Sample records for neutron triple-axis spectrometer

  1. MAGNETIC NEUTRON SCATTERING. And Recent Developments in the Triple Axis Spectroscopy

    E-Print Network [OSTI]

    Johnson, Peter D.

    Chapter 1 MAGNETIC NEUTRON SCATTERING. And Recent Developments in the Triple Axis Spectroscopy Igor.................................................................................... 2 2. Neutron interaction with matter and scattering cross-section ........ 6 2.1 Basic scattering theory and differential cross-section................ 7 2.2 Neutron interactions and scattering lengths

  2. Neutron Experiment descriptions: N1: Triple-Axis Spectrometers, HFIR HB1A & HB3

    E-Print Network [OSTI]

    Pennycook, Steve

    transport capabilities for large-scale EV applications. Studies on the lithium-ion motion properties phonons in these materials. With the large magnetoelastic interactions in such a material, it is also-Circle Diffractometer, HFIR HB3A Structure and lithium-ion motion in the triphylite LiFePO4 studied by single crystal

  3. Neutron range spectrometer

    DOE Patents [OSTI]

    Manglos, S.H.

    1988-03-10T23:59:59.000Z

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

  4. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    Pennycook, Steve

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574 Cold Neutron Triple-Axis Spectrometer CallforProposals neutrons.ornl.gov Neutron Scattering Science Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EDT, (NOON

  5. Portable neutron spectrometer and dosimeter

    DOE Patents [OSTI]

    Waechter, David A. (Los Alamos, NM); Erkkila, Bruce H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM)

    1985-01-01T23:59:59.000Z

    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.

  6. Neutron spectrometer for improved SNM search.

    SciTech Connect (OSTI)

    Vance, Andrew L.; Aigeldinger, Georg

    2007-03-01T23:59:59.000Z

    With the exception of large laboratory devices with very low sensitivities, a neutron spectrometer have not been built for fission neutrons such as those emitted by special nuclear materials (SNM). The goal of this work was to use a technique known as Capture Gated Neutron Spectrometry to develop a solid-state device with this functionality. This required modifications to trans-stilbene, a known solid-state scintillator. To provide a neutron capture signal we added lithium to this material. This unique triggering signal allowed identification of neutrons that lose all of their energy in the detector, eliminating uncertainties that arise due to partial energy depositions. We successfully implemented a capture gated neutron spectrometer and were able to distinguish an SNM like fission spectrum from a spectrum stemming from a benign neutron source.

  7. Neutron spectrometer for fast nuclear reactors

    E-Print Network [OSTI]

    Osipenko, M; Ricco, G; Caiffi, B; Pompili, F; Pillon, M; Angelone, M; Verona-Rinati, G; Cardarelli, R; Mila, G; Argiro, S

    2015-01-01T23:59:59.000Z

    In this paper we describe the development and first tests of a neutron spectrometer designed for high flux environments, such as the ones found in fast nuclear reactors. The spectrometer is based on the conversion of neutrons impinging on $^6$Li into $\\alpha$ and $t$ whose total energy comprises the initial neutron energy and the reaction $Q$-value. The $^6$LiF layer is sandwiched between two CVD diamond detectors, which measure the two reaction products in coincidence. The spectrometer was calibrated at two neutron energies in well known thermal and 3 MeV neutron fluxes. The measured neutron detection efficiency varies from 4.2$\\times 10^{-4}$ to 3.5$\\times 10^{-8}$ for thermal and 3 MeV neutrons, respectively. These values are in agreement with Geant4 simulations and close to simple estimates based on the knowledge of the $^6$Li(n,$\\alpha$)$t$ cross section. The energy resolution of the spectrometer was found to be better than 100 keV when using 5 m cables between the detector and the preamplifiers.

  8. Neutron spectrometer for fast nuclear reactors

    E-Print Network [OSTI]

    M. Osipenko; M. Ripani; G. Ricco; B. Caiffi; F. Pompili; M. Pillon; M. Angelone; G. Verona-Rinati; R. Cardarelli; G. Mila; S. Argiro

    2015-05-25T23:59:59.000Z

    In this paper we describe the development and first tests of a neutron spectrometer designed for high flux environments, such as the ones found in fast nuclear reactors. The spectrometer is based on the conversion of neutrons impinging on $^6$Li into $\\alpha$ and $t$ whose total energy comprises the initial neutron energy and the reaction $Q$-value. The $^6$LiF layer is sandwiched between two CVD diamond detectors, which measure the two reaction products in coincidence. The spectrometer was calibrated at two neutron energies in well known thermal and 3 MeV neutron fluxes. The measured neutron detection efficiency varies from 4.2$\\times 10^{-4}$ to 3.5$\\times 10^{-8}$ for thermal and 3 MeV neutrons, respectively. These values are in agreement with Geant4 simulations and close to simple estimates based on the knowledge of the $^6$Li(n,$\\alpha$)$t$ cross section. The energy resolution of the spectrometer was found to be better than 100 keV when using 5 m cables between the detector and the preamplifiers.

  9. Development of multichannel low-energy neutron spectrometer

    SciTech Connect (OSTI)

    Arikawa, Y., E-mail: arikawa-y@ile.osaka-u.ac.jp; Nagai, T.; Abe, Y.; Kojima, S.; Sakata, S.; Inoue, H.; Utsugi, M.; Iwasa, Y.; Sarukura, N.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka (Japan); Murata, T. [Kumamoto University, 2-40-1 Kurokami, Kumamoto 860-8555 (Japan)

    2014-11-15T23:59:59.000Z

    A multichannel low-energy neutron spectrometer for down-scattered neutron (DSN) measurements in inertial confinement fusion (ICF) experiments has been developed. Our compact-size 256-channel lithium-glass-scintillator-based spectrometer has been implemented and tested in ICF experiments with the GEKKO XII laser. We have performed time calibration of the 256-channel analog-to-digital convertor system used for DSN measurements via X-ray pulse signals. We have clearly observed the DD-primary fusion neutron signal and have successfully studied the detector's impulse response. Our detector is soon to be implemented in future ICF experiments.

  10. Ultracold-neutron infrastructure for the gravitational spectrometer GRANIT

    E-Print Network [OSTI]

    P. Schmidt-Wellenburg; K. H. Andersen; P. Courtois; M. Kreuz; S. Mironov; V. V. Nesvizhevsky; G. Pignol; K. V. Protasov; T. Soldner; F. Vezzu; O. Zimmer

    2009-01-29T23:59:59.000Z

    The gravitational spectrometer GRANIT will be set up at the Institut Laue Langevin. It will profit from the high ultracold neutron density produced by a dedicated source. A monochromator made of crystals from graphite intercalated with potassium will provide a neutron beam with 0.89 nm incident on the source. The source employs superthermal conversion of cold neutrons in superfluid helium, in a vessel made from BeO ceramics with Be windows. A special extraction technique has been tested which feeds the spectrometer only with neutrons with a vertical velocity component v < 20 cm/s, thus keeping the density in the source high. This new source is expected to provide a density of up to 800 1/cm3 for the spectrometer.

  11. Ultracold-neutron infrastructure for the gravitational spectrometer GRANIT

    E-Print Network [OSTI]

    Schmidt-Wellenburg, P; Courtois, P; Kreuz, M; Mironov, S; Nesvizhevsky, V V; Pignol, G; Protasov, K V; Soldner, T; Vezzu, F; Zimmer, O

    2008-01-01T23:59:59.000Z

    The gravitational spectrometer GRANIT will be set up at the Institut Laue Langevin. It will profit from the high ultracold neutron density produced by a dedicated source. A monochromator made of crystals from graphite intercalated with potassium will provide a neutron beam with 8.9 Angstrom incident on the source. The source employs superthermal conversion of cold neutrons in superfluid helium, in a vessel made from BeO ceramics with Be windows. A special extraction technique has been tested which feeds the spectrometer only with neutrons with a vertical velocity component v = 20 cm/s, thus keeping the density in the source high. This new source is expected to provide a density of up to R = 800 cm-3 for the spectrometer.

  12. A solenoidal electron spectrometer for a precision measurement of the neutron $?$-asymmetry with ultracold neutrons

    E-Print Network [OSTI]

    B. Plaster; R. Carr; B. W. Filippone; D. Harrison; J. Hsiao; T. M. Ito; J. Liu; J. W. Martin; B. Tipton; J. Yuan

    2008-06-12T23:59:59.000Z

    We describe an electron spectrometer designed for a precision measurement of the neutron $\\beta$-asymmetry with spin-polarized ultracold neutrons. The spectrometer consists of a 1.0-Tesla solenoidal field with two identical multiwire proportional chamber and plastic scintillator electron detector packages situated within 0.6-Tesla field-expansion regions. Select results from performance studies of the spectrometer with calibration sources are reported.

  13. Analysis of a time-of-flight neutron spectrometer

    SciTech Connect (OSTI)

    Biggs, F.

    1983-12-01T23:59:59.000Z

    A neutron spectrometer is analyzed. The spectrum is resolved using a time-of-flight method in which the angular position of a rapidly spinning wheel is used to measure time. The measurement method is summarized, the data-analysis problem is formulated, units are discussed, the calibration technique is described, and a spectral transformation is developed.

  14. Performance of a Moderating Neutron Spectrometer That Uses Scintillating Fibers

    SciTech Connect (OSTI)

    Bliss, Mary; Craig, Richard A.; Barnett, Debra S.; Anderson, Dale N.; Smart, John E.; Knopf, Michael A.; Hartley, Stacey A.

    2001-08-03T23:59:59.000Z

    The Bonner sphere is the canonical example of instruments that provide a measure of neutron spectra by using moderating and absorbing materials together with thermal-neutron detectors. For such spectrometers, the instrument response reflects a statistical average of the energy spectrum. Pacific Northwest National Laboratory has developed neutron-sensitive cerium-activated scintillating fibers composed of lithium-silicate glass. These fibers present an enabling technology for efficient neutron spectroscopy. A moderating spectrometer was built as a testbed for materials identification. Based on the results of Monte Carlo experiments, six fiber layers are separated by polyethylene layers whose thickness has been chosen to maximize neutron spectral information. The completed, self-contained instrument, including electronics and data logging computer has a mass less than 35 kg, slightly more than half of which is polyethylene. Measurements have been performed by this instrument with various sources representing hard and soft neutron spectra. Because this instrument is a technology testbed, the data are recorded as pulse-height spectra. Results and future directions are presented.

  15. The new cold neutron chopper spectrometer at the Spallation Neutron Source: Design and performance

    SciTech Connect (OSTI)

    Ehlers, G.; Podlesnyak, A. A.; Niedziela, J. L.; Iverson, E. B. [Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Sokol, P. E. [Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States)

    2011-08-15T23:59:59.000Z

    The design and performance of the new cold neutron chopper spectrometer (CNCS) at the Spallation Neutron Source in Oak Ridge are described. CNCS is a direct-geometry inelastic time-of-flight spectrometer, designed essentially to cover the same energy and momentum transfer ranges as IN5 at ILL, LET at ISIS, DCS at NIST, TOFTOF at FRM-II, AMATERAS at J-PARC, PHAROS at LANSCE, and NEAT at HZB, at similar energy resolution. Measured values of key figures such as neutron flux at sample position and energy resolution are compared between measurements and ray tracing Monte Carlo simulations, and good agreement (better than 20% of absolute numbers) has been achieved. The instrument performs very well in the cold and thermal neutron energy ranges, and promises to become a workhorse for the neutron scattering community for quasielastic and inelastic scattering experiments.

  16. The new Cold Neutron Chopper Spectrometer at the Spallation Neutron Source -- Design and Performance

    SciTech Connect (OSTI)

    Ehlers, Georg [ORNL; Podlesnyak, Andrey A [ORNL; Niedziela, Jennifer L [ORNL; Iverson, Erik B [ORNL; Sokol, Paul E [ORNL

    2011-01-01T23:59:59.000Z

    The design and performance of the new cold neutron chopper spectrometer (CNCS) at the Spallation Neutron Source in Oak Ridge are described. CNCS is a direct-geometry inelastic time-of-flight spectrometer, designed essentially to cover the same energy and momentum transfer ranges as IN5 at ILL, LET at ISIS, DCS at NIST, TOFTOF at FRM-II, AMATERAS at J-PARC, PHAROS at LANSCE, and NEAT at HZB, at similar energy resolution. Measured values of key figures such as neutron flux at sample position and energy resolution are compared between measurements and ray tracing Monte Carlo simulations, and good agreement (better than 20% of absolute numbers) has been achieved. The instrument performs very well in the cold and thermal neutron energy ranges, and promises to become a workhorse for the neutron scattering community for quasielastic and inelastic scattering experiments.

  17. Development of a compact in situ polarized {sup 3}He neutron spin filter at Oak Ridge National Laboratory

    SciTech Connect (OSTI)

    Jiang, C. Y.; Tong, X., E-mail: tongx@ornl.gov; Brown, D. R.; Kadron, B. J.; Robertson, J. L. [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Chi, S.; Christianson, A. D.; Winn, B. L. [Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-07-15T23:59:59.000Z

    We constructed a compact in situ polarized {sup 3}He neutron spin filter based on spin-exchange optical pumping which is capable of continuous pumping of the {sup 3}He gas while the system is in place in the neutron beam on an instrument. The compact size and light weight of the system simplifies its utilization on various neutron instruments. The system has been successfully tested as a neutron polarizer on the triple-axis spectrometer (HB3) and the hybrid spectrometer (HYSPEC) at Oak Ridge National Laboratory. Over 70% {sup 3}He polarization was achieved and maintained during the test experiments. Over 90% neutron polarization and an average of 25% transmission for neutrons of 14.7 meV and 15 meV was also obtained.

  18. A solenoidal electron spectrometer for a precision measurement of the neutron $\\beta$-asymmetry with ultracold neutrons

    E-Print Network [OSTI]

    Plaster, B; Filippone, B W; Harrison, D; Hsiao, J; Ito, T M; Liu, J; Martin, J W; Tipton, B; Yuan, J

    2008-01-01T23:59:59.000Z

    We describe an electron spectrometer designed for a precision measurement of the neutron $\\beta$-asymmetry with spin-polarized ultracold neutrons. The spectrometer consists of a 1.0-Tesla solenoidal field with two identical multiwire proportional chamber and plastic scintillator electron detector packages situated within 0.6-Tesla field-expansion regions. Select results from performance studies of the spectrometer with calibration sources are reported.

  19. A source of ultra-cold neutrons for the gravitational spectrometer GRANIT

    E-Print Network [OSTI]

    Schmidt-Wellenburg, P; Nesvizhevsky, V V; Plonka, C; Soldner, T; Vezzu, F; Zimmer, O

    2007-01-01T23:59:59.000Z

    We present the status of the development of a dedicated high density ultra-cold neutron (UCN) source dedicated to the gravitational spectrometer GRANIT. The source employs superthermal conversion of cold neutrons to UCN in superfluid helium. Tests have shown that UCN produced inside the liquid can be extracted into vacuum. Furthermore a dedicated neutron selection channel was tested to maintain high initial density and extract only neutrons with a vertical velocity component 20 cm/s for the spectrometer. This new source would have a phase-space density of 0.18 cm-3(m/s)-3 for the spectrometer.

  20. A source of ultra-cold neutrons for the gravitational spectrometer GRANIT

    E-Print Network [OSTI]

    P. Schmidt-Wellenburg; P. Geltenbort; V. V. Nesvizhevsky; C. Plonka; T. Soldner; F. Vezzu; O. Zimmer

    2007-08-21T23:59:59.000Z

    We present the status of the development of a dedicated high density ultra-cold neutron (UCN) source dedicated to the gravitational spectrometer GRANIT. The source employs superthermal conversion of cold neutrons to UCN in superfluid helium. Tests have shown that UCN produced inside the liquid can be extracted into vacuum. Furthermore a dedicated neutron selection channel was tested to maintain high initial density and extract only neutrons with a vertical velocity component 20 cm/s for the spectrometer. This new source would have a phase-space density of 0.18 cm-3(m/s)-3 for the spectrometer.

  1. Deuterium density profile determination at JET using a neutron camera and a neutron spectrometer

    SciTech Connect (OSTI)

    Eriksson, J., E-mail: jacob.eriksson@physics.uu.se; Castegnetti, G.; Conroy, S.; Ericsson, G.; Hellesen, C. [EURATOM-VR, Department of Physics and Astronomy, Uppsala University (Sweden); Giacomelli, L. [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); EURATOM-CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom)

    2014-11-15T23:59:59.000Z

    In this work we estimate the fuel ion density profile in deuterium plasmas at JET, using the JET neutron camera, the neutron time-of-flight spectrometer TOFOR, and fusion reactivities modeled by the transport code TRANSP. The framework has been tested using synthetic data, which showed that the density profile could be reconstructed with an average accuracy of the order of 10 %. The method has also been applied to neutron measurements from a neutral beam heated JET discharge, which gave n{sub d}/n{sub e} ? 0.6 ± 0.3 in the plasma core and n{sub d}/n{sub e} ? 0.4 ± 0.3 towards the edge. Correction factors for detector efficiencies, neutron attenuation, and back-scattering are not yet included in the analysis; future work will aim at refining the estimated density.

  2. The new very small angle neutron scattering spectrometer at Laboratoire Leon Brillouin

    E-Print Network [OSTI]

    Sylvain Desert; Vincent Thevenot; Julian Oberdisse; Annie Brulet

    2007-06-12T23:59:59.000Z

    The design and characteristics of the new very small angle neutron scattering spectrometer under construction at the Laboratoire Leon Brillouin is described. Its goal is to extend the range of scattering vectors magnitudes towards 2x10{-4} /A. The unique feature of this new spectrometer is a high resolution two dimensional image plate detector sensitive to neutrons. The wavelength selection is achieved by a double reflection supermirror monochromator and the collimator uses a novel multibeam design.

  3. Simulation-guided optimization of small-angle analyzer geometry in the neutron backscattering spectrometer SPHERES

    SciTech Connect (OSTI)

    Wuttke, Joachim; Zamponi, Michaela [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)] [Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)

    2013-11-15T23:59:59.000Z

    The resolution of neutron backscattering spectrometers deteriorates at small scattering angles where analyzers deviate from exact backscattering. By reducing the azimuth angle range of the analyzers, the resolution can be improved with little loss of peak intensity. Measurements at the spectrometer SPHERES are in excellent agreement with simulations, which proves the dominance of geometric effects.

  4. axis neutron spectrometer: Topics by E-print Network

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

    other hand, interact with nuclei mapped and measured via neutron imaging. N5: Small Angle Neutron Scattering, HFIR CG2 General Purpose Pennycook, Steve 3 Parabolic versus elliptic...

  5. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; Seguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D.; McCluskey, M.; et al

    2014-06-01T23:59:59.000Z

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al. , Opt. Commun.133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ~±10% accuracy, and mean neutron energy to ~±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burnmore »can be measured. Future improvements to reduce the neutron energy uncertainty to ±15-20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ~±25-40 km/s.« less

  6. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; Seguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D.; McCluskey, M.; Mastrosimone, D.; Glebov, V. Yu.; Forrest, C.; Stoeckl, C.; Sangster, T. C.

    2014-06-01T23:59:59.000Z

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al. , Opt. Commun.133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ?±10% accuracy, and mean neutron energy to ?±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15?20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ?±25?40 km/s.

  7. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    SciTech Connect (OSTI)

    Zylstra, A. B., E-mail: zylstra@mit.edu; Gatu Johnson, M.; Frenje, J. A.; Séguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); McCluskey, M.; Mastrosimone, D.; Glebov, V. Yu.; Forrest, C.; Stoeckl, C.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2014-06-15T23:59:59.000Z

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al., Opt. Commun. 133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ?±10% accuracy, and mean neutron energy to ?±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15?20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ?±25?40 km/s.

  8. A compact neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF

    SciTech Connect (OSTI)

    Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; Seguin, F. H.; Rinderknecht, H. G.; Rosenberg, M. J.; Sio, H. W.; Li, C. K.; Petrasso, R. D.; McCluskey, M.; Mastrosimone, D.; Glebov, V. Yu.; Forrest, C.; Stoeckl, C.; Sangster, T. C.

    2014-06-01T23:59:59.000Z

    A compact spectrometer for measurements of the primary deuterium-tritium neutron spectrum has been designed and implemented on the OMEGA laser facility [T. Boehly et al. , Opt. Commun.133, 495 (1997)]. This instrument uses the recoil spectrometry technique, where neutrons produced in an implosion elastically scatter protons in a plastic foil, which are subsequently detected by a proton spectrometer. This diagnostic is currently capable of measuring the yield to ~±10% accuracy, and mean neutron energy to ~±50 keV precision. As these compact spectrometers can be readily placed at several locations around an implosion, effects of residual fuel bulk flows during burn can be measured. Future improvements to reduce the neutron energy uncertainty to ±15-20 keV are discussed, which will enable measurements of fuel velocities to an accuracy of ~±25-40 km/s.

  9. Current Status and Future Works of Neutron Scattering Laboratory at BATAN in Serpong

    SciTech Connect (OSTI)

    Ikram, A. [Center of Technology for Nuclear Industrial Materials, National Nuclear Energy Agency of Indonesia (BATAN) Kawasan Puspiptek Serpong, Tangerang 15314 (Indonesia)

    2008-03-17T23:59:59.000Z

    Current status of neutron beam instruments using neutrons produced by the Multi Purpose Research Reactor--30MWth (MPR 30, RSG GA Siwabessy) located in Serpong is presented. Description of the reactor as the neutron source is mentioned briefly. There are six neutron beam tubes coming from the beryllium reflector surrounding half of the reactor core providing neutrons in the experimental hall of the reactor (XHR). Four of them are dedicated to R and D in materials science using neutron scattering techniques. Neutron Radiography Facility (NRF), Triple Axis Spectrometer (TAS) and Residual Stress Measurement (RSM) Diffractometer are installed respectively at beam tubes S2, S4 and S6. The largest neutron beam tube (S5) is exploited to accommodate two neutron guide tubes that transfer the neutrons to a neighbouring building called neutron guide hall (NGH). There are three other neutron beam instruments installed in this building, namely Small Angle Neutron Scattering (SANS) Spectrometer (SMARTer), High Resolution SANS (HRSANS) Spectrometer and High Resolution Powder Diffractometer (HRPD). In the XHR, a Four Circle and Texture Diffractometer (FCD/TD) is attached to one of the neutron guide tubes. These seven instruments were installed to utilize the neutrons for materials science research, and recently the RSM diffractometer has shown its capabilities in identifying different amount of stress left due to different treatments of welding in fuel cladding, while the SANS spectrometer is now gaining capabilities in identifying different sizes and shapes of macromolecules in polymers as well as investigations of magnetic samples. In the mean time, non-destructive tests using the NRF is gathering more confidence from some latest real time measurements eventhough there are still some shortcomings in the components and their alignments. Future works including improvement of each facility and its components, even replacement of some parts are necessary and have to be carried out carefully. A plan for developing a neutron reflectometer at one of the neutron guide in the Neutron Guide Hall is also part of the near future activities.

  10. Improving the resolution of chopper spectrometers at pulsed neutron sources

    SciTech Connect (OSTI)

    Carpenter, J.M. (Argonne National Lab., IL (USA)); Mildner, D.F.R. (National Bureau of Standards, Washington, DC (USA). Center for Analytical Chemistry)

    1990-01-01T23:59:59.000Z

    We examine the relationships between intensity and resolution in pulsed-source chopper spectrometers, including the effects of Soller collimation, narrower rotor slits and higher rotor speeds. The basis is a simplified description of a spectrometer, approximately optimizing the rotor pulse and lighthouse effects. the analysis includes a new treatment of the angular distribution transmitted through a system consisting of a coarse collimator and a Soller collimator. The results encourage the prospect for a reasonably easily accomplished, higher resolution, optional configuration of the pulsed source chopper spectrometers at IPNS. 6 refs., 5 figs.

  11. Design and Simulation of a Boron-loaded Neutron Spectrometer

    E-Print Network [OSTI]

    Martin, Thomas

    2012-10-19T23:59:59.000Z

    spectrometer, consisting of plastic scintillating fibers in a hexagonal array, was simulated via Monte Carlo. Fiber size and boron content were varied to optimize response characteristics. The results were compared to industry standard multi...

  12. Superconducting gamma and fast-neutron spectrometers with high energy resolution

    DOE Patents [OSTI]

    Friedrich, Stephan (San Jose, CA); , Niedermayr, Thomas R. (Oakland, CA); Labov, Simon E. (Berkeley, CA)

    2008-11-04T23:59:59.000Z

    Superconducting Gamma-ray and fast-neutron spectrometers with very high energy resolution operated at very low temperatures are provided. The sensor consists of a bulk absorber and a superconducting thermometer weakly coupled to a cold reservoir, and determines the energy of the incident particle from the rise in temperature upon absorption. A superconducting film operated at the transition between its superconducting and its normal state is used as the thermometer, and sensor operation at reservoir temperatures around 0.1 K reduces thermal fluctuations and thus enables very high energy resolution. Depending on the choice of absorber material, the spectrometer can be configured either as a Gamma-spectrometer or as a fast-neutron spectrometer.

  13. JOURNAL DE PHYSIQUE Colloque C6, supplment au n 8, Tome 39, aot 1978, page C6-918 INELASTIC NEUTRON SCATTERING ON THE SPIN GLASS : Pd_Mn 10 a t . %*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Research Foundation ECN, Petten-NH3 The Netherlands Résumé.- Par la contribution inélastique de la /5/. The measurements have been carried out on a triple axis spectrometer at the Petten HFR reactor

  14. Progress in development of neutron energy spectrometer for deuterium plasma operation in KSTAR

    SciTech Connect (OSTI)

    Tomita, H., E-mail: tomita@nagoya-u.jp; Yamashita, F.; Nakayama, Y.; Morishima, K.; Yamamoto, Y.; Sakai, Y.; Hayashi, S.; Kawarabayashi, J.; Iguchi, T. [Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Cheon, M. S. [Diagnostics Technology Team, ITER Korea, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Isobe, M. [The Graduate University for Advanced Studies, 322-6 Oroshi-cho, Toki 509-5292 (Japan); National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Ogawa, K. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan)

    2014-11-15T23:59:59.000Z

    Two types of DD neutron energy spectrometer (NES) are under development for deuterium plasma operation in KSTAR to understand behavior of beam ions in the plasma. One is based on the state-of-the-art nuclear emulsion technique. The other is based on a coincidence detection of a recoiled proton and a scattered neutron caused by an elastic scattering of an incident DD neutron, which is called an associated particle coincidence counting-NES. The prototype NES systems were installed at J-port in KSTAR in 2012. During the 2012 and 2013 experimental campaigns, multiple shots-integrated neutron spectra were preliminarily obtained by the nuclear emulsion-based NES system.

  15. HYSPEC : A CRYSTAL TIME OF FLIGHT HYBRID SPECTROMETER FOR THE SPALLATION NEUTRON SOURCE.

    SciTech Connect (OSTI)

    SHAPIRO,S.M.; ZALIZNYAK,I.A.

    2002-12-30T23:59:59.000Z

    This document lays out a proposal by the Instrument Development Team (IDT) composed of scientists from leading Universities and National Laboratories to design and build a conceptually new high-flux inelastic neutron spectrometer at the pulsed Spallation Neutron Source (SNS) at Oak Ridge. This instrument is intended to supply users of the SNS and scientific community, of which the IDT is an integral part, with a platform for ground-breaking investigations of the low-energy atomic-scale dynamical properties of crystalline solids. It is also planned that the proposed instrument will be equipped with a polarization analysis capability, therefore becoming the first polarized beam inelastic spectrometer in the SNS instrument suite, and the first successful polarized beam inelastic instrument at a pulsed spallation source worldwide. The proposed instrument is designed primarily for inelastic and elastic neutron spectroscopy of single crystals. In fact, the most informative neutron scattering studies of the dynamical properties of solids nearly always require single crystal samples, and they are almost invariably flux-limited. In addition, in measurements with polarization analysis the available flux is reduced through selection of the particular neutron polarization, which puts even more stringent limits on the feasibility of a particular experiment. To date, these investigations have mostly been carried out on crystal spectrometers at high-flux reactors, which usually employ focusing Bragg optics to concentrate the neutron beam on a typically small sample. Construction at Oak Ridge of the high-luminosity spallation neutron source, which will provide intense pulsed neutron beams with time-averaged fluxes equal to those at medium-flux reactors, opens entirely new opportunities for single crystal neutron spectroscopy. Drawing upon experience acquired during decades of studies with both crystal and time-of-flight (TOF) spectrometers, the IDT has developed a conceptual design for a focused-beam, hybrid time-of-flight instrument with a crystal monochromator for the SNS called HYSPEC (an acronym for hybrid spectrometer). The proposed instrument has a potential to collect data more than an order of magnitude faster than existing steady-source spectrometers over a wide range of energy transfer ({h_bar}{omega}) and momentum transfer (Q) space, and will transform the way that data in elastic and inelastic single-crystal spectroscopy are collected. HYSPEC is optimized to provide the highest neutron flux on sample in the thermal and epithermal neutron energy ranges at a good-to-moderate energy resolution. By providing a flux on sample several times higher than other inelastic instruments currently planned for the SNS, the proposed instrument will indeed allow unique ground-breaking measurements, and will ultimately make polarized beam studies at a pulsed spallation source a realistic possibility.

  16. A method to measure the resonance transitions between the gravitationally bound quantum states of neutrons in the GRANIT spectrometer

    E-Print Network [OSTI]

    Meyerovich, Alex

    of neutrons in the GRANIT spectrometer M. Kreuz a , V.V. Nesvizhevsky a,Ã?, P. Schmidt-Wellenburg a , T bound quantum states of neutrons in the GRANIT spectrometer. The purpose of GRANIT is to improve quantum states, the transition probability will sharply increase. The GRANIT experiment is motivated

  17. Application of the BINS superheated drop detector spectrometer to the {sup 9}Be(p,xn) neutron energy spectrum determination

    SciTech Connect (OSTI)

    Di Fulvio, A.; Ciolini, R.; Mirzajani, N.; Romei, C.; D'Errico, F. [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Universita di Pisa, Pisa (Italy); Bedogni, R. [INFN, Laboratori Nazionali di Frascati, Frascati (Roma) (Italy); Esposito, J.; Zafiropoulos, D.; Colautti, P. [INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova) (Italy)

    2013-07-18T23:59:59.000Z

    In the framework of TRASCO-BNCT project, a Bubble Interactive Neutron Spectrometer (BINS) device was applied to the characterization of the angle-and energy-differential neutron spectra generated by the {sup 9}Be(p,xn)reaction. The BINS spectrometer uses two superheated emulsion detectors, sequentially operated at different temperatures and thus provides a series of six sharp threshold responses, covering the 0.1-10 MeV neutron energy range. Spectrum unfolding of the data was performed by means of MAXED code. The obtained angle, energy-differential spectra were compared with those measured with a Bonner sphere spectrometer, a silicon telescope spectrometer and literature data.

  18. Results for the response function determination of the Compact Neutron Spectrometer

    E-Print Network [OSTI]

    F. Gagnon-Moisan; M. Reginatto; A. Zimbal

    2012-01-30T23:59:59.000Z

    The Compact Neutron Spectrometer (CNS) is a Joint European Torus (JET) Enhancement Project, designed for fusion diagnostics in different plasma scenarios. The CNS is based on a liquid scintillator (BC501A) which allows good discrimination between neutron and gamma radiation. Neutron spectrometry with a BC501A spectrometer requires the use of a reliable, fully characterized detector. The determination of the response matrix was carried out at the Ion Accelerator Facility (PIAF) of the Physikalisch-Technische Bundesanstalt (PTB). This facility provides several monoenergetic beams (2.5, 8, 10, 12 and 14 MeV) and a 'white field'(Emax ~17 MeV), which allows for a full characterization of the spectrometer in the region of interest (from ~1.5 MeV to ~17 MeV. The energy of the incoming neutrons was determined by the time of flight method (TOF), with time resolution in the order of 1 ns. To check the response matrix, the measured pulse height spectra were unfolded with the code MAXED and the resulting energy distributions were compared with those obtained from TOF. The CNS project required modification of the PTB BC501A spectrometer design, to replace an analog data acquisition system (NIM modules) with a digital system developed by the 'Ente per le Nuove tecnologie, l'Energia e l'Ambiente' (ENEA). Results for the new digital system were evaluated using new software developed specifically for this project.

  19. Quantum states of neutrons in the gravitational and centrifugal potentials in a new GRANIT spectrometer

    ScienceCinema (OSTI)

    None

    2011-10-06T23:59:59.000Z

    We will discuss the scientific program to be studied in a new gravitational spectrometer GRANIT in a broad context of quantum states (quantum behaviour) of ultracold neutrons (UCN) in gravitational [1] and centrifugal [2] potentials, as well as applications of these phenomena/spectrometer to various domains of physics, ranging from studies of fundamental short-range interactions and symmetries to neutron quantum optics and reflectometry using UCN. All these topics, as well as related instrumental and methodical developments have been discussed during dedicated GRANIT-2010 Workshop [3]. The GRANIT spectrometer has been recently installed at the Institut Laue-Langevin, Grenoble, France [4] and could become operational in near future. 1. V.V. Nesvizhevsky et al (2002), Nature 415, 297. 2. V.V. Nesvizhevsky et al (2010), Nature Physics 6, 114. 3. GRANIT-2010, Les Houches, 14-19 february 2010. 4. M. Kreuz et al (2009), NIM 611, 326.

  20. A radial collimator for a time-of-flight neutron spectrometer

    SciTech Connect (OSTI)

    Stone, M. B.; Abernathy, D. L. [Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Niedziela, J. L.; Loguillo, M. J.; Overbay, M. A. [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-08-15T23:59:59.000Z

    We have engineered and installed a radial collimator for use in the scattered beam of a neutron time-of-flight spectrometer at a spallation neutron source. The radial collimator may be used with both thermal and epithermal neutrons, reducing the detected scattering intensity due to material outside of the sample region substantially. The collimator is located inside of the sample chamber of the instrument, which routinely cycles between atmospheric conditions and cryogenic vacuum. The oscillation and support mechanism of the collimator allow it to be removed from use without breaking vacuum. We describe here the design and characterization of this radial collimator.

  1. Results for the response function determination of the Compact Neutron Spectrometer

    E-Print Network [OSTI]

    Gagnon-Moisan, F; Zimbal, A

    2012-01-01T23:59:59.000Z

    The Compact Neutron Spectrometer (CNS) is a Joint European Torus (JET) Enhancement Project, designed for fusion diagnostics in different plasma scenarios. The CNS is based on a liquid scintillator (BC501A) which allows good discrimination between neutron and gamma radiation. Neutron spectrometry with a BC501A spectrometer requires the use of a reliable, fully characterized detector. The determination of the response matrix was carried out at the Ion Accelerator Facility (PIAF) of the Physikalisch-Technische Bundesanstalt (PTB). This facility provides several monoenergetic beams (2.5, 8, 10, 12 and 14 MeV) and a 'white field'(Emax ~17 MeV), which allows for a full characterization of the spectrometer in the region of interest (from ~1.5 MeV to ~17 MeV. The energy of the incoming neutrons was determined by the time of flight method (TOF), with time resolution in the order of 1 ns. To check the response matrix, the measured pulse height spectra were unfolded with the code MAXED and the resulting energy distribut...

  2. Superresolution of a compact neutron spectrometer at energies relevant for fusion diagnostics

    SciTech Connect (OSTI)

    Reginatto, M.; Zimbal, A. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany)

    2011-03-14T23:59:59.000Z

    The ability to achieve resolution that is better than the instrument resolution (i.e., superresolution) is well known in optics, where it has been extensively studied. Unfortunately, there are only a handful of theoretical studies concerning superresolution of particle spectrometers, even though experimentalists are familiar with the enhancement of resolution that is achievable when appropriate methods of data analysis are used, such as maximum entropy and Bayesian methods. Knowledge of the superresolution factor is in many cases important. For example, in applications of neutron spectrometry to fusion diagnostics, the temperature of a burning plasma is an important physical parameter which may be inferred from the width of the peak of the neutron energy spectrum, and the ability to determine this width depends on the superresolution factor. Kosarev has derived an absolute limit for resolution enhancement using arguments based on a well known theorem of Shannon. Most calculations of superresolution factors in the literature, however, are based on the assumption of Gaussian, translationally invariant response functions and therefore not directly applicable to neutron spectrometers which typically have response functions not satisfying these requirements. In this work, we develop a procedure that allows us to overcome these difficulties and we derive estimates of superresolution for liquid scintillator spectrometers of a type commonly used for neutron measurements. Theoretical superresolution factors are compared to experimental results.

  3. Test of a prototype neutron spectrometer based on diamond detectors in a fast reactor

    E-Print Network [OSTI]

    M. Osipenko; F. Pompili; M. Ripani; M. Pillon; G. Ricco; B. Caiffi; R. Cardarelli; G. Verona-Rinati; S. Argiro

    2015-05-23T23:59:59.000Z

    A prototype of neutron spectrometer based on diamond detectors has been developed. This prototype consists of a $^6$Li neutron converter sandwiched between two CVD diamond crystals. The radiation hardness of the diamond crystals makes it suitable for applications in low power research reactors, while a low sensitivity to gamma rays and low leakage current of the detector permit to reach good energy resolution. A fast coincidence between two crystals is used to reject background. The detector was read out using two different electronic chains connected to it by a few meters of cable. The first chain was based on conventional charge-sensitive amplifiers, the other used a custom fast charge amplifier developed for this purpose. The prototype has been tested at various neutron sources and showed its practicability. In particular, the detector was calibrated in a TRIGA thermal reactor (LENA laboratory, University of Pavia) with neutron fluxes of $10^8$ n/cm$^2$s and at the 3 MeV D-D monochromatic neutron source named FNG (ENEA, Rome) with neutron fluxes of $10^6$ n/cm$^2$s. The neutron spectrum measurement was performed at the TAPIRO fast research reactor (ENEA, Casaccia) with fluxes of 10$^9$ n/cm$^2$s. The obtained spectra were compared to Monte Carlo simulations, modeling detector response with MCNP and Geant4.

  4. A diamond based neutron spectrometer for diagnostics of deuterium-tritium fusion plasmas

    SciTech Connect (OSTI)

    Cazzaniga, C., E-mail: carlo.cazzaniga@mib.infn.it; Nocente, M.; Gorini, G. [University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy); Rebai, M.; Giacomelli, L. [University of Milano Bicocca, Piazza della Scienza 3, Milano (Italy); Tardocchi, M.; Croci, G.; Grosso, G. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano (Italy); Calvani, P.; Girolami, M.; Trucchi, D. M. [CNR-ISM, Research Area Roma 1, Via Salaria km 29.300, 00015-Monterotondo Scalo (Rm) (Italy); Griesmayer, E. [Atominstitut, Vienna University of Technology, Vienna (Austria); Pillon, M. [Associazione EURATOM-ENEA sulla Fusione ENEA C.R. Frascati, Via E. Fermi, 45, 00044 Frascati (Roma) (Italy)

    2014-11-15T23:59:59.000Z

    Single crystal Diamond Detectors (SDD) are being increasingly exploited for neutron diagnostics in high power fusion devices, given their significant radiation hardness and high energy resolution capabilities. The geometrical efficiency of SDDs is limited by the size of commercially available crystals, which is often smaller than the dimension of neutron beams along collimated lines of sight in tokamak devices. In this work, we present the design and fabrication of a 14 MeV neutron spectrometer consisting of 12 diamond pixels arranged in a matrix, so to achieve an improved geometrical efficiency. Each pixel is equipped with an independent high voltage supply and read-out electronics optimized to combine high energy resolution and fast signals (<30 ns), which are essential to enable high counting rate (>1 MHz) spectroscopy. The response function of a prototype SDD to 14 MeV neutrons has been measured at the Frascati Neutron Generator by observation of the 8.3 MeV peak from the {sup 12}C(n, ?){sup 9}Be reaction occurring between neutrons and {sup 12}C nuclei in the detector. The measured energy resolution (2.5% FWHM) meets the requirements for neutron spectroscopy applications in deuterium-tritium plasmas.

  5. Data acquisition system with pulse height capability for the TOFED time-of-flight neutron spectrometer

    SciTech Connect (OSTI)

    Chen, Z. J.; Peng, X. Y.; Zhang, X.; Du, T. F.; Hu, Z. M.; Cui, Z. Q.; Ge, L. J.; Xie, X. F.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S., E-mail: tsfan@pku.edu.cn [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Gorini, G.; Nocente, M.; Tardocchi, M. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano, Piazza della Scienza 3, 20126 Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola”, EURATOM-ENEA-CNR Association, Via Cozzi 53, 20125 Milano (Italy); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, Anhui (China)

    2014-11-15T23:59:59.000Z

    A new time-of-flight neutron spectrometer TOFED has been constructed for installation at Experimental Advanced Superconducting Tokamak. A data acquisition system combining measurements of flight time and energy from the interaction of neutrons with the TOFED scintillators has been developed. The data acquisition system can provide a digitizing resolution better than 1.5% (to be compared with the >10% resolution of the recoil particle energy in the plastic scintillators) and a time resolution <1 ns. At the same time, it is compatible with high count rate event recording, which is an essential feature to investigate phenomena occurring on time scales faster than the slowing down time (?100 ms) of the beam ions in the plasma. Implications of these results on the TOFED capability to resolve fast ion signatures in the neutron spectrum from EAST plasmas are discussed.

  6. Test of a prototype neutron spectrometer based on diamond detectors in a fast reactor

    E-Print Network [OSTI]

    Osipenko, M; Ripani, M; Pillon, M; Ricco, G; Caiffi, B; Cardarelli, R; Verona-Rinati, G; Argiro, S

    2015-01-01T23:59:59.000Z

    A prototype of neutron spectrometer based on diamond detectors has been developed. This prototype consists of a $^6$Li neutron converter sandwiched between two CVD diamond crystals. The radiation hardness of the diamond crystals makes it suitable for applications in low power research reactors, while a low sensitivity to gamma rays and low leakage current of the detector permit to reach good energy resolution. A fast coincidence between two crystals is used to reject background. The detector was read out using two different electronic chains connected to it by a few meters of cable. The first chain was based on conventional charge-sensitive amplifiers, the other used a custom fast charge amplifier developed for this purpose. The prototype has been tested at various neutron sources and showed its practicability. In particular, the detector was calibrated in a TRIGA thermal reactor (LENA laboratory, University of Pavia) with neutron fluxes of $10^8$ n/cm$^2$s and at the 3 MeV D-D monochromatic neutron source na...

  7. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Casey, D. T. [MIT, Cambridge, MA (United States). Plasma Science and Fusion Center; Frenje, J. A. [MIT, Cambridge, MA (United States). Plasma Science and Fusion Center; Gatu Johnson, M. [MIT, Cambridge, MA (United States). Plasma Science and Fusion Center; Seguin, F. H. [MIT, Cambridge, MA (United States). Plasma Science and Fusion Center; Li, C. K. [MIT, Cambridge, MA (United States). Plasma Science and Fusion Center; Petrasso, R. D. [MIT, Cambridge, MA (United States). Plasma Science and Fusion Center; Glebov, V. Yu. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Katz, J. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Magoon, J. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Meyerhofer, D. D. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Sangster, T. C. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Shoup, M. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Ulreich, J. [Univ. of Rochester, NY (United States). Lab. for Laser Energitics; Ashabranner, R. C. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Bionta, R. M. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Carpenter, A. C. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Felker, B. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Khater, H. Y. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); LePape, S. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); MacKinnon, A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); McKernan, M. A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Moran, M. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Rygg, J. R. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Yeoman, M. F. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Zacharias, R. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Leeper, R. J. [Sandia National Laboratories, Albuquerque, NM (United States); Fletcher, K. [State Univ. of New York at Geneseo, NY (United States); Farrell, M. [General Atomics, San Diego, CA (United States); Jasion, D. [General Atomics, San Diego, CA (United States); Kilkenny, J. [General Atomics, San Diego, CA (United States); Paguio, R. [General Atomics, San Diego, CA (United States)

    2013-01-01T23:59:59.000Z

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describes ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.

  8. Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

    SciTech Connect (OSTI)

    Jacobsen, A. S., E-mail: Ajsen@fysik.dtu.dk; Salewski, M.; Korsholm, S. B.; Leipold, F.; Nielsen, S. K.; Rasmussen, J.; Stejner, M. [Association Euratom - DTU, Technical University of Denmark, Department of Physics, Kgs. Lyngby (Denmark); Eriksson, J.; Ericsson, G.; Hjalmarsson, A. [Association Euratom - VR, Uppsala University, Department of Physics and Astronomy, Uppsala (Sweden)

    2014-11-15T23:59:59.000Z

    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR.

  9. The magnetic recoil spectrometer for measurements of the absolute neutron spectrum at OMEGA and the NIF

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; et al

    2013-01-01T23:59:59.000Z

    The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, iontemperature, and areal-density. The Magnetic Recoil Spectrometer (MRS) has been used at both the OMEGA laser facility and the National Ignition Facility (NIF) to measure the absolute neutron spectrum from 3 to 30 MeV at OMEGA and 3 to 36 MeV at the NIF. These measurements have been used to diagnose the performance of cryogenic target implosions to unprecedented accuracy. Interpretation of MRS data requires a detailed understanding of the MRS response and background. This paper describesmore »ab initio characterization of the system involving Monte Carlo simulations of the MRS response in addition to the commission experiments for in situ calibration of the systems on OMEGA and the NIF.« less

  10. IBIS: An inverse geometry Brillouin inelastic neutron spectrometer for the SNS

    SciTech Connect (OSTI)

    Zhao, J. K.; Robertson, Lee; Herwig, Kenneth W. [Instrument and Source Development Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Wildgruber, Christoph U. [Chemical and Engineering Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2013-02-15T23:59:59.000Z

    The high power target station at the Spallation Neutron Source (SNS) currently has about 20 completed neutron scattering instruments. With a broad coverage of the momentum transfer (Q)-energy (E) space, these instruments serve an extensive user community. In an effort to further expand the scientific capabilities of the SNS instrument suites, we propose a low background, inverse geometry Brillouin inelastic spectrometer for the SNS which will expand the Q-E coverage of the current instrument suite and facilitate the study of inelastic and quasi-elastic scatterings at low Q values. The possible location for the proposed instrument is either beamline 8 which views the decoupled water moderator, or beamline 14A, which views a cold, coupled super critical hydrogen moderator. The instrument parameters, optimizations, and performances at these two beamline locations are discussed.

  11. Design of the radiation shielding for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    SciTech Connect (OSTI)

    Du, T. F.; Chen, Z. J.; Peng, X. Y.; Yuan, X.; Zhang, X.; Hu, Z. M.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S., E-mail: tsfan@pku.edu.cn [School of Physics, State Key Lab of Nuclear Physics and Technology, Peking University, Beijing (China); Gorini, G.; Nocente, M. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano (Italy); Istituto di Fisicadel Plasma “P. Caldirola,” Milano (Italy); Tardocchi, M. [Istituto di Fisicadel Plasma “P. Caldirola,” Milano (Italy); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, CAS, Hefei (China)

    2014-11-15T23:59:59.000Z

    A radiation shielding has been designed to reduce scattered neutrons and background gamma-rays for the new double-ring Time Of Flight Enhanced Diagnostics (TOFED). The shielding was designed based on simulation with the Monte Carlo code MCNP5. Dedicated model of the EAST tokamak has been developed together with the emission neutron source profile and spectrum; the latter were simulated with the Nubeam and GENESIS codes. Significant reduction of background radiation at the detector can be achieved and this satisfies the requirement of TOFED. The intensities of the scattered and direct neutrons in the line of sight of the TOFED neutron spectrometer at EAST are studied for future data interpretation.

  12. Triple-axis X-ray Reciprocal Space Mapping of In(y)Ga(1-y)As Thermophotovoltaic Diodes Grown on (100) InP Substrates

    SciTech Connect (OSTI)

    M Dashiell; H Ehsani; P Sander; F Newman; C Wang; Z Shellenbarger; D Donetski; N Gu; S Anikeev

    2006-02-16T23:59:59.000Z

    Analysis of the composition, strain-relaxation, layer-tilt, and the crystalline quality of In{sub y}Ga{sub 1-y}As/InP{sub 1-x}As{sub x} thermophotovoltaic (TPV) diodes grown by metal organic vapor phase epitaxy (MOVPE) is demonstrated using triple-axis x-ray reciprocal space mapping techniques. In{sub 0.53}Ga{sub 0.47}As (E{sub gap} = 0.74eV) n/p junction diodes are grown lattice matched (LM) to InP substrates and lattice mismatched (LMM) In{sub 0.67}Ga{sub 0.33}As (E{sub gap} = 0.6eV) TPV diodes are grown on three-step InP{sub 1-x}As{sub x} (0 < x < 0.32) buffer layers on InP substrates. X-ray reciprocal space maps about the symmetric (400) and asymmetric (533) reciprocal lattice points (RELPs) determine the in-plane and out-of-plane lattice parameters and strain of the In{sub y}Ga{sub 1-y}As TPV active layer and underlying InP{sub 1-x}As{sub x} buffers. Triple-axis x-ray rocking curves about the LMM In{sub 0.67}Ga{sub 0.33}As RELP show an order of magnitude increase of its full width at half maximum (FWHM) compared to that from the LM In{sub 0.53}Ga{sub 0.47}As (250asec vs. 30asec). Despite the significant RELP broadening the photovoltaic figure of merits show that the electronic quality of the LMM In{sub 0.67}Ga{sub 0.33}As approaches that of the lattice matched diode material. This indicates that misfit-related crystalline imperfections are not dominating the photovoltaic response of the optimized LMM In{sub 0.67}Ga{sub 0.33}As material compared with the intrinsic recombination processes and/or recombination through native point defects which would be present in both LMM and LM diode material. However, additional RELP broadening in non-optimized LMM In{sub 0.67}Ga{sub 0.33}As n/p junction diodes does correspond to significant degradation of TPV diode open circuit voltage and minority carrier lifetime demonstrating that there is correlation between x-ray FWHM and the electronic performance of the LMM TPV diodes.

  13. Design of a backscatter 14-MeV neutron time-of-flight spectrometer for experiments at ITER

    SciTech Connect (OSTI)

    Dzysiuk, N.; Hellesen, C.; Conroy, S.; Ericsson, G.; Hjalmarsson, A.; Skiba, M. [Div. Applied Nuclear Physics, Dept. Physics and Astronomy, Uppsala University, Box 516, Uppsala, 751 20 (Sweden)

    2014-08-21T23:59:59.000Z

    Neutron energy spectrometry diagnostics play an important role in present-day experiments related to fusion energy research. Measurements and thorough analysis of the neutron emission from the fusion plasma give information on a number of basic fusion performance quantities, on the condition of the neutron source and plasma behavior. Here we discuss the backscatter Time-of-Flight (bTOF) spectrometer concept as a possible instrument for performing high resolution measurements of 14 MeV neutrons. The instrument is based on two sets of scintillators, a first scatterer exposed to a collimated neutron beam and a second detector set placed in the backward direction. The scintillators of the first set are enriched in deuterium to achieve neutron backscattering. The energy resolution and efficiency of a bTOF instrument have been determined for various geometrical configurations. A preliminary design of optimal geometry for the two scintillator sets has been obtained by Monte Carlo simulations based on the MCNPX code.

  14. The magnetic shielding for the neutron decay spectrometer aSPECT

    E-Print Network [OSTI]

    Gertrud Konrad; Fidel Ayala Guardia; Stefan Baeßler; Michael Borg; Ferenc Glück; Werner Heil; Stefan Hiebel; Raquel Munoz Horta; Yury Sobolev

    2014-05-05T23:59:59.000Z

    Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magnet system. While the return yoke must reduce the stray magnetic field, the internal magnetic field and its homogeneity should not be affected. As in many cases, the magnetic shielding for aSPECT must manage with limited space. In addition, we must ensure that the additional magnetic forces on the magnet coils are not destructive. In order to determine the most suitable geometry for the magnetic shielding for aSPECT, we simulated a variety of possible geometries and combinations of shielding materials of non-linear permeability. The results of our simulations were checked through magnetic field measurements both with Hall and nuclear magnetic resonance probes. The experimental data are in good agreement with the simulated values: The mean deviation from the simulated exterior magnetic field is (-1.7+/-4.8)%. However, in the two critical regions, the internal magnetic field deviates by 0.2% respectively <1E-4 from the simulated values.

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

    SciTech Connect (OSTI)

    Lord, J. S.; McKenzie, I.; Baker, P. J.; Cottrell, S. P.; Giblin, S. R.; Hillier, A. D.; Holsman, B. H.; King, P. J. C.; Nightingale, J. B.; Pratt, F. L.; Rhodes, N. J. [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Blundell, S. J.; Lancaster, T. [Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom); Good, J.; Mitchell, R.; Owczarkowski, M.; Poli, S. [Cryogenic Limited, 30 Acton Park Industrial Estate, The Vale, Acton, London W3 7QE (United Kingdom); Scheuermann, R. [Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Salman, Z. [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom)

    2011-07-15T23:59:59.000Z

    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.

  16. A method to measure the resonance transitions between the gravitationally bound quantum states of neutrons in the GRANIT spectrometer

    E-Print Network [OSTI]

    Kreuz, M; Schmidt-Wellenburg, P; Soldner, T; Thomas, M; Boerner, H G; Naraghi, F; Pignol, G; Protasov, K V; Rebreyend, D; Vezzu, F; Flaminio, R; Michel, C; Pinard, L; Remillieux, A; Baessler, S; Gagarski, A M; Grigorieva, L A; Kuzmina, T M; Meyerovich, A E; Mezhov-Deglin, L P; Petrov, G A; Strelkov, A V; Voronin, A Yu

    2009-01-01T23:59:59.000Z

    We present a method to measure the resonance transitions between the gravitationally bound quantum states of neutrons in the GRANIT spectrometer. The purpose of GRANIT is to improve the accuracy of measurement of the quantum states parameters by several orders of magnitude, taking advantage of long storage of Ultracold neutrons at specula trajectories. The transitions could be excited using a periodic spatial variation of a magnetic field gradient. If the frequency of such a perturbation (in the frame of a moving neutron) coincides with a resonance frequency defined by the energy difference of two quantum states, the transition probability will sharply increase. The GRANIT experiment is motivated by searches for short-range interactions (in particular spin-dependent interactions), by studying the interaction of a quantum system with a gravitational field, by searches for extensions of the Standard model, by the unique possibility to check the equivalence principle for an object in a quantum state and by study...

  17. Prospects for measuring the fuel ion ratio in burning ITER plasmas using a DT neutron emission spectrometer

    SciTech Connect (OSTI)

    Hellesen, C.; Skiba, M., E-mail: mateusz.skiba@physics.uu.se; Dzysiuk, N.; Weiszflog, M.; Hjalmarsson, A.; Ericsson, G.; Conroy, S.; Andersson-Sundén, E.; Eriksson, J.; Binda, F. [Department of Physics and Astronomy, Uppsala University, Uppsala (EURATOM-VR Association), SE-75120 Uppsala (Sweden)

    2014-11-15T23:59:59.000Z

    The fuel ion ratio n{sub t}/n{sub d} is an essential parameter for plasma control in fusion reactor relevant applications, since maximum fusion power is attained when equal amounts of tritium (T) and deuterium (D) are present in the plasma, i.e., n{sub t}/n{sub d} = 1.0. For neutral beam heated plasmas, this parameter can be measured using a single neutron spectrometer, as has been shown for tritium concentrations up to 90%, using data obtained with the MPR (Magnetic Proton Recoil) spectrometer during a DT experimental campaign at the Joint European Torus in 1997. In this paper, we evaluate the demands that a DT spectrometer has to fulfill to be able to determine n{sub t}/n{sub d} with a relative error below 20%, as is required for such measurements at ITER. The assessment shows that a back-scattering time-of-flight design is a promising concept for spectroscopy of 14 MeV DT emission neutrons.

  18. Spin exchange optical pumping based polarized {sup 3}He filling station for the Hybrid Spectrometer at the Spallation Neutron Source

    SciTech Connect (OSTI)

    Jiang, C. Y.; Tong, X.; Brown, D. R.; Culbertson, H.; Kadron, B.; Robertson, J. L. [Instrument and Source Design Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Graves-Brook, M. K. [Research Accelerator Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Hagen, M. E. [Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Lee, W. T. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234 (Australia); Winn, B. [Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2013-06-15T23:59:59.000Z

    The Hybrid Spectrometer (HYSPEC) is a new direct geometry spectrometer at the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is equipped with polarization analysis capability with 60 Degree-Sign horizontal and 15 Degree-Sign vertical detector coverages. In order to provide wide angle polarization analysis for this instrument, we have designed and built a novel polarized {sup 3}He filling station based on the spin exchange optical pumping method. It is designed to supply polarized {sup 3}He gas to HYSPEC as a neutron polarization analyzer. In addition, the station can optimize the {sup 3}He pressure with respect to the scattered neutron energies. The depolarized {sup 3}He gas in the analyzer can be transferred back to the station to be repolarized. We have constructed the prototype filling station. Preliminary tests have been carried out demonstrating the feasibility of the filling station. Here, we report on the design, construction, and the preliminary results of the prototype filling station.

  19. Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak

    SciTech Connect (OSTI)

    Cui, Z. Q.; Chen, Z. J.; Xie, X. F.; Peng, X. Y.; Hu, Z. M.; Du, T. F.; Ge, L. J.; Zhang, X.; Yuan, X.; Fan, T. S.; Chen, J. X.; Li, X. Q., E-mail: lixq2002@pku.edu.cn, E-mail: guohuizhang@pku.edu.cn; Zhang, G. H., E-mail: lixq2002@pku.edu.cn, E-mail: guohuizhang@pku.edu.cn [School of Physics, State Key Lab of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Xia, Z. W. [Southwestern Institute of Physics, Chengdu 610225 (China); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, CAS, Hefei 230031 (China)

    2014-11-15T23:59:59.000Z

    The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

  20. Evaluation of a digital data acquisition system and optimization of n-{gamma} discrimination for a compact neutron spectrometer

    SciTech Connect (OSTI)

    Giacomelli, L.; Zimbal, A.; Reginatto, M.; Tittelmeier, K. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany)

    2011-01-15T23:59:59.000Z

    A compact NE213 liquid scintillation neutron spectrometer with a new digital data acquisition (DAQ) system is now in operation at the Physikalisch-Technische Bundesanstalt (PTB). With the DAQ system, developed by ENEA Frascati, neutron spectrometry with high count rates in the order of 5x10{sup 5} s{sup -1} is possible, roughly an order of magnitude higher than with an analog acquisition system. To validate the DAQ system, a new data analysis code was developed and tests were done using measurements with 14-MeV neutrons made at the PTB accelerator. Additional analysis was carried out to optimize the two-gate method used for neutron and gamma (n-{gamma}) discrimination. The best results were obtained with gates of 35 ns and 80 ns. This indicates that the fast and medium decay time components of the NE213 light emission are the ones that are relevant for n-{gamma} discrimination with the digital acquisition system. This differs from what is normally implemented in the analog pulse shape discrimination modules, namely, the fast and long decay emissions of the scintillating light.

  1. The Filter Difference Spectrometer

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

    Difference Spectrometer (FDS) is used for molecular vibrational spectroscopy by inelastic neutron scattering. The instrument is designed for high count rates by use of large...

  2. Digitized two-parameter spectrometer for neutron-gamma mixed field

    SciTech Connect (OSTI)

    Matej, Z. [Faculty of Informatics, Masaryk Univ., Botanicka 68a, 602 00 Brno (Czech Republic); Cvachovec, J.; Prenosil, V. [Masaryk Univ., Brno (Czech Republic); Cvachovec, F. [Univ. of Defence, Brno (Czech Republic); Zaritski, S. [Kurchatov Inst., Moscow (Russian Federation)

    2011-07-01T23:59:59.000Z

    This paper shows the results of digital processing of output pulses from combined photon-neutron detector using a commercially available digitizer ACQUIRIS DP 210. The advantage of digital processing is reduction of the apparatus in weight and size, acceleration of measurement, and increased resistance to pile-up of pulses. The neutron and photon spectrum of radionuclide source {sup 252}Cf is presented. (authors)

  3. Bayesian and maximum entropy methods for fusion diagnostic measurements with compact neutron spectrometers

    SciTech Connect (OSTI)

    Reginatto, Marcel; Zimbal, Andreas [Physikalisch-Technische Bundesanstalt, 38116 Braunschweig (Germany)

    2008-02-15T23:59:59.000Z

    In applications of neutron spectrometry to fusion diagnostics, it is advantageous to use methods of data analysis which can extract information from the spectrum that is directly related to the parameters of interest that describe the plasma. We present here methods of data analysis which were developed with this goal in mind, and which were applied to spectrometric measurements made with an organic liquid scintillation detector (type NE213). In our approach, we combine Bayesian parameter estimation methods and unfolding methods based on the maximum entropy principle. This two-step method allows us to optimize the analysis of the data depending on the type of information that we want to extract from the measurements. To illustrate these methods, we analyze neutron measurements made at the PTB accelerator under controlled conditions, using accelerator-produced neutron beams. Although the methods have been chosen with a specific application in mind, they are general enough to be useful for many other types of measurements.

  4. Forward fitting of experimental data from a NE213 neutron detector installed with the magnetic proton recoil upgraded spectrometer at JET

    SciTech Connect (OSTI)

    Binda, F., E-mail: federico.binda@physics.uu.se; Ericsson, G.; Eriksson, J.; Hellesen, C.; Conroy, S.; Sundén, E. Andersson [Department of Physics and Astronomy, EURATOM-VR Association, Uppsala University, Uppsala (Sweden); Collaboration: JET-EFDA Team

    2014-11-15T23:59:59.000Z

    In this paper, we present the results obtained from the data analysis of neutron spectra measured with a NE213 liquid scintillator at JET. We calculated the neutron response matrix of the instrument combining MCNPX simulations, a generic proton light output function measured with another detector and the fit of data from ohmic pulses. For the analysis, we selected a set of pulses with neutral beam injection heating (NBI) only and we applied a forward fitting procedure of modeled spectral components to extract the fraction of thermal neutron emission. The results showed the same trend of the ones obtained with the dedicated spectrometer TOFOR, even though the values from the NE213 analysis were systematically higher. This discrepancy is probably due to the different lines of sight of the two spectrometers (tangential for the NE213, vertical for TOFOR). The uncertainties on the thermal fraction estimates were from 4 to 7 times higher than the ones from the TOFOR analysis.

  5. Monte Carlo simulation of a Bonner sphere spectrometer for application to the determination of neutron field in the Experimental Advanced Superconducting Tokamak experimental hall

    SciTech Connect (OSTI)

    Hu, Z. M.; Xie, X. F.; Chen, Z. J.; Peng, X. Y.; Du, T. F.; Cui, Z. Q.; Ge, L. J.; Li, T.; Yuan, X.; Zhang, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S., E-mail: tsfan@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, CAS, Hefei 230031 (China); Gorini, G. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano 20126 (Italy); Istituto di Fisica del Plasma “P. Caldirola,” Milano 20126 (Italy)

    2014-11-15T23:59:59.000Z

    To assess the neutron energy spectra and the neutron dose for different positions around the Experimental Advanced Superconducting Tokamak (EAST) device, a Bonner Sphere Spectrometer (BSS) was developed at Peking University, with totally nine polyethylene spheres and a SP9 {sup 3}He counter. The response functions of the BSS were calculated by the Monte Carlo codes MCNP and GEANT4 with dedicated models, and good agreement was found between these two codes. A feasibility study was carried out with a simulated neutron energy spectrum around EAST, and the simulated “experimental” result of each sphere was obtained by calculating the response with MCNP, which used the simulated neutron energy spectrum as the input spectrum. With the deconvolution of the “experimental” measurement, the neutron energy spectrum was retrieved and compared with the preset one. Good consistence was found which offers confidence for the application of the BSS system for dose and spectrum measurements around a fusion device.

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

    SciTech Connect (OSTI)

    Peng, X. Y.; Chen, Z. J.; Zhang, X.; Hu, Z. M.; Du, T. F.; Cui, Z. Q.; Xie, X. F.; Ge, L. J.; Yuan, X.; Li, X. Q.; Zhang, G. H.; Chen, J. X.; Fan, T. S., E-mail: tsfan@pku.edu.cn [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Gorini, G.; Nocente, M. [Dipartimento di Fisica, Università di Milano-Bicocca, Milano, Piazza della Scienza 3, 20126 Milano (Italy); Istituto di Fisica del Plasma “P. Caldirola,” EURATOM-ENEA-CNR Association, Via Cozzi 53, 20125 Milano (Italy); Tardocchi, M. [Istituto di Fisica del Plasma “P. Caldirola,” EURATOM-ENEA-CNR Association, Via Cozzi 53, 20125 Milano (Italy); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, Anhui (China)

    2014-11-15T23:59:59.000Z

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

  7. Measurements of fuel and ablator ?R in Symmetry-Capsule implosions with the Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility

    SciTech Connect (OSTI)

    Gatu Johnson, M., E-mail: gatu@psfc.mit.edu; Frenje, J. A.; Li, C. K.; Séguin, F. H.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Bionta, R. M.; Casey, D. T.; Caggiano, J. A.; Hatarik, R.; Khater, H. Y.; Sayre, D. B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Knauer, J. P.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Herrmann, H. W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Kilkenny, J. D. [General Atomics, San Diego, California 92186 (United States)

    2014-11-15T23:59:59.000Z

    The Magnetic Recoil neutron Spectrometer (MRS) on the National Ignition Facility (NIF) measures the neutron spectrum in the energy range of 4–20 MeV. This paper describes MRS measurements of DT-fuel and CH-ablator ?R in DT gas-filled symmetry-capsule implosions at the NIF. DT-fuel ?R's of 80–140 mg/cm{sup 2} and CH-ablator ?R's of 400–680 mg/cm{sup 2} are inferred from MRS data. The measurements were facilitated by an improved correction of neutron-induced background in the low-energy part of the MRS spectrum. This work demonstrates the accurate utilization of the complete MRS-measured neutron spectrum for diagnosing NIF DT implosions.

  8. Implementation of the control and data acquisition system for a small angle neutron scattering spectrometer according to the "Juelich-Munich standard"

    E-Print Network [OSTI]

    H. Kleines; M. Drochner; H. Loevenich; M. Wagener; F. Suxdorf; F. -J. Kayser; K. Zwoll; L. Schaetzler; J. Heinen; M. Heiderich; D. Schwahn; J. Neuhaus; J. Krueger

    2002-10-24T23:59:59.000Z

    In Forschungszentrum Juelich the control and data acquisition systems for several neutron spectrometers are being built. Because some of these spectrometers will be commissioned to the new research reactor FRM-II at the technical university of Munich, there was a joint effort with the instrumentation group of the FRM-II to establish the "Juelich-Munich standard", which is basically a collection of tools and devices which are used for the implementation of the spectrometers. This includes: Siemens S7 PLCs for all axis movement issues, PROFIBUS DP for the connection of slow control equipment in the front end, TACO Middleware running on PC-Systems with Linux, python for scripting and Qt for the implementation of GUIs. The paper describes the implementation the control and data acquisition system of the KWS-1, the first experiment built according to the above standard

  9. The IPNS resonance detector spectrometer

    SciTech Connect (OSTI)

    Crawford, R.K.

    1986-01-01T23:59:59.000Z

    In the resonance detector method of neutron spectroscopy, a foil is placed in the scattered neutron beam and scattered neutrons having the resonance energy are detected by detecting the capture gammas resulting from the resonance absorption of the neutrons. A prototype resonance detector spectrometer called the Electron Volt Spectrometer (EVS) has been built and operated. The instrument is described, the current understanding of the background of the instrument is discussed, software developed to simulate the detector efficiency is described and compared with experimental results, and a test of the use of foil-thickness difference techniques to improve resolution is presented. (LEW)

  10. MnO spin-wave dispersion curves from neutron powder diffraction

    SciTech Connect (OSTI)

    Goodwin, Andrew L.; Dove, Martin T. [Department of Earth Sciences, Cambridge University, Downing Street, Cambridge CB2 3EQ (United Kingdom); Tucker, Matthew G. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Keen, David A. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford OX1 3PU (United Kingdom)

    2007-02-15T23:59:59.000Z

    We describe a model-independent approach for the extraction of spin-wave dispersion curves from powder neutron total scattering data. Our approach is based on a statistical analysis of real-space spin configurations to calculate spin-dynamical quantities. The RMCPROFILE implementation of the reverse Monte Carlo refinement process is used to generate a large ensemble of supercell spin configurations from MnO powder diffraction data collected at 100 K. Our analysis of these configurations gives spin-wave dispersion curves for MnO that agree well with those determined independently using neutron triple-axis spectroscopic techniques.

  11. Monolithic spectrometer

    DOE Patents [OSTI]

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

    1998-05-19T23:59:59.000Z

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

  12. Monolithic spectrometer

    DOE Patents [OSTI]

    Rajic, Slobodan (Knoxville, TN); Egert, Charles M. (Oak Ridge, TN); Kahl, William K. (Knoxville, TN); Snyder, Jr., William B. (Knoxville, TN); Evans, III, Boyd M. (Oak Ridge, TN); Marlar, Troy A. (Knoxville, TN); Cunningham, Joseph P. (Oak Ridge, TN)

    1998-01-01T23:59:59.000Z

    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.

  13. Study of thermal neutron capture gamma rays using a lithium-drifted germanium spectrometer / [by] Victor John Orphan [and] Norman C. Rasmussen

    E-Print Network [OSTI]

    Orphan, V. J.

    1967-01-01T23:59:59.000Z

    A gamma-ray spectrometer, using a 30 cc coaxial Ge(Li) detector, which can be operated as a pair spectrometer at high energies and in the Compton suppression mode at low energies provides an effective means of obtaining ...

  14. Correlation spectrometer

    DOE Patents [OSTI]

    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)

    2010-04-13T23:59:59.000Z

    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. Multidimensional spectrometer

    DOE Patents [OSTI]

    Zanni, Martin Thomas (Madison, WI); Damrauer, Niels H. (Boulder, CO)

    2010-07-20T23:59:59.000Z

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

  16. Asterix is a reflectometer/diffractometer/grazing-incidence-SANS/SESAME-enabled-SANS spectrometer that is primarily used for experiments or neutron scattering

    E-Print Network [OSTI]

    that is primarily used for experiments or neutron scattering techniques requiring polarized neutron beams detector arm is readily configurable for polarization or energy analysis of the scattered neutron beam be translated in the horizontal and vertical directions. Neutron detector (Spin Echo Scattering Angle

  17. A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER

    E-Print Network [OSTI]

    O'Donnell, Tom

    A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER FOR PRODUCTION OF NEUTRON-RICH NUCLEI ( 136 Xe Superconducting Cyclotron Laboratory's weekly \\Green Sheet," 30 July 1999 #12; c Thomas W. O'Donnell 2000 All

  18. AS{01 : MMM-98 Miami, Florida Nov 9{12 1998. Magnetic Ordering in Re-Doped a Fe 90 Zr 10

    E-Print Network [OSTI]

    Ryan, Dominic

    -line of DUALSPEC, a triple-axis spectrometer, at AECL, Chalk River. Initial polarisations of #24;96%

  19. Spectrometer gun

    DOE Patents [OSTI]

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

    1981-11-03T23:59:59.000Z

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

  20. Spectrometer gun

    DOE Patents [OSTI]

    Waechter, David A. (Los Alamos, NM); Wolf, Michael A. (Los Alamos, NM); Umbarger, C. John (Los Alamos, NM)

    1985-01-01T23:59:59.000Z

    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.

  1. Diagnosing inertial confinement fusion implosions at OMEGA and the NIF Using novel neutron spectrometry

    E-Print Network [OSTI]

    Casey, Daniel Thomas

    2012-01-01T23:59:59.000Z

    A novel neutron spectrometer, called the Magnetic Recoil Spectrometer (MRS), was designed, built, and implemented on the OMEGA laser facility and the National Ignition Facility (NIF) to measure the neutron spectra from ...

  2. Neutron scatter camera

    DOE Patents [OSTI]

    Mascarenhas, Nicholas; Marleau, Peter; Brennan, James S.; Krenz, Kevin D.

    2010-06-22T23:59:59.000Z

    An instrument that will directly image the fast fission neutrons from a special nuclear material source has been described. This instrument can improve the signal to background compared to non imaging neutron detection techniques by a factor given by ratio of the angular resolution window to 4.pi.. In addition to being a neutron imager, this instrument will also be an excellent neutron spectrometer, and will be able to differentiate between different types of neutron sources (e.g. fission, alpha-n, cosmic ray, and D-D or D-T fusion). Moreover, the instrument is able to pinpoint the source location.

  3. Associated Particle Tagging (APT) in Magnetic Spectrometers

    SciTech Connect (OSTI)

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

    2012-10-16T23:59:59.000Z

    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 alpha-particle spectrometer concept, and outlines challenges involved in the magnetic field design. Tagged photon interrogation: • We investigated a method for discriminating fissile from benign cargo-material response to an energy-tagged photon beam. The method relies upon coincident detection of the tagged photon and a photoneutron or photofission neutron produced in the target material. The method exploits differences in the shape of the neutron production cross section as a function of incident photon energy in order to discriminate photofission yield from photoneutrons emitted by non-fissile materials. Computational tests of the interrogation method as applied to material composition assay of a simple, multi-layer target suggest that the tagged-photon information facilitates precise (order 1% thickness uncertainty) reconstruction of the constituent thicknesses of fissile (uranium) and high-Z (Pb) constituents of the test targets in a few minutes of photon-beam exposure. We assumed an 18-MeV endpoint tagged photon beam for these simulations. • The report addresses several candidate design and data analysis issues for beamline infrastructure required to produce a tagged photon beam in a notional AI-dedicated facility, including the accelerator and tagging spectrometer.

  4. Extracting source parameters from beam monitors on a chopper spectrometer

    SciTech Connect (OSTI)

    Abernathy, Douglas L [ORNL; Niedziela, Jennifer L [ORNL; Stone, Matthew B [ORNL

    2015-01-01T23:59:59.000Z

    The intensity distributions of beam monitors in direct-geometry time-of-flight neutron spectrometers provide important information about the instrument resolution. For short-pulse spallation neutron sources in particular, the asymmetry of the source pulse may be extracted and compared to Monte Carlo source simulations. An explicit formula using a Gaussian-convolved Ikeda-Carpenter distribution is given and compared to data from the ARCS instrument at the Spallation Neutron Source.

  5. Spectrometer for new gravitational experiment with UCN

    E-Print Network [OSTI]

    Kulin, G V; Goryunov, S V; Kustov, D V; Geltenbort, P; Jentschel, M; Strepetov, A N; Bushuev, V A

    2015-01-01T23:59:59.000Z

    We describe an experimental installation for a new test of the weak equivalence principle for neutron. The device is a sensitive gravitational spectrometer for ultra-cold neutrons allowing to precisely compare the gain in kinetic energy of free falling neutrons to quanta of energy ${\\hbar}{\\Omega}$ transferred to the neutron via a non stationary device, i.e. a quantum modulator. The results of first test experiments indicate a collection rate allowing measurements of the factor of equivalence $ { \\gamma}$ with a statistical uncertainty in the order of $5{\\times}10^{-3}$ per day. A number of systematic effects were found, which partially can be easily corrected. For the elimination of others more detailed investigations and analysis are needed. Some possibilities to improve the device are also discussed.

  6. Study of Active Shielding for {gamma} - Spectrometers

    SciTech Connect (OSTI)

    Bikit, I.; Mrdja, D.; Forkapic, S.; Todorovic, N.; Veskovic, M.; Slivka, J.; Conkic, Lj.; Krmar, M.; Varga, E. [Department of Physics, Faculty of Sciences, University of Novi Sad, Trg Dositeja Obradovica 4, 21 000 Novi Sad (Serbia and Montenegro)

    2006-04-26T23:59:59.000Z

    The features of the ground located gamma ray spectrometer shielded passively with 12 cm of lead and actively by five 0.5m x 0.5m x 0.05m plastic veto shields are described. The detector mass related background was 0.345 C/kg s. The 511 keV annihilation line was reduced by the factor of 7 by the anticoincidence gate. It is shown that the plastic shields increase the neutron capture gamma line intensities due to neutron thermalization.

  7. Mobile Ice Nucleus Spectrometer

    SciTech Connect (OSTI)

    Kulkarni, Gourihar R.; Kok, G. L.

    2012-05-07T23:59:59.000Z

    This first year report presents results from a computational fluid dynamics (CFD) study to assess the flow and temperature profiles within the mobile ice nucleus spectrometer.

  8. Diamond neutral particle spectrometer for fusion reactor ITER

    SciTech Connect (OSTI)

    Krasilnikov, V.; Amosov, V.; Kaschuck, Yu.; Skopintsev, D. [Institution PROJECT CENTER ITER, 1, Akademik Kurchatov Sq., Moscow (Russian Federation)

    2014-08-21T23:59:59.000Z

    A compact diamond neutral particle spectrometer with digital signal processing has been developed for fast charge-exchange atoms and neutrons measurements at ITER fusion reactor conditions. This spectrometer will play supplementary role for Neutral Particle Analyzer providing 10 ms time and 30 keV energy resolutions for fast particle spectra in non-tritium ITER phase. These data will also be implemented for independent studies of fast ions distribution function evolution in various plasma scenarios with the formation of a single fraction of high-energy ions. In tritium ITER phase the DNPS will measure 14 MeV neutrons spectra. The spectrometer with digital signal processing can operate at peak counting rates reaching a value of 10{sup 6} cps. Diamond neutral particle spectrometer is applicable to future fusion reactors due to its high radiation hardness, fast response and high energy resolution.

  9. Applications of Bonner sphere detectors in neutron field dosimetry

    SciTech Connect (OSTI)

    Awschalom, M.; Sanna, R.S.

    1983-09-01T23:59:59.000Z

    The theory of neutron moderation and spectroscopy are briefly reviewed, and moderators that are useful for Bonner sphere spectrometers are discussed. The choice of the neutron detector for a Bonner sphere spectrometer is examined. Spectral deconvolution methods are briefly reviewed, including derivative, parametric, quadrature, and Monte Carlo methods. Calibration is then discussed. (LEW)

  10. hal-00154048,version1-12Jun2007 The new very small angle neutron scattering

    E-Print Network [OSTI]

    Boyer, Edmond

    hal-00154048,version1-12Jun2007 The new very small angle neutron scattering spectrometer The design and characteristics of the new very small angle neutron scattering spectrometer under construction in order to fill the gap between light scattering and classical small angle neutron scattering (SANS

  11. A Novel Detector for High Neutron Flux Measurements

    SciTech Connect (OSTI)

    Singo, T. D.; Wyngaardt, S. M. [Department of Physics, University of Stellenbosch, Private bag X1, Matieland, Stellenbosch (South Africa); Papka, P. [Department of Physics, University of Stellenbosch, Private bag X1, Matieland, Stellenbosch (South Africa); Nuclear Physics group, iThemba labs, P. O. Box 722, Somerset West 7129 (South Africa); Dobson, R. T. [Department of Mechanical and Mechatronic Engineering, University of Stellenbosch, Private bag X1, Matieland, Stellenbosch (South Africa)

    2010-01-05T23:59:59.000Z

    Measuring alpha particles from a neutron induced break-up reaction with a mass spectrometer can be an excellent tool for detecting neutrons in a high neutron flux environment. Break-up reactions of {sup 6}Li and {sup 12}C can be used in the detection of slow and fast neutrons, respectively. A high neutron flux detection system that integrates the neutron energy sensitive material and helium mass spectrometer has been developed. The description of the detector configuration is given and it is soon to be tested at iThemba LABS, South Africa.

  12. Broad band waveguide spectrometer

    SciTech Connect (OSTI)

    Goldman, D.S.

    1995-08-29T23:59:59.000Z

    A spectrometer is disclosed for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the waveguide and a sample material. A tapered portion forms a part of the entry of the waveguide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis. 16 figs.

  13. Broad band waveguide spectrometer

    DOE Patents [OSTI]

    Goldman, Don S. (Folsom, CA)

    1995-01-01T23:59:59.000Z

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

  14. Characterization of a Li-6 loaded liquid organic scintillator for fast neutron spectrometry and thermal neutron detection

    E-Print Network [OSTI]

    C. D. Bass; E. J. Beise; H. Breuer; C. R. Heimbach; T. Langford; J. S. Nico

    2013-02-07T23:59:59.000Z

    The characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% Li-6 is presented, including the performance of the scintillator in terms of its optical properties and neutron response. The scintillator was incorporated into a fast neutron spectrometer, and the light output spectra from 2.5 MeV, 14.1 MeV, and Cf-252 neutrons were measured using capture-gated coincidence techniques. The spectrometer was operated without coincidence to perform thermal neutron measurements. Possible improvements in spectrometer performance are discussed.

  15. Protons hog the momentum in neutron-rich nuclei | Argonne National...

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

    Jefferson Lab's CEBAF Large Acceptance Spectrometer collected the data in an experiment that found that protons and neutrons that have briefly paired up in the nucleus have...

  16. Measurements with the high flux lead slowing-down spectrometer at LANL

    E-Print Network [OSTI]

    Danon, Yaron

    slow down by scattering interactions with the lead and thus enable measurements of neutron.40.Sc Keywords: Lead-slowing-down spectrometer; Lithium; Alpha; Cross section; Neutron reactions 1.elsevier.com/locate/nimb Nuclear Instruments and Methods in Physics Research B 261 (2007) 953­955 NIM BBeam Interactions

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

    SciTech Connect (OSTI)

    Schooneveld, E. M.; Mayers, J.; Rhodes, N. J.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Gorini, G.; Perelli-Cippo, E.; Tardocchi, M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Consiglio Nazionale delle Ricerche-Istituto Nazionale per la Fisica della Materia, Universita degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Dipartimento di Fisica, Universita degli Studi di Roma 'Tor Vergata', Via della Ricerca Scientifica 1, 00133 Rome (Italy); Dipartimento di Fisica 'G. Occhialini', Universita degli Studi di Milano Bicocca, Piazza della Scienza 2, I-20126 Milan (Italy) and CNR-INFM, Universita degli Studi di Milano Bicocca, Piazza della Scienza 2, I-20126 Milan (Italy)

    2006-09-15T23:59:59.000Z

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

  18. The response of a Bonner Sphere spectrometer to charged hadrons

    E-Print Network [OSTI]

    Agosteo, S; Fassò, A; Silari, M; 10.1093/rpd/nch187

    2004-01-01T23:59:59.000Z

    Bonner sphere spectrometers (BSSs) are employed in neutron spectrometry and dosimetry since many years. Recent developments have seen the addition to a conventional BSS of one or more detectors (moderator plus thermal neutron counter) specifically designed to improve the overall response of the spectrometer to neutrons above 10 MeV. These additional detectors employ a shell of material with a high mass number (such as lead) within the polyethylene moderator, in order to slow down high-energy neutrons via (n, xn) reactions. A BSS can be used to measure neutron spectra both outside accelerator shielding and from an unshielded target. Measurements were recently performed at CERN of the neutron yield and spectral fluence at various angles from unshielded, semithick copper, silver and lead targets, bombarded by a mixed proton/pion beam with 40 GeV per c momentum. These experiments have provided evidence that under certain circumstances, the use of lead-enriched moderators may present a problem: these detectors wer...

  19. Bragg x-ray survey spectrometer for ITER

    SciTech Connect (OSTI)

    Varshney, S. K.; Jakhar, S. [ITER-India, Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India); Barnsley, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); O'Mullane, M. G. [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2012-10-15T23:59:59.000Z

    Several potential impurity ions in the ITER plasmas will lead to loss of confined energy through line and continuum emission. For real time monitoring of impurities, a seven channel Bragg x-ray spectrometer (XRCS survey) is considered. This paper presents design and analysis of the spectrometer, including x-ray tracing by the Shadow-XOP code, sensitivity calculations for reference H-mode plasma and neutronics assessment. The XRCS survey performance analysis shows that the ITER measurement requirements of impurity monitoring in 10 ms integration time at the minimum levels for low-Z to high-Z impurity ions can largely be met.

  20. Characterization of a Li-6 loaded liquid organic scintillator for fast neutron spectrometry and thermal neutron detection

    E-Print Network [OSTI]

    Bass, C D; Breuer, H; Heimbach, C R; Langford, T; Nico, J S

    2012-01-01T23:59:59.000Z

    We present the characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% Li-6. We report on its performance in terms of optical properties and neutron response. We incorporated the scintillator into a spectrometer and measured the light output spectra from 2.5 MeV, 14 MeV, and Cf-252 neutrons using capture-gated coincidence techniques. We operated the spectrometer without coincidence to perform thermal neutron measurements. We discuss possible improvements in spectrometer performance.

  1. The Manuel Lujan, Jr. Neutron Scattering Center LANSCE experiment reports 1989 run cycle

    SciTech Connect (OSTI)

    Hyer, D.K.; DiStravolo, M.A. (comps.)

    1990-10-01T23:59:59.000Z

    This report contains a listing and description of experiments carried on at the LANSCE neutron scattering facility in the following areas: High Density Powder Diffraction; Neutron Powder Diffractometer, (NPD); Single Crystal Diffractometer, (SCD); Low-Q Diffractometer, (LQD); Surface Profile Analysis Reflectometer, (SPEAR); Filter Difference Spectrometer, (FDS); and Constant-Q Spectrometer.

  2. Photo ion spectrometer

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL); Young, Charles E. (Westmont, IL); Pellin, Michael J. (Naperville, IL)

    1989-01-01T23:59:59.000Z

    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.

  3. Photo ion spectrometer

    DOE Patents [OSTI]

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

    1989-12-26T23:59:59.000Z

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

  4. Neutrons from multifragmentation reactions

    E-Print Network [OSTI]

    W. Trautmann; A. S. Botvina; J. Brzychczyk; N. Buyukcizmeci; I. N. Mishustin; P. Pawlowski; ALADIN2000 Collaboration

    2011-08-29T23:59:59.000Z

    The neutron emission in the fragmentation of stable and radioactive Sn and La projectiles of 600 MeV per nucleon has been studied with the Large Neutron Detector LAND coupled to the ALADIN forward spectrometer at SIS. A cluster-recognition algorithm is used to identify individual particles within the hit distributions registered with LAND. The obtained momentum distributions are extrapolated over the full phase space occupied by the neutrons from the projectile-spectator source. The mean multiplicities of spectator neutrons reach values of up to 12 and depend strongly on the isotopic composition of the projectile. An effective source temperature of T approx. 3 - 4 MeV is deduced from the transverse momentum distributions. For the interpretation of the data, calculations with the Statistical Multifragmentation Model for a properly chosen ensemble of excited sources were performed. The possible modification of the liquid-drop parameters of the fragment description in the hot environment is studied, and a significant reduction of the symmetry-term coefficient is found necessary to simultaneously reproduce the neutron multiplicities and the mean neutron-to-proton ratios /Z of Z <= 10 fragments. Because of the similarity of the freeze-out conditions with those encountered in supernova scenarios, this is of astrophysical interest.

  5. A field-deployable gamma-ray spectrometer utilizing xenon at high pressure

    SciTech Connect (OSTI)

    Smith, G.C.; Mahler, G.J.; Yu, B.; Salwen, C.; Kane, W.R.; Lemley, J.R.

    1996-10-01T23:59:59.000Z

    Prototype gamma-ray spectrometers utilizing xenon gas at high pressure, suitable for applications in the nuclear safeguards, arms control, and nonproliferation communities, have been developed at Brookhaven National Laboratory (BNL). These spectrometers function as ambient-temperature ionization chambers detecting gamma rays with good efficiency in the energy range 50 keV - 2 MeV, with an energy resolution intermediate between semiconductor (Ge) and scintillation (NaI) spectrometers. They are capable of prolonged, low-power operation without a requirement for cryogenic fluids or other cooling mechanisms, and with the addition of small quantities of {sup 3}He gas, can function simultaneously as efficient thermal neutron detectors.

  6. Aerosol mobility size spectrometer

    DOE Patents [OSTI]

    Wang, Jian (Port Jefferson, NY); Kulkarni, Pramod (Port Jefferson Station, NY)

    2007-11-20T23:59:59.000Z

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

  7. Photo ion spectrometer

    DOE Patents [OSTI]

    Gruen, Dieter M. (Downers Grove, IL); Young, Charles E. (Westmont, IL); Pellin, Michael J. (Naperville, IL)

    1989-01-01T23:59:59.000Z

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

  8. Photo ion spectrometer

    DOE Patents [OSTI]

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

    1989-08-08T23:59:59.000Z

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

  9. First Neutron Spectrometry Measurement at the HL-2A Tokamak

    E-Print Network [OSTI]

    Xi, Yuan; Xufei, Xie; Zhongjing, Chen; Xingyu, Peng; Tieshuan, Fan; Jinxiang, Chen; Xiangqing, Li; Guoliang, Yuan; Jinwei, Yang; Qingwei, Yang

    2013-01-01T23:59:59.000Z

    A compact neutron spectrometer based on the liquid scintillator is presented for the neutron energy spectrum measurement at the HL-2A tokamak. The spectrometer has been well characterized and a fast digital pulse shape discrimination software has been developed using the charge comparison method. A digitizer data acquisition system with the maximum frequency of 1 MHz can work under the high count rate environment at HL-2A. Specific radiation shielding and magnetic shielding for the spectrometerhas been designed for the neutron spectrum measurement at the HL-2A Tokamak. For the analysis of the pulse height spectrum, dedicated numerical simulation utilizing NUBEAM combining with GENESIS has been made to obtain the neutron energy spectrum, following which the transportation process from the plasma to the detector has been evaluated with Monte Carlo calculations. The distorted neutron energy spectrum has been folded with response matrix of the liquid scintillation spectrometer, and good consistency has been found...

  10. For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600.

    E-Print Network [OSTI]

    Pennycook, Steve

    For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574 Spectrometer (ARCS) CallforProposals neutrons.ornl.gov Neutron Scattering Science - Oak Ridge National Neutron Source (SNS) will be accepted via the web-based proposal system until 11:59 a.m. EST, (NOON

  11. Neutronic reactor

    DOE Patents [OSTI]

    Wende, Charles W. J. (Augusta, GA); Babcock, Dale F. (Wilmington, DE); Menegus, Robert L. (Wilmington, DE)

    1983-01-01T23:59:59.000Z

    A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

  12. Neutron Scattering Stiudies

    SciTech Connect (OSTI)

    Kegel, Gunter H.R.; Egan, James J

    2007-04-18T23:59:59.000Z

    This project covers four principal areas of research: Elastic and inelastic neutron scattering studies in odd-A terbium, thulium and other highly deformed nuclei near A=160 with special regard to interband transitions and to the investigation of the direct-interaction versus the compound-nucleus excitation process in these nuclei. Examination of new, fast photomultiplier tubes suitable for use in a miniaturized neutron-time-of-flight spectrometer. Measurement of certain inelastic cross sections of 238U. Determination of the multiplicity of prompt fission gamma rays in even-A fissile actinides. Energies and mean lives of fission isomers produced by fast fission of even-Z, even-A actinides. Study of the mean life of 7Be in different host matrices and its possible astro-physical significance.

  13. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

    1995-01-01T23:59:59.000Z

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

  14. Mini ion trap mass spectrometer

    DOE Patents [OSTI]

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

    1995-09-19T23:59:59.000Z

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

  15. First Neutron Spectrometry Measurement at the HL-2A Tokamak

    E-Print Network [OSTI]

    Yuan Xi; Zhang Xing; Xie Xufei; Chen Zhongjing; Peng Xingyu; Fan Tieshuan; Chen Jinxiang; Li Xiangqing; Yuan Guoliang; Yang Jinwei; Yang Qingwei

    2013-06-17T23:59:59.000Z

    A compact neutron spectrometer based on the liquid scintillator is presented for neutron energy spectrum measurements at the HL-2A tokamak. The spectrometer was well characterized and a fast digital pulse shape discrimination software was developed using the charge comparison method. A digitizer data acquisition system with a maximum frequency of 1 MHz can work under an environment with a high count rate at HL-2A tokamak. Specific radiation and magnetic shielding for the spectrometer were designed for the neutron spectrum measurement at the HL-2A tokamak. For pulse height spectrum analysis, dedicated numerical simulation utilizing NUBEAM combined with GENESIS was performed to obtain the neutron energy spectrum. Subsequently, the transportation process from the plasma to the detector was evaluated with Monte Carlo calculations. The distorted neutron energy spectrum was folded with the response matrix of the liquid scintillation spectrometer, and good consistency was found between the simulated and measured pulse height spectra. This neutron spectrometer based on a digital acquisition system could be well adopted for the investigation of the auxiliary heating behavior and the fast-ion related phenomenon on different tokamak devices.

  16. Report on First Activations with the Lead Slowing Down Spectrometer

    SciTech Connect (OSTI)

    Warren, Glen A.; Mace, Emily K.; Pratt, Sharon L.; Stave, Sean; Woodring, Mitchell L.

    2011-03-03T23:59:59.000Z

    On Feb. 17 and 18 2011, six items were irradiated with neutrons using the Lead Slowing Down Spectrometer. After irradiation, dose measurements and gamma-spectrometry measurements were completed on all of the samples. No contamination was found on the samples, and all but one provided no dose. Gamma-spectroscopy measurements qualitatively agreed with expectations based on the materials, with the exception of silver. We observed activation in the room in general, mostly due to 56Mn and 24Na. Most of the activation was short lived, with half-lives on the scale of hours, except for 198Au which has a half-life of 2.7 d.

  17. CAMEA ESS - The Continuous Angle Multi-Energy Analysis Indirect Geometry Spectrometer for the European Spallation Source

    E-Print Network [OSTI]

    Freeman, P G; Markó, M; Bertelsen, M; Larsen, J; Christensen, N B; Lefmann, K; Jacobsen, J; Niedermayer, Ch; Juranyi, F; Ronnow, H M

    2014-01-01T23:59:59.000Z

    The CAMEA ESS neutron spectrometer is designed to achieve a high detection efficiency in the horizontal scattering plane, and to maximize the use of the long pulse European Spallation Source. It is an indirect geometry time-of-flight spectrometer that uses crystal analysers to determine the final energy of neutrons scattered from the sample. Unlike other indirect gemeotry spectrometers CAMEA will use ten concentric arcs of analysers to analyse scattered neutrons at ten different final energies, which can be increased to 30 final energies by use of prismatic analysis. In this report we will outline the CAMEA instrument concept, the large performance gain, and the potential scientific advancements that can be made with this instrument.

  18. Time of flight mass spectrometer

    DOE Patents [OSTI]

    Ulbricht, Jr., William H. (Arvada, CO)

    1984-01-01T23:59:59.000Z

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

  19. MICE Spectrometer Magnet System Progress

    SciTech Connect (OSTI)

    Green, Michael A.; Virostek, Steve P.

    2007-08-27T23:59:59.000Z

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

  20. An improved scintillation beta spectrometer

    E-Print Network [OSTI]

    McClary, Jimmy Fred

    1964-01-01T23:59:59.000Z

    ~i'TILLATIGR 3ZTA SPECTROMETER ~ ~ ? ~ ~ ~ ~ ~ ~ o ~ o ~ ~ SPECTRAL eSPC. .TSZ: OP DIP. Z. -W. T 3110TOIXLTI" LIL"-i O'TiiODZS ZiISSIOH SPECTRA OP iaI(T1) AiiD AHTRRACZHZ. . . . . ?. . . . . . ~ . ~ ~ ~ ~ 7 TIIL' SCATTZRI'iG 1'ROBLZ. Iii 3ETA SPECTROSCOPY...

  1. E781 Hyperon Spectrometer Constants

    SciTech Connect (OSTI)

    Joseph T. Lach

    2004-05-04T23:59:59.000Z

    This is a discussion of the physical measurements, sizes, distances and magnetic fields of the Hyperon Spectrometer Magnet and its components. Some we get from construction drawings (like the target dimensions) and others from measurements in differing coordinate systems. Included also are the properties of the hyperon productions targets used in E781.

  2. PUBLISHED VERSION Gamma ray spectrometer for ITER

    E-Print Network [OSTI]

    Ray Scintillation Spectrometer Rev. Sci. Instrum. 24, 1096 (1953); 10.1063/1.1770609 An Automatic Recording Gamma for the spectrometer is presented. Keywords: tokamak, DT plasma, alpha- particles, diagnostics, gamma- spectrometry

  3. Sample rotating turntable kit for infrared spectrometers

    DOE Patents [OSTI]

    Eckels, Joel Del (Livermore, CA); Klunder, Gregory L. (Oakland, CA)

    2008-03-04T23:59:59.000Z

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

  4. Advanced Mass Spectrometers for Hydrogen Isotope Analyses

    SciTech Connect (OSTI)

    Chastagner, P.

    2001-08-01T23:59:59.000Z

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

  5. Ru-induced loss of long-range magnetic order in a-Fe90 xRuxZr10 Physics Department, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8, Canada

    E-Print Network [OSTI]

    Ryan, Dominic

    , The University of New South Wales, Sydney, NSW 2052, Australia Zin Tun AECL, Chalk River Laboratories, Chalk the DUALSPEC triple-axis spectrometer at AECL, Chalk River. Initial polarizations of 95% at 0.237 nm were

  6. Neutron skins and neutron stars

    SciTech Connect (OSTI)

    Piekarewicz, J. [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States)

    2013-11-07T23:59:59.000Z

    The neutron-skin thickness of heavy nuclei provides a fundamental link to the equation of state of neutron-rich matter, and hence to the properties of neutron stars. The Lead Radius Experiment ('PREX') at Jefferson Laboratory has recently provided the first model-independence evidence on the existence of a neutron-rich skin in {sup 208}Pb. In this contribution we examine how the increased accuracy in the determination of neutron skins expected from the commissioning of intense polarized electron beams may impact the physics of neutron stars.

  7. Delayed neutron studies of separated isotopes of Br, Rb, I, and Cs

    E-Print Network [OSTI]

    Reeder, R L; Wright, J F

    1976-01-01T23:59:59.000Z

    Discusses delayed neutron studies of separated isotopes of Br, Rb, I, and Cs are currently in progress at the Spectrometer for On-Line Analysis of Radionuclides (SOLAR) facility operated by Battelle, Pacific Northwest Laboratories. (2 refs).

  8. Neutron guide

    DOE Patents [OSTI]

    Greene, Geoffrey L. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

  9. Upgrade of the PNNL TEPC and Multisphere Spectrometer

    SciTech Connect (OSTI)

    Scherpelz, Robert I.; Conrady, Matthew M.

    2008-09-10T23:59:59.000Z

    The Pacific Northwest National Laboratory (PNNL) has used two types of instruments, the tissue equivalent proportional counter (TEPC) and the multisphere spectrometer for characterizing neutron radiation fields in support of neutron dosimetry at the Hanford site. The US Department of Energy recently issued new requirements for radiation protection standards in 10 CFR 835 which affect the way that neutron dose equivalent rates are evaluated. In response to the new requirements, PNNL has upgraded the analyses used in conjunction with the TEPC and multisphere. The analysis software for the TEPC was modified for this effort, and a new analysis code was selected for the multisphere. These new analysis techniques were implemented and tested with measurement data that had been collected in previous measurements. In order to test the effectiveness of the changes, measurements were taken in PNNL’s Low Scatter Room using 252Cf sources in both unmoderated and D2O-moderated configurations that generate well-characterized neutron fields. The instruments were also used at Los Alamos National Laboratory (LANL), in their Neutron Free-in-Air calibration room, also using neutron sources that generate well-characterized neutron fields. The results of the software modifications and the measurements are documented in this report. The TEPC measurements performed at PNNL agreed well with accepted dose equivalent rates using the traditional analysis, agreeing with the accepted value to within 13% for both unmoderated and moderated 252Cf sources. When the new analysis was applied to the TEPC measurement data, the results were high compared to the new accepted value. A similar pattern was seen for TEPC measurements at LANL. Using the traditional analysis method, results for all neutron sources showed good agreement with accepted values, nearly always less than 10%. For the new method of analysis, however, the TEPC responded with higher dose equivalent rates than accepted, by as much as 25%. The reason for the overresponse is that there is very little attenuation of the neutrons by tissue, so it cannot match the effect of attenuation by 1 cm of tissue called for in the new standards. This could be corrected with a modified instrument with a thicker wall, or by analytical means that would need to be developed. The multisphere spectrometer performed reasonably well both at PNNL and at LANL. It could produce a neutron spectrum that was similar to the accepted spectrum, and total flux values were usually within 15% of the accepted values. Dose equivalent rates were usually within 18% of the accepted values. The average energies, however, were usually lower than the accepted values. The performance of this instrument could be much better than seen in this study. If PNNL were to add some moderating spheres to its measurement set and calculate a new set of instrument response functions, performance could be improved. The multisphere could then be a more useful instrument for assessing the dose equivalent rate in the workplace.

  10. Automated mass spectrometer grows up

    SciTech Connect (OSTI)

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

    1984-01-01T23:59:59.000Z

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

  11. Nuclear Instruments and Methods in Physics Research A 476 (2002) 522526 A gamma-ray spectrometer system for fusion applications

    E-Print Network [OSTI]

    Martín-Solís, José Ramón

    Nuclear Instruments and Methods in Physics Research A 476 (2002) 522­526 A gamma-ray spectrometer electrons hitting the inconel poloidal limiter and/or the vessel; and (b) neutron capture gamma the bremsstrahlung spectra is in agreement with the runaway energy predicted by a test particle model of runaway

  12. Neutron Scattering Tutorials | Neutron Science | ORNL

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

    Neutron Scattering Tutorials SHARE Neutron Scattering Tutorials The following lectures were presented at the 2011 and 2010 National School on Neutron & X-Ray Scattering. This...

  13. Compact reflective imaging spectrometer utilizing immersed gratings

    DOE Patents [OSTI]

    Chrisp, Michael P. (Danville, CA)

    2006-05-09T23:59:59.000Z

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

  14. Non-destructive method for determining neutron exposure

    DOE Patents [OSTI]

    Gold, R.; McElroy, W.N.

    1983-11-01T23:59:59.000Z

    A non-destructive method for determination of neutron exposure in an object, such as a reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure at regions of interest within the object.

  15. Electron Spectrometer: Scanning Multiprobe Surface Analysis System...

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

    Scanning Multiprobe Surface Analysis System - Versaprobe Electron Spectrometer: Scanning Multiprobe Surface Analysis System - Versaprobe The SMSAS is a multi-technique surface...

  16. Electron Spectrometer: XPS with Laser Interface | EMSL

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

    with Laser Interface Electron Spectrometer: XPS with Laser Interface This ultrahigh vacuum machine can be applied as a routine means for analyzing the structure and chemical...

  17. Neutron detector

    DOE Patents [OSTI]

    Stephan, Andrew C. (Knoxville, TN); Jardret; Vincent D. (Powell, TN)

    2011-04-05T23:59:59.000Z

    A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

  18. Evaluation of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Moderate Resolution Imaging Spectrometer

    E-Print Network [OSTI]

    Evaluation of Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Moderate Resolution the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and the Moderate Resolution Imaging Spectrometer (MODIS). Key goals were to assess the nature of these relationships as they varied between sensors

  19. Birefringent Fourier-transform imaging spectrometer

    E-Print Network [OSTI]

    Harvey, Andy

    Birefringent Fourier-transform imaging spectrometer Andrew Robert Harvey and David William Fletcher.r.Harvey@hw.ac.uk http://www.ece.eps.hw.ac.uk/~arharvey Abstract: Fourier-transform imaging spectrometers offer important, for application in harsh environments, deployment of Fourier-transform instruments based on traditional moving

  20. Report on Second Activations with the Lead Slowing Down Spectrometer

    SciTech Connect (OSTI)

    Stave, Sean C.; Mace, Emily K.; Pratt, Sharon L.; Warren, Glen A.

    2012-04-27T23:59:59.000Z

    Summary On August 18 and 19 2011, five items were irradiated with neutrons using the Lead Slowing Down Spectrometer (LSDS). After irradiation, dose measurements and gamma-spectrometry measurements were completed on all of the samples. No contamination was found on the samples, and all but one provided no dose. Gamma-spectroscopy measurements qualitatively agreed with expectations based on the materials. As during the first activation run, we observed activation in the room in general, mostly due to 56Mn and 24Na. Most of the activation of the samples was short lived, with half-lives on the scale of hours to days, except for 60Co which has a half-life of 5.3 y.

  1. Neutron tubes

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Lou, Tak Pui (Berkeley, CA); Reijonen, Jani (Oakland, CA)

    2008-03-11T23:59:59.000Z

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  2. An Engine Exhaust Particle SizerTM Spectrometer for Transient...

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

    An Engine Exhaust Particle SizerTM Spectrometer for Transient Emission Particle Measurements An Engine Exhaust Particle SizerTM Spectrometer for Transient Emission Particle...

  3. Thermal neutron detection system

    DOE Patents [OSTI]

    Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

    2000-01-01T23:59:59.000Z

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  4. Gas sampling system for a mass spectrometer

    DOE Patents [OSTI]

    2003-12-30T23:59:59.000Z

    The present invention relates generally to a gas sampling system, and specifically to a gas sampling system for transporting a hazardous process gas to a remotely located mass spectrometer. The gas sampling system includes a capillary tube having a predetermined capillary length and capillary diameter in communication with the supply of process gas and the mass spectrometer, a flexible tube surrounding and coaxial with the capillary tube intermediate the supply of process gas and the mass spectrometer, a heat transfer tube surrounding and coaxial with the capillary tube, and a heating device in communication the heat transfer tube for substantially preventing condensation of the process gas within the capillary tube.

  5. Measurement of neutron spectrum in an AGN-201 reactor using a semiconductor neutron spectrometer

    E-Print Network [OSTI]

    Stephenson, S. E

    1961-01-01T23:59:59.000Z

    National Labora- tory (15). Wafers of 2700 ohm-cm resistivity, n-type silicon were hand lapped in Grit No. 240 and 600 silicon carbide powder. The wafers were then nickel plated in an electroless nickel plating bath (17). A No. 2 round head brass screw..., with the head filed flat, was soldered to the nickel film with ordinary 5-core 40/60 solder. The nickel on the other five diode faces was then lapped off with No. 600 silicon carbide powder. The remaining nickel plating was masked by apiezon wax dissolved...

  6. Method for studying a sample of material using a heavy ion induced mass spectrometer source

    DOE Patents [OSTI]

    Fries, David P. (St. Petersburg, FL); Browning, James F. (Palm Harbour, FL)

    1999-01-01T23:59:59.000Z

    A heavy ion generator is used with a plasma desorption mass spectrometer to provide an appropriate neutron flux in the direction of a fissionable material in order to desorb and ionize large molecules from the material for mass analysis. The heavy ion generator comprises a fissionable material having a high n,f reaction cross section. The heavy ion generator also comprises a pulsed neutron generator that is used to bombard the fissionable material with pulses of neutrons, thereby causing heavy ions to be emitted from the fissionable material. These heavy ions impinge on a material, thereby causing ions to desorb off that material. The ions desorbed off the material pass through a time-of-flight mass analyzer, wherein ions can be measured with masses greater than 25,000 amu.

  7. A user's guide to SWIFT: A Monte Carlo technique for inference of differential energy spectra from multisphere spectrometer measurements

    SciTech Connect (OSTI)

    Sanna, R.S.; O'Brien, K.

    1987-12-01T23:59:59.000Z

    SWIFT is a FORTRAN-77 program written for the VAX-11/750 computer. Its purpose is to unfold neutron spectra from multisphere spectrometer measurements using the Monte Carlo technique. This guide describes the code in sufficient detail to enable a user, with a background in FORTRAN programming, to alter the code for use with other spectrometers and/or to install it on computers other than the VAX-11/750. The code and the required input and resulting output are described. As an aid to its implementation, input and output for a sample problem are also presented. 19 refs., 1 fig., 6 tabs.

  8. LCLS Injector Straight-Ahead Spectrometer

    SciTech Connect (OSTI)

    Limborg-Deprey , C.

    2010-12-10T23:59:59.000Z

    The spectrometer design was modified to allow the measurement of uncorrelated energy spread for the nominal lattice. One bunch from every 120 each second would be sent to the straight ahead spectrometer while the transverse cavity is on. The implementation of this 'stealing mode' will not be available for the LCLS commissioning and the early stage of operation. However, the spectrometer was redesigned to retain that option. The energy feedback relies independently on the beam position of the beam in the dispersive section of dogleg 1 (DL1). The main modification of the spectrometer design is the Pole face rotation of 7.5 degrees on both entrance and exit faces. The location and range of operation of the 3 quadrupoles remains unchanged relative to those of the earlier design.

  9. Ultra High Mass Range Mass Spectrometer System

    DOE Patents [OSTI]

    Reilly, Peter T. A. [Knoxville, TN

    2005-12-06T23:59:59.000Z

    Applicant's present invention comprises mass spectrometer systems that operate in a mass range from 1 to 10.sup.16 DA. The mass spectrometer system comprising an inlet system comprising an aerodynamic lens system, a reverse jet being a gas flux generated in an annulus moving in a reverse direction and a multipole ion guide; a digital ion trap; and a thermal vaporization/ionization detector system. Applicant's present invention further comprises a quadrupole mass spectrometer system comprising an inlet system having a quadrupole mass filter and a thermal vaporization/ionization detector system. Applicant's present invention further comprises an inlet system for use with a mass spectrometer system, a method for slowing energetic particles using an inlet system. Applicant's present invention also comprises a detector device and a method for detecting high mass charged particles.

  10. Visible spectrometer utilizing organic thin film absorption

    E-Print Network [OSTI]

    Tiefenbruck, Laura C. (Laura Christine)

    2004-01-01T23:59:59.000Z

    In this thesis, I modeled and developed a spectrometer for the visible wavelength spectrum, based on absorption characteristics of organic thin films. The device uses fundamental principles of linear algebra to reconstruct ...

  11. Optical Calibration For Jefferson Lab HKS Spectrometer

    E-Print Network [OSTI]

    L. Yuan; L. Tang

    2005-11-04T23:59:59.000Z

    In order to accept very forward angle scattering particles, Jefferson Lab HKS experiment uses an on-target zero degree dipole magnet. The usual spectrometer optics calibration procedure has to be modified due to this on-target field. This paper describes a new method to calibrate HKS spectrometer system. The simulation of the calibration procedure shows the required resolution can be achieved from initially inaccurate optical description.

  12. Neutron Repulsion

    E-Print Network [OSTI]

    Oliver K. Manuel

    2011-02-08T23:59:59.000Z

    Earth is connected gravitationally, magnetically and electrically to its heat source - a neutron star that is obscured from view by waste products in the photosphere. Neutron repulsion is like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the solar core and decay into hydrogen that glows in the photosphere like a frosted light bulb. Neutron repulsion was recognized in nuclear rest mass data in 2000 as the overlooked source of energy, the keystone of an arch that locked together these puzzling space-age observations: 1.) Excess 136Xe accompanied primordial helium in the stellar debris that formed the solar system (Fig. 1); 2.) The Sun formed on the supernova core (Fig. 2); 3.) Waste products from the core pass through an iron-rich mantle, selectively carrying lighter elements and lighter isotopes of each element into the photosphere (Figs. 3-4); and 4.) Neutron repulsion powers the Sun and sustains life (Figs. 5-7). Together these findings offer a framework for understanding how: a.) The Sun generates and releases neutrinos, energy and solar-wind hydrogen and helium; b.) An inhabitable planet formed and life evolved around an ordinary-looking star; c.) Continuous climate change - induced by cyclic changes in gravitational interactions of the Sun's energetic core with planets - has favored survival by adaptation.

  13. Neutron Repulsion

    E-Print Network [OSTI]

    Manuel, Oliver K

    2011-01-01T23:59:59.000Z

    Earth is connected gravitationally, magnetically and electrically to its heat source - a neutron star that is obscured from view by waste products in the photosphere. Neutron repulsion is like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the solar core and decay into hydrogen that glows in the photosphere like a frosted light bulb. Neutron repulsion was recognized in nuclear rest mass data in 2000 as the overlooked source of energy, the keystone of an arch that locked together these puzzling space-age observations: 1.) Excess 136Xe accompanied primordial helium in the stellar debris that formed the solar system (Fig. 1); 2.) The Sun formed on the supernova core (Fig. 2); 3.) Waste products from the core pass through an iron-rich mantle, selectively carrying lighter elements and lighter isotopes of each element into the photosphere (Figs. 3-4); and 4.) Neutron repulsion powers the Sun and sustains life (Figs. 5-7). Together these findings offer a framework for understanding...

  14. Development for fissile assay in recycled fuel using lead slowing down spectrometer

    SciTech Connect (OSTI)

    Lee, Yong Deok; Je Park, C.; Kim, Ho-Dong; Song, Kee Chan [Korea Atomic Energy Research Institute - KAERI, 1045 Daedeok-daero, Daejeon, Korea, 305-353 (Korea, Republic of)

    2013-07-01T23:59:59.000Z

    A future nuclear energy system is under development to turn spent fuels produced by PWRs into fuels for a SFR (Sodium Fast Reactor) through the pyrochemical process. The knowledge of the isotopic fissile content of the new fuel is very important for fuel safety. A lead slowing down spectrometer (LSDS) is under development to analyze the fissile material content (Pu{sup 239}, Pu{sup 241} and U{sup 235}) of the fuel. The LSDS requires a neutron source, the neutrons will be slowed down through their passage in a lead medium and will finally enter the fuel and will induce fission reactions that will be analysed and the isotopic content of the fuel will be then determined. The issue is that the spent fuel emits intense gamma rays and neutrons by spontaneous fission. The threshold fission detector screens the prompt fast fission neutrons and as a result the LSDS is not influenced by the high level radiation background. The energy resolution of LSDS is good in the range 0.1 eV to 1 keV. It is also the range in which the fission reaction is the most discriminating for the considered fissile isotopes. An electron accelerator has been chosen to produce neutrons with an adequate target through (e{sup -},?)(?,n) reactions.

  15. Compact hydrogen/helium isotope mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O. (Los Alamos, NM); McComas, David J. (Los Alamos, NM); Scime, Earl E. (Morgantown, WV)

    1996-01-01T23:59:59.000Z

    The compact hydrogen and helium isotope mass spectrometer of the present invention combines low mass-resolution ion mass spectrometry and beam-foil interaction technology to unambiguously detect and quantify deuterium (D), tritium (T), hydrogen molecule (H.sub.2, HD, D.sub.2, HT, DT, and T.sub.2), .sup.3 He, and .sup.4 He concentrations and concentration variations. The spectrometer provides real-time, high sensitivity, and high accuracy measurements. Currently, no fieldable D or molecular speciation detectors exist. Furthermore, the present spectrometer has a significant advantage over traditional T detectors: no confusion of the measurements by other beta-emitters, and complete separation of atomic and molecular species of equivalent atomic mass (e.g., HD and .sup.3 He).

  16. Methods for absorbing neutrons

    DOE Patents [OSTI]

    Guillen, Donna P. (Idaho Falls, ID); Longhurst, Glen R. (Idaho Falls, ID); Porter, Douglas L. (Idaho Falls, ID); Parry, James R. (Idaho Falls, ID)

    2012-07-24T23:59:59.000Z

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  17. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, James L. (Drayton Plains, MI)

    1992-01-01T23:59:59.000Z

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

  18. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, J.L.

    1992-12-01T23:59:59.000Z

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

  19. Wide size range fast integrated mobility spectrometer

    DOE Patents [OSTI]

    Wang, Jian

    2013-10-29T23:59:59.000Z

    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.

  20. Compact Imaging Spectrometer Utilizing Immersed Gratings

    DOE Patents [OSTI]

    Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

    2006-03-21T23:59:59.000Z

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, a system for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the system for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the system for receiving the light and the system for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light through an optical element to the detector array.

  1. Electroweak Measurements of Neutron Densities in CREX and PREX at JLab, USA

    SciTech Connect (OSTI)

    Horowitz, Charles J. [Indiana U.; Kumar, Krishna S. [UMass; Michaels, Robert W. [JLAB

    2014-02-01T23:59:59.000Z

    Measurement of the parity-violating electron scattering asymmetry is an established technique at Jefferson Lab and provides a new opportunity to measure the weak charge distribution and hence pin down the neutron radius in nuclei in a relatively clean and model-independent way. This is because the Z boson of the weak interaction couples primarily to neutrons. We will describe the PREX and CREX experiments on ${}^{208}$Pb and ${}^{48}$Ca respectively; these are both doubly-magic nuclei whose first excited state can be discriminated by the high resolution spectrometers at JLab. The heavier lead nucleus, with a neutron excess, provides an interpretation of the neutron skin thickness in terms of properties of bulk neutron matter. For the lighter ${}^{48}$Ca nucleus, which is also rich in neutrons, microscopic nuclear theory calculations are feasible and are sensitive to poorly constrained 3-neutron forces.

  2. Non-destructive method for determining neutron exposure and constituent concentrations of a body

    DOE Patents [OSTI]

    Gold, R.; McElroy, W.N.

    1984-02-22T23:59:59.000Z

    A non-destructive method for determination of neutron exposure and constituent concentrations in an object, such as a reactor pressure vessel, is based on the observation of characteristic gamma-rays emitted by activation products in the object by using a unique continuous gamma-ray spectrometer. The spectrometer views the object through appropriate collimators to determine the absolute emission rate of these characteristic gamma-rays, thereby ascertaining the absolute activity of given activation products in the object. These data can then be used to deduce the spatial and angular dependence of neutron exposure or the spatial constituent concentrations at regions of interest within the object.

  3. Broadband Infrared Heterodyne Spectrometer: Final Report

    SciTech Connect (OSTI)

    Stevens, C G; Cunningham, C T; Tringe, J W

    2010-12-16T23:59:59.000Z

    This report summarizes the most important results of our effort to develop a new class of infrared spectrometers based on a novel broadband heterodyne design. Our results indicate that this approach could lead to a near-room temperature operation with performance limited only by quantum noise carried by the incoming signal. Using a model quantum-well infrared photodetector (QWIP), we demonstrated key performance features of our approach. For example, we directly measured the beat frequency signal generated by superimposing local oscillator (LO) light of one frequency and signal light of another through a spectrograph, by injecting the LO light at a laterally displaced input location. In parallel with the development of this novel spectrometer, we modeled a new approach to reducing detector volume though plasmonic resonance effects. Since dark current scales directly with detector volume, this ''photon compression'' can directly lead to lower currents. Our calculations indicate that dark current can be reduced by up to two orders of magnitude in an optimized ''superlens'' structure. Taken together, our spectrometer and dark current reduction strategies provide a promising path toward room temperature operation of a mid-wave and possibly long-wave infrared spectrometer.

  4. Imaging mass spectrometer with mass tags

    DOE Patents [OSTI]

    Felton, James S.; Wu, Kuang Jen; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2010-06-01T23:59:59.000Z

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  5. Imaging mass spectrometer with mass tags

    DOE Patents [OSTI]

    Felton, James S.; Wu, Kuang Jen J.; Knize, Mark G.; Kulp, Kristen S.; Gray, Joe W.

    2013-01-29T23:59:59.000Z

    A method of analyzing biological material by exposing the biological material to a recognition element, that is coupled to a mass tag element, directing an ion beam of a mass spectrometer to the biological material, interrogating at least one region of interest area from the biological material and producing data, and distributing the data in plots.

  6. Eleventh DOE workshop on personnel neutron dosimetry

    SciTech Connect (OSTI)

    Not Available

    1991-12-31T23:59:59.000Z

    Since its formation, the Office of Health (EH-40) has stressed the importance of the exchange of information related to and improvements in neutron dosimetry. This Workshop was the eleventh in the series sponsored by the Department of Energy (DOE). It provided a forum for operational personnel at DOE facilities to discuss current issues related to neutron dosimetry and for leading investigators in the field to discuss promising approaches for future research. A total of 26 papers were presented including the keynote address by Dr. Warren K. Sinclair, who spoke on, ``The 1990 Recommendations of the ICRP and their Biological Background.`` The first several papers discussed difficulties in measuring neutrons of different energies and ways of compensating or deriving correction factors at individual facilities. Presentations were also given by the US Navy and Air Force. Current research in neutron dosimeter development was the subject of the largest number of papers. These included a number on the development of neutron spectrometers. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  7. BREAKING NEWS! EMSL's 21 T mass spectrometer at field | EMSL

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

    a Q&A is available on the 21T FTICR mass spectrometer web page. EMSL's new 21 Tesla Fourier Transform Ion Cyclotron Resonance Mass Spectrometer is now at its full magnetic field...

  8. Development and performance of a miniature, low cost mass spectrometer

    E-Print Network [OSTI]

    Hemond, Brian D. (Brian David Thomson)

    2011-01-01T23:59:59.000Z

    A miniature, low cost mass spectrometer has been developed that is capable of unit resolution over a mass range of 10 to 50 AMU. The design of the mass spectrometer incorporates several new features that enhance the ...

  9. Study of elementary reactions with the HADES dielectron spectrometer

    E-Print Network [OSTI]

    B. Ramstein

    2009-12-14T23:59:59.000Z

    Results obtained with the HADES dielectron spectrometer at GSI are discussed, with emphasis on dilepton production in elementary reactions.

  10. Calibrations of a multichannel soft x-ray spectrometer

    SciTech Connect (OSTI)

    Blake, R.L.; Hockaday, R.G.; Grosso, J.S.

    1986-01-01T23:59:59.000Z

    A time resolved, 14 channel spectrometer with an absolutely calibrated response, was developed to cove an x-ray photon energy spectrum from 70 to 650 eV. The spectrometer utilized a combination of thin film prefilters, layered synthetic microstructure (LSM) diffractors, metal coated plastic scintillators, and photomultiplier detector tubes. Calibration of the spectrometer was done piecemeal for each component with standard techniques and the component calibrations were convolved to get a complete spectrometer response function. The two calibration procedures were compared.

  11. Development of Mossbauer spectrometer and it's application to characterization of

    E-Print Network [OSTI]

    FeCO3 Development of M¨ossbauer spectrometer and it's application to characterization of FeCO3 film #12; #12; FeCO3 Development of M¨ossbauer spectrometer and it. #12;#12;#12; Development of M¨ossbauer spectrometer and it's application to characterization of FeCO3

  12. Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV

    SciTech Connect (OSTI)

    Sakata, S., E-mail: sakata-s@ile.osaka-u.ac.jp; Arikawa, Y.; Kojima, S.; Ikenouchi, T.; Nagai, T.; Abe, Y.; Inoue, H.; Morace, A.; Utsugi, M.; Nishimura, H.; Nakai, M.; Shiraga, H.; Fujioka, S.; Azechi, H. [Institute of Laser Engineering, Osaka University, Suita 565-0871 (Japan); Kato, R. [Institute of Scientific and Industrial Research, Osaka University, Ibaraki 565-0047 (Japan)

    2014-11-15T23:59:59.000Z

    A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (N{sub e} = 1.0 × 10{sup ?6} C, E{sub e} = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%–70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (?h?/h?) of about 15%. Quantum efficiency of this spectrometer was designed to be 10{sup ?7}, 10{sup ?4}, 10{sup ?5}, respectively, for 2–10, 11–15, and 15–25 MeV of photon energy ranges.

  13. SHARP Neutronics Expanded

    Broader source: Energy.gov [DOE]

    The SHARP neutronics module, PROTEUS, includes neutron and gamma transport solvers and cross-section processing tools as well as the capability for depletion and fuel cycle analysis.

  14. A design study of VOR: a versatile optimal resolution chopper spectrometer for the ESS

    E-Print Network [OSTI]

    Deen, P P; Andersen, K H; Hall-Wilton, R

    2014-01-01T23:59:59.000Z

    VOR, the versatile optimal resolution chopper spectrometer, is designed to probe dynamic phenomena that are currently inaccessible for inelastic neutron scattering due to flux limitations. VOR is a short instrument by the standards of the European Spallation Source (ESS), 30.2 m moderator to sample, and provides instantaneous access to a broad dynamic range, 1 - 120 meV within each ESS period. The short instrument length combined with the long ESS pulse width enables a quadratic flux increase, even at longer wavelengths, by relaxing energy resolution from $\\Delta$E/E = 1% up to $\\Delta$E/E = 7%. This is impossible both on a long chopper spectrometer at the ESS and with instruments at short pulsed sources. In comparison to current day chopper spectrometers, VOR can offer an order of magnitude improvement in flux for equivalent energy resolutions, $\\Delta$E/E = 1-3%. Further relaxing the energy resolution enables VOR to gain an extra order of magnitude in flux. In addition, VOR has been optimised for repetition...

  15. Half-lives and delayed neutron emission probabilities of neutron-rich Li--Al nuclides (US)

    SciTech Connect (OSTI)

    Reeder, P.L.; Warner, R.A.; Hensley, W.K. (Pacific Northwest Laboratory, Richland, Washington (USA)); Vieira, D.J.; Wouters, J.M. (Los Alamos National Laboratory, Los Alamos, New Mexico (USA))

    1991-10-01T23:59:59.000Z

    Beta-decay half-lives and delayed neutron emission probabilities of very neutron-rich nuclides from Li to Al have been measured by a delayed coincidence technique. Neutron-rich nuclides were produced by reaction of 800-MeV protons on a {sup 232}Th target and were individually identified by use of the time-of-flight isochronous spectrometer. For 16 previously measured nucides, the half-lives determined here agree with literature values within the uncertainties. The previously unmeasured half-lives for {sup 25}F (59{plus minus}40 ms) and {sup 28}Ne (14{plus minus}10 ms) have been determined. Delayed neutron emission has been measured for {sup 12}Be, {sup 14}B, {sup 17}C, {sup 18}N, {sup 25}F, and {sup 28}Ne. Emission probabilities are reported for 19 precursors and upper limits are reported for 12 other nuclides. These data are compared with predictions of several beta-decay models.

  16. Method of multiplexed analysis using ion mobility spectrometer

    DOE Patents [OSTI]

    Belov, Mikhail E. (Richland, WA); Smith, Richard D. (Richland, WA)

    2009-06-02T23:59:59.000Z

    A method for analyzing analytes from a sample introduced into a Spectrometer by generating a pseudo random sequence of a modulation bins, organizing each modulation bin as a series of submodulation bins, thereby forming an extended pseudo random sequence of submodulation bins, releasing the analytes in a series of analyte packets into a Spectrometer, thereby generating an unknown original ion signal vector, detecting the analytes at a detector, and characterizing the sample using the plurality of analyte signal subvectors. The method is advantageously applied to an Ion Mobility Spectrometer, and an Ion Mobility Spectrometer interfaced with a Time of Flight Mass Spectrometer.

  17. Imaging spectrometer wide field catadioptric design

    DOE Patents [OSTI]

    Chrisp; Michael P. (Danville, CA)

    2008-08-19T23:59:59.000Z

    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.

  18. Compact imaging spectrometer utilizing immersed gratings

    DOE Patents [OSTI]

    Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR); Kuzmenko, Paul J. (Livermore, CA); Bennett, Charles L. (Livermore, CA)

    2007-07-03T23:59:59.000Z

    A compact imaging spectrometer with an immersive diffraction grating that compensates optical distortions. The imaging spectrometer comprises an entrance slit for transmitting light, means for receiving the light and directing the light, an immersion grating, and a detector array. The entrance slit, the means for receiving the light, the immersion grating, and the detector array are positioned wherein the entrance slit transmits light to the means for receiving the light and the means for receiving the light directs the light to the immersion grating and the immersion grating receives the light and directs the light to the means for receiving the light, and the means for receiving the light directs the light to the detector array.

  19. Portable gas chromatograph-mass spectrometer

    DOE Patents [OSTI]

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

    1996-06-11T23:59:59.000Z

    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.

  20. Portable gas chromatograph-mass spectrometer

    DOE Patents [OSTI]

    Andresen, Brian D. (Livermore, CA); Eckels, Joel D. (Livermore, CA); Kimmons, James F. (Manteca, CA); Myers, David W. (Livermore, CA)

    1996-01-01T23:59:59.000Z

    A gas chromatograph-mass spectrometer (GC-MS) 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.

  1. Capillary zone electrophoresis-mass spectrometer interface

    DOE Patents [OSTI]

    D'Silva, Arthur (Ames, IA)

    1996-08-06T23:59:59.000Z

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conducts is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer.

  2. Capillary zone electrophoresis-mass spectrometer interface

    DOE Patents [OSTI]

    D`Silva, A.

    1996-08-06T23:59:59.000Z

    A device for providing equal electrical potential between two loci unconnected by solid or liquid electrical conductors is provided. The device comprises a first electrical conducting terminal, a second electrical conducting terminal connected to the first terminal by a rigid dielectric structure, and an electrically conducting gas contacting the first and second terminals. This device is particularly suitable for application in the electrospray ionization interface between a capillary zone electrophoresis apparatus and a mass spectrometer. 1 fig.

  3. Expert overseer for mass spectrometer system

    DOE Patents [OSTI]

    Filby, Evan E. (Idaho Falls, ID); Rankin, Richard A. (Ammon, ID)

    1991-01-01T23:59:59.000Z

    An expert overseer for the operation and real-time management of a mass spectrometer and associated laboratory equipment. The overseer is a computer-based expert diagnostic system implemented on a computer separate from the dedicated computer used to control the mass spectrometer and produce the analysis results. An interface links the overseer to components of the mass spectrometer, components of the laboratory support system, and the dedicated control computer. Periodically, the overseer polls these devices and as well as itself. These data are fed into an expert portion of the system for real-time evaluation. A knowledge base used for the evaluation includes both heuristic rules and precise operation parameters. The overseer also compares current readings to a long-term database to detect any developing trends using a combination of statistical and heuristic rules to evaluate the results. The overseer has the capability to alert lab personnel whenever questionable readings or trends are observed and provide a background review of the problem and suggest root causes and potential solutions, or appropriate additional tests that could be performed. The overseer can change the sequence or frequency of the polling to respond to an observation in the current data.

  4. What Happened with Spectrometer Magnet 2B

    SciTech Connect (OSTI)

    Green, Michael A

    2010-05-27T23:59:59.000Z

    The spectrometer solenoid is supposed to be the first magnets installed in MICE [1]-[4]. This report described what happened during the test of the MICE spectrometer solenoid 2B. First, the report describes the temperatures in the magnet, the cooler top plate and the shield during the run where the magnet quenched at 258 A. During this quench, a lead between the bottom of the HTS leads and the diode bank burned out causing the magnet to quench. Second, three methods for measuring the net heat flow into the cold mass are described. Third, there is a discussion of possible resistive heating in the HTS leads between liquid helium temperature and the copper plate, which is at about 50 K. Fourth, there is a discussion of the measured first stage heat loads in the magnet, when there is no current in the magnet. The first stage heat load calculations are based on knowing the first stage temperatures of the three two-stage pulse tube coolers and the single stage GM cooler. Fifth, the estimated heat load to the first stage when the magnet has current in it is discussed. Sixth, there is a comparison of the stage 1 heat loads in magnet 1A [5], magnet 2A [6], and magnet 2B [7]. Finally there is a discussion of recommended changes for improving the spectrometer solenoids so that the coolers can keep them cold.

  5. Neutron Structure — New Results with CLAS at Jefferson Lab

    SciTech Connect (OSTI)

    Sebastian Kuhn

    2006-11-01T23:59:59.000Z

    New measurements using the 6 GeV continuous electron beam and the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab have collected information on the form factors and the unpolarized structure functions of the neutron, with minimal uncertainty from nuclear binding effects. One experiment has also tried to measure these binding effects more directly, using the method of ''spectator tagging''. These experiments are forerunners for an extensive program with the energy-upgraded 12 GeV accelerator at Jefferson Lab.

  6. Measurement of the neutron $\\beta$-asymmetry parameter $A_0$ with ultracold neutrons

    E-Print Network [OSTI]

    Plaster, B; Back, H O; Bowles, T J; Broussard, L J; Carr, R; Clayton, S; Currie, S; Filippone, B W; Garcia, A; Geltenbort, P; Hickerson, K P; Hoagland, J; Hogan, G E; Hona, B; Holley, A T; Ito, T M; Liu, C -Y; Liu, J; Makela, M; Mammei, R R; Martin, J W; Melconian, D; Mendenhall, M P; Morris, C L; Mortensen, R; Pattie, R W; Jr.,; Galvan, A Perez; Pitt, M L; Ramsey, J C; Russell, R; Saunders, A; Schmid, R; Seestrom, S J; Sjue, S; Sondheim, W E; Tatar, E; Tipton, B; Vogelaar, R B; VornDick, B; Wrede, C; Xu, Y P; Yan, H; Young, A R; Yuan, J

    2012-01-01T23:59:59.000Z

    We present a detailed report of a measurement of the neutron $\\beta$-asymmetry parameter $A_0$, the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T $2 \\times 2\\pi$ solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages located on both ends of the spectrometer. From an analysis of data acquired during runs in 2008 and 2009, we report $A_0 = -0.11966 \\pm 0.00089_{-0.00140} ^{+0.00123}$, from which we extract a value for the ratio of the weak axial-vector and vector coupling constants of the nucleon, $\\lambda = g...

  7. Measurement of the neutron $?$-asymmetry parameter $A_0$ with ultracold neutrons

    E-Print Network [OSTI]

    UCNA Collaboration; B. Plaster; R. Rios; H. O. Back; T. J. Bowles; L. J. Broussard; R. Carr; S. Clayton; S. Currie; B. W. Filippone; A. Garcia; P. Geltenbort; K. P. Hickerson; J. Hoagland; G. E. Hogan; B. Hona; A. T. Holley; T. M. Ito; C. -Y. Liu; J. Liu; M. Makela; R. R. Mammei; J. W. Martin; D. Melconian; M. P. Mendenhall; C. L. Morris; R. Mortensen; R. W. Pattie, Jr.; A. Perez Galvan; M. L. Pitt; J. C. Ramsey; R. Russell; A. Saunders; R. Schmid; S. J. Seestrom; S. Sjue; W. E. Sondheim; E. Tatar; B. Tipton; R. B. Vogelaar; B. VornDick; C. Wrede; Y. P. Xu; H. Yan; A. R. Young; J. Yuan

    2012-07-25T23:59:59.000Z

    We present a detailed report of a measurement of the neutron $\\beta$-asymmetry parameter $A_0$, the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T $2 \\times 2\\pi$ solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages located on both ends of the spectrometer. From an analysis of data acquired during runs in 2008 and 2009, we report $A_0 = -0.11966 \\pm 0.00089_{-0.00140} ^{+0.00123}$, from which we extract a value for the ratio of the weak axial-vector and vector coupling constants of the nucleon, $\\lambda = g_A/g_V = -1.27590 \\pm 0.00239_{-0.00377}^{+0.00331}$. Complete details of the analysis are presented.

  8. Neutrostriction in Neutron stars

    E-Print Network [OSTI]

    V. K. Ignatovich

    2006-06-29T23:59:59.000Z

    It is demonstrated that not only gravity, but also neutrostriction forces due to optical potential created by coherent elastic neutron-neutron scattering can hold a neutron star together. The latter forces can be stronger than gravitational ones. The effect of these forces on mass, radius and structure of the neutron star is estimated.

  9. Neutron reflecting supermirror structure

    DOE Patents [OSTI]

    Wood, James L. (Drayton Plains, MI)

    1992-01-01T23:59:59.000Z

    An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. One layer of each set of bilayers consist of titanium, and the second layer of each set of bilayers consist of an alloy of nickel with carbon interstitially present in the nickel alloy.

  10. Imaging with Scattered Neutrons

    E-Print Network [OSTI]

    H. Ballhausen; H. Abele; R. Gaehler; M. Trapp; A. Van Overberghe

    2006-10-30T23:59:59.000Z

    We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.

  11. Delayed neutron emission probabilities of Li-F nuclides

    SciTech Connect (OSTI)

    Reeder, P.L.; Warner, R.A.; Hensley, W.K. (Pacific Northwest Lab., Richland, WA (USA)); Vieira, D.J.; Wouters, J.M. (Los Alamos National Lab., NM (USA))

    1989-09-01T23:59:59.000Z

    Delayed neutron emission probabilities (P{sub n}) have been measured for 18 nuclides ranging from {sup 9}Li to {sup 25}F. Neutron-rich nuclides were produced by reaction of 800 MeV p on a {sup 232}Th target at the LAMPF accelerator at Los Alamos National Laboratory. Recoil nuclides were individually identified as to their mass, nuclear charged, and ionic charge by use of the Time-of-Flight Isochronous (TOFI) spectrometer. The distribution of time intervals between the arrival of a specific ion and the subsequent detection of a neutron was determined. The P{sub n} was calculated from the total number of ions observed, the initial neutron count rate, the neutron counting efficiency, and the half-life. The technique is shown to be valid for half-lives ranging from 10 ms ({sup 15}B) to 4 s ({sup 17}N) and for P{sub n} values as low as 0.3% ({sup 13}B). Delayed neutron emission has been measured for {sup 12}Be, {sup 14}B, {sup 17}C, {sup 18}N, {sup 21}N, and {sup 25}F for the first time. A small branch for beta-delayed two-neutron emission was observed in {sup 15}B (P{sub 2n} = 0.4 {plus minus} 0.2%). 14 refs., 6 figs., 1 tab.

  12. Small angle neutron scattering from high impact polystyrene

    SciTech Connect (OSTI)

    Pringle, O.A.

    1981-01-01T23:59:59.000Z

    High impact polystyrene (HIPS) is a toughened plastic composed of a polystyrene matrix containing a few percent rubber in the form of dispersed 0.1 to 10 micron diameter rubber particles. Some commercial formulations of HIPS include the addition of a few percent mineral oil, which improves the toughness of the plastic. Little is known about the mechanism by which the mineral oil helps toughen the plastic. It is hypothesized that the oil is distributed only in the rubber particles, but whether this hypothesis is correct was not known prior to this work. The size of the rubber particles in HIPS and their neutron scattering length density contrast with the polystyrene matrix cause HIPS samples to scatter neutrons at small angles. The variation of this small angle neutron scattering (SANS) signal with mineral oil content has been used to determine the location of the oil in HIPS. The SANS spectrometer at the University of Missouri Research Reactor Facility (MURR) was used to study plastic samples similar in composition to commercial HIPS. The MURR SANS spectrometer is used to study the small angle scattering of a vertical beam of 4.75 A neutrons from solid and liquid samples. The scattered neutrons are detected in a 54 x 60 cm/sup 2/ position sensitive detector designed and built at MURR. A series of plastic samples of varying rubber and oil content and different rubber domain sizes and shapes were examined on the MURR SANS spectrometer. Analysis of the scattering patterns showed that the mineral oil is about eight to ten times more likely to be found in the rubber particles than in the polystyrene matrix. This result confirmed the hypothesis that the mineral oil is distributed primarily in the rubber particles.

  13. Lead Slowing Down Spectrometer Status Report

    SciTech Connect (OSTI)

    Warren, Glen A.; Anderson, Kevin K.; Bonebrake, Eric; Casella, Andrew M.; Danon, Yaron; Devlin, M.; Gavron, Victor A.; Haight, R. C.; Imel, G. R.; Kulisek, Jonathan A.; O'Donnell, J. M.; Weltz, Adam

    2012-06-07T23:59:59.000Z

    This report documents the progress that has been completed in the first half of FY2012 in the MPACT-funded Lead Slowing Down Spectrometer project. Significant progress has been made on the algorithm development. We have an improve understanding of the experimental responses in LSDS for fuel-related material. The calibration of the ultra-depleted uranium foils was completed, but the results are inconsistent from measurement to measurement. Future work includes developing a conceptual model of an LSDS system to assay plutonium in used fuel, improving agreement between simulations and measurement, design of a thorium fission chamber, and evaluation of additional detector techniques.

  14. Dual waveband compact catadioptric imaging spectrometer

    DOE Patents [OSTI]

    Chrisp, Michael P.

    2012-12-25T23:59:59.000Z

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

  15. 140 GHz pulsed Fourier transform microwave spectrometer

    DOE Patents [OSTI]

    Kolbe, W.F.; Leskovar, B.

    1985-07-29T23:59:59.000Z

    A high frequency energy pulsing system suitable for use in a pulsed microwave spectrometer, including means for generating a high frequency carrier signal, and means for generating a low frequency modulating signal. The carrier signal is continuously fed to a modulator and the modulating signal is fed through a pulse switch to the modulator. When the pulse switch is on, the modulator will produce sideband signals above and below the carrier signal frequency. A frequency-responsive device is tuned to one of the sideband signals and sway from the carrier frequency so that the high frequency energization of the frequency-responsive device is controlled by the pulse switch.

  16. Micro-optical-mechanical system photoacoustic spectrometer

    DOE Patents [OSTI]

    Kotovsky, Jack; Benett, William J.; Tooker, Angela C.; Alameda, Jennifer B.

    2013-01-01T23:59:59.000Z

    All-optical photoacoustic spectrometer sensing systems (PASS system) and methods include all the hardware needed to analyze the presence of a large variety of materials (solid, liquid and gas). Some of the all-optical PASS systems require only two optical-fibers to communicate with the opto-electronic power and readout systems that exist outside of the material environment. Methods for improving the signal-to-noise are provided and enable mirco-scale systems and methods for operating such systems.

  17. Ion mobility spectrometer with virtual aperture grid

    DOE Patents [OSTI]

    Pfeifer, Kent B. (Los Lunas, NM); Rumpf, Arthur N. (Albuquerque, NM)

    2010-11-23T23:59:59.000Z

    An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

  18. Calibration of Time Of Flight Detectors Using Laser-driven Neutron Source

    E-Print Network [OSTI]

    Mirfayzi, S R; Ahmed, H; Krygier, A G; Green, A; Alejo, A; Clarke, R; Freeman, R R; Fuchs, J; Jung, D; Kleinschmidt, A; Morrison, J T; Najmudin, Z; Nakamura, H; Norreys, P; Oliver, M; Roth, M; Vassura, L; Zepf, M; Borghesi, M

    2015-01-01T23:59:59.000Z

    Calibration of three scintillators (EJ232Q, BC422Q and EJ410) in a time-of-flight (TOF) arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors are shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  19. Calibration of Time Of Flight Detectors Using Laser-driven Neutron Source

    E-Print Network [OSTI]

    S. R. Mirfayzi; S. Kar; H. Ahmed; A. G. Krygier; A. Green; A. Alejo; R. Clarke; R. R. Freeman; J. Fuchs; D. Jung; A. Kleinschmidt; J. T. Morrison; Z. Najmudin; H. Nakamura; P. Norreys; M. Oliver; M. Roth; L. Vassura; M. Zepf; M. Borghesi

    2015-06-15T23:59:59.000Z

    Calibration of three scintillators (EJ232Q, BC422Q and EJ410) in a time-of-flight (TOF) arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors are shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

  20. A compact proton spectrometer for measurement of the absolute DD proton spectrum from which yield and ?R are determined in thin-shell inertial-confinement-fusion implosions

    SciTech Connect (OSTI)

    Rosenberg, M. J., E-mail: mrosenbe@mit.edu; Zylstra, A. B.; Frenje, J. A.; Rinderknecht, H. G.; Gatu Johnson, M.; Waugh, C. J.; Séguin, F. H.; Sio, H.; Sinenian, N.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Glebov, V. Yu.; Hohenberger, M.; Stoeckl, C.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Yeamans, C. B.; LePape, S.; Mackinnon, A. J.; Bionta, R. M.; Talison, B. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2014-10-15T23:59:59.000Z

    A compact, step range filter proton spectrometer has been developed for the measurement of the absolute DD proton spectrum, from which yield and areal density (?R) are inferred for deuterium-filled thin-shell inertial confinement fusion implosions. This spectrometer, which is based on tantalum step-range filters, is sensitive to protons in the energy range 1-9 MeV and can be used to measure proton spectra at mean energies of ?1-3 MeV. It has been developed and implemented using a linear accelerator and applied to experiments at the OMEGA laser facility and the National Ignition Facility (NIF). Modeling of the proton slowing in the filters is necessary to construct the spectrum, and the yield and energy uncertainties are ±<10% in yield and ±120?keV, respectively. This spectrometer can be used for in situ calibration of DD-neutron yield diagnostics at the NIF.

  1. Non-destructive Assay Measurements Using the RPI Lead Slowing Down Spectrometer

    SciTech Connect (OSTI)

    Becker, Bjorn; Weltz, Adam; Kulisek, Jonathan A.; Thompson, J. T.; Thompson, N.; Danon, Yaron

    2013-10-01T23:59:59.000Z

    The use of a Lead Slowing-Down Spectrometer (LSDS) is consid- ered as a possible option for non-destructive assay of fissile material of used nuclear fuel. The primary objective is to quantify the 239Pu and 235U fissile content via a direct measurement, distinguishing them through their characteristic fission spectra in the LSDS. In this pa- per, we present several assay measurements performed at the Rensse- laer Polytechnic Institute (RPI) to demonstrate the feasibility of such a method and to provide benchmark experiments for Monte Carlo cal- culations of the assay system. A fresh UOX fuel rod from the RPI Criticality Research Facility, a 239PuBe source and several highly en- riched 235U discs were assayed in the LSDS. The characteristic fission spectra were measured with 238U and 232Th threshold fission cham- bers, which are only sensitive to fission neutron with energy above the threshold. Despite the constant neutron and gamma background from the PuBe source and the intense interrogation neutron flux, the LSDS system was able to measure the characteristic 235U and 239Pu responses. All measurements were compared to Monte Carlo simula- tions. It was shown that the available simulation tools and models are well suited to simulate the assay, and that it is possible to calculate the absolute count rate in all investigated cases.

  2. aerosol mass spectrometer: Topics by E-print Network

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

    2004. The concentration of a species Zhang, Qi 8 Development of a thermal desorption chemical ionization mobility mass spectrometer for the speciation of ultrafine aerosols. Open...

  3. alpha spectrometers: Topics by E-print Network

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

    Flight CERN Preprints Summary: The Alpha Magnetic Spectrometer (AMS) is a particle detector designed to detect antimatter. During the 10-day test flight on the space shuttle in...

  4. atomic emission spectrometer: Topics by E-print Network

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

    Websites Summary: Characterization of Tropospheric Emission Spectrometer (TES) CO2 for carbon cycle science Susan footprint ave ** Crevoisier et al., 2009 0.22K error at 700...

  5. The Results of Tests of the MICE Spectrometer Solenoids

    SciTech Connect (OSTI)

    Green, Michael A.; Virostek, Steve P.

    2009-10-19T23:59:59.000Z

    The Muon Ionization Cooling Experiment (MICE) spectrometer solenoid magnets will be the first magnets to be installed within the MICE cooling channel. The spectrometer magnets are the largest magnets in both mass and surface area within the MICE ooling channel. Like all of the other magnets in MICE, the spectrometer solenoids are kept cold using 1.5 W (at 4.2 K) pulse tube coolers. The MICE spectrometer solenoid is quite possibly the largest magnet that has been cooled using small coolers. Two pectrometer magnets have been built and tested. This report discusses the results of current and cooler tests of both magnets.

  6. antiparticle spectrometer gaps: Topics by E-print Network

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

    Next Page Last Page Topic Index 1 The General Antiparticle Spectrometer (GAPS) - Hunt for dark matter using low-energy antideuterons CERN Preprints Summary: The GAPS experiment is...

  7. alpha magnetic spectrometer: Topics by E-print Network

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

    23 24 25 Next Page Last Page Topic Index 1 Testing and Final Construction of the Superconducting Magnet for the Alpha Magnetic Spectrometer MIT - DSpace Summary: The Alpha...

  8. Neutron streak camera

    DOE Patents [OSTI]

    Wang, C.L.

    1981-05-14T23:59:59.000Z

    Apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon.

  9. Layered semiconductor neutron detectors

    DOE Patents [OSTI]

    Mao, Samuel S; Perry, Dale L

    2013-12-10T23:59:59.000Z

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  10. Neutron streak camera

    DOE Patents [OSTI]

    Wang, C.L.

    1983-09-13T23:59:59.000Z

    Disclosed is an apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon. 4 figs.

  11. Re-publication of the data from the BILL magnetic spectrometer: The cumulative $?$ spectra of the fission products of $^{235}$U, $^{239}$Pu, and $^{241}$Pu

    E-Print Network [OSTI]

    N. Haag; W. Gelletly; F. von Feilitzsch; L. Oberauer; W. Potzel; K. Schreckenbach; A. A. Sonzogni

    2014-05-30T23:59:59.000Z

    In the 1980s, measurements of the cumulative $\\beta$ spectra of the fission products following the thermal neutron induced fission of $^{235}$U, $^{239}$Pu, and $^{241}$Pu were performed at the magnetic spectrometer BILL at the ILL in Grenoble. This data was published in bins of 250 keV. In this paper, we re-publish the original data in a binning of 50 keV for $^{235}$U and 100 keV for $^{239}$Pu and $^{241}$Pu.

  12. Ultrafast neutron detector

    DOE Patents [OSTI]

    Wang, C.L.

    1985-06-19T23:59:59.000Z

    A neutron detector of very high temporal resolution is described. It may be used to measure distributions of neutrons produced by fusion reactions that persist for times as short as about 50 picoseconds.

  13. Neutron dose equivalent meter

    DOE Patents [OSTI]

    Olsher, Richard H. (Los Alamos, NM); Hsu, Hsiao-Hua (Los Alamos, NM); Casson, William H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM); Kleck, Jeffrey H. (Menlo Park, CA); Beverding, Anthony (Foster City, CA)

    1996-01-01T23:59:59.000Z

    A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

  14. Pulsed-neutron monochromator

    DOE Patents [OSTI]

    Mook, Jr., Herbert A. (Oak Ridge, TN)

    1985-01-01T23:59:59.000Z

    In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

  15. Pulsed-neutron monochromator

    DOE Patents [OSTI]

    Mook, H.A. Jr.

    1984-01-01T23:59:59.000Z

    In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

  16. Simulation of a D-T Neutron Source for Neutron Scattering Experiments

    E-Print Network [OSTI]

    Lou, T.P.; Ludewigt, B.A.; Vujic, J.L.; Leung, K.-N.

    2003-01-01T23:59:59.000Z

    T Neutron Source for Neutron Scattering Experiments T.P. Louor cold neutrons for neutron scattering experiments. Thisto simulate a neutron scattering setup and to estimate

  17. Experimental validation of GADRAS's coupled neutron-photon inverse radiation transport solver.

    SciTech Connect (OSTI)

    Mattingly, John K.; Mitchell, Dean James; Harding, Lee T.

    2010-08-01T23:59:59.000Z

    Sandia National Laboratories has developed an inverse radiation transport solver that applies nonlinear regression to coupled neutron-photon deterministic transport models. The inverse solver uses nonlinear regression to fit a radiation transport model to gamma spectrometry and neutron multiplicity counting measurements. The subject of this paper is the experimental validation of that solver. This paper describes a series of experiments conducted with a 4.5 kg sphere of {alpha}-phase, weapons-grade plutonium. The source was measured bare and reflected by high-density polyethylene (HDPE) spherical shells with total thicknesses between 1.27 and 15.24 cm. Neutron and photon emissions from the source were measured using three instruments: a gross neutron counter, a portable neutron multiplicity counter, and a high-resolution gamma spectrometer. These measurements were used as input to the inverse radiation transport solver to evaluate the solver's ability to correctly infer the configuration of the source from its measured radiation signatures.

  18. Exploration of ion temperature profile measurements at JET using the upgraded neutron profile monitor

    SciTech Connect (OSTI)

    Marocco, D.; Esposito, B.; Riva, M. [Associazione EURATOM-ENEA sulla Fusione, C.R. Frascati, C.P. 65, Frascati I-00044, Roma (Italy); Collaboration: JET-EFDA Contributors

    2012-10-15T23:59:59.000Z

    The neutron profile monitor (NPM), routinely used at the Joint European Torus for neutron emissivity profile measurements, consists of two fan-shaped arrays of collimators and each line of sight (LOS) is equipped with a NE213 liquid organic scintillator for simultaneous measurements of the 2.5 MeV and 14 MeV neutrons. A digital system developed in ENEA has replaced the analog acquisition electronics and now enables the NPM to perform spatially resolved neutron spectrometry by providing neutron pulse height spectra (PHS) for each LOS. However, the NPM was not originally designed as a spectrometer and, therefore, lacks several key features, such as detailed measurements of the detector response functions and the presence of detector stability monitors. We present a proof of principle of ion temperature profile measurements derived from the NPM PHS in high plasma current discharges using simulated detector response functions.

  19. Bouncing Neutrons and the Neutron Centrifuge

    E-Print Network [OSTI]

    P. J. S. Watson

    2003-02-26T23:59:59.000Z

    The recent observation of the quantum state of the neutron bouncing freely under gravity allows some novel experiments. A method of purifying the ground state is given, and possible applications to the measurement of the electric dipole moment of the neutron and the short distance behaviour of gravity are discussed.

  20. Advanced neutron absorber materials

    DOE Patents [OSTI]

    Branagan, Daniel J. (Idaho Falls, ID); Smolik, Galen R. (Idaho Falls, ID)

    2000-01-01T23:59:59.000Z

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  1. Arsenic activation neutron detector

    DOE Patents [OSTI]

    Jacobs, E.L.

    1980-01-28T23:59:59.000Z

    A detector of bursts of neutrons from a deuterium-deuteron reaction includes a quantity of arsenic adjacent a gamma detector such as a scintillator and photomultiplier tube. The arsenic is activated by the 2.5-MeV neutrons to release gamma radiation which is detected to give a quantitative representation of detected neutrons.

  2. Mass spectrometer vacuum housing and pumping system

    DOE Patents [OSTI]

    Coutts, Gerald W. (Livermore, CA); Bushman, John F. (Oakley, CA); Alger, Terry W. (Tracy, CA)

    1996-01-01T23:59:59.000Z

    A vacuum housing and pumping system for a portable gas chromatograph/mass spectrometer (GC/MS). The vacuum housing section of the system has minimum weight for portability while designed and constructed to utilize metal gasket sealed stainless steel to be compatible with high vacuum operation. The vacuum pumping section of the system consists of a sorption (getter) pump to remove atmospheric leakage and outgassing contaminants as well as the gas chromatograph carrier gas (hydrogen) and an ion pump to remove the argon from atmospheric leaks. The overall GC/MS system has broad application to contaminants, hazardous materials, illegal drugs, pollution monitoring, etc., as well as for use by chemical weapon treaty verification teams, due to the light weight and portability thereof.

  3. 140 GHz pulsed Fourier transform microwave spectrometer

    DOE Patents [OSTI]

    Kolbe, W.F.; Leskovar, B.

    1987-10-27T23:59:59.000Z

    A high frequency energy pulsing system suitable for use in a pulsed microwave spectrometer, including means for generating a high frequency carrier signal, and means for generating a low frequency modulating signal is disclosed. The carrier signal is continuously fed to a modulator and the modulating signal is fed through a pulse switch to the modulator. When the pulse switch is on, the modulator will produce sideband signals above and below the carrier signal frequency. A frequency-responsive device is tuned to one of the sideband signals and away from the carrier frequency so that the high frequency energization of the frequency-responsive device is controlled by the pulse switch. 5 figs.

  4. 140 GHz pulsed fourier transform microwave spectrometer

    DOE Patents [OSTI]

    Kolbe, William F. (Oakland, CA); Leskovar, Branko (Moraga, CA)

    1987-01-01T23:59:59.000Z

    A high frequency energy pulsing system suitable for use in a pulsed microwave spectrometer (10), including means (11, 19) for generating a high frequency carrier signal, and means (12) for generating a low frequency modulating signal. The carrier signal is continuously fed to a modulator (20) and the modulating signal is fed through a pulse switch (23) to the modulator. When the pulse switch (23) is on, the modulator (20) will produce sideband signals above and below the carrier signal frequency. A frequency-responsive device (31) is tuned to one of the sideband signals and away from the carrier frequency so that the high frequency energization of the frequency-responsive device (31) is controlled by the pulse switch (23).

  5. Mass spectrometer vacuum housing and pumping system

    SciTech Connect (OSTI)

    Coutts, G.W.; Bushman, J.F.; Alger, T.W.

    1996-07-23T23:59:59.000Z

    A vacuum housing and pumping system is described for a portable gas chromatograph/mass spectrometer (GC/MS). The vacuum housing section of the system has minimum weight for portability while designed and constructed to utilize metal gasket sealed stainless steel to be compatible with high vacuum operation. The vacuum pumping section of the system consists of a sorption (getter) pump to remove atmospheric leakage and outgassing contaminants as well as the gas chromatograph carrier gas (hydrogen) and an ion pump to remove the argon from atmospheric leaks. The overall GC/MS system has broad application to contaminants, hazardous materials, illegal drugs, pollution monitoring, etc., as well as for use by chemical weapon treaty verification teams, due to the light weight and portability thereof. 7 figs.

  6. An improved selective excitation double Mossbauer spectrometer J. van Lieropa)

    E-Print Network [OSTI]

    Ryan, Dominic

    An improved selective excitation double Mo¨ssbauer spectrometer J. van Lieropa) and D. H. Ryan, operation and performance of a selective excitation double Mo¨ssbauer SEDM spectrometer are described circuitry together with Wissel Mo¨ssbauer velocity transducers and electronics supplies energy

  7. MICROMACHINED FOURIER TRANSFORM SPECTROMETER ON SILICON OPTICAL BENCH PLATFORM

    E-Print Network [OSTI]

    Park, Namkyoo

    MICROMACHINED FOURIER TRANSFORM SPECTROMETER ON SILICON OPTICAL BENCH PLATFORM Kyoungsik Yu1 a miniaturized Fourier transform spectrometer implemented on a silicon optical bench platform. The optical-etching. A spectral resolution of 45 nm near 1550 nm wavelength is demonstrated. Keywords: Fourier transform

  8. LANL/Green Star spectrometer tests

    SciTech Connect (OSTI)

    Sampson, T.E.; Cremers, T.L.; Vo, D.T. [Los Alamos National Lab., NM (United States); Seldiakov, Y.P.; Dorin, A.B.; Kondrashov, M.V. [Green Star, Moscow (Russian Federation); Timoshin, V.I. [VNIINM, Moscow (Russian Federation)

    1997-12-01T23:59:59.000Z

    The US and Russia have agreed to the joint development of a nondestructive assay system for use to support the dismantlement of nuclear weapons in Russia. This nondestructive assay system will be used to measure plutonium produced by the conversion of Russian nuclear weapons. The NDA system for Russia will be patterned after the ARIES NDA system being constructed at Los Alamos. One goal of the program is to produce an NDA system for use in Russia that maximizes the use of Russian resources to facilitate maintenance and future upgrades. The Green Star SBS50 Single Board Spectrometer system (Green Star Ltd., Moscow, Russia) has been suggested for use as the data acquisition component for gamma ray instruments in the system. Possible uses are for plutonium isotopic analysis and also segmented gamma scanning. Green Star has also developed analysis software for the SBS50. This software, both plutonium isotopic analysis and uranium enrichment analysis, was developed specifically for customs/border inspection applications (low counting rate applications and identification as opposed to quantification) and was not intended for MC and A applications. Because of the relative immaturity of the Green Star plutonium isotopic analysis software (it has been under development for only one year and is patterned after US development circa 1980), it was tentatively agreed, before the tests, that the Russian NDA system would use the Los Alamos PC/FRAM software for plutonium isotopic analysis. However, it was also decided to include the Green Star plutonium isotopic software in the testing, both to quantify its performance for MC and A applications and also to provide additional data to Green Star for further development of their software. The main purpose of the testing was to evaluate the SBS-50 spectrometer as a data acquisition device for use with LANL software.

  9. Mass measurements near the $r$-process path using the Canadian Penning Trap mass spectrometer

    E-Print Network [OSTI]

    J. Van Schelt; D. Lascar; G. Savard; J. A. Clark; S. Caldwell; A. Chaudhuri; J. Fallis; J. P. Greene; A. F. Levand; G. Li; K. S. Sharma; M. G. Sternberg; T. Sun; B. J. Zabransky

    2012-04-09T23:59:59.000Z

    The masses of 40 neutron-rich nuclides from Z = 51 to 64 were measured at an average precision of $\\delta m/m= 10^{-7}$ using the Canadian Penning Trap mass spectrometer at Argonne National Laboratory. The measurements, of fission fragments from a $^{252}$Cf spontaneous fission source in a helium gas catcher, approach the predicted path of the astrophysical $r$ process. Where overlap exists, this data set is largely consistent with previous measurements from Penning traps, storage rings, and reaction energetics, but large systematic deviations are apparent in $\\beta$-endpoint measurements. Differences in mass excess from the 2003 Atomic Mass Evaluation of up to 400 keV are seen, as well as systematic disagreement with various mass models.

  10. Ion mobility spectrometer, spectrometer analyte detection and identification verification system, and method

    DOE Patents [OSTI]

    Atkinson, David A. (Idaho Falls, ID)

    2002-01-01T23:59:59.000Z

    Methods and apparatus for ion mobility spectrometry and analyte detection and identification verification system are disclosed. The apparatus is configured to be used in an ion mobility spectrometer and includes a plurality of reactant reservoirs configured to contain a plurality of reactants which can be reacted with the sample to form adducts having varying ion mobilities. A carrier fluid, such as air or nitrogen, is used to carry the sample into the spectrometer. The plurality of reactants are configured to be selectively added to the carrier stream by use inlet and outlet manifolds in communication with the reagent reservoirs, the reservoirs being selectively isolatable by valves. The invention further includes a spectrometer having the reagent system described. In the method, a first reactant is used with the sample. Following a positive result, a second reactant is used to determine whether a predicted response occurs. The occurrence of the second predicted response tends to verify the existence of a component of interest within the sample. A third reactant can also be used to provide further verification of the existence of a component of interest. A library can be established of known responses of compounds of interest with various reactants and the results of a specific multi-reactant survey of a sample can be compared against the library to determine whether a component detected in the sample is likely to be a specific component of interest.

  11. High energy neutron dosimeter

    DOE Patents [OSTI]

    Sun, Rai Ko S.F. (Albany, CA)

    1994-01-01T23:59:59.000Z

    A device for measuring dose equivalents in neutron radiation fields. The device includes nested symmetrical hemispheres (forming spheres) of different neutron moderating materials that allow the measurement of dose equivalents from 0.025 eV to past 1 GeV. The layers of moderating material surround a spherical neutron counter. The neutron counter is connected by an electrical cable to an electrical sensing means which interprets the signal from the neutron counter in the center of the moderating spheres. The spherical shape of the device allows for accurate measurement of dose equivalents regardless of its positioning.

  12. Semiconductor neutron detector

    DOE Patents [OSTI]

    Ianakiev, Kiril D. (Los Alamos, NM); Littlewood, Peter B. (Cambridge, GB); Blagoev, Krastan B. (Arlington, VA); Swinhoe, Martyn T. (Los Alamos, NM); Smith, James L. (Los Alamos, NM); Sullivan, Clair J. (Los Alamos, NM); Alexandrov, Boian S. (Los Alamos, NM); Lashley, Jason Charles (Santa Fe, NM)

    2011-03-08T23:59:59.000Z

    A neutron detector has a compound of lithium in a single crystal form as a neutron sensor element. The lithium compound, containing improved charge transport properties, is either lithium niobate or lithium tantalate. The sensor element is in direct contact with a monitor that detects an electric current. A signal proportional to the electric current is produced and is calibrated to indicate the neutrons sensed. The neutron detector is particularly useful for detecting neutrons in a radiation environment. Such radiation environment may, e.g. include gamma radiation and noise.

  13. High energy neutron dosimeter

    DOE Patents [OSTI]

    Rai, K.S.F.

    1994-01-11T23:59:59.000Z

    A device for measuring dose equivalents in neutron radiation fields is described. The device includes nested symmetrical hemispheres (forming spheres) of different neutron moderating materials that allow the measurement of dose equivalents from 0.025 eV to past 1 GeV. The layers of moderating material surround a spherical neutron counter. The neutron counter is connected by an electrical cable to an electrical sensing means which interprets the signal from the neutron counter in the center of the moderating spheres. The spherical shape of the device allows for accurate measurement of dose equivalents regardless of its positioning. 2 figures.

  14. The Neutron Lifetime

    E-Print Network [OSTI]

    F. E. Wietfeldt

    2014-11-13T23:59:59.000Z

    The decay of the free neutron into a proton, electron, and antineutrino is the prototype semileptonic weak decay and the simplest example of nuclear beta decay. The nucleon vector and axial vector weak coupling constants G_V and G_A determine the neutron lifetime as well as the strengths of weak interaction processes involving free neutrons and protons that are important in astrophysics, cosmology, solar physics and neutrino detection. In combination with a neutron decay angular correlation measurement, the neutron lifetime can be used to determine the first element of the CKM matrix Vud. Unfortunately the two main experimental methods for measuring the neutron lifetime currently disagree by almost 4 sigma. I will present a brief review of the status of the neutron lifetime and prospects for the future.

  15. Exploration of the neutron-rich mass surface from sup 11 Li to sup 66 Fe

    SciTech Connect (OSTI)

    Vieira, D.J.; Wouters, J.M.; Butler, G.W. (Los Alamos National Lab., NM (United States)); Seifert, H.L. (Los Alamos National Lab., NM (United States) Giessen Univ. (Germany). 2. Physikalisches Inst.); Zhou, Z.Y. (Los Alamos National Lab., NM (United States) Nanjing Univ., JS (China). Dept. of Physics and Astronomy); Zhou, X.G.; Tu, X.L.; Lind, V.G. (Utah State Univ., Logan, UT (United States). Dept.

    1991-01-01T23:59:59.000Z

    A small revolution in our ability to perform mass measurements of light-mass, neutron-rich nuclei has occurred during the last five years with the extension of the direct, total mass measurement method to fast recoiling nuclei. To date the work of two groups, one using the SPEG spectrometer at GANIL and the other using the TOFI spectrometer at LAMPF, has yielded over 85 mass measurements of which 62 had not been reported previously. Extending from the neutron-halo nucleus {sup 11}Li up to {sup 66}Fe, a region relevant to the astrophysical r-process, these measurements have provided a valuable first glimpse into the interesting nuclear structure present in many of these exotic nuclei. Herein we highlight the nuclear structure insight which as been gained from these measurements, especially that learned from a comparison to recent shell model calculations. Attention is given to: (1) the binding of loosely-bound neutron halo nuclei; (2) the N=14--16 region in the neutron-rich isotopes of O, F, and Ne where the strong two-body interaction plays an important role; (3) the deformed intruder state region around {sup 31}Na of long standing interest; (4) the neutron-rich isotopes of sulfur and chlorine; and (5) the question of the isospin dependence (or independence) of neutron and proton pairing energies in the fp shell. Only the briefest account of this work can be given here; emphasis is placed on the most recent results. 24 refs., 3 figs.

  16. Exploration of the neutron-rich mass surface from {sup 11}Li to {sup 66}Fe

    SciTech Connect (OSTI)

    Vieira, D.J.; Wouters, J.M.; Butler, G.W. [Los Alamos National Lab., NM (United States); Seifert, H.L. [Los Alamos National Lab., NM (United States)]|[Giessen Univ. (Germany). 2. Physikalisches Inst.; Zhou, Z.Y. [Los Alamos National Lab., NM (United States)]|[Nanjing Univ., JS (China). Dept. of Physics and Astronomy; Zhou, X.G.; Tu, X.L.; Lind, V.G. [Utah State Univ., Logan, UT (United States). Dept. of Physics; Loebner, K.E.G. [Muenchen Univ. (Germany). Sektion Physik

    1991-12-01T23:59:59.000Z

    A small revolution in our ability to perform mass measurements of light-mass, neutron-rich nuclei has occurred during the last five years with the extension of the direct, total mass measurement method to fast recoiling nuclei. To date the work of two groups, one using the SPEG spectrometer at GANIL and the other using the TOFI spectrometer at LAMPF, has yielded over 85 mass measurements of which 62 had not been reported previously. Extending from the neutron-halo nucleus {sup 11}Li up to {sup 66}Fe, a region relevant to the astrophysical r-process, these measurements have provided a valuable first glimpse into the interesting nuclear structure present in many of these exotic nuclei. Herein we highlight the nuclear structure insight which as been gained from these measurements, especially that learned from a comparison to recent shell model calculations. Attention is given to: (1) the binding of loosely-bound neutron halo nuclei; (2) the N=14--16 region in the neutron-rich isotopes of O, F, and Ne where the strong two-body interaction plays an important role; (3) the deformed intruder state region around {sup 31}Na of long standing interest; (4) the neutron-rich isotopes of sulfur and chlorine; and (5) the question of the isospin dependence (or independence) of neutron and proton pairing energies in the fp shell. Only the briefest account of this work can be given here; emphasis is placed on the most recent results. 24 refs., 3 figs.

  17. Neutron spectrometry - An essential tool for diagnosing implosions at the National Ignition Facility

    SciTech Connect (OSTI)

    Mackinnon, A J; Johnson, M G; Frenje, J A; Casey, D T; Li, C K; Seguin, F H; Petrasso, R; Ashabranner, R; Cerjan, C; Clancy, T J; Bionta, R; Bleuel, D; Bond, E J; Caggiano, J A; Capenter, A; Eckart, M J; Edwards, M J; Friedrich, S; Glenzer, S H; Haan, S W; Hartouni, E P; Hatarik, R; Hachett, S P; McKernan, M; Jones, O; Lepape, S; Lerche, R A; Landen, O L; Moran, M; Moses, E; Munro, D; McNaney, J; Rygg, J R; Sepke, S; Spears, B; Springer, P; Yeamans, C; Farrell, M; Kilkenny, J D; Nikroo, A; Paguio, R; Knauer, J; Glebov, V; Sangster, T; Betti, R; Stoeckl, C; Magoon, J; Shoup, M J; Grim, G P; Moran, G L; Murphy, T J; Leeper, R J; Ruiz, C

    2012-05-02T23:59:59.000Z

    DT neutron yield (Y{sub n}), ion temperature (T{sub i}) and down-scatter ratio (dsr) determined from measured neutron spectra are essential metrics for diagnosing the performance of Inertial Confinement Fusion (ICF) implosions at the National Ignition Facility (NIF). A suite of neutron-Time-Of-Flight (nTOF) spectrometers and a Magnetic Recoil Spectrometer (MRS) have been implemented in different locations around the NIF target chamber, providing good implosion coverage and the redundancy required for reliable measurements of Yn, Ti and dsr. From the measured dsr value, an areal density ({rho}R) is determined from the relationship {rho}R{sub tot} (g/cm{sup 2}) = (20.4 {+-} 0.6) x dsr{sub 10-12 MeV}. The proportionality constant is determined considering implosion geometry, neutron attenuation and energy range used for the dsr measurement. To ensure high accuracy in the measurements, a series of commissioning experiments using exploding pushers have been used for in situ calibration. The spectrometers are now performing to the required accuracy, as indicated by the good agreement between the different measurements over several commissioning shots. In addition, recent data obtained with the MRS and nTOFs indicate that the implosion performance of cryogenically layered DT implosions, characterized by the experimental Ignition Threshold Factor (ITFx) which is a function of dsr (or fuel {rho}R) and Y{sub n}, has improved almost two orders of magnitude since the first shot in September, 2010.

  18. Open-split interface for mass spectrometers

    DOE Patents [OSTI]

    Diehl, John W. (Grand Forks, ND)

    1991-01-01T23:59:59.000Z

    An open-split interface includes a connector body having four leg members projecting therefrom within a single plane, the first and third legs being coaxial and the second and fourth legs being coaxial. A tubular aperture extends through the first and third legs and a second tubular aperture extends through the second and fourth legs, connecting at a juncture within the center of the connector body. A fifth leg projects from the connector body and has a third tubular aperture extending therethrough to the juncture of the first and second tubular apertures. A capillary column extends from a gas chromatograph into the third leg with its end adjacent the juncture. A flow restrictor tube extends from a mass spectrometer through the first tubular aperture in the first and third legs and into the capillary columnm end, so as to project beyond the end of the third leg within the capillary column. An annular gap between the tube and column allows excess effluent to pass to the juncture. A pair of short capillary columns extend from separate detectors into the second tubular aperture in the second and fourth legs, and are oriented with their ends spaced slightly from the first capillary column end. A sweep flow tube is mounted in the fifth leg so as to supply a helium sweep flow to the juncture.

  19. The High-Acceptance Dielectron Spectrometer HADES

    E-Print Network [OSTI]

    The HADES Collaboration; G. Agakishiev; A. Balanda; B. Bannier; R. Bassini; D. Belver; A. V. Belyaev; A. Blanco; M. Boehmer; J. L. Boyard; P. Braun-Munzinger; P. Cabanelas; E. Castro; S. Chernenko; T. Christ; M. Destefanis; J. Diaz; F. Dohrmann; A. Dybczak; T. Eberl; W. Enghardt; L. Fabbietti; O. V. Fateev; P. Finocchiaro; P. Fonte; J. Friese; I. Froehlich; T. Galatyuk; J. A. Garzon; R. Gernhaeuser; A. Gil; C. Gilardi; M. Golubeva; D. Gonzalez-Diaz; F. Guber; M. Heilmann; T. Heinz; T. Hennino; R. Holzmann; A. Ierusalimov; I. Iori; A. Ivashkin; M. Jurkovic; B. Kaempfer; K. Kanaki; T. Karavicheva; D. Kirschner; I. Koenig; W. Koenig; B. W. Kolb; R. Kotte; F. Krizek; R. Kruecken; W. Kuehn; A. Kugler; A. Kurepin; S. Lang; J. S. Lange; K. Lapidus; T. Liu; L. Lopes; M. Lorenz; L. Maier; A. Mangiarotti; J. Markert; V. Metag; B. Michalska; J. Michel; D. Mishra; E. Moriniere; J. Mousa; C. Muentz; L. Naumann; J. Otwinowski; Y. C. Pachmayer; M. Palka; Y. Parpottas; V. Pechenov; O. Pechenova; T. PerezCavalcanti; J. Pietraszko; W. Przygoda; B. Ramstein; A. Reshetin; M. Roy-Stephan; A. Rustamov; A. Sadovsky; B. Sailer; P. Salabura; A. Schmah; E. Schwab; Yu. G. Sobolev; S. Spataro; B. Spruck; H. Stroebele; J. Stroth; C. Sturm; M. Sudol; A. Tarantola; K. Teilab; P. Tlusty; M. Traxler; R. Trebac; H. Tsertos; V. Wagner; M. Weber; M. Wisniowski; T. Wojcik; J. Wuestenfel; S. Yurevich; Y. V. Zanevsky; P. Zhou; P. Zumbruch

    2009-03-09T23:59:59.000Z

    HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion induced collisions. Its main features include a ring imaging gas Cherenkov detector for electron-hadron discrimination, a tracking system consisting of a set of 6 superconducting coils producing a toroidal field and drift chambers and a multiplicity and electron trigger array for additional electron-hadron discrimination and event characterization. A two-stage trigger system enhances events containing electrons. The physics program is focused on the investigation of hadron properties in nuclei and in the hot and dense hadronic matter. The detector system is characterized by an 85% azimuthal coverage over a polar angle interval from 18 to 85 degree, a single electron efficiency of 50% and a vector meson mass resolution of 2.5%. Identification of pions, kaons and protons is achieved combining time-of-flight and energy loss measurements over a large momentum range. This paper describes the main features and the performance of the detector system.

  20. The EUV Imaging Spectrometer for Hinode

    SciTech Connect (OSTI)

    Culhane,J.; Harra, L.; James, A.; Al-Janabi, K.; Bradley, L.; Chaudry, R.; Rees, K.; Tandy, J.; Thomas, P.; et al

    2007-01-01T23:59:59.000Z

    The EUV Imaging Spectrometer (EIS) on Hinode will observe solar corona and upper transition region emission lines in the wavelength ranges 170?-?210 Angstroms and 250?-?290 Angstroms . The line centroid positions and profile widths will allow plasma velocities and turbulent or non-thermal line broadenings to be measured. We will derive local plasma temperatures and densities from the line intensities. The spectra will allow accurate determination of differential emission measure and element abundances within a variety of corona and transition region structures. These powerful spectroscopic diagnostics will allow identification and characterization of magnetic reconnection and wave propagation processes in the upper solar atmosphere. We will also directly study the detailed evolution and heating of coronal loops. The EIS instrument incorporates a unique two element, normal incidence design. The optics are coated with optimized multilayer coatings. We have selected highly efficient, backside-illuminated, thinned CCDs. These design features result in an instrument that has significantly greater effective area than previous orbiting EUV spectrographs with typical active region 2?-?5 s exposure times in the brightest lines. EIS can scan a field of 6x8.5 arc?min with spatial and velocity scales of 1 arc?sec and 25 km?s-1 per pixel. The instrument design, its absolute calibration, and performance are described in detail in this paper. EIS will be used along with the Solar Optical Telescope (SOT) and the X-ray Telescope (XRT) for a wide range of studies of the solar atmosphere.

  1. Neutron Compound Refractive Prisms - DOE SBIR Phase II Final Report

    SciTech Connect (OSTI)

    Dr. Jay Theodore Cremer, Jr

    2011-06-25T23:59:59.000Z

    The results of the research led to a pulsed electromagnetic periodic magnetic field array (PMF), which coupled with a pair of collimation slits, and a mechanical chopper slit, were able to deflect spin-up neutrons to a band of line-fused neutrons a focal plane heights that correspond to the time-varying magnetic field amplitude. The electromagnetic field PMF produced 5.4 pulses per minute in which each pulse was 50 msec in duration with a full width half maximum (FWHM) of 7.5 msec. The calculated 7.7 mm vertical height of the band of focused spin-up neutrons corresponded closely to the measured 7.5 mm height of the center line of the imaged band of neutrons. The band of deflected spin-up neutrons was 5 mm in vertical width and the bottom of the band was 5 mm above the surface of the PMF pole. The limited exposure time of 3 hours and the smaller 0.78 T magnetic field allowed focused and near focused neutrons of 1.8 ���� to 2.6 ���� neutrons, which were in the tails of the McClellan Nuclear Radiation Center Bay 4 Maxwell Boltzmann distribution of neutrons with peak flux at 1.1-1.2 ����. The electromagnetic PMF was expected to produces a 2.0 T peak magnetic field amplitude, which would be operational at a higher duty factor, rather than the as built 7.5 msec FWHM with pulse repetition frequency of 5.4 pulses per minute. The fabricated pulsed electromagnetic PMF with chopper is expected to perform well on a cold, very cold or ultra cold beam line as a spectrometer or monochromator source of spin-up polarized neutron. In fact there may be a possible use of the PMF to do ultra-cold neutron trapping, see paper by A. I. Frank1, V. G. Nosov, Quantum Effects in a One-Dimensional Magnetic Gravitational Trap for Ultracold Neutrons, JETP Letters, Vol. 79, No. 7, 2004, pp. 313�¢����315. The next step is to find a cold or very cold neutron facility, where further testing or use of the pulsed magnetic field PMF can be pursued.

  2. Ion spectrometer composed of time-of-flight and Thomson parabola spectrometers for simultaneous characterization of laser-driven ions

    SciTech Connect (OSTI)

    Choi, I. W.; Kim, C. M.; Sung, J. H.; Yu, T. J.; Lee, S. K.; Kim, I. J.; Jin, Y.-Y.; Jeong, T. M.; Hafz, N.; Pae, K. H.; Noh, Y.-C.; Ko, D.-K.; Lee, J. [Advanced Photonics Research Institute and Center for Femto-Atto Science and Technology, GIST, Gwangju 500-712 (Korea, Republic of); Yogo, A.; Pirozhkov, A. S.; Ogura, K.; Orimo, S.; Sagisaka, A.; Nishiuchi, M.; Daito, I. [Advanced Photon Research Center and Photo Medical Research Center, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215 (Japan); and others

    2009-05-15T23:59:59.000Z

    An ion spectrometer, composed of a time-of-flight spectrometer (TOFS) and a Thomson parabola spectrometer (TPS), has been developed to measure energy spectra and to analyze species of laser-driven ions. Two spectrometers can be operated simultaneously, thereby facilitate to compare the independently measured data and to combine advantages of each spectrometer. Real-time and shot-to-shot characterizations have been possible with the TOFS, and species of ions can be analyzed with the TPS. The two spectrometers show very good agreement of maximum proton energy even for a single laser shot. The composite ion spectrometer can provide two complementary spectra measured by TOFS with a large solid angle and TPS with a small one for the same ion source, which are useful to estimate precise total ion number and to investigate fine structure of energy spectrum at high energy depending on the detection position and solid angle. Advantage and comparison to other online measurement system, such as the TPS equipped with microchannel plate, are discussed in terms of overlay of ion species, high-repetition rate operation, detection solid angle, and detector characteristics of imaging plate.

  3. BNL ACTIVITIES IN ADVANCED NEUTRON SOURCE DEVELOPMENT: PAST AND PRESENT

    SciTech Connect (OSTI)

    HASTINGS,J.B.; LUDEWIG,H.; MONTANEZ,P.; TODOSOW,M.; SMITH,G.C.; LARESE,J.Z.

    1998-06-14T23:59:59.000Z

    Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In the sections below the authors discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

  4. BNL Activities in Advanced Neutron Source Development: Past and Present

    SciTech Connect (OSTI)

    Hastings, J.B.; Ludewig, H.; Montanez, P.; Todosow, M.; Smith, G.C.; Larese, J.Z.

    1998-06-14T23:59:59.000Z

    Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In this report we discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

  5. Neutron sources and applications

    SciTech Connect (OSTI)

    Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    1994-01-01T23:59:59.000Z

    Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

  6. Spallation-neutron sources

    SciTech Connect (OSTI)

    Michaudon, A.

    1997-09-01T23:59:59.000Z

    Of particular interest for neutron-physics studies are spallation-neutron sources (SNSs) using intense proton beams with energies in the GeV range. Some SNSs already provide average fluxes of thermal and cold neutrons comparable with those of high-flux reactors. Most SNSs are pulsed with high peak fluxes that can be used with the powerful time-of-flight (TOF) method. Also, SNSs could be developed to much higher performance.

  7. Single-ultrafine-particle mass spectrometer development and application

    E-Print Network [OSTI]

    Glagolenko, Stanislav Yurievich

    2004-11-15T23:59:59.000Z

    A single-ultrafine-particle mass spectrometer was constructed and deployed for size-resolved ultrafine aerosol composition measurements during the winter of 2002-2003 in College Station, Texas. Three separate experiments were held between December...

  8. Tunable light source for use in photoacoustic spectrometers

    DOE Patents [OSTI]

    Bisson, Scott E.; Kulp, Thomas J.; Armstrong, Karla M.

    2005-12-13T23:59:59.000Z

    The present invention provides a photoacoustic spectrometer that is field portable and capable of speciating complex organic molecules in the gas phase. The spectrometer has a tunable light source that has the ability to resolve the fine structure of these molecules over a large wavelength range. The inventive light source includes an optical parametric oscillator (OPO) having combined fine and coarse tuning. By pumping the OPO with the output from a doped-fiber optical amplifier pumped by a diode seed laser, the inventive spectrometer is able to speciate mixtures having parts per billion of organic compounds, with a light source that has a high efficiency and small size, allowing for portability. In an alternative embodiment, the spectrometer is scanned by controlling the laser wavelength, thus resulting in an even more compact and efficient design.

  9. airborne imaging spectrometer: Topics by E-print Network

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

    ADC dynamic range, because the low-energy pulse signal has a larger gain than the high-energy pulse signal. The spectrometer can clearly distinguish the photopeaks at 239, 352,...

  10. TRACES Centre Thermo GFS35 Graphite Furnace Spectrometer

    E-Print Network [OSTI]

    Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

    TRACES Centre Thermo GFS35 Graphite Furnace Spectrometer Standard Operating Procedure 1. Turn. Click on the lamp icon a. ID the lamp of choice and click the `Off' button to `On' b. Non-Thermo lamps

  11. TRACES Centre Thermo iCE 3500 Flame AA Spectrometer

    E-Print Network [OSTI]

    Wells, Mathew G. - Department of Physical and Environmental Sciences, University of Toronto

    TRACES Centre Thermo iCE 3500 Flame AA Spectrometer Standard Operating Procedure 1. Turn on the lamp icon a. ID the lamp of choice and click the `Off' button to `On' b. Non-Thermo lamps MUST

  12. The FIRE infrared spectrometer at Magellan: construction and commissioning

    E-Print Network [OSTI]

    Simcoe, Robert A.

    We describe the construction and commissioning of FIRE, a new 0.8-2.5?m echelle spectrometer for the Magellan/ Baade 6.5 meter telescope. FIRE delivers continuous spectra over its full bandpass with nominal spectral ...

  13. atomic absorption spectrometer: Topics by E-print Network

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

    absorption spectrometer First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Educational Multiwavelength...

  14. Periodic magnetic fieldas a polarized and focusing thermal neutron spectrometer and monochromator

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    B828?. The aluminum spacers had dimensions 12.7 ? 2.54? 12.7magnet pole dimension ?axial width? Aluminum spacer width

  15. Neutron Science Forum | ORNL

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

    environment for discussion, innovation, and dissemination of information within the neutron scattering community as well as engaging closely related disciplines through...

  16. Lujan Neutron Scattering Center

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

    the inadvertent spread of Technetium 99 by employees and contractors at the Lujan Neutron Scattering Center August 27, 2012-The Laboratory is investigating the inadvertent...

  17. C-III flow measurements with a coherence imaging spectrometer

    SciTech Connect (OSTI)

    Weber, T. R.; Allen, S. L. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Howard, J. [Australian National University, Canberra, ACT 0200 (Australia)

    2012-10-15T23:59:59.000Z

    This work describes a coherence imaging spectrometer capable of making spatially resolved CIII flow measurements in the DIII-D lower divertor. The spectrometer exploits a periscope view of the plasma to produce line-of-sight averaged velocity measurements of CIII. From these chord averaged flow measurements, a 2D poloidal cross section of the CIII flow is tomographically reconstructed. Details of the diagnostic setup, acquired data, and data analysis will be presented, along with prospects for future applications.

  18. User's guide for revised SPEC-4 neutron spectrum unfolding code

    SciTech Connect (OSTI)

    Johnson, J.O.; Ingersoll, D.T.

    1980-08-01T23:59:59.000Z

    The SPEC-4 computer code was developed in the United Kingdom to solve the spectrum unfolding problem for spherical gas-filled proton-recoil neutron spectrometers. This report describes the ORNL version of SPEC-4 which has been applied to the analysis of data from the Tower Shielding Facility. Recent modifications are described which largely pertain to the graphical output routines. In addition, the input requirements are presented in considerable detail including suggestions and recommendations based on actual operating experience. Finally, auxiliary programs are discussed which can aid the SPEC-4 user.

  19. Neutron resonance spin flippers: Static coils manufactured by electrical discharge machining

    SciTech Connect (OSTI)

    Martin, N.; Kredler, L.; Häußler, W. [Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching (Germany); Physik-Department E21, Technische Universität München, 85748 Garching (Germany); Wagner, J. N. [Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Dogu, M.; Fuchs, C. [Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching (Germany); Böni, P. [Physik-Department E21, Technische Universität München, 85748 Garching (Germany)

    2014-07-15T23:59:59.000Z

    Radiofrequency spin flippers (RFSF) are key elements of Neutron Resonance Spin Echo (NRSE) spectrometers, which allow performing controlled manipulations of the beam polarization. We report on the design and test of a new type of RFSF which originality lies in the new manufacturing technique for the static coil. The largely automated procedure ensures reproducible construction as well as an excellent homogeneity of the neutron magnetic resonance condition over the coil volume. Two salient features of this concept are the large neutron window and the closure of the coil by a ?-metal yoke which prevents field leakage outside of the coil volume. These properties are essential for working with large beams and enable new applications with coils tilted with respect to the beam axis such as neutron Larmor diffraction or the study of dispersive excitations by inelastic NRSE.

  20. Mechanical Research and Development of monocrystalline silicon neutron beam window for CSNS

    E-Print Network [OSTI]

    Zhou Liang; Qu Hua-Min

    2014-11-24T23:59:59.000Z

    The monocrystalline silicon neutron beam window is one of the key components of neutron spectrometers and thin circular plate.Monocrystalline silicon is a brittle material and its strength is not constant but is consistent with the Weibull distribution. The window is designed not simply through the average strength, but according to the survival rate. Bending deformation is the main form of the window, so dangerous parts of the neutron beam window is stress-linearized to the combination of membrane stress and bending stress. According to the Weibull distribution of bending strength of monocrystalline silicon based on a large number of experimental data, finally the optimized neutron beam window is 1.5mm thick. Its survival rate is 0.9994 and its transmittance is 0.98447; it meets both physical requirements and the mechanical strength.

  1. Neutron Emission Characteristics of Two Mixed-Oxide Fuels: Simulations and Initial Experiments

    SciTech Connect (OSTI)

    D. L. Chichester; S. A. Pozzi; J. L. Dolan; M. Flaska; J. T. Johnson; E. H. Seabury; E. M. Gantz

    2009-07-01T23:59:59.000Z

    Simulations and experiments have been carried out to investigate the neutron emission characteristics of two mixed-oxide (MOX) fuels at Idaho National Laboratory (INL). These activities are part of a project studying advanced instrumentation techniques in support of the U.S. Department of Energy's Fuel Cycle Research and Development program and it's Materials Protection, Accounting, and Control for Transmutation (MPACT) campaign. This analysis used the MCNP-PoliMi Monte Carlo simulation tool to determine the relative strength and energy spectra of the different neutron source terms within these fuels, and then used this data to simulate the detection and measurement of these emissions using an array of liquid scintillator neutron spectrometers. These calculations accounted for neutrons generated from the spontaneous fission of the actinides in the MOX fuel as well as neutrons created via (alpha,n) reactions with oxygen in the MOX fuel. The analysis was carried out to allow for characterization of both neutron energy as well as neutron coincidences between multiple detectors. Coincidences between prompt gamma rays and neutrons were also analyzed. Experiments were performed at INL with the same materials used in the simulations to benchmark and begin validation tests of the simulations. Data was collected in these experiments using an array of four liquid scintillators and a high-speed waveform digitizer. Advanced digital pulse-shape discrimination algorithms were developed and used to collect this data. Results of the simulation and modeling studies are presented together with preliminary results from the experimental campaign.

  2. HFIR History - ORNL Neutron Sciences

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

    has grown to include materials irradiation, neutron activation, and, most recently, neutron scattering. In 2007, HFIR completed the most dramatic transformation in its...

  3. Compact neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Lou, Tak Pui

    2005-03-22T23:59:59.000Z

    A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

  4. Neutron capture therapies

    DOE Patents [OSTI]

    Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

    1999-01-01T23:59:59.000Z

    In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

  5. Measurement of the Neutron electric form factor at Q2=0.8 2(GeV\\\\c)

    SciTech Connect (OSTI)

    Derek Glazier

    2007-09-30T23:59:59.000Z

    Nucleon form factors allow a sensitive test for models of the nucleon. Recent experiments utilising polarisation observables have resulted, for the first time, in a model-independent determination of the neutron electric form factor GnE. This method employed an 80% longitudinally polarised, high intensity (10 uA) electon beam (883 MeV) that was quasi-elastically scattered off a liquid deuterium target in the reaction D (e, en)p. A neutron polarimeter was designed and installed to measure the ratio of transverse-to-longitudinal polarisation using neutron scattering asymmetries. This ratio allowed a determination of the neutron elastic form factor, GnE, free of the previous large systematic uncertainties associated with the deuterium wave function. The experiment took place in the A1 experimental hall at MAMI taking advantage of a high resolution magnetic spectrometer. A detailed investigation was carried out into the performance of the neutron polarimeter.

  6. Pocked surface neutron detector

    DOE Patents [OSTI]

    McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

    2003-04-08T23:59:59.000Z

    The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

  7. Pulsed neutron detector

    DOE Patents [OSTI]

    Robertson, deceased, J. Craig (late of Albuquerque, NM); Rowland, Mark S. (Livermore, CA)

    1989-03-21T23:59:59.000Z

    A pulsed neutron detector and system for detecting low intensity fast neutron pulses has a body of beryllium adjacent a body of hydrogenous material the latter of which acts as a beta particle detector, scintillator, and moderator. The fast neutrons (defined as having En>1.5 MeV) react in the beryllium and the hydrogenous material to produce larger numbers of slow neutrons than would be generated in the beryllium itself and which in the beryllium generate hellium-6 which decays and yields beta particles. The beta particles reach the hydrogenous material which scintillates to yield light of intensity related to the number of fast neutrons. A photomultiplier adjacent the hydrogenous material (scintillator) senses the light emission from the scintillator. Utilization means, such as a summing device, sums the pulses from the photo-multiplier for monitoring or other purposes.

  8. SINGLE CRYSTAL NEUTRON DIFFRACTION.

    SciTech Connect (OSTI)

    KOETZLE,T.F.

    2001-03-13T23:59:59.000Z

    Single-crystal neutron diffraction measures the elastic Bragg reflection intensities from crystals of a material, the structure of which is the subject of investigation. A single crystal is placed in a beam of neutrons produced at a nuclear reactor or at a proton accelerator-based spallation source. Single-crystal diffraction measurements are commonly made at thermal neutron beam energies, which correspond to neutron wavelengths in the neighborhood of 1 Angstrom. For high-resolution studies requiring shorter wavelengths (ca. 0.3-0.8 Angstroms), a pulsed spallation source or a high-temperature moderator (a ''hot source'') at a reactor may be used. When complex structures with large unit-cell repeats are under investigation, as is the case in structural biology, a cryogenic-temperature moderator (a ''cold source'') may be employed to obtain longer neutron wavelengths (ca. 4-10 Angstroms). A single-crystal neutron diffraction analysis will determine the crystal structure of the material, typically including its unit cell and space group, the positions of the atomic nuclei and their mean-square displacements, and relevant site occupancies. Because the neutron possesses a magnetic moment, the magnetic structure of the material can be determined as well, from the magnetic contribution to the Bragg intensities. This latter aspect falls beyond the scope of the present unit; for information on magnetic scattering of neutrons see Unit 14.3. Instruments for single-crystal diffraction (single-crystal diffractometers or SCDs) are generally available at the major neutron scattering center facilities. Beam time on many of these instruments is available through a proposal mechanism. A listing of neutron SCD instruments and their corresponding facility contacts is included in an appendix accompanying this unit.

  9. Total absorption {gamma}-ray spectroscopy of beta delayed neutron emitters

    SciTech Connect (OSTI)

    Valencia, E.; Algora, A.; Tain, J. L.; Agramunt, J.; Jordan, M. D.; Molina, F.; Estevez, E.; Rubio, B.; Perez, A. [IFIC, CSIC - Univ. Valencia, Valencia (Spain); Rice, S.; Bowry, M.; Gelletly, W.; Podolyak, Zs.; Regan, P. H.; Farrelly, G. F. [Univ. Surrey, Guildford (United Kingdom); Zakari-Issoufou, A.-A.; Porta, A.; Fallot, M.; Bui, V. M. [Subatech, CNRS/INP2P3, Nantes, EMN, Nantes (France); Caballero-Folch, R. [Univ. Pol. Catalunya, Barcelona (Spain); and others

    2013-06-10T23:59:59.000Z

    Preliminary results of the data analysis of the beta decay of {sup 94}Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above.

  10. A compact proton spectrometer for measurement of the absolute DD proton spectrum from which yield and pR are determined in thin-shell inertial-confinement-fusion implosions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rosenberg, M. J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Zylstra, A. B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Frenje, J. A. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Rinderknecht, H. G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Gatu Johnson, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Waugh, C. J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Seguin, F. H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Sio, H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Sinenian, N. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Li, C. K. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Petrasso, R. D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Plasma Science and Fusion Center; Glebov, V. Yu. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Hohenberger, M. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Stoeckl, C. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Sangster, T. C. [Univ. of Rochester, NY (United States). Lab. for Laser Energetics; Yeamans, C. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); LePape, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mackinnon, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bionta, R. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Talison, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Casey, D. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Landen, O. L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Moran, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zacharias, R. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kilkenny, J. D. [General Atomics, San Diego, CA (United States); Nikroo, A. [General Atomics, San Diego, CA (United States)

    2014-10-01T23:59:59.000Z

    A compact, step range filter proton spectrometer has been developed for the measurement of the absolute DD proton spectrum, from which yield and areal density (?R) are inferred for deuterium-filled thin-shell inertial confinement fusion implosions. This spectrometer, which is based on tantalum step-range filters, is sensitive to protons in the energy range 1-9 MeV and can be used to measure proton spectra at mean energies of ~1-3 MeV. It has been developed and implemented using a linear accelerator and applied to experiments at the OMEGA laser facility and the National Ignition Facility (NIF). Modeling of the proton slowing in the filters is necessary to construct the spectrum, and the yield and energy uncertainties are ±<10% in yield and ±120 keV, respectively. This spectrometer can be used for in situ calibration of DD-neutron yield diagnostics at the NIF

  11. EXTENDING THE USEFUL LIFE OF OLDER MASS SPECTROMETERS

    SciTech Connect (OSTI)

    Johnson, S.; Cordaro, J.; Holland, M.; Jones, V.

    2010-06-17T23:59:59.000Z

    Thermal ionization and gas mass spectrometers are widely used across the Department of Energy (DOE) Complex and contractor laboratories. These instruments support critical missions, where high reliability and low measurement uncertainty are essential. A growing number of these mass spectrometers are significantly older than their original design life. The reality is that manufacturers have declared many of the instrument models obsolete, with direct replacement parts and service no longer available. Some of these obsolete models do not have a next generation, commercially available replacement. Today's budget conscious economy demands for the use of creative funds management. Therefore, the ability to refurbish (or upgrade) these valuable analytical tools and extending their useful life is a cost effective option. The Savannah River Site (SRS) has the proven expertise to breathe new life into older mass spectrometers, at a significant cost savings compared to the purchase and installation of new instruments. A twenty-seven year old Finnigan MAT-261{trademark} Thermal Ionization Mass Spectrometer (TIMS), located at the SRS F/H Area Production Support Laboratory, has been successfully refurbished. Engineers from the Savannah River National Laboratory (SRNL) fabricated and installed the new electronics. These engineers also provide continued instrument maintenance services. With electronic component drawings being DOE Property, other DOE Complex laboratories have the option to extend the life of their aged Mass Spectrometers.

  12. Method for increasing the dynamic range of mass spectrometers

    DOE Patents [OSTI]

    Belov, Mikhail; Smith, Richard D.; Udseth, Harold R.

    2004-09-07T23:59:59.000Z

    A method for enhancing the dynamic range of a mass spectrometer by first passing a sample of ions through the mass spectrometer having a quadrupole ion filter, whereupon the intensities of the mass spectrum of the sample are measured. From the mass spectrum, ions within this sample are then identified for subsequent ejection. As further sampling introduces more ions into the mass spectrometer, the appropriate rf voltages are applied to a quadrupole ion filter, thereby selectively ejecting the undesired ions previously identified. In this manner, the desired ions may be collected for longer periods of time in an ion trap, thus allowing better collection and subsequent analysis of the desired ions. The ion trap used for accumulation may be the same ion trap used for mass analysis, in which case the mass analysis is performed directly, or it may be an intermediate trap. In the case where collection is an intermediate trap, the desired ions are accumulated in the intermediate trap, and then transferred to a separate mass analyzer. The present invention finds particular utility where the mass analysis is performed in an ion trap mass spectrometer or a Fourier transform ion cyclotron resonance mass spectrometer.

  13. Hypernuclear Physics for Neutron Stars

    E-Print Network [OSTI]

    Jurgen Schaffner-Bielich

    2008-01-24T23:59:59.000Z

    The role of hypernuclear physics for the physics of neutron stars is delineated. Hypernuclear potentials in dense matter control the hyperon composition of dense neutron star matter. The three-body interactions of nucleons and hyperons determine the stiffness of the neutron star equation of state and thereby the maximum neutron star mass. Two-body hyperon-nucleon and hyperon-hyperon interactions give rise to hyperon pairing which exponentially suppresses cooling of neutron stars via the direct hyperon URCA processes. Non-mesonic weak reactions with hyperons in dense neutron star matter govern the gravitational wave emissions due to the r-mode instability of rotating neutron stars.

  14. The effect of craters on the lunar neutron flux

    E-Print Network [OSTI]

    Eke, V R; Diserens, S; Ryder, M; Yeomans, P E L; Teodoro, L F A; Elphic, R C; Feldman, W C; Hermalyn, B; Lavelle, C M; Lawrence, D J

    2015-01-01T23:59:59.000Z

    The variation of remotely sensed neutron count rates is measured as a function of cratercentric distance using data from the Lunar Prospector Neutron Spectrometer. The count rate, stacked over many craters, peaks over the crater centre, has a minimum near the crater rim and at larger distances it increases to a mean value that is up to 1% lower than the mean count rate observed over the crater. A simple model is presented, based upon an analytical topographical profile for the stacked craters fitted to data from the Lunar Orbiter Laser Altimeter (LOLA). The effect of topography coupled with neutron beaming from the surface largely reproduces the observed count rate profiles. However, a model that better fits the observations can be found by including the additional freedom to increase the neutron emissivity of the crater area by ~0.35% relative to the unperturbed surface. It is unclear what might give rise to this effect, but it may relate to additional surface roughness in the vicinities of craters. The ampl...

  15. Wavelength calibration of the JWST-MIRI medium resolution spectrometer

    E-Print Network [OSTI]

    Martinez-Galarza, J R; Hernan-Caballero, A; Azzollini, R; Glasse, A; Kendrew, S; Brandl, B; Lahuis, F

    2010-01-01T23:59:59.000Z

    We present the wavelength and spectral resolution characterisation of the Integral Field Unit (IFU) Medium Resolution Spectrometer for the Mid-InfraRed Instrument (MIRI), to fly onboard the James Webb Space Telescope in 2014. We use data collected using the Verification Model of the instrument and develop an empirical method to calibrate properties such as wavelength range and resolving power in a portion of the spectrometer's full spectral range (5-28 microns). We test our results against optical models to verify the system requirements and combine them with a study of the fringing pattern in the instrument's detector to provide a more accurate calibration. We show that MIRI's IFU spectrometer will be able to produce spectra with a resolving power above R=2800 in the wavelength range 6.46-7.70 microns, and that the unresolved spectral lines are well fitted by a Gaussian profile.

  16. A mobile Magnetic Sensor Unit for the KATRIN Main Spectrometer

    E-Print Network [OSTI]

    Osipowicz, A; Letnev, J; Marte, P; Müller, A; Spengler, A; Unru, A; 10.1088/1748-0221/7/06/T06002

    2012-01-01T23:59:59.000Z

    The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to measure the electron neutrino mass with an unprecedented sensitivity of 0.2 eV/c2, using b decay electrons from tritium decay. For the control of magnetic field in the main spectrometer area of the KATRIN experiment a mobile magnetic sensor unit is constructed and tested at the KATRIN main spectrometer site. The unit moves on inner rails of the support structures of the low field shaping coils which are arranged along the the main spectrometer. The unit propagates on a caterpillar drive and contains an electro motor, battery pack, board electronics, 2 triaxial flux gate sensors and 2 inclination senors. During operation all relevant data are stored on board and transmitted to the master station after the docking station is reached.

  17. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

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

    1995-12-19T23:59:59.000Z

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

  18. Electron source for a mini ion trap mass spectrometer

    DOE Patents [OSTI]

    Dietrich, Daniel D. (Livermore, CA); Keville, Robert F. (Valley Springs, CA)

    1995-01-01T23:59:59.000Z

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

  19. The MARTE VNIR Imaging Spectrometer Experiment: Design and Analysis

    E-Print Network [OSTI]

    Brown, Adrian J; Dunagan, Stephen

    2014-01-01T23:59:59.000Z

    We report on the design, operation, and data analysis methods employed on the VNIR imaging spectrometer instrument that was part of the Mars Astrobiology Research and Technology Experiment (MARTE). The imaging spectrometer is a hyperspectral scanning pushbroom device sensitive to VNIR wavelengths from 400-1000 nm. During the MARTE project, the spectrometer was deployed to the Rio Tinto region of Spain. We analyzed subsets of 3 cores from Rio Tinto using a new band modeling technique. We found most of the MARTE drill cores to contain predominantly goethite, though spatially coherent areas of hematite were identified in Core 23. We also distinguished non Fe-bearing minerals that were subsequently analyzed by X-ray diffraction (XRD) and found to be primarily muscovite. We present drill core maps that include spectra of goethite, hematite, and non Fe-bearing minerals.

  20. Switchable radioactive neutron source device

    DOE Patents [OSTI]

    Stanford, G.S.; Rhodes, E.A.; Devolpi, A.; Boyar, R.E.

    1987-11-06T23:59:59.000Z

    This invention is a switchable neutron generating apparatus comprised of a pair of plates, the first plate having an alpha emitter section on it and the second plate having a target material portion on it which generates neutrons when its nuclei absorb an alpha particle. In operation, the alpha portion of the first plate is aligned with the neutron portion of the second plate to produce neutrons and brought out of alignment to cease production of neutrons. 3 figs.

  1. Switchable radioactive neutron source device

    DOE Patents [OSTI]

    Boyar, Robert E. (La Grange, IL); DeVolpi, Alexander (Bolingbrook, IL); Stanford, George S. (Downers Grove, IL); Rhodes, Edgar A. (Woodridge, IL)

    1989-01-01T23:59:59.000Z

    This invention is a switchable neutron generating apparatus comprised of a pair of plates, the first plate having an alpha emitter section on it and the second plate having a target material portion on it which generates neutrons when its nuclei absorb an alpha particle. In operation, the alpha portion of the first plate is aligned with the neutron portion of the second plate to produce neutrons and brought out of alignment to cease production of neutrons.

  2. Discrimination of gamma rays due to inelastic neutron scattering in AGATA

    E-Print Network [OSTI]

    A. Ataç; A. Kas¸kas A; S. Akkoyun A; M. S¸enyi?git A; T. Hüyük A; S. O. Kara A; J. Nyberg B

    Possibilities of discriminating neutrons and ? rays in the AGATA ?-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the Geant4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and ? rays from the center of AGATA. Three different methods were developed and tested in order to find “fingerprints ” of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and ten ? rays with energies between 150 and 1450 keV, the peak-to-background ratio at a ?-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25.

  3. LENDA, a Low Energy Neutron Detector Array for experiments with radioactive beams in inverse kinematics

    E-Print Network [OSTI]

    G. Perdikakis; M. Sasano; Sam M. Austin; D. Bazin; C. Caesar; S. Cannon; J. M. Deaven; H. J. Doster; C. J. Guess; G. W. Hitt; J. Marks; R. Meharchand; D. T. Nguyen; D. Peterman; A. Prinke; M. Scott; Y. Shimbara; K. Thorne; L. Valdez; R. G. T. Zegers

    2012-05-21T23:59:59.000Z

    The Low Energy Neutron Detector Array (LENDA) is a neutron time-of-flight (TOF) spectrometer developed at the National Superconducting Cyclotron Lab- oratory (NSCL) for use in inverse kinematics experiments with rare isotope beams. Its design has been motivated by the need to study the spin-isospin response of unstable nuclei using (p, n) charge-exchange reactions at intermediate energies (> 100 MeV/u). It can be used, however, for any reaction study that involves emission of low energy neutrons (150 keV - 10 MeV). The array consists of 24 plastic scintillator bars and is capable of registering the recoiling neutron energy and angle with high detection efficiency. The neutron energy is determined by the time-of-flight technique, while the position of interaction is deduced using the timing and energy information from the two photomultipliers of each bar. A simple test setup utilizing radioactive sources has been used to characterize the array. Results of test measurements are compared with simulations. A neutron energy threshold of efficiency > 20 % for neutrons below 4 MeV have been obtained.

  4. Discrimination of gamma rays due to inelastic neutron scattering in AGATA

    E-Print Network [OSTI]

    A. Ataç; A. Ka?ka?; S. Akkoyun; M. ?enyi?it; T. Hüyük; S. O. Kara; J. Nyberg

    2009-06-10T23:59:59.000Z

    Possibilities of discriminating neutrons and gamma rays in the AGATA gamma-ray tracking spectrometer have been investigated with the aim of reducing the background due to inelastic scattering of neutrons in the high-purity germanium crystals. This background may become a serious problem especially in experiments with neutron-rich radioactive ion beams. Simulations using the Geant4 toolkit and a tracking program based on the forward tracking algorithm were carried out by emitting neutrons and gamma rays from the center of AGATA. Three different methods were developed and tested in order to find 'fingerprints' of the neutron interaction points in the detectors. In a simulation with simultaneous emission of six neutrons with energies in the range 1-5 MeV and ten gamma rays with energies between 150 and 1450 keV, the peak-to-background ratio at a gamma-ray energy of 1.0 MeV was improved by a factor of 2.4 after neutron rejection with a reduction of the photopeak efficiency at 1.0 MeV of only a factor of 1.25.

  5. The NIF x-ray spectrometer calibration campaign at Omega

    SciTech Connect (OSTI)

    Pérez, F.; Kemp, G. E.; Barrios, M. A.; Pino, J.; Scott, H.; Ayers, S.; Chen, H.; Emig, J.; Colvin, J. D.; Fournier, K. B., E-mail: fournier2@llnl.gov [Lawrence Livermore National Laboratory, P. O. Box 808, Livermore, California 94551 (United States); Regan, S. P.; Bedzyk, M.; Shoup, M. J.; Agliata, A.; Yaakobi, B.; Marshall, F. J.; Hamilton, R. A. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Jaquez, J.; Farrell, M.; Nikroo, A. [General Atomics, P.O. Box 85608, San Diego, California 92186 (United States)

    2014-11-15T23:59:59.000Z

    The calibration campaign of the National Ignition Facility X-ray Spectrometer (NXS) was carried out at the OMEGA laser facility. Spherically symmetric, laser-driven, millimeter-scale x-ray sources of K-shell and L-shell emission from various mid-Z elements were designed for the 2–18 keV energy range of the NXS. The absolute spectral brightness was measured by two calibrated spectrometers. We compare the measured performance of the target design to radiation hydrodynamics simulations.

  6. Extended Evaluations of the Commercial Spectrometer Systems for Safeguards Applications

    SciTech Connect (OSTI)

    Duc T. Vo

    1999-08-01T23:59:59.000Z

    Safeguards applications require the best of the spectrometer system with excellent resolution, stability, and throughput. Instruments must perform well in all situations and environments. Data communication to the computer should be convenient, fast, and reliable. The software should have all the necessary tools and be easy to use. Portable systems should be small in size, lightweight, and have a long battery life. Nine commercially available spectrometer systems are tested with five different germanium detectors. Considering the performance of the Digital Signal Processors (DSP), digital-based spectroscope y may become the way of future gamma-ray spectroscopy.

  7. Waveguide-integrated photonic crystal spectrometer with camera readout

    SciTech Connect (OSTI)

    Meng, Fan; Shiue, Ren-Jye; Li, Luozhou; Nie, Jing; Harris, Nicholas C.; Chen, Edward H.; Schröder, Tim; Englund, Dirk, E-mail: englund@mit.edu [Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts 02139 (United States); Wan, Noel [Department of Physics, Columbia University, New York, New York 10027 (United States); Pervez, Nadia [Chromation Partners LLC, 18 Bridge Street Suite 2J, Brooklyn, New York 11201 (United States); Kymissis, Ioannis [Chromation Partners LLC, 18 Bridge Street Suite 2J, Brooklyn, New York 11201 (United States); Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States)

    2014-08-04T23:59:59.000Z

    We demonstrate an infrared spectrometer based on waveguide-coupled nanocavity filters in a planar photonic crystal structure. The input light is coupled into the waveguide, from which spectral components are dropped into the cavities and radiated off-chip for detection on a commercial InGaAs camera. The spectrometer has a footprint of only 60??m by 8??m. The spectral resolution is about 1?nm in the operation bandwidth of 1522–1545?nm. By substituting the membrane material and structure parameters, this design can be easily extended into the visible regime and developed for a variety of highly efficient, miniature photonic applications.

  8. The Results of Recent MICE Superconducting Spectrometer Solenoid Test

    SciTech Connect (OSTI)

    Green, Michael A; Virostek, Steve P.; Zisman, Michael S.

    2010-10-15T23:59:59.000Z

    The MICE spectrometer solenoid magnets will be the first magnets to be installed within the MICE cooling channel. The MICE spectrometer solenoids may be the largest magnets that have been cooled using small two stage coolers. During the previous test of this magnet, the cooler first stage temperatures were too high. The causes of some of the extra first stage heat load has been identified and corrected. The rebuilt magnet had a single stage GM cooler in addition to the three pulse tube coolers. The added cooler reduces the temperature of the top of the HTS leads, the shield and of the first stage of the pulse tube coolers.

  9. A 100-kc modulation system for an EPR microwave spectrometer

    E-Print Network [OSTI]

    Stewart, Frank Edwin

    1964-01-01T23:59:59.000Z

    LIST OF FIGURES FIGURE PAGE II-1 Molecular Structure of DPPH 22 II-2 11-3 III-1 IV-1 Hyperfine Splitting in the DPPH EPR Spectrum . 25 Hyperfine Splitting in the Mn EpR Spectrum , . 27 100-kc Field Modulation and Detection System . 4I Typical... spectrometer. Most EPR spectrometers induce transitions at microwave frequencies and split the Zeeman levels with a polarizing field of 3400 gauss' The inherent advantage of operating in this region is that high sensitivities can be realized from small...

  10. Cylindrical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA)

    2008-04-22T23:59:59.000Z

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  11. Cylindrical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA)

    2009-12-29T23:59:59.000Z

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  12. Strangeness in Neutron Stars

    E-Print Network [OSTI]

    Fridolin Weber; Alexander Ho; Rodrigo P. Negreiros; Philip Rosenfield

    2006-04-20T23:59:59.000Z

    It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which several intriguing particles processes may compete with each other. These range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and H-matter. There are theoretical suggestions of even more exotic processes inside neutron stars, such as the formation of absolutely stable strange quark matter. In the latter event, neutron stars would be largely composed of strange quark matter possibly enveloped in a thin nuclear crust. This paper gives a brief overview of these striking physical possibilities with an emphasis on the role played by strangeness in neutron star matter, which constitutes compressed baryonic matter at ultra-high baryon number density but low temperature which is no accessible to relativistic heavy ion collision experiments.

  13. Shifting scintillator neutron detector

    DOE Patents [OSTI]

    Clonts, Lloyd G; Cooper, Ronald G; Crow, Jr., Morris Lowell; Hannah, Bruce W; Hodges, Jason P; Richards, John D; Riedel, Richard A

    2014-03-04T23:59:59.000Z

    Provided are sensors and methods for detecting thermal neutrons. Provided is an apparatus having a scintillator for absorbing a neutron, the scintillator having a back side for discharging a scintillation light of a first wavelength in response to the absorbed neutron, an array of wavelength-shifting fibers proximate to the back side of the scintillator for shifting the scintillation light of the first wavelength to light of a second wavelength, the wavelength-shifting fibers being disposed in a two-dimensional pattern and defining a plurality of scattering plane pixels where the wavelength-shifting fibers overlap, a plurality of photomultiplier tubes, in coded optical communication with the wavelength-shifting fibers, for converting the light of the second wavelength to an electronic signal, and a processor for processing the electronic signal to identify one of the plurality of scattering plane pixels as indicative of a position within the scintillator where the neutron was absorbed.

  14. Cylindrical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2005-06-14T23:59:59.000Z

    A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

  15. Modulated optical solid-state spectrometer applications in plasma diagnostics

    E-Print Network [OSTI]

    Howard, John

    Modulated optical solid-state spectrometer applications in plasma diagnostics John Howard Plasma A new electro-optically modulated optical solid-state MOSS interferometer has been constructed for the measurement of the low order spectral moments of line emission from optically thin radiant media

  16. Integration and commissioning of the ATLAS Muon spectrometer

    E-Print Network [OSTI]

    Alberto Belloni; for the ATLAS collaboration

    2008-10-16T23:59:59.000Z

    The ATLAS experiment at the Large Hadron Collider (LHC) at CERN is currently waiting to record the first collision data in spring 2009. Its muon spectrometer is designed to achieve a momentum resolution of 10% pT(mu) = 1 TeV/c. The spectrometer consists of a system of three superconducting air-core toroid magnets and is instrumented with three layers of Monitored Drift Tube chambers (Cathode Strip Chambers in the extreme forward region) as precision detectors. Resistive Plate Chambers in the barrel and Thin Gap Chambers in the endcap regions provide a fast trigger system. The spectrometer passed important milestones in the last year. The most notable milestone was the installation of the inner layer of endcap muon chambers, which constituted the last big piece of the ATLAS detector to be lowered in the ATLAS cavern. In addition, during the last two years most of the muon detectors were commissioned with cosmic rays while being assembled in the underground experimental cavern. We will report on our experience with the precision and trigger chambers, the optical spectrometer alignment system, the level-1 trigger, and the ATLAS data acquisition system. Results of the global performance of the muon system from data with magnetic field will also be presented.

  17. Photonic Crystal Slot Waveguide Spectrometer for Detection of Methane

    E-Print Network [OSTI]

    Texas at Austin, University of

    Photonic Crystal Slot Waveguide Spectrometer for Detection of Methane 1 Funded by Environmental. of Electrical and Computer Engineering, University of Texas, Austin #12;Motivation No other chip based optical Similar to: Doping of Semiconductor 3 #12;4 Photonic Crystal Bio-Chemical Sensors Loncar et al, Appl. Phys

  18. Neutron-deuteron breakup reaction as a tool for studying neutron-neutron interactions

    SciTech Connect (OSTI)

    Konobeevski, E. S., E-mail: konobeev@inr.ru; Zuyev, S. V.; Mordovskoy, M. V.; Potashev, S. I.; Sharapov, I. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

    2013-11-15T23:59:59.000Z

    An analysis of the most recent data on the reaction nd {yields} pnn revealed a serious discrepancy between theoretical predictions and cross sections measured for this reaction in various configurations where the role of neutron-neutron interactions is important. In view of this, it seems necessary both to develop theoretical approaches and to obtain new experimental data. For this purpose, a setup for studying the neutron-deuteron breakup reaction was created at the Institute for Nuclear Research on the basis of the neutron beam in the RADEX channel and deuterium targets. This facility makes it possible to perform experiments over a broad region of primary-neutron energies (10-60 MeV) and in various (final-state interaction, quasifree scattering, and spatial-star) configurations. Preliminary results of the respective experiment were obtained for configurations of final-state neutron-neutron interaction and quasifree neutron-neutron scattering.

  19. Correction to ``Scanning Imaging Absorption Spectrometer for Atmospheric Chartography carbon monoxide total columns

    E-Print Network [OSTI]

    Laat, Jos de

    Correction to ``Scanning Imaging Absorption Spectrometer for Atmospheric Chartography carbon to ``Scanning Imaging Absorption Spectrometer for Atmospheric Chartography carbon monoxide total columns, doi:10.1029/2007JD009378. [1] In the paper ``Scanning Imaging Absorption Spec- trometer

  20. Oil Spill Detection and Mapping Along the Gulf of Mexico Coastline Based on Imaging Spectrometer Data

    E-Print Network [OSTI]

    Arslan, Meryem Damla

    2013-11-27T23:59:59.000Z

    based on hyperspectral images acquired along the coastline of the Gulf of Mexico. A number of AVIRIS (Airborne Visible/Infrared Imaging Spectrometer) imaging spectrometer images were investigated in this research collected over Bay Jimmy and Wilkinson...

  1. Mass Spectrometer: Time of Flight Secondary Ion (ToF SIMS) -...

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

    - 1997 Mass Spectrometer: Time of Flight Secondary Ion (ToF SIMS) - 1997 The Physical Electronics Instruments (PHI) Model T2100 time-of-flight secondary ion mass spectrometer...

  2. Mass Spectrometer: FT-ICR, 6T (Ion Surface Collisions) | EMSL

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

    Mass Spectrometer: FT-ICR, 6T (Ion Surface Collisions) The 6-Tesla High-Field Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FT-ICR MS), is a unique...

  3. Upgrade of the neon soft X-ray spectrometer for Alcator C-Mod

    E-Print Network [OSTI]

    Podpaly, Yuri Anatoly

    2007-01-01T23:59:59.000Z

    In order to study plasma rotation, temperature, and impurity density, a Neon Soft X-ray Spectrometer (NeSoXs) was installed on the Alcator C-Mod tokamak. This spectrometer used a spherically bent mica crystal as the ...

  4. Hard X-ray polarimetry with Caliste, a high performance CdTe based imaging spectrometer

    E-Print Network [OSTI]

    Antier, S; Limousin, O; Caroli, E; da Silva, R M Curado; Blondel, C; Chipaux, R; Honkimaki, V; Horeau, B; Laurent, P; Maia, J M; Meuris, A; Del Sordo, S; Stephen, J B

    2015-01-01T23:59:59.000Z

    Since the initial exploration of soft gamma-ray sky in the 60's, high-energy celestial sources have been mainly characterized through imaging, spectroscopy and timing analysis. Despite tremendous progress in the field, the radiation mechanisms at work in sources such as neutrons stars and black holes are still unclear. The polarization state of the radiation is an observational parameter which brings key additional information about the physical process. This is why most of the projects for the next generation of space missions covering the tens of keV to the MeV region require a polarization measurement capability. A key element enabling this capability is a detector system allowing the identification and characterization of Compton interactions as they are the main process at play. The hard X-ray imaging spectrometer module, developed in CEA with the generic name of Caliste module, is such a detector. In this paper, we present experimental results for two types of Caliste-256 modules, one based on a CdTe cr...

  5. Strangeness in Neutron Stars

    E-Print Network [OSTI]

    Fridolin Weber

    2000-08-23T23:59:59.000Z

    It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which numerous novel particles processes are likely to compete with each other. These processes range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and H-matter. There are theoretical suggestions of even more exotic processes inside neutron stars, such as the formation of absolutely stable strange quark matter, a configuration of matter even more stable than the most stable atomic nucleus, iron. In the latter event, neutron stars would be largely composed of pure quark matter, eventually enveloped in a thin nuclear crust. No matter which physical processes are actually realized inside neutron stars, each one leads to fingerprints, some more pronounced than others though, in the observable stellar quantities. This feature combined with the unprecedented progress in observational astronomy, which allows us to see vistas with remarkable clarity that previously were only imagined, renders neutron stars to nearly ideal probes for a wide range of physical studies, including the role of strangeness in dense matter.

  6. Measurements of neutron capture cross section for {sup 207,208}Pb

    SciTech Connect (OSTI)

    Segawa, M.; Toh, Y.; Harada, H.; Kitatani, F.; Koizumi, M.; Fukahori, T.; Iwamoto, N.; Iwamoto, O. [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Oshima, M. [Nuclear Science and Engineering Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan and Japan Chemical Analysis Center (Japan); Hatsukawa, Y. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Nagai, Y. [Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Igashira, M. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Kamada, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550, Japan and National Maritime Research Institute (Japan); Tajika, M. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Tokyo 152-8550, Japan and Hitachi Solutions, Ltd. (Japan)

    2014-05-02T23:59:59.000Z

    The neutron capture cross sections for {sup 207,208}Pb have been measured in the neutron energy region from 10 to 110 keV. The ?-rays cascaded from a capture state to the ground state or low-lying states of {sup 208,209}Pb were observed for the first time, using an anti-Compton Nal(Tl) spectrometer and a TOF method. The observed discrete ?-ray energy spectra enabled us to determine neutron capture cross sections for {sup 207,208}Pb with small systematic errors, since we could distinguish ?-ray of {sup 207,208}Pb(n,?) reactions from background ?-ray with use of the ?-ray spectra. The obtained cross sections include both contributions of resonance and direct capture components different from the previous TOF measurements.

  7. Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA

    E-Print Network [OSTI]

    C. Adloff

    1998-11-09T23:59:59.000Z

    Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the kinematic region 2 neutron with energy E' >= 160 GeV. The measurements are used to test production models and factorization hypotheses. A Regge model of leading baryon production which consists of pion, pomeron and secondary reggeon exchanges gives an acceptable description of both semi-inclusive cross sections in the region 0.7 neutron data are used to estimate for the first time the structure function of the pion at small Bjorken--x.

  8. Portable Neutron Sensors for Emergency Response Operations

    SciTech Connect (OSTI)

    Mukhopadhyay, S., Maurer, R., Detweiler, R.

    2012-06-22T23:59:59.000Z

    This slide-show presents neutron measurement work, including design, use and performance of different neutron detection systems.

  9. Neutron beam characterization at the Neutron Radiography Reactor (NRAD)

    SciTech Connect (OSTI)

    Imel, G.R.; Urbatsch, T.; Pruett, D.P.; Ross, J.R.

    1990-01-01T23:59:59.000Z

    The Neutron Radiography Reactor (NRAD) is a 250-kW TRIGA Reactor operated by Argonne National Laboratory and is located near Idaho Falls, Idaho. The reactor and its facilities regarding radiography are detailed in another paper at this conference; this paper summarizes neutron flux measurements and calculations that have been performed to better understand and potentially improve the neutronics characteristics of the reactor.

  10. High-precision CO2 isotopologue spectrometer with a difference-frequency-generation laser source

    E-Print Network [OSTI]

    High-precision CO2 isotopologue spectrometer with a difference-frequency-generation laser source A precision laser spectrometer for the detection of CO2 isotopes is reported. The spectrometer measures the fundamental absorption signatures of 13 C and 12 C isotopes in CO2 at 4.32 m using a tunable mid-IR laser

  11. Spherical neutron generator

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2006-11-21T23:59:59.000Z

    A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.

  12. Ultrafast neutron detector

    DOE Patents [OSTI]

    Wang, Ching L. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    The invention comprises a neutron detector (50) of very high temporal resolution that is particularly well suited for measuring the fusion reaction neutrons produced by laser-driven inertial confinement fusion targets. The detector comprises a biased two-conductor traveling-wave transmission line (54, 56, 58, 68) having a uranium cathode (60) and a phosphor anode (62) as respective parts of the two conductors. A charge line and Auston switch assembly (70, 72, 74) launch an electric field pulse along the transmission line. Neutrons striking the uranium cathode at a location where the field pulse is passing, are enabled to strike the phosphor anode and produce light that is recorded on photographic film (64). The transmission line may be variously configured to achieve specific experimental goals.

  13. Personnel electronic neutron dosimeter

    DOE Patents [OSTI]

    Falk, Roger B. (Lafayette, CO); Tyree, William H. (Boulder, CO)

    1984-12-18T23:59:59.000Z

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  14. Personnel electronic neutron dosimeter

    DOE Patents [OSTI]

    Falk, R.B.; Tyree, W.H.

    1982-03-03T23:59:59.000Z

    A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

  15. Neutron Scattering Tutorials | Neutron Science | ORNL

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering Tutorials SHARE

  16. Corrosion resistant neutron absorbing coatings

    DOE Patents [OSTI]

    Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2013-11-12T23:59:59.000Z

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  17. Corrosion resistant neutron absorbing coatings

    DOE Patents [OSTI]

    Choi, Jor-Shan (El Cerrito, CA); Farmer, Joseph C. (Tracy, CA); Lee, Chuck K. (Hayward, CA); Walker, Jeffrey (Gaithersburg, MD); Russell, Paige (Las Vegas, NV); Kirkwood, Jon (Saint Leonard, MD); Yang, Nancy (Lafayette, CA); Champagne, Victor (Oxford, PA)

    2012-05-29T23:59:59.000Z

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  18. Neutron Science and Technology

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering3 Neutron Science

  19. NEUTRON AND NON-NEUTRON NUCLEAR DATA FOR RADIATION DOSIMETRY

    SciTech Connect (OSTI)

    HOLDEN,N.E.

    1999-09-10T23:59:59.000Z

    NEUTRON NUCLEAR DATA THAT IS USED IN REACTOR DOSIMETRY INCLUDE THERMAL NEUTRON CROSS SECTIONS AND NEUTRON RESONANCE INTEGRALS, FISSION SPECTRUM AVERAGED CROSS SECTIONS FOR REACTIONS ON A TARGET NUCLEUS. NON-NEUTRON NUCLEAR DATA USED IN REACTOR DOSIMETRY INCLUDE ISOTOPIC COMPOSITIONS OF TARGET NUCLIDES AND RADIOACTIVE HALF-LIVES, GAMMA-RAY ENERGIES AND INTENSITIES OF REACTION PRODUCT NUCLIDES. ALL OF THESE DATA ARE PERIODICALLY EVALUATED AND RECOMMENDED VALUES ARE PROVIDED IN THE HANDBOOK OF CHEMISTRY AND PHYSICS. THE LATEST RECOMMENDED VALUES ARE DISCUSSED AND THEY ARE CONTRASTED WITH SOME EARLIER NUCLEAR DATA, WHICH WAS PROVIDED WITH NEUTRON DETECTOR FOILS.

  20. Single and pair neutron transfers at sub-barrier energies

    SciTech Connect (OSTI)

    Corradi, L.; Fioretto, E.; Michelagnoli, C.; Stefanini, A. M.; Valiente-Dobon, J. J. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Szilner, S. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, I-35020 Legnaro (Italy); Ruder Boskovic Institute, HR-10 001 Zagreb (Croatia); Pollarolo, G. [Dipartimento di Fisica Teorica, Universita di Torino, and Istituto Nazionale di Fisica Nucleare, I-10125 Torino (Italy); Colo, G. [Dipartimento di Fisica, Universita degli Studi di Milano and Istituto Nazionale di Fisica Nucleare, I-20133 Milano (Italy); Mason, P.; Farnea, E.; Montagnoli, G.; Montanari, D.; Scarlassara, F.; Ur, C. A. [Dipartimento di Fisica, Universita di Padova, and Istituto Nazionale di Fisica Nucleare, I-35131 Padova (Italy); Gadea, A. [IFIC, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Haas, F. [Institut Pluridisciplinaire Hubert Curien, CNRS-IN2P3, Universite de Strasbourg, F-67037 Strasbourg (France); Jelavic-Malenica, D.; Soic, N. [Ruder Boskovic Institute, HR-10 001 Zagreb (Croatia); Marginean, N. [Horia Hulubei National Institute of Physics and Nuclear Engineering, R-077125, Bucharest-Magurele (Romania)

    2011-09-15T23:59:59.000Z

    Multinucleon transfer cross sections in the {sup 96}Zr+{sup 40}Ca system have been measured, in inverse kinematics, at bombarding energies ranging from the Coulomb barrier to {approx}25% below. Targetlike recoils have been identified in A, Z and velocity with the large solid angle magnetic spectrometer PRISMA. The experimental data for one- and two-neutron transfer channels have been compared with semiclassical microscopic calculations. For the two-neutron transfer channels the relevance of the transitions to the ground state and to the 0{sup +} excited states of {sup 42}Ca are discussed by employing, for the reaction mechanism, the successive approximation. It is found that the transition to the 0{sup +} state at {approx}6 MeV, whose wave function is dominated by the two neutrons in the 2p{sub 3/2} shell, is much larger than the ground state one. The comparison with the inclusive data reveals that transitions to states with high multipolarity and non-natural parity are important. This suggests that more complex two-particle correlations have to be incorporated in the treatment of the transfer process.

  1. Inverse time-of-flight spectrometer for beam plasma research

    SciTech Connect (OSTI)

    Yushkov, Yu. G., E-mail: yuyushkov@gmail.com; Zolotukhin, D. B.; Tyunkov, A. V. [Tomsk State University of Control Systems and Radioelectronics, 40 Lenin Ave., Tomsk 634050 (Russian Federation); Oks, E. M. [Tomsk State University of Control Systems and Radioelectronics, 40 Lenin Ave., Tomsk 634050 (Russian Federation); Institute of High Current Electronics SB RAS, 2/3, Akademichesky Ave., Tomsk 634055 (Russian Federation); Savkin, K. P. [Institute of High Current Electronics SB RAS, 2/3, Akademichesky Ave., Tomsk 634055 (Russian Federation)

    2014-08-15T23:59:59.000Z

    The paper describes the design and principle of operation of an inverse time-of-flight spectrometer for research in the plasma produced by an electron beam in the forevacuum pressure range (5–20 Pa). In the spectrometer, the deflecting plates as well as the drift tube and the primary ion beam measuring system are at high potential with respect to ground. This provides the possibility to measure the mass-charge constitution of the plasma created by a continuous electron beam with a current of up to 300 mA and electron energy of up to 20 keV at forevacuum pressures in the chamber placed at ground potential. Research results on the mass-charge state of the beam plasma are presented and analyzed.

  2. Commissioning of the ATLAS Muon Spectrometer with Cosmic Rays

    E-Print Network [OSTI]

    The ATLAS Collaboration

    2010-08-02T23:59:59.000Z

    The ATLAS detector at the Large Hadron Collider has collected several hundred million cosmic ray events during 2008 and 2009. These data were used to commission the Muon Spectrometer and to study the performance of the trigger and tracking chambers, their alignment, the detector control system, the data acquisition and the analysis programs. We present the performance in the relevant parameters that determine the quality of the muon measurement. We discuss the single element efficiency, resolution and noise rates, the calibration method of the detector response and of the alignment system, the track reconstruction efficiency and the momentum measurement. The results show that the detector is close to the design performance and that the Muon Spectrometer is ready to detect muons produced in high energy proton-proton collisions.

  3. Compact mass spectrometer for plasma discharge ion analysis

    DOE Patents [OSTI]

    Tuszewski, Michel G. (Los Alamos, NM)

    1997-01-01T23:59:59.000Z

    A mass spectrometer and methods for mass spectrometry which are useful in characterizing a plasma. This mass spectrometer for determining type and quantity of ions present in a plasma is simple, compact, and inexpensive. It accomplishes mass analysis in a single step, rather than the usual two-step process comprised of ion extraction followed by mass filtering. Ions are captured by a measuring element placed in a plasma and accelerated by a known applied voltage. Captured ions are bent into near-circular orbits by a magnetic field such that they strike a collector, producing an electric current. Ion orbits vary with applied voltage and proton mass ratio of the ions, so that ion species may be identified. Current flow provides an indication of quantity of ions striking the collector.

  4. The tokamak as a neutron source

    SciTech Connect (OSTI)

    Hendel, H.W.; Jassby, D.L.

    1989-11-01T23:59:59.000Z

    This paper describes the tokamak in its role as a neutron source, with emphasis on experimental results for D-D neutron production. The sections summarize tokamak operation, sources of fusion and non-fusion neutrons, principal neutron detection methods and their calibration, neutron energy spectra and fluxes outside the tokamak plasma chamber, history of neutron production in tokamaks, neutron emission and fusion power gain from JET and TFTR (the largest present-day tokamaks), and D-T neutron production from burnup of D-D tritons. This paper also discusses the prospects for future tokamak neutron production and potential applications of tokamak neutron sources. 100 refs., 16 figs., 4 tabs.

  5. Polarization Measurements in Photoproduction with CEBAF Large Acceptance Spectrometer

    SciTech Connect (OSTI)

    E. Pasyuk

    2010-05-01T23:59:59.000Z

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

  6. Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings

    DOE Patents [OSTI]

    Lerner, Scott A. (Livermore, CA); Bennett, Charles L. (Livermore, CA); Bixler, Jay V. (Oakland, CA); Kuzmenko, Paul J. (Livermore, CA); Lewis, Isabella T. (San Jose, CA)

    2005-07-26T23:59:59.000Z

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

  7. Design and construction of an experimental mass spectrometer

    E-Print Network [OSTI]

    Wall, Robert F.

    1950-01-01T23:59:59.000Z

    Experiment Station, the Texas A and M Research Foundation, and the Westinghouse Electric Corporation. The Westinghouse Electric Corporation donated a mass spectrometer and recorder of their manufacture to the col? lege and established a fellowship... in mass spectrometry. This instrument is of the 90? magnetic sector type, and em? ploys automatic magnetic mass scanning and recording. The experience gained with this instrument and the assistance of the Westinghouse fellows has been invaluable...

  8. Low background HPGe spectrometer in investigations of 2? decay

    SciTech Connect (OSTI)

    Rukhadze, Ekaterina [Institute of Experimental and Applied Physics, CTU in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic)] [Institute of Experimental and Applied Physics, CTU in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Collaboration: OBELIX Collaboration; TGV Collaboration; SuperNEMO Collaboration; and others

    2013-08-08T23:59:59.000Z

    The low background high sensitive HPGe spectrometer called OBELIX is briefly described. The calibration measurements using {sup 152}Eu, {sup 133}Ba and La{sub 2}O{sub 3} sources in different geometries, the obtained efficiency curves for OBELIX HPGe detector, the results of measurements of radioactivity of the NEMO-3 sources ({sup 100}Mo, {sup 150}Nd) as well as future plans for OBELIX detector (e.g. 0?EC/EC decay of {sup 106}Cd) are presented.

  9. Neutron Absorbing Alloys

    DOE Patents [OSTI]

    Mizia, Ronald E. (Idaho Falls, ID); Shaber, Eric L. (Idaho Falls, ID); DuPont, John N. (Whitehall, PA); Robino, Charles V. (Albuquerque, NM); Williams, David B. (Bethlehem, PA)

    2004-05-04T23:59:59.000Z

    The present invention is drawn to new classes of advanced neutron absorbing structural materials for use in spent nuclear fuel applications requiring structural strength, weldability, and long term corrosion resistance. Particularly, an austenitic stainless steel alloy containing gadolinium and less than 5% of a ferrite content is disclosed. Additionally, a nickel-based alloy containing gadolinium and greater than 50% nickel is also disclosed.

  10. A short working distance multiple crystal x-ray spectrometer

    SciTech Connect (OSTI)

    Dickinson, B.; Seidler, G. T.; Webb, Z. W.; Bradley, J. A.; Nagle, K. P. [Department of Physics, University of Washington, Seattle, Washington 98195 (United States); Heald, S. M. [Advanced Photon Source, Argonne National Laboratories, Argonne, Illinois 60439 (United States); Gordon, R. A. [Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6 (Canada); Chou, I. M. [U.S. Geological Survey, Reston, Virginia 20192 (United States)

    2008-12-15T23:59:59.000Z

    For x-ray spot sizes of a few tens of microns or smaller, a millimeter-sized flat analyzer crystal placed {approx}1 cm from the sample will exhibit high energy resolution while subtending a collection solid angle comparable to that of a typical spherically bent crystal analyzer (SBCA) at much larger working distances. Based on this observation and a nonfocusing geometry for the analyzer optic, we have constructed and tested a short working distance (SWD) multicrystal x-ray spectrometer. This prototype instrument has a maximum effective collection solid angle of 0.14 sr, comparable to that of 17 SBCA at 1 m working distance. We find good agreement with prior work for measurements of the Mn K{beta} x-ray emission and resonant inelastic x-ray scattering for MnO, and also for measurements of the x-ray absorption near-edge structure for Dy metal using L{alpha}{sub 2} partial-fluorescence yield detection. We discuss future applications at third- and fourth-generation light sources. For concentrated samples, the extremely large collection angle of SWD spectrometers will permit collection of high-resolution x-ray emission spectra with a single pulse of the Linac Coherent Light Source. The range of applications of SWD spectrometers and traditional multi-SBCA instruments has some overlap, but also is significantly complementary.

  11. A multi-crystal wavelength dispersive x-ray spectrometer

    SciTech Connect (OSTI)

    Alonso-Mori, Roberto; Montanez, Paul; Delor, James; Bergmann, Uwe [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kern, Jan [LCLS, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States); Sokaras, Dimosthenis; Weng, Tsu-Chien; Nordlund, Dennis [SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Tran, Rosalie; Yachandra, Vittal K.; Yano, Junko [Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8099 (United States)

    2012-07-15T23:59:59.000Z

    A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.

  12. Dose-equivalent neutron dosimeter

    DOE Patents [OSTI]

    Griffith, R.V.; Hankins, D.E.; Tomasino, L.; Gomaa, M.A.M.

    1981-01-07T23:59:59.000Z

    A neutron dosimeter is disclosed which provides a single measurement indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer contaning conversion material such as /sup 6/Li and /sup 10/B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet.

  13. Solid state neutron detector array

    DOE Patents [OSTI]

    Seidel, J.G.; Ruddy, F.H.; Brandt, C.D.; Dulloo, A.R.; Lott, R.G.; Sirianni, E.; Wilson, R.O.

    1999-08-17T23:59:59.000Z

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors. 7 figs.

  14. Solid state neutron detector array

    DOE Patents [OSTI]

    Seidel, John G. (Pittsburgh, PA); Ruddy, Frank H. (Monroeville, PA); Brandt, Charles D. (Mount Lebanon, PA); Dulloo, Abdul R. (Pittsburgh, PA); Lott, Randy G. (Pittsburgh, PA); Sirianni, Ernest (Monroeville, PA); Wilson, Randall O. (Greensburg, PA)

    1999-01-01T23:59:59.000Z

    A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

  15. Coated Fiber Neutron Detector Test

    SciTech Connect (OSTI)

    Lintereur, Azaree T.; Ely, James H.; Kouzes, Richard T.; Stromswold, David C.

    2009-10-23T23:59:59.000Z

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Reported here are the results of tests of the 6Li/ZnS(Ag)-coated non-scintillating plastic fibers option. This testing measured the required performance for neutron detection efficiency and gamma ray rejection capabilities of a system manufactured by Innovative American Technology (IAT).

  16. Parity Violating Measurements of Neutron Densities: Implications for Neutron Stars

    E-Print Network [OSTI]

    C. J. Horowitz; J. Piekarewicz

    2002-01-08T23:59:59.000Z

    Parity violating electron scattering can measure the neutron density of a heavy nucleus accurately and model independently. This is because the weak charge of the neutron is much larger then that of the proton. The Parity Radius Experiment (PREX) at Jefferson Laboratory aims to measure the root mean square neutron radius of $^{208}$Pb with an absolute accuracy of 1% ($\\pm 0.05$ Fm). This is more accurate then past measurements with hadronic probes, which all suffer from controversial strong interaction uncertainties. PREX should clearly resolve the neutron-rich skin. Furthermore, this benchmark value for $^{208}$Pb will provide a calibration for hadronic probes, such as proton scattering, which can then be used to measure neutron densities of many exotic nuclei. The PREX result will also have many implications for neutron stars. The neutron radius of Pb depends on the pressure of neutron-rich matter: the greater the pressure, the larger the radius as neutrons are pushed out against surface tension. The same pressure supports a neutron star against gravity. The Pb radius is sensitive to the equation of state at normal densities while the radius of a 1.4 solar mass neutron star also depends on the equation of state at higher densities. Measurements of the radii of a number of isolated neutron stars such as Geminga and RX J185635-3754 should soon improve significantly. By comparing the equation of state information from the radii of both Pb and neutron stars one can search for a softening of the high density equation of state from a phase transition to an exotic state. Possibilities include kaon condensates, strange quark matter or color superconductors.

  17. What happened to the moon? A lunar history mission using neutrons

    SciTech Connect (OSTI)

    Breitkreutz, H.; Li, X. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz, FRM II, Technische Universitaet Muenchen, Lichtenbergstr. 1, D-85747 Garching (Germany); Burfeindt, J.; Bernhardt, H. G.; Hoffmann, P. [Kayser-Threde GmbH, Wolfratshauser Str. 48, D-81379 Muenchen (Germany); Trieloff, M.; Schwarz, W. H.; Hopp, J. [Institut fuer Geowissenschaften, Heidelberg, D-69120 Heidelberg (Germany); Jessberger, E. K.; Hiesinger, H. [Institut fuer Planetologie, Westfaelische Wilhelms-Universitaet Muenster, D-48149 Muenster (Germany)

    2011-07-01T23:59:59.000Z

    The ages of lunar rocks can be determined using the {sup 40}Ar -{sup 39}Ar technique that can be used in-situ on the moon if a neutron source, a noble gas mass spectrometer and a gas extraction and purification system are brought to the lunar surface. A possible instrument for such a task is ISAGE, which combines a strong {sup 252}Cf neutron source and a compact spectrometer for in-situ dating of e.g. the South Pole Aitken impact basin or the potentially very young basalts south of the Aristachus Plateau. In this paper, the design of the neutron source will be discussed. The source is assumed to be a hollow sphere surrounded by a reflector, a geometry that provides a very homogeneous flux at the irradiation position inside the sphere. The optimal source geometry depending on the experimental conditions, the costs of transportation for the reflector and the costs of the source itself are calculated. A minimum {sup 252}Cf mass of 1.5 mg is determined. (authors)

  18. Shell structure in neutron rich nuclei by means of binary reactions

    SciTech Connect (OSTI)

    Angelis, G. de [INFN, Laboratori Nazionali di Legnaro (Italy)

    2014-08-14T23:59:59.000Z

    Nuclear structure studies far from stability rely mainly on the availability of radioactive nuclear beams but can complementary be addressed by means of high intensity beams of stable ions. In such contest, deep-inelastic and multinucleon transfer reactions are a powerful tool to populate yrast and non yrast states in neutron-rich nuclei. Particularly successful is here the combination of large acceptance spectrometers with highly segmented gamma-detector arrays. Such devices can provide the necessary channel selectivity to identify very rare signals. The AGATA gamma-ray detector array coupled to the PRISMA spectrometer at the Legnaro National Laboratories (LNL) in Italy is one example. Large data sets have been collected at LNL for nuclei close to the N=20, 28, 40, 50 and 82 shell closures.

  19. Porous material neutron detector

    DOE Patents [OSTI]

    Diawara, Yacouba (Oak Ridge, TN); Kocsis, Menyhert (Venon, FR)

    2012-04-10T23:59:59.000Z

    A neutron detector employs a porous material layer including pores between nanoparticles. The composition of the nanoparticles is selected to cause emission of electrons upon detection of a neutron. The nanoparticles have a maximum dimension that is in the range from 0.1 micron to 1 millimeter, and can be sintered with pores thereamongst. A passing radiation generates electrons at one or more nanoparticles, some of which are scattered into a pore and directed toward a direction opposite to the applied electrical field. These electrons travel through the pore and collide with additional nanoparticles, which generate more electrons. The electrons are amplified in a cascade reaction that occurs along the pores behind the initial detection point. An electron amplification device may be placed behind the porous material layer to further amplify the electrons exiting the porous material layer.

  20. Fast neutron imaging device and method

    DOE Patents [OSTI]

    Popov, Vladimir; Degtiarenko, Pavel; Musatov, Igor V.

    2014-02-11T23:59:59.000Z

    A fast neutron imaging apparatus and method of constructing fast neutron radiography images, the apparatus including a neutron source and a detector that provides event-by-event acquisition of position and energy deposition, and optionally timing and pulse shape for each individual neutron event detected by the detector. The method for constructing fast neutron radiography images utilizes the apparatus of the invention.

  1. Proton recoil scintillator neutron rem meter

    DOE Patents [OSTI]

    Olsher, Richard H. (Los Alamos, NM); Seagraves, David T. (Los Alamos, NM)

    2003-01-01T23:59:59.000Z

    A neutron rem meter utilizing proton recoil and thermal neutron scintillators to provide neutron detection and dose measurement. In using both fast scintillators and a thermal neutron scintillator the meter provides a wide range of sensitivity, uniform directional response, and uniform dose response. The scintillators output light to a photomultiplier tube that produces an electrical signal to an external neutron counter.

  2. Neutron Science Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering

  3. Why Use Neutrons For Research? | Neutron Science | ORNL

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

    better understand how biomass can be efficiently converted into fuel. Neutrons have many properties that make them ideal for certain types of research. Because of their unique...

  4. REVIEW OF NON-NEUTRON AND NEUTRON NUCLEAR DATA, 2004.

    SciTech Connect (OSTI)

    HOLDEN, N.E.

    2004-09-26T23:59:59.000Z

    Review articles are in preparation for the 2004 edition of the CRC Handbook of Chemistry and Physics dealing with the evaluation of both non-neutron and neutron nuclear data. Data on the discovery of element 110, Darmstadtium, and element 111 have been officially accepted, while data on element 11 8 have been withdrawn. Data to be presented include revised values for very short-lived nuclides, long-lived nuclides and beta-beta decay measurements. There has been a reassessment of the spontaneous fission (sf) half-lives, which distinguishes between sf decay half-lives and cluster decay half-lives and with cluster-fission decay. New measurements of isotopic abundance values for many elements will be discussed with an emphasis on the minor isotopes of interest for use in neutron activation analysis measurements. Neutron resonance integrals will be discussed emphasizing the differences between the calculated values obtained from the analytical integration over neutron resonances and the measured values in a neutron reactor-spectrum, which does not quite conform to the assumed 1/E neutron energy spectrum. The method used to determine the neutron resonance integral from measurement, using neutron activation analysis, will be discussed.

  5. Review of Non-Neutron and Neutron Nuclear Data, 2004

    SciTech Connect (OSTI)

    Holden, Norman E. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2005-05-24T23:59:59.000Z

    Review articles are in preparation for the 2004 edition of the CRC Handbook of Chemistry and Physics dealing with the evaluation of both non-neutron and neutron nuclear data. Data on the discovery of element 110, Darmstadtium, and element 111 have been officially accepted, while data on element 118 have been withdrawn. Data to be presented include revised values for very short-lived nuclides, long-lived nuclides, and beta-beta decay measurements. There has been a reassessment of the spontaneous fission (sf) half-lives, which distinguishes between sf decay half-lives and cluster decay half-lives, and with cluster-fission decay. New measurements of isotopic abundance values for many elements will be discussed with an emphasis on the minor isotopes of interest for use in neutron activation analysis measurements. Neutron resonance integrals will be discussed emphasizing the differences between the calculated values obtained from the analytical integration over neutron resonances and the measured values in a neutron reactor-spectrum, which does not quite conform to the assumed 1/E neutron energy spectrum. The method used to determine the neutron resonance integral from measurement, using neutron activation analysis, will be discussed.

  6. Neutron cameras for ITER

    SciTech Connect (OSTI)

    Johnson, L.C.; Barnes, C.W.; Batistoni, P. [ITER San Diego Joint Work Site, La Jolla, CA (United States)] [and others

    1998-12-31T23:59:59.000Z

    Neutron cameras with horizontal and vertical views have been designed for ITER, based on systems used on JET and TFTR. The cameras consist of fan-shaped arrays of collimated flight tubes, with suitably chosen detectors situated outside the biological shield. The sight lines view the ITER plasma through slots in the shield blanket and penetrate the vacuum vessel, cryostat, and biological shield through stainless steel windows. This paper analyzes the expected performance of several neutron camera arrangements for ITER. In addition to the reference designs, the authors examine proposed compact cameras, in which neutron fluxes are inferred from {sup 16}N decay gammas in dedicated flowing water loops, and conventional cameras with fewer sight lines and more limited fields of view than in the reference designs. It is shown that the spatial sampling provided by the reference designs is sufficient to satisfy target measurement requirements and that some reduction in field of view may be permissible. The accuracy of measurements with {sup 16}N-based compact cameras is not yet established, and they fail to satisfy requirements for parameter range and time resolution by large margins.

  7. Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions

    SciTech Connect (OSTI)

    Vanier P. e.; Dioszegi, I.; Salwen, C.; Forman, L.

    2009-10-25T23:59:59.000Z

    We have investigated the response of a DoubleScatter Neutron Spectrometer (DSNS) for sources at long distances (gr than 200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators.Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges gr than 110 m is still significantly different from thecosmic ray background.

  8. Test of an LED Monitoring System for the PHOS Spectrometer

    E-Print Network [OSTI]

    Blick, A M; Erin, S V; Kharlov, Yu V; Lobanov, M O; Mikhailov, Yu V; Minaev, N G; Petrov, V A; Sadovsky, S A; Samoylenko, V D; Suzdalev, V I; Senko, V A; Tikhonov, V V

    1999-01-01T23:59:59.000Z

    Preprint submitted to Elsevier Print on 26th January 2000A prototype monitoring system for the Photon Spectrometer (PHOS) of the ALICE experiment at LHC is described in detail. The prototype consists of Control and Master modules. The first one is 8x8 matrix of Light Emitting Diodes coupled with stable generators of current pulses. The system provides an individual control for each of the 64 channels of PHOS prototype based on lead-tungstate crystals. A long term stability of order of 10-3 has been achieved in integral beam tests of the monitoring system and PHOS prototypes.

  9. Continuous time-of-flight ion mass spectrometer

    DOE Patents [OSTI]

    Funsten, Herbert O.; Feldman, William C.

    2004-10-19T23:59:59.000Z

    A continuous time-of-flight mass spectrometer having an evacuated enclosure with means for generating an electric field located in the evacuated enclosure and means for injecting a sample material into the electric field. A source of continuous ionizing radiation injects ionizing radiation into the electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between arrival of a secondary electron out of said ionized atoms or molecules at a first predetermined location and arrival of a sample ion out of said ionized atoms or molecules at a second predetermined location.

  10. Miniature quadrupole mass spectrometer having a cold cathode ionization source

    DOE Patents [OSTI]

    Felter, Thomas E. (Livermore, CA)

    2002-01-01T23:59:59.000Z

    An improved quadrupole mass spectrometer is described. The improvement lies in the substitution of the conventional hot filament electron source with a cold cathode field emitter array which in turn allows operating a small QMS at much high internal pressures then are currently achievable. By eliminating of the hot filament such problems as thermally "cracking" delicate analyte molecules, outgassing a "hot" filament, high power requirements, filament contamination by outgas species, and spurious em fields are avoid all together. In addition, the ability of produce FEAs using well-known and well developed photolithographic techniques, permits building a QMS having multiple redundancies of the ionization source at very low additional cost.

  11. New results from the LASS (Large Aperture Superconducting Solenoid) spectrometer

    SciTech Connect (OSTI)

    Aston, D.; Awaji, N.; Bienz, T.; Bird, F.; D'Amore, J.; Dunwoodie, W.; Endorf, R.; Fujii, K.; Hayashii, H.; Iwata, S.

    1987-06-22T23:59:59.000Z

    New results are presented from analyses of several mesonic and baryonic states containing one or more strange quarks. The data are taken from a high statistics (4 events/nb) study of K p interactions at 11 GeV/c carried out in the LASS Spectrometer at SLAC. New information is reported on the underlying K* states and also evidence for selective coupling of K eta to the K*'s; on the strangeonium members of the axial vector nonets in the K anti K channel; and on evidence for an * state.

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

    SciTech Connect (OSTI)

    Volker Crede

    2011-12-01T23:59:59.000Z

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

  13. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    SciTech Connect (OSTI)

    Aalseth, Craig E.; Bonicalzi, Ricco; Fast, James E.; Hossbach, Todd W.; Orrell, John L.; Overman, Cory T.; VanDevender, Brent A.

    2013-04-01T23:59:59.000Z

    Abstract: This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is presented. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  14. Cryostat for Ultra-low-energy Threshold Germanium Spectrometers

    E-Print Network [OSTI]

    Craig E. Aalseth; Ricco M. Bonicalzi; James E. Fast; Todd W. Hossbach; John L. Orrell; Cory T. Overman; Brent A. Vandevender

    2012-10-08T23:59:59.000Z

    This paper presents progress on the development of a cryostat intended to improve upon the low-energy threshold (below 0.5 keV) of p-type point contact germanium gamma-ray spectrometers. Ultra-low energy thresholds are important in the detection of low-energy nuclear recoils, an event class relevant to both dark matter direct detection and measurement of coherent neutrino-nucleus scattering. The cryostat design, including a thermal and electrical-field model, is given. A prototype cryostat has been assembled and data acquired to evaluate its vacuum and thermal performance.

  15. Material characterization using a hyperspectral infrared imaging spectrometer

    SciTech Connect (OSTI)

    Aimonetti, W D; Bixler, J V; Roberts, R S

    1998-10-30T23:59:59.000Z

    Fourier transform spectroscopy has found application in many areas including chemometrics, biomedical and biochemical studies, and atmospheric chemistry. This paper describes an investigation into the application of the LLNL Hyperspectral Infrared Imaging Spectrometer (HIRIS) to the non-destructive evaluation of man-made and natural materials. We begin by describing the HIRIS system and the objects studied in the investigation. Next, we describe the technique used to collect the hyperspec- tral imagery, and discuss the processing required to transform the data into usable form. We then describe a technique to analyze the data, and provide some preliminary results.

  16. SWEPP Gamma-Ray Spectrometer System software design description

    SciTech Connect (OSTI)

    Femec, D.A.; Killian, E.W.

    1994-08-01T23:59:59.000Z

    To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system.

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

    DOE Patents [OSTI]

    Funsten, Herbert O. (Los Alamos, NM); Feldman, William C. (Los Alamos, NM)

    2008-06-10T23:59:59.000Z

    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.

  18. FTIR spectrometer with solid-state drive system

    DOE Patents [OSTI]

    Rajic, Slobodan (Knoxville, TN); Seals, Roland D. (Oak Ridge, TN); Egert, Charles M. (Oak Ridge, TN)

    1999-01-01T23:59:59.000Z

    An FTIR spectrometer (10) and method using a solid-state drive system with thermally responsive members (27) that are subject to expansion upon heating and to contraction upon cooling. Such members (27) are assembled in the device (10) so as to move an angled, reflective surface (22) a small distance. The sample light beam (13) is received at a detector (24) along with a reference light beam (13) and there it is combined into a resulting signal. This allows the "interference" between the two beams to occur for spectral analysis by a processor (29).

  19. Positron lifetime spectrometer using a DC positron beam

    DOE Patents [OSTI]

    Xu, Jun; Moxom, Jeremy

    2003-10-21T23:59:59.000Z

    An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The electrical potential difference between the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by the energy distribution of the secondary electrons. In addition, the sample, sample holder, entrance grid, and entrance face of the multichannel plate electron detector assembly are made parallel to each other, and are arranged at a tilt angle to the axis of the positron beam to effectively separate the path of the secondary electrons from the path of the incident positrons.

  20. Neutron Detector Gamma Insensitivity Criteria

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Stephens, Daniel L.

    2009-10-21T23:59:59.000Z

    The shortage of 3He has triggered the search for an effective alternative neutron detection technology for radiation portal monitor applications. Any new detection technology must satisfy two basic criteria: 1) it must meet the neutron detection efficiency requirement, and 2) it must be insensitive to gamma ray interference at a prescribed level, while still meeting the neutron detection requirement. It is the purpose of this document to define this latter criterion.

  1. Lessons Learned for the MICE Coupling Solenoid from the MICE Spectrometer Solenoids

    SciTech Connect (OSTI)

    Green, Michael A.; Wang, Li; Pan, Heng; Wu, Hong; Guo, Xinglong; Li, S. Y.; Zheng, S. X.; Virostek, Steve P.; DeMello, Allen J.; Li, Derun; Trillaud, Frederick; Zisman, Michael S.

    2010-05-30T23:59:59.000Z

    Tests of the spectrometer solenoids have taught us some important lessons. The spectrometer magnet lessons learned fall into two broad categories that involve the two stages of the coolers that are used to cool the magnets. On the first spectrometer magnet, the problems were centered on the connection of the cooler 2nd-stage to the magnet cold mass. On the first test of the second spectrometer magnet, the problems were centered on the cooler 1st-stage temperature and its effect on the operation of the HTS leads. The second time the second spectrometer magnet was tested; the cooling to the cold mass was still not adequate. The cryogenic designs of the MICE and MuCOOL coupling magnets are quite different, but the lessons learned from the tests of the spectrometer magnets have affected the design of the coupling magnets.

  2. Hard X-ray polarimetry with Caliste, a high performance CdTe based imaging spectrometer

    E-Print Network [OSTI]

    S. Antier; P. Ferrando; O. Limousin; E. Caroli; R. M. Curado da Silva; C. Blondel; R. Chipaux; V. Honkimaki; B. Horeau; P. Laurent; J. M. Maia; A. Meuris; S. Del Sordo; J. B. Stephen

    2015-05-05T23:59:59.000Z

    Since the initial exploration of soft gamma-ray sky in the 60's, high-energy celestial sources have been mainly characterized through imaging, spectroscopy and timing analysis. Despite tremendous progress in the field, the radiation mechanisms at work in sources such as neutrons stars and black holes are still unclear. The polarization state of the radiation is an observational parameter which brings key additional information about the physical process. This is why most of the projects for the next generation of space missions covering the tens of keV to the MeV region require a polarization measurement capability. A key element enabling this capability is a detector system allowing the identification and characterization of Compton interactions as they are the main process at play. The hard X-ray imaging spectrometer module, developed in CEA with the generic name of Caliste module, is such a detector. In this paper, we present experimental results for two types of Caliste-256 modules, one based on a CdTe crystal, the other one on a CdZnTe crystal, which have been exposed to linearly polarized beams at the European Synchrotron Radiation Facility. These results, obtained at 200-300 keV, demonstrate their capability to give an accurate determination of the polarization parameters (polarization angle and fraction) of the incoming beam. Applying a selection to our data set, equivalent to select 90 degrees Compton scattered interactions in the detector plane, we find a modulation factor Q of 0.78. The polarization angle and fraction are derived with accuracies of approximately 1 degree and 5%. The modulation factor remains larger than 0.4 when essentially no selection is made at all on the data. These results prove that the Caliste-256 modules have performances allowing them to be excellent candidates as detectors with polarimetric capabilities, in particular for future space missions.

  3. CHRPR Neutron Board Replacement Manual

    SciTech Connect (OSTI)

    Erikson, Rebecca L.; Myjak, Mitchell J.

    2013-03-31T23:59:59.000Z

    This document will walk through the steps to exchange the neutron channel boards with gamma channel boards in the CHRPR box.

  4. Centrifugal quantum states of neutrons

    E-Print Network [OSTI]

    V. V. Nesvizhevsky; A. K. Petukhov; K. V. Protasov; A. Yu. Voronin

    2008-06-24T23:59:59.000Z

    We propose a method for observation of the quasi-stationary states of neutrons, localized near the curved mirror surface. The bounding effective well is formed by the centrifugal potential and the mirror Fermi-potential. This phenomenon is an example of an exactly solvable "quantum bouncer" problem that could be studied experimentally. It could provide a promising tool for studying fundamental neutron-matter interactions, as well as quantum neutron optics and surface physics effects. We develop formalism, which describes quantitatively the neutron motion near the mirror surface. The effects of mirror roughness are taken into account.

  5. Analytical applications for delayed neutrons

    SciTech Connect (OSTI)

    Eccleston, G.W.

    1983-01-01T23:59:59.000Z

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes.

  6. PRISMA Spectrometer EVR Spectra And Collection Efficiencies In Gas-Filled Mode

    SciTech Connect (OSTI)

    Dragosavac, D. R.; Ujic, P. N.; Subotic, K. M. [Institute of Nuclear Sciences VINCA, PO Box 522, 11001 Belgrade (Serbia and Montenegro); Scarlassara, F. [Universita di Padova, Padova (Italy); INFN Sezione di Padova, Padova (Italy)

    2007-04-23T23:59:59.000Z

    In order to study nuclear fusion reaction, the heavy-ion magnetic spectrometer PRISMA installed at INFN Legnaro is planned to be modified to work in Gas-Filled Mode. For that purpose, the possible response of the spectrometer will be examined in Rutherford scattering experiments which simulate the fusion reaction products. predictions for the evaporation residue (EVR) position spectra and collection efficiencies, as well as the respective spectrometer set ups, as determined using the algorithm of ANAMARI code, are presented.

  7. High gain, Fast Scan, Broad Spectrum Parallel Beam Wavelength Dispersive X-ray Spectrometer for SEM

    SciTech Connect (OSTI)

    OHara, David

    2009-05-08T23:59:59.000Z

    During contract # DE-FG02-ER83545, Parallax Research, Inc. developed a High gain, Fast Scan Broad Spectrum Parallel beam Wavelength Dispersive X-ray Spectrometer for use on Scanning Electron Microscopes (SEM). This new spectrometer allows very fast high resolution elemental analysis of samples in an electron microscope. By comparison to previous WDS spectrometers, it can change from one energy position to another very quickly and has an extended range compared to some similar products.

  8. Neutron-deuteron breakup and quasielastic scattering

    E-Print Network [OSTI]

    Ohlson, Alice Elisabeth

    2009-01-01T23:59:59.000Z

    Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The ...

  9. Requirements, possible alternatives & international NEUTRON SCATTERING

    E-Print Network [OSTI]

    Dimeo, Robert M.

    Requirements, possible alternatives & international NEUTRON SCATTERING DETECTORS for Rob Dimeo NIST neutron scattering instruments are the most demanding require background low #12;#12;The Helium-3 Supply Crisis ­ Alternative Techniques to Helium-3 based Detectors for Neutron Scattering Applications

  10. Light ion transfer reactions with the HELIOS spectrometer

    SciTech Connect (OSTI)

    Back, B. B. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Collaboration: HELIOS Collaboration

    2012-10-20T23:59:59.000Z

    Light-ion induced transfer and inelastic scattering reactions on stable or long-lived targets have been used extensively to study the structure of nuclei near the line of {beta}-stability, and much of the detailed information on the single-particle structure of nuclei has been derived from such studies. Recently, however, a substantial expansion of the range of isotopes, for which this nuclear structure information can be obtained, has presented itself by using radioactive beams in inverse kinematics reactions. Such beams are now available at a number of facilities around the world, including the in-flight production method and CARIBU facility at ATLAS. The HELIOS spectrometer, which has been used since August 2008 at ATLAS, circumvents many of the problems associated with inverse kinematics. In this talk I will discuss the principle of the spectrometer as well as some of main physics results that have been obtained to date in nuclei ranging from {sup 13}B to {sup 137}Xe using both stable and radioactive beams.

  11. High resolution, high rate X-ray spectrometer

    DOE Patents [OSTI]

    Goulding, Frederick S. (Lafayette, CA); Landis, Donald A. (Pinole, CA)

    1987-01-01T23:59:59.000Z

    A pulse processing system (10) for use in an X-ray spectrometer in which a ain channel pulse shaper (12) and a fast channel pulse shaper (13) each produce a substantially symmetrical triangular pulse (f, p) for each event detected by the spectrometer, with the pulse width of the pulses being substantially independent of the magnitude of the detected event and with the pulse width of the fast pulses (p) being substantially shorter than the pulse width of the main channel pulses (f). A pile-up rejector circuit (19) allows output pulses to be generated, with amplitudes linearly related to the magnitude of the detected events, whenever the peak of a main channel pulse (f) is not affected by a preceding or succeeding main channel pulse, while inhibiting output pulses wherein peak magnitudes of main channel pulses are affected by adjacent pulses. The substantially symmetrical triangular main channel pulses (f) are generated by the weighted addition (27-31) of successive RC integrations (24, 25, 26) of an RC differentiated step wave (23). The substantially symmetrical triangular fast channel pulses (p) are generated by the RC integration ( 43) of a bipolar pulse (o) in which the amplitude of the second half is 1/e that of the first half, with the RC time constant of integration being equal to one-half the width of the bipolar pulse.

  12. Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS

    E-Print Network [OSTI]

    Silvia Niccolai; for the CLAS Collaboration

    2012-07-13T23:59:59.000Z

    This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH3) and deuterons (ND3) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

  13. Deeply virtual Compton scattering on longitudinally polarized protons and neutrons at CLAS

    SciTech Connect (OSTI)

    Silvia Niccolai

    2012-04-01T23:59:59.000Z

    This paper focuses on a measurement of deeply virtual Compton scattering (DVCS) performed at Jefferson Lab using a nearly-6-GeV polarized electron beam, two longitudinally polarized (via DNP) solid targets of protons (NH{sub 3}) and deuterons (ND{sub 3}) and the CEBAF Large Acceptance Spectrometer. Here, preliminary results for target-spin asymmetries and double (beam-target) asymmetries for proton DVCS, as well as a very preliminary extraction of beam-spin asymmetry for neutron DVCS, are presented and linked to Generalized Parton Distributions.

  14. A new measurement of Beam Asymmetry in Pion Photoproduction from the Neutron using CLAS

    SciTech Connect (OSTI)

    D. Sokhan, D. Watts, D. Branford, F. Klein

    2010-08-01T23:59:59.000Z

    We present a preliminary analysis of the photon beam asymmetry observable (Sigma) from the photoproduction reaction channel gamma+ n -> p + pi-. This new data was obtained using the near-4pi CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory, USA, employing a linearly polarised photon beam with an energy range 1.1 - 2.3 GeV. The measurement will provide new data to address the poorly established neutron excitation spectrum and will greatly expand the sparse world data-set both in energy and angle.

  15. New neutron physics using spallation sources

    SciTech Connect (OSTI)

    Bowman, C.D.

    1988-01-01T23:59:59.000Z

    The extraordinary neutron intensities available from the new spallation pulsed neutron sources open up exciting opportunities for basic and applied research in neutron nuclear physics. The energy range of neutron research which is being explored with these sources extends from thermal energies to almost 800 MeV. The emphasis here is on prospective experiments below 100 keV neutron energy using the intense neutron bursts produced by the Proton Storage Ring (PSR) at Los Alamos. 30 refs., 10 figs.

  16. Measuring the Neutron's Mean Square Charge Radius Using Neutron Interferometry

    E-Print Network [OSTI]

    F. E. Wietfeldt; M. Huber; T. C. Black; H. Kaiser; M. Arif; D. L. Jacobson; S. A. Werner

    2005-09-14T23:59:59.000Z

    The neutron is electrically neutral, but its substructure consists of charged quarks so it may have an internal charge distribution. In fact it is known to have a negative mean square charge radius (MSCR), the second moment of the radial charge density. In other words the neutron has a positive core and negative skin. In the first Born approximation the neutron MSCR can be simply related to the neutron-electron scattering length b_ne. In the past this important quantity has been extracted from the energy dependence of the total transmission cross-section of neutrons on high-Z targets, a very difficult and complicated process. A few years ago S.A. Werner proposed a novel approach to measuring b_ne from the neutron's dynamical phase shift in a perfect crystal close to the Bragg condition. We are conducting an experiment based on this method at the NIST neutron interferometer which may lead to a five-fold improvement in precision of b_ne and hence the neutron MSCR.

  17. Neutron Multiplicity Measurements With 3He Alternative: Straw Neutron Detectors

    SciTech Connect (OSTI)

    Mukhopadhyay, Sanjoy

    2015-01-01T23:59:59.000Z

    Counting neutrons emitted by special nuclear material (SNM) and differentiating them from the background neutrons of various origins is the most effective passive means of detecting SNM. Unfortunately, neutron detection, counting, and partitioning in a maritime environment are complex due to the presence of high-multiplicity spallation neutrons (commonly known as ‘‘ship effect ’’) and to the complicated nature of the neutron scattering in that environment. A prototype neutron detector was built using 10B as the converter in a special form factor called ‘‘straws’’ that would address the above problems by looking into the details of multiplicity distributions of neutrons originating from a fissioning source. This paper describes the straw neutron multiplicity counter (NMC) and assesses the performance with those of a commercially available fission meter. The prototype straw neutron detector provides a large-area, efficient, lightweight, more granular (than fission meter) neutron-responsive detection surface (to facilitate imaging) to enhance the ease of application of fission meters. Presented here are the results of preliminary investigations, modeling, and engineering considerations leading to the construction of this prototype. This design is capable of multiplicity and Feynman variance measurements. This prototype may lead to a near-term solution to the crisis that has arisen from the global scarcity of 3He by offering a viable alternative to fission meters. This paper describes the work performed during a 2-year site-directed research and development (SDRD) project that incorporated straw detectors for neutron multiplicity counting. The NMC is a two-panel detector system. We used 10B (in the form of enriched boron carbide: 10B4C) for neutron detection instead of 3He. In the first year, the project worked with a panel of straw neutron detectors, investigated its characteristics, and developed a data acquisition (DAQ) system to collect neutron multiplicity information from spontaneous fission sources using a single panel consisting of 60 straws equally distributed over three rows in high-density polyethylenemoderator. In the following year, we developed the field-programmable gate array and associated DAQ software. This SDRD effort successfully produced a prototype NMC with*33% detection efficiency compared to a commercial fission meter.

  18. Time-resolved neutron imaging at ANTARES cold neutron beamline

    E-Print Network [OSTI]

    Tremsin, A S; Tittelmeier, K; Schillinger, B; Schulz, M; Lerche, M; Feller, W B

    2015-01-01T23:59:59.000Z

    In non-destructive evaluation with X-rays light elements embedded in dense, heavy (or high-Z) matrices show little contrast and their structural details can hardly be revealed. Neutron radiography, on the other hand, provides a solution for those cases, in particular for hydrogenous materials, owing to the large neutron scattering cross section of hydrogen and uncorrelated dependency of neutron cross section on the atomic number. The majority of neutron imaging experiments at the present time is conducted with static objects mainly due to the limited flux intensity of neutron beamline facilities and sometimes due to the limitations of the detectors. However, some applications require the studies of dynamic phenomena and can now be conducted at several high intensity beamlines such as the recently rebuilt ANTARES beam line at the FRM-II reactor. In this paper we demonstrate the capabilities of time resolved imaging for repetitive processes, where different phases of the process can be imaged simultaneously and...

  19. HFIR Experiment Facilities | ORNL Neutron Sciences

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

    Scattering Neutron Scattering Facilities at HFIR The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be...

  20. Search for: "neutron scattering" | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    neutron scattering" Find + Advanced Search Advanced Search All Fields: "neutron scattering" Title: Full Text: Bibliographic Data: Creator Author: Name Name ORCID Search...

  1. 11th LANSCE School on Neutron Scattering

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

    11th LANSCE School on Neutron Scattering LANSCE 11th LANSCE School on Neutron Scattering Home Abstract Lecturers Lecturer Abstracts Hands-On Experiments Free Day About the...

  2. LANSCE | International Collaboration on Advanced Neutron Sources...

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

    LINAC Outreach Affiliations Visiting LANSCE Facilities Isotope Production Facility Lujan Neutron Scattering Center Materials Test Station Proton Radiography Ultra-Cold Neutrons...

  3. Physics of Neutron Star Crusts

    E-Print Network [OSTI]

    N. Chamel; P. Haensel

    2008-12-20T23:59:59.000Z

    The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.

  4. Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments

    SciTech Connect (OSTI)

    Abe, Y., E-mail: abe-y@ile.osaka-u.ac.jp; Hosoda, H.; Arikawa, Y.; Nagai, T.; Kojima, S.; Sakata, S.; Inoue, H.; Iwasa, Y.; Iwano, K.; Yamanoi, K.; Fujioka, S.; Nakai, M.; Sarukura, N.; Shiraga, H.; Norimatsu, T.; Azechi, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2014-11-15T23:59:59.000Z

    The characteristics of oxygen-enriched liquid scintillators with very low afterglow are investigated and optimized for application to a single-hit neutron spectrometer for fast ignition experiments. It is found that 1,2,4-trimethylbenzene has better characteristics as a liquid scintillator solvent than the conventional solvent, p-xylene. In addition, a benzophenon-doped BBQ liquid scintillator is shown to demonstrate very rapid time response, and therefore has potential for further use in neutron diagnostics with fast time resolution.

  5. Fast neutron environments.

    SciTech Connect (OSTI)

    Buchheit, Thomas Edward; Kotula, Paul Gabriel; Lu, Ping; Brewer, Luke N. (Naval Postgraduate School, Monterey, CA); Goods, Steven Howard (Sandia National Laboratories, Livermore, CA); Foiles, Stephen Martin; Puskar, Joseph David; Hattar, Khalid Mikhiel; Doyle, Barney Lee; Boyce, Brad Lee; Clark, Blythe G.

    2011-10-01T23:59:59.000Z

    The goal of this LDRD project is to develop a rapid first-order experimental procedure for the testing of advanced cladding materials that may be considered for generation IV nuclear reactors. In order to investigate this, a technique was developed to expose the coupons of potential materials to high displacement damage at elevated temperatures to simulate the neutron environment expected in Generation IV reactors. This was completed through a high temperature high-energy heavy-ion implantation. The mechanical properties of the ion irradiated region were tested by either micropillar compression or nanoindentation to determine the local properties, as a function of the implantation dose and exposure temperature. In order to directly compare the microstructural evolution and property degradation from the accelerated testing and classical neutron testing, 316L, 409, and 420 stainless steels were tested. In addition, two sets of diffusion couples from 316L and HT9 stainless steels with various refractory metals. This study has shown that if the ion irradiation size scale is taken into consideration when developing and analyzing the mechanical property data, significant insight into the structural properties of the potential cladding materials can be gained in about a week.

  6. Neutron tube design study for boron neutron capture therapy application

    SciTech Connect (OSTI)

    Verbeke, J.M.; Lee, Y.; Leung, K.N.; Vujic, J.; Williams, M.D.; Wu, L.K.; Zahir, N.

    1999-05-06T23:59:59.000Z

    Radio-frequency (RF) driven ion sources are being developed in Lawrence Berkeley National Laboratory (LBNL) for sealed-accelerator-tube neutron generator application. By using a 5-cm-diameter RF-driven multicusp source H{sup +} yields over 95% have been achieved. These experimental findings will enable one to develop compact neutron generators based on the D-D or D-T fusion reactions. In this new neutron generator, the ion source, the accelerator and the target are all housed in a sealed metal container without external pumping. Recent moderator design simulation studies have shown that 14 MeV neutrons could be moderated to therapeutically useful energy ranges for boron neutron capture therapy (BNCT). The dose near the center of the brain with optimized moderators is about 65% higher than the dose obtained from a typical neutron spectrum produced by the Brookhaven Medical Research Reactor (BMRR), and is comparable to the dose obtained by other accelerator-based neutron sources. With a 120 keV and 1 A deuteron beam, a treatment time of {approx}35 minutes is estimated for BNCT.

  7. Dynamic multiplexed analysis method using ion mobility spectrometer

    DOE Patents [OSTI]

    Belov, Mikhail E [Richland, WA

    2010-05-18T23:59:59.000Z

    A method for multiplexed analysis using ion mobility spectrometer in which the effectiveness and efficiency of the multiplexed method is optimized by automatically adjusting rates of passage of analyte materials through an IMS drift tube during operation of the system. This automatic adjustment is performed by the IMS instrument itself after determining the appropriate levels of adjustment according to the method of the present invention. In one example, the adjustment of the rates of passage for these materials is determined by quantifying the total number of analyte molecules delivered to the ion trap in a preselected period of time, comparing this number to the charge capacity of the ion trap, selecting a gate opening sequence; and implementing the selected gate opening sequence to obtain a preselected rate of analytes within said IMS drift tube.

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

    DOE Patents [OSTI]

    Cheng, Meng-Dawn (Oak Ridge, TN)

    2002-01-01T23:59:59.000Z

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

  9. Isotopic response with small scintillator based gamma-ray spectrometers

    DOE Patents [OSTI]

    Madden, Norman W. (Sparks, NV); Goulding, Frederick S. (Lafayette, CA); Asztalos, Stephen J. (Oakland, CA)

    2012-01-24T23:59:59.000Z

    The intrinsic background of a gamma ray spectrometer is significantly reduced by surrounding the scintillator with a second scintillator. This second (external) scintillator surrounds the first scintillator and has an opening of approximately the same diameter as the smaller central scintillator in the forward direction. The second scintillator is selected to have a higher atomic number, and thus has a larger probability for a Compton scattering interaction than within the inner region. Scattering events that are essentially simultaneous in coincidence to the first and second scintillators, from an electronics perspective, are precluded electronically from the data stream. Thus, only gamma-rays that are wholly contained in the smaller central scintillator are used for analytic purposes.

  10. THE ABSOLUTE CALIBRATION OF THE EUV IMAGING SPECTROMETER ON HINODE

    SciTech Connect (OSTI)

    Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Landi, Enrico [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2014-07-01T23:59:59.000Z

    We investigate the absolute calibration of the EUV Imaging Spectrometer (EIS) on Hinode by comparing EIS full-disk mosaics with irradiance observations from the EUV Variability Experiment on the Solar Dynamics Observatory. We also use extended observations of the quiet corona above the limb combined with a simple differential emission measure model to establish new effective area curves that incorporate information from the most recent atomic physics calculations. We find that changes to the EIS instrument sensitivity are a complex function of both time and wavelength. We find that the sensitivity is decaying exponentially with time and that the decay constants vary with wavelength. The EIS short wavelength channel shows significantly longer decay times than the long wavelength channel.

  11. Linear electronic field time-of-flight ion mass spectrometers

    DOE Patents [OSTI]

    Funsten, Herbert O. (Los Alamos, NM)

    2010-08-24T23:59:59.000Z

    Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.

  12. Two wide-angle imaging neutral-atom spectrometers

    SciTech Connect (OSTI)

    McComas, D.J.

    1997-12-31T23:59:59.000Z

    The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission provides a new capability for stereoscopically imaging the magnetosphere. By imaging the charge exchange neutral atoms over a broad energy range (1 < E , {approximately} 100 keV) using two identical instruments on two widely-spaced high-altitude, high-inclination spacecraft, TWINS will enable the 3-dimensional visualization and the resolution of large scale structures and dynamics within the magnetosphere for the first time. These observations will provide a leap ahead in the understanding of the global aspects of the terrestrial magnetosphere and directly address a number of critical issues in the ``Sun-Earth Connections`` science theme of the NASA Office of Space Science.

  13. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    SciTech Connect (OSTI)

    Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory

    2012-05-04T23:59:59.000Z

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  14. Delayed neutron energy spectra following fast fission of [sup 238]U

    SciTech Connect (OSTI)

    Villani, M.F.

    1992-01-01T23:59:59.000Z

    Delayed neutron energy spectra have been measured for six delay-time intervals following the fast fission of [sup 238]U nuclei. The delay-time intervals span the range 0.17 to 10.2 seconds following initial fission while the measured spectra span neutron energies from 10 keV to 4 MeV. The experiment was performed utilizing the UMass/Lowell 5.5 MV Van de Graff accelerator to produce fast neutrons for inducing fission in a [sup 238]U lined fission chamber. The fission fragments were flushed via a helium jet stream to a well-shielded counting room where they were deposited onto a moving tape (magnetic audio tape) and transferred to a beta-neutron time-of-flight spectrometer. By adjusting the tape speed, composite delayed neutron time-of-flight spectra were measured for several different delay-time intervals. These measurements involved beta-neutron coincidences with [sup 6]Li-loaded glass scintillators for neutron energies from 10 keV to 450 keV and Bicron BC 501 liquid scintillators for the neutron energy range 200 keV-4 MeV. The measured composite delayed neutron energy spectra for [sup 238]U are compared to the composite spectra for [sup 235]U and [sup 239]Pu, and also to composite spectra derived for [sup 238]U from the ENDF/B-VI database, which is based on summation calculations of individual precursor data supplemented by theoretical estimates. The composite spectra of [sup 235]U and [sup 239]Pu were obtained from previous measurements of delayed neutron spectra at this laboratory. The composite spectra are also decomposed into Keepin six-group spectra and compared with those for [sup 239]Pu and [sup 235]U. In addition, an equilibrium spectrum has been calculated from the measured composite spectra using several different analytical techniques and is also compared with the equilibrium spectrum of [sup 238]U measured in an earlier study at this lab.

  15. Echelle grating multi-order imaging spectrometer utilizing a catadioptric lens

    DOE Patents [OSTI]

    Chrisp, Michael P; Bowers, Joel M

    2014-05-27T23:59:59.000Z

    A cryogenically cooled imaging spectrometer that includes a spectrometer housing having a first side and a second side opposite the first side. An entrance slit is on the first side of the spectrometer housing and directs light to a cross-disperser grating. An echelle immersions grating and a catadioptric lens are positioned in the housing to receive the light. A cryogenically cooled detector is located in the housing on the second side of the spectrometer housing. Light from the entrance slit is directed to the cross-disperser grating. The light is directed from the cross-disperser grating to the echelle immersions grating. The light is directed from the echelle immersions grating to the cryogenically cooled detector on the second side of the spectrometer housing.

  16. Neutron capture therapy with deep tissue penetration using capillary neutron focusing

    DOE Patents [OSTI]

    Peurrung, Anthony J. (Richland, WA)

    1997-01-01T23:59:59.000Z

    An improved method for delivering thermal neutrons to a subsurface cancer or tumor which has been first doped with a dopant having a high cross section for neutron capture. The improvement is the use of a guide tube in cooperation with a capillary neutron focusing apparatus, or neutron focusing lens, for directing neutrons to the tumor, and thereby avoiding damage to surrounding tissue.

  17. Neutron Beta-Decay Jeff Martin

    E-Print Network [OSTI]

    Martin, Jeff

    : ­ superthermal sources for UCN, SNS's for CN #12;Example Experiment: The most precise measurements of neutron

  18. Boron nitride solid state neutron detector

    DOE Patents [OSTI]

    Doty, F. Patrick

    2004-04-27T23:59:59.000Z

    The present invention describes an apparatus useful for detecting neutrons, and particularly for detecting thermal neutrons, while remaining insensitive to gamma radiation. Neutrons are detected by direct measurement of current pulses produced by an interaction of the neutrons with hexagonal pyrolytic boron nitride.

  19. The Magnetism of Neutron States

    E-Print Network [OSTI]

    B. G. Sidharth

    2003-10-01T23:59:59.000Z

    The recent measurement by Bignami and co-workers of the magnetic field of a neutron star for the first time gives a value that differs by about two orders of magnitude from the expected value. The speculation has been that the nuclear matter in the neutron stars exhibits some exotic behaviour. In this note we argue that this exotic behaviour is an anomalous statistics obeyed by the neutrons, and moreover these considerations lead to a value of the magnetic field that agrees with the observation. The same considerations also correctly give the magnetic fields of the earth and Jupiter.

  20. Scattered neutron tomography based on a neutron transport problem 

    E-Print Network [OSTI]

    Scipolo, Vittorio

    2005-11-01T23:59:59.000Z

    scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

  1. Scattered neutron tomography based on a neutron transport problem

    E-Print Network [OSTI]

    Scipolo, Vittorio

    2005-11-01T23:59:59.000Z

    scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

  2. Modulating the Neutron Flux from a Mirror Neutron Source

    SciTech Connect (OSTI)

    Ryutov, D D

    2011-09-01T23:59:59.000Z

    A 14-MeV neutron source based on a Gas-Dynamic Trap will provide a high flux of 14 MeV neutrons for fusion materials and sub-component testing. In addition to its main goal, the source has potential applications in condensed matter physics and biophysics. In this report, the author considers adding one more capability to the GDT-based neutron source, the modulation of the neutron flux with a desired frequency. The modulation may be an enabling tool for the assessment of the role of non-steady-state effects in fusion devices as well as for high-precision, low-signal basic science experiments favoring the use of the synchronous detection technique. A conclusion is drawn that modulation frequency of up to 1 kHz and modulation amplitude of a few percent is achievable. Limitations on the amplitude of modulations at higher frequencies are discussed.

  3. Lead Slowing Down Spectrometer FY2013 Annual Report

    SciTech Connect (OSTI)

    Warren, Glen A.; Kulisek, Jonathan A.; Gavron, Victor A.; Danon, Yaron; Weltz, Adam; Harris, Jason; Stewart, T.

    2013-10-29T23:59:59.000Z

    Executive Summary The Lead Slowing Down Spectrometry (LSDS) project, funded by the Materials Protection And Control Technology campaign, has been evaluating the feasibility of using LSDS techniques to assay fissile isotopes in used nuclear fuel assemblies. The approach has the potential to provide considerable improvement in the assay of fissile isotopic masses in fuel assemblies compared to other non-destructive techniques in a direct and independent manner. This report is a high level summary of the progress completed in FY2013. This progress included: • Fabrication of a 4He scintillator detector to detect fast neutrons in the LSDS operating environment. Testing of the detector will be conducted in FY2014. • Design of a large area 232Th fission chamber. • Analysis using the Los Alamos National Laboratory perturbation model estimated the required number of neutrons for an LSDS measurement to be 10 to the 16th source neutrons. • Application of the algorithms developed at Pacific Northwest National Laboratory to LSDS measurement data of various fissile samples conducted in 2012. The results concluded that the 235U could be measured to 2.7% and the 239Pu could be measured to 6.3%. Significant effort is yet needed to demonstrate the applicability of these algorithms for used-fuel assemblies, but the results reported here are encouraging in demonstrating that we are making progress toward that goal. • Development and cost-analysis of a research plan for the next critical demonstration measurements. The plan suggests measurements on fresh fuel sub assemblies as a means to experimentally test self-attenuation and the use of fresh mixed-oxide fuel as a means to test simultaneous measurement of 235U and 239Pu.

  4. The nuclear physics of neutron stars

    SciTech Connect (OSTI)

    Piekarewicz, J. [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States)

    2014-05-09T23:59:59.000Z

    We explore the unique and fascinating structure of neutron stars. Although neutron stars are of interest in many areas of Physics, our aim is to provide an intellectual bridge between Nuclear Physics and Astrophysics. We argue against the naive perception of a neutron star as a uniform assembly of neutrons packed to enormous densities. Rather, by focusing on the many exotic phases that are speculated to exist in a neutron star, we show how the reality is different and far more interesting.

  5. Proposal for the award of thin-walled precision aluminium alloy tubes for the Atlas Muon Spectrometer

    E-Print Network [OSTI]

    1999-01-01T23:59:59.000Z

    Proposal for the award of thin-walled precision aluminium alloy tubes for the Atlas Muon Spectrometer

  6. Present status and plans for upgrading the Lujan neutron scattering center

    SciTech Connect (OSTI)

    Rhyne, James J [LANSCE-LC

    2010-01-01T23:59:59.000Z

    The Lujan Center, part of the LANSCE accelerator complex at Los Alamos National Laboratory, operates a comprehensive neutron scattering facility for the U.S. Department of Energy that serves approximately 300 users per year. This paper will discuss the current instruments and status of the facility and also focus on the plans for a major upgrade of the Center including new instruments and enhancements to specific existing instruments. The instrument suite currently includes two reflectometers (one with full polarization), an engineering diffraction machine, a diffractometer specialized to pair-distribution analysis, 2 general purpose powder diffractometers, and 2 inelastic spectrometers. To complement these spectrometers, a full range of pressure, temperature, and magnetic field sample environments is available for users. As part of the planning for a forthcoming enhancement of Lujan Center, a series of workshops have been held over the past year to encourage user input to the design for new instruments as well as major upgrades of existing machines. Many of the planned facilities are designed to take advantage of the Lujan Center 20 Hz pulse repetition rate and cold source moderators, both of which are beneficial for high-resolution instruments using long neutron wavelengths.

  7. Los Alamos Neutron Science Center The Los Alamos Neutron Science Center (LANSCE) is a

    E-Print Network [OSTI]

    a target of tungsten metal, neutrons are produced. These neutrons and protons are used to investigate, high explosives used to initiate weapons detonations, and radioisotope production for medical the Isotope Production Facility, Lujan Center, Proton Radiography Facility, Ultracold Neutrons Facility

  8. Distribution of neutron resonance widths

    E-Print Network [OSTI]

    Hans A. Weidenmueller

    2011-10-28T23:59:59.000Z

    Recent data on neutron resonance widths indicate disagreement with the Porter-Thomas distribution (PTD). I discuss the theoretical arguments for the PTD, possible theoretical modifications, and I summarize the experimantal evidence.

  9. Coherent control of neutron interferometry

    E-Print Network [OSTI]

    Pushin, Dmitry A

    2007-01-01T23:59:59.000Z

    In this thesis, several novel techniques are proposed and demonstrated for measuring the coherent properties of materials and testing aspects of quantum information processing using a single crystal neutron interferometer. ...

  10. Materials for spallation neutron sources

    SciTech Connect (OSTI)

    Sommer, W.F.; Daemen, L.L. [comps.

    1996-03-01T23:59:59.000Z

    The Workshop on Materials for Spallation Neutron Sources at the Los Alamos Neutron Science Center, February 6 to 10, 1995, gathered scientists from Department of Energy national laboratories, other federal institutions, universities, and industry to discuss areas in which work is needed, successful designs and use of materials, and opportunities for further studies. During the first day of the workshop, speakers presented overviews of current spallation neutron sources. During the next 3 days, seven panels allowed speakers to present information on a variety of topics ranging from experimental and theoretical considerations on radiation damage to materials safety issues. An attempt was made to identify specific problems that require attention within the context of spallation neutron sources. This proceedings is a collection of summaries from the overview sessions and the panel presentations.

  11. Ion chamber based neutron detectors

    DOE Patents [OSTI]

    Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

    2014-12-16T23:59:59.000Z

    A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

  12. acp safeguards neutron: Topics by E-print Network

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

    29 Supercool Neutrons (Ultracold Neutrons) Physics Websites Summary: . Korobkina, NCSU Neutron scattering is a valuable tool to study the structure of materials. Because Helium...

  13. Neutron Scattering: Condensed Matter and Magnetic Science, MPA...

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

    Neutron Scattering Neutron Scattering Capability description: Neutron scattering is a powerful probe of structure and collective modes of condensed matter. We are focused on direct...

  14. Application of neutron computed tomography in the geosciences

    E-Print Network [OSTI]

    Wilding, M.; Shields, K.; Lesher, C. E.

    2005-01-01T23:59:59.000Z

    of neutron computed tomography in the geosciences Martinthat applies neutron computed tomography (CT) to geologicalthe use of neutron computed tomography (CT) in the analy-

  15. 11th LANSCE School on Neutron Scattering | About the School

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

    students calculate results About the LANSCE School on Neutron Scattering The annual Los Alamos Neutron Science Center (LANSCE) School on Neutron Scattering is 9- to 10-day school...

  16. Neutron detectors comprising boron powder

    DOE Patents [OSTI]

    Wang, Zhehui; Morris, Christopher; Bacon, Jeffrey Darnell; Makela, Mark F; Spaulding, Randy Jay

    2013-05-21T23:59:59.000Z

    High-efficiency neutron detector substrate assemblies comprising a first conductive substrate, wherein a first side of the substrate is in direct contact with a first layer of a powder material comprising .sup.10boron, .sup.10boron carbide or combinations thereof, and wherein a conductive material is in proximity to the first layer of powder material; and processes of making said neutron detector substrate assemblies.

  17. Alternative Neutron Detection Testing Summary

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Ely, James H.; Erikson, Luke E.; Kernan, Warnick J.; Lintereur, Azaree T.; Siciliano, Edward R.; Stromswold, David C.; Woodring, Mitchell L.

    2010-04-08T23:59:59.000Z

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. Most currently deployed radiation portal monitors (RPMs) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large area neutron detector. This type of neutron detector is used in the TSA and other RPMs installed in international locations and in the Ludlum and Science Applications International Corporation RPMs deployed primarily for domestic applications. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated wavelength-shifting plastic fibers. Reported here is a summary of the testing carried out at Pacific Northwest National Laboratory on these technologies to date, as well as measurements on 3He tubes at various pressures. Details on these measurements are available in the referenced reports. Sponsors of these tests include the Department of Energy (DOE), Department of Homeland Security (DHS), and the Department of Defense (DoD), as well as internal Pacific Northwest National Laboratory funds.

  18. Upgrades of the high resolution imaging x-ray crystal spectrometers on experimental advanced superconducting tokamak

    SciTech Connect (OSTI)

    Lu, B.; Wang, F.; Fu, J.; Li, Y.; Wan, B. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Shi, Y. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon (Korea, Republic of); Bitter, M.; Hill, K. W. [Princeton Plasma Physics Laboratory, MS37-B332, Princeton, New Jersey 08543-0451 (United States); Lee, S. G. [National Fusion Research Institute, 52 Eoeun-Dong, Yusung-Gu, Daejeon (Korea, Republic of)

    2012-10-15T23:59:59.000Z

    Two imaging x-ray crystal spectrometers, the so-called 'poloidal' and 'tangential' spectrometers, were recently implemented on experimental advanced superconducting tokamak (EAST) to provide spatially and temporally resolved impurity ion temperature (T{sub i}), electron temperature (T{sub e}) and rotation velocity profiles. They are derived from Doppler width of W line for Ti, the intensity ratio of Li-like satellites to W line for Te, and Doppler shift of W line for rotation. Each spectrometer originally consisted of a spherically curved crystal and a two-dimensional multi-wire proportional counter (MWPC) detector. Both spectrometers have now been upgraded. The layout of the tangential spectrometer was modified, since it had to be moved to a different port, and the spectrometer was equipped with two high count rate Pilatus detectors (Model 100 K) to overcome the count rate limitation of the MWPC and to improve its time resolution. The poloidal spectrometer was equipped with two spherically bent crystals to record the spectra of He-like and H-like argon simultaneously and side by side on the original MWPC. These upgrades are described, and new results from the latest EAST experimental campaign are presented.

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

    DOE Patents [OSTI]

    Fan, N.Q.; Clarke, J.

    1993-10-19T23:59:59.000Z

    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. 7 figures.

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

    DOE Patents [OSTI]

    Fan, Non Q. (San Diego, CA); Clarke, John (Berkeley, CA)

    1993-01-01T23:59:59.000Z

    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.

  1. A high-resolution imaging x-ray crystal spectrometer for high energy density plasmas

    SciTech Connect (OSTI)

    Chen, Hui, E-mail: chen33@llnl.gov, E-mail: bitter@pppl.gov; Magee, E.; Nagel, S. R.; Park, J.; Schneider, M. B.; Stone, G.; Williams, G. J.; Beiersdorfer, P. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550-9234 (United States); Bitter, M., E-mail: chen33@llnl.gov, E-mail: bitter@pppl.gov; Hill, K. W. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Kerr, S. [Department of Applied Science, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada)

    2014-11-15T23:59:59.000Z

    Adapting a concept developed for magnetic confinement fusion experiments, an imaging crystal spectrometer has been designed and tested for HED plasmas. The instrument uses a spherically bent quartz [211] crystal with radius of curvature of 490.8 mm. The instrument was tested at the Titan laser at Lawrence Livermore National Laboratory by irradiating titanium slabs with laser intensities of 10{sup 19}–10{sup 20} W/cm{sup 2}. He-like and Li-like Ti lines were recorded, from which the spectrometer performance was evaluated. This spectrometer provides very high spectral resolving power (E/dE > 7000) while acquiring a one-dimensional image of the source.

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

    SciTech Connect (OSTI)

    Shumack, A. E., E-mail: amy.shumack@ccfe.ac.uk [JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); FOM Institute DIFFER, P.O. Box 1207, NL-3430 BE Nieuwegein (Netherlands); Rzadkiewicz, J. [National Centre for Nuclear Research, Andrzeja So?tana 7, 05-400 Otwock (Poland); Chernyshova, M.; Czarski, T.; Karpinski, L. [Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw (Poland); Jakubowska, K. [Institute of Plasma Physics and Laser Microfusion, Hery 23, 01-497 Warsaw (Poland); Université Bordeaux, CNRS, CEA, CELIA, UMR 5107, F-33405 Talence (France); Scholz, M. [Institute of Nuclear Physics PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Byszuk, A.; Cieszewski, R.; Kasprowicz, G.; Pozniak, K.; Wojenski, A.; Zabolotny, W. [Institute of Electronic Systems, Warsaw University of Technology, 00-665 Warsaw (Poland); Dominik, W. [Faculty of Physics, Institute of Experimental Physics, Warsaw University, 00-681 Warsaw (Poland); Conway, N. J.; Dalley, S.; Tyrrell, S.; Zastrow, K.-D. [JET-EFDA, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Figueiredo, J. [EFDA-CSU, Culham Science Centre, Abingdon OX14 3DB (United Kingdom); Associação EURATOM/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Av Rovisco Pais, 1049-001 Lisbon (Portugal); and others

    2014-11-15T23:59:59.000Z

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

  3. High-Sensitivity Delayed-Coincidence Spectrometer to Search for Short-Lived Nuclear States

    E-Print Network [OSTI]

    Morozov, V A; Norseev, Yu V; Sereeter, Z; Zlokazov, V B

    2002-01-01T23:59:59.000Z

    A high-sensitivity four-dimensional triple-coincidence spectrometer with two detectors is developed on the basis of an autocorrelation single-crystal scintillation time 4{\\pi} spectrometer and a semiconductor HPGe detector. The delayed-coincidence spectrometer is designed for searching for isomeric nano- and microsecond states in short-lived nuclei and for their related gamma-rays. Half-lives of short-lived states are measured in the range from 4 ns to 4 {\\mu}s. The sufficient activity of the monoisotopic source for the investigations does not exceed 0.01 {\\mu}Ci.

  4. First Measurements with a Lead Slowing-Down Spectrometer at LANSCE

    E-Print Network [OSTI]

    Danon, Yaron

    the 750 µs proton pulses from the linac into pulses of typically 250-300 ns. The neutron production is realized by spallation in a tungsten target. The tungsten target is a cylinder 25 cm long and 736 CP769. The neutron spectrum from the tungsten is a typical spallation neutron flux, with a maximum at 2 MeV. Energy

  5. ASIC for SDD-Based X-Ray Spectrometers

    SciTech Connect (OSTI)

    G De Geronimo; P Rehak; K Ackley; G Carini; W Chen; J Fried; J Keister; S Li; Z Li; et al.

    2011-12-31T23:59:59.000Z

    We present an application-specific integrated circuit (ASIC) for high-resolution x-ray spectrometers (XRS). The ASIC reads out signals from pixelated silicon drift detectors (SDDs). The pixel does not have an integrated field effect transistor (FET); rather, readout is accomplished by wire-bonding the anodes to the inputs of the ASIC. The ASIC dissipates 32 mW, and offers 16 channels of low-noise charge amplification, high-order shaping with baseline stabilization, discrimination, a novel pile-up rejector, and peak detection with an analog memory. The readout is sparse and based on custom low-power tristatable low-voltage differential signaling (LPT-LVDS). A unit of 64 SDD pixels, read out by four ASICs, covers an area of 12.8 cm{sup 2} and dissipates with the sensor biased about 15 mW/cm{sup 2}. As a tile-based system, the 64-pixel units cover a large detection area. Our preliminary measurements at -44 C show a FWHM of 145 eV at the 5.9 keV peak of a {sup 55}Fe source, and less than 80 eV on a test-pulse line at 200 eV.

  6. In-situ droplet monitoring for self-tuning spectrometers

    DOE Patents [OSTI]

    Montaser, Akbar (Potomac, MD); Jorabchi, Kaveh (Arlington, VA); Kahen, Kaveh (Kleinburg, CA)

    2010-09-28T23:59:59.000Z

    A laser scattering based imaging technique is utilized in order to visualize the aerosol droplets in an inductively coupled plasma (ICP) torch from an aerosol source to the site of analytical measurements. The resulting snapshots provide key information about the spatial distribution of the aerosol introduced by direct and indirect injection devices: 1) a direct injection high efficiency nebulizer (DIHEN); 2) a large-bore DIHEN (LB-DIHEN); and 3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. Moreover, particle image velocimetry (PIV) is used to study the in-situ behavior of the aerosol before interaction with, for example, plasma, while the individual surviving droplets are explored by particle tracking velocimetry (PTV). Further, the velocity distribution of the surviving droplets demonstrates the importance of the initial droplet velocities in complete desolvation of the aerosol for optimum analytical performance in ICP spectrometries. These new observations are important in the design of the next-generation direct injection devices for lower sample consumption, higher sensitivity, lower noise levels, suppressed matrix effects, and for developing smart spectrometers. For example, a controller can be provided to control the output of the aerosol source by controlling the configuration of the source or the gas flow rate via feedback information concerning the aerosol.

  7. Multichannel CdZnTe Gamma Ray Spectrometer

    SciTech Connect (OSTI)

    F. P. Doty; C. L. Lingren; B. A. Apotovsky; J. Brunsch; J. F. Butler; T. Collins; R. L. Conwell; S. Friesenhahn; J. Gormley; B. Pi; S. Zhao (Digirad Corp., San Diego, CA); F. L. Augustine, Augustine Engineering, Encinitas, CA; B. A. Bennet; E. Cross; R. B. James (Sandia Nat'l. Labs.)

    1998-07-22T23:59:59.000Z

    A 3 cm{sup 3} multichannel gamma spectrometer for DOE applications is under development by Digirad Corporation. The device is based on a position sensitive detector packaged in a compact multi-chip module (MCM) with integrated readout circuitry. The modular, multichannel design will enable identification and quantitative analysis of radionuclides in extended sources, or sources containing low levels of activity. The MCM approach has the advantages that the modules are designed for imaging applications, and the sensitivity can be arbitrarily increased by increasing the number of pixels, i.e. adding modules to the instrument. For a high sensitivity probe, the outputs for each pixel can be corrected for gain and offset variations, and summed digitally. Single pixel results obtained with discrete low noise readout indicate energy resolution of 3 keV can be approached with currently available CdZnTe. The energy resolution demonstrated to date with MCMs for 511 keV gamma rays is 10 keV.

  8. System and apparatus for neutron radiography

    SciTech Connect (OSTI)

    Whittemore, W.L.

    1991-07-02T23:59:59.000Z

    This patent describes a neutron radiography apparatus. It comprises an imaging plane; a neutron moderator having a cavity defining a convergent collimator, the cavity having a base and converging walls of neutron moderating material terminating at an aperture; a divergent collimator coaxially joined to the cavity at the aperture, the divergent collimator having diverging walls of radiation- absorbing material extending from the aperture to an expanded distal opening for irradiating the imaging plane; sources of neutrons disposed symmetrically about the base of the cavity; a neutron moderating material disposed for maximum neutron thermalization between the sources and the base of the cavity; and means for substantially shielding the plane from electromagnetic energy.

  9. atomic bomb neutrons: Topics by E-print Network

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

    the neutron density. Finally, in the case of neutron stars, where again the neutron-neutron scattering length is negative and fixed, we determine the condensate fraction as a...

  10. Addition and recombination reactions of unsaturated radicals using a novel laser kinetics spectrometer

    E-Print Network [OSTI]

    Ismail, Huzeifa

    2008-01-01T23:59:59.000Z

    This thesis describes the construction of a novel, low-noise laser kinetics spectrometer. A quasi-CW (picosecond pulse), tunable Ti:Sapphire laser is used to detect various transient species in laser flash photolysis ...

  11. What Caused the Lead burn-out in Spectrometer Magnet 2B

    E-Print Network [OSTI]

    Green, Michael A

    2011-01-01T23:59:59.000Z

    MICE Note 324 What Caused the Lead burn-out in SpectrometerThe magnet failed because a lead to coil M2 failed before itof the magnet when the lead failure occurred. The lead that

  12. Flat Quartz-Crystal X-ray Spectrometer for Nuclear Forensics Applications

    E-Print Network [OSTI]

    Goodsell, Alison

    2012-10-19T23:59:59.000Z

    structure. The higher energy background radiation was blocked from reaching the detector using a customized collimator and shielding system. A flat quartz-crystal x-ray spectrometer system was designed specifically to fit the constraints and requirements...

  13. Calibration of a gated flat field spectrometer as a function of x-ray intensity

    SciTech Connect (OSTI)

    Xiong, Gang; Yang, Guohong; Li, Hang; Zhang, Jiyan, E-mail: zhangjiyanzjy@sina.com; Zhao, Yang; Hu, Zhimin; Wei, Minxi; Qing, Bo; Yang, Jiamin; Liu, Shenye; Jiang, Shaoen [Research Center of Laser Fusion, China Academy of Engineering Physics, P. O. Box 919-986, Mianyang 621900 (China)] [Research Center of Laser Fusion, China Academy of Engineering Physics, P. O. Box 919-986, Mianyang 621900 (China)

    2014-04-15T23:59:59.000Z

    We present an experimental determination of the response of a gated flat-field spectrometer at the Shenguang-II laser facility. X-rays were emitted from a target that was heated by laser beams and then were divided into different intensities with a step aluminum filter and collected by a spectrometer. The transmission of the filter was calibrated using the Beijing Synchrotron Radiation Facility. The response characteristics of the spectrometer were determined by comparing the counts recorded by the spectrometer with the relative intensities of the x-rays transmitted through the step aluminum filter. The response characteristics were used to correct the transmission from two shots of an opacity experiment using the same samples. The transmissions from the two shots are consistent with corrections, but discrepant without corrections.

  14. Progress on the Modeling and Modification of the MICE Superconducting Spectrometer Solenoids

    E-Print Network [OSTI]

    Virostek, S.P.

    2013-01-01T23:59:59.000Z

    updated calculations confirmed the measured heat load of ~6of these calculations was the direct heat load into the coldcalculations was carried out in order to characterize the spectrometer solenoid heat loads

  15. Characterization of AP-MALDI and ESI for a differential mobility spectrometer

    E-Print Network [OSTI]

    Agrawal, Priya

    2005-01-01T23:59:59.000Z

    The following thesis entails the construction, testing, modification, and analysis of two systems that couple sample ion introduction methods with a Differential Mobility Spectrometer (DMS). The sample ionization methods ...

  16. 2013 Review of Neutron and Non-Neutron Nuclear Data

    SciTech Connect (OSTI)

    Holden, N. E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-05-23T23:59:59.000Z

    The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature over the past three years since the ISRD-14 Symposium has been performed and the highlights are presented. Included in the data review are the status of new chemical elements, new measurements of the isotopic composition for many chemical elements and the resulting change in the atomic weight values. New half-life measurements for both short-lived and longlived nuclides, some alpha decay and double beta decay measurements for quasistable nuclides are discussed. The latest evaluation of atomic masses has been published. Data from new measurements on the very heavy (trans-meitnerium) elements are discussed and tabulated. Data on various recent neutron cross section and resonance integral measurements are discussed and tabulated.

  17. - and -delayed neutron- decay of neutron-rich copper isotopes

    SciTech Connect (OSTI)

    Korgul, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Winger, J. A. [Oak Ridge Associated Universities (ORAU); Ilyushkin, S. [Mississippi State University (MSU); Gross, Carl J [ORNL; Batchelder, J. C. [Oak Ridge Associated Universities (ORAU); Bingham, C. R. [University of Tennessee, Knoxville (UTK); Borzov, Ivan N [ORNL; Goodin, C. [Vanderbilt University; Grzywacz, Robert Kazimierz [ORNL; Hamilton, Joseph H [ORNL; Krolas, W. [Joint Institute for Heavy Ion Research, Oak Ridge; Liddick, S. N. [Oak Ridge Associated Universities (ORAU); Mazzocchi, C. [University of Warsaw; Nelson, C. [Vanderbilt University; Nowacki, F. [Institut Pluridisciplinaire Hubert Curien, Strasbourg, France; Padgett, Stephen [University of Tennessee, Knoxville (UTK); Piechaczek, A. [Louisiana State University; Rajabali, M. M. [University of Tennessee, Knoxville (UTK); Shapira, Dan [ORNL; Sieja, K. [Technische Universitat Darmstadt, Germany; Zganjar, E. F. [Louisiana State University

    2012-01-01T23:59:59.000Z

    The {beta}-decay properties of neutron-rich Cu isotopes produced in proton-induced fission of {sup 238}U were studied at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory. The data were collected using high-resolution online mass separation, reacceleration, and digital {beta}-{gamma} spectroscopy methods. An improved decay scheme of N = 49 {sup 78}Cu and the first observation of N = 50 {sup 79}Cu {beta}-delayed neutron decay followed by a gamma transition are reported. Spin and parity (5{sup -}) are deduced for {sup 78gs}Cu. The {beta}-delayed neutron branching ratios (P{sub {beta}n}) for the {sup 77}Cu and {sup 79}Cu precursors are analyzed with the help of nuclear structure models.

  18. Measurement of the Wolfenstein parameters for proton-proton and proton-neutron scattering at 500 MeV

    SciTech Connect (OSTI)

    Marshall, J.A.

    1984-07-01T23:59:59.000Z

    Using liquid hydrogen and liquid deuterium targets respectively, forward angle (ten degrees to sixty degrees in the center of Mass) free proton-proton and quasielastic proton-proton and proton-neutron triple scattering data at 500 MeV have been obtained using the high resolution spectrometer at the Los Alamos Meson Physics Facility. The data are in reasonable agreement with recent predictions from phase shift analyses, indicating that the proton-nucleon scattering amplitudes are fairly well determined at 500 MeV. 32 references.

  19. Old and new neutron stars

    SciTech Connect (OSTI)

    Ruderman, M.

    1984-09-01T23:59:59.000Z

    The youngest known radiopulsar in the rapidly spinning magnetized neutron star which powers the Crab Nebula, the remnant of the historical supernova explosion of 1054 AD. Similar neutron stars are probably born at least every few hundred years, but are less frequent than Galactic supernova explosions. They are initially sources of extreme relativistic electron and/or positron winds (approx.10/sup 38/s/sup -1/ of 10/sup 12/ eV leptons) which greatly decrease as the neutron stars spin down to become mature pulsars. After several million years these neutron stars are no longer observed as radiopulsars, perhaps because of large magnetic field decay. However, a substantial fraction of the 10/sup 8/ old dead pulsars in the Galaxy are the most probable source for the isotropically distributed ..gamma..-ray burst detected several times per week at the earth. Some old neutron stars are spun-up by accretion from companions to be resurrected as rapidly spinning low magnetic field radiopulsars. 52 references, 6 figures, 3 tables.

  20. BF3 Neutron Detector Tests

    SciTech Connect (OSTI)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.; Woodring, Mitchell L.

    2009-12-09T23:59:59.000Z

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world; thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and detection capabilities are being investigated. Reported here are the results of tests of the efficiency of BF3 tubes at a pressure of 800 torr. These measurements were made partially to validate models of the RPM system that have been modified to simulate the performance of BF3-filled tubes. While BF3 could be a potential replacement for 3He, there are limitations to its use in deployed systems.

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

    SciTech Connect (OSTI)

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

    2012-06-15T23:59:59.000Z

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

  2. Charge exchange neutral particle measurements with natural diamond detector under the deuterium-deuterium neutron field on JT-60U tokamak

    SciTech Connect (OSTI)

    Ishikawa, M.; Kusama, Y.; Takechi, M.; Nishitani, T.; Morioka, A.; Sasao, M.; Isobe, M.; Krasilnikov, A.; Kaschuck, Yu. A. [Japan Atomic Energy Research Institute, Naka-machi, Naka-gun, Ibaraki 319-0193 (Japan); Tohoku University, Sendai-shi, Miyagi 980-8578 (Japan); National Institute for Fusion Science, Toki, Gihu 509-5292 (Japan); Troitsk Institute of Innovating and Fusion Research (TRINITI) Troitsk, Moscow Region 142092 (Russian Federation)

    2004-10-01T23:59:59.000Z

    A natural diamond detector (NDD) has been installed on the JT-60U tokamak to measure the flux and the energy distribution of charge exchange (CX) fast neutral particles. A NDD has many important advantages to be used as a CX neutral particle analyzer, for example very compact size, high energy resolution, and high radiation hardness etc., while the neutrons and {gamma} rays are a large noise source in the deuterium plasma. The shield was set up around the NDD to reduce those noises. Time-resolved energy distribution of CX neutral particles corresponding to injected beam energy have been successfully obtained under high intensity neutron yield Y{sub n}>10{sup 15} n/s. Further enhanced neutral particle fluxes during sawtooth oscillation and Alfven eigenmodes were observed with the NDD. The performance of the NDD as CX neutral particle spectrometer under high intensity neutron yield was demonstrated for the first time on JT-60U in this work.

  3. Neutronic fuel element fabrication

    DOE Patents [OSTI]

    Korton, George (Cincinnati, OH)

    2004-02-24T23:59:59.000Z

    This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure by encompassing the sides of the fuel element between the header plates.

  4. Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.

    SciTech Connect (OSTI)

    Franco, Manuel,

    2014-08-01T23:59:59.000Z

    The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential experimental configurations and neutron spectra for component irradiation. The final product of this work is a MCNP model validated by measurements, an overall understanding of neutron irradiation system including photon/neutron transport and effective dose rates throughout the system, and possible experimental configurations for future irradiation of components.

  5. Preliminary results from the lunar prospector alpha particle spectrometer

    SciTech Connect (OSTI)

    Lawson, S. L. (Stefanie L.)

    2001-01-01T23:59:59.000Z

    The Lunar Prospector Alpha Particle Spectrometer (LP APS) builds on Apollo heritage and maps the distribution of outgassing sites on the Moon. The APS searches for lunar surface gas release events and maps their distribution by detecting alpha particles produced by the decay of gaseous radon-222 (5.5 MeV, 3.8 day half-life) and solid polonium-210 (5.3 MeV, 138 day half-life, but remains on the surface with a 21 year half-life as lead-210), which are radioactive daughters from the decay of uranium-238. Radon is in such small quantities that it is not released directly from the lunar interior, rather it is entrained in a stream of gases and serves as a tracer for such gases. Once released, the radon spreads out by 'bouncing' across the surface on ballistic trajectories in a random-walk process. The 3.8 day half-life of radon-222 allows the gas to spread out by several 100 km before it decays and allows the APS to detect gas release events up to a few days after they occur. The long residence time (10s of years) of the lead-210 precursor to the polonium-210 allows the mapping of gas vents which have been active over the last approximately 50 years. Because radon and polonium are daughter products of the decay of uranium, the background level of alpha particle activity is a function of the lunar crustal uranium distribution. Using radioactive radon and polonium as tracers, the Apollo 15 and 16 Command Module orbital alpha particle experiments obtained evidence for the release of gases at several sites beneath the orbit tracks, especially over the Aristarchus Plateau and Mare Fecunditatis [1]. Aristarchus crater had previously been identified by ground-based observers as the site of transient optical events [2]. The Apollo 17 surface mass spectrometer showed that argon-40 is released from the lunar interior every few months, apparently in concert with some of the shallow moonquakes that are believed to be of tectonic origin [3]. The latter tectonic events could be associated with very young scarps identified in the lunar highlands [4] and are believed to indicate continued global contraction. Such quakes could open fissures leading to the release of gases that are trapped below the surface. The detection of radon-222 outgassing events at the margins of Fecunditatis basin was surprising because the observed surface distribution of uranium and thorium do not extend sufficiently eastward to cover Fecunditatis. If the Apollo detections prove sound, then those alpha particle emissions indicate substantial subsurface concentrations of uranium-238 within Fecunditatis. A primary goal of the APS was to map gas-release events, thus allowing both an appraisal of the current level of tectonic activity on the Moon and providing a probe of subsurface uranium concentrations.

  6. Neutron Imaging of Diesel Particulate Filters

    Broader source: Energy.gov (indexed) [DOE]

    August 3 2009 Non-invasive, non-destructive technique based on attenuation of the neutron beam. Neutrons interact with nuclei and their scattering power does not vary in...

  7. 10th LANSCE School on Neutron Scattering

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

    10th LANSCE School on Neutron Scattering LANSCE 10th LANSCE School on Neutron Scattering Home Abstract Lecturers Hands-On Experiments Free Day About the School Sponsors FAQ's...

  8. SEARCH FOR NEUTRON ANTI-NEUTRON OSCILLATION AT THE SUDBURY NEUTRINO OBSERVATORY

    E-Print Network [OSTI]

    Waltham, Chris

    SEARCH FOR NEUTRON ANTI-NEUTRON OSCILLATION AT THE SUDBURY NEUTRINO OBSERVATORY A Thesis Presented to explain the baryon asymmetry of the universe. In this thesis, a limit on the neutron anti-neutron (nnbar is sampled from the three phases of the SNO experiment to construct a three-phase blind analysis. The profile

  9. Proposal for a 30-T Pulsed Magnet Suitable for Neutron Scattering Experiments

    E-Print Network [OSTI]

    Robinson Eyssa Schneider-Muntau; R. A. Robinson (a; Y. M. Eyssa (b; H. J. Schneider-muntau (b; H. J. Boenig (a

    this paper, we describe a conceptual design for a 30-T pulsed magnet that could be used in conjunction with neutron-scattering apparatus, along with the scientific opportunities that such a magnet might open up. Neutron diffraction has long been the technique of choice for determining the arrangements (magnetic structures) of magnetic moments in solids, the spatial extent of the magnetic electrons around their parent ions (form factors) and the full moment-density distribution function in real space. The proposed 30-T magnet would enable one to study such spatial aspects of many field-induced phase transitions for the first time, whether they are driven by competing exchange interactions, single-ion anisotropy, or a more radical change, say from an itinerant to a localised state. Inelastic Neutron Scattering, on the other hand, is the best general-purpose tool for the study of magnetic excitations like spin waves, crystal-field levels and spin fluctuations. These excitations manifest themselves in the imaginary part of the generalised magnetic susceptibility c"(Q,w), which is measured directly in a neutron scattering experiment. A field of 30T acting on a moment of 1 B corresponds to an energy of 1.7 meV, and we should be able to generate splittings or close gaps of this order. The present generation of spectrometers at spallation neutron sources have both sufficient resolution (as good as 10 eV) and sufficient dynamic range (up to 2 eV) to cover the effects that might be induced by such a field.

  10. Neutron scattering and models: Titanium

    SciTech Connect (OSTI)

    Smith, A.B.

    1997-07-01T23:59:59.000Z

    Differential neutron elastic-scattering cross sections of elemental titanium were measured from 4.5 {r_arrow} 10.0 MeV in incident energy increments of {approx} 0.5 MeV. At each energy the measurements were made at forty or more scattering angles distributed between {approx} 17 and 160{degree}. Concurrently, differential neutron inelastic-scattering cross sections were measured for observed excitations of 0.975 {+-} 0.034, 1.497 {+-} 0.033, 2.322 {+-} 0.058, 3.252 {+-} 0.043, 3.700 {+-} 0.093, 4.317 {+-} 0.075 and 4.795 {+-} 0.100 MeV. All of the observed inelastically-scattered neutron groups were composites of contributions from several isotopes and/or levels. The experimental results were used to develop energy-average optical, statistical and coupled-channels models.

  11. Measurement of the structure function of the nearly free neutron using spectator tagging in inelastic $^2$H(e, e'p)X scattering with CLAS

    E-Print Network [OSTI]

    S. Tkachenko; N. Baillie; S. E. Kuhn; J. Zhang; J. Arrington; P. Bosted; S. Bültmann; M. E. Christy; D. Dutta; R. Ent; H. Fenker; K. A. Griffioen; M. Ispiryan; N. Kalantarians; C. E. Keppel; W. Melnitchouk; V. Tvaskis; K. P. Adhikari; M. Aghasyan; M. J. Amaryan; S. Anefalos Pereira; H. Avakian; J. Ball; N. A. Baltzell; M. Battaglieri; I. Bedlinskiy; A. S. Biselli; W. J. Briscoe; W. K. Brooks; V. D. Burkert; D. S. Carman; A. Celentano; S. Chandavar; G. Charles; P. L. Cole; M. Contalbrigo; O. Cortes; V. Crede; A. D'Angelo; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; C. Djalali; G. E. Dodge; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; L. Elouadrhiri; P. Eugenio; G. Fedotov; J. A. Fleming; B. Garillon; N. Gevorgyan; Y. Ghandilyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; E. Golovatch; R. W. Gothe; M. Guidal; L. Guo; K. Hafidi; H. Hakobyan; C. Hanretty; N. Harrison; M. Hattawy; K. Hicks; D. Ho; M. Holtrop; C . E. Hyde; Y. Ilieva; D. G. Ireland; B. S. Ishkhanov; H. S. Jo; D. Keller; M. Khandaker; A. Kim; W. Kim; P. M. King; A. Klein; F. J. Klein; S. Koirala; V. Kubarovsky; S. V. Kuleshov; P. Lenisa; S. Lewis; K. Livingston; H. Lu; M. MacCormick; I. J. D. MacGregor; N. Markov; M. Mayer; B. McKinnon; T. Mineeva; M. Mirazita; V. Mokeev; R. A. Montgomery; H. Moutarde; C. Munoz Camacho; P. Nadel-Turonski; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; L. L. Pappalardo; R. Paremuzyan; K. Park; E. Pasyuk; J. J. Phillips; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; A. J . R. Puckett; D. Rimal; M. Ripani; A. Rizzo; G. Rosner; P. Rossi; P. Roy; F. Sabatié; D. Schott; R. A. Schumacher; E. Seder; I. Senderovich; Y. G. Sharabian; A. Simonyan; G. D. Smith; D. I. Sober; D. Sokhan; S. Stepanyan; S. S. Stepanyan; S. Strauch; W. Tang; M. Ungaro; A. V. Vlassov; H. Voskanyan; E. Voutier; N. K. Walford; D. Watts; X. Wei; L. B. Weinstein; M. H. Wood; L. Zana; I. Zonta

    2014-10-03T23:59:59.000Z

    Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear binding and nucleon off-shell effects. These corrections are model dependent and have significant uncertainties, especially for large values of the Bjorken scaling variable x. The Barely Off-shell Nucleon Structure (BONuS) experiment at Jefferson Lab measured the inelastic electron deuteron scattering cross section, tagging spectator protons in coincidence with the scattered electrons. This method reduces nuclear binding uncertainties significantly and has allowed for the first time a (nearly) model independent extraction of the neutron structure function. A novel compact radial time projection chamber was built to detect protons with momentum between 70 and 150 MeV/c. For the extraction of the free neutron structure function $F_{2n}$, spectator protons at backward angle and with momenta below 100 MeV/c were selected, ensuring that the scattering took place on a nearly free neutron. The scattered electrons were detected with Jefferson Lab's CLAS spectrometer. The extracted neutron structure function $F_{2n}$ and its ratio to the deuteron structure function $F_{2d}$ are presented in both the resonance and deep inelastic regions. The dependence of the cross section on the spectator proton momentum and angle is investigated, and tests of the spectator mechanism for different kinematics are performed. Our data set can be used to study neutron resonance excitations, test quark hadron duality in the neutron, develop more precise parametrizations of structure functions, as well as investigate binding effects (including possible mechanisms for the nuclear EMC effect) and provide a first glimpse of the asymptotic behavior of d/u as x goes to 1.

  12. LAT and Solar Neutrons: Preliminary estimates

    SciTech Connect (OSTI)

    Longo, Francesco [Department of Physics, University of Trieste, Trieste, via Valerio 2, 34127 Trieste (Italy)]|[INFN, Trieste, via Valerio 2, 34127 Trieste (Italy)

    2007-07-12T23:59:59.000Z

    GLAST LAT will detect several solar flares in gamma rays. Motivated by the CGRO results on neutrons emitted during a solar flare, we try to estimate the possibility of the LAT to detect solar neutrons. Besides gamma rays, neutrons could indeed interact in the LAT instrument and mimic a gamma-ray signal. An estimate of the contamination of gamma-ray detection in solar flares by the neutron component is given.

  13. Nuclear Physics of Neutron Stars

    E-Print Network [OSTI]

    J. Piekarewicz

    2009-01-28T23:59:59.000Z

    Understanding the equation of state (EOS) of cold nuclear matter, namely, the relation between the pressure and energy density, is a central goal of nuclear physics that cuts across a variety of disciplines. Indeed, the limits of nuclear existence, the collision of heavy ions, the structure of neutron stars, and the dynamics of core-collapse supernova, all depend critically on the equation of state of hadronic matter. In this contribution I will concentrate on the special role that nuclear physics plays in constraining the EOS of cold baryonic matter and its impact on the properties of neutron stars.

  14. CHINA SPALLATION NEUTRON SOURCE DESIGN.

    SciTech Connect (OSTI)

    WEI,J.

    2007-01-29T23:59:59.000Z

    The China Spallation Neutron Source (CSNS) is an accelerator-based high-power project currently in preparation under the direction of the Chinese Academy of Sciences (CAS). The complex is based on an H- linear accelerator, a rapid cycling proton synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station, and five initial instruments for spallation neutron applications. The facility will operate at 25 Hz repetition rate with a phase-I beam power of about 120 kW. The major challenge is to build a robust and reliable user's facility with upgrade potential at a fractional of ''world standard'' cost.

  15. High-pressure neutron diffraction

    SciTech Connect (OSTI)

    Xu, Hongwu [Los Alamos National Laboratory

    2011-01-10T23:59:59.000Z

    This lecture will cover progress and prospect of applications of high-pressure neutron diffraction techniques to Earth and materials sciences. I will first introduce general high-pressure research topics and available in-situ high-pressure techniques. Then I'll talk about high-pressure neutron diffraction techniques using two types of pressure cells: fluid-driven and anvil-type cells. Lastly, I will give several case studies using these techniques, particularly, those on hydrogen-bearing materials and magnetic transitions.

  16. Neutron Transversity at Jefferson Lab

    SciTech Connect (OSTI)

    Jian-Ping Chen; Xiaodong Jiang; Jen-chieh Peng; Lingyan Zhu

    2005-09-07T23:59:59.000Z

    Nucleon transversity and single transverse spin asymmetries have been the recent focus of large efforts by both theorists and experimentalists. On-going and planned experiments from HERMES, COMPASS and RHIC are mostly on the proton or the deuteron. Presented here is a planned measurement of the neutron transversity and single target spin asymmetries at Jefferson Lab in Hall A using a transversely polarized {sup 3}He target. Also presented are the results and plans of other neutron transverse spin experiments at Jefferson Lab. Finally, the factorization for semi-inclusive DIS studies at Jefferson Lab is discussed.

  17. Neutron Science | More Science | ORNL

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire Solar541,9337, 2011 at3,Neutron Scattering3 Neutron

  18. A neutron transmission study of environmental Gd

    E-Print Network [OSTI]

    Cristiana Oprea; Ioan Alexandru Oprea; Alexandru Mihul

    2014-06-02T23:59:59.000Z

    A new method for the determination of environmental Gd by neutron transmission (NT) experiments is proposed. The NT method is based on the measurements of neutron spectra passing through a target. From the attenuation neutron spectra new data as concentration, width, resonance energies and cross section have been obtained.

  19. Neutron Scattering Studies of Correlated Electron Systems

    E-Print Network [OSTI]

    Boothroyd, Andrew

    Neutron Scattering Studies of Correlated Electron Systems Lucy Helme Thesis submitted submitted for the Degree of Doctor of Philosophy, Trinity Term 2006 This thesis presents neutron scatteringO2, through inelastic neutron scattering studies of the crystal field transitions above and below

  20. RisR1125(EN) Neutron Scattering

    E-Print Network [OSTI]

    Risø­R­1125(EN) Neutron Scattering Studies of Modulated Magnetic Structures Steen Aagaard Sørensen investigations of the magnetic systems DyFe4Al8 and MnSi by neutron scattering and in the former case also by X and the correlations between the scattering entities of the sample. The theoretical framework of neutron scattering

  1. Measurements of the Thermal Neutron Scattering Kernel

    E-Print Network [OSTI]

    Danon, Yaron

    Measurements of the Thermal Neutron Scattering Kernel Li (Emily) Liu, Yaron Danon, Bjorn Becker and discussions Problems and Future study Questions #12;3 M. Mattes and J. Keinert, Thermal Neutron Scattering experimental data used was from 1973-1974! M. Mattes and J. Keinert, Thermal Neutron Scattering Data

  2. Neutron production enhancements for the Intense Pulsed Neutron Source.

    SciTech Connect (OSTI)

    Iverson, E. B.

    1999-01-04T23:59:59.000Z

    The Intense Pulsed Neutron Source (IPNS) was the first high energy spallation neutron source in the US dedicated to materials research. It has operated for sixteen years, and in that time has had a very prolific record concerning the development of new target and moderator systems for pulsed spallation sources. IPNS supports a very productive user program on its thirteen instruments, which are oversubscribed by more than two times, meanwhile having an excellent overall reliability of 95%. Although the proton beam power is relatively low at 7 kW, the target and moderator systems are very efficient. The typical beam power which gives an equivalent flux for long-wavelength neutrons is about 60 kW, due to the use of a uranium target and liquid and solid methane moderators, precluded at some sources due to a higher accelerator power. The development of new target and moderator systems is by no means stagnant at IPNS. They are presently considering numerous enhancements to the target and moderators that offer prospects for increasing the useful neutron production by substantial factors. Many of these enhancements could be combined, although their combined benefit has not yet been well established. Meanwhile, IPNS is embarking on a coherent program of study concerning these improvements and their possible combination and implementation. Moreover, any improvements accomplished at IPNS would immediately increase the performance of IPNS instruments.

  3. 2002 REVIEW OF NEUTRON AND NON NEUTRON NUCLEAR DATA.

    SciTech Connect (OSTI)

    HOLDEN,N.E.

    2002-08-18T23:59:59.000Z

    Review articles are in preparation for the 2003 edition of the CRC's Handbook of Chemistry and Physics dealing with both non-neutron and neutron nuclear data. Highlights include: withdrawal of the claim for discovery of element 118; new measurements of isotopic abundances have led to changes for many elements; a new set of recommended standards for calibration of {gamma}-ray energies have been published for many nuclides; new half-life measurements reported for very short lived isotopes, many long-lived nuclides and {beta}{beta} decay measurements for quasi-stable nuclides; a new reassessment of spontaneous fission (sf) half-lives for ground state nuclides, distinguishing half-lives from sf decay and cluster decay half-lives and the new cluster-fission decay; charged particle cross sections, (n,p) and (n,{alpha}) measurements for thermal neutrons incident on light nuclides; new thermal (n,{gamma}) cross sections and neutron resonance integrals measured. Details are presented.

  4. Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem

    SciTech Connect (OSTI)

    William Charlton

    2007-07-01T23:59:59.000Z

    Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.

  5. Neutron producing target for accelerator based neutron source for

    E-Print Network [OSTI]

    Taskaev, Sergey Yur'evich

    therapy [1, 2]. Lithium targets for two modes of neutron beam production are developed. The first one. Target will be created as a 2 ­ 3 µm thick lithium layer on the surface of tungsten disk cooled by liquidW cm­2 . ii) Production of target with lithium layer thickness of 2 ­ 3 µm. #12;248 iii) Evaporation

  6. Neutron capture therapy with deep tissue penetration using capillary neutron focusing

    DOE Patents [OSTI]

    Peurrung, A.J.

    1997-08-19T23:59:59.000Z

    An improved method is disclosed for delivering thermal neutrons to a subsurface cancer or tumor which has been first doped with a dopant having a high cross section for neutron capture. The improvement is the use of a guide tube in cooperation with a capillary neutron focusing apparatus, or neutron focusing lens, for directing neutrons to the tumor, and thereby avoiding damage to surrounding tissue. 1 fig.

  7. The Manuel Lujan Jr. Neutron Scattering Center (LANSCE) experiment reports 1993 run cycle. Progress report

    SciTech Connect (OSTI)

    Farrer, R.; Longshore, A. [comps.

    1995-06-01T23:59:59.000Z

    This year the Manuel Lujan Jr. Neutron Scattering Center (LANSCE) ran an informal user program because the US Department of Energy planned to close LANSCE in FY1994. As a result, an advisory committee recommended that LANSCE scientists and their collaborators complete work in progress. At LANSCE, neutrons are produced by spallation when a pulsed, 800-MeV proton beam impinges on a tungsten target. The proton pulses are provided by the Clinton P. Anderson Meson Physics Facility (LAMPF) accelerator and a associated Proton Storage Ring (PSR), which can Iter the intensity, time structure, and repetition rate of the pulses. The LAMPF protons of Line D are shared between the LANSCE target and the Weapons Neutron Research (WNR) facility, which results in LANSCE spectrometers being available to external users for unclassified research about 80% of each annual LAMPF run cycle. Measurements of interest to the Los Alamos National Laboratory (LANL) may also be performed and may occupy up to an additional 20% of the available beam time. These experiments are reviewed by an internal program advisory committee. This year, a total of 127 proposals were submitted. The proposed experiments involved 229 scientists, 57 of whom visited LANSCE to participate in measurements. In addition, 3 (nuclear physics) participating research teams, comprising 44 scientists, carried out experiments at LANSCE. Instrument beam time was again oversubscribed, with 552 total days requested an 473 available for allocation.

  8. Data for Users of Handheld Ion Mobility Spectrometers

    SciTech Connect (OSTI)

    Keith A. Daum; Sandra L. Fox

    2008-05-01T23:59:59.000Z

    Chemical detection technology end-user surveys conducted by Idaho National Laboratory (INL) in 2005 and 2007 indicated that first responders believed manufacturers’ claims for instruments sometimes were not supported in field applications, and instruments sometimes did not meet their actual needs. Based on these findings, the Department of Homeland Security (DHS) asked INL to conduct a similar survey for handheld ion mobility spectrometers (IMS), which are used by a broad community of first responders as well as for other applications. To better access this broad community, the INL used the Center for Technology Commercialization, Inc. (CTC), Public Safety Technology Center (PSTC) to set up an online framework to gather information from users of handheld IMS units. This framework (Survey Monkey) was then used to perform an online Internet survey, augmented by e-mail prompts, to get information from first responders and personnel from various agencies about their direct experience with handheld IMS units. Overall, 478 individuals responded to the survey. Of these, 174 respondents actually owned a handheld IMS. Performance and satisfaction data from these 174 respondents are captured in this report. The survey identified the following observations: • The most common IMS unit used by respondents was the Advanced Portable Detector (APD 2000), followed by ChemRae, Sabre 4000, Sabre 2000, Draeger Multi IMS, Chemical Agent Monitor-2, Chemical Agent Monitor, Vapor Tracer, and Vapor Tracer 2. • The primary owners were HazMat teams (20%), fire services (14%), local police (12%), and sheriffs’ departments (9%). • IMS units are seldom used as part of an integrated system for detecting and identifying chemicals but instead are used independently. • Respondents are generally confused about the capabilities of their IMS unit. This is probably a result of lack of training. • Respondents who had no training or fewer than 8 hours were not satisfied with the overall operation of the handheld IMS unit. • IMS units were used for detecting a range of analytes. The most common use was for detection of hazardous chemicals, followed by detection of explosives, illicit drugs, chemical warfare, nerve agents, and radiation. One IMS unit had dual capability as a radiation detector. • Respondents who did not own an IMS listed prohibitive cost of equipment as the main factor for not having one. • Respondents who were highly satisfied with the overall operation of the handheld IMS obtained the IMS through a direct purchase. In comparison, the respondents who were not satisfied had obtained the handheld IMS through a DHS grant.

  9. Maximally incompressible neutron star matter

    E-Print Network [OSTI]

    Timothy S. Olson

    2000-12-07T23:59:59.000Z

    Relativistic kinetic theory, based on the Grad method of moments as developed by Israel and Stewart, is used to model viscous and thermal dissipation in neutron star matter and determine an upper limit on the maximum mass of neutron stars. In the context of kinetic theory, the equation of state must satisfy a set of constraints in order for the equilibrium states of the fluid to be thermodynamically stable and for perturbations from equilibrium to propagate causally via hyperbolic equations. Application of these constraints to neutron star matter restricts the stiffness of the most incompressible equation of state compatible with causality to be softer than the maximally incompressible equation of state that results from requiring the adiabatic sound speed to not exceed the speed of light. Using three equations of state based on experimental nucleon-nucleon scattering data and properties of light nuclei up to twice normal nuclear energy density, and the kinetic theory maximally incompressible equation of state at higher density, an upper limit on the maximum mass of neutron stars averaging 2.64 solar masses is derived.

  10. Neutron Detection via Bubble Chambers

    SciTech Connect (OSTI)

    Jordan, David V.; Ely, James H.; Peurrung, Anthony J.; Bond, Leonard J.; Collar, J. I.; Flake, Matthew; Knopf, Michael A.; Pitts, W. K.; Shaver, Mark W.; Sonnenschein, Andrew; Smart, John E.; Todd, Lindsay C.

    2005-10-06T23:59:59.000Z

    The results of a Pacific Northwest National Laboratory (PNNL) exploratory research project investigating the feasibility of fast neutron detection using a suitably prepared and operated, pressure-cycled bubble chamber are described. The research was conducted along two parallel paths. Experiments with a slow pressure-release Halon chamber at the Enrico Fermi Institute at the University of Chicago showed clear bubble nucleation sensitivity to an AmBe neutron source and insensitivity to the 662 keV gammas from a 137Cs source. Bubble formation was documented via high-speed (1000 frames/sec) photography, and the acoustic signature of bubble formation was detected using a piezo-electric transducer element mounted on the base of the chamber. The chamber’s neutron sensitivity as a function of working fluid temperature was mapped out. The second research path consisted of the design, fabrication, and testing of a fast pressure-release Freon-134a chamber at PNNL. The project concluded with successful demonstrations of the PNNL chamber’s AmBe neutron source sensitivity and 137Cs gamma insensitivity. The source response tests of the PNNL chamber were documented with high-speed photography.

  11. Experiment Design and Analysis Guide - Neutronics & Physics

    SciTech Connect (OSTI)

    Misti A Lillo

    2014-06-01T23:59:59.000Z

    The purpose of this guide is to provide a consistent, standardized approach to performing neutronics/physics analysis for experiments inserted into the Advanced Test Reactor (ATR). This document provides neutronics/physics analysis guidance to support experiment design and analysis needs for experiments irradiated in the ATR. This guide addresses neutronics/physics analysis in support of experiment design, experiment safety, and experiment program objectives and goals. The intent of this guide is to provide a standardized approach for performing typical neutronics/physics analyses. Deviation from this guide is allowed provided that neutronics/physics analysis details are properly documented in an analysis report.

  12. Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities

    E-Print Network [OSTI]

    M. Lundin; J. -O. Adler; M. Boland; K. Fissum; T. Glebe; K. Hansen; L. Isaksson; O. Kaltschmidt; M. Karlsson; K. Kossert; M. I. Levchuk; P. Lilja; B. Lindner; A. I. L'vov; B. Nilsson; D. E. Oner; C. Poech; S. Proff; A. Sandell; B. Schröder; M. Schumacher; D. A. Sims

    2003-06-13T23:59:59.000Z

    Differential cross sections for Compton scattering from the deuteron were measured at MAX-lab for incident photon energies of 55 MeV and 66 MeV at nominal laboratory angles of $45^\\circ$, $125^\\circ$, and $135^\\circ$. Tagged photons were scattered from liquid deuterium and detected in three NaI spectrometers. By comparing the data with theoretical calculations in the framework of a one-boson-exchange potential model, the sum and difference of the isospin-averaged nucleon polarizabilities, $\\alpha_N + \\beta_N = 17.4 \\pm 3.7$ and $\\alpha_N - \\beta_N = 6.4 \\pm 2.4$ (in units of $10^{-4}$ fm$^3$), have been determined. By combining the latter with the global-averaged value for $\\alpha_p - \\beta_p$ and using the predictions of the Baldin sum rule for the sum of the nucleon polarizabilities, we have obtained values for the neutron electric and magnetic polarizabilities of $\\alpha_n= 8.8 \\pm 2.4$(total) $\\pm 3.0$(model) and $\\beta_n = 6.5 \\mp 2.4$(total) $\\mp 3.0$(model), respectively.

  13. Neutron sources: Present practice and future potential

    SciTech Connect (OSTI)

    Cierjacks, S.; Smith, A.B.

    1988-01-01T23:59:59.000Z

    The present capability and future potential of accelerator-based monoenergetic and white neutron sources are outlined in the context of fundamental and applied neutron-nuclear research. The neutron energy range extends from thermal to 500 MeV, and the time domain from steady-state to pico-second pulsed sources. Accelerator technology is summarized, including the production of intense light-ion, heavy-ion and electron beams. Target capabilities are discussed with attention to neutron-producing efficiency and power-handling capabilities. The status of underlying neutron-producing reactions is summarized. The present and future use of neutron sources in: fundamental neutron-nuclear research, nuclear data acquisition, materials damage studies, engineering tests, and biomedical applications are discussed. Emphasis is given to current status, near-term advances well within current technology, and to long-range projections. 90 refs., 4 figs.

  14. A simplified spectrometer based on a fast digital oscilloscope for the measurement of high energy $?$-rays

    E-Print Network [OSTI]

    S. S. Markochev; N. V. Eremin

    2014-05-28T23:59:59.000Z

    A simplified digital spectrometer for the study of $\\gamma$-rays with energies up to $\\sim100$ MeV is presented and tested. The spectrometer is only consisted of a fast digital oscilloscope and three scintillation detectors which can work in single or in coincidence modes: two BGO-detectors comprising $\\varnothing\\,7.62\\times7.62$ cm BGO-crystalls and one plastic detector which includes an organic polystyrene-based scintillator. The basic properties of the spectrometer (energy resolution, time resolution, $\\gamma$-rays detection efficiency) were studied exhaustively also using a Geant4-based Monte-Carlo simulation. Several numerical algorithms for processing of waveforms in offline mode were proposed and tested to perform digital timing, pulse area measurement and processing of pile-up events without rejection. As a result, the spectrometer demonstrated $\\sim10\\%$ better energy resolution than was obtained by a common 10-bit CAMAC ADC with the same detectors. And the developed algorithm based on the pulse shape analysis for processing of pile-up events showed high efficiency under severe conditions (the portion of pile-ups contained $\\sim30\\%$). The measured maximum counting rate of the spectrometer was $1.8\\times10^5$ waveforms/sec.

  15. Comparison of improved Aura Tropospheric Emission Spectrometer (TES) CO2 with HIPPO and SGP aircraft profile measurements

    E-Print Network [OSTI]

    Kulawik, S.S.

    2013-01-01T23:59:59.000Z

    Spectrometer stare ozone profiles with ARC-IONS sondespriori of trace gas profile estimates from the TroposphericHIPPO and SGP aircraft profile measurements S. S. Kulawik ,

  16. Delayed neutron yield from fast neutron induced fission of sup 2 sup 3 sup 8 U

    E-Print Network [OSTI]

    Piksaikin, V M; Isaev, S G; Kazakov, L E; Roshchenko, V A; Tertytchnyi, R G

    2001-01-01T23:59:59.000Z

    The measurements of the total delayed neutron yield from fast neutron induced fission of sup 2 sup 3 sup 8 U were made. The experimental method based on the periodic irradiation of the fissionable sample by neutrons from a suitable nuclear reaction had been employed. The preliminary results on the energy dependence of the total delayed neutron yield from fission of sup 2 sup 3 sup 8 U are obtained. According to the comparison of experimental data with our prediction based on correlation properties of delayed neutron characteristics, it is concluded that the value of the total delayed neutron yield near the threshold of (n,f) reaction is not a constant.

  17. Development and characterization of a multiple-coincidence ion-momentum imaging spectrometer

    SciTech Connect (OSTI)

    Laksman, J.; Céolin, D.; Månsson, E. P.; Sorensen, S. L.; Gisselbrecht, M. [Department of Synchrotron Radiation Research, Lund University, Box 118, S-221 00 Lund (Sweden)] [Department of Synchrotron Radiation Research, Lund University, Box 118, S-221 00 Lund (Sweden)

    2013-12-15T23:59:59.000Z

    The design and performance of a high-resolution momentum-imaging spectrometer for ions which is optimized for experiments using synchrotron radiation is presented. High collection efficiency is achieved by a focusing electrostatic lens; a long drift tube improves mass resolution and a position-sensitive detector enables measurement of the transverse momentum of ions. The optimisation of the lens for particle momentum measurement at the highest resolution is described. We discuss the overall performance of the spectrometer and present examples demonstrating the momentum resolution for both kinetics and for angular measurements in molecular fragmentation for carbon monoxide and fullerenes. Examples are presented that confirm that complete space-time focussing is possible for a two-field three-dimensional imaging spectrometer.

  18. Characterization of a new modular decay total absorption gamma-ray spectrometer (DTAS) for FAIR

    SciTech Connect (OSTI)

    Montaner Piza, A.; Tain, J. L.; Agramunt, J.; Algora, A.; Guadilla, V.; Marin, E.; Rice, S.; Rubio, B. [Instituto de Fisica Corpuscular, CSIC-Univ. de Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain)

    2013-06-10T23:59:59.000Z

    Beta-decay studies are one of the main goals of the DEcay SPECtroscopy experiment (DESPEC) to be installed at the future Facility for Antiproton and Ion Research (FAIR). DESPEC aims at the study of nuclear structure of exotic nuclei. A new modular Decay Total Absorption gamma-ray Spectrometer (DTAS) is being built at IFIC and is specially adapted to studies at fragmentation facilities such as the Super Fragment Separator (Super-FRS) at FAIR. The designed spectrometer is composed of 16 identical NaI(Tl) scintillation crystals. This work focuses on the characterization of these independent modules, as an initial step for the characterization of the full spectrometer. Monte Carlo simulations have been performed in order to understand the detector response.

  19. A firmware-defined digital direct-sampling NMR spectrometer for condensed matter physics

    SciTech Connect (OSTI)

    Pikulski, M., E-mail: marekp@ethz.ch; Shiroka, T.; Ott, H.-R.; Mesot, J. [Laboratorium für Festkörperphysik, ETH Hönggerberg, CH-8093 Zürich, Switzerland and Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2014-09-15T23:59:59.000Z

    We report on the design and implementation of a new digital, broad-band nuclear magnetic resonance (NMR) spectrometer suitable for probing condensed matter. The spectrometer uses direct sampling in both transmission and reception. It relies on a single, commercially-available signal processing device with a user-accessible field-programmable gate array (FPGA). Its functions are defined exclusively by the FPGA firmware and the application software. Besides allowing for fast replication, flexibility, and extensibility, our software-based solution preserves the option to reuse the components for other projects. The device operates up to 400?MHz without, and up to 800?MHz with undersampling, respectively. Digital down-conversion with ±10?MHz passband is provided on the receiver side. The system supports high repetition rates and has virtually no intrinsic dead time. We describe briefly how the spectrometer integrates into the experimental setup and present test data which demonstrates that its performance is competitive with that of conventional designs.

  20. Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report

    SciTech Connect (OSTI)

    NONE

    1998-02-15T23:59:59.000Z

    A laser sampling system was attached to a Perkin Elmer Optima 3000 inductively-coupled plasma, atomic emission spectrometer that was already installed and operating in the Chemistry and Geochemistry Department at the Colorado School of Mines. The use of the spectrometer has been highly successful. Graduate students and faculty from at least four different departments across the CSM campus have used the instrument. The final report to NSF is appended to this final report. Appendices are included which summarize several projects utilizing this instrument: acquisition of an inductively-coupled plasma atomic emission spectrometer for the geochemistry program; hydrogen damage susceptibility assessment for high strength steel weldments through advanced hydrogen content analysis, 1996 and 1997 annual reports; and methods for determination of hydrogen distribution in high strength steel welds.

  1. Cyclotron-based neutron source for BNCT

    SciTech Connect (OSTI)

    Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K. [Sumitomo Heavy Industries, Ltd (Japan); Tanaka, H.; Sakurai, Y.; Maruhashi, A. [Kyoto University Research Reactor Institute (Japan)

    2013-04-19T23:59:59.000Z

    Kyoto University Research Reactor Institute (KURRI) and Sumitomo Heavy Industries, Ltd. (SHI) have developed a cyclotron-based neutron source for Boron Neutron Capture Therapy (BNCT). It was installed at KURRI in Osaka prefecture. The neutron source consists of a proton cyclotron named HM-30, a beam transport system and an irradiation and treatment system. In the cyclotron, H- ions are accelerated and extracted as 30 MeV proton beams of 1 mA. The proton beams is transported to the neutron production target made by a beryllium plate. Emitted neutrons are moderated by lead, iron, aluminum and calcium fluoride. The aperture diameter of neutron collimator is in the range from 100 mm to 250 mm. The peak neutron flux in the water phantom is 1.8 Multiplication-Sign 109 neutrons/cm{sup 2}/sec at 20 mm from the surface at 1 mA proton beam. The neutron source have been stably operated for 3 years with 30 kW proton beam. Various pre-clinical tests including animal tests have been done by using the cyclotron-based neutron source with {sup 10}B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

  2. Synthesize Neutron-Drip-Line-Nuclides with Free-Neutron Bose-Einstein Condensates Experimentally

    E-Print Network [OSTI]

    Bao-Guo Dong

    2014-09-22T23:59:59.000Z

    We first show a possible way to create a new type of matter, free-neutron Bose-Einstein condensate by the ultracold free-neutron-pair Bose-Einstein condensation and then determine the neutron drip line experimentally. The Bose-Einstein condensation of bosonic and fermionic atoms in atomic gases was performed experimentally and predicted theoretically early. Neutrons are similar to fermionic atoms. We found free neutrons could be cooled to ultracold neutrons with very low energy by other colder neutral atoms which are cooled by the laser. These neutrons form neutron pairs with spin zero, and then ultracold neutron-pairs form Bose-Einstein condensate. Our results demonstrate how these condensates can react with accelerated ion beams at different energy to synthesize very neutron-rich nuclides near, on or/and beyond the neutron drip line, to determine the neutron drip line and whether there are long-life nuclide or isomer islands beyond the neutron drip line experimentally. Otherwise, these experimental results will confirm our prediction that is in the whole interacting region or distance of nuclear force in all energy region from zero to infinite, Only repulsive nuclear force exists among identical nucleons and only among different nucleons exists attractive nuclear force.

  3. Workshop on neutron capture therapy

    SciTech Connect (OSTI)

    Fairchild, R.G.; Bond, V.P. (eds.)

    1986-01-01T23:59:59.000Z

    Potentially optimal conditions for Neutron Capture Therapy (NCT) may soon be in hand due to the anticipated development of band-pass filtered beams relatively free of fast neutron contaminations, and of broadly applicable biomolecules for boron transport such as porphyrins and monoclonal antibodies. Consequently, a number of groups in the US are now devoting their efforts to exploring NCT for clinical application. The purpose of this Workshop was to bring these groups together to exchange views on significant problems of mutual interest, and to assure a unified and effective approach to the solutions. Several areas of preclinical investigation were deemed to be necessary before it would be possible to initiate clinical studies. As neither the monomer nor the dimer of sulfhydryl boron hydride is unequivocally preferable at this time, studies on both compounds should be continued until one is proven superior.

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

    SciTech Connect (OSTI)

    Huth, Michael; Schumann, Frank O. [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Chiang, Cheng-Tien; Trützschler, Andreas; Kirschner, Jürgen [Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany); Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Saale) (Germany); Widdra, Wolf [Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Von-Danckelmann-Platz 3, D-06120 Halle (Saale) (Germany); Max Planck Institute of Microstructure Physics, Weinberg 2, D-06120 Halle (Germany)

    2014-02-10T23:59:59.000Z

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

  5. Next-Generation Germanium Spectrometer Background Reduction Techniques at 2 MeV

    SciTech Connect (OSTI)

    Brodzinski, Ronald L.

    2005-04-01T23:59:59.000Z

    The Majorana project, a next-generation 76Ge neutrinoless double-beta decay experiment being undertaken by a large international collaboration, has the goal of measuring the neutrinoless double-beta decay rate by observing monochromatic events at 2039 keV in 500 kg of isotopically enriched 76Ge gamma-ray spectrometers. In order to achieve the desired sensitivity limit, the background in the 2037-2041 keV region must be reduced to <1 event per year in the entire germanium array. The effects of various background reduction techniques, and the combination thereof, to produce a huge 76Ge spectrometer array with virtually zero background are discussed.

  6. Progress on Neutron-Target Multipoles above 1 GeV

    SciTech Connect (OSTI)

    Strakovsky, I I; Gao, H; Briscoe, W J; Dutta, D; Kudryavtsev, A E; Mirazite, M; Paris, M; Rossi, P; Stepanyan, S; Tarasov, V E

    2012-12-01T23:59:59.000Z

    We report a new extraction of nucleon resonance couplings using ?{sup ?} photo-production cross sections on the neutron. The world database for the process ?n ? ?{sup ?}p above 1 GeV has quadrupled with the addition of new differential cross sections from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab in Hall B. Differential cross sections from CLAS have been improved with a new final-state interaction determination using a diagrammatic technique taking into account the SAID phenomenological NN and ?N final-state interaction amplitudes. Resonance couplings have been extracted and compared to previous determinations. With the addition of these new cross sections, significant changes are seen in the high-energy behavior of the SAID cross sections and amplitudes.

  7. New insights into water bonding during early tricalcium silicate hydration with quasielastic neutron scattering

    SciTech Connect (OSTI)

    Gutberlet, T., E-mail: gutberlet@cbm.bv.tum.de [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany); Hilbig, H.; Beddoe, R.E. [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany)] [Centre for Building Materials (CBM), Technische Universität München, Baumbachstraße 7, 81245 Munich (Germany); Lohstroh, W. [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany)] [Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstraße 1, 85748 Garching (Germany)

    2013-09-15T23:59:59.000Z

    New information on the water bonding during the first 36 h of hydration of tricalcium silicate was obtained using the high neutron flux at the sample position of the time-of-flight spectrometer (TOFTOF), FRM II in Garching, Germany, together with {sup 29}Si NMR and X-ray diffraction measurements. A rapid increase in the amount of constrained water was observed at the beginning of the induction period. This is attributed to the formation of an early C-S-H with a large specific surface area (around 800 m{sup 2}/g). During subsequent hydration, the amount of constrained water, as given by the total surface area of the hydration products, is controlled by (a) the formation of new metastable early C-S-H which increases total surface area and (b) polymerisation processes which reduce total surface area. The relative contribution of these processes varies during hydration.

  8. COMBINED GAMMA-RAY AND NEUTRON DETECTOR FOR MEASURING THE CHEMICAL COMPOSITION OF AIRLESS PLANETARY BODIES.

    SciTech Connect (OSTI)

    Lawrence, David J. (David Jeffery),; Barraclough, B. L. (Bruce L.); Feldman, W. C. (William C.); Prettyman, T. H. (Thomas H.); Wiens, R. C. (Roger C.)

    2001-01-01T23:59:59.000Z

    Galactic cosmic rays (GCR) constant1,y itnpinge all planetary bodies and produce characteristic gamma-ray lines and leakage neutrons as reaction products. Together with gamma-ray lines produced by radioactive decay, these nuclear emissions provide a powerful technique for remotely measuring the chemical composition of airless planetary surfaces. While lunar gamma-ray spectroscopy was first demonstrated with Apollo Gamma-Ray measurements, the full value of combined gamma-ray and neutron spectroscopy was shown for the first time with the Lunar Prospector Gamma-Ray (LP-GRS) and Neutron Spectrometers (LP-NS). Any new planetary mission will likely have the requirement that instrument mass and power be kept to a minimum. To satisfy such requirements, we have been designing a GR/NS instrument which combines all the functionality of the LP-GRS and LP-NS for a fraction of the mass and power. Specifically, our design uses a BGO scintillator crystal to measure gamma-rays from 0.5-10 MeV. A borated plastic scintillator and a lithium gliiss scintillator are used to separately measure thermal, epithermal, and fast neutrons as well as serve as an anticoincidence shield for the BGO. All three scintillators are packaged together in a compact phoswich design. Modifications to this design could include a CdZnTe gamma-ray detector for enhanced energy resolution at low energies (0.5-3 MeV). While care needs to be taken to ensure that an adequate count rate is achieved for specific mission designs, previous mission successes demonstrate that a cornbined GR/NS provides essential information about planetary surfaces.

  9. General Electric PETtrace cyclotron as a neutron source for boron neutron capture therapy 

    E-Print Network [OSTI]

    Bosko, Andrey

    2005-11-01T23:59:59.000Z

    This research investigates the use of a PETtrace cyclotron produced by General Electric (GE) as a neutron source for boron neutron capture therapy (BNCT). The GE PETtrace was chosen for this investigation because this type of cyclotron is popular...

  10. Measurement of delayed-neutron yield from {sup 237}Np fission induced by thermal neutrons

    SciTech Connect (OSTI)

    Gundorin, N. A.; Zhdanova, K. V.; Zhuchko, V. E.; Pikelner, L. B., E-mail: plb@nf.jinr.ru; Rebrova, N. V.; Salamatin, I. M.; Smirnov, V. I.; Furman, V. I. [Joint Institute for Nuclear Research (Russian Federation)

    2007-06-15T23:59:59.000Z

    The delayed-neutron yield from thermal-neutron-induced fission of the {sup 237}Np nucleus was measured using a sample periodically exposed to a pulsed neutron beam with subsequent detection of neutrons during the time intervals between pulses. The experiment was realized on an Isomer-M setup mounted in the IBR-2 pulsed reactor channel equipped with a mirror neutron guide. The setup and the experimental procedure are described, the background sources are thoroughly analyzed, and the experimental data are presented. The total delayed-neutron yield from {sup 237}Np fission induced by thermal neutrons is {nu}{sub d} = 0.0110 {+-} 0.0009. This study was performed at the Frank Laboratory of Neutron Physics (JINR, Dubna)

  11. Ion sources for sealed neutron tubes

    SciTech Connect (OSTI)

    Burns, E.J.T. [Sandia National Labs., Albuquerque, NM (United States). Neutron Tube Dept.; Bischoff, G.C. [Lockheed Martin Specialty Components, Largo, FL (United States)

    1996-11-01T23:59:59.000Z

    Fast and thermal neutron activation analysis with sealed neutron generators has been used to detect oil (oil logging), hazardous waste, fissile material, explosives, and contraband (drugs). Sealed neutron generators, used in the above applications, must be small and portable, have good electrical efficiency and long life. The ion sources used in the sealed neutron tubes require high gas utilization efficiencies or low pressure operation with high ionization efficiencies. In this paper, the authors compare a number of gas ion sources that can be used in sealed neutron tubes. The characteristics of the most popular ion source, the axial Penning discharge will be discussed as part of the zetatron neutron generator. Other sources to be discussed include the SAMIS source and RF ion source.

  12. Aerial Neutron Detection: Neutron Signatures for Nonproliferation and Emergency Response Applications

    SciTech Connect (OSTI)

    Maurer, Richard J.; Stampahar, Thomas G.; Smith, Ethan X.; Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Rourke, Timothy J.; LeDonne, Jeffrey P.; Avaro, Emanuele; Butler, D. Andre; Borders, Kevin L.; Stampahar, Jezabel; Schuck, William H.; Selfridge, Thomas L.; McKissack, Thomas M.; Duncan, William W.; Hendricks, Thane J.

    2012-10-17T23:59:59.000Z

    From 2007 to the present, the Remote Sensing Laboratory has been conducting a series of studies designed to expand our fundamental understanding of aerial neutron detection with the goal of designing an enhanced sensitivity detection system for long range neutron detection. Over 35 hours of aerial measurements in a helicopter were conducted for a variety of neutron emitters such as neutron point sources, a commercial nuclear power reactor, nuclear reactor spent fuel in dry cask storage, depleted uranium hexafluoride and depleted uranium metal. The goals of the project were to increase the detection sensitivity of our instruments such that a 5.4 × 104 neutron/second source could be detected at 100 feet above ground level at a speed of 70 knots and to enhance the long-range detection sensitivity for larger neutron sources, i.e., detection ranges above 1000 feet. In order to increase the sensitivity of aerial neutron detection instruments, it is important to understand the dynamics of the neutron background as a function of altitude. For aerial neutron detection, studies have shown that the neutron background primarily originates from above the aircraft, being produced in the upper atmosphere by galactic cosmic-ray interactions with air molecules. These interactions produce energetic neutrons and charged particles that cascade to the earth’s surface, producing additional neutrons in secondary collisions. Hence, the neutron background increases as a function of altitude which is an impediment to long-range neutron detection. In order to increase the sensitivity for long range detection, it is necessary to maintain a low neutron background as a function of altitude. Initial investigations show the variation in the neutron background can be decreased with the application of a cosmic-ray shield. The results of the studies along with a representative data set are presented.

  13. Ferromagnetism in neutron matter and its implication for the neutron star equation of state

    SciTech Connect (OSTI)

    Diener, J. P. W. [Institute of Theoretical Physics, Stellenbosch University, P.O. Box X1, Matieland, 7602 (South Africa); Scholtz, F. G. [Institute of Theoretical Physics, Stellenbosch University, P.O. Box X1, Matieland, 7602 (South Africa); National Institute for Theoretical Physics, P.O. Box X1, Matieland, 7602 (South Africa)

    2011-09-21T23:59:59.000Z

    We investigate the possible contribution of the ferromagnetic phase of neutron matter in the neutron star interior to the star's magnetic field. We introduce a relativistic, self-consistent calculation of the ferromagnetic phase in neutron matter within the context of the relativistic mean-field approximation. The presence of the ferromagnetic phase stiffens the star's equation of state which implies a larger neutron star radius compared to the non-ferromagnetic case.

  14. Neutron Generators for Spent Fuel Assay

    SciTech Connect (OSTI)

    Ludewigt, Bernhard A

    2010-12-30T23:59:59.000Z

    The Next Generation Safeguards Initiative (NGSI) of the U.S. DOE has initiated a multi-lab/university collaboration to quantify the plutonium (Pu) mass in, and detect the diversion of pins from, spent nuclear fuel (SNF) assemblies with non-destructive assay (NDA). The 14 NDA techniques being studied include several that require an external neutron source: Delayed Neutrons (DN), Differential Die-Away (DDA), Delayed Gammas (DG), and Lead Slowing-Down Spectroscopy (LSDS). This report provides a survey of currently available neutron sources and their underlying technology that may be suitable for NDA of SNF assemblies. The neutron sources considered here fall into two broad categories. The term 'neutron generator' is commonly used for sealed devices that operate at relatively low acceleration voltages of less than 150 kV. Systems that employ an acceleration structure to produce ion beam energies from hundreds of keV to several MeV, and that are pumped down to vacuum during operation, rather than being sealed units, are usually referred to as 'accelerator-driven neutron sources.' Currently available neutron sources and future options are evaluated within the parameter space of the neutron generator/source requirements as currently understood and summarized in section 2. Applicable neutron source technologies are described in section 3. Commercially available neutron generators and other source options that could be made available in the near future with some further development and customization are discussed in sections 4 and 5, respectively. The pros and cons of the various options and possible ways forward are discussed in section 6. Selection of the best approach must take a number of parameters into account including cost, size, lifetime, and power consumption, as well as neutron flux, neutron energy spectrum, and pulse structure that satisfy the requirements of the NDA instrument to be built.

  15. Information from leading neutrons at HERA

    E-Print Network [OSTI]

    V. A. Khoze; A. D. Martin; M. G. Ryskin

    2006-06-20T23:59:59.000Z

    In principle, leading neutrons produced in photoproduction and deep-inelastic scattering at HERA have the potential to determine the pion structure function, the neutron absorptive cross section and the form of the pion flux. To explore this potential we compare theoretical predictions for the x_L and p_t spectra of leading neutrons, and the Q^2 dependence of the cross section, with the existing ZEUS data.

  16. Neutrons used to study model vascular systems

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

    the endothelial cells and the supporting substrate. In what may be the first use of neutron scattering to study complex bio-medical systems under dynamic conditions, Los...

  17. Spallation Neutron Source reaches megawatt power

    ScienceCinema (OSTI)

    Dr. William F. Brinkman

    2010-01-08T23:59:59.000Z

    The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

  18. Neutron Imaging of Advanced Engine Technologies

    Broader source: Energy.gov (indexed) [DOE]

    Science Division Hassina Z. Bilheux & Sophie Voisin Oak Ridge National Laboratory Neutron Scattering Science Division Jens Gregor University of Tennessee - Knoxville Dept....

  19. The Neutron Imaging Diagnostic at NIF

    SciTech Connect (OSTI)

    Merrill, F E; Buckles, R; Clark, D; Danly, C R; Drury, O B; Dzenitis, J M; Fatherly, V E; Fittinghoff, D N; Gallegos, R; Grim, G P; Guler, N; Loomis, E N; Lutz, S; Malone, R M; Martinson, D D; Mares, D; Morley, D J; Morgan, G L; Oertel, J A; Tregillis, I L; Volegov, P L; Weiss, P B; Wilde, C H

    2012-10-01T23:59:59.000Z

    A neutron imaging diagnostic has recently been commissioned at the National Ignition Facility (NIF). This new system is an important diagnostic tool for inertial fusion studies at the NIF for measuring the size and shape of the burning DT plasma during the ignition stage of ICF implosions. The imaging technique utilizes a pinhole neutron aperture, placed between the neutron source and a neutron detector. The detection system measures the two dimensional distribution of neutrons passing through the pinhole. This diagnostic has been designed to collect two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically the first image measures the distribution of the 14 MeV neutrons and the second image of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core.

  20. Neutronic Characterization of the Megapie Target

    E-Print Network [OSTI]

    Stefano Panebianco; Olivier Bringer; Pavel Bokov; Sebastien Chabod; Frederic Chartier; Emmeric Dupont; Diane Dore; Xavier Ledoux; Alain Letourneau; Ludovic Oriol; Aurelien Prevost; Danas Ridikas; Jean-Christian Toussaint

    2007-10-31T23:59:59.000Z

    The MEGAPIE project is one of the key experiments towards the feasibility of Accelerator Driven Systems. On-line operation and post-irradiation analysis will provide the scientific community with unique data on the behavior of a liquid spallation target under realistic irradiation conditions. A good neutronics performance of such a target is of primary importance towards an intense neutron source, where an extended liquid metal loop requires some dedicated verifications related to the delayed neutron activity of the irradiated PbBi. In this paper we report on the experimental characterization of the MEGAPIE neutronics in terms of the prompt neutron (PN) flux inside the target and the delayed neutron (DN) flux on the top of it. For the PN measurements, a complex detector, made of 8 microscopic fission chambers, has been built and installed in the central part of the target to measure the absolute neutron flux and its spatial distribution. Moreover, integral information on the neutron energy distribution as a function of the position along the beam axis could be extracted, providing integral constraints on the neutron production models implemented in transport codes such as MCNPX. For the DN measurement, we used a standard 3He counter and we acquired data during the start-up phase of the target irradiation in order to take sufficient statistics at variable beam power. Experimental results obtained on the PN flux characteristics and their comparison with MCNPX simulations are presented, together with a preliminary analysis of the DN decay time spectrum.