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Sample records for axial field spectrometer

  1. View of the Axial Field Spectrometer

    CERN Multimedia

    1980-01-01

    The Axial Field Spectrometer, with the vertical uranium/scintillator calorimeter and the central drift chamber retracted for service. One coil of the Open Axial Field Magnet is just visible to the right.

  2. View of the Axial Field Spectrometer (R807)

    CERN Multimedia

    1980-01-01

    In this view of the Axial Field Spectrometer at I8, the vertical uranium/scintillator hadron calorimeter (just left of centre) is retracted to give access to the cylindrical central drift chamber. The yellow iron structure served as a filter to identify muons, with MWPCs and the array of Cherenkov counters to the right.

  3. Overview of the Axial Field Spectrometer in the ISR tunnel

    CERN Multimedia

    1980-01-01

    A view of the Axial Field Spectrometer – the last large experiment at the ISR. The horizontal top and vertical outer arrays of the uranium-scintillator hadron calorimeter are clear to be seen, with the blue cylindrical pole piece of the magnet just visible. The pipes that are visible in front of the pole piece are cryogenic feed pipes for the superconducting low-beta quadrupoles.

  4. Compton backscattering axial spectrometer

    International Nuclear Information System (INIS)

    Rad'ko, V.E.; Mokrushin, A.D.; Razumovskaya, I.V.

    1981-01-01

    Compton gamma backscattering axial spectrometer of new design with the 200 time larger aperture as compared with the known spectrometers at the equal angular resolution (at E=159 keV) is described. Collimator unit, radiation source and gamma detector are located in the central part of the spectrometer. The investigated specimen (of cylindrical form) and the so called ''black body'' used for absorption of photons, passed through the specimen are placed in the peripheric part. Both these parts have an imaginary symmetry axis that is why the spectrometer is called axial. 57 Co is used as the gamma source. The 122 keV spectral line which corresponds to the 83 keV backscattered photon serves as working line. Germanium disk detector of 10 mm diameter and 4 mm height has energy resolution not worse than 900 eV. The analysis of results of test measurements of compton water profile and their comparison with data obtained earlier show that only finity of detector resolution can essentially affect the form of Compton profile. It is concluded that the suggested variant of the spectrometer would be useful for determination of Compton profiles of chemical compounds of heavy elements [ru

  5. Effect of the first axial field spectrometer in the CERN intersecting storage rings (ISR) on the circulating beams

    International Nuclear Information System (INIS)

    Bryant, P.J.; Kantardjian, G.

    1977-01-01

    The effect on a circulating beam of a superconducting solenoid spectrometer which was installed in the ISR is shown. This spectrometer consists of a superconducting solenoid magnet with a nominal central field of 1.5T, cylindrical drift chambers, scintillation counters and two arrays of the lead glass Cherenkov counters. No operational restrictions have been imposed on the ISR by the solenoid and physical conditions have not been in any way degraded. In the low-β run where β is betatron amplitudes, at 26 GeV/c with the solenoid, the beam currents were 27x27A 2 and the starting luminosity was 3.6x10 31 cm -2 s -1 with an average beam decay rate of 3x10 -6 )min -1 over the 63-hour run

  6. Study of $ \\bar{p} $ and $ \\bar{n} $ annihilations at LEAR with OBELIX, a large acceptance and high resolution detector based on the Open Axial Field Spectrometer

    CERN Multimedia

    2002-01-01

    % PS201 Study of $\\bar{p}$ and $\\bar{n}$ annihilations at LEAR with OBELIX, a large acceptance and high resolution detector based on the Open Axial Field Spectrometer \\\\ \\\\OBELIX is designed to study exclusive final states of antiproton and antineutron annihilations at low energies with protons and nuclei. \\\\ \\\\The physics motivations of the experiment are:\\\\ \\\\\\begin{itemize} \\item (gg, ggg), hybrids ($ q \\bar{q} g $), multiquarks ($ q q \\bar{q} \\bar{q} $) and light mesons ($ q \\bar{q} $) produced in $ N \\bar{N} $ annihilations and study of their spectroscopy and decays. Also broad structures will be searched for by comparing identical decay modes in exclusive final states of the same type occuring from initial states with different angular momentum or isospin. \\item Study of the dynamics of $ N \\bar{N} $ interactions and of the dependence of the final and intermediate resonant states of annihilation upon the quantum numbers of the initial $ N \\bar{N} $ state (angular momentum: S and P-wave in $\\bar{p}p $ at...

  7. Axial magnetic field produced by axially and radially magnetized permanent rings

    International Nuclear Information System (INIS)

    Peng, Q.L.; McMurry, S.M.; Coey, J.M.D.

    2004-01-01

    Axial magnetic fields produced by axially and radially magnetized permanent magnet rings were studied. First, the axial magnetic field produced by a current loop is introduced, from which the axial field generated by an infinitely thin solenoid and by an infinitely thin current disk can be derived. Then the axial fields produced by axially and by radially magnetized permanent magnet rings can be obtained. An analytic formula for the axial fields produced by two axially magnetized rings is given. A permanent magnet with a high axial gradient field is fabricated, the measured results agree with the theoretical calculation very well. As an example, the axial periodic field produced by an arrangement of alternating axially and radially magnetized rings has been discussed

  8. Ion Mobility Spectrometer Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Nicholas [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; McLain, Derek [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Steeb, Jennifer [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2017-12-20

    The Morpho Saffran Itemizer 4DX Ion Mobility Spectrometer previously used to detect uranium signatures in FY16 was used at the former New Brunswick Facility, a past uranium facility located on site at Argonne National Laboratory. This facility was chosen in an attempt to detect safeguards relevant signatures and has a history of processing uranium at various enrichments, chemical forms, and purities; various chemicals such as nitric acid, uranium fluorides, phosphates and metals are present at various levels. Several laboratories were sampled for signatures of nuclear activities around the laboratory. All of the surfaces that were surveyed were below background levels of the radioanalytical instrumentation and determined to be radiologically clean.

  9. Magnetic field measurements of the BLAST spectrometer

    International Nuclear Information System (INIS)

    Dow, Karen A.; Botto, Tancredi; Goodhue, Abigail; Hasell, Douglas; Loughnan, Dylan; Murphy, Kilian; Smith, Timothy Paul; Ziskin, Vitaliy

    2009-01-01

    The Bates Large Acceptance Spectrometer Toroid has been built to study nuclear physics reactions using a stored, polarized electron beam and a variety of polarized targets internal to the storage ring. The spectrometer consists of eight coils surrounding the target cell. There is a requirement of nominally zero field along the centerline of the spectrometer for proper electron beam storage. In addition, the polarized internal targets require a low field gradient in the target region. Magnetic field measurements were made near the beam centerline to guide the alignment of the coils and satisfy the field magnitude and gradient requirements. After the coils were aligned, the magnetic field was measured in the detector regions to provide information for particle tracking.

  10. Imaging spectrometer wide field catadioptric design

    Science.gov (United States)

    Chrisp,; Michael, P [Danville, CA

    2008-08-19

    A wide field catadioptric imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The catadioptric design has zero Petzval field curvature. The imaging spectrometer comprises an entrance slit for transmitting light, a system with a catadioptric lens and a dioptric lens 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 the system for receiving the light to the detector array.

  11. A wide field of view plasma spectrometer

    Science.gov (United States)

    Skoug, R. M.; Funsten, H. O.; Möbius, E.; Harper, R. W.; Kihara, K. H.; Bower, J. S.

    2016-07-01

    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 are 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. We present laboratory prototype measurements and simulations demonstrating the instrument concept and discuss optimizations of the instrument design for application to space measurements.

  12. Thermocapillary Convection in Floating Zone with Axial Magnetic Fields

    Science.gov (United States)

    Liang, Ruquan; Yang, Shuo; Li, Jizhao

    2014-02-01

    Numerical simulations on the effects of axial magnetic fields on the thermocapillary convection in a liquid bridge of silicone-oil-based ferrofluid under zero gravity have been conducted. The Navier-Stokes equations coupled with the energy conservation equation are solved on a staggered grid, and the mass conserving level set approach is used to capture the free surface deformation of the liquid bridge. The obvious effects of the magnetic fields on the flow pattern as well as the velocity and temperature distributions in the liquid bridge can be detected. The axial magnetic fields suppress the thermocapillary convection and a stagnant flow zone is formed between the circulating flow and the symmetric axis as the magnetic fields increase. The axial magnetic fields affect not only the velocity level inside the liquid bridge but also the velocity level on the free surface. The temperature contours near the free surface illustrates conduction-type temperature profiles at moderate strength fields.

  13. Axial Field Electric Motor and Method

    National Research Council Canada - National Science Library

    Cho, Chahee P

    2007-01-01

    .... A hybrid field, brushless, permanent magnet electric motor utilizing a rotor with two sets of permanent magnets oriented such that the flux produced by the two sets of magnets is perpendicular to each...

  14. Partial view of the Axial Field Spectrometer (version R808)

    CERN Multimedia

    1980-01-01

    The endplates of the cylindrical drift chamber is removed to access the electronics. The vertical Uranium/Scintillator Calorimeter is retracted. The detector on the frontface is a matrix of NaI-crystals for photon spectroscopy

  15. A calorimeter trigger system for the ISR axial field spectrometer

    International Nuclear Information System (INIS)

    Rosselet, L.

    1981-01-01

    A fast and flexible trigger processor system designed to run in parallel up to 51 different types of trigger is used in a large hadron calorimeter experiment at CERN-ISR. A very fast data bus connected to 255 10 bit address ECE memory chips allows programmable selection of events according to their topology and energy pattern in less than 150 ns. In addition this system can interrogate two programmable processors (ESOP) to isolate events characterized by a large energy flow in the central drift chamber (< 500 μs). All functions of the trigger processor can be checked externally by a computer through injecting in parallel simulated input signals into various stages of the system. Salient features and performances will be discussed. (orig.)

  16. Study and construction of a β-spectrometer of uniform axial magnetic field fitted with a β-γ coincidence selector. Study of the β spectra of 32P, 203Hg, 198Au. Measurement of the conversion coefficients of 203Ti and of 198Hg

    International Nuclear Information System (INIS)

    Parsignault, D.

    1964-06-01

    In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The β-ray and γ-ray detectors and the device for selecting coincidences with a 2 τ resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The β spectrum of 60 Co has a statistical form with an accuracy of 1 per cent; the maximum energy E 0 is 316.5 ± 1.5 keV. That of the 7/2 + → 11/2 transition for 137 Cs has a unique form, once forbidden. E 0 = 522 ± 3 keV. Conversion coefficients α k = 96 ± 1 X 10 -3 αL + M + N = 20.9 ± 0.5 X 10 -3 . The two β spectra of 59 Fe, separated by coincidence with the gamma, have the statistical form E 0 = 462 ± 2 keV (55.1 + 0,3 per cent) and E 1 = 275 ± 4 keV (44.9 ± 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of 33 P. The study of the 203 Hg β spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the various elements of the matrix. (author) [fr

  17. Axially symmetric, stationary gravitational field equations and pseudospherical surfaces

    International Nuclear Information System (INIS)

    Tomimatsu, Akira.

    1981-04-01

    For axially symmetric, stationary gravitational field equations, a new Lax pair of the inverse scattering method is presented from a geometrical point of view. The metric coefficient e sup(2γ) (= -g sub(rho rho)g sub(tt)sup(-1)) is taken as the basic field variable, which satisfies an equation describing pseudospherical surfaces, i.e., surfaces of constant negative Gaussian curvature. The equations for other metric coefficients are also discussed. (author)

  18. Electric and magnetic field optimization procedure for Penning trap mass spectrometers

    CERN Document Server

    Beck, D; Bollen, G; Delahaye, P; George, S; Guénaut, C; Herfurth, F; Herlert, A; Lunney, D; Schweikhard, L; Yazidjian, C

    2009-01-01

    Significant systematic errors in high-precision Penning trap mass spectrometry can result from electric and magnetic field imperfections. An experimental procedure to minimize these uncertainties is presented for the on-line Penning trap mass spectrometer ISOLTRAP, located at ISOLDE/CERN. The deviations from the ideal magnetic and electric fields are probed by measuring the cyclotron frequency and the reduced cyclotron frequency, respectively, of stored ions as a function of the time between the ejection of ions from the preparation trap and their capture in the precision trap, which influences the energy of their axial motion. The correction parameters are adjusted to minimize the frequency shifts.

  19. Axial magnetic field injection in magnetized liner inertial fusion

    Science.gov (United States)

    Gourdain, P.-A.; Adams, M. B.; Davies, J. R.; Seyler, C. E.

    2017-10-01

    MagLIF is a fusion concept using a Z-pinch implosion to reach thermonuclear fusion. In current experiments, the implosion is driven by the Z-machine using 19 MA of electrical current with a rise time of 100 ns. MagLIF requires an initial axial magnetic field of 30 T to reduce heat losses to the liner wall during compression and to confine alpha particles during fusion burn. This field is generated well before the current ramp starts and needs to penetrate the transmission lines of the pulsed-power generator, as well as the liner itself. Consequently, the axial field rise time must exceed hundreds of microseconds. Any coil capable of being submitted to such a field for that length of time is inevitably bulky. The space required to fit the coil near the liner, increases the inductance of the load. In turn, the total current delivered to the load decreases since the voltage is limited by driver design. Yet, the large amount of current provided by the Z-machine can be used to produce the required 30 T field by tilting the return current posts surrounding the liner, eliminating the need for a separate coil. However, the problem now is the field penetration time, across the liner wall. This paper discusses why skin effect arguments do not hold in the presence of resistivity gradients. Numerical simulations show that fields larger than 30 T can diffuse across the liner wall in less than 60 ns, demonstrating that external coils can be replaced by return current posts with optimal helicity.

  20. Axial Magnetic Field Compression in Laboratory Plasma Jets

    Science.gov (United States)

    Byvank, Tom; Potter, William; Greenly, John; Seyler, Charles; Kusse, Bruce

    2017-10-01

    Compression of an axial magnetic field correlates with density hollowing and azimuthal rotation of a plasma jet generated by the COBRA pulsed power machine (1 MA peak current in 100 ns rise time) in a radial foil (thin disk of 15 μm Al or Ti) configuration. The plasma jet compresses an initially uniform 1 T axial magnetic field (Bz) as it collimates along the central z-axis. Experimental measurements use a Bdot magnetic probe placed in the center of the hollow plasma jet. Experimental results show compression of an applied 1.0 +/-0.1 T Bz to 2.4 +/-0.3 T with aluminum jets and to 2.2 +/-0.2 T with titanium jets. Predictions made by the extended magnetohydrodynamics (XMHD) code, PERSEUS, show compression to a 3.4 T Bz at the probe location for aluminum plasmas. For titanium plasmas, implementing radiation into the code is in progress. Additionally using the XMHD simulation, we explore the effects of changing current directions and how the magnetic field being tied to the electrons in Hall MHD (rather than being frozen to the ions in ideal MHD) influences the magnetic field advection. We overview physical reasons for the discrepancy between the experimental and simulation magnetic field compression measurements, including: surface plasma on Bdot probes, 2D and 3D simulation effects, and differences between ablation of a solid foil compared to a foil initialized as a plasma. Work supported by NNSA SSAP under DOE Cooperative Agreement DE-NA0001836 and NSF Grant PHY-1102471.

  1. Magnetic field calculation of the Na-4 muon spectrometer

    International Nuclear Information System (INIS)

    Cvach, J.; Il'yushchenko, V.I.; Savin, I.A.; Vorozhtsov, S.B.

    1980-01-01

    A NA-4 muon spectrometer is described. Preliminary results of calculating a magnetic field in a toroidal magnetic detector are given. The spectrometer includes 10 similar supermodules each of which consists of 32 iron discs with 275 cm outer diameter magnetized up to saturation. Each module is an independent detector. The POISSON program is used for calculating magnetic field distribution in a toroidal spectrometer magnet. The results obtained show that a magnetic field of iron is a toroidal one and drops approximately according to the logarithmic law from 21.1 kGs on an inner magnet rig to 17.7 kGs on an outer. Magnet support gives approximately 2 % error

  2. Atomic Beam Laser Spectrometer for In-field Isotopic Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Alonso [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Actinide Analytical Chemistry Group

    2016-06-22

    This is a powerpoint presentation for the DTRA quarterly program review that goes into detail about the atomic beam laser spectrometer for in-field isotopic analysis. The project goals are the following: analysis of post-detonation debris, determination of U and Pu isotopic composition, and fieldable prototype: < 2ft3, < 1000W.

  3. Commissioning of the magnetic field in the ATLAS muon spectrometer

    CERN Document Server

    Arnaud, M; Bergsma, F; Bobbink, G; Bruni, A; Chevalier, L; Ennes, P; Fleischmann, P; Fontaine, M; Formica, A; Gautard, V; Groenstege, H; Guyot, C; Hart, R; Kozanecki, W; Iengo, P; Legendre, M; Nikitina, T; Perepelkin, E; Ponsot, P; Richardson, A; Vorozhtsov, A; Vorozthsov, S

    2008-01-01

    ATLAS is a general-purpose detector at the 14 TeV proton-proton Large Hadron Collider at CERN. The muon spectrometer will operate in the magnetic field provided by a large, eight-coil barrel toroid magnet bracketed by two smaller toroidal end-caps. The toroidal field is non-uniform, with an average value of about 0.5 T in the barrel region, and is monitored using three-dimensional Hall sensors which must be accurate to 1 mT. The barrel coils were installed in the cavern from 2004 to 2006, and recently powered up to their nominal current. The Hall-sensor measurements are compared with calculations to validate the magnetic models, and used to reconstruct the position and shape of the coil windings. Field perturbations by the magnetic materials surrounding the muon spectrometer are found in reasonable agreement with finite-element magnetic-field simulations.

  4. DISEASE DETECTION FROM FIELD SPECTROMETER DATA

    Directory of Open Access Journals (Sweden)

    O. H. Tawfik

    2013-11-01

    Full Text Available ABSTRACT: Oil palm plants have been planted in large scale of areas. Ganoderma disease has been recognized and diagnosed in oil palm plants to infect almost half of the oil palm plants in Malaysia. To deal with this problem, the use of vegetation indices analysis on hyper spectral field data we will examine the ability of this data in discrimination between Ganoderma disease stages in oil palm plants which will be helpful in control the spread of the diseases. By using vegetation indices the oil palm plants could be classified into 1 (T1 healthy, 2 (T2 semi healthy and 3 (T3 severe damage plant classes accurately. The results showed that the best vegetation index is the Modified Red Edge Simple Ratio (MSR705 among the vegetation indices to discriminate between oil palm health stages. It was realized that the modification that was applied to the Modified Red Edge Simple Ratio (MSR705 index of Narrowband greenness VIs has been exhibited an acceptable results in differentiate between the oil palm plant stage 1 (T1 healthy and stage 2 (T2 semi healthy. ABSTRAK: Tanaman kelapa sawit ditanam secara meluas.  Penyakit ganoderma dikenali dan didiagnosikan menjangkiti hampir separuh tanaman kelapa sawit di Malaysia. Untuk mengawal penyakit ini daripada merebak, analisis indeks tanaman dijalankan ke atas data kawasan spektrum melampau di mana keupayaan data ini diuji dalam membezakan peringkat-peringkat penyakit Ganoderma terhadap tanaman kelapa sawit. Dengan menggunakan indeks tanaman, kelapa sawit dapat diklasifikasikan kepada 1 (T1 sihat, 2 (T2 separa sihat dan 3 (T3 rosak; kelas tanaman dengan tepat. Keputusan menunjukkan indeks tanaman terbaik sebagai Modified Red Edge Simple Ratio (MSR705 yang merupakan indeks tanaman dalam membezakan peringkat kesihatan kelapa sawit. Adalah didapati pengubahsuaian terhadap indeks Modified Red Edge Simple Ratio (MSR705 yang juga indeks Jalur Sempit Hijau VI telah memberikan keputusan yang munasabah dalam

  5. Linear electric field time-of-flight ion mass spectrometer

    Science.gov (United States)

    Funsten, Herbert O [Los Alamos, NM; Feldman, William C [Los Alamos, NM

    2008-06-10

    A linear electric field ion mass spectrometer having an evacuated enclosure with means for generating a linear electric field located in the evacuated enclosure and means for injecting a sample material into the linear electric field. A source of pulsed ionizing radiation injects ionizing radiation into the linear electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between ionization of atoms or molecules and arrival of an ion out of the ionized atoms or molecules at a predetermined position.

  6. Gas identification field test based on FTIR imaging spectrometer

    Science.gov (United States)

    Wang, Chensheng; Liu, Xingchao; Zhang, Zhijie; Yu, Hui

    2017-10-01

    Gas detection and identification is based on the spectral absorption peak feature, which is acquired by the spectrometer. FTIR imaging spectrometer has the advantages of high spectral resolution and good sensitivity, which are both suitable for the unknown or mixture gas identification applications, such as plume pollution monitoring, chemical agents detection and leakage detection. According to the application requirement, a dual band FTIR imaging spectrometer has been developed and verified. This FTIR imaging spectrometer combines the infrared thermal imaging sensor and Michelson interferometer to form the three dimensional data cube. Based on this instrument, the theoretical analysis and algorithm is introduced, and the numerical method is explained to illuminate the basic idea in gas identification based on spectral features. After that, the field verification test is setup and completed. Firstly, the FTIR imaging spectrometer is used to detect SF6, NH3 and the mixture gas, while the gas is exhausted out from the storage vase with a specific speed. Secondly, the instrument is delivered to the industrial area to monitor the plume emission, and analyze the components in plume. Finally, the instrument is utilized to monitoring the oil spill in ocean, and the practical maritime trial is realized. Further, the gas concentration evaluation method is discussed. Quantitative issue in gas identification is an important topic. The test results show that, based on the gas identification method introduced in this paper, FTIR imaging spectrometer can be utilized to identify the unknown gas or mixture gas in real time. The instrument will play a key role in environmental emergency and monitoring application.

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

    International Nuclear Information System (INIS)

    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.

    2010-01-01

    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.

  8. Topological invariants and the dynamics of an axial vector torsion field

    International Nuclear Information System (INIS)

    Drechsler, W.

    1983-01-01

    A generalized throry of gravitation is discussed which is based on a Riemann-Cartan space-time, U 4 , with an axial vector torsion field. Besides Einstein's equations determining the metric of the U 4 a system of nonlinear field equations is established coupling an axial vector source current to the axial vector torsion field. The properties of the solutions of these equations are discussed assuming a London-type condition relating the axial current and torsion field. To characterize the solutions use is made of the Euler and Pontrjagin forms and the associated quadratic curvature invariants for the U 4 space-time. It is found that there exists for a Riemann-Cartan space-time a relation between the zeros of the axial vector torsion field and the singularities of the Pontrjagin invariant, which is analogous to the well-known Hopf relation between the zeros of vector fields and the Euler characteristic. (author)

  9. Inhomogeneous oscillatory electric field time-of-flight mass spectrometer

    International Nuclear Information System (INIS)

    Carrico, J.P.

    1977-01-01

    The mass-to-charge ratio of an ion can be determined from the measurement of its flight time in an inhomogeneous, oscillatory electric field produced by the potential distribution V(x, y, t) = Vsub(DC) + Vsub(AC) cos ωt) (αsub(x)X 2 + αsub(y)Y 2 + αsub(z)Z 2 ). The governing equation of motion is the Mathieu equation. The principle of operation of this novel mass spectrometer is described and results of computer calculations of the flight time and resolution are reported. An experimental apparatus and results and results demonstrating the feasibility of this mass spectrometer principle are described. (author)

  10. Tunable axial gauge fields in engineered Weyl semimetals: semiclassical analysis and optical lattice implementations

    Science.gov (United States)

    Roy, Sthitadhi; Kolodrubetz, Michael; Goldman, Nathan; Grushin, Adolfo G.

    2018-04-01

    In this work, we describe a toolbox to realize and probe synthetic axial gauge fields in engineered Weyl semimetals. These synthetic electromagnetic fields, which are sensitive to the chirality associated with Weyl nodes, emerge due to spatially and temporally dependent shifts of the corresponding Weyl momenta. First, we introduce two realistic models, inspired by recent cold-atom developments, which are particularly suitable for the exploration of these synthetic axial gauge fields. Second, we describe how to realize and measure the effects of such axial fields through center-of-mass observables, based on semiclassical equations of motion and exact numerical simulations. In particular, we suggest realistic protocols to reveal an axial Hall response due to the axial electric field \

  11. Wide-Field Ultraviolet Spectrometer for Planetary Exospheres and Thermospheres

    Science.gov (United States)

    Fillingim, M. O.; Wishnow, E. H.; Miller, T.; Edelstein, J.; Lillis, R. J.; Korpela, E.; England, S.; Shourt, W. V.; Siegmund, O.; McPhate, J.; Courtade, S.; Curtis, D. W.; Deighan, J.; Chaffin, M.; Harmoul, A.; Almatroushi, H. R.

    2016-12-01

    Understanding the composition, structure, and variability of a planet's upper atmosphere - the exosphere and thermosphere - is essential for understanding how the upper atmosphere is coupled to the lower atmosphere, magnetosphere and near-space environment, and the Sun. Ultraviolet spectroscopy can directly observe emissions from constituents in the exosphere and thermosphere. From such observations, the structure, composition, and variability can be determined.We will present the preliminary design for a wide field ultraviolet imaging spectrometer for remote sensing of planetary atmospheres. The imaging spectrometer achieves an extremely large instantaneous 110 degree field of view with no moving scanning mirror. The imaging resolution is very appropriate for extended atmospheric emission studies, with a resolution of better than 0.3 degrees at the center to 0.4 degrees at the edges of the field. The spectral range covers 120 - 170 nm, encompassing emissions from H, O, C, N, CO, and N2, with an average spectral resolution of 1.5 nm. The instrument is composed of a 2-element wide-field telescope, a 3-element Offner spectrometer, and a sealed MCP detector system contained within a compact volume of about 40 x 25 x 20 cm. We will present the optical and mechanical design as well as the predicted optical performance.The wide instantaneous FOV simplifies instrument and spacecraft operations by removing the need for multiple scans (either from a scan mirror or spacecraft slews) to cover the regions of interest. This instrumentation can allow for two-dimensional spectral information to be built up with simple spacecraft operation or just using spacecraft motion. Applications to the terrestrial geocorona and thermosphere will be addressed as well as applications to the upper atmospheres of other planetary objects.

  12. Survey results for oblique field magnetic flux leakage survey in comparison to axial field

    Energy Technology Data Exchange (ETDEWEB)

    Simek, James [T.D. Williamson, Inc., Tulsa, OK (United States)

    2012-07-01

    Pipeline operators worldwide have implemented integrity management programs in an effort to improve operation and maintenance efficiency along with continued safe operation of pipeline systems. Several types of monitoring and data collection activities are incorporated into these programs, with in line inspection (ILI) tools providing data for detection and quantification of features that may impact the integrity of the pipeline system. Magnetic flux leakage (MFL) ILI tools are among the most widely used in pipeline systems. Primarily used for metal loss detection and quantification, these tools are extremely robust, performing successfully in the harsh environments found in operating pipelines, with the majority of MFL tools in service today relying upon axially oriented magnetic fields. For feature classes whose principal axis is aligned parallel to the pipe axis, the use of an axially applied magnetic field may quite often result in decreased performance due to difficulties in detection and sizing. Through the use of fields applied either perpendicular or in an oblique direction to the principal axis, the magnetic leakage levels generated at feature locations are increased, providing usable signal levels. When used concurrently with an axially oriented magnetizer, an obliquely applied magnetic field may provide the ability to detect, quantify, or otherwise aid in discrimination of volumetric versus non-volumetric features. Providing the ability to collect both of these data sets in a single survey would allow operators to minimize the number of surveys required to address all categories of metal loss features that may be present within pipeline systems. This paper will discuss some of the variables that affect detection and sizing of metal loss zones with respect to the applied field direction, including graphs and tables to quantify the effects of angular displacement for specific feature shapes. Several classes of features have been chosen for evaluation

  13. An active pixels spectrometers for neutronic fields metrology

    International Nuclear Information System (INIS)

    Taforeau, Julien

    2013-01-01

    The fundamental metrology is responsible for the sustainability of the measurement systems and handles to supply the reference standards. Concerning the metrology of ionizing radiations and, in particular the neutron metrology, detectors standards are used to characterize reference fields, in terms of energy and fluence. The dosimeters or particle detectors are calibrated on these reference fields. This thesis presents the development of a neutron spectrometer neutron candidate to the status of primary standard for the characterization of neutron fields in the range from 5 to 20 MeV. The spectrometer uses the recoil proton telescope as detection principle; the CMOS technology, through three sensor positions, is taking advantage to realize the tracking of protons. A Si(Li) detector handles the measure of the residual proton energy. The device simulations, realized under MCNPX, allow to estimate its performances and to validate the neutron energy reconstruction. An essential step of characterization of the telescope elements and in particular of CMOS sensors is also proposed to guarantee the validity of posterior experimental measurements. The tests realized as well in mono-energy fields as in radionuclide source show the very good performances of the system. The quantification of uncertainties indicates an energy estimation with 1.5 % accuracy and a resolution of less than 6 %. The fluence measurement is performed with an uncertainty about 4 to 6%. (author)

  14. Self-field effects on electron dynamics in free-electron lasers with axial magnetic field

    International Nuclear Information System (INIS)

    Mirzanejhad, S.; Maraghechi, B.; Mohsenpour, T.

    2004-01-01

    A self-consistent method for the analysis of self-magnetic field for a free-electron laser with a one-dimensional helical wiggler and an axial guide magnetic field is presented. The equilibrium orbits and their stability, under the influence of self-electric and self-magnetic fields, are analyzed. New unstable orbits, in the first part of the Group I orbits and in the resonance region of the Group II orbits, are found. It is shown that an increase in the defocusing effect of self-fields will widen the unstable orbits. An anomalous self-field regime is found where an increase in the defocusing effect of self-fields can have stabilizing effect on the resonance region

  15. Field transportable beta spectrometer. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-12-01

    The objective of the Large-Scale Demonstration Project (LSDP) is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) Chicago Pile-5 Test Reactor (CP-5). The purpose of the LSDP is to demonstrate that by using innovative and improved deactivation and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies. One such capability being addressed by the D and D Focus Area is rapid characterization for facility contaminants. The technology was field demonstrated during the period January 7 through January 9, 1997, and offers several potential benefits, including faster turn-around time, cost reduction, and reduction in secondary waste. This report describes a PC controlled, field-transportable beta counter-spectrometer which uses solid scintillation coincident counting and low-noise photomultiplier tubes to count element-selective filters and other solid media. The dry scintillation counter used in combination with an element-selective technology eliminates the mess and disposal costs of liquid scintillation cocktails. Software in the instrument provides real-time spectral analysis. The instrument can detect and measure Tc-99, Sr-90, and other beta emitters reaching detection limits in the 20 pCi range (with shielding). Full analysis can be achieved in 30 minutes. The potential advantages of a field-portable beta counter-spectrometer include the savings gained from field generated results. The basis for decision-making is provided with a rapid turnaround analysis in the field. This technology would be competitive with the radiometric analysis done in fixed laboratories and the associated chain of custody operations

  16. Laboratory Calibration of a Field Imaging Spectrometer System

    Directory of Open Access Journals (Sweden)

    Qingxi Tong

    2011-02-01

    Full Text Available A new Field Imaging Spectrometer System (FISS based on a cooling area CCD was developed. This paper describes the imaging principle, structural design, and main parameters of the FISS sensor. The FISS was spectrally calibrated with a double grating monochromator to determine the center wavelength and FWHM of each band. Calibration results showed that the spectral range of the FISS system is 437–902 nm, the number of channels is 344 and the spectral resolution of each channel is better than 5 nm. An integrating sphere was used to achieve absolute radiometric calibration of the FISS with less than 5% calibration error for each band. There are 215 channels with signal to noise ratios (SNRs greater than 500 (62.5% of the bands. The results demonstrated that the FISS has achieved high performance that assures the feasibility of its practical use in various fields.

  17. On the adge field effect of a quadrupole mass spectrometer on a charged particle beam

    International Nuclear Information System (INIS)

    Usacheva, T.V.; Kuz'min, A.F.

    1982-01-01

    Functional parameter dependences of charged particle beam transport in the edge field of a quadrupole mass spectrometer on the parameters of the spectrometer and the potential are presented, making an assumption of linear potential change in the direction parallel to the spectrometer electrodes. Obtained are: inequality, convenient for the passage through the edge field of ion beams with point source vertex and axis of symmetry, parallel to the spectrometer electrodes; inequality, giving the upper bound of maximal ion approach to the spectrometer electrodes in the edge field; inequality, estimating the maximum value of charged particle velocity on a plane, being perpendicular to the spectrometer electrodes at the particle passage through the edge field. The inequalities obtained have been determined the relationships among the ion beam, the spectrometer and the edge field parameters

  18. Field neutron spectrometer using 3He, TEPC, and multisphere detectors

    International Nuclear Information System (INIS)

    Brackenbush, L.W.

    1991-01-01

    Since the last DOE Neutron Dosimetry Workshop, there have been a number of changes in radiation protection standards proposed by national and international advisory bodies. These changes include: increasing quality factors for neutrons by a factor of two, defining quality factors as a function of lineal energy rather than linear energy transfer (see ACCRUE-40; Joint Task Group 1986), and adoption of effective dose equivalent methodologies. In order to determine the effects of these proposed changes, it is necessary to know the neutron energy spectrum in the work place. In response to the possible adoption of these proposals, the Department of Energy (DOE) initiated a program to develop practical neutron spectrometry systems for use by health physicists. One part of this program was the development of a truly portable, battery operated liquid scintillator spectrometer using proprietary electronics developed at Lawrence Livermore National Laboratory (LLNL); this instrument will be described in the following paper. The second part was the development at PNL of a simple transportable spectrometer based on commercially available electronics. This open-quotes field neutron spectrometerclose quotes described in this paper is intended to be used over a range of neutron energies extending from thermal to 20 MeV

  19. spectrometer

    Directory of Open Access Journals (Sweden)

    J. K. Hedelius

    2016-08-01

    Full Text Available Bruker™ EM27/SUN instruments are commercial mobile solar-viewing near-IR spectrometers. They show promise for expanding the global density of atmospheric column measurements of greenhouse gases and are being marketed for such applications. They have been shown to measure the same variations of atmospheric gases within a day as the high-resolution spectrometers of the Total Carbon Column Observing Network (TCCON. However, there is little known about the long-term precision and uncertainty budgets of EM27/SUN measurements. In this study, which includes a comparison of 186 measurement days spanning 11 months, we note that atmospheric variations of Xgas within a single day are well captured by these low-resolution instruments, but over several months, the measurements drift noticeably. We present comparisons between EM27/SUN instruments and the TCCON using GGG as the retrieval algorithm. In addition, we perform several tests to evaluate the robustness of the performance and determine the largest sources of errors from these spectrometers. We include comparisons of XCO2, XCH4, XCO, and XN2O. Specifically we note EM27/SUN biases for January 2015 of 0.03, 0.75, –0.12, and 2.43 % for XCO2, XCH4, XCO, and XN2O respectively, with 1σ running precisions of 0.08 and 0.06 % for XCO2 and XCH4 from measurements in Pasadena. We also identify significant error caused by nonlinear sensitivity when using an extended spectral range detector used to measure CO and N2O.

  20. Coherent and incoherent radiation from free-electron lasers with an axial guide field

    OpenAIRE

    Freund, Henry P.; Sprangle, P.; Dillenburg, Darcy; Jornada, Eda Homrich da; Liberman, Bernardo; Schneider, Ruth de Souza

    1981-01-01

    The spontaneous and induced emission from a free-electron laser is treated for the case in which an axial magnetic field is imposed in addition to the helical, axially periodic wiggler magnetic field. The classes of possible single-particle trajectories in this configuration are discussed, and the results are applied to a calculation of the incoherent radiation from a beam of relativistic electrons in the system. The coherent radiation is treated by solving the Vlasov-Maxwell equations for th...

  1. Gauge anomaly with vector and axial-vector fields in 6D curved space

    Science.gov (United States)

    Yajima, Satoshi; Eguchi, Kohei; Fukuda, Makoto; Oka, Tomonori

    2018-03-01

    Imposing the conservation equation of the vector current for a fermion of spin 1/2 at the quantum level, a gauge anomaly for the fermion coupling with non-Abelian vector and axial-vector fields in 6D curved space is expressed in tensorial form. The anomaly consists of terms that resemble the chiral U(1) anomaly and the commutator terms that disappear if the axial-vector field is Abelian.

  2. OLYMPEX Counterflow Spectrometer and Impactor Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Poellot, Michael [Univ. of North Dakota, Grand Forks, ND (United States)

    2016-07-01

    The U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s ARM Aerial Facility (AAF) Counterflow Spectrometer and Impactor (CSI) probe was flown on the University of North Dakota Cessna Citation research aircraft during the Olympic Mountain Experiment (OLYMPEX). The field campaign took place from November 12 through December 19, 2015, over the Olympic Mountains and coastal waters of Washington State as part of a National Aeronautics and Space Administration (NASA) Global Precipitation Measurement (GPM) validation campaign. The CSI was added to the Citation instrument suite to support the NASA Aerosol-Cloud Ecosystem (ACE) satellite program and flights of the NASA Lockheed Earth Resources (ER-2) aircraft. ACE funded extra ER-2 flights to focus on clouds that are weakly precipitating, which are also of interest to the DOE Atmospheric System Research (ASR) program.

  3. Melt Motion Due to Peltier Marking During Bridgman Crystal Growth with an Axial Magnetic Field

    Science.gov (United States)

    Sellers, C. C.; Walker, John S.; Szofran, Frank R.; Motakef, Shariar

    2000-01-01

    This paper treats a liquid-metal flow inside an electrically insulating cylinder with electrically conducting solids above and below the liquid region. There is a uniform axial magnetic field, and there is an electric current through the liquid and both solids. Since the lower liquid-solid interface is concave into the solid and since the liquid is a better electrical conductor than the adjacent solid, the electric current is locally concentrated near the centerline. The return to a uniform current distribution involves a radial electric current which interacts with the axial magnetic field to drive an azimuthal flow. The axial variation of the centrifugal force due to the azimuthal velocity drives a meridional circulation with radial and axial velocities. This problem models the effects of Peltier marking during the vertical Bridgman growth of semiconductor crystals with an externally applied magnetic field, where the meridional circulation due to the Peltier Current may produce important mixing in the molten semiconductor.

  4. Flat-field VLS spectrometers for laboratory applications

    Science.gov (United States)

    Ragozin, Evgeny N.; Belokopytov, Aleksei A.; Kolesnikov, Aleksei O.; Muslimov, Eduard R.; Shatokhin, Aleksei N.; Vishnyakov, Eugene A.

    2017-05-01

    Our intention is to develop high-resolution stigmatic spectral imaging in the XUV (2 - 40 nm). We have designed, aligned and tested a broadband stigmatic spectrometer for a range of 12-30 nm, which makes combined use of a normalincidence multilayer mirror (MM) (in particular, a broadband aperiodic MM) and a grazing-incidence plane varied linespace (VLS) reflection grating. The concave MM produces a slightly astigmatic image of the radiation source (for instance, the entrance slit), and the VLS grating produces a set of its dispersed stigmatic spectral images. The multilayer structure determines the spectral width of the operating range, which may amount to more than an octave in wavelength (e.g. 12.5-30 nm for an aperiodic Mo/Si MM), while the VLS grating controls the spectral focal curve. The stigmatism condition is satisfied simultaneously for two wavelengths, 14 and 27 nm. In this case, the condition of non-rigorous stigmatism is fulfilled for the entire wavelength range. A LiF laser plasma spectrum was recorded in one 0.5 J laser shot. A spatial resolution of 26 μm and a spectral resolution of 900 were demonstrated in the 12.5 - 25 nm range. We also report the design of a set of flat-field spectrometers of Harada type with VLS gratings. VLS gratings were made by ebeam and interference lithography. A technique (analytical + numerical) was developed for calculating optical schemes for writing plane and concave VLS gratings with predefined line density variation.

  5. Atom-probe field-ion-microscope mass spectrometer

    International Nuclear Information System (INIS)

    Nishikawa, Osamu

    1983-01-01

    The titled analyzer, called simply atom-probe, has been developed by combining a field ion microscope (FIM) and a mass spectrometer, and is divided into the time-of-flight type, magnetic sector type, and quadrupole type depending on the types of mass spectrometers. In this paper, the author first describes on the principle and construction of a high resolution, time-of-flight atom-probe developed and fabricated in his laboratory. The feature of the atom-probe lies in the analysis of atoms and molecules in hyper-fine structure region one by one utilizing the high resolution of FIM. It also has the advantages of directly determining the composition by a ratio of the numbers of respective ions because of a constant detection sensitivity regardless of mass numbers, of the resolution as high as single atom layer in depth direction, and of detecting the positional relationship among detected ions by the order of detection in a sample. To determine the composition in a hyperfine structure region, the limited small number of atoms and molecules in the region must be identified distinctly one by one. In the analyzed result of Ni-silicide formed by heating Si evaporated on a Ni tip at 1000 K for 5 minutes, each isotope was not only clearly separated, but also their abundance ratio was very close to the natural abundance ratio. The second half of the paper reports on the analysis of TiC promising for a cold cathode material, adsorption of CO and alcohol, and the composition and structure of silicides, as a few application examples. (Wakatsuki, Y.)

  6. Investigation of Axial Electric Field Measurements with Grounded-Wire TEM Surveys

    Science.gov (United States)

    Zhou, Nan-nan; Xue, Guo-qiang; Li, Hai; Hou, Dong-yang

    2018-01-01

    The grounded-wire transient electromagnetic (TEM) surveying is often performed along the equatorial direction with its observation lines paralleling to the transmitting wire with a certain transmitter-receiver distance. However, such method takes into account only the equatorial component of the electromagnetic field, and a little effort has been made on incorporating the other major component along the transmitting wire, here denoted as axial field. To obtain a comprehensive understanding of its fundamental characteristics and guide the designing of the corresponding observation system for reliable anomaly detection, this study for the first time investigates the axial electric field from three crucial aspects, including its decay curve, plane distribution, and anomaly sensitivity, through both synthetic modeling and real application to one major coal field in China. The results demonstrate a higher sensitivity to both high- and low-resistivity anomalies by the electric field in axial direction and confirm its great potentials for robust anomaly detection in the subsurface.

  7. Research on a novel axial-flux magnetic-field-modulated brushless double-rotor machine with low axial force and high efficiency

    Directory of Open Access Journals (Sweden)

    Chengde Tong

    2017-05-01

    Full Text Available The axial-flux magnetic-field-modulated brushless double-rotor machine (MFM-BDRM is a possible alternative as a power-split device for hybrid electric vehicles (HEVs. However, the existence of large axial force may lead to assembly problems and rich inner air-gap harmonics could result in high PM loss and low efficiency. This paper proposes a novel axial-flux MFM-BDRM with improved PM rotor structure. 2-D analytical method to predict the magnetic-field distribution of the proposed MFM-BDRM is developed and the design procedure of the proposed machine is illustrated. The impact of key geometrical parameters on axial force and torque is investigated. To evaluate the advantage of the proposed machine, a comparison is made with a conventional one with respect to electromagnetic performances. Results show that the proposed machine is effective in reducing PM eddy loss and axial force by 60% and 35%, respectively.

  8. Axial acoustic radiation force on a sphere in Gaussian field

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Rongrong; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-10-28

    Based on the finite series method, the acoustical radiation force resulting from a Gaussian beam incident on a spherical object is investigated analytically. When the position of the particles deviating from the center of the beam, the Gaussian beam is expanded as a spherical function at the center of the particles and the expanded coefficients of the Gaussian beam is calculated. The analytical expression of the acoustic radiation force on spherical particles deviating from the Gaussian beam center is deduced. The acoustic radiation force affected by the acoustic frequency and the offset distance from the Gaussian beam center is investigated. Results have been presented for Gaussian beams with different wavelengths and it has been shown that the interaction of a Gaussian beam with a sphere can result in attractive axial force under specific operational conditions. Results indicate the capability of manipulating and separating spherical spheres based on their mechanical and acoustical properties, the results provided here may provide a theoretical basis for development of single-beam acoustical tweezers.

  9. Axial-field permanent magnet motors for electric vehicles

    Science.gov (United States)

    Campbell, P.

    1981-01-01

    The modelling of an anisotropic alnico magnet for the purpose of field computation involves assigning a value for the material's permeability in the transverse direction. This is generally based upon the preferred direction properties, being all that are easily available. By analyzing the rotation of intrinsic magnetization due to the self demagnetizing field, it is shown that the common assumptions relating the transverse to the preferred direction are not accurate. Transverse magnetization characteristics are needed, and these are given for Alnico 5, 5-7, and 8 magnets, yielding appropriate permeability values.

  10. Accelerating field spectrometer for photons and electrons simultaneous measurement. Application to decay schemes study

    International Nuclear Information System (INIS)

    Busani, Jean.

    1982-09-01

    An original spectrometer was built to improve the measurement of the absolute emission intensities of radionuclides with converted low energy gamma transitions. In this spectrometer, the same Si(Li) detector simultaneously measures electrons and photons emitted by the studied radionuclide; an electrostatic field may be established between the source and the detector to modify the electrons energy. This field allows the electron and photon peaks to be separated, and the absorption and energy straggling by detector windows to be decreased. Special attention has been given to determine spectrometer efficiency calibration curves for electrons and photons. 147 Nd and 133 Ba were used to test the spectrometer improvement and the method used [fr

  11. Multipactor in a Coaxial Line Under the Presence of an Axial DC Magnetic Field

    CERN Document Server

    González-Iglesias, D; Anza, S; Vague, J; Gimeno, B; Boria, V E; Raboso, D; Vicente, C; Gil, J; Caspers, F; Conde, L

    2012-01-01

    The main goal of this letter is the analysis of the multipactor effect within a coaxial waveguide structure when an external axial dc magnetic field is applied. We have designed and manufactured a coaxial waveguide sample that has been immersed within a long solenoid. Numerical and experimental results confirm a significant change in the RF breakdown behavior with regard to the case without the axial dc magnetic field, as well as the existence of single- and double-surface multipactor regimes. Good agreement between theory and experimental data has been found.

  12. Coherent control of quantum jumps in an optical lattice by a weak axial magnetic field

    International Nuclear Information System (INIS)

    Bhattacherjee, Aranyabhuti

    2001-07-01

    As an extension to our earlier work [Opt. Commun. 191, 83 (2001)] we study how a weak axial magnetic field applied along the axis of an optical lattice can coherently control the photon statistics of a trapped cold metastable Helium atom. (author)

  13. Imaging axial and radial electric field components in dielectric targets under plasma exposure

    Science.gov (United States)

    Slikboer, Elmar; Sobota, Ana; Guaitella, Olivier; Garcia-Caurel, Enric

    2018-03-01

    This work presents new ways to investigate the individual electric field components in a dielectric target induced by a non thermal atmospheric pressure plasma jet. Mueller polarimetry is applied to investigate electro-optic crystals under exposure of guided ionization waves produced by a plasma jet. Three different cases are examined to visualize the different electric field components induced in the crystals by charges deposited on the surface by impact of the ionization waves. Investigating a Bi12 SiO20 (BSO) crystal at normal incidence allows measurement and visualization of the axial field, while if the crystal is examined at 45° both radial and axial electric field components are combined. For the first time, a Fe:LiNbO3 (Felinbo) crystal is examined using Mueller polarimetry under influence of a plasma jet. In this case, exclusively the patterns and local values of the radial field are obtained and not the axial field. These unique imaging options in the target for the individual electric field components allow a new and more complete investigation of the dynamics of surface discharges on dielectric materials.

  14. Direct measurement of the beam deflection angle using the axial B-dot field

    Directory of Open Access Journals (Sweden)

    Xiaozhong He

    2011-05-01

    Full Text Available Beam position monitors are an important diagnostics tool for particle accelerator operation and related beam dynamics research. The measurement of the beam deflection angle, or moving direction of a charged particle beam with respect to the beam pipe axis, can provide useful additional information. Beam monitors sensitive to the beam’s azimuthal B-dot field (sometimes referred as B dots are used to measure the displacement (position of the beam centroid, as the beam generates a dipole term of the azimuthal magnetic field. Similarly, a dipole term of the axial magnetic field will be generated by the beam moving in a direction not parallel to the axis of the beam pipe. In this paper, a new method using the axial B-dot field is presented to measure the beam deflection angle directly, including the theoretical background. Simulations using the MAFIA numerical code have been performed, demonstrating a good agreement to the new established analytical model.

  15. Portable mass spectrometer for field and laboratory use

    International Nuclear Information System (INIS)

    Newton, J.C.; Crawford, R.W.; Stump, R.K.

    1975-01-01

    A rugged, portable mass spectrometer is described that can be used for gas analyses in remote areas, yet is suitable for laboratory use. Representative results from several studies, including preshot gas analyses of atmospheres from canisters used in the Cannikin Event, are given. Operational procedures and performance experience are included. (auth)

  16. A new calibration method for tri-axial field sensors in strap-down navigation systems

    International Nuclear Information System (INIS)

    Li, Xiang; Li, Zhi

    2012-01-01

    This paper presents a novel calibration method for tri-axial field sensors, such as magnetometers and accelerometers, in strap-down navigation systems. Strap-down tri-axial sensors have been widely used as they have the advantages of small size and low cost, but they need to be calibrated in order to ensure their accuracy. The most commonly used calibration method for a tri-axial field sensor is based on ellipsoid fitting, which has no requirement for external references. However, the self-calibration based on ellipsoid fitting is unable to determine and compensate the mutual misalignment between different sensors in a multi-sensor system. Therefore, a novel calibration method that employs the invariance of the dot product of two constant vectors is introduced in this paper. The proposed method, which is named dot product invariance method, brings a complete solution for the error model of tri-axial field sensors, and can solve the problem of alignment in a multi-sensor system. Its effectiveness and superiority over the ellipsoid fitting method are illustrated by numerical simulations, and its application on a digital magnetic compass shows significant enhancement of the heading accuracy. (paper)

  17. Vacuum arcing behavior between transverse magnetic field contacts subjected to variable axial magnetic field

    International Nuclear Information System (INIS)

    Ma, Hui; Wang, Jianhua; Liu, Zhiyuan; Geng, Yingsan; Wang, Zhenxing; Yan, Jing

    2016-01-01

    The objective of this work is to reveal the effects of an axial magnetic field (AMF) on the vacuum arc characteristics between transverse magnetic field (TMF) contacts. These vacuum arc characteristics include the vacuum arcing behavior and the arc voltage waveform. In the experiments, an external AMF was applied to a pair of TMF contacts. The external AMF flux density B AMF can be adjusted from 0 to 110 mT. The arc current in the tests varied over a range from 0 to 20 kA rms at 45 Hz. The contact material was CuCr25 (25% Cr). A high-speed charge-coupled device video camera was used to record the vacuum arc evolution. The experimental results show that the application of the AMF effectively reduces the TMF arc voltage noise component and reduces the formation of liquid metal drops between the contacts. The diffuse arc duration increases linearly with increasing AMF flux density, but it also decreases linearly with increasing arc current under application of the external AMF. The results also indicate that the diffuse arc duration before the current zero is usually more than 1 ms under the condition that the value of the AMF per kiloampere is more than 2.0 mT/kA. Finally, under application of the AMF, the arc column of the TMF contacts may constrict and remain in the center region without transverse rotation. Therefore, the combined TMF–AMF contacts should be designed such that they guarantee that the AMF is not so strong as to oppose transverse rotation of the arc column.

  18. Vacuum arcing behavior between transverse magnetic field contacts subjected to variable axial magnetic field

    Science.gov (United States)

    Ma, Hui; Wang, Jianhua; Liu, Zhiyuan; Geng, Yingsan; Wang, Zhenxing; Yan, Jing

    2016-06-01

    The objective of this work is to reveal the effects of an axial magnetic field (AMF) on the vacuum arc characteristics between transverse magnetic field (TMF) contacts. These vacuum arc characteristics include the vacuum arcing behavior and the arc voltage waveform. In the experiments, an external AMF was applied to a pair of TMF contacts. The external AMF flux density BAMF can be adjusted from 0 to 110 mT. The arc current in the tests varied over a range from 0 to 20 kA rms at 45 Hz. The contact material was CuCr25 (25% Cr). A high-speed charge-coupled device video camera was used to record the vacuum arc evolution. The experimental results show that the application of the AMF effectively reduces the TMF arc voltage noise component and reduces the formation of liquid metal drops between the contacts. The diffuse arc duration increases linearly with increasing AMF flux density, but it also decreases linearly with increasing arc current under application of the external AMF. The results also indicate that the diffuse arc duration before the current zero is usually more than 1 ms under the condition that the value of the AMF per kiloampere is more than 2.0 mT/kA. Finally, under application of the AMF, the arc column of the TMF contacts may constrict and remain in the center region without transverse rotation. Therefore, the combined TMF-AMF contacts should be designed such that they guarantee that the AMF is not so strong as to oppose transverse rotation of the arc column.

  19. Vacuum arcing behavior between transverse magnetic field contacts subjected to variable axial magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hui; Wang, Jianhua; Liu, Zhiyuan, E-mail: liuzy@mail.xjtu.edu.cn; Geng, Yingsan; Wang, Zhenxing; Yan, Jing [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2016-06-15

    The objective of this work is to reveal the effects of an axial magnetic field (AMF) on the vacuum arc characteristics between transverse magnetic field (TMF) contacts. These vacuum arc characteristics include the vacuum arcing behavior and the arc voltage waveform. In the experiments, an external AMF was applied to a pair of TMF contacts. The external AMF flux density B{sub AMF} can be adjusted from 0 to 110 mT. The arc current in the tests varied over a range from 0 to 20 kA rms at 45 Hz. The contact material was CuCr25 (25% Cr). A high-speed charge-coupled device video camera was used to record the vacuum arc evolution. The experimental results show that the application of the AMF effectively reduces the TMF arc voltage noise component and reduces the formation of liquid metal drops between the contacts. The diffuse arc duration increases linearly with increasing AMF flux density, but it also decreases linearly with increasing arc current under application of the external AMF. The results also indicate that the diffuse arc duration before the current zero is usually more than 1 ms under the condition that the value of the AMF per kiloampere is more than 2.0 mT/kA. Finally, under application of the AMF, the arc column of the TMF contacts may constrict and remain in the center region without transverse rotation. Therefore, the combined TMF–AMF contacts should be designed such that they guarantee that the AMF is not so strong as to oppose transverse rotation of the arc column.

  20. Radiofrequency hydrogen ion source with permanent magnets providing axial magnetic field.

    Science.gov (United States)

    Oikawa, Kohei; Saito, Yuta; Komizunai, Shota; Takahashi, Kazunori; Ando, Akira

    2014-02-01

    Uniform axial magnetic field of about 70 G is applied to a radiofrequency (rf) hydrogen ion source by arrays of permanent magnets. The plasma density and electron temperature downstream of the source and near the magnetic filter are compared with those in the previously described ion source, where the axial field has been applied by two solenoids. The source is operated at ∼350 kHz and above 10 kW rf power with a field-effect-transistor-based invertor power supply in 1.5 Pa hydrogen. The results show that the plasma density of ∼10(19) m(-3) near the source exit and ∼10(18) m(-3) near the magnetic filter can be obtained, which are higher than those with the solenoids.

  1. Development results of portable gamma-radiation HPGe spectrometer with electric cooling for field applications

    International Nuclear Information System (INIS)

    Kondrat'ev, V.; Loshevich, E.; Pchelintsev, A.; Sokolov, A.; Gostilo, V.

    2015-01-01

    The paper presents development results of a portable spectrometer based on high purity germanium (HPGe spectrometer) with Stirling electric cooler for field applications. The spectrometer cryostat allows installation of HPGe coaxial detectors with efficiency up to 40% and planar detectors with sensitive area up to 3000 mm2. The detector cooling time is not more than 8 hours. Despite the mechanical vibrations due to electric cooler operation, the obtained energy resolution of the spectrometer with coaxial detector of 10% efficiency was less than 1,0 and 2,0 keV by energies 122 and 1332 keV accordingly. Miniature processor device (Android) allows control for all operation modes of the spectrometer, provides self diagnostics, initial procession, indication and spectra accumulation

  2. Magnetic field calculations for the technical proposal of the TESLA spectrometer magnet

    International Nuclear Information System (INIS)

    Morozov, N.A.; Schreiber, H.J.

    2003-01-01

    The TESLA electron-positron linear collider is under consideration at DESY (Hamburg). The realization of the physical program at this collider requires the knowledge of the beam energy of both beams (e + and e - ) with a precision of ΔE/E ≤ 10 -4 . The magnetic spectrometer was proposed as an energy measuring device. The report describes calculations for the preliminary conceptual design of this type of the spectrometer. The 2D calculations of the magnetic field for the spectrometer magnet have been performed by POISSON SUPERFISH computer code. The basic technical parameters of the magnet have been determined. These data will serve as a basis for the technical design of the spectrometer magnet and discuss its integration in the spectrometer

  3. Influence of an axial magnetic field on the density profile of capillary plasma channels

    CERN Document Server

    Ivanov, V V; Toma, E S; Bijkerk, F

    2003-01-01

    A narrow capillary plasma channel, with a sizeable depletion of the electron density on the channel axis, has been proposed to guide a laser pulse over a length of several to several tens of centimetres. We discuss the possibility to significantly improve the wave-guiding properties of such a channel by applying an axial magnetic field. Our analytical and numerical studies show that a pulsed axial magnetic field of 10 T in a hydrogen capillary plasma at a pressure of 50 Torr will reduce the on-axis plasma density by a factor of three, and the full width at half maximum of the density profile by a factor of two. The resulting parabolic plasma density profile is expected to be more efficient in guiding laser pulses.

  4. Combined influence of azimuthal and axial magnetic fields on resonant electron acceleration in plasma

    Science.gov (United States)

    Singh, Arvinder; Rajput, Jyoti; Kant, Niti

    2017-11-01

    Resonant enhancement in electron acceleration due to a circularly polarized laser pulse in plasma, under the combined influence of external azimuthal and axial magnetic fields, is studied. We have investigated direct electron acceleration in plasma by employing a relativistic single particle simulation. The plasma is magnetized with an azimuthal magnetic field applied in the perpendicular plane and an axial magnetic field applied along the direction of laser beam propagation. Resonance takes place between electron and electric field of the laser pulse for the optimum value of the combined magnetic field, which supports electron acceleration to higher energies, up to the betatron resonance point. The optimum value of these magnetic fields is highly sensitive to laser initial intensity and laser initial spot size. The effects of laser intensity, initial spot size, and laser pulse duration are taken into consideration in optimizing the magnetic field for efficient electron acceleration. Higher electron energy gain, of the order of GeV, is observed by employing terawatt circularly polarized laser pulses in plasma under the influence of combined magnetic field of about 10 MG.

  5. DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers

    Science.gov (United States)

    Fan, Non Q.; Clarke, John

    1993-01-01

    A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced.

  6. Theory and compensation method of axial magnetic error induced by axial magnetic field in a polarization-maintaining fiber optic gyro

    Science.gov (United States)

    Zhou, Yanru; Zhao, Yuxiang; Tian, Hui; Zhang, Dengwei; Huang, Tengchao; Miao, Lijun; Shu, Xiaowu; Che, Shuangliang; Liu, Cheng

    2016-12-01

    In an axial magnetic field (AMF), which is vertical to the plane of the fiber coil, a polarization-maintaining fiber optic gyro (PM-FOG) appears as an axial magnetic error. This error is linearly related to the intensity of an AMF, the radius of the fiber coil, and the light wavelength, and also influenced by the distribution of fiber twist. When a PM-FOG is manufactured completely, this error only appears a linear correlation with the AMF. A real-time compensation model is established to eliminate the error, and the experimental results show that the axial magnetic error of the PM-FOG is decreased from 5.83 to 0.09 deg/h in 12G AMF with 18-dB suppression.

  7. A simplified numerical analysis of helical instabilities of arcs in axial magnetic field

    International Nuclear Information System (INIS)

    Gong Ye; Lu Wenyan; Liu Jinyuan; Zheng Shu; Gong Jiquan

    2002-01-01

    The energy equations were simplified by the correct electrostatic ordering under electrostatic approximation. The effects of the external axial magnetic field, the current profiles and arc currents on the helical instabilities of arcs were studied by using numerical method. In the presence of the external magnetic field, numerical results show that when the current profile of an arc column is the uniform distribution, the short wavelength perturbation can be stabilized by positive direction magnetic field, whereas the long wavelength perturbation can be stabilized by reverse magnetic field. When the current profile of an arc column has a parabolic distribution, in the short wavelength perturbation case, the effect of positive direction magnetic field on the arc stability is very small. However, its stabilizing effect is enhanced for the long wavelength perturbation. The intermediate and long wavelength perturbations can also be stabilized by reverse magnetic field

  8. One half of the central detector for the Axial Field Spectrometer (AFS)experiment R807

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    This experiment was setup at the ISR intersection I-8 by the Brookhaven-CERN-Copenhagen-Lund-Rutherford Lab.-Tel Aviv Collaboration to study large transverse momentum phenomena (see Annual Report 1979 p. 69). The central detector (here shown for a part) was a cylindrical drift chamber with fine azimuthal segmentation.

  9. Compression, heating and fusion in dynamic pinches stabilized by an axial magnetic field

    International Nuclear Information System (INIS)

    Libermann, M.A.; Golberg, S.M.; Velikovich, A.L.

    1990-01-01

    The inertial confinement Z-pinch fusion systems have at least one advantage: there is no limitation on I like I PB , the current can be as high as the pulsed power driver is capable to deliver. When a dynamic Z-pinch is treated as an ICF system, its most important characteristic is stability of compression. The idea of combining the advantages of inertial and magnetic approaches to controlled fusion in some hybrid scheme has been discussed for a long time. It was shown that a sufficiently strong magnetic field in the ICF systems can localize the ignition by suppressing the electron thermal conductivity and diffusion of the α-particles, and also provide an initial preheating of the compressed plasma. It was also pointed out that perhaps the most important is the possibility to inhibit the development of hydrodynamic instabilities in the course of compression with the aid of the magnetic field, thus increasing the degree of stable radial compression. It was shown, that a relatively small axial magnetic field can significantly improve the uniform radial compression by suppressing the most dangerous sausage and kink modes of RT instability associated with inward acceleration of an annular plasma by the azimuthal magnetic field. This allows one to obtain higher degrees of stable radial compression up to 22-fold compression achieved instead of convetnional -8. The stabilizing effect of axial magnetic field on pinch implosions can be explained with the aid of an ideal MHD model. Stability of an implosion can be expected if the final number of e-folding of the dominating perturbation modes n ef is shown to be small or, at least, limited in comparison with the case when no axial magnetic field is present. (author) 9 refs., 1 fig

  10. An investigation of a flow field in one and half axial turbine stage

    Science.gov (United States)

    Němec, Martin; Jelínek, Tomáš; Milčák, Petr

    2017-09-01

    An investigation of one and half axial turbine stage configuration was carried out in a closed-loop wind tunnel. The investigation was addressed to that impact how the previous stage outlet flow field influences a flow structures in the next stator in steam multistage turbines. The detailed measurement behind the rotor and the second stator was performed with a pneumatic probes to gain a useful data for an impact analysis. Various rotor shroud clearances were also tested to capture the shroud outlet flow field influences.

  11. Personnel neutron dose assessment upgrade: Volume 2, Field neutron spectrometer for health physics applications

    International Nuclear Information System (INIS)

    Brackenbush, L.W.; Reece, W.D.; Miller, S.D.

    1988-07-01

    Both the (ICRP) and the (NCPR) have recommended an increase in neutron quality factors and the adoption of effective dose equivalent methods. The series of reports entitled Personnel Neutron Dose Assessment Upgrade (PNL-6620) addresses these changes. Volume 1 in this series of reports (Personnel Neutron Dosimetry Assessment) provided guidance on the characteristics, use, and calibration of personnel neutron dosimeters in order to meet the new recommendations. This report, Volume 2: Field Neutron Spectrometer for Health Physics Applications describes the development of a portable field spectrometer which can be set up for use in a few minutes by a single person. The field spectrometer described herein represents a significant advance in improving the accuracy of neutron dose assessment. It permits an immediate analysis of the energy spectral distribution associated with the radiation from which neutron quality factor can be determined. It is now possible to depart from the use of maximum Q by determining and realistically applying a lower Q based on spectral data. The field spectrometer is made up of two modules: a detector module with built-in electronics and an analysis module with a IBM PC/reg sign/-compatible computer to control the data acquisition and analysis of data in the field. The unit is simple enough to allow the operator to perform spectral measurements with minimal training. The instrument is intended for use in steady-state radiation fields with neutrons energies covering the fission spectrum range. The prototype field spectrometer has been field tested in plutonium processing facilities, and has been proven to operate satisfactorily. The prototype field spectrometer uses a 3 He proportional counter to measure the neutron energy spectrum between 50 keV and 5 MeV and a tissue equivalent proportional counter (TEPC) to measure absorbed neutron dose

  12. Effect of axial magnetic field on a 2.45 GHz permanent magnet ECR ion source

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, T., E-mail: tsubasa@oshima-k.ac.jp; Wada, H.; Furuse, M. [National Institute of Technology, Oshima College, 1091-1 Komatsu, Suouoshima, Oshima, Yamaguchi 742-2193 (Japan); Asaji, T. [National Institute of Technology, Toyama College, 13 Hongo, Toyama 939-8630 (Japan)

    2016-02-15

    Herein, we conduct a fundamental study to improve the generation efficiency of a multi-charged ion source using argon. A magnetic field of our electron cyclotron resonance ion source is composed of a permanent magnet and a solenoid coil. Thereby, the axial magnetic field in the chamber can be tuned. Using the solenoid coil, we varied the magnetic field strength in the plasma chamber and measured the ion beam current extracted at the electrode. We observed an approximately three times increase in the Ar{sup 4+} ion beam current when the magnetic field on the extractor-electrode side of the chamber was weakened. From our results, we can confirm that the multi-charged ion beam current changes depending on magnetic field intensity in the plasma chamber.

  13. Computation of the magnetic field of a spectrometer in detectors region

    International Nuclear Information System (INIS)

    Zhidkov, E.P.; Yuldasheva, M.B.; Yudin, I.P.; Yuldashev, O.I.

    1995-01-01

    Computed results of the 3D magnetic field of a spectrometer intended for investigation of hadron production of charmed particles and the indication of the narrow resonances in neutron-nucleus interactions are presented. The methods used in computations: finite element method and finite element method with suggested new infinite elements are described. For accuracy control the computations were carried out on a sequence of three-dimensional meshes. Special attention is devoted to behaviour of the magnetic field in the basic detector (proportional chambers) region. The performed results can be used for the field behaviour estimate of similar spectrometer magnets. (orig.)

  14. A high efficiency ultrahigh vacuum compatible flat field spectrometer for extreme ultraviolet wavelengths

    International Nuclear Information System (INIS)

    Blagojevic, B.; Le Bigot, E.-O.; Fahy, K.; Aguilar, A.; Makonyi, K.; Takacs, E.; Tan, J.N.; Pomeroy, J.M.; Burnett, J.H.; Gillaspy, J.D.; Roberts, J.R.

    2005-01-01

    A custom, flat field, extreme ultraviolet spectrometer built specifically for use with low power light sources that operate under ultrahigh vacuum conditions is reported. The spectral range of the spectrometer extends from 4 nm to 40 nm. The instrument optimizes the light gathering power and signal-to-noise ratio while achieving good resolution. A detailed description of the spectrometer and design considerations are presented, as well as a procedure that could be used to obtain a synthetic wavelength calibration with the aid of only a single known spectral feature. This synthetic wavelength calibration is compared to a standard wavelength calibration obtained from previously reported spectral lines of Xe, Ar, and Ne ions recorded with this spectrometer

  15. Detailed measurement of the flow field in an axial transonic compressor; Mesure detaillee des ecoulements dans un compresseur axial transsonique

    Energy Technology Data Exchange (ETDEWEB)

    Fradin, C.

    1998-07-01

    The prediction of flow structure and performances of an axial transonic compressor requires accurate solvers. Taking into account the complex flow patterns, it is important to validate codes by comparing it with experimental results. It is well understood that the availability of experimental data is fundamentally important for the improvement of the solvers. An axial transonic compressor has been fitted in the ERECA test facility of ONERA. The rotor of this compressor is isolated from stators. This experimental configuration allows to obtain a steady flow into the relative frame linked to the rotor. Due to this fact, experimental tests became easier because the basic phenomena are not hidden by mutual interactions rotor-stator. Measurements have been made in a test section far upstream the rotor, to provide the inlet conditions in the computation domain. Non intrusive and fast response measurement techniques allow to obtain the detailed flow structure in several test sections located in the rotor and far downstream it. All tests were carried out at four operating conditions of the compressor. Results provide good test cases for numerical prediction methods using three-dimensional Navier-Stokes solvers. (author)

  16. Frame dragging, vorticity and electromagnetic fields in axially symmetric stationary spacetimes

    International Nuclear Information System (INIS)

    Herrera, L; Gonzalez, G A; Pachon, L A; Rueda, J A

    2006-01-01

    We present a general study about the relation between the vorticity tensor and the Poynting vector of the electromagnetic field for axially symmetric stationary electrovacuum metrics. The obtained expressions allow us to understand the role of the Poynting vector in the dragging of inertial frames. The particular case of the rotating massive charged magnetic dipole is analysed in detail. In addition, the electric and magnetic parts of the Weyl tensor are calculated and the link between the latter and the vorticity is established. Then we show that, in the vacuum case, the necessary and sufficient condition for the vanishing of the magnetic part is that the spacetime be static

  17. A thermal model for czochralski silicon crystal growth with an axial magnetic field

    Science.gov (United States)

    Hjellming, L. N.

    1990-07-01

    This paper presents a thermal model for molten silicon in a Czochralski crystal puller system with an applied uniform axial magnetic field. The melt depth is treated as continually decreasing, which affects the thermal environment of the melt and crystal. The radiative heat loss and the input heat flux are treated as functions of time, with a constraint placed on the heat lost to the crystal from the melt. As the melt motion reaches a steady state rapidly, the temperature and flow fields are treated as instantaneously steady at each melt depth. The heat transport is a mixture of conduction and convection, and by considering the crystal and crucible to be rotating with the same angular velocity, the flows driven by buoyancy and thermocapillarity are isolated and provide the convective heat transport in the melt for the range of magnetic field strengths 0.2 ≤ B ≤ 1.0T.

  18. TAURUS - a wide field imaging Fabry-Perot spectrometer

    International Nuclear Information System (INIS)

    Atherton, P.D.; Taylor, K.

    1983-01-01

    TAURUS, an imaging Fabry-Perot system developed by the Royal Greenwich Observatory and Imperial College London, is described. The imaging process is explained and the technique is compared with grating spectrographs. It is argued that TAURUS is superior for obtaining field information from extended emission line sources. (Auth.)

  19. Numerical analysis of branched cracks in bi-axial stress fields

    International Nuclear Information System (INIS)

    Kovac, M.; Cizelj, L.

    1998-01-01

    The stress corrosion cracks as seen for example in PWR steam generator tubing made of Inconel 600 are usually found to be of highly irregular kinked and branched shapes. Numerical analysis of kinked and branched cracks in bi-axial plane stress fields using methods such as finite or boundary element method may provide useful and cost effective solutions. However, accurate analysis of complex shaped cracks requires very fine meshes and, consequently, excessively high computational efforts. This paper discusses some possible strategies of numerical modeling of kinked and branched cracks in general bi-axial stress field using the general-purpose finite element code ABAQUS. The strategies discussed include J-integral and stress intensity factor solutions with different mesh densities. The accuracy of the numerical results obtained is compared with reference solutions from the literature. The main result of the paper is an optimal numerical strategy, which maximizes the accuracy of the result at as low computational efforts as feasible. The selected optimal strategy is expected to be used in the future simulations of large networks of inter-granular stress corrosion cracks at the grain-size scale using incomplete random tessellation.(author)

  20. Axial magnetic field extraction type microwave ion source with a permanent magnet

    International Nuclear Information System (INIS)

    Ishikawa, Junzo; Takagi, Toshinori

    1984-01-01

    A new type of microwave ion source in which a permanent magnet generates an axially directed magnetic field needed for the electron cyclotron resonance was developed. The electron cyclotron resonance produces a high density plasma in the ion source. A mA-order ion beam can be extracted. Compared with usual microwave ion sources, this source has a distinguished feature in that the axially directed magnetic field is formed by use of a permanent magnet. Shape of magnetic force lines near the ion extraction aperture was carefully investigated. The extracted ion current as a function of the ion extraction voltage was measured. The experimental data are in good agreement with the theoretical line. The ion source can be heated up to 500 deg C, and extraction of the alkaline metal ions is possible. The extracted ion current for various elements are shown in the table. The current density normalized by the proton was 350-650 mA/cm 2 which was nearly equal to the upper limit of the extractable positive ion current density. The plasma density was estimated and was 2 - 3 x 10 12 cm -3 . The mass spectrum of a Cesium ion beam was obtained. A negligible amount of impurities was observed. The emittance diagram of the extracted ion beam was measured. The result shows that a low emittance and high brightness ion source is constructed. (Kato, T.)

  1. Exact and analytic solutions of the Ernst equation governing axially symmetric stationary vacuum gravitational fields

    International Nuclear Information System (INIS)

    Baxter, Mathew; Van Gorder, Robert A

    2013-01-01

    We obtain solutions to a transformation of the axially symmetric Ernst equation, which governs a class of exact solutions of Einstein's field equations. Physically, the equation serves as a model of axially symmetric stationary vacuum gravitational fields. By an application of the method of homotopy analysis, we are able to construct approximate analytic solutions to the relevant boundary value problem in the case where exact solutions are not possible. The results presented constitute a solution for a complicated nonlinear and singular initial value problem. Through appropriate selection of the auxiliary linear operator and convergence control parameter, we are able to obtain low order approximations which minimize residual error over the problem domain. The benefit to such approach is that we obtain very accurate approximations after computing very few terms, hence the computational efficiency is high. Finally, an exact solution is provided in a special case, and this corresponds to the analytical solutions obtained in the more general case. The approximate solutions agree qualitatively with the exact solutions. (paper)

  2. Electron states in quantum rings with structural distortions under axial or in-plane magnetic fields

    International Nuclear Information System (INIS)

    Planelles, J; Rajadell, F; Climente, J I

    2007-01-01

    A comprehensive study of anisotropic quantum rings, QRs, subject to axial and in-plane magnetic field, both aligned and transverse to the anisotropy direction, is carried out. Elliptical QRs for a wide range of eccentricity values and also perfectly circular QRs including one or more barriers disturbing the QR current are considered. These models mimic anisotropic geometry deformations and mass diffusion occurring in the QR fabrication process. Symmetry considerations and simplified analytical models supply physical insight into the obtained numerical results. Our study demonstrates that, except for unusual extremely large eccentricities, QR geometry deformations only appreciably influence a few low-lying states, while the effect of barriers disturbing the QR current is stronger and affects all studied states to a similar extent. We also show that the response of the electron states to in-plane magnetic fields provides accurate information on the structural anisotropy

  3. Far-field analysis of axially symmetric three-dimensional directional cloaks.

    Science.gov (United States)

    Ciracì, Cristian; Urzhumov, Yaroslav; Smith, David R

    2013-04-22

    Axisymmetric radiating and scattering structures whose rotational invariance is broken by non-axisymmetric excitations present an important class of problems in electromagnetics. For such problems, a cylindrical wave decomposition formalism can be used to efficiently obtain numerical solutions to the full-wave frequency-domain problem. Often, the far-field, or Fraunhofer region is of particular interest in scattering cross-section and radiation pattern calculations; yet, it is usually impractical to compute full-wave solutions for this region. Here, we propose a generalization of the Stratton-Chu far-field integral adapted for 2.5D formalism. The integration over a closed, axially symmetric surface is analytically reduced to a line integral on a meridional plane. We benchmark this computational technique by comparing it with analytical Mie solutions for a plasmonic nanoparticle, and apply it to the design of a three-dimensional polarization-insensitive cloak.

  4. Intensity-modulated radiation therapy: overlapping co-axial modulated fields

    International Nuclear Information System (INIS)

    Metcalfe, P; Tangboonduangjit, P; White, P

    2004-01-01

    The Varian multi-leaf collimator has a 14.5 cm leaf extension limit from each carriage. This means the target volumes in the head and neck region are sometimes too wide for standard width-modulated fields to provide adequate dose coverage. A solution is to set up asymmetric co-axial overlapping fields. This protects the MLC carriage while in return the MLC provides modulated dose blending in the field overlap region. Planar dose maps for coincident fields from the Pinnacle radiotherapy treatment planning system are compared with planar dose maps reconstructed from radiographic film and electronic portal images. The film and portal images show small leaf-jaw matchlines at each field overlap border. Linear profiles taken across each image show that the observed leaf-jaw matchlines from the accelerator images are not accounted for by the treatment planning system. Dose difference between film reconstructed electronic portal images and planning system are about 2.5 cGy in a modulated field at d max . While the magnitude of the dose differences are small improved round end leaf modelling combined with a finer dose calculation grid may minimize the discrepancy between calculated and delivered dose

  5. Field spectrometer measurement errors in presence of partially polarized light; evaluation of ground truth measurement accuracy.

    Science.gov (United States)

    Lévesque, Martin P; Dissanska, Maria

    2016-11-28

    Considering that natural light is always partially polarized (reflection, Rayleigh scattering, etc.) and the alteration of the spectral response of spectrometers due to the polarization, some concerns were raised about the accuracy and variability of spectrometer outdoor measurements in field campaigns. We demonstrated by simple experiments that, in some circumstances, spectral measurements can be affected by the polarization. The signal variability due to polarization sensitivity of the spectrometer for the measured sample was about 5-10%. We noted that, measuring surfaces at right angle (a frequently used measurement protocol) minimized the problems due to polarization, producing valid results. On the other hand, measurements acquired with a slant angle are more or less accurate; an important proportion of the signal variability is due to the polarization. Direct sun reflection and reflection from close objects must be avoided.

  6. An EUV Wide-Field Imager and Spectrometer for the ISS

    Science.gov (United States)

    Golub, Leon; Savage, Sabrina

    2016-01-01

    The Coronal Spectrographic Imager in the EUV, COSIE, combines a wide-field solar coronal EUV imager (EUVC) and an on-disk EUV imaging spectrometer (EUVS). Located on the International Space Station (ISS), the goal of the mission is to enhance our understanding of the dynamics of the Transition Corona (the region in which the coronal magnetic field transitions from closed to open), and to provide improved detection and tracking of solar eruptive events for space weather research.

  7. Design and construction of an Offner spectrometer based on geometrical analysis of ring fields.

    Science.gov (United States)

    Kim, Seo Hyun; Kong, Hong Jin; Lee, Jong Ung; Lee, Jun Ho; Lee, Jai Hoon

    2014-08-01

    A method to obtain an aberration-corrected Offner spectrometer without ray obstruction is proposed. A new, more efficient spectrometer optics design is suggested in order to increase its spectral resolution. The derivation of a new ring equation to eliminate ray obstruction is based on geometrical analysis of the ring fields for various numerical apertures. The analytical design applying this equation was demonstrated using the optical design software Code V in order to manufacture a spectrometer working in wavelengths of 900-1700 nm. The simulation results show that the new concept offers an analytical initial design taking the least time of calculation. The simulated spectrometer exhibited a modulation transfer function over 80% at Nyquist frequency, root-mean-square spot diameters under 8.6 μm, and a spectral resolution of 3.2 nm. The final design and its realization of a high resolution Offner spectrometer was demonstrated based on the simulation result. The equation and analytical design procedure shown here can be applied to most Offner systems regardless of the wavelength range.

  8. Advanced axial field D.C. motor development for electric passenger vehicle

    Science.gov (United States)

    Jones, W. J.

    1982-01-01

    A wound-field axial-flux dc motor was developed for an electric vehicle drive system. The motor is essentially an axial-flux version of the classical Gramme-ring winding motor, but the active conductors are recessed into slots cut into the two opposite faces of the laminated tape-wound core ring. Three motors were built and tested in the program. The second (functional) model was a six-pole machine which weighed 88.5 kg. It developed 16.9 km (33.0 hp), and a max speed of 4800 rpm. Full load efficiency was 92% and predicted SAE D-cycle efficiency was 88%. The last engineering) model was a 4-pole machine with compoles, allowing a weight reduction to 45 kg (100 lbs.) while addressing some manufacturability problems. The engineering model was rated at 13.2 kw (17.6 hp) at 3000 rpm, with a peak power of 19.8 km (26.4 hp) and a max speed of 7200 rpm. Initial test results on this motor showed poor commutation and efficiency; the program was terminated without resolution of these problems.

  9. Flow of conductive fluid between parallel disks in an axial magnetic field, (2)

    International Nuclear Information System (INIS)

    Koike, Kazuo; Kamiyama, Shin-ichi

    1981-01-01

    The basic characteristics of the flow in a disc type non-equilibrium MHD power generator were studied. The flow of conductive fluid between parallel disks in an axial magnetic field was analyzed as the subsonic MHD turbulent approach flow of viscous compressible fluid, taking the electron temperature dependence of conductivity into account. The equations for the flow between disks are described by ordinary electromagnetic hydrodynamic approximation. Practical numerical calculation was performed for the non-equilibrium argon plasma seeded with potassium. The effects of the variation of characteristics of non-equilibrium plasma in main flow and boundary layer on the flow characteristics became clear. The qualitative tendency of the properties of MHD generators can be well explained. (Kato, T.)

  10. Analytical solutions to the electromagnetic field in a cylindrical shell excited by external axial current

    International Nuclear Information System (INIS)

    Jing, Wu; Chun-Yan, Xiao

    2010-01-01

    The solutions to the electromagnetic field excited by a long axial current outside a conductive and magnetic cylindrical shell of finite length are studied in this paper. The more accurate analytical solutions are obtained by solving the proper boundary value problems by the separation variable method. Then the solutions are simplified according to asymptotic formulas of Bessel functions. Compared with the accurate solutions, the simplified solutions do not contain the Bessel functions and the inverse operation of the singular matrix, and can be calculated out fast by computers. The simplified solutions are more suitable for the cylindrical shell of high permeability and conductivity excited by a high frequency source. Both of the numerical results and the physical experimental results validate the simplified solutions obtained. (classical areas of phenomenology)

  11. Proportional 4π detector with an electric field of axial symmetry

    International Nuclear Information System (INIS)

    Guevara, E.A.; Costello, E.D.

    1984-01-01

    A gas-flow proportional 4π counter, with an electric field of axial symmetry, designed and constructed by the authors, whose characteristics allow to work at positive gaseous pressure, is described. Based on the results from the measurements performed, the new detector proved to be suitable for the absolute calibration of beta-emitting radioactive sources and that the accuracy of the determinations can be compared with that achieved at metrologic laboratories of recognized accuracy. The slight dependence of the detector's efficiency on the nuclide's beta energy within the limits studied and its good performance for the measurements of non-punctual sources, are emphasized. Moreover, the spectra obtained, the disintegration schemes and the type of beta transition for each calibrated nuclide are presented. Some detector's parameters of certain interest, the capacity of the chambers in air and the loss of current at the working voltage are included in an annex. (M.E.L.) [es

  12. Combining axial and radial nanowire heterostructures: radial Esaki diodes and tunnel field-effect transistors.

    Science.gov (United States)

    Dey, Anil W; Svensson, Johannes; Ek, Martin; Lind, Erik; Thelander, Claes; Wernersson, Lars-Erik

    2013-01-01

    The ever-growing demand on high-performance electronics has generated transistors with very impressive figures of merit (Radosavljevic et al., IEEE Int. Devices Meeting 2009, 1-4 and Cho et al., IEEE Int. Devices Meeting 2011, 15.1.1-15.1.4). The continued scaling of the supply voltage of field-effect transistors, such as tunnel field-effect transistors (TFETs), requires the implementation of advanced transistor architectures including FinFETs and nanowire devices. Moreover, integration of novel materials with high electron mobilities, such as III-V semiconductors and graphene, are also being considered to further enhance the device properties (del Alamo, Nature 2011, 479, 317-323, and Liao et al., Nature 2010, 467, 305-308). In nanowire devices, boosting the drive current at a fixed supply voltage or maintaining a constant drive current at a reduced supply voltage may be achieved by increasing the cross-sectional area of a device, however at the cost of deteriorated electrostatics. A gate-all-around nanowire device architecture is the most favorable electrostatic configuration to suppress short channel effects; however, the arrangement of arrays of parallel vertical nanowires to address the drive current predicament will require additional chip area. The use of a core-shell nanowire with a radial heterojunction in a transistor architecture provides an attractive means to address the drive current issue without compromising neither chip area nor device electrostatics. In addition to design advantages of a radial transistor architecture, we in this work illustrate the benefit in terms of drive current per unit chip area and compare the experimental data for axial GaSb/InAs Esaki diodes and TFETs to their radial counterparts and normalize the electrical data to the largest cross-sectional area of the nanowire, i.e. the occupied chip area, assuming a vertical device geometry. Our data on lateral devices show that radial Esaki diodes deliver almost 7 times higher peak

  13. Dynamics of liquid metal droplets and jets influenced by a strong axial magnetic field

    Science.gov (United States)

    Hernández, D.; Karcher, Ch

    2017-07-01

    Non-contact electromagnetic control and shaping of liquid metal free surfaces is crucial in a number of high-temperature metallurgical processes like levitation melting and electromagnetic sealing, among others. Other examples are the electromagnetic bending or stabilization of liquid metal jets that frequently occur in casting or fusion applications. Within this context, we experimentally study the influence of strong axial magnetic fields on the dynamics of falling metal droplets and liquid metal jets. GaInSn in eutectic composition is used as test melt being liquid at room temperature. In the experiments, we use a cryogen-free superconducting magnet (CFM) providing steady homogeneous fields of up to 5 T and allowing a tilt angle between the falling melt and the magnet axis. We vary the magnetic flux density, the tilt angle, the liquid metal flow rate, and the diameter and material of the nozzle (electrically conducting/insulating). Hence, the experiments cover a parameter range of Hartmann numbers Ha, Reynolds numbers Re, and Weber numbers We within 0 rotation ceases and the droplets are stretched in the field direction. Moreover, we observe that the jet breakup into droplets (spheroidization) is suppressed, and in the case of electrically conducting nozzles and tilt, the jets are bent towards the field axis.

  14. Dynamics of multiple viscoelastic carbon nanotube based nanocomposites with axial magnetic field

    International Nuclear Information System (INIS)

    Karličić, Danilo; Cajić, Milan; Murmu, Tony; Kozić, Predrag; Adhikari, Sondipon

    2014-01-01

    Nanocomposites and magnetic field effects on nanostructures have received great attention in recent years. A large amount of research work was focused on developing the proper theoretical framework for describing many physical effects appearing in structures on nanoscale level. Great step in this direction was successful application of nonlocal continuum field theory of Eringen. In the present paper, the free transverse vibration analysis is carried out for the system composed of multiple single walled carbon nanotubes (MSWCNT) embedded in a polymer matrix and under the influence of an axial magnetic field. Equivalent nonlocal model of MSWCNT is adopted as viscoelastically coupled multi-nanobeam system (MNBS) under the influence of longitudinal magnetic field. Governing equations of motion are derived using the Newton second low and nonlocal Rayleigh beam theory, which take into account small-scale effects, the effect of nanobeam angular acceleration, internal damping and Maxwell relation. Explicit expressions for complex natural frequency are derived based on the method of separation of variables and trigonometric method for the “Clamped-Chain” system. In addition, an analytical method is proposed in order to obtain asymptotic damped natural frequency and the critical damping ratio, which are independent of boundary conditions and a number of nanobeams in MNBS. The validity of obtained results is confirmed by comparing the results obtained for complex frequencies via trigonometric method with the results obtained by using numerical methods. The influence of the longitudinal magnetic field on the free vibration response of viscoelastically coupled MNBS is discussed in detail. In addition, numerical results are presented to point out the effects of the nonlocal parameter, internal damping, and parameters of viscoelastic medium on complex natural frequencies of the system. The results demonstrate the efficiency of the suggested methodology to find the closed form

  15. The use of a Bonner sphere spectrometer for determining the spatial distribution of neutron fields

    CERN Document Server

    Varela, A; Jimenez, F; Calvillo, J

    1999-01-01

    The directional properties of a modified Bonner-type spectrometer, using spheres with a radial hole, are described in this report. It was found that spheres with these modifications are able to detect the spatial distribution of a neutron field. The neutrons were generated by the sup 9 Be(d,n) sup 1 sup 0 B reaction, produced by bombarding a thick Be target with 4 MeV deutrons provided by a tandem Van de Graaff accelerator.

  16. Noncontact measurement of electrostatic fields: Verification of modeled potentials within ion mobility spectrometer drift tube designs

    International Nuclear Information System (INIS)

    Scott, Jill R.; Tremblay, Paul L.

    2007-01-01

    The heart of an ion mobility spectrometer is the drift region where ion separation occurs. While the electrostatic potentials within a drift tube design can be modeled, no method for independently validating the electrostatic field has previously been reported. Two basic drift tube designs were modeled using SIMION 7.0 to reveal the expected electrostatic fields: (1) A traditional alternating set of electrodes and insulators and (2) a truly linear drift tube. One version of the alternating electrode/insulator drift tube and two versions of linear drift tubes were then fabricated. The stacked alternating electrodes/insulators were connected through a resistor network to generate the electrostatic gradient in the drift tube. The two linear drift tube designs consisted of two types of resistive drift tubes with one tube consisting of a resistive coating within an insulating tube and the other tube composed of resistive ferrites. The electrostatic fields within each type of drift tube were then evaluated by a noncontact method using a Kelvin-Zisman type electrostatic voltmeter and probe (results for alternative measurement methods provided in supplementary material). The experimental results were then compared with the electrostatic fields predicted by SIMION. Both the modeling and experimental measurements reveal that the electrostatic fields within a stacked ion mobility spectrometer drift tube are only pseudo-linear, while the electrostatic fields within a resistive drift tube approach perfect linearity

  17. Portable, remotely operated, computer-controlled, quadrupole mass spectrometer for field use

    International Nuclear Information System (INIS)

    Friesen, R.D.; Newton, J.C.; Smith, C.F.

    1982-04-01

    A portable, remote-controlled mass spectrometer was required at the Nevada Test Site to analyze prompt post-event gas from the nuclear cavity in support of the underground testing program. A Balzers QMG-511 quadrupole was chosen for its ability to be interfaced to a DEC LSI-11 computer and to withstand the ground movement caused by this field environment. The inlet system valves, the pumps, the pressure and temperature transducers, and the quadrupole mass spectrometer are controlled by a read-only-memory-based DEC LSI-11/2 with a high-speed microwave link to the control point which is typically 30 miles away. The computer at the control point is a DEC LSI-11/23 running the RSX-11 operating system. The instrument was automated as much as possible because the system is run by inexperienced operators at times. The mass spectrometer has been used on an initial field event with excellent performance. The gas analysis system is described, including automation by a novel computer control method which reduces operator errors and allows dynamic access to the system parameters

  18. Determination of the bending field integral of the LEP spectrometer dipole

    CERN Document Server

    Chritin, R; Dehning, Bernd; Hidalgo, A; Hildreth, M; Kalbreier, Willi; Leclère, P; Mugnai, G; Palacios, J; Roncarolo, F; Torrence, E; Wilkinson, G

    2005-01-01

    The LEP spectrometer performed calibrations of the beam energy in the 2000 LEP run, in order to provide a kinematical constraint for the W boson mass measurement. The beam was deflected in the spectrometer by a steel core dipole, and the bending angle was measured by Beam-Position Monitors on either side of the magnet. The energy determination relies on measuring the change in bending angle when ramping the beam from a reference point at 50 GeV to an energy within the LEP W physics regime, typically 93 GeV. The ratio of integrated bending fields at these settings (approximately 1.18 Tm/0:64 Tm) must be known with a precision of a few 10-5. The paper reports on the field mapping measurements which were conducted to determine the bending integral under a range of excitation currents and coil temperatures. These were made in the laboratory before and after spectrometer operation, using a test-bench equipped with a moving arm, carrying an NMR probe and Hall probes, and in the LEP tunnel itself, with a mapping tro...

  19. Permanent Magnet Spiral Motor for Magnetic Gradient Energy Utilization: Axial Magnetic Field

    Science.gov (United States)

    Valone, Thomas F.

    2010-01-01

    power for magnetic field switching device can be achieved in order to deflect the rotor magnet in transit. The Wiegand effect itself (bistable FeCoV wire called "Vicalloy") invented by John Wiegand (Switchable Magnetic Device, US Patent ♯4,247,601), utilizing Barkhausen jumps of magnetic domains, is also applied for a similar achievement (Dilatush, 1977). Conventional approaches for spiral magnetic gradient force production have not been adequate for magnetostatic motors to perform useful work. It is proposed that integrating a magnetic force control device with a spiral stator inhomogeneous axial magnetic field motor is a viable approach to add a sufficient nonlinear boundary shift to apply the angular momentum and potential energy gained in 315 degrees of the motor cycle.

  20. Curvature aided efficient axial field emission from carbon nanofiber–reduced graphene oxide superstructures on tungsten wire substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Arunava [School of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700032 (India); Roy, Rajarshi; Sen, Dipayan [Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata 700032 (India); Chattopadhyay, Kalyan K., E-mail: kalyan_chattopadhyay@yahoo.com [School of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700032 (India); Thin Film and Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata 700032 (India)

    2016-03-15

    Graphical abstract: - Highlights: • Efficient axial field emitter was fabricated through deposition of thin RGO layer by Langmuir–Blodgett method. • Tungsten wire substrate was used. • The CNF–RGO superstructure produced better field emission characteristics compared to bare CNF. - Abstract: Field emission characteristics found in reduced graphene oxide (RGO) and RGO based composite systems have always been an area of research interest mainly due to presence of prolific quasi aligned edges working as emitter sites. However, the specific role and extent of edge curvature geometry in RGO systems in regards to the enhancement of field emission has not discussed thoroughly prior to this work. In this work we demonstrate enhanced axial field emission due to top assembly of thin RGO layer over a quasi-vertically aligned carbon nanofiber thin film supported on a tungsten wire substrate. Furthermore, simulation analysis for our RGO based hybrid system using finite element modeling showed that two-stage local field amplification in RGO is responsible for the overall improvement of field emission characteristics. In support of our findings, a tentative explanation has been proposed based on the additional emission from RGO edges in between the CNF network resulting to the enhancement of axial field emission in the nanocomposite superstructure.

  1. Portable scintillation gamma-spectrometer for field measurement of radioactivity in extensive objects

    International Nuclear Information System (INIS)

    Besshejko, O.A.; Vishnevskij, I.N.; Denisenko, R.V.; Malyuk, I.A.; Petrosyan, Eh.E.; Karpenko, S.A.; Prijmak, V.N.

    2011-01-01

    The portable scintillated gamma-spectrometer for field measurement of radioactivity in the volume objects was designed. The crystal CdWO 4 that has weak dependence of light yield from temperature in combination with PMT was applied as the gamma-rays detector. The design of the device provides the possibility for measuring radioactivity of the extensive objects in 4π-geometry without background measurements. In this case the value of the efficiency needed for specific activity calculation in close approximation depends only from crystal geometry and density of measuring object and may be set as the device parameter without efficiency calibration procedure during the operation. The spectrometer does not have an auxiliary radio-active source and connecting cables in the composition. The smartphone operated under Windows Mobile is used as the control module. Bluetooth connection provides data exchange between smartphone and measurement head.

  2. Dual cascade time-of-flight mass spectrometer basing on electrostatic mirrors with two dimensional fields

    International Nuclear Information System (INIS)

    Glikman, L. G.; Goloskokov, Yu. V.; Karetskaya, S.P.; Mit', A.G.

    1999-01-01

    In the report [1] we have suggested the scheme of time-of-flight spectrometer containing two electrostatic mirrors with two dimensional field that doesn't depend on one of the Cartesian coordinates). In the articles [2,3] there have been found conditions for obtaining high quality of time-of-flight and spatial focusing. One of basic advantages of this scheme - is availability of intermediate stigmatic image. In the plane where this image is it's possible to place controlled diaphragm that limits ion scatter along the energy if the scatter is too large. With the help of this diaphragm at the spectrometer you can register mass spectrum with the selected energy. Good focusing quality allows reducing of initial ion energy by this increasing the time of their flight and thus analyzers resolving ability. Ion source and receiver are spaced at rather a long distances. This can be useful to solve some practical tasks

  3. DC SQUID Spectrometers for Nuclear Quadrupole and Low-Field Nuclear Magnetic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    TonThat, Dinh M. [Univ. of California, Berkeley, CA (United States)

    1998-04-01

    The dc Superconducting Quantum Interference Device (SQUJD) is a very sensitive detector of magnetic flux, with a typical flux noise of the order of 1 μΦ0Hz-1/2 at liquid helium temperature (Φ0=h/2e). This inherent flux sensitivity of the SQUID is used in a spectrometer for the detection of nuclear magnetic resonance (NMR.)and nuclear quadruple resonance (NQR). The processing magnetic field from the nuclear spins is coupled to the SQUID by mean of a flux transformer. The SQUID NMR spectrometer is used to measure the longitudinal relaxation time T1 of solid 129Xe at 4.2 K down to 0.1 mT.

  4. Dependence of Moessbauer resonance intensities on vibrational lattice anisotropy in case of an axial electric field gradient

    International Nuclear Information System (INIS)

    Friedt, J.M.

    1976-01-01

    The change in the hyperfine line intensities is discussed for various Moessbauer transitions in cases involving axial vibrational lattice anisotropy and axial electric field gradient at the resonant nucleus. The change in the relative intensities of the spectral components has been calculed numerically for the different types of Moessbauer transitions. Polynomial expansions are given to describe the functional dependence of the relative intensities on the magnitude of the vibration anisotropy. They may be used to extract the relevant parameters from experimental data without requiring the numerical integrations implied in the description of the Goldanskii-Karyagin effect [fr

  5. Calculation of the zero-field splitting D and g(perp)parameters in EPR for d3 spin systems in strong and moderate axial fields

    NARCIS (Netherlands)

    Kool, Th.W.; Bollegraaf, B.

    2010-01-01

    Numerical and analytical methods are used to investigate the calculation of the zero field splitting |2D| and g(perp) parameters in EPR for octahedrally surrounded d3 spin systems (S = 3/2) in strong and moderate axial crystal fields (|D|>=h{\

  6. Sound field near hydrothermal vents on Axial Seamount, Juan de Fuca Ridge. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Little, S.A.; Stolzenbach, K.D.; Purdy, G.M.

    1990-08-10

    High-quality acoustic noise measurements were obtained by two hydrophones located 3 m and 40 m from an active hydrothermal vent on Axial Seamount, Juan de Fuca Ridge, in an effort to determine the feasibility of monitoring hydrothermal vent activity through flow noise generation. Most of the measured noise field could be attributed to ambient ocean noise sources of microseisms, distant shipping, and weather, punctuated by local ships and biological sources. Long-period, low-velocity, water/rock interface waves were detected with high amplitudes which rapidly decayed with distance from the seafloor. Detection of vent signals was hampered by unexpected spatial nonstationarity due to the shadowing effects of the calders wall. No continuous vent signals were deemed significant based on a criterion of 90% probability of detection and 5% probability of false alarm. However, a small signal near 40 Hz, with a power level of 0.0001 Pa sq/Hz was noticed on two records taken within 3 m of the Inferno black smoker. The frequency of this signal is consistent with predictions, and the power level suggests the occurrence of jet noise amplification due to convected density inhomogeneities. Keywords: Seamounts; Flow noise; Underwater acoustics; Acoustic measurement; Geothermy/noise; Ocean ridges; Underwater sound signals; Reprints; North Pacific Ocean. (EDC).

  7. Numerical simulation and comparative analysis of flow field in axial blood pumps.

    Science.gov (United States)

    Peng, Yuhua; Wu, Yaqin; Tang, Xiaoying; Liu, Weifeng; Chen, Duanduan; Gao, Tianxin; Xu, Yong; Zeng, Yanjun

    2014-05-01

    The objective study was to estimate the rheological properties and physiological compatibility of the blood pump by simulating the internal flow field of the blood pump. In this study we use computational fluid dynamics method to simulate and analyse two models of axial blood pumps with a three-blade diffuser and a six-blade diffuser, named pump I and pump II, respectively, and to compare the flow patterns of these two kinds of blood pumps while both of them satisfy the conditions of the normal human blood differential pressure and blood flow. Results indicate that (i) the high shear force occurs between the diffuser and the rotor in which the crucial place leads to haemolysis and (ii) under the condition of 100 mmHg pressure head and 5 l/min flow rate, the difference between the two kinds of blood pumps, as far as the haemolytic performance is concerned, is notable. The haemolysis index of the two pumps is 0.32% and 0.2%. In conclusion, the performance of the blood pump is influenced by the diffusers' blade number. Pump II performed better than pump I, which can be the basic model for blood pump option.

  8. Two-dimensional model of the Penning discharge in a cylindrical chamber with the axial magnetic field

    Science.gov (United States)

    Surzhikov, S. T.

    2017-08-01

    The drift-diffusion model of a Penning discharge in molecular hydrogen under pressures of about 1 Torr with regard to the external electric circuit has been proposed. A two-dimensional axially symmetric discharge geometry with a cylindrical anode and flat cathodes perpendicular to the symmetry axis has been investigated. An external magnetic field of about 0.1 T is applied in the axial direction. Using the developed drift-diffusion model, the electrodynamic structure of a Penning discharge in the pressure range of 0.5-5 Torr at a current source voltage of 200-500 V is numerically simulated. The evolution of the discharge electrodynamic structure upon pressure variations in zero magnetic field (the classical glow discharge mode) and in the axial magnetic field (Penning discharge) has been studied using numerical experiments. The theoretical predictions of the existence of an averaged electron and ion motion in a Penning discharge both in the axial and radial directions and in the azimuthal direction have been confirmed by the calculations.

  9. Characterization of electromagnetic fields in the aSPECT spectrometer and reduction of systematic errors

    Energy Technology Data Exchange (ETDEWEB)

    Ayala Guardia, Fidel

    2011-10-15

    The aSPECT spectrometer has been designed to measure, with high precision, the recoil proton spectrum of the free neutron decay. From this spectrum, the electron antineutrino angular correlation coefficient a can be extracted with high accuracy. The goal of the experiment is to determine the coefficient a with a total relative error smaller than 0.3%, well below the current literature value of 5%. First measurements with the aSPECT spectrometer were performed in the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich. However, time-dependent background instabilities prevented us from reporting a new value of a. The contents of this thesis are based on the latest measurements performed with the aSPECT spectrometer at the Institut Laue-Langevin (ILL) in Grenoble, France. In these measurements, background instabilities were considerably reduced. Furthermore, diverse modifications intended to minimize systematic errors and to achieve a more reliable setup were successfully performed. Unfortunately, saturation effects of the detector electronics turned out to be too high to determine a meaningful result. However, this and other systematics were identified and decreased, or even eliminated, for future aSPECT beamtimes. The central part of this work is focused on the analysis and improvement of systematic errors related to the aSPECT electromagnetic fields. This work yielded in many improvements, particularly in the reduction of the systematic effects due to electric fields. The systematics related to the aSPECT magnetic field were also minimized and determined down to a level which permits to improve the present literature value of a. Furthermore, a custom NMR-magnetometer was developed and improved during this thesis, which will lead to reduction of magnetic field-related uncertainties down to a negligible level to determine a with a total relative error of at least 0.3%.

  10. Field and frequency modulated sub-THz electron spin resonance spectrometer

    Directory of Open Access Journals (Sweden)

    Christian Caspers

    2016-05-01

    Full Text Available 260-GHz radiation is used for a quasi-optical electron spin resonance (ESR spectrometer which features both field and frequency modulation. Free space propagation is used to implement Martin-Puplett interferometry with quasi-optical isolation, mirror beam focusing, and electronic polarization control. Computer-aided design and polarization pathway simulation lead to the design of a compact interferometer, featuring lateral dimensions less than a foot and high mechanical stability, with all components rated for power levels of several Watts suitable for gyrotron radiation. Benchmark results were obtained with ESR standards (BDPA, DPPH using field modulation. Original high-field ESR of 4f electrons in Sm3+-doped Ceria was detected using frequency modulation. Distinct combinations of field and modulation frequency reach a signal-to-noise ratio of 35 dB in spectra of BDPA, corresponding to a detection limit of about 1014 spins.

  11. Frequency- and axial-field-dependent circular magnetization reversal in a stress-annealed Fe-based nanocrystalline wire

    International Nuclear Information System (INIS)

    Li, Y.F.; Vazquez, M.; Yin, S.Z.

    2009-01-01

    Absract: After suitable annealing under a tensile stress, Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 amorphous wire becomes the nano-structured material together with a transverse anisotropy field H k =-3.2 kA/m. Its circular permeability, μ=μ'-jμ'', was determined from the measurements of the impedance, as a function of the frequency (f=333-33,333 Hz) and amplitude (I AC =0.1-100 mA) of AC current and the axially applied DC field (H=0-89 kA/m). We found that the circular technical magnetization of this sample carried out by the spontaneous domain nucleation process. The influences of the AC current frequency and the axial DC field on the circular magnetization have been studied

  12. Quantum regime of a plasma-wave-pumped free-electron laser in the presence of an axial magnetic field.

    Science.gov (United States)

    Shirvani, H; Jafari, S

    2018-03-01

    The quantum regime of a plasma-whistler-wave-pumped free-electron laser (FEL) in the presence of an axial-guide magnetic field is presented. By quantizing both the plasma whistler field and axial magnetic field, an N-particle three-dimensional Hamiltonian of quantum-FEL (QFEL) has been derived. Employing Heisenberg evolution equations and introducing a new collective operator which controls the vertical motion of electrons, a quantum dispersion relation of the plasma whistler wiggler has been obtained analytically. Numerical results indicate that, by increasing the intrinsic quantum momentum spread and/or increasing the axial magnetic field strength, the bunching and the radiation fields grow exponentially. In addition, a spiking behavior of the spectrum was observed with increasing cyclotron frequency which provides an enormous improvement in the coherence of QFEL radiation even in a limit close-to-classical regime, where an overlapping of these spikes is observed. Also, an upper limit of the intrinsic quantum momentum spread which depends on the value of the cyclotron frequency was found.

  13. Fully-automated field mapping of a dipole magnet of a multi-passage spectrometer (MPS)

    Energy Technology Data Exchange (ETDEWEB)

    Meissner, Robert; Thirolf, Peter; Weber, Christine [Fakultaet fuer Physik, LMU - Muenchen (Germany)

    2013-07-01

    MLLTRAP is a Penning-trap mass-spectrometer facility, which is currently being commissioned at the Maier-Leibnitz Laboratory in Garching. Here, atomic mass values are determined by measuring cyclotron frequencies of stored ions in a strong magnetic field. In the future, highly-charged ions should be utilized for an improvement in the achievable mass accuracy. For this purpose, singly-charged ions will have to be injected into a charge-breeding device, such as an EBIT, and transferred back towards the Penning traps, while being q/A selected. To fulfill these tasks a multi-passage-spectrometer (MPS) is being built. It consists of a fast-ramping, round-pole dipole magnet with an electrostatic mirror system. A basic requirement for building the MPS is a detailed knowledge on the magnetic field produced by the magnet. It is necessary to simulate the trajectories of the ions and gain knowledge on the design and geometry of the electrostatic mirror system and the vacuum chamber. For this purpose, a robot was designed, which - powered by three step motors - measures the magnetic field fully automated. The robot moves a Hall probe within three dimensions with a resolution of 1 mm and an uncertainty of 0.5 mm. In this presentation, the development of the robot, its control and data acquisition via LabView and the results are presented.

  14. Wide-Field InfraRed Survey Telescope (WFIRST) Slitless Spectrometer: Design, Prototype, and Results

    Science.gov (United States)

    Gong, Qian; Content, David; Dominguez, Margaret; Emmett, Thomas; Griesmann, Ulf; Hagopian, John; Kruk, Jeffrey; Marx, Catherine; Pasquale, Bert; Wallace, Thomas; hide

    2016-01-01

    The slitless spectrometer plays an important role in the Wide-Field InfraRed Survey Telescope (WFIRST) mission for the survey of emission-line galaxies. This will be an unprecedented very wide field, HST quality 3D survey of emission line galaxies. The concept of the compound grism as a slitless spectrometer has been presented previously. The presentation briefly discusses the challenges and solutions of the optical design, and recent specification updates, as well as a brief comparison between the prototype and the latest design. However, the emphasis of this paper is the progress of the grism prototype: the fabrication and test of the complicated diffractive optical elements and powered prism, as well as grism assembly alignment and testing. Especially how to use different tools and methods, such as IR phase shift and wavelength shift interferometry, to complete the element and assembly tests. The paper also presents very encouraging results from recent element tests to assembly tests. Finally we briefly touch the path forward plan to test the spectral characteristic, such as spectral resolution and response.

  15. The new high field photoexcitation muon spectrometer at the ISIS pulsed neutron and muon source.

    Science.gov (United States)

    Yokoyama, K; Lord, J S; Murahari, P; Wang, K; Dunstan, D J; Waller, S P; McPhail, D J; Hillier, A D; Henson, J; Harper, M R; Heathcote, P; Drew, A J

    2016-12-01

    A high power pulsed laser system has been installed on the high magnetic field muon spectrometer (HiFi) at the International Science Information Service pulsed neutron and muon source, situated at the STFC Rutherford Appleton Laboratory in the UK. The upgrade enables one to perform light-pump muon-probe experiments under a high magnetic field, which opens new applications of muon spin spectroscopy. In this report we give an overview of the principle of the HiFi laser system and describe the newly developed techniques and devices that enable precisely controlled photoexcitation of samples in the muon instrument. A demonstration experiment illustrates the potential of this unique combination of the photoexcited system and avoided level crossing technique.

  16. Electromagnetic fields in an axial symmetric waveguide with variable cross section

    International Nuclear Information System (INIS)

    Kheifets, S.

    1980-07-01

    A new class of separable variables is found which allows one to find an approximate analytical solution of the Maxwell equations for axial symmetric waveguides with slow (but not necessarily small) varying boundary surfaces. An example of the solution is given. Possible applications and limitations of this approach are discussed

  17. GoAmazon 2014/15 Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, JN [Univ. of California, Irvine, CA (United States)

    2016-04-01

    The Thermal Desorption Chemical Ionization Mass Spectrometer (TDCIMS) deployment to the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility T3 site in Manacapuru, Brazil, was motivated by two main scientific objectives of the Green Ocean Amazon (GoAmazon) 2014/15 field campaign. 1) Study the interactions between anthropogenic and biogenic emissions by determining important molecular species in ambient nanoparticles. To address this, TDCIMS data will be combined with coincident measurements such as gas-phase sulfuric acid to determine the contribution of sulfuric acid condensation to nucleation and growth. We can then compare that result to TDCIMS-derived nanoparticle composition to determine the fraction of growth that can be attributed to the uptake of organic compounds. The molecular composition of sampled particles will also be used to attribute specific chemical species and mechanisms to growth, such as the condensation of low-volatility species or the oligomerization of α-dicarbonyl compounds. 2) Determine the source of new ambient nanoparticles in the Amazon. The hypothesis prior to measurements was that potassium salts formed from the evaporation of primary particles emitted by fungal spores can provide a unique and important pathway for new particle production in the Amazon basin. To explore this hypothesis, the TDCIMS recorded the mass spectra of sampled ambient particles using a protonated water cluster Chemical Ionization Mass Spectrometer (CIMS). Laboratory tests performed using potassium salts show that the TDCIMS can detect potassium with high sensitivity with this technique.

  18. Axial diagnostic package for Z

    International Nuclear Information System (INIS)

    Nash, T.J.; Derzon, M.S.; Chandler, G.

    1998-06-01

    The authors have developed and fielded an axial diagnostic package for the 20 MA, 100 ns, z-pinch driver Z. The package is used to diagnose dynamic hohlraum experiments which require an axial line of sight. The heart of the package is a reentrant cone originally used to diagnose ion-beam-driven hohlraums on PBFA-H. It has one diagnostic line of sight at 0 degrees, 4 at 6 degrees, and 4 at 9 degrees. In addition it has a number of viewing, alignment, and vacuum feedthrough ports. The front of the package sits approximately 5 feet from the pinch. This allows much closer proximity to the pinch, with inherently better resolution and signal, than is presently possible in viewing the pinch from the side. Debris that is preferentially directed along the axis is mitigated by two apertures for each line of sight, and by fast valves and imaging pinholes or cross slits for each diagnostic. In the initial run with this package they fielded a time resolved pinhole camera, a five-channel pinhole-apertured x-ray diode array, a bolometer, a spatially resolved time-integrated crystal spectrometer, and a spatially and temporally resolved crystal spectrometer. They present data obtained from these diagnostics in the dynamic hohlraum research conducted on Z

  19. Field evaluation of a transportable open-path FTIR spectrometer for real-time air monitoring.

    Science.gov (United States)

    Ross, Kiley R; Todd, Lori A

    2002-02-01

    To effectively and accurately evaluate human exposures to chemicals, it is important to quantify mixtures of chemicals in air, at low levels, and in real time. The purpose of this study was to evaluate, in the field, a prototype of a new transportable instrument that can fill an important gap in methods available to industrial hygienists. This instrument is a cross between extractive and open-path Fourier Transform Infrared spectrometers and measures chemicals passively and in real time in the vicinity of the breathing zone. The spectrometer has a folded optical path that can be enclosed, similar to an extractive system. The enclosure can be removed, enabling the optical path to be open to the atmosphere; thus, the instrument could be operated as an open-path spectrometer. A field study was conducted in three different occupational settings, including a prosthodontics dental laboratory, a surgery recovery area, and a cytology laboratory. Chemicals that were identified and quantified included methyl methacrylate, nitrous oxide, xylene isomers, toluene, and ethanol. Simultaneous side-by-side sampling was conducted with the prototype instrument and recognized National Institute of Occupational Safety and Health (NIOSH) analytical methods. The distinct infrared "fingerprint" of each chemical made identification and quantification of multiple chemicals possible with the prototype instrument. This attribute allowed the industrial hygienist to quantify short-term exposures and ceiling levels, correlate work practices with concentration levels, evaluate the effectiveness of engineering controls, and identify the presence of unexpected compounds. There was no significant difference between the mean time-weighted averages (TWAs) of the prototype instrument and traditional methods (p > 0.03). Regression analysis found good correlation between the two methods with no significant differences between the slope and unity and between the y-intercept and zero (p > 0.03). The

  20. Strong room-temperature negative transconductance in an axial Si/Ge hetero-nanowire tunneling field-effect transistor

    Science.gov (United States)

    Zhang, Peng; Le, Son T.; Hou, Xiaoxiao; Zaslavsky, A.; Perea, Daniel E.; Dayeh, Shadi A.; Picraux, S. T.

    2014-08-01

    We report on room-temperature negative transconductance (NTC) in axial Si/Ge hetero-nanowire tunneling field-effect transistors. The NTC produces a current peak-to-valley ratio >45, a high value for a Si-based device. We characterize the NTC over a range of gate VG and drain VD voltages, finding that NTC persists down to VD = -50 mV. The physical mechanism responsible for the NTC is the VG-induced depletion in the p-Ge section that eventually reduces the maximum electric field that triggers the tunneling ID, as confirmed via three-dimensional (3D) technology computer-aided design simulations.

  1. Dispersion relation for space-charge waves in a warm plasma-filled elliptical waveguide in an infinite axial magnetic field

    Science.gov (United States)

    Abdoli-Arani, A.; Safari, S.

    2015-04-01

    A perfectly conducting elliptical cylinder filled with a warm plasma and immersed in an infinite axial magnetic field is considered. Using Maxwell's equations and dielectric tensor, a Mathieu differential equation for axial component of electric field is obtained. Considering the boundary conditions, dispersion relation for waves in a plasma of warm electrons and immobile ions, which fills an elliptical waveguide and it is under the action of infinite axial magnetic field are calculated. Furthermore, dispersion relation and scalar potential in the quasi-static approximation in a cold magnetized plasma elliptical waveguide is calculated. The obtained results are graphically presented.

  2. Ultralow power complementary inverter circuits using axially doped p- and n-channel Si nanowire field effect transistors.

    Science.gov (United States)

    Van, Ngoc Huynh; Lee, Jae-Hyun; Whang, Dongmok; Kang, Dae Joon

    2016-06-09

    We have successfully synthesized axially doped p- and n-type regions on a single Si nanowire (NW). Diodes and complementary metal-oxide-semiconductor (CMOS) inverter devices using single axial p- and n-channel Si NW field-effect transistors (FETs) were fabricated. We show that the threshold voltages of both p- and n-channel Si NW FETs can be lowered to nearly zero by effectively controlling the doping concentration. Because of the high performance of the p- and n-type Si NW channel FETs, especially with regard to the low threshold voltage, the fabricated NW CMOS inverters have a low operating voltage (power dissipation (≤0.3 pW) at an input voltage of ±3 V. This result offers a viable way for the fabrication of a high-performance high-density logic circuit using a low-temperature fabrication process, which makes it suitable for flexible electronics.

  3. Drift motion of a charged particle in the crossed axial magnetic and radial electric fields, and the electric field of a rotating potential wave

    International Nuclear Information System (INIS)

    Eliseev, Yu.N.; Stepanov, K.N.

    1983-01-01

    In the drift motion approximation solution of the problem is obtained on the motion of a nonrelativistic charged particle in the crossed axial magnetic and radial electric fields, and the electric field of a rotating potential wave under cherenkov and modified cyclotron resonances. The static radial electric field potential is supposed to be close to the parabolic one. The drift motion equations and their integrals are preseOted. The experimentally obtained effect of plasma ionic component division in the crossed fields under the excitation of ion cyclotron oscillations is explained with the help of the theory developed in the paper

  4. Account of magnetic field effects of polarized proton target on charged particle trajectories in experiments with magnetic spectrometers

    International Nuclear Information System (INIS)

    Telegin, Yu.N.; Ranyuk, Yu.N.; Karnaukhov, I.M.; Lukhanin, A.A.; Sporov, E.A.

    1980-01-01

    Some effects of the influence of magnetic field of a polarized proton target (PPT) on trajectories of secondary particles in experiments using magnetic spectrometers are considered. It is shown that these effects can be eliminated by the target shift relatively to the spectrometer rotation axis and variation of the spectrometer installation angle. Numerical calculations of the correction values were performed for emitted particle momenta of 100-800 MeB/s and working intensity of the H 0 magnetic field H 0 =27 kG. The influence of the PPT magnetic field on the functions of angular and energy resolution in the γp→π + n experiment is investigated. The results obtained can be used in experiments with a polarized proton target

  5. Precipitation and Hydrology Experiment Counter-Flow Spectrometer and Impactor Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Poellot, Michael [University of North Dakota

    2016-03-01

    The U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility Aerial Facility (ARM AAF) counter-flow spectrometer and impactor (CSI) probe was flown on the University of North Dakota Cessna Citation research aircraft during the Integrated Precipitation and Hydrology Experiment (IPHEX). The field campaign took place during May and June of 2014 over North Carolina and its coastal waters as part of a National Aeronautics and Space Administration (NASA) Global Precipitation Measurement validation campaign. The CSI was added to the Citation instrument suite to support the involvement of Jay Mace through the NASA Advanced Composition Explorer (ACE) satellite program and flights of the NASA ER-2 aircraft, which is a civilian version of the Air Force’s U2-S reconnaissance platform. The ACE program funded extra ER-2 flights to focus on clouds that are weakly precipitating, which are also of interest to the Atmospheric System Research program sponsored by DOE.

  6. Characterizing LEDAPS surface reflectance products by comparisons with AERONET, field spectrometer, and MODIS data

    Science.gov (United States)

    Maiersperger, Tom; Scaramuzza, Pat; Leigh, Larry; Shrestha, S.; Gallo, Kevin; Jenkerson, Calli B.; Dwyer, John L.

    2013-01-01

    This study provides a baseline quality check on provisional Landsat Surface Reflectance (SR) products as generated by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center using Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software. Characterization of the Landsat SR products leveraged comparisons between aerosol optical thickness derived from LEDAPS and measured by Aerosol Robotic Network (AERONET), as well as reflectance correlations with field spectrometer and Moderate Resolution Imaging Spectroradiometer (MODIS) data. Results consistently indicated similarity between LEDAPS and alternative data products in longer wavelengths over vegetated areas with no adjacent water, while less reliable performance was observed in shorter wavelengths and sparsely vegetated areas. This study demonstrates the strengths and weaknesses of the atmospheric correction methodology used in LEDAPS, confirming its successful implementation to generate Landsat SR products.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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

  8. Rapid and Deep Proteomes by Faster Sequencing on a Benchtop Quadrupole Ultra-High-Field Orbitrap Mass Spectrometer

    DEFF Research Database (Denmark)

    Kelstrup, Christian D; Jersie-Christensen, Rosa R; Batth, Tanveer Singh

    2014-01-01

    Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage is evalu......Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage...

  9. Design and commissioning of a high magnetic field muon spin relaxation spectrometer at the ISIS pulsed neutron and muon source.

    Science.gov (United States)

    Lord, J S; McKenzie, I; Baker, P J; Blundell, S J; Cottrell, S P; Giblin, S R; Good, J; Hillier, A D; Holsman, B H; King, P J C; Lancaster, T; Mitchell, R; Nightingale, J B; Owczarkowski, M; Poli, S; Pratt, F L; Rhodes, N J; Scheuermann, R; Salman, Z

    2011-07-01

    The high magnetic field (HiFi) muon instrument at the ISIS pulsed neutron and muon source is a state-of-the-art spectrometer designed to provide applied magnetic fields up to 5 T for muon studies of condensed matter and molecular systems. The spectrometer is optimised for time-differential muon spin relaxation studies at a pulsed muon source. We describe the challenges involved in its design and construction, detailing, in particular, the magnet and detector performance. Commissioning experiments have been conducted and the results are presented to demonstrate the scientific capabilities of the new instrument.

  10. Mass spectrometers

    International Nuclear Information System (INIS)

    Manojlov, V.E.; Nedelin, P.N.; Lukichev, A.N.; Sapozhkov, L.K.; Turubarov, V.I.

    1980-01-01

    Mass spectrometers of different types are suggested to use for qualitative and quantitative analyses of gas. The operation principles of static and dynamic mass spectrometer are studied. In static mass spectrometers mass separation of ions is performed by changing the value of accelerating voltage in the ion source when retaining the magnetic field intensity. Such devices are stationary. The device mass is conditioned by the magnet mass. Mass separation in dynamic mass spectrometers is dependent on the degree of energy increment of ions in HF-electric fields. Radio frequency mass spectrometers are used with advantage for studying upper layers of an atmosphere and are installed on radiosondes and satellites. The main technical characteristics of the MX-1330 mass spectrometer, the basis of which is the analyzer with 180 deg deviation of an ion beam in the field of permanent magnet, are presented. The device is intended for controlling the environment and permits to analyze gases with a molecular mass up to 450 using various systems of gas filling. The error of determination of molecular substance is not greater than +-3 %; the magnetic field intensity constitutes 4.8x10 5 A/m; the supply voltage is 380/220 V; the total power is 5.0 kVA [ru

  11. A broadband microwave Corbino spectrometer at ³He temperatures and high magnetic fields.

    Science.gov (United States)

    Liu, Wei; Pan, LiDong; Armitage, N P

    2014-09-01

    We present the technical details of a broadband microwave spectrometer for measuring the complex conductance of thin films covering the range from 50 MHz up to 16 GHz in the temperature range 300 mK-6 K and at applied magnetic fields up to 8 T. We measure the complex reflection from a sample terminating a coaxial transmission line and calibrate the signals with three standards with known reflection coefficients. Thermal isolation of the heat load from the inner conductor is accomplished by including a section of NbTi superconducting cable (transition temperature around 8-9 K) and hermetic seal glass bead adapters. This enables us to stabilize the base temperature of the sample stage at 300 mK. However, the inclusion of this superconducting cable complicates the calibration procedure. We document the effects of the superconducting cable on our calibration procedure and the effects of applied magnetic fields and how we control the temperature with great repeatability for each measurement. We have successfully extracted reliable data in this frequency, temperature, and field range for thin superconducting films and highly resistive graphene samples.

  12. Nuclear axial current operators to fourth order in chiral effective field theory

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, H., E-mail: hermann.krebs@rub.de [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Epelbaum, E., E-mail: evgeny.epelbaum@rub.de [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93016 (United States); Meißner, U.-G., E-mail: meissner@hiskp.uni-bonn.de [Helmholtz-Institut für Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn (Germany); Institut für Kernphysik, Institute for Advanced Simulation, and Jülich Center for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); JARA - High Performance Computing, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2017-03-15

    We present the complete derivation of the nuclear axial charge and current operators as well as the pseudoscalar operators to fourth order in the chiral expansion relative to the dominant one-body contribution using the method of unitary transformation. We demonstrate that the unitary ambiguity in the resulting operators can be eliminated by the requirement of renormalizability and by matching of the pion-pole contributions to the nuclear forces. We give expressions for the renormalized single-, two- and three-nucleon contributions to the charge and current operators and pseudoscalar operators including the relevant relativistic corrections. We also verify explicitly the validity of the continuity equation.

  13. Cathode-constriction and column-constriction in high current vacuum arcs subjected to an axial magnetic field

    Science.gov (United States)

    Zhang, Zaiqin; Ma, Hui; Liu, Zhiyuan; Geng, Yingsan; Wang, Jianhua

    2018-04-01

    The influence of the applied axial magnetic field on the current density distribution in the arc column and electrodes is intensively studied. However, the previous results only provide a qualitative explanation, which cannot quantitatively explain a recent experimental data on anode current density. The objective of this paper is to quantitatively determine the current constriction subjected to an axial magnetic field in high-current vacuum arcs according to the recent experimental data. A magnetohydrodynamic model is adopted to describe the high current vacuum arcs. The vacuum arc is in a diffuse arc mode with an arc current ranged from 6 kArms to 14 kArms and an axial magnetic field ranged from 20 mT to 110 mT. By a comparison of the recent experimental work of current density distribution on the anode, the modelling results show that there are two types of current constriction. On one hand, the current on the cathode shows a constriction, and this constriction is termed as the cathode-constriction. On the other hand, the current constricts in the arc column region, and this constriction is termed as the column-constriction. The cathode boundary is of vital importance in a quantitative model. An improved cathode constriction boundary is proposed. Under the improved boundary, the simulation results are in good agreement with the recent experimental data on the anode current density distribution. It is demonstrated that the current density distribution at the anode is sensitive to that at the cathode, so that measurements of the anode current density can be used, in combination with the vacuum arc model, to infer the cathode current density distribution.

  14. Analysis and Design Considerations of a High-Power Density, Dual Air Gap, Axial-Field Brushless, Permanent Magnet Motor.

    Science.gov (United States)

    Cho, Chahee Peter

    1995-01-01

    Until recently, brush dc motors have been the dominant drive system because they provide easily controlled motor speed over a wide range, rapid acceleration and deceleration, convenient control of position, and lower product cost. Despite these capabilities, the brush dc motor configuration does not satisfy the design requirements for the U.S. Navy's underwater propulsion applications. Technical advances in rare-earth permanent magnet materials, in high-power semiconductor transistor technology, and in various rotor position-sensing devices have made using brushless permanent magnet motors a viable alternative. This research investigates brushless permanent magnet motor technology, studying the merits of dual-air gap, axial -field, brushless, permanent magnet motor configuration in terms of power density, efficiency, and noise/vibration levels. Because the design objectives for underwater motor applications include high-power density, high-performance, and low-noise/vibration, the traditional, simplified equivalent circuit analysis methods to assist in meeting these goals were inadequate. This study presents the development and verification of detailed finite element analysis (FEA) models and lumped parameter circuit models that can calculate back electromotive force waveforms, inductance, cogging torque, energized torque, and eddy current power losses. It is the first thorough quantification of dual air-gap, axial -field, brushless, permanent magnet motor parameters and performance characteristics. The new methodology introduced in this research not only facilitates the design process of an axial field, brushless, permanent magnet motor but reinforces the idea that the high-power density, high-efficiency, and low-noise/vibration motor is attainable.

  15. Magnetic flux density distribution in superconducting cylinders of arbitrary cross section subjected to an axial magnetic field

    Science.gov (United States)

    Fournet, G.

    1982-07-01

    We show here how the application of the critical state model allows one to determine the magnetic flux density B⃗ in each point of a superconducting cylinder with an arbitrary cross section subjected to axial magnetic fields Hz; the B = 0 boundaries of the regions occupied by the vortices are so defined. We successively consider the cases where the critical current density Jc is either isotropic (constant or an arbitrary function of B) or tensorial, which means, for our problem, the use of two components Jcx and Jcy (either constant or depending on B but Jcx/Jcy remaining constant).

  16. Numerical and experimental research of flow and sound fields in an axial-flow check valve and its optimization

    Directory of Open Access Journals (Sweden)

    Jianping Yu

    2015-11-01

    Full Text Available In order to find a proper method to study the flow and sound fields in an axial-flow check valve, the jetting noise at a nozzle is investigated with simulations and experiments. Based on optimization principle, the main channel of the valve body is numerically investigated and optimized twice. The results show that the resistance coefficient and the maximum noise of the valve are decreased by 0.37 and 23.8 dB, respectively, and the head and the tail of the valve plug are optimized when streamline design is employed on the main channel structure of the valve body.

  17. A three-step calibration method for tri-axial field sensors in a 3D magnetic digital compass

    International Nuclear Information System (INIS)

    Zhu, Xiaoning; Zhao, Ta; Zhou, Zhijian; Cheng, Defu

    2017-01-01

    In a 3D magnetic compass, it is important to calibrate the tri-axial magnetometers and accelerometers so the compass will provide accurate heading and attitude information. Previous researchers have used two methods to calibrate these two field sensors separately, i.e. the classic independent ellipsoid fitting method and the independent dot product invariant method, respectively. Both methods are easy to use, and no highly accurate, external equipment is required. However, self-calibration with ellipsoid fitting has the disadvantage that it interfuses an orthogonal matrix, and the dot product invariant method requires the use of pre-calibrated internal field sensors, which may be unavailable in many cases. In this paper, we have introduced and unified an error model of two tri-axial field sensors. Accordingly, the orthogonal matrix caused by ellipsoid fitting was mathematically proved to be the combination of two sources, the mounting misalignment and the rotation misalignment. Moreover, a new method, which we call optimal resultant vector, was proposed to further calibrate multi-sensor systems on the basis of ellipsoid fitting and dot product invariant methods, establishing a new, three-step calibration method. The superiority of the proposed method over the state-of-the-art approaches were demonstrated by simulations and a 3D compass experiment. (paper)

  18. A three-step calibration method for tri-axial field sensors in a 3D magnetic digital compass

    Science.gov (United States)

    Zhu, Xiaoning; Zhao, Ta; Cheng, Defu; Zhou, Zhijian

    2017-04-01

    In a 3D magnetic compass, it is important to calibrate the tri-axial magnetometers and accelerometers so the compass will provide accurate heading and attitude information. Previous researchers have used two methods to calibrate these two field sensors separately, i.e. the classic independent ellipsoid fitting method and the independent dot product invariant method, respectively. Both methods are easy to use, and no highly accurate, external equipment is required. However, self-calibration with ellipsoid fitting has the disadvantage that it interfuses an orthogonal matrix, and the dot product invariant method requires the use of pre-calibrated internal field sensors, which may be unavailable in many cases. In this paper, we have introduced and unified an error model of two tri-axial field sensors. Accordingly, the orthogonal matrix caused by ellipsoid fitting was mathematically proved to be the combination of two sources, the mounting misalignment and the rotation misalignment. Moreover, a new method, which we call optimal resultant vector, was proposed to further calibrate multi-sensor systems on the basis of ellipsoid fitting and dot product invariant methods, establishing a new, three-step calibration method. The superiority of the proposed method over the state-of-the-art approaches were demonstrated by simulations and a 3D compass experiment.

  19. Self-Dual Yang-Mills Fields in Static Axially Symmetric Case and Related Topics

    Science.gov (United States)

    Hou, Bo-yuan; Wang, Pei

    1985-09-01

    In this article we will present an explicit geometric picture about the complete integrability of the static axially symmetric SDYM equation and the gravitational Ernst equation, interpret the correspondence between their Bäcklund transformation formulae and the transformations from one focal surface of Weingarten congruence to the other, and give the matrix Riccati equation so that the integrability of the B.T. will be proved. It is shown that for the axially symmetric SDYM equation and gravitational Ernst equation the adjoint space of the group (SL(2r)) is a 3-dimensional Minkowski space, and the corresponding soliton surfaces have negative variable curvature. After introducing the generator R we can explain the B.T. as the rotation around the common tangent between two surfaces of solitons. Using Riccati equation we will confirm in this paper the integrability of B.T. and prove that the B.T. is strong, i.e., the new and old solutions satisfy equations of motion separately. Some related topics are also discussed.

  20. A simple ionizing radiation spectrometer/dosimeter based on radiation sensing field effect transistors (RadFETs)

    International Nuclear Information System (INIS)

    Moreno, D.J.; Hughes, R.C.; Jenkins, M.W.; Drumm, C.R.

    1997-01-01

    This paper reports on the processing steps in a silicon foundry leading to improved performance of the Radiation Sensing Field Effect Transistor (RadFET) and the use of multiple RadFETs in a handheld, battery operated, combination spectrometer/dosimeter

  1. Detector tests in a high magnetic field and muon spectrometer triggering studies on a small prototype for an LHC experiment

    CERN Document Server

    Ambrosi, G; Basile, M; Battiston, R; Bergsma, F; Castro, H; Cifarelli, Luisa; Cindolo, F; Contin, A; De Pasquale, S; Gálvez, J; Gentile, S; Giusti, P; Laurent, G; Levi, G; Lin, Q; Maccarrone, G D; Mattern, D; Nania, R; Rivera, F; Schioppa, M; Sharma, A; CERN. Geneva. Detector Research and Development Committee

    1990-01-01

    The "Large Area Devices" group of the LAA project is working on R&D for muon detection at a future super-collider. New detectors are under development and the design of a muon spectrometer for an LHC experiment is under study. Our present choice is for a compact, high field, air-core toroidal muon spectrometer. Good momentum resolution is achievable in this compact solution, with at least one plane of detection elements inside the high field region. A new detector, the Blade Chamber, making use of blades instead of wires, has been developed for the forward and backward regions of the spectrometer, where polar coordinate readings are desirable.The assembling of a CERN high energy beam line, equipped with high resolution drift chambers and a strong field magnet could give us the opportunity to test our chambers in a high magnetic field and to study the muon trigger capabilities of a spectrometer, like the one proposed, on a small prototype.

  2. Ferrofluid spiral formations and continuous-to-discrete phase transitions under simultaneously applied DC axial and AC in-plane rotating magnetic fields

    International Nuclear Information System (INIS)

    Rhodes, Scott; Perez, Juan; Elborai, Shihab; Lee, Se-Hee; Zahn, Markus

    2005-01-01

    New flows and instabilities are presented for a ferrofluid drop contained in glass Hele-Shaw cells with simultaneously applied in-plane clockwise rotating and DC axial uniform magnetic fields. When a ferrofluid drop is stressed by a uniform DC axial magnetic field, up to ∼250 G in 0.9-1.4 mm gap Hele-Shaw cells, the drop forms a labyrinth pattern. With subsequent application of an in-plane uniform rotating magnetic field, up to ∼100 G rms at frequency 20-40 Hz, smooth spirals form from viscous shear due to ferrofluid flow. If the rotating magnetic field is applied first, the drop is held together without a labyrinth. Gradual increase of the DC axial magnetic field, to a critical magnetic field value, results in an abrupt phase transformation from a large drop to many small discrete droplets. A preliminary minimum magnetization and surface energy analysis is presented to model the phase transformation

  3. Life estimation of low-cycle fatigue of pipe elbows. Proposed criteria of low-cycle fatigue life under the multi-axial stress field

    International Nuclear Information System (INIS)

    Ando, Kotoji; Takahashi, Koji; Matsuo, Kazuya; Urabe, Yoshio

    2013-01-01

    Pipe elbows were important parts frequently used in the pipelines of nuclear power, thermal power and chemical plants, and their integrity needed to be assured under seismic loads and thermal stresses considering local wall thinning or complex stress distribution due to special configuration different from straight pipe. This article investigated in details elastic-plastic stress-strain state of pipe elbow using finite element analysis and clarified there existed high bi-axial stress field at side inner surface of pipe elbow axial cracks initiated. Bi-axial stress factor was around 0.6 for sound elbow and up to 0.95 for local wall thinning at crown. Fracture strain of 1.15 was reduced to around 0.15 for bi-axial stress factor from 0.6 to 0.9. Normalized fatigue life for bi-axial stress field (0.6 - 0.8) was largely reduced to around 15, 19 and 10% of fatigue life of uni-axial state dependent on material strength level. Proposed revised universal slopes taking account of multi-axial stress factor could explain qualitatively effects of strain range, internal pressure and ratchet strain (pre-strain) on low-cycle fatigue life of pipe elbow. (T. Tanaka)

  4. Formation mechanism of axial macrosegregation of primary phases induced by a static magnetic field during directional solidification

    Science.gov (United States)

    Li, Xi; Fautrelle, Yves; Ren, Zhongming; Moreau, Rene

    2017-04-01

    Understanding the macrosegregation formed by applying magnetic fields is of high commercial importance. This work investigates how static magnetic fields control the solute and primary phase distributions in four directionally solidified alloys (i.e., Al-Cu, Al-Si, Al-Ni and Zn-Cu alloys). Experimental results demonstrate that significant axial macrosegregation of the solute and primary phases (i.e., Al2Cu, Si, Al3Ni and Zn5Cu phases) occurs at the initial solidification stage of the samples. This finding is accompanied by two interface transitions in the mushy zone: quasi planar → sloping → quasi planar. The amplitude of the macrosegregation of the primary phases under the magnetic field is related to the magnetic field intensity, temperature gradient and growth speed. The corresponding numerical simulations present a unidirectional thermoelectric (TE) magnetic convection pattern in the mushy zone as a consequence of the interaction between the magnetic field and TE current. Furthermore, a model is proposed to explain the peculiar macrosegregation phenomenon by considering the effect of the forced TE magnetic convection on the solute distribution. The present study not only offers a new approach to control the solute distribution by applying a static magnetic field but also facilitates the understanding of crystal growth in the solute that is controlled by the static magnetic field during directional solidification.

  5. X-ray Si(Li) spectrometer with thermoelectric cooling and prospects of its application in different fields

    International Nuclear Information System (INIS)

    Mejer, V.A.; Zhukovskij, A.N.; Ponomarev, V.S.; Kharitonov, Yu.P.; Subbotin, V.G.; Kushniruk, V.F.

    1976-01-01

    To overcome difficulties, associated with design shortcomings of hole devices with liquid nitrogen, a spectrometer with thermoelectric cooling has been designed. This spectrometer is portable, convenient in operation, and extends applications of semiconducting radiation detectors. A Si(Li)-detector and a field-effect transistor of amplifier first cascade are mounted on cold joints of the thermoelectric cooler and together with the latter are enclosed into an capsule. The capsule has a beryllium input window and a metal base, i.e. a radiator. The capsule is 32 mm in diameter, 80 mm in length, and weighs 300 g. The thermoelectric battery with power of 15 W provides the temperature of cold joints of -89 deg C for the vacuum in the capsule of 10 -3 torr and temperature of hot joints of 20 deg C (the latter being cooled by water). When tests were made, the energy resolution of the spectrometer was found to be: for MnKα line (5.9 keV) 470 eV, for AgKα (22.2 keV) 800 eV. The tests have shown that apart the convenience in use the spectrometer designed has much greater potentialities than conventional geological spectrometers with proportional and scintillation counters

  6. Self-field effects on instability of wave modes in a two-stream free-electron laser with an axial magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Mohsenpour, Taghi, E-mail: mohsenpour@umz.ac.ir; Rezaee Rami, Omme Kolsoum [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, Babolsar (Iran, Islamic Republic of)

    2014-07-15

    Free electron lasers (FEL) play major roles in the Raman Regime, due to the charge and current densities of the beam self-field. The method of perturbation has been applied to study the influence of self-electric and self-magnetic fields. A dispersion relation for two-stream free electron lasers with a helical wiggler and an axial magnetic field has been found. This dispersion relation is solved numerically to investigate the influence of self-fields on the FEL coupling and the two-stream instability. It was found that self-fields can produce very large effects on the FEL coupling, but they have almost negligible effects on two-stream instability.

  7. Field Observation of the Green Ocean Amazon. Neutral Cluster Air Ion Spectrometer (NAIS) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Petaja, T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Backman, J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Manninen, H. E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wimmer, D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The neutral cluster and air ion spectrometer (NAIS) was deployed to the T3 site for Intensive Operations Periods 1 and 2 (IOP1 and IOP2). The NAIS is an instrument that measures aerosol particle and ion number size distributions in the mobility diameter range of 0.8 to 42 nm, corresponding to electrical mobility range between 3.2 and 0.0013 cm2 V-1 s-1. New particle formation (NPF) events were detected using the NAIS at the T3 field site during IOP1 and IOP2. Secondary NPF is a globally important source of aerosol number. To fully explain atmospheric NPF and subsequent growth, we need to directly measure the initial steps of the formation processes in different environments, including rain forest. Particle formation characteristics, such as formation and growth rates, were used as indicators of the relevant processes and participating compounds in the initial formation. In a case of parallel ion and neutral cluster measurements, we estimated the relative contribution of ion-induced and neutral nucleation to the total particle formation.

  8. A Monolithic, Non-Field-Widened Spatial Heterodyne Spectrometer for Solar System Exploration, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to produce a monolithic Spatial Heterodyne Spectrometer (a Fourier Transform Interferometer) for use in Solar System exploration. In...

  9. MASS SPECTROMETER

    Science.gov (United States)

    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.

  10. Current–voltage characteristics of hydrogen DC plasma torches with different sizes in an external axial magnetic field

    International Nuclear Information System (INIS)

    Ma Jie; Wen Guang-Dong; Su Bao-Gen; Yang Yi-Wen; Ren Qi-Long

    2015-01-01

    Current–voltage (I–V) characteristics of hydrogen DC plasma torches with different sizes in an external axial magnetic field under atmospheric pressure are reported. Three anodes with different diameters are adopted in a 50-kW torch: 25 mm, 30 mm, and 35 mm, respectively. Two different diameters of anodes, that is, 100 mm and 130 mm, are adopted in a 1-MW plasma torch. The arc voltage shows a negative trend with the increase of arc current under the operating regimes. On the contrary, arc voltage shows a positive trend as the flow rate of carrier gas increases, and a similar trend is found with increasing the external magnetic flux density. A similarity formula is constructed to correlate the experimental data of the torches mentioned above. Linear fitting shows that the Pearson correlation coefficient is 0.9958. (paper)

  11. Prediction of satellite motions in the earth's gravitational field with axial symmetry by the KS regularized theory.

    Science.gov (United States)

    Adel Sharaf, M.; El-Sayed Awad, M.; Banaja, M. A.

    1987-05-01

    Economical and stable recurrence formulae for the Earth's zonal potential and its gradient for the KS regularized theory are established for any number N of the zonal harmonic coefficient. A general recursive computational algorithm based on these formulae is also established for the initial value problem of the KS theory for the prediction of artificial satellites in the Earth's gravitational field with axial symmetry. Applications of the algorithm for the problem of the final state prediction are illustrated by numerical examples of three test orbits each for two geopotential models corresponding to N = 2 and N = 36. A final state of any desired accuracy is obtained for each case study, a result which shows the flexibility of the algorithm.

  12. Analysis of axially symmetric wire antennas by the use of exact kernel of electric field integral equation

    Directory of Open Access Journals (Sweden)

    Krneta Aleksandra J.

    2016-01-01

    Full Text Available The paper presents a new method for the analysis of wire antennas with axial symmetry. Truncated cones have been applied to precisely model antenna geometry, while the exact kernel of the electric field integral equation has been used for computation. Accuracy and efficiency of the method has been further increased by the use of higher order basis functions for current expansion, and by selecting integration methods based on singularity cancelation techniques for the calculation of potential and impedance integrals. The method has been applied to the analysis of a typical dipole antenna, thick dipole antenna and a coaxial line. The obtained results verify the high accuracy of the method. [Projekat Ministarstva nauke Republike Srbije, br. TR-32005

  13. Perturbative formulation of pure space-like axial gauge QED with infrared divergences regularized by residual gauge fields

    International Nuclear Information System (INIS)

    Nakawaki, Yuji; McCartor, Gary

    2006-01-01

    We construct a new perturbative formulation of pure space-like axial gauge QED in which the inherent infrared divergences are regularized by residual gauge fields. For this purpose, we carry out our calculations in the coordinates x μ =(x + , x - , x 1 , x 2 ), where x + =x 0 sinθ + x 3 cosθ and x - = x 0 cosθ - x 3 sinθ. Here, A=A 0 cosθ + A 3 sinθ = n·A=0 is taken as the gauge fixing condition. We show in detail that, in perturbation theory, infrared divergences resulting from the residual gauge fields cancel infrared divergences resulting from the physical parts of the gauge field. As a result, we obtain the gauge field propagator proposed by Mandelstam and Leibbrandt. By taking the limit θ→π/4, we are able to construct a light-cone formulation that is free from infrared divergences. With that analysis complete, we next calculate the one-loop electron self-energy, something not previously done in the light-cone quantization and light-cone gauge. (author)

  14. Design and Simulation of a Spin Rotator for Longitudinal Field Measurements in the Low Energy Muons Spectrometer

    Science.gov (United States)

    Salman, Z.; Prokscha, T.; Keller, P.; Morenzoni, E.; Saadaoui, H.; Sedlak, K.; Shiroka, T.; Sidorov, S.; Suter, A.; Vrankovic, V.; Weber, H.-P.

    We usedGeant4 to accurately model the low energy muons (LEM) beam line, including scattering due to the 10-nm thin carbon foil in the trigger detector. Simulations of the beam line transmission give excellent agreement with experimental results for beam energies higher than ∼ 12keV.We use these simulations to design and model the operation of a spin rotator for the LEM spectrometer, which will enable longitudinal field measurements in the near future.

  15. Magnetic field modeling and optimal operational control of a single-side axial-flux permanent magnet motor with center poles

    International Nuclear Information System (INIS)

    Liu, C.-T.; Lee, S.-C.

    2006-01-01

    A detailed approach for analyzing magnetic field distributions of a single-sided axial-flux permanent magnet motor with center poles will be provided. Based on the devised flux model, the related position-dependent torque and axial force of the motor can be systematically developed. By incorporating adequate control designs, the optimal operational performance of the motor system can be conveniently achieved. Results showed that not only the motor structure is suitable for related military and transportation applications, but also the magnetic field model can provide appropriate mathematical basis for relative operational realizations

  16. Misalignment of axial B-field in the advanced test accelerator

    International Nuclear Information System (INIS)

    Lauer, E.J.; Caporaso, G.J.; Prono, D.S.; Weir, J.T.

    1986-01-01

    The Advanced Test Accelerator (ATA) has solenoidal magnets to focus and guide the electron beam. The transverse position of the center of mass of the beam is measured at many positions along the accelerator using the wall current monitors. With the steering coils off, the beam drifts off axis a few cm in the length of the machine. The drift is independent of several parameters: field strength, beam current, and beam energy. Further measurements to locate the source of the misalignment will be discussed. 1 ref., 4 figs

  17. Wide-Field Gamma-Spectrometer BDRG: GRB Monitor On-Board the Lomonosov Mission

    Science.gov (United States)

    Svertilov, S. I.; Panasyuk, M. I.; Bogomolov, V. V.; Amelushkin, A. M.; Barinova, V. O.; Galkin, V. I.; Iyudin, A. F.; Kuznetsova, E. A.; Prokhorov, A. V.; Petrov, V. L.; Rozhkov, G. V.; Yashin, I. V.; Gorbovskoy, E. S.; Lipunov, V. M.; Park, I. H.; Jeong, S.; Kim, M. B.

    2018-02-01

    The study of GRB prompt emissions (PE) is one of the main goals of the Lomonosov space mission. The payloads of the GRB monitor (BDRG) with the wide-field optical cameras (SHOK) and the ultra-fast flash observatory (UFFO) onboard the Lomonosov satellite are intended for the observation of GRBs, and in particular, their prompt emissions. The BDRG gamma-ray spectrometer is designed to obtain the temporal and spectral information of GRBs in the energy range of 10-3000 keV as well as to provide GRB triggers on several time scales (10 ms, 1 s and 20 s) for ground and space telescopes, including the UFFO and SHOK. The BDRG instrument consists of three identical detector boxes with axes shifted by 90° from each other. This configuration allows us to localize a GRB source in the sky with an accuracy of ˜ 2°. Each BDRG box contains a phoswich NaI(Tl)/CsI(Tl) scintillator detector. A thick CsI(Tl) crystal in size of \\varnothing 130 × 17 mm is placed underneath the NaI(Tl) as an active shield in the soft energy range and as the main detector in the hard energy range. The ratio of the CsI(Tl) to NaI(Tl) event rates at varying energies can be employed as an independent metric to distinguish legitimate GRB signals from false positives originating from electrons in near-Earth vicinities. The data from three detectors are collected in a BA BDRG information unit, which generates a GRB trigger and a set of data frames in output format. The scientific data output is ˜ 500 Mb per day, including ˜ 180 Mb of continuous data for events with durations in excess of 100 ms for 16 channels in each detector, detailed energy spectra, and sets of frames with ˜ 5 Mb of detailed information for each burst-like event. A number of pre-flight tests including those for the trigger algorithm and calibration were carried out to confirm the reliability of the BDRG for operation in space.

  18. Nonlinear theory of a free electron laser with a helical wiggler and an axial guide magnetic field

    Directory of Open Access Journals (Sweden)

    N. S. Ginzburg

    2013-09-01

    Full Text Available A 1D nonlinear theory of a free electron laser (FEL with a helical wiggler and an axial guide magnetic field is developed based on averaged equations of the electron motion. By averaging we separated two different cases of the e-beam/rf-wave interaction. The first one corresponds to the traditional wiggler synchronism (resonance of rf wave with the electrons moving along stationary helical trajectories. The second one corresponds to combination resonances distinguishing by excitation of oscillation of the electrons near the stationary helical trajectory. Comparative analysis of the FEL operation in different regimes has been studied under the traditional wiggler synchronism condition. It was shown that FELs operated far from cyclotron resonance (including a reversed guide field orientation possess low sensitivity to the initial velocity spread in the driving beam resulting in high electron efficiency. In contrast, under the weak guide field (the gyrofrequency is less than the bounce frequency of a conventional orientation, the FEL efficiency is restricted by a significant increase in the transverse velocity of the electrons during the interaction with the rf wave that results in violation of the synchronism conditions and is accompanied by electron current losses. An additional mechanism of FEL efficiency enhancement under the conventional guide field orientation in the conditions when the gyrofrequency is higher than the bounce frequency, based on the dependence of the effective mass of the oscillating electrons on their energy, was demonstrated. Results of the theoretical analysis are compared with the results of experimental studies of FEL oscillators. The specific features of energy extraction from the electron beam under condition of an abnormal Doppler effect in the case of the combination resonance are described. This regime is beneficial to increase radiation frequency keeping wiggler period and electron energies.

  19. Field scale simulation of axial hydrokinetic turbines in a natural marine environment

    Science.gov (United States)

    Chawdhary, Saurabh; Angelidis, Dionysios; Shen, Lian; Sotiropoulos, Fotis

    2016-11-01

    Commercialization of marine and hydrokinetic (MHK) energy technologies is still in the development stage. Existing technologies need fundamental research to enable efficient energy extraction from identified MHK sites. We propose a large eddy simulation (LES)-based framework to investigate the site-specific flow dynamics past MHK arrays in a real-life marine environment. To this end, we use advanced computational tools developed at the Saint Anthony Falls Laboratory (SAFL) to resolve the vast range of scales present in the flow. The new generation unstructured Cartesian flow solver, coupled with a sharp interface immersed boundary method for 3D incompressible flows, is used to numerically investigate New York City's East River, where an array of MHK turbines is to be deployed as part of the Roosevelt Island Tidal Energy (RITE) Project. Multi-resolution simulations on locally refined grids are used to simulate the flow in a section of the East River with detailed river bathymetry and inset turbines at field scale. The results are analyzed in terms of the wake recovery, overall wake dynamics, and the power produced by the turbines. These results will help develop design guidelines for the site-specific turbine array configuration. This work was supported by NSF Grant IIP-1318201.

  20. Computations for nanofluid flow near a stretchable rotating disk with axial magnetic field and convective conditions

    Directory of Open Access Journals (Sweden)

    A. Mushtaq

    Full Text Available In this paper, the classical Von Kármán problem of infinite disk is extended when an electrically conducting nanofluid fills the space above the rotating disk which also stretches uniformly in the radial direction. Buongiorno model is considered in order to incorporate the novel Brownian motion and thermophoresis effects. Heat transport mechanism is modeled through more practically feasible convective conditions while Neumann type condition for nanoparticle concentration is adopted. Modified Von Kármán transformations are utilized to obtain self-similar differential system which is treated through a numerical method. Stretching phenomenon yields an additional parameter c which compares the stretch rate with the swirl rate. The effect of parameter c is to reduce the temperature and nanoparticle concentration profiles. Torque required to main steady rotation of the disk increases for increasing values of c while an improvement in cooling rate is anticipated in case of radial stretching, which is important in engineering processes. Brownian diffusion does not influence the heat flux from the stretching wall. Moreover, the wall heat flux has the maximum value for the situation in which thermoporetic force is absent. Keywords: Rotating disk, Nanofluid, Buongiorno model, Shooting method, Convective condition, Magnetic field

  1. Axial myopathy

    DEFF Research Database (Denmark)

    Witting, Nanna; Andersen, Linda K; Vissing, John

    2016-01-01

    Classically, myopathies are categorized according to limb or cranial nerve muscle affection, but with the growing use of magnetic resonance imaging it has become evident that many well-known myopathies have significant involvement of the axial musculature. New disease entities with selective axial...

  2. Numerical simulations of a cylinder wake under a strong axial magnetic field

    Science.gov (United States)

    Dousset, Vincent; Pothérat, Alban

    2008-01-01

    We study the flow of a liquid metal in a square duct past a circular cylinder in a strong externally imposed magnetic field. In these conditions, the flow is quasi-two-dimensional, which allows us to model it using a two-dimensional (2D) model. We perform a parametric study by varying the two control parameters Re and Ha (Ha2 is the ratio of Lorentz to viscous forces) in the ranges [0…6000] and [0…2160], respectively. The flow is found to exhibit a sequence of four regimes. The first three regimes are similar to those of the non-magnetohydrodynamic (non-MHD) 2D circular wake, with transitions controlled by the friction parameter Re /Ha. The fourth one is characterized by vortices raising from boundary layer separations at the duct side walls, which strongly disturbs the Kármán vortex street. This provides the first explanation for the breakup of the 2D Kármán vortex street first observed experimentally by Frank, Barleon, and Müller [Phys. Fluids 13, 2287 (2001)]. We also show that, for high values of Ha (Ha⩾1120), the transition to the fourth regime occurs for Re ∝0.56Ha, and that it is accompanied by a sudden drop in the Strouhal number. In the first three regimes, we show that the drag coefficient and the length of the steady recirculation regions located behind the cylinder are controlled by the parameter Re /Ha4/5. Also, the free shear layer that separates the recirculation region from the free stream is similar to a free MHD parallel layer, with a thickness of the order of Ha-1/2 that is quite different to that of the non-MHD case, and therefore strongly influences the dynamics of this region. We also present one case at Re =3×104 and Ha =1120, where this layer undergoes an instability of the Kelvin-Helmholtz-type.

  3. Ultrasonic field generated by a transducer non axially located at the end of a cylindrical waveguide surrounded by an elastic medium

    Science.gov (United States)

    Yaacoubi, Slah; Ducasse, Éric; Deschamps, Marc; Laguerre, Laurent

    2010-01-01

    The calculation of the ultrasonic field generated by a transducer non axially located at the end of a semi-infinite cylindrical waveguide surrounded by an elastic medium is performed. Numerical results representing power flow, waveforms and dispersion diagrams to highlight non-axisymmetric waves are discussed.

  4. Gd-123 bulk field pole magnets cooled with condensed neon for axial-gap type synchronous motor

    International Nuclear Information System (INIS)

    Sano, T.; Kimura, Y.; Sugyo, D.; Yamaguchi, K.; Izumi, M.; Ida, T.; Sugimoto, H.; Miki, M.

    2008-01-01

    We have conducted to develop an axial-gap type synchronous propulsion motor with Gd-bulk HTS field pole magnets. It has been established on the fundamental technology upon the liquid nitrogen cooling. In the present study, we aimed an output improvement of the motor by the magnetic flux density enhancement of the bulk HTS, in a word, the trapped magnetic flux density on the HTS bulk. The output of the motor depends on the physics of the motor, the magnetic flux density, and the electric current density flowing through the armature. We have employed a condensed neon with a helium GM refrigerator. The bulk HTS placed on the rotor disk inside the motor frame was successfully cooled down with circulating condensed neon. The temperature at the bulk HTS surface reached 38 K. Upon magnetization, we developed controlled magnetic field density distribution coil (CMDC) composed of a couple of pulsed copper armature coil. In the magnetization procedure, with decreasing magnetization temperature, minute by minute, after Sander and Kamijyo that the step cooling magnetization method was used. In addition, the CMDC coil has enabled to control the applied flux distribution. Three parameters as the temperature, the applied magnetic field, and the effective applied flux density distribution were changed within eight times pulsed magnetizations in total. Up to 4th pulsed magnetization, we kept (1st step) high temperature, and subsequent pulsed magnetizations were done at low temperature. As a result, the highest maximum trapped magnetic flux density was reached 1.31 T, about 2.5 times compared to the value obtained upon cooling with liquid nitrogen. Consequently, the output of the motor has been enhanced to 25 kW from 10 kW taken in the previous operation

  5. Continuous Measurements of Dissolved Ne, Ar, Kr, and Xe Ratios with a Field-Deployable Gas Equilibration Mass Spectrometer.

    Science.gov (United States)

    Manning, Cara C; Stanley, Rachel H R; Lott, Dempsey E

    2016-03-15

    Noble gases dissolved in natural waters are useful tracers for quantifying physical processes. Here, we describe a field-deployable gas equilibration mass spectrometer (GEMS) that provides continuous, real-time measurements of Ne, Ar, Kr, and Xe mole ratios in natural waters. Gas is equilibrated with a membrane contactor cartridge and measured with a quadrupole mass spectrometer, after in-line purification with reactive metal alloy getters. We use an electron energy of 35 V for Ne to eliminate isobaric interferences, and a higher electron energy for the other gases to improve sensitivity. The precision is 0.7% or better and 1.0% or better for all mole ratios when the instrument is installed in a temperature-controlled environment and a variable-temperature environment, respectively. In the lab, the accuracy is 0.9% or better for all gas ratios using air as the only calibration standard. In the field (and/or at greater levels of disequilbrium), the accuracy is 0.7% or better for Ne/Kr, Ne/Ar, and Ar/Kr, and 2.5% or better for Ne/Xe, Ar/Xe, and Kr/Xe using air as the only calibration standard. The field accuracy improves to 0.6% or better for Ne/Xe, Ar/Xe, and Kr/Xe when the data is calibrated using discrete water samples run on a laboratory-based mass spectrometer. The e-folding response time is 90-410 s. This instrument enables the collection of a large number of continuous, high-precision and accuracy noble gas measurements at substantially reduced cost and labor compared to traditional methods.

  6. Ignition method of corona discharge with modulation of the field in ion source of ion mobility spectrometer

    International Nuclear Information System (INIS)

    Gromov, Evgeniy

    2011-01-01

    The new method for the ignition of the corona discharge has been developed, which improves the stability of the ion mobility spectrometer and the resolution of the instrument. The system of forming a corona discharge without additional electrodes, which are used in a number of known structures for the pre-ionization, has been developed. This simplifies the design of the proposed source and an electronic control circuit. IMS technology is widely used in different civil and military fields for vapor-phase detection of explosive, narcotics, chemical warfare agents, biology molecules and so on. There are set of methods whose are used for the ionization of molecules under analysis. They are the following: radioactive ionization, ultraviolet photoionization, laser ionization, electric field ionization, corona spray ionization, electro spray ionization, roentgen ionization, and surface ionization. All these methods has their own advantages and disadvantages. A comparing of ion mobility spectra of non-polar hydrocarbons for photoionization, corona discharge ionization and 63 Ni ionization, had carried in. In our work we have investigated four types of IMS spectrometers whose use different sources for molecules under analysis ionization. They use radioactive ionization, ultraviolet photoionization, laser ionization, and roentgen ionization. The traditional explosives had investigated in experiments. In electricity, a corona discharge is an electrical discharge brought on by the ionization of a fluid surrounding a conductor, which occurs when the potential gradient (the strength of the electric field) exceeds a certain value, but conditions are insufficient to cause complete electrical breakdown or arcing.

  7. Numerical simulation of turbulent Taylor-Couette flow between conducting cylinders in an axial magnetic field at low magnetic Reynolds number

    Science.gov (United States)

    Leng, Xueyuan; Kolesnikov, Yurii B.; Krasnov, Dmitry; Li, Benwen

    2018-01-01

    The effect of an axial homogeneous magnetic field on the turbulence in the Taylor-Couette flow confined between two infinitely long conducting cylinders is studied by the direct numerical simulation using a periodic boundary condition in the axial direction. The inner cylinder is rotating, and the outer one is fixed. We consider the case when the magnetic Reynolds number Rem ≪ 1, i.e., the influence of the induced magnetic field on the flow is negligible that is typical for industry and laboratory study of liquid metals. Relevance of the present study is based on the similarity of flow characteristics at moderate and high magnetic field for the cases with periodic and end-wall conditions at the large flow aspect ratio, as proven in the earlier studies. Two sets of Reynolds numbers 4000 and 8000 with several Hartmann numbers varying from 0 to 120 are employed. The results show that the mean radial induced electrical current, resulting from the interaction of axial magnetic field with the mean flow, leads to the transformation of the mean flow and the modification of the turbulent structure. The effect of turbulence suppression is dominating at a strong magnetic field, but before reaching the complete laminarization, we capture the appearance of the hairpin-like structures in the flow.

  8. Magnetic resonance in zero-field: construction of a spectrometer, evaluation of a method for structure studies

    International Nuclear Information System (INIS)

    Llor, M.

    1987-01-01

    The method known as Nuclear Resonance in the zero-field, applied to the spectral analysis of powders, is discussed. In the method, the anisotropy due to the preferential direction of the magnetic field is suppressed, but a high sensitivity is keeped. For powders spectra, the process allows the obtention resolutions, of dipolar and quadrupolar couplings, in the range of those only obtained on monocrystals under strong fields. By suitable magnetic field oscillations, and by the effect of the high field on the RMN signal, the transient evolutions of the spins are obtained. Concerning the absence of a preferred direction in the zero-field, a powder or the monocrystals show nearly the same behavior. In such conditions, a much more interesting spectra than those from a powder in a strong field, can be obtained. The RMN spectrometer is described. The possibilities, the experimental and theoretical limits of the proposed method, are analyzed. Applications on dipolar (proton and phosphor) and quadrupolar (deuterium) interactions, on hydrated salts and on cyclophasphazenes are carried out [fr

  9. Axial spondyloarthritis.

    Science.gov (United States)

    Sieper, Joachim; Braun, Jürgen; Dougados, Maxime; Baeten, Dominique

    2015-07-09

    The term axial spondyloarthritis covers both non-radiographic disease and radiographic disease (also known as ankylosing spondylitis). Some studies have been performed to investigate the prevalence of axial spondyloarthritis, although most are limited to patients with radiographic disease. A strong genetic association has been shown between axial spondyloarthritis and human leukocyte antigen-B27 (HLA-B27), but the pathogenetic role of HLA-B27 has not yet been clarified. Tumour necrosis factor (TNF), IL-17, IL-23 and downstream pathways also seem to be important - based on the good results of therapies directed against these molecules - but their exact role in the inflammatory process is also not yet clear. Elucidating the interaction between osteoproliferation and inflammation will be crucial for the prevention of long-term structural damage of the bone. The development of new criteria for classification, diagnosis and screening of patients with axial spondyloarthritis will enable earlier intervention for this chronic inflammatory disease. MRI has become an important tool for the early detection of axial spondyloarthritis. NSAIDs and TNF blockers are effective therapies, including in the early non-radiographic stage. Therapeutic blockade of IL-17 or IL-23 seems to be a promising new treatment option. Tools for measuring quality of life in axial spondyloarthritis have become relevant to assess the impact that the disease has on patients. These diagnostic and therapeutic advances will continue to change the management of axial spondyloarthritis, and new insights into the disease pathogenesis will hopefully accelerate this process. For an illustrated summary of this Primer, visit: http://go.nature.com/51b1af.

  10. Prototype development and field measurements of high etendue spatial heterodyne imaging spectrometer

    Science.gov (United States)

    Cai, Qisheng; Xiangli, Bin; Huang, Min; Han, Wei; Pei, Linlin; Bu, Meixia

    2018-03-01

    High etendue spatial heterodyne imaging spectrometer (HESHIS) is a new pushbroom Fourier transform hyperspectral imager with no moving parts. It is based on a Sagnac interferometer combined with a pair of parallel gratings. In this paper, the basic principle of HESHIS is reviewed and the first prototype of HESHIS is designed and developed. The spectral band of this prototype is designed at O2-A band (757 nm to 777 nm) and the average spectral resolution is 0.04 nm. Using the prototype, the pushbroom imaging experiments are carried out and the original interference images are obtained. The spectral data cube is generated using spectrum reconstruction method and high-resolution spectra are achieved.

  11. The degrees of tri-axial orientation in RE-doped Bi2212 powders aligned in a modulated rotation magnetic field

    International Nuclear Information System (INIS)

    Nagai, R.; Horii, S.; Maeda, T.; Haruta, M.; Shimoyama, J.

    2013-01-01

    Highlights: •Tri-axial magnetic alignment of Bi2212 with rare-earth (RE) doping was attempted. •Magnetization axes depended on the type of doped RE ions. •RE-doping increased degrees of inplane orientation and inplane magnetic anisotropy. -- Abstract: We report relationship between the degrees of tri-axial orientation and doping level of rare earth (RE) ions in Bi 2 Sr 2 (Ca 1−x RE x )Cu 2 O y (RE-doped Bi2212; RE = Dy, Ho, Er and Tm) powder samples aligned under a modulated rotation magnetic field (MRF) of 10 T. Tri-axial magnetic alignment of the RE-doped Bi2212 with x = 0–0.5 was achieved by single-ion magnetic anisotropy of RE 3+ and tri-axial magnetic anisotropy induced by modulation microstructure in a grain level. The degrees of in-plane and c-axis orientation with ∼3° were achieved for the case of the Tm-doped Bi2212 with x = 0.5. The findings in the present study give us important information for the fabrication of triaxially oriented Bi-based cuprate superconductor materials by the magneto-scientific process

  12. The SPEDE spectrometer

    Science.gov (United States)

    Papadakis, P.; Cox, D. M.; O'Neill, G. G.; Borge, M. J. G.; Butler, P. A.; Gaffney, L. P.; Greenlees, P. T.; Herzberg, R.-D.; Illana, A.; Joss, D. T.; Konki, J.; Kröll, T.; Ojala, J.; Page, R. D.; Rahkila, P.; Ranttila, K.; Thornhill, J.; Tuunanen, J.; Van Duppen, P.; Warr, N.; Pakarinen, J.

    2018-03-01

    The electron spectrometer, SPEDE, has been developed and will be employed in conjunction with the Miniball spectrometer at the HIE-ISOLDE facility, CERN. SPEDE allows for direct measurement of internal conversion electrons emitted in-flight, without employing magnetic fields to transport or momentum filter the electrons. Together with the Miniball spectrometer, it enables simultaneous observation of γ rays and conversion electrons in Coulomb excitation experiments using radioactive ion beams.

  13. FieldSpec: A field portable mass spectrometer prototype for high frequency measurements of δ (2) H and δ (18) O ratios in water

    Science.gov (United States)

    López Días, Veneranda; Quang Hoang, Hung; Martínez-Carreras, Núria; Barnich, François; Wirtz, Tom; Pfister, Laurent; McDonnell, Jeffrey

    2016-04-01

    Hydrological studies relying on stable water isotopes to better understand water sources, flowpaths and transit times are currently limited by the coarse temporal resolution of sampling and analysis protocols. At present, two kinds of lab-based instruments are used : (i) the standard isotope ratio mass spectrometers (IRMS) [1] and (ii) the laser-based instruments [2, 3]. In both cases, samples need to be collected in the field and then transferred to the laboratory for the water isotopic ratio measurements (even further complex sample preparation is required for the IRMS). Hence, past and ongoing research targets the development of field deployable instruments for measuring stable water isotopes at high temporal frequencies. While recent studies have demonstrated that laser-based instruments may be taken to the field [4, 5], their size and power consumption still restrict their use to sites equipped with mains power or generators. Here, we present progress on the development of a field portable mass spectrometer (FieldSpec) for direct high frequency measurements of δ2H and δ18O ratios in water. The FieldSpec instrument is based upon the use of a double focusing magnetic sector mass spectrometer in combination with an electron impact ion source and a membrane dual inlet system. The instrument directly collects liquid water samples in the field, which are then converted into water vapour before being injected into the mass spectrometer for the stable isotope analysis. δ2H and δ18O are derived from the measured mass spectra. All the components are arranged in a vacuum case having a suit case type dimension with portable electronics and battery. Proof-of-concept experiments have been carried out to characterize the instrument. The results show that the FieldSpec instrument has good linearity (R2 = 0.99). The reproducibility of the instrument ranges between 1 and 4 ‰ for δ2H and between 0.1 and 0.4 ‰ for δ18O isotopic ratio measurements. A measurement

  14. SPITZER INFRARED SPECTROMETER 16 μm OBSERVATIONS OF THE GOODS FIELDS

    International Nuclear Information System (INIS)

    Teplitz, Harry I.; Chary, Ranga; Elbaz, David; Le Floc'h, Emeric; Dickinson, Mark; Bridge, Carrie; Howell, Justin H.; Siana, Brian; Colbert, James; Scarlata, Claudia; Frayer, David T.; Koo, David C.; Phillips, Andrew; Papovich, Casey; Spinrad, Hyron; Stern, Daniel

    2011-01-01

    We present Spitzer 16 μm imaging of the Great Observatories Origins Deep Survey (GOODS) fields. We survey 150 arcmin 2 in each of the two GOODS fields (North and South), to an average 3σ depth of 40 and 65 μJy, respectively. We detect ∼1300 sources in both fields combined. We validate the photometry using the 3-24 μm spectral energy distribution of stars in the fields compared to Spitzer spectroscopic templates. Comparison with ISOCAM and AKARI observations in the same fields shows reasonable agreement, though the uncertainties are large. We provide a catalog of photometry, with sources cross-correlated with available Spitzer, Chandra, and Hubble Space Telescope data. Galaxy number counts show good agreement with previous results from ISOCAM and AKARI with improved uncertainties. We examine the 16-24 μm flux ratio and find that for most sources it lies within the expected locus for starbursts and infrared luminous galaxies. A color cut of S 16 /S 24 >1.4 selects mostly sources which lie at 1.1 -2 sr -1 .

  15. Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

    Science.gov (United States)

    Xiang, B.; Nelson, D. D.; McManus, J. B.; Zahniser, M. S.; Wehr, R. A.; Wofsy, S. C.

    2014-12-01

    We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO2) with high precision (0.02 μmol mol-1, or ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell with known CO2 column density. Compared to a previously described prototype, the field instrument has better stability and benefits from more precise thermal control of the optics and more accurate pressure measurements in the sample cell (at the mTorr level). The instrument has been deployed at a long-term ecological research site (the Harvard Forest, USA), where it has measured for 8 months without on-site calibration and with minimal maintenance, showing drift bounds of less than 0.1 ppm. Field measurements agree well with those of a commercially available cavity ring-down CO2 instrument (Picarro G2301) run with a standard calibration protocol. This field test demonstrates that ABC is capable of performing high-accuracy, unattended, continuous field measurements with minimal use of reference gas cylinders.

  16. IN5 Polarisation Option (IPOP) and HIgh FIeld Magnet Option (HIFIMO) for the IN5 time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Ollivier, J.; Mutka, H.

    2011-01-01

    The new secondary spectrometer for the cold neutron time-of-flight (ToF) instrument IN5 was built with non-magnetic material, keeping in mind the upgrade option of polarisation analysis (PA) and the possibility of applying high continuous magnetic fields. The refurbished instrument has a high incident flux and elevated count-rate and offers a unique opportunity for applying polarised neutron methods for high resolution inelastic scattering, including single crystal investigations. On IN5 the polarised option would use the PASTIS concept of three sets of compact perpendicular coils (see the PANTHER proposal) allowing XYZPA and a 3 He analyser banana. As for high magnetic fields: a magnet suitable for ToF instruments must place a minimal amount of material in the incoming and outgoing beams and provide a large asymmetric view towards the detectors. An homogeneous field area of about 20 mm diameter over 30 mm height is also required. There is a size constraint set by the 800 mm diameter sample chamber and the optimal angular acceptance towards the detectors is -12 degrees / +135 degrees in the equatorial plane and +/- 22 degrees in the vertical direction

  17. Measurements and Monte Carlo calculations with the extended-range Bonner sphere spectrometer at high-energy mixed fields

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00406842; Bay, Aurelio; Silari, Marco; Aroua, Abbas

    The use of spectrometry to provide information for neutron radiation protection has become an increasingly important activity over recent years. The need for spectral data arises because neither area survey instruments nor personal dosimeters give the correct dose equivalent results at all neutron energies. It is important therefore to know the spectra of the fields in which these devices are used. One of the systems most commonly employed in neutron spectrometry and dosimetry is the Bonner Sphere Spectrometers (BSS). The extended- range BSS that was used for this work, consists of 7 spheres with an overall response to neutrons up to 2 GeV. A 3He detector is used as a thermal counter in the centre of each sphere. In the context of this thesis the BSS was calibrated in monoenergetic neutron fields at low and intermediate energies. It was also used for measurements in several high energy mixed fields. These measurements have led to the calculation of neutron yields and spectral fluences from unshielded targets....

  18. Time-of-flight mass spectrometer using an imaging detector and a rotating electric field

    International Nuclear Information System (INIS)

    Katayama, Atsushi; Kameo, Yutaka; Nakashima, Mikio

    2008-01-01

    A new technique for minor isotope analysis that uses a rotating electric field and an imaging detector is described. The rotating electric field is generated by six cylindrically arranged plane electrodes with multi-phase sinusoidal wave voltage. When ion packets that are discriminated by time-of-flight enter the rotating electric field, they are circularly deflected, rendering a spiral image on the fluorescent screen of the detector. This spiral image represents m/z values of ions as the position and abundance of ions as brightness. For minor isotopes analyses, the micro channel plate detector under gate control operation is used to eliminate the influence of high intensity of major isotopes. (author)

  19. Triacetone triperoxide detection using low reduced-field proton transfer reaction mass spectrometer

    Science.gov (United States)

    Shen, Chengyin; Li, Jianquan; Han, Haiyan; Wang, Hongmei; Jiang, Haihe; Chu, Yannan

    2009-08-01

    Proton transfer reaction mass spectrometry (PTR-MS) was applied to on-line detection of the explosive triacetone triperoxide (TATP) using a discharge gas of water vapor or alternative ammonia in the ion source. The dependence of ionic intensity on reduced-field in the drift tube was investigated, and the results indicate that an irregular operation using low reduced-field can enhance TATP detection due to reduced collision-induced dissociation in the drift tube. When water vapor is used as the discharge gas, the characteristic ions for TATP identification are [TATP + H]+ which are detectable at a reduced-field about 50 Td. If ammonia is the discharge gas, PTR-MS exhibits a better sensitivity, the explosive TATP can be discriminated according to the adduct ions [TATP + NH4]+, and a limit of detection at ppb level can be achieved at a reduced-field around 100 Td in this PTR-MS apparatus. PTR-MS is suggested as a potential tool for on-site detection of the explosive TATP with the advantages of rapid response and high sensitivity without sample pretreatment.

  20. Standoff Laser-Induced Breakdown Spectroscopy (LIBS) Using a Miniature Wide Field of View Spatial Heterodyne Spectrometer with Sub-Microsteradian Collection Optics.

    Science.gov (United States)

    Barnett, Patrick D; Lamsal, Nirmal; Angel, S Michael

    2017-04-01

    A spatial heterodyne spectrometer (SHS) is described for standoff laser-induced breakdown spectroscopy (LIBS) measurements. The spatial heterodyne LIBS spectrometer (SHLS) is a diffraction grating based interferometer with no moving parts that offers a very large field of view, high light throughput, and high spectral resolution in a small package. The field of view of the SHLS spectrometer is shown to be ∼1° in standoff LIBS measurements. In the SHLS system described here, the collection aperture was defined by the 10 mm diffraction gratings in the SHS and standoff LIBS measurements were made up to 20 m with no additional collection optics, corresponding to a collection solid angle of 0.2 μsr, or f/2000, and also using a small telescope to increase the collection efficiency. The use of a microphone was demonstrated to rapidly optimize laser focus for 20 m standoff LIBS measurements.

  1. Neutron Spectrometer Prospecting in the Mojave Volatiles Project Analog Field Test

    Science.gov (United States)

    Elphic, R. C.; Heldmann, J. L.; Colaprete, A.; Hunt, D. R.; Deans, M. C.; Lim, D. S.; Foil, G.; Fong, T.

    2015-01-01

    We know that volatiles are sequestered at the poles of the Moon. While we have evidence of water ice and a number of other compounds based on remote sensing, the detailed distribution, and physical and chemical form are largely unknown. Additional orbital studies of lunar polar volatiles may yield further insights, but the most important next step is to use landed assets to fully characterize the volatile composition and distribution at scales of tens to hundreds of meters. To achieve this range of scales, mobility is needed. Because of the proximity of the Moon, near real-time operation of the surface assets is possible, with an associated reduction in risk and cost. This concept of operations is very different from that of rovers on Mars, and new operational approaches are required to carry out such real-time robotic exploration. The Mojave Volatiles Project (MVP) was a Moon-Mars Analog Mission Activities (MMAMA) program project aimed at (1) determining effective approaches to operating a real-time but short-duration lunar surface robotic mission, and (2) performing prospecting science in a natural setting, as a test of these approaches. Here we describe some results from the first such test, carried out in the Mojave Desert between 16 and 24 October, 2014. The test site was an alluvial fan just E of the Soda Mountains, SW of Baker, California. This site contains desert pavements, ranging from the late Pleistocene to early-Holocene in age. These pavements are undergoing dissection by the ongoing development of washes. A principal objective was to determine the hydration state of different types of desert pavement and bare ground features. The mobility element of the test was provided by the KREX-2 rover, designed and operated by the Intelligent Robotics Group at NASA Ames Research Center. The rover-borne neutron spectrometer measured the neutron albedo at both thermal and epithermal energies. Assuming uniform geochemistry and material bulk density, hydrogen as

  2. Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

    OpenAIRE

    B. Xiang; D. D. Nelson; J. B. McManus; M. S. Zahniser; R. Wehr; S. C. Wofsy

    2014-01-01

    We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO2) with high precision (0.02 ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell with known...

  3. Wide field imaging spectrometer for ESA's future X-ray mission: XEUS

    CERN Document Server

    Strüder, L

    1999-01-01

    An active pixel sensor (APS) based on the DEpleted P-channel junction Field Effect Transistor (DEPFET) concept will be described as a potential wide field imager for ESA's high resolution, high throughput mission: 'X-ray Evolving Universe Spectroscopy' (XEUS). It comprises a parallel multichannel readout, low noise at high speed readout, backside illumination and a fill factor of 100% over the whole field of view. The depleted thickness will be 500 microns. These design parameters match the scientific requirements of the mission. The fabrication techniques of the DEPFET arrays are related to the high resistivity process of the X-ray pn-CCDs. Potential extensions of the already realized DEPFET structures are a non-destructive repetitive readout of the signal charges. This concept will be presented. As an alternative solution, frame store pn-CCDs are considered having the same format and pixel sizes as the proposed DEPFET arrays. Their development is a low risk, straightforward continuation of the XMM devices. ...

  4. Monolithic spectrometer

    Science.gov (United States)

    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.

  5. Development and field testing of a rapid and ultra-stable atmospheric carbon dioxide spectrometer

    OpenAIRE

    B. Xiang; D. D. Nelson; J. B. McManus; M. S. Zahniser; R. A. Wehr; S. C. Wofsy

    2014-01-01

    We present field test results for a new spectroscopic instrument to measure atmospheric carbon dioxide (CO2) with high precision (0.02 μmol mol−1, or ppm at 1 Hz) and demonstrate high stability (within 0.1 ppm over more than 8 months), without the need for hourly, daily, or even monthly calibration against high-pressure gas cylinders. The technical novelty of this instrument (ABsolute Carbon dioxide, ABC) is the spectral null method using an internal quartz reference cell wi...

  6. Technical Note: Use of a beam width probe in an Aerosol Mass Spectrometer to monitor particle collection efficiency in the field

    OpenAIRE

    Salcedo, D.; Onasch, T. B.; Canagaratna, M. R.; Dzepina, K.; Huffman, J. A.; Jayne, J. T.; Worsnop, D. R.; Kolb, C. E.; Weimer, S.; Drewnick, F.; Allan, J. D.; Delia, A. E.; Jimenez, J. L.

    2007-01-01

    International audience; Two Aerodyne Aerosol Mass Spectrometers (Q-AMS) were deployed in Mexico City, during the Mexico City Metropolitan Area field study (MCMA-2003) from 29 March?4 May 2003 to investigate particle concentrations, sources, and processes. We report the use of a particle beam width probe (BWP) in the field to quantify potential losses of particles due to beam broadening inside the AMS caused by particle shape (nonsphericity) and particle size. Data from this probe show that no...

  7. New automated magnetic electron X-ray spectrometers: spectometer with technological accessories and manipulators, spectrometer for investigation of melts

    International Nuclear Information System (INIS)

    Shabanova, I.N.; Dobysheva, L.V.; Varganov, D.V.

    1986-01-01

    Two unique automated magnetic electron X-ray spectrometers are described: spectrometer with technological aceessories and spectrometer for investigation of melts. The spectrometer design is based on the model of precision iron-free beta spectrometer with double focusing by nonuniform transverse magnetic field of axial symmetry. Characterictic X-radiation with energy depending on the choice of anode material is used for electron excitation in a sample. Photoelectrons escape from sample surface at 90 deg angle from the direction of quantum incidence angle and enter the analyzer through the inlet slit. The width of analyzed layer depends at that on quantum incidence angle and changes from tens uo to hundred Angstrom. Energy analyzer magnetic field produced in a gap between two coaxial coils provides double electron focusing. Electrons with different energy are focused depending on the current in coils creating the field. Focused electrons enter the detector through the outlet slit of energy analyzer. The detector signals enter pre-amplifier and then the scaling unit

  8. A table-top PXI based low-field spectrometer for solution dynamic nuclear polarization.

    Science.gov (United States)

    Biller, Joshua R; Stupic, Karl F; Moreland, J

    2018-03-01

    We present the development of a portable dynamic nuclear polarization (DNP) instrument based on the PCI eXtensions for Instrumentation platform. The main purpose of the instrument is for study of 1 H polarization enhancements in solution through the Overhauser mechanism at low magnetic fields. A DNP probe set was constructed for use at 6.7 mT, using a modified Alderman-Grant resonator at 241 MHz for saturation of the electron transition. The solenoid for detection of the enhanced 1 H signal at 288 kHz was constructed with Litz wire. The largest observed 1 H enhancements (ε) at 6.7 mT for 14 N-CTPO radical in air saturated aqueous solution was ε~65. A concentration dependence of the enhancement is observed, with maximum ε at 5.5 mM. A low resonator efficiency for saturation of the electron paramagnetic resonance transition results in a decrease in ε for the 10.3 mM sample. At high incident powers (42 W) and long pump times, capacitor heating effects can also decrease the enhancement. The core unit and program described here could be easily adopted for multi-frequency DNP work, depending on available main magnets and selection of the "plug and play" arbitrary waveform generator, digitizer, and radiofrequency synthesizer PCI eXtensions for Instrumentatione cards. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  9. Design optimization of an axial-field eddy-current magnetic coupling based on magneto-thermal analytical model

    Directory of Open Access Journals (Sweden)

    Fontchastagner Julien

    2018-03-01

    Full Text Available This paper presents a design optimization of an axial-flux eddy-current magnetic coupling. The design procedure is based on a torque formula derived from a 3D analytical model and a population algorithm method. The main objective of this paper is to determine the best design in terms of magnets volume in order to transmit a torque between two movers, while ensuring a low slip speed and a good efficiency. The torque formula is very accurate and computationally efficient, and is valid for any slip speed values. Nevertheless, in order to solve more realistic problems, and then, take into account the thermal effects on the torque value, a thermal model based on convection heat transfer coefficients is also established and used in the design optimization procedure. Results show the effectiveness of the proposed methodology.

  10. Characterization of extended range Bonner Sphere Spectrometers in the CERF high-energy broad neutron field at CERN

    Science.gov (United States)

    Agosteo, S.; Bedogni, R.; Caresana, M.; Charitonidis, N.; Chiti, M.; Esposito, A.; Ferrarini, M.; Severino, C.; Silari, M.

    2012-12-01

    The accurate determination of the ambient dose equivalent in the mixed neutron-photon fields encountered around high-energy particle accelerators still represents a challenging task. The main complexity arises from the extreme variability of the neutron energy, which spans over 10 orders of magnitude or more. Operational survey instruments, which response function attempts to mimic the fluence-to-ambient dose equivalent conversion coefficient up to GeV neutrons, are available on the market, but their response is not fully reliable over the entire energy range. Extended range rem counters (ERRC) do not require the exact knowledge of the energy distribution of the neutron field and the calibration can be done with a source spectrum. If the actual neutron field has an energy distribution different from the calibration spectrum, the measurement is affected by an added uncertainty related to the partial overlap of the fluence-to-ambient dose equivalent conversion curve and the response function. For this reason their operational use should always be preceded by an "in-field" calibration, i.e. a calibration made against a reference instrument exposed in the same field where the survey-meter will be employed. In practice the extended-range Bonner Sphere Spectrometer (ERBSS) is the only device which can serve as reference instrument in these fields, because of its wide energy range and the possibility to assess the neutron fluence and the ambient dose equivalent (H*(10)) values with the appropriate accuracy. Nevertheless, the experience gained by a number of experimental groups suggests that mandatory conditions for obtaining accurate results in workplaces are: (1) the use of a well-established response matrix, thus implying validation campaigns in reference monochromatic neutrons fields, (2) the expert and critical use of suitable unfolding codes, and (3) the performance test of the whole system (experimental set-up, elaboration and unfolding procedures) in a well

  11. Characterization of the neutron field at the ISIS-VESUVIO facility by means of a bonner sphere spectrometer

    Science.gov (United States)

    Bedogni, Roberto; Esposito, Adolfo; Andreani, Carla; Senesi, Roberto; De Pascale, Maria Pia; Picozza, Piergiorgio; Pietropaolo, Antonino; Gorini, Giuseppe; Frost, Christopher D.; Ansell, Stewart

    2009-12-01

    One of the more actual and promising fields of applied neutron physics is the investigation of the malfunctions induced by high-energy neutrons naturally present in the atmosphere in electronic devices, called single event effects (SEE). These studies are of primary importance for the design of devices that have to fulfill high reliability requirements and those that are likely to be exposed to enhanced levels of cosmic rays background, e.g. in aerospace and avionic applications. Particle accelerators-driven neutron sources constitute valuable irradiation facilities for these purposes as they provide an opportunity for accelerated testing of the effects of these naturally occurring neutrons, provided the neutron spectrum is comparable with the atmospheric one and the neutron fields are known with high accuracy. The latter can be achieved through the use of appropriate radiation transport codes and neutron spectrometry techniques. In view of the design and construction of CHIPIR, a dedicated beam line for SEE studies at the ISIS pulsed neutron source second target station (UK) [1] ( http://ts-2.isis.rl.ac.uk/instruments/phase2/index.htm), a spectrometric characterization was performed on the VESUVIO beamline [2] (Senesi et al.,2000). The spectrometric technique was the bonner sphere spectrometer (BSS), widely used to determine neutron spectra and dose quantities around high-energy accelerators. The experimental campaign provided a complete spectrometric investigation of the VESUVIO neutron beam, allowing the integral quantities (total fluence rate, fraction of fluence in given energy intervals) to be estimated with uncertainties lower than 10%.

  12. A high-field magnetic resonance imaging spectrometer using an oven-controlled crystal oscillator as the local oscillator of its radio frequency transceiver

    Science.gov (United States)

    Liang, Xiao; Tang, Xin; Tang, Weinan; Gao, Jia-Hong

    2014-09-01

    A home-made high-field magnetic resonance imaging (MRI) spectrometer with multiple receiving channels is described. The radio frequency (RF) transceiver of the spectrometer consists of digital intermediate frequency (IF) circuits and corresponding mixing circuits. A direct digital synthesis device is employed to generate the IF pulse; the IF signal from a down-conversion circuit is sampled and followed by digital quadrature detection. Both the IF generation and the IF sampling use a 50 MHz clock. An oven-controlled crystal oscillator, which has outstanding spectral purity and a compact circuit, is used as the local oscillator of the RF transceiver. A digital signal processor works as the pulse programmer of the spectrometer, as a result, 32 control lines can be generated simultaneously while an event is triggered. Field programmable gate array devices are utilized as the auxiliary controllers of the IF generation, IF receiving, and gradient control. High performance, including 1 μs time resolution of the soft pulse, 1 MHz receiving bandwidth, and 1 μs time resolution of the gradient waveform, is achieved. High-quality images on a 1.5 T MRI system using the spectrometer are obtained.

  13. Columnar-to-Equiaxed Transition and Equiaxed Grain Alignment in Directionally Solidified Ni3Al Alloy Under an Axial Magnetic Field

    Science.gov (United States)

    Liu, Huan; Xuan, Weidong; Xie, Xinliang; Li, Chuanjun; Wang, Jiang; Yu, Jianbo; Li, Xi; Zhong, Yunbo; Ren, Zhongming

    2017-09-01

    The effect of an axial magnetic field on the solidification structure in directionally solidified Ni-21.5Al-0.4Zr-0.1B (at. pct) alloy was investigated. The experimental results indicated that the application of a high magnetic field caused the deformation of dendrites and the occurrence of columnar-to-equiaxed transition (CET). The magnetic field tended to orient the 〈001〉 crystal direction of the equiaxed grains along the magnetic field direction. The bulk solidification experiment under a high magnetic field showed that the crystal exhibited magnetic crystalline anisotropy. Further, the thermoelectric (TE) magnetic force and TE magnetic convention were analyzed by three-dimensional (3-D) numerical simulations. The results showed that the maximum value of TE magnetic force localized in the vicinity of the secondary dendrite arm root, which should be responsible for the dendrite break and CET. Based on the high-temperature creep mechanism, a simple model was proposed to describe the magnetic field intensity needed for CET: B ≥ kG^{ - 1.5} R^{1.25} . The model is in good agreement with the experiment results. The experimental results should be attributed to the combined action of TE magnetic effects and the magnetic moment.

  14. Correlation spectrometer

    Science.gov (United States)

    Sinclair, Michael B [Albuquerque, NM; Pfeifer, Kent B [Los Lunas, NM; Flemming, Jeb H [Albuquerque, NM; Jones, Gary D [Tijeras, NM; Tigges, Chris P [Albuquerque, NM

    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.

  15. Vector and axial constants of the baryon decuplet

    International Nuclear Information System (INIS)

    Belyaev, V.M.; Blok, B.Y.; Kogan, Y.I.

    1985-01-01

    On the basis of the QCD sum rules for the polarization operator in external axial and vector fields we determine the vector and axial transition constants in the 3/2 + baryon decuplet. We show that the renormalization of the axial constant is due to the interaction of the external axial field with the quark condensate

  16. 3D deformation field in growing plant roots reveals both mechanical and biological responses to axial mechanical forces.

    Science.gov (United States)

    Bizet, François; Bengough, A Glyn; Hummel, Irène; Bogeat-Triboulot, Marie-Béatrice; Dupuy, Lionel X

    2016-10-01

    Strong regions and physical barriers in soils may slow root elongation, leading to reduced water and nutrient uptake and decreased yield. In this study, the biomechanical responses of roots to axial mechanical forces were assessed by combining 3D live imaging, kinematics and a novel mechanical sensor. This system quantified Young's elastic modulus of intact poplar roots (32MPa), a rapid 3D. Measured critical elongation force was accurately predicted from an Euler buckling model, indicating that no biologically mediated accommodation to mechanical forces influenced bending during this short period of time. Force applied by growing roots increased more than 15-fold when buckling was prevented by lateral bracing of the root. The junction between the growing and the mature zones was identified as a zone of mechanical weakness that seemed critical to the bending process. This work identified key limiting factors for root growth and buckling under mechanical constraints. The findings are relevant to crop and soil sciences, and advance our understanding of root growth in heterogeneous structured soils. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. Multidimensional spectrometer

    Science.gov (United States)

    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.

  18. Development of a Portable Field Imaging Spectrometer: Application for the Identification of Sun-Dried and Sulfur-Fumigated Chinese Herbals.

    Science.gov (United States)

    Zhang, Hongming; Wu, Taixia; Zhang, Lifu; Zhang, Peng

    2016-05-01

    We fabricated a visible-near-infrared (Vis-NIR) portable field imaging spectrometer with a prism-grating-prism element and a scanning mirror. The developed Vis-NIR imaging spectrometer, consisting of an INFINITY 3-1 detector and a V10E spectrometer from Specim Corporation, is designed to measure the spectral range between 0.4 and 1 µm with spectral resolution of 2-4 nm. In recent years, sulfur fumigation has been abused during the processing of certain freshly harvested Chinese herbs. Fourier transform infrared spectroscopy, fiber optic NIR spectrometry, and liquid chromatography-mass spectrometry are typically used to analyze the chemical profiles of sulfur-fumigated and sun-dried Chinese herbs. Field imaging spectrometry is rarely used to identify sulfur-fumigated herbs. In this study, field imaging spectrometry, principal component analysis, and the partial least squares-discriminant analysis multivariate data analysis method are used to distinguish sun-dried and sulfur-fumigated Chinese medicinal herbs with a sensitivity of 96.4% and a specificity of 98.3% for RPA identification. These results suggest that hyperspectral imaging is a potential technique to control medicine quality for medical applications. © The Author(s) 2016.

  19. A new signal restoration method based on deconvolution of the Point Spread Function (PSF) for the Flat-Field Holographic Concave Grating UV spectrometer system

    Science.gov (United States)

    Dai, Honglin; Luo, Yongdao

    2013-12-01

    In recent years, with the development of the Flat-Field Holographic Concave Grating, they are adopted by all kinds of UV spectrometers. By means of single optical surface, the Flat-Field Holographic Concave Grating can implement dispersion and imaging that make the UV spectrometer system design quite compact. However, the calibration of the Flat-Field Holographic Concave Grating is very difficult. Various factors make its imaging quality difficult to be guaranteed. So we have to process the spectrum signal with signal restoration before using it. Guiding by the theory of signals and systems, and after a series of experiments, we found that our UV spectrometer system is a Linear Space- Variant System. It means that we have to measure PSF of every pixel of the system which contains thousands of pixels. Obviously, that's a large amount of calculation .For dealing with this problem, we proposes a novel signal restoration method. This method divides the system into several Linear Space-Invariant subsystems and then makes signal restoration with PSFs. Our experiments turn out that this method is effective and inexpensive.

  20. Wiggler Effects on the Growth Rate of a Raman Free-electron Laser with Axial Magnetic Field or Ion-Channel Guiding

    CERN Document Server

    Maraghechi, Behrouz

    2004-01-01

    A relativistic theory for Raman backscattering in the beam frame of electrons is presented and is used to find the growth rate of a free-electron laser (FEL), in the Raman regime. A one dimensional helical wiggler and an axial magnetic field are considered. The effects of static self-electric and self-magnetic fields, induced by the steady-state charge density and currents of the non-neutral electron beam, are taken into account to find the steady-state trajectories. The wiggler effects on the linear dispersion relations of the space-charge wave and radiation are included in the analysis. A numerical computation is conducted to compare the growth rate of the excited waves with nonrelativistic treatment. It was found that self-field effects increase the growth rate in the group II orbits and decrease it in the group I orbits. However, the wiggler effects on growth rate are stronger and increase the growth rate on both group I and group II orbits. The discontinuity, due to the cyclotron resonance with the radia...

  1. Automatic device for compensating the earths, magnetic field around a {beta} spectrometer; Ensemble automatique de compensation du champ terrestre autour d'un spectrometre

    Energy Technology Data Exchange (ETDEWEB)

    Ristori, Ch. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1967-02-15

    This paper shows how the earth magnetic field inside a double focusing, {pi}{radical}2, iron free, beta ray spectrometer (radius 50 cm ) has been compensated. Three orthogonal magnetic fields are generated by three square coils sets. Each stabilized power supply is regulated through its own magnetometer (of the fluxgate type) and the earth field inside the spectrometer is compensated to 10{sup -4} Oe whatever the earth field or power supply oscillation could be. (author) [French] Cette etude a pour but de compenser le champ magnetique terrestre autour d'un spectrometre beta {pi}{radical}2 a double focalisation, a bobines sans fer et de rayon moyen des trajectoires de 50 cm. Le champ magnetique terrestre est compense par superposition de trois champs orthogonaux, chacun cree par un ensemble de cadres carres. Chacune de ces composantes est mesuree par un magnetometre. Cet ensemble permet de travailler en regulation de courant ou en regulation de champ. En regulation de courant, l'operation est manuelle. En regulation de champ, pour chaque groupe de cadres, l'alimentation stabilisee est asservie par son magnetometre et malgre les variations du champ terrestre ou de la tension secteur, la compensation du champ terrestre se fait toujours correctement au niveau du spectrometre, a 10{sup -4} Oe pres. (auteur)

  2. A TIME-OF-FLIGHT MASS SPECTROMETER FOR SIMS AND FIELD IONISED NEUTRAL ANALYSIS USING A PULSED LMIS

    OpenAIRE

    Waugh, A.; Kingham, D.; Richardson, C.; Goff, M.

    1987-01-01

    A new surface analysis instrument has been developed using an energy-compensated time-of-flight mass spectrometer. Samples are ionised for analysis either by microfocussed laser irradiation or by sputtering with a microfocussed (< 0.25 µm) mass-filtered beam of Ga+ ions from a liquid metal ion source. A framestore-based data system allows the simultaneous capture o f both SIMS mass spectra and mass-resolved ion images. Data are presented illustrating both SIMS and Laser Microprobe performance...

  3. Light axial vector mesons

    Science.gov (United States)

    Chen, Kan; Pang, Cheng-Qun; Liu, Xiang; Matsuki, Takayuki

    2015-04-01

    Inspired by the abundant experimental observation of axial-vector states, we study whether the observed axial-vector states can be categorized into the conventional axial-vector meson family. In this paper we carry out an analysis based on the mass spectra and two-body Okubo-Zweig-Iizuka-allowed decays. Besides testing the possible axial-vector meson assignments, we also predict abundant information for their decays and the properties of some missing axial-vector mesons, which are valuable for further experimental exploration of the observed and predicted axial-vector mesons.

  4. Electric machines with axial magnetic flux

    Science.gov (United States)

    Nuca, I.; Ambros, T.; Burduniuc, M.; Deaconu, S. I.; Turcanu, A.

    2018-01-01

    The paper contains information on the performance of axial machines compared to cylindrical ones. At the same time, various constructive schemes of synchronous electromechanical converters with permanent magnets and asynchronous with short-circuited rotor are presented. In the developed constructions, the aim is to maximize the usage of the material of the stator windings. The design elements of the axial machine magnetic system are presented. The FEMM application depicted the array of the magnetic field of an axial machine.

  5. Axial vector mass spectrum and mixing angles

    International Nuclear Information System (INIS)

    Caffarelli, R.V.; Kang, K.

    1976-01-01

    Spectral sum rules of the axial-vector current and axial-vector current-pseudoscalar field are used to study the axial-vector mass spectrum and mixing angles, as well as the decay constants and mixing angles of the pseudoscalar mesons. In general, the result is quite persuasive for the existence of the Jsup(PC) = 1 ++ multiplet in which one has a canonical D-E mixing. (Auth.)

  6. Effect of Partial Shrouds on the Performance and Flow Field of a Low-Aspect-Ratio Axial-Flow Fan Rotor

    Directory of Open Access Journals (Sweden)

    N. Sitaram

    2011-01-01

    Full Text Available The flow field at the rotor exit of a low aspect ratio axial flow fan for different tip geometries and for different flow coefficients is measured in the present study. The following configurations are tested: (1 rotor without partial shroud, designated as rotor (wos, (2 rotor with partial shroud, designated as rotor (ws, and (3 rotor with perforated (perforations in the shape of discrete circular holes partial shroud, designated as rotor (wps. From steady state measurements, the performance of rotor (wps is found to be the best. Both the rotors with partial shrouds have stalled at a higher flow coefficient compared to that of rotor (wos. From periodic flow measurements, it is concluded that the low velocity region near the tip section is considerably reduced with the use of partial shrouds with perforations. The extent of this low velocity region for both rotor (wos and rotor (wps increases with decreasing flow coefficient due to increased stage loading. This core of low momentum fluid has moved inwards of the annulus and towards the pressure side as the flow coefficient decreases. The extent of the low momentum fluid is smaller for rotor (wps than that of rotor (wos at all flow coefficients.

  7. Spectrometer gun

    Science.gov (United States)

    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.

  8. Radial and axial compression of pure electron

    International Nuclear Information System (INIS)

    Park, Y.; Soga, Y.; Mihara, Y.; Takeda, M.; Kamada, K.

    2013-01-01

    Experimental studies are carried out on compression of the density distribution of a pure electron plasma confined in a Malmberg-Penning Trap in Kanazawa University. More than six times increase of the on-axis density is observed under application of an external rotating electric field that couples to low-order Trivelpiece-Gould modes. Axial compression of the density distribution with the axial length of a factor of two is achieved by controlling the confining potential at both ends of the plasma. Substantial increase of the axial kinetic energy is observed during the axial compression. (author)

  9. Dissipative Axial Inflation

    CERN Document Server

    Notari, Alessio

    2016-12-22

    We analyze in detail the background cosmological evolution of a scalar field coupled to a massless abelian gauge field through an axial term $\\frac{\\phi}{f_\\gamma} F \\tilde{F}$, such as in the case of an axion. Gauge fields in this case are known to experience tachyonic growth and therefore can backreact on the background as an effective dissipation into radiation energy density $\\rho_R$, which which can lead to inflation without the need of a flat potential. We analyze the system, for momenta $k$ smaller than the cutoff $f_\\gamma$, including numerically the backreaction. We consider the evolution from a given static initial condition and explicitly show that, if $f_\\gamma$ is smaller than the field excursion $\\phi_0$ by about a factor of at least ${\\cal O} (20)$, there is a friction effect which turns on before that the field can fall down and which can then lead to a very long stage of inflation with a generic potential. In addition we find superimposed oscillations, which would get imprinted on any kind of...

  10. The Spectrometer

    Science.gov (United States)

    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…

  11. Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography.

    Science.gov (United States)

    McBride, E L; Rao, A; Zhang, G; Hoyne, J D; Calco, G N; Kuo, B C; He, Q; Prince, A A; Pokrovskaya, I D; Storrie, B; Sousa, A A; Aronova, M A; Leapman, R D

    2018-02-01

    Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach. Copyright © 2018. Published by Elsevier Inc.

  12. Observations and Modeling of the Green Ocean Amazon 2014/15: Hydroxyl Radical (OH) Chemical Ionization Mass Spectrometer (CIMS) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Saewung [Univ. of California, Irvine, CA (United States)

    2016-05-01

    The University of California, Irvine, science team (Dr. Saewung Kim, Dr. Roger Seco, Dr. Alex Guenther, and Dr. Jim Smith) deployed a chemical ionization mass spectrometer system for hydroxyl radical (OH) and sulfuric acid quantifications. As part of the GoAmazon 2014/15 field campaign. Hydroxyl radical determines tropospheric oxidation capacity and had been expected to be very low in the pristine rain forest region such as the Brazilian Amazon because of the presence of significant levels of highly reactive biogenic volatile organic compounds and very low levels of NO, which is an OH recycling agent. However, several recent in situ OH observations provided by a laser-induced fluorescence system reported unaccountably high OH concentrations. To address this discrepancy, a series of laboratory and theoretical studies has postulated chemical reaction mechanisms of isoprene that may regenerate OH in photo-oxidation processes. Along with these efforts, potential artifacts on the laser induced fluorescence system from isoprene and its oxidation products also have been explored. Therefore, the first chemical ionization mass spectrometer observations at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s T3 site in Manacapuru, Brazil, are expected to provide a critical experimental constraint to address uncertainty in constraining oxidation capacity over pristine rain forest environments. In addition, we deployed a National Center for Atmospheric Research (NCAR) proton transfer reaction time-of-flight mass spectrometer to characterize atmospheric volatile organic compound levels, especially isoprene and its oxidation products, which are critical input parameters for box modeling to simulate OH with different isoprene photo-oxidation schemes. As there has been no report on noticeable new particle formation events, our first in situ sulfuric acid observations in the Amazon rain forest were expected to constrain the

  13. Using an Array of Ion Mobility Spectrometers in the Field for Real-Time Reporting of Chemical Vapor Concentration Measurements

    National Research Council Canada - National Science Library

    Blethen, Gretchen E; Harden, Charles S; McHugh, Vincent M; Shoff, Donal B; Ince, Brian S; Harper, Stephen E; Schafer, Robert J; Arnold, Paul D; Pavitt, Simon W; Thomas, Martin A; Espander, William R; Ciborowski, Steven M

    2004-01-01

    Field tests were carried out where hundreds of kilograms of chemical agent surrogates were explosively disseminated to gather real time chemical concentration information at specific ground locations...

  14. Using the VentCam and Optical Plume Velocimetry to Measure High-Temperature Hydrothermal Fluid Flow Rates in the ASHES Vent Field on Axial Volcano

    Science.gov (United States)

    Crone, T. J.; Mittelstaedt, E. L.; Fornari, D. J.

    2014-12-01

    Fluid flow rates through high-temperature mid-ocean ridge hydrothermal vents are likely quite sensitive to poroelastic forcing mechanisms such as tidal loading and tectonic activity. Because poroelastic deformation and flow perturbations are estimated to extend to considerable depths within young oceanic crust, observations of flow rate changes at seafloor vents have the potential to provide constraints on the flow geometry and permeability structure of the underlying hydrothermal systems, as well as the quantities of heat and chemicals they exchange with overlying ocean, and the potential biological productivity of ecosystems they host. To help provide flow rate measurements in these challenging environments, we have developed two new optical flow oriented technologies. The first is a new form of Optical Plume Velocimetry (OPV) which relies on single-frame temporal cross-correlation to obtain time-averaged image velocity fields from short video sequences. The second is the VentCam, a deep sea camera system that can collect high-frame-rate video sequences at focused hydrothermal vents suitable for analysis with OPV. During the July 2014 R/V Atlantis/Alvin expedition to Axial Seamount, we deployed the VentCam at the ~300C Phoenix vent within the ASHES vent field and positioned it with DSRV Alvin. We collected 24 seconds of video at 50 frames per second every half-hour for approximately 10 days beginning July 22nd. We are currently applying single-frame lag OPV to these videos to estimate relative and absolute fluid flow rates through this vent. To explore the relationship between focused and diffuse venting, we deployed a second optical flow camera, the Diffuse Effluent Measurement System (DEMS), adjacent to this vent at a fracture within the lava carapace where low-T (~30C) fluids were exiting. This system collected video sequences and diffuse flow measurements at overlapping time intervals. Here we present the preliminary results of our work with VentCam and OPV

  15. Development of a Robust, High Current, Low Power Field Emission Electron Gun for a Spaceflight Reflectron Time-of-Flight Mass Spectrometer

    Science.gov (United States)

    Southard, Adrian E.; Getty, Stephanie A.; Feng, Steven; Glavin, Daniel P.; Auciello, Orlando; Sumant, Anirudha

    2012-01-01

    Carbon materials, including carbon nanotubes (CNTs) and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD), have been of considerable interest for field emission applications for over a decade. In particular, robust field emission materials are compelling for space applications due to the low power consumption and potential for miniaturization. A reflectron time-of-flight mass spectrometer (TOF-MS) under development for in situ measurements on the Moon and other Solar System bodies uses a field emitter to generate ions from gaseous samples, using electron ionization. For these unusual environments, robustness, reliability, and long life are of paramount importance, and to this end, we have explored the field emission properties and lifetime of carbon nanotubes and nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) thin films, the latter developed and patented by Argonne National Laboratory. We will present recent investigations of N-UNCD as a robust field emitter, revealing that this material offers stable performance in high vacuum for up to 1000 hours with threshold voltage for emission of about 3-4 V/lJm and current densities in the range of tens of microA. Optimizing the mass resolution and sensitivity of such a mass spectrometer has also been enabled by a parallel effort to scale up a CNT emitter to an array measuring 2 mm x 40 mm. Through simulation and experiment of the new extended format emitter, we have determined that focusing the electron beam is limited due to the angular spread of the emitted electrons. This dispersion effect can be reduced through modification of the electron gun geometry, but this reduces the current reaching the ionization region. By increasing the transmission efficiency of the electron beam to the anode, we have increased the anode current by two orders of magnitude to realize a corresponding enhancement in instrument sensitivity, at a moderate cost to mass resolution. We will report recent experimental and

  16. Axis Spectrometer

    International Nuclear Information System (INIS)

    Park, Sungil

    2006-01-01

    The Cold Neutron Research Facility (CNRF) project carried out by Korea Atomic Energy Research Institute (KAERI) is an effort to bring cold neutron instrumentation to Korea's only large scale research reactor, HANARO, located in Daejeon. As part of the CNRF project, a cold neutron triple-axis spectrometer (Cold-TAS) is being developed along with other five: 40 m long and 12 m long small angle neutron scattering instruments (40m-SANS and 12m-SANS), disk-chopper time-of-flight spectrometer (DC-ToF), Bio- Reflectometer (Bio-REF) and the reflectometer with vertical sample geometry (REF-V). For those cold neutron instruments, the performance of an individual instrument depends not only on its design but also on the guide that feeds cold neutrons to the instrument. Therefore, the quality of the neutron flux at an instrument position has to be checked with the specification of the instrument. As for the Cold-TAS, since the instrument requires a tall beam and a high flux of short wavelength neutrons, it was tentatively decided that it would use the cold guide 4 (CG4). The detailed specification of the guide is listed. Checking the neutron flux of the guide at the instrument position is the obvious next step

  17. Axial model in curved space-time

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J.; Farina, C.; Vaidya, A.N.

    1986-12-11

    We study the axial model in a background gravitational field. Using the zeta-function regularization, we obtain explicitly the anomalous divergence of the axial-vector current and the exact generating functional of the theory. We show that, as a consequence of a space-time-dependent metric, all differential equations involved in the theory generalize to their covariantized forms. We also comment on the finite-mass renormalization exhibited by the pseudoscalar field and the form of the fermion propagator.

  18. A Field-Portable, Fiber-Optic Based Near-Infrared Spectrometer and its Applications to Fuels Analysis

    Science.gov (United States)

    1991-05-28

    is usually not available. Field testing may help to identify adulterated or otherwise substandard materials before their use. Early identification of...clinical analyses (25,26), agricultural materials analysis (27,28,29), and determinations such as the fat content in milk (30), and the identity of

  19. Estimation of total soluble solids in grape berries using a hand-held NIR spectrometer under field conditions.

    Science.gov (United States)

    Urraca, Ruben; Sanz-Garcia, Andres; Tardaguila, Javier; Diago, Maria P

    2016-07-01

    Recent studies have reported the potential of near infrared (NIR) spectral analysers for monitoring the ripeness of grape berries as an alternative to wet chemistry methods. This study covers various aspects regarding the calibration and implementation of predictive models of total soluble solids (TSS) in grape berries using laboratory and in-field collected NIR spectra. The performance of the calibration models obtained under laboratory conditions indicated that at least 700 berry samples are required to assure enough prediction accuracy. A statistically significant error reduction (ΔRMSECV = 0.1°Brix) with P berries without epicuticular wax, which was negligible from a practical point of view. Under field conditions, the prediction errors (RMSEP = 1.68°Brix, and SEP = 1.67°Brix) were close to those obtained with the laboratory dataset (RMSEP = 1.42°Brix, SEP = 1.40°Brix). This work clarifies several methodological factors to develop a protocol for in-field assessing TSS in grape berries using an affordable, non-invasive, portable NIR spectral analyser. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Experimental test of a newly developed single-moderator, multi-detector, directional neutron spectrometer in reference monochromatic fields from 144 keV to 16.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Bedogni, R., E-mail: roberto.bedogni@lnf.infn.it [INFN – LNF, via E. Fermi n. 40, 00044 Frascati (Roma) (Italy); Gómez-Ros, J.M. [INFN – LNF, via E. Fermi n. 40, 00044 Frascati (Roma) (Italy); CIEMAT, Av. Complutense 40, 28040 Madrid (Spain); Pola, A.; Bortot, D. [Politecnico di Milano, Dipartimento di Energia, via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria 16, 20133 Milano (Italy); Gentile, A. [INFN – LNF, via E. Fermi n. 40, 00044 Frascati (Roma) (Italy); Introini, M.V. [Politecnico di Milano, Dipartimento di Energia, via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria 16, 20133 Milano (Italy); Buonomo, B. [INFN – LNF, via E. Fermi n. 40, 00044 Frascati (Roma) (Italy); Lorenzoli, M. [Politecnico di Milano, Dipartimento di Energia, via La Masa 34, 20156 Milano (Italy); INFN – Milano, Via Celoria 16, 20133 Milano (Italy); Mazzitelli, M. [INFN – LNF, via E. Fermi n. 40, 00044 Frascati (Roma) (Italy); Sacco, D. [INFN – LNF, via E. Fermi n. 40, 00044 Frascati (Roma) (Italy); INAIL – DPIA, Via di Fontana Candida n.1, 00040 Monteporzio Catone (Italy)

    2015-05-11

    A new directional neutron spectrometer called CYSP (CYlindrical SPectrometer) was developed within the NESCOFI@BTF (2011–2013) collaboration. The device, composed by seven active thermal neutron detectors located along the axis of a cylindrical moderator, was designed to simultaneously respond from the thermal domain up to hundreds of MeV neutrons. The new spectrometer condenses the performance of the Bonner Sphere Spectrometer in a single moderator; thus requiring only one exposure to determine the whole spectrum. The CYSP response matrix, determined with MCNP, has been experimentally evaluated with monochromatic reference neutron fields from 144 keV to 16.5 MeV, plus a {sup 252}Cf source, available at NPL (Teddington, UK). The results of the experiment confirmed the correctness of the response matrix within an overall uncertainty of ±2.5%. The new active spectrometer CYSP offers an innovative option for real-time monitoring of directional neutron fields as those produced in neutron beam-lines.

  1. Wide band ENDOR spectrometer

    International Nuclear Information System (INIS)

    Mendonca Filho, C.

    1973-01-01

    The construction of an ENDOR spectrometer operating from 0,5 to 75 MHz within a single band, with ore Klystron and homodine detection, and no fundamental changes on the electron spin resonance spectrometer was described. The ENDOR signal can be detected both by amplitude modulation of the frequency field, or direct detection of the ESR output, which is taken to a signal analyser. The signal-to-noise ratio is raised by averaging rather than filtering avoiding the use of long time constants, providing natural line widths. The experimental apparatus and the spectra obtained are described. A discussion, relating the ENDOR line amplitudes with the experimental conditions is done and ENDOR mechanism, in which there is a relevant presence of cross relaxation is proposed

  2. Measurement of the neutron fields produced by a 62 MeV proton beam on a PMMA phantom using extended range Bonner sphere spectrometers

    Science.gov (United States)

    Amgarou, K.; Bedogni, R.; Domingo, C.; Esposito, A.; Gentile, A.; Carinci, G.; Russo, S.

    2011-10-01

    The experimental characterization of the neutron fields produced as parasitic effect in medical accelerators is assuming an increased importance for either the patient protection or the facility design aspects. Medical accelerators are diverse in terms of particle type (electrons or hadrons) and energy, but the radiation fields around them have in common (provided that a given threshold energy is reached) the presence of neutrons with energy span over several orders of magnitude. Due to the large variability of neutron energy, field or dosimetry measurements in these workplaces are very complex, and in general, cannot be performed with ready-to-use commercial instruments. In spite of its poor energy resolution, the Bonner Sphere Spectrometer (BSS) is the only instrument able to simultaneously determine all spectral components in such workplaces. The energy range of this instrument is limited to Emeasurements at hadron therapy facilities, an ERBSS experiment was carried out at the Centro di AdroTerapia e Applicazioni Nucleari Avanzate (CATANA) of INFN—LNS (Laboratori Nazionali del Sud), where a proton beam routinely used for ophthalmic cancer treatments is available. The 62 MeV beam was directed towards a PMMA phantom, simulating the patient, and two neutron measurement points were established at 0° and 90° with respect to the beam-line. Here the ERBSS of UAB (Universidad Autónoma de Barcelona— Grup de Física de les Radiacions) and INFN (Istituto Nazionale di Fisica Nucleare—Laboratori Nazionali di Frascati) were exposed to characterize the "forward" and "sideward" proton-induced neutron fields. The use of two ERBSS characterized by different set of spheres, central detectors, and independently established and calibrated, is important for guaranteeing the robustness of the measured spectra and estimating their overall uncertainties.

  3. Fourier Transform Spectrometer

    Data.gov (United States)

    National Aeronautics and Space Administration — The Fourier Transform Spectrometer project demonstrates the efficacy of a miniaturized spectrometer for flight applications.A spectrometer is an instrument used to...

  4. Comparison of Uncalibrated Rgbvi with Spectrometer-Based Ndvi Derived from Uav Sensing Systems on Field Scale

    Science.gov (United States)

    Bareth, G.; Bolten, A.; Gnyp, M. L.; Reusch, S.; Jasper, J.

    2016-06-01

    The development of UAV-based sensing systems for agronomic applications serves the improvement of crop management. The latter is in the focus of precision agriculture which intends to optimize yield, fertilizer input, and crop protection. Besides, in some cropping systems vehicle-based sensing devices are less suitable because fields cannot be entered from certain growing stages onwards. This is true for rice, maize, sorghum, and many more crops. Consequently, UAV-based sensing approaches fill a niche of very high resolution data acquisition on the field scale in space and time. While mounting RGB digital compact cameras to low-weight UAVs (digital compact camera was flown to acquire RGB images which are used to compute the RGBVI and (ii) NDVI is computed from a newly modified version of the Yara N-Sensor. The latter is a well-established tractor-based hyperspectral sensor for crop management and is available on the market since a decade. It was modified for this study to fit the requirements of UAV-based data acquisition. Consequently, we focus on three objectives in this contribution: (1) to evaluate the potential of the uncalibrated RGBVI for monitoring nitrogen status in winter wheat, (2) investigate the UAV-based performance of the modified Yara N-Sensor, and (3) compare the results of the two different UAV-based sensing approaches for winter wheat.

  5. Smartphone Spectrometers

    Science.gov (United States)

    Willmott, Jon R.; Mims, Forrest M.; Parisi, Alfio V.

    2018-01-01

    Smartphones are playing an increasing role in the sciences, owing to the ubiquitous proliferation of these devices, their relatively low cost, increasing processing power and their suitability for integrated data acquisition and processing in a ‘lab in a phone’ capacity. There is furthermore the potential to deploy these units as nodes within Internet of Things architectures, enabling massive networked data capture. Hitherto, considerable attention has been focused on imaging applications of these devices. However, within just the last few years, another possibility has emerged: to use smartphones as a means of capturing spectra, mostly by coupling various classes of fore-optics to these units with data capture achieved using the smartphone camera. These highly novel approaches have the potential to become widely adopted across a broad range of scientific e.g., biomedical, chemical and agricultural application areas. In this review, we detail the exciting recent development of smartphone spectrometer hardware, in addition to covering applications to which these units have been deployed, hitherto. The paper also points forward to the potentially highly influential impacts that such units could have on the sciences in the coming decades. PMID:29342899

  6. Smartphone Spectrometers

    Directory of Open Access Journals (Sweden)

    Andrew J.S. McGonigle

    2018-01-01

    Full Text Available Smartphones are playing an increasing role in the sciences, owing to the ubiquitous proliferation of these devices, their relatively low cost, increasing processing power and their suitability for integrated data acquisition and processing in a ‘lab in a phone’ capacity. There is furthermore the potential to deploy these units as nodes within Internet of Things architectures, enabling massive networked data capture. Hitherto, considerable attention has been focused on imaging applications of these devices. However, within just the last few years, another possibility has emerged: to use smartphones as a means of capturing spectra, mostly by coupling various classes of fore-optics to these units with data capture achieved using the smartphone camera. These highly novel approaches have the potential to become widely adopted across a broad range of scientific e.g., biomedical, chemical and agricultural application areas. In this review, we detail the exciting recent development of smartphone spectrometer hardware, in addition to covering applications to which these units have been deployed, hitherto. The paper also points forward to the potentially highly influential impacts that such units could have on the sciences in the coming decades.

  7. Smartphone Spectrometers.

    Science.gov (United States)

    McGonigle, Andrew J S; Wilkes, Thomas C; Pering, Tom D; Willmott, Jon R; Cook, Joseph M; Mims, Forrest M; Parisi, Alfio V

    2018-01-14

    Smartphones are playing an increasing role in the sciences, owing to the ubiquitous proliferation of these devices, their relatively low cost, increasing processing power and their suitability for integrated data acquisition and processing in a 'lab in a phone' capacity. There is furthermore the potential to deploy these units as nodes within Internet of Things architectures, enabling massive networked data capture. Hitherto, considerable attention has been focused on imaging applications of these devices. However, within just the last few years, another possibility has emerged: to use smartphones as a means of capturing spectra, mostly by coupling various classes of fore-optics to these units with data capture achieved using the smartphone camera. These highly novel approaches have the potential to become widely adopted across a broad range of scientific e.g., biomedical, chemical and agricultural application areas. In this review, we detail the exciting recent development of smartphone spectrometer hardware, in addition to covering applications to which these units have been deployed, hitherto. The paper also points forward to the potentially highly influential impacts that such units could have on the sciences in the coming decades.

  8. Axial resolution improvement by spectral data fusion in simultaneous dual-band optical coherence tomography

    Science.gov (United States)

    Cimalla, Peter; Gaertner, Maria; Walther, Julia; Koch, Edmund

    2011-06-01

    A method for axial resolution improvement by adequate spectral data fusion of two parallel acquired disjunct wavelength bands in the 0.8 μm and 1.3 μm region in the field of simultaneous dual-band optical coherence tomography (OCT) is presented. The applied spectral domain dual-band OCT system is illuminated by a supercontinuum laser light source and allows simultaneous imaging at 800 nm and 1250 nm with free-space axial resolutions better than 4.5 μm and 7 μm, respectively, over the entire depth scan range. Each wavelength band is analyzed with an individual spectrometer at an A-scan rate of 12 kHz. To further improve axial resolution, the 1250 nm spectra are fused with the 800 nm spectra considering the spectrometer-inherent non-linear fringe frequency course of the interference light. The phase and amplitude of the 1250 nm spectra are matched to the 800 nm spectra by means of short time Fourier transform analysis in order to obtain ideally continuous joint spectra. The joint spectra then undergo conventional spectral shaping, wave number resampling, windowing and fast Fourier transformation. First results for single A-scans of a glass slide as well as entire cross-sectional images of biological tissue yield an axial resolution improvement of 52 % compared to conventional single band imaging at 800 nm. The obtained A-scans show a good sharpness with a side lobe suppression of 30 dB. Additional investigations have to be employed for the full understanding of the underlying physical background and the optimization of the applied data processing for further image quality enhancement.

  9. A field-portable membrane introduction mass spectrometer for real-time quantitation and spatial mapping of atmospheric and aqueous contaminants.

    Science.gov (United States)

    Bell, Ryan J; Davey, Nicholas G; Martinsen, Morten; Collin-Hansen, Christian; Krogh, Erik T; Gill, Christopher G

    2015-02-01

    Environmental concentrations of volatile and semivolatile organic compounds (VOC/SVOCs) can vary dramatically in time and space under the influence of environmental conditions. In an industrial setting, multiple point and diffuse sources can contribute to fugitive emissions. Assessments and monitoring programs using periodic grab sampling provide limited information, often with delay times of days or weeks. We report the development and use of a novel, portable membrane introduction mass spectrometry (MIMS) system capable of resolving and quantifying VOC and SVOCs with high spatial and temporal resolution, in the field, in real-time. An electron impact ionization cylindrical ion trap mass spectrometer modified with a capillary hollow fiber polydimethylsiloxane membrane interface was used for continuous air and water sampling. Tandem mass spectrometry and selected ion monitoring scans performed in series allowed for the quantitation of target analytes, and full scan mode was used to survey for unexpected analytes. Predeployment and in-field external calibrations were combined with a continuously infused internal standard to enable real-time quantitation and monitor instrument performance. The system was operated in a moving vehicle with internet-linked data processing and storage. Software development to integrate MIMS and relevant meta-data for visualization and geospatial presentation in Google Earth is presented. Continuous quantitation enables the capture of transient events that may be missed or under-represented by traditional grab sampling strategies. Real-time geospatial maps of chemical concentration enable adaptive sampling and in-field decision support. Sample datasets presented in this work were collected in Northern Alberta in 2010-2012.

  10. A Field-Portable Membrane Introduction Mass Spectrometer for Real-time Quantitation and Spatial Mapping of Atmospheric and Aqueous Contaminants

    Science.gov (United States)

    Bell, Ryan J.; Davey, Nicholas G.; Martinsen, Morten; Collin-Hansen, Christian; Krogh, Erik T.; Gill, Christopher G.

    2015-02-01

    Environmental concentrations of volatile and semivolatile organic compounds (VOC/SVOCs) can vary dramatically in time and space under the influence of environmental conditions. In an industrial setting, multiple point and diffuse sources can contribute to fugitive emissions. Assessments and monitoring programs using periodic grab sampling provide limited information, often with delay times of days or weeks. We report the development and use of a novel, portable membrane introduction mass spectrometry (MIMS) system capable of resolving and quantifying VOC and SVOCs with high spatial and temporal resolution, in the field, in real-time. An electron impact ionization cylindrical ion trap mass spectrometer modified with a capillary hollow fiber polydimethylsiloxane membrane interface was used for continuous air and water sampling. Tandem mass spectrometry and selected ion monitoring scans performed in series allowed for the quantitation of target analytes, and full scan mode was used to survey for unexpected analytes. Predeployment and in-field external calibrations were combined with a continuously infused internal standard to enable real-time quantitation and monitor instrument performance. The system was operated in a moving vehicle with internet-linked data processing and storage. Software development to integrate MIMS and relevant meta-data for visualization and geospatial presentation in Google Earth is presented. Continuous quantitation enables the capture of transient events that may be missed or under-represented by traditional grab sampling strategies. Real-time geospatial maps of chemical concentration enable adaptive sampling and in-field decision support. Sample datasets presented in this work were collected in Northern Alberta in 2010-2012.

  11. A quantum cascade laser infrared spectrometer for CO2 stable isotope analysis: Field implementation at a hydrocarbon contaminated site under bio-remediation.

    Science.gov (United States)

    Guimbaud, Christophe; Noel, Cécile; Chartier, Michel; Catoire, Valéry; Blessing, Michaela; Gourry, Jean Christophe; Robert, Claude

    2016-02-01

    Real-time methods to monitor stable isotope ratios of CO2 are needed to identify biogeochemical origins of CO2 emissions from the soil-air interface. An isotope ratio infra-red spectrometer (IRIS) has been developed to measure CO2 mixing ratio with δ(13)C isotopic signature, in addition to mixing ratios of other greenhouse gases (CH4, N2O). The original aspects of the instrument as well as its precision and accuracy for the determination of the isotopic signature δ(13)C of CO2 are discussed. A first application to biodegradation of hydrocarbons is presented, tested on a hydrocarbon contaminated site under aerobic bio-treatment. CO2 flux measurements using closed chamber method is combined with the determination of the isotopic signature δ(13)C of the CO2 emission to propose a non-intrusive method to monitor in situ biodegradation of hydrocarbons. In the contaminated area, high CO2 emissions have been measured with an isotopic signature δ(13)C suggesting that CO2 comes from petroleum hydrocarbon biodegradation. This first field implementation shows that rapid and accurate measurement of isotopic signature of CO2 emissions is particularly useful in assessing the contribution of contaminant degradation to the measured CO2 efflux and is promising as a monitoring tool for aerobic bio-treatment. Copyright © 2016. Published by Elsevier B.V.

  12. Axial static mixer

    Science.gov (United States)

    Sandrock, H.E.

    1982-05-06

    Static axial mixing apparatus includes a plurality of channels, forming flow paths of different dimensions. The axial mixer includes a flow adjusting device for adjustable selective control of flow resistance of various flow paths in order to provide substantially identical flows through the various channels, thereby reducing nonuniform coating of interior surfaces of the channels. The flow adjusting device may include diaphragm valves, and may further include a pressure regulating system therefor.

  13. Development of an ion time-of-flight spectrometer for neutron depth profiling

    Science.gov (United States)

    Cetiner, Mustafa Sacit

    signal. Without loss of generality, the secondary signal is obtained by the passage of the ion through a thin carbon foil, which produces ion-induced secondary electron emission (IISEE). The time-of-flight spectrometer physically acts as an ion/electron separator. The electrons that enter the active volume of the spectrometer are transported onto the microchannel plate detector to generate the secondary signal. The electron optics can be designed in variety of ways depending on the nature of the measurement and physical requirements. Two ion time-of-flight spectrometer designs are introduced: the parallel electric and magnetic (PEM) field spectrometer and the cross electric and magnetic (CEM) field spectrometer. The CEM field spectrometers have been extensively used in a wide range of applications where precise mass differentiation is required. The PEM field spectrometers have lately found interest in mass spectroscopy applications. The application of the PEM field spectrometer for energy measurements is a novel approach. The PEM field spectrometer used in the measurements employs axial electric and magnetic fields along the nominal direction of the incident ion. The secondary electrons are created by a thin carbon foil on the entrance disk and transported on the microchannel plate that faces the carbon foil. The initial angular distribution of the secondary electrons has virtually no effect on the transport time of the secondary electrons from the surface of the carbon foil to the electron microchannel plate detector. Therefore, the PEM field spectrometer can offer high-resolution energy measurement for relatively lower electric fields. The measurements with the PEM field spectrometer were made with the Tandem linear particle accelerator at the IBM T. J. Watson Research Center at Yorktown Heights, NY. The CEM field spectrometer developed for the thesis employs axial electric field along the nominal direction of the ion, and has perpendicular magnetic field. As the

  14. Technical Note: Use of a beam width probe in an Aerosol Mass Spectrometer to monitor particle collection efficiency in the field

    Directory of Open Access Journals (Sweden)

    D. Salcedo

    2007-01-01

    Full Text Available Two Aerodyne Aerosol Mass Spectrometers (Q-AMS were deployed in Mexico City, during the Mexico City Metropolitan Area field study (MCMA-2003 from 29 March–4 May 2003 to investigate particle concentrations, sources, and processes. We report the use of a particle beam width probe (BWP in the field to quantify potential losses of particles due to beam broadening inside the AMS caused by particle shape (nonsphericity and particle size. Data from this probe show that no significant mass of particles was lost due to excessive beam broadening; i.e. the shape- and size-related collection efficiency (Es of the AMS during this campaign was approximately one. Comparison of the BWP data from MCMA-2003 with other campaigns shows that the same conclusion holds for several other urban, rural and remotes sites. This means that the aerodynamic lens in the AMS is capable of efficiently focusing ambient particles into a well defined beam and onto the AMS vaporizer for particles sampled in a wide variety of environments. All the species measured by the AMS during MCMA-2003 have similar attenuation profiles which suggests that the particles that dominate the mass concentration were internally mixed most of the time. Only for the smaller particles (especially below 300 nm, organic and inorganic species show different attenuation versus particle size which is likely due to partial external mixing of these components. Changes observed in the focusing of the particle beam in time can be attributed, in part, to changes in particle shape (i.e. due to relative humidity and size of the particles sampled. However, the relationships between composition, atmospheric conditions, and particle shape and size appear to be very complex and are not yet completely understood.

  15. Inverse-magnetron mass spectrometer

    International Nuclear Information System (INIS)

    Pakulin, V.N.

    1979-01-01

    Considered is the operation of a typical magnetron mass spectrometer with an internal ion source and that of an inverse magnetron mass spectrometer with an external ion source. It is found that for discrimination of the same mass using the inverse design of mass spectrometers it is possible to employ either r 2 /r 1 times lesser magnetic fields at equal accelerating source-collector voltages, or r 2 /r 1 higher accelerating voltages at equal magnetic fields, as compared to the typical design (r 1 and r 2 being radii of the internal and external electrodes of the analyser, respectively). The design of an inverse-magnetron mass spectrometer is described. The mass analyzer is formed by a cylindrical electrode of 3 mm diameter and a coaxial tubular cylinder of 55 mm diameter. External to the analyzer is an ionizing chamber at the pressure of up to 5x10 -6 torr. The magnetic field along the chamber axis produced by a solenoid was 300 Oe. At the accelerating voltage of 100 V and mass 28, the spectrometer has a resolution of 30 at a half-peak height

  16. High harmonic generation from axial chiral molecules.

    Science.gov (United States)

    Wang, Dian; Zhu, Xiaosong; Liu, Xi; Li, Liang; Zhang, Xiaofan; Lan, Pengfei; Lu, Peixiang

    2017-09-18

    Axial chiral molecules, whose stereogenic element is an axis rather than a chiral center, have attracted widespread interest due to their important application, such as asymmetric synthesis and chirality transfer. We investigate high harmonic generation from axial chiral molecules with bichromatic counterrotating circularly polarized laser fields. High harmonic generation from three typical molecules: (Sa)-3-chloropropa-1,2-dien-1-ol, propadiene, and (Ra)-2,3-pentadiene is simulated with time-dependent density-functional theory and strong field approximation. We found that harmonic spectra for 3D oriented axial chiral molecules exhibit obvious circular dichroism. However, the circular dichroism of High harmonic generation from an achiral molecule is much trivial. Moreover, the dichroism of high harmonic generation still exists when axial chiral molecules are 1D oriented,such as (Sa) -3-chloropropa-1,2-dien-1-ol. For a special form of axial chiral molecules with the formula abC=C=Cab (a, b are different substituents), like (Ra)-2,3-pentadiene, the dichroism discriminations disappear when the molecules are only in 1D orientation. The circular dichroism of high harmonic generation from axial chiral molecules is well explained by the trajectory analysis based on the semiclassical three-step mechanism.

  17. Chemical Composition of African Biomass Burning Aerosols Over the Southeast Atlantic: Aerosol Mass Spectrometer Results from the 2016 and 2017 ORACLES Field Campaigns.

    Science.gov (United States)

    Dobracki, A. N.; Howell, S. G.; Freitag, S.; Smirnow, N.; Podolske, J. R.

    2017-12-01

    Biomass burning (BB) is one of the largest contributors of anthropogenic aerosols in the atmosphere. During BB events, organic and inorganic gases and particles are emitted into the atmosphere. Because of their abundance, particle size, and radiative properties, BB aerosols play an important role in global climate. Southern Africa produces 30% of the Earth's BB aerosol particles. Organics, Nitrates, sulfates, and refractory black carbon, along with other chemical species are lofted into the free troposphere and transported over the Southeast Atlantic Ocean. However, considerate uncertainty remains in the chemical composition of these plumes with its large variety of organic and inorganic species. As part of the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) 2016 and 2017 airborne field campaigns, an Aerosol Mass Spectrometer (AMS) was used to sample the chemical composition and chemical structure of the aerosol in this region. Results show constant vertical stratification within the plume over the course of the campaign (August 2017 / September 2016). Using nitrate (NO3) and organic carbon (OC) as two tracers, the structure of the September 2016 plume had a ratio of 1:8 (NO3:OC) in the upper plume (3km-5km), while the lower plume (1km-2.5km) had a ratio of 1:12 (NO3:OC). AMS measurements were supported by carbon monoxide (CO) and carbon dioxide (CO2) measurements. This data revealed a modified combustion efficiency (MCE= ΔCO2/ΔCO2 + ΔCO) of 0.97 in the lower plume. An MCE above 0.9 represents efficient burning processes. Additionally, concentrations of C2(H2O)2 (m/z60), a common chemical fragment from breaking up carbohydrates (primarily levoglucosan) emitted by burning biomass only represented <1% of total organics throughout the campaign. These low concentrations are due to efficient combustion rather than oxidation during transport. These results are consistent with earlier studies of efficient fires.

  18. Modeling mini-orange electron spectrometers

    International Nuclear Information System (INIS)

    Canzian da Silva, Nelson; Dietzsch, Olacio

    1994-01-01

    A method for calculating the transmission of mini-orange electron spectrometers is presented. The method makes use of the analytical solution for the magnetic field of a plane magnet in the calculation of the spectrometer spatial field distribution by superimposing the fields of the several magnets that compose the system. Electron trajectories through the spectrometer are integrated numerically in a Monte Carlo calculation and the transmission of the spectrometer as a function of the electron energy is evaluated. A six-magnet mini-orange spectrometer was built and its transmission functions for several distances from source to detector were measured and compared to the calculations. The overall agreement is found to be good. The method is quite general and can be applied to the design of systems composed of plane magnets, predicting their performance before assembling them. ((orig.))

  19. The MIRI Medium Resolution Spectrometer calibration pipeline

    NARCIS (Netherlands)

    Labiano, A.; Azzollini, R.; Bailey, J.; Beard, S.; Dicken, D.; García-Marín, M.; Geers, V.; Glasse, A.; Glauser, A.; Gordon, K.; Justtanont, K.; Klaassen, P.; Lahuis, F.; Law, D.; Morrison, J.; Müller, M.; Rieke, G.; Vandenbussche, B.; Wright, G.

    2016-01-01

    The Mid-Infrared Instrument (MIRI) Medium Resolution Spectrometer (MRS) is the only mid-IR Integral Field Spectrometer on board James Webb Space Telescope. The complexity of the MRS requires a very specialized pipeline, with some specific steps not present in other pipelines of JWST instruments,

  20. EBSD Study on the Effect of a Strong Axial Magnetic Field on the Microstructure and Crystallography of Al-Ni Alloys During Solidification

    Science.gov (United States)

    Li, Xi; Fautrelle, Yves; Gagnoud, Annie; Moreau, Rene; Du, Dafan; Ren, Zhongming; Lu, Xionggang

    2016-03-01

    The effect of a strong magnetic field on the microstructure and crystallography of the primary and eutectic Al3Ni phases in Al-Ni alloys was investigated by using EBSD. The results show that the magnetic field significantly affected the microstructures and crystallography during both volume and directional solidification. As a result, the Al3Ni primary phases were aligned with the crystal direction along the magnetic field and formed a layer-like structure. The magnetic field intensity, solidification temperature, growth speed, and alloy composition played important roles during the alignment process of the Al3Ni primary phase. Indeed, the alignment degree increased with the magnetic field and the solidification temperature during normal solidification. Moreover, the effect of the magnetic field on the crystallography of the Al-Al3Ni eutectic in the Al-Ni alloys was also studied. The applied magnetic field modified the orientation of the preferred growth direction of the Al3Ni eutectic fiber and the crystallographic orientation relationship of the Al-Al3Ni eutectic. The orientation of the preferred growth direction of the Al3Ni eutectic fiber depended mainly on the solidification direction and the alignment of the Al3Ni primary phase. Furthermore, a method for controlling the crystallization process by adjusting the angle between the solidification direction and the magnetic field was proposed.

  1. Prototype Neutron Energy Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Contribution to the study of magnetic fields in a configuration having radial symmetry; Contribution a l'etude des champs magnetiques dans une configuration a symetrie axiale

    Energy Technology Data Exchange (ETDEWEB)

    Bliaux, T.; Durand, J.P.; Giraud-Carrier, C.; Merard, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    First, the method for tracing on 'Teledeltos' paper magnetic induction lines (by analogy with electrical equipotential lines) in order to obtain rapid and qualitative results, is recalled. Then the authors present, computed from the law of Biot and Savart, the values of radial and tangential components of the magnetic induction. These results are presented under the form of abaci for a configuration of parallel conductors in a rotational symmetry. Each configuration is defined by the number of conductors 1 {<=} N {<=} 12 and by the the radius R of the circle. The domain of computation of the value of the magnetic induction at point M (r, {theta}) is limited by symmetry in a sector defined by 0 {<=} r {<=} 2,5*R and 0 {<=} {theta} {<=} {theta}{sub max}. (authors) [French] Apres un rappel du trace sur papier semi-conducteur 'Teledeltos' des lignes d'induction magnetique (par analogie avec des lignes equipotentielles electriques), methode rapide qui donne des resultats qualitatifs, les auteurs presentent sous forme d'abaques les valeurs des composantes radiale et tangentielle de l'induction magnetique calculees par la loi de Biot et Savart, pour une configuration de conducteurs paralleles dans une symetrie axiale de revolution. La configuration est definie par le nombre N de conducteurs [1 {<=} N {<=} 12] et par le rayon R du cercle de repartition des conducteurs. Le point courant M (r, {theta}) est limite, pour des raisons de symetrie, dans un secteur defini par [0 {<=} r {<=} 2,5*R] et 0 {<=} {theta} {<=} {theta}{sub max}. (auteurs)

  3. Triple-axis spectrometer

    International Nuclear Information System (INIS)

    Toeroek, Gy.

    2001-01-01

    A triple-axis spectrometer has been designed for structural and dynamical studies of condensed matter. Because of the limited number of other operational equipment the triple axis spectrometer was used in a multi purpose regime, e.g. high resolution diffractometry, strain analysis, reflectometry, quasielastic and inelastic scattering. A polarization setup was also tested on this spectrometer. (R.P.)

  4. Band gap modulation of mono and bi-layer hexagonal ZnS under transverse electric field and bi-axial strain: A first principles study

    Science.gov (United States)

    Rai, D. P.; Kaur, Sumandeep; Srivastava, Sunita

    2018-02-01

    Density functional theory has been employed to study the electronic and mechanical properties of the monolayer and bilayer ZnS. AB stacked ZnS bilayer is found to be energetically more favorable over the AA stacked ZnS bilayer. The electronic bandgap decreases on moving from monolayer to bilayer. Application of positive transverse electric field in AA/AB stacked bilayers leads to a semiconductor to metal transition at 1.10 V/Å. Reversed polarity of electric field, on the other hand, leads to an asymmetric behavior of the bandgap for AB stacking while the behavior of the bandgap in AA stacking is polarity independent. The strong dependency of bandgap on polarity of electric field in AB stacked ZnS bilayer is due to the balancing of external field with the induced internal field which arises due the electronegativity and heterogeneity in the arrangements of atoms. The electronic structure varies with the variation of applied biaxial strain (compression/tensile). We report an increase in band gap in both single and double layers under compression up to -8.0%, which can be attributed to greater superposition of atomic orbitals (Zn-d and S-p hybridization). We expect that our results may stimulate more theoretical and experimental work on hexagonal multi-layers of ZnS employing external field (temperature, pressure, field etc.) for future applications of our present work.

  5. The barrel muon spectrometer of the ATLAS detector has acquired its first cosmic event in a magnetic field produced by the barrel toroid magnet.

    CERN Multimedia

    2006-01-01

    A 3-D event display of a cosmic muon event, showing the path of a muon travelling through three layers of the barrel muon spectrometer. Three of the eight coils of the barrel toroid magnet can be seen in the top half of the drawing.

  6. Axial tomographic scanner

    International Nuclear Information System (INIS)

    1976-01-01

    An axial tomographic system is described comprising axial tomographic means for collecting sets of data corresponding to the transmission or absorption of a number of beams of penetrating radiation through a planar slice of an object. It includes means to locate an object to be analyzed, a source and detector for directing one or more beams of penetrating radiation through the object from the source to the detector, and means to rotate (and optionally translate) the source as well as means to process the collected sets of data. Data collection, data processing, and data display can each be conducted independently of each other. An additional advantage of the system described is that the raw data (i.e., the originally collected data) are not destroyed by the data processing but instead are retained intact for further reference or use, if needed

  7. A Moessbauer effect spectrometer

    International Nuclear Information System (INIS)

    Fayek, M.K.; Abbas, Y.M.; Bahgat, A.A.

    1983-01-01

    A Moessbauer effect spectrometer of Harwell type is installed and put in operation. The driving system is of a constant acceleration mode with a velocity range 40mm/sec. and associated to a 1024 multichannel analyser working in a multiscalar time mode. The gamma ray sources are 50 mCi Co 57 in Pd and 20 mCi Snsup(119m) in Ba Sn(O) 3 . Measurements are taken with the source kept at room temperature, while the absorber can be maintained at various temperatures. Gamma ray resonance spectra of different standard samples are obtained. Zero velocity and magnetic field calibration curves are deduced. Examples of some Moessbauer spectra for running investigated materials with a comprehensive general description are also given

  8. Photo ion spectrometer

    Science.gov (United States)

    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.

  9. Equation of motion for the axial gravitational superfield

    International Nuclear Information System (INIS)

    Ogievetsky, V.; Sokatchev, E.

    1980-01-01

    Transformation properties of the axial supergravitational field variants are investigated. The equation of motion for the axial gravitational superfield is derived by direct variation of the N = 1 supergravity action. The left-hand side of this equation is a component of the torsion tensor, and the right-hand side is the supercurrent. The question about the cosmological term in supergravity is discussed

  10. Plasma measurements with the TMX-U E parallel to B end-loss-ion spectrometers

    International Nuclear Information System (INIS)

    Foote, J.H.; Wood, B.E.; Brown, M.D.; Curnow, G.M.

    1986-01-01

    Two E parallel to B end-loss-ion spectrometers (ELIS) are now making plasma measurements on Tandem Mirror Experiment-Upgrade (TMX-U). One instrument is mounted on each end of this open-ended tandem-mirror machine. These spectrometers observe plasma losses along magnetic-field lines. They operate reliably and with a minimum of attention during an experimental run. Their data, which are quickly acquired and analyzed, help guide the experimental sequence. The parallel electric and magnetic fields separate the end-loss ions according to mass (D + and H + ) and energy. Each spectrometer detects ions with an array of 128 flat collector plates that are made from copper-coated G10 epoxy fiberglass, normally used for printed-circuit boards. The ELIS diagnostic system produces a wealth of experimental information, including data on peak plasma potential, central-cell ion temperature, potentials in the thermal-barrier region, axial confinement and ion-end-loss plugging, energetic-electron losses, and hydrogen/deuterium concentrations. 6 refs., 5 figs

  11. Spherical grating spectrometers

    Science.gov (United States)

    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.

  12. Study on spectrometer based upon volume holographic transmission grating

    Science.gov (United States)

    Huang, Zhen; Liu, Guodong; Ren, Zhong; Zeng, Lvming

    2010-10-01

    In this present paper, a spectrometer based upon axial transmissive optical structure with the volume-phase holographic (VPH) transmission grating technology is introduced. We give a physical insight for the structure and mechanism of photorefractive volume holographic gratings and theoretically analyze some important performance parameters of the spectrometer device using the coupled wave theory, which should be considered in the process of the following design for the device with volume phase holographic transmission gratings. The experimental results show, owing to its axial transmissive optical geometry and the perfect performance of the VPH transmission grating, the spectrometer based on the volume-phase holographic transmission grating has satisfactory high resolution and wavelength accuracy. It has great promise to be widely used in the future.

  13. Recent ion optics and mass spectrometers

    International Nuclear Information System (INIS)

    Matsuda, Hisashi

    1976-01-01

    The establishment of the third order approximation method for computing the orbit of the ion optical system for mass spectrometers and the completion of its computer program are reported. A feature of this orbit computation is in that the effect of the fringing field can be considered with the accuracy of third order approximation. Several new ion optical systems for mass spectrometers have been proposed by using such orbit computing programs. Brief explanation and the description on the future prospect and problems are made on the following items: the vertual image double focusing mass spectrometer, the second order double focusing mass spectrometer, the E x B superposed field mass spectrometer, and the apparatus with a cylindrical electric field and Q-lens. In the E x B superposed field with Matsuda plates, if the magnetic field is generated by an electromagnet instead of a permanent magnet, the dispersion of mass and energy can be changed at will. The Matsuda plates are known as the auxiliary electrodes positioned at the top and bottom of a cylindrical capacitor. Utilizing those characteristics, a zoom spectrometer can be made, with which only a necessary part of mass spectra can be investigated in detail, but the whole spectra are investigated roughly. In addition, the distribution of energy can be investigated simultaneously after the separation of ionic mass similarly to the parabola apparatus. (Iwakiri, K.)

  14. Oxford MDM-2 magnetic spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pringle, D.M.; Catford, W.N.; Winfield, J.S.; Lewis, D.G.; Jelley, N.A.; Allen, K.W.; Coupland, J.H.

    1986-05-01

    A new high resolution magnetic spectrometer - the Oxford MDM-2 spectrometer - has been designed, installed and tested. The layout of the magnetic elements is in the order: entrance sextupole and multipole, gradient-field dipole and exit multipole. The device has a ''normal'' focal plane, and the 1.6 m radius dipole magnet has a maximum mass-energy product of 315 MeV amu. At the maximum solid angle of 8 msr, the ratio of energies that can be accepted by the spectrometer (Esub(max)/Esub(min)) is 1.31. Precise measurements have been performed on the magnetic elements. The dipole magnet has very low hysteresis and field integral errors that amount to less than 1 part in 10/sup 4/. After some in situ modifications the field distributions of the magnets closely approximated the original design specifications. On-line tests with various ion-beams have revealed the optimum setting for each element. These are close to theoretical predictions from the program RAYTRACE, incorporating the parameterised results of the magnetic measurements. An aberration limited resolution (E/..delta..E) of greater than 3000 has been observed at 8 msr solid angle.

  15. Degenerate seaweed to tilted dendrite transition and their growth dynamics in directional solidification of non-axially oriented crystals: a phase-field study

    Science.gov (United States)

    Xing, Hui; Dong, Xianglei; Wu, Hongjing; Hao, Guanhua; Wang, Jianyuan; Chen, Changle; Jin, Kexin

    2016-05-01

    We report the results of a phase-field study of degenerate seaweed to tilted dendrite transition and their growth dynamics during directional solidification of a binary alloy. Morphological selection maps in the planes of (G, Vp) and (ε4, Vp) show that lower pulling velocity, weaker anisotropic strength and higher thermal gradient can enhance the formation of the degenerate seaweed. The tip undercooling shows oscillations in seaweed growth, but it keeps at a constant value in dendritic growth. The M-S instability on the tips and the surface tension anisotropy of the solid-liquid interface are responsible for the formation of the degenerate seaweed. It is evidenced that the place where the interfacial instability occurs determines the morphological transition. The transient transition from degenerate seaweed to tilted dendrite shows that dendrites are dynamically preferred over seaweed. For the tilted dendritic arrays with a large tilted angle, primary spacing is investigated by comparing predicted results with the classical scaling power law, and the growth direction is found to be less sensitive to the pulling velocity and the primary spacing. Furthermore, the effect of the initial interface wavelength on the morphological transition is investigated to perform the history dependence of morphological selection.

  16. Axial weak currents in the Wess-Zumino term

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo.

    1985-03-01

    The conventional axial gauging of the Wess-Zumino term leads to the results which do not necessarily agree with the expectations on the basis of quark level Ward-Takahashi identities. This discrepancy arises from the fact that the quark level anomalous identities reflect the short distance structure of QCD, whereas the gauging of the Wess-Zumino term reflects the axial symmetry in the spontaneously broken chiral phase. The low energy theorem for axial weak fields is not sharply defined, in contrast to the case of vector fields where no such complications arise. (author)

  17. Silicon spectrometer with a Peltier refrigerator

    International Nuclear Information System (INIS)

    Belcarz, E.; Chwaszczewska, J.; Hahn, G.; Nowicki, W.; Sawicka, B.; Skoczek, K.; Slapa, M.; Szymczak, M.

    1974-01-01

    This paper describes a spectrometer with a Si(Li) detector cooled by a Peltier refrigerator. The spectrometer is able to analyse samples of practically all most frequently encountered emitters of alpha, beta and low energy gamma radiation. The energy resolution were about 1.3-1.5 keV for 14 keV gamma radiation. The system can also operate in field conditions in the fluorescence analysis. (author)

  18. The Omicron Spectrometer

    CERN Document Server

    Allardyce, B W

    1976-01-01

    It is intended to build a spectrometer with a large solid angle and a large momentum acceptance at the reconstructed synchrocyclotron at CERN. This spectrometer will have an energy resolution of about 1 MeV for particles with momenta up to about 400 MeV/c.

  19. Axial skeletal CT densitometry

    International Nuclear Information System (INIS)

    Lampmann, L.E.H.

    1982-01-01

    Since the discovery of the Roentgen ray a precise and accurate assessment of bone mineral content has been a challenge to many investigators. A number of methods have been developed but no one satisfied. Considering its technical possibilities computed tomography is very promising in determination of bone mineral content (BMC). The new modality enables BMC estimations in the axial skeletal trabecular bone. CT densitometry can be performed on a normal commercially available third generation whole body CT scanner. No dedicated device in a special clinical set-up is necessary. In this study 106 patients, most of them clinically suspected of osteoporosis, were examined. The new method CT densitometry has been evaluated. The results have been correlated to alternative BMC determination methods. (Auth.)

  20. Axial polarizability and weak currents in nuclei

    International Nuclear Information System (INIS)

    Ericson, M.

    1977-01-01

    The weak interaction nucleonic coupling constants in nuclei are modified by the presence of the neighbouring nucleons. One type of modification is due to the virtual excitation of the isobars through meson exchange. The influence of the isobars is described by means of the nuclear axial polarizability coefficient. This polarizability is known; it is linked to the p-wave πN scattering volume. A relation is derived between the axial nuclear current and the pion field which incorporates the polarizability effects. This relation has an electromagnetic analogue. It is then possible to derive the axial and pseudoscalar coupling constants from a knowledge of the pion field. This field in turn obeys a Klein-Gordon equation which has to include the isobaric excitations. The propagation of the pion field is similar to that of an electromagnetic wave in a dielectric medium. The strong interaction coupling constant is shown to be renormalized in nuclei by the effect of the various types of correlations. (author)

  1. Wide swath imaging spectrometer utilizing a multi-modular design

    Science.gov (United States)

    Chrisp, Michael P.

    2010-10-05

    A wide swath imaging spectrometer utilizing an array of individual spectrometer modules in the telescope focal plane to provide an extended field of view. The spectrometer modules with their individual detectors are arranged so that their slits overlap with motion on the scene providing contiguous spatial coverage. The number of modules can be varied to take full advantage of the field of view available from the telescope.

  2. The effect of blood inflow and B(1)-field inhomogeneity on measurement of the arterial input function in axial 3D spoiled gradient echo dynamic contrast-enhanced MRI.

    Science.gov (United States)

    Roberts, Caleb; Little, Ross; Watson, Yvonne; Zhao, Sha; Buckley, David L; Parker, Geoff J M

    2011-01-01

    A major potential confound in axial 3D dynamic contrast-enhanced magnetic resonance imaging studies is the blood inflow effect; therefore, the choice of slice location for arterial input function measurement within the imaging volume must be considered carefully. The objective of this study was to use computer simulations, flow phantom, and in vivo studies to describe and understand the effect of blood inflow on the measurement of the arterial input function. All experiments were done at 1.5 T using a typical 3D dynamic contrast-enhanced magnetic resonance imaging sequence, and arterial input functions were extracted for each slice in the imaging volume. We simulated a set of arterial input functions based on the same imaging parameters and accounted for blood inflow and radiofrequency field inhomogeneities. Measured arterial input functions along the vessel length from both in vivo and the flow phantom agreed with simulated arterial input functions and show large overestimations in the arterial input function in the first 30 mm of the vessel, whereas arterial input functions measured more centrally achieve accurate contrast agent concentrations. Use of inflow-affected arterial input functions in tracer kinetic modeling shows potential errors of up to 80% in tissue microvascular parameters. These errors emphasize the importance of careful placement of the arterial input function definition location to avoid the effects of blood inflow. © 2010 Wiley-Liss, Inc.

  3. first principles derivation of a stress function for axially symmetric

    African Journals Online (AJOL)

    HOD

    found to be identical with the Love stress function. The stress function was then applied to solve the axially symmetric problem of finding the stress fields, strain fields and displacement fields in the semi-infinite linear elastic, isotropic homogeneous medium subject to a point load P acting at the origin of coordinates also ...

  4. Fourier Transform Spectrometer System

    Science.gov (United States)

    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.

  5. Improved Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Improved Mass Spectrometer project will develop system requirements and analyze the path to space qualification.   The results of this project...

  6. Micro Plasma Spectrometer

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this IRAD project is to develop a preliminary design elements of miniature electron and ion plasma spectrometers and supporting electronics, focusing...

  7. Digital positron annihilation spectrometer

    International Nuclear Information System (INIS)

    Cheng Bin; Weng Huimin; Han Rongdian; Ye Bangjiao

    2010-01-01

    With the high speed development of digital signal process, the technique of the digitization and processing of signals was applied in the domain of a broad class of nuclear technique. The development of digital positron lifetime spectrometer (DPLS) is more promising than the conventional positron lifetime spectrometer equipped with nuclear instrument modules. And digital lifetime spectrometer has many advantages, such as low noise, long term stability, flexible online or offline digital processing, simple setup, low expense, easy to setting, and more physical information. Digital constant fraction discrimination is for timing. And a new method of optimizing energy windows setting for digital positron lifetime spectrometer is also developed employing the simulated annealing for the convenient use. The time resolution is 220ps and the count rate is 200cps. (authors)

  8. Neutral Kaon Spectrometer 2

    Science.gov (United States)

    Kaneta, M.; Beckford, B.; Fujii, T.; Fujii, Y.; Futatsukawa, K.; Han, Y. C.; Hashimoto, O.; Hirose, K.; Ishikawa, T.; Kanda, H.; Kimura, C.; Maeda, K.; Nakamura, S. N.; Suzuki, K.; Tsukada, K.; Yamamoto, F.; Yamazaki, H.

    2018-04-01

    A large-acceptance spectrometer, Neutral Kaon Spectrometer 2 (NKS2), was newly constructed to explore various photoproduction reactions in the gigaelectronvolt region at the Laboratory of Nuclear Science (LNS, currently ELPH), Tohoku University. The spectrometer consisted of a dipole magnet, drift chambers, and plastic scintillation counters. NKS2 was designed to separate pions and protons in a momentum range of less than 1 GeV/ c, and was placed in a tagged photon beamline. A cryogenic H2/D2 target fitted to the spectrometer were designed. The design and performance of the detectors are described. The results of the NKS2 experiment on analyzing strangeness photoproduction data using a 0.8-1.1 GeV tagged photon beam are also presented.

  9. Characterization of Multiflux Axial Compressors

    International Nuclear Information System (INIS)

    Brasnarof, Daniel; Kyung Kyu-Hyung; Rivarola, Martin; Gonzalez Jose; Florido, Pablo; Orellano, Pablo; Bergallo, Juan

    2003-01-01

    In the present work the results of analytical models of performance are compared with experimental data acquired in the multi flux axial compressor test facility, built in The Pilcaniyeu Technological Complex for the SIGMA project.We describe the experimental circuit and the data of the dispersion inside the axial compressor obtained using a tracer gas through one of the annular inlets.The attained results can be used to validate the design code for the multi flux axial compressors and SIGMA industrial plant

  10. Axial magnetic field and toroidally streaming fast ions in the dense plasma focus are natural consequences of conservation laws in the curved axisymmetric geometry of the current sheath. II. Towards a first principles theory

    Science.gov (United States)

    Auluck, S. K. H.

    2017-11-01

    This paper continues earlier discussion [S. K. H. Auluck, Phys. Plasmas 21, 102515 (2014)] concerning the formulation of conservation laws of mass, momentum, and energy in a local curvilinear coordinate system in the dense plasma focus. This formulation makes use of the revised Gratton-Vargas snowplow model [S. K. H. Auluck, Phys. Plasmas 20, 112501 (2013)], which provides an analytically defined imaginary surface in three dimensions which resembles the experimentally determined shape of the plasma. Unit vectors along the local tangent to this surface, along the azimuth, and along the local normal define a right-handed orthogonal local curvilinear coordinate system. The simplifying assumption that physical quantities have significant variation only along the normal enables writing laws of conservation of mass, momentum, and energy in the form of effectively one-dimensional hyperbolic conservation law equations using expressions for various differential operators derived for this coordinate system. This formulation demonstrates the highly non-trivial result that the axial magnetic field and toroidally streaming fast ions, experimentally observed by multiple prestigious laboratories, are natural consequences of conservation of mass, momentum, and energy in the curved geometry of the dense plasma focus current sheath. The present paper continues the discussion in the context of a 3-region shock structure similar to the one experimentally observed: an unperturbed region followed by a hydrodynamic shock containing some current followed by a magnetic piston. Rankine-Hugoniot conditions are derived, and expressions are obtained for the specific volumes and pressures using the mass-flux between the hydrodynamic shock and the magnetic piston and current fraction in the hydrodynamic shock as unknown parameters. For the special case of a magnetic piston that remains continuously in contact with the fluid being pushed, the theory gives closed form algebraic results for the

  11. Study of neutron spectrometers for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Kaellne, Jan

    2005-11-15

    A review is presented of the developments in the field of neutron emission spectrometry (NES) which is of relevance for identifying the role of NES diagnostics on ITER and selecting suitable instrumentation. Neutron spectrometers will be part of the ITER neutron diagnostic complement and this study makes a special effort to examine which performance characteristics the spectrometers should possess to provide the best burning plasma diagnostic information together with neutron cameras and neutron yield monitors. The performance of NES diagnostics is coupled to how much interface space can be provided which has lead to an interest to find compact instruments and their NES capabilities. This study assesses all known spectrometer types of potential interest for ITER and makes a ranking of their performance (as demonstrated or projected), which, in turn, are compared with ITER measurement requirements as a reference; the ratio of diagnostic performance to interface cost for different spectrometers is also discussed for different spectrometer types. The overall result of the study is an assessment of which diagnostic functions neutron measurements can provide in burning plasma fusion experiments on ITER and the role that NES can play depending on the category of instrument installed. Of special note is the result that much higher quality diagnostic information can be obtained from neutron measurements with total yield monitors, profile flux cameras and spectrometers when the synergy in the data is considered in the analysis and interpretation.

  12. Fluorescence axial nanotomography with plasmonics.

    Science.gov (United States)

    Cade, Nicholas I; Fruhwirth, Gilbert O; Krasavin, Alexey V; Ng, Tony; Richards, David

    2015-01-01

    We present a novel imaging technique with super-resolution axial sensitivity, exploiting the changes in fluorescence lifetime above a plasmonic substrate. Using conventional confocal fluorescence lifetime imaging, we show that it is possible to deliver down to 6 nm axial position sensitivity of fluorophores in whole biological cell imaging. We employ this technique to map the topography of the cellular membrane, and demonstrate its application in an investigation of receptor-mediated endocytosis in carcinoma cells.

  13. A Review of the Handheld X-Ray Fluorescence Spectrometer as a Tool for Field Geologic Investigations on Earth and in Planetary Surface Exploration

    Science.gov (United States)

    Young, Kelsey E.; Evans, Cynthia A.; Hodges, Kip V.; Bleacher, Jacob E.; Graff, Trevor G.

    2016-01-01

    X-ray fluorescence (XRF) spectroscopy is a well-established and commonly used technique in obtaining diagnostic compositional data on geological samples. Recently, developments in X-ray tube and detector technologies have resulted in miniaturized, field-portable instruments that enable new applications both in and out of standard laboratory settings. These applications, however, have not been extensively applied to geologic field campaigns. This study investigates the feasibility of using developing handheld XRF (hXRF) technology to enhance terrestrial field geology, with potential applications in planetary surface exploration missions. We demonstrate that the hXRF is quite stable, providing reliable and accurate data continuously over a several year period. Additionally, sample preparation is proved to have a marked effect on the strategy for collecting and assimilating hXRF data. While the hXRF is capable of obtaining data that are comparable to laboratory XRF analysis for several geologically-important elements (such as Si, Ca, Ti, and K), the instrument is unable to detect other elements (such as Mg and Na) reliably. While this limits the use of the hXRF, especially when compared to laboratory XRF techniques, the hXRF is still capable of providing the field user with significantly improved contextual awareness of a field site, and more work is needed to fully evaluate the potential of this instrument in more complex geologic environments.

  14. The dilepton spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Yegneswaran, A.; Claesson, G.; Fulton, R.; Hendrie, D.L.; Krebs, G.F.; Lallier, E.; Letessier-Selvon, A.; Matis, H.S.; Mulera, T.; Naudet, C.; Nesbitt, D.; Roche, G.; Schroeder, L.S.; Seidl, P.A. (Lawrence Berkeley Lab., CA (USA)); Beedoe, S.; Bystricky, J.; Carroll, J.; Gordon, J.; Igo, G.; Oillataguerre, P. (California Univ., Los Angeles (USA)); Christo, S.; Gilot, J.F.; Kirk, P.; Wang, Z.; Xu, I. (Louisiana State Univ., Baton Rouge (USA)); Force, P.; Landaud, G. (Clermont-Ferrand-2 Univ., 63 - Aubiere (France)); Hallman, T.; Madansky, L.; Welsh, R. (Johns Hopkins Univ., Baltimore, MD (USA)); Miller, D. (Northwestern Univ., Evanston, IL (USA))

    1990-05-01

    The dilepton spectrometer (DLS) at Lawrence Berkeley Laboratory's Bevalac has been designed and constructed to investigate the production of electron-positron pairs with low mass and low transverse momentum in proton-nucleus and nucleus-nucleus collisions for incident-beam kinetic energies of 5 A GeV and less. This article briefly recalls the physics objectives of the program, discusses the methodology of the measurement, presents details of the design of the spectrometer and the detector elements, and reports on their performance. Selected experimental results are given to illustrate the capability of the DLS and to demonstrate the level to which it is possible to realize the physics objectives with the spectrometer. (orig.).

  15. Development of a portable cavity-enhanced absorption spectrometer for the measurement of ambient NO3 and N2O5: experimental setup, lab characterizations, and field applications in a polluted urban environment

    Science.gov (United States)

    Wang, Haichao; Chen, Jun; Lu, Keding

    2017-04-01

    A small and portable incoherent broadband cavity-enhanced absorption spectrometer (IBBCEAS) for NO3 and N2O5 measurement has been developed. The instrument features a mechanically aligned non-adjustable optical mounting system, and the novel design of the optical mounting system enables a fast setup and stable operation in field applications. To remove the influence of the strong nonlinear absorption by water vapour, a dynamic reference spectrum through NO titration is used for the spectrum analysis. The wall loss effects of the sample system were extensively studied, and the total transmission efficiencies were determined to be 85 and 55 % for N2O5 and NO3, respectively, for our experimental setup. The limit of detection (LOD) was estimated to be 2.4 pptv (1σ) and 2.7 pptv (1σ) at 1 s intervals for NO3 and N2O5, respectively. The associated uncertainty of the field measurement was estimated to be 19 % for NO3 and 22-36 % for N2O5 measurements from the uncertainties of transmission efficiency, absorption cross section, effective cavity length, and mirror reflectivity. The instrument was successfully deployed in two comprehensive field campaigns conducted in the winter and summer of 2016 in Beijing. Up to 1.0 ppb NO3+N2O5 was observed with the presence of high aerosol loadings, which indicates an active night-time chemistry in Beijing.

  16. Atlanto-Axial Subluxation After Adenoidectomy.

    Science.gov (United States)

    Gross, Isabel Theresia; Bahar-Posey, Laleh

    2017-06-01

    Atlanto-axial subluxation is a rare but potentially serious complication after otolaryngological procedures. We are describing a case of a 4-year-old child who developed atlanto-axial subluxation of the cervical spine after adenoidectomy. Our patient underwent adenoidectomy and, 18 days later, presented to the emergency department with her neck tilted to the left in a cock-robin position and complaining of neck pain persisting since the surgery. A multiplanar 3-dimensional computed tomography was obtained and confirmed the diagnosis of an atlanto-axial subluxation (Fielding type 3). She was managed conservatively with the application of a cervical collar, anti-inflammatory medication, and manual reduction under anesthesia later in the course because of persistence of her symptoms. It is important to consider this diagnosis in any child who undergoes ENT surgical procedures complaining of neck pain subsequent to surgery or holding the head in a fixed position persistently after surgery. Early diagnosis is important to reduce the time between the onset of symptoms and reduction to reduce the risk or need for surgical intervention.

  17. Bone formation in axial spondyloarthritis.

    Science.gov (United States)

    Lories, Rik J; Haroon, Nigil

    2014-10-01

    The success of targeted therapies directed against tumor necrosis factor for patients with spondyloarthritis has shifted the focus of physicians and scientists towards the prevention of structural damage to the involved structures, in particular the sacroiliac joints and the spine, to avoid loss of function and disability. Structural damage to the skeleton as witnessed by radiography mainly consists of new bone formation potentially progressively leading to spine or joint ankylosis. This important long-term outcome parameter has been difficult to study, not alone because the time window for change may be long but also because human tissues with direct translational relevance are rarely available. Data from rodent models have identified growth factor signaling pathways as relevant targets. Both human and animal studies have tried to understand the link between inflammation and new bone formation. At the current moment, most evidence points towards a strong link between both but with the question still lingering about the sequence of events, disease triggers, and the interdependence of both features of disease. New discoveries such as a masterswitch T cell population that carries the IL23 receptor and the analysis of auto-antibodies directed again noggin and sclerostin are contributing to innovative insights into the pathophysiology of disease. Long-term data with tumor necrosis factor (TNF) inhibitors also suggest that some window of opportunity may exist to inhibit structural disease progression. All these data provide support for a further critical analysis of the available datasets and boost research in the field. The introduction of novel disease definitions, in particular the characterization of non-radiographic axial spondyloarthritis patients, will likely be instrumental in our further understanding of structural damage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Development of triple axis neutron spectrometer (Paper No. 24)

    International Nuclear Information System (INIS)

    Pal, B.C.; Wadhwa, N.R.; Goveas, S.H.

    1987-02-01

    The triple axis neutron spectrometers are the basic instruments intended for use with neutron beams from reactors. Various types of spectrometers, each devoted to different kinds of measurement can be designed and manufactured, once a prototype having all the attributes of a versatile instrument is designed and developed. With the view to achieving self reliance in this field, Central Workshops of Bhabha Atomic Research Centre (BARC), Bombay designed and developed a prototype of triple axis spectrometer meeting the specifications prepared by Nuclear Physics Division of BARC . This spectrometer, with a moving wedge system was successfully manufactured and installed at 'DHRUVA'. Another version of this spectrometer, called the 'Polarised Neutron Spectrometer' was also built and exported to South Korea and installed at Korea Advanced Energy Research Institute, Seoul. This paper deals with basic concept, development of design, engineering of mechanical assemblies, the manufacturing approach and problems encountered during manufacture. (author). 3 figs

  19. Time-of-flight spectrometers

    International Nuclear Information System (INIS)

    Carrico, J.P.

    1976-01-01

    The flight time of an ion in an inhomogeneous, oscillatory electric field (IOFE) is an m/e-dependent property of this field and is independent of the initial position and velocity. The d.c. component of the equation of motion for an ion in the IOFE describes a harmonic oscillation of constant period. When ions oscillate for many periods with one species overtaking another the motion may no longer be truly periodic although the resulting period or 'quasi-period' still remains independent of the initial conditions. This period or 'quasi-period' is used in the time-of-flight mass spectrometer described. The principle of operation is also described and both analytical and experimental results are reported. (B.D.)

  20. Characteristics of unsteady flow field and flow-induced noise for an axial cooling fan used in a rack mount server computer Characteristics of unsteady flow field and flow-induced noise for an axial cooling fan used in a rack mount server computer

    International Nuclear Information System (INIS)

    Lim, Tae Gyun; Jeon, Wan Ho; Minorikawa, Gaku

    2016-01-01

    The recent development of small and lightweight rack mount servers and computers has resulted in the decrease of the size of cooling fans. However, internal fans still need to achieve a high performance to release the heat generated from interior parts, and they should emit low noise. On the contrary, measurement data, such as flow properties and flow visualizations, cannot be obtained easily when cooling fans are small. Thus, a numerical analysis approach is necessary for the performance evaluation and noise reduction of small cooling fans. In this study, the noise of a small cooling fan used for computers or servers was measured and then compared with the aeroacoustic noise result based on a numerical analysis. Three-dimensional Navier-Stokes equations were solved to predict the unsteady flow field and surface pressure fluctuation according to the blades and casing surface used. The simplified Ffowcs Williams and Hawkings equation was used to predict aeroacoustic noise by assuming that a dipole is the major cause of fan noise. Results of the aeroacoustic noise analysis agreed well with that of the experiment, and a tonal noise whose frequency was lower than the first blade passing frequency could be identified in the noise spectrum. This phenomenon is caused by the shape of the bell mouth. A coherence analysis was performed to examine the correlation between the shape of the cooling fan and the noise

  1. Characteristics of unsteady flow field and flow-induced noise for an axial cooling fan used in a rack mount server computer Characteristics of unsteady flow field and flow-induced noise for an axial cooling fan used in a rack mount server computer

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Tae Gyun; Jeon, Wan Ho [Technical Research Lab., CEDIC Co., Seoul (Korea, Republic of); Minorikawa, Gaku [Dept. of f Mechanical Engineering, Faculty of Science and Engineering, Hosei University, Tokyo (Japan)

    2016-10-15

    The recent development of small and lightweight rack mount servers and computers has resulted in the decrease of the size of cooling fans. However, internal fans still need to achieve a high performance to release the heat generated from interior parts, and they should emit low noise. On the contrary, measurement data, such as flow properties and flow visualizations, cannot be obtained easily when cooling fans are small. Thus, a numerical analysis approach is necessary for the performance evaluation and noise reduction of small cooling fans. In this study, the noise of a small cooling fan used for computers or servers was measured and then compared with the aeroacoustic noise result based on a numerical analysis. Three-dimensional Navier-Stokes equations were solved to predict the unsteady flow field and surface pressure fluctuation according to the blades and casing surface used. The simplified Ffowcs Williams and Hawkings equation was used to predict aeroacoustic noise by assuming that a dipole is the major cause of fan noise. Results of the aeroacoustic noise analysis agreed well with that of the experiment, and a tonal noise whose frequency was lower than the first blade passing frequency could be identified in the noise spectrum. This phenomenon is caused by the shape of the bell mouth. A coherence analysis was performed to examine the correlation between the shape of the cooling fan and the noise.

  2. The Omega spectrometer

    CERN Multimedia

    1972-01-01

    The Omega spectrometer which came into action during the year. An array of optical spark chambers can be seen withdrawn from the magnet aperture. In the 'igloo' above the magnet is located the Plumbicon camera system which collects information from the spark chambers.

  3. Speckle-based spectrometer

    DEFF Research Database (Denmark)

    Chakrabarti, Maumita; Jakobsen, Michael Linde; Hanson, Steen Grüner

    2015-01-01

    A novel spectrometer concept is analyzed and experimentally verified. The method relies on probing the speckle displacement due to a change in the incident wavelength. A rough surface is illuminated at an oblique angle, and the peak position of the covariance between the speckle patterns observed...

  4. MIRI spectrometer optical design

    NARCIS (Netherlands)

    Kruizinga, B.; Visser, H.; Pel, J.W.; Moddemeijer, K.; Smorenburg, C.

    2004-01-01

    MIRI (the Mid InfraRed Instrument) is one of the focal plane instruments of the James Webb Space Telescope. The instrument comprises a camera and a spectrometer module. The instrument plays the following key roles in the JWST science program. Discovery of the "first light". Assembly of galaxies:

  5. Magnetic spectrometer Grand Raiden

    International Nuclear Information System (INIS)

    Fujiwara, M.; Akimune, H.; Daito, I.; Fujimura, H.; Fujita, Y.; Hatanaka, K.; Ikegami, H.; Katayama, I.; Nagayama, K.; Matsuoka, N.; Morinobu, S.; Noro, T.; Yoshimura, M.; Sakaguchi, H.; Sakemi, Y.; Tamii, A.; Yosoi, M.

    1999-01-01

    A high-resolution magnetic spectrometer called 'Grand Raiden' is operated at the RCNP ring cyclotron facility in Osaka for nuclear physics studies at intermediate energies. This magnetic spectrometer has excellent ion-optical properties. In the design of the spectrometer, the second-order dispersion matching condition has been taken into account, and almost all the aberration terms such as (x vertical bar θ 3 ), (x vertical bar θφ 2 ), (x vertical bar θ 2 δ) and (x vertical bar θδ 2 ) in a third-order matrix calculation are optimized. A large magnetic rigidity of the spectrometer (K = 1400 MeV) gives a great advantage to measure the charge-exchange ( 3 He, t) reactions at 450 MeV. The ability of the high-resolution measurement has been demonstrated. Various coincidence measurements are performed to study the nuclear structures of highly excited states through decay properties of nuclear levels following nuclear reactions at intermediate energies

  6. Heat of vaporization spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, D. Jr.

    1979-03-01

    Multilayer desorption measurements of various substances adsorbed on a stainless-steel substrate are found to exhibit desorption profiles consistent with a zeroth-order desorption model. The singleness of the desorption transients together with their narrow peak widths makes the technique ideally suited for a heat of vaporization spectrometer for either substance analysis or identification.

  7. Heat of vaporization spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, D. Jr.

    1978-01-01

    Multilayer desorption measurements of various substances adsorbed on a stainless steel substrate are found to exhibit desorption profiles consistent with a zeroth order desorption model. The singleness of the desorption transients together with their narrow peak widths makes the technique ideally suited for a heat of vaporization spectrometer for either substance analysis or identification.

  8. Coastal Research Imaging Spectrometer

    Science.gov (United States)

    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

  9. Program for beam optical computation of axial symmetrical electrostatic systems

    International Nuclear Information System (INIS)

    Ke Jianlin; Wu Chunlei; Zhou Changgeng

    2012-01-01

    The beam optical computation of axial symmetrical electrostatic systems is very important in the design and test of low-energy accelerators such as Cock-Croft and Van de Graaf accelerators. In this paper, a program for the beam optical computation of these structures has been developed using transfer matrix method. The electrostatic field region is divided into several small intervals in the program, and then the beam envelope is calculated interval-to-interval from the axial potential distribution, which is calculated by other electromagnetic field simulation software such as Maxwell SV. Space charge effect is included so that the program can be used in the computation of intense beam, while nonlinear effect is beyond its ability. The program can be used in the calculation of beam optics in most complicated axial symmetrical electrostatic fields, and the computing time required is very short. (authors)

  10. Wide size range fast integrated mobility spectrometer

    Science.gov (United States)

    Wang, Jian

    2013-10-29

    A mobility spectrometer to measure a nanometer particle size distribution is disclosed. The mobility spectrometer includes a conduit and a detector. The conduit is configured to receive and provide fluid communication of a fluid stream having a charged nanometer particle mixture. The conduit includes a separator section configured to generate an electrical field of two dimensions transverse to a dimension associated with the flow of the charged nanometer particle mixture through the separator section to spatially separate charged nanometer particles of the charged nanometer particle mixture in said two dimensions. The detector is disposed downstream of the conduit to detect concentration and position of the spatially-separated nanometer particles.

  11. Characterization of a Carbon Nanotube Field Emission Electron Gun for the VAPoR Miniaturized Pyrolysis-Time-of-Flight Mass Spectrometer

    Science.gov (United States)

    Getty, Stephanie; Li, Mary; Costen, Nicholas; Hess, Larry; Feng, Steve; King, Todd; Brinckerhoff, William; Mahaffy, Paul; Glavin, Daniel

    2009-01-01

    We are developing the VAPoR (Volatile Analysis by Pyrolysis of Regolith) instrument towards studying soil composition, volatiles, and trapped noble gases in the polar regions of the Moon. VAPOR will ingest a soil sample and conduct analysis by pyrolysis and time-of-flight mass spectrometry (ToF-MS). Here, we describe miniaturization efforts within this development, including a carbon nanotube (CNT) field emission electron gun that is under consideration for use as the electron impact ionization source for the ToF-MS.

  12. CO-AXIAL DISCHARGES

    Science.gov (United States)

    Luce, J.S.; Smith, L.P.

    1960-11-22

    A method and apparatus are given for producing coaxial arc discharges in an evacuated enclosure and within a strong, confining magnetic field. The arcs are maintained at a high potential difference. Electrons will diffuse to the more positive arc from the negative arc, and positive ions will diffuse from the more positive arc to the negative arc. Coaxial arc discharges have the advantage that ions which return to strike the positive arc discharge will lose no energy since they do not strike a solid wall or electrode. Those discharges are useful in confining an ionized plasma between the discharges, and have the advantage of preventing impurities from the walls of the enclosure from entering ihe plasma area because of the arc barrier set up bv the cylindrical outer arc.

  13. In Situ Mass Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The In Situ Mass Spectrometer projects focuses on a specific subsystem to leverage advanced research for laser-based in situ mass spectrometer development...

  14. Characterization of MEMS FTIR spectrometer

    Science.gov (United States)

    Khalil, Diaa; Sabry, Yasser; Omran, Haitham; Medhat, Mostafa; Hafez, Amr; Saadany, Bassam

    2011-03-01

    In this work we present the full characterization of an optical MEMS Fourier Transform Infra Red FTIR spectrometer fabricated by Deep Reactive Ion Etching DRIE Technology on Silicon substrate. Both electrical and optical properties of the spectrometer are measured. The presented techniques allows to build an engineering model for the spectrometer and to predict its main specifications taking into account the specificity of the MEMS technology used in the spectrometer fabrication.

  15. The ISRU Field Tests 2010 and 2012 at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

    Science.gov (United States)

    Klingelhoefer, G.; Morris, R. V.; Blumers, M; Bernhardt, B.; Graff, T.

    2014-01-01

    The 2010 and 2012 In-Situ Resource Utilization Analogue Test (ISRU) [1] on the Mauna Kea volcano in Hawai'i was coordinated by the Northern Centre for Advanced Technology (NORCAT) in collaboration with the Canadian Space Agency (CSA), the German Aerospace Center (DLR), and the National Aeronautics and Space Administration (NASA), through the PISCES program. Several instruments were tested as reference candidates for future analogue testing at the new field test site at the Mauna Kea volcano in Hawai'i. The fine-grained, volcanic nature of the material is a suitable lunar and martian analogue, and can be used to test excavation, site preparation, and resource utilization techniques. The 2010 location Pu'u Hiwahine, a cinder cone located below the summit of Mauna Kea (19deg45'39.29" N, 155deg28'14.56" W) at an elevation of 2800 m, provides a large number of slopes, rock avalanches, etc. to perform mobility tests, site preparation or resource prospecting. Besides hardware testing of technologies and systems related to resource identification, also in situ science measurements played a significant role in integration of ISRU and science instruments. For the advanced Mössbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform Xray fluorescence analysis simultaneously to Mössbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The 2010 and 2012 field campaigns demonstrated that in-situ Mössbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments.

  16. Long-term field performance of a tunable diode laser absorption spectrometer for analysis of carbon isotopes of CO2 in forest air

    Directory of Open Access Journals (Sweden)

    D. R. Bowling

    2008-09-01

    Full Text Available Tunable diode laser absorption spectrometry (TDLAS is gaining in popularity for measuring the mole fraction [CO2] and stable isotopic composition (δ13C of carbon dioxide (CO2 in air in studies of biosphere-atmosphere gas exchange. Here we present a detailed examination of the performance of a commercially-available TDLAS located in a high-altitude subalpine coniferous forest (the Niwot Ridge AmeriFlux site, providing the first multi-year analysis of TDLAS instrument performance for measuring CO2 isotopes in the field. Air was sampled from five to nine vertical locations in and above the forest canopy every ten minutes for 2.4 years. A variety of methods were used to assess instrument performance. Measurement of two compressed air cylinders that were in place over the entire study establish the long-term field precision of 0.2 μmol mol−1 for [CO2] and 0.35‰ for δ13C, but after fixing several problems the isotope precision improved to 0.2permil (over the last several months. The TDLAS provided detail on variability of δ13C of atmospheric CO2 that was not represented in weekly flask samples, as well as information regarding the influence of large-scale (regional seasonal cycle and local forest processes on [CO2] and δ13C of CO2. There were also clear growing season and winter differences in the relative contributions of photosynthesis and respiration on the [CO2] and δ13C of forest air.

  17. Reactive control of subsonic axial fan noise in a duct.

    Science.gov (United States)

    Liu, Y; Choy, Y S; Huang, L; Cheng, L

    2014-10-01

    Suppressing the ducted fan noise at low frequencies without varying the flow capacity is still a technical challenge. This study examines a conceived device consisting of two tensioned membranes backed with cavities housing the axial fan for suppression of the sound radiation from the axial fan directly. The noise suppression is achieved by destructive interference between the sound fields from the axial fan of a dipole nature and sound radiation from the membrane via vibroacoustics coupling. A two-dimensional model with the flow effect is presented which allows the performance of the device to be explored analytically. The air flow influences the symmetrical behavior and excites the odd in vacuo mode response of the membrane due to kinematic coupling. Such an asymmetrical effect can be compromised with off-center alignment of the axial fan. Tension plays an important role to sustain the performance to revoke the deformation of the membrane during the axial fan operation. With the design of four appropriately tensioned membranes covered by a cylindrical cavity, the first and second blade passage frequencies of the axial fan can be reduced by at least 20 dB. The satisfactory agreement between experiment and theory demonstrates that its feasibility is practical.

  18. Axial structure of the nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Veronique Bernard; Latifa Elouadrhiri; Ulf-G Meissner

    2002-01-01

    We review the current status of experimental and theoretical understanding of the axial nucleon structure at low and moderate energies. Topics considered include (quasi)elastic (anti)neutrino-nucleon scattering, charged pion electroproduction off nucleons and ordinary as well as radiative muon capture on the proton.

  19. Axial stability of Taylor bubbles

    NARCIS (Netherlands)

    Lu, X.; Prosperetti, Andrea

    2006-01-01

    Long gas bubbles rising in a vertical tube are observed to lose axial symmetry and become unstable in a downward liquid flow. In this paper an approximate linear stability analysis of this phenomenon is presented. It is found that, under the combined effect of gravity and the pressure gradient which

  20. FAST NEUTRON SPECTROMETER

    Science.gov (United States)

    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.

  1. Mark III spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, D.; Bernstein, J.; Bunnell, K.; Burgueno, G.; Cassell, R.; Collins, B.; Coward, D.; Einsweiler, K.; Eisele, R.; Haber, B.

    1984-10-01

    This paper describes the design, construction and performance of the Mark III, a new general purpose large solid angle spectrometer at SPEAR, the SLAC 2-8 GeV e/sup +/e storage ring. The detector has been designed for the study of exclusive final states in e/sup +/e annihilation, which requires large solid angle coverage combined with charged particle momentum resolution, particle identification, and photon detection efficiency at low energies. (orig.).

  2. Mark III spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, D.; Bernstein, J.; Bunnell, K.; Burgueno, G.; Cassell, R.; Collins, B.; Coward, D.; Einsweiler, K.; Eisele, R.; Haber, B. (Stanford Linear Accelerator Center, CA (USA))

    1984-10-01

    This paper describes the design, construction and performance of the Mark III, a new general purpose large solid angle spectrometer at SPEAR, the SLAC 2-8 GeV e/sup +/e/sup -/ storage ring. The detector has been designed for the study of exclusive final states in e/sup +/e/sup -/ annihilation, which requires large solid angle coverage combined with charged particle momentum resolution, particle identification, and photon detection efficiency at low energies.

  3. Magnetic spectrometer control system

    International Nuclear Information System (INIS)

    Lecca, L.A.; Di Paolo, Hugo; Fernandez Niello, Jorge O.; Marti, Guillermo V; Pacheco, Alberto J.; Ramirez, Marcelo

    2003-01-01

    The design and implementation of a new computerized control system for the several devices of the magnetic spectrometer at TANDAR Laboratory is described. This system, as a main difference from the preexisting one, is compatible with almost any operating systems of wide spread use available in PC. This allows on-line measurement and control of all signals from any terminal of a computer network. (author)

  4. ALICE photon spectrometer crystals

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    Members of the mechanical assembly team insert the last few crystals into the first module of ALICE's photon spectrometer. These crystals are made from lead-tungstate, a crystal as clear as glass but with nearly four times the density. When a high-energy particle passes through one of these crystals it will scintillate, emitting a flash of light allowing the energy of photons, electrons and positrons to be measured.

  5. Miniaturized Ion Mobility Spectrometer

    Science.gov (United States)

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

    2017-01-01

    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 (IMS) 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 degrees Centigrade, and is uniquely sensitive, particularly to explosive chemicals.

  6. A spectrometer for the NSF

    International Nuclear Information System (INIS)

    Sanderson, N.E.

    1979-01-01

    It is shown that the capabilities of a magnetic spectrometer are needed to fully exploit the research programme involving charged particle detection to be carried out on the Nuclear Structure Facility (NSF) presently under construction at Daresbury. Performance requirements for such a spectrometer are examined indicating that the QMG/2 spectrometer of the Groningen type is very well suited to the high resolution work which will be possible using beams of light - heavy ions (A < 40). Consequently, and following the recommendations of the Magnetic Spectrometer Working Party, this spectrometer is to be installed at the NSF. (U.K.)

  7. Metamorphosis of helical magnetorotational instability in the presence axial electric current

    OpenAIRE

    Priede, Jānis

    2014-01-01

    This paper presents numerical linear stability analysis of a cylindrical Taylor-Couette flow of liquid metal carrying axial electric current in a generally helical external magnetic field. Axially symmetric disturbances are considered in the inductionless approximation corresponding to zero magnetic Prandtl number. Axial symmetry allows us to reveal an entirely new electromagnetic instability. First, we show that the electric current passing through the liquid can extend the range of helical ...

  8. Axial anomaly and magnetism of nuclear and quark matter

    Science.gov (United States)

    Son, D. T.; Stephanov, M. A.

    2008-01-01

    We consider the response of the QCD ground state at finite baryon density to a strong magnetic field B. We point out the dominant role played by the coupling of neutral Goldstone bosons, such as π0, to the magnetic field via the axial triangle anomaly. We show that, in vacuum, above a value of B˜mπ2/e, a metastable object appears—the π0 domain wall. Because of the axial anomaly, the wall carries a baryon number surface density proportional to B. As a result, for B≳1019G a stack of parallel π0 domain walls is energetically more favorable than nuclear matter at the same density. Similarly, at higher densities, somewhat weaker magnetic fields of order B≳1017 1018G transform the color-superconducting ground state of QCD into new phases containing stacks of axial isoscalar (η or η') domain walls. We also show that a quark-matter state known as “Goldstone current state,” in which a gradient of a Goldstone field is spontaneously generated, is ferromagnetic due to the axial anomaly. We estimate the size of the fields created by such a state in a typical neutron star to be of order 1014 1015G.

  9. Size and mass determination of silver nanoparticles in an aqueous matrix using asymmetric flow field flow fractionation coupled to inductively coupled plasma mass spectrometer and ultraviolet-visible detectors.

    Science.gov (United States)

    Geiss, Otmar; Cascio, Claudia; Gilliland, Douglas; Franchini, Fabio; Barrero-Moreno, Josefa

    2013-12-20

    The powerful antibacterial properties of engineered silver nanoparticles (AgNPs) have, in recent years, led to a great increase in their use in consumer products such as textiles and personal care products offers. This widespread and often indiscriminate use of nano-silver is inevitably increasing the probability that such materials be accidentally or deliberately lost into the environment. Once present in the environment the normally useful antibacterial properties of the silver may instead become a potential hazard to both man and the environment. In the face of such concerns it therefore desirable to develop easy, reliable and sensitive analytical methods for the determination of nano-sized silver in various matrices. This paper describes a method for the simultaneous determination of particles-size and mass-concentration of citrate-stabilized silver nano-particles in aqueous matrices by asymmetric flow field flow fractionation coupled to an ICP-mass spectrometer and UV/vis detector. In particular, this work has evaluated the use of pre-channel injections of mono-dispersed silver nano-particles as a means of accurate size and mass-calibration. The suitability of the method as a means to generate accurate and reliable results was verified by determination of parameters such as precision under repeatability conditions, linearity, accuracy, recovery and analytical sensitivity. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Continuous millennial decrease of the Earth's magnetic axial dipole

    Science.gov (United States)

    Poletti, Wilbor; Biggin, Andrew J.; Trindade, Ricardo I. F.; Hartmann, Gelvam A.; Terra-Nova, Filipe

    2018-01-01

    Since the establishment of direct estimations of the Earth's magnetic field intensity in the first half of the nineteenth century, a continuous decay of the axial dipole component has been observed and variously speculated to be linked to an imminent reversal of the geomagnetic field. Furthermore, indirect estimations from anthropologically made materials and volcanic derivatives suggest that this decrease began significantly earlier than direct measurements have been available. Here, we carefully reassess the available archaeointensity dataset for the last two millennia, and show a good correspondence between direct (observatory/satellite) and indirect (archaeomagnetic) estimates of the axial dipole moment creating, in effect, a proxy to expand our analysis back in time. Our results suggest a continuous linear decay as the most parsimonious long-term description of the axial dipole variation for the last millennium. We thus suggest that a break in the symmetry of axial dipole moment advective sources occurred approximately 1100 years earlier than previously described. In addition, based on the observed dipole secular variation timescale, we speculate that the weakening of the axial dipole may end soon.

  11. Simulations of axial B-dot monitors inside a groove in the beam pipe

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiaozhong, E-mail: hexiaozhong@tsinghua.org.cn [Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, Sichuan (China); Pang, Jian; Li, Qin [Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang, Sichuan (China); Du, Yingchao [Department of Engineering Physics, Tsinghua University, Beijing (China)

    2013-11-21

    Beam tilt measurement is important for understanding the beam dynamics. Our previous theoretical studies and simulations have shown that the axial B-dot in smooth beam pipe can be used to measure the beam tilt directly. Practical azimuthal B-dot loops typically are placed inside a groove in the beam pipe to avoid direct beam interception. For the same purpose, practical axial B-dot loops should also be placed inside such a groove. In this paper, responses of axial magnetic field to the beam tilt and to the beam offset, in the presence of the groove, are investigated by simulations. The simulation results show that the axial magnetic field in the central plane of the groove is proportional to the beam tilt and independent on the centroid position. The ratio between the axial magnetic field and the beam tilt depends on the position of the axial B-dot loop and the dimensions of the groove. -- Highlights: •MAFIA simulations were carried out to analyze the influence of recessed groove to axial B dots. •It is found that axial B dots still works in the central plane of the recessed groove. •The dimensions of the groove greatly influence the signal strength of axial B dots. •Results can be used for future optimizations.

  12. Current scaling of axially radiated power in dynamic hohlraums and dynamic hohlraum load design for ZR

    International Nuclear Information System (INIS)

    Mock, Raymond Cecil; Nash, Thomas J.; Sanford, Thomas W. L.

    2007-01-01

    We present designs for dynamic hohlraum z-pinch loads on the 28 MA, 140 ns driver ZR. The scaling of axially radiated power with current in dynamic hohlraums is reviewed. With adequate stability on ZR this scaling indicates that 30 TW of axially radiated power should be possible. The performance of the dynamic hohlraum load on the 20 MA, 100 ns driver Z is extensively reviewed. The baseline z-pinch load on Z is a nested tungsten wire array imploding onto on-axis foam. Data from a variety of x-ray diagnostics fielded on Z are presented. These diagnostics include x-ray diodes, bolometers, fast x-ray imaging cameras, and crystal spectrometers. Analysis of these data indicates that the peak dynamic radiation temperature on Z is between 250 and 300 eV from a diameter less than 1 mm. Radiation from the dynamic hohlraum itself or from a radiatively driven pellet within the dynamic hohlraum has been used to probe a variety of matter associated with the dynamic hohlraum: the tungsten z-pinch itself, tungsten sliding across the end-on apertures, a titanium foil over the end aperture, and a silicon aerogel end cap. Data showing the existence of asymmetry in radiation emanating from the two ends of the dynamic hohlraum is presented, along with data showing load configurations that mitigate this asymmetry. 1D simulations of the dynamic hohlraum implosion are presented and compared to experimental data. The simulations provide insight into the dynamic hohlraum behavior but are not necessarily a reliable design tool because of the inherently 3D behavior of the imploding nested tungsten wire arrays

  13. Numerical simulation of breakup and detachment of an axially ...

    Indian Academy of Sciences (India)

    Kishore Singh Patel

    Abstract. The extensional, breakup and detachment dynamics of an axially stretching Newtonian liquid bridge are investigated numerically with a dynamic domain multiphase incompressible flow solver. The mul- tiphase flow solver employs a Cahn–Hilliard phase field model to describe the evolution of the diffuse interface.

  14. Portable, low-power, mechanically cooled Ge spectrometer

    International Nuclear Information System (INIS)

    Becker, J.A.; Cork, C.P.; Fabris, L.; Madden, N.W.

    2003-01-01

    A light-weight portable mechanically cooled γ-ray spectrometer has been constructed and tested. The spectrometer is based on a high-purity n-type Ge coaxial crystal, ∼5 cm longx5 cm diameter, a small, low-power Stirling cycle microcooler, and a low-power custom electronics package. The energy resolution of the spectrometer is ∼3.5 keV at E γ =662 keV, the power requirements are ∼15 W DC, and the combined weight of the Ge, housing, and controller is approximately 10 pounds. The spectrometer qualifies therefore as ''hand held''. It is suitable for field operations, because of its light-weight, low-power draw, and operational lifetime. The microcooler itself has a MTBF >30,000 h, and the spectrometer runs for several months (at least 6) before a 2 day recycle is required

  15. MASS SPECTROMETER LEAK

    Science.gov (United States)

    Shields, W.R.

    1960-10-18

    An improved valve is described for precisely regulating the flow of a sample fluid to be analyzed, such as in a mass spectrometer, where a gas sample is allowed to "leak" into an evacuated region at a very low, controlled rate. The flow regulating valve controls minute flow of gases by allowing the gas to diffuse between two mating surfaces. The structure of the valve is such as to prevent the corrosive feed gas from contacting the bellows which is employed in the operation of the valve, thus preventing deterioration of the bellows.

  16. Light-front view of the axial anomaly

    International Nuclear Information System (INIS)

    Ji, C.; Rey, S.

    1996-01-01

    Motivated by an apparent puzzle of the light-front vacua incompatible with the axial anomaly, we have considered the two-dimensional massless Schwinger model for an arbitrary interpolating angle of Hornbostel close-quote s interpolating quantization surface. By examining spectral deformation of the Dirac sea under an external electric field semiclassically, we have found that the axial anomaly is quantization angle independent. This indicates an intricate nontrivial vacuum structure present even in the light-front limit. copyright 1996 The American Physical Society

  17. The SPEDE electron spectrometer

    CERN Document Server

    O'Neill, George

    This thesis presents SPEDE (SPectrometer for Electron DEtection) and documents its construction, testing and performance during commissioning at Jyvaskyla, Finland, before deployment at the HIE-ISOLDE facility at CERN coupled with the MINIBALL array to perform in-beam electron-gamma spectroscopy using post-accelerated radioactive ion beams. Commissioning experiments took place in two two-day stints during spring 2015, coupled with several JUROGAMII gamma-detectors. This spectrometer will help aid in fully understanding exotic regions of the nuclear chart such as regions with a high degree of octupole deformation, and in those nuclei exhibiting shape coexistence. For the rst time, electron spectroscopy has been performed at the target position from states populated in accelerated nuclei via Coulomb excitation. The FWHM of SPEDE is approximately 7 keV at 320 keV, and Doppler correction was possible to improve Doppler broadened peaks. The results are intended to give the reader a full understanding of the dete...

  18. LADEE Neutral Mass Spectrometer Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains the data collected by the Neutral Mass Spectrometer (NMS) instrument aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE)...

  19. Development and Testing of an Axial Halbach Magnetic Bearing

    Science.gov (United States)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2006-01-01

    The NASA Glenn Research Center has developed and tested a revolutionary Axial Halbach Magnetic Bearing. The objective of this work is to develop a viable non-contact magnetic thrust bearing utilizing Halbach arrays for all-electric flight, and many other applications. This concept will help to reduce harmful emissions, reduce the Nation s dependence on fossil fuels and mitigate many of the concerns and limitations encountered in conventional axial bearings such as bearing wear, leaks, seals and friction loss. The Axial Halbach Magnetic Bearing is inherently stable and requires no active feedback control system or superconductivity as required in many magnetic bearing designs. The Axial Halbach Magnetic Bearing is useful for very high speed applications including turbines, instrumentation, medical systems, computer memory systems, and space power systems such as flywheels. Magnetic fields suspend and support a rotor assembly within a stator. Advanced technologies developed for particle accelerators, and currently under development for maglev trains and rocket launchers, served as the basis for this application. Experimental hardware was successfully designed and developed to validate the basic principles and analyses. The report concludes that the implementation of Axial Halbach Magnetic Bearings can provide significant improvements in rotational system performance and reliability.

  20. Design and Test of Portable Hyperspectral Imaging Spectrometer

    Directory of Open Access Journals (Sweden)

    Chunbo Zou

    2017-01-01

    Full Text Available We design and implement a portable hyperspectral imaging spectrometer, which has high spectral resolution, high spatial resolution, small volume, and low weight. The flight test has been conducted, and the hyperspectral images are acquired successfully. To achieve high performance, small volume, and regular appearance, an improved Dyson structure is designed and used in the hyperspectral imaging spectrometer. The hyperspectral imaging spectrometer is suitable for the small platform such as CubeSat and UAV (unmanned aerial vehicle, and it is also convenient to use for hyperspectral imaging acquiring in the laboratory and the field.

  1. The nanopore mass spectrometer

    Science.gov (United States)

    Bush, Joseph; Maulbetsch, William; Lepoitevin, Mathilde; Wiener, Benjamin; Mihovilovic Skanata, Mirna; Moon, Wooyoung; Pruitt, Cole; Stein, Derek

    2017-11-01

    We report the design of a mass spectrometer featuring an ion source that delivers ions directly into high vacuum from liquid inside a capillary with a sub-micrometer-diameter tip. The surface tension of water and formamide is sufficient to maintain a stable interface with high vacuum at the tip, and the gas load from the interface is negligible, even during electrospray. These conditions lifted the usual requirement of a differentially pumped system. The absence of a background gas also opened up the possibility of designing ion optics to collect and focus ions in order to achieve high overall transmission and detection efficiencies. We describe the operation and performance of the instrument and present mass spectra from solutions of salt ions and DNA bases in formamide and salt ions in water. The spectra show singly charged solute ions clustered with a small number of solvent molecules.

  2. BNL multiparticle spectrometer software

    International Nuclear Information System (INIS)

    Saulys, A.C.

    1984-01-01

    This paper discusses some solutions to problems common to the design, management and maintenance of a large high energy physics spectrometer software system. The experience of dealing with a large, complex program and the necessity of having the program controlled by various people at different levels of computer experience has led us to design a program control structure of mnemonic and self-explanatory nature. The use of this control language in both on-line and off-line operation of the program will be discussed. The solution of structuring a large program for modularity so that substantial changes to the program can be made easily for a wide variety of high energy physics experiments is discussed. Specialized tools for this type of large program management are also discussed

  3. Comparison of a transmission grating spectrometer to a reflective grating spectrometer for standoff laser-induced breakdown spectroscopy measurements

    International Nuclear Information System (INIS)

    Weisberg, Arel; Craparo, Joseph; De Saro, Robert; Pawluczyk, Romuald

    2010-01-01

    We evaluate a new transmission grating spectrometer for standoff laser-induced breakdown spectroscopy (LIBS) measurements. LIBS spectra collected from standoff distances are often weak, with smaller peaks blending into the background and noise. Scattered light inside the spectrometer can also contribute to poor signal-to-background and signal-to-noise ratios for smaller emission peaks. Further, collecting standoff spectra can be difficult because most spectrometers are designed for laboratory environments and not for measurements in the field. To address these issues, a custom-designed small, lightweight transmission grating spectrometer with no moving parts was built that is well suited for standoff LIBS field measurements. The performance of the spectrometer was quantified through 10 m standoff LIBS measurements collected from aluminum alloy samples and measurements from spectra of a Hg-Ar lamp. The measurements were compared to those collected using a Czerny-Turner reflective grating spectrometer that covered a similar spectral range and used the same ICCD camera. Measurements using the transmission grating spectrometer had a 363% improved signal-to-noise ratio when measured using the 669 nm aluminum emission peak.

  4. The Philippine spectrometer

    International Nuclear Information System (INIS)

    Juliano, J.O.

    1965-01-01

    A notable project for international collaboration, in which participants from Indonesia, Korea, Thailand, China and the Philippines are working together, has been launched in the Philippines with Indian assistance under the aegis of the Agency. This is a regional training and research programme using a neutron crystal spectrometer, which has been established since January 1965 at the Philippine Atomic Research Centre in Diliman, Quezon City, Philippines. It is called the IPA Project after the signatories to a five year trilateral agreement, namely, the Government of India,the Republic of the Philippines, and the International Atomic Energy Agency. The programme is administered by a Joint Committee composed of one representative each of the Philippines, India and the Agency. The objective of this cooperative venture is to establish a research centre on neutron diffraction in which scientists and technicians from any Member State of IAEA in South Asia, South-East Asia and Pacific, or Far East regions could come to participate in research and training. Studies in solid state physics, such a s the structure determination of alloys and organic crystals, studies on the orientation of magnetic moments in the lattice of magnetic substances, and other problems based on elastic and inelastic scattering of neutrons are undertaken. There are a number of research reactors in this region where neutron spectrometers can be utilized and the recent establishment of this cooperative international research and training programme has been a timely one for this area of the world. Indeed, a number of other countries have shown a strong growing interest in the development of the project

  5. Magnetic quadrupole and solenoidal spectrometers

    International Nuclear Information System (INIS)

    Laurent, H.; Schapira, J.P.

    1979-01-01

    General optical properties of magnetic quadrupole spectrometers are reviewed, together with experimental purposes for nuclear physics: background reduction, magnetic rigidity filtering for extreme forward angles measurements, light charged particle discrimination, ionic charge state separation, time of flight mass spectrometry and fast collection of radioactive nuclear reaction products. Possibility of alternative devices such as superconducting quadrupoles or solenoid spectrometers are discussed. (Auth.)

  6. The ALICE forward muon spectrometer

    Indian Academy of Sciences (India)

    ICE detector will allow to identify the quarkonium states through both the dielectron and the dimuon channels. For this purpose the apparatus is equipped with a transition radiation detector in its central part and with a forward muon spectrometer at small angles. After a brief description of the forward muon spectrometer, ...

  7. ATF beamline 1 analysis spectrometer

    International Nuclear Information System (INIS)

    Fernow, R.C.; Kirk, H.G.; Ulc, S.

    1993-01-01

    We describe the design parameters and expected performance of the analysis spectrometer for beamline 1 at the BNL Accelerator Test Facility. The spectrometer should be well suited for measuring the change in energy caused by the first generation laser acceleration experiments

  8. Calibration and field testing of cavity ring-down laser spectrometers measuring CH4, CO2, and δ13CH4 deployed on towers in the Marcellus Shale region

    Science.gov (United States)

    Miles, Natasha L.; Martins, Douglas K.; Richardson, Scott J.; Rella, Christopher W.; Arata, Caleb; Lauvaux, Thomas; Davis, Kenneth J.; Barkley, Zachary R.; McKain, Kathryn; Sweeney, Colm

    2018-03-01

    Four in situ cavity ring-down spectrometers (G2132-i, Picarro, Inc.) measuring methane dry mole fraction (CH4), carbon dioxide dry mole fraction (CO2), and the isotopic ratio of methane (δ13CH4) were deployed at four towers in the Marcellus Shale natural gas extraction region of Pennsylvania. In this paper, we describe laboratory and field calibration of the analyzers for tower-based applications and characterize their performance in the field for the period January-December 2016. Prior to deployment, each analyzer was tested using bottles with various isotopic ratios, from biogenic to thermogenic source values, which were diluted to varying degrees in zero air, and an initial calibration was performed. Furthermore, at each tower location, three field tanks were employed, from ambient to high mole fractions, with various isotopic ratios. Two of these tanks were used to adjust the calibration of the analyzers on a daily basis. We also corrected for the cross-interference from ethane on the isotopic ratio of methane. Using an independent field tank for evaluation, the standard deviation of 4 h means of the isotopic ratio of methane difference from the known value was found to be 0.26 ‰ δ13CH4. Following improvements in the field tank testing scheme, the standard deviation of 4 h means was 0.11 ‰, well within the target compatibility of 0.2 ‰. Round-robin style testing using tanks with near-ambient isotopic ratios indicated mean errors of -0.14 to 0.03 ‰ for each of the analyzers. Flask to in situ comparisons showed mean differences over the year of 0.02 and 0.08 ‰, for the east and south towers, respectively. Regional sources in this region were difficult to differentiate from strong perturbations in the background. During the afternoon hours, the median differences of the isotopic ratio measured at three of the towers, compared to the background tower, were &minus0.15 to 0.12 ‰ with standard deviations of the 10 min isotopic ratio differences of 0.8

  9. Calibration and field testing of cavity ring-down laser spectrometers measuring CH4, CO2, and δ13CH4 deployed on towers in the Marcellus Shale region

    Directory of Open Access Journals (Sweden)

    N. L. Miles

    2018-03-01

    Full Text Available Four in situ cavity ring-down spectrometers (G2132-i, Picarro, Inc. measuring methane dry mole fraction (CH4, carbon dioxide dry mole fraction (CO2, and the isotopic ratio of methane (δ13CH4 were deployed at four towers in the Marcellus Shale natural gas extraction region of Pennsylvania. In this paper, we describe laboratory and field calibration of the analyzers for tower-based applications and characterize their performance in the field for the period January–December 2016. Prior to deployment, each analyzer was tested using bottles with various isotopic ratios, from biogenic to thermogenic source values, which were diluted to varying degrees in zero air, and an initial calibration was performed. Furthermore, at each tower location, three field tanks were employed, from ambient to high mole fractions, with various isotopic ratios. Two of these tanks were used to adjust the calibration of the analyzers on a daily basis. We also corrected for the cross-interference from ethane on the isotopic ratio of methane. Using an independent field tank for evaluation, the standard deviation of 4 h means of the isotopic ratio of methane difference from the known value was found to be 0.26 ‰ δ13CH4. Following improvements in the field tank testing scheme, the standard deviation of 4 h means was 0.11 ‰, well within the target compatibility of 0.2 ‰. Round-robin style testing using tanks with near-ambient isotopic ratios indicated mean errors of −0.14 to 0.03 ‰ for each of the analyzers. Flask to in situ comparisons showed mean differences over the year of 0.02 and 0.08 ‰, for the east and south towers, respectively. Regional sources in this region were difficult to differentiate from strong perturbations in the background. During the afternoon hours, the median differences of the isotopic ratio measured at three of the towers, compared to the background tower, were &minus0.15 to 0.12 ‰ with standard deviations of the 10

  10. 3-D Simulation of Vertical-Axial Tidal Current Turbine

    Directory of Open Access Journals (Sweden)

    Zhiyang Zhang

    2016-12-01

    Full Text Available Vertical-axial tidal current turbine is the key for the energy converter, which has the advantages of simple structure, adaptability to flow and uncomplex convection device. It has become the hot point for research and application recently. At present, the study on the hydrodynamic performance of vertical-axial tidal current turbine is almost on 2-D numerical simulation, without the consideration of 3-D effect. CFD (Computational Fluid Dynamics method and blade optimal control technique are used to improve accuracy in the prediction of tidal current turbine hydrodynamic performance. Numerical simulation of vertical-axial tidal current turbine is validated. Fixed and variable deflection angle turbine are comparatively studied to analysis the influence of 3-D effect and the character of fluid field and pressure field. The method, put the plate on the end of blade, of reduce the energy loss caused by 3-D effect is proposed. The 3-D CFD numerical model of vertical-axial tidal current turbine hydrodynamic performance in this study may provide theoretical, methodical and technical reference for the optimal design of turbine.

  11. Sensing systems using chip-based spectrometers

    Science.gov (United States)

    Nitkowski, Arthur; Preston, Kyle J.; Sherwood-Droz, Nicolás.; Behr, Bradford B.; Bismilla, Yusuf; Cenko, Andrew T.; DesRoches, Brandon; Meade, Jeffrey T.; Munro, Elizabeth A.; Slaa, Jared; Schmidt, Bradley S.; Hajian, Arsen R.

    2014-06-01

    Tornado Spectral Systems has developed a new chip-based spectrometer called OCTANE, the Optical Coherence Tomography Advanced Nanophotonic Engine, built using a planar lightwave circuit with integrated waveguides fabricated on a silicon wafer. While designed for spectral domain optical coherence tomography (SD-OCT) systems, the same miniaturized technology can be applied to many other spectroscopic applications. The field of integrated optics enables the design of complex optical systems which are monolithically integrated on silicon chips. The form factors of these systems can be significantly smaller, more robust and less expensive than their equivalent free-space counterparts. Fabrication techniques and material systems developed for microelectronics have previously been adapted for integrated optics in the telecom industry, where millions of chip-based components are used to power the optical backbone of the internet. We have further adapted the photonic technology platform for spectroscopy applications, allowing unheard-of economies of scale for these types of optical devices. Instead of changing lenses and aligning systems, these devices are accurately designed programmatically and are easily customized for specific applications. Spectrometers using integrated optics have large advantages in systems where size, robustness and cost matter: field-deployable devices, UAVs, UUVs, satellites, handheld scanning and more. We will discuss the performance characteristics of our chip-based spectrometers and the type of spectral sensing applications enabled by this technology.

  12. Various experiments with the omicron spectrometer

    CERN Document Server

    Allardyce, Brian W; Bailey, J; Bos, K; Bressani, Tullio; Chiavassa, E; Costa, S; Davies, J D; Dellacasa, G; Frame, D; Gallio, M; Kernel, G; Michaelis, E G; Musso, A; Panighini, M; Stanovnik, A; Tanner, N W; Van Dantzig, R; Van Doesburg, W

    1977-01-01

    A series of experiments are to be performed using a spectrometer with both a large solid angle and a large momentum acceptance; it will have an energy resolution of about 1 MeV for particles with momenta up to about 400 MeV/c. Pion scattering from light nuclei will be the prime use of the spectrometer. The spectrometer consists of a large magnet with a usable field volume of 1 m*2 m*0.85 m. The magnetic field is homogeneous to within about 10% over this volume, in which it is intended to place planes of multiwire chambers in front of a target, followed by arrays of multiwire and draft chambers and thin scintillators. Various geometries are possible, but the intention is to detect inside the magnet both the incident particle and the one(s) leaving the target over a large angular range. The information from the various detectors will be handled on-line by an HP computer system, which also performs some preliminary analysis.

  13. Portable gas chromatograph-mass spectrometer

    Science.gov (United States)

    Andresen, B.D.; Eckels, J.D.; Kimmons, J.F.; Myers, D.W.

    1996-06-11

    A gas chromatograph-mass spectrometer (GC-MS) is described for use as a field portable organic chemical analysis instrument. The GC-MS is designed to be contained in a standard size suitcase, weighs less than 70 pounds, and requires less than 600 watts of electrical power at peak power (all systems on). The GC-MS includes: a conduction heated, forced air cooled small bore capillary gas chromatograph, a small injector assembly, a self-contained ion/sorption pump vacuum system, a hydrogen supply, a dual computer system used to control the hardware and acquire spectrum data, and operational software used to control the pumping system and the gas chromatograph. This instrument incorporates a modified commercial quadrupole mass spectrometer to achieve the instrument sensitivity and mass resolution characteristic of laboratory bench top units. 4 figs.

  14. PAC Spectrometer for Condensed Matter Investigation

    CERN Document Server

    Brudanin, V B; Kochetov, O I; Korolev, N A; Milanov, M; Ostrovsky, I V; Pavlov, V N; Salamatin, A V; Timkin, V V; Velichkov, A I; Fomicheva, L N; Tsvyaschenko, A V; Akselrod, Z Z

    2005-01-01

    A four-detector spectrometer of perturbed angular $\\gamma \\gamma $ correlations is developed for investigation of hyperfine interactions in condensed matter. It allows measurements with practically any types of detectors. A unique circuit design involving a specially developed Master PAC unit combined with a computer allows a substantially higher efficiency, reduced setup time and simpler operation in comparison with traditional PAC spectrometers. A cryostat and a high-temperature oven allow measurements in the temperature range from 120 to 1300 K. An encased electromagnet makes it possible to generate a magnetic field up to 2 T on a sample. The measurement system includes a press with a specially designed high-pressure chamber allowing on-line PAC measurements in samples under pressure up to 60 GPa.

  15. MEMS tunable grating micro-spectrometer

    Science.gov (United States)

    Tormen, Maurizio; Lockhart, R.; Niedermann, P.; Overstolz, T.; Hoogerwerf, A.; Mayor, J.-M.; Pierer, J.; Bosshard, C.; Ischer, R.; Voirin, G.; Stanley, R. P.

    2017-11-01

    The interest in MEMS based Micro-Spectrometers is increasing due to their potential in terms of flexibility as well as cost, low mass, small volume and power savings. This interest, especially in the Near-Infrared and Mid- Infrared, ranges from planetary exploration missions to astronomy, e.g. the search for extra solar planets, as well as to many other terrestrial fields of application such as, industrial quality and surface control, chemical analysis of soil and water, detection of chemical pollutants, exhausted gas analysis, food quality control, process control in pharmaceuticals, to name a few. A compact MEMS-based Spectrometer for Near- Infrared and Mid-InfraRed operation have been conceived, designed and demonstrated. The design based on tunable MEMS blazed grating, developed in the past at CSEM [1], achieves state of the art results in terms of spectral resolution, operational wavelength range, light throughput, overall dimensions, and power consumption.

  16. Cryogenic system for a superconducting spectrometer

    International Nuclear Information System (INIS)

    Porter, J.

    1983-03-01

    The Heavy Ion Spectrometer System (HISS) relies upon superconducting coils of cryostable, pool boiling design to provide a maximum particle bending field of 3 tesla. This paper describes the cryogenic facility including helium refrigeration, gas management, liquid nitrogen system, and the overall control strategy. The system normally operates with a 4 K heat load of 150 watts; the LN 2 circuits absorb an additional 4000 watts. 80K intercept control is by an LSI 11 computer. Total available refrigeration at 4K is 400 watts using reciprocating expanders at the 20K and 4K level. The minicomputer has the capability of optimizing overall utility input cost by varying operating points. A hybrid of pneumatic, analog, and digital control is successful in providing full time unattended operation. The 7m diameter magnet/cryostat assembly is rotatable through 180 degrees to provide a variety of spectrometer orientations

  17. On the axially symmetric non-rotating vacuum solutions of Rosen's equations

    International Nuclear Information System (INIS)

    Bozhkov, Y.

    1990-10-01

    It is shown that all axially symmetric nonrotating solutions of Rosen's field equations can be expressed in terms of two harmonic functions. It is also shown that the total energy of Rosen's metric is Mc 2 . (author). 8 refs

  18. Design of ITER divertor VUV spectrometer and prototype test at KSTAR tokamak

    International Nuclear Information System (INIS)

    Seon, C.; An, Y.; Lee, H.; Pak, S.; Cheon, M.S.; Choi, J.; Kim, H.; Hong, J.; Song, I.; Jang, J.; Lee, H.; Jeon, T.; Park, J.; Choe, W.; Kim, B.; Biel, W.; Bernascolle, P.; Barnsley, R.; O'Mullane, M.

    2017-01-01

    Design and development of the ITER divertor VUV spectrometer have been performed from the year 1998, and it is planned to be installed in the year 2027. Currently, the design of the ITER divertor VUV spectrometer is in the phase of detail design. It is optimized for monitoring of chord-integrated VUV signals from divertor plasmas, chosen to contain representative lines emission from the tungsten as the divertor material, and other impurities. Impurity emission from overall divertor plasmas is collimated through the relay optics onto the entrance slit of a VUV spectrometer with working wavelength range of 14.6-32 nm. To validate the design of the ITER divertor VUV spectrometer, two sets of VUV spectrometers have been developed and tested at KSTAR tokamak. One set of spectrometer without the field mirror employs a survey spectrometer with the wavelength ranging from 14.6 nm to 32 nm, and it provides the same optical specification as the spectrometer part of the ITER divertor VUV spectrometer system. The other spectrometer with the wavelength range of 5-25 nm consists of a commercial spectrometer with a concave grating, and the relay mirrors with the same geometry as the relay mirrors of the ITER divertor VUV spectrometer. From test of these prototypes, alignment method using backward laser illumination could be verified. To validate the feasibility of tungsten emission measurement, furthermore, the tungsten powder was injected in KSTAR plasmas, and the preliminary result could be obtained successfully with regard to the evaluation of photon throughput. (authors)

  19. Imaging spectrometers developments in Italian space agency

    Science.gov (United States)

    de Cosmo, V.

    2017-11-01

    The imaging spectroscopy is a very powerful tool for the Remote Sensing of the Solar Planets and, in particular, of the Earth. This technique permits to get not only the geometrical information but also the spectral information of the scenario under observation. The number of potential data-products obtainable in this way could be very high, useful and of benefit in several fields of Earth Observation. If these are the advantages on the other side the new dimension will increase the number of data by the number of spectral band, and for this it will increase the technical requirements, mainly, on the Instrument Optical Design, Focal Plane Array, Storage/Compressor Data Unit, Data Transmission etc. The instruments able to produce 3-dimensional data (cube image) are the imaging spectrometers, which depending on the way how the spectral contents is obtained, can be divided in two main categories: •The Fourier Imaging spectrometers •The Dispersing Imaging spectrometers Each one of the above categories of spectrometers has advantages and disadvantages and a choice between the two types can be made only performing a trade-off with the mission requirements. The Italian Space Agency (ASI) from long time is promoting and funding, to industrial and scientific levels, several activities covering almost all the aspects related to the imaging spectroscopy: from the applications to the instruments, from the data compressors to future hyperspectral missions. Purpose of this paper is to present the main results of the activities supported by ASI in this field with particular emphasis on the activities related to the studies and developments of new instruments.

  20. Neutron range spectrometer

    Science.gov (United States)

    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.

  1. UCN gravitational spectrometer

    International Nuclear Information System (INIS)

    Kawabata, Yuji

    1988-01-01

    Concept design is carried out of two types of ultra cold neutron scallering equipment using the fall-focusing principle. One of the systems comprises a vertical gravitational spectrometer and the other includes a horizontal gravitation analyzer. A study is made of their performance and the following results are obtained. Fall-focusing type ultra cold neutron scattering equipment can achieve a high accuracy for measurement of energy and momentum. Compared with conventional neutron scattering systems, this type of equipment can use neutron very efficiently because scattered neutrons within a larger solid angle can be used. The maximum solid angle is nearly 4π and 2π for the vertical and horizontal type, respectively. Another feature is that the size of equipment can be reduced. In the present concept design, the equipment is spherical with a diameter of about 1 m, as compared with NESSIE which is 6.7 m in length and 4.85 m in height with about the same accuracy. Two horizontal analyzers and a vertical spectroscope are proposed. They are suitable for angle-dependent non-elastic scattering in the neutron velocity range of 6∼15 m/s, pure elastic scattering in the range of 4∼7 m/s, or angle-integration non-elastic scattering in the range of 4∼15 m/s. (N.K.)

  2. Respiratory mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Mostert, J.W. (Pretoria Univ. (South Africa). Dept. of Anesthesiology)

    1983-06-01

    The high degree of technical perfection of the respiratory mass spectrometer has rendered the instrument feasible for routine monitoring of anesthetized patients. It is proposed that the difference between inspired and expired oxygen tension in mm Hg be equated with whole body oxygen consumption in ml/min/M/sup 2/ body-surface area at STPD, by the expedient of multiplying tension-differences by a factor of 2. Years of experience have confirmed the value of promptly recognizing sudden drops in this l/E tension difference below 50 mm Hg indicative of metabolic injury from hypovolemia or respiratory depression. Rises in l/E tension-differences were associated with shivering as well as voluntary muscle activity. Tension differences of less than 25 mm Hg (equated with a whole-body O/sub 2/ consumption of less than 50 ml O/sub 2//min/M/sup 2/) occurred in a patient in the sitting position for posterior fossa exploration without acidosis, hypoxia or hypotension for several hours prior to irreversible cardiac arrest. The value of clinical monitoring by mass spectrometry is especially impressive in open-heart surgery.

  3. Centrifugal and axial compressor control

    CERN Document Server

    McMillan, Gregory K

    2009-01-01

    Control engineers, mechanical engineers and mechanical technicians will learn how to select the proper control systems for axial and centrifugal compressors for proper throughput and surge control, with a particular emphasis on surge control. Readers will learn to understand the importance of transmitter speed, digital controller sample time, and control valve stroking time in helping to prevent surge. Engineers and technicians will find this book to be a highly valuable guide on compressor control schemes and the importance of mitigating costly and sometimes catastrophic surge problems. It can be used as a self-tutorial guide or in the classroom with the book's helpful end-of-chapter questions and exercises and sections for keeping notes.

  4. Axial channeling of uttrarelativistic electrons

    Energy Technology Data Exchange (ETDEWEB)

    Telegin, V.I.; Khokonov, M.Kh. (Moskovskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Yadernoj Fiziki)

    1982-07-01

    The dynamics of motion of ultrarelativistic electrons under axial channeling conditions is investigated. The analysis is based on the solution of the kinetic equation obtained recently by Beloshitsky and Kumakhov. The particle dechanneling function is investigated as depending on the type of a crystal, particle energy and angle of entrance into the single crystal. It is found that for most of the beam the major diffusion mechanism is scattering by electrons. It is shown that an optimal depth range exists for which the fraction of channeled particles sharply increases at the expense of the quasi-channeled particles. In a number of cases the dechanneling length for crystals with high atomic numbers may be greater than that of light elements.

  5. Axial channeling of uttrarelativistic electrons

    International Nuclear Information System (INIS)

    Telegin, V.I.; Khokonov, M.Kh.

    1982-01-01

    The dynamics of motion of ultrarelativistic electrons under axial channeling conditions is investigated. The analysis is based on the solution of the kinetic equation obtained recently by Beloshitsky and Kumakhov. The particle dechanneling function is investigated as depending on the type of a crystal, particle energy and angle of entrance into the single crystal. It is found that for most of the beam the major diffusion mechanism is scattering by electrons. It is shown that an optimal depth range exists for which the fraction of channeled particles sharply increases at the expense of the quasi-channeled particles. In a number of cases the dechanneling length for crystals with high atomic numbers may be greater than that of light elements

  6. Mass spectrometer beam monitor

    International Nuclear Information System (INIS)

    McKinney, C.R.

    1980-01-01

    Improved apparatus and system were developed for determining the field desorption characteristics of a sample prior to field desorption mass spectrometry. A portion of the ion beam from the ion source is disabled so that it is undeflected in the beam analyzer. When sample ions are detected by a sensor in this portion of the beam it is then allowed to be deflected and the mass analysis occurs. Thus the source position, temperature and electric field strength can be varied until ions are produced from the sample and the field desorption characteristics can be determined. The source characteristics can be varied either automatically or manually. (DN)

  7. Axial and Radial Oxylipin Transport.

    Science.gov (United States)

    Gasperini, Debora; Chauvin, Adeline; Acosta, Ivan F; Kurenda, Andrzej; Stolz, Stéphanie; Chételat, Aurore; Wolfender, Jean-Luc; Farmer, Edward E

    2015-11-01

    Jasmonates are oxygenated lipids (oxylipins) that control defense gene expression in response to cell damage in plants. How mobile are these potent mediators within tissues? Exploiting a series of 13-lipoxygenase (13-lox) mutants in Arabidopsis (Arabidopsis thaliana) that displays impaired jasmonic acid (JA) synthesis in specific cell types and using JA-inducible reporters, we mapped the extent of the transport of endogenous jasmonates across the plant vegetative growth phase. In seedlings, we found that jasmonate (or JA precursors) could translocate axially from wounded shoots to unwounded roots in a LOX2-dependent manner. Grafting experiments with the wild type and JA-deficient mutants confirmed shoot-to-root oxylipin transport. Next, we used rosettes to investigate radial cell-to-cell transport of jasmonates. After finding that the LOX6 protein localized to xylem contact cells was not wound inducible, we used the lox234 triple mutant to genetically isolate LOX6 as the only JA precursor-producing LOX in the plant. When a leaf of this mutant was wounded, the JA reporter gene was expressed in distal leaves. Leaf sectioning showed that JA reporter expression extended from contact cells throughout the vascular bundle and into extravascular cells, revealing a radial movement of jasmonates. Our results add a crucial element to a growing picture of how the distal wound response is regulated in rosettes, showing that both axial (shoot-to-root) and radial (cell-to-cell) transport of oxylipins plays a major role in the wound response. The strategies developed herein provide unique tools with which to identify intercellular jasmonate transport routes. © 2015 American Society of Plant Biologists. All Rights Reserved.

  8. Associated Particle Tagging (APT) in Magnetic Spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, David V.; Baciak, James E.; Stave, Sean C.; Chichester, David; Dale, Daniel; Kim, Yujong; Harmon, Frank

    2012-10-16

    Summary In Brief The Associated Particle Tagging (APT) project, a collaboration of Pacific Northwest National Laboratory (PNNL), Idaho National Laboratory (INL) and the Idaho State University (ISU)/Idaho Accelerator Center (IAC), has completed an exploratory study to assess the role of magnetic spectrometers as the linchpin technology in next-generation tagged-neutron and tagged-photon active interrogation (AI). The computational study considered two principle concepts: (1) the application of a solenoidal alpha-particle spectrometer to a next-generation, large-emittance neutron generator for use in the associated particle imaging technique, and (2) the application of tagged photon beams to the detection of fissile material via active interrogation. In both cases, a magnetic spectrometer momentum-analyzes charged particles (in the neutron case, alpha particles accompanying neutron generation in the D-T reaction; in the tagged photon case, post-bremsstrahlung electrons) to define kinematic properties of the relevant neutral interrogation probe particle (i.e. neutron or photon). The main conclusions of the study can be briefly summarized as follows: Neutron generator: • For the solenoidal spectrometer concept, magnetic field strengths of order 1 Tesla or greater are required to keep the transverse size of the spectrometer smaller than 1 meter. The notional magnetic spectrometer design evaluated in this feasibility study uses a 5-T magnetic field and a borehole radius of 18 cm. • The design shows a potential for 4.5 Sr tagged neutron solid angle, a factor of 4.5 larger than achievable with current API neutron-generator designs. • The potential angular resolution for such a tagged neutron beam can be less than 0.5o for modest Si-detector position resolution (3 mm). Further improvement in angular resolution can be made by using Si-detectors with better position resolution. • The report documents several features of a notional generator design incorporating the

  9. Adaptive Computed Tomography Imaging Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The present proposal describes the development of an adaptive Computed Tomography Imaging Spectrometer (CTIS), or "Snapshot" spectrometer which can "instantaneously"...

  10. Detection system for optical coherence tomography: Czerny-Turner spectrometer

    Science.gov (United States)

    Kamińska, Aleksandra

    2017-08-01

    Research methods based on spectral analysis have powerful impact on development in many field of science. Signal spectrum can be a source of useful and important data. It enables to obtain information about physical and chemical properties of tested materials. This paper has been devoted to describe optical design for high resolution spectrometer, which is significant element of optical coherence tomography (OCT) systems. Designed spectrometer is working in visible range (450-830 nm). Czerny-Turner configuration enables to correcting astigmatism and coma aberration over full bandwidth. Moreover, spectrometer has uncomplicated construction. Merely, two mirrors and diffraction gratings allows to design low - cost spectrometer with satisfying optical properties. Spectrum detection has been realized using CMOS line scan sensors with 6144 pixels. It provides high speed and resolution of the system.

  11. Axial weak currents in the Wess-Zumino term

    International Nuclear Information System (INIS)

    Fujikawa, Kazuo

    1986-01-01

    In a simplified model lagrangian of 3 quarks with an SU(2)sub(L) gauging of chiral SU(3)sub(L)xSU(3)sub(R) to introduce W-boson, we analyse certain complications associated with the low-energy theorem including axial weak fields. We first show that the low-energy amplitude is independent of the form of the quark-level anomalous identity, whether in the covariant form or the consistent form. However, the interplay of the short-distance dynamics (anomalous identity) and the long-distance dynamics (low-energy theorem) becomes involved in the presence of axial fields. We then discuss what kinds of conditions single out the gauged Wess-Zumino term as a low-energy effective action. The connection of the low-energy theorem with the 't Hooft anomaly matching condition is also discussed. (orig.)

  12. Axial sheath dynamics in a plasma focus

    International Nuclear Information System (INIS)

    Soliman, H.M.; El-Khalafawy, T.A.; Masoud, M.M.

    1990-01-01

    This paper presents the result of investigation with a 10 kJ Mather type plasma focus. It is operated in hydrogen gas at ambient pressure of 0.15--1 torr and charging voltage of 8--11 kV. Radial distribution of the current sheath density with axial distance has been estimated. Plasma rotation in the expansion chamber in the absence of external magnetic field has been detected. A plasma flare from the plasma focus region propagating in the radial direction has been observed. Streak photography shows two plasma streams flowing simultaneously out of the muzzle. The mean energy of the electron beam ejected from the pinch region of the focused plasma, was measured by retarding field analyzer to be 0.32 keV. The electron temperature of the plasma focus at peak compression was determined by measuring the X-ray intensity as a function of absorber thickness at a distance of 62 cm from the focus. The electron temperature has been found to 3 keV

  13. Renormalisation group flows for gauge theories in axial gauges

    CERN Document Server

    Litim, Daniel F; Litim, Daniel F.; Pawlowski, Jan M.

    2002-01-01

    Gauge theories in axial gauges are studied using Exact Renormalisation Group flows. We introduce a background field in the infrared regulator, but not in the gauge fixing, in contrast to the usual background field gauge. It is shown how heat-kernel methods can be used to obtain approximate solutions to the flow and the corresponding Ward identities. Expansion schemes are discussed, which are not applicable in covariant gauges. As an application, we derive the one-loop effective action for covariantly constant field strength, and the one-loop beta-function for arbitrary regulator.

  14. Parametric design of tri-axial nested Helmholtz coils.

    Science.gov (United States)

    Abbott, Jake J

    2015-05-01

    This paper provides an optimal parametric design for tri-axial nested Helmholtz coils, which are used to generate a uniform magnetic field with controllable magnitude and direction. Circular and square coils, both with square cross section, are considered. Practical considerations such as wire selection, wire-wrapping efficiency, wire bending radius, choice of power supply, and inductance and time response are included. Using the equations provided, a designer can quickly create an optimal set of custom coils to generate a specified field magnitude in the uniform-field region while maintaining specified accessibility to the central workspace. An example case study is included.

  15. Axial drive to nonlinear flow between rotating cylinders

    Science.gov (United States)

    Ashrafi, Nariman; Hazbavi, Abbas

    2014-02-01

    Stability of pseudoplastic rotational flow between cylinders in presence of an independent axial component is investigated. The fluid is assumed to follow the Carreau model and mixed boundary conditions are imposed. The conservation of mass and momentum equations give rise to a four-dimensional low-order dynamical system, including additional nonlinear terms in the velocity components originated from the shear-dependent viscosity. In absence of the axial flow, as the pseudoplasticity effects increases, the purely-azimuthal base flow loses its stability to the vortex structure at a lower critical Taylor number. Emergence of the vortices corresponds to the onset of a supercritical bifurcation also present in the flow of a linear fluid. However, unlike the Newtonian case, pseudoplastic Taylor vortices lose their stability as the Taylor number reaches a second critical number corresponding to the onset of a Hopf bifurcation. Existence of an axial flow induced by a pressure gradient appears to further advance each critical point on the bifurcation diagram. In continuation, complete flow field together with viscosity maps is analyzed for different flow scenarios. Through evaluation of the Lyapunov exponent, flow stability and temporal behavior of the system for cases with and without axial flow are brought to attention.

  16. Elements of Tiny Plasma Spectrometers

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to advance major elements of a miniaturized plasma spectrometer for flight on future missions. This type of instrument has been developed and successfully...

  17. Moessbauer spectrometer on integrated circuits

    International Nuclear Information System (INIS)

    Tomov, T.; Spasov, A.; Kunov, B.

    1978-01-01

    Two versions of the small-size high-quality Moessbauer spectrometer for 57 Fe spectroscopy are developed. The first version includes a proportion counter, a preamplifier, a one-chennel analyzer, a timer, and a scaler. The spectrometer is intended for measuring characteristic points of the Moessbauer-spectra and operates at constant velocities. The spectrometer parameters are as follows: integral non-linearity of the entire channel about 1%, maximum load for 14 keV line 8x10 4 pulse/s. The second version uses a multichannel time analyzer as a recording device. The spectrometer operates in the saw-toothed velocity modulation, the integral nonlinearity of the modulation being at least 0.1%

  18. Miniaturized Waveguide Fourier Transform Spectrometer

    Data.gov (United States)

    National Aeronautics and Space Administration — To demonstrate the efficacy of a spectrometer-on-chip system for in-situ and remote monitoring of planetary atmospheric and surface chemistry, physics, and surface...

  19. Versatile central spectrometer for ISABELLE

    International Nuclear Information System (INIS)

    Cheng, D.; Goulianso, K.; Knapp, B.; Rosen, J.; Schlein, P.

    1975-01-01

    A large aperture magnetic spectrometer is proposed to study hadrons and leptons produced in the central region at Isabelle. The essential element of the spectrometer is a large double-dipole magnet system with common flux return straddling the intersection region. The air gaps provide magnetic analysis of charged particle for up to 50 percent of the azimuthal angular range. Drift chambers, Cherenkov counters and shower detectors positioned on both sides of the beam lines comprise two spectrometers for analysis of hadrons and electrons. Muons can be momentum analyzed over a large fraction at the azimuthal angle by utilizing the upper and lower sections on the magnet yoke to provide hadron filtering and magnetic deflection. Cylindrical chambers around the vacuum pipe provide multiplicity information for events of interest. The proposed magnet configuration allows unobscured coverage of smaller angle particles with the addition of septum magnet spectrometers downstream of the central magnet in both arms.

  20. Portable Remote Imaging Spectrometer (PRISM)

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an UV-NIR (350nm to 1050 nm) portable remote imaging spectrometer (PRISM) for flight on a variety of airborne platforms with high SNR and response uniformity...

  1. Electron spectrometers with internal conversion

    International Nuclear Information System (INIS)

    Suita, J.C.; Lemos Junior, O.F.; Auler, L.T.; Silva, A.G. da

    1981-01-01

    The efforts that the Department of Physics (DEFI) of Institute of Nuclear Engineering (IEN) are being made aiming at adjusting the electron spectrometers with internal conversion to its necessity, are shown. (E.G.) [pt

  2. Optical Design of a Compact Imaging Spectrometer for Planetary Mineralogy

    Science.gov (United States)

    Mouroulis, Pantazis; Sellar, R. Glenn; Wilson, Daniel W.; Shea, James J.; Green, Robert O.

    2007-01-01

    We present the design of a compact, wide-angle pushbroom imaging spectrometer suitable for exploration of solar system bodies from low orbit. The spectrometer is based on a single detector array with a broadband response that covers the range 400 to 3000 nm and provides a spectral sampling of 10 nm. The telescope has a 24-deg field of view with 600 spatially resolved elements (detector pixels). A specially designed convex diffraction grating permits optimization of the signal-to-noise ratio through the entire spectral band. Tolerances and design parameters permit the achievement of high uniformity of response through field and wavelength. The spectrometer performance is evaluated in terms of predicted spectral and spatial response functions and from the point of view of minimizing their variation through field and wavelength. The design serves as an example for illustrating the design principles specific to this type of system.

  3. The GRANIT spectrometer; Le spectrometre GRANIT

    Energy Technology Data Exchange (ETDEWEB)

    Baessler, St. [University of Virginia, Charlottesville, VA 22904 (United States); Oak Ridge Nat. Lab., Oak Ridge, TN 37831 (United States); Beau, M.; Kreuz, M.; Nesvizhevsky, V.V. [ILL, 6 rue Jules Horowitz, Grenoble, F-3804(France); Kurlov, V.N. [ISSP, 2 Institutskaia, Chernogolovka, RU-142432 (Russian Federation); Pignol, G.; Protasov, K.V.; Vezzu, F. [LPSC/IN2P3-UJF-INPG, 53 rue des Martyrs, Grenoble, F-38026 (France); Voronin, A.Y. [Lebedev Institute, 53 Leninskii pr., Moscow, RU-119991 (Russian Federation)

    2010-10-15

    The existence of quantum states of matter in a gravitational field was demonstrated recently in the Institut Laue-Langevin (ILL), Grenoble, in a series of experiments with ultra cold neutrons (UCN). UCN in low quantum states is an excellent probe for fundamental physics, in particular for constraining extra short-range forces; as well as a tool in quantum optics and surface physics. The GRANIT is a follow-up project based on a second-generation spectrometer with ultra-high energy resolution, permanently installed in ILL. It will become operational in 2011. The spectrometer consists of several neutron-optics elements and UCN detectors installed on a massive granite table in an aluminium vacuum chamber with a volume of about 1.5 m{sup 3}. 3 types of detectors will be used at the first stage of the GRANIT experiment: {sup 3}He gaseous proportional counters with extremely low background, position-sensitive nuclear-track UCN detectors will be used to study the spatial distribution in quantum states, and real-time position-sensitive detectors with a resolution of a few hundred microns to measure velocity distributions of neutrons in quantum states. The key elements of the GRANIT spectrometer is a set of mirrors to shape/analyze neutron spectra and to store neutrons in quantum states

  4. Health and imaging outcomes in axial spondyloarthritis

    NARCIS (Netherlands)

    Machado, P.M.

    2016-01-01

    This thesis focuses on the assessment and monitoring of health and imaging outcomes in axial spondyloarthritis (SpA) and the relationship between these outcomes. Four major contributions to the understanding and management of axial SpA were made: 1) the improvement and facilitation of the assessment

  5. Aryabhata and Axial Rotation of Earth

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE. Aryabhata and Axial Rotation of Earth. 3. A Brief History. Amartya Kumar Datta is in the Stat-Math Unit of. Indian Statistic.llnstiutte,. Kolkata. His research ... historical account of some of Aryabha~a's views on axial rotation of Earth, ..... and stress on periodic observations and updating of the parameters.

  6. Synchronized high speed scanning infrared spectrometer.

    Science.gov (United States)

    Camm, J C; Taylor, R L; Lynch, R

    1967-05-01

    A spectrometer which scans a wavelength band of 0.6 micro in 30 microsec and is useful from 2-6 micro is described. The instrument can be synchronized with a pulsed source with a minimum triggering delay of 15microsec. The instrument is basically an Ebert spectrometer equipped with an indium antimonide detector at the exit slit, an aluminum scanning mirror placed 5 cm before the exit slit, and a wavelength calibration signal generator. The scanning mirror, which is supported on pivots inside a helical coil, deflects the spectrum through an angle of approximately 90 degrees onto the exit slit. When a capacitor is discharged through the coil, the resulting magnetic field spins the aluminum mirror causing the spectrum to move across the exit slit. The wavelength calibration signal generator produces a series of electrical pulses as the scanning mirror turns, permitting wavelength calibration when the pulses are displayed below the spectrometer signal on a dual beam oscilloscope. Using this instrument on a shock tube, data have bee obtained on the absolute spectral radiation intensity of air, nitrogen, neon, and argon heated by reflected shocks to equilibrium temperatures in the range of 6000 degrees K to 10,000 degrees K. In this temperature region with these gases, an important source of continuum radiation is neutral Bremsstrahlung caused by the inelastic scattering of electrons from neutral atoms and molecules. By employing the scanning ir spectrometer it has been possible to separate the continuum radiation from contributions owing to lines and bands and determine the cross section for the neutral Bremsstrahlung.

  7. Concave Grating Enabled Compact Mid-IR Upconversion Spectrometer

    DEFF Research Database (Denmark)

    Barh, Ajanta; Tidemand-Lichtenberg, Peter; Pedersen, Christian

    2017-01-01

    The paper demonstrates a wide-band (3.6 - 4.8 µm) compact mid-infrared grating spectrometer combining a nonlinear frequency upconversion process and a flat-field aberration corrected concave grating with overall system dimension of 25cm×50cm.......The paper demonstrates a wide-band (3.6 - 4.8 µm) compact mid-infrared grating spectrometer combining a nonlinear frequency upconversion process and a flat-field aberration corrected concave grating with overall system dimension of 25cm×50cm....

  8. Axial anomalies of Lifshitz fermions

    CERN Document Server

    Bakas, Ioannis

    2011-01-01

    We compute the axial anomaly of a Lifshitz fermion theory with anisotropic scaling z=3 which is minimally coupled to geometry in 3+1 space-time dimensions. We find that the result is identical to the relativistic case using path integral methods. An independent verification is provided by showing with spectral methods that the eta-invariant of the Dirac and Lifshitz fermion operators in three dimensions are equal. Thus, by the integrated form of the anomaly, the index of the Dirac operator still accounts for the possible breakdown of chiral symmetry in non-relativistic theories of gravity. We apply this framework to the recently constructed gravitational instanton backgrounds of Horava-Lifshitz theory and find that the index is non-zero provided that the space-time foliation admits leaves with harmonic spinors. Using Hitchin's construction of harmonic spinors on Berger spheres, we obtain explicit results for the index of the fermion operator on all such gravitational instanton backgrounds with SU(2)xU(1) isom...

  9. Computerized mass spectrometer data system at LLL

    International Nuclear Information System (INIS)

    Friesen, R.D.; Dupzyk, R.J.

    1976-01-01

    The data systems on the three mass spectrometers at LLL are computer-controlled, pulse-counting systems synchronized to a repeatedly swept magnetic field. The data are accumulated in the memory of the computer or in a Nuclear Data ND 180 in a multi-scaler mode of operation. This mode of data acquisition allows a continuous check of the background stability and makes tune-up easier. But the main benefit is a reduction in the required ion emission rate stability. By the use of standards to set the system dead time, we have been able to utilize the sensitivity of a pulse counting system without the expense of exotic equipment

  10. Mass spectrometer data system at LLL

    International Nuclear Information System (INIS)

    Friesen, R.D.

    1975-01-01

    The data systems on the three mass spectrometers at LLL are computer-controlled, pulse-counting systems synchronized to a repeatedly-swept magnetic field. The data are accumulated in the memory of the computer or in a Nuclear Data ND 180 in a multi-scaler mode of operation. This mode of sweeping allows a continuous check of the background stability and makes tune-up easier. But the main benefit is a reduction in the required ion emission rate stability. By the use of standards to set the system dead time, we have been able to utilize the sensitivity of a pulse counting system without the expense of exotic equipment

  11. Microprocessor-controlled portable neutron spectrometer

    International Nuclear Information System (INIS)

    Hunt, G.F.; Kaifer, R.C.; Slaughter, D.R.; Strout, R.E. II; Rueppel, D.W.

    1979-01-01

    A neutron spectrometer that acquires and unfolds data in the field has been developed for use in the energy range from 1 to 20 MeV. The system includes an NE213 organic scintillation detector, automatic gain stabilization, automatically stabilized pulseshape discrimination, an LSl-11 microprocessor for control and data reduction, and a multichannel analyzer for data acquisition. The system, with the exception of the multichannel analyzer, is mounted in a suitcase 47 by 66 by 23.5 cm. The mass is 23.5 kg

  12. Pre-studies to the spectrometers of the KATRIN experiment

    International Nuclear Information System (INIS)

    Flatt, B.

    2004-01-01

    In the framework of this thesis preparatory work for KATRIN was performed. So the Mainz spectrometer was changed in order to study different mechanisms of the background suppression in MAC-E filters. As main contribution to the background counting rate electrons, which have their origin on the electrodes, were found. These electrons can be hindered by a screen-grid electrode to penetrate into the sensitive spectrometer volume. This screen-grid electrode must exhibit an as low as possible surface coverage, in order to become not itself a source for secondary electrons. Such an electrode was realized. By this procedure it succeeded to reduce the background counting rate from an average value of 15 mHz during the tritium measurements to 2.8 mHz. The pure detector background amounted during the measurement 1.6 mHz, so that only 1.2 mHz contribute to the spectrometer background. The obtained results flowed into the design of the KATRIN pre-spectrometer, which was also elaborated in this thesis. The pres-spectrometer will consist of a vacuum tank, which will lie on high voltage, to spectrometer solenoids, and an inner electrode system. The electrode systems serves for the formation of the electric retardation field and consists of three electrodes, one of which will be a screen-grid electrode, as it was tested in the Mainz arrangement

  13. Spectrometers for compact neutron sources

    Science.gov (United States)

    Voigt, J.; Böhm, S.; Dabruck, J. P.; Rücker, U.; Gutberlet, T.; Brückel, T.

    2018-03-01

    We discuss the potential for neutron spectrometers at novel accelerator driven compact neutron sources. Such a High Brilliance Source (HBS) relies on low energy nuclear reactions, which enable cryogenic moderators in very close proximity to the target and neutron optics at comparably short distances from the moderator compared to existing sources. While the first effect aims at increasing the phase space density of a moderator, the second allows the extraction of a large phase space volume, which is typically requested for spectrometer applications. We find that competitive spectrometers can be realized if (a) the neutron production rate can be synchronized with the experiment repetition rate and (b) the emission characteristics of the moderator can be matched to the phase space requirements of the experiment. MCNP simulations for protons or deuterons on a Beryllium target with a suitable target/moderator design yield a source brightness, from which we calculate the sample fluxes by phase space considerations for different types of spectrometers. These match closely the figures of todays spectrometers at medium flux sources. Hence we conclude that compact neutron sources might be a viable option for next generation neutron sources.

  14. HTS axial flux induction motor with analytic and FEA modeling

    International Nuclear Information System (INIS)

    Li, S.; Fan, Y.; Fang, J.; Qin, W.; Lv, G.; Li, J.H.

    2013-01-01

    Highlights: •A high temperature superconductor axial flux induction motor and a novel maglev scheme are presented. •Analytic method and finite element method have been adopted to model the motor and to calculate the force. •Magnetic field distribution in HTS coil is calculated by analytic method. •An effective method to improve the critical current of HTS coil is presented. •AC losses of HTS coils in the HTS axial flux induction motor are estimated and tested. -- Abstract: This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested

  15. Metrology for terahertz time-domain spectrometers

    Science.gov (United States)

    Molloy, John F.; Naftaly, Mira

    2015-12-01

    In recent years the terahertz time-domain spectrometer (THz TDS) [1] has emerged as a key measurement device for spectroscopic investigations in the frequency range of 0.1-5 THz. To date, almost every type of material has been studied using THz TDS, including semiconductors, ceramics, polymers, metal films, liquid crystals, glasses, pharmaceuticals, DNA molecules, proteins, gases, composites, foams, oils, and many others. Measurements with a TDS are made in the time domain; conversion from the time domain data to a frequency spectrum is achieved by applying the Fourier Transform, calculated numerically using the Fast Fourier Transform (FFT) algorithm. As in many other types of spectrometer, THz TDS requires that the sample data be referenced to similarly acquired data with no sample present. Unlike frequency-domain spectrometers which detect light intensity and measure absorption spectra, a TDS records both amplitude and phase information, and therefore yields both the absorption coefficient and the refractive index of the sample material. The analysis of the data from THz TDS relies on the assumptions that: a) the frequency scale is accurate; b) the measurement of THz field amplitude is linear; and c) that the presence of the sample does not affect the performance characteristics of the instrument. The frequency scale of a THz TDS is derived from the displacement of the delay line; via FFT, positioning errors may give rise to frequency errors that are difficult to quantify. The measurement of the field amplitude in a THz TDS is required to be linear with a dynamic range of the order of 10 000. And attention must be given to the sample positioning and handling in order to avoid sample-related errors.

  16. Determining plasma fueling sources with an end-loss ion spectrometers

    International Nuclear Information System (INIS)

    Grubb, D.P.; Foote, J.H.

    1986-01-01

    The authors report their use of a mass-sensitive, E parallel B, end-loss ion spectrometer (ELIS) mounted near the center line of TMX-U to help identify the major sources of fueling gas. They set the electric field in the ELIS to simultaneously measure the axial loss currents of both hydrogen and deuterium. They then initiated plasma discharges where we injected either hydrogen or deuterium gas into the central-cell. They also selected and deselected central-cell neutral beams that were fueled with hydrogen gas. The end-cell neutral beams were always selected and fueled with deuterium. By taking the ratio of the hydrogen end-loss current (with a known deuterium-gas fed rate), they were able to infer the effective fueling rates that were due to wall reflux, central cell beams, and end cell beams. The results were the following: wall reflux, 6 Torr x l/s; central cell beams, 20 Torrxl/s; and end cell beams, 1 Torr x l/s

  17. Determining plasma-fueling sources with an end-loss ion spectrometer. Revision 1

    International Nuclear Information System (INIS)

    Grubb, D.P.; Foote, J.H.

    1986-01-01

    To help identify the major sources of fueling gas in Tandem Mirror Experiment-Upgrade (TMX-U), we mounted a mass-sensitive, E parallel B, end-loss ion spectrometer (ELIS) near the machine's centerline. We set the electric field in the ELIS to simultaneously measure the axial loss currents of both hydrogen and deuterium. We then initiated plasma discharges, where we injected either hydrogen or deuterium gas into the central cell. We also selected and deselected the central-cell neutral beams that were fueled with hydrogen gas. The end-cell neutral beams were always selected and fueled with deuterium. By taking the ratio of the hydrogen end-loss current to the deuterium end-loss current (with a known deuterium-gas feed rate), we were able to infer the effective fueling rates that were due to wall reflux, central-cell beams, and end-cell beams. The results were the following: wall reflux, 6 Torr x 1/s; central-cell beams, 15 Torr x 1/s; and end-cell beams 1 Torr x 1/s

  18. Determining plasma-fueling sources with an end-loss ion spectrometer

    International Nuclear Information System (INIS)

    Grubb, D.P.; Foote, J.H.

    1986-01-01

    To help identify the major sources of fueling gas in Tandem Mirror Experiment-Upgrade (TMX-U), we mounted a mass-sensitive, EVertical BarVertical BarB, end-loss ion spectrometer (ELIS) near the machine's centerline. We set the electric field in the ELIS to simultaneously measure the axial loss currents of both hydrogen and deuterium. We then initiated plasma discharges, where we injected either hydrogen or deuterium gas into the central cell. We also selected and deselected the central-cell neutral beams that were fueled with hydrogen gas. The end-cell neutral beams were always selected and fueled with deuterium. By taking the ratio of the hydrogen end-loss current to the deuterium end-loss current (with a known deuterium-gas feed rate), we were able to infer the effective fueling rates that were due to wall reflux, central-cell beams, and end-cell beams. The results were the following: wall reflux, 6 Torr l/s; central-cell beams, 15 Torr l/s; and end-cell beams 1 Torr l/s

  19. Determining plasma-fueling sources with an end-loss ion spectrometer

    International Nuclear Information System (INIS)

    Grubb, D.P.; Foote, J.H.

    1986-01-01

    To help identify the major sources of fueling gas in Tandem Mirror Experiment-Upgrade (TMX-U), we mounted a mass-sensitive, E parallel to B, end-loss ion spectrometer (ELIS) near the machine's centerline. We set the electric field in the ELIS to simultaneously measure the axial loss currents of both hydrogen and deuterium. We then initiated plasma discharges, where we injected either hydrogen or deuterium gas into the central cell. We also selected and deselected the central-cell neutral beams that were fueled with hydrogen gas. The end-cell neutral beams were always selected and fueled with deuterium. By taking the ratio of the hydrogen end-loss current to the deuterium end-loss current (with a known deuterium-gas feed rate), we were able to infer the effective fueling rates that were due to wall reflux, central-cell beams, and end-cell beams. The results were the following: wall reflux, 6 Torr.l/s; central-cell beams, 15 Torr.l/s; and end-cell beams 1 Torr.l/s. 3 refs., 3 figs., 1 tab

  20. Diagnostic value of axial CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Kiuchi, Sousuke (Tsukuba Univ., Sakura, Ibaraki (Japan))

    1983-03-01

    Axial CT scan was used to investigate the radiological details of the temporal bone of 33 patients with chronic otitis media, secondary cholesteatoma, sensorineural hearing loss, Meniere disease, vertigo, facial spasm, and neoplasma. The axial scans showed anatomic details of the temporal bone, and at the same time clearly demonstrated the extent of the soft-tissue masses in the middle ears, as well as the destructions of the ossicles. Bone changes of the anterior walls of the epitympanum and external auditory meatus were more clearly demonstrated than by coronary CT scan. However, the axial scan had the disadvantages in demonstrating the stapes, crista transversa, and the mastoid portion of the facial canal.

  1. Axial force measurement for esophageal function testing

    DEFF Research Database (Denmark)

    Gravesen, Flemming Holbæk; Funch-Jensen, Peter; Gregersen, Hans

    2009-01-01

    force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external...... documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe...

  2. Organocatalyzed Asymmetric Synthesis of Axially, Planar, and Helical Chiral Compounds.

    Science.gov (United States)

    Shirakawa, Seiji; Liu, Shiyao; Kaneko, Shiho

    2016-02-04

    Axially, planar, and helical chiral compounds are indispensable building blocks in modern organic synthesis. A wide variety of chiral ligands and catalysts were designed based on these chiral scaffolds, and these chiral ligands and catalysts were used for various catalytic asymmetric transformations to produce important chiral compounds in an optically enriched form. Furthermore, these chiral skeletons are found in the structure of biologically active natural products. Thus, the development of efficient enantioselective methods for the synthesis of these chiral compounds is an important task in the field of organic chemistry. In the last few years, organocatalyzed approaches, which are one of the most reliable catalytic asymmetric methods, became a hot topic. This Focus Review summarizes asymmetric organocatalytic methods for the synthesis of axially, planar, and helical chiral compounds as useful chiral building blocks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Axial Ge/Si nanowire heterostructure tunnel FETs

    Energy Technology Data Exchange (ETDEWEB)

    Picraux, Sanuel T [Los Alamos National Laboratory; Daych, Shadi A [Los Alamos National Laboratory

    2010-01-01

    The vapor-liquid-solid (VLS) growth of semiconductor nanowires allows doping and composition modulation along their axis and the realization of axial 1 D heterostructures. This provides additional flexibility in energy band-edge engineering along the transport direction which is difficult to attain by planar materials growth and processing techniques. We report here on the design, growth, fabrication, and characterization of asymmetric heterostructure tunnel field-effect transistors (HTFETs) based on 100% compositionally modulated Si/Ge axial NWs for high on-current operation and low ambipolar transport behavior. We discuss the optimization of band-offsets and Schottky barrier heights for high performance HTFETs and issues surrounding their experimental realization. Our HTFET devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a measured current drive exceeding 100 {mu}A/{mu}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios.

  4. Three-band, 1.9-μm axial resolution full-field optical coherence microscopy over a 530-1700 nm wavelength range using a single camera

    OpenAIRE

    Federici, Antoine; Dubois, Arnaud

    2014-01-01

    International audience; Full-field optical coherence microscopy is an established optical technology based on low-coherence interference microscopy for high-resolution imaging of semitransparent samples. In this Letter, we demonstrate an extension of the technique using a visible to short-wavelength infrared camera and a halogen lamp to image in three distinct bands centered at 635, 870, and 1170 nm. Reflective microscope objectives are employed to minimize chromatic aberrations of the imagin...

  5. Axially symmetric static scalar solitons and black holes with scalar hair

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: kleihaus@theorie.physik.uni-oldenburg.de; Kunz, Jutta; Radu, Eugen; Subagyo, Bintoro

    2013-10-01

    We construct static, asymptotically flat black hole solutions with scalar hair. They evade the no-hair theorems by having a scalar potential which is not strictly positive. By including an azimuthal winding number in the scalar field ansatz, we find hairy black hole solutions which are static but axially symmetric only. These solutions possess a globally regular limit, describing scalar solitons. A branch of axially symmetric black holes is found to possess a positive specific heat.

  6. Evaluation of the ROTAX spectrometer

    International Nuclear Information System (INIS)

    Tietze-Jaensch, H.; Schmidt, W.; Geick, R.

    1997-01-01

    After installation of the new-type rotating crystal analyser spectrometer ROTAX at ISIS, we report on practical experience and describe its current status. The rotating analyser technique works feasibly and reliably and provides an ultimate scan flexibility on a pulsed time-of-flight neutron spectrometer. The spinning analyser achieves a mulitplex advantage factor of ca. 50 without compromising the resolution of the instrument. Despite these instrument merits its individual beam position at ISIS has only an unsatisfactorily weak flux, thus hindering this instrument yet to become fully competitive with other high-performance neutron spectrometers based at high-flux reactors. However, we strongly recommend a ROTAX-type instrument to be emphasized when the instrumentation suite of the future European spallation source ESS will come under scrutiny. (orig.)

  7. How to Design a Spectrometer.

    Science.gov (United States)

    Scheeline, Alexander

    2017-10-01

    Designing a spectrometer requires knowledge of the problem to be solved, the molecules whose properties will contribute to a solution of that problem and skill in many subfields of science and engineering. A seemingly simple problem, design of an ultraviolet, visible, and near-infrared spectrometer, is used to show the reasoning behind the trade-offs in instrument design. Rather than reporting a fully optimized instrument, the Yin and Yang of design choices, leading to decisions about financial cost, materials choice, resolution, throughput, aperture, and layout are described. To limit scope, aspects such as grating blaze, electronics design, and light sources are not presented. The review illustrates the mixture of mathematical rigor, rule of thumb, esthetics, and availability of components that contribute to the art of spectrometer design.

  8. Advanced Neutron Spectrometer

    Science.gov (United States)

    Christl, Mark; Dobson, Chris; Norwood, Joseph; Kayatin, Matthew; Apple, Jeff; Gibson, Brian; Dietz, Kurt; Benson, Carl; Smith, Dennis; Howard, David; hide

    2013-01-01

    Energetic neutron measurements remain a challenge for space science investigations and radiation monitoring for human exploration beyond LEO. We are investigating a new composite scintillator design that uses Li6 glass scintillator embedded in a PVT block. A comparison between Li6 and Boron 10 loaded scintillators are being studied to assess the advantages and shortcomings of these two techniques. We present the details of the new Li6 design and results from the comparison of the B10 and Li6 techniques during exposures in a mixed radiation field produced by high energy protons interacting in a target material.

  9. Imaging spectrometer - An advanced multispectral imaging concept

    Science.gov (United States)

    Wellman, J. B.; Breckinridge, J. B.; Kupferman, P. N.; Salazar, R.

    1982-01-01

    The concept of an imaging spectrometer, which is being studied as a potential Space Shuttle experiment, is evaluated as a 'push-broom' imager that includes a spectrometer to disperse each line of imaging information into its spectral components. Using this instrument, the dispersed energy falls upon a two-dimensional focal plane array that detects both spatial and spectral information. As the line field of view is advanced over the earth by the motion of the spacecraft, the focal plane is read out constantly, which produces 'push-broom' images at multiple wavelengths. Ground instantaneous fields of view of 10 m in the visual and 20 m in the infrared are provided by the system, at a spectral resolution of 20 nm over the range from 0.4-2.5 microns. The system utilizes a triple-pass Schmidt optical system with a mosaic focal plane. A subset of the data stream is selected and encoded for transmission by the use of onboard processing.

  10. Capacitive axial position and speed transduction system

    International Nuclear Information System (INIS)

    Jimenez D, H.; Flores Ll, H.; Cabral P, A.; Ramirez J, F.J.; Galindo, S.

    1984-01-01

    A new and inexpensive circuit arrangement of a capacitive axial position and speed transduction system is described. Design details and the theory of operation of the device are briefly outlined together with performance results. (author)

  11. Two pad axially grooved hydrostatic bearing

    Science.gov (United States)

    San Andres, Luis A. (Inventor)

    1995-01-01

    A hydrostatic bearing having two axial grooves on opposite sides of the bearing for breaking the rotational symmetry in the dynamic force coefficients thus reducing the whirl frequency ratio and increasing the damping and stiffness of the hydrostatic bearing.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

    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

  13. High temperature co-axial winding transformers

    Science.gov (United States)

    Divan, Deepakraj M.; Novotny, Donald W.

    1993-01-01

    The analysis and design of co-axial winding transformers is presented. The design equations are derived and the different design approaches are discussed. One of the most important features of co-axial winding transformers is the fact that the leakage inductance is well controlled and can be made low. This is not the case in conventional winding transformers. In addition, the power density of co-axial winding transformers is higher than conventional ones. Hence, using co-axial winding transformers in a certain converter topology improves the power density of the converter. The design methodology used in meeting the proposed specifications of the co-axial winding transformer specifications are presented and discussed. The final transformer design was constructed in the lab. Co-axial winding transformers proved to be a good choice for high power density and high frequency applications. They have a more predictable performance compared with conventional transformers. In addition, the leakage inductance of the transformer can be controlled easily to suit a specific application. For space applications, one major concern is the extraction of heat from power apparatus to prevent excessive heating and hence damaging of these units. Because of the vacuum environment, the only way to extract heat is by using a cold plate. One advantage of co-axial winding transformers is that the surface area available to extract heat from is very large compared to conventional transformers. This stems from the unique structure of the co-axial transformer where the whole core surface area is exposed and can be utilized for cooling effectively. This is a crucial issue here since most of the losses are core losses.

  14. Dechanneling function for relativistic axially channeled electrons

    International Nuclear Information System (INIS)

    Muralev, V.A.; Telegin, V.I.

    1981-01-01

    Behaviour of the x(t) dechanneling function depending on the depth is theoretically studied. Theoretical consideration of x(t) for axial channeled relativistic electrons in anisotropic medium results in two-dimensional kinetic equation with mixed derivatives of the parabolic type. The kinetic equation in the approximation of the continuous Lindchard model for relativistic axial channeled electrons is numerically solved. The depth dependence of the x(t) dechanneling function is obtained [ru

  15. Axial forces in centrifugal compressor couplings

    Science.gov (United States)

    Ivanov, A. N.; Ivanov, N. M.; Yun, V. K.

    2017-08-01

    The article presents the results of the theoretical and experimental investigation of axial forces arising in the toothed and plate couplings of centrifugal compressor shaft lines. Additional loads on the thrust bearing are considered that can develop in the toothed couplings as a result of coupled rotors misalignment. Design relationships to evaluate the level of axial forces and recommendations for their reduction in the operating conditions are given.

  16. Atmospheric Measurements by Ultra-Light SpEctrometer (AMULSE Dedicated to Vertical Profile in Situ Measurements of Carbon Dioxide (CO2 Under Weather Balloons: Instrumental Development and Field Application

    Directory of Open Access Journals (Sweden)

    Lilian Joly

    2016-09-01

    Full Text Available The concentration of greenhouse gases in the atmosphere plays an important role in the radiative effects in the Earth’s climate system. Therefore, it is crucial to increase the number of atmospheric observations in order to quantify the natural sinks and emission sources. We report in this paper the development of a new compact lightweight spectrometer (1.8 kg called AMULSE based on near infrared laser technology at 2.04 µm coupled to a 6-m open-path multipass cell. The measurements were made using the Wavelength Modulation Spectroscopy (WMS technique and the spectrometer is hence dedicated to in situ measuring the vertical profiles of the CO2 at high precision levels (σAllan = 0.96 ppm in 1 s integration time (1σ and with high temporal/spatial resolution (1 Hz/5 m using meteorological balloons. The instrument is compact, robust, cost-effective, fully autonomous, has low-power consumption, a non-intrusive probe and is plug & play. It was first calibrated and validated in the laboratory and then used for 17 successful flights up to 10 km altitude in the region Champagne—Ardenne, France in 2014. A rate of 100% of instrument recovery was validated due to the pre-localization prediction of the Météo—France based on the flight simulation software.

  17. Mid infrared MEMS FTIR spectrometer

    Science.gov (United States)

    Erfan, Mazen; Sabry, Yasser M.; Mortada, Bassem; Sharaf, Khaled; Khalil, Diaa

    2016-03-01

    In this work we report, for the first time to the best of our knowledge, a bulk-micromachined wideband MEMS-based spectrometer covering both the NIR and the MIR ranges and working from 1200 nm to 4800 nm. The core engine of the spectrometer is a scanning Michelson interferometer micro-fabricated using deep reactive ion etching (DRIE) technology. The spectrum is obtained using the Fourier Transform techniques that allows covering a very wide spectral range limited by the detector responsivity. The moving mirror of the interferometer is driven by a relatively large stroke electrostatic comb-drive actuator. Zirconium fluoride (ZrF4) multimode optical fibers are used to connect light between the white light source and the interferometer input, as well as the interferometer output to a PbSe photoconductive detector. The recorded signal-to-noise ratio is 25 dB at the wavelength of 3350 nm. The spectrometer is successfully used in measuring the absorption spectra of methylene chloride, quartz glass and polystyrene film. The presented solution provides a low cost method for producing miniaturized spectrometers in the near-/mid-infrared.

  18. Development of multi-moderator neutron spectrometer using a pair of 6Li and 7Li glass scintillators

    International Nuclear Information System (INIS)

    Taniguchi, Shingo; Takada, Masashi; Nakamura, Takashi

    2001-01-01

    A multi-moderator spectrometer using a pair of 6 Li and 7 Li glass scintillators has been developed. This new type of neutron spectrometer can measure the neutron spectrum in a mixed field of neutrons, charged particles and gamma-rays. The particle identification capability was investigated in neutron-gamma-ray and neutron-proton mixed fields and the neutron response functions of the spectrometer were obtained by calculations and experiments up to 200 MeV. This spectrometer has been applied to measure neutron spectrum in a neutron-proton mixed field, produced by bombarding a Be target by 70 MeV protons from the cyclotron

  19. Renormalization of the axial-vector current in QCD

    International Nuclear Information System (INIS)

    Chiu, C.B.; Pasupathy, J.; Wilson, S.L.

    1985-01-01

    Following the method of Ioffe and Smilga, the propagation of the baryon current in an external constant axial-vector field is considered. The close similarity of the operator-product expansion with and without an external field is shown to arise from the chiral invariance of gauge interactions in perturbation theory. Several sum rules corresponding to various invariants both for the nucleon and the hyperons are derived. The analysis of the sum rules is carried out by two independent methods, one called the ratio method and the other called the continuum method, paying special attention to the nondiagonal transitions induced by the external field between the ground state and excited states. Up to operators of dimension six, two new external-field-induced vacuum expectation values enter the calculations. Previous work determining these expectation values from PCAC (partial conservation of axial-vector current) are utilized. Our determination from the sum rules of the nucleon axial-vector renormalization constant G/sub A/, as well as the Cabibbo coupling constants in the SU 3 -symmetric limit (m/sub s/ = 0), is in reasonable accord with the experimental values. Uncertainties in the analysis are pointed out. The case of broken flavor SU 3 symmetry is also considered. While in the ratio method, the results are stable for variation of the fiducial interval of the Borel mass parameter over which the left-hand side and the right-hand side of the sum rules are matched, in the continuum method the results are less stable. Another set of sum rules determines the value of the linear combination 7F-5D to be roughly-equal0, or D/(F+D)roughly-equal(7/12). .AE

  20. Stimulated emission during axial channeling

    International Nuclear Information System (INIS)

    Ternov, I.M.; Khalilov, V.R.; Kholomai, B.V.

    1985-01-01

    A quantum-mechanical analysis shows that it would be possible to achieve stimulated emission in an axisymmetric focusing electric field by a mechanism based on the nonuniform spacing of levels in the electron energy spectrum and on recoil effects during the emission and absorption of photons by the electrons

  1. Ultra-compact MEMS FTIR spectrometer

    Science.gov (United States)

    Sabry, Yasser M.; Hassan, Khaled; Anwar, Momen; Alharon, Mohamed H.; Medhat, Mostafa; Adib, George A.; Dumont, Rich; Saadany, Bassam; Khalil, Diaa

    2017-05-01

    Portable and handheld spectrometers are being developed and commercialized in the late few years leveraging the rapidly-progressing technology and triggering new markets in the field of on-site spectroscopic analysis. Although handheld devices were commercialized for the near-infrared spectroscopy (NIRS), their size and cost stand as an obstacle against the deployment of the spectrometer as spectral sensing components needed for the smart phone industry and the IoT applications. In this work we report a chip-sized microelectromechanical system (MEMS)-based FTIR spectrometer. The core optical engine of the solution is built using a passive-alignment integration technique for a selfaligned MEMS chip; self-aligned microoptics and a single detector in a tiny package sized about 1 cm3. The MEMS chip is a monolithic, high-throughput scanning Michelson interferometer fabricated using deep reactive ion etching technology of silicon-on-insulator substrate. The micro-optical part is used for conditioning the input/output light to/from the MEMS and for further light direction to the detector. Thanks to the all-reflective design of the conditioning microoptics, the performance is free of chromatic aberration. Complemented by the excellent transmission properties of the silicon in the infrared region, the integrated solution allows very wide spectral range of operation. The reported sensor's spectral resolution is about 33 cm-1 and working in the range of 1270 nm to 2700 nm; upper limited by the extended InGaAs detector. The presented solution provides a low cost, low power, tiny size, wide wavelength range NIR spectral sensor that can be manufactured with extremely high volumes. All these features promise the compatibility of this technology with the forthcoming demand of smart portable and IoT devices.

  2. A wavefront analyzer for terahertz time-domain spectrometers

    DEFF Research Database (Denmark)

    Abraham, E.; Brossard, M.; Fauche, P.

    2017-01-01

    We report on the development of a terahertz wavefront sensor able to determine the optical aberrations of a terahertz time-domain spectrometer. The system measures point-by-point the amplitude and phase of the terahertz electric field in a given plane. From this measurement, we reconstruct...... the terahertz wavefront and calculate its Zernike coefficients. In particular, we especially show that the focus spot of the spectrometer suffers from optical aberrations such as remaining defocus, first and second order astigmatisms, as well as spherical aberration. This opens a route to wavefront correction...... for improved terahertz imaging and spectroscopy....

  3. A highly integrated FPGA-based nuclear magnetic resonance spectrometer.

    Science.gov (United States)

    Takeda, Kazuyuki

    2007-03-01

    The digital circuits required for a nuclear magnetic resonance (NMR) spectrometer, including a pulse programmer, a direct digital synthesizer, a digital receiver, and a PC interface, have been built inside a single chip of the field-programmable gate-array (FPGA). By combining the FPGA chip with peripheral analog components, a compact, laptop-sized homebuilt spectrometer has been developed, which is capable of a rf output of up to 400 MHz with amplitude-, phase-, frequency-, and pulse-modulation. The number of rf channels is extendable up to three without further increase in size.

  4. Taming axial dispersion in hydrodynamic chromatography columns through wall patterning

    Science.gov (United States)

    Adrover, Alessandra; Cerbelli, Stefano; Giona, Massimiliano

    2018-04-01

    A well-known limitation of hydrodynamic chromatography arises from the synergistic interaction between transverse diffusion and streamwise convection, which enhances axial dispersion through the Taylor-Aris mechanism. We show that a periodic sequence of slip/no-slip conditions at the channel walls (e.g., representing wall indentations hosting stable air pockets) can significantly reduce axial dispersion, thus enhancing separation performance. The theoretical/numerical analysis is based on a generalization of Brenner's macrotransport approach to solute transport, here modified to account for the finite-size of the suspended particles. The most effective dispersion-taming outcome is observed when the alternating sequence of slip/no-slip conditions yields non-vanishing cross-sectional flow components. The combination of these components with the hindering interaction between the channel boundaries and the finite-sized particles gives rise to a non-trivial solution of Brenner's problem on the unit periodic cell, where the cross-sectional particle number density departs from the spatially homogeneous condition. In turn, this effect impacts upon the solution of the so-called b-field defining the large-scale dispersion tensor, with an overall decremental effect on the axial dispersion coefficient and on the Height Equivalent of a Theoretical Plate.

  5. Imaging results and TOF studies with axial PET detectors

    Science.gov (United States)

    Joram, Christian

    2013-12-01

    We have developed a fully operational PET demonstrator setup which allows true 3D reconstruction of the 511 keV photons and therefore leads to practically parallax free images. The AX-PET concept is based on thin 100 mm long scintillation crystals (LYSO), axially oriented and arranged in layers around the field of view. Layers of wavelength shifting plastic strips mounted in between the crystal layers give the axial coordinate. Both crystals and WLS strips are individually read out by G-APD (SiPM) photodetectors. The fully scalable concept overcomes the dilemma of sensitivity versus spatial resolution which is inherent to classical PET designs. A demonstrator set-up based on two axial modules was exhaustively characterized using point-like sources, phantoms filled with radiotracer and finally rats and a mouse. The results entirely meet the performance expectations (PET concept making use of the novel digital SiPM detectors by Philips. After reproducing comparable energy and spatial resolution on a small digital AX-PET set-up with 100 mm long crystals, we demonstrated a coincidence resolving time of about 210 ps FWHM.

  6. Simultaneous Rotational and Axial Flow of Nonlinear Fluids

    Science.gov (United States)

    Ashrafi, Nariman; Yektapour, Mehdi; Shafahi, Mehdi

    2017-11-01

    An axial flow is introduced to the rotational flow of pseudoplastic fluids in the gap between concentric cylinders. The outer cylinder is fixed while the inner one has simultaneous and independent rotational and translational motions. The fluid follows the Carreau-Bird model and mixed boundary conditions are imposed. The four-dimensional low-order equations resulted from Galerkin projection of the conservation of mass and momentum equations, includes highly non-linear terms in the velocity components. Without axial flow, stability of the base radial flow is lost to the vortex structure at a lower critical Taylor number, with increase of the fluid pseudoplasticity. The vortices imply onset of a supercritical bifurcation which occurs in the rotational flow of linear fluids as well. In contrast to the Newtonian case, pseudoplastic Taylor vortices lose their stability at a second critical Taylor number is reached a second critical number that corresponds to the onset of a Hopf bifurcation. The axial flow, caused by the translational motion of the inner cylinder advance each critical point on the bifurcation diagram. The flow field and viscosity maps are provided for major stability regions.

  7. Compact Spectrometers Based on Linear Variable Filters

    Data.gov (United States)

    National Aeronautics and Space Administration — Demonstrate a linear-variable spectrometer with an H2RG array. Linear Variable Filter (LVF) spectrometers provide attractive resource benefits – high optical...

  8. Controllable rectification of the axial expansion in the thermally driven artificial muscle

    Science.gov (United States)

    Yue, Donghua; Zhang, Xingyi; Yong, Huadong; Zhou, Jun; Zhou, You-He

    2015-09-01

    At present, the concept of artificial muscle twisted by polymers or fibers has become a hot issue in the field of intelligent material research according to its distinguishing advantages, e.g., high energy density, large-stroke, non-hysteresis, and inexpensive. The axial thermal expansion coefficient is an important parameter which can affect its demanding applications. In this letter, a device with high accuracy capacitive sensor is constructed to measure the axial thermal expansion coefficient of the twisted carbon fibers and yarns of Kevlar, and a theoretical model based on the thermal elasticity and the geometrical features of the twisted structure are also presented to predict the axial expansion coefficient. It is found that the calculated results take good agreements with the experimental data. According to the present experiment and analyses, a method to control the axial thermal expansion coefficient of artificial muscle is proposed. Moreover, the mechanism of this kind of thermally driven artificial muscle is discussed.

  9. Dynamic interaction between rotor and axially-magnetized passive magnetic bearing considering magnetic eccentricity

    DEFF Research Database (Denmark)

    Enemark, Søren; Santos, Ilmar

    2014-01-01

    by two passive magnetic bearings using axially-aligned neodymium cylinder magnets. The magnetic bearing housings are flexibly supported, allowing horizontal motions. The housings are connected to each other by means of elastic beams. The shaft is free in one end and coupled to a DC motor on the other......-linear stiffness. In this investigation passive magnetic bearings using axially- aligned neodymium cylinder magnets are investigated. The cylinder magnets are axially magnetised for rotor as well as bearings. Compared to bearings with radial magnetisation, the magnetic stiffness of axially-aligned bearings...... with a multibody system composed of rigid rotor and flexible foundation. The magnetic eccentricities of the shaft magnets are modelled using the distances (amplitudes) and directions (phase angles) between the shaft axis and the centre of the magnetic fields generated. A perturbation method, i.e. harmonic...

  10. Isotensor Axial Polarizability and Lattice QCD Input for Nuclear Double-β Decay Phenomenology

    Science.gov (United States)

    Shanahan, Phiala E.; Tiburzi, Brian C.; Wagman, Michael L.; Winter, Frank; Chang, Emmanuel; Davoudi, Zohreh; Detmold, William; Orginos, Kostas; Savage, Martin J.; Nplqcd Collaboration

    2017-08-01

    The potential importance of short-distance nuclear effects in double-β decay is assessed using a lattice QCD calculation of the n n →p p transition and effective field theory methods. At the unphysical quark masses used in the numerical computation, these effects, encoded in the isotensor axial polarizability, are found to be of similar magnitude to the nuclear modification of the single axial current, which phenomenologically is the quenching of the axial charge used in nuclear many-body calculations. This finding suggests that nuclear models for neutrinoful and neutrinoless double-β decays should incorporate this previously neglected contribution if they are to provide reliable guidance for next-generation neutrinoless double-β decay searches. The prospects of constraining the isotensor axial polarizabilities of nuclei using lattice QCD input into nuclear many-body calculations are discussed.

  11. BATS - Backscattering And Time-of-flight Spectrometer

    International Nuclear Information System (INIS)

    Van Eijck, L.; Seydel, T.; Frick, B.; Schober, H.

    2011-01-01

    The new backscattering spectrometer IN16b will go into commissioning end 2011, providing in its final state about ten times higher count rate than its predecessor, IN16. Here we propose to increase its dynamic range by a factor of 7 with the TOF mode extension, BATS. This will make IN16b the leading high resolution backscattering spectrometer for incoherent quasi-elastic and inelastic neutron scattering; it will be competitive to the coarser resolution inverted geometry backscattering spectrometers that are being brought online at spallation sources. The increased dynamic range will extend the scope of science addressed on IN16b, generating considerable potential in fields such as the hydrogen economy (proton conduction, fuel cells, hydrogen storage), soft matter, biology and nano-science (nano-scale confinement, functionalized polymers). Such a large impact can be achieved using only a moderate investment. (authors)

  12. SWIFTS: on-chip very high spectral resolution spectrometer

    Science.gov (United States)

    le Coarer, E.; Venancio, L. G.; Kern, P.; Ferrand, J.; Puget, P.; Ayraud, M.; Bonneville, C.; Demonte, B.; Morand, A.; Boussey, J.; Barbier, D.; Blaize, S.; Gonthiez, T.

    2017-11-01

    The size and the weight of state of the art spectrometers is a serious issue regarding space applications. SWIFTS (Stationary Wave Integrated Fourier Transform Spectrometer) is a new FTS family without any moving part. This very promising technology is an original way to fully sample the Fourier interferogram obtained in a waveguide by either a reflection (SWIFTS Lippmann) or counter-propagative (SWIFTS Gabor) interference phenomenon. The sampling is simultaneously performed the optical path thanks to "nano-detectors" located in the evanescent field of the waveguide. For instance a 1.7cm long waveguide properly associated to the detector achieves directly a resolution of 0.13cm-1 on a few centimetre long instruments. Here, firstly we present the development status of this new kind of spectrometers and the first results obtained with on going development of spectrometer covering simultaneously the visible domain from 400 to 1000 nm like an Echelle spectrometer. Valuable technologies allows one to extend the concept to various wavelength domains. Secondly, we present the results obtained in the frame of an activity funded by the European Space Agency where several potential applications in space missions have been identified and studied.

  13. Performance Validation of the ATLAS Muon Spectrometer

    CERN Document Server

    Mair, Katharina

    ATLAS (A Toroidal LHC ApparatuS) is a general-purpose experiment for the future Large Hadron Collider (LHC) at CERN, which is scheduled to begin operation in the year 2007, providing experiments with proton-proton collisions. The center-of-mass energy of 14TeV and the design luminosity of 1034 cm−2s−1 will allow to explore many new aspects of fundamental physics. The ATLAS Muon Spectrometer aims at a momentum resolution better than 10% for transverse momentum values ranging from pT = 6 GeV to pT = 1TeV. Precision tracking will be performed by Ar-CO2-gas filled Monitored Drift Tube chambers (MDTs), with a single wire resolution of < 100 μm. In total, about 1 200 chambers, arranged in a large structure, will allow muon track measurements over distances up to 15m in a magnetic field of 0.5 T. Given the large size of the spectrometer it is impossible to keep the shape of the muon chambers and their positions stable within the requested tracking accuracy of 50 μm. Therefore the concept of an optical alig...

  14. New imaging spectrometer for auroral research

    International Nuclear Information System (INIS)

    Rairden, R.; Swenson, G.

    1994-01-01

    A Loral 1024 x 1024 CCD array with 15-micron pixels has been incorporated as the focal plane detector in a new imaging spectrometer for auroral research. The large format low-noise CCD provides excellent dynamic range and signal to noise characteristics with image integration times on the order of 60 seconds using f/1.4 camera optics. Further signal enhancement is achieved through on-CCD pixel binning. In the nominal binned mode the instrument wavelength resolution varies from 15 to 30 angstrom across the 5000 to 8600 angstrom spectral range. Images are acquired and stored digitally on a Macintosh computer. This instrument was operated at a field site in Godhavn, Greenland during the past two winters (1993, 1994) to measure the altitude distribution of the various spectral emissions within auroral arcs. The height resolution on an auroral feature 300 km distant is ∼1 km. Examples of these measurements are presented here in snapshot and summary image formats illustrating the wealth of quantitative information provided by this new imaging spectrometer

  15. Study on the electrostatic prismatic spectrometer with quadrupole lenses

    International Nuclear Information System (INIS)

    Petrov, I.A.

    1975-01-01

    The mosk-up structure of electrostatic prismatic spectrometer with quadrupole lenses is described and its parameters are investigated. The gap between the electrodes of the prism is chosen to be 20 mm to ensure greater transmission. The relative angular dispersion of the prism is 4.69. The spectrometer consists of the main vacuum chamber, source chamber, and detector chamber. All parts of the spectrometer have been made from non-magnetic materials. A permalloy magnetostatic screen 1.5 mm thick serves to protect the instrument from disturbing fields, above all, the geomagnetic field. Using a three-electrode electron gun with a V-shaped tungsten cathode, which serves as an imitator for the adjustment of the spectrometer and for the determination of its parameters, have been measured the solid angle of particle acceptance by the instrument and the height of the source slit. The dependence of the spectrometer transmission on the height of the entrance slit and on the half-angle of the electron beam from the source has been obtained. An analysis of the experiments carried out indicates that the height of the source slit providing the maximum contribution to the line intensity is about 4 mm and the spectrometer transmission is close to unity at half-angle values of about 1 deg 30'. The experimental value of the instrument luminosity obtained for the source slit height and the electron divergence angle ensuring the main contribution to the line intesity is L=0.04x1x4=0.16% mm 2 with a resolving power of 1.000

  16. Nucleon axial form factor from lattice QCD

    International Nuclear Information System (INIS)

    Liu, K.F.; Dong, S.J.; Draper, T.; Wu, J.M.; Wilcox, W.

    1994-01-01

    Results for the isovector axial form factors of the proton from a lattice QCD calculation are presented for both the point-split and local currents. They are obtained on a quenched 16 3 x24 lattice at β=6.0 with Wilson fermions for a range of quark masses from strange to twice the charm mass. For each quark mass, we find that the axial form factor falls off slower than the corresponding proton electric form factor. Results extrapolated to the chiral limit show that the q 2 dependence of the axial form factor agrees quite well with experiment. The axial vector coupling constant g A calculated for the point-split and local currents is 1.20±0.11 and 1.18±0.11. The central values are 4% and 6% smaller than the experimental value of 1.254, respectively. We also consider the large ma correction and renormalization for the axial vector current of heavy quarks

  17. Electron spectrometer for gas-phase spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bozek, J.D.; Schlachter, A.S. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    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.

  18. Optimization of residual heat removal pump axial thrust and axial bearing

    International Nuclear Information System (INIS)

    Schubert, F.

    1996-01-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies

  19. Optimization of residual heat removal pump axial thrust and axial bearing

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, F.

    1996-12-01

    The residual heat removal (RHR) pumps of German 1300 megawatt pressurized-water reactor (PWR) power plants are of the single stage end suction type with volute casing or with diffuser and forged circular casing. Due to the service conditions the pumps have to cover the full capacity range as well as a big variation in suction static pressure. This results in a big difference in the axial thrust that has to be borne by the axial bearing. Because these pumps are designed to operate without auxiliary systems (things that do not exist can not fail), they are equipped with antifriction bearings and sump oil lubrication. To minimize the heat production within the bearing casing, a number of PWR plants have pumps with combined axial/radial bearings of the ball type. Due to the fact that the maximum axial thrust caused by static pressure and hydrodynamic forces on the impeller is too big to be borne by that type of axial bearing, the impellers were designed to produce a hydrodynamic axial force that counteracts the static axial force. Thus, the resulting axial thrust may change direction when the static pressure varies.

  20. An analysis of the extension of a ZnO piezoelectric semiconductor nanofiber under an axial force

    Science.gov (United States)

    Zhang, Chunli; Wang, Xiaoyuan; Chen, Weiqiu; Yang, Jiashi

    2017-02-01

    This paper presents a theoretical analysis on the axial extension of an n-type ZnO piezoelectric semiconductor nanofiber under an axial force. The phenomenological theory of piezoelectric semiconductors consisting of Newton’s second law of motion, the charge equation of electrostatics and the conservation of charge was used. The equations were linearized for small axial force and hence small electron concentration perturbation, and were reduced to one-dimensional equations for thin fibers. Simple and analytical expressions for the electromechanical fields and electron concentration in the fiber were obtained. The fields are either totally or partially described by hyperbolic functions relatively large near the ends of the fiber and change rapidly there. The behavior of the fields is sensitive to the initial electron concentration and the applied axial force. For higher initial electron concentrations the fields are larger near the ends and change more rapidly there.

  1. Plasticity around an Axial Surface Crack in a Cylindrical Shell

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    field in an axially cracked cylindrical shell arising from use of classical eighth order shallow shell theory is removed when use is made of a tenth order shell theory which accounts for transverse shear deformations. Although the membrane stresses are only moderately affected, the influence...... and Ratwani,3–5 it generalises Dugdale's assumption of a concentrated yield zone in the plane of the crack but, contrary to that model, transverse shear effects are included and a continuous stress distribution is assumed in the yield zone. The inherent difficulties arising from the use of shell theory...

  2. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    1991-01-01

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  3. Wave propagation in axially moving periodic strings

    DEFF Research Database (Denmark)

    Sorokin, Vladislav S.; Thomsen, Jon Juel

    2017-01-01

    The paper deals with analytically studying transverse waves propagation in an axially moving string with periodically modulated cross section. The structure effectively models various relevant technological systems, e.g. belts, thread lines, band saws, etc., and, in particular, roller chain drives...... for diesel engines by capturing both their spatial periodicity and axial motion. The Method of Varying Amplitudes is employed in the analysis. It is shown that the compound wave traveling in the axially moving periodic string comprises many components with different frequencies and wavenumbers....... This is in contrast to non-moving periodic structures, for which all components of the corresponding compound wave feature the same frequency. Due to this "multi-frequency" character of the wave motion, the conventional notion of frequency band-gaps appears to be not applicable for the moving periodic strings. Thus...

  4. Space-Resolved VUV and EUV Spectrometers in HL-2A

    International Nuclear Information System (INIS)

    Cui Zhengying; Zhou Hangyu; Fu Bingzhong; Sun Ping; Gao Yadong; Xu Yuan; Yang Qingwei; Morita, S.; Goto, M.; Dong Chunfeng

    2013-01-01

    A normal incidence vacuum ultraviolet (VUV) and a grazing incidence extreme ultraviolet (EUV) spectrometers have been developed for the edge and core impurity measurements in HL-2A tokamak. The VUV and the EUV spectrometers cover wavelength ranges of 300∼3200 Å and 50∼500 Å, respectively. A spatial resolution of 2 mm has been achieved for the VUV spectrometer when a space-resolved slit 50 μm in width is used. The space-resolved slit is placed between the entrance slit and the grating of the spectrometer. The spectral resolutions of 0.15 Å for the VUV spectrometer in the wavelength coverage of the concave 1200 grooves/mm grating and of 0.22 Å for the EUV spectrometer at λ=200 Å with a flat-field laminar-type holographic grating are obtained. The sensitivity of the VUV spectrometer was calibrated in situ with the plasma bremsstrahlung radiation. The experimental results from both spectrometers are presented, especially the line intensity radial profiles measured by the VUV spectrometer. (magnetically confined plasma)

  5. Heavy-ion-spectrometer system

    International Nuclear Information System (INIS)

    1982-05-01

    LBL safety policy (Pub 300 Appendix E) states that every research operation with a Class A risk potential (DOE 5484.1) should identify potentially hazardous procedures associated with the operation and develop methods for accomplishing the operation safely without personnel injury or property damage. The rules and practices that management deems to be minimally necessary for the safe operations of the Heavy Ion Spectrometer System (HISS) in the Bevatron Experimental Hall (51B) are set forth in this Operation Safety Procedures

  6. Heavy-ion-spectrometer system

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-01

    LBL safety policy (Pub 300 Appendix E) states that every research operation with a Class A risk potential (DOE 5484.1) should identify potentially hazardous procedures associated with the operation and develop methods for accomplishing the operation safely without personnel injury or property damage. The rules and practices that management deems to be minimally necessary for the safe operations of the Heavy Ion Spectrometer System (HISS) in the Bevatron Experimental Hall (51B) are set forth in this Operation Safety Procedures (OSP).

  7. The HISS spectrometer at LBL

    International Nuclear Information System (INIS)

    Greiner, D.

    1981-01-01

    The Heavy Ion Spectrometer System at LBL is designed to be a general purpose experimental work bench able to support a wide variety of experiments. Our philosophy is to provide instruments capable of investigating, with multi-particle sensitivity, a large portion of phase space. We have not chosen a particular region such as mid-rapidity or projectile frame, but instead, have made sure that the magnet and the instrumentation allow these choices as well as many others. (orig.)

  8. Low-power Radiation Tolerant 4GHz Bandwidth 16k Channel Spectrometer ASIC, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Spectrometers currently employed or under development by NASA are based on a printed circuit board (PCB) including field programmable arrays (FPGAs) and a number of...

  9. Extended Hamiltonian formalism of the pure space-like axial gauge Schwinger model

    International Nuclear Information System (INIS)

    Nakawaki, Yuji; Mccartor, Gary

    2001-01-01

    We demonstrate that pure space-like axial gauge quantizations of gauge fields can be constructed in ways that are free from infrared divergences. To do so, we must extend the Hamiltonian formalism to include residual gauge fields. We construct an operator solution and an extended Hamiltonian of the pure space-like axial gauge Schwinger model. We begin by constructing an axial gauge formation in auxiliary coordinates, x μ =(x + , x - ), where x + =x 0 sinθ + x 1 cosθ, x - =x 0 cosθ - x 1 sinθ, and we take A=A 0 cosθ + A 1 sin θ=0 as the gauge fixing condition. In the region 0 - as the evolution parameter and construct a traditional canonical formulation of the temporal gauge Schwinger model in which residual gauge fields dependent only on x + are static canonical variables. Then we extrapolate the temporal gauge operator solution into the axial region, π / 4 + is taken as the evolution parameter. In the axial region we find that we have to take the representation of the residual gauge fields realizing the Mandelstam-Leibbrandt prescription in order for the infrared divergences resulting from (∂) -1 to be canceled by corresponding ones resulting from the inverse of the hyperbolic Laplace operator. We overcome the difficulty of constructing the Hamiltonian for the residual gauge fields by employing McCartor and Robertson's method, which gives us a term integrated over x - =constant. Finally, by taking the limit θ→π / 2 - 0, we obtain an operator solution and the Hamiltonian of the axial gauge (Coulomb gauge) Schwinger model in ordinary coordinates. That solution includes auxiliary fields, and the representation space is of indefinite metric, providing further evidence that 'physical' gauges are no more physical than 'unphysical' gauges. (author)

  10. Design of ITER divertor VUV spectrometer and prototype test at KSTAR tokamak

    Science.gov (United States)

    Seon, Changrae; Hong, Joohwan; Song, Inwoo; Jang, Juhyeok; Lee, Hyeonyong; An, Younghwa; Kim, Bosung; Jeon, Taemin; Park, Jaesun; Choe, Wonho; Lee, Hyeongon; Pak, Sunil; Cheon, MunSeong; Choi, Jihyeon; Kim, Hyeonseok; Biel, Wolfgang; Bernascolle, Philippe; Barnsley, Robin; O'Mullane, Martin

    2017-12-01

    Design and development of the ITER divertor VUV spectrometer have been performed from the year 1998, and it is planned to be installed in the year 2027. Currently, the design of the ITER divertor VUV spectrometer is in the phase of detail design. It is optimized for monitoring of chord-integrated VUV signals from divertor plasmas, chosen to contain representative lines emission from the tungsten as the divertor material, and other impurities. Impurity emission from overall divertor plasmas is collimated through the relay optics onto the entrance slit of a VUV spectrometer with working wavelength range of 14.6-32 nm. To validate the design of the ITER divertor VUV spectrometer, two sets of VUV spectrometers have been developed and tested at KSTAR tokamak. One set of spectrometer without the field mirror employs a survey spectrometer with the wavelength ranging from 14.6 nm to 32 nm, and it provides the same optical specification as the spectrometer part of the ITER divertor VUV spectrometer system. The other spectrometer with the wavelength range of 5-25 nm consists of a commercial spectrometer with a concave grating, and the relay mirrors with the same geometry as the relay mirrors of the ITER divertor VUV spectrometer. From test of these prototypes, alignment method using backward laser illumination could be verified. To validate the feasibility of tungsten emission measurement, furthermore, the tungsten powder was injected in KSTAR plasmas, and the preliminary result could be obtained successfully with regard to the evaluation of photon throughput. Contribution to the Topical Issue "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, Grzegorz Karwasz.

  11. The superconducting kaon spectrometer - SKS

    International Nuclear Information System (INIS)

    Fukuda, T.; Takahashi, T.; Aoki, K.; Doi, Y.; Kondo, Y.; Makida, Y.; Nomachi, M.; Noumi, H.; Sasaki, O.; Shintomi, T.; Bhang, H.; Park, H.; Youn, M.; Yu, H.; Gavrilov, Y.; Ajimura, S.; Kishimoto, T.; Ohkusu, A.; Shinkai, N.; Maeda, K.; Sawafta, R.

    1995-01-01

    A superconducting kaon spectrometer has been installed in the north experimental hall of the KEK 12-GeV proton synchrotron. The spectrometer was designed to serve for nuclear physics experiments with meson beams in the 1 GeV/c region, particular emphasis being laid on study of Λ-hypernuclei via (π + ,K + ) reactions. In order to obtain Λ-hypernuclear data with better statistics and energy resolution, it was designed to have a good momentum resolution of 0.1% FWHM and a large acceptance of 100 msr. It consists of a large superconducting dipole magnet, tracking chambers, and trigger counters that can efficiently select kaons from large background of pions and protons. The overall energy resolution for scattering is realized together with a beam-line spectrometer in the K6 beam line, the momentum resolution of which was also designed to be better than 0.1% FWHM. A good energy resolution of better than 2 MeV FWHM has been confirmed in π - - 12 C elastic scattering and in the (π + ,K + ) reaction on 12 C. (orig.)

  12. A NMR spectrometer for educational purposes

    International Nuclear Information System (INIS)

    Colnago, Luiz A.; Torre Neto, Andre

    1991-01-01

    A NMR spectrometer has been constructed for educational purposes, such as teaching of the technique basic principles and instrumentation. The spectrometer has been designed with a minimum number of components so that the students may have acquittance with both the spectrometer, through block diagrams, and the small numbers of existent components . The device was based on a 0.t Tesla magnet from the continuous wave spectrometer (E M 300 - Varian) existent at the Instituto Militar de Engenharia, and it is expected to facilitate the comprehension of the commercial spectrometers

  13. Axial pico turbine - construction and experimental research

    Science.gov (United States)

    Peczkis, G.; Goryca, Z.; Korczak, A.

    2017-08-01

    The paper concerns axial water turbine of power equal to 1 kW. The example of axial water turbine constructional calculations was provided, as well as turbine rotor construction with NACA profile blades. The laboratory test rig designed and built to perform measurements on pico turbine was described. The turbine drove three-phase electrical generator. On the basis of highest efficiency parameters, pico turbine basic characteristics were elaborated. The experimental research results indicated that pico turbine can achieve maximum efficiency close to the values of larger water turbines.

  14. Axial Vircator for Electronic Warfare Applications

    Directory of Open Access Journals (Sweden)

    L. Drazan

    2009-12-01

    Full Text Available This paper deals with a high power microwave generator with virtual cathode – vircator in axial release for electronic warfare applications. The classification of directed energy weapons microwave (DEWM is introduced together with basic block diagrams of a particular class of DEWM. In the paper, methods for designing vircator pulsed power supply, axial vircator structure, measurement methods and experimental results are presented. The vircator in electromagnetic ammunition is powered by magneto-cumulative generator and in weapons for defense of objects (WDO, it is powered by Marx generator. The possible applications of a vircator in the DEWM area are discussed.

  15. Installation of a triple axis spectrometer at Siloe for neutron inelastic scattering experiments

    International Nuclear Information System (INIS)

    Roudaut, E.; Rossat-Mignod, J.

    1975-01-01

    An old DN1 power spectrometer was converted to an inelastic spectrometer in order to widen the research possibilities of the laboratory, especially in the field of spin waves. The installation of the shielding-spectrometer unit was finished at the end of 1974 and the piloting programmes were established and tested. The performance and possibilities of the apparatus were checked by reproducing two kinds of experiment: determination of spin wave dispersion curves in magnetite; determination of crystal field levels in the compounds Ersub(0.2)Ysub(0.8)Cu and HoRh [fr

  16. An electrostatic autoresonant ion trap mass spectrometer

    International Nuclear Information System (INIS)

    Ermakov, A. V.; Hinch, B. J.

    2010-01-01

    A new method for ion extraction from an anharmonic electrostatic trap is introduced. Anharmonicity is a common feature of electrostatic traps which can be used for small scale spatial confinement of ions, and this feature is also necessary for autoresonant ion extraction. With the aid of ion trajectory simulations, novel autoresonant trap mass spectrometers (ART-MSs) have been designed based on these very simple principles. A mass resolution ∼60 is demonstrated for the prototypes discussed here. We report also on the pressure dependencies, and the (mV) rf field strength dependencies of the ART-MS sensitivity. Importantly the new MS designs do not require heavy magnets, tight manufacturing tolerances, introduction of buffer gases, high power rf sources, nor complicated electronics. The designs described here are very inexpensive to implement relative to other instruments, and can be easily miniaturized. Possible applications are discussed.

  17. The Alpha Magnetic Spectrometer Silicon Tracker

    CERN Document Server

    Burger, W J

    1999-01-01

    The Alpha Magnetic Spectrometer (AMS) is designed as a independent module for installation on the International Space Station Alpha (ISSA) in the year 2002 for an operational period of three years. The principal scientific objectives are the searches for antimatter and dark matter in cosmic rays. The AMS uses 5.5 m sup 2 of silicon microstrip sensors to reconstruct charged particle trajectories in the field of a permanent magnet. The detector design and construction covered a 3 yr period which terminated with a test flight on the NASA space shuttle Discovery during June 2-12, 1988. In this contribution, we describe the shuttle version of the AMS silicon tracker, including preliminary results of the tracker performance during the flight. (author)

  18. J-NSE: Neutron spin echo spectrometer

    Directory of Open Access Journals (Sweden)

    Olaf Holderer

    2015-08-01

    Full Text Available Neutron Spin-Echo (NSE spectroscopy is well known as the only neutron scattering technique that achieves energy resolution of several neV. By using the spin precession of polarized neutrons in magnetic field one can measure tiny velocity changes of the individual neutron during the scattering process. Contrary to other inelastic neutron scattering techniques, NSE measures the intermediate scattering function S(Q,t in reciprocal space and time directly. The Neutron Spin-Echo spectrometer J-NSE, operated by JCNS, Forschungszentrum Jülich at the Heinz Maier-Leibnitz Zentrum (MLZ in Garching, covers a time range (2 ps to 200 ns on length scales accessible by small angle scattering technique. Along with conventional NSE spectroscopy that allows bulk measurements in transmission mode, J-NSE offers a new possibility - gracing incidence spin echo spectroscopy (GINSENS, developed to be used as "push-button" option in order to resolve the depth dependent near surface dynamics.

  19. Setup of Mössbauer spectrometers at RCPTM

    Science.gov (United States)

    Pechoušek, J.; Jančík, D.; Frydrych, J.; Navařík, J.; Novák, P.

    2012-10-01

    Setup of Mössbauer spectrometers (MS) for structural, phase, and magnetic characterization of iron-or tin-containing samples is presented. This comprehensive line of 57Fe and 119Sn Mössbauer spectrometers covers transmission spectrometers (TMS) for roomtemperature (RT) measurements, temperature dependent measurements and measurements in an external magnetic field. An RT Conversion Electron/Conversion X-ray Mössbauer technique (CEMS/CXMS) is also available. The main concept of the RT MS is a table-top spectrometric bench with a control unit based on special-purpose hardware or standard PC platform. The first way offers a compact design and PC independent spectra collection system. The second setup, a PC-based system, which uses commercial devices and LabVIEW software, offers easy customization and enables advancement in spectrometer construction. The both types of control systems are able to operate special parts (velocity transducers, gamma-ray detectors) of unusual spectrometric benches. The standard velocity axis range is up to ±20 mm/s with a maximum nonlinearity of 0.1%. Applicable measuring conditions of presented TMSs cover a cryogenic temperature range from 1.5 up to 300 K and high temperature range from RT up to 1000 °C. With in-field low-temperature MS, we are able to analyze samples normally in the external magnetic fields up to 8 T (in temperature interval from 1.5 up to 300 K). In addition, special modes of measurements can be applied including backscattering gamma-ray geometry or measurement in an inert or controlled-humidity atmosphere. Technical details and construction aspects of spectrometers are presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hunka, Deborah E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Austin, Daniel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    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).

  2. Performance of the ATLAS muon spectrometer

    International Nuclear Information System (INIS)

    Aleksa, M.

    1999-09-01

    ATLAS is a general-purpose experiment for the future large hadron collider (LHC) at CERN. Its Muon Spectrometer will require ∼5500 m 2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5 m to 15 m length, embedded in a magnetic field of ∼0.5 T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ∼1200 drift chambers. The LHC physics discovery range indicates the need for a momentum resolution of ∼10 % for muons with a transverse momentum of p T =1 TeV/c. Following a detailed engineering optimisation of the magnetic-field strength versus the chamber resolution, the ATLAS collaboration opted for a drift-chamber system with very high spatial resolution, σ 2 93/7). Measurements performed in a high-background environment - similar to the ATLAS operational environment - gave us a complete understanding of the individual effects which deteriorate the spatial resolution at high rates. Four effects responsible for a resolution deterioration have been identified: two electronics effects which depend on the count rate of a tube (baseline shift and baseline fluctuations), and two space-charge effects that depend on the local count rate (gain drop and field fluctuations). The understanding of these effects had a major impact on the choice of the drift gas and the front-end electronics. The strong dependence of the drift velocity on the drift field is one major disadvantage of the baseline gas. In this work the full set of effects which lead to systematic errors to the track-position measurement in one tube (e.g. variations of the background rate) was investigated and quantified for realistic LHC operating conditions. For the biggest effects analytical corrections are presented. Finally, the muon-system performance was investigated and a calibration method for the absolute mass scale developed. By means of simulation it was shown that the energy

  3. Axial crystals macroscopic symmetry and tensor properties

    Czech Academy of Sciences Publication Activity Database

    Janovec, Václav

    2017-01-01

    Roč. 90, č. 1 (2017), s. 1-10 ISSN 0141-1594 Institutional support: RVO:68378271 Keywords : axial * polar * pseudopolar * chiral * enantiomorphism * optical activity Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.060, year: 2016

  4. Optimisation of efficiency of axial fans

    NARCIS (Netherlands)

    Kruyt, Nicolaas P.; Pennings, P.C.; Faasen, R.

    2014-01-01

    A three-stage research project has been executed to develop ducted axial-fans with increased efficiency. In the first stage a design method has been developed in which various conflicting design criteria can be incorporated. Based on this design method, an optimised design has been determined

  5. The design of axial shaftless pump

    Science.gov (United States)

    Schmirler, Michal; Netrebska, Hana

    The axial shaftless pump with a rotary casing has been proposed. The pump is unique in its small space requirements and the ability to draw a liquid with a high content of impurities and fibers. Modern motor with an external commutation was used to propel the pump rotor. The pump can be used for both pumping of liquids and marine propulsion.

  6. VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR

    African Journals Online (AJOL)

    Dr Obe

    1984-09-01

    Sep 1, 1984 ... VERY SLOW SPEED AXIAL MOTION RELUCTANCE MOTOR by. L. A. Agu. Electrical Engineering Department. University of Nigeria, Nsukka. ABSTRACT. This paper presents the scheme for a very slow speed linear machine which uses conventional laminations and with which speeds of the same low.

  7. Aryabha~ and Axial Rotation of Earth

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 4. Aryabhata and Axial Rotation of Earth - Naksatra Dina (the Sidereal Day). Amartya Kumar Dutta. General Article Volume 11 Issue 4 April 2006 pp 56-74. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Aryabhala and Axial Rotation of Earth

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 3. Aryabhata and Axial Rotation of Earth - Khagola (The Celestial Sphere). Amartya Kumar Dutta. General Article Volume 11 Issue 3 March 2006 pp 51-68. Fulltext. Click here to view fulltext PDF. Permanent link:

  9. The axial polarizability of nucleons and nuclei

    International Nuclear Information System (INIS)

    Ericson, M.; Figureau, A.

    1981-02-01

    The part of the static nuclear axial polarizability arising from the nucleonic excitations is derived from the low energy expansion of the πN amplitude. It is shown that the contribution of the Δ intermediate state, though dominant, does not saturate the nucleonic response. A similar effect, though more pronounced, is known to occur for the magnetic susceptibility

  10. Excitation modes in non-axial nuclei

    International Nuclear Information System (INIS)

    Leviatan, A.; Ginnochio, J.N.

    1990-01-01

    Excitation modes of non-axial quadrupole shapes are investigated in the framework of interacting boson models. Both γ-unstable and γ-rigid nuclear shapes are considered for systems with one type of boson as well as with proton-neutron bosons. 6 refs

  11. Excitation modes in non-axial nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leviatan, A.; Ginnochio, J.N.

    1990-01-01

    Excitation modes of non-axial quadrupole shapes are investigated in the framework of interacting boson models. Both {gamma}-unstable and {gamma}-rigid nuclear shapes are considered for systems with one type of boson as well as with proton-neutron bosons. 6 refs.

  12. AERODYNAMIC DESIGN OF HIGH PRESSRE AXIAL FAN

    Directory of Open Access Journals (Sweden)

    Y. A. Ryzhov

    2014-01-01

    Full Text Available The paper presents the results of numerical studies of flow in a high axial fan of H-2, the geometric parameters are carefully designed by the author. The coefficients of performance, the total pressure, efficiency and capacity. Shows the benefits of fan of H-2 on several other fans, expressed in increased efficiency with equal dimensions and angles of blade setting.

  13. Co-axial, high energy gamma generator

    Science.gov (United States)

    Reijonen, Jani Petteri [Princeton, NJ; Gicquel, Frederic [Pennington, NJ

    2011-08-16

    A gamma ray generator includes an ion source in a first chamber. A second chamber is configured co-axially around the first chamber at a lower second pressure. Co-axially arranged plasma apertures separate the two chambers and provide for restricted passage of ions and gas from the first to the second chamber. The second chamber is formed by a puller electrode having at least one long channel aperture to draw ions from the first chamber when the puller electrode is subject to an appropriate applied potential. A plurality of electrodes rings in the third chamber in third pressure co-axially surround the puller electrode and have at least one channel corresponding to the at least one puller electrode aperture and plasma aperture. The electrode rings increase the energy of the ions to a selected energy in stages in passing between successive pairs of the electrodes by application of an accelerating voltage to the successive pairs of accelerator electrodes. A target disposed co-axially around the plurality of electrodes receives the beam of accelerated ions, producing gamma rays.

  14. Axial U(1) current in Grabowska and Kaplan's formulation

    Science.gov (United States)

    Hamada, Yu; Kawai, Hikaru

    2017-06-01

    Recently, Grabowska and Kaplan [Phys. Rev. Lett. 116, 211602 (2016); Phys. Rev. D 94, 114504 (2016)] suggested a nonperturbative formulation of a chiral gauge theory, which consists of the conventional domain-wall fermion and a gauge field that evolves by gradient flow from one domain wall to the other. We introduce two sets of domain-wall fermions belonging to complex conjugate representations so that the effective theory is a 4D vector-like gauge theory. Then, as a natural definition of the axial-vector current, we consider a current that generates simultaneous phase transformations for the massless modes in 4 dimensions. However, this current is exactly conserved and does not reproduce the correct anomaly. In order to investigate this point precisely, we consider the mechanism of the conservation. We find that this current includes not only the axial current on the domain wall but also a contribution from the bulk, which is nonlocal in the sense of 4D fields. Therefore, the local current is obtained by subtracting the bulk contribution from it.

  15. Avaliação de ICP OES com configuração axial ou radial para determinação de iodo em sal de cozinha

    Directory of Open Access Journals (Sweden)

    Adriana A. Oliveira

    2012-01-01

    Full Text Available The performance of inductively-coupled plasma optical emission spectrometers with axial and radial views for determination of iodine in table salt was evaluated. Interference and memory effects in nitric acid and water-soluble tertiary amines (CFA-C media were studied. Based on a factorial experiment, one optimum instrument operational condition for axial configuration, and two optima conditions for radial configuration was established. The ICP OES with axial view was 5-fold more sensitive than the radial view. Both matrix matching and standard addition methods were used for iodine quantification and for most samples, both strategies of calibration led to similar results. Recoveries ranged from 104 to 114%.

  16. DESIGN IMPROVEMENT OF A LIQUID-MODERATOR-BASED NEUTRON SPECTROMETER FOR BNCT.

    Science.gov (United States)

    Tamaki, Shingo; Kusaka, Sachie; Sato, Fuminobu; Murata, Isao

    2017-10-27

    Boron neutron capture therapy is known to be an effective radiation cancer therapy that requires neutron irradiation. A neutron field generated by an accelerator-based neutron source has various energy spectra, and it is necessary to evaluate the neutron spectrum in the treatment field. However, the method used to measure the neutron spectrum in the treatment field is not well established. Many researchers are making efforts to improve the spectrometers. To solve this problem, we are developing a liquid-moderator-based neutron spectrometer that is based on the same theory as that of the Bonner sphere spectrometer. The spectrometer uses a liquid moderator and absorber. In the present study, we performed a design study to improve the previously developed liquid-moderator-based neutron spectrometer. By carrying out a numerical simulation of the designed new spectrometer, we finally assessed and confirmed the validity of this spectrometer numerically. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. Neutronographic investigations of supramolecular structures on upgraded small-angle spectrometer YuMO

    International Nuclear Information System (INIS)

    Kuklin, A I; Rogachev, A V; Soloviov, D V; Ivankov, O I; Kovalev, Yu S; Kutuzov, S A; Soloviev, A G; Rulev, M I; Gordeliy, V I; Utrobin, P K

    2017-01-01

    Abstract.The work is a review of neutronographic investigations of supramolecular structures on upgraded small-angle spectrometer YuMO. Here, key parameters of small-angle spectrometers are considered. It is shown that two-detector system is the basis of YuMO upgrade. It allows to widen the dynamic q-range twice. In result, the available q-range is widened and dynamic q-range and data collection rate are doubled. The detailed description of YuMO spectrometer is given.The short review of experimental researches made on the spectrometer in the polymers field, biology, material science and physical chemistry is given. The current investigations also have a methodological aspect. It is shown that upgraded spectrometer provides advanced world level of research of supramolecular structures. (paper)

  18. The Alpha Magnetic Spectrometer (AMS)

    CERN Document Server

    Alcaraz, J; Ambrosi, G; Anderhub, H; Ao, L; Arefev, A; Azzarello, P; Babucci, E; Baldini, L; Basile, M; Barancourt, D; Barão, F; Barbier, G; Barreira, G; Battiston, R; Becker, R; Becker, U; Bellagamba, L; Bene, P; Berdugo, J; Berges, P; Bertucci, B; Biland, A; Bizzaglia, S; Blasko, S; Bölla, G; Boschini, M; Bourquin, Maurice; Brocco, L; Bruni, G; Buénerd, M; Burger, J D; Burger, W J; Cai, X D; Camps, C; Cannarsa, P; Capell, M; Casadei, D; Casaus, J; Castellini, G; Cecchi, C; Chang, Y H; Chen, H F; Chen, H S; Chen, Z G; Chernoplekov, N A; Tzi Hong Chiueh; Chuang, Y L; Cindolo, F; Commichau, V; Contin, A; Crespo, P; Cristinziani, M; Cunha, J P D; Dai, T S; Deus, J D; Dinu, N; Djambazov, L; Dantone, I; Dong, Z R; Emonet, P; Engelberg, J; Eppling, F J; Eronen, T; Esposito, G; Extermann, P; Favier, Jean; Fiandrini, E; Fisher, P H; Flügge, G; Fouque, N; Galaktionov, Yu; Gervasi, M; Giusti, P; Grandi, D; Grimm, O; Gu, W Q; Hangarter, K; Hasan, A; Hermel, V; Hofer, H; Huang, M A; Hungerford, W; Ionica, M; Ionica, R; Jongmanns, M; Karlamaa, K; Karpinski, W; Kenney, G; Kenny, J; Kim, W; Klimentov, A; Kossakowski, R; Koutsenko, V F; Kraeber, M; Laborie, G; Laitinen, T; Lamanna, G; Laurenti, G; Lebedev, A; Lee, S C; Levi, G; Levchenko, P M; Liu, C L; Liu, H T; Lopes, I; Lu, G; Lü, Y S; Lübelsmeyer, K; Luckey, D; Lustermann, W; Maña, C; Margotti, A; Mayet, F; McNeil, R R; Meillon, B; Menichelli, M; Mihul, A; Mourao, A; Mujunen, A; Palmonari, F; Papi, A; Park, I H; Pauluzzi, M; Pauss, Felicitas; Perrin, E; Pesci, A; Pevsner, A; Pimenta, M; Plyaskin, V; Pozhidaev, V; Postolache, V; Produit, N; Rancoita, P G; Rapin, D; Raupach, F; Ren, D; Ren, Z; Ribordy, M; Richeux, J P; Riihonen, E; Ritakari, J; Röser, U; Roissin, C; Sagdeev, R; Sartorelli, G; Schwering, G; Scolieri, G; Seo, E S; Shoutko, V; Shoumilov, E; Siedling, R; Son, D; Song, T; Steuer, M; Sun, G S; Suter, H; Tang, X W; Ting, Samuel C C; Ting, S M; Tornikoski, M; Torsti, J; Ulbricht, J; Urpo, S; Usoskin, I; Valtonen, E; Vandenhirtz, J; Velcea, F; Velikhov, E P; Verlaat, B; Vetlitskii, I; Vezzu, F; Vialle, J P; Viertel, Gert M; Vitè, Davide F; Gunten, H V; Wallraff, W; Wang, B C; Wang, J Z; Wang, Y H; Wiik, K; Williams, C; Wu, S X; Xia, P C; Yan, J L; Yan, L G; Yang, C G; Yang, M; Ye, S W; Yeh, P; Xu, Z Z; Zhang, H Y; Zhang, Z P; Zhao, D X; Zhu, G Y; Zhu, W Z; Zhuang, H L; Zichichi, A; Zimmermann, B

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m sup 2) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS.

  19. The Alpha Magnetic Spectrometer (ams)

    Science.gov (United States)

    Ionica, Maria

    2004-01-01

    The Alpha Magnetic Spectrometer (AMS), once installed on the International Space Station will provide precise measurements of the cosmic ray spectra up to TeV energy range, and will search for cosmological antimatter and missing matter. A prototype version of the detector was operated successfully on the space shuttle Discovery in June 1998 (STS-91). Here we briefly report on the design of the AMS apparatus and present the results of the measurements of the fluxes of proton, electron, positron and helium from the STS-91 flight.

  20. Portable neutron spectrometer and dosimeter

    Science.gov (United States)

    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.

  1. New spectrometer for charged particles

    International Nuclear Information System (INIS)

    Wajsfelner, Rene

    1970-02-01

    This thesis is devoted to the study and development of an electrostatic spectrometer which is not only more accurate for the determination of size distributions of electrically charged radio-active atmospheric aerosols, but which can also be used for measuring the grain-size distribution of any cloud of particles which will previously have been charged according to a known, reproducible law. An experimental study has been made of the development of this precipitator and also of its calibration. The electrical charge on spherical polystyrene latex particles suspended in air by atomization has been studied; a theoretical explanation of these results is put forward. (author) [fr

  2. The Alpha Magnetic Spectrometer (AMS)

    International Nuclear Information System (INIS)

    Alcaraz, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello, P.; Babucci, E.; Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Bene, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Bizzaglia, S.; Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.; Brocco, L.; Bruni, G.; Buenerd, M.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Camps, C.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cecchi, C.; Chang, Y.H.; Chen, H.F.; Chen, H.S.; Chen, Z.G.; Chernoplekov, N.A.; Chiueh, T.H.; Chuang, Y.L.; Cindolo, F.; Commichau, V.; Contin, A.; Crespo, P.; Cristinziani, M.; Cunha, J.P. da; Dai, T.S.; Deus, J.D.; Dinu, N.; Djambazov, L.; DAntone, I.; Dong, Z.R.; Emonet, P.; Engelberg, J.; Eppling, F.J.; Eronen, T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P.H.; Fluegge, G.; Fouque, N.; Galaktionov, Yu.; Gervasi, M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W.Q.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Huang, M.A.; Hungerford, W.; Ionica, M.; Ionica, R.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kenny, J.; Kim, W.; Klimentov, A.; Kossakowski, R.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lee, S.C.; Levi, G.; Levtchenko, P.; Liu, C.L.; Liu, H.T.; Lopes, I.; Lu, G.; Lu, Y.S.; Luebelsmeyer, K.; Luckey, D.; Lustermann, W.; Mana, C.; Margotti, A.; Mayet, F.; McNeil, R.R.; Meillon, B.; Menichelli, M.; Mihul, A.; Mourao, A.; Mujunen, A.; Palmonari, F.; Papi, A.; Park, I.H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci, A.; Pevsner, A.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Postolache, V.; Produit, N.; Rancoita, P.G.; Rapin, D.; Raupach, F.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J.P.; Riihonen, E.; Ritakari, J.; Roeser, U.; Roissin, C.; Sagdeev, R.; Sartorelli, G.; Schultz von Dratzig, A.; Schwering, G.; Scolieri, G.; Seo, E.S.; Shoutko, V.; Shoumilov, E.; Siedling, R.; Son, D.; Song, T.; Steuer, M.; Sun, G.S.; Suter, H.; Tang, X.W.; Ting, S.C.C.Samuel C.C.; Ting, S.M.; Tornikoski, M.; Torsti, J.; Tr umper, J.; Ulbricht, J.; Urpo, S.; Usoskin, I.; Valtonen, E.; Vandenhirtz, J.; Velcea, F.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J.P.; Viertel, G.; Vite, D.; Gunten, H. Von; Wicki, S.W.S. Waldmeier; Wallraff, W.; Wang, B.C.; Wang, J.Z.; Wang, Y.H.; Wiik, K.; Williams, C.; Wu, S.X.; Xia, P.C.; Yan, J.L.; Yan, L.G.; Yang, C.G.; Yang, M.; Ye, S.W.; Yeh, P.; Xu, Z.Z.; Zhang, H.Y.; Zhang, Z.P.; Zhao, D.X.; Zhu, G.Y.; Zhu, W.Z.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m 2 ) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS

  3. Metamorphosis of helical magnetorotational instability in the presence of axial electric current.

    Science.gov (United States)

    Priede, Jānis

    2015-03-01

    This paper presents numerical linear stability analysis of a cylindrical Taylor-Couette flow of liquid metal carrying axial electric current in a generally helical external magnetic field. Axially symmetric disturbances are considered in the inductionless approximation corresponding to zero magnetic Prandtl number. Axial symmetry allows us to reveal an entirely new electromagnetic instability. First, we show that the electric current passing through the liquid can extend the range of helical magnetorotational instability (HMRI) indefinitely by transforming it into a purely electromagnetic instability. Two different electromagnetic instability mechanisms are identified. The first is an internal pinch-type instability, which is due to the interaction of the electric current with its own magnetic field. Axisymmetric mode of this instability requires a free-space component of the azimuthal magnetic field. When the azimuthal component of the magnetic field is purely rotational and the axial component is nonzero, a new kind of electromagnetic instability emerges. The latter, driven by the interaction of electric current with a weak collinear magnetic field in a quiescent fluid, gives rise to a steady meridional circulation coupled with azimuthal rotation.

  4. Axial and radial velocities in the creeping flow in a pipe

    Directory of Open Access Journals (Sweden)

    Zuykov Andrey L'vovich

    2014-05-01

    Full Text Available The article is devoted to analytical study of transformation fields of axial and radial velocities in uneven steady creeping flow of a Newtonian fluid in the initial portion of the cylindrical channel. It is shown that the velocity field of the flow is two-dimensional and determined by the stream function. The article is a continuation of a series of papers, where normalized analytic functions of radial axial distributions in uneven steady creeping flow in a cylindrical tube with azimuthal vorticity and stream function were obtained. There is Poiseuille profile for the axial velocity in the uniform motion of a fluid at an infinite distance from the entrance of the pipe (at x = ∞, here taken equal to zero radial velocity. There is uniform distribution of the axial velocity in the cross section at the tube inlet at x = 0, at which the axial velocity is constant along the current radius. Due to the axial symmetry of the flow on the axis of the pipe (at r = 0, the radial velocities and the partial derivative of the axial velocity along the radius, corresponding to the condition of the soft function extremum, are equal to zero. The authors stated vanishing of the velocity of the fluid on the walls of the pipe (at r = R , where R - radius of the tube due to its viscous sticking and tightness of the walls. The condition of conservation of volume flow along the tube was also accepted. All the solutions are obtained in the form of the Fourier - Bessel. It is shown that the hydraulic losses at uniform creeping flow of a Newtonian fluid correspond to Poiseuille - Hagen formula.

  5. R×B drift momentum spectrometer with high resolution and large phase space acceptance.

    Science.gov (United States)

    Wang, X; Konrad, G; Abele, H

    2013-02-11

    We propose a new type of momentum spectrometer, which uses the R × B drift effect to disperse the charged particles in a uniformly curved magnetic field, and measures the particles with large phase space acceptance and high resolution. This kind of R × B spectrometer is designed for the momentum analyses of the decay electrons and protons in the PERC (Proton and Electron Radiation Channel) beam station, which provides a strong magnetic field to guide the charged particles in the instrument. Instead of eliminating the guiding field, the R × B spectrometer evolves the field gradually to the analysing field, and the charged particles can be adiabatically transported during the dispersion and detection. The drifts of the particles have similar properties as their dispersion in the normal magnetic spectrometer. Besides, the R × B spectrometer is especially ideal for the measurements of particles with low momenta and large incident angles. We present a design of the R × B spectrometer, which can be used in PERC. For the particles with solid angle smaller than 88 msr, the maximum aberration is below 10 -4 . The resolution of the momentum spectra can reach 14.4 keV/ c , if the particle position measurements have a resolution of 1 mm.

  6. Experimental investigation of axially aligned flow past spinning cylinders

    Science.gov (United States)

    Carlucci, Pasquale; Buckley, Liam; Mehmedagic, Igbal; Carlucci, Donald; Thangam, Siva

    2016-11-01

    Experimental and numerical results of ongoing subsonic investigations of the flow field about axially aligned spinning cylinders with variable inter-cylinder spacing are presented. The experimental design is capable of investigating wake dynamics of the modeled system up to a Reynolds Number of 300,000 and rotation numbers up to 2. The experimental results are used to validate and confirm numerical simulations with and without the effects of swirl. The focus of the overall effort is an understanding of the dynamics of multi-body problems in a flow field, as such we relate the ongoing effort to previous studies by both the authors and the community at large and our ongoing work in developing accurate plant models for use in engineering analysis and design. Funded in part by U. S. Army ARDEC, Picatinny Arsenal, NJ.

  7. Ion cyclotron resonance spectrometer with fourier transformation

    International Nuclear Information System (INIS)

    Pikver, R.; Suurmaa, Eh.; Syugis, A.; Tammik, A.; Lippmaa, Eh.

    1983-01-01

    The ion cyclotron resonance spectrometer with Fourier transformation intended for investigating mass specta and chemical reaction kinetics in the gaseous phase is described. The mass-spectrum of CO and N 2 positive ions is shown. The spectrometer consists of an electromagnet with power supply, a vacuum system, a cell with electronic equipment and a minicomputer. In the vacuum system (5x10 -9 Torr) there is a cubic measuring cell heated up to 400 deg C. The spectrometer mass resolution is of the 10 5 order. The spectrometer is able to operate as a high-resolution analytical mass-spectrometer of positive and negative ions. The experience of the spectrometer operation confirms its effectiveness for investigating ion-molecular reactions, in particular, proton transfer reactions

  8. Digital Spectrometers for Interplanetary Science Missions

    Science.gov (United States)

    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.

  9. The construction of the SPEG spectrometer

    International Nuclear Information System (INIS)

    Gastebois, J.

    1979-01-01

    About two years ago, two distinct types of magnetic spectrometer were proposed. Since then for essentially financial reasons, only one type has been retained by the Scientific Council: the SPEG ('Energy loss spectrometer for GANIL'). This spectrometer is described in a technical document of April 1978. An overall view of the equipment is given here together with a survey of the means necessary for its realization [fr

  10. A computer based Moessbauer spectrometer system

    International Nuclear Information System (INIS)

    Jin Ge; Li Yuzhi; Yin Zejie; Yao Chunbo; Li Tie; Tan Yexian; Wang Jian

    1999-01-01

    A computer based Moessbauer spectrometer system with a single chip processor for online control and data acquisition is developed. The spectrometer is designed as a single-width NIM module and can be performed directly in NIM crate. Because the structure of the spectrometer is designed to be quite flexible, the system is easy to be configured with other kinds of Moessbauer driver, and can be used in other data acquisition systems

  11. Miniature near-infrared (NIR) spectrometer engine for handheld applications

    Science.gov (United States)

    O'Brien, Nada A.; Hulse, Charles A.; Friedrich, Donald M.; Van Milligen, Fred J.; von Gunten, Marc K.; Pfeifer, Frank; Siesler, Heinz W.

    2012-06-01

    While substantial progress has been made recently towards the miniaturization of Raman, mid-infrared (IR), and near-infrared (NIR) spectrometers, there remains continued interest from end-users and product developers in pushing the technology envelope toward even smaller and lower cost analyzers. The potential of these instruments to revolutionize on-site and on-line applications can only be realized if the reduction in size does not compromise performance of the spectrometer beyond the practical need of a given application. In this paper, the working principle of a novel, extremely miniaturized NIR spectrometer will be presented. The ultra-compact spectrometer relies on thin-film linear variable filter (LVF) technology for the light dispersing element. We will also report on an environmental study whereby the contamination of soil by oil is determined quantitatively in the range of 0-12% by weight of oil contamination. The achieved analytical results will be discussed in terms of the instrument's competitiveness and suitability for on-site and in-the-field measurements.

  12. Visible Imaging Fourier Transform Spectrometer: Design and Calibration

    International Nuclear Information System (INIS)

    Wishnow, E.H.; Wurtz, R.; Blais-Ouellette, S.; Cook, K.H.; Carr, D.; Lewis, I.; Grandmont, F.; Stubbs, C.W.

    2002-01-01

    We present details of the design, operation and calibration of an astronomical visible-band imaging Fourier transform spectrometer (IFTS). This type of instrument produces a spectrum for every pixel in the field of view where the spectral resolution is flexible. The instrument is a dual-input/dual-output Michelson interferometer coupled to the 3.5 meter telescope at the Apache Point Observatory. Imaging performance and interferograms and spectra from calibration sources and standard stars are discussed

  13. An Advanced Neutron Spectrometer for Future Manned Exploration Missions

    Science.gov (United States)

    Christl, Mark; Apple, Jeffrey A.; Cox, Mark D.; Dietz, Kurtis L.; Dobson, Christopher C.; Gibson, Brian F.; Howard, David E.; Jackson, Amanda C.; Kayatin, Mathew J.; Kuznetsov, Evgeny N.; hide

    2014-01-01

    An Advanced Neutron Spectrometer (ANS) is being developed to support future manned exploration missions. This new instrument uses a refined gate and capture technique that significantly improves the identification of neutrons in mixed radiation fields found in spacecraft, habitats and on planetary surfaces. The new instrument is a composite scintillator comprised of PVT loaded with litium-6 glass scintillators. We will describe the detection concept and show preliminary results from laboratory tests and exposures at particle accelerators

  14. Optical design and performance of the SASP spectrometer at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Walden, P.L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Walton, T.G. [University College of the Cariboo, 900 McGill Road, Kamloops, BC (Canada); Miller, C.A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Yen, S. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Abegg, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Auld, E.G. [Univ. of British Columbia, Vancouver, BC (Canada); Campbell, J. [Univ. of Manitoba, Winnipeg, MB (Canada); Chakhalyan, J. [Univ. of British Columbia, Vancouver, BC (Canada); Churchman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Duncan, F. [Univ. of British Columbia, Vancouver, BC (Canada); Falk, W. [Univ. of Manitoba, Winnipeg, MB (Canada); Frekers, D. [Univ. Muenster, Munster D-48149 (Germany); Green, A. [Univ. of Manitoba, Winnipeg, MB (Canada); Green, P.E.W. [Univ. of Alberta, Edmonton, AB (Canada); Hartig, M. [Univ. Muenster, Munster D-48149 (Germany); Haeusser, O. [Simon Fraser Univ., Burnaby, BC (Canada); Haddock, C. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Hicks, K. [Ohio Univ., Athens, OH 45701 (United States); Hutcheon, D. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Jones, G. [Univ. of British Columbia, Vancouver, BC (Canada); Ke, Y. [Simon Fraser Univ., Burnaby, BC (Canada); Korkmaz, E.J. [Univ. of Northern British Columbia, Prince George, BC (Canada); Khan, N. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Ling, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Lobb, D.E. [Univ. of Victoria, Victoria, BC (Canada); Naqvi, S.I.H. [Univ. of Regina, Regina, SK (Canada); Olsen, W.C. [Univ. of Alberta, Edmonton, AB (Canada); Opper, A. [Ohio University, Athens, OH 45701 (United States); Otter, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); Punyasena, M. [University of Alberta, Edmonton, AB (Canada); Reeve, P.; Zhao, J. [Oregon State University, Corvallis, OR 97331 (United States)

    1999-01-21

    A new Q-Q-Clamshell magnetic spectrometer called SASP has been commissioned in the proton hall at TRIUMF. The principal optical characteristics are: a solid angle acceptance of 13.5 msr, a momentum bite of 25%, a momentum resolution of {delta}p/p=2x10{sup -4}, and a maximum central momentum of 720 MeV/c. We describe the optical design, the magnetostatic design, the magnetic field mapping procedure, and the performance of this instrument.

  15. Optical design and performance of the SASP spectrometer at TRIUMF

    CERN Document Server

    Walden, P L; Miller, C A; Yen, S; Abegg, R; Auld, E G; Campbell, J; Chakhalyan, J; Churchman, R; Duncan, F; Falk, W; Frekers, D; Green, A; Green, P E W; Hartig, M; Häusser, O; Haddock, C; Hicks, K; Hutcheon, D; Jones, G; Ke, Y; Korkmaz, E J; Khan, N; Ling, A; Lobb, D E; Naqvi, S I H; Olsen, W C; Opper, A; Otter, Alan J; Punyasena, M; Reeve, P; Zhao, J

    1999-01-01

    A new Q-Q-Clamshell magnetic spectrometer called SASP has been commissioned in the proton hall at TRIUMF. The principal optical characteristics are: a solid angle acceptance of 13.5 msr, a momentum bite of 25%, a momentum resolution of DELTA p/p=2x10 sup - sup 4 , and a maximum central momentum of 720 MeV/c. We describe the optical design, the magnetostatic design, the magnetic field mapping procedure, and the performance of this instrument.

  16. Review of Axial Burnup Distribution Considerations for Burnup Credit Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, J.C.; DeHart, M.D.

    2000-03-01

    This report attempts to summarize and consolidate the existing knowledge on axial burnup distribution issues that are important to burnup credit criticality safety calculations. Recently released Nuclear Regulatory Commission (NRC) staff guidance permits limited burnup credit, and thus, has prompted resolution of the axial burnup distribution issue. The reactivity difference between the neutron multiplication factor (keff) calculated with explicit representation of the axial burnup distribution and keff calculated assuming a uniform axial burnup is referred to as the ``end effect.'' This end effect is shown to be dependent on many factors, including the axial-burnup profile, total accumulated burnup, cooling time, initial enrichment, assembly design, and the isotopics considered (i.e., actinide-only or actinides plus fission products). Axial modeling studies, efforts related to the development of axial-profile databases, and the determination of bounding axial profiles are also discussed. Finally, areas that could benefit from further efforts are identified.

  17. Review of Axial Burnup Distribution Considerations for Burnup Credit Calculations

    International Nuclear Information System (INIS)

    Wagner, J.C.; DeHart, M.D.

    2000-01-01

    This report attempts to summarize and consolidate the existing knowledge on axial burnup distribution issues that are important to burnup credit criticality safety calculations. Recently released Nuclear Regulatory Commission (NRC) staff guidance permits limited burnup credit, and thus, has prompted resolution of the axial burnup distribution issue. The reactivity difference between the neutron multiplication factor (keff) calculated with explicit representation of the axial burnup distribution and keff calculated assuming a uniform axial burnup is referred to as the ''end effect.'' This end effect is shown to be dependent on many factors, including the axial-burnup profile, total accumulated burnup, cooling time, initial enrichment, assembly design, and the isotopics considered (i.e., actinide-only or actinides plus fission products). Axial modeling studies, efforts related to the development of axial-profile databases, and the determination of bounding axial profiles are also discussed. Finally, areas that could benefit from further efforts are identified

  18. Piping inspection carriage having axially displaceable sensor

    Science.gov (United States)

    Zollinger, W.T.; Treanor, R.C.

    1994-12-06

    A pipe inspection instrument carriage is described for use with a pipe crawler for performing internal inspections of piping surfaces. The carriage has a front leg assembly, a rear leg assembly and a central support connecting the two assemblies and for mounting an instrument arm having inspection instruments. The instrument arm has a Y-arm mounted distally thereon for axially aligning the inspection instrumentation and a mounting block, a linear actuator and axial movement arm for extending the inspection instruments radially outward to operably position the inspection instruments on the piping interior. Also, the carriage has a rotation motor and gear assembly for rotating the central support and the front leg assembly with respect to the rear leg assembly so that the inspection instruments azimuthally scan the piping interior. The instrument carriage allows performance of all piping inspection operations with a minimum of moving parts, thus decreasing the likelihood of performance failure. 4 figures.

  19. Ventajas de los motores de flujo axial

    Directory of Open Access Journals (Sweden)

    Alberto M Basanta Otero

    2011-03-01

    Full Text Available Es importante conocer sobre una familia de motores que a diferencia de los convencionales o tradicionales no presentanun flujo rotatorio radial, denominados motores de flujo axial. Dichos motores presentan altos valores de par motriz abajas velocidades, una alta eficiencia y alta densidad de potencia. Este trabajo constituye un breve análisis dealgunos motores de la referencia bibliográfica.  Is important to know about a family of motors that at difference whit the traditional, don't have a rotator radial flux,called, axial flux motors. These motors have high torque for low speed, high efficiency and high power density. Thiswork is a brief analysis of several motors of the bibliographic references.

  20. Cross-flow filtration and axial filtration

    International Nuclear Information System (INIS)

    Kraus, K.A.

    1974-01-01

    Two relatively novel alternative solid-liquid-separation techniques of filtration are discussed. In cross-flow filtration, the feed is pumped past the filtering surface. While in axial filtration the filter, mounted on a rotor, is moved with respect to the feed. While large-scale application of the axial filter is still in doubt, it permits with little expenditure of time and money, duplication of many hydrodynamic aspects of cross-flow filtration for fine-particle handling problems. The technique has been applied to municipal wastes, low-level radioactive waste treatment plant, lead removal from industrial wastes, removal of pulp-mill contaminants, textile-mill wastes, and pretreatment of saline waters by lime-soda process in preparation for hyperfiltration. Economics and energy requirements are also discussed

  1. Axial velocity distribution of a two-component plasma in a ...

    African Journals Online (AJOL)

    In this study we investigate the combined effects of channel indentation and presence of neutral gas (impurities) on the flow of a two-component plasma gas through a magnetized cylinder with indentation. For small indentation, expressed in e, analytic solutions are obtained for the axial velocities, induced magnetic fields, ...

  2. Axially Symmetric Cosmological Model with Bulk Stress in Saez-Ballester Theory of Gravitation

    Science.gov (United States)

    Mete, V. G.; Nimkar, A. S.; Elkar, V. D.

    2016-01-01

    An Axially symmetric non-static space time is considered in presence of bulk stress in scalar tensor theory formulated by Saez and Ballester (Phys. Lett. A113, 467 1985). For solving the field equations, relation between metric potential and shear velocity is proportional to scale expansion are used. Also various physical and geometrical properties of the model have been discussed.

  3. Simplifying Touch Data from Tri-axial Sensors Using a New Data Visualization Tool

    Science.gov (United States)

    SALUD, Lawrence H.; KWAN, Calvin; PUGH, Carla M.

    2013-01-01

    Quantification and evaluation of palpation is a growing field of research in medicine and engineering. A newly developed tri-axial touch sensor has been designed to capture a multi-dimensional profile of touch-loaded forces. We have developed a data visualization tool as a first step in simplifying interpretation of touch for assessing hands-on clinical performance. PMID:23400186

  4. Mathematical Model of Induction Heating Processes in Axial Symmetric Inductor-Detail Systems

    Directory of Open Access Journals (Sweden)

    Maik Streblau

    2014-05-01

    Full Text Available The wide variety of models for analysis of processes in the inductor-detail systems makes it necessary to summarize them. This is a difficult task because of the variety of inductor-detail system configurations. This paper aims to present a multi physics mathematical model for complex analysis of electromagnetic and thermal fields in axial symmetric systems inductor-detail.

  5. Axial pattern skin flaps in cats.

    Science.gov (United States)

    Remedios, A M; Bauer, M S; Bowen, C V; Fowler, J D

    1991-01-01

    The major direct cutaneous vessels identified in the cat include the omocervical, thoracodorsal, deep circumflex iliac, and caudal superficial epigastric arteries. Axial pattern skin flaps based on the thoracodorsal and caudal superficial epigastric arteries have been developed in cats. Rotation of these flaps as islands allows skin coverage to the carpus and metatarsus, respectively. The thoracodorsal and caudal superficial epigastric flaps provide a practical, one-step option in the reconstruction of large skin defects involving the distal extremities of cats.

  6. Atlanto-axial subluxation: a case report

    OpenAIRE

    Thurlow, Robert D

    1988-01-01

    One of the causes of death in rheumatoid patients is cord compression following atlanto-axial subluxation. Dislocations in the cervical spine are common with patients who have rheumatoid arthritis. Anterior subluxation occurs in up to 35%, followed by vertical subluxation in 22.2%, lateral subluxation in 20.6% and rarely posterior subluxation. A case report is presented to illustrate such a complication.

  7. Axial flux permanent magnet brushless machines

    CERN Document Server

    Gieras, Jacek F; Kamper, Maarten J

    2008-01-01

    Axial Flux Permanent Magnet (AFPM) brushless machines are modern electrical machines with a lot of advantages over their conventional counterparts. They are being increasingly used in consumer electronics, public life, instrumentation and automation system, clinical engineering, industrial electromechanical drives, automobile manufacturing industry, electric and hybrid electric vehicles, marine vessels and toys. They are also used in more electric aircrafts and many other applications on larger scale. New applications have also emerged in distributed generation systems (wind turbine generators

  8. Cervical Spine Axial Rotation Goniometer Design

    OpenAIRE

    Emin Ulaş Erdem; Filiz Can

    2012-01-01

    To evaluate the cervical spine rotation movement is quiet harder than other joints. Configuration and arrangement of current goniometers and devices is not always practic in clinics and some methods are quiet expensive. The cervical axial rotation goniometer designed by the authors is consists of five pieces (head apparatus, chair, goniometric platform, eye pads and camera). With this goniometer design a detailed evaluation of cervical spine range of motion can be obtained. Besides, measureme...

  9. Axial gravity, massless fermions and trace anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Bonora, L. [International School for Advanced Studies (SISSA), Trieste (Italy); KEK, Tsukuba (Japan). KEK Theory Center; INFN, Sezione di Trieste (Italy); Cvitan, M.; Giaccari, S.; Stemberga, T. [Zagreb Univ. (Croatia). Dept. of Physics; Prester, P.D. [Rijeka Univ. (Croatia). Dept. of Physics; Pereira, A.D. [UERJ-Univ. Estadual do Rio de Janeiro (Brazil). Dept. de Fisica Teorica; UFF-Univ. Federal Fluminense, Niteroi (Brazil). Inst. de Fisica

    2017-08-15

    This article deals with two main topics. One is odd parity trace anomalies in Weyl fermion theories in a 4d curved background, the second is the introduction of axial gravity. The motivation for reconsidering the former is to clarify the theoretical background underlying the approach and complete the calculation of the anomaly. The reference is in particular to the difference between Weyl and massless Majorana fermions and to the possible contributions from tadpole and seagull terms in the Feynman diagram approach. A first, basic, result of this paper is that a more thorough treatment, taking account of such additional terms and using dimensional regularization, confirms the earlier result. The introduction of an axial symmetric tensor besides the usual gravitational metric is instrumental to a different derivation of the same result using Dirac fermions, which are coupled not only to the usual metric but also to the additional axial tensor. The action of Majorana and Weyl fermions can be obtained in two different limits of such a general configuration. The results obtained in this way confirm the previously obtained ones. (orig.)

  10. Dynamic control of knee axial deformities

    Directory of Open Access Journals (Sweden)

    E. E. Malyshev

    2013-01-01

    Full Text Available The authors have evaluated the clinical examination of the patients with axial malalignments in the knee by the original method and device which was named varovalgometer. The measurements were conducted by tension of the cord through the spina iliaca anterior superior and the middle of the lower pole of patella. The deviation of the center of the ankle estimated by metal ruler which was positioned perpendicular to the lower leg axis on the level of the ankle joint line. The results of comparison of our method and computer navigation in 53 patients during the TKA show no statistically significant varieties but they differ by average 5° of valgus in clinical examination in comparison with mechanical axis which was identified by computer navigation. The dynamic control of axial malalignment can be used in clinical practice for estimation of the results of treatment of pathology with axial deformities in the knee; for the control of reduction and secondary displacement of the fractures around the knee; for assessment of instability; in planning of correctional osteotomies and intraoperative control of deformity correction; for estimation of Q angle in subluxation and recurrent dislocation of patella; in planning of TKA; during the growth of child it allows to assess the progression of deformity.

  11. Respiratory effects of transient axial acceleration.

    Science.gov (United States)

    Loring, S H; Lee, H T; Butler, J P

    2001-06-01

    Whereas gravity has an inspiratory effect in upright subjects, transient upward acceleration is reported to have an expiratory effect. To explore the respiratory effects of transient axial accelerations, we measured axial acceleration at the head and transrespiratory pressure or airflow in five subjects as they were dropped or lifted on a platform. For the first 100 ms, upward acceleration caused a decrease in mouth pressure and inspiratory flow, and downward acceleration caused the opposite. We also simulated these experimental observations by using a computational model of a passive respiratory system based on anatomical data and normal respiratory characteristics. After 100 ms, respiratory airflow in our subjects became highly variable, no longer varying with acceleration. Electromyograms of thoracic and abdominal respiratory muscles showed bursts of activity beginning 40-125 ms after acceleration, suggesting reflex responses responsible for subsequent flow variability. We conclude that, in relaxed subjects, transient upward axial acceleration causes inspiratory airflow and downward acceleration causes expiratory airflow, but that after ~100 ms, reflex activation of respiratory musculature largely determines airflow.

  12. Competition between modes with different axial structures in gyrotrons

    International Nuclear Information System (INIS)

    Khutoryan, Eduard M.; Nusinovich, Gregory S.; Sinitsyn, Oleksandr V.

    2014-01-01

    This study was motivated by some experiments in which it was found that during the voltage rise, instead of expected excitation of a high-frequency parasitic mode, the excitation of a lower-frequency parasitic mode takes place in a certain range of voltages. For explaining this fact, the dependence of start currents of possible competing modes on the beam voltage was carried out in the cold-cavity approximation and by using the self-consistent approach. It was found that in the case of cavities, which consist of the combination of a section of constant radius waveguide and a slightly uptapered waveguide, these two approaches yield completely different results. Thus, experimentally observed excitation of the low-frequency parasitic mode can be explained by the self-consistent modification of the axial profile of the excited field, which has strong influence on the diffractive quality factor of competing modes. This modification is especially pronounced in the case of excitation of modes with many axial variations which can be excited in the region of beam interaction with the backward-wave component of such modes

  13. Axial anomaly and index theorem for Dirac-Kaehler fermions

    International Nuclear Information System (INIS)

    Fonseca Junior, C.A.L. da.

    1985-02-01

    Some aspects of topological influence on gauge field theory are analysed, considering the geometry and differential topology methods. A review of concepts of differential forms, fibered spaces, connection and curvature, showing an interpretation of gauge theory in this context, is presented. The question of fermions, analysing in details the Dirac-Kaehler which fermionic particle is considered a general differential form, is studied. It is shown how the explicit expressions in function of the Dirac spinor components vary with the Dirac matrix representation. The Dirac-Kahler equation contains 4 times (in 4 dimensions) the Dirac equation, each particle being associated an ideal at left of the algebra of general differential forms. These ideals and the SU(4) symmetry among them are also studied on the point of view of spinors and, the group of reduction to one of the ideals is identified as the Cartan subalgebra of this SU(4). Finally, the axial anomaly is calculated through the functional determinant given by the Dirac-Kaehler operator. The regularization method is the Seeley's coefficients. From that results a comparison of the index theorems for the twisted complexes of signature and spin, which proportionality is given by the number of the algebra ideals contained in the Dirac-Kaehler equation and which also manifests in the respective axial anomaly equations. (L.C.) [pt

  14. Axial and parity anomalies and vacuum charge: A direct approach

    International Nuclear Information System (INIS)

    Boyanovsky, D.; Blankenbecler, R.

    1985-01-01

    We study the axial and parity anomalies in Abelian gauge theories using the direct yet intuitive approach of counting the relative number of states of one chirality with respect to the other. A fundamental gauge-invariant quantity, the determinantal ratio, is introduced for this purpose. We find that the number of states is conserved and that the gauge fields differentially phase shift states of opposite chirality at infinite energies. This implies a relative flow of states at very large energies which must be compensated by a rearrangement of the density of states at finite energies. We then derive a sum rule which yields two alternative formulas for the index of a Dirac operator. One expresses the index in terms of its high-energy behavior, and the other in terms of the low-energy properties; these are the ''zero modes'' of definite chirality. Two examples are worked out in detail to clarify our general result. The physics of the axial anomaly is shown to translate into that of the parity anomaly in 2+1 dimensions, in which parity and chirality have interchanged roles. We also analyze the vacuum charge in regard to its high- and low-energy origin. The possibility of spectral flow is formulated and briefly discussed. In short, we provide a physical interpretation of certain mathematical indices, relate them to an extended version of Levinson's theorem of potential scattering, and simplify their evaluation

  15. The deep structure of Axial Volcano

    Science.gov (United States)

    West, Michael Edwin

    The subsurface structure of Axial Volcano, near the intersection of the Juan de Fuca Ridge and the Cobb-Eickelberg seamount chain in the northeast Pacific, is imaged from an active source seismic experiment. At a depth of 2.25 to 3.5 km beneath Axial lies an 8 km x 12 km region of very low seismic velocities that can only be explained by the presence of magma. In the center of this magma storage chamber at 2--3.5 km below sea floor, the crust is at least 10--20% melt. At depths of 4--5 km there is evidence of additional low concentrations of magma (a few percent) over a larger area. In total, 5--11 km3 of magma are stored in the mid-crust beneath Axial. This is more melt than has been positively identified under any basaltic volcano on Earth. It is also far more than the 0.1--0.2 km3 emplaced during the 1998 eruption. The implied residence time in the magma reservoir of a few hundred to a few thousand years agrees with geochemical trends which suggest prolonged storage and mixing of magmas. The large volume of melt bolsters previous observations that Axial provides much of the material to create crust along its 50 km rift zones. A high velocity ring-shaped feature sits above the magma chamber just outside the caldera walls. This feature is believed to be the result of repeated dike injections from the magma body to the surface during the construction of the volcanic edifice. A rapid change in crustal thickness from 8 to 11 km within 15 km of the caldera implies focused delivery of melt from the mantle. The high flux of magma suggests that melting occurs deeper in the mantle than along the nearby ridge. Melt supply to the volcano is not connected to any plumbing system associated with the adjacent segments of the Juan de Fuca Ridge. This suggests that, despite Axial's proximity to the ridge, the Cobb hot spot currently drives the supply of melt to the volcano.

  16. The BNL multiparticle spectrometer software

    International Nuclear Information System (INIS)

    Saulys, A.C.

    1985-01-01

    This paper discusses some solutions to problems common to the design, management and maintenance of a large high energy physics spectrometer software system. The experience of dealing with a large, complex program and the necessity of having the programm controlled by various people at different levels of computer experience has led us to design a program control structure of mnemonic and self-explanatory nature. The use of this control language in both ''on-line'' and ''off-line'' operation of the program will be discussed. The solution of structuring a large program for modularity so that substantial changes to the program can be made easily for a wide variety of high energy physics experiments is discussed. Specialized tools for this type of large program management are also discussed. (orig.)

  17. Investigation of unsteady flow in axial turbine stage

    Directory of Open Access Journals (Sweden)

    Němec Martin

    2012-04-01

    Full Text Available The never ending process to increase the efficiency of turbine stages introduced an idea to create an axial turbine stage test rig as part of closed loop transonic wind tunnel at Vyzkumny a zkusebni letecky ustav (VZLU. Studying of unsteady flow field behaviours in turbine stages is nowadays essential in the development process. Therefore, the test rig was designed with focusing on possibility of detailed studying of unsteady flow fields in turbine stages. New methodologies and new instrumentations were developed at VZLU and successfully integrated to gain valuable information from experiments with turbine stages. Two different turbine stages were tested during the facility introduction process. The measurement of these two models demonstrated how flexible the test rig is. One of them was an enlarged model of small gas turbine stage. The other was scaled-down model of stage of intermediate-pressure steam turbine. The external characteristics of both models were acquired during experiments as well as the detailed unsteady flow field measurement. Turbine stages were tested in various regimes in order to check the capabilities of the facility, methodology and instrumentation together. The paper presents results of unsteady flow field investigation in the enlarged turbine stage with unshrouded rotor. The interaction of structures developed in a stator with the rotor flow field is depicted and the influence of turbine load on evolution of secondary flows in rotor is analysed.

  18. The Geostationary Fourier Transform Spectrometer

    Science.gov (United States)

    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.

  19. The reversed and normal flux contributions to axial dipole decay for 1880-2015

    Science.gov (United States)

    Metman, M. C.; Livermore, P. W.; Mound, J. E.

    2018-03-01

    The axial dipole component of Earth's internal magnetic field has been weakening since at least 1840, an effect widely believed to be attributed to the evolution of reversed flux patches (RFPs). These are regions on the core-mantle boundary (CMB) where the sign of radial flux deviates from that of the dominant sign of hemispheric radial flux. We study dipole change over the past 135 years using the field models gufm1, COV-OBS.x1 and CHAOS-6; we examine the impact of the choice of magnetic equator on the identification of reversed flux, the contribution of reversed and normal flux to axial dipole decay, and how reversed and normal field evolution has influenced the axial dipole. We show that a magnetic equator defined as a null-flux curve of the magnetic field truncated at spherical harmonic degree 3 allows us to robustly identify reversed flux, which we demonstrate is a feature of at least degree 4 or 5. Additionally, our results indicate that the evolution of reversed flux accounts for approximately two-thirds of the decay of the axial dipole, while one third of the decay is attributed to the evolution of the normal field. We find that the decay of the axial dipole over the 20th century is associated with both the expansion and poleward migration of reversed flux patches. In contrast to this centennial evolution, changes in the structure of secular variation since epoch 2000 indicate that poleward migration currently plays a much reduced role in the ongoing dipole decay.

  20. A novel dual-detector micro-spectrometer

    Science.gov (United States)

    Otto, Thomas; Saupe, Ray; Stock, Volker; Bruch, Reinhard; Gruska, Bernd; Gessner, Thomas

    2005-01-01

    Infrared analysis is a well-established tool for measuring composition and purity of various materials in industrial-, medical- and environmental applications. Traditional spectrometers, for example Fourier Transform Infrared (FTIR) Instruments are mainly designed for laboratory use and are generally, too large, heavy, costly and delicate to handle for remote applications. With important advances in the miniaturization, ruggedness and cost efficiency we have designed and created a new type of a micromirror spectrometer that can operate in harsh temperature and vibrating environments This device is ideally suited for environmental monitoring, chemical and biological applications as well as detection of biological warfare agents and sensing in important security locations In order to realize such compact, portable and field-deployable spectrometers we have applied MOEMS technology. Thus our novel dual detector micro mirror system is composed of a scanning micro mirror combined with a diffraction grating and other essential optical components in order to miniaturize the basic modular set-up. Especially it periodically disperses polychromatic radiation into its spectral components, which are measured by a combination of a visible (VIS) and near infrared (NIR) single element detector. By means of integrated preamplifiers high-precise measurements over a wide dynamic wavelength range are possible. In addition the spectrometer, including the radiation source, detectors and electronics can be coupled to a minimum-volume liquid or gas-flow cell. Furthermore a SMA connector as a fiber optical input allows easy attachment of fiber based probes. By utilizing rapid prototyping techniques, where all components are directly integrated, the micro mirror spectrometer is manufactured for the 700-1700 nm spectral range. In this work the advanced optical design and integration of the electronic interface will be reviewed. Furthermore we will demonstrate the performance of the system