "Delta-Doped CCDs as Low-Energy-Particle Detectors" (NPO-20178) on page 48 and "Delta- Doped CCDs for Measuring Energies of Positive Ions" (NPO-20253) on page 50. In the present developmental miniature mass spectrometers, the above mentioned miniaturization and performance advantages contributed by the use of delta-doped CCDs are combined with the advantages afforded by the Mattauch-Herzog design. The Mattauch- Herzog design is a double-focusing spectrometer design involving an electric and a magnetic sector, where the ions of different masses are spatially separated along the focal plane of magnetic sector. A delta-doped CCD at the focal plane measures the signals of all the charged-particle species simultaneously at high sensitivity and high resolution, thereby nearly instantaneously providing a complete, high-quality mass spectrum. The simultaneous nature of the measurement of ions stands in contrast to that of a

  19. The SAGE spectrometer

    NASA Astrophysics Data System (ADS)

    Pakarinen, J.; Papadakis, P.; Sorri, J.; Herzberg, R.-D.; Greenlees, P. T.; Butler, P. A.; Coleman-Smith, P. J.; Cox, D. M.; Cresswell, J. R.; Jones, P.; Julin, R.; Konki, J.; Lazarus, I. H.; Letts, S. C.; Mistry, A.; Page, R. D.; Parr, E.; Pucknell, V. F. E.; Rahkila, P.; Sampson, J.; Sandzelius, M.; Seddon, D. A.; Simpson, J.; Thornhill, J.; Wells, D.

    2014-03-01

    The SAGE spectrometer has been constructed for in-beam nuclear structure studies. SAGE combines a Ge-detector array and an electron spectrometer for detection of -rays and internal conversion electrons, respectively, and allows simultaneous observation of both electrons and -rays emitted from excited nuclei. SAGE is set up in the Accelerator Laboratory of the University of Jyväskylä and works in conjunction with the RITU gas-filled recoil separator and the GREAT focal-plane spectrometer allowing the use of the recoil-decay tagging method.

  20. Composite Spectrometer Prisms

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Page, N. A.; Rodgers, J. M.

    1985-01-01

    Efficient linear dispersive element for spectrometer instruments achieved using several different glasses in multiple-element prism. Good results obtained in both two-and three-element prisms using variety of different glass materials.

  1. The SLIM spectrometer.

    PubMed

    Cantrell, Kevin M; Ingle, James D

    2003-01-01

    A new spectrometer, here denoted the SLIM (simple, low-power, inexpensive, microcontroller-based) spectrometer, was developed that exploits the small size and low cost of solid-state electronic devices. In this device, light-emitting diodes (LED), single-chip integrated circuit photodetectors, embedded microcontrollers, and batteries replace traditional optoelectronic components, computers, and power supplies. This approach results in complete customizable spectrometers that are considerably less expensive and smaller than traditional instrumentation. The performance of the SLIM spectrometer, configured with a flow cell, was evaluated and compared to that of a commercial spectrophotometer. Thionine was the analyte, and the detection limit was approximately 0.2 microM with a 1.5-mm-path length flow cell. Nonlinearity due to the broad emission profile of the LED light sources is discussed. PMID:12530815

  2. Imaging Fourier transform spectrometer

    SciTech Connect

    Bennett, C.L.

    1993-09-13

    This invention is comprised of an imaging Fourier transform spectrometer having a Fourier transform infrared spectrometer providing a series of images to a focal plane array camera. The focal plane array camera is clocked to a multiple of zero crossing occurrences as caused by a moving mirror of the Fourier transform infrared spectrometer and as detected by a laser detector such that the frame capture rate of the focal plane array camera corresponds to a multiple of the zero crossing rate of the Fourier transform infrared spectrometer. The images are transmitted to a computer for processing such that representations of the images as viewed in the light of an arbitrary spectral ``fingerprint`` pattern can be displayed on a monitor or otherwise stored and manipulated by the computer.

  3. The imaging spectrometer approach

    NASA Technical Reports Server (NTRS)

    Wellman, J. B.

    1982-01-01

    Two important sensor design drivers are the requirement for spatial registration of the spectral components and the implementation of the advanced multispectral capability, including spectral band width, number of bands and programmability. The dispersive approach, fundamental to the imaging spectrometer concept, achieves these capabilities by utilizing a spectrometer to disperse the spectral content while preserving the spatial identity of the information in the cross-track direction. Area array detectors in the spectrometer focal plane detect and store the spatial and multispectral content for each line of the image. The choice of spectral bands, image IFOV and swath width is implemented by programmed readout of the focal plane. These choices in conjunction with data compression are used to match the output data rate with the telemetry link capability. Progress in the key technologies of optics, focal plane detector arrays, onboard processing, and focal plane cooling supports the viability of the imaging spectrometer approach.

  4. Microbolometer imaging spectrometer.

    PubMed

    Johnson, William R; Hook, Simon J; Shoen, Steven M

    2012-03-01

    Newly developed, high-performance, long-wave- and mid-wave-IR Dyson spectrometers offer a compact, low-distortion, broadband, imaging spectrometer design. The design is further accentuated when coupled to microbolometer array technology. This novel coupling allows radiometric and spectral measurements of high-temperature targets. It also serves to be unique since it allows for the system to be aligned warm. This eliminates the need for cryogenic temperature cycling. Proof of concept results are shown for a spectrometer with a 7.5 to 12.0 μm spectral range and approximately 20 nm per spectral band (~200 bands). Results presented in this Letter show performance for remote hot targets (>200 °C) using an engineering grade spectrometer and IR commercial lens assembly. PMID:22378399

  5. A Simple Raman Spectrometer.

    ERIC Educational Resources Information Center

    Blond, J. P.; Boggett, D. M.

    1980-01-01

    Discusses some basic physical ideas about light scattering and describes a simple Raman spectrometer, a single prism monochromator and a multiplier detector. This discussion is intended for British undergraduate physics students. (HM)

  6. Fourier Transform Spectrometer System

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F. (Inventor)

    2014-01-01

    A Fourier transform spectrometer (FTS) data acquisition system includes an FTS spectrometer that receives a spectral signal and a laser signal. The system further includes a wideband detector, which is in communication with the FTS spectrometer and receives the spectral signal and laser signal from the FTS spectrometer. The wideband detector produces a composite signal comprising the laser signal and the spectral signal. The system further comprises a converter in communication with the wideband detector to receive and digitize the composite signal. The system further includes a signal processing unit that receives the composite signal from the converter. The signal processing unit further filters the laser signal and the spectral signal from the composite signal and demodulates the laser signal, to produce velocity corrected spectral data.

  7. X-ray imaging crystal spectrometer for extended X-ray sources

    DOEpatents

    Bitter, Manfred L.; Fraenkel, Ben; Gorman, James L.; Hill, Kenneth W.; Roquemore, A. Lane; Stodiek, Wolfgang; von Goeler, Schweickhard E.

    2001-01-01

    Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45. For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.

  8. Spectrometer design approaching the limit

    NASA Astrophysics Data System (ADS)

    Riesenberg, Rainer; Wuttig, Andreas; Peschel, Thomas; Damm, Christoph; Dobschal, Hans-Jürgen

    2008-09-01

    The design limits of grating array spectral sensors are discussed. The limit of a grating spectrometer with respect to the resolution is given by the diffraction limit of the grating. To approach the limit for the visible spectral region the entrance slits should reach a width of 2 μm and larger depending on wavelength and numerical aperture. The detector pixel sizes should be in the same range, which is achieved virtually by the discussed double array arrangement with a transmissive, static slit array and detector array. A number of techniques are applied for optimizing the performance as well as for miniaturization. A sub-pixel imaging including a sub-pixel analysis based on the double array arrangement virtually reduces the detector pixel sizes down to about 20%. To avoid the imaging aberrations the spectra is imaged from different entrance positions by the entrance slit array. The throughput can be increased by using a two dimensional entrance slit array, which includes a multiplex pattern or a fixed adaptive pattern. The design example of a UV-Raman spectral sensor is presented including spectral measurements.

  9. Compact imaging spectrometer utilizing immersed gratings

    DOEpatents

    Lerner, Scott A.

    2005-12-20

    A compact imaging spectrometer comprising an entrance slit for directing light, lens means for receiving the light, refracting the light, and focusing the light; an immersed diffraction grating that receives the light from the lens means and defracts the light, the immersed diffraction grating directing the detracted light back to the lens means; and a detector that receives the light from the lens means.

  10. High intensity line source for x-ray spectrometer calibration

    SciTech Connect

    Thoe, R.S.

    1986-06-01

    A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

  11. Electron-proton spectrometer

    NASA Technical Reports Server (NTRS)

    Winckler, J. R.

    1973-01-01

    An electron-proton spectrometer was designed to measure the geomagnetically trapped radiation in a geostationary orbit at 6.6 earth radii in the outer radiation belt. This instrument is to be flown on the Applications Technology Satellite-F (ATS-F). The electron-proton spectrometer consists of two permanent magnet surface barrier detector arrays and associated electronics capable of selecting and detecting electrons in three energy ranges: (1) 30-50 keV, (2) 150-200 keV, and (3) 500 keV and protons in three energy ranges. The electron-proton spectrometer has the capability of measuring the fluxes of electrons and protons in various directions with respect to the magnetic field lines running through the satellite. One magnet detector array system is implemented to scan between EME north and south through west, sampling the directional flux in 15 steps. The other magnet-detector array system is fixed looking toward EME east.

  12. Compact Grism Spectrometer

    NASA Astrophysics Data System (ADS)

    Teare, S. W.

    2003-05-01

    Many observatories and instrument builders are retrofitting visible and near-infrared spectrometers into their existing imaging cameras. Camera designs that reimage the focal plane and have the optical filters located in a pseudo collimated beam are ideal candidates for the addition of a spectrometer. One device commonly used as the dispersing element for such spectrometers is a grism. The traditional grism is constructed from a prism that has had a diffraction grating applied on one surface. The objective of such a design is to use the prism wedge angle to select the desired "in-line" or "zero-deviation" wavelength that passes through on axis. The grating on the surface of the prism provides much of the dispersion for the spectrometer. A grism can also be used in a "constant-dispersion" design which provides an almost linear spatial scale across the spectrum. In this paper we provide an overview of the development of a grism spectrometer for use in a near infrared camera and demonstrate that a compact grism spectrometer can be developed on a very modest budget that can be afforded at almost any facility. The grism design was prototyped using visible light and then a final device was constructed which provides partial coverage in the near infrared I, J, H and K astronomical bands using the appropriate band pass filter for order sorting. The near infrared grism presented here provides a spectral resolution of about 650 and velocity resolution of about 450 km/s. The design of this grism relied on a computer code called Xspect, developed by the author, to determine the various critical parameters of the grism. This work was supported by a small equipment grant from NASA and administered by the AAS.

  13. TAIPAN: First Results from the Thermal Triple-axis Spectrometer at OPAL Research Reactor

    NASA Astrophysics Data System (ADS)

    Danilkin, S. A.; Yethiraj, M.; Saerbeck, T.; Klose, F.; Ulrich, C.; Fujioka, J.; Miyasaka, S.; Tokura, Y.; Keimer, B.

    2012-02-01

    The thermal triple-axis spectrometer TAIPAN is the first instrument for inelastic neutron scattering at the new Australian research reactor OPAL. TAIPAN started operation in February 2009 and is in full user service since November 2010. Conceptually, it is similar to the triple-axis spectrometers IN8 (ILL) and PANDA (FRM-II) with variable incident and final energies and a secondary spectrometer with a single detector. The instrument can be operated either in a high flux mode with a double-focusing monochromator and analyser, or with Soller collimators - gaining resolution at the expense of intensity. Presently the PG (002) double-focusing monochromator and analyser are in use. The incident energy range on the TAIPAN TAS is from ~5 meV up to ~100 meV with neutron flux at sample position of 2.4<=107 n/cm2/s at incident energy of 14.8 meV. First experiments were performed with superionic conductor Cu2-δSe. The measurements reveal the presence of a soft mode related to ordering of Cu atoms followed by α - β phase transition at a lower temperature. The evolution of the magnetic structure with temperature in a magnetically modulated FePt3 thin film was investigated in the diffraction mode of TAIPAN. The results show that the film fabricated by modulation of the chemical order parameter consists of a magnetic FM/AFM superlattice in single-crystalline FePt3. The spin wave and phonon dispersion was recently investigated in TbVO3 single crystal. The acoustic and optical magnon branches were observed in the same energy range. This indicates that the 'orbital Peiers state' also exists in TbVO3.

  14. Broad band waveguide spectrometer

    DOEpatents

    Goldman, Don S.

    1995-01-01

    A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

  15. The Apollo Alpha Spectrometer.

    NASA Technical Reports Server (NTRS)

    Jagoda, N.; Kubierschky, K.; Frank, R.; Carroll, J.

    1973-01-01

    Located in the Science Instrument Module of Apollo 15 and 16, the Alpha Particle Spectrometer was designed to detect and measure the energy of alpha particles emitted by the radon isotopes and their daughter products. The spectrometer sensor consisted of an array of totally depleted silicon surface barrier detectors. Biased amplifier and linear gate techniques were utilized to reduce resolution degradation, thereby permitting the use of a single 512 channel PHA. Sensor identification and in-flight radioactive calibration were incorporated to enhance data reduction.

  16. Comparison of imaging spectrometers

    SciTech Connect

    Bennett, C

    2000-01-09

    Realistic signal to noise performance estimates for the various types of instruments being considered for NGST are compared, based on the point source detection values quoted in the available ISIM final reports. The corresponding sensitivity of the various types of spectrometers operating in a full field imaging mode, for both emission line objects and broad spectral distribution objects, is computed and displayed. For the purpose of seeing the earliest galaxies, or the faintest possible emission line sources, the imaging Fourier transform spectrometer emerges superior to all others, by orders of magnitude in speed.

  17. Differences in quantification of DNA double-strand breaks assessed by 53BP1/γH2AX focus formation assays and the comet assay in mammalian cells treated with irradiation and N-acetyl-L-cysteine

    PubMed Central

    Kurashige, Tomomi; Shimamura, Mika; Nagayama, Yuji

    2016-01-01

    The biological effect of ionizing radiation (IR) on genomic DNA is thought to be either direct or indirect; the latter is mediated by IR induction of free radicals and reactive oxygen species (ROS). This study was designed to evaluate the effect of N-acetyl-L-cysteine (NAC), a well-known ROS-scavenging antioxidant, on IR induction of genotoxicity, cytotoxicity and ROS production in mammalian cells, and aimed to clarify the conflicting data in previous publications. Although we clearly demonstrate the beneficial effect of NAC on IR-induced genotoxicity and cytotoxicity (determined using the micronucleus assay and cell viability/clonogenic assays), the data on NAC's effect on DNA double-strand break (DSB) formation were inconsistent in different assays. Specifically, mitigation of IR-induced DSBs by NAC was readily detected by the neutral comet assay, but not by the γH2AX or 53BP1 focus assays. NAC is a glutathione precursor and exerts its effect after conversion to glutathione, and presumably it has its own biological activity. Assuming that the focus assay reflects the biological responses to DSBs (detection and repair), while the comet assay reflects the physical status of genomic DNA, our results indicate that the comet assay could readily detect the antioxidant effect of NAC on DSB formation. However, NAC's biological effect might affect the detection of DSB repair by the focus assays. Our data illustrate that multiple parameters should be carefully used to analyze DNA damage when studying potential candidates for radioprotective compounds. PMID:26951077

  18. Differences in quantification of DNA double-strand breaks assessed by 53BP1/γH2AX focus formation assays and the comet assay in mammalian cells treated with irradiation and N-acetyl-L-cysteine.

    PubMed

    Kurashige, Tomomi; Shimamura, Mika; Nagayama, Yuji

    2016-06-01

    The biological effect of ionizing radiation (IR) on genomic DNA is thought to be either direct or indirect; the latter is mediated by IR induction of free radicals and reactive oxygen species (ROS). This study was designed to evaluate the effect of N-acetyl-L-cysteine (NAC), a well-known ROS-scavenging antioxidant, on IR induction of genotoxicity, cytotoxicity and ROS production in mammalian cells, and aimed to clarify the conflicting data in previous publications. Although we clearly demonstrate the beneficial effect of NAC on IR-induced genotoxicity and cytotoxicity (determined using the micronucleus assay and cell viability/clonogenic assays), the data on NAC's effect on DNA double-strand break (DSB) formation were inconsistent in different assays. Specifically, mitigation of IR-induced DSBs by NAC was readily detected by the neutral comet assay, but not by the γH2AX or 53BP1 focus assays. NAC is a glutathione precursor and exerts its effect after conversion to glutathione, and presumably it has its own biological activity. Assuming that the focus assay reflects the biological responses to DSBs (detection and repair), while the comet assay reflects the physical status of genomic DNA, our results indicate that the comet assay could readily detect the antioxidant effect of NAC on DSB formation. However, NAC's biological effect might affect the detection of DSB repair by the focus assays. Our data illustrate that multiple parameters should be carefully used to analyze DNA damage when studying potential candidates for radioprotective compounds. PMID:26951077

  19. A double-blind, randomized trial, including frequent patient–physician contacts and Ramadan-focused advice, assessing vildagliptin and gliclazide in patients with type 2 diabetes fasting during Ramadan: the STEADFAST study

    PubMed Central

    Hassanein, Mohamed; Abdallah, Khalifa; Schweizer, Anja

    2014-01-01

    Background Several observational studies were conducted with vildagliptin in patients with type 2 diabetes mellitus (T2DM) fasting during Ramadan, showing significantly lower incidences of hypoglycemia with vildagliptin versus sulfonylureas, including gliclazide. It was of interest to complement the existing real-life evidence with data from a randomized, double-blind, clinical trial. Clinical Trials Identifier NCT01758380. Methods This multiregional, double-blind study randomized 557 patients with T2DM (mean glycated hemoglobin [HbA1c], 6.9%), previously treated with metformin and any sulfonylurea to receive either vildagliptin (50 mg twice daily) or gliclazide plus metformin. The study included four office visits (three pre-Ramadan) and multiple telephone contacts, as well as Ramadan-focused advice. Hypoglycemic events were assessed during Ramadan; HbA1c and weight were analyzed before and after Ramadan. Results The proportion of patients reporting confirmed (<3.9 mmol/L and/or severe) hypoglycemic events during Ramadan was 3.0% with vildagliptin and 7.0% with gliclazide (P=0.039; one-sided test), and this was 6.0% and 8.7%, respectively, for any hypoglycemic events (P=0.173). The adjusted mean change pre- to post-Ramadan in HbA1c was 0.05%±0.04% with vildagliptin and −0.03%±0.04% with gliclazide, from baselines of 6.84% and 6.79%, respectively (P=0.165). In both groups, the adjusted mean decrease in weight was −1.1±0.2 kg (P=0.987). Overall safety was similar between the treatments. Conclusion In line with the results from previous observational studies, vildagliptin was shown in this interventional study to be an effective, safe, and well-tolerated treatment in patients with T2DM fasting during Ramadan, with a consistently low incidence of hypoglycemia across studies, accompanied by good glycemic and weight control. In contrast, gliclazide showed a lower incidence of hypoglycemia in the present interventional than the previous observational studies. This

  20. Mass Spectrometers in Space!

    NASA Technical Reports Server (NTRS)

    Brinckerhoff, William B.

    2012-01-01

    Exploration of our solar system over several decades has benefitted greatly from the sensitive chemical analyses offered by spaceflight mass spectrometers. When dealing with an unknown environment, the broadband detection capabilities of mass analyzers have proven extremely valuable in determining the composition and thereby the basic nature of space environments, including the outer reaches of Earth s atmosphere, interplanetary space, the Moon, and the planets and their satellites. Numerous mass analyzer types, including quadrupole, monopole, sector, ion trap, and time-of-flight have been incorporated in flight instruments and delivered robotically to a variety of planetary environments. All such instruments went through a rigorous process of application-specific development, often including significant miniaturization, testing, and qualification for the space environment. Upcoming missions to Mars and opportunities for missions to Venus, Europa, Saturn, Titan, asteroids, and comets provide new challenges for flight mass spectrometers that push to state of the art in fundamental analytical technique. The Sample Analysis at Mars (SAM) investigation on the recently-launch Mars Science Laboratory (MSL) rover mission incorporates a quadrupole analyzer to support direct evolved gas as well as gas chromatograph-based analysis of martian rocks and atmosphere, seeking signs of a past or present habitable environment. A next-generation linear ion trap mass spectrometer, using both electron impact and laser ionization, is being incorporated into the Mars Organic Molecule Analyzer (MOMA) instrument, which will be flown to Mars in 2018. These and other mass spectrometers and mission concepts at various stages of development will be described.

  1. Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Understanding the global atmospheric changes is difficult with today's current technology. However, with high resolution and nearly continuous observations from a satellite, it's possible to transform our understanding of the atmosphere. To enable the next generation of atmospheric science, a new class of orbiting atmospheric sensors is being developed. The foundation of this advanced concept is the Fourier Transform Spectrometer, or FTS.

  2. Cyclotrons as mass spectrometers

    SciTech Connect

    Clark, D.J.

    1984-04-01

    The principles and design choices for cyclotrons as mass spectrometers are described. They are illustrated by examples of cyclotrons developed by various groups for this purpose. The use of present high energy cyclotrons for mass spectrometry is also described. 28 references, 12 figures.

  3. Effectiveness of Dual Focus Mutual Aid for Co-occurring Substance Use and Mental Health Disorders: A Review and Synthesis of the “Double Trouble” in Recovery Evaluation

    PubMed Central

    Magura, Stephen

    2010-01-01

    Over five million adults in the U.S. have a co-occurring substance use disorder and serious psychological distress. Mutual aid (“self-help”) can usefully complement treatment, but people with co-occurring substance use and psychiatric disorders often encounter a lack of empathy and acceptance in traditional mutual aid groups. Double Trouble in Recovery (DTR) is a dual focus fellowship whose mission is to bring the benefits of mutual aid to persons recovering from co-occurring disorders. An evaluation of DTR was conducted by interviewing 310 persons attending 24 DTR meetings in New York City in 1998 and following them up for two years, in 1999 and 2000. The evaluation produced 13 articles in 12 peer reviewed journals, the main results of which are summarized here. The sample’s characteristics were: mean age, 40 years; women, 28%; black, 59%; white, 25%; Hispanic, 14%; never married, 63%; live in supported community residence, 53%; high school graduate or GED, 60%; arrested as adult, 63%; diagnoses of: schizophrenia, 39%; major depression, 21%; or bipolar disorder; 20%; currently prescribed psychiatric medication, 92%; primary substance used, current or past: cocaine/crack, 42%; alcohol 34%; or heroin, 11%. Overall, the findings indicate that DTR participation has both direct and indirect effects on several important components of recovery: drug/alcohol abstinence, psychiatric medication adherence, self-efficacy for recovery, and quality of life. The study also identified several “common” therapeutic factors (e.g., internal motivation, social support) and unique mutual aid processes (helper-therapy, reciprocal learning) that mediate the influence of DTR participation on recovery. For clinicians, these results underline the importance of fostering stable affiliation with specialized dual focus 12-step groups for their patients with co-occurring disorders, as part of a comprehensive recovery-oriented treatment approach. PMID:19016171

  4. Longwave infrared (LWIR) coded aperture dispersive spectrometer.

    PubMed

    Fernandez, C; Guenther, B D; Gehm, M E; Brady, D J; Sullivan, M E

    2007-04-30

    We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array at the detector plane. The two-dimensional aperture code is based on a row-doubled Hadamard mask with transmissive and opaque openings. The independent column code nature of the matrix makes for a mathematically well-defined pattern that spatially and spectrally maps the source information to the detector plane. Post-processing techniques on the data provide spectral estimates of the source. Comparative experimental results between a slit and coded aperture for emission spectroscopy from a CO(2) laser are demonstrated. PMID:19532832

  5. Smartphone spectrometer for colorimetric biosensing.

    PubMed

    Wang, Yi; Liu, Xiaohu; Chen, Peng; Tran, Nhung Thi; Zhang, Jinling; Chia, Wei Sheng; Boujday, Souhir; Liedberg, Bo

    2016-05-23

    We report on a smartphone spectrometer for colorimetric biosensing applications. The spectrometer relies on a sample cell with an integrated grating substrate, and the smartphone's built-in light-emitting diode flash and camera. The feasibility of the smartphone spectrometer is demonstrated for detection of glucose and human cardiac troponin I, the latter in conjunction with peptide-functionalized gold nanoparticles. PMID:27163736

  6. Tropospheric and Airborne Emission Spectrometers

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas; Beer, Reinhard

    1996-01-01

    X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

  7. Simulation of the SAGE spectrometer

    NASA Astrophysics Data System (ADS)

    Cox, D. M.; Konki, J.; Greenlees, P. T.; Hauschild, K.; Herzberg, R.-D.; Pakarinen, J.; Papadakis, P.; Rahkila, P.; Sandzelius, M.; Sorri, J.

    2015-06-01

    The SAGE spectrometer combines a Ge-detector array with a Si detector to allow simultaneous detection of γ-rays and electrons. A comprehensive GEANT4 simulation package of the SAGE spectrometer has been developed with the ability to simulate the expected datasets based on user input files. The measured performance of the spectrometer is compared to the results obtained from the simulations.

  8. Imaging Fourier Transform Spectrometer

    SciTech Connect

    Bennett, C.L.; Carter, M.R.; Fields, D.J.; Hernandez, J.

    1993-04-14

    The operating principles of an Imaging Fourier Transform Spectrometer (IFTS) are discussed. The advantages and disadvantages of such instruments with respect to alternative imaging spectrometers are discussed. The primary advantages of the IFTS are the capacity to acquire more than an order of magnitude more spectral channels than alternative systems with more than an order of magnitude greater etendue than for alternative systems. The primary disadvantage of IFTS, or FTS in general, is the sensitivity to temporal fluctuations, either random or periodic. Data from the IRIFTS (ir IFTS) prototype instrument, sensitive in the infrared, are presented having a spectral sensitivity of 0.01 absorbance units, a spectral resolution of 6 cm{sup {minus}1} over the range 0 to 7899 cm{sup {minus}1}, and a spatial resolution of 2.5 mr.

  9. FAST NEUTRON SPECTROMETER

    DOEpatents

    Davis, F.J.; Hurst, G.S.; Reinhardt, P.W.

    1959-08-18

    An improved proton recoil spectrometer for determining the energy spectrum of a fast neutron beam is described. Instead of discriminating against and thereby"throwing away" the many recoil protons other than those traveling parallel to the neutron beam axis as do conventional spectrometers, this device utilizes protons scattered over a very wide solid angle. An ovoidal gas-filled recoil chamber is coated on the inside with a scintillator. The ovoidal shape of the sensitive portion of the wall defining the chamber conforms to the envelope of the range of the proton recoils from the radiator disposed within the chamber. A photomultiplier monitors the output of the scintillator, and a counter counts the pulses caused by protons of energy just sufficient to reach the scintillator.

  10. The Composite Infrared Spectrometer

    NASA Technical Reports Server (NTRS)

    Calcutt, Simon; Taylor, Fredric; Ade, Peter; Kunde, Virgil; Jennings, Donald

    1992-01-01

    The Composite Infrared Spectrometer (CIRS) is a remote sensing instrument to be flown on the Cassini orbiter. It contains two Fourier transform spectrometers covering wavelengths of 7-1000 microns. The instrument is expected to have higher spectral resolution, smaller field of view, and better signal-to-noise performance than its counterpart, IRIS, on the Voyager missions. These improvements allow the study of the variability of the composition and temperature of the atmospheres of both Saturn and Titan with latitude, longitude and height, as well as allowing the possibility of discovery of previously undetected chemical species in these atmospheres. The long wavelengths accessible to CIRS allow sounding deeper into both atmospheres than was possible with IRIS.

  11. Surface Plasmon Based Spectrometer

    NASA Astrophysics Data System (ADS)

    Wig, Andrew; Passian, Ali; Boudreaux, Philip; Ferrell, Tom

    2008-03-01

    A spectrometer that uses surface plasmon excitation in thin metal films to separate light into its component wavelengths is described. The use of surface plasmons as a dispersive medium sets this spectrometer apart from prism, grating, and interference based variants and allows for the miniaturization of this device. Theoretical and experimental results are presented for two different operation models. In the first case surface plasmon tunneling in the near field is used to provide transmission spectra of different broad band-pass, glass filters across the visible wavelength range with high stray-light rejection at low resolution as well as absorption spectra of chlorophyll extracted from a spinach leaf. The second model looks at the far field components of surface plasmon scattering.

  12. Ion mass spectrometer

    NASA Technical Reports Server (NTRS)

    Neugebauer, M. (Inventor); Clay, D. R.; Goldstein, B. E.; Goldstein, R.

    1984-01-01

    An ion mass spectrometer is described which detects and indicates the characteristics of ions received over a wide angle, and which indicates the mass to charge ratio, the energy, and the direction of each detected ion. The spectrometer includes a magnetic analyzer having a sector magnet that passes ions received over a wide angle, and an electrostatic analyzer positioned to receive ions passing through the magnetic analyzer. The electrostatic analyzer includes a two dimensional ion sensor at one wall of the analyzer chamber, that senses not only the lengthwise position of the detected ion to indicate its mass to charge ratio, but also detects the ion position along the width of the chamber to indicate the direction in which the ion was traveling.

  13. Miniaturized Ion Mobility Spectrometer

    NASA Technical Reports Server (NTRS)

    Kaye, William J. (Inventor); Stimac, Robert M. (Inventor)

    2015-01-01

    By utilizing the combination of a unique electronic ion injection control circuit in conjunction with a particularly designed drift cell construction, the instantly disclosed ion mobility spectrometer achieves increased levels of sensitivity, while achieving significant reductions in size and weight. The instant IMS is of a much simpler and easy to manufacture design, rugged and hermetically sealed, capable of operation at high temperatures to at least 250.degree. C., and is uniquely sensitive, particularly to explosive chemicals.

  14. The Cryogenic Grating Spectrometer

    NASA Technical Reports Server (NTRS)

    Erickson, Edwin F.; Haas, Michael R.; Colgan, Sean W. J.; Simpson, Janet P.; Rubin, Robert H.

    1995-01-01

    The Cryogenic Grating Spectrometer (CGS) first flew on the KAO in 1982 December and has been open to guest investigators since 1984 October. In the past 12 years it has completed over 100 research flights supporting 13 different principal investigators studying a variety of objects. We briefly describe the instrument, its capabilities and accomplishments, and acknowledge the people who have contributed to its development and operation.

  15. Spherical electrostatic electron spectrometer

    NASA Astrophysics Data System (ADS)

    Yang, T.-S.; Kolk, B.; Kachnowski, T.; Trooster, J.; Benczer-Koller, N.

    1982-06-01

    A high transmission, low energy spherical electrostatic electron spectrometer particularly suited to the geometry required for Mössbauer-conversion electron spectroscopy was built. A transmission of 13% at an energy resolution of 2% was obtained with an 0.5 cm diameter source of 13.6 keV electrons. Applications to the study of hyperfine interactions of surfaces and interfaces are discussed.

  16. X-ray Spectrometer

    NASA Technical Reports Server (NTRS)

    Porter, F. Scott

    2004-01-01

    The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare X R S microcalorimeter spectrometer at the EBIT-I facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolution. The X R S microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully controlling the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration "library" for the Astro-E2 observatory.

  17. A Low Cost Grism Spectrometer for Small Telescopes

    NASA Astrophysics Data System (ADS)

    Ludovici, Dominic

    2016-06-01

    We have designed and built a low cost (appx. $500) low resolution (R ~ 300) grating-prism (grism) spectrometer for the University of Iowa's robotic observatory. Grism spectrometers differ from simple transmission grating systems by partially compensating for the curved focal plane using a wedge prism. The spectrometer has five optical elements, and was designed using a ray tracing program. The collimating and focusing optics are easily modified for other telescope optics. The optics are mounted in an enclosure made with a 3-d printer. The spectrometer was installed in a modified (extended) filter wheel and has been in routine operation since January 2016. I will show sample spectra using this system and discuss spectral calibration, and optical design considerations for other telescopes. I will also discuss how low-resolution spectrometers can be used in undergraduate teaching laboratories.

  18. Mass spectrometers: instrumentation

    NASA Astrophysics Data System (ADS)

    Cooks, R. G.; Hoke, S. H., II; Morand, K. L.; Lammert, S. A.

    1992-09-01

    Developments in mass spectrometry instrumentation over the past three years are reviewed. The subject is characterized by an enormous diversity of designs, a high degree of competition between different laboratories working with either different or similar techniques and by extremely rapid progress in improving analytical performance. Instruments can be grouped into genealogical charts based on their physical and conceptual interrelationships. This is illustrated using mass analyzers of different types. The time course of development of particular instrumental concepts is illustrated in terms of the s-curves typical of cell growth. Examples are given of instruments which are at the exponential, linear and mature growth stages. The prime examples used are respectively: (i) hybrid instruments designed to study reactive collisions of ions with surfaces: (ii) the Paul ion trap; and (iii) the triple quadrupole mass spectrometer. In the area of ion/surface collisions, reactive collisions such as hydrogen radical abstraction from the surface by the impinging ion are studied. They are shown to depend upon the chemical nature of the surface through the use of experiments which utilize self-assembled monolayers as surfaces. The internal energy deposited during surface-induced dissociation upon collision with different surfaces in a BEEQ instrument is also discussed. Attention is also given to a second area of emerging instrumentation, namely technology which allows mass spectrometers to be used for on-line monitoring of fluid streams. A summary of recent improvements in the performance of the rapidly developing quadrupole ion trap instrument illustrates this stage of instrument development. Improvements in resolution and mass range and their application to the characterization of biomolecules are described. The interaction of theory with experiment is illustrated through the role of simulations of ion motion in the ion trap. It is emphasized that mature instruments play a

  19. A transmission grating spectrometer for plasma diagnostics

    SciTech Connect

    Bartlett, R.J.; Hockaday, R.G.; Gallegos, C.H.; Gonzales, J.M.; Mitton, V.

    1995-09-01

    Radiation temperature is an important parameter in characterizing the properties of hot plasmas. In most cases this temperature is time varying caused by the short lived and/or time dependent nature of the plasma. Thus, a measurement of the radiation flux as a function of time is quite valuable. To this end the authors have developed a spectrometer that can acquire spectra with a time resolution of less than 1 ns and covers the spectral energy range from {approximately} 60 to 1,000 eV. The spectrometer consists of an entrance slit placed relatively near the plasma, a thin gold film transmission grating with aperture, a micro channel plate (MCP) detector with a gold cathode placed at the dispersion plane and an electron lens to focus the electrons from the MCP onto a phosphor coated fiber optic plug. The phosphor (In:CdS) has a response time of {approximately} 500 ps. This detector system, including the fast phosphor is similar to one that has been previously described. The spectrometer is in a vacuum chamber that is turbo pumped to a base pressure of {approximately} 5 x 10{sup 7} torr. The light from the phosphor is coupled to two streak cameras through 100 m long fiber optic cables. The streak cameras with their CCD readouts provide the time resolution of the spectrum. The spectrometer has a built in alignment system that uses an alignment telescope and retractable prism.

  20. A transmission grating spectrometer for plasma diagnostics

    NASA Astrophysics Data System (ADS)

    Bartlett, Roger J.; Hockaday, Robert G.; Gallegos, Cenobio H.; Gonzales, Joseph M.; Mitton, Vance

    Radiation temperature is an important parameter in characterizing the properties of hot plasmas. In most cases this temperature is time varying caused by the short lived and/or time dependent nature of the plasma. Thus, a measurement of the radiation flux as a function of time is quite valuable. To this end the authors have developed a spectrometer that can acquire spectra with a time resolution of less than 1 ns and covers the spectral energy range from approximately 60 to 1,000 eV. The spectrometer consists of an entrance slit placed relatively near the plasma, a thin gold film transmission grating with aperture, a micro channel plate (MCP) detector with a gold cathode placed at the dispersion plane and an electron lens to focus the electrons from the MCP onto a phosphor coated fiber optic plug. The phosphor (In:CdS) has a response time of (approximately) 500 ps. This detector system, including the fast phosphor is similar to one that has been previously described. The spectrometer is in a vacuum chamber that is turbo pumped to a base pressure of approximately 5 x 10(exp 7) torr. The light from the phosphor is coupled to two streak cameras through 100 m long fiber optic cables. The streak cameras with their CCD readouts provide the time resolution of the spectrum. The spectrometer has a built in alignment system that uses an alignment telescope and retractable prism.

  1. Mossbauer spectrometer radiation detector

    NASA Technical Reports Server (NTRS)

    Singh, J. J. (Inventor)

    1973-01-01

    A Mossbauer spectrometer with high efficiencies in both transmission and backscattering techniques is described. The device contains a sodium iodide crystal for detecting radiation caused by the Mossbauer effect, and two photomultipliers to collect the radiation detected by the crystal. When used in the transmission technique, the sample or scatterer is placed between the incident radiation source and the detector. When used in a backscattering technique, the detector is placed between the incident radiation source and the sample of scatterer such that the incident radiation will pass through a hole in the crystal and strike the sample. Diagrams of the instrument are provided.

  2. Automated transportable mass spectrometer

    NASA Astrophysics Data System (ADS)

    Echo, M. W.

    1981-09-01

    The need was identified for a mass spectrometer (MS) which can be conveniently transported among several facilities for rapid verification of the isotopic composition of special nuclear material. This requirement for a light weight, transportable MS for U and Pu mass analysis was met by deleting the gas chromograph (GC) portions of a Hewlett-Packard Model 5992 Quadrupole GCMS and substituting a vacuum lock sample entry system. A programmable power supply and vacuum gauge were added and circuitry modifications were made to enable use of the supplied software.

  3. Neutron range spectrometer

    DOEpatents

    Manglos, S.H.

    1988-03-10

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are colliminated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. 1 fig.

  4. Compact catadioptric imaging spectrometer utilizing reflective grating

    DOEpatents

    Lerner, Scott A.

    2005-12-27

    An imaging spectrometer apparatus comprising an entrance slit for directing light, a light means for receiving the light and directing the light, a grating that receives the light from the light means and defracts the light back onto the light means which focuses the light, and a detector that receives the focused light. In one embodiment the light means is a rotationally symmetric ZNSE aspheric lens. In another embodiment the light means comprises two ZNSE aspheric lenses that are coaxial. In another embodiment the light means comprises an aspheric mirror and a ZNSE aspheric lens.

  5. Improved multisphere spectrometer system

    SciTech Connect

    Shonka, J.J.; Schwahn, S.O.; Rogers, P.E.; Misko, C.J.

    1991-01-01

    Shonka Research Associated undertook a research program to improve the capabilities and ease of use of the Bonner sphere spectrometer system. Two key elements formed the heart of this research: replacement of the lithium iodide (LiI(Eu)) detector normally used in the spectrometer system with a spherical boron triflouride (BF{sub 3}) proportional counter and exploitation of an optimized set of nested polyethylene spheres, including boron-loaded spherical shells. Use of a spherical BF{sub 3} detector offers many advantages over the LiI(Eu) crystal. The BF{sub 3} detectors are insensitive to gamma radiation. Lack of gamma sensitivity permits acquiring data with simple electronics and allows determination of neutron spectra and dose in lower neutron-to-gamma ratio fields, including background terrestrial radiation fields. The importance of the lack of gamma sensitivity is underscored by the pending changes in neutron quality factors. The nearly perfect spherical symmetry offers advantages for BF{sub 3} over LiI(Eu) detectors as well. A light pipe, which perturbs measurements, is not needed. The bare BF{sub 3} detector response is not affected by the moderation of neutrons as is the case of the organic light pipe used with LiI(Eu). The spherical symmetry permits the use of smaller diameter shells, which add to the number of response functions.

  6. Spectrometers beyond the laboratory

    SciTech Connect

    Wadsworth, W.

    1996-11-01

    Two new types of miniature Fourier Transform Spectrometers (FTS) presently being built have enabled this technology to be taken out of the laboratory and into the field. Both designs are very rugged, use little power to run, and can be made extremely small and lightweight. They are excellent candidates for airborne use, both in aircraft and satellite applications. One, the Mcro FT, is a mass balanced linear reciprocating scan operating in the 1-2 scan per second speed range. The other, the Turbo FT, uses a rotary scan, enabling it to run at much higher speeds, from 10 to 1000 scans per second. Either type can be built in the visible, near K and thermal IR wavelength ranges, and provide spectral resolution of 1-2 wave-numbers. Results obtained in all these wavelength ranges are presented here. The rotary configuration is more suited to airborne and satellite survey type deployments, due mostly to its rapid scan rate. Either of these sensors will fit into a small, commercially available stabilized pod which can easily be attached to a helicopter or light plane. This results in a very economical flight spectrometer system. 11 figs.

  7. The Athena Raman Spectrometer

    NASA Technical Reports Server (NTRS)

    Wang, Alian; Haskin, Larry A.; Jolliff, Bradley; Wdowiak, Tom; Agresti, David; Lane, Arthur L.

    2000-01-01

    Raman spectroscopy provides a powerful tool for in situ mineralogy, petrology, and detection of water and carbon. The Athena Raman spectrometer is a microbeam instrument intended for close-up analyses of targets (rock or soils) selected by the Athena Pancam and Mini-TES. It will take 100 Raman spectra along a linear traverse of approximately one centimeter (point-counting procedure) in one to four hours during the Mars' night. From these spectra, the following information about the target will extracted: (1) the identities of major, minor, and trace mineral phases, organic species (e.g., PAH or kerogen-like polymers), reduced inorganic carbon, and water-bearing phases; (2) chemical features (e.g. Mg/Fe ratio) of major minerals; and (3) rock textural features (e.g., mineral clusters, amygdular filling and veins). Part of the Athena payload, the miniaturized Raman spectrometer has been under development in a highly interactive collaboration of a science team at Washington University and the University of Alabama at Birmingham, and an engineering team at the Jet Propulsion Laboratory. The development has completed the brassboard stage and has produced the design for the engineering model.

  8. Resonant ultrasound spectrometer

    DOEpatents

    Migliori, Albert; Visscher, William M.; Fisk, Zachary

    1990-01-01

    An ultrasound resonant spectrometer determines the resonant frequency spectrum of a rectangular parallelepiped sample of a high dissipation material over an expected resonant response frequency range. A sample holder structure grips corners of the sample between piezoelectric drive and receive transducers. Each transducer is mounted on a membrane for only weakly coupling the transducer to the holder structure and operatively contacts a material effective to remove system resonant responses at the transducer from the expected response range. i.e., either a material such as diamond to move the response frequencies above the range or a damping powder to preclude response within the range. A square-law detector amplifier receives the response signal and retransmits the signal on an isolated shield of connecting cabling to remove cabling capacitive effects. The amplifier also provides a substantially frequency independently voltage divider with the receive transducer. The spectrometer is extremely sensitive to enable low amplitude resonance to be detected for use in calculating the elastic constants of the high dissipation sample.

  9. Prototype Neutron Energy Spectrometer

    SciTech Connect

    Stephen Mitchell, Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff

    2010-06-16

    The project goals are: (1) Use three to five pressurized helium tubes with varying polyethylene moderators to build a neutron energy spectrometer that is most sensitive to the incident neutron energy of interest. Neutron energies that are of particular interest are those from the fission neutrons (typically around 1-2 MeV); (2) Neutron Source Identification - Use the neutron energy 'selectivity' property as a tool to discriminate against other competing processes by which neutrons are generated (viz. Cosmic ray induced neutron production [ship effect], [a, n] reactions); (3) Determine the efficiency as a function of neutron energy (response function) of each of the detectors, and thereby obtain the composite neutron energy spectrum from the detector count rates; and (4) Far-field data characterization and effectively discerning shielded fission source. Summary of the presentation is: (1) A light weight simple form factor compact neutron energy spectrometer ready to be used in maritime missions has been built; (2) Under laboratory conditions, individual Single Neutron Source Identification is possible within 30 minutes. (3) Sources belonging to the same type of origin viz., (a, n), fission, cosmic cluster in the same place in the 2-D plot shown; and (4) Isotopes belonging to the same source origin like Cm-Be, Am-Be (a, n) or Pu-239, U-235 (fission) do have some overlap in the 2-D plot.

  10. Compact Catadioptric Imaging Spectrometer Designs Utilizing Immersed Gratings

    DOEpatents

    Lerner, Scott A.

    2006-02-28

    An imaging spectrometer comprising an entrance slit for directing light, a lens that receives said light and reflects said light, a grating that defracts said light back onto said lens which focuses said light, and a detector array that receives said focused light. In one embodiment the grating has rulings immersed into a germanium surface.

  11. On the effect of tilted roof reflectors in Martin-Puplett spectrometers

    NASA Astrophysics Data System (ADS)

    Schillaci, Alessandro; de Bernardis, Paolo

    2012-01-01

    In this paper we analyze theoretically and experimentally the effect of tilt of the roof mirrors in a double pendulum Martin-Puplett Polarizing Interferometer (MPI), focusing on the polarization of the interfering beams. In principle, the tilt affects the efficiency and polarimetric properties of the interferometer. The case of a moderate resolution spectrometer is analysed in detail. Using the Stokes formalism we recover the analytical expressions for the orientation angle and the ellipticity of the beam reflected from a metallic surface, and we compute these quantities for the roof-mirror of a MPI. We find that the polarization rotation and depolarization are small. Using the Jones formalism we propagate their effect on the measured interferogram and spectrum, and demonstrate that the performance degradation is small compared to other systematic effects.

  12. ISS Update: Alpha Magnetic Spectrometer

    NASA Video Gallery

    NASA Public Affairs Officer Kelly Humphries interviews Trent Martin, Johnson Space Center project manager for the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. Questions...

  13. Emerging double helical nanostructures

    NASA Astrophysics Data System (ADS)

    Zhao, Meng-Qiang; Zhang, Qiang; Tian, Gui-Li; Wei, Fei

    2014-07-01

    As one of the most important and land-mark structures found in nature, a double helix consists of two congruent single helices with the same axis or a translation along the axis. This double helical structure renders the deoxyribonucleic acid (DNA) the crucial biomolecule in evolution and metabolism. DNA-like double helical nanostructures are probably the most fantastic yet ubiquitous geometry at the nanoscale level, which are expected to exhibit exceptional and even rather different properties due to the unique organization of the two single helices and their synergistic effect. The organization of nanomaterials into double helical structures is an emerging hot topic for nanomaterials science due to their promising exceptional unique properties and applications. This review focuses on the state-of-the-art research progress for the fabrication of double-helical nanostructures based on `bottom-up' and `top-down' strategies. The relevant nanoscale, mesoscale, and macroscopic scale fabrication methods, as well as the properties of the double helical nanostructures are included. Critical perspectives are devoted to the synthesis principles and potential applications in this emerging research area. A multidisciplinary approach from the scope of nanoscience, physics, chemistry, materials, engineering, and other application areas is still required to the well-controlled and large-scale synthesis, mechanism, property, and application exploration of double helical nanostructures.

  14. Photo ion spectrometer

    DOEpatents

    Gruen, D.M.; Young, C.E.; Pellin, M.J.

    1989-12-26

    A charged particle spectrometer is described for performing ultrasensitive quantitative analysis of selected atomic components removed from a sample. Significant improvements in performing energy and angular refocusing spectroscopy are accomplished by means of a two dimensional structure for generating predetermined electromagnetic field boundary conditions. Both resonance and non-resonance ionization of selected neutral atomic components allow accumulation of increased chemical information. A multiplexed operation between a SIMS mode and a neutral atomic component ionization mode with EARTOF analysis enables comparison of chemical information from secondary ions and neutral atomic components removed from the sample. An electronic system is described for switching high level signals, such as SIMS signals, directly to a transient recorder and through a charge amplifier to the transient recorder for a low level signal pulse counting mode, such as for a neutral atomic component ionization mode. 12 figs.

  15. Photo ion spectrometer

    DOEpatents

    Gruen, Dieter M.; Young, Charles E.; Pellin, Michael J.

    1989-01-01

    A charged particle spectrometer for performing ultrasensitive quantitative analysis of selected atomic components removed from a sample. Significant improvements in performing energy and angular refocusing spectroscopy are accomplished by means of a two dimensional structure for generating predetermined electromagnetic field boundary conditions. Both resonance and non-resonance ionization of selected neutral atomic components allow accumulation of increased chemical information. A multiplexed operation between a SIMS mode and a neutral atomic component ionization mode with EARTOF analysis enables comparison of chemical information from secondary ions and neutral atomic components removed from the sample. An electronic system is described for switching high level signals, such as SIMS signals, directly to a transient recorder and through a charge amplifier to the transient recorder for a low level signal pulse counting mode, such as for a neutral atomic component ionization mode.

  16. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Lucey, Paul G.; Williams, Timothy; Horton, Keith A.

    2002-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote-sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly.

  17. Optical fiber smartphone spectrometer.

    PubMed

    Hossain, Md Arafat; Canning, John; Cook, Kevin; Jamalipour, Abbas

    2016-05-15

    An optical fiber-based smartphone spectrometer incorporating an endoscopic fiber bundle is demonstrated. The endoscope allows transmission of the smartphone camera LED light to a sample, removing complications from varying background illumination. The reflected spectra collected from a surface or interface is dispersed onto the camera CMOS using a reflecting diffraction grating. A spectral resolution as low as δλ∼2.0  nm over a bandwidth of Δλ∼250  nm is obtained using a slit width, ωslit=0.7  mm. The instrument has vast potential in a number of industrial applications including agricultural produce analysis. Spectral analysis of apples shows straightforward measurement of the pigments anthocyanins, carotenoid, and chlorophyll, all of which decrease with increasing storage time. PMID:27176971

  18. Cryogenic Neutron Spectrometer Development

    SciTech Connect

    Niedermayr, T; Hau, I D; Friedrich, S; Burger, A; Roy, U N; Bell, Z W

    2006-03-08

    Cryogenic microcalorimeter detectors operating at temperatures around {approx}0.1 K have been developed for the last two decades, driven mostly by the need for ultra-high energy resolution (<0.1%) in X-ray astrophysics and dark matter searches [1]. The Advanced Detector Group at Lawrence Livermore National Laboratory has developed different cryogenic detector technologies for applications ranging from X-ray astrophysics to nuclear science and non-proliferation. In particular, we have adapted cryogenic detector technologies for ultra-high energy resolution gamma-spectroscopy [2] and, more recently, fast-neutron spectroscopy [3]. Microcalorimeters are essentially ultra-sensitive thermometers that measure the energy of the radiation from the increase in temperature upon absorption. They consist of a sensitive superconducting thermometer operated at the transition between its superconducting and its normal state, where its resistance changes very rapidly with temperature such that even the minute energies deposited by single radiation quanta are sufficient to be detectable with high precision. The energy resolution of microcalorimeters is fundamentally limited by thermal fluctuations to {Delta}E{sub FWHM} {approx} 2.355 (k{sub B}T{sup 2}C{sub abs}){sup 1/2}, and thus allows an energy below 1 keV for neutron spectrometers for an operating temperature of T {approx} 0.1 K . The {Delta}E{sub FWHM} does not depend on the energy of the incident photon or particle. This expression is equivalent to the familiar (F{var_epsilon}E{sub {gamma}}){sup 1/2} considering that an absorber at temperature T contains a total energy C{sub abs}T, and the associated fluctuation are due to variations in uncorrelated (F=1) phonons ({var_epsilon} = k{sub B}T) dominated by the background energy C{sub abs}T >> E{gamma}. The rationale behind developing a cryogenic neutron spectrometer is the very high energy resolution combined with the high efficiency. Additionally, the response function is simple

  19. A magnetic-bottle multi-electron-ion coincidence spectrometer

    NASA Astrophysics Data System (ADS)

    Matsuda, Akitaka; Fushitani, Mizuho; Tseng, Chien-Ming; Hikosaka, Yasumasa; Eland, John H. D.; Hishikawa, Akiyoshi

    2011-10-01

    A novel multi-electron-ion coincidence spectrometer developed on the basis of a 1.5 m-long magnetic-bottle electron spectrometer is presented. Electrons are guided by an inhomogeneous magnetic field to a detector at the end of the flight tube, while a set of optics is used to extract counterpart ions to the same detector, by a pulsed inhomogeneous electric field. This setup allows ion detection with high mass resolution, without impairing the high collection efficiency for electrons. The performance of the coincidence spectrometer was tested with double ionization of carbon disulfide, CS2 → CS_2^{2+} + e- + e-, in ultrashort intense laser fields (2.8 × 1013 W/cm2, 280 fs, 1030 nm) to clarify the electron correlation below the rescattering threshold.

  20. A magnetic-bottle multi-electron-ion coincidence spectrometer.

    PubMed

    Matsuda, Akitaka; Fushitani, Mizuho; Tseng, Chien-Ming; Hikosaka, Yasumasa; Eland, John H D; Hishikawa, Akiyoshi

    2011-10-01

    A novel multi-electron-ion coincidence spectrometer developed on the basis of a 1.5 m-long magnetic-bottle electron spectrometer is presented. Electrons are guided by an inhomogeneous magnetic field to a detector at the end of the flight tube, while a set of optics is used to extract counterpart ions to the same detector, by a pulsed inhomogeneous electric field. This setup allows ion detection with high mass resolution, without impairing the high collection efficiency for electrons. The performance of the coincidence spectrometer was tested with double ionization of carbon disulfide, CS(2) → CS(2)(2+) + e(-) + e(-), in ultrashort intense laser fields (2.8 × 10(13) W/cm(2), 280 fs, 1030 nm) to clarify the electron correlation below the rescattering threshold. PMID:22047278

  1. A magnetic-bottle multi-electron-ion coincidence spectrometer

    SciTech Connect

    Matsuda, Akitaka; Hishikawa, Akiyoshi; Fushitani, Mizuho; Tseng, Chien-Ming; Hikosaka, Yasumasa; Eland, John H. D.

    2011-10-15

    A novel multi-electron-ion coincidence spectrometer developed on the basis of a 1.5 m-long magnetic-bottle electron spectrometer is presented. Electrons are guided by an inhomogeneous magnetic field to a detector at the end of the flight tube, while a set of optics is used to extract counterpart ions to the same detector, by a pulsed inhomogeneous electric field. This setup allows ion detection with high mass resolution, without impairing the high collection efficiency for electrons. The performance of the coincidence spectrometer was tested with double ionization of carbon disulfide, CS{sub 2} {yields} CS{sub 2}{sup 2+} + e{sup -} + e{sup -}, in ultrashort intense laser fields (2.8 x 10{sup 13} W/cm{sup 2}, 280 fs, 1030 nm) to clarify the electron correlation below the rescattering threshold.

  2. Neutron nano-spin-echo spectrometer based on magnetic nanostructures

    NASA Astrophysics Data System (ADS)

    Aksenov, V. L.; Nikitenko, Yu. V.; Osipov, A. A.

    2007-09-01

    A neutron spin-echo spectrometer based on spin precessors in the form of magnetic layered nanostructures is described. A model of a spin-echo spectrometer is developed on beam no. 9 in the IBR-2 reactor. In this model, spin precession occurs during motion of neutrons in a magnetic field and their double reflection from Al(30 nm)/Fe(15 nm)/Al(120 nm)/Cu(150 nm) magnetic layered structures. The obtained spectrometer parameters make it possible to investigate excitations in films with a wave vector oriented along the neutron beam direction in the range from 10-3 to 10-1 Å-1 and perpendicularly to the beam in the range from 10-4 to 10-5 Å-1.

  3. Lunar orbital mass spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Lord, W. P.

    1971-01-01

    The design, development, manufacture, test and calibration of five lunar orbital mass spectrometers with the four associated ground support equipment test sets are discussed. A mass spectrometer was installed in the Apollo 15 and one in the Apollo 16 Scientific Instrument Module within the Service Module. The Apollo 15 mass spectrometer was operated with collection of 38 hours of mass spectra data during lunar orbit and 50 hours of data were collected during transearth coast. The Apollo 16 mass spectrometer was operated with collection of 76 hours of mass spectra data during lunar orbit. However, the Apollo 16 mass spectrometer was ejected into lunar orbit upon malfunction of spacecraft boom system just prior to transearth insection and no transearth coast data was possible.

  4. Ion focusing

    SciTech Connect

    Cooks, Robert Graham; Baird, Zane; Peng, Wen-Ping

    2015-11-10

    The invention generally relates to apparatuses for focusing ions at or above ambient pressure and methods of use thereof. In certain embodiments, the invention provides an apparatus for focusing ions that includes an electrode having a cavity, at least one inlet within the electrode configured to operatively couple with an ionization source, such that discharge generated by the ionization source is injected into the cavity of the electrode, and an outlet. The cavity in the electrode is shaped such that upon application of voltage to the electrode, ions within the cavity are focused and directed to the outlet, which is positioned such that a proximal end of the outlet receives the focused ions and a distal end of the outlet is open to ambient pressure.

  5. Neutron optics of the ILL high-flux polarized neutron three-axis spectrometer IN20B

    NASA Astrophysics Data System (ADS)

    Kulda, Jiri; Courtois, Pierre; Saroun, Jan; Thomas, Michel; Enderle, M.; Flores, P.

    2001-11-01

    The three-axis spectrometer IN20 has been upgraded to enhance significantly the data collection rate in experiments using polarized neutrons to study magnetic excitations in the (higher) thermal energy range. To increase the monochromatic polarized neutron flux, a new geometry of the primary spectrometer, optimized by detailed ray-tracing simulations, has been adopted. The main ingredients are a neutron source of a diameter increased from 100 mm to 170 mm and a large double focusing monochromator, illuminated through a heavy input slit (virtual source) of adjustable width. This geometry permits to keep the background at a possibly low level while maximizing the solid angle available for monochromatic focusing. The real challenge of the project has been the new Heusler monochromator. With its active surface of 230 x 150 mm2, consisting of 75 crystal plates mounted in 15 columns, it is the largest polarizing crystal assembly ever built. In combination with the horizontally focusing analyzer of a similar design, implemented in spring 2000, the data collection rate in the polarization analysis mode has increased by a factor 30 - 50 in April 2001 as compared to the original IN20, which up to now has provided world's highest polarized neutron flux in the thermal energy range.

  6. [Effect of spectrum distortion on modulation transfer function in imaging fiber-optic spectrometer].

    PubMed

    Cheng, Xin; Wang, Jing; Zhang, Bao; Hong, Yong-Feng

    2011-10-01

    Imaging fiber bundles were introduced to dispersion imaging spectrometer and substituted for slit, connecting the telescope and spectrometer to yield the imaging fiber-optic spectrometer. It is a double sampling system, the misalignment between image of optical fiber and detector pixel has arisen because of the spectrum distortion of spectrometer, which affected the second sampling process, and the modulation transfer function (MTF) therefore degraded. Optical transfer function of sampling process was derived from line spread function. The effect of spectrum distortion on system MTF was analyzed, and a model evaluating the MTF of imaging fiber-optic spectrometer was developed. Compared to the computation model of MTF of slit imaging spectrometer, a MTF item of sampling by optical fiber and a MTF item of misalignment arising from spectrum distortion were added in this model. Employing this, the MTF of an airborne imaging fiber-optic spectrometer for visible near infrared band was evaluated. The approach ro deriving and developing the MTF model has a reference signification for the computation of MTF of double sampling system, which can direct the design of imaging fiber-optic spectrometer also. PMID:22250572

  7. Focusing adaptive-optics for neutron spectroscopy at extreme conditions

    SciTech Connect

    Simeoni, G. G.; Valicu, R. G.; Borchert, G.; Böni, P.; Rasmussen, N. G.; Yang, F.; Kordel, T.; Holland-Moritz, D.; Kargl, F.; Meyer, A.

    2015-12-14

    Neutron Spectroscopy employing extreme-conditions sample environments is nowadays a crucial tool for the understanding of fundamental scientific questions as well as for the investigation of materials and chemical-physical properties. For all these kinds of studies, an increased neutron flux over a small sample area is needed. The prototype of a focusing neutron guide component, developed and produced completely at the neutron source FRM II in Garching (Germany), has been installed at the time-of-flight (TOF) disc-chopper neutron spectrometer TOFTOF and came into routine-operation. The design is based on the compressed Archimedes' mirror concept for finite-size divergent sources. It represents a unique device combining the supermirror technology with Adaptive Optics, suitable for broad-bandwidth thermal-cold TOF neutron spectroscopy (here optimized for 1.4–10 Å). It is able to squeeze the beam cross section down to a square centimeter, with a more than doubled signal-to-background ratio, increased efficiency at high scattering angles, and improved symmetry of the elastic resolution function. We present a comparison between the simulated and measured beam cross sections, as well as the performance of the instrument within real experiments. This work intends to show the unprecedented opportunities achievable at already existing instruments, along with useful guidelines for the design and construction of next-generation neutron spectrometers.

  8. Focusing adaptive-optics for neutron spectroscopy at extreme conditions

    NASA Astrophysics Data System (ADS)

    Simeoni, G. G.; Valicu, R. G.; Borchert, G.; Böni, P.; Rasmussen, N. G.; Yang, F.; Kordel, T.; Holland-Moritz, D.; Kargl, F.; Meyer, A.

    2015-12-01

    Neutron Spectroscopy employing extreme-conditions sample environments is nowadays a crucial tool for the understanding of fundamental scientific questions as well as for the investigation of materials and chemical-physical properties. For all these kinds of studies, an increased neutron flux over a small sample area is needed. The prototype of a focusing neutron guide component, developed and produced completely at the neutron source FRM II in Garching (Germany), has been installed at the time-of-flight (TOF) disc-chopper neutron spectrometer TOFTOF and came into routine-operation. The design is based on the compressed Archimedes' mirror concept for finite-size divergent sources. It represents a unique device combining the supermirror technology with Adaptive Optics, suitable for broad-bandwidth thermal-cold TOF neutron spectroscopy (here optimized for 1.4-10 Å). It is able to squeeze the beam cross section down to a square centimeter, with a more than doubled signal-to-background ratio, increased efficiency at high scattering angles, and improved symmetry of the elastic resolution function. We present a comparison between the simulated and measured beam cross sections, as well as the performance of the instrument within real experiments. This work intends to show the unprecedented opportunities achievable at already existing instruments, along with useful guidelines for the design and construction of next-generation neutron spectrometers.

  9. Polarization Measurements in Photoproduction with CEBAF Large Acceptance Spectrometer

    SciTech Connect

    E. Pasyuk

    2010-05-01

    A significant part of the experimental program in Hall-B of the Jefferson Lab is dedicated to the studies of the structure of baryons. CEBAF Large Acceptance Spectrometer (CLAS), availability of circularly and linearly polarized photon beams and recent addition of polarized targets provides remarkable opportunity for single, double and in some cases triple polarization measurements in photoproduction. An overview of the experiments will be presented.

  10. Oblique focus ICCD laboratory evaluation

    NASA Technical Reports Server (NTRS)

    York, D. G.

    1982-01-01

    An oblique focus intensified charge coupled device (ICCD) was constructed and operated in a vacuum system. Special gratings were obtained and an optical system set up to try to model a candidate UV spectrometer (Milieu Interstellaire et Intergalactique-MISIG), and to produce small enough images to test the theoretical subpixel resolution capability of the ICCD system. The efforts were only partly successful. Based on the results, a similar detector was built and flown successfully on a Princeton rocket program.

  11. Neutron resonance spin-echo upgrade at the three-axis spectrometer FLEXX.

    PubMed

    Groitl, F; Keller, T; Quintero-Castro, D L; Habicht, K

    2015-02-01

    We describe the upgrade of the neutron resonance spin-echo setup at the cold neutron triple-axis spectrometer FLEXX at the BER II neutron source at the Helmholtz-Zentrum Berlin. The parameters of redesigned key components are discussed, including the radio frequency (RF) spin-flip coils, the magnetic shield, and the zero field coupling coils. The RF-flippers with larger beam windows allow for an improved neutron flux transfer from the source to the sample and further to the analyzer. The larger beam cross sections permit higher coil inclination angles and enable measurements on dispersive excitations with a larger slope of the dispersion. Due to the compact design of the spin-echo units in combination with the increased coil tilt angles, the accessible momentum-range in the Larmor diffraction mode is substantially enlarged. In combination with the redesigned components of the FLEXX spectrometer, including the guide, the S-bender polarizer, the double focusing monochromator, and a Heusler crystal analyzer, the count rate increased by a factor of 15.5, and the neutron beam polarization is enhanced. The improved performance extends the range of feasible experiments, both for inelastic scattering on excitation lifetimes in single crystals, and for high-resolution Larmor diffraction. The experimental characterization of the instrument components demonstrates the reliable performance of the new neutron resonance spin-echo option, now available for the scientific community at FLEXX. PMID:25725891

  12. Neutron resonance spin-echo upgrade at the three-axis spectrometer FLEXX

    SciTech Connect

    Groitl, F. Quintero-Castro, D. L.; Habicht, K.; Keller, T.

    2015-02-15

    We describe the upgrade of the neutron resonance spin-echo setup at the cold neutron triple-axis spectrometer FLEXX at the BER II neutron source at the Helmholtz-Zentrum Berlin. The parameters of redesigned key components are discussed, including the radio frequency (RF) spin-flip coils, the magnetic shield, and the zero field coupling coils. The RF-flippers with larger beam windows allow for an improved neutron flux transfer from the source to the sample and further to the analyzer. The larger beam cross sections permit higher coil inclination angles and enable measurements on dispersive excitations with a larger slope of the dispersion. Due to the compact design of the spin-echo units in combination with the increased coil tilt angles, the accessible momentum-range in the Larmor diffraction mode is substantially enlarged. In combination with the redesigned components of the FLEXX spectrometer, including the guide, the S-bender polarizer, the double focusing monochromator, and a Heusler crystal analyzer, the count rate increased by a factor of 15.5, and the neutron beam polarization is enhanced. The improved performance extends the range of feasible experiments, both for inelastic scattering on excitation lifetimes in single crystals, and for high-resolution Larmor diffraction. The experimental characterization of the instrument components demonstrates the reliable performance of the new neutron resonance spin-echo option, now available for the scientific community at FLEXX.

  13. The electronic subsystem design of the interference imaging spectrometer on CE-1 satellite

    NASA Astrophysics Data System (ADS)

    Qiu, Yue-Hong; Wen, De-sheng; Zhao, Bao-chang

    2009-07-01

    The Interference Imaging Spectrometer (IIS) is the one of payloads of the Chang'e-1 (CE-1) lunar satellite, which is used to acquire the spectral information and the global distribution information about lunar minerals. In this paper, some information about the electronic subsystem design of the Interference Imaging Spectrometer (IIS) is given. First, the technical specifications and requirements, architecture, function and operating modes of the electronic subsystem are described briefly. Secondly, the focus plane assembly (FPA) including CCD, CCD driving circuits, CCD buffering circuits, CCD biasing circuits and low-noise preamp circuits is introduced. Thirdly, the video processing and control assembly including the correlated double sampling(CDS) circuit, the programmable gain amplifier circuit, the active filter circuit, the A/D conversion circuit, digital video signal buffers, the timing module, the output interface circuit is treated. Fourthly, the timing description and logical architecture are given. Finally, some results are supplied. After careful design, thorough analyses and simulation, sufficient debug and test, the design has satisfied the technical requirements and achieved the goal of the one-year on-orbit operation.

  14. VEGAS: VErsatile GBT Astronomical Spectrometer

    NASA Astrophysics Data System (ADS)

    Bussa, Srikanth; VEGAS Development Team

    2012-01-01

    The National Science Foundation Advanced Technologies and Instrumentation (NSF-ATI) program is funding a new spectrometer backend for the Green Bank Telescope (GBT). This spectrometer is being built by the CICADA collaboration - collaboration between the National Radio Astronomy Observatory (NRAO) and the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California Berkeley.The backend is named as VErsatile GBT Astronomical Spectrometer (VEGAS) and will replace the capabilities of the existing spectrometers. This backend supports data processing from focal plane array systems. The spectrometer will be capable of processing up to 1.25 GHz bandwidth from 8 dual polarized beams or a bandwidth up to 10 GHz from a dual polarized beam.The spectrometer will be using 8-bit analog to digital converters (ADC), which gives a better dynamic range than existing GBT spectrometers. There will be 8 tunable digital sub-bands within the 1.25 GHz bandwidth, which will enhance the capability of simultaneous observation of multiple spectral transitions. The maximum spectral dump rate to disk will be about 0.5 msec. The vastly enhanced backend capabilities will support several science projects with the GBT. The projects include mapping temperature and density structure of molecular clouds; searches for organic molecules in the interstellar medium; determination of the fundamental constants of our evolving Universe; red-shifted spectral features from galaxies across cosmic time and survey for pulsars in the extreme gravitational environment of the Galactic Center.

  15. Cascaded interferometric imaging spectrometer.

    PubMed

    Swinyard, Bruce; Ferlet, Marc

    2007-09-01

    We present what we believe to be a novel method for order sorting a Fabry-Perot interferometer using a Fourier transform spectrometer (FTS) in tandem. We demonstrate how the order sorting is achieved using a model instrument response as an example of an instrument working in the 5-25 microm band, although the method is generally applicable at all wavelengths. We show that an instrument of this type can be realized with a large bandwidth, a large field of view, and good transmission efficiency. These attributes make this instrument concept a useful technique in applications where true imaging spectroscopy is required, such as mapping large astronomical sources. We compare the performance of the new instrument to grating and standard FTS instruments in circumstances where the measurement is background and detector noise limited. We use a figure of merit based on the field of view and speed of detection and find that the new system has a speed advantage over a FTS with the same field of view in all circumstances. The instrument will be faster than a grating instrument with the same spectral resolution once the field of view is >13 times larger under high background conditions and >50 times larger with detector performances that match the photon noise from Zodiacal light. PMID:17805378

  16. Neutron range spectrometer

    DOEpatents

    Manglos, Stephen H.

    1989-06-06

    A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

  17. Aerosol mobility size spectrometer

    DOEpatents

    Wang, Jian; Kulkarni, Pramod

    2007-11-20

    A device for measuring aerosol size distribution within a sample containing aerosol particles. The device generally includes a spectrometer housing defining an interior chamber and a camera for recording aerosol size streams exiting the chamber. The housing includes an inlet for introducing a flow medium into the chamber in a flow direction, an aerosol injection port adjacent the inlet for introducing a charged aerosol sample into the chamber, a separation section for applying an electric field to the aerosol sample across the flow direction and an outlet opposite the inlet. In the separation section, the aerosol sample becomes entrained in the flow medium and the aerosol particles within the aerosol sample are separated by size into a plurality of aerosol flow streams under the influence of the electric field. The camera is disposed adjacent the housing outlet for optically detecting a relative position of at least one aerosol flow stream exiting the outlet and for optically detecting the number of aerosol particles within the at least one aerosol flow stream.

  18. Modular reconfigurable matched spectral filter spectrometer

    NASA Astrophysics Data System (ADS)

    Schundler, Elizabeth; Engel, James R.; Gruber, Thomas; Vaillancourt, Robert; Benedict-Gill, Ryan; Mansur, David J.; Dixon, John; Potter, Kevin; Newbry, Scott

    2015-06-01

    OPTRA is currently developing a modular, reconfigurable matched spectral filter (RMSF) spectrometer for the monitoring of greenhouse gases. The heart of this spectrometer will be the RMSF core, which is a dispersive spectrometer that images the sample spectrum from 2000 - 3333 cm-1 onto a digital micro-mirror device (DMD) such that different columns correspond to different wavebands. By applying masks to this DMD, a matched spectral filter can be applied in hardware. The core can then be paired with different fore-optics or detector modules to achieve active in situ or passive remote detection of the chemicals of interest. This results in a highly flexible system that can address a wide variety of chemicals by updating the DMD masks and a wide variety of applications by swapping out fore-optic and detector modules. In either configuration, the signal on the detector is effectively a dot-product between the applied mask and the sample spectrum that can be used to make detection and quantification determinations. Using this approach significantly reduces the required data bandwidth of the sensor without reducing the information content, therefore making it ideal for remote, unattended systems. This paper will focus on the design of the RMSF core.

  19. Multislit optimized spectrometer: fabrication and assembly update

    NASA Astrophysics Data System (ADS)

    Valle, Tim; Hardesty, Chuck; Good, William; Seckar, Chris; Shea, Don; Spuhler, Peter; Davis, Curtiss O.; Tufillaro, Nicholas

    2013-09-01

    The NASA ESTO funded Multi-slit Optimized Spectrometer (MOS) Instrument Incubator Program will advance a spatial multiplexing spectrometer for coastal ocean remote sensing from lab demonstration to flight like environment testing. Vibration testing to meet the GEVS requirements for a geostationary orbit launch will be performed. The multiple slit design reduces the required telescope aperture leading to mass and volume reductions over conventional spectrometers when applied to the GEO-CAPE oceans mission. The MOS program is entering year 3 of the 3-year program where assembly and test activities will demonstrate the performance of the MOS concept. This paper discusses the instrument design, fabrication and assembly. It outlines the test plan to realize a technology readiness level of 6. Testing focuses on characterizing radiometric impacts of the multiple slit images multiplexed onto a common focal plane, and assesses the resulting uncertainties imparted to the ocean color data products. The MOS instrument implementation for GEO-CAPE provides system benefits that can lead to cost savings and risk reduction while meeting the science objectives of understanding the dynamic coastal ocean environment.

  20. Method for calibrating mass spectrometers

    DOEpatents

    Anderson, Gordon A [Benton City, WA; Brands, Michael D [Richland, WA; Bruce, James E [Schwenksville, PA; Pasa-Tolic, Ljiljana [Richland, WA; Smith, Richard D [Richland, WA

    2002-12-24

    A method whereby a mass spectra generated by a mass spectrometer is calibrated by shifting the parameters used by the spectrometer to assign masses to the spectra in a manner which reconciles the signal of ions within the spectra having equal mass but differing charge states, or by reconciling ions having known differences in mass to relative values consistent with those known differences. In this manner, the mass spectrometer is calibrated without the need for standards while allowing the generation of a highly accurate mass spectra by the instrument.

  1. The MAGNEX spectrometer: Results and perspectives

    NASA Astrophysics Data System (ADS)

    Cappuzzello, F.; Agodi, C.; Carbone, D.; Cavallaro, M.

    2016-06-01

    This review discusses the main achievements and future perspectives of the MAGNEX spectrometer at the INFN-LNS laboratory in Catania (Italy). MAGNEX is a large-acceptance magnetic spectrometer for the detection of the ions emitted in nuclear collisions below Fermi energy. In the first part of the paper an overview of the MAGNEX features is presented. The successful application to the precise reconstruction of the momentum vector, to the identification of the ion masses and to the determination of the transport efficiency is demonstrated by in-beam tests. In the second part, an overview of the most relevant scientific achievements is given. Results from nuclear elastic and inelastic scattering as well as from transfer and charge-exchange reactions in a wide range of masses of the colliding systems and incident energies are shown. The role of MAGNEX in solving old and new puzzles in nuclear structure and direct reaction mechanisms is emphasized. One example is the recently observed signature of the long searched Giant Pairing Vibration. Finally, the new challenging opportunities to use MAGNEX for future experiments are briefly reported. In particular, the use of double charge-exchange reactions toward the determination of the nuclear matrix elements entering in the expression of the half-life of neutrinoless double beta decay is discussed. The new NUMEN project of INFN, aiming at these investigations, is introduced. The challenges connected to the major technical upgrade required by the project in order to investigate rare processes under high fluxes of detected heavy ions are outlined.

  2. Dual waveband compact catadioptric imaging spectrometer

    DOEpatents

    Chrisp, Michael P.

    2012-12-25

    A catadioptric dual waveband imaging spectrometer that covers the visible through short-wave infrared, and the midwave infrared spectral regions, dispersing the visible through shortwave infrared with a zinc selenide grating and midwave infrared with a sapphire prism. The grating and prism are at the cold stop position, enabling the pupil to be split between them. The spectra for both wavebands are focused onto the relevant sections of a single dual waveband detector. Spatial keystone distortion is controlled to less than one tenth of a pixel over the full wavelength range, facilitating the matching of the spectra in the midwave infrared with the shorter wavelength region.

  3. Atmospheric electron x-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Feldman, Jason E. (Inventor); George, Thomas (Inventor); Wilcox, Jaroslava Z. (Inventor)

    2002-01-01

    The present invention comprises an apparatus for performing in-situ elemental analyses of surfaces. The invention comprises an atmospheric electron x-ray spectrometer with an electron column which generates, accelerates, and focuses electrons in a column which is isolated from ambient pressure by a:thin, electron transparent membrane. After passing through the membrane, the electrons impinge on the sample in atmosphere to generate characteristic x-rays. An x-ray detector, shaping amplifier, and multi-channel analyzer are used for x-ray detection and signal analysis. By comparing the resultant data to known x-ray spectral signatures, the elemental composition of the surface can be determined.

  4. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote-sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly.anomaly. Both the visible and infrared subsystems scan in "pushbroom" mode: that is, an aircraft carrying the system moves along a ground track, the system is aimed downward, and image data are acquired in acrosstrack linear arrays of pixels. Both subsystems operate at a frame rate of 30 Hz. The infrared and visible-light optics are adjusted so that both subsystems are aimed at the same moving swath, which has across-track angular width of 15. Data from the infrared and visible imaging subsystems are stored in the same file along with aircraft-position data acquired by a Global Positioning System receiver. The combination of the three sets of data is used to construct infrared and hyperspectral maps of scanned areas shown.

  5. The spin-echo spectrometer at the Spallation Neutron Source (SNS)

    NASA Astrophysics Data System (ADS)

    Ohl, M.; Monkenbusch, M.; Arend, N.; Kozielewski, T.; Vehres, G.; Tiemann, C.; Butzek, M.; Soltner, H.; Giesen, U.; Achten, R.; Stelzer, H.; Lindenau, B.; Budwig, A.; Kleines, H.; Drochner, M.; Kaemmerling, P.; Wagener, M.; Möller, R.; Iverson, E. B.; Sharp, M.; Richter, D.

    2012-12-01

    A novel neutron spin-echo spectrometer with superconducting main coils enabling enclosure by a double walled μ-metal magnetic shielding chamber has been built and set into operation at the spallation neutron source in Oak Ridge. The layout of the spectrometer is described. Performance with emphasis on the superconducting main solenoids and the time-of-flight operation is described. Data on resolution, stability and first experiments are shown.

  6. Alpha Magnetic Spectrometer (AMS) Overview

    NASA Video Gallery

    The Alpha Magnetic Spectrometer (AMS) is flying to the station on STS-134. The AMS experiment is a state-of-the-art particle physics detector being operated by an international team composed of 60 ...

  7. Micromachined Slits for Imaging Spectrometers

    NASA Technical Reports Server (NTRS)

    Wilson, Daniel; Kenny, James; White, Victor

    2008-01-01

    Slits for imaging spectrometers can now be fabricated to a precision much greater than previously attainable. What makes this possible is a micromachining process that involves the use of microlithographic techniques.

  8. Versatile cluster based photoelectron spectrometer

    SciTech Connect

    Knappenberger, K. L. Jr.; Jones, C. E. Jr.; Sobhy, M. A.; Castleman, A. W. Jr.

    2006-12-15

    A recently constructed cluster based photoelectron spectrometer is described. This instrumentation is unique in that it enables the kinetic energy analysis of electrons ejected from both anions and neutral clusters. This capability permits the investigation of discrete electronic levels in all charge states (anionic, neutral, and cationic). A laser vaporization plasma reactor cluster source affixed with a sublimation cell is employed to produce a variety of metal clusters, and the resulting cluster distributions are analyzed with time-of-flight mass spectrometry. The corresponding electronic structure is analyzed with a 'magnetic bottle' photoelectron spectrometer. Examples of instrument performance operating in both anion photodetachment and neutral multiphoton ionization (MPI) modes are provided. In the case of neutral MPI, the corresponding product distribution is collected with a Wiley-McLaren [Rev. Sci. Instrum. 26, 1150 (1955)] mass spectrometer mounted perpendicular to the magnetic bottle photoelectron spectrometer.

  9. Fast-neutron spectrometer developments

    NASA Technical Reports Server (NTRS)

    Moler, R. B.; Zagotta, W. E.; Baker, S. I.

    1973-01-01

    Li6 sandwich-type neutron spectrometer is equipped with proportional counter for particle identification. System uses current-sensitive preamplifiers to minimize pile-up of gamma-ray and particle pulses.

  10. Tsunami focusing

    NASA Astrophysics Data System (ADS)

    Spillane, M. C.; Titov, V. V.; Moore, C. W.; Aydin, B.; Kanoglu, U.; Synolakis, C. E.

    2010-12-01

    Tsunamis are long waves generated by impulsive disturbances of the seafloor or coastal topography caused by earthquakes, submarine/subaerial mass failures. They evolve substantially through three dimensional - 2 spatial+1 temporal - spreading as the initial surface deformation propagates. This is referred to as its directivity and focusing. A directivity function was first defined by Ben-Menahem (1961, Bull. Seismol. Soc. Am. 51, 401-435) using the source length and the rupture velocity. Okal (2003, Pure Appl. Geophys. 160, 2189-2221) discussed the details of the analysis of Ben-Menahem (1961) and demonstrated the distinct difference between the directivity patterns of landslide and earthquake generated tsunamis. Marchuk and Titov (1989, Proc. IUGG/IOC International Tsunami Symposium, July 31 - August 3, 1989, Novosibirsk, USSR. p.11-17) described the process of tsunami focusing for a rectangular initial deformation combining positive and negative surface displacements. They showed the existence of a focusing point where abnormal tsunami wave height can be registered. Here, first, we describe and quantify numerically tsunami focusing processes for a combined positive and negative - N-wave type - strip source representing the 17 July 1998 Papua New Guinea and 17 July 2006 Java events. Specifically, considering field observations and tsunami focusing, we propose a source mechanism for the 17 July 2006 Java event. Then, we introduce a new analytical solution for a strip source propagating over a flat bottom using the linear shallow-water wave equation. The analytical solution of Carrier and Yeh (2005, Computer Modeling In Engineering & Sciences, 10(2), 113-121) appears to have two drawbacks. One, the solution involves singular complete elliptic integral of the first kind which results in a self-similar approximate solution for the far-field at large times. Two, only the propagation of Gaussian shaped finite-crest wave profiles can be modeled. Our solution is not only

  11. Resonance-filtered beam spectrometer

    SciTech Connect

    Brugger, R.M.; Taylor, A.D.; Olsen, C.E.; Goldstone, J.A.; Soper, A.K.

    1982-01-01

    A new inelastic neutron scattering spectrometer which operates in the range 1 eV to 15 eV has been developed at the Los Alamos pulsed spallation source WNR. Based on a nuclear resonance filtering the beam, the concept has been tested in direct, inverted and sample geometries. A number of resonance filters have been tested to determine their effectiveness. The spectrometer is described and examples of data are presented.

  12. Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In the new generation interferometer, incident photons pass through the entrance aperture of the insturment and are divided by a beam splitter into two paths. In each path, the photons experience multiple reflections from optical components. Eventually, the photons are recombined at the beamsplitter and are focused on an array of detectors. The energy from the photons is then converted into electrical analog signals.

  13. Optical design of prism-grating-prism imaging spectrometers

    NASA Astrophysics Data System (ADS)

    Zhu, Shanbing; Tang, Minxue; Ji, Yiqun; Gong, Guangbiao; Zhang, Ruirui; Shen, Weimin

    2008-12-01

    Imaging spectrometers can provide imagery and spectrum information of objects and form so-called three-dimensional spectral imagery, two spatial and one spectral dimension. Most of imaging spectrometers use conventional spectroscopic elements or systems, such as reflective diffraction gratings, prisms, filters, spatial modulated interferometers, and so on. Here a special imaging spectrometer which is based on a novel cemented Prism-Grating-Prism (PGP) is reported. Its spectroscopic element PGP consists of two prisms and a holographic transmission volume grating, which is cemented between these prisms. The two prisms mainly function as beam deviation, the grating as a disperser. In addition to the high light efficiency of the volume gratings that is required for high spectral resolution, the cementing difficulty when surface relief gratings are used can be avoided due to its voluminal characteristic. The PGP imaging spectrometer has advantages of direct vision, dispersion uniform, compactness, low cost, and facility to be used. The principle, structure, and optimized design of the PGP imaging spectrometer are given in detail. Its front collimation optics and rear focusing lenses are same so as to reduce its cost further. The spectral coverage, resolution, and track length of the designed system are respectively visible light from 400nm to 800nm, 1.6nm/pixel, and 85mm. From its performance evaluation, it is shown that the PGP imaging spectrometer has the potentiality to be used in microscopic hyperspectral imagers and hyperspectral imaging remote sensors.

  14. Coastal Research Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Lucey, Paul G.; Williams, Timothy; Horton, Keith A.

    2004-01-01

    The Coastal Research Imaging Spectrometer (CRIS) is an airborne remote sensing system designed specifically for research on the physical, chemical, and biological characteristics of coastal waters. The CRIS includes a visible-light hyperspectral imaging subsystem for measuring the color of water, which contains information on the biota, sediment, and nutrient contents of the water. The CRIS also includes an infrared imaging subsystem, which provides information on the temperature of the water. The combination of measurements enables investigation of biological effects of both natural and artificial flows of water from land into the ocean, including diffuse and point-source flows that may contain biological and/or chemical pollutants. Temperature is an important element of such measurements because temperature contrasts can often be used to distinguish among flows from different sources: for example, a sewage outflow could manifest itself in spectral images as a local high-temperature anomaly. Both the visible and infrared subsystems scan in pushbroom mode: that is, an aircraft carrying the system moves along a ground track, the system is aimed downward, and image data are acquired in across-track linear arrays of pixels. Both subsystems operate at a frame rate of 30 Hz. The infrared and visible-light optics are adjusted so that both subsystems are aimed at the same moving swath, which has across-track angular width of 15 . Data from the infrared and visible imaging subsystems are stored in the same file along with aircraft- position data acquired by a Global Positioning System receiver. The combination of the three sets of data is used to construct infrared and hyperspectral maps of scanned areas (see figure). The visible subsystem is based on a grating spectrograph and a rapid-readout charge-coupled-device camera. Images of the swatch are acquired in 256 spectral bands at wavelengths from 400 to 800 nm. The infrared subsystem, which is sensitive in a single

  15. Electrophoretic Focusing

    NASA Technical Reports Server (NTRS)

    Snyder, Robert S.

    2001-01-01

    Electrophoretic focusing is a new method of continuous flow electrophoresis that introduces precision flow control to achieve high resolution separations. The electric field is applied perpendicular to an incoming sample lamina and buffer but also perpendicular to the broad faces of the thin rectangular chamber. A uniform fluid cross-flow then enters and exits the separation chamber through the same broad faces which are porous. A balance is achieved by adjusting either the electric field or the cross-flow so the desired sample fraction with its specific migration velocity encounters an opposing flow of the same velocity. Applying an electric field transverse to the incoming sample lamina and opposing this field with a carefully configured buffer flow, a sample constituent can be selected and focused into a narrow stream for subsequent analysis. Monotonically changing either electric field or buffer cross-flow will yield a scan of all constituents of the sample. Stopping the scan increases the collection time for minor constituents to improve their analysis. Using the high voltage gradients and/or cross-flow to rapidly deflect extraneous sample through the porous screens and into either of the side (purge) chambers, the selected sample is focused in the center plane of the separation chamber and collected without contact or interaction with the separation chamber walls. Results will be presented on the separation of a range of materials including dyes, proteins, and monodisperse polystyrene latexes. Sources of sample dispersion inherent in other electrokinetic techniques will be shown to be negligible for a variety of sample concentrations, buffer properties and operating conditions.

  16. The rotating spectrometer: Biotechnology for cell separations

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1991-01-01

    An instrument for biochemical studies, called the rotating spectrometer, separates previously inseparable cell cultures. The rotating spectrometer is intended for use in pharmacological studies which require fractional splitting of heterogeneous cell cultures based on cell morphology and swimming behavior. As a method to separate and concentrate cells in free solution, the rotating method requires active organism participation and can effectively split the large class of organisms known to form spontaneous patterns. Examples include the biochemical star, an organism called Tetrahymena pyriformis. Following focusing in a rotating frame, the separation is accomplished using different radial dependencies of concentrated algal and protozoan species. The focusing itself appears as concentric rings and arises from the coupling between swimming direction and Coriolis forces. A dense cut is taken at varying radii, and extraction is replenished at an inlet. Unlike standard separation and concentrating techniques such as filtration or centrifugation, the instrument is able to separate motile from immotile fractions. For a single pass, typical split efficiencies can reach 200 to 300 percent compared to the inlet concentration.

  17. Study on optical design of all-reflective Fourier transform imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Liang, Min-yong; Liao, Ning-fang

    2008-03-01

    The Fourier Transform Imaging Spectrometer (FTIS) used for remote sensing has been developed rapidly in the past two decades. Most of the Temporarily Modulated FTIS and the Spatially Modulated FTIS include a beam splitter structure, such as Sagnac prism or double refraction crystal beam splitter. The material of the beam splitter which is optical glass, crystalline materials or plastic optical materials all have the transmission limitation, so the spectrum range would be limited; the transparent material also would cause the chromatic aberration. We presented an all-reflective optical structure based on the Fresnel double mirror interference structure that could overcome these two shortcomings. The three-mirror anastigmat (TMA) telescope is employed to realize all-reflective fore-optics, it has a compact structure, wide field of view (FOV) and competent modulation transfer function (MTF). An abaxial parabolic-cylindrical mirror has been designed to focus the interference fringes onto the plane focal array (FPA) which would increase the signal to noise ratio (SNR).

  18. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)

    NASA Technical Reports Server (NTRS)

    Macenka, Steven A.; Chrisp, Michael P.

    1988-01-01

    The development of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has been completed at JPL. This paper outlines the functional requirements of the spectrometer optics subsystem, and describes the spectrometer optical design. The optical subsystem performance is shown in terms of spectral modulation transfer functions, radial energy distributions, and system transmission at selected wavelengths for the four spectrometers. An outline of the spectrometer alignment is included.

  19. Imaging spectrometers for remote sensing from space

    NASA Technical Reports Server (NTRS)

    Chrisp, M. P.; Breckinridge, J. B.; Macenka, S. A.; Page, N. A.

    1986-01-01

    Three imaging spectrometers and two camera systems for remote sensing are described. Two of the imaging spectrometers are versions of the Visible and Infrared Mapping Spectrometer (VIMS) for Mars Observer and the Comet Rendezvous Asteroid Flyby (CRAF) mission. The other spectrometer is the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) which is currently under construction. The optical imaging systems are the wide angle and narrow angle cameras for the CRAF mission.

  20. A Novel MOEMS NIR Spectrometer

    NASA Astrophysics Data System (ADS)

    Zhihai, Zhang; Xiangxia, Mo; Yuanjun, Guo; Wei, Wang

    In order to detect luminous intensity of light signal in NIR (Near-infrared) wavelength range, a novel MOEMS(Micro-Opto-Electro-Mechanical Systems) NIR spectrometer is proposed in the paper. It uses DMD (Digital Micro-mirror Device) to band filter the input spectrum. The merits of DMD are small size, low price and high scan speed. Especially, when DMD acts as a Hadamard Transform encoding mask, the SNR (signal-to-noise-ratio) can be improved by multiplexing the light intensities. The structure and the theory of this spectrometer are analyzed. The Hadamard-S matrix and mask of 63-order and 127-order are designed. The output spectrum of the new spectrometer coincides with experimental result of Shimadzu spectrometer. The resolution of the new spectrometer is 19 nm over the spectral range between 900∼1700 nm while single scan time is only 2.4S. The SNR is 44.67:1. The size of optical path is 70mm × 130 mm, and it has a weight less than 1Kg. It can meet the requirement of real time measurement and portable application.

  1. Resolution-enhanced Mapping Spectrometer

    NASA Technical Reports Server (NTRS)

    Kumer, J. B.; Aubrun, J. N.; Rosenberg, W. J.; Roche, A. E.

    1993-01-01

    A familiar mapping spectrometer implementation utilizes two dimensional detector arrays with spectral dispersion along one direction and spatial along the other. Spectral images are formed by spatially scanning across the scene (i.e., push-broom scanning). For imaging grating and prism spectrometers, the slit is perpendicular to the spatial scan direction. For spectrometers utilizing linearly variable focal-plane-mounted filters the spatial scan direction is perpendicular to the direction of spectral variation. These spectrometers share the common limitation that the number of spectral resolution elements is given by the number of pixels along the spectral (or dispersive) direction. Resolution enhancement by first passing the light input to the spectrometer through a scanned etalon or Michelson is discussed. Thus, while a detector element is scanned through a spatial resolution element of the scene, it is also temporally sampled. The analysis for all the pixels in the dispersive direction is addressed. Several specific examples are discussed. The alternate use of a Michelson for the same enhancement purpose is also discussed. Suitable for weight constrained deep space missions, hardware systems were developed including actuators, sensor, and electronics such that low-resolution etalons with performance required for implementation would weigh less than one pound.

  2. Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings

    DOEpatents

    Lerner, Scott A.; Bennett, Charles L.; Bixler, Jay V.; Kuzmenko, Paul J.; Lewis, Isabella T.

    2005-07-26

    A compact imaging spectrometer comprising an entrance slit for directing light, a first means for receiving the light and focusing the light, an immersed diffraction grating that receives the light from the first means and defracts the light, a second means for receiving the light from the immersed diffraction grating and focusing the light, and an image plane that receives the light from the second means

  3. Double Photoionization into Double Core-Hole States in Xe

    SciTech Connect

    Hikosaka, Y.; Kaneyasu, T.; Shigemasa, E.; Lablanquie, P.; Penent, F.; Eland, J. H. D.; Aoto, T.; Ito, K.

    2007-05-04

    Double photoionization (DPI) leading to double core-hole states of Xe{sup 2+} 4d{sup -2} has been studied using a magnetic bottle time-of-flight spectrometer. The assignments of the Xe{sup 2+} 4d{sup -2} states are confirmed by the Auger lines extracted from fourfold coincidences including two photoelectrons and two Auger electrons. It is estimated that the core-core DPI into Xe{sup 2+} 4d{sup -2} at a photon energy of 301.6 eV has a favored cross section of about 0.3 MB. The intense core-core DPI is due to mixing of the 4d{sup -2} continuum with the 4p single photoionization, which is manifested in the relative intensities of the Xe{sup 2+} 4d{sup -2} components.

  4. Double photoionization into double core-hole states in Xe.

    PubMed

    Hikosaka, Y; Lablanquie, P; Penent, F; Kaneyasu, T; Shigemasa, E; Eland, J H D; Aoto, T; Ito, K

    2007-05-01

    Double photoionization (DPI) leading to double core-hole states of Xe2+ 4d(-2) has been studied using a magnetic bottle time-of-flight spectrometer. The assignments of the Xe2+ 4d(-2) states are confirmed by the Auger lines extracted from fourfold coincidences including two photoelectrons and two Auger electrons. It is estimated that the core-core DPI into Xe2+ 4d(-2) at a photon energy of 301.6 eV has a favored cross section of about 0.3 MB. The intense core-core DPI is due to mixing of the 4d(-2) continuum with the 4p single photoionization, which is manifested in the relative intensities of the Xe2+ 4d(-2) components. PMID:17501570

  5. Evaluating Mass Analyzers as Candidates for Small, Portable, Rugged Single Point Mass Spectrometers for Analysis of Permanent Gases

    NASA Technical Reports Server (NTRS)

    Arkin, C. Richard; Ottens, Andrew K.; Diaz, Jorge A.; Griffin, Timothy P.; Follestein, Duke; Adams, Fredrick; Steinrock, T. (Technical Monitor)

    2001-01-01

    For Space Shuttle launch safety, there is a need to monitor the concentration Of H2, He, O2, and Ar around the launch vehicle. Currently a large mass spectrometry system performs this task, using long transport lines to draw in samples. There is great interest in replacing this stationary system with several miniature, portable, rugged mass spectrometers which act as point sensors which can be placed at the sampling point. Five commercial and two non-commercial analyzers are evaluated. The five commercial systems include the Leybold Inficon XPR-2 linear quadrupole, the Stanford Research (SRS-100) linear quadrupole, the Ferran linear quadrupole array, the ThermoQuest Polaris-Q quadrupole ion trap, and the IonWerks Time-of-Flight (TOF). The non-commercial systems include a compact double focusing sector (CDFMS) developed at the University of Minnesota, and a quadrupole ion trap (UF-IT) developed at the University of Florida.

  6. Mobile spectrometer measures radar backscatter

    NASA Technical Reports Server (NTRS)

    Gogineni, S.; Moore, R. K.; Onstott, R. G.; Kim, Y. S.; Bushnell, D.

    1984-01-01

    The present article is concerned with a helicopter-borne spectrometer (Heloscat), which has been developed to permit high-quality scattering measurements from a mobile platform at remote sites. The term 'spectrometer' referes to a class of scatterometers. The term 'scatterometer' is employed to denote a specialized radar for measuring scattering coefficients as a function of angle. A spectrometer, on the other hand, is a scatterometer which can measure backscatter at several frequencies. The Heloscat system is discussed, taking into account two antennas, RF hardware, and an externally mounted pendulum for angle encoding. A dual-antenna configuration is used for cross-polarized measurements, while a single-antenna system is used for like-polarized measurements. Attention is also given to oscillator characteristics, efficient data handling, and aspects of calibration.

  7. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, D.D.; Keville, R.F.

    1995-09-19

    An ion trap is described which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10{sup 9} and commercial mass spectrometers requiring 10{sup 4} ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products. 10 figs.

  8. Mini ion trap mass spectrometer

    DOEpatents

    Dietrich, Daniel D.; Keville, Robert F.

    1995-01-01

    An ion trap which operates in the regime between research ion traps which can detect ions with a mass resolution of better than 1:10.sup.9 and commercial mass spectrometers requiring 10.sup.4 ions with resolutions of a few hundred. The power consumption is kept to a minimum by the use of permanent magnets and a novel electron gun design. By Fourier analyzing the ion cyclotron resonance signals induced in the trap electrodes, a complete mass spectra in a single combined structure can be detected. An attribute of the ion trap mass spectrometer is that overall system size is drastically reduced due to combining a unique electron source and mass analyzer/detector in a single device. This enables portable low power mass spectrometers for the detection of environmental pollutants or illicit substances, as well as sensors for on board diagnostics to monitor engine performance or for active feedback in any process involving exhausting waste products.

  9. Thermal Infrared Profiling Spectrometer (TIPS)

    NASA Astrophysics Data System (ADS)

    Lanzl, Franz; Miosga, G.; Lehmann, F.; Richter, R.; Tank, V.

    1989-12-01

    An airborne/spaceborne sensor concept developed for scientific observations in remote sensing of the earth surface is presented. The spectrometer design is based on a fast scanning Fourier spectrometer using a rotating retroreflector. The spectrometer covers the 3-13-micron band with a spectral resolution of 5/cm. The measured signal is an interferogramm, while derived quantities are spectral emissivity, spectral radiance, and surface temperature. The optical system consists of an aperture-filling plane tilting mirror to provide off-nadir observation and calibration modes. The collecting mirror focal length and the detector area yield an instantaneous field of view of 1.2 mrad, noise equivalent temperature resolution of 0.004 K, and a noise equivalent change in emissivity of 0.0006. The simulation results of signal-to-noise performance of the TIPS are presented and discussed.

  10. Multichannel Spectrometer of Time Distribution

    NASA Astrophysics Data System (ADS)

    Akindinova, E. V.; Babenko, A. G.; Vakhtel, V. M.; Evseev, N. A.; Rabotkin, V. A.; Kharitonova, D. D.

    2015-06-01

    For research and control of characteristics of radiation fluxes, radioactive sources in particular, for example, in paper [1], a spectrometer and methods of data measurement and processing based on the multichannel counter of time intervals of accident events appearance (impulses of particle detector) MC-2A (SPC "ASPECT") were created. The spectrometer has four independent channels of registration of time intervals of impulses appearance and correspondent amplitude and spectrometric channels for control along the energy spectra of the operation stationarity of paths of each of the channels from the detector to the amplifier. The registration of alpha-radiation is carried out by the semiconductor detectors with energy resolution of 16-30 keV. Using a spectrometer there have been taken measurements of oscillations of alpha-radiation 239-Pu flux intensity with a subsequent autocorrelative statistical analysis of the time series of readings.

  11. The GRAVITY spectrometers: thermal behaviour

    NASA Astrophysics Data System (ADS)

    Wank, Imke; Straubmeier, Christian; Wiest, Michael; Yazici, Senol; Fischer, Sebastian; Eisenhauer, Frank; Perrin, Guy S.; Perraut, Karine; Brandner, Wolfgang; Amorim, Antonio; Schöller, Markus; Eckart, Andreas

    2014-07-01

    GRAVITY is a 2nd generation VLTI Instrument o which operates on 6 interferometric baselines by using all 4 Unit Telescopes. It will deliver narrow angle astrometry with 10μas accuracy at the infrared K-band. At the 1. Physikalische Institut of the University of Cologne, which is part of the international GRAVITY consortium, two spectrometers, one for the sciene object, and one for the fringe tracking object, have been designed, manufactured and tested. These spectrometers are two individual devices, each with own housing and interfaces. For a minimized thermal background, the spectrometers are actively cooled down to an operating temperature of 80K in the ambient temperature environment of the Beam Combiner Instrument (BCI) cryostat. The outer casings are mounted thermal isolated to the base plate by glass fiber reinforced plastic (GRP) stands, copper cooling structures conduct the cold inside the spectrometers where it is routed to components via Cu cooling stripes. The spectrometers are covered with shells made of multi insulation foil. There will be shown and compared 3 cooling installations: setups in the Cologne test dewar, in the BCI dewar and in a mock-up cad model. There are some striking differences between the setup in the 2 different dewars. In the Cologne Test dewar the spectrometers are connected to the coldplate (80K); a Cu cooling structure and the thermal isolating GRP stands are bolted to the coldplate. In the BCI dewer Cu cooling structure is connected to the bottom of the nitrogen tank (80K), the GRP stands are bolted to the base plate (240K). The period of time during the cooldown process will be analyzed.

  12. Portable smartphone optical fibre spectrometer

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Arafat; Canning, John; Cook, Kevin; Jamalipour, Abbas

    2015-09-01

    A low cost, optical fibre based spectrometer has been developed on a smartphone platform for field-portable spectral analysis. Light of visible wavelength is collected using a multimode optical fibre and diffracted by a low cost nanoimprinted diffraction grating. A measurement range over 300 nm span (λ = 400 to 700 nm) is obtained using the smartphone CMOS chip. The spectral resolution is Δλ ~ 0.42 nm/screen pixel. A customized Android application processed the spectra on the same platform and shares with other devices. The results compare well with commercially available spectrometer.

  13. The Bruny Island Radio Spectrometer

    NASA Astrophysics Data System (ADS)

    Erickson, W. C.

    1997-11-01

    A radio spectrometer has been built on Bruny Island, south of Hobart, for the study of solar bursts in the rarely observed frequency range from 3 to 20 MHz. This spectrometer is an adaptive device that employs digital techniques to avoid most of the strong terrestrial interference prevalent in this frequency range. The residual interference that cannot be avoided is excised during off-line processing. As a result, successful observations are made down to the minimum frequency that can propagate through the ionosphere to the antenna. This minimum frequency depends upon the zenith distance of the Sun and it is usually between 4 and 8 MHz.

  14. JPL Fourier transform ultraviolet spectrometer

    NASA Technical Reports Server (NTRS)

    Cageao, R. P.; Friedl, R. R.; Sander, Stanley P.; Yung, Y. L.

    1994-01-01

    The Fourier Transform Ultraviolet Spectrometer (FTUVS) is a new high resolution interferometric spectrometer for multiple-species detection in the UV, visible and near-IR. As an OH sensor, measurements can be carried out by remote sensing (limb emission and column absorption), or in-situ sensing (long-path absorption or laser-induced fluorescence). As a high resolution detector in a high repetition rate (greater than 10 kHz) LIF system, OH fluorescence can be discriminated against non-resonant background emission and laser scatter, permitting (0, 0) excitation.

  15. A cometary ion mass spectrometer

    NASA Technical Reports Server (NTRS)

    Shelley, E. G.; Simpson, D. A.

    1984-01-01

    The development of flight suitable analyzer units for that part of the GIOTTO Ion Mass Spectrometer (IMS) experiment designated the High Energy Range Spectrometer (HERS) is discussed. Topics covered include: design of the total ion-optical system for the HERS analyzer; the preparation of the design of analyzing magnet; the evaluation of microchannel plate detectors and associated two-dimensional anode arrays; and the fabrication and evaluation of two flight-suitable units of the complete ion-optical analyzer system including two-dimensional imaging detectors and associated image encoding electronics.

  16. Forward spectrometers at the SSC

    SciTech Connect

    Bjorken, J.D.

    1986-01-01

    Most of SSC phase space and a great deal of physics potential is in the forward/backward region (absolute value of theta < 100 mrad). Comprehensive open-geometry spectrometers are feasible and very cost effective. Examples of such devices are sketched. Because such spectrometers are very long and may operate at high ..beta.. and longer bunch spacing, they impact now on SSC interaction - region design. The data acquisition load is as heavy as for central detectors, although there may be less emphasis on speed and more emphasis on sophisticated parallel and/or distributed processing for event selection, as well as on high-capacity buffering.

  17. Towed seabed gamma ray spectrometer

    SciTech Connect

    Jones, D.G. )

    1994-08-01

    For more than 50 years, the measurement of radioactivity has been used for onshore geological surveys and in laboratories. The British Geological Survey (BGS) has extended the use of this type of equipment to the marine environment with the development of seabed gamma ray spectrometer systems. The present seabed gamma ray spectrometer, known as the Eel, has been successfully used for sediment and solid rock mapping, mineral exploration, and radioactive pollution studies. The range of applications for the system continues to expand. This paper examines the technological aspects of the Eel and some of the applications for which it has been used.

  18. Mass spectrometers and atomic oxygen

    NASA Technical Reports Server (NTRS)

    Hunton, D. E.; Trzcinski, E.; Cross, J. B.; Spangler, L. H.; Hoffbauer, M. H.; Archuleta, F. H.; Visentine, J. T.

    1987-01-01

    The likely role of atmospheric atomic oxygen in the recession of spacecraft surfaces and in the shuttle glow has revived interest in the accurate measurement of atomic oxygen densities in the upper atmosphere. The Air Force Geophysics Laboratory is supplying a quadrupole mass spectrometer for a materials interactions flight experiment being planned by the Johnson Space Center. The mass spectrometer will measure the flux of oxygen on test materials and will also identify the products of surface reactions. The instrument will be calibrated at a new facility for producing high energy beams of atomic oxygen at the Los Alamos National Laboratory. The plans for these calibration experiments are summarized.

  19. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (Editor); Moorehead, Tauna W. (Editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  20. Spectrometers for RF breakdown studies for CLIC

    NASA Astrophysics Data System (ADS)

    Jacewicz, M.; Ziemann, V.; Ekelöf, T.; Dubrovskiy, A.; Ruber, R.

    2016-08-01

    An e+e- collider of several TeV energy will be needed for the precision studies of any new physics discovered at the LHC collider at CERN. One promising candidate is CLIC, a linear collider which is based on a two-beam acceleration scheme that efficiently solves the problem of power distribution to the acceleration structures. The phenomenon that currently prevents achieving high accelerating gradients in high energy accelerators such as the CLIC is the electrical breakdown at very high electrical field. The ongoing experimental work within the CLIC collaboration is trying to benchmark the theoretical models focusing on the physics of vacuum breakdown which is responsible for the discharges. In order to validate the feasibility of accelerating structures and observe the characteristics of the vacuum discharges and their eroding effects on the structure two dedicated spectrometers are now commissioned at the high-power test-stands at CERN. First, the so called Flashbox has opened up a possibility for non-invasive studies of the emitted breakdown currents during two-beam acceleration experiments. It gives a unique possibility to measure the energy of electrons and ions in combination with the arrival time spectra and to put that in context with accelerated beam, which is not possible at any of the other existing test-stands. The second instrument, a spectrometer for detection of the dark and breakdown currents, is operated at one of the 12 GHz stand-alone test-stands at CERN. Built for high repetition rate operation it can measure the spatial and energy distributions of the electrons emitted from the acceleration structure during a single RF pulse. Two new analysis tools: discharge impedance tracking and tomographic image reconstruction, applied to the data from the spectrometer make possible for the first time to obtain the location of the breakdown inside the structure both in the transversal and longitudinal direction thus giving a more complete picture of the

  1. Interfacing an aspiration ion mobility spectrometer to a triple quadrupole mass spectrometer

    SciTech Connect

    Adamov, Alexey; Viidanoja, Jyrki; Kaerpaenoja, Esko; Paakkanen, Heikki; Ketola, Raimo A.; Kostiainen, Risto; Sysoev, Alexey; Kotiaho, Tapio

    2007-04-15

    This article presents the combination of an aspiration-type ion mobility spectrometer with a mass spectrometer. The interface between the aspiration ion mobility spectrometer and the mass spectrometer was designed to allow for quick mounting of the aspiration ion mobility spectrometer onto a Sciex API-300 triple quadrupole mass spectrometer. The developed instrumentation is used for gathering fundamental information on aspiration ion mobility spectrometry. Performance of the instrument is demonstrated using 2,6-di-tert-butyl pyridine and dimethyl methylphosphonate.

  2. Grazing-incidence spectrometer on the SSPX spheromak

    SciTech Connect

    Clementson, J; Beiersdorfer, P; Magee, E W

    2008-05-02

    The Silver Flat Field Spectrometer (SFFS) is a high-resolution grazing-incidence diagnostic for magnetically confined plasmas. It covers the wavelength range of 25-450 {angstrom} with a resolution of {Delta}{lambda} = 0.3 {angstrom} FWHM. The SFFS employs a spherical 1200 lines/mm grating for flat-field focusing. The imaging is done using a back-illuminated Photometrics CCD camera allowing a bandwidth of around 200 {angstrom} per spectrum. The spectrometer has been used for atomic spectroscopy on electron beam ion traps and for plasma spectroscopy on magnetic confinement devices. The design of the SFFS and the spectrometer setup at the Sustained Spheromak Physics Experiment (SSPX) in Livermore will be presented.

  3. Fieldable Fourier transform spectrometer

    NASA Astrophysics Data System (ADS)

    Hatchell, Brian K.; Harper, Warren W.; Schultz, John F.

    2004-10-01

    The infrared sensors group at the Pacific Northwest National Laboratory (PNNL) is focused on the science and technology of remote and in-situ chemical sensors for detecting proliferation and countering terrorism. To support these vital missions, PNNL is developing frequency-modulation techniques for remote probing over long optical paths by means of differential-absorption light detecting and ranging (LIDAR). This technique can easily monitor large areas, or volumes, that could only be accomplished with a large network of point sensors. Recently, PNNL began development of a rugged frequency-modulation differential-abosrption LIDAR (FM-DIAL) system to conduct field experiments. To provide environmentla protection for the system and facilitate field deployments and operations, a large, well insulated, temperature controlled trailer was specified and acquired. The trailer was outfitted with a shock-mounted optical bench, an electronics rack, a liquid nitrogen Dewar, and a power generator. A computer-controlled gimbal-mounted mirror was added to allow the telescope beam to be accurately pointed in both the vertical and horizontal plane. This turned out to be the most complicated addition, and is described in detail. This paper provides an overview of the FM-DIAL system and illustrates innovative solutions developed to overcome several alignment and stability issues encountered in the field.

  4. Design and Calibration of a Raman Spectrometer for use in a Laser Spectroscopy Instrument Intended to Analyze Martian Surface and Atmospheric Characteristics for NASA

    NASA Technical Reports Server (NTRS)

    Lucas, John F.; Hornef, James

    2016-01-01

    This project's goal is the design of a Raman spectroscopy instrument to be utilized by NASA in an integrated spectroscopy strategy that will include Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Induced Florescence Spectroscopy (LIFS) for molecule and element identification on Mars Europa, and various asteroids. The instrument is to be down scaled from a dedicated rover mounted instrument into a compact unit with the same capabilities and accuracy as the larger instrument. The focus for this design is a spectrometer that utilizes Raman spectroscopy. The spectrometer has a calculated range of 218 nm wavelength spectrum with a resolution of 1.23 nm. To filter out the laser source wavelength of 532 nm the spectrometer design utilizes a 532 nm wavelength dichroic mirror and a 532 nm wavelength notch filter. The remaining scatter signal is concentrated by a 20 x microscopic objective through a 25-micron vertical slit into a 5mm diameter, 1cm focal length double concave focusing lens. The light is then diffracted by a 1600 Lines per Millimeter (L/mm) dual holographic transmission grating. This spectrum signal is captured by a 1-inch diameter double convex 3 cm focal length capture lens. An Intensified Charge Couple Device (ICCD) is placed within the initial focal cone of the capture lens and the Raman signal captured is to be analyzed through spectroscopy imaging software. This combination allows for accurate Raman spectroscopy to be achieved. The components for the spectrometer have been bench tested in a series of prototype developments based on theoretical calculations, alignment, and scaling strategies. The mounting platform is 2.5 cm wide by 8.8 cm long by 7 cm height. This platform has been tested and calibrated with various sources such as a neon light source and ruby crystal. This platform is intended to be enclosed in a ruggedized enclosure for mounting on a rover platform. The size and functionality of the Raman spectrometer allows for the rover to

  5. A Wide Field of View Plasma Spectrometer

    DOE PAGESBeta

    Skoug, Ruth M.; Funsten, Herbert O.; Moebius, Eberhard; Harper, Ron W.; Kihara, Keith H.; Bower, Jonathan S.

    2016-07-23

    Here we present a fundamentally new type of space plasma spectrometer, the wide field of view plasma spectrometer, whose field of view is >1.25π ster using fewer resources than traditional methods. The enabling component is analogous to a pinhole camera with an electrostatic energy-angle filter at the image plane. Particle energy-per-charge is selected with a tunable bias voltage applied to the filter plate relative to the pinhole aperture plate. For a given bias voltage, charged particles from different directions are focused by different angles to different locations. Particles with appropriate locations and angles can transit the filter plate and aremore » measured using a microchannel plate detector with a position-sensitive anode. Full energy and angle coverage are obtained using a single high-voltage power supply, resulting in considerable resource savings and allowing measurements at fast timescales. Lastly, we present laboratory prototype measurements and simulations demonstrating the instrument concept and discuss optimizations of the instrument design for application to space measurements.« less

  6. MICE Spectrometer Magnet System Progress

    SciTech Connect

    Green, Michael A.; Virostek, Steve P.

    2007-08-27

    The first magnets for the muon ionization cooling experimentwill be the tracker solenoids that form the ends of the MICE coolingchannel. The primary purpose of the tracker solenoids is to provide auniform 4 T field (to better than +-0.3 percent over a volume that is 1meter long and 0.3 meters in diameter) spectrometer magnet field for thescintillating fiber detectors that are used to analyze the muons in thechannel before and after ionization cooling. A secondary purpose for thetracker magnet is the matching of the muon beam between the rest of theMICE cooling channel and the uniform field spectrometer magnet. Thetracker solenoid is powered by three 300 amp power supplies. Additionaltuning of the spectrometer is provided by a pair of 50 amp power suppliesacross the spectrometer magnet end coils. The tracker magnet will becooled using a pair of 4 K pulse tube coolers that each provide 1.5 W ofcooling at 4.2 K. Final design and construction of the tracker solenoidsbegan during the summer of 2006. This report describes the progress madeon the construction of the tracker solenoids.

  7. A simple digital TDPAC spectrometer

    NASA Astrophysics Data System (ADS)

    Webb, T. A.; Nikkinen, Leo; Gallego, Juan; Ryan, D. H.

    2013-05-01

    We present a simplified digital time differential perturbed γ - γ angular correlation (TDPAC) spectrometer that demonstrates that such instruments can be built using primarily commercial components and with relatively modest coding effort. The system handles data rates of 70 kcps/detector with a timing resolution of better than 500 ps, and has been used with both 111In and 181Hf.

  8. Convex Diffraction Grating Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Chrisp, Michael P. (Inventor)

    1999-01-01

    A 1:1 Offner mirror system for imaging off-axis objects is modified by replacing a concave spherical primary mirror that is concentric with a convex secondary mirror with two concave spherical mirrors M1 and M2 of the same or different radii positioned with their respective distances d1 and d2 from a concentric convex spherical diffraction grating having its grooves parallel to the entrance slit of the spectrometer which replaces the convex secondary mirror. By adjusting their distances d1 and d2 and their respective angles of reflection alpha and beta, defined as the respective angles between their incident and reflected rays, all aberrations are corrected without the need to increase the spectrometer size for a given entrance slit size to reduce astigmatism, thus allowing the imaging spectrometer volume to be less for a given application than would be possible with conventional imaging spectrometers and still give excellent spatial and spectral imaging of the slit image spectra over the focal plane.

  9. Acoustically-tuned optical spectrometer

    NASA Technical Reports Server (NTRS)

    Sklar, E.

    1981-01-01

    Lens arrangement corrects for aberrations and gives resolution of 0.7 seconds of arc. In spectrometer, light from telescope is relayed by doublet lens to acoustically tuned optical filter. Selected wavelengths are relayed by triplet lens to charge coupled device camera. Intervening cylindrical lens, tilted at 12 degree angle, corrects for astigmatism and coma introduced by two element birefringent crystal in filter.

  10. IPNS-I chopper spectrometers

    SciTech Connect

    Price, D.L.; Carpenter, J.M.; Pelizzari, C.A.; Sinha, S.K.; Bresof, I.; Ostrowski, G.E.

    1982-01-01

    We briefly describe the layout and operation of the two chopper experiments at IPNS-I. The recent measurement on solid /sup 4/He by Hilleke et al. provides examples of time-of-flight data from the Low Resolution Chopper Spectrometer.

  11. Alpha proton x ray spectrometer

    NASA Technical Reports Server (NTRS)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  12. Time of flight mass spectrometer

    DOEpatents

    Ulbricht, Jr., William H.

    1984-01-01

    A time-of-flight mass spectrometer is described in which ions are desorbed from a sample by nuclear fission fragments, such that desorption occurs at the surface of the sample impinged upon by the fission fragments. This configuration allows for the sample to be of any thickness, and eliminates the need for complicated sample preparation.

  13. Tracking System for Infrared Spectrometer

    NASA Technical Reports Server (NTRS)

    Johnson, R. A.; Webster, C. R.; Menzies, R. T.; Morrison, G. B.; Riccio, J. H.

    1986-01-01

    Visible laser tracking system for infrared laser spectometer keeps probe infrared laser beam aimed at moving reflector, thereby keeping reflector image and return laser beam within spectrometer field of view. System includes tracking mirror tilted by stepping motors under microprocessor control to deflect beams toward continually changing reflector position.

  14. Imaging IR spectrometer, phase 2

    NASA Technical Reports Server (NTRS)

    Gradie, Jonathan; Lewis, Ralph; Lundeen, Thomas; Wang, Shu-I

    1990-01-01

    The development is examined of a prototype multi-channel infrared imaging spectrometer. The design, construction and preliminary performance is described. This instrument is intended for use with JPL Table Mountain telescope as well as the 88 inch UH telescope on Mauna Kea. The instrument is capable of sampling simultaneously the spectral region of 0.9 to 2.6 um at an average spectral resolution of 1 percent using a cooled (77 K) optical bench, a concave holographic grating and a special order sorting filter to allow the acquisition of the full spectral range on a 128 x 128 HgCdTe infrared detector array. The field of view of the spectrometer is 0.5 arcsec/pixel in mapping mode and designed to be 5 arcsec/pixel in spot mode. The innovative optical design has resulted in a small, transportable spectrometer, capable of remote operation. Commercial applications of this spectrometer design include remote sensing from both space and aircraft platforms as well as groundbased astronomical observations.

  15. Focusing polycapillary to reduce parasitic scattering for inelastic x-ray measurements at high pressure

    SciTech Connect

    Chow, P. Xiao, Y. M.; Rod, E.; Bai, L. G.; Shen, G. Y.; Sinogeikin, S.; Gao, N.; Ding, Y.; Mao, H.-K.

    2015-07-15

    The double-differential scattering cross-section for the inelastic scattering of x-ray photons from electrons is typically orders of magnitude smaller than that of elastic scattering. With samples 10-100 μm size in a diamond anvil cell at high pressure, the inelastic x-ray scattering signals from samples are obscured by scattering from the cell gasket and diamonds. One major experimental challenge is to measure a clean inelastic signal from the sample in a diamond anvil cell. Among the many strategies for doing this, we have used a focusing polycapillary as a post-sample optic, which allows essentially only scattered photons within its input field of view to be refocused and transmitted to the backscattering energy analyzer of the spectrometer. We describe the modified inelastic x-ray spectrometer and its alignment. With a focused incident beam which matches the sample size and the field of view of polycapillary, at relatively large scattering angles, the polycapillary effectively reduces parasitic scattering from the diamond anvil cell gasket and diamonds. Raw data collected from the helium exciton measured by x-ray inelastic scattering at high pressure using the polycapillary method are compared with those using conventional post-sample slit collimation.

  16. Clinical Safety of a High Dose of Phycocyanin-Enriched Aqueous Extract from Arthrospira (Spirulina) platensis: Results from a Randomized, Double-Blind, Placebo-Controlled Study with a Focus on Anticoagulant Activity and Platelet Activation

    PubMed Central

    Drapeau, Cassandra; Lenninger, Miki; Benson, Kathleen F.

    2016-01-01

    Abstract The goal for this study was to evaluate safety regarding anticoagulant activity and platelet activation during daily consumption of an aqueous cyanophyta extract (ACE), containing a high dose of phycocyanin. Using a randomized, double-blind, placebo-controlled study design, 24 men and women were enrolled after informed consent, and consumed either ACE (2.3 g/day) or placebo daily for 2 weeks. The ACE dose was equivalent to ∼1 g phycocyanin per day, chosen based on the highest dose Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration. Consuming ACE did not alter markers for platelet activation (P-selectin expression) or serum P-selectin levels. No changes were seen for activated partial thromboplastin time, thrombin clotting time, or fibrinogen activity. Serum levels of aspartate transaminase (AST) showed a significant reduction after 2 weeks of ACE consumption (P < .001), in contrast to placebo where no changes were seen; the difference in AST levels between the two groups was significant at 2 weeks (P < .02). Reduced levels of alanine transaminase (ALT) were also seen in the group consuming ACE (P < .08). Previous studies showed reduction of chronic pain when consuming 1 g ACE per day. The higher dose of 2.3 g/day in this study was associated with significant reduction of chronic pain at rest and when physically active (P < .05). Consumption of ACE showed safety regarding markers pertaining to anticoagulant activity and platelet activation status, in conjunction with rapid and robust relief of chronic pain. Reduction in AST and ALT suggested improvement in liver function and metabolism. PMID:27362442

  17. Clinical Safety of a High Dose of Phycocyanin-Enriched Aqueous Extract from Arthrospira (Spirulina) platensis: Results from a Randomized, Double-Blind, Placebo-Controlled Study with a Focus on Anticoagulant Activity and Platelet Activation.

    PubMed

    Jensen, Gitte S; Drapeau, Cassandra; Lenninger, Miki; Benson, Kathleen F

    2016-07-01

    The goal for this study was to evaluate safety regarding anticoagulant activity and platelet activation during daily consumption of an aqueous cyanophyta extract (ACE), containing a high dose of phycocyanin. Using a randomized, double-blind, placebo-controlled study design, 24 men and women were enrolled after informed consent, and consumed either ACE (2.3 g/day) or placebo daily for 2 weeks. The ACE dose was equivalent to ∼1 g phycocyanin per day, chosen based on the highest dose Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration. Consuming ACE did not alter markers for platelet activation (P-selectin expression) or serum P-selectin levels. No changes were seen for activated partial thromboplastin time, thrombin clotting time, or fibrinogen activity. Serum levels of aspartate transaminase (AST) showed a significant reduction after 2 weeks of ACE consumption (P < .001), in contrast to placebo where no changes were seen; the difference in AST levels between the two groups was significant at 2 weeks (P < .02). Reduced levels of alanine transaminase (ALT) were also seen in the group consuming ACE (P < .08). Previous studies showed reduction of chronic pain when consuming 1 g ACE per day. The higher dose of 2.3 g/day in this study was associated with significant reduction of chronic pain at rest and when physically active (P < .05). Consumption of ACE showed safety regarding markers pertaining to anticoagulant activity and platelet activation status, in conjunction with rapid and robust relief of chronic pain. Reduction in AST and ALT suggested improvement in liver function and metabolism. PMID:27362442

  18. Barrel Calorimeter for the Hall D Spectrometer

    SciTech Connect

    David Urner

    1998-06-01

    The barrel calorimeter for the hall D spectrometer is discussed for standard pointing geometry and a parallel geometry using Lead Scintillating fibres as active material. A comparison with a CSI spectrometer is shown.

  19. New Positron Spectrometer for MEG Experiment Upgrade

    NASA Astrophysics Data System (ADS)

    Nishimura, M.

    2014-08-01

    An upgrade of the MEG experiment, which searches for the lepton flavor violating decay, μ → eγ, at the highest sensitivity ever, is planned in order to improve the sensitivity down to ∼ 5 ×10-14. We plan to employ a stereo wire drift chamber with a unique volume for the tracking and a pixelated scintillation detector with silicon photomultiplier (SiPM) readout for the timing measurement with improved efficiency and resolutions. We will describe the expected performance and the R&D status of the new spectrometer especially focusing on the new timing counter, which is expected to contribute better resolution of the relative timing between positron and gamma-ray.

  20. Acousto-optic spectrometer for radio astronomy

    NASA Technical Reports Server (NTRS)

    Chin, G.; Buhl, D.; Florez, J. M.

    1980-01-01

    Recent developments in acousto-optic techniques and in photodetector arrays have made feasible a new type of RF spectrometer, offering the advantages of wide bandwidth, high resolution, large number of channels in compact, lightweight, energy efficient, and relatively low cost systems. Such a system employs an acousto-optic diffraction cell which serves the key role of converting RF signals to ultrasonic traveling-waves modulating the optical index of the cell. The cell is illuminated across its aperture by a monochromatic laser beam. A fraction of the light is diffracted by the acoustic waves. A focusing lens follows the cell and essentially performs a Fourier transform of the RF signal into a far-field intensity pattern. CSIRO in Australia and the Tokyo Astronomical Observatory in Japan have taken the lead in using acousto-optic techniques in astronomical applications. The first practical device was successfully made at CSIRO for obtaining dynamical spectrographs of solar radio emission.

  1. Spectrometer system for diffuse extreme ultraviolet radiation

    NASA Technical Reports Server (NTRS)

    Labov, Simon E.

    1989-01-01

    A unique grazing incidence spectrometer system has been designed to study diffuse line emission between 80 and 650 A with 10-30 A resolution. The minimum detectable emission line strength during a 5-min observation ranges from 100-2000 ph/sq cm sec str. The instrument uses mechanically ruled reflection gratings placed in front of a linear array of mirrors. These mirrors focus the spectral image on microchannel plate detectors located behind thin filters. The field of view is 40 min of arc by 15 deg, and there is no spatial imaging. This instrument has been fabricated, calibrated, and successfully flown on a sounding rocket to observe the astronomical background radiation.

  2. [Design of a Component and Transmission Imaging Spectrometer].

    PubMed

    Sun, Bao-peng; Zhang, Yi; Yue, Jiang; Han, Jing; Bai, Lian-fa

    2015-05-01

    In the reflection-based imaging spectrometer, multiple reflection(diffraction) produces stray light and it is difficult to assemble. To address that, a high performance transmission spectral imaging system based on general optical components was developed. On the basis of simple structure, the system is easy to assemble. And it has wide application and low cost compared to traditional imaging spectrometers. All components in the design can be replaced according to different application situations, having high degree of freedom. In order to reduce the influence of stray light, a method based on transmission was introduced. Two sets of optical systems with different objective lenses were simulated; the parameters such as distortion, MTF and aberration.were analyzed and optimized in the ZEMAX software. By comparing the performance of system with different objective len 25 and 50 mm, it can be concluded that the replacement of telescope lens has little effect on imaging quality of whole system. An imaging spectrometer is developed successfully according design parameters. The telescope lens uses double Gauss structures, which is beneficial to reduce field curvature and distortion. As the craftsmanship of transmission-type plane diffraction grating is mature, it can be used without modification and it is easy to assemble, so it is used as beam-split. component of the imaging spectrometer. In addition, the real imaging spectrometer was tested for spectral resolution and distortion. The result demonstrates that the system has good ability in distortion control, and spectral resolution is 2 nm. These data satisfy the design requirement, and obtained spectrum of deuterium lamp through calibrated system are ideal results. PMID:26415470

  3. Design of camera and spectrometer dual-use system

    NASA Astrophysics Data System (ADS)

    Qi, Yong-hong; Xue, Bin; Zhao, Yi-yi; Tao, Jin-you

    2013-08-01

    Imaging spectrometers based on prism-grating-prism (PGP) have advantage of direct vision, as a basis for the design of an optical system for a spectrometer and camera dual-use, the system can plug the light splitting element to switch between the spectrometer and camera. This paper has discussed the working principles and structure of the PGP and spectrometer, collimating and focusing lens design principles, then the design result has been presented. The spectral range of the system is 400-800nm, the pixel size of CCD used is 10um × 10um, 1010 × 1018 pixels, the object space numerical aperture is 0.1. In order to reduce the cost and eliminate aberration, collimating lens and focusing lens have symmetric structure, in order to improve the diffraction efficiency, PGP uses the volume phase holographic transmission grating. After optimization the design by ZEMAX software, the whole spectral range resolution is better than 1nm in average, the MTF at Nyquist frequency is greater than 0.7, the length of the whole system is 87mm.

  4. Cryogenic Scan Mechanism for Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Brasunas, John C.; Francis, John L.

    2011-01-01

    A compact and lightweight mechanism has been developed to accurately move a Fourier transform spectrometer (FTS) scan mirror (a cube corner) in a near-linear fashion with near constant speed at cryogenic temperatures. This innovation includes a slide mechanism to restrict motion to one dimension, an actuator to drive the motion, and a linear velocity transducer (LVT) to measure the speed. The cube corner mirror is double-passed in one arm of the FTS; double-passing is required to compensate for optical beam shear resulting from tilting of the moving cube corner. The slide, actuator, and LVT are off-the-shelf components that are capable of cryogenic vacuum operation. The actuator drives the slide for the required travel of 2.5 cm. The LVT measures translation speed. A proportional feedback loop compares the LVT voltage with the set voltage (speed) to derive an error signal to drive the actuator and achieve near constant speed. When the end of the scan is reached, a personal computer reverses the set voltage. The actuator and LVT have no moving parts in contact, and have magnetic properties consistent with cryogenic operation. The unlubricated slide restricts motion to linear travel, using crossed roller bearings consistent with 100-million- stroke operation. The mechanism tilts several arc seconds during transport of the FTS mirror, which would compromise optical fringe efficiency when using a flat mirror. Consequently, a cube corner mirror is used, which converts a tilt into a shear. The sheared beam strikes (at normal incidence) a flat mirror at the end of the FTS arm with the moving mechanism, thereby returning upon itself and compensating for the shear

  5. The Pharmacopsychometric Triangle to Illustrate the Effectiveness of T-PEMF Concomitant with Antidepressants in Treatment Resistant Patients: A Double-Blind, Randomised, Sham-Controlled Trial Revisited with Focus on the Patient-Reported Outcomes

    PubMed Central

    Bech, P.; Gefke, M.; Lunde, M.; Lauritzen, L.; Martiny, K.

    2011-01-01

    Background. Our T-PEMF trial has been revisited with focus on the pharmacopsychometric triangle in which effect size is used when comparing wanted versus unwanted clinical effects and quality of life as outcomes. In this analysis, we have especially focused on the self-reported HAM-D6. Methods. The antidepressive medication which the patients were resistant to was kept unchanged during the five weeks of active versus sham T-PEMF. Results. In total 21, patients received active T-PEMF, and 19 patients received sham T-PEMF. The effect size was 1.02 and 0.90, respectively, on HAM-D6 and HAM-D6-S. Concerning side effects, the active T-PEMF reduced the baseline score on concentration problems with an effect size of 0.44 while inducing more autonomic symptoms than sham T-PEMF with an effect size of −0.41. The advantage of active over sham T-PEMF obtained an effect size of 0.48. Conclusion. Active T-PEMF was found superior to sham T-PEMF within the pharmacopsychometric triangle with a clinically significant effect size level above 0.40. PMID:21738869

  6. Sample rotating turntable kit for infrared spectrometers

    DOEpatents

    Eckels, Joel Del; Klunder, Gregory L.

    2008-03-04

    An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

  7. Measuring Transmission Efficiencies Of Mass Spectrometers

    NASA Technical Reports Server (NTRS)

    Srivastava, Santosh K.

    1989-01-01

    Coincidence counts yield absolute efficiencies. System measures mass-dependent transmission efficiencies of mass spectrometers, using coincidence-counting techniques reminiscent of those used for many years in calibration of detectors for subatomic particles. Coincidences between detected ions and electrons producing them counted during operation of mass spectrometer. Under certain assumptions regarding inelastic scattering of electrons, electron/ion-coincidence count is direct measure of transmission efficiency of spectrometer. When fully developed, system compact, portable, and used routinely to calibrate mass spectrometers.

  8. Electron/proton spectrometer certification documentation analyses

    NASA Technical Reports Server (NTRS)

    Gleeson, P.

    1972-01-01

    A compilation of analyses generated during the development of the electron-proton spectrometer for the Skylab program is presented. The data documents the analyses required by the electron-proton spectrometer verification plan. The verification plan was generated to satisfy the ancillary hardware requirements of the Apollo Applications program. The certification of the spectrometer requires that various tests, inspections, and analyses be documented, approved, and accepted by reliability and quality control personnel of the spectrometer development program.

  9. Beam shaping system based on a prism array for improving the throughput of a dispersive spectrometer.

    PubMed

    Shi, Zhendong; Fang, Liang; Fan, Bin; Zhou, Chongxi

    2015-04-01

    A beam shaping system (BSS) for improving the throughput of a dispersive spectrometer is presented by employing two anamorphic lenses and a prism array to segment the beam. The BSS was designed based on the inverse method of beam shaping for laser diode bars and the means of an optical slicer. In an experiment, a BSS was set up so that the incident light of a neon lamp with a circular spot from an input fiber was transformed into an elliptical spot coupled into a slit of a spectrometer without a change of divergence. Spectral measurement results demonstrate that the throughput of the dispersive spectrometer was doubled without loss of spectral resolution. The BSS can be combined with the existing dispersive spectrometer to improve the luminous flux and signal-to-noise ratio. PMID:25967181

  10. PILGRIM, a Multi-Reflection Time-of-Flight Mass Spectrometer for Spiral2-S3 at GANIL

    NASA Astrophysics Data System (ADS)

    Chauveau, P.; Delahaye, P.; De France, G.; El Abir, S.; Lory, J.; Merrer, Y.; Rosenbusch, M.; Schweikhard, L.; Wolf, R. N.

    2016-06-01

    PILGRIM is a Multi-Reflection Time-of-Flight Mass Spectrometer currently under development at GANIL for the S3 (Super Separator Spectrometer) collaboration and dedicated to the study of the ground-state properties of exotic nuclei. MR-ToF devices have proven to be effective tools for isobar separation (with mass resolving powers in excess of 105) and high-precision mass measurements (relative mass uncertainty down to a few 10-7) within a few tens of milliseconds. These features make them extremely interesting for ensuring beam purity and accurate mass determinations of very exotic, short lived nuclei. PILGRIM is to be set up in the future low energy branch of the S3-Spiral2 project and may also be used as a beam purifier in front of the double Penning trap PIPERADE at DESIR-Spiral2. An electrostatic 90 degree quadrupole deflector to be placed between an RFQ cooler-buncher (for beam preparation) and PILGRIM is also under study. The study on the deflector focuses on conserving the beam features, especially the time-of-flight spread of the ion bunches which has a direct impact on the resolving power of a multi-reflection device.

  11. Light Baryon Spectroscopy using the CLAS Spectrometer at Jefferson Laboratory

    SciTech Connect

    Volker Crede

    2011-12-01

    Baryons are complex systems of confined quarks and gluons and exhibit the characteristic spectra of excited states. The systematics of the baryon excitation spectrum is important to our understanding of the effective degrees of freedom underlying nucleon matter. High-energy electrons and photons are a remarkably clean probe of hadronic matter, providing a microscope for examining the nucleon and the strong nuclear force. Current experimental efforts with the CLAS spectrometer at Jefferson Laboratory utilize highly-polarized frozen-spin targets in combination with polarized photon beams. The status of the recent double-polarization experiments and some preliminary results are discussed in this contribution.

  12. Electron line shape of the KATRIN monitor spectrometer

    NASA Astrophysics Data System (ADS)

    Slezák, M.; Bauer, S.; Dragoun, O.; Erhard, M.; Schlösser, K.; Špalek, A.; Vénos, D.; Zbořil, M.

    2013-12-01

    Conversion electrons emitted from 83mKr implanted into a solid substrate will serve as a powerful tool for monitoring of the energy scale stability in the KATRIN neutrino experiment. An appropriate description of the conversion line shape is essential to determine the energy of the emitted electrons. It is shown that the Doniach-Šunjić line shape gives a significantly better fit to the conversion electron spectra than the previously used double Voigt model. The electron spectra were obtained with the KATRIN MAC-E filter monitor spectrometer.

  13. Advanced Mass Spectrometers for Hydrogen Isotope Analyses

    SciTech Connect

    Chastagner, P.

    2001-08-01

    This report is a summary of the results of a joint Savannah River Laboratory (SRL) - Savannah River Plant (SRP) ''Hydrogen Isotope Mass Spectrometer Evaluation Program''. The program was undertaken to evaluate two prototype hydrogen isotope mass spectrometers and obtain sufficient data to permit SRP personnel to specify the mass spectrometers to replace obsolete instruments.

  14. Electron spectrometer for gas-phase spectroscopy

    SciTech Connect

    Bozek, J.D.; Schlachter, A.S.

    1997-04-01

    An electron spectrometer for high-resolution spectroscopy of gaseous samples using synchrotron radiation has been designed and constructed. The spectrometer consists of a gas cell, cylindrical electrostatic lens, spherical-sector electron energy analyzer, position-sensitive detector and associated power supplies, electronics and vacuum pumps. Details of the spectrometer design are presented together with some representative spectra.

  15. Multilayer scintillation spectrometer for charged pionium detection

    NASA Astrophysics Data System (ADS)

    Krasnov, V. A.; Karnyushina, L. V.; Kuznetsov, S. N.; Kurepin, A. B.; Livanov, A. N.; Pilyar, A. V.

    2013-01-01

    The design description and characteristics of a 14-layer scintillation spectrometer for meson recording are given. The results from testing the spectrometer, calibrating it with cosmic-ray particles, and using the particle beams at energies reaching 1 GeV are presented. The spectrometer design is based on flat scintillation plates glued with wavelength-shifting optic fibers.

  16. Analysis and implementation of a space resolving spherical crystal spectrometer for x-ray Thomson scattering experiments

    SciTech Connect

    Harding, E. C.; Ao, T.; Bailey, J. E.; Loisel, G.; Sinars, D. B.; Geissel, M.; Rochau, G. A.; Smith, I. C.

    2015-04-15

    The application of a space-resolving spectrometer to X-ray Thomson Scattering (XRTS) experiments has the potential to advance the study of warm dense matter. This has motivated the design of a spherical crystal spectrometer, which is a doubly focusing geometry with an overall high sensitivity and the capability of providing high-resolution, space-resolved spectra. A detailed analysis of the image fluence and crystal throughput in this geometry is carried out and analytical estimates of these quantities are presented. This analysis informed the design of a new spectrometer intended for future XRTS experiments on the Z-machine. The new spectrometer collects 6 keV x-rays with a spherically bent Ge (422) crystal and focuses the collected x-rays onto the Rowland circle. The spectrometer was built and then tested with a foam target. The resulting high-quality spectra prove that a spherical spectrometer is a viable diagnostic for XRTS experiments.

  17. Analysis and implementation of a space resolving spherical crystal spectrometer for x-ray Thomson scattering experiments.

    PubMed

    Harding, E C; Ao, T; Bailey, J E; Loisel, G; Sinars, D B; Geissel, M; Rochau, G A; Smith, I C

    2015-04-01

    The application of a space-resolving spectrometer to X-ray Thomson Scattering (XRTS) experiments has the potential to advance the study of warm dense matter. This has motivated the design of a spherical crystal spectrometer, which is a doubly focusing geometry with an overall high sensitivity and the capability of providing high-resolution, space-resolved spectra. A detailed analysis of the image fluence and crystal throughput in this geometry is carried out and analytical estimates of these quantities are presented. This analysis informed the design of a new spectrometer intended for future XRTS experiments on the Z-machine. The new spectrometer collects 6 keV x-rays with a spherically bent Ge (422) crystal and focuses the collected x-rays onto the Rowland circle. The spectrometer was built and then tested with a foam target. The resulting high-quality spectra prove that a spherical spectrometer is a viable diagnostic for XRTS experiments. PMID:25933859

  18. SIEMENS ADVANCED QUANTRA FTICR MASS SPECTROMETER FOR ULTRA HIGH RESOLUTION AT LOW MASS

    SciTech Connect

    Spencer, W; Laura Tovo, L

    2008-07-08

    The Siemens Advanced Quantra Fourier Transform Ion Cyclotron Resonance (FTICR) mass spectrometer was evaluated as an alternative instrument to large double focusing mass spectrometers for gas analysis. High resolution mass spectrometers capable of resolving the common mass isomers of the hydrogen isotopes are used to provide data for accurate loading of reservoirs and to monitor separation of tritium, deuterium, and helium. Conventional double focusing magnetic sector instruments have a resolution that is limited to about 5000. The Siemens FTICR instrument achieves resolution beyond 400,000 and could possibly resolve the tritium ion from the helium-3 ion, which differ by the weight of an electron, 0.00549 amu. Working with Y-12 and LANL, SRNL requested Siemens to modify their commercial Quantra system for low mass analysis. To achieve the required performance, Siemens had to increase the available waveform operating frequency from 5 MHz to 40 MHz and completely redesign the control electronics and software. However, they were able to use the previous ion trap, magnet, passive pump, and piezo-electric pulsed inlet valve design. NNSA invested $1M in this project and acquired four systems, two for Y-12 and one each for SRNL and LANL. Siemens claimed a $10M investment in the Quantra systems. The new Siemens Advanced Quantra demonstrated phenomenal resolution in the low mass range. Resolution greater than 400,000 was achieved for mass 2. The new spectrometer had a useful working mass range to 500 Daltons. However, experiments found that a continuous single scan from low mass to high was not possible. Two useful working ranges were established covering masses 1 to 6 and masses 12 to 500 for our studies. A compromise performance condition enabled masses 1 to 45 to be surveyed. The instrument was found to have a dynamic range of about three orders of magnitude and quantitative analysis is expected to be limited to around 5 percent without using complex fitting algorithms

  19. Imaging X-ray spectrometer

    NASA Astrophysics Data System (ADS)

    Grant, P. A.; Jackson, J. W., Jr.; Alcorn, G. E.; Marshall, F. E.

    1984-09-01

    An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging.

  20. Exploiting a Transmission Grating Spectrometer

    SciTech Connect

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  1. Concerning the Spatial Heterodyne Spectrometer.

    PubMed

    Lenzner, Matthias; Diels, Jean-Claude

    2016-01-25

    A modified Spatial Heterodyne Spectrometer (SHS) is used for measuring atomic emission spectra with high resolution. This device is basically a Fourier Transform Spectrometer, but the Fourier transform is taken in the directions perpendicular to the optical propagation and heterodyned around one preset wavelength. In recent descriptions of this device, one specific phenomenon - the tilt of the energy front of wave packets when diffracted from a grating - was neglected. This led to an overestimate of the resolving power of this spectrograph, especially in situations when the coherence length of the radiation under test is in the order of the effective aperture of the device. The limits of usability are shown here together with some measurements of known spectral lines. PMID:26832561

  2. Concerning the Spatial Heterodyne Spectrometer

    DOE PAGESBeta

    Lenzner, Matthias; Diels, Jean -Claude

    2016-01-22

    A modified Spatial Heterodyne Spectrometer (SHS) is used for measuring atomic emission spectra with high resolution. This device is basically a Fourier Transform Spectrometer, but the Fourier transform is taken in the directions perpendicular to the optical propagation and heterodyned around one preset wavelength. In recent descriptions of this device, one specific phenomenon - the tilt of the energy front of wave packets when diffracted from a grating - was neglected. This led to an overestimate of the resolving power of this spectrograph, especially in situations when the coherence length of the radiation under test is in the order ofmore » the effective aperture of the device. In conclusion, the limits of usability are shown here together with some measurements of known spectral lines.« less

  3. Temporal dispersion of a spectrometer.

    PubMed

    Visco, A; Drake, R P; Froula, D H; Glenzer, S H; Pollock, B B

    2008-10-01

    The temporal dispersion of an optical spectrometer has been characterized for a variety of conditions related to optical diagnostics to be fielded at the National Ignition Facility (e.g., full-aperture backscatter station, Thomson scattering). Significant time smear is introduced into these systems by the path length difference through the spectrometer. The temporal resolution is shown to depend only on the order of the grating, wavelength, and the number of grooves illuminated. To enhance the temporal resolution, the spectral gratings can be masked limiting the number of grooves illuminated. Experiments have been conducted to verify these calculations. The size and shape of masks are investigated and correlated with the exact shape of the temporal instrument function, which is required when interpreting temporally resolved data. The experiments used a 300 fs laser pulse and a picosecond optical streak camera to determine the temporal dispersion. This was done for multiple spectral orders, gratings, and optical masks. PMID:19044687

  4. On-chip plasmonic spectrometer.

    PubMed

    Tsur, Yuval; Arie, Ady

    2016-08-01

    We report a numerical and experimental study of an on-chip optical spectrometer, utilizing propagating surface plasmon polaritons in the telecom spectral range. The device is based on two holographic gratings, one for coupling, and the other for decoupling free-space radiation with the surface plasmons. This 800 μm×100 μm on-chip spectrometer resolves 17 channels spectrally separated by 3.1 nm, spanning a freely tunable spectral window, and is based on standard lithography fabrication technology. We propose two potential applications for this new device; the first employs the holographic control over the amplitude and phase of the input spectrum, for intrinsically filtering unwanted frequencies, like pump radiation in Raman spectroscopy. The second prospect utilizes the unique plasmonic field enhancement at the metal-dielectric boundary for the spectral analysis of very small samples (e.g., Mie scatterers) placed between the two gratings. PMID:27472609

  5. Imaging X-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Grant, P. A.; Jackson, J. W., Jr.; Alcorn, G. E.; Marshall, F. E. (Inventor)

    1984-01-01

    An X-ray spectrometer for providing imaging and energy resolution of an X-ray source is described. This spectrometer is comprised of a thick silicon wafer having an embedded matrix or grid of aluminum completely through the wafer fabricated, for example, by thermal migration. The aluminum matrix defines the walls of a rectangular array of silicon X-ray detector cells or pixels. A thermally diffused aluminum electrode is also formed centrally through each of the silicon cells with biasing means being connected to the aluminum cell walls and causes lateral charge carrier depletion between the cell walls so that incident X-ray energy causes a photoelectric reaction within the silicon producing collectible charge carriers in the form of electrons which are collected and used for imaging.

  6. Gamma-ray spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Arnold, J. R.; Peterson, L. E.; Metzger, A. E.; Trombka, J. I.

    1972-01-01

    The experiments in gamma-ray spectrometry to determine the geochemical composition of the lunar surface are reported. The theory is discussed of discrete energy lines of natural radioactivity, and the lines resulting from the bombardment of the lunar surface by high energy cosmic rays. The gamma-ray spectrometer used in lunar orbit and during transearth coast is described, and a preliminary analysis of the results is presented.

  7. Landsat swath imaging spectrometer design

    NASA Astrophysics Data System (ADS)

    Mouroulis, Pantazis; Green, Robert O.; Van Gorp, Byron; Moore, Lori B.; Wilson, Daniel W.; Bender, Holly A.

    2016-01-01

    This paper describes the design of a high-throughput and high-uniformity pushbroom imaging spectrometer and telescope system that is capable of Landsat swath and resolution while providing better than 10 nm per pixel spectral resolution over the full visible to short-wave infrared band. The design is based on a 3200×480 element×18 μm pixel size focal plane array, two of which are utilized to cover the full swath. At an optical speed of F/1.8, the system is the fastest proposed to date to our knowledge. The utilization of only two Dyson-type spectrometer modules fed from the same telescope reduces system complexity while providing a solution within achievable detector technology. Two telescope designs are shown to achieve the required swath and resolution from different altitudes. Predictions of complete system response are shown. Also, it is shown that detailed ghost analysis is a requirement for this type of spectrometer and forms an essential part of a complete design.

  8. Thermal Infrared Profiling Spectrometer (TIPS)

    NASA Astrophysics Data System (ADS)

    Lanzl, Franz; Miosga, Gerhard; Lehmann, Frank; Richter, Rudolf; Tank, Volker; Boehl, R.

    1990-01-01

    The Thermal Infrared Profiling Spectrometer (TIPS) is an airborne/spaceborne sensor concept developed at DLR-Institute for Optoelectronics for scientific observations in remote sensing of the earth surface. The patented spectrometer design is based on a fast scanning Fourier spectrometer (FSM) using a rotating retroreflector to achieve the appropriate path alteration thus avoiding the usual linear movement of one of the mirrors in an conventional Michelson interferometer. The spectral band covers the 3 - 13 μm band with a spectral resolution of 5 cm-1 (50 nm at 10 μm). The measured signal is an interferogramm, derived quantities are spectral emissivity, spectral radiance and surface temperature. The optical system consists of an aperture filling plane tilting mirror to provide off-nadir observation and calibration mode. The collecting mirror focal length and the detector area yields an instantaneous field of view (ifov) of 1.2 mrad, noise equivalent temperature resolution of 0.04K (300K), and a noise equivalent change in emissivity Δɛof 6 x 10-4. Calibration is performed by two aperture filling area blackbodies at two different temperatures. An extensive simulation of signal/noise performance of the TIPS has been evaluated by means of the simulation programm SENSAT9, developed by DI.R. This simulation comprises the sensor performance, typical variations of atmospheric conditions and selected spectra from ground surfaces. Results of this simulation are discussed and a description of the sensor is presented.

  9. Grazing incidence extreme ultraviolet spectrometer fielded with time resolution in a hostile Z-pinch environment

    NASA Astrophysics Data System (ADS)

    Williamson, K. M.; Kantsyrev, V. L.; Safronova, A. S.; Wilcox, P. G.; Cline, W.; Batie, S.; LeGalloudec, B.; Nalajala, V.; Astanovitsky, A.

    2011-09-01

    This recently developed diagnostic was designed to allow for time-gated spectroscopic study of the EUV radiation (4 nm < λ < 15 nm) present during harsh wire array z-pinch implosions. The spectrometer utilizes a 25 μm slit, an array of 3 spherical blazed gratings at grazing incidence, and a microchannel plate (MCP) detector placed in an off-Rowland position. Each grating is positioned such that its diffracted radiation is cast over two of the six total independently timed frames of the MCP. The off-Rowland configuration allows for a much greater spectral density on the imaging plate but only focuses at one wavelength per grating. The focal wavelengths are chosen for their diagnostic significance. Testing was conducted at the Zebra pulsed-power generator (1 MA, 100 ns risetime) at the University of Nevada, Reno on a series of wire array z-pinch loads. Within this harsh z-pinch environment, radiation yields routinely exceed 20 kJ in the EUV and soft x-ray. There are also strong mechanical shocks, high velocity debris, sudden vacuum changes during operation, energic ion beams, and hard x-ray radiation in excess of 50 keV. The spectra obtained from the precursor plasma of an Al double planar wire array contained lines of Al IX and AlX ions indicating a temperature near 60 eV during precursor formation. Detailed results will be presented showing the fielding specifications and the techniques used to extract important plasma parameters using this spectrometer.

  10. Grazing incidence extreme ultraviolet spectrometer fielded with time resolution in a hostile Z-pinch environment

    SciTech Connect

    Williamson, K. M.; Kantsyrev, V. L.; Safronova, A. S.; Wilcox, P. G.; Cline, W.; Batie, S.; LeGalloudec, B.; Nalajala, V.; Astanovitsky, A.

    2011-09-15

    This recently developed diagnostic was designed to allow for time-gated spectroscopic study of the EUV radiation (4 nm < {lambda} < 15 nm) present during harsh wire array z-pinch implosions. The spectrometer utilizes a 25 {mu}m slit, an array of 3 spherical blazed gratings at grazing incidence, and a microchannel plate (MCP) detector placed in an off-Rowland position. Each grating is positioned such that its diffracted radiation is cast over two of the six total independently timed frames of the MCP. The off-Rowland configuration allows for a much greater spectral density on the imaging plate but only focuses at one wavelength per grating. The focal wavelengths are chosen for their diagnostic significance. Testing was conducted at the Zebra pulsed-power generator (1 MA, 100 ns risetime) at University of Nevada, Reno on a series of wire array z-pinch loads. Within this harsh z-pinch environment, radiation yields routinely exceed 20 kJ in the EUV and soft x-ray. There are also strong mechanical shocks, high velocity debris, sudden vacuum changes during operation, energic ion beams, and hard x-ray radiation in excess of 50 keV. The spectra obtained from the precursor plasma of an Al double planar wire array contained lines of Al IX and AlX ions indicating a temperature near 60 eV during precursor formation. Detailed results will be presented showing the fielding specifications and the techniques used to extract important plasma parameters using this spectrometer.

  11. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) spectrometer design and performance

    NASA Technical Reports Server (NTRS)

    Macenka, Steven A.; Chrisp, Michael P.

    1987-01-01

    The development of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has been completed at JPL. This paper outlines the functional requirements of the spectrometer optics subsystem, and describes the spectrometer optical design. The optical subsystem performance is shown in terms of spectral modulation transfer functions, radial energy distributions, and system transmission at selected wavelengths for the four spectrometers. An outline of the spectrometer alignment is included.

  12. The PNL high-transmission three-stage mass spectrometer

    NASA Astrophysics Data System (ADS)

    Stoffels, J. J.; Ells, D. R.; Bond, L. A.; Freedman, P. A.; Tattersall, B. N.; Lagergren, C. R.

    1992-12-01

    We have constructed a three-stage isotope-ratio mass spectrometer of unique ion-optical design that achieves high ion transmission efficiency and high abundance sensitivity. The spectrometer has tandem 90 deg deflection magnets with boundaries 18 deg off normal. The magnet drift lengths are 1.48 times the 27-cm radius of deflection. This extended geometry gives a mass dispersion equivalent to a 40-cm-radius magnet with normal boundaries. The first magnet renders the ion beam parallel in the vertical plane and provides a focus in the horizontal plane of mass dispersion. The second magnet brings the beam to a stigmatic focus. This novel ion-optical design gives 100 percent transmission without the need for intermediate focusing lenses. It also provides a 16 percent increase in mass resolution over the traditional tandem geometry with normal magnet boundaries. Complete transmission of ions is maintained through a third-stage cylindrical electric sector of 38-cm radius, which provides increased isotope-abundance sensitivity. The isotope-abundance sensitivity of the new mass spectrometer is an order of magnitude better than similar instruments with normal magnet boundaries. This is because the vertical focusing of the ion beam prevents ion scattering from the top and bottom of the flight tube. The measured values of the isotope-abundance sensitivity one-half mass unit away from the rhenium ion peaks at masses 185 and 187 are M - 1/2 = (6.5 +/- 0.5)(10)(exp -10) and M + 1/2 = (3.1 +/- 0.8)(10)(exp -10). By extrapolation, the uranium isotope-abundance sensitivity is M - 1 = 1(10)(exp -10). Construction of the instrument was facilitated by using standard commercial mass spectrometer components.

  13. High-efficiency electron ionizer for a mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Darrach, Murray R. (Inventor); Orient, Otto J. (Inventor)

    2001-01-01

    The present invention provides an improved electron ionizer for use in a quadrupole mass spectrometer. The improved electron ionizer includes a repeller plate that ejects sample atoms or molecules, an ionizer chamber, a cathode that emits an electron beam into the ionizer chamber, an exit opening for excess electrons to escape, at least one shim plate to collimate said electron beam, extraction apertures, and a plurality of lens elements for focusing the extracted ions onto entrance apertures.

  14. Ion mobility spectrometer / mass spectrometer (IMS-MS).

    SciTech Connect

    Hunka Deborah Elaine; Austin, Daniel E.

    2005-07-01

    The use of Ion Mobility Spectrometry (IMS) in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400). Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS) is described. The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.

  15. Ion Mobility Spectrometer / Mass Spectrometer (IMS-MS).

    SciTech Connect

    Hunka, Deborah E; Austin, Daniel

    2005-10-01

    The use of Ion Mobility Spectrometry (IMS)in the Detection of Contraband Sandia researchers use ion mobility spectrometers for trace chemical detection and analysis in a variety of projects and applications. Products developed in recent years based on IMS-technology include explosives detection personnel portals, the Material Area Access (MAA) checkpoint of the future, an explosives detection vehicle portal, hand-held detection systems such as the Hound and Hound II (all 6400), micro-IMS sensors (1700), ordnance detection (2500), and Fourier Transform IMS technology (8700). The emphasis to date has been on explosives detection, but the detection of chemical agents has also been pursued (8100 and 6400).Combining Ion Mobility Spectrometry (IMS) with Mass Spectrometry (MS)The IMS-MS combination overcomes several limitations present in simple IMS systems. Ion mobility alone is insufficient to identify an unknown chemical agent. Collision cross section, upon which mobility is based, is not sufficiently unique or predictable a priori to be able to make a confident peak assignment unless the compounds present are already identified. Molecular mass, on the other hand, is much more readily interpreted and related to compounds. For a given compound, the molecular mass can be determined using a pocket calculator (or in one's head) while a reasonable value of the cross-section might require hours of computation time. Thus a mass spectrum provides chemical specificity and identity not accessible in the mobility spectrum alone. In addition, several advanced mass spectrometric methods, such as tandem MS, have been extensively developed for the purpose of molecular identification. With an appropriate mass spectrometer connected to an ion mobility spectrometer, these advanced identification methods become available, providing greater characterization capability.3 AcronymsIMSion mobility spectrometryMAAMaterial Access AreaMSmass spectrometryoaTOForthogonal acceleration time

  16. Double Bass

    NASA Astrophysics Data System (ADS)

    Askenfelt, Anders

    The study of the acoustics of bowed instruments has for several reasons focused on the violin. A substantial amount of knowledge has been accumulated over the last century (see Hutchins 1975, 1976; Hutchins and Benade 1997). The violin is discussed in Chap. 13, while the cello is discussed in Chap. 14. The bow is discussed in Chap. 16.

  17. Key elements of a low voltage, ultracompact plasma spectrometer

    NASA Astrophysics Data System (ADS)

    Scime, E. E.; Barrie, A.; Dugas, M.; Elliott, D.; Ellison, S.; Keesee, A. M.; Pollock, C. J.; Rager, A.; Tersteeg, J.

    2016-02-01

    Taking advantage of technological developments in wafer-scale processing over the past two decades, such as deep etching, 3-D chip stacking, and double-sided lithography, we have designed and fabricated the key elements of an ultracompact (1.5 cm)3 plasma spectrometer that requires only low-voltage power supplies, has no microchannel plates, and has a high aperture area to instrument volume ratio. The initial design of the instrument targets the measurement of charged particles in the 3-20 keV range with a highly directional field of view and a 100% duty cycle; i.e., the entire energy range is continuously measured. In addition to reducing mass, size, and voltage requirements, the new design will affect the manufacturing process of plasma spectrometers, enabling large quantities of identical instruments to be manufactured at low individual unit cost. Such a plasma spectrometer is ideal for heliophysics plasma investigations, particularly for small satellite and multispacecraft missions. Two key elements of the instrument have been fabricated: the collimator and the energy analyzer. An initial collimator transparency of 20% with 3° × 3° angular resolution was achieved. The targeted 40% collimator transparency appears readily achievable. The targeted energy analyzer scaling factor of 1875 was achieved; i.e., 20 keV electrons were selected for only a 10.7 V bias voltage in the energy analyzer.

  18. Accuracy of Information Processing under Focused Attention.

    ERIC Educational Resources Information Center

    Bastick, Tony

    This paper reports the results of an experiment on the accuracy of information processing during attention focused arousal under two conditions: single estimation and double estimation. The attention of 187 college students was focused by a task requiring high level competition for a monetary prize ($10) under severely limited time conditions. The…

  19. Fast temperature spectrometer for samples under extreme conditions

    SciTech Connect

    Zhang, Dongzhou; Jackson, Jennifer M.; Sturhahn, Wolfgang; Zhao, Jiyong; Alp, E. Ercan; Toellner, Thomas S.; Hu, Michael Y.

    2015-01-15

    We have developed a multi-wavelength Fast Temperature Readout (FasTeR) spectrometer to capture a sample’s transient temperature fluctuations, and reduce uncertainties in melting temperature determination. Without sacrificing accuracy, FasTeR features a fast readout rate (about 100 Hz), high sensitivity, large dynamic range, and a well-constrained focus. Complimenting a charge-coupled device spectrometer, FasTeR consists of an array of photomultiplier tubes and optical dichroic filters. The temperatures determined by FasTeR outside of the vicinity of melting are, generally, in good agreement with results from the charge-coupled device spectrometer. Near melting, FasTeR is capable of capturing transient temperature fluctuations, at least on the order of 300 K/s. A software tool, SIMFaster, is described and has been developed to simulate FasTeR and assess design configurations. FasTeR is especially suitable for temperature determinations that utilize ultra-fast techniques under extreme conditions. Working in parallel with the laser-heated diamond-anvil cell, synchrotron Mössbauer spectroscopy, and X-ray diffraction, we have applied the FasTeR spectrometer to measure the melting temperature of {sup 57}Fe{sub 0.9}Ni{sub 0.1} at high pressure.

  20. 320-channel dual phase lock-in optical spectrometer

    NASA Astrophysics Data System (ADS)

    Fodor, P. S.; Rothenberger, S.; Jevy, J.

    2005-01-01

    The development of a multiple-channel lock-in optical spectrometer (LIOS) is presented, which enables parallel phase-sensitive detection at the output of an optical spectrometer. The light intensity from a spectrally broad source is modulated at the reference frequency, and focused into a high-resolution imaging spectrometer. The height at which the light enters the spectrometer is controlled by an acousto-optic deflector, and the height information is preserved at the output focal plane. A two-dimensional InGaAs focal plane array collects light that has been dispersed in wavelength along the horizontal direction, and in time along the vertical direction. The data is demodulated using a high performance computer-based digital signal processor. This parallel approach greatly enhances (by more than 100x) the speed at which spectrally resolved lock-in data can be acquired. The noise performance of a working system optimized for the 1.3 μm wavelength range is analyzed using a laser diode light source. Time-resolved absorption traces are obtained for InAs quantum dots embedded in a GaAs matrix, and for dispersed films of PbSe nanocrystals.

  1. Fast temperature spectrometer for samples under extreme conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Dongzhou; Jackson, Jennifer M.; Zhao, Jiyong; Sturhahn, Wolfgang; Alp, E. Ercan; Toellner, Thomas S.; Hu, Michael Y.

    2015-01-01

    We have developed a multi-wavelength Fast Temperature Readout (FasTeR) spectrometer to capture a sample's transient temperature fluctuations, and reduce uncertainties in melting temperature determination. Without sacrificing accuracy, FasTeR features a fast readout rate (about 100 Hz), high sensitivity, large dynamic range, and a well-constrained focus. Complimenting a charge-coupled device spectrometer, FasTeR consists of an array of photomultiplier tubes and optical dichroic filters. The temperatures determined by FasTeR outside of the vicinity of melting are, generally, in good agreement with results from the charge-coupled device spectrometer. Near melting, FasTeR is capable of capturing transient temperature fluctuations, at least on the order of 300 K/s. A software tool, SIMFaster, is described and has been developed to simulate FasTeR and assess design configurations. FasTeR is especially suitable for temperature determinations that utilize ultra-fast techniques under extreme conditions. Working in parallel with the laser-heated diamond-anvil cell, synchrotron Mössbauer spectroscopy, and X-ray diffraction, we have applied the FasTeR spectrometer to measure the melting temperature of 57Fe0.9Ni0.1 at high pressure.

  2. Fast temperature spectrometer for samples under extreme conditions.

    PubMed

    Zhang, Dongzhou; Jackson, Jennifer M; Zhao, Jiyong; Sturhahn, Wolfgang; Alp, E Ercan; Toellner, Thomas S; Hu, Michael Y

    2015-01-01

    We have developed a multi-wavelength Fast Temperature Readout (FasTeR) spectrometer to capture a sample's transient temperature fluctuations, and reduce uncertainties in melting temperature determination. Without sacrificing accuracy, FasTeR features a fast readout rate (about 100 Hz), high sensitivity, large dynamic range, and a well-constrained focus. Complimenting a charge-coupled device spectrometer, FasTeR consists of an array of photomultiplier tubes and optical dichroic filters. The temperatures determined by FasTeR outside of the vicinity of melting are, generally, in good agreement with results from the charge-coupled device spectrometer. Near melting, FasTeR is capable of capturing transient temperature fluctuations, at least on the order of 300 K/s. A software tool, SIMFaster, is described and has been developed to simulate FasTeR and assess design configurations. FasTeR is especially suitable for temperature determinations that utilize ultra-fast techniques under extreme conditions. Working in parallel with the laser-heated diamond-anvil cell, synchrotron Mössbauer spectroscopy, and X-ray diffraction, we have applied the FasTeR spectrometer to measure the melting temperature of (57)Fe0.9Ni0.1 at high pressure. PMID:25638070

  3. The Pickup Ion Composition Spectrometer

    NASA Astrophysics Data System (ADS)

    Gilbert, Jason A.; Zurbuchen, Thomas H.; Battel, Steven

    2016-06-01

    Observations of newly ionized atoms that are picked up by the magnetic field in the expanding solar wind contain crucial information about the gas or dust compositions of their origins. The pickup ions (PUIs) are collected by plasma mass spectrometers and analyzed for their density, composition, and velocity distribution. In addition to measurements of PUIs from planetary sources, in situ measurements of interstellar gas have been made possible by spectrometers capable of differentiating between heavy ions of solar and interstellar origin. While important research has been done on these often singly charged ions, the instruments that have detected many of them were designed for the energy range and ionic charge states of the solar wind and energized particle populations, and not for pickup ions. An instrument optimized for the complete energy and time-of-flight characterization of pickup ions will unlock a wealth of data on these hitherto unobserved or unresolved PUI species. The Pickup Ion Composition Spectrometer (PICSpec) is one such instrument and can enable the next generation of pickup ion and isotopic mass composition measurements. By combining a large-gap time-of-flight-energy sensor with a -100 kV high-voltage power supply for ion acceleration, PUIs will not only be above the detection threshold of traditional solid-state energy detectors but also be resolved sufficiently in time of flight that isotopic composition can be determined. This technology will lead to a new generation of space composition instruments, optimized for measurements of both heliospheric and planetary pickup ions.

  4. Achievement of 1 H-19 F heteronuclear experiments using the conventional spectrometer with a shared single high band amplifier.

    PubMed

    Sakuma, Chiseko; Kurita, Jun-ichi; Furihata, Kazuo; Tashiro, Mitsuru

    2015-05-01

    The (1)H-(19) F heteronuclear NMR experiments were achieved using the conventional spectrometer equipped with a single high band amplifier and a (1)H/(19)F/(13) C double-tuned probe. Although double high band amplifiers are generally required to perform such experiments, a simple modification of pathway in the conventional spectrometer was capable of acquiring various (1)H-(19)F heteronuclear spectra. The efficiency of the present technique was demonstrated in an application for (19)F{(1)H} and (1)H{(19)F} saturation transfer difference experiments. PMID:25808615

  5. [Biological Process Oriented Online Fourier Transform Infrared Spectrometer].

    PubMed

    Xie, Fei; Wu, Qiong-shui; Zeng, Li-bo

    2015-08-01

    An online Fourier Transform Infrared Spectrometer and an ATR (Attenuated Total Reflection) probe, specifically at the application of real time measurement of the reaction substrate concentration in biological processes, were designed. (1) The spectrometer combined the theories of double cube-corner reflectors and flat mirror, which created a kind of high performance interferometer system. The light path folding way was utilized to makes the interferometer compact structure. Adopting double cube-corner reflectors, greatly reduces the influence of factors in the process of moving mirror movement such as rotation, tilt, etc. The parallelogram oscillation flexible support device was utilized to support the moving mirror moves. It cancelled the friction and vibration during mirror moving, and ensures the smooth operation. The ZnSe splitter significantly improved the hardware reliability in high moisture environment. The method of 60° entrance to light splitter improves the luminous flux. (2) An ATR in situ measuring probe with simple structure, large-flux, economical and practical character was designed in this article. The transmission of incident light and the light output utilized the infrared pipe with large diameter and innerplanted-high plating membrane, which conducted for the infrared transmission media of ATR probe. It greatly reduced the energy loss of infrared light after multiple reflection on the inner wall of the light pipe. Therefore, the ATR probe obtained high flux, improved the signal strength, which make the signal detected easily. Finally, the high sensitivity of MCT (Mercury Cadmium Telluride) detector was utilized to realize infrared interference signal collection, and improved the data quality of detection. The test results showed that the system yields the advantages of perfect moisture-proof performance, luminous flux, online measurement, etc. The designed online Fourier infrared spectrometer can real-time measured common reactant substrates

  6. Double-Knudsen-Cell Apparatus Measures Alloy-Component Activities

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Moore, Warren A.

    1995-01-01

    Double-Knudsen-cell apparatus provides molecular beam from selected one of two Knudsen cells. Both cells maintained at same temperature. Molecular beam directed into mass spectrometer for measurement of vapor pressure of selected material component. Designed to minimize undesired thermal gradients, provides appropriate translation to place selected cell in position for sampling, and minimizes mixing of molecular beams from cells.

  7. Alpha-particle spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Gorenstein, P.; Bjorkholm, P.

    1972-01-01

    Mapping the radon emanation of the moon was studied to find potential areas of high activity by detection of radon isotopes and their daughter products. It was felt that based on observation of regions overflown by Apollo spacecraft and within the field of view of the alpha-particle spectrometer, a radon map could be constructed, identifying and locating lunar areas of outgassing. The basic theory of radon migration from natural concentrations of uranium and thorium is discussed in terms of radon decay and the production of alpha particles. The preliminary analysis of the results indicates no significant alpha emission.

  8. FPGA based pulsed NQR spectrometer

    NASA Astrophysics Data System (ADS)

    Hemnani, Preeti; Rajarajan, A. K.; Joshi, Gopal; Motiwala, Paresh D.; Ravindranath, S. V. G.

    2014-04-01

    An NQR spectrometer for the frequency range of 1 MHz to 5 MHZ has been designed constructed and tested using an FPGA module. Consisting of four modules viz. Transmitter, Probe, Receiver and computer controlled (FPGA & Software) module containing frequency synthesizer, pulse programmer, mixer, detection and display, the instrument is capable of exciting nuclei with a power of 200W and can detect signal of a few microvolts in strength. 14N signal from NaNO2 has been observed with the expected signal strength.

  9. Static Fourier transform infrared spectrometer.

    PubMed

    Schardt, Michael; Murr, Patrik J; Rauscher, Markus S; Tremmel, Anton J; Wiesent, Benjamin R; Koch, Alexander W

    2016-04-01

    Fourier transform spectroscopy has established itself as the standard method for spectral analysis of infrared light. Here we present a robust and compact novel static Fourier transform spectrometer design without any moving parts. The design is well suited for measurements in the infrared as it works with extended light sources independent of their size. The design is experimentally evaluated in the mid-infrared wavelength region between 7.2 μm and 16 μm. Due to its large etendue, its low internal light loss, and its static design it enables high speed spectral analysis in the mid-infrared. PMID:27137061

  10. Automated mass spectrometer grows up

    SciTech Connect

    McInteer, B.B.; Montoya, J.G.; Stark, E.E.

    1984-01-01

    In 1980 we reported the development of an automated mass spectrometer for large scale batches of samples enriched in nitrogen-15 as ammonium salts. Since that time significant technical progress has been made in the instrument. Perhaps more significantly, administrative and institutional changes have permitted the entire effort to be transferred to the private sector from its original base at the Los Alamos National Laboratory. This has ensured the continuance of a needed service to the international scientific community as revealed by a development project at a national laboratory, and is an excellent example of beneficial technology transfer to private industry.

  11. Wide-range CCD spectrometer

    NASA Astrophysics Data System (ADS)

    Sokolova, Elena A.; Reyes Cortes, Santiago D.

    1996-08-01

    The utilization of wide range spectrometers is a very important feature for the design of optical diagnostics. This paper describes an innovative approach, based on charged coupled device, which allows to analyze different spectral intervals with the same diffraction grating. The spectral interval is varied by changing the position of the entrance slit when the grating is stationary. The optical system can also include a spherical mirror. In this case the geometric position of the mirror is calculated aiming at compensating the first order astigmatism and the meridional coma of the grating. This device is planned to be used in Thomson scattering diagnostic of the TOKAMAK of Instituto Superior Tecnico, Lisbon (ISTTOK).

  12. The MAGNEX large acceptance spectrometer

    SciTech Connect

    Cavallaro, M.; Cappuzzello, F.; Cunsolo, A.; Carbone, D.; Foti, A.

    2010-03-01

    The main features of the MAGNEX large acceptance magnetic spectrometer are described. It has a quadrupole + dipole layout and a hybrid detector located at the focal plane. The aberrations due to the large angular (50 msr) and momentum (+- 13%) acceptance are reduced by an accurate hardware design and then compensated by an innovative software ray-reconstruction technique. The obtained resolution in energy, angle and mass are presented in the paper. MAGNEX has been used up to now for different experiments in nuclear physics and astrophysics confirming to be a multipurpose device.

  13. High-Resolution Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff; Goetz, Alexander F. H.

    1990-01-01

    Earth resources observed in greater detail. High-Resolution Imaging Spectrometer, undergoing development for use in NASA's Earth Observing System, measures reflectance of Earth's surface in visible and near-infrared wavelengths. From an orbit around Earth, instrument scans surface of Earth in 200 wavelength bands simultaneously. Produces images enabling identification of minerals in rocks and soils, important algal pigments in oceans and inland waters, changes in spectra associated with biochemistry of plant canopies, compositions of atmospheric aerosols, sizes of grains in snow, and contamination of snow by impurities that absorb visible light.

  14. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, D.A.; Erkkila, B.H.; Vasilik, D.G.

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  15. Portable neutron spectrometer and dosimeter

    DOEpatents

    Waechter, David A.; Erkkila, Bruce H.; Vasilik, Dennis G.

    1985-01-01

    The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

  16. X-ray crystal spectrometer upgrade for ITER-like wall experiments at JET

    SciTech Connect

    Shumack, A. E.; Rzadkiewicz, J.; Chernyshova, M.; Czarski, T.; Karpinski, L.; Jakubowska, K.; Scholz, M.; Byszuk, A.; Cieszewski, R.; Kasprowicz, G.; Pozniak, K.; Wojenski, A.; Zabolotny, W.; Dominik, W.; Conway, N. J.; Dalley, S.; Tyrrell, S.; Zastrow, K.-D.; Figueiredo, J. [EFDA-CSU, Culham Science Centre, Abingdon OX14 3DB; Associação EURATOM and others

    2014-11-15

    The high resolution X-Ray crystal spectrometer at the JET tokamak has been upgraded with the main goal of measuring the tungsten impurity concentration. This is important for understanding impurity accumulation in the plasma after installation of the JET ITER-like wall (main chamber: Be, divertor: W). This contribution provides details of the upgraded spectrometer with a focus on the aspects important for spectral analysis and plasma parameter calculation. In particular, we describe the determination of the spectrometer sensitivity: important for impurity concentration determination.

  17. X-ray crystal spectrometer upgrade for ITER-like wall experiments at JET.

    PubMed

    Shumack, A E; Rzadkiewicz, J; Chernyshova, M; Jakubowska, K; Scholz, M; Byszuk, A; Cieszewski, R; Czarski, T; Dominik, W; Karpinski, L; Kasprowicz, G; Pozniak, K; Wojenski, A; Zabolotny, W; Conway, N J; Dalley, S; Figueiredo, J; Nakano, T; Tyrrell, S; Zastrow, K-D; Zoita, V

    2014-11-01

    The high resolution X-Ray crystal spectrometer at the JET tokamak has been upgraded with the main goal of measuring the tungsten impurity concentration. This is important for understanding impurity accumulation in the plasma after installation of the JET ITER-like wall (main chamber: Be, divertor: W). This contribution provides details of the upgraded spectrometer with a focus on the aspects important for spectral analysis and plasma parameter calculation. In particular, we describe the determination of the spectrometer sensitivity: important for impurity concentration determination. PMID:25430332

  18. Resonant inelastic X-ray scattering spectrometer with 25meV resolution at the Cu K -edge

    DOE PAGESBeta

    Ketenoglu, Didem; Harder, Manuel; Klementiev, Konstantin; Upton, Mary; Taherkhani, Mehran; Spiwek, Manfred; Dill, Frank-Uwe; Wille, Hans-Christian; Yavaş, Hasan

    2015-06-27

    An unparalleled resolution is reported with an inelastic X-ray scattering instrument at the CuK-edge. Based on a segmented concave analyzer, featuring single-crystal quartz (SiO2) pixels, the spectrometer delivers a resolution near 25meV (FWHM) at 8981eV. Besides the quartz analyzer, the performance of the spectrometer relies on a four-bounce Si(553) high-resolution monochromator and focusing Kirkpatrick–Baez optics. The measured resolution agrees with the ray-tracing simulation of an ideal spectrometer. The performance of the spectrometer is demonstrated by reproducing the phonon dispersion curve of a beryllium single-crystal.

  19. A versatile pulsed X-band ENDOR spectrometer

    NASA Astrophysics Data System (ADS)

    Shane, J. J.; Gromov, I.; Vega, S.; Goldfarb, D.

    1998-09-01

    A versatile high power X-band (8.5-9.5 GHz) pulsed EPR/ENDOR (electron-nuclear double resonance) spectrometer which can generate hundreds of microwave (MW) and rf pulses is described. The pulse programmer is constructed from a word generator with 32 channels and 4 ns resolution, coupled to five digital delay generators which can produce a total of ten pulses with a resolution better than 1 ns. The spectrometer contains two MW and two rf channels that allow independent variation of the frequency, amplitude, and phase of the MW and rf pulses. The ENDOR probe head is based on a bridged loop gap (BLG) resonator, coupling is achieved via a coupling loop connected to a waveguide, and the rf coil serves as a MW shield as well. The adjustment of the coupling is done by an up/down motion of the of the resonator assembly with respect to the fixed coupling loop. A flexible and user friendly data acquisition program written in C++ (Borland version 4.5), which uses the Windows-95 Multiple Document Interface (MDI) programming model, was developed to run the spectrometer. This program allows easy programming of any pulse sequence with sophisticated phase cycling. The performance of the spectrometer is demonstrated by two experiments. The first is the triple resonance hyperfine-selective (HS) ENDOR experiment carried out on a frozen solution of the copper protein laccase. The second is the two-dimensional hyperfine-ENDOR (HYEND) correlation experiment performed on a single crystal of γ-irradiated malonic acid.

  20. Multi-electron coincidence spectroscopy: double photoionization from molecular inner-shell orbitals

    NASA Astrophysics Data System (ADS)

    Hikosaka, Y.; Lablanquie, P.; Penent, F.; Nakano, M.; Ito, K.

    2014-04-01

    We have studied double photoionization from molecular inner-shell orbitals and investigated the properties of the resultant double core-hole states in molecules, by multi-electron coincidence spectroscopy with a magnetic bottle electron spectrometer. A brief summary of our previous studies is presented.

  1. Atomic data for the ITER Core Imaging X-ray Spectrometer

    SciTech Connect

    Clementson, J; Beiersdorfer, P; Biedermann, C; Bitter, M; Delgado-Aparicio, L F; Graf, A; Gu, M F; Hill, K W; Barnsley, R

    2012-06-15

    The parameters of the ITER core plasmas will be measured using the Core Imaging X-ray Spectrometer (CIXS), a high-resolution crystal spectrometer focusing on the L-shell spectra of highly ionized tungsten atoms. In order to correctly infer the plasma properties accurate atomic data are required. Here, some aspects of the underlying physics are discussed using experimental data and theoretical predictions from modeling.

  2. Foil cycling technique for the VESUVIO spectrometer operating in the resonance detector configuration

    SciTech Connect

    Schooneveld, E. M.; Mayers, J.; Rhodes, N. J.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Gorini, G.; Perelli-Cippo, E.; Tardocchi, M.

    2006-09-15

    This article reports a novel experimental technique, namely, the foil cycling technique, developed on the VESUVIO spectrometer (ISIS spallation source) operating in the resonance detector configuration. It is shown that with a proper use of two foils of the same neutron absorbing material it is possible, in a double energy analysis process, to narrow the width of the instrumental resolution of a spectrometer operating in the resonance detector configuration and to achieve an effective subtraction of the neutron and gamma backgrounds. Preliminary experimental results, obtained from deep inelastic neutron scattering measurements on lead, zirconium hydride, and deuterium chloride samples, are presented.

  3. Electron pair emission detected by time-of-flight spectrometers: Recent progress

    SciTech Connect

    Huth, Michael; Schumann, Frank O.; Chiang, Cheng-Tien; Trützschler, Andreas; Kirschner, Jürgen; Widdra, Wolf

    2014-02-10

    We present results for electron coincidence spectroscopy using two time-of-flight (ToF) spectrometers. Excited by electron impact, the energy and momentum distribution of electron pairs emitted from the Cu(111) surface are resolved and a spectral feature related to the Shockley surface state is identified. By combining the two ToF spectrometers with a high-order harmonic generation light source, we demonstrate double photoemission spectroscopy in the laboratory that required synchrotron radiation in the past. Utilizing this setup, we report results for (γ,2e) on NiO(001) on Ag(001) excited with light at 30 eV photon energy.

  4. Experimental measurement of Au M-band flux in indirectly driven double-shell implosions

    SciTech Connect

    Robey, H.F.; Perry, T.S.; Park, H.-S.; Amendt, P.; Sorce, C.M.; Compton, S.M.; Campbell, K.M.; Knauer, J.P.

    2005-07-15

    Indirectly driven double-shell implosions are being investigated as a possible noncryogenic path to ignition on the National Ignition Facility [J. A. Paisner, J. D. Boyes, S. A. Kumpan, W. H. Lowdermilk, and M. S. Sorem, Laser Focus World 30, 75 (1994)]. In recent double-shell experiments, the inner shell trajectory was shown to exhibit a strong sensitivity to the temporal history of the M-band (2-5 keV) radiation emitted from the Au hohlraum wall. A large time-dependent discrepancy was observed between measurement and simulation of the x-ray flux in this range. In order to better characterize the radiation environment seen in these implosions, an experimental campaign was conducted on the Omega laser. A number of diagnostics were used to measure both the temporal and spectral nature of the M-band flux. Results were obtained from an absolutely calibrated 12-channel filtered x-ray diode array (Dante) as well as two streaked crystal spectrometers and an absolutely calibrated time-integrated spectrometer (Henway). X-ray backlighting was also used to directly measure the effect of M-band radiation on the trajectory of the inner shell. The data from all diagnostics are shown to be in excellent agreement and provide a consistent picture of the M-band flux. These results are being used to constrain and improve the simulation of hohlraum-generated M-band radiation that will be necessary for the design of future double-shell implosions employing higher-Z inner shells.

  5. Seeing Double

    NASA Astrophysics Data System (ADS)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  6. Double inflation

    SciTech Connect

    Silk, J.; Turner, M.S.

    1986-04-01

    The Zel'dovich spectrum of adiabatic density perturbations is a generic prediction of inflation. There is increasing evidence that when the spectrum is normalized by observational data on small scales, there is not enough power on large scales to account for the observed large-scale structure in the Universe. Decoupling the spectrum on large and small scales could solve this problem. As a means of decoupling the large and small scales we propose double inflation (i.e., two episodes of inflation). In this scenario the spectrum on large scales is determined by the first episode of inflation and those on small scales by a second episode of inflation. We present three models for such a scenario. By nearly saturating the large angular-scale cosmic microwave anisotropy bound, we can easily account for the observed large-scale structure. We take the perturbations on small scales to be very large, deltarho/rho approx. = 0.1 to 0.01, which results in the production of primordial black holes (PBHs), early formation of structure, reionization of the Universe, and a rich array of astrophysical events. The ..cap omega..-problem is also addressed by our scenario. Allowing the density perturbations produced by the second episode of inflation to be large also lessens the fine-tuning required in the scalar potential and makes reheating much easier. We briefly speculate on the possibility that the second episode of inflation proceeds through the nucleation of bubbles, which today manifest themselves as empty bubbles whose surfaces are covered with galaxies. 37 refs., 1 fig.

  7. Coherent modeling and stray light in a static Fourier transform spectrometer

    NASA Astrophysics Data System (ADS)

    Etcheto, Pierre; Rosak, Alain; Parant, Philippe; Vigier, Odile

    2004-02-01

    Atmospheric sounding requires high-resolution spectrometers, such as Fourier transform interferometers. Classical ones need moving mirrors to scan the spectrum, but static interferometers with stepped mirrors can achieve high resolution in within a narrow spectral band. CNES is developing such an instrument for CO2 flow monitoring. The breadboard includes two stepped mirrors, a separating plate, a double imaging system and a detector array. To simulate the actual instrument response, we developed a physically realistic model of the full optical system with ASAP, a software well suited for broad sources, partial coherence and non-sequential propagation. After checking the theoretical interferogram and the resulting instrument spectral response for a point source, we simulated the effects of field, coherence length and chromatism. Then we studied the complex ghost reflections between the mirrors, the separating plate, the optics and the detector, taking coherence into account. Resulting interferograms and spectra were compared to the nominal ones. It appears that the most critical ghosts are not the most intense but the best focused, especially when interfering with the nominal waves. Scatter is tolerable, as it is incoherent and relatively uniform. These results led to design improvements and alignment requirements on the breadboard. This study illustrates how physical modeling can contribute to the early design of complex, non-imaging systems.

  8. Engine spectrometer probe and method of use

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, Sarkis (Inventor); Kittinger, Scott A. (Inventor)

    2006-01-01

    The engine spectrometer probe and method of using the same of the present invention provides a simple engine spectrometer probe which is both lightweight and rugged, allowing an exhaust plume monitoring system to be attached to a vehicle, such as the space shuttle. The engine spectrometer probe can be mounted to limit exposure to the heat and debris of the exhaust plume. The spectrometer probe 50 comprises a housing 52 having an aperture 55 and a fiber optic cable 60 having a fiber optic tip 65. The fiber optic tip 65 has an acceptance angle 87 and is coupled to the aperture 55 so that the acceptance angle 87 intersects the exhaust plume 30. The spectrometer probe can generate a spectrum signal from light in the acceptance angle 506 and the spectrum signal can be provided to a spectrometer 508.

  9. Imaging spectrometer/camera having convex grating

    NASA Technical Reports Server (NTRS)

    Reininger, Francis M. (Inventor)

    2000-01-01

    An imaging spectrometer has fore-optics coupled to a spectral resolving system with an entrance slit extending in a first direction at an imaging location of the fore-optics for receiving the image, a convex diffraction grating for separating the image into a plurality of spectra of predetermined wavelength ranges; a spectrometer array for detecting the spectra; and at least one concave sperical mirror concentric with the diffraction grating for relaying the image from the entrance slit to the diffraction grating and from the diffraction grating to the spectrometer array. In one embodiment, the spectrometer is configured in a lateral mode in which the entrance slit and the spectrometer array are displaced laterally on opposite sides of the diffraction grating in a second direction substantially perpendicular to the first direction. In another embodiment, the spectrometer is combined with a polychromatic imaging camera array disposed adjacent said entrance slit for recording said image.

  10. Miniature Ion-Array Spectrometer

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.

    2006-01-01

    A figure is shown that depicts a proposed miniature ion-mobility spectrometer that would share many features of design and operation of the instrument described in another article. The main differences between that instrument and this one would lie in the configuration and mode of operation of the filter and detector electrodes. A filter electrode and detector electrodes would be located along the sides of a drift tube downstream from the accelerator electrode. These electrodes would apply a combination of (1) a transverse AC electric field that would effect differential transverse dispersal of ions and (2) a transverse DC electric field that would drive the dispersed ions toward the detector electrodes at different distances along the drift tube. The electric current collected by each detector electrode would be a measure of the current, and thus of the abundance of the species of ions impinging on that electrode. The currents collected by all the detector electrodes could be measured simultaneously to obtain continuous readings of abundances of species. The downstream momentum of accelerated ions would be maintained through neutralization on the electrodes; the momentum of the resulting neutral atoms would serve to expel gases from spectrometer, without need for a pump.

  11. Signal Processing Issues in Fourier Transform Spectrometers

    NASA Astrophysics Data System (ADS)

    Hayes, Monson H.

    2002-12-01

    There are a number of interesting and challenging signal processing problems related to the design of a Fourier Transform Spectrometer (FTS). In this project, we look at a few of these problems in two different types of spectrometers-the Geostationary Imaging Fourier Transform Spectrometer (GIFTS), and a Far Infrared (FIR) FTS. One of the si nal processing challenges in GIFTS is the reduction of the massive data rate (2.4 x 109 bps) to an affordable telemetry rate of less than 60 Mbps. Since the GIFTS interferograms are heavily over-sampled, the first step is to decimate (down-sample) the interferograms with minimal distortion while keeping the signal processing algorithms simple enough to be implemented in the GIFTS hardware. Therefore, the first problem we looked at was the design of the decimation filters. Specifically, we performed a detailed analysis of two competing approaches that were being considered. The first, proposed by the Space Dynamics Lab (SDL), was to use a double sideband (real) band-pass filter. The second, proposed by Lincoln Laboratories (LL), was to use a single sideband (complex) band-pass filter. What the study showed was that a complex filter (LL approach) results in a savings of about 25% in the filtering requirements for the long-wave band, while in the mid-wave band the savings are approximately 50%. As a result, the decision was made to use a complex filter. Once the decision to use a complex filter had been made, we looked at some of the consequences of this decision. The most significant of these was the discovery that, with a complex filter, it is possible to extend the long-wave IR band beyond the folding frequency of 1174/cm and recover the SO2 line at 1176.5/cm. What this requires is the design of a band-pass decimation filter with a wider passband, and consequently of higher order. Specifically, it was shown that with about 25% more filter operations, the elusive SO2 line, believed to be irretrievable, could in fact be recovered

  12. GIOVE, a shallow laboratory Ge-spectrometer with 100 μBq/kg sensitivity

    SciTech Connect

    Heusser, G.; Weber, M.; Denz, T.; Hakenmueller, J.; Hofacker, R.; Lackner, R.; Lindner, M.; Maneschg, W.; Reisfelder, M.; Simgen, H.; Schreiner, J.; Stolzenburg, D.; Strecker, H.; Westermann, J.

    2013-08-08

    A new germanium gamma spectrometer called GIOVE (Germanium spectrometer with Inner and Outer Veto) has been set up at the underground/shallow laboratory (15 m w.e.) of MPI-K. Its double plastic scintillator veto system and neutron moderation interlayer lower the background by more than one order of magnitude compared to the other existing spectrometer at this facility. The integral (40-2700 keV) background rate of about 290 counts (day kg){sup −1} is just a factor 4 to 8 above that of the GeMPI spectrometers operated at LNGS (3800 m w.e.) and thus proves that even under shallow overburden sub mBq/kg sensitivities are achievable. Extended material screening and neutron attenuation studies preceded the final design of the spectrometer. The technical realization of the spectrometer is described in detail with special emphasis on the inner veto system. For its optimisation a simulation model was developed for light collection on small low activity PMT’s under various geometrical conditions. Radon suppression is accomplished by employing a gas tight sample container and a nitrogen flushed glove-box system with an airlock. The active volume of the crystal was modelled by absorption scanning measurements and Monte Carlo simulations. The complete shield is implemented in a Geant4 based simulation framework.

  13. Digital Spectrometers for Interplanetary Science Missions

    NASA Technical Reports Server (NTRS)

    Jarnot, Robert F.; Padmanabhan, Sharmila; Raffanti, Richard; Richards, Brian; Stek, Paul; Werthimer, Dan; Nikolic, Borivoje

    2010-01-01

    A fully digital polyphase spectrometer recently developed by the University of California Berkeley Wireless Research Center in conjunction with the Jet Propulsion Laboratory provides a low mass, power, and cost implementation of a spectrum channelizer for submillimeter spectrometers for future missions to the Inner and Outer Solar System. The digital polyphase filter bank spectrometer (PFB) offers broad bandwidth with high spectral resolution, minimal channel-to-channel overlap, and high out-of-band rejection.

  14. [Hadamard transform spectrometer mixed pixels' unmixing method].

    PubMed

    Yan, Peng; Hu, Bing-Liang; Liu, Xue-Bin; Sun, Wei; Li, Li-Bo; Feng, Yu-Tao; Liu, Yong-Zheng

    2011-10-01

    Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery. PMID:22250574

  15. A Neutron Spectrometer for Small Satellite Opportunities

    NASA Astrophysics Data System (ADS)

    de Nolfo, Georgia; Bloser, Peter; Dumonthier, J.; Garcia-Burgos, A.; Ryan, James Michael; Suarez, G.; Winkert, G. E.

    2015-04-01

    The detection of fast neutrons has important implications in such diverse fields as geospace physics, solar physics, and applications within Defense and Security programs. In particular, neutrons provide key observations that complement gamma-ray observations in understanding the magnetic topology and particle acceleration processes at the Sun. Solar neutrons have been observed by space-based missions such as CGRO/COMPTEL and ground-based neutron monitors with energies > 20 MeV. Below 20 MeV, given the neutron half-life of ~15min, the detection of neutrons must take place close to the Sun. The challenge is to build instrumentation that conforms to small satellite platforms making inner heliospheric observations possible as well as Earth-orbiting CubeSats. Scintillator-based technologies have a proven track record for the detection of fast neutrons with high stopping power, good energy resolution, and fast timing. Modern organic scintillators such as stilbene and p-terphenyl, offer improved light output and pulse shape discrimination — the ability to distinguish gamma from neutron-induced signals. Modern readout devices such as silicon photomultipliers (SiPMs) offer an ideal alternative to photomultiplier tubes given their inherently compact size and the very low operating voltages required. The combination of modern scintillators and silicon photomultipliers enables new designs for instruments that conform to small satellite platforms such as CubeSats. We discuss the performance of a double scatter neutron spectrometer based on p-terphenyl coupled to arrays of silicon photomultipliers for readout. In addition, we present preliminary results for pulse shape discrimination using advanced waveform digitization techniques.

  16. Miniature Mass Spectrometers on Space and Planetary Missions

    NASA Technical Reports Server (NTRS)

    Brinckerhoff, William

    2008-01-01

    Space flight mass spectrometers contribute our understanding of the origin and evolution of our solar system and even of life itself. This fundamental role has motivated increasing interest in miniature mass spectrometry for planetary missions. Several remarkable new instruments are en route or under development to investigate the composition of planetary bodies such as Mars and comets. For instance, the Sample Analysis at Mars (SAM) suite on the 2009 Mars Science Laboratory (MSL) mission includes a quadrupole mass spectrometer with a sophisticated gas processing system as well as pyrolysis and chemical derivatization protocols for solid samples. Future missions will require even lighter, lower power, and yet more capable mass spectrometers, particularly to analyze samples in situ on planetary surfaces. We have been developing laser-based mass spectrometers for elemental and organic/molecular analysis of rock, ice, or fine particle samples. These typically use time-of-flight (TOF) mass analyzers, which are readily miniaturized and can detect both atomic species and complex organics that occur in a variety of planetary materials. For example, nonvolatile polycyclic aromatic hydrocarbons and kerogen-like macromolecular carbon are found in some carbonaceous meteorites, which derived from asteroid parent bodies. A single focused laser pulse is able to volatilize and ionize some of these compounds for direct TOF analysis. While this is possible without any sample preparation or contact, sensitivity and quantitative performance can improve significantly with some sample handling. As such we have also been examining robotic mechanisms and protocols to accompany space flight mass spectrometers. In addition, sensors in early development may significantly improve these capabilities, via use of techniques such as switchable polarity, ambient pressure, or resonant ionization; tandem mass spectrometry (TOF or ion trap); and chemical imaging.

  17. 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.

  18. 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.

  19. Development of double-pulse lasers ablation system for generating gold ion source under applying an electric field

    NASA Astrophysics Data System (ADS)

    Khalil, A. A. I.

    2015-12-01

    Double-pulse lasers ablation (DPLA) technique was developed to generate gold (Au) ion source and produce high current under applying an electric potential in an argon ambient gas environment. Two Q-switched Nd:YAG lasers operating at 1064 and 266 nm wavelengths are combined in an unconventional orthogonal (crossed-beam) double-pulse configuration with 45° angle to focus on a gold target along with a spectrometer for spectral analysis of gold plasma. The properties of gold plasma produced under double-pulse lasers excitation were studied. The velocity distribution function (VDF) of the emitted plasma was studied using a dedicated Faraday-cup ion probe (FCIP) under argon gas discharge. The experimental parameters were optimized to attain the best signal to noise (S/N) ratio. The results depicted that the VDF and current signals depend on the discharge applied voltage, laser intensity, laser wavelength and ambient argon gas pressure. A seven-fold increases in the current signal by increasing the discharge applied voltage and ion velocity under applying double-pulse lasers field. The plasma parameters (electron temperature and density) were also studied and their dependence on the delay (times between the excitation laser pulse and the opening of camera shutter) was investigated as well. This study could provide significant reference data for the optimization and design of DPLA systems engaged in laser induced plasma deposition thin films and facing components diagnostics.

  20. [Optical Design of Miniature Infrared Gratings Spectrometer Based on Planar Waveguide].

    PubMed

    Li, Yang-yu; Fang, Yong-hua; Li, Da-cheng; Liu, Yang

    2015-03-01

    In order to miniaturize an infrared spectrometer, we analyze the current optical design of miniature spectrometers and propose a method for designing a miniature infrared gratings spectrometer based on planar waveguide. Common miniature spectrometer uses miniature optical elements to reduce the size of system, which also shrinks the effective aperture. So the performance of spectrometer has dropped. Miniaturization principle of planar waveguide spectrometer is different from the principle of common miniature spectrometer. In planar waveguide spectrometer, the propagation of light is limited in a thin planar waveguide, which looks like the whole optical system is squashed flat. In the direction parallel to the planar waveguide, the light through the slit is collimated, dispersed and focused. And a spectral image is formed in the detector plane. This propagation of light is similar to the light in common miniature spectrometer. In the direction perpendicular to the planar waveguide, light is multiple reflected by the upper and lower surfaces of the planar waveguide and propagates in the waveguide. So the size of corresponding optical element could be very small in the vertical direction, which can reduce the size of the optical system. And the performance of the spectrometer is still good. The design method of the planar waveguide spectrometer can be separated into two parts, Czerny-Turner structure design and planar waveguide structure design. First, by using aberration theory an aberration-corrected (spherical aberration, coma, focal curve) Czerny-Turner structure is obtained. The operation wavelength range and spectral resolution are also fixed. Then, by using geometrical optics theory a planar waveguide structure is designed for reducing the system size and correcting the astigmatism. The planar waveguide structure includes a planar waveguide and two cylindrical lenses. Finally, they are modeled together in optical design software and are optimized as a whole. An

  1. The Design and Construction of the MICE Spectrometer Solenoids

    SciTech Connect

    Wang, Bert; Wahrer, Bob; Taylor, Clyde; Xu, L.; Chen, J. Y.; Wang, M.; Juang, Tiki; Zisman, Michael S.; Virostek, Steve P.; Green, Michael A.

    2008-08-02

    The purpose of the MICE spectrometer solenoid is to provide a uniform field for a scintillating fiber tracker. The uniform field is produced by a long center coil and two short end coils. Together, they produce 4T field with a uniformity of better than 1% over a detector region of 1000 mm long and 300 mm in diameter. Throughout most of the detector region, the field uniformity is better than 0.3%. In addition to the uniform field coils, we have two match coils. These two coils can be independently adjusted to match uniform field region to the focusing coil field. The coil package length is 2544 mm. We present the spectrometer solenoid cold mass design, the powering and quench protection circuits, and the cryogenic cooling system based on using three cryocoolers with re-condensers.

  2. A Fast Terahertz Spectrometer Based on Frequency Selective Surface Filters

    NASA Astrophysics Data System (ADS)

    Carelli, P.; Chiarello, F.; Cibella, S.; Di Gaspare, A.; Leoni, R.; Ortolani, M.; Torrioli, G.

    2012-05-01

    We present a fast spectrometer working in the 0.7-4.8 THz range. Broadband radiation from a blackbody source is focused first on a rotating silicon wafer, whose surface was patterned with 18 metal band-pass filters, then on the sample under test and finally is detected by a superconducting microbolometer with microsecond time constant. The bolometer sensor is coupled to a spiral antenna whose frequency band matches the spectral range of the filters. The spectral resolution is set by the filters quality factor of about 3. A dynamic range of 100 and a S/N ratio of 20 are achieved by integrating for less than 10 second. The detector can operate up to 6 K in a closed-cycle cooler, hence making the present apparatus suitable for building up a simple terahertz video-rate spectrometer.

  3. A visible-infrared imaging spectrometer for planetary missions

    NASA Technical Reports Server (NTRS)

    McCord, Thomas (Principal Investigator); Voelker, Mark; Owensby, Pam; Warren, Cris; Mooradian, Greg

    1996-01-01

    This final report summarizes the design effort for the construction of a visible-infrared imaging spectrometer for planetary missions, funded by NASA under the Planetary Instrument Definition and Development Program. The goal was to design and develop a prototype brassboard pushbroom imaging spectrometer covering the 0.35 gm to 2.5 gm spectral region using a simplified optical layout that would minimize the size, mass and parts count of the instrument by using a single holographic grating to disperse and focus light from a single slit onto both the infrared and visible focal plane arrays. Design approaches are presented and analyzed, along with problems encountered and recommended solutions to those problems. In particular, a new type of grating, incorporating two sets of rulings and a filter in a layered structure, is presented for further development.

  4. Indigenous development of static laser light scattering (SLS) spectrometer

    NASA Astrophysics Data System (ADS)

    Joseph, David; Kumar, Amit

    2013-02-01

    An indigenous laser light scattering spectrometer is being developed for the studies of biological cells, macromolecules and their interactions. A laboratory spectrometer is used and modified as scattering arm, Turn Table and Collimating arm. Both the arms have polarizers, one acting as polarizer and the other as analyzer. The scattered light from the scattering cell is analyzed by an analyzer and is fed to a PMT and a photon counting module. Except for the PMT all the accessories are being fabricated indigenously. The studies are based initially on the studies of red blood cells. Studies are focused on for their single particle and their aggregation behavior. Using the ORT program developed by Otto Glatter the morphology of red blood cells will be analyzed.

  5. How to measure color using spectrometers and calibrated photographs.

    PubMed

    Johnsen, Sönke

    2016-03-01

    The measurement of color in biology has become increasingly common. These measurements are not limited to color vision research, but are also found in studies of communication, signaling, camouflage, evolution and behavior, and in the examination of environmental, artificial and biogenic light. Although the recent availability of portable spectrometers has made it simpler to measure color, guidance on how to make these measurements has not kept pace. Because most biologists receive little training in optics, many measure the wrong thing, or measure the right thing in the wrong way. This Commentary attempts to give biologists a brief overview of how to measure light and color using spectrometers and calibrated photographs. It focuses in particular on the inherent ambiguities of many optical measurements, and how these can be addressed. PMID:26985049

  6. Planar prism spectrometer based on adiabatically connected waveguiding slabs

    NASA Astrophysics Data System (ADS)

    Civitci, F.; Hammer, M.; Hoekstra, H. J. W. M.

    2016-04-01

    The device principle of a prism-based on-chip spectrometer for TE polarization is introduced. The spectrometer exploits the modal dispersion in planar waveguides in a layout with slab regions having two different thicknesses of the guiding layer. The set-up uses parabolic mirrors, for the collimation of light of the input waveguide and focusing of the light to the receiver waveguides, which relies on total internal reflection at the interface between two such regions. These regions are connected adiabatically to prevent unwanted mode conversion and loss at the edges of the prism. The structure can be fabricated with two wet etching steps. The paper presents basic theory and a general approach for device optimization. The latter is illustrated with a numerical example assuming SiON technology.

  7. Characterization and calibration of compact array spectrometers in the ultraviolet spectral region

    SciTech Connect

    Shindo, Francois; Woolliams, Emma; Scott, Barry; Harris, Subrena

    2013-05-10

    Array-based spectrometers, with their compact size, low weight, low cost, and fast measurement time, are now frequently used in place of both conventional single-channel scanning monochromators, and broadband meters. Their rapid measurement capability makes them an attractive option for routine solar UV spectral measurements, where shortterm variability in signal is a challenge. However, compactness, portability, low cost and high speed are achieved at the expense of the spectrometer's optical and electronic performance. Thus such spectrometers are more prone to measurement error from environmental changes, and more prone to other intrinsic sources of error such as stray light and detector non-linearity, which significantly affect solar UV measurements, than a scanning monochromator. The effects of stray light and non-linearity can be reduced either by improved optical and detector design or by a detailed spectrometer characterization. We present in this paper our investigation of the performance of three different commercial array spectrometers: two mini-spectrometers, and a more elaborate array spectrometer with an on-board image amplifier device. These were tested for a subset of performance parameters: their wavelength accuracy and stability, electronic linearity, responsivity linearity, stray light sensitivity, and mechanical stability and repeatability. With all three spectrometers we found that these parameters, particularly but not limited to stray light, had a significant impact on the measurement of the incoming optical radiation. This meant that, without characterization, the instruments would be unable to accurately measure the UV component of any source with significant visible radiation. We discuss various simple and low-cost solutions for improving the performance of these instruments, and providing a rigorous calibration using a straightforward set-up including optical filters and the quasi-monochromatic light from a double monochromator.

  8. A New Generation TDPAC Spectrometer

    NASA Astrophysics Data System (ADS)

    Herden, Christian H.; Alves, Mauro A.; Becker, Klaus D.; Gardner, John A.

    2004-12-01

    Time Differential gamma gamma Perturbed Angular Correlation spectroscopy has traditionally been done using scintillation detectors along with constant fraction discriminators, spectroscopy amplifiers, single channel analyzers, and time to amplitude detectors. We describe a new generation spectrometer where these electronics are replaced by high speed digital transient recorders that record the output from each scintillation detector. The energy and time-of-arrival of gamma rays in any detector can be determined accurately. Many experimental difficulties related to electronics are eliminated; the number of detectors can be increased with no increase in complexity of the apparatus; coincidences among any two detectors are measurable; and coincidences separated by as little as a ns are detectable in principle within one detector. All energies are collected, and energy windows are imposed by software filtering, permitting both high energy resolution and high data-gathering power.

  9. Airborne imaging spectrometer development tasks

    NASA Astrophysics Data System (ADS)

    Bolten, John

    The tasks that must be completed to design and build an airborne imaging spectrometer are listed. The manpower and resources required to do these tasks must be estimated by the people responsible for that work. The tasks are broken down by instrument subsystem or discipline. The instrument performance can be assessed at various stages during the development. The initial assessment should be done with the preliminary computer model. The instrument calibration facilities should be designed, but no calibration facilities are needed. The intermediate assessment can be done when the front end has been assembled. The preliminary instrument calibration facility should be available at this stage. The final assessment can only be done when the instrument is complete and ready for flight. For this, the final instrument calibration facility and the flight qualification facilities must be ready. The final assessment is discussed in each discipline under the section on integration and test.

  10. Clementine RRELAX SRAM Particle Spectrometer

    NASA Technical Reports Server (NTRS)

    Buehler, M.; Soli, G.; Blaes, B.; Ratliff, J.; Garrett, H.

    1994-01-01

    The Clementine RRELAX radiation monitor chip consists of a p-FET total dose monitor and a 4-kbit SRAM particle spectrometer. Eight of these chips were included in the RRELAX and used to detect the passage of the Clementine (S/C) and the innerstage adapter (ISA) through the earth's radiation belts and the 21-Feb 1994 solar flare. This is the first space flight for this 1.2 micron rad-soft custom CMOS radiation monitor. This paper emphasizes results from the SRAM particle detector which showed that it a) has a detection range of five orders of magnitude relative to the 21-Feb solar flare, b) is not affected by electrons, and c) detected microflares occurring with a 26.5 day period.

  11. Fluorescence imaging spectrometer optical design

    NASA Astrophysics Data System (ADS)

    Taiti, A.; Coppo, P.; Battistelli, E.

    2015-09-01

    The optical design of the FLuORescence Imaging Spectrometer (FLORIS) studied for the Fluorescence Explorer (FLEX) mission is discussed. FLEX is a candidate for the ESA's 8th Earth Explorer opportunity mission. FLORIS is a pushbroom hyperspectral imager foreseen to be embarked on board of a medium size satellite, flying in tandem with Sentinel-3 in a Sun synchronous orbit at a height of about 815 km. FLORIS will observe the vegetation fluorescence and reflectance within a spectral range between 500 and 780 nm. Multi-frames acquisitions on matrix detectors during the satellite movement will allow the production of 2D Earth scene images in two different spectral channels, called HR and LR with spectral resolution of 0.3 and 2 nm respectively. A common fore optics is foreseen to enhance by design the spatial co-registration between the two spectral channels, which have the same ground spatial sampling (300 m) and swath (150 km). An overlapped spectral range between the two channels is also introduced to simplify the spectral coregistration. A compact opto-mechanical solution with all spherical and plane optical elements is proposed, and the most significant design rationales are described. The instrument optical architecture foresees a dual Babinet scrambler, a dioptric telescope and two grating spectrometers (HR and LR), each consisting of a modified Offner configuration. The developed design is robust, stable vs temperature, easy to align, showing very high optical quality along the whole field of view. The system gives also excellent correction for transverse chromatic aberration and distortions (keystone and smile).

  12. A colloidal quantum dot spectrometer

    NASA Astrophysics Data System (ADS)

    Bao, Jie; Bawendi, Moungi G.

    2015-07-01

    Spectroscopy is carried out in almost every field of science, whenever light interacts with matter. Although sophisticated instruments with impressive performance characteristics are available, much effort continues to be invested in the development of miniaturized, cheap and easy-to-use systems. Current microspectrometer designs mostly use interference filters and interferometric optics that limit their photon efficiency, resolution and spectral range. Here we show that many of these limitations can be overcome by replacing interferometric optics with a two-dimensional absorptive filter array composed of colloidal quantum dots. Instead of measuring different bands of a spectrum individually after introducing temporal or spatial separations with gratings or interference-based narrowband filters, a colloidal quantum dot spectrometer measures a light spectrum based on the wavelength multiplexing principle: multiple spectral bands are encoded and detected simultaneously with one filter and one detector, respectively, with the array format allowing the process to be efficiently repeated many times using different filters with different encoding so that sufficient information is obtained to enable computational reconstruction of the target spectrum. We illustrate the performance of such a quantum dot microspectrometer, made from 195 different types of quantum dots with absorption features that cover a spectral range of 300 nanometres, by measuring shifts in spectral peak positions as small as one nanometre. Given this performance, demonstrable avenues for further improvement, the ease with which quantum dots can be processed and integrated, and their numerous finely tuneable bandgaps that cover a broad spectral range, we expect that quantum dot microspectrometers will be useful in applications where minimizing size, weight, cost and complexity of the spectrometer are critical.

  13. The Geostationary Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Key, Richard; Sander, Stanley; Eldering, Annmarie; Miller, Charles; Frankenberg, Christian; Natra, Vijay; Rider, David; Blavier, Jean-Francois; Bekker, Dmitriy; Wu, Yen-Hung

    2012-01-01

    The Geostationary Fourier Transform Spectrometer (GeoFTS) is an imaging spectrometer designed for an earth science mission to measure key atmospheric trace gases and process tracers related to climate change and human activity. The GeoFTS instrument is a half meter cube size instrument designed to operate in geostationary orbit as a secondary "hosted" payload on a commercial geostationary satellite mission. The advantage of GEO is the ability to continuously stare at a region of the earth, enabling frequent sampling to capture the diurnal variability of biogenic fluxes and anthropogenic emissions from city to continental scales. The science goal is to obtain a process-based understanding of the carbon cycle from simultaneous high spatial resolution measurements of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and chlorophyll fluorescence (CF) many times per day in the near infrared spectral region to capture their spatial and temporal variations on diurnal, synoptic, seasonal and interannual time scales. The GeoFTS instrument is based on a Michelson interferometer design with a number of advanced features incorporated. Two of the most important advanced features are the focal plane arrays and the optical path difference mechanism. A breadboard GeoFTS instrument has demonstrated functionality for simultaneous measurements in the visible and IR in the laboratory and subsequently in the field at the California Laboratory for Atmospheric Remote Sensing (CLARS) observatory on Mt. Wilson overlooking the Los Angeles basin. A GeoFTS engineering model instrument is being developed which will make simultaneous visible and IR measurements under space flight like environmental conditions (thermal-vacuum at 180 K). This will demonstrate critical instrument capabilities such as optical alignment stability, interferometer modulation efficiency, and high throughput FPA signal processing. This will reduce flight instrument development risk and show that the Geo

  14. The Geostationary Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Key, Richard; Sander, Stanley; Eldering, Annmarie; Blavier, Jean-Francois; Bekker, Dmitriy; Manatt, Ken; Rider, David; Wu, Yen-Hung

    2012-01-01

    The Geostationary Fourier Transform Spectrometer (GeoFTS) is an imaging spectrometer designed for a geostationary orbit (GEO) earth science mission to measure key atmospheric trace gases and process tracers related to climate change and human activity. GEO allows GeoFTS to continuously stare at a region of the earth for frequent sampling to capture the variability of biogenic fluxes and anthropogenic emissions from city to continental spatial scales and temporal scales from diurnal, synoptic, seasonal to interannual. The measurement strategy provides a process based understanding of the carbon cycle from contiguous maps of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and chlorophyll fluorescence (CF) collected many times per day at high spatial resolution (2.7kmx2.7km at nadir). The CO2/CH4/CO/CF measurement suite in the near infrared spectral region provides the information needed to disentangle natural and anthropogenic contributions to atmospheric carbon concentrations and to minimize uncertainties in the flow of carbon between the atmosphere and surface. The half meter cube size GeoFTS instrument is based on a Michelson interferometer design that uses all high TRL components in a modular configuration to reduce complexity and cost. It is self-contained and as independent of the spacecraft as possible with simple spacecraft interfaces, making it ideal to be a "hosted" payload on a commercial communications satellite mission. The hosted payload approach for measuring the major carbon-containing gases in the atmosphere from the geostationary vantage point will affordably advance the scientific understating of carbon cycle processes and climate change.

  15. Spin Spectrometer at the ALS and APS

    SciTech Connect

    Lawrence Livermore National Laboratory; University of Missouri-Rolla; Boyd Technologies; Morton, Simon A; Morton, Simon A; Tobin, James G; Yu, Sung Woo; Komesu, Takashi; Waddill, George D; Boyd, Peter

    2007-04-20

    A spin-resolving photoelectron spectrometer, the"Spin Spectrometer," has been designed and built. It has been utilized at both the Advanced Light Source in Berkeley, CA, and the Advanced Photon Source in Argonne, IL. Technical details and an example of experimental results are presented here.

  16. An improved nuclear magnetic resonance spectrometer

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.; Manatt, S. L.

    1967-01-01

    Cylindrical sample container provides a high degree of nuclear stabilization to a nuclear magnetic resonance /nmr/ spectrometer. It is placed coaxially about the nmr insert and contains reference sample that gives a signal suitable for locking the field and frequency of an nmr spectrometer with a simple audio modulation system.

  17. A Mass Spectrometer Simulator in Your Computer

    ERIC Educational Resources Information Center

    Gagnon, Michel

    2012-01-01

    Introduced to study components of ionized gas, the mass spectrometer has evolved into a highly accurate device now used in many undergraduate and research laboratories. Unfortunately, despite their importance in the formation of future scientists, mass spectrometers remain beyond the financial reach of many high schools and colleges. As a result,…

  18. Apodization Control of Line Shape in Spectrometer

    NASA Technical Reports Server (NTRS)

    Pires, Antonio; Niple, Edward; Evans, Nathan L.

    1987-01-01

    Kaiser-Bessel apodization function reduces unwanted sidebands. Report discusses apodization in Fourier-transform spectrometer (FTS) for Advanced Moisture and Temperature Sounder (AMTS). Purpose of apodization in instrument to control shape of spectrum in wavenumber space to keep radiation at other wavelengths in passband of spectrometer out of AMTS wavenumber channel.

  19. Design, construction, and performance of a magnetically shielded room for a neutron spin echo spectrometer

    NASA Astrophysics Data System (ADS)

    Soltner, Helmut; Pabst, Ulrich; Butzek, Michael; Ohl, Michael; Kozielewski, Tadeusz; Monkenbusch, Michael; Sokol, Don; Maltin, Larry; Lindgren, Eric; Koch, Stuart; Fugate, David

    2011-07-01

    A double-layer magnetically shielded room (MSR) has been designed and constructed for the neutron spin echo (NSE) spectrometer at the Spallation Neutron Source (SNS) in Oak Ridge, Tennessee. The primary objective of the MSR is to ensure an undisturbed operation of the spectrometer in terms of external magnetic fields from high-field magnets at neighboring beamlines and from other external devices. Because of the required mobility of the spectrometer along its beamline the MSR features a total length of about 17 m, which makes it the largest MSR worldwide. Several physics and engineering aspects addressed in the design phase and during the construction of this unique MSR are described in this article.

  20. Fast wavelength calibration method for spectrometers based on waveguide comb optical filter

    SciTech Connect

    Yu, Zhengang; Huang, Meizhen Zou, Ye; Wang, Yang; Sun, Zhenhua; Cao, Zhuangqi

    2015-04-15

    A novel fast wavelength calibration method for spectrometers based on a standard spectrometer and a double metal-cladding waveguide comb optical filter (WCOF) is proposed and demonstrated. By using the WCOF device, a wide-spectrum beam is comb-filtered, which is very suitable for spectrometer wavelength calibration. The influence of waveguide filter’s structural parameters and the beam incident angle on the comb absorption peaks’ wavelength and its bandwidth are also discussed. The verification experiments were carried out in the wavelength range of 200–1100 nm with satisfactory results. Comparing with the traditional wavelength calibration method based on discrete sparse atomic emission or absorption lines, the new method has some advantages: sufficient calibration data, high accuracy, short calibration time, fit for produce process, stability, etc.

  1. Optical system design of the Dyson imaging spectrometer based on the Fery prism

    NASA Astrophysics Data System (ADS)

    Pei, Linlin; Xiangli, Bin; Lv, Qunbo; Shao, Xiaopeng

    2016-08-01

    Imaging spectrometer has obtained wide development since rich feature information can be obtained by it; now, we focus on its high spectral resolution and miniaturization. In this paper, we design the Dyson imaging spectrometer system based on Fery prism. The average spectral resolution is 4.3 nm and the structure of the total length is 229 mm. It is a small, high-spectrometer imaging system. The front and rear surface of the traditional prism are plane, but the surfaces of the Fery prism are spherical, which can provide some optical power to realize imaging function and produce the dispersion effect. The Fery prism does not need to be placed in the parallel optical path, which simplifies the collimator lens and the imaging lens and are necessary in the prism spectrometer, making it possible to obtain a compact spectrometer. Full-spectrum transmittance of the prism is up to 94 %. Compared to the convex grating, the energy efficiency is greatly improved, and the free spectral range is wider, and its dispersion will not bring higher-order spectral aliasing problem. The small high spectrometer only includes two components. Its spectral range is from 400 to 1000 nm, covering the near-ultraviolet to near-infrared. The various aberrations of the typical spectrum are corrected. The spectrometer is excellent in performance.

  2. Optical system design of the Dyson imaging spectrometer based on the Fery prism

    NASA Astrophysics Data System (ADS)

    Pei, Linlin; Xiangli, Bin; Lv, Qunbo; Shao, Xiaopeng

    2016-07-01

    Imaging spectrometer has obtained wide development since rich feature information can be obtained by it; now, we focus on its high spectral resolution and miniaturization. In this paper, we design the Dyson imaging spectrometer system based on Fery prism. The average spectral resolution is 4.3 nm and the structure of the total length is 229 mm. It is a small, high-spectrometer imaging system. The front and rear surface of the traditional prism are plane, but the surfaces of the Fery prism are spherical, which can provide some optical power to realize imaging function and produce the dispersion effect. The Fery prism does not need to be placed in the parallel optical path, which simplifies the collimator lens and the imaging lens and are necessary in the prism spectrometer, making it possible to obtain a compact spectrometer. Full-spectrum transmittance of the prism is up to 94 %. Compared to the convex grating, the energy efficiency is greatly improved, and the free spectral range is wider, and its dispersion will not bring higher-order spectral aliasing problem. The small high spectrometer only includes two components. Its spectral range is from 400 to 1000 nm, covering the near-ultraviolet to near-infrared. The various aberrations of the typical spectrum are corrected. The spectrometer is excellent in performance.

  3. LIFTIRS, the Livermore imaging FTIR spectrometer

    SciTech Connect

    Bennett, C.L.

    1998-06-01

    The imaging FTIR spectrometer was invented 25 years ago. Only recently, however, with the development of infrared focal plane array technology and high speed microprocessors, has the imaging FTIR spectrometer become a practical instrument. Among the class of imaging spectrometer instruments, the imaging Fourier transform spectrometer enjoys a great advantage in terms of calibratibility, sensitivity, broad band coverage and resolution flexibility. Recent experience with the LIFTIRS instrument is summarized. As a concrete example of the acquisition, calibration, and comprehension of the data from an imaging Fourier transform spectrometer, the case history of a geological sample is discussed in great detail. In particular, the importance of principle component analysis to imaging spectroscopy is especially emphasized. It is shown how the various spatial/spectral constituents within a sample can be detected, located, identified and quantified. {copyright} {ital 1998 American Institute of Physics.}

  4. Compact time-of-flight mass spectrometer

    SciTech Connect

    Belov, A.S.; Kubalov, S.A.; Kuzik, V.F.; Yakushev, V.P.

    1986-02-01

    This paper describes a time-of-flight mass spectrometer developed for measuring the parameters of a pulsed hydrogen beam. The duration of an electron-beam current pulse in the ionizer of the mass spectrometer can be varied within 2-20 usec, the pulse electron current is 0.6 mA, and the electron energy is 250 eV. The time resolution of the mass spectrometer is determined by the repetition period of the electron-beam current pulses and is 40 usec. The mass spectrometer has 100% transmission in the direction of motion of molecular-beam particles. The dimension of the mass spectrometer is 7 cm in this direction. The mass resolution is sufficient for determination of the composition of the hydrogen beam.

  5. Investigations of 2β decay measured by low background HPGe spectrometer OBELIX

    SciTech Connect

    Rukhadze, Ekaterina [Institute of Experimental and Applied Physics, CTU in Prague, Horska 3a Collaboration: OBELIX Collaboration; SuperNEMO Collaboration

    2013-12-30

    A low background high sensitive HPGe spectrometer OBELIX was installed at the Modane Underground Laboratory (LSM, France, 4800 m w.e.). The detector was designed to measure a contamination of enriched isotopes and radio-impurities in construction materials, to investigate rare nuclear processes such as resonance neutrinoless double electron capture and two-neutrino double beta decay to excited states of daughter nuclei. Spectrometer sensitivity, contamination of NEMO-3 sources and results of 2ν2β{sup −} decay of {sup 100}Mo to the 0{sup +} (1130 keV) and 2{sup +} (540 keV) excited states as well as future plans for OBELIX detector are given.

  6. An analysis of two classes of grazing incidence mirrors for use with Rowland circle spectrometers

    NASA Astrophysics Data System (ADS)

    Green, James; Bowyer, Stuart

    1986-01-01

    Results are presented of a comparative analysis of Hettrick Bowyer Type II (HBII) and Wolter-Schwarzschild Type II (WSII) optics for use with Rowland circle spectrometers. The HBII can substitute, with few exceptions, for a WSII in any Rowland circle with little change in spectrometer performance or design. However, the HBII telescope offers several clear advantages over the WSII in these configurations. Because the HBII employs a virtual focus, it requires a much shorter instrument length than a WSII. For example, a 3-m Rowland circle spectrometer, fed by an optimized, f/10, 1-m diameter WSII, has a total instrument length of 6 m. If a HBII is used to feed the identical spectrometer, the entire instrument length can be as little as 3 m. In addition, the improved imaging gained with the larger graze angles of the HBII design results in better resolution in slitless operation modes.

  7. Fan analyzer of neutron beam polarization on REMUR spectrometer at IBR-2 pulsed reactor

    NASA Astrophysics Data System (ADS)

    Nikitenko, Yu. V.; Ul'yanov, V. A.; Pusenkov, V. M.; Kozhevnikov, S. V.; Jernenkov, K. N.; Pleshanov, N. K.; Peskov, B. G.; Petrenko, A. V.; Proglyado, V. V.; Syromyatnikov, V. G.; Schebetov, A. F.

    2006-08-01

    The new spectrometer of polarized neutrons REMUR has been created and put in operation in the Frank Laboratory of Neutron Physics (JINR, Dubna). The spectrometer is dedicated to investigations of multiplayer structures and surfaces by registering the reflection of polarized neutrons and of the inhomogeneous state of solid matter by measuring the small-angle scattering of polarized neutrons. The spectrometer's working range of neutron wavelengths is 1.5-10 Å. The spectrometer is equipped with a linear position-sensitive detector and a focused supermirror polarization analyzer (fan-like polarization analyzer) with a solid angle of neutron detection of 2.2×10 -4 rad. This article describes the design and the principle of operation of the fan analyzer of neutron polarization together with the results of its tests on a polarized neutron beam.

  8. Miniature Ion-Mobility Spectrometer

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T.

    2006-01-01

    The figure depicts a proposed miniature ion-mobility spectrometer that would be fabricated by micromachining. Unlike prior ion-mobility spectrometers, the proposed instrument would not be based on a time-of-flight principle and, consequently, would not have some of the disadvantageous characteristics of prior time-of-flight ion-mobility spectrometers. For example, one of these characteristics is the need for a bulky carrier-gas-feeding subsystem that includes a shutter gate to provide short pulses of gas in order to generate short pulses of ions. For another example, there is need for a complex device to generate pulses of ions from the pulses of gas and the device is capable of ionizing only a fraction of the incoming gas molecules; these characteristics preclude miniaturization. In contrast, the proposed instrument would not require a carrier-gas-feeding subsystem and would include a simple, highly compact device that would ionize all the molecules passing through it. The ionization device in the proposed instrument would be a 0.1-micron-thick dielectric membrane with metal electrodes on both sides. Small conical holes would be micromachined through the membrane and electrodes. An electric potential of the order of a volt applied between the membrane electrodes would give rise to an electric field of the order of several megavolts per meter in the submicron gap between the electrodes. An electric field of this magnitude would be sufficient to ionize all the molecules that enter the holes. Ionization (but not avalanche arcing) would occur because the distance between the ionizing electrodes would be less than the mean free path of gas molecules at the operating pressure of instrument. An accelerating grid would be located inside the instrument, downstream from the ionizing membrane. The electric potential applied to this grid would be negative relative to the potential on the inside electrode of the ionizing membrane and would be of a magnitude sufficient to

  9. Double-resonance spectroscopy of autoionizing states of ammonia

    NASA Astrophysics Data System (ADS)

    Raptis, C. A.; Bacon, J. A.; Pratt, S. T.

    2000-02-01

    New double-resonance ionization data are presented on the autoionizing Rydberg states of NH3 excited via selected rotational levels of the C˜' 1A1(0100) and (0200) states. Extrapolation of the Rydberg series provides a determination of the adiabatic ionization energy of NH3 that is in excellent agreement with that obtained by using zero kinetic energy photoelectron spectroscopy (ZEKE-PES). A comparison is presented between the field-free spectrum obtained by using a time-of-flight mass spectrometer and the 1-Tesla-spectrum obtained by using a magnetic-bottle electron spectrometer. Finally, the rotational and vibrational autoionization mechanisms are discussed.

  10. The hot plasma spectrometers on Freja

    NASA Astrophysics Data System (ADS)

    Norberg, O.; Eliasson, L.

    1991-11-01

    The hot plasma instrumentation F3H on the Swedish-German Freja satellite due for launch in 1992 will consist of electron and ion spectrometers. The spectrometer Magnetic imaging Two dimensional Electron (MATE) will measure the two dimensional electron distribution in the spin plane in the energy range 0.1 to 120 keV. The ion mass spectrometer Three dimensional Ion Composition Spectrometer (TICS) measures a full three dimensional distribution in the energy range 0.5 to 15000 eV/q with high mass resolution. The instruments use a particle 'imaging' detector technique based on a large diameter microchannel plate with position sensitive anode. The topics to be studied with the Freja hot plasma spectrometers include auroral particle acceleration, heating and acceleration of ionospheric ions, and the dynamics of auroral arc systems. Of special importance to the scientific objectives is the high data rate from the Freja instrumentation, the MATE and TICS spectrometers will be sampled every 10 ms, corresponding to a spatial resolution better than 70 m at ionospheric heights. The design, simulation, and calibration of the spectrometers are discussed.

  11. Handheld spectrometers: the state of the art

    NASA Astrophysics Data System (ADS)

    Crocombe, Richard A.

    2013-05-01

    "Small" spectrometers fall into three broad classes: small versions of laboratory instruments, providing data, subsequently processed on a PC; dedicated analyzers, providing actionable information to an individual operator; and process analyzers, providing quantitative or semi-quantitative information to a process controller. The emphasis of this paper is on handheld dedicated analyzers. Many spectrometers have historically been large, possible fragile, expensive and complicated to use. The challenge over the last dozen years, as instruments have moved into the field, has been to make spectrometers smaller, affordable, rugged, easy-to-use, but most of all capable of delivering actionable results. Actionable results can dramatically improve the efficiency of a testing process and transform the way business is done. There are several keys to this handheld spectrometer revolution. Consumer electronics has given us powerful mobile platforms, compact batteries, clearly visible displays, new user interfaces, etc., while telecomm has revolutionized miniature optics, sources and detectors. While these technologies enable miniature spectrometers themselves, actionable information has demanded the development of rugged algorithms for material confirmation, unknown identification, mixture analysis and detection of suspicious materials in unknown matrices. These algorithms are far more sophisticated than the `correlation' or `dot-product' methods commonly used in benchtop instruments. Finally, continuing consumer electronics advances now enable many more technologies to be incorporated into handheld spectrometers, including Bluetooth, wireless, WiFi, GPS, cameras and bar code readers, and the continued size shrinkage of spectrometer `engines' leads to the prospect of dual technology or `hyphenated' handheld instruments.

  12. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1998-01-01

    The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

  13. Miniature quadrupole mass spectrometer array

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor); Hecht, Michael H. (Inventor); Orient, Otto J. (Inventor)

    1997-01-01

    The present invention provides a minature quadrupole mass spectrometer array for the separation of ions, comprising a first pair of parallel, planar, nonmagnetic conducting rods each having an axis of symmetry, a second pair of planar, nonmagnetic conducting rods each having an axis of symmetry parallel to said first pair of rods and disposed such that a line perpendicular to each of said first axes of symmetry and a line perpendicular to each of said second axes of symmetry bisect each other and form a generally 90 degree angle. A nonconductive top positioning plate is positioned generally perpendicular to the first and second pairs of rods and has an aperture for ion entrance along an axis equidistant from each axis of symmetry of each of the parallel rods, a nonconductive bottom positioning plate is generally parallel to the top positioning plate and has an aperture for ion exit centered on an axis equidistant from each axis of symmetry of each of the parallel rods, means for maintaining a direct current voltage between the first and second pairs of rods, and means for applying a radio frequency voltage to the first and second pairs of rods.

  14. Ultraviolet spectrometer observations of Uranus

    NASA Technical Reports Server (NTRS)

    Broadfoot, A. L.; Herbert, F.; Holberg, J. B.; Hunten, D. M.; Kumar, S.; Sandel, B. R.; Shemansky, D. E.; Dessler, A. J.; Linick, S.; Springer, R.

    1986-01-01

    The Voyager 2 UV spectrometer was used to scan the Uranus atmosphere at wavelengths from 500-1700 A with a field of view of 0.1 x 0.86 deg. The temperature and composition of the upper atmosphere were determined through occultations of light from gamma Pegasi, nu Geminorum and the sun. The data indicated a substantial gas density (100 million H atoms/cu cm) at about 28,000 km from the Uranus center, suggesting that gas drag plays a significant role in ring evolution. The distributions of CH4 and C2H2 in the lower atmosphere were also estimated. An electroglow emission was detected on the sunlit side, and attributed to emissions from atomic and molecular hydrogen excited by low energy electrons. An auroral glow was also observed, and exhibited evidence of an energy input equal to that of the electroglow. Finally, estimates of the C2H2 mixing ratio and the vertical column abundance of H2 are calculated.

  15. Large Isotope Spectrometer for Astromag

    NASA Technical Reports Server (NTRS)

    Binns, W. R.; Klarmann, J.; Israel, M. H.; Garrard, T. L.; Mewaldt, R. A.; Stone, E. C.; Ormes, J. F.; Streitmatter, R. E.; Rasmussen, I. L.; Wiedenbeck, M. E.

    1990-01-01

    The Large Isotope Spectrometer for Astromag (LISA) is an experiment designed to measure the isotopic composition and energy spectra of cosmic rays for elements extending from beryllium through zinc. The overall objectives of this investigation are to study the origin and evolution of galactic matter; the acceleration, transport, and time scales of cosmic rays in the galaxy; and search for heavy antinuclei in the cosmic radiation. To achieve these objectives, the LISA experiment will make the first identifications of individual heavy cosmic ray isotopes in the energy range from about 2.5 to 4 GeV/n where relativistic time dilation effects enhance the abundances of radioactive clocks and where the effects of solar modulation and cross-section variations are minimized. It will extend high resolution measurements of individual element abundances and their energy spectra to energies of nearly 1 TeV/n, and has the potential for discovering heavy anti-nuclei which could not have been formed except in extragalactic sources.

  16. High-Resolution Mass Spectrometers

    NASA Astrophysics Data System (ADS)

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  17. Near-Infrared Grating Spectrometer for Mobile Phone Applications

    PubMed Central

    Knobbe, Jens; Grüger, Heinrich

    2016-01-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro–electro–mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm3. Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications. PMID:27170776

  18. Near-Infrared Grating Spectrometer for Mobile Phone Applications.

    PubMed

    Pügner, Tino; Knobbe, Jens; Grüger, Heinrich

    2016-05-01

    Near-infrared (NIR) spectroscopy is a well-established technique for the chemical analysis of organic and inorganic matter. Accordingly, spectroscopic instrumentation of different complexity has been developed and is currently commercially available. However, there are an increasing number of new mobile applications that have come into focus and that cannot be addressed by the existing technology due to size and cost. Therefore, a new miniaturized scanning grating spectrometer for NIR spectroscopy has been developed at Fraunhofer IPMS. It is based on micro-electro-mechanical systems (MEMS) technology, and has been designed to meet the requirements for mobile application, regarding spectral range, resolution, overall size, robustness, and cost. The MEMS spectrometer covers a spectral range from 950 nm to 1900 nm at a resolution of 10 nm. The instrument is extremely small and has a volume of only 2.1 cm(3) Therefore, it is well suited for integration, even into a mobile phone. A first sample of the new spectrometer has been manufactured and put into operation. The results of a series of test measurements are in good agreement with the requirements and specifications. PMID:27170776

  19. In-flight performances of the PAMELA magnetic spectrometer

    NASA Astrophysics Data System (ADS)

    Vannuccini, Elena

    PAMELA cosmic-ray detector is orbiting around the Earth on board the Resurs DK1 satellite since June 2006. The experiment is designed to study charged particles in the cosmic radiation, being optimized in particular for antiprotons and positrons. The core of the detector is a spectrometer composed of six planes of silicon microstrip sensors, which are placed inside the cavity of a permanent magnet. The detector has been designed to determine precisely the rigidity (up to 1 TV) and the electric charge (up to berillium) of particles crossing the apparatus. The spectrometer plays a crucial role in the high-energy antiproton analysis, where the main source of background comes from protons which recostructed trajectories have a negative curvature due to the finite resolution of the tracking system ("spillover" background). In this work the in-flight performances of the spectrometer will be presented, with main focus on the momentum resolution of singly-charged particles. A key point of track reconstruction is the alignment of the tracking system, which is done with the help of the energy information provided by the calorimeter for electrons and positrons. The good quality of flight data and the agreement with simulation indicate that the instrument provides a reliable estimate of the particle rigidity over a wide energy range. Finally, the criteria applied to minimize the spillover background in the antiproton sample and extend the identification to high energy will be discussed.

  20. 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.

  1. Mini-orange spectrometer at CIAE

    NASA Astrophysics Data System (ADS)

    Zheng, Yun; Wu, Xiao-Guang; Li, Guang-Sheng; Li, Cong-Bo; He, Chuang-Ye; Chen, Qi-Ming; Zhong, Jian; Zhou, Wen-Kui; Deng, Li-Tao; Zhu, Bao-Ji

    2016-08-01

    A mini-orange spectrometer used for in-beam measurements of internal conversion electrons, consisting of a Si(Li) detector and different sets of SmO5 permanent magnets for filtering and transporting the conversion electrons to the Si(Li) detector, has been developed at the China Institute of Atomic Energy. The working principles and configuration of the mini-orange spectrometer are described. The performance of the setup is illustrated by measured singles conversion electron spectra using the mini-orange spectrometer. Supported by National Natural Science Foundation of China (11305269, 11375267, 11475072, 11405274, 11205068, 11175259)

  2. Gas sampling system for a mass spectrometer

    DOEpatents

    Taylor, Charles E; Ladner, Edward P

    2003-12-30

    The present invention relates generally to a gas sampling system, and specifically to a gas sampling system for transporting a hazardous process gas to a remotely located mass spectrometer. The gas sampling system includes a capillary tube having a predetermined capillary length and capillary diameter in communication with the supply of process gas and the mass spectrometer, a flexible tube surrounding and coaxial with the capillary tube intermediate the supply of process gas and the mass spectrometer, a heat transfer tube surrounding and coaxial with the capillary tube, and a heating device in communication the heat transfer tube for substantially preventing condensation of the process gas within the capillary tube.

  3. Spectrometer for cluster ion beam induced luminescence

    SciTech Connect

    Ryuto, H. Sakata, A.; Takeuchi, M.; Takaoka, G. H.; Musumeci, F.

    2015-02-15

    A spectrometer to detect the ultra-weak luminescence originated by the collision of cluster ions on the surfaces of solid materials was constructed. This spectrometer consists of 11 photomultipliers with band-pass interference filters that can detect the luminescence within the wavelength ranging from 300 to 700 nm and of a photomultiplier without filter. The calibration of the detection system was performed using the photons emitted from a strontium aluminate fluorescent tape and from a high temperature tungsten filament. Preliminary measurements show the ability of this spectrometer to detect the cluster ion beam induced luminescence.

  4. Isomeric ratio measurements with the ILL LOHENGRIN spectrometer

    NASA Astrophysics Data System (ADS)

    Chebboubi, A.; Kessedjian, G.; Litaize, O.; Serot, O.; Faust, H.; Bernard, D.; Blanc, A.; Köster, U.; Méplan, O.; Mutti, P.; Sage, C.

    2016-03-01

    The modelling of γ heating and neutron damage inside a nuclear reactor is essential to design the next generation of nuclear reactors. The determination of the fission fragment momentum is a key element to perform accurate calculations of the γ heating. One way to assess this information is to look at the isomeric ratio of different nuclei. According to the lifetime of the isomeric state, different experimental techniques were developed at the LOHENGRIN spectrometer. A focus on the measurement of isomeric ratios of 136I in neutron induced fission of 241Pu is presented. A discussion with the current assumptions used in the evaluation process for isomeric ratio is also shown.

  5. A cryogenic scan mechanism for use in Fourier transform spectrometers

    NASA Technical Reports Server (NTRS)

    Hakun, Claef F.; Blumenstock, Kenneth A.

    1995-01-01

    This paper describes the requirements, design, assembly and testing of the linear Scan Mechanism (SM) of the Composite Infrared Spectrometer (CIRS) Instrument. The mechanism consists of an over constrained flexible structure, an innovative moving magnet actuator, passive eddy current dampers, a Differential Eddy Current (DEC) sensor, Optical Limit Sensors (OLS), and a launch lock. Although all the components of the mechanism are discussed, the flexible structure and the magnetic components are the primary focus. Several problems encountered and solutions implemented during the development of the scan mechanism are also described.

  6. A double-double/double-single computation package

    SciTech Connect

    Bailey, David H.

    2004-12-01

    The DDFUNIDSFUN software permits a new or existing Fortran-90 program to utilize double-double precision (approx. 31 digits) or double-single precision (approx. 14 digits) arithmetic. Double-double precision is required by a rapidly expandirtg body of scientific computations in physics and mathematics, for which the conventional 64-bit IEEE computer arithmetic (about 16 decimal digit accuracy) is not sufficient. Double-single precision permits users of systems that do not have hardware 64-bit IEEE arithmetic (such as some game systems) to perform arithmetic at a precision nearly as high as that of systems that do. Both packages run significantly faster Than using multiple precision or arbitrary precision software for this purpose. The package includes an extensive set of low-level routines to perform high-precision arithmetic, including routines to calculate various algebraic and transcendental functions, such as square roots, sin, ccc, exp, log and others. In addition, the package includes high-level translation facilities, so that Fortran programs can utilize these facilities by making only a few changes to conventional Fortran programs. In most cases, the only changes that are required are to change the type statements of variables that one wishes to be treated as multiple precision, plus a few other minor changes. The DDFUN package is similar in functionality to the double-double part of the GD package, which was previously written at LBNL. However, the DDFUN package is written exclusively in Fortran-90, thus avoidIng difficulties that some users experience when using GD, which includes both Fortran-90 and C++ code.

  7. A double-double/double-single computation package

    Energy Science and Technology Software Center (ESTSC)

    2004-12-01

    The DDFUNIDSFUN software permits a new or existing Fortran-90 program to utilize double-double precision (approx. 31 digits) or double-single precision (approx. 14 digits) arithmetic. Double-double precision is required by a rapidly expandirtg body of scientific computations in physics and mathematics, for which the conventional 64-bit IEEE computer arithmetic (about 16 decimal digit accuracy) is not sufficient. Double-single precision permits users of systems that do not have hardware 64-bit IEEE arithmetic (such as some game systems)more » to perform arithmetic at a precision nearly as high as that of systems that do. Both packages run significantly faster Than using multiple precision or arbitrary precision software for this purpose. The package includes an extensive set of low-level routines to perform high-precision arithmetic, including routines to calculate various algebraic and transcendental functions, such as square roots, sin, ccc, exp, log and others. In addition, the package includes high-level translation facilities, so that Fortran programs can utilize these facilities by making only a few changes to conventional Fortran programs. In most cases, the only changes that are required are to change the type statements of variables that one wishes to be treated as multiple precision, plus a few other minor changes. The DDFUN package is similar in functionality to the double-double part of the GD package, which was previously written at LBNL. However, the DDFUN package is written exclusively in Fortran-90, thus avoidIng difficulties that some users experience when using GD, which includes both Fortran-90 and C++ code.« less

  8. "Only" and Focus.

    ERIC Educational Resources Information Center

    Vallduvi, Enric

    The relationship of the word "only," one of a class of words known as scalar particles, focus adverbs, focus inducers, or focus-sensitive particles, with the "focus" of the sentence is examined. It is suggested, based on analysis of discourse structure, that this "association with focus" is not an inherent property of this scalar particle. The…

  9. Double-line spectroscopic orbit for Capella

    SciTech Connect

    Shen, L.-Z.; Beavers, W.I.; Eitter, J.J.; Salzer, J.J.

    1985-08-01

    Radial-velocity spectrometer measurements of both components of the double-line Capella system have been combined with earlier radial-velocity measurements from four previous studies to produce an improved double-line orbit. The resulting mass ratio M1/M2 = 1.18 + or - 0.02 differs by only 2 percent from the virtually ignored previous determination by Struve (1939). Combining the new radial-velocity elements with McAlister's (1981) recent interferometric orbit allows the determination of the individual masses of M1 = 3.31 + or 0.08 solar mass and M2 = 2.80 + or - 0.05 solar mass. This mass difference is perhaps too great for both stars to be on the first crossing of the Hertzsprung gap as proposed by Boesgaard (1971). 38 references.

  10. Spectrometer Observations Near Mawrth Vallis

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This targeted image from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) shows a region of heavily altered rock in Mars' ancient cratered highlands. The featured region is just south of Mawrth Vallis, a channel cut by floodwaters deep into the highlands.

    CRISM acquired the image at 1216 UTC (8:16 a.m. EDT) on Oct. 2, 2006, near 25.4 degrees north latitude, 340.7 degrees east longitude. It covers an area about 13 kilometers (8 miles) long and, at the narrowest point, about 9 kilometers (5.6 miles) wide. At the center of the image, the spatial resolution is as good as 35 meters (115 feet) per pixel. The image was taken in 544 colors covering 0.36-3.92 micrometers.

    This image includes four renderings of the data, all map-projected. At top left is an approximately true-color representation. At top right is false color showing brightness of the surface at selected infrared wavelengths. In the two bottom views, brightness of the surface at different infrared wavelengths has been compared to laboratory measurements of minerals, and regions that match different minerals have been colored. The bottom left image shows areas high in iron-rich clay, and the bottom right image shows areas high in aluminum-rich clay.

    Clay minerals are important to understanding the history of water on Mars because their formation requires that rocks were exposed to liquid water for a long time. Environments where they form include soils, cold springs, and hot springs. There are many clay minerals, and which ones form depends on the composition of the rock, and the temperature, acidity, and salt content of the water. CRISM's sister instrument on the Mars Express spacecraft, OMEGA, has spectrally mapped Mars at lower spatial resolution and found several regions rich in clay minerals. The Mawrth Vallis region, in particular, was found to contain iron-rich clay. CRISM is observing these regions at several tens of times higher spatial resolution, to correlate the

  11. The Cambridge Double Star Atlas

    NASA Astrophysics Data System (ADS)

    MacEvoy, Bruce; Tirion, Wil

    2015-12-01

    Preface; What are double stars?; The binary orbit; Double star dynamics; Stellar mass and the binary life cycle; The double star population; Detecting double stars; Double star catalogs; Telescope optics; Preparing to observe; Helpful accessories; Viewing challenges; Next steps; Appendices: target list; Useful formulas; Double star orbits; Double star catalogs; The Greek alphabet.

  12. Imaging Spectrometer on a Chip

    NASA Technical Reports Server (NTRS)

    Wang, Yu; Pain, Bedabrata; Cunningham, Thomas; Zheng, Xinyu

    2007-01-01

    A proposed visible-light imaging spectrometer on a chip would be based on the concept of a heterostructure comprising multiple layers of silicon-based photodetectors interspersed with long-wavelength-pass optical filters. In a typical application, this heterostructure would be replicated in each pixel of an image-detecting integrated circuit of the active-pixel-sensor type (see figure). The design of the heterostructure would exploit the fact that within the visible portion of the spectrum, the characteristic depth of penetration of photons increases with wavelength. Proceeding from the front toward the back, each successive long-wavelength-pass filter would have a longer cutoff wavelength, and each successive photodetector would be made thicker to enable it to absorb a greater proportion of incident longer-wavelength photons. Incident light would pass through the first photodetector and encounter the first filter, which would reflect light having wavelengths shorter than its cutoff wavelength and pass light of longer wavelengths. A large portion of the incident and reflected shorter-wavelength light would be absorbed in the first photodetector. The light that had passed through the first photodetector/filter pair of layers would pass through the second photodetector and encounter the second filter, which would reflect light having wavelengths shorter than its cutoff wavelength while passing light of longer wavelengths. Thus, most of the light reflected by the second filter would lie in the wavelength band between the cutoff wavelengths of the first and second filters. Thus, further, most of the light absorbed in the second photodetector would lie in this wavelength band. In a similar manner, each successive photodetector would detect, predominantly, light in a successively longer wavelength band bounded by the shorter cutoff wavelength of the preceding filter and the longer cutoff wavelength of the following filter.

  13. The GIANO-TNG spectrometer

    NASA Astrophysics Data System (ADS)

    Oliva, E.; Origlia, L.; Baffa, C.; Biliotti, C.; Bruno, P.; D'Amato, F.; Del Vecchio, C.; Falcini, G.; Gennari, S.; Ghinassi, F.; Giani, E.; Gonzalez, M.; Leone, F.; Lolli, M.; Lodi, M.; Maiolino, R.; Mannucci, F.; Marcucci, G.; Mochi, I.; Montegriffo, P.; Rossetti, E.; Scuderi, S.; Sozzi, M.

    2006-06-01

    GIANO is an infrared (0.9-2.5 μm cross-dispersed echelle spectrometer designed to achieve high resolution, high throughput, wide band coverage and very high stability for accurate radial velocity measurements. It also includes polarimetric capabilities and a low resolution mode with RS ~ 400 and complete 0.75-2.5 μm coverage. This makes it a very versatile, common user instrument which will be permanently mounted and available on the Nasmyth-B foci of the Telescopio Nazionale Galileo (TNG) located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. The project is fast-track and relies on well known, relatively standard technologies. It has been recognized as one of the top priority instrumental projects of INAF (the Italian National Institute of Astronomy) and received its first financing for the phase-A study in October 2003. Integration in the laboratory is planned to start before the end of 2006, commissioning at the telescope is foreseen within 2007 and scientific operations in 2008. One of the most important scientific goals is the search for rocky planets with habitable conditions around low-mass stars. If completed on time, GIANO will be the first and only IR instrument operating worldwide providing the combination of efficiency, spectral resolution, wavelength coverage and stability necessary for this type of research. With its unique combination of high and low resolution modes, GIANO will also be a very flexible common-user instrument ideal e.g. for quantitative spectroscopy of brown dwarfs, stars and stellar clusters as well as for the determination of the spectral energy distribution of faint/red objects such as high redshift galaxies. The expected limiting magnitudes are such that GIANO will be able to deliver good quality HR spectra of any 2MASS object and LR spectra of any object detected in the UKIDSS large area survey.

  14. A tandem time-of-flight spectrometer for negative-ion/positive-ion coincidence measurements with soft x-ray excitation

    NASA Astrophysics Data System (ADS)

    Strâhlman, Christian; Sankari, Rami; Kivimäki, Antti; Richter, Robert; Coreno, Marcello; Nyholm, Ralf

    2016-01-01

    We present a newly constructed spectrometer for negative-ion/positive-ion coincidence spectroscopy of gaseous samples. The instrument consists of two time-of-flight ion spectrometers and a magnetic momentum filter for deflection of electrons. The instrument can measure double and triple coincidences between mass-resolved negative and positive ions with high detection efficiency. First results include identification of several negative-ion/positive-ion coincidence channels following inner-shell photoexcitation of sulfur hexafluoride (SF6).

  15. A tandem time-of-flight spectrometer for negative-ion/positive-ion coincidence measurements with soft x-ray excitation.

    PubMed

    Stråhlman, Christian; Sankari, Rami; Kivimäki, Antti; Richter, Robert; Coreno, Marcello; Nyholm, Ralf

    2016-01-01

    We present a newly constructed spectrometer for negative-ion/positive-ion coincidence spectroscopy of gaseous samples. The instrument consists of two time-of-flight ion spectrometers and a magnetic momentum filter for deflection of electrons. The instrument can measure double and triple coincidences between mass-resolved negative and positive ions with high detection efficiency. First results include identification of several negative-ion/positive-ion coincidence channels following inner-shell photoexcitation of sulfur hexafluoride (SF6). PMID:26827311

  16. Double outlet right ventricle

    MedlinePlus

    ... medlineplus.gov/ency/article/007328.htm Double outlet right ventricle To use the sharing features on this page, please enable JavaScript. Double outlet right ventricle (DORV) is a heart disease that is ...

  17. AUTOMATION OF AN ULTRAVIOLET-VISIBLE SPECTROMETER

    EPA Science Inventory

    This report is an overview of the functional description and major features of an automated ultraviolet-visible spectrometer system intended for environmental measurements application. As such, it defines functional specifications and requirements which are divided into the chlor...

  18. AVIRIS Spectrometer Maps Total Water Vapor Column

    NASA Technical Reports Server (NTRS)

    Conel, James E.; Green, Robert O.; Carrere, Veronique; Margolis, Jack S.; Alley, Ronald E.; Vane, Gregg A.; Bruegge, Carol J.; Gary, Bruce L.

    1992-01-01

    Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) processes maps of vertical-column abundances of water vapor in atmosphere with good precision and spatial resolution. Maps provide information for meteorology, climatology, and agriculture.

  19. Electronically-Scanned Fourier-Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Ocallaghan, F. G.

    1984-01-01

    Instrument efficient, lightweight, and stable. Fourier-transform spectrometer configuration uses electronic, instead of mechanical, scanning. Configuration insensitive to vibration-induced sampling errors introduced into mechanically scanned systems.

  20. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-O IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 micron (1000-4000/cm) to allow high-resolution, high-speed hyperspectral imaging applications. One application will be the remote sensing of the measurement of a large number of different atmospheric gases simultaneously in the same airmass. Due to the use of a combination of birefringent phase retarders and multiple achromatic phase switches to achieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventional Fourier transform spectrometer but without any moving parts. In this paper, the principle of operations, system architecture and recent experimental progress will be presented.

  1. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-0IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 pm (1000 -4000 cm-') to allow high-resolution, high-speed hyperspectral imaging applications [l-51. One application will be theremote sensing of the measurement of a large number of different atmospheric gases simultaneously in the sameairmass. Due to the use of a combination of birefiingent phase retarders and multiple achromatic phase switches toachieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventionalFourier transform spectrometer but without any moving parts. In this paper, the principle of operations, systemarchitecture and recent experimental progress will be presen.

  2. Ultra High Mass Range Mass Spectrometer System

    DOEpatents

    Reilly, Peter T. A. [Knoxville, TN

    2005-12-06

    Applicant's present invention comprises mass spectrometer systems that operate in a mass range from 1 to 10.sup.16 DA. The mass spectrometer system comprising an inlet system comprising an aerodynamic lens system, a reverse jet being a gas flux generated in an annulus moving in a reverse direction and a multipole ion guide; a digital ion trap; and a thermal vaporization/ionization detector system. Applicant's present invention further comprises a quadrupole mass spectrometer system comprising an inlet system having a quadrupole mass filter and a thermal vaporization/ionization detector system. Applicant's present invention further comprises an inlet system for use with a mass spectrometer system, a method for slowing energetic particles using an inlet system. Applicant's present invention also comprises a detector device and a method for detecting high mass charged particles.

  3. Laboratory automation of a quadrupole mass spectrometer

    NASA Astrophysics Data System (ADS)

    Thompson, J. M.

    1983-12-01

    Efforts directed toward interfacing an LSI II bus of a PDP 11/23 desktop computer with a quadrupole mass spectrometer for the purpose of providing a convenient system whereby mass spectral data, of the products of thermal decomposition, may be rapidly acquired and processed under programmed conditions are described. The versatility and operations of the quadrupole mass spectrometer are discussed as well as the procedure for configurating the LSI II bus of the PDP 11/23 desktop computer for interfacing with the quadrupole mass spectrometer system. Data from the mass filter and other units of the spectrometer are digitally transferred to the computer whereupon mass spectral data and related data are generated.

  4. Laboratory Automation of a Quadrupole Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Thompson, J. M.

    1983-01-01

    Efforts directed toward interfacing an LSI II bus of a PDP 11/23 desktop computer with a quadrupole mass spectrometer for the purpose of providing a convenient system whereby mass spectral data, of the products of thermal decomposition, may be rapidly acquired and processed under programmed conditions are described. The versatility and operations of the quadrupole mass spectrometer are discussed as well as the procedure for configurating the LSI II bus of the PDP 11/23 desktop computer for interfacing with the quadrupole mass spectrometer system. Data from the mass filter and other units of the spectrometer are digitally transferred to the computer whereupon mass spectral data and related data are generated.

  5. Chromosome doubling method

    DOEpatents

    Kato, Akio

    2006-11-14

    The invention provides methods for chromosome doubling in plants. The technique overcomes the low yields of doubled progeny associated with the use of prior techniques for doubling chromosomes in plants such as grasses. The technique can be used in large scale applications and has been demonstrated to be highly effective in maize. Following treatment in accordance with the invention, plants remain amenable to self fertilization, thereby allowing the efficient isolation of doubled progeny plants.

  6. Ruggedized Spectrometers Are Built for Tough Jobs

    NASA Technical Reports Server (NTRS)

    2015-01-01

    The Mars Curiosity Chemistry and Camera instrument, or ChemCam, analyzes the elemental composition of materials on the Red Planet by using a spectrometer to measure the wavelengths of light they emit. Principal investigator Roger Wiens worked with Ocean Optics, out of Dunedin, Florida, to rework the company's spectrometer to operate in cold and rowdy conditions and also during the stresses of liftoff. Those improvements have been incorporated into the firm's commercial product line.

  7. Optical Calibration For Jefferson Lab HKS Spectrometer

    SciTech Connect

    L. Yuan; L. Tang

    2005-11-04

    In order to accept very forward angle scattering particles, Jefferson Lab HKS experiment uses an on-target zero degree dipole magnet. The usual spectrometer optics calibration procedure has to be modified due to this on-target field. This paper describes a new method to calibrate HKS spectrometer system. The simulation of the calibration procedure shows the required resolution can be achieved from initially inaccurate optical description.

  8. 1987 calibration of the TFTR neutron spectrometers

    SciTech Connect

    Barnes, C.W.; Strachan, J.D.; Princeton Univ., NJ . Plasma Physics Lab.)

    1989-12-01

    The {sup 3}He neutron spectrometer used for measuring ion temperatures and the NE213 proton recoil spectrometer used for triton burnup measurements were absolutely calibrated with DT and DD neutron generators placed inside the TFTR vacuum vessel. The details of the detector response and calibration are presented. Comparisons are made to the neutron source strengths measured from other calibrated systems. 23 refs., 19 figs., 6 tabs.

  9. Mass Spectrometer for Airborne Micro-Organisms

    NASA Technical Reports Server (NTRS)

    Sinha, M. P.; Friedlander, S. K.

    1986-01-01

    Bacteria and other micro-organisms identified continously with aid of new technique for producing samples for mass spectrometer. Technique generates aerosol of organisms and feeds to spectrometer. Given species of organism produces characteristic set of peaks in mass spectrum and thereby identified. Technique useful for monitoring bacterial makeup in environmental studies and in places where cleanliness is essential, such as hospital operating rooms, breweries, and pharmaceutical plants.

  10. Earthquakes with non--double-couple mechanisms.

    PubMed

    Frohlich, C

    1994-05-01

    Seismological observations confirm that the pattern of seismic waves from some earthquakes cannot be produced by slip along a planar fault surface. More than one physical mechanism is required to explain the observed varieties of these non-double-couple earthquakes. The simplest explanation is that some earthquakes are complex, with stress released on two or more suitably oriented, nonparallel fault surfaces. However, some shallow earthquakes in volcanic and geothermal areas require other explanations. Current research focuses on whether fault complexity explains most observed non-double-couple earthquakes and to what extent ordinary earthquakes have non-double-couple components. PMID:17794721

  11. Double emulsions in a microfluidic device

    NASA Astrophysics Data System (ADS)

    Pannacci, Nicolas; Lockhart, Thibaut; Willaime, Hervé; Tabeling, Patrick

    2007-11-01

    Double emulsions (emulsion of two liquids dispersed in a third liquid phase) are widely used in cosmetics, medicine or food industry. We are interested in producing very well controlled double emulsions in a microfluidic device and predicting the morphology (complete engulfing, non-engulfing or partial engulfing called ``janus'') from classical energetic considerations. We use a double flow focusing geometry with a 100 micrometers cross section for the PDMS microsystem. We compare theoretical and experimental morphologies flowing thirty triplets of immiscible fluids. We observe quite a good agreement and show that microfluidic technology may permit to get non standard objects.

  12. SUB 1-Millimeter Size Fresnel Micro Spectrometer

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon; Koch, Laura; Song, Kyo D.; Park, Sangloon; King, Glen; Choi, Sang

    2010-01-01

    An ultra-small micro spectrometer with less than 1mm diameter was constructed using Fresnel diffraction. The fabricated spectrometer has a diameter of 750 nmicrometers and a focal length of 2.4 mm at 533nm wavelength. The micro spectrometer was built with a simple negative zone plate that has an opaque center with an ecliptic shadow to remove the zero-order direct beam to the aperture slit. Unlike conventional approaches, the detailed optical calculation indicates that the ideal spectral resolution and resolving power do not depend on the miniaturized size but only on the total number of rings. We calculated 2D and 3D photon distribution around the aperture slit and confirmed that improved micro-spectrometers below 1mm size can be built with Fresnel diffraction. The comparison between mathematical simulation and measured data demonstrates the theoretical resolution, measured performance, misalignment effect, and improvement for the sub-1mm Fresnel micro-spectrometer. We suggest the utilization of an array of micro spectrometers for tunable multi-spectral imaging in the ultra violet range.

  13. Commissioning Measurements of the KATRIN Main Spectrometer

    NASA Astrophysics Data System (ADS)

    Wierman, Kevin; Katrin Collaboration

    2013-10-01

    Beginning in May 2013, the KArlsruhe TRItium Neutrino experiment (KATRIN) collaboration began measurements to commission the 10-m diameter main spectrometer. KATRIN utilizes the spectrometer to provide magnetic adiabatic collimation and electrostatic filtering designed to analyze the tritium beta decay spectrum for contributions from the neutrino mass. In order to achieve an order-of-magnitude improvement on previous neutrino mass experiments the desired sensitivity of the apparatus must be 200 meV in the decay endpoint region. Goals of the recent measurements include identification and reduction of backgrounds and determination of the spectrometer transfer function. Backgrounds have been probed by utilizing electromagnetic field configurations to explore decays in the spectrometer, Penning traps and field emission. A 148-pixel PIN diode array is employed to detect particles exiting the spectrometer, which permits angular and radial distributions of particles to be analyzed. This has allowed for high precision comparison between measurements and simulations of expected backgrounds to be investigated in order to commission the spectrometer. This work is supported by grants from the DOE Office of Nuclear Physics and the Helmholtz Association.

  14. Volume 1. Preliminary design study: AXAF x ray calibration spectrometers. Volume 2. Revised preliminary design study: AXAF x ray calibration spectrometers

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The objective of this work was to provide a preliminary design concept for a Flux Monitor Spectrometer (FMS) for use at the X Ray Astrophysics Facility (XRAF) during High Resolution Mirror Assembly (HRMA) testing that met the requirements of SAO-AXAF-88-025 dated July 31, 1991. The calibration test team determined that the spectral resolution of the FMS had to be greater than or equal to twice that of all the AXAF spectrometers throughout the 0.1 to 10 KeV range of x-ray energies. Since this effectively doubled the resolution required by SAO-AXAF-88-025, a change order was approved by the Marshall Space Flight Center and given to Radiation Sciences to revise their study.

  15. Dissociative and double photoionization of CO2 from threshold to 90 A

    NASA Technical Reports Server (NTRS)

    Masuoka, T.; Samson, J. A. R.

    1979-01-01

    The molecular photoionization, dissociative photoionization and double photoionization cross sections for CO2 were measured from their onsets down to 90 A by using various combinations of mass spectrometers (a coincidence time-of-flight mass spectrometer and a magnetic mass spectrometer) and light sources (synchrotron radiation, and glow and spark discharge). It is concluded that the one broad peak and the three shoulders in the total adsorption cross section curve between 640 and 90 A are caused completely by dissociative ionization processes. Several peaks observed in the cross section curve for the total fragmentation CO(+)3, O(+) and C(+) are compared with those in the photoelectron spectrum reported for CO2.

  16. Improved Cloud Condensation Nucleus Spectrometer

    NASA Technical Reports Server (NTRS)

    Leu, Ming-Taun

    2010-01-01

    An improved thermal-gradient cloud condensation nucleus spectrometer (CCNS) has been designed to provide several enhancements over prior thermal- gradient counters, including fast response and high-sensitivity detection covering a wide range of supersaturations. CCNSs are used in laboratory research on the relationships among aerosols, supersaturation of air, and the formation of clouds. The operational characteristics of prior counters are such that it takes long times to determine aerosol critical supersaturations. Hence, there is a need for a CCNS capable of rapid scanning through a wide range of supersaturations. The present improved CCNS satisfies this need. The improved thermal-gradient CCNS (see Figure 1) incorporates the following notable features: a) The main chamber is bounded on the top and bottom by parallel thick copper plates, which are joined by a thermally conductive vertical wall on one side and a thermally nonconductive wall on the opposite side. b) To establish a temperature gradient needed to establish a supersaturation gradient, water at two different regulated temperatures is pumped through tubes along the edges of the copper plates at the thermally-nonconductive-wall side. Figure 2 presents an example of temperature and supersaturation gradients for one combination of regulated temperatures at the thermally-nonconductive-wall edges of the copper plates. c) To enable measurement of the temperature gradient, ten thermocouples are cemented to the external surfaces of the copper plates (five on the top plate and five on the bottom plate), spaced at equal intervals along the width axis of the main chamber near the outlet end. d) Pieces of filter paper or cotton felt are cemented onto the interior surfaces of the copper plates and, prior to each experimental run, are saturated with water to establish a supersaturation field inside the main chamber. e) A flow of monodisperse aerosol and a dilution flow of humid air are introduced into the main

  17. The JPL Field Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Hook, Simon J.; Kahle, Anne B.

    1995-01-01

    The Jet Propulsion Laboratory (JPL) Field Emission Spectrometer (FES) was built by Designs and Prototypes based on a set of functional requirements supplied by JPL. The instrument has a spectral resolution of 6 wavenumbers (wn) and can acquire spectra from either the Mid Infrared (3-5 mu m) or the Thermal Infrared (8-12 pm) depending on whether the InSb or HgCdTe detector is installed respectively. The instrument consists of an optical head system unit and battery. The optical head which is tripod mounted includes the interferometer and detector dewar assembly. Wavelength calibration of the interferometer is achieved using a Helium-Neon laser diode. The dewar needs replenishing with liquid Nitrogen approximately every four hours. The system unit includes the controls for operation and the computer used for acquiring viewing and processing spectra. Radiometric calibration is achieved with an external temperature-controlled blackbody that mounts on the fore-optics of the instrument. The blackbody can be set at 5 C increments between 10 and 55 C. The instrument is compact and weighs about 33 kg. Both the wavelength calibration and radiometric calibration of the instrument have been evaluated. The wavelength calibration was checked by comparison of the position of water features in a spectrum of the sky with their position in the output from a high resolution atmospheric model. The results indicatethat the features in the sky spectrum are within 6-8 wn of their position ill the model spectrum. The radiometric calibration was checked by first calibrating the instrument using the external blackbody supplied with the instrument and then measuring the radiance from another external blackbody at a series of temperatures. The temperatures of these radiance spectra were then recovered by inventing Planck's law and the recovered temperatures compared lo the measured blackbody temperature. These results indicate that radiometric calibration is good to 0.5 C over the range of

  18. The design and simulation of single detector MIR spectrometer based on MEMS scanning mirror

    NASA Astrophysics Data System (ADS)

    Zhang, Zhong-wei; Wen, Zhi-yu; Zeng, Tian-ling; Wei, Kang-lin

    2011-08-01

    Infrared (IR) spectrometers are very important optical equipments that can be used in industry, science, medicine, agriculture, biology and food safety etc., and the market is growing. However, most traditional IR spectrometers, such as Fourier transform spectrometer (FTS) that based on Michelson interferometer principle and scanning monochromator that based on grating scanning, are expensive, relative large volume, and stationary, which can't meet the requirements of specific application such as rapidity, special environment and some special samples. To overcome these drawbacks, innovatory technology-micro electro mechanical systems (MEMS) technology was used in micro IR spectrometers in the past few years. And several prototypes and products that based on several operational principles have been emerged. In this paper, a novel IR micro spectrometer which based on MEMS technology and used single element detector was presented over a wide spectral range (from 2500nm to 5000nm) in the mid infrared (MIR) wavelength regime, and the optical system of it was designed on the basis of traditional scanning monochromator principle. In the optical system, there is a highlighted characteristic that dual spherical focus mirror was used to focus the diffraction light of the diffraction grating, which improved the spectral resolution of the optical system. Finally, using Zemax optical software, three torsion angle locations were selected to simulate the optical system of the spectrometer with the slit's size 0.1mm×1mm. The simulation result indicated that in the whole wavelength range the spectral resolution of the optical system was less than 30nm, and a high accuracy MIR spectrometer with compact volume will be realized in future hopefully.

  19. EDITORIAL: Focus on Graphene

    NASA Astrophysics Data System (ADS)

    Peres, N. M. R.; Ribeiro, Ricardo M.

    2009-09-01

    Graphene physics is currently one of the most active research areas in condensed matter physics. Countless theoretical and experimental studies have already been performed, targeting electronic, magnetic, thermal, optical, structural and vibrational properties. Also, studies that modify pristine graphene, aiming at finding new physics and possible new applications, have been considered. These include patterning nanoribbons and quantum dots, exposing graphene's surface to different chemical species, studying multilayer systems, and inducing strain and curvature (modifying in this way graphene's electronic properties). This focus issue includes many of the latest developments on graphene research. Focus on Graphene Contents Electronic properties of graphene and graphene nanoribbons with 'pseudo-Rashba' spin-orbit coupling Tobias Stauber and John Schliemann Strained graphene: tight-binding and density functional calculations R M Ribeiro, Vitor M Pereira, N M R Peres, P R Briddon and A H Castro Neto The effect of sublattice symmetry breaking on the electronic properties of doped graphene A Qaiumzadeh and R Asgari Interfaces within graphene nanoribbons J Wurm, M Wimmer, I Adagideli, K Richter and H U Baranger Weak localization and transport gap in graphene antidot lattices J Eroms and D Weiss Electronic properties of graphene antidot lattices J A Fürst, J G Pedersen, C Flindt, N A Mortensen, M Brandbyge, T G Pedersen and A-P Jauho Splitting of critical energies in the n=0 Landau level of graphene Ana L C Pereira Double-gated graphene-based devices S Russo, M F Craciun, M Yamamoto, S Tarucha and A F Morpurgo Pinning and switching of magnetic moments in bilayer graphene Eduardo V Castro, M P López-Sancho and M A H Vozmediano Electronic transport properties of graphene nanoribbons Katsunori Wakabayashi, Yositake Takane, Masayuki Yamamoto and Manfred Sigrist Many-body effects on out-of-plane phonons in graphene J González and E Perfetto Graphene zigzag ribbons, square

  20. The rotating spectrometer: New biotechnology for cell separations

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Matsos, Helen C.

    1990-01-01

    An instrument for biochemical studies, called the rotating spectrometer, separates previously inseparable cell cultures. The rotating spectrometer is intended for use in pharmacological studies which require fractional splitting of heterogeneous cell cultures based on cell morphology and swimming behavior. As a method to separate and concentrate cells in free solution, the rotating method requires active organism participation and can effectively split the large class of organisms known to form spontaneous patterns. Examples include the biochemical star, an organism called Tetrahymena pyriformis. Following focusing in a rotated frame, the separation is accomplished using different radial dependencies of concentrated algal and protozoan species. The focusing itself appears as concentric rings and arises from the coupling between swimming direction and Coriolis forces. A dense cut is taken at varying radii and extraction is replenished at an inlet. Unlike standard separation and concentrating techniques such as filtration or centrifugation, the instrument is able to separate motile from immotile fractions. For a single pass, typical split efficiencies can reach 200 to 300 percent compared to the inlet concentration.

  1. Experiment TGV II: results on double electron capture in 106Cd

    NASA Astrophysics Data System (ADS)

    Cermak, P.; Benes, P.; Briançon, C.; Brudanin, V. B.; Egorov, V. G.; Gusev, K. N.; Klimenko, A. A.; Kovalenko, V. E.; Kovalik, A.; Rukhadze, N. I.; Salamatin, A. V.; Simkovic, F.; Stekl, I.; Timkin, V. V.; Vylov, T.

    2008-06-01

    The TGV II (Telescope Germanium Vertical) facility is a low background spectrometer operated in Modane Underground Laboratory. It aims at the study of double electron capture of 106Cd. The spectrometer is composed of 32 HPGe planar detectors interleaved with thin-foil samples made of 106Cd enriched to 75%. In 2006, the main run of phase I (1 year duration) was terminated yielding a new limit on half-life for two-neutrino double electron capture in 106Cd as 2.0x1020y. The new limit is significantly higher (by almost three orders of magnitude) than those already published.

  2. Multielectron Spectroscopy: The Xenon 4d Hole Double Auger Decay

    SciTech Connect

    Penent, F.; Palaudoux, J.; Lablanquie, P.; Andric, L.; Feifel, R.; Eland, J.H.D.

    2005-08-19

    A magnetic bottle spectrometer of the type recently developed by Eland et al. [Phys. Rev. Lett. 90, 053003 (2003).] has been implemented for use with synchrotron radiation, allowing multidimensional electron spectroscopy. Its application to the Xe 4d double Auger decay reveals all the energy pathways involved. The dominant path is a cascade process with a rapid (6 fs) ejection of a first Auger electron followed by the slower (>23 fs) emission of a second Auger electron. Weaker processes implying 3 electron processes are also revealed, namely, direct double Auger and associated Rydberg series.

  3. The LASS (Larger Aperture Superconducting Solenoid) spectrometer

    SciTech Connect

    Aston, D.; Awaji, N.; Barnett, B.; Bienz, T.; Bierce, R.; Bird, F.; Bird, L.; Blockus, D.; Carnegie, R.K.; Chien, C.Y.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K and K interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K p interactions during 1977 and 1978, which is also described briefly.

  4. The balloon-borne experiment with a superconducting spectrometer (BESS) program

    NASA Astrophysics Data System (ADS)

    Mitchell, John; Hams, Thomas; Yamamoto, A.; Mitchell, J. W.; Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Lee, M. H.; Makida, Y.; Matsuda, S.; Matsukawa, Y.; Matsumoto, K.; Moiseev, A. A.; Myers, Z.; Nishimura, J.; Nozaki, M.; Orito, R.; Ormes, J. F.; Sakai, K.; Sasaki, M.; Seo, E. S.; Shikaze, Y.; Shinoda, R.; Streitmatter, R. E.; Suzuki, J.; Takasugi, Y.; Takeuchi, K.; Tanaka, K.; Thakur, N.; Yamagami, T.; Yoshida, T.; Yoshimura, K.

    In eleven balloon flights since 1993, nine over the northern hemisphere and two over Antarctica, the BESS collaboration has precisely measured the spectra of cosmic-ray antiprotons and light nuclei and conducted sensitive searches for antihelium and antideuterons. BESS antiproton measurements constrain candidate models for dark matter and, together with the measured elemental and isotopic spectra of H and He, probe cosmic-ray transport in the Galaxy and Solar System. The BESS antihelium search investigates the symmetry of matter and antimatter in the Universe. Using superconducting magnetic-rigidity spectrometers with time-of-flight and aerogel Cherenkov detectors, BESS instruments fully identify incident particles by charge, charge sign, mass, and energy. The long-duration BESS-Polar I instrument flew over Antarctica for 8.5 days in 2004, recording 900 million events. BESS-Polar II, with extended magnet lifetime, improved detector and electronic performance, and greater data storage capacity, flew in 2007-2008, recording 4.7 billion events, more than double the combined data from all previous BESS flights, in 24.5 days. This flight took place near Solar minimum when the sensitivity of the antiproton measurements to a low-energy primary component is greatest. The BESS-Polar II recorded 10-20 times more antiprotons than the combined BESS 95-97 dataset at the previous Solar minimum and will provide a definitive test of the possible primary source suggested by those data. BESS-Polar II landed about 1800 km from McMurdo Station and recovery was successfully accomplished in January 2010. We will review the BESS program, focusing on the flight and recovery of BESS-Polar II. Details of the BESS-Polar II instrument and its in-flight performance are reported in other papers at this conference.

  5. Martian Neutron Energy Spectrometer (MANES)

    NASA Technical Reports Server (NTRS)

    Maurer, R. H.; Roth, D. R.; Kinnison, J. D.; Goldsten, J. O.; Fainchtein, R.; Badhwar, G.

    2000-01-01

    High energy charged particles of extragalactic, galactic, and solar origin collide with spacecraft structures and planetary atmospheres. These primaries create a number of secondary particles inside the structures or on the surfaces of planets to produce a significant radiation environment. This radiation is a threat to long term inhabitants and travelers for interplanetary missions and produces an increased risk of carcinogenesis, central nervous system (CNS) and DNA damage. Charged particles are readily detected; but, neutrons, being electrically neutral, are much more difficult to monitor. These secondary neutrons are reported to contribute 30-60% of the dose equivalent in the Shuttle and MIR station. The Martian atmosphere has an areal density of 37 g/sq cm primarily of carbon dioxide molecules. This shallow atmosphere presents fewer mean free paths to the bombarding cosmic rays and solar particles. The secondary neutrons present at the surface of Mars will have undergone fewer generations of collisions and have higher energies than at sea level on Earth. Albedo neutrons produced by collisions with the Martian surface material will also contribute to the radiation environment. The increased threat of radiation damage to humans on Mars occurs when neutrons of higher mean energy traverse the thin, dry Martian atmosphere and encounter water in the astronaut's body. Water, being hydrogeneous, efficiently moderates the high energy neutrons thereby slowing them as they penetrate deeply into the body. Consequently, greater radiation doses can be deposited in or near critical organs such as the liver or spleen than is the case on Earth. A second significant threat is the possibility of a high energy heavy ion or neutron causing a DNA double strand break in a single strike.

  6. Matrix-assisted laser desorption using a fast-atom bombardment ion source and a magnetic mass spectrometer.

    PubMed

    Annan, R S; Köchling, H J; Hill, J A; Biemann, K

    1992-04-01

    A conventional fast-atom bombardment (FAB) ion source was used to achieve matrix-assisted laser desorption (MALD) in a high-mass, double-focusing, magnetic mass spectrometer. The pulsed ion signals generated by irradiation of a mixture of sample and matrix (2,5-dihydroxybenzoic acid) with either a XeF excimer laser (353 nm) or a nitrogen laser (337 nm) were recorded with a focal-plane detector. A resolution (full-width at half maximum) of 4500 was achieved at m/z 1347.7 (the peptide substance P), 2500 for CsI cluster ions at m/z 10,005.7, and 1250 for the isotope cluster of the small protein cytochrome c (horse) [M+H]+ = m/z 12,360 (average). Sensitivity is demonstrated with 11 fmol of substance P. A survey scan is taken to locate the m/z of the sample molecular ion. The segment that contains the sample can then be integrated for a longer time to produce a better signal-to-noise ratio. In addition to higher sensitivity and lower matrix interference, the advantage of MALD over FAB is the former's lower susceptibility to the presence of salts, and competition between hydrophobic and hydrophilic components of a mixture. This feature is demonstrated by the complete MALD spectrum of a crude partial tryptic digest of sperm-whale apomyoglobin, containing 24 peptides, representing the entire sequence of this protein. PMID:1373978

  7. Laboratory investigation of photochemical oxidation of organic aerosol from wood fires Part 2: Analysis of aerosol mass spectrometer data

    NASA Astrophysics Data System (ADS)

    Grieshop, A. P.; Donahue, N. M.; Robinson, A. L.

    2008-09-01

    Experiments were conducted to investigate the effects of photo-oxidation on organic aerosol (OA) in dilute wood smoke by exposing emissions from soft- and hard-wood fires to UV light in a smog chamber. This paper focuses on changes in OA composition measured using a unit mass resolution quadrupole Aerosol Mass Spectrometer (AMS). The results highlight how photochemical processing can lead to considerable evolution of the mass, the volatility and the level of oxygenation of biomass-burning OA. Photochemical oxidation produced substantial new OA, more than doubling the primary contribution after a few hours of aging under typical summertime conditions. Aging decreased the OA volatility of the total OA as measured with a thermodenuder; it also made the OA progressively more oxygenated in every experiment. With explicit knowledge of the condensed-phase mass spectrum (MS) of the primary emissions from each fire, each MS can be decomposed into primary and residual spectra throughout the experiment. The residual spectra provide an estimate of the composition of the photochemically produced OA. These spectra are also very similar to those of the oxygenated OA that dominates ambient AMS datasets. In addition, aged wood smoke spectra are shown to be similar to those from OA created by photo-oxidized dilute diesel exhaust and aged biomass-burning OA measured in urban and remote locations. This demonstrates that the oxygenated OA observed in the atmosphere can be produced by photochemical aging of dilute emissions from combustion of fuels containing both modern and fossil carbon.

  8. Imaging Spectrometers Using Concave Holographic Gratings

    NASA Technical Reports Server (NTRS)

    Gradie, J.; Wang, S.

    1993-01-01

    Imaging spectroscopy combines the spatial attributes of imaging with the compositionally diagnostic attributes of spectroscopy. For spacebased remote sensing applications, mass, size, power, data rate, and application constrain the scanning approach. For the first three approaches, substantial savings in mass and size of the spectrometer can be achieved in some cases with a concave holographic grating and careful placement of an order-sorting filter. A hologram etched on the single concave surface contains the equivalent of the collimating, dispersing, and camera optics of a conventional grating spectrometer and provides substantial wavelength dependent corrections for spherical aberrations and a flat focal field. These gratings can be blazed to improve efficiency when used over a small wavelength range or left unblazed for broadband uniform efficiency when used over a wavelength range of up to 2 orders. More than 1 order can be imaged along the dispersion axis by placing an appropriately designed step order-sorting filter in front of the one- or two-dimensional detector. This filter can be shaped for additional aberration corrections. The VIRIS imaging spectrometer based on the broadband design provides simultaneous imaging of the entrance slit from lambda = 0.9 to 2.6 microns (1.5 orders) onto a 128 x 128 HgCdTe detector (at 77 K). The VIRIS spectrometer was used for lunar mapping with the UH 24.in telescope at Mauna Kea Observatory. The design is adaptable for small, low mass, space based imaging spectrometers.

  9. Latest Double Chooz results

    NASA Astrophysics Data System (ADS)

    Lasserre, Thierry; Double Chooz Collaboration

    2016-05-01

    I report the latest results from the Double Chooz experiment on the θ13 neutrino mixing angle. Two detectors are located at distances of 400 m and 1050 m from the reactor cores of the Chooz nuclear power station (France) to measure the disappearance of electron antineutrinos. The far detector has been taking data since 2011, accumulating a live time of 467.90 days (66.5 GW-ton-year). In this article we focus on the latest measurement using neutrino-induced neutron capture on hydrogen. A new analysis improved the signal efficiency and reduced the backgrounds and systematic uncertainties, leading to sin2 2θ 13 = 0.095+0.039 -0.038. When combined with the Gadolinium-based analysis this leads to sin2 2θ13 = 0.088+0.33 -0.033. The distortion from the prediction above a visible energy of 4 MeV is confirmed. The near detector started data taking in 2014 and first results shall be reported in 2016.

  10. Laser double Doppler flowmeter

    NASA Astrophysics Data System (ADS)

    Poffo, L.; Goujon, J.-M.; Le Page, R.; Lemaitre, J.; Guendouz, M.; Lorrain, N.; Bosc, D.

    2014-05-01

    The Laser Doppler flowmetry (LDF) is a non-invasive method for estimating the tissular blood flow and speed at a microscopic scale (microcirculation). It is used for medical research as well as for the diagnosis of diseases related to circulatory system tissues and organs including the issues of microvascular flow (perfusion). It is based on the Doppler effect, created by the interaction between the laser light and tissues. LDF measures the mean blood flow in a volume formed by the single laser beam, that penetrate into the skin. The size of this measurement volume is crucial and depends on skin absorption, and is not directly reachable. Therefore, current developments of the LDF are focused on the use of always more complex and sophisticated signal processing methods. On the other hand, laser Double Doppler Flowmeter (FL2D) proposes to use two laser beams to generate the measurement volume. This volume would be perfectly stable and localized at the intersection of the two laser beams. With FL2D we will be able to determine the absolute blood flow of a specific artery. One aimed application would be to help clinical physicians in health care units.

  11. Modeling of the generic spatial heterodyne spectrometer and comparison with conventional spectrometer

    SciTech Connect

    Powell, Ian; Cheben, Pavel

    2006-12-20

    We describe the modeling of the generic spatial heterodyne spectrometer. This instrument resembles a somewhat modified Michelson interferometer, in which the power spectrum of the input source is determined by performing a one-dimensional Fourier transform on the output intensity profile. Code has been developed to analyze the performance of this type of spectrometer by determining the dependence of both spectral resolution and throughput on parameters such as aperture and field of view. An example of a heterodyne spectrometer is developed to illustrate the techniques employed in the modeling and a comparison undertaken between its performance and that of a conventional spectrometer. Unlike the traditional Fourier transform infrared system, the heterodyne spectrometer has the very desirable feature of having no moving components.

  12. Bulk and integrated acousto-optic spectrometers for molecular astronomy with heterodyne spectrometers

    NASA Technical Reports Server (NTRS)

    Chin, G.; Buhl, D.; Florez, J. M.

    1981-01-01

    A survey of acousto-optic spectrometers for molecular astronomy is presented, noting a technique of combining the acoustic bending of a collimated coherent light beam with a Bragg cell followed by an array of sensitive photodetectors. This acousto-optic spectrometer has a large bandwidth, a large number of channels, high resolution, and is energy efficient. Receiver development has concentrated on high-frequency heterodyne systems for the study of the chemical composition of the interstellar medium. RF spectrometers employing acousto-optic diffraction cells are described. Acousto-optic techniques have been suggested for applications to electronic warfare, electronic countermeasures and electronic support systems. Plans to use integrated optics for the further miniaturization of acousto-optic spectrometers are described. Bulk acousto-optic spectrometers with 300 MHz and 1 GHz bandwidths are being developed for use in the back-end of high-frequency heterodyne receivers for astronomical research.

  13. Experiments TGV I (double-beta decay of 48Ca) and TGV II (double-beta decay of 106Cd and 48Ca)

    NASA Astrophysics Data System (ADS)

    Štekl, I.; Čermák, P.; Beneš, P.; Brudanin, V. B.; Rukhadze, N. I.; Egorov, V. G.; Kovalenko, V. E.; Kovalík, A.; Salamatin, A. V.; Tsoupko-Sitnikov, V. V.; Vylov, Ts.; Briancon, Ch.; Šimkovic, F.

    2000-04-01

    Present status of experiments TGV I and TGV II is given. The TGV I collaboration has studied the double-beta decay of 48Ca with a low-background and high sensitivity Ge multi-detector spectrometer TGV (Telescope Germanium Vertical). The preliminary results of years and years (90% CL) for double-beta decay of 48 Ca has been found after the processing of experimental data obtained after 8700 hours of measuring time using approximately 1 gramme of 48Ca. The aim of the experiment TGV II is the development of the experimental methods, construction of spectrometers and measurement of the decay (++, β+/EC, EC/EC) of 106Cd particularly the 2νEC/EC mode. The theoretical description and performance of the TGV II spectrometer are also given.

  14. Focus Curriculum Manual; A Focus Dissemination Project.

    ERIC Educational Resources Information Center

    Human Resource Associates, Inc., Hastings, Minn.

    This training manual is for use in preparing staff members to use the Focus Model, which is a "school within a school" for disaffected high school students. The material is designed to be used as a resource aid following participation in an in-service workshop. Information is presented to help implement a contracting system to establish and…

  15. Cylindrical Crystal Imaging Spectrometer (CCIS) for cosmic X-ray spectroscopy

    NASA Technical Reports Server (NTRS)

    Schnopper, H. W.; Taylor, P. O.

    1981-01-01

    A "stigmatic" focusing, Bragg crystal spectrometer was developed and used for high spectral resolution X-ray emission line diagnostics on hot laboratory plasmas. The concept be applied at the focal plane of an orbiting X-ray telescope where it offers several advantages over conventional spectrometers, i.e., mechanical simplicity, high resolving power and sensitivity, simultaneous measurement of an extended segment of spectrum, and good imaging properties. The instrument features a simple, unambiguous, non-scanning spectrum readout that is not adversely affected by either spacecraft pointing error or source extent. The performance of the instrument is estimated in the context of the Advanced X-Ray Astrophysical Facility mission.

  16. The Fly's Eye Energetic Particle Spectrometer (FEEPS) Sensors for the Magnetospheric Multiscale (MMS) Mission

    NASA Astrophysics Data System (ADS)

    Blake, J. B.; Mauk, B. H.; Baker, D. N.; Carranza, P.; Clemmons, J. H.; Craft, J.; Crain, W. R.; Crew, A.; Dotan, Y.; Fennell, J. F.; Friedel, R. H.; Friesen, L. M.; Fuentes, F.; Galvan, R.; Ibscher, C.; Jaynes, A.; Katz, N.; Lalic, M.; Lin, A. Y.; Mabry, D. M.; Nguyen, T.; Pancratz, C.; Redding, M.; Reeves, G. D.; Smith, S.; Spence, H. E.; Westlake, J.

    2016-03-01

    The Energetic Particle Detector (EPD) Investigation is one of five particles and fields investigations on the Magnetospheric Multiscale (MMS) mission. This mission consists of four satellites operating in close proximity in elliptical, low-inclination orbits, and is focused upon the fundamental physics of magnetic reconnection. The Energetic Particle Detector (EPD) investigation aboard the four MMS spacecraft consists of two instrument designs, the EIS (Energetic Ion Spectrometer) and the FEEPS (Fly's Eye Electron Proton Spectrometer). This present paper describes FEEPS from an instrument physics and engineering point of view, and provides some test and calibration data to facilitate effective analysis and use of the flight data for scientific purposes.

  17. An imaging spectrometer with a convex crystal for pulsed x rays in plasma experiments

    NASA Astrophysics Data System (ADS)

    Yanagidaira, Takeshi; Shimoda, Katsuji; Ono, Yasushi; Hirano, Katsumi

    2000-01-01

    An imaging spectrometer with a convex rubidium acid phthalate (RbAP) crystal is designed and examined. Using the ray tracing technique based on the kinematical theory of diffraction, resolution power, dispersion, linearity, spatial resolution and dynamic range of the monochromatic image are discussed. Broadening by a rocking curve is also taken into account. Performance of the spectrometer is successfully examined using the so-called hot spots as the soft x-ray source which are generated in the pinched plasma by the plasma focus facility with an additional gas puff.

  18. Dual purpose optical instrument capable of simultaneously acting as spectrometer and diffractometer

    NASA Technical Reports Server (NTRS)

    Dasgupta, K.; Schnopper, H. W.; Metzger, A. E. (Inventor)

    1969-01-01

    A dual purpose optical instrument is described capable of simultaneously acting as a spectrometer and diffractometer to respectively perform elemental and structural analysis of an unknown sample. The diffractometer portion of the instrument employs a modified form of Seeman-Bohlin focusing which involves providing a line source of X-rays, a sample, and a detector, all on the same focal circle. The spectrometer portion of the instrument employs a fixedly mounted X-ray energy detector mounted outside of the plane of the focal circle.

  19. Mass- and energy-analyses of ions from plasma by means of a miniature Thomson spectrometer

    SciTech Connect

    Sadowski, M. J.; Czaus, K.; Malinowski, K.; Skladnik-Sadowska, E.; Zebrowski, J.

    2009-05-15

    The paper presents an improved version of a miniature mass-spectrometer of the Thomson-type, which has been adopted for ion analysis near the dense plasma region inside a vacuum chamber. Problems connected with the separation of ions from plasma streams are considered. Input diaphragms and pumping systems, needed to ensure good vacuum inside the analyzing region, are described. The application of the miniature Thomson-type analyzer is illustrated by ion parabolas recorded in plasma-focus facility and rod plasma injector experiment. A quantitative analysis of the recorded ion parabolas is presented. Factors influencing accuracy of the ion analysis are discussed and methods of the spectrometer calibration are described.

  20. Mass- and energy-analyses of ions from plasma by means of a miniature Thomson spectrometer

    NASA Astrophysics Data System (ADS)

    Sadowski, M. J.; Czaus, K.; Malinowski, K.; Skladnik-Sadowska, E.; Zebrowski, J.

    2009-05-01

    The paper presents an improved version of a miniature mass-spectrometer of the Thomson-type, which has been adopted for ion analysis near the dense plasma region inside a vacuum chamber. Problems connected with the separation of ions from plasma streams are considered. Input diaphragms and pumping systems, needed to ensure good vacuum inside the analyzing region, are described. The application of the miniature Thomson-type analyzer is illustrated by ion parabolas recorded in plasma-focus facility and rod plasma injector experiment. A quantitative analysis of the recorded ion parabolas is presented. Factors influencing accuracy of the ion analysis are discussed and methods of the spectrometer calibration are described.

  1. Focus Intonation in Bengali

    ERIC Educational Resources Information Center

    Hasan, Md. Kamrul

    2015-01-01

    This work attempts to investigate the role of prosody in the syntax of focus in Bangla. The aim of this study is to show the intonation pattern of Bangla in emphasis and focus. In order to do that, the author has looked at the pattern of focus without-i/o as well as with the same. Do they really pose any different focus intonation pattern from…

  2. Focus screen optimization.

    PubMed

    Plummer, W T

    1975-11-01

    Ground glass used for camera focus screens often has far from optimum diffusion properties. An analysis of the function of the focus screen shows that a screen with random (Gaussian) diffusion properties can be constructed with both brightness and focus efficiencies above 84%. These considerations have led to the design of an unusually bright and effective focus screen for the Polaroid SX-70 Land camera. PMID:20155099

  3. Partial pressure measurements with an active spectrometer

    SciTech Connect

    Brooks, N.H.; Jensen, T.H.; Colchin, R.J.; Maingi, R.; Wade, M.R.; Finkenthal, D.F.; Naumenko, N.; Tugarinov, S.

    1998-07-01

    Partial pressure neutral ga measurements have been made using a commercial Penning gauge in conjunction with an active spectrometer. In prior work utilizing bandpass filters and conventional spectrometers, trace concentrations of the hydrogen isotopes H, D, T and of the noble gases He, Ne and Ar were determined from characteristic spectral lines in the light emitted by the neutral species of these elements. For all the elements mentioned, the sensitivity was limited by spectral contamination from a pervasive background of molecular hydrogen radiation. The active spectrometer overcomes this limitations by means of a digital lock-in method and correlation with reference spectra. Preliminary measurements of an admixture containing a trace amount of neon in deuterium show better than a factor of 20 improvement in sensitivity over conventional techniques. This can be further improved by correlating the relative intensities of multiple lines to sets of reference spectra.

  4. Acousto-optical spectrometers' frequency performance stability

    NASA Astrophysics Data System (ADS)

    Ivanov, Sergei I.; Lavrov, Aleksandr P.; Molodyakov, Sergey A.; Saenko, Igor I.

    2004-02-01

    Performance characteristics of the acoutsto-optical spectrometers for some radioastronomical applications are discussed. The main attention is given to the long-term stability of the acousto-optical spectrometer's frequency characteristics. It is shown that a problem of the frequency scale thermal instabilities can be overcome by using the suitable correction, based on the proposed model of the frequency scale drifts. For the acousto-optical spectrometers under consideration a simple method of the frequency scale drifts correction by using the data from measuring of a single reference signal's frequency was developed and applied for correction of molecular lines observations data. More careful procedure for more exigent applications, such as pulsar timing, is considered.

  5. Fast neutron detection with a segmented spectrometer

    NASA Astrophysics Data System (ADS)

    Langford, T. J.; Bass, C. D.; Beise, E. J.; Breuer, H.; Erwin, D. K.; Heimbach, C. R.; Nico, J. S.

    2015-01-01

    A fast neutron spectrometer consisting of segmented plastic scintillator and 3He proportional counters was constructed for the measurement of neutrons in the energy range 1-200 MeV. We discuss its design, principles of operation, and the method of analysis. The detector is capable of observing very low neutron fluxes in the presence of ambient gamma background and does not require scintillator pulse-shape discrimination. The spectrometer was characterized for its energy response in fast neutron fields of 2.5 MeV and 14 MeV, and the results are compared with Monte Carlo simulations. Measurements of the fast neutron flux and energy response at 120 m above sea-level (39.130°N, 77.218°W) and at a depth of 560 m in a limestone mine are presented. Finally, the design of a spectrometer with improved sensitivity and energy resolution is discussed.

  6. Automated calibration of a flight particle spectrometer

    NASA Technical Reports Server (NTRS)

    Torbert, Roy B.

    1986-01-01

    An automatic calibration system was designed for use in the vacuum facility at the Space Science Laboratory of the Marshall Space Flight Center. That system was developed and used in the intervening winter to calibrate the ion spectrometer that eventually flew in May 1986 aboard the NASA project, CRIT 1. During this summer, it is planned to implement the calibration of both an ion and electron spectrometer of a new design whose basic elements were conceived during the winter of 1985 to 1986. This spectrometer was completed in the summer and successfully mounted in the vacuum tank for calibration. However, the source gate valve malfunctioned, and, at the end of the summer, it still needed a replacement. During the inevitable delays in the experimental research, the numerical model of the Critical Velocity effect was completed and these results were presented.

  7. A compact multichannel spectrometer for Thomson scattering

    SciTech Connect

    Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R.

    2012-10-15

    The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} < 100 eV are achieved by a 2971 l/mm VPH grating and measurements T{sub e} > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

  8. Plasma Spectrochemistry with a Fourier Transform Spectrometer.

    NASA Astrophysics Data System (ADS)

    Manning, Thomas Joseph John

    1990-01-01

    This dissertation can be interpreted as being two-dimensional. The first dimension uses the Los Alamos Fourier Transform Spectrometer to uncover various physical aspects of a Inductively Coupled Plasma. The limits of wavenumber accuracy and resolution are pushed to measure line shifts and line profiles in an Inductively Coupled Argon Plasma. This is new physical information that the plasma spectroscopy community has been seeking for several years. Other plasma spectroscopy carried out includes line profile studies, plasma diagnostics, and exact identification of diatomic molecular spectra. The second aspect of the dissertation involves studies of light sources for Fourier Transform Spectroscopy. Sources developed use an inductively coupled plasma (ICP) power supply. New sources (neon ICP, closed cell ICP, and helium ICP) were developed and new methods to enhance the performance and understand a Fourier Transform Spectrometer were studied including a novel optical filter, a spectrum analyzer to study noises, and a standard to calibrate and evaluate a Fourier Transform Spectrometer.

  9. Compact real-time birefringent imaging spectrometer.

    PubMed

    Kudenov, Michael W; Dereniak, Eustace L

    2012-07-30

    The design and experimental demonstration of a snapshot hyperspectral imaging Fourier transform (SHIFT) spectrometer is presented. The sensor, which is based on a multiple-image FTS (MFTS), offers significant advantages over previous implementations using Michelson interferometers. Specifically, its use of birefringent interferometry creates a vibration insensitive and ultra-compact (15x15x10 mm(3)) common-path interferometer while offering rapid reconstruction rates through the graphics processing unit. The SHIFT spectrometer's theory and experimental prototype are described in detail. Included are reconstruction and spectral calibration procedures, followed by the spectrometer's validation using measurements of gas-discharge lamps. Lastly, outdoor measurements demonstrate the sensor's ability to resolve spectral signatures in typical outdoor lighting and environmental conditions. PMID:23038346

  10. SPEG: An energy loss spectrometer for GANIL

    NASA Astrophysics Data System (ADS)

    Bianchi, L.; Fernandez, B.; Gastebois, J.; Gillibert, A.; Mittig, W.; Barrette, J.

    1989-04-01

    Since July 1985, an energy loss spectrometer (SPEG) is under operation at the National Heavy Ion Laboratory (GANIL), at Caen (France). It has been designed to allow the study of quantum states populated in reactions induced by nuclei accelerated at energies up to 100 A MeV. The spectrometer has been designed by P. Birien. The optical properties and the main magnetic features have been calculated by Birien and Valero. A detailed reported of their study is given in ref. [1]. In the first part of the present paper, after recalling the specifications of the spectrometer, we shall give an overall description of the main characteristics, together with indications about the various shimming procedures which have been used to achieve the desired resolution (sections 1-4). In the second part, we shall describe various accessories and the different kinds of detectors which are used during experiments, with several illustrations of experimental results (sections 5 and 6).

  11. Miniature, sub-nanometer resolution Talbot spectrometer.

    PubMed

    Ye, Erika; Atabaki, Amir H; Han, Ningren; Ram, Rajeev J

    2016-06-01

    Miniaturization of optical spectrometers has a significant practical value as it can enable compact, affordable spectroscopic systems for chemical and biological sensing applications. For many applications, the spectrometer must gather light from sources that span a wide range of emission angles and wavelengths. Here, we report a lens-free spectrometer that is simultaneously compact (<0.6  cm3), of high resolution (<1  nm), and has a clear aperture (of 10×10  mm). The wavelength-scale pattern in the dispersive element strongly diffracts the input light to produce non-paraxial mid-field diffraction patterns that are then recorded using an optimally matched image sensor and processed to reconstruct the spectrum. PMID:27244382

  12. Miniature Neutron-Alpha Activation Spectrometer

    NASA Astrophysics Data System (ADS)

    Rhodes, Edgar; Holloway, James Paul; He, Zhong; Goldsten, John

    2002-10-01

    We are developing a miniature neutron-alpha activation spectrometer for in-situ analysis of chem-bio samples, including rocks, fines, ices, and drill cores, suitable for a lander or Rover platform for Mars or outer-planet missions. In the neutron-activation mode, penetrating analysis will be performed of the whole sample using a γ spectrometer and in the α-activation mode, the sample surface will be analyzed using Rutherford-backscatter and x-ray spectrometers. Novel in our approach is the development of a switchable radioactive neutron source and a small high-resolution γ detector. The detectors and electronics will benefit from remote unattended operation capabilities resulting from our NEAR XGRS heritage and recent development of a Ge γ detector for MESSENGER. Much of the technology used in this instrument can be adapted to portable or unattended terrestrial applications for detection of explosives, chemical toxins, nuclear weapons, and contraband.

  13. Compact snapshot birefringent imaging Fourier transform spectrometer

    NASA Astrophysics Data System (ADS)

    Kudenov, Michael W.; Dereniak, Eustace L.

    2010-08-01

    The design and implementation of a compact multiple-image Fourier transform spectrometer (FTS) is presented. Based on the multiple-image FTS originally developed by A. Hirai, the presented device offers significant advantages over his original implementation. Namely, its birefringent nature results in a common-path interferometer which makes the spectrometer insensitive to vibration. Furthermore, it enables the potential of making the instrument ultra-compact, thereby improving the portability of the sensor. The theory of the birefringent FTS is provided, followed by details of its specific embodiment. A laboratory proof of concept of the sensor, designed and developed at the Optical Detection Lab, is also presented. Spectral measurements of laboratory sources are provided, including measurements of light-emitting diodes and gas-discharge lamps. These spectra are verified against a calibrated Ocean Optics USB2000 spectrometer. Other data were collected outdoors, demonstrating the sensor's ability to resolve spectral signatures in standard outdoor lighting and environmental conditions.

  14. Testing of Josephson Spectrometer with Waveguide Coupling

    NASA Astrophysics Data System (ADS)

    Lyatti, M.; Gundareva, I.; Pavlovskii, V.; Poppe, U.; Divin, Y.

    2014-05-01

    One of the challenges in public security is the quick and reliable identification of threat liquids in bottles, when vapour analysis is not possible. Recently, we demonstrated that it is possible to rapidly identify liquids by EM measurements of their dielectric functions in the sub-THz range with a high-Tc Josephson spectrometer. Following this approach, we have developed a Josephson spectrometer with a new radiation coupling system, based on dielectric waveguides. In this paper, we present the results of spectroscopic measurements on liquid samples of various purities including 30% H2O2/H2O, performed using our Josephson spectrometer with waveguide coupling. Also, the signal and noise characteristics of a classical Josephson detector used in our liquid identifier were numerically simulated and the power dynamic range was estimated for a wide spread of junction parameters.

  15. Compact hydrogen/helium isotope mass spectrometer

    DOEpatents

    Funsten, Herbert O.; McComas, David J.; Scime, Earl E.

    1996-01-01

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  16. Adaptive Tunable Laser Spectrometer for Space Applications

    NASA Technical Reports Server (NTRS)

    Flesch, Gregory; Keymeulen, Didier

    2010-01-01

    An architecture and process for the rapid prototyping and subsequent development of an adaptive tunable laser absorption spectrometer (TLS) are described. Our digital hardware/firmware/software platform is both reconfigurable at design time as well as autonomously adaptive in real-time for both post-integration and post-launch situations. The design expands the range of viable target environments and enhances tunable laser spectrometer performance in extreme and even unpredictable environments. Through rapid prototyping with a commercial RTOS/FPGA platform, we have implemented a fully operational tunable laser spectrometer (using a highly sensitive second harmonic technique). With this prototype, we have demonstrated autonomous real-time adaptivity in the lab with simulated extreme environments.

  17. Miniaturized Energy Spectrometer for Space Plasma Measurements

    NASA Astrophysics Data System (ADS)

    Goes de Lima, Raphaela; Scime, Earl; Keesee, Amy; Lusk, Greg

    2015-11-01

    Taking advantage of technological developments in lithographic fabrication techniques over the past two decades, we have designed an ultra-compact plasma spectrometer that requires only low voltage power supplies, no microchannel plates, and has a high aperture area to instrument area ratio. The designed target is for ions in the 3- 20 keV range with a highly directional field of view. In addition to reducing mass, size, and voltage requirements, the new design will revolutionize the manufacturing process of plasma spectrometers, enabling large quantities of identical instruments to be manufactured at low individual unit cost. Such a plasma spectrometer is ideal for Heliophysics plasma investigations, particularly for small satellite and multi-spacecraft missions. Here we present initial measurements of the performance of the instrument components and designs of the electronics for the low energy threshold solid state detector. Work Support under NASA grant - NNX14AJ36G.

  18. Performance of an INTEGRAL spectrometer model

    NASA Technical Reports Server (NTRS)

    Jean, P.; Naya, J. E.; vonBallmoos, P.; Vedrenne, G.; Teegarden, B.

    1997-01-01

    Model calculations for the INTEGRAL spectrometer (SPI) onboard the future INTErnational Gamma Ray Astrophysics Laboratory (INTEGAL) are presented, where the sensitivity for narrow lines is based on estimates of the background level and the detection efficiency. The instrumental background rates are explained as the sum of various components that depend on the cosmic ray intensity and the spectrometer characteristics, such as the mass distribution around the Ge detectors, the passive material, the characteristics of the detector system and the background reduction techniques. Extended background calculations were performed with Monte Carlo simulations and using semi-empirical and calculated neutron and proton cross sections. In order to improve the INTEGRAL spectrometer sensitivity, several designs and background reduction techniques were compared for an instrument with a fixed detector volume.

  19. A neutron spectrometer using nested moderators.

    PubMed

    Dubeau, J; Hakmana Witharana, S S; Atanackovic, J; Yonkeu, A; Archambault, J P

    2012-06-01

    The design, simulation results and measurements of a new neutron energy spectrometer are presented. The device, which may be called NNS, for Nested Neutron Spectrometer, works under the same principles as a Bonner Sphere Spectrometer (BSS) System, i.e. whereby a thermal neutron detector is surrounded by a polyethylene moderator. However, the moderator is cylindrical in shape. The different thicknesses of moderator are created by inserting one cylinder into another, much like nested Russian dolls. This design results in a much lighter instrument that is also easier to use in the field. Simulations and measurements show that, despite its shape, the device can be made to offer a near angular isotropic response to neutrons and that unfolded neutron spectra are in agreement with those obtained with a more traditional BSS. PMID:21964903

  20. Alternating phase focused linacs

    DOEpatents

    Swenson, Donald A.

    1980-01-01

    A heavy particle linear accelerator employing rf fields for transverse and ongitudinal focusing as well as acceleration. Drift tube length and gap positions in a standing wave drift tube loaded structure are arranged so that particles are subject to acceleration and succession of focusing and defocusing forces which contain the beam without additional magnetic or electric focusing fields.

  1. Degradation Free Spectrometers for Solar EUV Measurements

    NASA Astrophysics Data System (ADS)

    Wieman, S. R.; Didkovsky, L. V.; Judge, D. L.; McMullin, D. R.

    2011-12-01

    Solar EUV observations will be made using two new degradation-free EUV spectrometers on a sounding rocket flight scheduled for summer 2012. The two instruments, a rare gas photoionization-based Optics-Free Spectrometer (OFS) and a Dual Grating Spectrometer (DGS), are filter-free and optics-free. OFS can measure the solar EUV spectrum with a spectral resolution comparable to that of grating-based EUV spectrometers. The DGS selectable spectral bandwidth is designed to provide solar irradiance in a 10 nm band centered on the Lyman-alpha 121.6 nm line and a 4 nm band centered on the He-II 30.4 nm line to overlap EUV observations from the SDO/EUV Variability Experiment (EVE) and the SOHO/Solar EUV Monitor (SEM). A clone of the SOHO/SEM flight instrument and a Rare Gas Ionization Cell (RGIC) absolute EUV detector will also be flown to provide additional measurements for inter-comparison. Program delays related to the sounding rocket flight termination system, which was no longer approved by the White Sands Missile Range prevented the previously scheduled summer 2011 launch of these instruments. During this delay several enhancements have been made to the sounding rocket versions of the DFS instruments, including a lighter, simplified vacuum housing and gas system for the OFS and an improved mounting for the DGS, which allows more accurate co-alignment of the optical axes of the DGS, OFS, and the SOHO/SEM clone. Details of these enhancements and results from additional lab testing of the instruments are reported here. The spectrometers are being developed and demonstrated as part of the Degradation Free Spectrometers (DFS) project under NASA's Low Cost Access to Space (LCAS) program and are supported by NASA Grant NNX08BA12G.

  2. Pure rotational spectrometers for trace-level VOC detection and chemical sensing

    NASA Astrophysics Data System (ADS)

    Neill, Justin L.; Harris, Brent J.; Pulliam, Robin L.; Muckle, Matt T.; Reynolds, Roger; McDaniel, David; Pate, Brooks H.

    2014-05-01

    Pure rotational spectroscopy in the centimeter, millimeter, and THz regions of the electromagnetic spectrum is a powerful technique for the characterization of polar molecules in the gas phase. Although this technology has a long history in the research sector for structural characterization, recent advances in digital electronics have only recently made commercial instruments competitive with established chemical analysis techniques. BrightSpec is introducing a platform of pure rotational spectrometers in response to critical unmet needs in chemical analysis. These instruments aim to deliver the operational simplicity of Fourier transform infrared spectrometers in conjunction with the chemical analysis capabilities of mass spectrometers. In particular, the BrightSpec ONE instrument a broadband gas mixture analyzer with full capabilities for chemical analysis. This instrument implements Fourier transform millimeter-wave emission spectroscopy, wherein a brief excitation pulse is applied to the sample, followed by the measurement of the coherent free induction decay responses of all molecular transitions within the excitation bandwidth. After sample injection and characterization, the spectrometer returns a list of all known species detected in the sample, along with their concentrations in the mixture. No prior knowledge about the sample composition is required. The instrument can then perform double-resonance measurements (analogous to 2-D COSY NMR), direct mass determination through analysis of the time profile of the molecular signal, and automated isotopic identification as part of a suite of tools that can return the structural identity of the unknowns in the sample.

  3. Three infrared spectrometers, an atmospheric chemistry suite for the ExoMars 2016 trace gas orbiter

    NASA Astrophysics Data System (ADS)

    Korablev, Oleg; Trokhimovsky, Alexander; Grigoriev, Alexei V.; Shakun, Alexei; Ivanov, Yuriy S.; Moshkin, Boris; Anufreychik, Konstantin; Timonin, Denis; Dziuban, Ilia; Kalinnikov, Yurii K.; Montmessin, Franck

    2014-01-01

    The atmospheric chemistry suite (ACS) package is a part of the Russian contribution to the ExoMars ESA-Roscosmos mission. ACS consists of three separate infrared spectrometers, sharing common mechanical, electrical, and thermal interfaces. The near-infrared (NIR) channel is a versatile spectrometer for the spectral range of 0.7-1.6 μm with a resolving power of ˜20,000. The instrument employs the principle of an echelle spectrometer with an acousto-optical tunable filter (AOTF) as a preselector. NIR will be operated in nadir, in solar occultations, and possibly on the limb. Scientific targets of NIR are the measurements of water vapor, aerosols, and dayside or nightside airglows. The mid-infrared (MIR) channel is a cross-dispersion echelle instrument dedicated to solar occultation measurements in the range of 2.2-4.4 μm targeting the resolving power of 50,000. MIR is dedicated to sensitive measurements of trace gases. The thermal infrared channel (TIRVIM) is a 2-inch double pendulum Fourier-transform spectrometer for the spectral range of 1.7-17 μm with apodized resolution varying from 0.2 to 1.6 cm-1. TIRVIM is primarily dedicated to the monitoring of atmospheric temperatures and aerosol states in nadir. The present paper describes the concept of the instrument, and in more detail, the optical design and the expected parameters of its three parts channel by channel.

  4. Observing Double Stars

    NASA Astrophysics Data System (ADS)

    Genet, Russell M.; Fulton, B. J.; Bianco, Federica B.; Martinez, John; Baxter, John; Brewer, Mark; Carro, Joseph; Collins, Sarah; Estrada, Chris; Johnson, Jolyon; Salam, Akash; Wallen, Vera; Warren, Naomi; Smith, Thomas C.; Armstrong, James D.; McGaughey, Steve; Pye, John; Mohanan, Kakkala; Church, Rebecca

    2012-05-01

    Double stars have been systematically observed since William Herschel initiated his program in 1779. In 1803 he reported that, to his surprise, many of the systems he had been observing for a quarter century were gravitationally bound binary stars. In 1830 the first binary orbital solution was obtained, leading eventually to the determination of stellar masses. Double star observations have been a prolific field, with observations and discoveries - often made by students and amateurs - routinely published in a number of specialized journals such as the Journal of Double Star Observations. All published double star observations from Herschel's to the present have been incorporated in the Washington Double Star Catalog. In addition to reviewing the history of visual double stars, we discuss four observational technologies and illustrate these with our own observational results from both California and Hawaii on telescopes ranging from small SCTs to the 2-meter Faulkes Telescope North on Haleakala. Two of these technologies are visual observations aimed primarily at published "hands-on" student science education, and CCD observations of both bright and very faint doubles. The other two are recent technologies that have launched a double star renaissance. These are lucky imaging and speckle interferometry, both of which can use electron-multiplying CCD cameras to allow short (30 ms or less) exposures that are read out at high speed with very low noise. Analysis of thousands of high speed exposures allows normal seeing limitations to be overcome so very close doubles can be accurately measured.

  5. Automated calibration of a flight particle spectrometer

    NASA Technical Reports Server (NTRS)

    Torbert, R. B.

    1986-01-01

    A system for calibrating both electron and ion imaging particle spectrometers was devised to calibrate flight instruments in a large vacuum facility in the Space Science Laboratory at the Marshall Space Flight Center. An IBM-compatible computer was used to control, via an IEEE 488 buss protocol, a two-axis gimbled table, constructed to fit inside the tank. Test settings of various diagnostic voltages were also acquired via the buss. These spectrometers constructed by the author at UCSD were calibrated in an automatic procedure programmed on the small computer. Data was up-loaded to the SSL VAX where a program was developed to plot the results.

  6. Modular Spectrometers in the Undergraduate Chemistry Laboratory

    NASA Astrophysics Data System (ADS)

    Bernazzani, Paul; Paquin, Francine

    2001-06-01

    A rapid evolution of fiber-optic and computer technology led to the concept of modular spectrometers. The Ocean Optics S2000 series of spectroscopic instruments, based on a 2048-element linear CCD-array, are examples of such equipment. We have introduced two of these modular systems into our undergraduate laboratory courses, for experiments that serve as an introduction to signal processing. The Ocean Optics spectrometers have proven to be both rapid and inexpensive and have improved the quality of learning of our students.

  7. Improved real-time imaging spectrometer

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Chao, Tien-Hsin (Inventor); Yu, Jeffrey W. (Inventor); Cheng, Li-Jen (Inventor)

    1993-01-01

    An improved AOTF-based imaging spectrometer that offers several advantages over prior art AOTF imaging spectrometers is presented. The ability to electronically set the bandpass wavelength provides observational flexibility. Various improvements in optical architecture provide simplified magnification variability, improved image resolution and light throughput efficiency and reduced sensitivity to ambient light. Two embodiments of the invention are: (1) operation in the visible/near-infrared domain of wavelength range 0.48 to 0.76 microns; and (2) infrared configuration which operates in the wavelength range of 1.2 to 2.5 microns.

  8. Compact Imaging Spectrometer Utilizing Immersed Gratings

    DOEpatents

    Chrisp, Michael P.; Lerner, Scott A.; Kuzmenko, Paul J.; Bennett, Charles L.

    2006-03-21

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

  9. A multichannel magneto-chiral dichroism spectrometer

    NASA Astrophysics Data System (ADS)

    Kopnov, G.; Rikken, G. L. J. A.

    2014-05-01

    In this work, we describe a multichannel magneto-chiral dichroism spectrometer for the visible and near infrared wavelength ranges. The optical signal acquisition is based on commercially available Czerny-Turner spectrograph systems equipped with solid state detector arrays. The signal analysis method is based on post-processing phase sensitive detection, where the optical properties of the sample are modulated by an alternating external magnetic field. As an illustration of the performance of this spectrometer, magneto-chiral dichroism was measured in crystals of α - NiSO4 . 6H2O and good agreement with literature results was obtained.

  10. Dyson spectrometers for infrared earth remote sensing

    NASA Astrophysics Data System (ADS)

    Warren, David W.; Gutierrez, David J.; Hall, Jeffrey L.; Keim, Eric R.

    2008-08-01

    The Dyson spectrometer form is capable of providing high throughput, excellent image quality, low spatial and spectral distortions, and high tolerance to fabrication and alignment errors in a compact format with modest demands for weight, volume, and cooling resources. These characteristics make it attractive for hyperspectral imaging from a space-based platform. After a brief discussion of history and basic principles, we present two examples of Dyson spectrometers being developed for airborne applications. We conclude with a concept for an earth science instrument soon to begin development under the Instrument Incubator Program of NASA's Earth Science Technology Office.

  11. A compact collinear AOTF Raman spectrometer.

    PubMed

    Gupta, N; Fell, N F

    1997-12-19

    A compact, lightweight, completely packaged, uncooled, fully-automated collinear acousto-optic tunable-filter (AOTF) based spectrometer has been used to measure Raman spectra of three organic energetic materials (NQ, HMX, and TNT) using argon-ion laser excitation. Even though the resolution of the AOTF spectrometer is modest (7.4 cm(-1)) and it was not specifically designed for measuring Raman spectra, it has performed impressively. Such an instrument is specially useful for remote sensing and field measurements. In this paper, we will describe this instrument, present the measured Raman spectra and their comparison with the corresponding FT-IR spectra. PMID:18967003

  12. Acousto-optic spectrometer for radio astronomy

    NASA Technical Reports Server (NTRS)

    Chin, G.; Buhl, D.; Florez, J. M.

    1980-01-01

    A prototype acousto-optic spectrometer which uses a discrete bulk acoustic wave Itek Bragg cell, 5 mW Helium Neon laser, and a 1024 element Reticon charge coupled photodiode array is described. The analog signals from the photodiode array are digitized, added, and stored in a very high speed custom built multiplexer board which allows synchronous detection of weak signals to be performed. The experiment is controlled and the data are displayed and stored with an LSI-2 microcomputer system with dual floppy discs. The performance of the prototype acousto-optic spectrometer obtained from initial tests is reported.

  13. The Constellation-X Reflection Grating Spectrometer

    NASA Technical Reports Server (NTRS)

    Allen, Jean C.

    2006-01-01

    The Reflection Grating Spectrometer on the Constellation-X mission will provide high sensitivity, high-resolution spectra in the soft x-ray band. The RGS performance requirements are specified as a resolving power of greater than 300 and an effective area of greater than 1000 sq cm across most of the 0.25 to 2.0 keV band. These requirements are driven by the science goals of the mission. We will describe the performance requirements and goals, the reference design of the spectrometer, and examples of science cases where we expect data from the RGS to significantly advance our current understanding of the universe.

  14. The Electron Spectrometer for the Cassini spacecraft

    NASA Astrophysics Data System (ADS)

    Coates, A. J.; Alsop, C.; Coker, A. J.; Linder, D. R.; Johnstone, A. D.; Woodliffe, R. D.; Grande, M.; Preece, A.; Burge, S.; Hall, D. S.

    1992-09-01

    One of the major aims of the Cassini spacecraft is to characterize in detail the interaction of the solar wind with the Saturnian system. The Cassini Plasma Spectrometer (CAPS) addresses this aim by measuring the plasma particles, ions and electrons, with a suite of three complementary state-of-the-art sensors. The Electron Spectrometer (ELS), contributed by the UK with assistance from Norway, will measure the energy and angular distributions of solar wind and magnetospheric electrons with unprecedented accuracy. This paper describes the scientific aims and design of CAPS concentrating particularly on the ELS sensor.

  15. The Diffuse X-ray Spectrometer Experiment

    NASA Technical Reports Server (NTRS)

    Sanders, W. T.; Edgar, R. J.; Juda, M.; Kraushaar, W. L.; Mccammon, D.; Snowden, S. L.; Zhang, J.; Skinner, M. A.

    1992-01-01

    The Diffuse X-ray Spectrometer Experiment, or 'DXS', is designed to measure the spectrum of the low-energy diffuse X-ray background with about 10 eV energy resolution and 15-deg spatial resolution. During a 5-day Space Shuttle mission, DXS is to measure the spectrum of ten 15 x 15 deg regions lying along a single 150-deg-long great circle arc on the sky. DXS carries two large-area X-ray Bragg spectrometers for the 44-84 A wavelength range; these permit measurement of the wavelength spectrum of the cosmic low-energy diffuse X-ray background with good spectral resolution.

  16. NEAR Gamma Ray Spectrometer Characterization and Repair

    NASA Technical Reports Server (NTRS)

    Groves, Joel Lee; Vajda, Stefan

    1998-01-01

    This report covers the work completed in the third year of the contract. The principle activities during this period were (1) the characterization of the NEAR 2 Gamma Ray Spectrometer using a neutron generator to generate complex gamma ray spectra and a large Ge Detecter to identify all the major peaks in the spectra; (2) the evaluation and repair of the Engineering Model Unit of the Gamma Ray Spectrometer for the NEAR mission; (3) the investigation of polycapillary x-ray optics for x-ray detection; and (4) technology transfer from NASA to forensic science.

  17. MICE Spectrometer Solenoid Magnetic Field Measurements

    SciTech Connect

    Leonova, M.

    2013-09-01

    The Muon Ionization Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with an absolute measurement accuracy of 0.1%. To measure emittances, MICE uses two solenoidal spectrometers, with Solenoid magnets designed to have 4 T fields, uniform at 3 per mil level in the tracking volumes. Magnetic field measurements of the Spectrometer Solenoid magnet SS2, and analysis of coil parameters for input into magnet models will be discussed.

  18. Time-of-flight Fourier UCN spectrometer

    NASA Astrophysics Data System (ADS)

    Kulin, G. V.; Frank, A. I.; Goryunov, S. V.; Kustov, D. V.; Geltenbort, P.; Jentschel, M.; Lauss, B.; Schmidt-Wellenburg, P.

    2016-05-01

    We describe a new time-of-flight Fourier spectrometer for investigation of UCN diffraction by a moving grating. The device operates in the regime of a discrete set of modulation frequencies. The results of the first experiments show that the spectrometer may be used for obtaining UCN energy spectra in the energy range of 60 - 200 neV with a resolution of about 5 neV. The accuracy of determination of the line position was estimated to be several units of 10-10 eV.

  19. Development and characterization of a multiple-coincidence ion-momentum imaging spectrometer

    NASA Astrophysics Data System (ADS)

    Laksman, J.; Céolin, D.; Mânsson, E. P.; Sorensen, S. L.; Gisselbrecht, M.

    2013-12-01

    The design and performance of a high-resolution momentum-imaging spectrometer for ions which is optimized for experiments using synchrotron radiation is presented. High collection efficiency is achieved by a focusing electrostatic lens; a long drift tube improves mass resolution and a position-sensitive detector enables measurement of the transverse momentum of ions. The optimisation of the lens for particle momentum measurement at the highest resolution is described. We discuss the overall performance of the spectrometer and present examples demonstrating the momentum resolution for both kinetics and for angular measurements in molecular fragmentation for carbon monoxide and fullerenes. Examples are presented that confirm that complete space-time focussing is possible for a two-field three-dimensional imaging spectrometer.

  20. Development and characterization of a multiple-coincidence ion-momentum imaging spectrometer.

    PubMed

    Laksman, J; Céolin, D; Månsson, E P; Sorensen, S L; Gisselbrecht, M

    2013-12-01

    The design and performance of a high-resolution momentum-imaging spectrometer for ions which is optimized for experiments using synchrotron radiation is presented. High collection efficiency is achieved by a focusing electrostatic lens; a long drift tube improves mass resolution and a position-sensitive detector enables measurement of the transverse momentum of ions. The optimisation of the lens for particle momentum measurement at the highest resolution is described. We discuss the overall performance of the spectrometer and present examples demonstrating the momentum resolution for both kinetics and for angular measurements in molecular fragmentation for carbon monoxide and fullerenes. Examples are presented that confirm that complete space-time focussing is possible for a two-field three-dimensional imaging spectrometer. PMID:24387426