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1

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

E-Print Network [OSTI]

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

Johnson, Peter D.

2

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

E-Print Network [OSTI]

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

Pennycook, Steve

3

Neutron range spectrometer  

DOE Patents [OSTI]

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.

Manglos, S.H.

1988-03-10T23:59:59.000Z

4

Neutron range spectrometer  

DOE Patents [OSTI]

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

Manglos, Stephen H. (East Syracuse, NY)

1989-06-06T23:59:59.000Z

5

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

E-Print Network [OSTI]

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

Pennycook, Steve

6

Portable neutron spectrometer and dosimeter  

DOE Patents [OSTI]

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.

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

1985-01-01T23:59:59.000Z

7

Neutron spectrometer for improved SNM search.  

SciTech Connect (OSTI)

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.

Vance, Andrew L.; Aigeldinger, Georg

2007-03-01T23:59:59.000Z

8

Development of multichannel low-energy neutron spectrometer  

SciTech Connect (OSTI)

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.

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

9

Ultracold-neutron infrastructure for the gravitational spectrometer GRANIT  

E-Print Network [OSTI]

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.

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

10

Ultracold-neutron infrastructure for the gravitational spectrometer GRANIT  

E-Print Network [OSTI]

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.

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

11

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

E-Print Network [OSTI]

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.

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

12

The new Triple-Axis detector (TAD) uses a unique geometry and employs an improved electron multiplier design that  

E-Print Network [OSTI]

The new Triple-Axis detector (TAD) uses a unique geometry and employs an improved electron signal is greatly enhanced and neutral noise reduced with the TAD. The increased signal provides many, and calibration curves with greater slopes. In operation, because the TAD is more sensitive, the user will find

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

13

Analysis of a time-of-flight neutron spectrometer  

SciTech Connect (OSTI)

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.

Biggs, F.

1983-12-01T23:59:59.000Z

14

A compact stilbene crystal neutron spectrometer for EAST D-D plasma neutron diagnostics  

SciTech Connect (OSTI)

A new compact stilbene crystal neutron spectrometer has been investigated and applied in the neutron emission spectroscopy on the EAST tokamak. A new components analysis method is presented to study the anisotropic light output in the stilbene crystal detector. A Geant4 code was developed to simulate the neutron responses in the spectrometer. Based on both the optimal light output function and the fitted pulse height resolution function, a reliable neutron response matrix was obtained by Geant4 simulations and validated by 2.5 MeV and 14 MeV neutron measurements at a 4.5 MV Van de Graaff accelerator. The spectrometer was used to diagnose the ion temperature in plasma discharges with lower hybrid wave injection and ion cyclotron resonance heating on the EAST tokamak.

Zhang Xing; Yuan Xi; Xie Xufei; Chen Zhongjing; Peng Xingyu; Chen Jinxiang; Zhang Guohui; Li Xiangqing; Fan Tieshuan [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Chengfu Road 201, 100871 Beijing (China); Zhong Guoqiang; Hu Liqun; Wan Baonian [Institute of Plasma Physics, Chinese Academy of Sciences, PO Box 1126, 230031 Hefei, Anhui (China)

2013-03-15T23:59:59.000Z

15

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

SciTech Connect (OSTI)

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.

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

16

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

SciTech Connect (OSTI)

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.

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

17

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

SciTech Connect (OSTI)

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.

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

18

E-Print Network 3.0 - axis neutron spectrometer Sample Search...  

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

results for: axis neutron spectrometer Page: << < 1 2 3 4 5 > >> 1 For more information: Neutron Scattering Science User Office, neutronusers@ornl.gov or (865) 574-4600. Summary:...

19

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

E-Print Network [OSTI]

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.

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

20

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

E-Print Network [OSTI]

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.

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

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

E-Print Network [OSTI]

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.

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

2007-08-21T23:59:59.000Z

22

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

SciTech Connect (OSTI)

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.

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

23

A neutron spectrometer for precise measurements of DT neutrons from 10 to 18 MeV at OMEGA and the National Ignition Facility  

E-Print Network [OSTI]

A neutron spectrometer for precise measurements of DT neutrons from 10 to 18 MeV at OMEGA to determine fuel R is to measure the energy spectrum and yield of elastically scattered primary neutrons, a novel spectrometer for measurements of neutrons in the energy range 10­18 MeV is proposed. From

24

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

E-Print Network [OSTI]

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.

Sylvain Desert; Vincent Thevenot; Julian Oberdisse; Annie Brulet

2007-06-12T23:59:59.000Z

25

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

SciTech Connect (OSTI)

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.

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

26

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)

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.

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

27

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

SciTech Connect (OSTI)

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.

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

28

Design and Simulation of a Boron-loaded Neutron Spectrometer  

E-Print Network [OSTI]

The measurement of the distribution of kinetic energy carried by neutron particles is of interest to the health physics and radiation protection industry. Neutron particle spectral fluence is essential to the calculation of absorbed dose, equivalent...

Martin, Thomas

2012-10-19T23:59:59.000Z

29

Improving the resolution of chopper spectrometers at pulsed neutron sources  

SciTech Connect (OSTI)

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.

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

30

Superconducting gamma and fast-neutron spectrometers with high energy resolution  

DOE Patents [OSTI]

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.

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

2008-11-04T23:59:59.000Z

31

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

SciTech Connect (OSTI)

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.

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

32

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

SciTech Connect (OSTI)

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.

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

2002-12-30T23:59:59.000Z

33

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

E-Print Network [OSTI]

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

Meyerovich, Alex

34

Measuring the absolute DT neutron yield using the Magnetic Recoil Spectrometer at OMEGA and the NIF  

SciTech Connect (OSTI)

A Magnetic Recoil Spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion (ICF) implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

Mackinnon, A; Casey, D; Frenje, J A; Johnson, M G; Seguin, F H; Li, C K; Petrasso, R D; Glebov, V Y; Katz, J; Knauer, J; Meyerhofer, D; Sangster, T; Bionta, R; Bleuel, D; Hachett, S P; Hartouni, E; Lepape, S; Mckernan, M; Moran, M; Yeamans, C

2012-05-03T23:59:59.000Z

35

Neutron Time-Of-Flight Spectrometer Based on HIRFL for Studies of Spallation Reactions Related to ADS Project  

E-Print Network [OSTI]

A Neutron Time-Of-Flight (NTOF) spectrometer based on Heavy Ion Research Facility in Lanzhou (HIRFL) is developed for studies of neutron production of proton induced spallation reactions related to the ADS project. After the presentation of comparisons between calculated spallation neutron production double-differential cross sections and the available experimental one, a detailed description of NTOF spectrometer is given. Test beam results show that the spectrometer works well and data analysis procedures are established. The comparisons of the test beam neutron spectra with those of GEANT4 simulations are presented.

Suyalatu Zhang; Zhiqiang Chen; Rui Han; Roy Wada; Xingquan Liu; Weiping Lin; Jianli Liu; Fudong Shi; Peipei Ren; Guoyu Tian; Fei Luo

2014-11-20T23:59:59.000Z

36

Results for the response function determination of the Compact Neutron Spectrometer  

E-Print Network [OSTI]

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.

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

2012-01-30T23:59:59.000Z

37

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

ScienceCinema (OSTI)

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.

None

2011-10-06T23:59:59.000Z

38

On the kinematics and resolution of spectrometers for neutron Brillouin scattering  

SciTech Connect (OSTI)

Neutron Brillouin scattering involves measurement of excitations at smaller Q values than in currently customary. We outline the kinematic constraints on scattering angle and incident energy for excitations with both linear dispersion (sound waves) and parabolic dispersion (ferromagnetic spin waves), and discuss the resolution characteristics of the chopper spectrometer proposed for LANSCE which should be suitable for such studies. In particular, we demonstrate that longitudinal resolution focusing can be exploited both in neutron energy gain and in neutron energy loss. 13 refs., 8 figs., 1 tab.

Robinson, R.A.

1988-01-01T23:59:59.000Z

39

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

SciTech Connect (OSTI)

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.

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

40

Results for the response function determination of the Compact Neutron Spectrometer  

E-Print Network [OSTI]

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...

Gagnon-Moisan, F; Zimbal, A

2012-01-01T23:59:59.000Z

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41

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

SciTech Connect (OSTI)

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.

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

2011-03-14T23:59:59.000Z

42

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

SciTech Connect (OSTI)

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.

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

43

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

SciTech Connect (OSTI)

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.

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

44

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

SciTech Connect (OSTI)

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.

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

45

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)

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.

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

46

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

SciTech Connect (OSTI)

The neutron spectrum produced by deuterium-tritium (DT) inertial confinement fusion implosions contains a wealth of information about implosion performance including the DT yield, ion-temperature, 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.

Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Glebov, V. Yu.; Katz, J.; Magoon, J.; Meyerhofer, D. D.; Sangster, T. C.; Shoup, M.; Ulreich, J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Ashabranner, R. C.; Bionta, R. M.; Carpenter, A. C.; Felker, B.; Khater, H. Y.; LePape, S.; MacKinnon, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2013-04-15T23:59:59.000Z

47

A comparison of four direct geometry time-of-flight spectrometers at the Spallation Neutron Source  

SciTech Connect (OSTI)

The Spallation Neutron Source at Oak Ridge National Laboratory now hosts four direct geometry time-of-flight chopper spectrometers. These instruments cover a range of wave-vector and energy transfer space with varying degrees of neutron flux and resolution. The regions of reciprocal and energy space available to measure at these instruments are not exclusive and overlap significantly. We present a direct comparison of the capabilities of this instrumentation, conducted by data mining the instrument usage histories, and specific scanning regimes. In addition, one of the common science missions for these instruments is the study of magnetic excitations in condensed matter systems. We have measured the powder averaged spin wave spectra in one particular sample using each of these instruments, and use these data in our comparisons.

Stone, M. B.; Abernathy, D. L.; Ehlers, G.; Garlea, O.; Podlesnyak, A.; Winn, B. [Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Quantum Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Niedziela, J. L.; DeBeer-Schmitt, L.; Graves-Brook, M. [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Granroth, G. E. [Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Neutron Data Analysis and Visualization Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Kolesnikov, A. I. [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2014-04-15T23:59:59.000Z

48

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

SciTech Connect (OSTI)

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.

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

49

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

SciTech Connect (OSTI)

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.

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

2006-02-16T23:59:59.000Z

50

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

SciTech Connect (OSTI)

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.

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

51

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

SciTech Connect (OSTI)

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.

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

52

Measuring the absolute deuterium-tritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF  

SciTech Connect (OSTI)

A magnetic recoil spectrometer (MRS) has been installed and extensively used on OMEGA and the National Ignition Facility (NIF) for measurements of the absolute neutron spectrum from inertial confinement fusion implosions. From the neutron spectrum measured with the MRS, many critical implosion parameters are determined including the primary DT neutron yield, the ion temperature, and the down-scattered neutron yield. As the MRS detection efficiency is determined from first principles, the absolute DT neutron yield is obtained without cross-calibration to other techniques. The MRS primary DT neutron measurements at OMEGA and the NIF are shown to be in excellent agreement with previously established yield diagnostics on OMEGA, and with the newly commissioned nuclear activation diagnostics on the NIF.

Casey, D. T.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, MIT, Cambridge, Massachusetts 02139 (United States); Glebov, V. Yu.; Katz, J.; Knauer, J. P.; Meyerhofer, D. D.; Sangster, T. C. [Laboratory for Laser Energetics, UR, Rochester, New York 14623 (United States); Bionta, R. M.; Bleuel, D. L.; Doeppner, T.; Glenzer, S.; Hartouni, E.; Hatchett, S. P.; Le Pape, S.; Ma, T.; MacKinnon, A. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-10-15T23:59:59.000Z

53

The magnetic shielding for the neutron decay spectrometer aSPECT  

E-Print Network [OSTI]

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.

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

54

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

SciTech Connect (OSTI)

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.

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

55

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

E-Print Network [OSTI]

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...

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

56

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

SciTech Connect (OSTI)

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.

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

57

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

SciTech Connect (OSTI)

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.

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

58

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

SciTech Connect (OSTI)

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.

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

59

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

SciTech Connect (OSTI)

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.

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

2011-01-15T23:59:59.000Z

60

A new chopper spectrometer for neutron Brillouin scattering and low-angle neutron inelastic scattering: PHAROS (Phase 1)  

SciTech Connect (OSTI)

Phase I of PHAROS, the new chopper spectrometer at LANSCE, is described in detail. The main components are a water moderator, a 60-Hz double-bladed T-zero chopper, a 600Hz magnetic-bearing Fermi chopper, a 6m-long vacuum vessel with thin aluminium-alloy vacuum window and a 1.2m{sup 2} array of linear position-sensitive detectors.

Robinson, R.A.; Nutter, M.; Ricketts, R.L.; Larson, E.; Sandoval, J.P.; Lysaght, P.; Olivier, B.J.

1993-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

A new chopper spectrometer for neutron Brillouin scattering and low-angle neutron inelastic scattering: PHAROS (Phase 1)  

SciTech Connect (OSTI)

Phase I of PHAROS, the new chopper spectrometer at LANSCE, is described in detail. The main components are a water moderator, a 60-Hz double-bladed T-zero chopper, a 600Hz magnetic-bearing Fermi chopper, a 6m-long vacuum vessel with thin aluminium-alloy vacuum window and a 1.2m[sup 2] array of linear position-sensitive detectors.

Robinson, R.A.; Nutter, M.; Ricketts, R.L.; Larson, E.; Sandoval, J.P.; Lysaght, P.; Olivier, B.J.

1993-01-01T23:59:59.000Z

62

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

E-Print Network [OSTI]

Lawrence Livermore National Laboratory, Livermore, California 94550, USA 3 Laboratory for Laser Energetics Spectrometer (MRS) on the National Ignition Facility (NIF) measures the neutron spectrum in the energy range-filled symmetry-capsule implosions at the NIF. DT-fuel R's of 80­140 mg/cm2 and CH-ablator R's of 400­680 mg/cm2

63

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

SciTech Connect (OSTI)

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.

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

2008-02-15T23:59:59.000Z

64

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

SciTech Connect (OSTI)

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.

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

65

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

E-Print Network [OSTI]

, USA 3 Lawrence Livermore National Laboratory, Livermore, California 94550, USA 4 Sandia National and the NIF D. T. Casey, J. A. Frenje, M. Gatu Johnson, F. H. Séguin, C. K. Li et al. Citation: Rev. Sci for measurements of the absolute neutron spectrum at OMEGA and the NIF D. T. Casey,1,a) J. A. Frenje,1 M. Gatu

66

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)

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.

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

67

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)

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.

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

68

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)

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.

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

69

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]

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

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

70

JOURNAL DE PHYSIQUE Colloque C I, supplkment au no 2-3, Tome 32, Fkvrier-Mars 1971, page C 1 -882 MAGNETIC NEUTRON SCATTERING FROM K,NiF4  

E-Print Network [OSTI]

la temperature de tran- sition dans I'antiferromagnetique a deux dimensions K2NiF4. L in the two-dimensional antiferromagnet K2NiF4. Inelastic studies on a triple-axis spectrometer have indicated is structurally composed of NiF, layers separated by two K F layers [I]. The relative isolation of the NiF, layers

Paris-Sud XI, Université de

71

MnO spin-wave dispersion curves from neutron powder diffraction  

SciTech Connect (OSTI)

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.

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

72

The IPNS resonance detector spectrometer  

SciTech Connect (OSTI)

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)

Crawford, R.K.

1986-01-01T23:59:59.000Z

73

First measurements of the absolute neutron spectrum using the magnetic recoil spectrometer at OMEGA ,,invited...a...  

E-Print Network [OSTI]

of Rochester, Rochester, New York 14623, USA 3 Lawrence Livermore National Laboratory, Livermore, California neutron spectrum are presented. In addition, measuring R at the National Ignition Facility NIF G. H. To accomplish this, we are also developing an MRS for the NIF. As much of the research and development

74

Monolithic spectrometer  

DOE Patents [OSTI]

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.

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

75

Monolithic spectrometer  

DOE Patents [OSTI]

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.

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

76

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]

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 ...

Orphan, V. J.

1967-01-01T23:59:59.000Z

77

Correlation spectrometer  

DOE Patents [OSTI]

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.

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

78

Multidimensional spectrometer  

DOE Patents [OSTI]

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.

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

2010-07-20T23:59:59.000Z

79

A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER  

E-Print Network [OSTI]

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

O'Donnell, Tom

80

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

E-Print Network [OSTI]

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

Ryan, Dominic

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

MAGNETIC NEUTRON SCATTERING  

SciTech Connect (OSTI)

Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science, ranging from large-scale structures and dynamics of polymers and biological systems, to electronic properties of today's technological materials. Neutron scattering developed into a vast field, encompassing many different experimental techniques aimed at exploring different aspects of matter's atomic structure and dynamics. Modern magnetic neutron scattering includes several specialized techniques designed for specific studies and/or particular classes of materials. Among these are magnetic reflectometry aimed at investigating surfaces, interfaces, and multilayers, small-angle scattering for the large-scale structures, such as a vortex lattice in a superconductor, and neutron spin-echo spectroscopy for glasses and polymers. Each of these techniques and many others offer exciting opportunities for examining magnetism and warrant extensive reviews, but the aim of this chapter is not to survey how different neutron-scattering methods are used to examine magnetic properties of different materials. Here, we concentrate on reviewing the basics of the magnetic neutron scattering, and on the recent developments in applying one of the oldest methods, the triple axis spectroscopy, that still is among the most extensively used ones. The developments discussed here are new and have not been coherently reviewed. Chapter 2 of this book reviews magnetic small-angle scattering, and modern techniques of neutron magnetic reflectometry are discussed in Chapter 3.

ZALIZNYAK,I.A.; LEE,S.H.

2004-07-30T23:59:59.000Z

82

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

E-Print Network [OSTI]

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 ...

Casey, Daniel Thomas

2012-01-01T23:59:59.000Z

83

Associated Particle Tagging (APT) in Magnetic Spectrometers  

SciTech Connect (OSTI)

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.

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

2012-10-16T23:59:59.000Z

84

Study of Active Shielding for {gamma} - Spectrometers  

SciTech Connect (OSTI)

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.

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

85

Mobile Ice Nucleus Spectrometer  

SciTech Connect (OSTI)

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.

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

2012-05-07T23:59:59.000Z

86

Diamond neutral particle spectrometer for fusion reactor ITER  

SciTech Connect (OSTI)

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.

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

87

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

E-Print Network [OSTI]

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

Boyer, Edmond

88

A Novel Detector for High Neutron Flux Measurements  

SciTech Connect (OSTI)

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.

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

89

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

E-Print Network [OSTI]

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.

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

2013-02-07T23:59:59.000Z

90

ablation laser spectrometer  

E-Print Network [OSTI]

ablation laser mass spectrometer molecular beam REMPI laser NREL has designed and developed a combined laser ablation/ pulsed sample introduction/mass spectrometry platform that integrates pyrolysis and/or laser ablation with resonance- enhanced multiphoton ionization (REMPI) time-of-flight mass

91

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

E-Print Network [OSTI]

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

Danon, Yaron

92

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

SciTech Connect (OSTI)

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.

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

93

The response of a Bonner Sphere spectrometer to charged hadrons  

E-Print Network [OSTI]

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...

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

2004-01-01T23:59:59.000Z

94

Bragg x-ray survey spectrometer for ITER  

SciTech Connect (OSTI)

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.

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

95

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

E-Print Network [OSTI]

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.

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

2012-01-01T23:59:59.000Z

96

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

SciTech Connect (OSTI)

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.

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

1990-10-01T23:59:59.000Z

97

Neutron coincidence detectors employing heterogeneous materials  

DOE Patents [OSTI]

A neutron detector relies upon optical separation of different scintillators to measure the total energy and/or number of neutrons from a neutron source. In pulse mode embodiments of the invention, neutrons are detected in a first detector which surrounds the neutron source and in a second detector surrounding the first detector. An electronic circuit insures that only events are measured which correspond to neutrons first detected in the first detector followed by subsequent detection in the second detector. In spectrometer embodiments of the invention, neutrons are thermalized in the second detector which is formed by a scintillator-moderator and neutron energy is measured from the summed signals from the first and second detectors.

Czirr, J. Bartley (Mapleton, UT); Jensen, Gary L. (Orem, UT)

1993-07-27T23:59:59.000Z

98

Neutronic reactor  

DOE Patents [OSTI]

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.

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

1983-01-01T23:59:59.000Z

99

First Neutron Spectrometry Measurement at the HL-2A Tokamak  

E-Print Network [OSTI]

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...

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

100

Monte Carlo study of the performance of a time-of-flight multichopper spectrometer  

SciTech Connect (OSTI)

The Monte Carlo method is a powerful technique for neutron transport studies. While it has been applied for many years to the study of nuclear systems, there are few codes available for neutron transport in the optical regime. The recent surge of interest in so-called next generation spallation neutron sources and the desire to design new and optimized instruments for these facilities has led us to develop a Monte Carlo code geared toward the simulation of neutron scattering instruments. The time-of-flight multichopper spectrometer, of which IN5 at the ILL is the prototypical example, is the first spectrometer studied with the code. Some of the results of a comparison between the IN5 performance at a reactor and at a Long Pulse Spallation Source (LPSS) are summarized here.

Daemen, L.L.; Eckert, J.; Pynn, R. [and others

1995-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

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

E-Print Network [OSTI]

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

Pennycook, Steve

102

Magnetic excitations and polarized neutrons  

SciTech Connect (OSTI)

We review the historical development of polarized beam techniques for studies of condensed matter physics. In particular we describe, in some detail, the recent advance of the triple axis technique with polarization analysis. It is now possible to carry out quantitative characterization of magnetic cross sections S(Q,..omega..), in absolute units, for a wide range of energy and momentum transfers. We will discuss some examples of recent inelastic measurements on 3d ferromagnets and heavy Fermions. 35 refs., 11 figs., 2 tabs.

Shirane, G.

1985-01-01T23:59:59.000Z

103

Neutron Scattering Stiudies  

SciTech Connect (OSTI)

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.

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

2007-04-18T23:59:59.000Z

104

First Neutron Spectrometry Measurement at the HL-2A Tokamak  

E-Print Network [OSTI]

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.

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

105

Report on First Activations with the Lead Slowing Down Spectrometer  

SciTech Connect (OSTI)

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.

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

2011-03-03T23:59:59.000Z

106

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

E-Print Network [OSTI]

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.

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

107

MICE Spectrometer Magnet System Progress  

SciTech Connect (OSTI)

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.

Green, Michael A.; Virostek, Steve P.

2007-08-27T23:59:59.000Z

108

Educational Multiwavelength Atomic Emission Spectrometer  

E-Print Network [OSTI]

atomic absorption is the capability for simultaneous multielement analysis. It can be used colleges had acquired atomic absorption instruments by the year 1990.[2] In contrast, atomic emission with the acetylene-air flame source taken from an existing atomic absorption instrument. Two spectrometer units

Nazarenko, Alexander

109

E781 Hyperon Spectrometer Constants  

SciTech Connect (OSTI)

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.

Joseph T. Lach

2004-05-04T23:59:59.000Z

110

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

111

Sample rotating turntable kit for infrared spectrometers  

DOE Patents [OSTI]

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.

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

2008-03-04T23:59:59.000Z

112

Advanced Mass Spectrometers for Hydrogen Isotope Analyses  

SciTech Connect (OSTI)

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.

Chastagner, P.

2001-08-01T23:59:59.000Z

113

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]

, 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

Ryan, Dominic

114

Neutron skins and neutron stars  

SciTech Connect (OSTI)

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.

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

2013-11-07T23:59:59.000Z

115

Neutron guide  

DOE Patents [OSTI]

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.

Greene, Geoffrey L. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

116

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

E-Print Network [OSTI]

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).

Reeder, R L; Wright, J F

1976-01-01T23:59:59.000Z

117

Upgrade of the PNNL TEPC and Multisphere Spectrometer  

SciTech Connect (OSTI)

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.

Scherpelz, Robert I.; Conrady, Matthew M.

2008-09-10T23:59:59.000Z

118

Automated mass spectrometer grows up  

SciTech Connect (OSTI)

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.

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

1984-01-01T23:59:59.000Z

119

Neutron detector  

DOE Patents [OSTI]

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.

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

2011-04-05T23:59:59.000Z

120

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

E-Print Network [OSTI]

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

Martín-Solís, José Ramón

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Non-destructive method for determining neutron exposure  

DOE Patents [OSTI]

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.

Gold, R.; McElroy, W.N.

1983-11-01T23:59:59.000Z

122

Neutron tubes  

DOE Patents [OSTI]

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.

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

2008-03-11T23:59:59.000Z

123

Neutron diffraction studies of antiferromagnetism in manganous fluoride and some isomorphous compounds  

E-Print Network [OSTI]

FLUORIDE AND SOME ISOMORPHOUS COMPOUNDS Major Subject: Physics 1 2 11 16 16 18 27 29 31 38 38 54 58 63 67 75 77 TABLE OF CONTENTS CHAPTER I. INTRODUCTION . . . ......................... II. MAGNETIC PROPERTY CONSIDERATIONS............... Ill. RELATIONS FOE THE MAGNETIC SCATTERING OF NEUTRONS IV. APPARATUS AND PROCEDURE................... . A. The Neutron Spectrometer.............. B. The Low Temperature Cryostat.......... C. Lov Temperature Coolants. . . . . . . . . D. Sample...

Erickson, Richard Ames

1952-01-01T23:59:59.000Z

124

Report on Second Activations with the Lead Slowing Down Spectrometer  

SciTech Connect (OSTI)

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.

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

2012-04-27T23:59:59.000Z

125

Thermal neutron detection system  

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

126

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

E-Print Network [OSTI]

safely exceed the maximum triton range. The detectors could be refined for the specific application. A detector pair may be miniaturized 29 30 for in-core reactor spectra measurements between fuel-bearing plates and between elements. Low flux..., this point is considered to be essentially valid and free from thermal and low epi- thermal event overlap. Figure 11 presents the result of this research. The reactor core flux spectrum is believed to be valid from 0. 25 Mev to 3. 0 Mev. The measurement...

Stephenson, S. E

2012-06-07T23:59:59.000Z

127

SPEC-DOC: A USER'S GUIDE TO SPECTROMETER SOFTWARE  

E-Print Network [OSTI]

SPECTROMETER SOFTWARE S. Sinton, J.R. Garbow, J.L. Ackerman,to Spectrometer Software" S. Sinton, J. R. Garbow, J. L.

Sinton, S.

2008-01-01T23:59:59.000Z

128

Neutron Tomography and Space  

E-Print Network [OSTI]

Kevin Shields, “Optimization of neutron tomography for rapidNEUTRON TOMOGRAPHY AND SPACE Hal Egbert, Ronald Walker, R.industrial applications[1]. Neutron Computed Tomography was

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

129

Gas sampling system for a mass spectrometer  

DOE Patents [OSTI]

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.

2003-12-30T23:59:59.000Z

130

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

DOE Patents [OSTI]

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.

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

1999-01-01T23:59:59.000Z

131

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

SciTech Connect (OSTI)

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.

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

1987-12-01T23:59:59.000Z

132

Visible spectrometer utilizing organic thin film absorption  

E-Print Network [OSTI]

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 ...

Tiefenbruck, Laura C. (Laura Christine)

2004-01-01T23:59:59.000Z

133

Ultra High Mass Range Mass Spectrometer System  

DOE Patents [OSTI]

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.

Reilly, Peter T. A. [Knoxville, TN

2005-12-06T23:59:59.000Z

134

Optical Calibration For Jefferson Lab HKS Spectrometer  

E-Print Network [OSTI]

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.

L. Yuan; L. Tang

2005-11-04T23:59:59.000Z

135

Neutron Repulsion  

E-Print Network [OSTI]

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.

Oliver K. Manuel

2011-02-08T23:59:59.000Z

136

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  

E-Print Network [OSTI]

Energetics, University of Rochester, Rochester, New York 14623, USA 3 Lawrence Livermore National Laboratory neutron spectrometer for characterizing inertial confinement fusion implosions at OMEGA and the NIF Rev, Livermore, California 94550, USA 4 General Atomics, San Diego, California 92186, USA (Received 5 June 2014

137

Methods for absorbing neutrons  

DOE Patents [OSTI]

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.

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

138

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS  

E-Print Network [OSTI]

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS AND POLARIZED 3He R. GOLUB~and Steve K REPORTS (Review Section of Physics Letters) 237, No. 1(1994)1--62. PHYSICS REPORTS North-Holland Neutron electric-dipole moment, ultracold neutrons and polarized 3He R. Goluba and Steve K. Lamoreauxb a

139

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

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.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

140

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

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.

Wood, J.L.

1992-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Compact hydrogen/helium isotope mass spectrometer  

DOE Patents [OSTI]

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).

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

1996-01-01T23:59:59.000Z

142

Wide size range fast integrated mobility spectrometer  

DOE Patents [OSTI]

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.

Wang, Jian

2013-10-29T23:59:59.000Z

143

Compact Imaging Spectrometer Utilizing Immersed Gratings  

DOE Patents [OSTI]

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.

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

144

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

SciTech Connect (OSTI)

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.

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

2014-02-01T23:59:59.000Z

145

Neutron Brillouin scattering in a metallic glass  

SciTech Connect (OSTI)

The dispersion of collective modes in a metallic glass (Mg{sub 70}Zn{sub 30}) measured earlier at the thermal neutron time-of-flight spectrometer IN4 of the HFR of the ILL could be extended towards lower momentum transfers down to the first pseudo-Brillouin zone for the first time. This extension to momentum transfer not accessible up to now was possible using the highly resolving time-of-flight spectrometer HET of the new spallation source ISIS. In the region of overlap the two parts of the dispersion determined with different samples of the same metallic glass on different instruments agree very well. Also the earlier discrepancies with the dispersion determined for this metallic glass from a computer simulation could be nearly completely eliminated due to a more recent and more complete investigations of this glass.

Suck, J.B. (Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Nukleare Festkoerperphysik); Egelstaff, P.A. (Guelph Univ., ON (Canada). Dept. of Physics); Robinson, R.A.; Sivia, D.S. (Los Alamos National Lab., NM (United States)); Taylor, A.D. (Rutherford Appleton Lab., Chilton (United Kingdom))

1991-01-01T23:59:59.000Z

146

Lens system for a photo ion spectrometer  

DOE Patents [OSTI]

A lens system in a photo ion spectrometer for manipulating a primary ion beam and ionized atomic component is disclosed. The atomic components are removed from a sample by a primary ion beam using the lens system, and the ions are extracted for analysis. The lens system further includes ionization resistant coatings for protecting the lens system. 8 figs.

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

1990-11-27T23:59:59.000Z

147

Eleventh DOE workshop on personnel neutron dosimetry  

SciTech Connect (OSTI)

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.

Not Available

1991-12-31T23:59:59.000Z

148

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

DOE Patents [OSTI]

A non-destructive method for determination of neutron exposure and constituent concentrations in an object, such as 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 concentration at regions of interest within the object.

Gold, Raymond (Richland, WA); McElroy, William N. (Richland, WA)

1986-01-01T23:59:59.000Z

149

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

DOE Patents [OSTI]

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.

Gold, R.; McElroy, W.N.

1984-02-22T23:59:59.000Z

150

Development and performance of a miniature, low cost mass spectrometer  

E-Print Network [OSTI]

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 ...

Hemond, Brian D. (Brian David Thomson)

2011-01-01T23:59:59.000Z

151

Study of elementary reactions with the HADES dielectron spectrometer  

E-Print Network [OSTI]

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

B. Ramstein

2009-12-14T23:59:59.000Z

152

Study of elementary reactions with the HADES dielectron spectrometer  

E-Print Network [OSTI]

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

,

2009-01-01T23:59:59.000Z

153

Publications | Neutron Science | ORNL  

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

Publications SHARE Publications The Neutron Science publications system contains peer-reviewed publications based on research conducted at ORNL's Neutron Science facilities or...

154

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.

155

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

SciTech Connect (OSTI)

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.

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

156

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

SciTech Connect (OSTI)

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.

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

157

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

E-Print Network [OSTI]

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...

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

2014-01-01T23:59:59.000Z

158

Portable gas chromatograph-mass spectrometer  

DOE Patents [OSTI]

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.

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

159

Imaging spectrometer wide field catadioptric design  

DOE Patents [OSTI]

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.

Chrisp; Michael P. (Danville, CA)

2008-08-19T23:59:59.000Z

160

Compact imaging spectrometer utilizing immersed gratings  

DOE Patents [OSTI]

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.

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

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Portable gas chromatograph-mass spectrometer  

DOE Patents [OSTI]

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.

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

1996-06-11T23:59:59.000Z

162

Quench anaylsis of MICE spectrometer superconducting solenoid  

SciTech Connect (OSTI)

MICE superconducting spectrometer solenoids fabrication and tests are in progress now. First tests of the Spectrometer Solenoid discovered some issues which could be related to the chosen passive quench protection system. Both solenoids do not have heaters and quench propagation relied on the 'quench back' effect, cold diodes, and shunt resistors. The solenoids have very large inductances and stored energy which is 100% dissipated in the cold mass during a quench. This makes their protection a challenging task. The paper presents the quench analysis of these solenoids based on 3D FEA solution of coupled transient electromagnetic and thermal problems. The simulations used the Vector Fields QUENCH code. It is shown that in some quench scenarios, the quench propagation is relatively slow and some areas can be overheated. They describe ways of improving the solenoids quench protection in order to reduce the risk of possible failure.

Kashikhin, Vladimir; Bross, Alan; /Fermilab; Prestemon, Soren; / /LBL, Berkeley

2011-09-01T23:59:59.000Z

163

Interface for liquid chromatograph-mass spectrometer  

DOE Patents [OSTI]

A moving belt interface for real-time, high-performance liquid chromatograph (HPLC)/mass spectrometer (MS) analysis which strips away the HPLC solvent as it emerges from the end of the HPLC column and leaves a residue suitable for mass-spectral analysis. The interface includes a portable, stand-alone apparatus having a plural stage vacuum station, a continuous ribbon or belt, a drive train magnetically coupled to an external drive motor, a calibrated HPLC delivery system, a heated probe tip and means located adjacent the probe tip for direct ionization of the residue on the belt. The interface is also capable of being readily adapted to fit any mass spectrometer.

Andresen, Brian D. (Pleasanton, CA); Fought, Eric R. (Livermore, CA)

1989-01-01T23:59:59.000Z

164

Interface for liquid chromatograph-mass spectrometer  

DOE Patents [OSTI]

A moving belt interface is described for real-time, high-performance liquid chromatograph (HPLC)/mass spectrometer (MS) analysis which strips away the HPLC solvent as it emerges from the end of the HPLC column and leaves a residue suitable for mass-spectral analysis. The interface includes a portable, stand-alone apparatus having a plural stage vacuum station, a continuous ribbon or belt, a drive train magnetically coupled to an external drive motor, a calibrated HPLC delivery system, a heated probe tip and means located adjacent the probe tip for direct ionization of the residue on the belt. The interface is also capable of being readily adapted to fit any mass spectrometer. 8 figs.

Andresen, B.D.; Fought, E.R.

1989-09-19T23:59:59.000Z

165

Method of multiplexed analysis using ion mobility spectrometer  

DOE Patents [OSTI]

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.

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

2009-06-02T23:59:59.000Z

166

Expert overseer for mass spectrometer system  

DOE Patents [OSTI]

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.

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

1991-01-01T23:59:59.000Z

167

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

E-Print Network [OSTI]

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...

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

168

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

E-Print Network [OSTI]

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.

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

169

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

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.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

170

Neutron-Mirror-Neutron Oscillations in a Trap  

E-Print Network [OSTI]

We calculate the rate of neutron-mirror-neutron oscillations for ultracold neutrons trapped in a storage vessel. Recent experimental bounds on the oscillation time are discussed.

B. Kerbikov; O. Lychkovskiy

2008-04-03T23:59:59.000Z

171

Imaging with Scattered Neutrons  

E-Print Network [OSTI]

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.

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

2006-10-30T23:59:59.000Z

172

Tomographic analysis of neutron and gamma pulse shape distributions from liquid scintillation detectors at Joint European Torus  

SciTech Connect (OSTI)

The Joint European Torus (JET, Culham, UK) is the largest tokamak in the world devoted to nuclear fusion experiments of magnetic confined Deuterium (D)/Deuterium-Tritium (DT) plasmas. Neutrons produced in these plasmas are measured using various types of neutron detectors and spectrometers. Two of these instruments on JET make use of organic liquid scintillator detectors. The neutron emission profile monitor implements 19 liquid scintillation counters to detect the 2.45 MeV neutron emission from D plasmas. A new compact neutron spectrometer is operational at JET since 2010 to measure the neutron energy spectra from both D and DT plasmas. Liquid scintillation detectors are sensitive to both neutron and gamma radiation but give light responses of different decay time such that pulse shape discrimination techniques can be applied to identify the neutron contribution of interest from the data. The most common technique consists of integrating the radiation pulse shapes within different ranges of their rising and/or trailing edges. In this article, a step forward in this type of analysis is presented. The method applies a tomographic analysis of the 3-dimensional neutron and gamma pulse shape and pulse height distribution data obtained from liquid scintillation detectors such that n/? discrimination can be improved to lower energies and additional information can be gained on neutron contributions to the gamma events and vice versa.

Giacomelli, L. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom) [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); Conroy, S. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom) [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom); Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); Gorini, G. [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy)] [Department of Physics, Università degli Studi di Milano-Bicocca, Milano (Italy); Horton, L.; Murari, A.; Popovichev, S.; Syme, D. B. [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)] [JET-EFDA, Culham Science Centre, Abingdon, OX14 3DB (United Kingdom)

2014-02-15T23:59:59.000Z

173

A neutron diffraction study of the magnetic structure for the perovskite-type mixed oxides La(Mn, Cr)03 and (La, Sr)Fe03  

E-Print Network [OSTI]

to be equivalent, the structure factors must be based on the same cell size, or normalization is necessary. The usual practice in X-ray diffraction is to obtain ratios of in? tensities of many lines, while in neutron diffraction the absolute inte? grated... Amplitude Form Factor Dependence for 3d Shell . . 2^ 5* Ideal Cubic Perovskite (ABO^) Structure .................. 32 6. Plan View of Neutron Spectrometer....................... ^0 7. Spectral Distribution of X-Rays and Pile Neutrons........1+1 8...

Bents, Ulrich H.

2013-10-04T23:59:59.000Z

174

Delayed neutron emission probabilities of Li-F nuclides  

SciTech Connect (OSTI)

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.

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

175

Measurement of Neutron Background at the Pyhasalmi mine for CUPP Project, Finland  

E-Print Network [OSTI]

A natural neutron flux is one of significant kind of background in high-sensitive underground experiments. Therefore, when scheduling a delicate underground measurements one needs to measure neutron background. Deep underground the most significant source of neutrons are the U-Th natural radioactive chains giving a fission spectrum with the temperature of 2-3 MeV. Another source is the U-Th alpha-reactions on light nuclei of mine rock giving neutrons with different spectra in the 1-15 MeV energy region. Normal basalt mine rocks contain 1 ppm g/g of U-238 and less. Deep underground those rocks produce natural neutron fluxes of 10^{-7} - 10^{-6} cm^{-2}s^{-1} above 1 MeV. To measure such a background one needs a special techniques. In the Institute for Nuclear Research, Moscow, the neutron spectrometer was developed and built which is sensitive to such a low neutron fluxes. At the end of 2001 the collection of neutron data at the Pyhasalmi mine was started for the CUPP project. During 2002 the background and rough energy spectra of neutron at underground levels 410, 660, 990 and 1410 m were measured. The result of the measurement of the neutron background at different levels of the Pyhasalmi mine is presented and discussed. Data analysis is performed in different energy ranges from thermal neutrons up to 25 MeV and above.

J. N. Abdurashitov; V. N. Gavrin; V. L. Matushko; A. A. Shikhin; V. E. Yants; J. Peltoniemi; T. Keranen

2006-07-20T23:59:59.000Z

176

Dual waveband compact catadioptric imaging spectrometer  

DOE Patents [OSTI]

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.

Chrisp, Michael P.

2012-12-25T23:59:59.000Z

177

Lead Slowing Down Spectrometer Status Report  

SciTech Connect (OSTI)

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.

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

178

Ion mobility spectrometer with virtual aperture grid  

DOE Patents [OSTI]

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.

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

2010-11-23T23:59:59.000Z

179

Micro-optical-mechanical system photoacoustic spectrometer  

DOE Patents [OSTI]

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.

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

2013-01-01T23:59:59.000Z

180

Layered semiconductor neutron detectors  

DOE Patents [OSTI]

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.

Mao, Samuel S; Perry, Dale L

2013-12-10T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Neutron streak camera  

DOE Patents [OSTI]

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.

Wang, C.L.

1981-05-14T23:59:59.000Z

182

Wide swath imaging spectrometer utilizing a multi-modular design  

DOE Patents [OSTI]

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

Chrisp, Michael P. (Danville, CA)

2010-10-05T23:59:59.000Z

183

The TFTR E Parallel B Spectrometer for Mass and Energy Resolved Multi-Ion Charge Exchange Diagnostics  

SciTech Connect (OSTI)

The Charge Exchange Neutral Analyzer diagnostic for the Tokamak Fusion Test Reactor was designed to measure the energy distributions of both the thermal ions and the supra thermal populations arising from neutral-beam injection and ion cyclotron radio-frequency heating. These measurements yield the plasma ion temperature, as well as several other plasma parameters necessary to provide an understanding of the plasma condition and the performance of the auxiliary heating methods. For this application, a novel charge-exchange spectrometer using a dee-shaped region of parallel electric and magnetic fields was developed at the Princeton Plasma Physics Laboratory. The design and performance of this spectrometer is described in detail, including the effects of exposure of the microchannel plate detector to magnetic fields, neutrons, and tritium.

A.L. Roquemore; S.S. Medley

1998-01-01T23:59:59.000Z

184

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)

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.

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

185

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...

186

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...

187

Neutron dose equivalent meter  

DOE Patents [OSTI]

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.

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

188

Ultrafast neutron detector  

DOE Patents [OSTI]

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.

Wang, C.L.

1985-06-19T23:59:59.000Z

189

Pulsed-neutron monochromator  

DOE Patents [OSTI]

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.

Mook, H.A. Jr.

1984-01-01T23:59:59.000Z

190

Pulsed-neutron monochromator  

DOE Patents [OSTI]

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.

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

1985-01-01T23:59:59.000Z

191

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]

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.

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

2014-05-30T23:59:59.000Z

192

Neutron computed tomography  

E-Print Network [OSTI]

to make the Donner Algorithms run. TABLE OF CONTEliiTS CHAPTF. . R I NEI. TRON RADIOGRAPHY . I. 1 Background . I. 2 Theory . l. 3 Neutron Beam Characterization I. 4 Image Detectors . COMPI'TED TOMOGRAPHY . Il I Background . II. 2 Notation II. 3... data which is generated by rays traveling (and being attenuated) in straight lines. However in neutron radiography, what is measured is, to most extents, the levels of neutrons which are not attenuated. Neutrons are particles. They scatter...

Russell, Clifford Marlow

2012-06-07T23:59:59.000Z

193

Advanced neutron absorber materials  

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

194

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

SciTech Connect (OSTI)

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.

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

195

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

SciTech Connect (OSTI)

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.

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

2010-08-01T23:59:59.000Z

196

Mass spectrometer vacuum housing and pumping system  

DOE Patents [OSTI]

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.

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

1996-01-01T23:59:59.000Z

197

Mass spectrometer vacuum housing and pumping system  

DOE Patents [OSTI]

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.

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

1996-07-23T23:59:59.000Z

198

Semiconductor neutron detector  

DOE Patents [OSTI]

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.

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

199

High energy neutron dosimeter  

DOE Patents [OSTI]

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.

Rai, K.S.F.

1994-01-11T23:59:59.000Z

200

High energy neutron dosimeter  

DOE Patents [OSTI]

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.

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

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
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to obtain the most current and comprehensive results.


201

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

E-Print Network [OSTI]

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.

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

202

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

DOE Patents [OSTI]

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.

Atkinson, David A. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

203

The Neutron Lifetime  

E-Print Network [OSTI]

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.

F. E. Wietfeldt

2014-11-13T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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.

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

205

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

SciTech Connect (OSTI)

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.

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

206

Lead iodide X-ray and gamma-ray spectrometers for room and high temperature operation  

SciTech Connect (OSTI)

In this study the authors report on the results of the investigation of lead iodide material properties. The effectiveness of a zone refining purification method on the material purity is determined by ICP-MS and ICP-OES and correlated to the electrical and physical material properties. They show that this zone refining method is very efficient in removing impurities from lead iodide, and they also determine the segregation coefficient for some of these impurities. Triple axis X-ray diffraction (TAD) analysis has been used to determine the crystalline perfection of the lead iodide after applying various cutting, etching and fabrication methods. The soft lead iodide crystal was found to be damaged when cleaved by a razor blade, but by using a diamond wheel saw, followed by etching, the crystallinity of the material was much improved, as observed by TAD. Low temperature photoluminescence also indicates an improvement in the material properties of the purified lead iodide. Electrical properties of lead iodide such as carrier mobility, were calculated based on carrier-phonon scattering. The results for the electrical properties were in good agreement with the experimental data.

Hermon, H.; James, R.B.; Lund, J. [Sandia National Labs., Livermore, CA (United States)] [and others

1998-12-31T23:59:59.000Z

207

Lead iodide X-ray and gamma-ray spectrometers for room and high temperature operation  

SciTech Connect (OSTI)

In this study, we report on the results of the investigation of lead iodide material properties. The effectiveness of zone refining purification methods on the material purity is determined by ICP-MS and ICP-OES and correlated to the electrical and physical material properties. We show that this zone refining method is very efficient in removing impurities from lead iodide and we also determine the segregation coefficient for some of these impurities. Triple axis x- ray diffraction (TAD) analysis has been used to determine the crystalline perfection of the lead iodide after applying various cutting, etching, and fabrication methods. The soft lead iodide crystal was found to be damaged when cleaved by a razor blade, but by using a diamond wheel saw, followed by etching, the crystallinity of the material was improved, as observed by TAD. Low temperature photoluminescence also indicates an improvement in the material properties of the purified lead iodide. Electrical properties of lead iodide such as carrier mobility, were calculated based on carrier- phonon scattering. The results for the electrical properties were in good agreement with the experimental data.

Hermon, H.; James, R.B.; Cross, E. [and others

1997-02-01T23:59:59.000Z

208

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

SciTech Connect (OSTI)

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.

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

209

Open-split interface for mass spectrometers  

DOE Patents [OSTI]

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.

Diehl, John W. (Grand Forks, ND)

1991-01-01T23:59:59.000Z

210

The EUV Imaging Spectrometer for Hinode  

SciTech Connect (OSTI)

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.

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

211

The High-Acceptance Dielectron Spectrometer HADES  

E-Print Network [OSTI]

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.

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

212

The High-Acceptance Dielectron Spectrometer HADES  

E-Print Network [OSTI]

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 featur...

Agakichiev, G; Bannier, B; Bassini, R; Belver, D; Belyaev, A V; Blanco, A; Boehmer, M; Boyard, J L; Braun-Munzinger, P; Cabanelas, P; Castro, E; Chernenko, S; Christ, T; Destefanis, M; Díaz, J; Dohrmann, F; Dybczak, A; Eberl, T; Enghardt, W; Fabbietti, L; Fateev, O V; Finocchiaro, P; Fonte, Paulo J R; Friese, J; Fröhlich, I; Galatyuk, T; Garzón, J A; Gernhäuser, R; Gil1, A; Gilardi, C; Golubeva, M; Gonzalez-Diaz, D; Guber, F; Heilmann, M; Heinz, T; Hennino, T; Holzmann, R; Ierusalimov, A; Iori, I; Ivashkin, A; Jurkovic, M; Kämpfer, B; Kanaki, K; Karavicheva, T; Kirschner, D; König, I; König, W; Kolb, B W; Kotte, R; Krizek, F; Krücken, R; Kühn, W; Kugler, A; Kurepin, A; Lang, S; Lange, J S; Lapidus, K; Liu, T; Lopes, L; Lorenz, M; Maier, L; Mangiarotti, A; Markert, J; Metag, V; Michalska, B; Michel, J; Mishra, D; Moriniere, E; Mousa, J; Müntz, C; Naumann, Lutz; Otwinowski, J; Pachmayer, Y C; Palka, M; Parpottas, Y; Pechenov, V; Pechenova, O; PerezCavalcanti, T; Pietraszko, J; Przygoda, W; Ramstein, B; Reshetin, A; Roy-Stephan, M; Rustamov, A; Sadovskii, A; Sailer, B; Salabura, P; Schmah, A; Schwab, E; Sobolev, Yu G; Spataro, S; Spruck, B; Ströbele, H; Stroth, J; Sturm, C; Sudol, M; Tarantola, A; Teilab, K; Tlustý, P; Traxler, M; Trebac, R; Tsertos, H; Wagner, V; Weber, M; Wisniowski, M; Wojcik, T; Wuestenfel, J; Yurevich, S; Zanevsky, Yu V; Zhou, P; Zumbruch, P

2009-01-01T23:59:59.000Z

213

Neutron Compound Refractive Prisms - DOE SBIR Phase II Final Report  

SciTech Connect (OSTI)

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.

Dr. Jay Theodore Cremer, Jr

2011-06-25T23:59:59.000Z

214

Neutron sources and applications  

SciTech Connect (OSTI)

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.

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

215

BNL ACTIVITIES IN ADVANCED NEUTRON SOURCE DEVELOPMENT: PAST AND PRESENT  

SciTech Connect (OSTI)

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.

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

1998-06-14T23:59:59.000Z

216

BNL Activities in Advanced Neutron Source Development: Past and Present  

SciTech Connect (OSTI)

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.

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

1998-06-14T23:59:59.000Z

217

Conceptual design of the gamma-to-electron magnetic spectrometer for the National Ignition Facility  

SciTech Connect (OSTI)

The Gamma-to-Electron Magnetic Spectrometer (GEMS) diagnostic is designed to measure the prompt ?-ray energy spectrum during high yield deuterium-tritium (DT) implosions at the National Ignition Facility (NIF). The prompt ?-ray spectrum will provide “burn-averaged” observables, including total DT fusion yield, total areal density (?R), ablator ?R, and fuel ?R. These burn-averaged observables are unique because they are essentially averaged over 4?, providing a global reference for the line-of-sight-specific measurements typical of x-ray and neutron diagnostics. The GEMS conceptual design meets the physics-based requirements: ?E/E = 3%–5% can be achieved in the range of 2–25 MeV ?-ray energy. Minimum DT neutron yields required for 15% measurement uncertainty at low-resolution mode are: 5 × 10{sup 14} DT-n for ablator ?R (at 0.2 g/cm{sup 2}); 2 × 10{sup 15} DT-n for total DT yield (at 4.2 × 10{sup ?5} ?/n); and 1 × 10{sup 16} DT-n for fuel ?R (at 1 g/cm{sup 2})

Kim, Y., E-mail: yhkim@lanl.gov; Herrmann, H. W.; Jorgenson, H. J.; Barlow, D. B.; Young, C. S.; Lopez, F. E.; Oertel, J. A.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Stoeffl, W.; Casey, D.; Clancy, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hilsabeck, T. [General Atomics, San Diego, California 92186 (United States); Moy, K. [National Security Technologies, Special Technologies Laboratory, Santa Barbara, California 93111 (United States)

2014-11-15T23:59:59.000Z

218

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...

219

Neutron wave packet tomography  

E-Print Network [OSTI]

A tomographic technique is introduced in order to determine the quantum state of the center of mass motion of neutrons. An experiment is proposed and numerically analyzed.

G. Badurek; P. Facchi; Y. Hasegawa; Z. Hradil; S. Pascazio; H. Rauch; J. Rehacek; T. Yoneda

2005-03-29T23:59:59.000Z

220

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...

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Measuring the absolute deuteriumtritium neutron yield using the magnetic recoil spectrometer at OMEGA and the NIF  

E-Print Network [OSTI]

S. Le Pape,3 T. Ma,3 A. MacKinnon,3 M. A. Mckernan,3 M. Moran,3 E. Moses,3 H.-S. Park,3 J. Ralph,3 B, California 94550, USA 4 Los Alamos National Laboratory, Los Alamos, New Mexico 97545, USA 5 Sandia National

222

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

E-Print Network [OSTI]

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

2010-01-01T23:59:59.000Z

223

Mass spectrometer having a derivatized sample presentation apparatus  

DOE Patents [OSTI]

A mass spectrometer having a derivatized sample presentation apparatus is provided. The sample presentation apparatus has a complex bound to the surface of the sample presentation apparatus. This complex includes a molecule which may chemically modify a biomolecule.

Nelson, Randall W. (Phoenix, AZ)

2000-07-25T23:59:59.000Z

224

Temperature response of the ultra-high throughput mutational spectrometer  

E-Print Network [OSTI]

The Ultra-High Throughput Mutational Spectrometer is an instrument designed to separate mutant from wild type DNA through capillary electrophoresis. Since this technique uses the melting point of the molecule to distinguish ...

Suen, Timothy W. (Timothy Wu)

2005-01-01T23:59:59.000Z

225

The FIRE infrared spectrometer at Magellan: construction and commissioning  

E-Print Network [OSTI]

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 ...

Simcoe, Robert A.

226

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,...

227

The X-ray Microcalorimeter Spectrometer onboard of IXO  

E-Print Network [OSTI]

One of the instruments on the International X-ray Observatory (IXO), under study with NASA, ESA and JAXA, is the X-ray Microcalorimeter Spectrometer (XMS). This instrument, which will provide high spectral resolution images, ...

Figueroa-Feliciano, Enectali

228

Single-ultrafine-particle mass spectrometer development and application  

E-Print Network [OSTI]

SINGLE-ULTRAFINE-PARTICLE MASS SPECTROMETER DEVELOPMENT AND APPLICATION A Thesis by STANISLAV Y. GLAGOLENKO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 2004 Major Subject: Mechanical Engineering SINGLE-ULTRAFINE-PARTICLE MASS SPECTROMETER DEVELOPMENT AND APPLICATION A Thesis by STANISLAV Y. GLAGOLENKO Submitted to Texas A&M University in partial...

Glagolenko, Stanislav Yurievich

2004-11-15T23:59:59.000Z

229

C-III flow measurements with a coherence imaging spectrometer  

SciTech Connect (OSTI)

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.

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

230

Analytical techniques for instrument design -- Matrix methods  

SciTech Connect (OSTI)

The authors take the traditional Cooper-Nathans approach, as has been applied for many years for steady-state triple-axis spectrometers, and consider its generalization to other inelastic scattering spectrometers. This involves a number of simple manipulations of exponentials of quadratic forms. In particular, they discuss a toolbox of matrix manipulations that can be performed on the 6-dimensional Cooper-Nathans matrix. They show how these tools can be combined to solve a number of important problems, within the narrow-band limit and the gaussian approximation. They will argue that a generalized program that can handle multiple different spectrometers could (and should) be written in parallel to the Monte-Carlo packages that are becoming available. They also discuss the complementarity between detailed Monte-Carlo calculations and the approach presented here. In particular, Monte-Carlo methods traditionally simulate the real experiment as performed in practice, given a model scattering law, while the Cooper-Nathans method asks the inverse question: given that a neutron turns up in a particular spectrometer configuration (e.g. angle and time of flight), what is the probability distribution of possible scattering events at the sample? The Monte-Carlo approach could be applied in the same spirit to this question.

Robinson, R.A.

1997-12-31T23:59:59.000Z

231

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...

232

Neutron Stars and Fractal Dimensionality  

E-Print Network [OSTI]

We argue that the material inside Neutron stars behaves anomalously with fractal statistics and that in principle, we could induce mini Neutron stars, with the release of energy.

Burra G. Sidharth

2008-05-06T23:59:59.000Z

233

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

E-Print Network [OSTI]

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.

Zhou Liang; Qu Hua-Min

2014-11-24T23:59:59.000Z

234

Compact neutron generator  

DOE Patents [OSTI]

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.

Leung, Ka-Ngo; Lou, Tak Pui

2005-03-22T23:59:59.000Z

235

Neutron capture therapies  

DOE Patents [OSTI]

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.

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

1999-01-01T23:59:59.000Z

236

Pocked surface neutron detector  

DOE Patents [OSTI]

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.

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

2003-04-08T23:59:59.000Z

237

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect (OSTI)

Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

2004-10-16T23:59:59.000Z

238

Pulsed neutron detector  

DOE Patents [OSTI]

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.

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

1989-03-21T23:59:59.000Z

239

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

SciTech Connect (OSTI)

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.

Derek Glazier

2007-09-30T23:59:59.000Z

240

Neutron LifetimeNeutron Lifetime IUCF Colloquium April 13,  

E-Print Network [OSTI]

Neutron LifetimeNeutron Lifetime IUCF Colloquium April 13, 2007 Albert Steyerl Department 940 878.5±0.8 885.7±0.8 new result neutronlifetime(),s year world average Neutron lifetime data #12 world average Neutron lifetime data A. Serebrov et al. 2005Storage of ultra-cold neutrons878.5 ±±±± 0

Steyerl, Albert

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

SciTech Connect (OSTI)

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.

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

242

Hyperons in neutron stars  

E-Print Network [OSTI]

Using the Dirac-Brueckner-Hartree-Fock approach, the properties of neutron-star matter including hyperons are investigated. In the calculation, we consider both time and space components of the vector self-energies of baryons as well as the scalar ones. Furthermore, the effect of negative-energy states of baryons is partly taken into account. We obtain the maximum neutron-star mass of $2.08\\,M_{\\odot}$, which is consistent with the recently observed, massive neutron stars. We discuss a universal, repulsive three-body force for hyperons in matter.

Katayama, Tetsuya

2015-01-01T23:59:59.000Z

243

Switchable radioactive neutron source device  

DOE Patents [OSTI]

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.

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

1987-11-06T23:59:59.000Z

244

Sample introducing apparatus and sample modules for mass spectrometer  

DOE Patents [OSTI]

An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus.

Thompson, Cyril V. (Knoxville, TN); Wise, Marcus B. (Kingston, TN)

1993-01-01T23:59:59.000Z

245

Sample introducing apparatus and sample modules for mass spectrometer  

DOE Patents [OSTI]

An apparatus for introducing gaseous samples from a wide range of environmental matrices into a mass spectrometer for analysis of the samples is described. Several sample preparing modules including a real-time air monitoring module, a soil/liquid purge module, and a thermal desorption module are individually and rapidly attachable to the sample introducing apparatus for supplying gaseous samples to the mass spectrometer. The sample-introducing apparatus uses a capillary column for conveying the gaseous samples into the mass spectrometer and is provided with an open/split interface in communication with the capillary and a sample archiving port through which at least about 90 percent of the gaseous sample in a mixture with an inert gas that was introduced into the sample introducing apparatus is separated from a minor portion of the mixture entering the capillary discharged from the sample introducing apparatus. 5 figures.

Thompson, C.V.; Wise, M.B.

1993-12-21T23:59:59.000Z

246

SPEC-DOC: a user's guide to spectrometer software  

SciTech Connect (OSTI)

SPEC is the name of the operating system designed to control NMR spectrometers. SPEC is actually one large program which handles many functions necessary to control each spectrometer. The SPEC operating system is documented. The general operation of SPEC is discussed, including how to get into the program and how to issue commands. The commands are discussed in detail, as well as the operation of the microprocessor based pulse programmer, spectrometer peripherals, supporting programs, and how to create and load a TEMP program. Appended are details on bootstrapping procedures, hardware specifics, a technical description of SPEC and how to change or recreate it, a description of microcode loading and the procedure for formatting floppies, disks, and recreating RDOS. (LEW)

Sinton, S.; Garbow, J.R.; Ackerman, J.L.; Drobny, G.; Ruben, D.J.; Pines, A.

1983-05-01T23:59:59.000Z

247

The MARTE VNIR Imaging Spectrometer Experiment: Design and Analysis  

E-Print Network [OSTI]

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.

Brown, Adrian J; Dunagan, Stephen

2014-01-01T23:59:59.000Z

248

Strangeness in Neutron Stars  

E-Print Network [OSTI]

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.

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

2006-04-20T23:59:59.000Z

249

Shifting scintillator neutron detector  

DOE Patents [OSTI]

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.

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

250

Cylindrical neutron generator  

DOE Patents [OSTI]

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.

Leung, Ka-Ngo

2005-06-14T23:59:59.000Z

251

Cylindrical neutron generator  

DOE Patents [OSTI]

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.

Leung, Ka-Ngo (Hercules, CA)

2008-04-22T23:59:59.000Z

252

Cylindrical neutron generator  

DOE Patents [OSTI]

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.

Leung, Ka-Ngo (Hercules, CA)

2009-12-29T23:59:59.000Z

253

Discrimination of gamma rays due to inelastic neutron scattering in AGATA  

E-Print Network [OSTI]

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.

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

2009-06-10T23:59:59.000Z

254

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

E-Print Network [OSTI]

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 20 % for neutrons below 4 MeV have been obtained.

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

255

Discrimination of gamma rays due to inelastic neutron scattering in AGATA  

E-Print Network [OSTI]

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.

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

256

Extended Evaluations of the Commercial Spectrometer Systems for Safeguards Applications  

SciTech Connect (OSTI)

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.

Duc T. Vo

1999-08-01T23:59:59.000Z

257

Waveguide-integrated photonic crystal spectrometer with camera readout  

SciTech Connect (OSTI)

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.

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

258

The NIF x-ray spectrometer calibration campaign at Omega  

SciTech Connect (OSTI)

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.

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

259

The Results of Recent MICE Superconducting Spectrometer Solenoid Test  

SciTech Connect (OSTI)

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.

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

2010-10-15T23:59:59.000Z

260

X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator  

SciTech Connect (OSTI)

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60 deg. between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.; Caffrey, A. J. [Idaho National Laboratory, 2525 N. Freemont Avenue, Idaho Falls, Idaho 83415 (United States); Simpson, J.; Lemchak, M. [Thermo-Fisher Scientific/MF Physics, 5074 List Drive, Colorado Springs, Colorado 80919 (United States)

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Measurement of the keV-neutron capture cross section and capture gamma-ray spectrum of isotopes around N=82 region  

SciTech Connect (OSTI)

The keV-neutron capture cross section and capture {gamma}-ray spectra of nuclides with a neutron magic number N= 82, {sup 139}La and {sup 142}Nd, were newly measured by the time-of-flight method. Capture {gamma}-rays were detected with an anti-Compton NaI(T1) spectrometer, and the pulse-height weighting technique was applied to derive the neutron capture cross section. The results were provided with our previous measurements of other nuclides around N= 82, {sup 140}Ce, {sup 141}Pr, {sup 143}Nd and {sup 145}Nd.

Katabuchi, Tatsuya; Igashira, Masayuki [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2012-11-12T23:59:59.000Z

262

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

SciTech Connect (OSTI)

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.

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

263

Design of and data reduction from compact Thomson parabola spectrometers  

SciTech Connect (OSTI)

Thomson parabola spectrometers are used to characterize MeV ion beams produced in high intensity laser interactions. These spectrometers disperse multiple ion species according to their charge to mass ratio through the use of parallel electric and magnetic fields. Analytical solutions for ion deflection in electric and magnetic fields have been used to extract ion spectra with the assumption that fringing effects are negligible. Experimental space restrictions and dynamic range requirements necessitate designs that stress the analytical assumptions. Depending on design parameters, the error in the analytical assumption can be comparable to the energy resolution. Estimates are provided to approximate the error on the total ion deflection. A method for modeling ion trajectories including fringing effects is presented using software freely available or in common use. The magnetostatic fields are modeled in 3D, including material properties of nearby magnetic materials using RADIA. Electrostatic fields are modeled in 2D for a spectrometer implementing angled plates using the partial differential equation toolbox in MATLAB. Using these models to calculate the ion trajectory allows for analysis of a Thomson parabola spectrometer with an arbitrary field configuration.

Morrison, J. T.; Willis, C.; Freeman, R. R.; Van Woerkom, L. [Physics Department, Ohio State University, Columbus, Ohio 43210 (United States)

2011-03-15T23:59:59.000Z

264

Optical system for high resolution spectrometer/monochromator  

DOE Patents [OSTI]

An optical system for use in a spectrometer or monochromator employing a mirror which reflects electromagnetic radiation from a source to converge with same in a plane is disclosed. A straight grooved, varied-spaced diffraction grating receives the converging electromagnetic radiation from the mirror and produces a spectral image for capture by a detector, target or like receiver. 11 figs.

Hettrick, M.C.; Underwood, J.H.

1988-10-11T23:59:59.000Z

265

Compact Catadioptric Imaging Spectrometer Designs Utilizing Immersed Gratings  

DOE Patents [OSTI]

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

Lerner, Scott A. (Livermore, CA)

2006-02-28T23:59:59.000Z

266

Modulated optical solid-state spectrometer applications in plasma diagnostics  

E-Print Network [OSTI]

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

Howard, John

267

A fourier spectrometer for studying the radiation from Josephson Junctions  

SciTech Connect (OSTI)

The paper describes a Fourier spectrometer designed to study the radiation generated by a Josephson junction in the millimeter and FIR bands with a resolution of {approx}2 GHz in the two-pass mode and {approx}1 GHz in the multipass mode. A feature is that one Josephson junctions operates as both generator and detector at the same time.

Verevkin, A.A.; Il`in, V.A.; Lipatov, A.P. [V.I. Lenin Moscow Pedagogical State Univ., Moscow (Russian Federation)

1995-06-01T23:59:59.000Z

268

Electron-neutron scattering and transport properties of neutron stars  

E-Print Network [OSTI]

We show that electrons can couple to the neutron excitations in neutron stars and find that this can limit their contribution to the transport properties of dense matter, especially the shear viscosity. The coupling between electrons and neutrons is induced by protons in the core, and by ions in the crust. We calculate the effective electron-neutron interaction for the kinematics of relevance to the scattering of degenerate electrons at high density. We use this interaction to calculate the electron thermal conductivity, electrical conductivity, and shear viscosity in the neutron star inner crust, and in the core where we consider both normal and superfluid phases of neutron-rich matter. In some cases, particularly when protons are superconducting and neutrons are in their normal phase, we find that electron-neutron scattering can be more important than the other scattering mechanisms considered previously.

Bertoni, Bridget; Rrapaj, Ermal

2014-01-01T23:59:59.000Z

269

Novel neutron focusing mirrors for compact neutron sources  

E-Print Network [OSTI]

We demonstrated neutron beam focusing and neutron imaging using axisymmetric optics, based on pairs of confocal ellipsoid and hyperboloid mirrors. Such systems, known as Wolter mirrors, are commonly used in x-ray telescopes. ...

Gubarev, M.V.

270

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

SciTech Connect (OSTI)

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before: the probability of UCN losses from the trap was only 1% of that for neutron {beta} decay. The neutron lifetime obtained, 878.5{+-}0.7{sub stat}{+-}0.3{sub sys} s, is the most accurate experimental measurement to date.

Serebrov, A. P.; Varlamov, V. E.; Kharitonov, A. G.; Fomin, A. K.; Krasnoschekova, I. A.; Lasakov, M. S.; Taldaev, R. R.; Vassiljev, A. V.; Zherebtsov, O. M. [Petersburg Nuclear Physics Institute, Russian Academy of Sciences, RU-188300 Gatchina, Leningrad District (Russian Federation); Pokotilovski, Yu. N. [Joint Institute for Nuclear Research, RU-141980 Dubna, Moscow Region (Russian Federation); Geltenbort, P. [Institut Max von Laue Paul Langevin, Boite Postal 156, F-38042 Grenoble Cedex 9 (France)

2008-09-15T23:59:59.000Z

271

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

E-Print Network [OSTI]

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before:the probability of UCN losses from the trap was only 1% of that for neutron beta decay. The neutron lifetime obtained,878.5+/-0.7stat+/-0.3sys s, is the most accurate experimental measurement to date.

A. P. Serebrov; V. E. Varlamov; A. G. Kharitonov; A. K. Fomin; Yu. N. Pokotilovski; P. Geltenbort; I. A. Krasnoschekova; M. S. Lasakov; R. R. Taldaev; A. V. Vassiljev; O. M. Zherebtsov

2007-02-06T23:59:59.000Z

272

Precision Measurement Of The Neutron's Beta Asymmetry Using Ultra-Cold Neutrons  

SciTech Connect (OSTI)

A measurement of A{beta}, the correlation between the electron momentum and neutron (n) spin (the beta asymmetry) in n beta-decay, together with the n lifetime, provides a method for extracting fundamental parameters for the charged-current weak interaction of the nucleon. In particular when combined with decay measurements, one can extract the Vud element of the CKM matrix, a critical element in CKM unitarity tests. By using a new SD2 super-thermal source at LANSCE, large fluxes of UCN (ultra-cold neutrons) are expected for the UCNA project. These UCN will be 100% polarized using a 7 T magnetic field, and directed into the {beta} spectrometer. This approach, together with an expected large reduction in backgrounds, will result in an order of magnitude reduction in the critical systematic corrections associated with current n {beta}-asymmetry measurements. This paper will give an overview of the UCNA A{beta} measurement as well as an update on the status of the experiment.

Makela, M. [Los Alamos National Lab., P.O. Box 1663, Los Alamos, NM 87545 (United States); Back, H. O. [North Carolina State University Raleigh, NC 27695 (United States); Melconian, D. [University of Washington, Department of Physics, Box 351560 Seattle, WA 98195 (United States); Plaster, B. [California Institute of Technology, Kellogg Radiation Lab, Pasadena, CA 91125 (United States)

2006-07-11T23:59:59.000Z

273

FINGERPRINTING INORGANIC ARSENIC AND ORGANOARSENIC COMPOUNDS IN IN SITU OIL SHALE RETORT AND PROCESS VOTERS USING A LIQUID CHROMATOGRAPH COUPLED WITH AN ATOMIC ABSORPTION SPECTROMETER AS A DETECTOR  

E-Print Network [OSTI]

COUPLED WITH AN ATOMIC ABSORPTION SPECTROMETER AS A DETECTORCoupled with an Atomic Absorption Spectrometer as a DetectorcOUPLED WITH AN ATOMIC ABSORPTION SPECTROMETER AS A DETECTOR

Fish, Richard H.

2013-01-01T23:59:59.000Z

274

Strangeness in Neutron Stars  

E-Print Network [OSTI]

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.

Fridolin Weber

2000-08-23T23:59:59.000Z

275

Portable Neutron Sensors for Emergency Response Operations  

SciTech Connect (OSTI)

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

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

2012-06-22T23:59:59.000Z

276

Neutron beam characterization at the Neutron Radiography Reactor (NRAD)  

SciTech Connect (OSTI)

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.

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

1990-01-01T23:59:59.000Z

277

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...

278

A co-axially configured submillimeter spectrometer and investigations of hydrogen bound molecular complexes  

E-Print Network [OSTI]

The development of a co-axially configured submillimeter spectrometer is reported. The spectrometer has been constructed to observe molecular complexes that exhibit non-covalent interactions with energies much less than that of a traditional...

McElmurry, Blake Anthony

2009-05-15T23:59:59.000Z

279

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

E-Print Network [OSTI]

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 ...

Podpaly, Yuri Anatoly

2007-01-01T23:59:59.000Z

280

E-Print Network 3.0 - anti-compton gamma-ray spectrometer Sample...  

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

compton gamma-ray spectrometer Search Powered by Explorit Topic List Advanced Search Sample search results for: anti-compton gamma-ray spectrometer Page: << < 1 2 3 4 5 > >> 1...

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Spherical neutron generator  

DOE Patents [OSTI]

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.

Leung, Ka-Ngo

2006-11-21T23:59:59.000Z

282

Personnel electronic neutron dosimeter  

DOE Patents [OSTI]

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.

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

1984-12-18T23:59:59.000Z

283

Personnel electronic neutron dosimeter  

DOE Patents [OSTI]

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.

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

1982-03-03T23:59:59.000Z

284

Neutron field parameter measurements on the JET tokamak by means of super-heated fluid detectors  

SciTech Connect (OSTI)

The neutron field parameters (fluence and energy distribution) at a specific location outside the JET Torus Hall have been measured by means of super-heated fluid detectors (or 'bubble detectors') in combination with an independent, time-of-flight, technique. The bubble detector assemblies were placed at the end of a vertical line of sight at about 16 m from the tokamak mid plane. Spatial distributions of the neutron fluence along the radial and toroidal directions have been obtained using two-dimensional arrays of bubble detectors. Using a set of three bubble detector spectrometers the neutron energy distribution was determined over a broad energy range, from about 10 keV to above 10 MeV, with an energy resolution of about 30% at 2.5 MeV. The very broad energy response allowed for the identification of energy features far from the main fusion component (around 2.45 MeV for deuterium discharges).

Gherendi, M.; Craciunescu, T.; Pantea, A. [Association EURATOM-MEdC, National Institute for Laser, Plasma and Radiation Physics, Magurele (Romania); Zoita, V. L. [Association EURATOM-MEdC, National Institute for Laser, Plasma and Radiation Physics, Magurele (Romania); EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Johnson, M. Gatu; Hellesen, C.; Conroy, S. [Association EURATOM-VR, Uppsala University, Uppsala (Sweden); Baltog, I. [Association EURATOM-MEdC, National Institute for Material Physics, Magurele (Romania); Edlington, T.; Kiptily, V.; Popovichev, S. [Association EURATOM-CCFE, Culham Science Centre, Abingdon (United Kingdom); Murari, A. [EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Association EURATOM-ENEA, RFX, Padova (Italy); Collaboration: JET EFDA Contributors

2012-10-15T23:59:59.000Z

285

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

SciTech Connect (OSTI)

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.

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

286

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of1, 2007Transmission toBeamNDiscoveryNeutron

287

Corrosion resistant neutron absorbing coatings  

DOE Patents [OSTI]

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.

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

288

Corrosion resistant neutron absorbing coatings  

DOE Patents [OSTI]

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.

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

289

Fast neutron dosimetry  

SciTech Connect (OSTI)

This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

DeLuca, P.M. Jr.; Pearson, D.W.

1992-01-01T23:59:59.000Z

290

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

291

NEUTRON AND NON-NEUTRON NUCLEAR DATA FOR RADIATION DOSIMETRY  

SciTech Connect (OSTI)

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.

HOLDEN,N.E.

1999-09-10T23:59:59.000Z

292

Polyethylene-reflected plutonium metal sphere : subcritical neutron and gamma measurements.  

SciTech Connect (OSTI)

Numerous benchmark measurements have been performed to enable developers of neutron transport models and codes to evaluate the accuracy of their calculations. In particular, for criticality safety applications, the International Criticality Safety Benchmark Experiment Program (ICSBEP) annually publishes a handbook of critical and subcritical benchmarks. Relatively fewer benchmark measurements have been performed to validate photon transport models and codes, and unlike the ICSBEP, there is no program dedicated to the evaluation and publication of photon benchmarks. Even fewer coupled neutron-photon benchmarks have been performed. This report documents a coupled neutron-photon benchmark for plutonium metal reflected by polyethylene. A 4.5-kg sphere of ?-phase, weapons-grade plutonium metal was measured in six reflected configurations: (1) Bare; (2) Reflected by 0.5 inch of high density polyethylene (HDPE); (3) Reflected by 1.0 inch of HDPE; (4) Reflected by 1.5 inches of HDPE; (5) Reflected by 3.0 inches of HDPE; and (6) Reflected by 6.0 inches of HDPE. Neutron and photon emissions from the plutonium sphere were measured using three instruments: (1) A gross neutron counter; (2) A neutron multiplicity counter; and (3) A high-resolution gamma spectrometer. This report documents the experimental conditions and results in detail sufficient to permit developers of radiation transport models and codes to construct models of the experiments and to compare their calculations to the measurements. All of the data acquired during this series of experiments are available upon request.

Mattingly, John K.

2009-11-01T23:59:59.000Z

293

Single and pair neutron transfers at sub-barrier energies  

SciTech Connect (OSTI)

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.

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

294

Neutron Absorbing Alloys  

DOE Patents [OSTI]

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.

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

295

Solid state neutron detector array  

DOE Patents [OSTI]

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.

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

296

Solid state neutron detector array  

DOE Patents [OSTI]

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.

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

297

Dose-equivalent neutron dosimeter  

DOE Patents [OSTI]

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.

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

1981-01-07T23:59:59.000Z

298

The Design and Construction of the MICE Spectrometer Solenoids  

SciTech Connect (OSTI)

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

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

2008-08-02T23:59:59.000Z

299

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents [OSTI]

A mass spectrometer and methods are disclosed 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. 7 figs.

Tuszewski, M.G.

1997-07-22T23:59:59.000Z

300

Commissioning of the ATLAS Muon Spectrometer with Cosmic Rays  

E-Print Network [OSTI]

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.

The ATLAS Collaboration

2010-08-02T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Compact mass spectrometer for plasma discharge ion analysis  

DOE Patents [OSTI]

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.

Tuszewski, Michel G. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

302

Inverse time-of-flight spectrometer for beam plasma research  

SciTech Connect (OSTI)

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.

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

303

Compact Refractive Imaging Spectrometer Designs Utilizing Immersed Gratings  

DOE Patents [OSTI]

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

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

304

Imaging Spectrometer Designs Utilizing Immersed Gratings With Accessible Entrance Slit  

DOE Patents [OSTI]

A compact imaging spectrometer comprises an entrance slit, a catadioptric lens with a mirrored surface, a grating, and a detector array. The entrance slit directs light to the mirrored surface of the catadioptric lens; the mirrored surface reflects the light back through the lens to the grating. The grating receives the light from the catadioptric lens and diffracts the light to the lens away from the mirrored surface. The lens transmits the light and focuses it onto the detector array.

Chrisp, Michael P. (Danville, CA); Lerner, Scott A. (Corvallis, OR)

2006-03-21T23:59:59.000Z

305

Polarization Measurements in Photoproduction with CEBAF Large Acceptance Spectrometer  

SciTech Connect (OSTI)

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.

E. Pasyuk

2010-05-01T23:59:59.000Z

306

Polarimeters and Energy Spectrometers for the ILC Beam Delivery System  

SciTech Connect (OSTI)

This article gives an overview of current plans and issues for polarimeters and energy spectrometers in the Beam Delivery System of the ILC. It is meant to serve as a useful reference for the Detector Letter of Intent documents currently being prepared. Concepts for high precision polarization and energy measurements exist. These concepts have resulted in detailed system layouts that are included in the RDR description for the Beam Delivery System. The RDR includes both upstream and downstream polarimeters and energy spectrometers for both beams. This provides needed complementarity and redundancy for achieving the precision required, with adequate control and demonstration of systematic errors. The BDS polarimeters and energy spectrometers need to be a joint effort of the ILC BDS team and the Detector collaborations, with collaboration members responsible for the performance and accuracy of the measurements. Details for this collaboration and assigning of responsibilities remain to be worked out. There is also a demonstrated need for Detector physicists to play an active role in the design and evaluation of accelerator components that impact beam polarization and beam energy capabilities, including the polarized source and spin rotator systems. A workshop was held in 2008 on ILC Polarization and Energy measurements, which resulted in a set of recommendations for the ILC design and operation. Additional input and action is needed on these from the Detector collaborations, the Research Director and the GDE. Work is continuing during the ILC engineering design phase to further optimize the polarimeter and energy spectrometer concepts and fully implement them in the ILC. This includes consideration for alternative methods, detailed design and cost estimates, and prototype and test beam activities.

Boogert, S.; /Royal Holloway, U. of London; Hildreth, M.; /Notre Dame U.; Kafer, D.; List, J.; Monig, K.; /DESY; Moffeit, K.C.; /SLAC; Moortgat-Pick, G.; /Durham U., IPPP; Riemann, S.; Schreiber, H.J.; Schuler, P.; /DESY; Torrence, E.; /Oregon U.; Woods, M.; /SLAC

2009-02-24T23:59:59.000Z

307

Search for neutron - mirror neutron oscillations in a laboratory experiment with ultracold neutrons  

E-Print Network [OSTI]

Mirror matter is considered as a candidate for dark matter. In connection with this an experimental search for neutron - mirror neutron (nn') transitions has been carried out using storage of ultracold neutrons in a trap with different magnetic fields. As a result, a new limit for the neutron - mirror neutron oscillation time has been obtained, tau_osc >= 448 s (90% C.L.), assuming that there is no mirror magnetic field larger than 100 nT. Besides a first attempt to obtain some restriction for mirror magnetic field has been done.

A. P. Serebrov; E. B. Aleksandrov; N. A. Dovator; S. P. Dmitriev; A. K. Fomin; P. Geltenbort; A. G. Kharitonov; I. A. Krasnoschekova; M. S. Lasakov; A. N. Murashkin; G. E. Shmelev; V. E. Varlamov; A. V. Vassiljev; O. M. Zherebtsov; O. Zimmer

2008-09-29T23:59:59.000Z

308

The neutron electric form factor to Q² = 1.45 (GeV/c)²  

SciTech Connect (OSTI)

The nucleon elastic electromagnetic form factors are fundamental quantities needed for an understanding of nucleon and nuclear electromagnetic structure. The evolution of the Sachs electric and magnetic form factors with Q2, the square of the four-momentum transfer, is related to the distribution of charge and magnetization within the nucleon. High precision measurements of the nucleon form factors are essential for stringent tests of our current theoretical understanding of confinement within the nucleon. Measurements of the neutron form factors, in particular, those of the neutron electric form factor, have been notoriously difficult due to the lack of a free neutron target and the vanishing integral charge of the neutron. Indeed, a precise measurement of the neutron electric form factor has eluded experimentalists for decades; however, with the advent of high duty-factor polarized electron beam facilities, experiments employing polarization degrees of freedom have finally yielded the first precise measurements of this fundamental quantity. Following a general overview of the experimental and theoretical status of the nucleon form factors, a detailed description of an experiment designed to extract the neutron electric form factor from measurements of the neutron's recoil polarization in quasielastic 2H(e, e')1H scattering is presented. The experiment described here employed the Thomas Jefferson National Accelerator Facility's longitudinally polarized electron beam, a magnetic spectrometer for detection of the scattered electron, and a neutron polarimeter designed specifically for this experiment. Measurements were conducted at three Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2, and the final results extracted from an analysis of the data acquired in this experiment are reported and compared with recent theoretical predictions for the nucleon form factors.

Bradley Plaster

2004-02-01T23:59:59.000Z

309

Porous material neutron detector  

DOE Patents [OSTI]

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.

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

2012-04-10T23:59:59.000Z

310

Neutron electric polarizability  

E-Print Network [OSTI]

We use the background field method to extract the "connected" piece of the neutron electric polarizability. We present results for quenched simulations using both clover and Wilson fermions and discuss our experience in extracting the mass shifts and the challenges we encountered when we lowered the quark mass. For the neutron we find that as the pion mass is lowered below $500\\MeV$, the polarizability starts rising in agreement with predictions from chiral perturbation theory. For our lowest pion mass, $m_\\pi=320\\MeV$, we find that $\\alpha_n = 3.8(1.3)\\times 10^{-4}\\fm^3$, which is still only one third of the experimental value. We also present results for the neutral pion; we find that its polarizability turns negative for pion masses smaller than $500\\MeV$ which is puzzling.

Andrei Alexandru; Frank X. Lee

2009-11-13T23:59:59.000Z

311

Fast neutron imaging device and method  

DOE Patents [OSTI]

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.

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

2014-02-11T23:59:59.000Z

312

Proton recoil scintillator neutron rem meter  

DOE Patents [OSTI]

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.

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

2003-01-01T23:59:59.000Z

313

Spallation Neutron Sources Around the World  

E-Print Network [OSTI]

Spallation Neutron Sources Around the World Bernie Riemer Thanks to others for the many shamelessly Laboratory #12;2 Managed by UT-Battelle for the U.S. Department of Energy Spallation Neutron Source Facilities Spallation Neutron Source Facilities Serve Neutron Science Programs · Neutron beams to suites

McDonald, Kirk

314

Di-neutron correlation in light neutron-rich nuclei  

E-Print Network [OSTI]

Using a three-body model with density-dependent contact interaction, we discuss the root mean square distance between the two valence neutrons in $^{11}$Li nuclues as a function of the center of mass of the neutrons relative to the core nucleus $^9$Li. We show that the mean distance takes a pronounced minimum around the surface of the nucleus, indicating a strong surface di-neutron correlation. We demonstrate that the pairing correlation plays an essential role in this behavior. We also discuss the di-neutron structure in the $^8$He nucleus.

K. Hagino; H. Sagawa; P. Schuck

2008-12-03T23:59:59.000Z

315

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

SciTech Connect (OSTI)

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.

HOLDEN, N.E.

2004-09-26T23:59:59.000Z

316

Review of Non-Neutron and Neutron Nuclear Data, 2004  

SciTech Connect (OSTI)

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.

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

2005-05-24T23:59:59.000Z

317

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

SciTech Connect (OSTI)

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)

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

318

Hubble Sees a Neutron Star Alone in Space Nearest Known Neutron Star  

E-Print Network [OSTI]

Hubble Sees a Neutron Star Alone in Space Nearest Known Neutron Star #12;Birth of a Neutron Star In the core, nuclei are smashed into protons & neutrons; the protons combine with electrons to make neutrons & neutrinos. The birth temperature of a neutron star is ~5Ã?1011 K, but neutrino emission cools it to `only

Barnes, Joshua Edward

319

Shell structure in neutron rich nuclei by means of binary reactions  

SciTech Connect (OSTI)

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.

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

2014-08-14T23:59:59.000Z

320

CHRPR Neutron Board Replacement Manual  

SciTech Connect (OSTI)

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

Erikson, Rebecca L.; Myjak, Mitchell J.

2013-03-31T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

A 4. pi. tracking TPC magnetic spectrometer for RHIC  

SciTech Connect (OSTI)

The primary physics objective of the 4{pi} TPC magnetic spectrometer proposal is to search for the Quark-Gluon Plasma. In previous workshops we have discussed what the possible hadronic signatures of such a state of matter would be. Succinctly, the QGP is a direct prediction of non-perturbative QCD. Therefore the question of the existence of this new state of matter bears directly on the validity of non-perturbative QCD. However, since non-perturbative QCD has never been established, it is apparent that what may await us is a host of new phenomena that will go beyond the standard model.

Danby, G.; Eiseman, S.E.; Etkin, A.; Foley, K.J.; Hackenburg, R.W.; Longacre, R.S.; Love, W.A.; Morris, T.W.; Platner, E.D.; Saulys, A.C.; Van Dijk, J.H. (Brookhaven National Lab., Upton, NY (USA)); Lindenbaum, S.J. (Brookhaven National Lab., Upton, NY (USA) City Coll., New York, NY (USA)); Chan, C.S.; Kramer, M.A.; Zhao, K. (City Coll., New York, NY (USA)); Biswas, N.; Kenney, P.; Piekarz, J. (Notre Dame Univ

1990-01-01T23:59:59.000Z

322

A 100-kc modulation system for an EPR microwave spectrometer  

E-Print Network [OSTI]

A 100-kc FIELD MODULATION SYSTEM FOR AN EPR MICROWAVE SPECTROMETER A Thesis By Frank Edwin Stewart Approved as to style and content by: /I i r Chairman of Committee C ead of Dep rtment Member ember August 1964 ACM ONLEDGi PENT... 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...

Stewart, Frank Edwin

2012-06-07T23:59:59.000Z

323

Light Baryon Spectroscopy using the CLAS Spectrometer at Jefferson Laboratory  

SciTech Connect (OSTI)

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.

Volker Crede

2011-12-01T23:59:59.000Z

324

SWEPP Gamma-Ray Spectrometer System software design description  

SciTech Connect (OSTI)

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.

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

1994-08-01T23:59:59.000Z

325

Linear electric field time-of-flight ion mass spectrometer  

DOE Patents [OSTI]

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.

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

2008-06-10T23:59:59.000Z

326

Continuous time-of-flight ion mass spectrometer  

DOE Patents [OSTI]

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.

Funsten, Herbert O.; Feldman, William C.

2004-10-19T23:59:59.000Z

327

Positron lifetime spectrometer using a DC positron beam  

DOE Patents [OSTI]

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.

Xu, Jun; Moxom, Jeremy

2003-10-21T23:59:59.000Z

328

Test of an LED Monitoring System for the PHOS Spectrometer  

E-Print Network [OSTI]

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.

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

329

Miniature quadrupole mass spectrometer having a cold cathode ionization source  

DOE Patents [OSTI]

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.

Felter, Thomas E. (Livermore, CA)

2002-01-01T23:59:59.000Z

330

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

SciTech Connect (OSTI)

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.

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

331

ARM - Evaluation Product - Airborne Visible/Infrared Imaging Spectrometer  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcal Documentation(AVIRIS) ProductsAirborne Visible/Infrared Imaging Spectrometer (AVIRIS) ARM Data Discovery

332

Neutron-deuteron breakup and quasielastic scattering  

E-Print Network [OSTI]

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 ...

Ohlson, Alice Elisabeth

2009-01-01T23:59:59.000Z

333

Neutron Generators for Spent Fuel Assay  

E-Print Network [OSTI]

of a High Fluence Neutron Source for NondestructiveAugust 8-13, 2010. [11] D-D Neutron Generator Development at2005. [12] High-yield DT Neutron Generator, B.A. Ludewigt et

Ludewigt, Bernhard A

2011-01-01T23:59:59.000Z

334

NEUTRON EMISSION IN RELATIVISTIC NUCLEAR COLLISIONS  

E-Print Network [OSTI]

Figure Captions Figure l. Neutron-to-proton ratio at 30° labapparent anomalies in the neutron-to-proton fragment ratio.3 proton data. Figure 2. Neutron-to-proton ratio R 1 , Solid

Stevenson, J.D.

2013-01-01T23:59:59.000Z

335

NEUTRON PRODUCTION BY NEUTRAL BEAM SOURCES  

E-Print Network [OSTI]

HORSE Code—A Hultigroup Neutron and Gamma-Say Honte CarloR. Smith, "A Tantalus Fast Neutron Integrator," UCRL-17051.FiS- 9 Neutron dose during 3 months of typical TSUI

Berkner, K.H.

2010-01-01T23:59:59.000Z

336

PRACTICAL NEUTRON DOSIMETRY AT HIGH ENERGIES  

E-Print Network [OSTI]

and Chupp, E. L. "Cosmic Ray Neutron Energy Spectrum." Phys.Study of Cosmic-Ray Neutrons." National Aero­ nautics andStudy of Cosmic-Ray Neutrons: Mid-Latitude Flights." Health

McCaslin, J.B.

2010-01-01T23:59:59.000Z

337

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons  

E-Print Network [OSTI]

The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing scintillation light that is detected using photomultiplier tubes. Statistical limitations of the previous apparatus will be alleviated by significant increases in field strength and trap volume resulting in twenty times more trapped neutrons.

C. M. O'Shaughnessy; R. Golub; K. W. Schelhammer; C. M. Swank; P. -N. Seo; P. R. Huffman; S. N. Dzhosyuk; C. E. H. Mattoni; L. Yang; J. M. Doyle; K. J. Coakley; A. K. Thompson; H. P. Mumm; S. K. Lamoreaux; G. Yang

2009-03-31T23:59:59.000Z

338

Slow neutron leakage spectra from spallation neutron sources  

SciTech Connect (OSTI)

An efficient technique is described for Monte Carlo simulation of neutron beam spectra from target-moderator-reflector assemblies typical of pulsed spallation neutron sources. The technique involves the scoring of the transport-theoretical probability that a neutron will emerge from the moderator surface in the direction of interest, at each collision. An angle-biasing probability is also introduced which further enhances efficiency in simple problems. These modifications were introduced into the VIM low energy neutron transport code, representing the spatial and energy distributions of the source neutrons approximately as those of evaporation neutrons generated through the spallation process by protons of various energies. The intensity of slow neutrons leaking from various reflected moderators was studied for various neutron source arrangements. These include computations relating to early measurements on a mockup-assembly, a brief survey of moderator materials and sizes, and a survey of the effects of varying source and moderator configurations with a practical, liquid metal cooled uranium source Wing and slab, i.e., tangential and radial moderator arrangements, and Be vs CH/sub 2/ reflectors are compared. Results are also presented for several complicated geometries which more closely represent realistic arrangements for a practical source, and for a subcritical fission multiplier such as might be driven by an electron linac. An adaptation of the code was developed to enable time dependent calculations, and investigated the effects of the reflector, decoupling and void liner materials on the pulse shape.

Das, S.G.; Carpenter, J.M.; Prael, R.E.

1980-02-01T23:59:59.000Z

339

Measuring the Neutron's Mean Square Charge Radius Using Neutron Interferometry  

E-Print Network [OSTI]

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.

F. E. Wietfeldt; M. Huber; T. C. Black; H. Kaiser; M. Arif; D. L. Jacobson; S. A. Werner

2005-09-14T23:59:59.000Z

340

New neutron physics using spallation sources  

SciTech Connect (OSTI)

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.

Bowman, C.D.

1988-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Neutron structure effects in the deuteron and one neutron halos  

E-Print Network [OSTI]

Although the neutron (n) does not carry a total electric charge, its charge and magnetization distributions represented in momentum space by the electromagnetic form factors, $F_1^{(n)} (q^2)$ and $F_2^{(n)} (q^2)$, lead to an electromagnetic potential of the neutron. Using this fact, we calculate the electromagnetic corrections to the binding energy, $B_d$, of the deuteron and a one neutron halo nucleus (11Be), by evaluating the neutron-proton and the neutron-charged core (10Be) potential, respectively. The correction to $B_d$ (~9 keV) is comparable to that arising due to the inclusion of the $\\Delta$-isobar component in the deuteron wave function. In the case of the more loosely bound halo nucleus, 11Be, the correction is close to about 2 keV.

M. Nowakowski; N. G. Kelkar; T. Mart

2005-11-28T23:59:59.000Z

342

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

SciTech Connect (OSTI)

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.

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

343

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

SciTech Connect (OSTI)

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.

OHara, David

2009-05-08T23:59:59.000Z

344

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...

345

Neutron Imaging of Advanced Engine Technologies  

Broader source: Energy.gov (indexed) [DOE]

the development process * Spallation Neutron Source (SNS) - Most intense pulsed neutron beams in the world; energy selective - Multi-laboratory effort funded by DOE Office of...

346

Probing thermonuclear burning on accreting neutron stars.  

E-Print Network [OSTI]

??Neutron stars are the most compact stars that can be directly observed, which makes them ideal laboratories to study physics at extreme densities. Neutron stars… (more)

Keek, L.

2008-01-01T23:59:59.000Z

347

Optical apparatus for forming correlation spectrometers and optical processors  

DOE Patents [OSTI]

Optical apparatus is disclosed for forming correlation spectrometers and optical processors. The optical apparatus comprises one or more diffractive optical elements formed on a substrate for receiving light from a source and processing the incident light. The optical apparatus includes an addressing element for alternately addressing each diffractive optical element thereof to produce for one unit of time a first correlation with the incident light, and to produce for a different unit of time a second correlation with the incident light that is different from the first correlation. In preferred embodiments of the invention, the optical apparatus is in the form of a correlation spectrometer; and in other embodiments, the apparatus is in the form of an optical processor. In some embodiments, the optical apparatus comprises a plurality of diffractive optical elements on a common substrate for forming first and second gratings that alternately intercept the incident light for different units of time. In other embodiments, the optical apparatus includes an electrically-programmable diffraction grating that may be alternately switched between a plurality of grating states thereof for processing the incident light. The optical apparatus may be formed, at least in part, by a micromachining process. 24 figs.

Butler, M.A.; Ricco, A.J.; Sinclair, M.B.; Senturia, S.D.

1999-05-18T23:59:59.000Z

348

Light ion transfer reactions with the HELIOS spectrometer  

SciTech Connect (OSTI)

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.

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

2012-10-20T23:59:59.000Z

349

The Neutron EDM Experiment  

E-Print Network [OSTI]

The neutron EDM experiment has played an important part over many decades in shaping and constraining numerous models of CP violation. This review article discusses some of the techniques used to calculate EDMs under various theoretical scenarios, and highlights some of the implications of EDM limits upon such models. A pedagogical introduction is given to the experimental techniques employed in the recently completed ILL experiment, including a brief discussion of the dominant systematic uncertainties. A new and much more sensitive version of the experiment, which is currently under development, is also outlined.

P. G. Harris

2007-09-19T23:59:59.000Z

350

SPEC-DOC: A USER'S GUIDE TO SPECTROMETER SOFTWARE  

SciTech Connect (OSTI)

SPEC is the name of the operating system designed to control the NMR spectrometers in lab. SPEC is actually one large program which handles many functions necessary to control each spectrometer. The program handles all I/O with peripheral devices such as the console ('terminal' or 'CRT'). The program carries out its operations by accepting commands which each invoke specific subroutines to perform their function. There are a total of 60 commands in SPEC, each carrying out a different function. Because so many commands make SPEC a very large program, not all of the program is core resident. Rather, each command calls in an overlay handler which loads into memory the appropriate overlay from the disk and begins execution of the command. Thus SPEC is an independent disk based operating system. The commands in SPEC are capable of operating the microprocessor based pulse programmer, starting and acquiring data from the spectrometer data acquisition system, storing data on disk and manipulating it mathematically, displaying and plotting data. All arithmetic operations within SPEC are performed on integers. Since the DATA GENERAL computers are 16 bit machines operating in two's complement mode, the integer range is +32767. Many of the mathematical operations of SPEC are done in double precision integer mode with the final result always scaled to the above range. For many of the commands, integer overflow is detected and reported as an error message. Overflowed points are set to +32767. SPEC accepts command input from the console or reads a string of commands previously entered on the disk. The later command structure is called a macro. Macros may be nested and may have constants passed to them at execution time, thus allowing for a powerful supercommand structure. Both forms of commands are discussed in the next section. SPEC is designed to run on a DATA GENERAL computer with 32K words of memory and a 10Mbyte hard disk system. There are minor differences between the various computers in lab which are discussed in one of the appendices. The disk systems consist of two. 5Mbyte platters, one fixed and one in a removable pack. While running SPEC, all disk I/O is with the fixed disk. All pulse programs, data records, phase box records, etc. reside on the fixed disk. Thus each disk drive is specific to one spectrometer. When running under RDOS (the DG operating system) these disk files may also be accessed. All the source listings of SPEC subroutines, the SPEC program library, and all supporting programs reside on one of the removable packs (labeled 'SPEC'). This pack will normally be in the drive but it is not required to run SPEC. It is required to run any of the supporting programs discussed in another chapter. This manual attempts to document the SPEC operating system and related topics. The following section discusses the general operation of SPEC including how to get into the program and how to issue commands. The following chapters discuss the commands in detail, operation of the microprocessor based pulse programmer, spectrometer peripherals, supporting programs, and how to create and load a 'TEMP' program. The appendices contain details on bootstrapping procedures, hardware specifics, a technical description of SPEC and how to change or recreate it, a description of microcode loading and the procedure for formatting floppy, disks and recreating RDGS.

Sinton, S.

1983-05-01T23:59:59.000Z

351

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

E-Print Network [OSTI]

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.

Silvia Niccolai; for the CLAS Collaboration

2012-07-13T23:59:59.000Z

352

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

SciTech Connect (OSTI)

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.

Silvia Niccolai

2012-04-01T23:59:59.000Z

353

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

SciTech Connect (OSTI)

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.

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

2010-08-01T23:59:59.000Z

354

Measuring the proton spectrum in neutron decay - latest results with aSPECT  

E-Print Network [OSTI]

The retardation spectrometer aSPECT was built to measure the shape of the proton spectrum in free neutron decay with high precision. This allows us to determine the antineutrino electron angular correlation coefficient a. We aim for a precision more than one order of magnitude better than the present best value, which is Delta_a /a = 5%. In a recent beam time performed at the Institut Laue-Langevin during April / May 2008 we reached a statistical accuracy of about 2% per 24 hours measurement time. Several systematic effects were investigated experimentally. We expect the total relative uncertainty to be well below 5%.

M. Simson; F. Ayala Guardia; S. Baeßler; M. Borg; F. Glück; W. Heil; I. Konorov; G. Konrad; R. Muñoz Horta; K. K. H. Leung; Yu. Sobolev; T. Soldner; H. -F. Wirth; O. Zimmer

2008-11-24T23:59:59.000Z

355

Measuring the proton spectrum in neutron decay - latest results with aSPECT  

E-Print Network [OSTI]

The retardation spectrometer aSPECT was built to measure the shape of the proton spectrum in free neutron decay with high precision. This allows us to determine the antineutrino electron angular correlation coefficient a. We aim for a precision more than one order of magnitude better than the present best value, which is Delta_a /a = 5%. In a recent beam time performed at the Institut Laue-Langevin during April / May 2008 we reached a statistical accuracy of about 2% per 24 hours measurement time. Several systematic effects were investigated experimentally. We expect the total relative uncertainty to be well below 5%.

Simson, M; Baeßler, S; Borg, M; Glück, F; Heil, W; Konorov, I; Konrad, G; Horta, R Muñoz; Leung, K K H; Sobolev, Yu; Soldner, T; Wirth, H F; Zimmer, O

2008-01-01T23:59:59.000Z

356

E-Print Network 3.0 - atomic emission spectrometer Sample Search...  

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

spectrometer (MOSS) that is sensitive to the temporal ... Source: Howard, John - Plasma Research Laboratory, Research School of Physical Sciences and Engineering, Australian...

357

E-Print Network 3.0 - absorption gamma-ray spectrometer Sample...  

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

by Explorit Topic List Advanced Search Sample search results for: absorption gamma-ray spectrometer Page: << < 1 2 3 4 5 > >> 1 The detection of nitrogen using nuclear...

358

Physics of Neutron Star Crusts  

E-Print Network [OSTI]

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.

N. Chamel; P. Haensel

2008-12-20T23:59:59.000Z

359

Fast neutron environments.  

SciTech Connect (OSTI)

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.

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

360

Search for Redshifted 2.2 MeV Neutron Capture Line From A0535+262 in Outburst  

E-Print Network [OSTI]

The Be/X-ray binary system A0535+262 underwent a giant outburst in May-June 2005, followed by a dimmer outburst in August-September 2005. This increased intensity provided an opportunity to search for redshifted neutron-capture lines from the surface of the neutron star. If discovered, such lines would constrain the neutron star equation of state, providing the motivation of this search. The spectrometer (SPI) on board the INTEGRAL satellite observed the dimmer outburst and provided the data for this research. We have not detected a line with enough significance, with the width-dependent upper limits on the broadened and redshifted neutron capture line in the range of (2 - 11) x 10^(-4) photons cm^(-2) s^(-1). To our knowledge, these are the strongest upper limits on the redshifted 2.2 MeV emission from an accreting neutron star. Our analysis of the transparency of the neutron star surface for 2.2 MeV photons shows that photons have a small but finite chance of leaving the atmosphere unscattered, which diminishes the possibility of detection.

Sirin Caliskan; Emrah Kalemci; Matthew G. Baring; Steven E. Boggs; Peter Kretschmar

2008-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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to obtain the most current and comprehensive results.


361

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons  

E-Print Network [OSTI]

The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing sci...

O'Shaughnessy, C M; Schelhammer, K W; Swank, C M; Seo, P -N; Huffman, P R; Dzhosyuk, S N; Mattoni, C E H; Yang, L; Doyle, J M; Coakley, K J; Thompson, A K; Mumm, H P; Lamoreaux, S K; Yang, G

2009-01-01T23:59:59.000Z

362

Characterizing a fast-response, low-afterglow liquid scintillator for neutron time-of-flight diagnostics in fast ignition experiments  

SciTech Connect (OSTI)

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.

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

363

Proton-hole states in the N=30 neutron-rich {sup 49}K isotope.  

SciTech Connect (OSTI)

Excited states in the N=30 neutron-rich isotope {sup 49}K have been studied using multinucleon transfer reactions with thin targets and the PRISMA-CLARA spectrometer combined with thick-target {gamma}-coincidence data from Gammasphere. The d{sub 3/2} proton-hole state is located 92 keV above the s{sub 1/2} ground state, and the proton-particle f{sub 7/2} state is suggested at 2104 keV. Three other levels are established as involving the coupling to 2{sup +} of two neutrons above the N=28 shell. The measured or estimated lifetimes served to reinforce the interpretation of the observed level structure, which is found to be in satisfactory agreement with shell-model calculations.

Broda, R.; Wrzesinski, J.; Gadea, A.; Marginean, N.; Fornal, B.; Carpenter, M. P.; Janssens, R. V. F.; Zhu, S. (Physics); (Niewodniczanski Inst. of Nuclear Physics); (INFN Lab. Nazionali di Legnaro); (Dipartimento di Fisica dell' Universita); (INFN-Sezione di Napoli); (Michigan State Univ.); (National Inst. for Physics and Nuclear Engineering); (Ruder Boskovic Inst.); (CSIC-Univ. de Valencia); (Univ. of West of Scotland)

2010-09-22T23:59:59.000Z

364

Two wide-angle imaging neutral-atom spectrometers  

SciTech Connect (OSTI)

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.

McComas, D.J.

1997-12-31T23:59:59.000Z

365

Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration  

SciTech Connect (OSTI)

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.

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

366

Dynamic multiplexed analysis method using ion mobility spectrometer  

DOE Patents [OSTI]

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.

Belov, Mikhail E [Richland, WA

2010-05-18T23:59:59.000Z

367

Aerosol beam-focus laser-induced plasma spectrometer device  

DOE Patents [OSTI]

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.

Cheng, Meng-Dawn (Oak Ridge, TN)

2002-01-01T23:59:59.000Z

368

Two wide-angle imaging neutral-atom spectrometers (TWINS)  

SciTech Connect (OSTI)

Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) is a revolutionary new mission designed to stereoscopically image the magnetosphere in charge exchange neutral atoms for the first time. The authors propose to fly two identical TWINS instruments as a mission of opportunity on two widely-spaced high-altitude, high-inclination US Government spacecraft. Because the spacecraft are funded independently, TWINS can provide a vast quantity of high priority science observations (as identified in an ongoing new missions concept study and the Sun-Earth Connections Roadmap) at a small fraction of the cost of a dedicated mission. Because stereo observations of the near-Earth space environs will provide a particularly graphic means for visualizing the magnetosphere in action, and because of the dedication and commitment of the investigator team to the principles of carrying space science to the broader audience, TWINS will also be an outstanding tool for public education and outreach.

McComas, D.J. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States); Blake, B. [Aerospace Corp., CA (United States)] [Aerospace Corp., CA (United States); Burch, J. [Southwest Research Inst., San Antonio, TX (United States)] [and others] [Southwest Research Inst., San Antonio, TX (United States); and others

1998-11-01T23:59:59.000Z

369

Isotopic response with small scintillator based gamma-ray spectrometers  

DOE Patents [OSTI]

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.

Madden, Norman W. (Sparks, NV); Goulding, Frederick S. (Lafayette, CA); Asztalos, Stephen J. (Oakland, CA)

2012-01-24T23:59:59.000Z

370

Measurement of the energy, multiplicity and angular correlation of ?-rays from the thermal neutron capture reaction Gd(n, ?) using JPARC-ANNRI  

SciTech Connect (OSTI)

We conducted an experiment using the JPARC-ANNRI spectrometer to measure the energy, multiplicity and correlation of ?-rays from the neutron capture of natural gadolinium. We incorporated the GEANT4 Monte Carlo (MC) simulation into the detector, and compared the data with the results of the MC simulation. We report our data analysis and compare our data with those obtained by the MC simulation.

Ou, Iwa; Yamada, Yoshiyuki; Yano, Takatomi; Mori, Takaaki; Kayano, Tsubasa; Sakuda, Makoto [Department of Physics, Okayama University, Okayama, 700-8530 (Japan); Kimura, Atsushi; Harada, Hideo [Japan Atomic Energy Agency, 2-4 Shirakata Shirane, Tokai, Naka, Ibaraki 319-1195 (Japan)

2014-05-02T23:59:59.000Z

371

Research on fusion neutron sources  

SciTech Connect (OSTI)

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. 'Fusion for Neutrons' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P. [Tokamak Solutions UK, Culham Science Centre, Abingdon, OXON, OX133DB (United Kingdom)

2012-06-19T23:59:59.000Z

372

First neutron generation in the BINP accelerator based neutron source B. Bayanova  

E-Print Network [OSTI]

First neutron generation in the BINP accelerator based neutron source B. Bayanova , A. Burdakova c l e i n f o Keywords: Epithermal neutrons Lithium target Neutron capture therapy Tandem accelerator a b s t r a c t Pilot innovative facility for neutron capture therapy was built at Budker

Taskaev, Sergey Yur'evich

373

neutron density. The neutron density (nn) of the source was modeled by solving the simul-  

E-Print Network [OSTI]

neutron density. The neutron density (nn) of the source was modeled by solving the simul- taneousT is the thermal neutron velocity, l is the decay constant, Ns is the s-process abun- dance, bsÃ? is the maxwellian-averaged neutron capture cross-section, and t0 is the average neutron exposure (21). The branching decay of 186Re

West, Stuart

374

A neutron producing target for BINP accelerator-based neutron source B. Bayanova  

E-Print Network [OSTI]

A neutron producing target for BINP accelerator-based neutron source B. Bayanova , E. Kashaeva b l e i n f o Keywords: Target Lithium Neutron capture therapy Epithermal neutrons a b s t r a c t An innovative accelerator-based neutron source for BNCT has just started operation at the Budker Institute

Taskaev, Sergey Yur'evich

375

Neutron capture therapy with deep tissue penetration using capillary neutron focusing  

DOE Patents [OSTI]

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.

Peurrung, Anthony J. (Richland, WA)

1997-01-01T23:59:59.000Z

376

Neutron Reflectometers -a bibliography Adrian R. Rennie  

E-Print Network [OSTI]

Neutron Reflectometers - a bibliography Adrian R. Rennie Background A short catalogue of neutron on the evolution of the design of neutron reflectometers. The papers listed in the bibliography are restricted "Gravity Diffractometer" for Ultracold-Neutron Optics' Nuclear Instruments and Methods, 179, (1981), 393

Rennie, Adrian

377

Delayed neutron energy spectra following fast fission of [sup 238]U  

SciTech Connect (OSTI)

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.

Villani, M.F.

1992-01-01T23:59:59.000Z

378

The data processing pipeline for the Herschel/SPIRE Imaging Fourier Transform Spectrometer  

E-Print Network [OSTI]

The data processing pipeline for the Herschel/SPIRE Imaging Fourier Transform Spectrometer Trevor R the data processing pipeline to generate calibrated data products from the Spectral and Photometric Imaging Receiver (SPIRE) imaging Fourier Transform Spectrometer. The pipeline processes telemetry from SPIRE point

Naylor, David A.

379

The Magnetism of Neutron States  

E-Print Network [OSTI]

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.

B. G. Sidharth

2003-10-01T23:59:59.000Z

380

Scattered neutron tomography based on a neutron transport problem  

E-Print Network [OSTI]

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...

Scipolo, Vittorio

2005-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

How the Spallation Neutron Source Works | ORNL Neutron Sciences  

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

high-energy proton pulses strike a heavy-metal target, which is a container of liquid mercury. Corresponding pulses of neutrons freed by the spallation process are slowed down in...

382

Echelle grating multi-order imaging spectrometer utilizing a catadioptric lens  

DOE Patents [OSTI]

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.

Chrisp, Michael P; Bowers, Joel M

2014-05-27T23:59:59.000Z

383

Delayed neutrons from the neutron irradiation of ²³?U  

E-Print Network [OSTI]

&M University Nuclear Science Center Reactor (NSCR) to verify 235U delayed neutron emission rates. A custom device was created to accurately measure a sample’s pneumatic flight time and the Nuclear Science Center’s (NSC’s) pneumatic transfer system (PTS... parameter measurements, including two 235U samples, an array of three 3He cylindrical neutron detectors, signal processing circuitry, the PTS, a reactor core sensor and a computerized control system. A. Fissile Material Isotope Products Laboratories...

Heinrich, Aaron David

2008-10-10T23:59:59.000Z

384

The nuclear physics of neutron stars  

SciTech Connect (OSTI)

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.

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

2014-05-09T23:59:59.000Z

385

Lead Slowing Down Spectrometer FY2013 Annual Report  

SciTech Connect (OSTI)

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.

Warren, Glen A.; Kulisek, Jonathan A.; Gavron, Victor A.; Danon, Yaron; Weltz, Adam; Harris, Jason; Stewart, T.

2013-10-29T23:59:59.000Z

386

Symmetry energy, neutron skin, and neutron star radius from chiral effective field theory interactions  

E-Print Network [OSTI]

We discuss neutron matter calculations based on chiral effective field theory interactions and their predictions for the symmetry energy, the neutron skin of 208 Pb, and for the radius of neutron stars.

K. Hebeler; A. Schwenk

2014-01-22T23:59:59.000Z

387

Chiral condensate in neutron matter  

E-Print Network [OSTI]

A recent chiral perturbation theory calculation of the in-medium quark condensate $$ is extended to the isospin-asymmetric case of pure neutron matter. In contrast to the behavior in isospin-symmetric nuclear matter we find only small deviations from the linear density approximation. This feature originates primarily from the reduced weight factors (e.g. 1/6 for the dominant contributions) of the $2\\pi$-exchange mechanisms in pure neutron matter. Our result suggests therefore that the tendencies for chiral symmetry restoration are actually favored in systems with large neutron excess (e.g. neutron stars). We also analyze the behavior of the density-dependent quark condensate $(\\rho_n)$ in the chiral limit $m_\\pi\\to 0$.

N. Kaiser; W. Weise

2008-08-06T23:59:59.000Z

388

Coherent control of neutron interferometry  

E-Print Network [OSTI]

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. ...

Pushin, Dmitry A

2007-01-01T23:59:59.000Z

389

Ion chamber based neutron detectors  

DOE Patents [OSTI]

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.

Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

2014-12-16T23:59:59.000Z

390

Properties of zinc selenide grown by chemical vapor transport and its application to room-temperature radiation detection  

SciTech Connect (OSTI)

The authors have characterized ZnSe material grown by chemical vapor transport in iodine using triple-axis X-ray diffraction (TAD), photo-induced current transient spectroscopy (PICTS), photoluminescence (PL), current-voltage measurements and gamma-ray spectroscopy. The material was found to have inadequate carrier transport for nuclear spectrometer use, but there was a discernible difference in performance between crystals which could be correlated with crystallinity as determined by the TAD rocking curves.

Brunett, B.A.; Toney, J.E.; Schlesinger, T.E. [Carnegie Mellon Univ., Pittsburgh, PA (United States); Yoon, H.; Goorsky, M.S. [Univ. of California, Los Angeles, CA (United States). Dept. of Materials Science and Engineering; Schieber, M.; James, R.B. [Sandia National Labs., Livermore, CA (United States); Rudolph, P. [Inst. fuer KrystallZuechtung, Berlin (Germany)

1998-12-31T23:59:59.000Z

391

Neutron detectors comprising boron powder  

SciTech Connect (OSTI)

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.

Wang, Zhehui; Morris, Christopher; Bacon, Jeffrey Darnell; Makela, Mark F; Spaulding, Randy Jay

2013-05-21T23:59:59.000Z

392

Alternative Neutron Detection Testing Summary  

SciTech Connect (OSTI)

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.

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

393

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...

394

Comment on 'Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes'  

SciTech Connect (OSTI)

In their article ''Existence of Long-Lived Isomeric States in Naturally-Occuring Neutron-Deficient Th Isotopes''[Phys. Rev. C 76, 021303 (2007)], Marinov et al. fail to demonstrate that basic mass spectrometric protocols, such as abundance sensitivity, linearity, and freedom from possible interferences, have been met. In particular, the claim that four isomeric states of Th have been discovered, using an inductively coupled plasma-sector field mass spectrometer (ICP-SFMS), with abundances from (1-10)x10{sup -11} relative to {sup 232}Th, cannot be accepted, given the known abundance sensitivities of other sector field mass spectrometers. Accelerator mass spectrometry is the only mass spectrometric methodology capable of measuring relative abundances of the magnitude claimed by Marinov et al.

Barber, R. C.; De Laeter, J. R. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Department of Applied Physics, Curtin University, Perth, Western Australia (Australia)

2009-04-15T23:59:59.000Z

395

First Measurements with a Lead Slowing-Down Spectrometer at LANSCE  

E-Print Network [OSTI]

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

Danon, Yaron

396

Neutron Reactions in Astrophysics  

E-Print Network [OSTI]

The quest for the origin of matter in the Universe had been the subject of philosophical and theological debates over the history of mankind, but quantitative answers could be found only by the scientific achievements of the last century. A first important step on this way was the development of spectral analysis by Kirchhoff and Bunsen in the middle of the 19$^{\\rm th}$ century, which provided first insight in the chemical composition of the sun and the stars. The energy source of the stars and the related processes of nucleosynthesis, however, could be revealed only with the discoveries of nuclear physics. A final breakthrough came eventually with the compilation of elemental and isotopic abundances in the solar system, which are reflecting the various nucleosynthetic processes in detail. This review is focusing on the mass region above iron, where the formation of the elements is dominated by neutron capture, mainly in the slow ($s$) and rapid ($r$) processes. Following a brief historic account and a sketch of the relevant astrophysical models, emphasis is put on the nuclear physics input, where status and perspectives of experimental approaches are presented in some detail, complemented by the indispensable role of theory.

R. Reifarth; C. Lederer; F. Käppeler

2014-03-22T23:59:59.000Z

397

Multichannel CdZnTe Gamma Ray Spectrometer  

SciTech Connect (OSTI)

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.

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

398

In-situ droplet monitoring for self-tuning spectrometers  

DOE Patents [OSTI]

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.

Montaser, Akbar (Potomac, MD); Jorabchi, Kaveh (Arlington, VA); Kahen, Kaveh (Kleinburg, CA)

2010-09-28T23:59:59.000Z

399

THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE LOW RESOLUTION SPECTROMETER  

SciTech Connect (OSTI)

Absolute spectrophotometric measurements of diffuse radiation at 1 {mu}m to 2 {mu}m are crucial to our understanding of the radiative content of the universe from nucleosynthesis since the epoch of reionization, the composition and structure of the zodiacal dust cloud in our solar system, and the diffuse galactic light arising from starlight scattered by interstellar dust. The Low Resolution Spectrometer (LRS) on the rocket-borne Cosmic Infrared Background Experiment is a {lambda}/{Delta}{lambda} {approx} 15-30 absolute spectrophotometer designed to make precision measurements of the absolute near-infrared sky brightness between 0.75 {mu}m <{lambda} < 2.1 {mu}m. This paper presents the optical, mechanical, and electronic design of the LRS, as well as the ground testing, characterization, and calibration measurements undertaken before flight to verify its performance. The LRS is shown to work to specifications, achieving the necessary optical and sensitivity performance. We describe our understanding and control of sources of systematic error for absolute photometry of the near-infrared extragalactic background light.

Tsumura, K.; Arai, T.; Matsumoto, T.; Matsuura, S.; Murata, K. [Department of Space Astronomy and Astrophysics, Institute of Space and Astronoutical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Battle, J.; Bock, J. [Jet Propulsion Laboratory (JPL), National Aeronautics and Space Administration (NASA), Pasadena, CA 91109 (United States); Brown, S.; Lykke, K.; Smith, A. [Optical Technology Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Cooray, A. [Center for Cosmology, University of California, Irvine, Irvine, CA 92697 (United States); Hristov, V.; Levenson, L. R.; Mason, P. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Keating, B.; Renbarger, T. [Department of Physics, University of California, San Diego, San Diego, CA 92093 (United States); Kim, M. G. [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, D. H.; Nam, U. W. [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Sullivan, I., E-mail: tsumura@ir.isas.jaxa.jp [Department of Physics, The University of Washington, Seattle, WA 98195 (United States); and others

2013-08-15T23:59:59.000Z

400

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

SciTech Connect (OSTI)

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.

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

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

High-Sensitivity Delayed-Coincidence Spectrometer to Search for Short-Lived Nuclear States  

E-Print Network [OSTI]

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.

Morozov, V A; Norseev, Yu V; Sereeter, Z; Zlokazov, V B

2002-01-01T23:59:59.000Z

402

A high-resolution imaging x-ray crystal spectrometer for high energy density plasmas  

SciTech Connect (OSTI)

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.

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

403

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

DOE Patents [OSTI]

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.

Fan, N.Q.; Clarke, J.

1993-10-19T23:59:59.000Z

404

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

DOE Patents [OSTI]

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.

Fan, Non Q. (San Diego, CA); Clarke, John (Berkeley, CA)

1993-01-01T23:59:59.000Z

405

- and -delayed neutron- decay of neutron-rich copper isotopes  

SciTech Connect (OSTI)

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.

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

406

Neutronic fuel element fabrication  

DOE Patents [OSTI]

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.

Korton, George (Cincinnati, OH)

2004-02-24T23:59:59.000Z

407

BPS Skyrmions as neutron stars  

E-Print Network [OSTI]

The BPS Skyrme model has been demonstrated already to provide a physically intriguing and quantitatively reliable description of nuclear matter. Indeed, the model has both the symmetries and the energy-momentum tensor of a perfect fluid, and thus represents a field theoretic realization of the "liquid droplet" model of nuclear matter. In addition, the classical soliton solutions together with some obvious corrections (spin-isospin quantization, Coulomb energy, proton-neutron mass difference) provide an accurate modeling of nuclear binding energies for heavier nuclei. These results lead to the rather natural proposal to try to describe also neutron stars by the BPS Skyrme model coupled to gravity. We find that the resulting self-gravitating BPS Skyrmions provide excellent results as well as some new perspectives for the description of bulk properties of neutron stars when the parameter values of the model are extracted from nuclear physics. Specifically, the maximum possible mass of a neutron star before black-hole formation sets in is a few solar masses, the precise value depending on the precise values of the model parameters, and the resulting neutron star radius is of the order of 10 km.

C. Adam; C. Naya; J. Sanchez-Guillen; R. Vazquez; A. Wereszczynski

2014-07-14T23:59:59.000Z

408

Neutron-Neutron Correlations in the Dissociation of Halo Nuclei  

E-Print Network [OSTI]

Studies attempting to probe the spatial configuration of the valence neutrons in two-neutron halo nuclei using the technique of intensity interferometry are described. Following a brief review of the method and its application to earlier measurements of the breakup of 6He, 11Li and 14Be, the results of the analysis of a high statistics data set for 6He are presented. The limitations of the technique, including the assumption of incoherent emission in the breakup and the sensitivity to the continuum states populated in the dissociation rather than the ground state, are discussed.

N. A. Orr

2008-03-06T23:59:59.000Z

409

Flat Quartz-Crystal X-ray Spectrometer for Nuclear Forensics Applications  

E-Print Network [OSTI]

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...

Goodsell, Alison

2012-10-19T23:59:59.000Z

410

Progress on the Design and Fabircation of the MICE SpectrometerSolenoids  

SciTech Connect (OSTI)

The Muon Ionization Cooling Experiment (MICE) willdemonstrate ionization cooling in a short section of a realistic coolingchannel using a muon beam at Rutherford Appleton Laboratory (RAL) in theUK. A five-coil, superconducting spectrometer solenoid magnet at each endof the cooling channel will provide a 4 T uniform field region for thescintillating fiber tracker within the magnet bore tubes. The trackermodules are used to measure the muon beam emittance as it enters andexits the cooling channel. The cold mass for the 400 mm warm bore magnetconsists of two sections: a three-coil spectrometer magnet and a two-coilmatching section that matches the uniform field of the solenoid into theMICE cooling channel. The spectrometer solenoid detailed designandanalysis has been completed, and the fabrication of the magnets is wellunder way. The primary features of the spectrometer solenoid magnet andmechanical designs are presented along with a summary of key fabricationissues and photos of the construction.

Virostek, S.P.; Green, M.A.; Lia, D.; Sizman, M.S.

2007-06-20T23:59:59.000Z

411

E-Print Network 3.0 - atomic absorption spectrometer Sample Search...  

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

Search Powered by Explorit Topic List Advanced Search Sample search results for: atomic absorption spectrometer Page: << < 1 2 3 4 5 > >> 1 In the post-genome era, the...

412

Progress on the Modeling and Modification of the MICE Superconducting Spectrometer Solenoids  

E-Print Network [OSTI]

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

Virostek, S.P.

2013-01-01T23:59:59.000Z

413

Addition and recombination reactions of unsaturated radicals using a novel laser kinetics spectrometer  

E-Print Network [OSTI]

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 ...

Ismail, Huzeifa

2008-01-01T23:59:59.000Z

414

Characterization of AP-MALDI and ESI for a differential mobility spectrometer  

E-Print Network [OSTI]

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 ...

Agrawal, Priya

2005-01-01T23:59:59.000Z

415

Calibration of a gated flat field spectrometer as a function of x-ray intensity  

SciTech Connect (OSTI)

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.

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

416

A simple scanning spectrometer based on a stretchable elastomeric reflective grating  

SciTech Connect (OSTI)

We report a scanning optical spectrometer based on the use of a stretchable elastomeric reflective grating. The grating is obtained by supersonic cluster beam implantation of silver nanoparticles on polydimethylsiloxane previously grooved by molding to create a replica of a commercial digital versatile disk grating. The use of a stretchable grating allows the spectrometer spanning the whole optical wavelength range by solely extending the diffraction element by more than 100% of its original dimensions. The stretchable reflective optical grating shows excellent performances and stability upon thousands of stretching cycles. The use of this elastomeric element makes the optical layout and the mechanics of the spectrometer extremely simple and advantageous for those applications where spectral resolution is not a major requirement. As a proof of principle, we present the absorption spectrum of Rhodamine B in solution obtained by our spectrometer and compared to commercial instruments.

Ghisleri, C.; Milani, P., E-mail: paolo.milani@mi.infn.it [CIMAINA and Dipartimento di Fisica, Università di Milano, via Celoria 16, 20133 Milano (Italy); WISE srl, Piazza Duse 2, 20122 Milano (Italy); Potenza, M. A. C.; Bellacicca, A. [CIMAINA and Dipartimento di Fisica, Università di Milano, via Celoria 16, 20133 Milano (Italy); Ravagnan, L. [WISE srl, Piazza Duse 2, 20122 Milano (Italy)

2014-02-10T23:59:59.000Z

417

E-Print Network 3.0 - airborne gamma-ray spectrometer Sample...  

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

Powered by Explorit Topic List Advanced Search Sample search results for: airborne gamma-ray spectrometer Page: << < 1 2 3 4 5 > >> 1 GAMMA RAYS FROM MAJOR ELEMENTS BY THERMAL...

418

Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.  

SciTech Connect (OSTI)

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.

Franco, Manuel,

2014-08-01T23:59:59.000Z

419

Neutrons from the SNS's target are channeled  

E-Print Network [OSTI]

of Science. The five instruments under the SING (SNS Instruments - Next Generation) project the project. SCIENCE Project's completion gives neutron science community reason to SING Table of Contents Project's completion gives neutron science community reason to SING . . . . . . . . . . . 1 Oral

Pennycook, Steve

420

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...

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Neutron Matter from Low to High Density  

E-Print Network [OSTI]

Neutron matter is an intriguing nuclear system with multiple connections to other areas of physics. Considerable progress has been made over the last two decades in exploring the properties of pure neutron fluids. Here we begin by reviewing work done to explore the behavior of very low density neutron matter, which forms a strongly paired superfluid and is thus similar to cold Fermi atoms, though at energy scales differing by many orders of magnitude. We then increase the density, discussing work that ties the study of neutron matter with the determination of the properties of neutron-rich nuclei and neutron-star crusts. After this, we review the impact neutron matter at even higher densities has on the mass-radius relation of neutron stars, thereby making contact with astrophysical observations.

Gandolfi, Stefano; Carlson, J

2015-01-01T23:59:59.000Z

422

Measurement of the Wolfenstein parameters for proton-proton and proton-neutron scattering at 500 MeV  

SciTech Connect (OSTI)

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.

Marshall, J.A.

1984-07-01T23:59:59.000Z

423

SEARCH FOR NEUTRON ANTI-NEUTRON OSCILLATION AT THE SUDBURY NEUTRINO OBSERVATORY  

E-Print Network [OSTI]

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

Waltham, Chris

424

Neutron scattering and models: Titanium  

SciTech Connect (OSTI)

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.

Smith, A.B.

1997-07-01T23:59:59.000Z

425

Developing improved nuclear magnetic resonance marginal oscillator spectrometers for advanced teaching laboratories  

E-Print Network [OSTI]

DEVELOPING IMPROVED NUCLEAR MAGNETIC RESONANCE MARGINAL OSCILLATOR SPECTROMETERS FOR ADVANCED TEACHING LABORATORIES A Thesis by FRANK PHILLIP WILLINGHAM Submitted to the Office of Graduate Studies of Texas ASM University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE D e cemb er 1988 Major Subject: Physics DEVELOPING IMPROVED NUCLEAR MAGNETIC RESONANCE MARGINAL OSCILLATOR SPECTROMETERS FOR ADVANCED TEACHING LABORATORIES A Thesis by FRANK PHILLIP...

Willingham, Frank Phillip

1988-01-01T23:59:59.000Z

426

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

SciTech Connect (OSTI)

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

Shindo, Francois [Measurement Standards Laboratory of New Zealand, Industrial Research, Lower Hutt (New Zealand); Woolliams, Emma; Scott, Barry; Harris, Subrena [National Physical Laboratory, Teddington (United Kingdom)

2013-05-10T23:59:59.000Z

427

Electron Positron Proton Spectrometer for use at Laboratory for Laser Energetics  

SciTech Connect (OSTI)

The Electron Positron Proton Spectrometer (EPPS) is mounted in a TIM (Ten-Inch Manipulator) system on the Omega-60 or Omega-EP laser facilities at the University of Rochester, Laboratory for Laser Energetics (LLE), when in use, see Fig. 1. The Spectrometer assembly, shown in Fig. 2, is constructed of a steel box containing magnets, surrounded by Lead 6% Antimony shielding with SS threaded insert, sitting on an Aluminum 6061-T6 plate.

Ayers, S L

2010-04-07T23:59:59.000Z

428

Novel endothermic and exothermic ion-molecule reactions as observed in a Fourier transform mass spectrometer  

E-Print Network [OSTI]

NOVEL ENDOTHERMIC AND EXOTHERMIC ION-MOLECULE REACTIONS AS OBSERVED IN A FOURIER TRANSFORM MASS SPECTROMETER Thesis by DONALD LEE BRICKER II Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE AUGUST 1986 Major Subject: Chemistry NOVEL ENDOTHERMIC AND EXOTHERMIC ION-MOLECULE REACTIONS AS OBSERVED IN A FOURIER TRANSFORM MASS SPECTROMETER A Thesis by Donald Lee Bricker II Approved as to style and content by...

Bricker, Donald Lee

1986-01-01T23:59:59.000Z

429

Atomic data for the ITER Core Imaging X-ray Spectrometer  

SciTech Connect (OSTI)

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.

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

430

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source  

E-Print Network [OSTI]

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source

Gubin, K V; Bak, P A; Kot, N K; Logatchev, P V

2001-01-01T23:59:59.000Z

431

Proposal for a 30-T Pulsed Magnet Suitable for Neutron Scattering Experiments  

E-Print Network [OSTI]

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.

Robinson Eyssa Schneider-Muntau; R. A. Robinson (a; Y. M. Eyssa (b; H. J. Schneider-muntau (b; H. J. Boenig (a

432

CHINA SPALLATION NEUTRON SOURCE DESIGN.  

SciTech Connect (OSTI)

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.

WEI,J.

2007-01-29T23:59:59.000Z

433

High-pressure neutron diffraction  

SciTech Connect (OSTI)

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.

Xu, Hongwu [Los Alamos National Laboratory

2011-01-10T23:59:59.000Z

434

Nuclear Physics of Neutron Stars  

E-Print Network [OSTI]

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.

J. Piekarewicz

2009-01-28T23:59:59.000Z

435

Neutron Transversity at Jefferson Lab  

SciTech Connect (OSTI)

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.

Jian-Ping Chen; Xiaodong Jiang; Jen-chieh Peng; Lingyan Zhu

2005-09-07T23:59:59.000Z

436

Protein crystallography with spallation neutrons  

SciTech Connect (OSTI)

proteins and oriented molecular complexes. With spallation neutrons and their time dependent wavelength structure, one can select data with an optimal wavelength bandwidth and cover the whole Laue spectrum as time (wavelength) resolved diffraction data. This optimizes data quality with best peak to background ratios and provides spatial and energy resolution to eliminate peak overlaps. Such a Protein Crystallography Station (PCS) has been built and tested at Los Alamos Neutron Science Center. A partially coupled moderator is used to increase flux and data are collected by a Cylindrical He3 detector covering 120' with 200mm height. The PCS is described along with examples of data collected from a number of proteins.

Langan, P. (Paul); Schoenborn, Benno P.

2003-01-01T23:59:59.000Z

437

A neutron transmission study of environmental Gd  

E-Print Network [OSTI]

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.

Cristiana Oprea; Ioan Alexandru Oprea; Alexandru Mihul

2014-06-02T23:59:59.000Z

438

Measurements of the Thermal Neutron Scattering Kernel  

E-Print Network [OSTI]

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

Danon, Yaron

439

Neutron Scattering Studies of Correlated Electron Systems  

E-Print Network [OSTI]

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

Boothroyd, Andrew

440

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

Note: This page contains sample records for the topic "neutron triple-axis spectrometer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Requirements, possible alternatives & international NEUTRON SCATTERING  

E-Print Network [OSTI]

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

Dimeo, Robert M.

442

Neutron Electric Dipole Moment Matt Eichenfield  

E-Print Network [OSTI]

Neutron Electric Dipole Moment (NEDM) Matt Eichenfield 04/20/2007 #12;P and T Violations EDM to explain the Baryonic asymmetry of the universe #12;The Neutron's Constituents Three quarks Two down (q d neutron radius, the separation causing the SM NEDM

Golwala, Sunil

443

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]

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.

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; 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

444

Neutron production enhancements for the Intense Pulsed Neutron Source.  

SciTech Connect (OSTI)

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.

Iverson, E. B.

1999-01-04T23:59:59.000Z

445

Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem  

SciTech Connect (OSTI)

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.

William Charlton

2007-07-01T23:59:59.000Z

446

2002 REVIEW OF NEUTRON AND NON NEUTRON NUCLEAR DATA.  

SciTech Connect (OSTI)

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.

HOLDEN,N.E.

2002-08-18T23:59:59.000Z

447

Neutron producing target for accelerator based neutron source for  

E-Print Network [OSTI]

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

Taskaev, Sergey Yur'evich

448

Neutron capture therapy with deep tissue penetration using capillary neutron focusing  

DOE Patents [OSTI]

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.

Peurrung, A.J.

1997-08-19T23:59:59.000Z

449

Experiment Design and Analysis Guide - Neutronics & Physics  

SciTech Connect (OSTI)

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.

Misti A Lillo

2014-06-01T23:59:59.000Z

450

E-Print Network 3.0 - aerial neutron detection Sample Search...  

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

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451

Neutron sources: Present practice and future potential  

SciTech Connect (OSTI)

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.

Cierjacks, S.; Smith, A.B.

1988-01-01T23:59:59.000Z

452

Shell evolution in neutron-rich carbon isotopes: Unexpected enhanced role of neutron-neutron correlation  

E-Print Network [OSTI]

Full shell-model diagonalization has been performed to study the structure of neutron-rich nuclei around $^{20}$C. We investigate in detail the roles played by the different monopole components of the effective interaction in the evolution of the N=14 shell in C, N and O isotopes. It is found that the relevant neutron-neutron monopole terms, $V^{nn}_{d_{5/2}d_{5/2}}$ and $V^{nn}_{s_{1/2}s_{1/2}}$, contribute significantly to the reduction of the N=14 shell gap in C and N isotopes in comparison with that in O isotopes. The origin of this unexpectedly large effect, which is comparable with (sometimes even larger than) that caused by the proton-neutron interaction, is related to the enhanced configuration mixing in those nuclei due to many-body correlations. Such a scheme is also supported by the large B(E2) value in the nucleus $^{20}$C which has been measured recently.

Cenxi Yuan; Chong Qi; Furong Xu

2012-09-25T23:59:59.000Z

453

Compton Scattering from the Deuteron and Extracted Neutron Polarizabilities  

E-Print Network [OSTI]

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.

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

454

A simplified spectrometer based on a fast digital oscilloscope for the measurement of high energy $?$-rays  

E-Print Network [OSTI]

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.

S. S. Markochev; N. V. Eremin

2014-05-28T23:59:59.000Z

455

Delayed neutron yield from fast neutron induced fission of sup 2 sup 3 sup 8 U  

E-Print Network [OSTI]

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.

Piksaikin, V M; Isaev, S G; Kazakov, L E; Roshchenko, V A; Tertytchnyi, R G

2001-01-01T23:59:59.000Z

456

2010 Review of neutron and non-neutron nuclear data  

SciTech Connect (OSTI)

The results of a review and evaluation of neutron and non-neutron nuclear data published in the scientific literature over the past three years are presented. The status of new chemical elements is examined. Ten elements have had their atomic weight and uncertainty replaced by interval values of upper and lower bounds. Data on revised values for the isotopic composition of the elements are reviewed and new recommended values are presented for germanium. Radioactive half-lives are reviewed and latest values presented which include measurements on nuclides of interest and very long-lived nuclides such as double beta decay, double electron capture, long-lived alpha decay, and long-lived beta decay. The latest information and the status on the evaluation of atomic masses are discussed. Data from new measurements on the very heavy elements (trans-meitnerium elements) are discussed and tabulated. Data on various recent neutron cross-section and resonance integral measurements are also discussed and the latest measurements are tabulated in both cases. The JENDL-4.0 and ENDF/B-VII.1 nuclear data libraries are discussed. A new initiative on the existence and importance of isotopes is presented. (authors)

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

2011-07-01T23:59:59.000Z

457

Neutron charge radius and the neutron electric form factor  

SciTech Connect (OSTI)

For nearly forty years, the Galster parametrization has been employed to fit existing data for the neutron electric form factor, G{sub E}{sup n}, vs the square of the four-momentum transfer, Q{sup 2}. Typically this parametrization is constrained to be consistent with experimental data for the neutron charge radius. However, we find that the Galster form does not have sufficient freedom to accommodate reasonable values of the radius without constraining or compromising the fit. In addition, the G{sub E}{sup n} data are now at sufficient precision to motivate a two-parameter fit (or three parameters if we include thermal neutron data). Here we present a modified form of a two-dipole parametrization that allows this freedom and fits both G{sub E}{sup n} (including recent data at both low and high four-momentum transfer) and the charge radius well with simple, well-defined parameters. Analysis reveals that the Galster form is essentially a two-parameter approximation to the two-dipole form but becomes degenerate if we try to extend it naturally to three parameters.

Gentile, T. R. [Stop 8461, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Crawford, C. B. [University of Kentucky, Lexington, Kentucky 40506 (United States)

2011-05-15T23:59:59.000Z

458

Cyclotron-based neutron source for BNCT  

SciTech Connect (OSTI)

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.

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

459

Synthesize Neutron-Drip-Line-Nuclides with Free-Neutron Bose-Einstein Condensates Experimentally  

E-Print Network [OSTI]

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.

Bao-Guo Dong

2014-09-22T23:59:59.000Z

460

Temperature and nonlinearity corrections for a photodiode array spectrometer used in the field  

SciTech Connect (OSTI)

Temperature and nonlinearity effects are two important factors that limit the use of photodiode array spectrometers. Usually the spectrometer is calibrated at a known temperature against a reference source of a particular spectral radiance, and then it is used at different temperatures to measure sources of different spectral radiances. These factors are expected to be problematic for nontemperature-stabilized instruments used for in-the-field experiments, where the radiant power of the site changes continuously with the sun tilt. This paper describes the effect of ambient temperature on a nontemperature-stabilized linear photodiode array spectrometer over the temperature range from 5 deg. C to 40 deg. C. The nonlinearity effects on both signal amplification and different levels of radiant power have also been studied and are presented in this paper.

Salim, Saber G. R.; Fox, Nigel P.; Theocharous, Evangelos; Sun, Tong; Grattan, Kenneth T. V.

2011-02-20T23:59:59.000Z

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461

A firmware-defined digital direct-sampling NMR spectrometer for condensed matter physics  

SciTech Connect (OSTI)

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.

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

462

Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report  

SciTech Connect (OSTI)

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.

NONE

1998-02-15T23:59:59.000Z

463

Parallel Monte Carlo reactor neutronics  

SciTech Connect (OSTI)

The issues affecting implementation of parallel algorithms for large-scale engineering Monte Carlo neutron transport simulations are discussed. For nuclear reactor calculations, these include load balancing, recoding effort, reproducibility, domain decomposition techniques, I/O minimization, and strategies for different parallel architectures. Two codes were parallelized and tested for performance. The architectures employed include SIMD, MIMD-distributed memory, and workstation network with uneven interactive load. Speedups linear with the number of nodes were achieved.

Blomquist, R.N.; Brown, F.B.

1994-03-01T23:59:59.000Z

464

Neutron skin of 208 Pb in consistency with  

E-Print Network [OSTI]

Neutron skin of 208 Pb in consistency with neutron star observations K. Miyazaki E-mail: miyazakiro as varying the neutron radius of 208Pb. The neutron skin thickness Sn is determined in the comparison with the astronomical observations of massive neutron stars (NSs), the standard scenario of NS cooling

465

Neutron diagnostics for mirror hybrids  

SciTech Connect (OSTI)

Fusion-fission (FuFi) hybrids will need instrumentation to diagnose the deuteriumtritium plasma, whose 14-MeV neutron emission is the driver of the sub-critical fission core. While the fission neutron yield rate (Y{sub fi} and hence power P{sub fi}) can be monitored with standard instrumentation, fusion plasmas in hybrids require special diagnostics where the determination of Y{sub th} ({proportional_to}P{sub fu}) is a challenge. Information on Y{sub fu} is essential for assessing the fusion plasma performance which together with Y{sub fi} allows for the validation of the neutron multiplication factor (k) of the subcritical fission core. Diagnostics for hybrid plasmas are heuristically discussed with special reference to straight field line mirror (SFLM). Relevant DT plasma experience from JET and plans for ITER in the main line of fusion research were used as input. It is shown that essential SFLM plasma information can potentially be obtained with proposed instrumentation, but the state of the hybrid plasma must be predictably robust as derived from fully diagnosed dedicated experiments without interface restrictions of the hybrid application.

Kaellne, Jan; Noack, Klaus; Agren, Olov; Gorini, Giuseppe; Tardocchi, Marco; Grosso, Giovanni [Department of Engineering Sciences, Uppsala University, Box 256, SE-751 21 Uppsala (Sweden); Universita degli Studi di Milano - Bicocca, Dip. di Fisica 'G. Occhialini', Piazza della Scienza 3, 20126, Milan (Italy)

2012-06-19T23:59:59.000Z

466

Measurement of delayed-neutron yield from {sup 237}Np fission induced by thermal neutrons  

SciTech Connect (OSTI)

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)

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

467

Prospects for neutron-antineutron transition search  

SciTech Connect (OSTI)

Presently-available sources of free neutrons can allow an improvement in the discovery potential of a neutron-antineutron transition search by four orders of magnitude as compared to that of the most recent reactor-based search experiment performed at ILL in Grenoble. This would be equivalent to a characteristic neutron-antineutron transition time limit of >10{sup 10} seconds. With future dedicated neutron-source Facilities, with further progress in cold-neutron- moderator techniques, and with a vertical experiment layout, the discovery potential could ultimately be pushed by another factor of {approximately}100 corresponding to a characteristic transition time limit of {approximately}10{sup 11} seconds. Prospects for, and relative merits of, a neutron-antineutron oscillation search in intranuclear transitions are also discussed.

Kamyshkov, Y. [Oak Ridge National Lab., TN (United States)][Tennessee Univ., Knoxville, TN (United States). Dept. of Physics

1996-12-31T23:59:59.000Z

468

DIRECTIONAL DETECTION OF A NEUTRON SOURCE.  

SciTech Connect (OSTI)

Advantages afforded by the development of new directional neutron detectors and imagers are discussed. Thermal neutrons have mean free paths in air of about 20 meters, and can be effectively imaged using coded apertures. Fission spectrum neutrons have ranges greater than 100 meters, and carry enough energy to scatter at least twice in multilayer detectors which can yield both directional and spectral information. Such strategies allow better discrimination between a localized spontaneous fission source and the low, but fluctuating, level of background neutrons generated by cosmic rays. A coded aperture thermal neutron imager will be discussed as well as a proton-recoil double-scatter fast-neutron directional detector with time-of-flight energy discrimination.

VANIER, P.E.; FORMAN, L.

2006-10-23T23:59:59.000Z

469

Neutron-Proton Analyzing Power Measurements from 375 to 775 Mev  

E-Print Network [OSTI]

of the PPT. Then, from the measurement of proton momentum provided by the spectrometer, with the assumption that the event was a n-p elastic scattering, the momentum of the scattered neutron was predicted, along with the hor- izontal (x ) and vertical (y...-hand side: P(ri-p) ?(n-p)?P'(p-p) ?(pp)- =P (n p) (n-p-)+P '(n p) (n-p) . -dQ CD 0) 85- LLJ 80- (3 z 75- O lX 70- CL LIJ x Arn o Ch CI Cn ~ Dz Si v Th o Ti Wr ZU This I Expt. I 2QO I ~ I, I 4QO 600 T?(MeV) FIG. 7. Zero...

Newsom, C. R.; Hollas, C. L.; Ransome, R. D.; Riley, P. J.; Bonner, BE; Boissevain, J. G. J.; Jarmer, J. J.; McNaughton, M. W.; Simmons, J. E.; Bhatia, T. S.; Glass, G.; Hiebert, John C.; Northcliffe, L. C.; Tippens, W. B.

1989-01-01T23:59:59.000Z

470

Progress on Neutron-Target Multipoles above 1 GeV  

SciTech Connect (OSTI)

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.