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Note: This page contains sample records for the topic "optical televiewer neutron" from the National Library of EnergyBeta (NLEBeta).
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1

Borehole-Wall Imaging with Acoustic and Optical Televiewers for  

Open Energy Info (EERE)

Borehole-Wall Imaging with Acoustic and Optical Televiewers for Borehole-Wall Imaging with Acoustic and Optical Televiewers for Fractured-Bedrock Aquifer Investigations Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Borehole-Wall Imaging with Acoustic and Optical Televiewers for Fractured-Bedrock Aquifer Investigations Abstract Imaging with acoustic and optical televiewers results in continuous and oriented 360 degree views of the borehole wall from which the character and orientation of lithologic and structural features can be defined for fractured-bedrock aquifer investigations. Fractures are more clearly defined under a wider range of conditions on acoustic images than on optical images including dark-colored rocks, cloudy borehole water, and coated borehole walls. However, optical images allow for the direct viewing

2

Grant Reference Principal Investigator Research Organisation Project Title NE/J013544/1 Professor B Hubbard Aberystwyth University Extended-range optical televiewer imaging of the NEEM deep ice borehole, Greenland  

E-Print Network (OSTI)

Grant Reference Principal Investigator Research Organisation Project Title NE/J013544/1 Professor B Hubbard Aberystwyth University Extended-range optical televiewer imaging of the NEEM deep ice borehole/1 Dr A Bedford Edge Hill University Late Holocene temperature reconstruction from Hawes Water northwest

3

Definition: Acoustic Televiewer | Open Energy Information  

Open Energy Info (EERE)

Televiewer Televiewer Jump to: navigation, search Dictionary.png Acoustic Televiewer The Acoustic Televiewer (ATV) log provides a very-high resolution, sonic image of the borehole wall. The tool consists of an ultrasonic transducer coupled with a downhole inclinometer. These devices are used to generate an oriented image of seismic velocity variation and wave amplitude. These images are then examined and highlighted to reveal fractures, bedding planes and orientation of those features. The log is useful for strata and fracture delineation, and can also be used to evaluate compressional-wave velocity, borehole deviation and eccentricity.[1] References ↑ http://www.dot.ca.gov/hq/esc/geotech/gg/atv_log.htm Ret LikeLike UnlikeLike You like this.Sign Up to see what your friends like.

4

Development of a geothermal acoustic borehole televiewer  

SciTech Connect

Most geothermal wells are drilled in hard rock formations where fluid flow is through systems of open fractures. Productivity of these wells is usually determined by the extent of intersection of the wellbore with the fracture system. A need exists for fracture mapping methods and tools which can operate in a geothermal environment. In less hostile environments, the acoustic borehole televiewer has been shown to be a useful tool for determining location, orientation, and characterization of fractures as they intersect the borehole and for general wellbore and casing inspection. The development conducted at Sandia National Laboratories to adapt an acoustic borehole televiewer for operation in a geothermal environment is described. The modified instrument has been successfully tested at temperatures as high as 280/sup 0/C and pressures up to 5000 psi, and used successfully to map fractures and casing damage in geothermal wells.

Heard, F.E.; Bauman, T.J.

1983-08-01T23:59:59.000Z

5

Coherence lengths and neutron optics  

Science Journals Connector (OSTI)

The dynamical diffraction of divergent beams and its application to neutron interferometry are considered. The coherence properties of thermal neutrons are studied, and it is shown that the extreme anisotropy of dynamically diffracted wave packets should be included in the discussion of coherence lengths. Finally, the mechanism leading to a nondispersive phase shift is investigated.

D. Petrascheck

1987-05-01T23:59:59.000Z

6

Borehole-Wall Imaging with Acoustic and Optical Televiewers for...  

Open Energy Info (EERE)

data from packer testing and monitoring. Authors John H. Williams and Carole D. Johnson Conference Seventh International Symposium on Borehole Geophysics for Minerals,...

7

Use of an acoustic borehole televiewer to investigate casing corrosion in geothermal wells  

SciTech Connect

Corrosion of well and surface equipment due to the presence of hot, corrosive brines is one of the major problems facing geothermal operators. For wellbore casing, this problem is complicated by the fact that in-place inspection is difficult at best. In an attempt to improve this situation, a prototype acoustic borehole televiewer designed to operate in geothermal wells was used to study the corrosion damage to casing in three commercial wells. The results of this experiment were promising. The televiewer returns helped to define areas of major corrosion damage and to indicate the extent of the damage. This paper briefly discusses the corrosion problem, describes the acoustic borehole televiewer, and then summarizes the results of the field test of the televiewer's capability for investigating corrosion.

Carson, C.C.; Bauman, T.

1986-03-01T23:59:59.000Z

8

Neutron and gamma radiation effects in proton exchanged optical waveguides  

Science Journals Connector (OSTI)

The effect of neutron and gamma ray irradiations on the optical properties of proton exchanged Z-cut lithium niobate optical planar waveguides were investigated. The damage thresholds...

Passaro, Vittorio; Armenise, Mario

2002-01-01T23:59:59.000Z

9

ABAREX: A neutron spherical optical-statistical model code  

SciTech Connect

The spherical optical-statistical model is briefly reviewed and the capabilities of the neutron scattering code, ABAREX, are presented. Input files for ten examples, in which neutrons are scattered by various nuclei, are given and the output of each run is discussed in detail.

Lawson, R.D.

1992-06-01T23:59:59.000Z

10

Ship Effect Measurements With Fiber Optic Neutron Detector  

SciTech Connect

The main objectives of this research project was to assemble, operate, test and characterize an innovatively designed scintillating fiber optic neutron radiation detector manufactured by Innovative American Technology with possible application to the Department of Homeland Security screening for potential radiological and nuclear threats at US borders (Kouzes 2004). One goal of this project was to make measurements of the neutron ship effect for several materials. The Virginia State University DOE FaST/NSF summer student-faculty team made measurements with the fiber optic radiation detector at PNNL above ground to characterize the ship effect from cosmic neutrons, and underground to characterize the muon contribution.

King, Kenneth L.; Dean, Rashe A.; Akbar, Shahzad; Kouzes, Richard T.; Woodring, Mitchell L.

2010-08-10T23:59:59.000Z

11

Neutron star equations of state with optical potential constraint  

E-Print Network (OSTI)

Nuclear matter and neutron stars are studied in the framework of an extended relativistic mean-field (RMF) model with higher-order derivative and density dependent couplings of nucleons to the meson fields. The derivative couplings lead to an energy dependence of the scalar and vector self-energies of the nucleons. It can be adjusted to be consistent with experimental results for the optical potential in nuclear matter. Several parametrisations, which give identical predictions for the saturation properties of nuclear matter, are presented for different forms of the derivative coupling functions. The stellar structure of spherical, non-rotating stars is calculated for these new equations of state (EoS). A substantial softening of the EoS and a reduction of the maximum mass of neutron stars is found if the optical potential constraint is satisfied.

Antic, Sofija

2015-01-01T23:59:59.000Z

12

Neutron star equations of state with optical potential constraint  

E-Print Network (OSTI)

Nuclear matter and neutron stars are studied in the framework of an extended relativistic mean-field (RMF) model with higher-order derivative and density dependent couplings of nucleons to the meson fields. The derivative couplings lead to an energy dependence of the scalar and vector self-energies of the nucleons. It can be adjusted to be consistent with experimental results for the optical potential in nuclear matter. Several parametrisations, which give identical predictions for the saturation properties of nuclear matter, are presented for different forms of the derivative coupling functions. The stellar structure of spherical, non-rotating stars is calculated for these new equations of state (EoS). A substantial softening of the EoS and a reduction of the maximum mass of neutron stars is found if the optical potential constraint is satisfied.

Sofija Antic; Stefan Typel

2015-01-29T23:59:59.000Z

13

Comparison of SEM and Optical Analysis of DT Neutron Tracks in CR-39 Detectors  

SciTech Connect

A solid state nuclear track detector, CR-39, was exposed to DT neutrons. After etching, the resultant tracks were analyzed using both an optical microscope and a scanning electron microscope (SEM). In this communication, both methods of analyzing DT neutron tracks are discussed.

P.A. Mosier-Boss, L.P.G. Forsley, P. Carbonnelle, M.S. Morey, J.R. Tinsley, J. P. Hurley, F.E. Gordon

2012-01-01T23:59:59.000Z

14

Fast-neutron radiation effects in a silica-core optical fiber studied by a CCD-camera spectrometer  

Science Journals Connector (OSTI)

A simple CCD-camera spectrometer was deployed at the Los Alamos Spallation Radiation Effects Facility to characterize fast-neutron irradiation effects in several silica-based optical...

Griscom, D L; Gingerich, M E; Friebele, E J; Putnam, M; Unruh, W

1994-01-01T23:59:59.000Z

15

ABAREX -- A neutron spherical optical-statistical-model code -- A user`s manual  

SciTech Connect

The contemporary version of the neutron spherical optical-statistical-model code ABAREX is summarized with the objective of providing detailed operational guidance for the user. The physical concepts involved are very briefly outlined. The code is described in some detail and a number of explicit examples are given. With this document one should very quickly become fluent with the use of ABAREX. While the code has operated on a number of computing systems, this version is specifically tailored for the VAX/VMS work station and/or the IBM-compatible personal computer.

Smith, A.B. [ed.; Lawson, R.D.

1998-06-01T23:59:59.000Z

16

Neutron scattering from elemental indium, the optical model, and the bound-state potential  

SciTech Connect

Neutron differential elastic-scattering cross sections of elemental indium are measured from 4.5 to 10 MeV at incident-energy intervals of {approx}500 keV. Seventy or more differential values are obtained at each incident energy, distributed between {approx}18{degree} and 160{degree}. These experimental results are combined with lower-energy values previously obtained at this laboratory, and with 11 and 14 MeV results in the literature, to form a comprehensive elastic-scattering database extending from {approx}1.5 to 14 MeV. These data are interpreted in terms of a conventional spherical optical model. The resulting potential is extrapolated to the bound-state regime. It is shown that in the middle of the 50--82 neutron shell, the potential derived from the scattering results adequately describes the binding energies of article states, but does not do well for hole states. The latter shortcoming is attributed to the holes states having occupational probabilities sufficiently different from unity, so that the exclusion principle become a factor, and to the rearrangement of the neutron core. 68 refs.

Chiba, S. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Guenther, P.T.; Lawson, R.D.; Smith, A.B. (Argonne National Lab., IL (USA))

1990-06-01T23:59:59.000Z

17

Development of a tiny neutron probe with an optical fibre for BNCT  

Science Journals Connector (OSTI)

......Institute of Advanced Industrial...2 Research Reactor Institute...Institute and the Heavy Water Neutron Irradiation...KUR Heavy Water Neutron Irradiation...field at the Heavy Water Neutron Irradiation...University Reactor. In: Proceedings...Institute of Advanced Industrial......

Y. Ito; G. Katano; H. Harano; T. Matsumoto; A. Uritani; K. Kudo; K. Kobayashi; T. Yoshimoto; Y. Sakurai; T. Kobayashi; C. Mori

2004-08-01T23:59:59.000Z

18

Simulation of optical configurations and signal processing methods in Anger-type neutron-position scintillation detector  

SciTech Connect

The spatial linearity and resolution of Anger-type neutron-position scintillation detectors are studied using a semi-empirical model. Detector optics with either an air gap or optical grease between the scintillator and the dispersive light guide are considered. Three signal processing methods which truncate signals from PMT's distant from the scintillation are compared with the linear resistive weighting method. Air gap optics yields a 15% improvement in spatial resolution and 50% reduction in differential and integral nonlinearity relative to grease coupled optics, using linear processing. Using signal truncation instead of linear processing improves the resolution 15-20% for the air gap and 20-30% for the grease coupling case. Thus, the initial discrepancy in the resolution between the two optics nearly vanished, however the linearity of the grease coupled system is still significantly poorer.

Roche, C.T.; Strauss, M.G.; Brenner, R.

1984-01-01T23:59:59.000Z

19

Fiber optic thermal/fast neutron and gamma ray scintillation detector  

DOE Patents (OSTI)

A system for detecting fissile and fissionable material originating external to the system includes: a .sup.6Li loaded glass fiber scintillator for detecting thermal neutrons, x-rays and gamma rays; a fast scintillator for detecting fast neutrons, x-rays and gamma rays, the fast scintillator conjoined with the glass fiber scintillator such that the fast scintillator moderates fast neutrons prior to their detection as thermal neutrons by the glass fiber scintillator; and a coincidence detection system for processing the time distributions of arriving signals from the scintillators.

Neal, John S. (Knoxville, TN); Mihalczo, John T (Oak Ridge, TN)

2007-10-30T23:59:59.000Z

20

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

SciTech Connect

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

Note: This page contains sample records for the topic "optical televiewer neutron" 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

EARLY X-RAY AND OPTICAL AFTERGLOW OF GRAVITATIONAL WAVE BURSTS FROM MERGERS OF BINARY NEUTRON STARS  

SciTech Connect

Double neutron star mergers are strong sources of gravitational waves. The upcoming advanced gravitational wave detectors are expected to make the first detection of gravitational wave bursts (GWBs) associated with these sources. Proposed electromagnetic counterparts of a GWB include a short gamma-ray burst, an optical macronova, and a long-lasting radio afterglow. Here we suggest that at least some GWBs could be followed by an early afterglow lasting for thousands of seconds, if the post-merger product is a highly magnetized, rapidly rotating, massive neutron star rather than a black hole. This afterglow is powered by dissipation of a proto-magnetar wind. The X-ray flux is estimated to be as bright as (10{sup -8}-10{sup -7}) erg s{sup -1} cm{sup -2}. The optical flux is subject to large uncertainties but could be as bright as 17th magnitude in R band. We provide observational hints of such a scenario, and discuss the challenge and strategy to detect these signals.

Zhang Bing [Kavli Institute of Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

2013-01-20T23:59:59.000Z

22

Neutron imaging with bent perfect crystals. I. Imaging conditions  

Science Journals Connector (OSTI)

Neutron imaging with bent crystals is considered in the linear approximation of neutron optics. A matrix formalism analogous to that of conventional lens optics is developed.

Stoica, A.D.

2001-05-22T23:59:59.000Z

23

Scintillator fiber optic long counter  

DOE Patents (OSTI)

A flat response position sensitive neutron detector capable of providing neutron spectroscopic data utilizing scintillator fiber optic filaments embedded in a neutron moderating housing having an open end through which neutrons enter to be detected.

McCollum, Tom (Sterling, VA); Spector, Garry B. (Fairfax, VA)

1994-01-01T23:59:59.000Z

24

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.

25

Principles of neutron reflection  

SciTech Connect

Neutron reflection is perhaps the most developed branch of slow neutrons optics, which in itself is a direct consequence of the undulatory nature of the neutron. After reviewing the basic types of interactions (nuclear and magnetic) between neutrons and matter, the formalism is introduced to calculate the reflectivity from a sample composed of stacked flat layers and, inversely, to calculate the stacking from reflectivity measurements. Finally, a brief survey of the applications of neutron reflection is given, both in technology and in fundamental research. 32 refs., 6 figs.

Felcher, G.P.

1988-08-01T23:59:59.000Z

26

Optical  

NLE Websites -- All DOE Office Websites (Extended Search)

Optical Optical fiber-based single-shot picosecond transient absorption spectroscopy Andrew R. Cook a͒ and Yuzhen Shen Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, USA ͑Received 27 January 2009; accepted 29 May 2009; published online 17 July 2009͒ A new type of single-shot transient absorption apparatus is described based on a bundle of optical fibers. The bundle contains 100 fibers of different lengths, each successively giving ϳ15 ps longer optical delay. Data are collected by imaging light from the exit of the bundle into a sample where it is overlapped with an electron pulse or laser excitation pulse, followed by imaging onto a charge coupled device ͑CCD͒ detector where the intensity of light from each fiber is measured simultaneously. Application to both ultrafast pump-probe spectroscopy and pulse radiolysis is demonstrated. For pulse

27

Optics  

Science Journals Connector (OSTI)

Optical components such as lenses, mirrors and diffraction gratings are widely used in many inspection systems. These include not only those for visual inspection with CCD cameras, but also in areas of distanc...

C. Loughlin

1993-01-01T23:59:59.000Z

28

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

29

Neutron reflectometry  

Science Journals Connector (OSTI)

Neutron reflectivity is a powerful tool for the ... chapter include: the theory of elastic specular neutron diffraction; polarized neutron reflectivity; surface roughness; experimental methodology; resolution in ...

G. S. Smith; C. F. Majkrzak

2004-01-01T23:59:59.000Z

30

Neutron-Neutron Interaction  

Science Journals Connector (OSTI)

The present status of the problem of charge dependence is discussed. The information about the neutron-neutron interaction derived from the two-neutron system, three-nucleon systems, final-state interactions in multiparticle reactions, and peripheral processes is critically evaluated. The experimental data indicate the breakdown of charge independence by about 3-5%. Evidence concerning the violation of charge symmetry is inconclusive, but it seems that most of the data are consistent with the assumption that charge symmetry is satisfied within 0.5-1%. The most suitable studies which might improve the knowledge of the neutron-neutron forces are indicated.

IVO LAUS

1967-07-01T23:59:59.000Z

31

Neutron phase echo  

Science Journals Connector (OSTI)

The coherent overlap of the waves traversing the two legs of a perfect-crystal neutron interferometer is altered by a material with a neutron-nuclear optical potential. The fringe visibility is limited by the longitudinal coherence length. The loss of interference contrast caused by a slab of material of positive optical potential can be restored by placing another slab of material with a negative optical potential in the same leg of the interferometer. This paper describes the observation and detailed characterization of this quantum-mechanical phenomenon, which we call the phase-echo effect.

R. Clothier; H. Kaiser; S. A. Werner; H. Rauch; H. Wlwitsch

1991-11-01T23:59:59.000Z

32

Fundamental phenomena of quantum mechanics explored with neutron interferometers  

E-Print Network (OSTI)

Ongoing fascination with quantum mechanics keeps driving the development of the wide field of quantum-optics, including its neutron-optics branch. Application of neutron-optical methods and, especially, neutron interferometry and polarimetry has a long-standing tradition for experimental investigations of fundamental quantum phenomena. We give an overview of related experimental efforts made in recent years.

J. Klepp; S. Sponar; Y. Hasegawa

2014-07-09T23:59:59.000Z

33

The HST contribution to neutron star astronomy  

E-Print Network (OSTI)

While isolated neutron stars (INSs) are among the brightest gamma-ray sources, they are among the faintest ones in the optical, and their study is a challenging task which require the most powerful telescopes. HST has lead neutron star optical astronomy yielding nearly all the identifications achieved since the early 1990s. Here, the major HST contributions in the optical studies of INSs and their relevance for neutron stars' astronomy are reviewed.

R. P. Mignani

2007-10-29T23:59:59.000Z

34

Installation and commissioning of a large area coating system for neutron and X-ray optical devices  

SciTech Connect

A 9 meter long DC/RF sputtering cylindrical coating system which is designed and built indigenously for coating of neutron supermirrors and grazing incidence hard X-ray mirrors on large area substrates has been installed and commissioned recently. The performance of the system has been tested by depositing Ti films on glass substrate of 1500mm X 150mm size. By depositing Ti films on several small area c-Si substrates placed over the length and breadth of the substrate holder, and by subsequent characterization by GIXR measurement, it has been observed that films with bulk-like density and very low surface roughness can be obtained in the above system. The thickness uniformity achieved in the deposited films is within 3.5% over the 1500mm length and within 4.8% over the 150mm width.

Biswas, A., E-mail: arupb@barc.gov.in; Haque, Sk. Maidul, E-mail: arupb@barc.gov.in; Misal, J., E-mail: arupb@barc.gov.in; Sampathkumar, R.; Ajaykumar,; Bhattacharyya, D.; Sahoo, N. K. [Atomic and Molecular Physics Division, Bhabha Atomic Research Center, Mumbai-400085 (India); Lagoo, K. D.; Veerapur, R. D.; Padmanabhan, M.; Puri, R. K. [Division of Remote Handling and Robotics, Bhabha Atomic Research Center, Mumbai-400085 (India); Bhattacharya, Debarati [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai-400085 (India)

2014-04-24T23:59:59.000Z

35

Neutron Polarimetry  

Science Journals Connector (OSTI)

8 July 1993 research-article Neutron Polarimetry P. Jane Brown J. Bruce Forsyth Francis Tasset Zero-field neutron polarimetry is a technique which has...polarization analysis to be carried out in a neutron scattering experiment. The incident...

1993-01-01T23:59:59.000Z

36

Neutron Production, Neutron Facilities and Neutron Instrumentation  

Science Journals Connector (OSTI)

...Mexico, 87545, U.S.A, e-mail: sven@lanl.gov Hans-Georg Priesmeyer Geesthacht Neutron Scattering Facility, GKSS Research Center, 21502 Geesthacht, Germany, e-mail: hans-georg.priesmeyer@gkss.de NEUTRON GENERATION The...

Sven C. Vogel; Hans-Georg Priesmeyer

37

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

38

Neutron Reflectivity  

Science Journals Connector (OSTI)

Neutron Reflectivity ... This article is part of the Neutron Reflectivity special issue. ... The articles in this special issue on neutron reflectivity cover a broad range of the applications of this technique and the related X-ray and neutron scattering experiments of SAXS, SANS, GISAXS, and GISANS. ...

Jeffrey Penfold

2009-03-31T23:59:59.000Z

39

About Neutrons  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Basics Neutron Basics A neutron is one of the fundamental particles that make up matter. This uncharged particle exists in the nucleus of a typical atom, along with its positively charged counterpart, the proton. Protons and neutrons each have about the same mass, and both can exist as free particles away from the nucleus. In the universe, neutrons are abundant, making up more than half of all visible matter. Find Out What a Neutron Is Youtube icon Properties of Neutrons How Can Neutrons Be Used for Research? Image of glucose movement in plants Neutron imaging techniques have been able to determine the precise movement of glucose in plants. This knowledge can help scientists better understand how biomass can be efficiently converted into fuel. Neutrons have many properties that make them ideal for certain types of

40

Neutron-Neutron Scattering Length  

Science Journals Connector (OSTI)

The final-state interaction of the two neutrons from the reaction ?-+d?2n+? has a pronounced and distinctive effect on the momentum spectrum of the outgoing particles. In particular, the neutron spectrum is sharply peaked in the neighborhood of 2 Mev, with a shape that is quite sensitive to the strength of the nn interaction. In the region of this peak, the relative neutron-neutron momentum is so small that the nn interaction is completely characterized by its scattering length. Hence it is proposed that a measurement of the shape of the neutron spectrum from this reaction may provide a convenient means of measuring the neutron-neutron scattering length. Neutron spectra are calculated in an impulse approximation, for several assumed values of the scattering length. It appears from their shapes that, in this way, present neutron-detection techniques should be capable of determining the scattering length to within 25%.

Kirk W. McVoy

1961-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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.


41

Neutron skins and neutron stars  

SciTech Connect

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

42

Neutron scattering  

Science Journals Connector (OSTI)

... likely to be able to contribute to many different branches of chemistry and secondly because neutron ...neutronscattering ...

A. J. Leadbetter

1977-12-01T23:59:59.000Z

43

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

44

Neutron Diffraction  

Science Journals Connector (OSTI)

22 February 1949 research-article Neutron Diffraction G. E. Bacon J. Thewlis The problem of neutron diffraction by crystals is treated by analogy...deals with a comparison between X-ray and neutron diffraction and it is shown that quantitatively...

1949-01-01T23:59:59.000Z

45

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

46

Neutron diffraction by perfect crystals  

Science Journals Connector (OSTI)

The dynamical theory of neutron diffraction has been formulated to include the reflected waves from the boundaries of a crystal. This formulation allows a unified treatment of the neutron optical and diffraction phenomena in crystals. It is shown that the neutron propagation in the crystal is determined by two structure factors characterizing the lattice: the total structure factor and the structure factor of the neutron-spin-neutron-orbit interaction. Diffraction by a parallel crystal plate has been studied in considerable detail. It has been found that for a definite neutron-spin orientation, the diffracted and transmitted beams are modulated by six terms periodic in the thickness of the crystal. The period of the dominant term, in this Pendellsung fringe structure, has been calculated in several cases of experimental importance. If the glancing angle of incidence substantially exceeds the critical angle for total reflection, the results are identical with those obtained by a simple extension, to the neutron case, of the x-ray dynamical theory. The diffraction by a magnetized crystal has been examined in some detail and it is shown that measurement of the Pendellsung periods for the two neutron-spin orientations may be used to determine both the nuclear and magnetic neutron scattering amplitude.

C. Stassis and J. A. Oberteuffer

1974-12-15T23:59:59.000Z

47

Neutron skins and neutron stars  

Science Journals Connector (OSTI)

Background: The neutron skin of a heavy nucleus as well as many neutron-star properties are highly sensitive to the poorly constrained density dependence of the symmetry energy.Purpose: To provide for the first time meaningful theoretical errors and to assess the degree of correlation between the neutron-skin thickness of 208Pb and several neutron-star properties.Methods: A proper covariance analysis based on the predictions of an accurately calibrated relativistic functional FSUGold is used to quantify theoretical errors and correlation coefficients.Results: We find correlation coefficients of nearly 1 (or ?1) between the neutron-skin thickness of 208Pb and a host of observables of relevance to the structure, dynamics, and composition of neutron stars.Conclusions: We suggest that a follow-up Lead Radius Experiment (PREX) measurement, ideally with a 0.5% accuracy, could significantly constrain the equation of state of neutron-star matter.

F. J. Fattoyev and J. Piekarewicz

2012-07-05T23:59:59.000Z

48

Neutron Scattering Tutorials | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

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

49

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

50

Neutron Scattering  

Science Journals Connector (OSTI)

... Magnetic Neutron Diffraction By Yurii A. Izyumov and Ruslan P. Ozerov. Translated from the Russian. ... York; Heydon: London, June 1970.) 350s; $37.50; 150 DM.

G. L. SQUIRES

1970-12-05T23:59:59.000Z

51

Neutron activation analysis  

Science Journals Connector (OSTI)

Neutron activation analysis ... Describes the science and techniques of neutron activation analysis. ...

H. R. Lukens

1967-01-01T23:59:59.000Z

52

Neutron Microscope  

Science Journals Connector (OSTI)

We report successful operation of a neutron microscope using ultracold neutrons at the high-flux reactor at Grenoble. A sharp, achromatic image of an object slit was obtained at a magnification of 50. The measured resolution of 0.1 mm was limited mainly by the available beam intensity, not by aberrations.

P. Herrmann; K. -A. Steinhauser; R. Ghler; A. Steyerl; W. Mampe

1985-05-06T23:59:59.000Z

53

Neutron scattering  

Science Journals Connector (OSTI)

... statements that the EMBL outstation in Grenoble "[has an] uncertain future" and that "neutrons have not turned out to be particularly useful for biologists" in Peter Newmark's ... on the European Molecular Biology Laboratory (Nature 338, 724; 1989) require some comment.Neutron ...

S. CUSACK; B. JACROT; R. LEBERMAN; R. MAY; P. TlMMINS; G. ZACCAI

1989-06-01T23:59:59.000Z

54

Decoherence-free neutron interferometry  

SciTech Connect

Perfect single-crystal neutron interferometers are adversely sensitive to environmental disturbances, particularly mechanical vibrations. The sensitivity to vibrations results from the slow velocity of thermal neutrons and the long measurement time that are encountered in a typical experiment. Consequently, to achieve a good interference solutions for reducing vibration other than those normally used in optical experiments must be explored. Here we introduce a geometry for a neutron interferometer that is less sensitive to low-frequency vibrations. This design may be compared with both dynamical decoupling methods and decoherence-free subspaces that are described in quantum information processing. By removing the need for bulky vibration isolation setups, this design will make it easier to adopt neutron interferometry to a wide range of applications and increase its sensitivity.

Pushin, D. A.; Cory, D. G. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Arif, M. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

2009-05-15T23:59:59.000Z

55

Neutron Polarization  

Science Journals Connector (OSTI)

The production of polarized neutrons in magnetized iron has been studied, using the intense neutron beams available at the Argonne heavy water pile. The theoretical work of Halpern et al., used as a guide in the experiments, has been checked in many respects, with the exception that the polarization cross section p has a measured value of 3.15 barns compared to the theoretical 1 barn. The application of neutron polarization to the measurement of the approach to saturation in ferromagnets is described and preliminary results are reported.

D. J. Hughes; J. R. Wallace; R. H. Holtzman

1948-06-01T23:59:59.000Z

56

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

57

Neutron Checkup  

Science Journals Connector (OSTI)

Neutron activation analysis is yet another technique in the arsenal of diagnostic methods that physicians can draw on to examine the health of their patients. The University of Washington's school of medicine in Seattle is the first facility in the ...

1969-11-10T23:59:59.000Z

58

Neutron Reflectometry  

Science Journals Connector (OSTI)

Neutron reflectometry is a relatively new technique [1,2]. In the last years, it has been extensively used for solving soft matter problems like polymer mixing [3,4] or the structure of liquids at the surface [5,

Claude Fermon; Frdric Ott; Alain Menelle

1999-01-01T23:59:59.000Z

59

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

60

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

Note: This page contains sample records for the topic "optical televiewer neutron" 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

E-Print Network 3.0 - average prompt neutron Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Plasma Physics and Fusion 62 EARLY OPTICAL AFTERGLOW LIGHT CURVES OF NEUTRON-FED GAMMA-RAY BURSTS Y. Z. Fan,1,2,3 Summary: neutrons shell (i.e., the N-ejecta), most of which is...

62

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

63

Fast-Neutron Handbook  

Science Journals Connector (OSTI)

... FAST neutron physics, in the present context, concerns the study of interactions of atomic nuclei with neutrons ...

J. H. MONTAGUE

1961-06-10T23:59:59.000Z

64

Neutron Scattering User Program | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

User Program SHARE Neutron Scattering Can Benefit Your Research Neutron scattering has applications in almost every technical and scientific field, from biology and chemistry to...

65

Neutron Polarization  

Science Journals Connector (OSTI)

Experiments for the determination of the polarization cross section p of iron with monochromatic and non-monochromatic neutrons are described. The absolute value of p as well as its dependence on the neutron velocity is found to be in good agreement with the recent calculations of Steinberger and Wick and also with other experiments. For a complex neutron spectrum originating from a paraffin moderator p is found to be (2.350.1)10-24 cm2 in agreement with previous investigations. It is shown that the larger value of 3.1510-24 cm2 found by Hughes, Wallace, and Holtzman must be due to spectral differences. The approach of the magnetization of iron towards saturation is also investigated.

J. Fleeman; D. B. Nicodemus; H. H. Staub

1949-12-15T23:59:59.000Z

66

Neutron Imaging Explored as Complementary Technique for Improving Cancer  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Imaging Explored as Complementary Technique for Improving Cancer Neutron Imaging Explored as Complementary Technique for Improving Cancer Detection August 05, 2013 Researcher Maria Cekanova analyzes the neutron radiographs of a canine breast tumor (black color in top image of monitor screen) using the software to visualize in color the various intensities of neutron transmissions through the breast tissue. ORNL and University of Tennessee collaboration now analyzing first results from neutron radiographs of cancerous tissue samples Today's range of techniques for detection of breast and other cancers include mammography, computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, positron emission tomography (PET), and optical imaging. Each technology has advantages and disadvantages, with limitations either

67

The Neutron  

Science Journals Connector (OSTI)

The writers point out that the postulation of the existence of the "neutron," a combination of an electron and a proton, of small size and low energy would be very useful in explaining a number of atomic and cosmic phenomena. They find that a mathematical treatment based on existing theory leads to indications of such a state but no definite proof.

R. M. Langer and N. Rosen

1931-06-15T23:59:59.000Z

68

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

69

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

70

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

71

Breast Tissue Imaging | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron scattering measures samples too hot to hold Neutron scattering measures samples too hot to hold Research Contact: Kenneth Kelton August 2013 Liquids and glasses can have unique optical, electronic, and structural applications but are poorly understood compared to crystalline materials, limiting the ability to take advantage of the characteristics of glasses in a range of applications. Containers can react with molten samples at high temperatures or can favor the growth of crystals over the formation of glasses. Using the chemical and isotopic sensitivity of neutron scattering to understand these disordered structures requires a new capability to hold samples in a neutron beam at high temperature without using a solid physical container. New sample environment equipment at Oak Ridge National Laboratory's (ORNL) Spallation Neutron Source (SNS) enables scientists to

72

Neutron scattering instrumentation at reactor based installations  

Science Journals Connector (OSTI)

During the past decade neutron scattering techniques have been applied to an increasingly wide range of scientific problems. Concurrently a number of substantial improvements of neutron scattering instrumentation have occurred to stimulate this trend. In this article several such developments which have occurred at reactor?based installations are described. Individual spectrometer components which are discussed in some detail include: neutron?optical devices such as guide tubes supermirrors and multilayer systems; neutronmonochromators with optimum reflectivity mosaic and focusing characteristics; position?sensitive detectors of several types; and equipment required for neutronpolarizationanalysis. Several novel spectrometers which have enhanced the role of neutron scattering during the past ten years are also described. These include spectrometers for small?angle scattering backscattering and neutron spin echo. An extensive bibliography is included which covers both early and more recent developments.

Roger Pynn

1984-01-01T23:59:59.000Z

73

Neutron Scattering Facilities 1982  

NLE Websites -- All DOE Office Websites (Extended Search)

NEUTRON SOURCES NEUTRON SOURCES Types of Sources U.S. Sources Available for Users Plans for the Future The Neutron Scattering Society of America (NSSA) SNS/ANL School on Neutron and x-Ray Scattering, June 2011 Jim Rhyne Lujan Neutron Scattering Center Los Alamos National Lab. What do we need to do neutron scattering? * Neutron Source - produces neutrons * Diffractometer or Spectrometer - Allows neutrons to interact with sample - Sorts out discrete wavelengths by monochromator (reactor) or by time of flight (pulse source) - Detectors pick up neutrons scattered from sample * Analysis methods to determine material properties * Brain power to interpret results Sources of neutrons for scattering * Nuclear Reactor - Neutrons produced from fission of 235 U - Fission spectrum neutrons

74

Demonstration of achromatic cold-neutron microscope utilizing axisymmetric focusing mirrors  

E-Print Network (OSTI)

An achromatic cold-neutron microscope with magnification 4 is demonstrated. The image-forming optics is composed of nested coaxial mirrors of full figures of revolution, so-called Wolter optics. The spatial resolution, ...

Liu, Dazhi

75

Neutron Polarization  

Science Journals Connector (OSTI)

The neutron polarization cross section of iron has been measured as a function of energy from 0.7 to 3.3A by two methods: using the single transmission effect in a block of polycrystalline iron at energies selected by a quartz crystal monochromator; and using a single crystal of magnetized magnetite to analyze the beam emerging from the iron polarizer, the magnetite crystal itself serving as monochromator. The measured values are compared with those of other observers and the theoretically expected values. These are found to agree fairly well within the limits of accuracy of the measurements and existing knowledge of the wave function of the iron 3d shell. The two techniques were used also to determine the average polarization (32 percent) as seen by a 1v detector in a beam of reactor neutrons emerging from a 4-cm thick polarizing block of iron. Problems and techniques associated with the measurement of the average polarization of a continuous spectrum are discussed. A simplified experimental treatment of the problem of beam "hardening" is described. A description is given of the use of the magnetic resonance method in conjunction with a single-crystal magnetite analyzer for the measurement of neutron polarization.

C. P. Stanford; T. E. Stephenson; L. W. Cochran; S. Bernstein

1954-04-15T23:59:59.000Z

76

Neutron Gas  

Science Journals Connector (OSTI)

We assume that the neutron-neutron potential is well-behaved and velocity-dependent. We can then apply perturbation theory to find the energy per particle of a neutron gas, in the range of Fermi wave numbers 0.5

J. S. Levinger and L. M. Simmons

1961-11-01T23:59:59.000Z

77

Publications | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (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...

78

Neutron Scattering Facilities  

Science Journals Connector (OSTI)

The past history, present performance and future prospects for neutron scattering facilities will be discussed. Special features of neutron scattering techniques applicable to biological problems will be ... . Th...

D. L. Price

1996-01-01T23:59:59.000Z

79

Calculations of neutron spectra after neutronneutron scattering  

Science Journals Connector (OSTI)

A direct neutronneutron scattering length, ann, measurement with the goal of 3% accuracy (0.5 fm) is under preparation at the aperiodic pulsed reactor YAGUAR. A direct measurement of ann will not only help resolve conflicting results of ann by indirect means, but also in comparison to the protonproton scattering length, app, shed light on the charge-symmetry of the nuclear force. We discuss in detail the analysis of the nn-scattering data in terms of a simple analytical expression. We also discuss calibration measurements using the time-of-flight spectra of neutrons scattered on He and Ar gases and the neutron activation technique. In particular, we calculate the neutron velocity and time-of-flight spectra after scattering neutrons on neutrons and after scattering neutrons on He and Ar atoms for the proposed experimental geometry, using a realistic neutron flux spectrumMaxwellian plus epithermal tail. The shape of the neutron spectrum after scattering is appreciably different from the initial spectrum, due to collisions between thermalthermal and thermalepithermal neutrons. At the same time, the integral over the Maxwellian part of the realistic scattering spectrum differs by only about 6 per cent from that of a pure Maxwellian nn-scattering spectrum.

B E Crawford; S L Stephenson; C R Howell; G E Mitchell; W Tornow; W I Furman; E V Lychagin; A Yu Muzichka; G V Nekhaev; A V Strelkov; E I Sharapov; V N Shvetsov

2004-01-01T23:59:59.000Z

80

Spallation Neutron Source | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Spallation Neutron Source SNS site, Spring 2012 The 80-acre SNS site is located on the east end of the ORNL campus and is about a three-minute drive from her sister neutron...

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Science | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Science Neutron Science Neutron Scattering Science Neutrons are one of the fundamental particles that make up matter and have properties that make them ideal for certain types of research. In the universe, neutrons are abundant, making up more than half of all visible matter. Neutron scattering provides information about the positions, motions, and magnetic properties of solids. When a beam of neutrons is aimed at a sample, many neutrons will pass through the material. But some will interact directly with atomic nuclei and "bounce" away at an angle, like colliding balls in a game of pool. This behavior is called neutron diffraction, or neutron scattering. Using detectors, scientists can count scattered neutrons, measure their energies and the angles at which they scatter, and map their final position

82

Neutron lifetime measured with stored ultracold neutrons  

Science Journals Connector (OSTI)

The neutron lifetime has been measured by counting the neutrons remaining in a fluid-walled bottle as a function of the duration of storage. Losses of neutrons caused by the wall reflections are eliminated by varying the bottle volume-to-surface ratio. The result obtained is ??=887.63 s.

W. Mampe; P. Ageron; C. Bates; J. M. Pendlebury; A. Steyerl

1989-08-07T23:59:59.000Z

83

Neutron-Neutron Quasifree Scattering  

Science Journals Connector (OSTI)

The reaction D(n ,2n)p has been measured at Einc=14.1 MeV, ?n (3)=?n(4)=30?, ?=180?, and the results are compared with the predictions of two separable-potential models. Neutron-proton and proton-proton quasifree scattering from nucleon + deuteron reactions at 14 MeV are also compared with the predictions of the same models. The upper limit of 2 mb/sr2 is determined for the reaction D(n,n?)d.

Ivo Slaus; J. W. Sunier; G. Thompson; J. C. Young; J. W. Verba; D. J. Margaziotis; P. Doherty; R. T. Cahill

1971-03-29T23:59:59.000Z

84

Optimizing moderator dimensions for neutron scattering at the spallation neutron source  

SciTech Connect

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source (SNS). In a recent study of the planned second target station at the SNS facility, we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter over a smaller viewing area. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories: those with natural collimation and those that use neutron guide systems. For instruments using natural collimation, the optimal moderator selection depends on the size of the moderator, the sample, and the moderator brightness. The desired beam divergence only plays a role in determining the distance between sample and moderator. For instruments using neutron optical systems, the smallest moderator available that is larger than the entrance dimension of the closest optical element will perform the best (assuming, as is the case here that smaller moderators are brighter)

Zhao, J. K.; Robertson, J. L.; Herwig, Kenneth W.; Gallmeier, Franz X.; Riemer, Bernard W. [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-12-15T23:59:59.000Z

85

Kaon condensation in neutron star using relativistic mean field models  

E-Print Network (OSTI)

We use the modified quark-meson coupling and the quantum hadrodynamics models to study the properties of neutron star. Coupling constants of both models are adjusted to reproduce the same saturation properties. The onset of kaon condensation in neutron star matter is studied in detail over a wide range of kaon optical potential values. Once the kaon condensation takes place, the population of kaons increases very rapidly, and kaons become the dominant component, possibly making the neutron star matter a kaonic matter if the kaon optical potential is large.

S. W. Hong; C. H. Hyun; C. Y. Ryu

2007-02-08T23:59:59.000Z

86

Core Vessel Insert Handling Robot for the Spallation Neutron Source  

SciTech Connect

The Spallation Neutron Source provides the world's most intense pulsed neutron beams for scientific research and industrial development. Its eighteen neutron beam lines will eventually support up to twenty-four simultaneous experiments. Each beam line consists of various optical components which guide the neutrons to a particular instrument. The optical components nearest the neutron moderators are the core vessel inserts. Located approximately 9 m below the high bay floor, these inserts are bolted to the core vessel chamber and are part of the vacuum boundary. They are in a highly radioactive environment and must periodically be replaced. During initial SNS construction, four of the beam lines received Core Vessel Insert plugs rather than functional inserts. Remote replacement of the first Core Vessel Insert plug was recently completed using several pieces of custom-designed tooling, including a highly complicated Core Vessel Insert Robot. The design of this tool are discussed.

Graves, Van B [ORNL; Dayton, Michael J [ORNL

2011-01-01T23:59:59.000Z

87

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

88

Direct Measurement of Neutron?Neutron Scattering  

Science Journals Connector (OSTI)

In order to resolve long?standing discrepancies in indirect measurements of the neutron?neutron scattering length ann and contribute to solving the problem of the charge symmetry of the nuclear force the collaboration DIANNA (Direct Investigation of ann Association) plans to measure the neutron?neutron scattering cross section ? nn . The key issue of our approach is the use of the through?channel in the Russia reactor YAGUAR with a peak neutron flux of 1018 /cm2/s. The proposed experimental setup is described. Results of calculations are presented to connect ? nn with the nn?collision detector count rate and the neutron flux density in the reactor channel. Measurements of the thermal neutron fields inside polyethylene converters show excellent prospects for the realization of the direct nn?experiment.

E. I. Sharapov; C. D. Bowman; B. E. Crawford; W. I. Furman; C. R. Howell; B. G. Levakov; V. I. Litvin; W. I. Lychagin; A. E. Lyzhin; E. P. Magda; G. E. Mitchell; G. V. Muzichka; G. V. Nekhaev; Yu. V. Safronov; V. N. Shvetsov; S. L. Stephenson; A. V. Strelkov; W. Tornow

2003-01-01T23:59:59.000Z

89

Method and apparatus for detecting neutrons  

DOE Patents (OSTI)

The instant invention is a method for making and using an apparatus for detecting neutrons. Scintillating optical fibers are fabricated by melting SiO.sub.2 with a thermal neutron capturing substance and a scintillating material in a reducing atmosphere. The melt is then drawn into fibers in an anoxic atmosphere. The fibers may then be coated and used directly in a neutron detection apparatus, or assembled into a geometrical array in a second, hydrogen-rich, scintillating material such as a polymer. Photons generated by interaction with thermal neutrons are trapped within the coated fibers and are directed to photoelectric converters. A measurable electronic signal is generated for each thermal neutron interaction within the fiber. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. When the fibers are arranged in an array within a second scintillating material, photons generated by kinetic neutrons interacting with the second scintillating material and photons generated by thermal neutron capture within the fiber can both be directed to photoelectric converters. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation.

Perkins, Richard W. (Richland, WA); Reeder, Paul L. (Richland, WA); Wogman, Ned A. (Richland, WA); Warner, Ray A. (Benton City, WA); Brite, Daniel W. (Richland, WA); Richey, Wayne C. (Richland, WA); Goldman, Don S. (Orangevale, CA)

1997-01-01T23:59:59.000Z

90

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

91

Neutronmirror-neutron oscillations in a trap  

Science Journals Connector (OSTI)

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

B. Kerbikov and O. Lychkovskiy

2008-06-27T23:59:59.000Z

92

Manuel Lujan Jr. Neutron Scattering Center Los Alamos Neutron...  

NLE Websites -- All DOE Office Websites (Extended Search)

2013 LANSCE School on Neutron Scattering Geosciences & Materials in Extreme Environments Manuel Lujan Jr. Neutron Scattering Center Los Alamos Neutron Science Center Los Alamos...

93

Neutron crystallography aids drug design  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron crystallography aids drug design Neutron crystallography aids drug design Researchers have used neutron crystallography for the first time to determine the structure of a...

94

Los Alamos Neutron Science Center  

NLE Websites -- All DOE Office Websites (Extended Search)

LINAC Outreach Affiliations Visiting LANSCE Facilities Isotope Production Facility Lujan Neutron Scattering Center MaRIE Proton Radiography Ultracold Neutrons Weapons Neutron...

95

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

96

Neutron Generator as a Neutron Source for BNCT  

Science Journals Connector (OSTI)

A neutron generator was investigated for a neutron source for BNCT. Neutron generators have some obvious advantages over nuclear reactors for this purpose. The neutron source is the reaction D(d,n)3He. Moderation...

Gad Shani; Lev Tsvang; Semion Rozin; Michael Quastel

1996-01-01T23:59:59.000Z

97

Neutron scattering on deformed nuclei  

Science Journals Connector (OSTI)

Measurements of neutron elastic and inelastic differential cross sections around 14 MeV for 9Be C 181 Ta 232Th 238U and 239Pu have been analyzed using a coupled channel (CC) formalism for deformed nuclei and phenomenological global optical model potentials (OMP). For the actinide targets these results are compared with the predictions of a semi?microscopic calculation using Jeukenne Lejeune and Mahaux (JLM) microscopic OMP and a deformed ground state nuclear density. The overall agreement between calculations and the measurements is reasonably good even for the very light nuclei where the quality of the fits is better than those obtained with spherical OMP.

L. F. Hansen; R. C. Haight; B. A. Pohl; C. Wong; Ch. Lagrange

1985-01-01T23:59:59.000Z

98

Neutron producing target for accelerator based neutron source for  

E-Print Network (OSTI)

247 Neutron producing target for accelerator based neutron source for NCT V. Belov1 , S. Fadeev1, Russia Summary Neutron producing targets for novel accelerator based neutron source [1, 2] are presented Neutron producing target is one of the main elements of proposed accelerator based facility for neutron

Taskaev, Sergey Yur'evich

99

Scattering of Fast Neutrons by Magnesium  

Science Journals Connector (OSTI)

Angular distributions for the scattering of fast neutrons by magnesium have been obtained for incident neutron energies of 2.0, 3.0, 4.0, and 5.0 Mev. The results for the elastic scattering have been compared with optical model calculations. The results for the inelastic scattering have been compared with calculations based on Hauser-Feshbach theory, and with direct interaction predictions. Over the range of conditions investigated, compound nucleus formation appears to be the dominant mechanism for the inelastic scattering.

D. B. Thomson; L. Cranberg; J. S. Levin

1962-03-15T23:59:59.000Z

100

Neutron scattering measurements at intermediate energies  

E-Print Network (OSTI)

The study of elastic neutron scattering at intermediate energies is essential for the understanding of the isovector term in the nucleon-nucleus interaction, as well as for the development of macroscopic and microscopic optical potentials at these energies. The techniques used for neutron scattering measurements is presented in this paper, as well as the di culties encountered. The few facilities that have been used are reviewed, and a newly installed setup for such measurements in Uppsala is described. Finally, the normalization problem is speci cally addressed. 1

N. Olsson; J. Blomgren; E. Ramstrom

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101

Total Cross Sections for Neutron Scattering  

E-Print Network (OSTI)

Measurements of neutron total cross-sections are both extensive and extremely accurate. Although they place a strong constraint on theoretically constructed models, there are relatively few comparisons of predictions with experiment. The total cross-sections for neutron scattering from $^{16}$O and $^{40}$Ca are calculated as a function of energy from $50-700$~MeV laboratory energy with a microscopic first order optical potential derived within the framework of the Watson expansion. Although these results are already in qualitative agreement with the data, the inclusion of medium corrections to the propagator is essential to correctly predict the energy dependence given by the experiment.

C. R. Chinn; Ch. Elster; R. M. Thaler; S. P. Weppner

1994-10-19T23:59:59.000Z

102

Neutron and gamma width correlations in neutron capture reactions: A comparative study  

Science Journals Connector (OSTI)

Three different procedures are generally adopted in the analysis of correlation observed between neutron and ? widths in neutron capture experiments. We present a quantitative comparison of the three methods, the valence model, optical model, and shell model with an "exact" calculation including core excitation effects. The Sn28(n,?) reaction is taken as an example which demonstrates that the approximation used for the single particle amplitudes and the omission of core excitation effects are possible sources of error in conventional calculations. Among the conventional procedures we conclude that because of possible external region contributions and its lack of sensitivity to the potential used, the optical model formulation of Lane and Mughabgab represent the most useful alternative.NUCLEAR REACTIONS (?,?) reaction, neutron and ? width correlation.

D. Halderson and B. Castel

1978-09-01T23:59:59.000Z

103

Instruments | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

NScD Careers NScD Careers Supporting Organizations Neutron Science Home | Science & Discovery | Neutron Science | Instruments SHARE Instruments at SNS and HFIR SNS Instrument Name HFIR Instrument Name 1B NOMAD - Nanoscale-Ordered Materials Diffractometer CG-1 Development Beam Line 2 BASIS - Backscattering Spectrometer CG-1D IMAGING - Neutron Imaging Prototype Facility 3 SNAP - Spallation Neutrons and Pressure Diffractometer CG-2 GP-SANS - General-Purpose Small-Angle Neutron Scattering Diffractometer 4A MR - Magnetism Reflectometer CG-3 Bio-SANS - Biological Small-Angle Neutron Scattering Instrument 4B LR - Liquids Reflectometer CG-4C CTAX - Cold Neutron Triple-Axis Spectrometer 5 CNCS - Cold Neutron Chopper Spectrometer HB-1 PTAX - Polarized Triple-Axis Spectrometer

104

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

105

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

106

The Harwell Neutron Project  

Science Journals Connector (OSTI)

... 2 cm. thick, placed on three sides of the neutron booster. A layer of boron-10 metal placed between these tanks and the uranium-235 core prevents return of slow neutrons ...

M. J. POOLE; E. R. RAE

1960-01-30T23:59:59.000Z

107

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

108

Neutrons - 88-Inch Cyclotron  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutrons Neutron beams are available at the 88-Inch Cyclotron. Available energies range of from 8 to 30 MeV, with fluxes of up to 1E8 neutronscm2sec. For more information,...

109

Thermal Neutron Scattering  

Science Journals Connector (OSTI)

... of its title. It is not for the nuclear physicist, nor even for the neutron physicist, but for the student of solids and liquids. "Thermal ... physicist, but for the student of solids and liquids. "Thermal neutron ...

G. E. BACON

1968-11-09T23:59:59.000Z

110

Neutron activation analysis  

Science Journals Connector (OSTI)

Neutron activation analysis (NAA) is an that relies on the measurement of ?-rays emitted from a sample that was irradiated by neutrons. The rate at which ?-rays are emitted from an element in a sample is dir...

James R. Budahn

1998-01-01T23:59:59.000Z

111

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

112

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

113

Neutron scattering and ribosomes  

Science Journals Connector (OSTI)

... the complexity of intra-ribosomal interactions. This is however by no means the case with neutron ...neutronscattering ...

Richard Brimacombe

1977-06-23T23:59:59.000Z

114

More about neutron - mirror neutron oscillation  

E-Print Network (OSTI)

It was pointed out recently that oscillation of the neutron $n$ into mirror neutron $n'$, a sterile twin of the neutron with exactly the same mass, could be a very fast process with the the baryon number violation, even faster than the neutron decay itself. This process is sensitive to the magnetic fields and it could be observed by comparing the neutron lose rates in the UCN storage chambers for different magnetic backgrounds. We calculate the probability of $n-n'$ oscillation in the case when a mirror magnetic field $\\vec{B}'$ is non-zero and show that in this case it can be suppressed or resonantly enhanced by applying the ordinary magnetic field $\\vec{B}$, depending on its strength and on its orientation with respect to $\\vec{B}'$. The recent experimental data, under this hypothesis, still allow the $n-n'$ oscillation time order 1 s or even smaller. Moreover, they indicate that the neutron losses are sensitive to the orientation of the magnetic field. %at about $3\\sigma$ level. If these hints will be confirmed in the future experiments, this would point to the presence of the mirror magnetic field on the Earth of the order of 0.1 G, or some equivalent spin-dependent force of the other origin that makes a difference between the neutron and mirror neutron states.

Zurab Berezhiani

2008-04-13T23:59:59.000Z

115

Neutron removal cross section as a measure of neutron skin  

Science Journals Connector (OSTI)

We study the relation between neutron removal cross section (?-N) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between ?-N and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

D. Q. Fang (???); Y. G. Ma (???); X. Z. Cai (???); W. D. Tian (???); H. W. Wang (???)

2010-04-07T23:59:59.000Z

116

The neutron warhead decision  

Science Journals Connector (OSTI)

The neutron warhead decision ... Nuclear war moved a step closer last week with the U.S.'s decision to move ahead with production of so-called neutron warheads for use on short-range missiles and in artillery shells. ... And neutron weapons would be almost as effective on ... ...

MICHAEL HEYLIN

1981-08-17T23:59:59.000Z

117

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

118

Fast-Neutron Scattering from Germanium  

Science Journals Connector (OSTI)

Elastic and inelastic neutron scattering cross sections of natural germanium were measured in the incident neutron energy range 0.3-1.5 MeV with incident energy resolutions of ?20 keV. Neutron-velocity and ?-ray spectroscopic methods were employed to resolve the scattering to individual low-lying states. The results were interpreted in terms of the optical model and the statistical compound-nucleus model including effects due to fluctuations and correlations of resonance widths. Measured cross sections for inelastic scattering to a number of excited states in even Ge isotopes were reasonably well described by the statistical model of Hauser and Feshbach without corrections for width fluctuations and correlations.

D. Lister and A. B. Smith

1969-07-20T23:59:59.000Z

119

On neutron numbers and atomic masses  

Science Journals Connector (OSTI)

On neutron numbers and atomic masses ... Assigning neutron numbers, correct neutron numbers, and atomic masses and nucleon numbers. ...

R. Heyrovsk

1992-01-01T23:59:59.000Z

120

Colossal Light-Induced Refractive-Index Modulation for Neutrons in Holographic Polymer-Dispersed Liquid Crystals  

SciTech Connect

We report strong diffraction of cold neutrons from an only 30 {mu}m thick holographic polymer-dispersed liquid crystal (H-PDLC) transmission grating. The light-induced refractive-index modulation for neutrons is about 10{sup -6}, i.e., nearly 2 orders of magnitude larger than in the best photo-neutron-refractive materials probed up to now. This makes H-PDLCs a promising candidate for fabricating neutron-optical devices.

Fally, Martin; Ellabban, Mostafa A. [Nonlinear Physics Group, Faculty of Physics, Universitaet Wien, Boltzmanngasse 5, A-1090 Vienna (Austria); Drevensek-Olenik, Irena [Nonlinear Physics Group, Faculty of Physics, Universitaet Wien, Boltzmanngasse 5, A-1090 Vienna (Austria); Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, and J. Stefan Institute, Jamova 39, SI 1001 Ljubljana (Slovenia); Pranzas, Klaus P.; Vollbrandt, Juergen [GKSS Forschungszentrum, D-21502 Geesthacht (Germany)

2006-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Spallation Neutron Source, SNS  

NLE Websites -- All DOE Office Websites (Extended Search)

Spallation Neutron Source Spallation Neutron Source Providing the most intense pulsed neutron beams in the world... Accumulator Ring Commissioning Latest Step for Spallation Neutron Source The Spallation Neutron Source, located at Oak Ridge National Laboratory, has passed another milestone on the way to completion this year--the commissioning of the proton accumulator ring. Brookhaven led the design and construction of the accumulator ring, which will allow an order of magnitude more beam power than any other facility in the world. The Spallation Neutron Source (SNS) is an accelerator-based neutron source being built in Oak Ridge, Tennessee, by the U.S. Department of Energy. The figure on the right shows a schematic of the accumulator ring and transport beam lines that are being designed and built by Brookhaven

122

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.

Wietfeldt, F E

2014-01-01T23:59:59.000Z

123

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

124

Imaging and Neutrons - IAN 2006 - Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS Home Saturday, January 11, 2014 SNS Home Saturday, January 11, 2014 Go IAN 2006 Imaging and Neutrons 2006 October 23-25, 2006 Iran Thomas Auditorium Central Laboratory and Office Building Spallation Neutron Source Oak Ridge National Laboratory, Oak Ridge, TN Who Should Attend Synopsis Goals and Expected Outcomes Application Areas Techniques International Advisory Committee Local Organizing Committee Agenda with Presentations NEW Confirmed Speakers Frequently Asked Questions - FAQ Satellite Workshop - Progress in Electron Volt Neutron Spectroscopy eV Worshop Agenda presentations NEW Lodging, Transportation, Bus Schedule Location Directions and Map Registration CLOSED Abstracts, Posters, Contributed Talks Scholarships Sponsors Vendors May Attend Relevant Reports Important Dates Weather Attractions

125

Optical Fibers Optics and Photonics  

E-Print Network (OSTI)

Optical Fibers Optics and Photonics Dr. Palffy-Muhoray Ines Busuladzic Department of Theoretical and Applied Mathematics The University of Akron April 21, 2008 #12;Outline · History of optical fibers · What are optical fibers? · How are optical fibers made? · Light propagation through optical fibers · Application

Palffy-Muhoray, Peter

126

Neutron-proton mass difference in isospin asymmetric nuclear matter  

E-Print Network (OSTI)

Isospin-breaking effects in the baryonic sector are studied in the framework of a medium-modified Skyrme model. The neutron-proton mass difference in infinite, asymmetric nuclear matter is discussed. In order to describe the influence of the nuclear environment on the skyrmions, we include energy-dependent charged and neutral pion optical potentials in the s- and p-wave channels. The present approach predicts that the neutron-proton mass difference is mainly dictated by its strong part and that it strongly decreases in neutron matter.

Ulf-G. Meiner; A. M. Rakhimov; A. Wirzba; U. T. Yakhshiev

2007-05-24T23:59:59.000Z

127

Compounds for neutron radiation detectors and systems thereof  

DOE Patents (OSTI)

A material according to one embodiment exhibits an optical response signature for neutrons that is different than an optical response signature for gamma rays, said material exhibiting performance comparable to or superior to stilbene in terms of distinguishing neutrons from gamma rays, wherein the material is not stilbene, the material comprising a molecule selected from a group consisting of: two or more benzene rings, one or more benzene rings with a carboxylic acid group, one or more benzene rings with at least one double bound adjacent to said benzene ring, and one or more benzene rings for which at least one atom in the benzene ring is not carbon.

Payne, Stephen A; Stoeffl, Wolfgang; Zaitseva, Natalia P; Cherepy, Nerine J; Carman, M. Leslie

2014-05-27T23:59:59.000Z

128

Cold neutron research facility at the Budapest Neutron Centre  

Science Journals Connector (OSTI)

The new cold neutron research facility has been routinely operated at the Budapest Neutron Centre (BNC) since February 2001. This ... of equipment consists of a liquid hydrogen cold neutron source, an optimised s...

L. Rosta

2002-12-01T23:59:59.000Z

129

Measurement of Thermal Neutron Flux in Photo-Neutron Source  

Science Journals Connector (OSTI)

The Photo-Neutron Source (PNS) project is a study ... design, simulation and construction an accelerator based neutron source for Boron Neutron Capture Therapy (BNCT). The system uses ... medical linear accelerat...

A. Taheri; A. Torkamani; A. Pazirandeh

2013-01-01T23:59:59.000Z

130

Neutron sources and applications  

SciTech Connect

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

131

Spallation Neutron Source  

NLE Websites -- All DOE Office Websites (Extended Search)

D/gim D/gim Spallation Neutron Source SNS is an accelerator-based neutron source. This one-of-a-kind facility pro- vides the most intense pulsed neutron beams in the world. When ramped up to its full beam power of 1.4 MW, SNS will be eight times more powerful than today's best facility. It will give researchers more detailed snapshots of the smallest samples of physical and biological materials than ever before

132

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Industry banner Industry banner Neutron scattering research has applications in practically every field, and neutron research at ORNL is leading to productive partnerships with the industrial and business communities. We welcome proposals for all types of research, including those involving proprietary work. Recent studies have led to discoveries with potential applications in fields such as medicine, energy, and various metals technologies. For more information, please see our recent research highlights. Research Collaborations Industry-Driven Research Benefits Plastics Manufacturing Corning uses VULCAN to test limits of ceramic material for car emission controls, filtration devices Neutrons Probe Inner Workings of Batteries Industry and Neutron Science: Working To Make a Match

133

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

134

Neutron Science Forum | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

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

135

Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

User Office User Program Manager Laura Morris Edwards 865.574.2966 ORNL study uses neutron scattering, supercomputing to demystify forces at play in biofuel production Full...

136

Polarizability of the Neutron  

Science Journals Connector (OSTI)

Experiments on scattering of low-energy neutrons by heavy elements may give information concerning the electric polarizability of the neutron. The relation of the electric polarizability to the low-energy neutron scattering data is developed. One pertinent experiment is discussed and from this an upper bound on the polarizability is obtained. This upper bound to the polarizability ? is an order of magnitude larger than the meson-theoretic estimate of ?. If the value of ? is as small as is predicted by meson theory, or by an analysis of the pion photoproduction data, then it is unlikely to be observed in neutron scattering experiments of the presently achievable accuracy.

R. M. Thaler

1959-05-01T23:59:59.000Z

137

Neutron superfluidity and unusual nuclear shapes in neutron stars crusts  

Science Journals Connector (OSTI)

We calculate in the frame-work of a semiclassical model the neutron superfluidity in the crust of neutron stars, accounting for the presence of unusual....

G. Lazzari; F. V. De Blasio

1994-01-01T23:59:59.000Z

138

Neutron capture cross sections for neutron-rich isotopes  

Science Journals Connector (OSTI)

Average continuum (Hauser-Feshbach) and resonance (Breit-Wigner) neutron capture rates for neutron-rich isotopes, determined on the basis of...

B. Leist; W. Ziegert; M. Wiescher

1985-01-01T23:59:59.000Z

139

Neutron Diffraction Studies of Proteins  

Science Journals Connector (OSTI)

20 November 1980 research-article Neutron Diffraction Studies of Proteins G. A. Bentley S. A. Mason Neutrons interact differently with protein crystals...hydrogen or deuterium atoms diffract neutrons relatively more strongly, but in addition...

1980-01-01T23:59:59.000Z

140

Neutron and Nuclear Science News  

NLE Websites -- All DOE Office Websites (Extended Search)

News Recent news and events related to neutron and nuclear science at LANSCE. Neutron and Nuclear Science News Links Neutron and Nuclear Science News Media Links Profiles Events at...

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Neutron Scattering Methods in Chemistry  

Science Journals Connector (OSTI)

Starting with basic properties of the neutron, this chapter reviews the most important neutron scattering methods that provide valuable information for a ... wide, from standard methods of crystallography to neutron

L. Pusztai

2011-01-01T23:59:59.000Z

142

Superconducting magnetic Wollaston prism for neutron spin encoding  

SciTech Connect

A magnetic Wollaston prism can spatially split a polarized neutron beam into two beams with different neutron spin states, in a manner analogous to an optical Wollaston prism. Such a Wollaston prism can be used to encode the trajectory of neutrons into the Larmor phase associated with their spin degree of freedom. This encoding can be used for neutron phase-contrast radiography and in spin echo scattering angle measurement (SESAME). In this paper, we show that magnetic Wollaston prisms with highly uniform magnetic fields and low Larmor phase aberration can be constructed to preserve neutron polarization using high temperature superconducting (HTS) materials. The Meissner effect of HTS films is used to confine magnetic fields produced electromagnetically by current-carrying HTS tape wound on suitably shaped soft iron pole pieces. The device is cooled to ?30 K by a closed cycle refrigerator, eliminating the need to replenish liquid cryogens and greatly simplifying operation and maintenance. A HTS film ensures that the magnetic field transition within the prism is sharp, well-defined, and planar due to the Meissner effect. The spin transport efficiency across the device was measured to be ?98.5% independent of neutron wavelength and energizing current. The position-dependent Larmor phase of neutron spins was measured at the NIST Center for Neutron Research facility and found to agree well with detailed simulations. The phase varies linearly with horizontal position, as required, and the neutron beam shows little depolarization. Consequently, the device has advantages over existing devices with similar functionality and provides the capability for a large neutron beam (20 mm 30 mm) and an increase in length scales accessible to SESAME to beyond 10 ?m. With further improvements of the external coupling guide field in the prototype device, a larger neutron beam could be employed.

Li, F., E-mail: fankli@indiana.edu; Parnell, S. R.; Wang, T.; Baxter, D. V. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States)] [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Hamilton, W. A. [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)] [Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Maranville, B. B. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)] [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Semerad, R. [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany)] [Ceraco Ceramic Coating GmbH, Ismaning 85737 (Germany); Cremer, J. T. [Adelphi Technology Inc., Redwood City, California 94063 (United States)] [Adelphi Technology Inc., Redwood City, California 94063 (United States); Pynn, R. [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States) [Center for Exploration of Energy and Matter, Indiana University, Bloomington, Indiana 47408 (United States); Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)

2014-05-15T23:59:59.000Z

143

Neutron Diffraction @ TOPAZ  

NLE Websites -- All DOE Office Websites (Extended Search)

Topaz Guide Bender Topaz Guide Bender Neutron Diffraction @ TOPAZ Workshop on Single Crystal Neutron Diffraction picture 2 September 29 - October 1, 2011 * Spallation Neutron Source * Oak Ridge National Laboratory * Oak Ridge TN, USA TOPAZ 2011 Home Contacts Agenda and Important Deadlines Registration and Payment filler Workshop summary and purpose A workshop on single crystal neutron diffraction will be held at the Spallation Neutron Source at the Oak Ridge National Laboratory (ORNL). It will present invited and contributed talks to showcase cutting edge science and examples where neutron diffraction can make significant contributions; and provide training in neutron structure analysis and sample screening for the preparation of instrument beam-time proposals. TOPAZ is a high resolution wavelength-resolved Laue diffractometer with a versatile sample environment. Commissioning user experiments have demonstrated successfully the instrument capability for structural study of a vitamin B12 derivative, ion distribution in Li-ion battery materials, order and disorder in shape memory intermetallics, magnetic phase transition in multiferroic single crystal and functional thin films. The workshop is directed towards experienced neutron diffraction users and new users alike and encourages members to highlight their research and interest in structure analysis and investigation. The workshop will give opportunity to bring your own single crystal and screen sample quality and scattering power on TOPAZ @ room temperature, to evaluate data collection time and quality for an anticipated experiment. Finally, an opportunity to compose a proposal for neutron beam time (http://neutrons.ornl.gov/users/proposals.shtml) with staff will be provided in the framework of the workshop. The workshop format is well suited for researchers to contribute by showcasing their research and bring their research group or graduate student, who would like to test a single crystal sample. User access training for the ORNL neutron scattering facility will be included. It will be valid for future experiments.

144

Neutron activation experiments in radiochemistry  

Science Journals Connector (OSTI)

Neutron activation experiments in radiochemistry ... Describes experimentation involving the neutron activation of a variety of samples irradiated in a subcritical reactor and a paraffin-moderated source. ...

Karl S. Vorres

1960-01-01T23:59:59.000Z

145

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

146

A history of the neutron  

Science Journals Connector (OSTI)

A history of the neutron ... Describes some of the individuals and the work they did leading to the discovery of the neutron. ...

Vasilis Lavrakas

1952-01-01T23:59:59.000Z

147

Neutron and Nuclear Science Publications  

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Publications Recent publications related to neutron and nuclear science at LANSCE. Neutron and Nuclear Science Publications Chi-Nu Publications DANCE Publications GEANIE...

148

Neutron and Nuclear Science News  

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News Recent news and events related to neutron and nuclear science at LANSCE. Neutron and Nuclear Science News Nuclear science observations and opportunities at the Los Alamos...

149

Neutron Science Research Areas | ORNL  

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Home | Science & Discovery | Neutron Science | Research Areas SHARE Research Areas Neutron scattering research at ORNL covers four broad research areas: biology and soft...

150

LANSCE School on Neutron Scattering:  

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11 th LANSCE School on Neutron Scattering: Materials at the Mesoscale Lujan Center Los Alamos Neutron Science Center Los Alamos National Laboratory lansce.lanl.govneutronschool...

151

Advances in specular neutron reflectometry  

Science Journals Connector (OSTI)

Specular neutron reflectometry provides a depth profile of the scattering ... material. To date, numerous productive applications of neutron reflectometry have been demonstrated. With the new development ... stil...

C.F. Majkrzak; N.F. Berk

2002-12-01T23:59:59.000Z

152

NSE: the Neutron Spin Echo Spectrometer at SNS | ORNL Neutron Sciences  

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Spin Echo Spectrometer at SNS Spin Echo Spectrometer at SNS NSE NSE is funded and operated by the Jülich Centre for Neutron Science. The SNS NSE instrument provides ultrahigh resolution spectroscopy with a Fourier time range that covers τ = 1 ps to a nominal 350 ns with a high effective neutron flux, aiming to be the best of its class in both resolution and dynamic range (please refer to the instrument fact sheet for a detailed current status). Researchers use this instrument to investigate soft condensed matter and complex fluids applications in a variety of fields. The planned optional ferromagnetic and intensity-modulated modes will allow for detailed investigation of magnetic samples and phenomena. The design of the NSE spectrometer takes full advantage of recent progress in neutron optics and polarizing supermirror microbenders,1,2 resulting in

153

Category:Neutron Log | Open Energy Information  

Open Energy Info (EERE)

Neutron Log page? For detailed information on Neutron Log, click here. Category:Neutron Log Add.png Add a new Neutron Log Technique Pages in category "Neutron Log" This category...

154

Neutron Capture Therapy  

Science Journals Connector (OSTI)

... . Only those elements which have a high thermal-neutron capture cross-section, such as boron-10, lithium-6, and uranium-235, are useful. This suggestion was first put forward ... was first put forward in 1936 by Locher. The utilization of thermal neutron capture by boron-10 for the treatment of human-brain tumours, chiefly glioblastoma multiforme, has been under investigation ...

1961-09-23T23:59:59.000Z

155

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

156

Neutron calibration facilities  

Science Journals Connector (OSTI)

......shut down. A recent development for a thermal neutron calibration field is a neutron guide used at the research reactor GKSS Geesthacht(35). The result is a high-intensity thermal beam providing a flux of up to 106 s1 with a field size of about 2.5 2......

H. Schuhmacher

2004-08-01T23:59:59.000Z

157

Neutron Scattering Software  

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Software Software A new portal for neutron scattering has just been established at neutronsources.org. The information contained here in the Neutron Scattering Web has been transferred to the new site. We will leave the current content here for archival purposes but no new content will be added. We encourage everyone interested in neutron scattering to take full advantage of this exciting new resource for our community. Neutronsources.org Data Formats NeXus: Neutron and X-ray Data Format Crystallographic Binary Format (CBF/imgCIF) Hierarchical Data Format (HDF) Data Analysis and Visualization Data Analysis for Neutron Scattering Experiments (DANSE): distributed data analysis project Large Array Manipulation Program (LAMP): IDL-based data analysis and visualization

158

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Industry and Neutron Science Industry and Neutron Science Industry and Neutron Science: Working To Make a Match "In fundamental research, we want to know everything. Industry wants to know enough to answer a question." Research Contact: Mike Crawford September 2011, Written by Deborah Counce Mike Crawford and Souleymane Diallo Mike Crawford of Dupont (right) and Souleymane Diallo, instrument scientist for the Backscattering Spectrometer at SNS, prepare a material sample for an experiment on the instrument. Industrial users are starting to eye the potential of neutron science for solving problems that can't be solved in any other way. At the same time, the SNS and HFIR neutron science facilities at ORNL are exploring ways to woo such users and to make a match of it, to the benefit of both.

159

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

160

Structure of the Neutron  

Science Journals Connector (OSTI)

In an earlier paper, the contribution of the meson current to the electromagnetic structure of the nucleon was calculated by use of the dispersion relations for pion-nucleon scattering. Here the contribution of the nucleon current to the electromagnetic structure of the neutron is obtained analogously by use of the dispersion relations for neutron-proton scattering. Only the contribution from the one-pion and two-pion states of nucleon-nucleon scattering is considered. It is found that both states reduce the neutron-electron potential, i.e., leads to a smaller charge radius of the neutron. The contribution from the deuteron state is shown to be negligible. The resulting mean-square radii of the neutron, including the contributions of both meson and nucleon current, are (0.2310-13cm)2 for the charge distribution and (0.4110-13cm)2 for the magnetic moment distribution with f2=0.08.

Katsumi Tanaka

1959-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect

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

162

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect

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

KOETZLE,T.F.

2001-03-13T23:59:59.000Z

163

Demonstration of achromatic cold-neutron microscope utilizing axisymmetric focusing mirrors  

SciTech Connect

An achromatic cold-neutron microscope with magnification 4 is demonstrated. The image-forming optics is composed of nested coaxial mirrors of full figures of revolution, so-called Wolter optics. The spatial resolution, field of view, and depth of focus are measured and found consistent with ray-tracing simulations. Methods of increasing the resolution and magnification are discussed, as well as the scientific case for the neutron microscope. In contrast to traditional pinhole-camera neutron imaging, the resolution of the microscope is determined by the mirrors rather than by the collimation of the beam, leading to possible dramatic improvements in the signal rate and resolution.

Liu, D.; Khaykovich, B. [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States)] [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States); Hussey, D.; Jacobson, D.; Arif, M. [Physical Measurement Laboratory, NIST, Gaithersburg, Maryland 20899-8461 (United States)] [Physical Measurement Laboratory, NIST, Gaithersburg, Maryland 20899-8461 (United States); Gubarev, M. V.; Ramsey, B. D. [Marshall Space Flight Center, NASA, VP62, Huntsville, Alabama 35812 (United States)] [Marshall Space Flight Center, NASA, VP62, Huntsville, Alabama 35812 (United States); Moncton, D. E. [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States) [Nuclear Reactor Laboratory, Massachusetts Institute of Technology, 138 Albany St., Cambridge, Massachusetts 02139 (United States); Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)

2013-05-06T23:59:59.000Z

164

OPTICS5  

NLE Websites -- All DOE Office Websites (Extended Search)

Optics5 (5.1.02) Knowledge Base Optics5 (5.1.02) Knowledge Base Last Updated: 09/11/13 Table of Contents INSTALLATION EXECUTION bullet ** Operating Systems -- Microsoft Windows 7 and Vista ** bullet ** Running Optics5 with Microsoft Windows 7 and Vista ** bullet ** Running Optics5 with Microsoft Windows 7 and Vista 64 bit ** Optics5 may not work correctly with regional/locale settings using "," as a decimal separator. bullet Which Windows operating systems can be used to run Optics? "Class Does Not Support Automation or Expected Interface" error message bullet How much hard disk space should be available to install Optics? Optics user manual bullet I receive a virus warning (nimda-virus) when installing Optics. What should I do? NFRC Procedure for Applied Films bullet I have installed Optics but I can't find the program or the icon.

165

Anisotropic thermal emission from magnetized neutron stars  

E-Print Network (OSTI)

The thermal emission from isolated neutron stars is not well understood. The X-ray spectrum is very close to a blackbody but there is a systematic optical excess flux with respect to the extrapolation to low energy of the best blackbody fit. This fact, in combination with the observed pulsations in the X-ray flux, can be explained by anisotropies in the surface temperature distribution.We study the thermal emission from neutron stars with strong magnetic fields in order to explain the origin of the anisotropy. We find (numerically) stationary solutions in axial symmetry of the heat transportequations in the neutron star crust and the condensed envelope. The anisotropy in the conductivity tensor is included consistently. The presence of magnetic fields of the expected strength leads to anisotropy in the surface temperature. Models with toroidal components similar to or larger than the poloidal field reproduce qualitatively the observed spectral properties and variability of isolated neutron stars. Our models also predict spectral features at energies between 0.2 and 0.6 keV.

J. F. Perez-Azorin; J. A. Miralles; J. A. Pons

2005-10-24T23:59:59.000Z

166

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

167

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

168

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

PartTec PartTec ORNL, PartTec Inc. Licensing Agreement ORNL and PartTec sign licensing agreement (Front) ORNL Deputy Director for Science & Technology Thomas Zacharia and PartTec CEO Herschel Workman. (Back) Bruce Hannan (SNS), PartTec production manager Craig Kline, Rick Riedel (SNS), Jason Hodges (SNS) and Ron Cooper (SNS). The SNS guys were on the development team. Representatives from Oak Ridge National Laboratory and PartTec, an Indiana-based firm, formally signed a licensing agreement Thursday, Aug. 12, to market an advanced neutron detector system developed for the Spallation Neutron Source. The Shifting Scintillator Neutron Detector can determine the time and position of captured neutrons, which enables researchers to obtain very accurate time-of-flight measurements.

169

Education | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Education banner Education banner Sunil Sinha A Chat with Sunil Sinha, Distinguished Professor of Physics at the University of California-San Diego and speaker at the recent CNMS-SNS Research Forum more... The purpose of the Spallation Neutron Source and the High Flux Isotope Reactor is to facilitate neutron scattering as an integral tool for scientific research and technological development across many scientific and engineering domains within the scientific, academic,and industrial communities. Coupled with this role is a recognized need to inspire, educate, and facilitate the next generation of users and hence foster enhanced use of the unique neutron scattering facilities at ORNL. This is the central theme of the education activities within the Neutron Sciences Directorate (NScD).

170

ORNL Neutron Sciences Instruments  

NLE Websites -- All DOE Office Websites (Extended Search)

Instruments banner Instruments banner ORNL Neutron Sciences Instruments SNS and HFIR provide researchers with two complementary world-class suites of neutron scattering instruments and beam lines. All the instruments are supported by a variety of sample environments and data analysis and visualization capabilities. Before submitting a proposal for a specific instrument, please contact the appropriate instrument scientist to make sure your research is feasible for that instrument. Instruments Currently Available to Users SNS Beam Line Instrument Name HFIR Beam Line Instrument Name 1B NOMAD Nanoscale-Ordered Materials Diffractometer CG-1 Development Beam Line 2 BASIS Backscattering Spectrometer CG-1D IMAGING Neutron Imaging Prototype Facility 3 SNAP Spallation Neutrons and Pressure Diffractometer CG-2 GP-SANS

171

Pulsed Neutron Powder Diffraction  

Science Journals Connector (OSTI)

The nature and scope of powder diffraction with a white, pulsed beam of neutrons is discussed. Analysis of the data by the Rietveld profile technique is described in brief, and a range of applications in solid...

A. K. Cheetham

1988-01-01T23:59:59.000Z

172

Neutron Science Center  

NLE Websites -- All DOE Office Websites (Extended Search)

to have rare opportunity to tour Neutron Science Center May 10, 2011 LANL Rosenfest will celebrate life of LANSCE founder Louis Rosen and offer tour LOS ALAMOS, New Mexico, May 10,...

173

Scattering of Slow Neutrons  

Science Journals Connector (OSTI)

1 September 1937 research-article Scattering of Slow Neutrons M. Goldhaber G. H. Briggs The Royal Society is collaborating with JSTOR to digitize, preserve, and extend access to Proceedings...

1937-01-01T23:59:59.000Z

174

Neutron Diffraction Texture Analysis  

Science Journals Connector (OSTI)

...conducted at Chalk River (Canada), Geesthacht (Germany), LLB (France) and NIST...deformed limestone that was measured at Geesthacht with this method. It is also possible...with monochromatic neutrons at GKSS, Geesthacht. Equal area projection, linear contours...

Hans-Rudolf Wenk

175

Neutron stars - thermal emitters  

E-Print Network (OSTI)

Confronting theoretical models with observations of thermal radiation emitted by neutron stars is one of the most important ways to understand the properties of both, superdense matter in the interiors of the neutron stars and dense magnetized plasmas in their outer layers. Here we review the theory of thermal emission from the surface layers of strongly magnetized neutron stars, and the main properties of the observational data. In particular, we focus on the nearby sources for which a clear thermal component has been detected, without being contaminated by other emission processes (magnetosphere, accretion, nebulae). We also discuss the applications of the modern theoretical models of the formation of spectra of strongly magnetized neutron stars to the observed thermally emitting objects.

Potekhin, A Y; Pons, J A

2014-01-01T23:59:59.000Z

176

Clifford G. Shull, Neutron Diffraction, Hydrogen Atoms, and Neutron  

Office of Scientific and Technical Information (OSTI)

Clifford Shull, Neutron Diffraction, and Neutron Scattering Clifford Shull, Neutron Diffraction, and Neutron Scattering Resources with Additional Information Clifford G. Shull was awarded the 1994 Nobel Prize in Physics "for the development of the neutron diffraction technique". 'Professor Shull's prize was awarded for his pioneering work in neutron scattering, a technique that reveals where atoms are within a material like ricocheting bullets reveal where obstacles are in the dark. Clifford Shull Photo Courtesy of Oak Ridge National Laboratory When a beam of neutrons is directed at a given material, the neutrons bounce off, or are scattered by, atoms in the sample being investigated. The neutrons' directions change, depending on the location of the atoms they hit, and a diffraction pattern of the atoms' positions can then be obtained.

177

Data Analysis & Visualization | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Data Analysis and Visualization SHARE Neutron Data Analysis and Visualization As the data sets generated by the increasingly powerful neutron scattering instruments at HFIR...

178

Science Education Programs | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

with Neutrons Graduate & Post-doctoral Programs Student & Teacher Programs Science Forum Neutron Scattering Tutorials Kids' Corner NScD Careers Supporting Organizations Neutron...

179

Fast Pulsing Neutron Generators for Security Application  

E-Print Network (OSTI)

FAST PULSING NEUTRON GENERATORS FOR SECURITY APPLICATION* Q.time/fast pulsing neutron generator is needed primarily forA compact neutron generator, currently being developed in

Ji, Q.

2010-01-01T23:59:59.000Z

180

Leading neutron spectra  

E-Print Network (OSTI)

It is shown that the observation of the spectra of leading neutrons from proton beams can be a good probe of absorptive and migration effects. We quantify how these effects modify the Reggeized pion-exchange description of the measurements of leading neutrons at HERA. We are able to obtain a satisfactory description of all the features of these data. We also briefly discuss the corresponding data for leading baryons produced in hadron-hadron collisions.

A. B. Kaidalov; V. A. Khoze; A. D. Martin; M. G. Ryskin

2006-02-23T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Probing Matter Radii of Neutron-Rich Nuclei by Antiproton Scattering  

E-Print Network (OSTI)

We propose to use antiprotons to investigate the sizes of stable and neutron-rich exotic nuclei by measurements of the $\\pbar A$ absorption cross section along isotopic chains in inverse kinematics. The expected effects are studied theoretically in a microscopic model. The $\\pbar U$ optical potentials are obtained by folding free space $\\pbar N$ scattering amplitudes with HFB ground state densities and solving the scattering equations by direct integration. The mass dependence of absorption cross sections is found to follow closely the nuclear root-mean-square radii. The total absorption cross section is shown to be a superposition of cross sections describing partial absorption on neutrons and protons, respectively. Thus measuring the differential cross sections for absorption on neutrons and protons will give information on their respective distributions. In neutron-rich nuclei the outer neutron layer shields the absorption on the protons giving access to investigations of antiproton-neutron interactions in matter.

H. Lenske; P. Kienle

2005-02-21T23:59:59.000Z

182

MAGNETIC NEUTRON SCATTERING  

SciTech Connect

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

183

Nonimaging Optics  

Science Journals Connector (OSTI)

The nonimaging optical system, by definition, does not produce an image of the light source. Instead, it is designed to concentrate radiation at a density as high as theoretically possible. Nonimaging optics h...

Dr. Ralf Leutz; Dr. Akio Suzuki

2001-01-01T23:59:59.000Z

184

Optical Switch  

NLE Websites -- All DOE Office Websites (Extended Search)

seven wonders Optical Switch A key component in the laser chain, an optical switch called a plasma electrode Pockels cell (PEPC), was invented and developed at LLNL. A Pockels cell...

185

Neutron Radii in Nuclei and the Neutron Equation of State  

Science Journals Connector (OSTI)

The root-mean-square radius for neutrons in nuclei is investigated in the Skyrme Hartree-Fock model. The main source of theoretical variation comes from the exchange part of the density-dependent interaction which can be related to a basic property of the neutron equation of state. A precise measurement of the neutron radius in 208Pb would place an important new constraint on the equation of state for neutron matter. The Friedman-Pandharipande neutron equation of state would lead to a very precise value of 0.160.02 fm for the difference between the neutron and the proton root-mean-square radius in 208Pb.

B. Alex Brown

2000-12-18T23:59:59.000Z

186

Off-specular scattering in neutron reflectometry  

SciTech Connect

When neutrons are scattered at small angles from planar, laterally homogeneous, stratified media, only specular (mirror like) reflection is observed. Sample inhomogeneities, such as interfacial roughness or voids, give rise to off-specular scattering which has been observed in many experiments with neutrons and x-rays. The easiest way to describe this scattering theoretically is based on the distorted-wave Born approximation (DWBA), which uses the neutron wavefunctions that describe reflection from a smooth surface as the basis functions for perturbation theory. From the DWBA one may obtain a number of qualitative results which are supported by experiment. Examples include the Yoneda fringes observed in reflection experiments with microscopically rough surfaces and the constant-q{sub z} fringes observed for multilayers with correlated, rough interfaces. One must, however, use the DWBA with care. When the correlation range within the reflecting interfaces is large--for example, when a surface is composed of misoriented facets--the approximation breaks down. Some authors have also reported a lack of quantitative agreement between versions of the DWBA calculations and the scattering observed with microscopically rough surfaces. A remarkable feature of neutron (or x-ray) reflectometry is the length scales that are probed within reflecting surfaces. These range from a few hundred Angstroms up to several microns, allowing neutron scattering to probe objects of a size normally visible by optical microscopy! The intent of this paper is to provide a simple description of scattering from rough surfaces that is accessible to a wide audience. Mathematical completeness is sacrificed in favor of intuitive arguments and experimental examples.

Pynn, R.; Baker, S.M.; Smith, G.; Fitzsimmons, M. [Los Alamos National Lab., NM (United States). Manuel Lujan Jr. Neutron Scattering Center

1995-03-01T23:59:59.000Z

187

Device for Writing the Time Tail from Spallation Neutron Pulses  

SciTech Connect

Recent work at Los Alamos Neutron Science Center (LANSCE), has shown that there are large gains in neutron beam intensity to be made by using coupled moderators at spallation neutron sources. Most of these gains result from broadening the pulse-width in time. However the accompanying longer exponential tail at large emission times can be a problem in that it introduces relatively large beam-related backgrounds at high resolutions. We have designed a device that can reshape the moderated neutron beam by cutting the time-tail so that a sharp time resolution can be re-established without a significant loss in intensity. In this work the basic principles behind the tail-cutter and some initial results of Monte Carlo simulations are described. Unwanted neutrons in the long time-tail are diffracted out of the transmitted neutron beam by a nested stack of aperiodic multi-layers, rocking at the same frequency as the source. Nested aperiodic multi-layers have recently been used at X-ray sources and as band-pass filters in quasi-Laue neutron experiments at reactor neutron sources. Optical devices that rock in synchronization with a pulsed neutron beam are relatively new but are already under construction at LANSCE. The tail-cutter described here is a novel concept that uses existing multi-layer technology in a new way for spallation neutrons. Coupled moderators in combination with beam shaping devices offer the means of increasing flux whilst maintaining a sharp time distribution. A prototype device is being constructed for the protein crystallography station at LANSCE. The protein crystallography station incorporates a water moderator that has been judiciously coupled in order to increase the flux over neutron energies that are important to structural biology (3-80meV). This development in moderator design is particularly important because protein crystallography is flux limited and because conventional ambient water and cold hydrogen moderators do not provide relatively large neutron fluxes over this neutron energy range.

Langan, P. (Paul); Schoenborn, Benno P.; Langan, P. (Paul); Schoenborn, Benno P.; Daemen, L. L. (Luc L.)

2001-01-01T23:59:59.000Z

188

Multiwavelength Phenomenology of Isolated Neutron Stars  

E-Print Network (OSTI)

After reviewing the multifrequency behaviour of the Isolated Neutron Stars detected so far, we analyze for each object the efficiency of conversion of the star's rotational energy loss into optical, X and gamma radiation. Although the number of pulsars detected at different wavelengths is rather limited, a pattern is seen to emerge from our analysis pointing towards the period derivative as the leading parameter to describe the multifrequency emission of INS. One object in particular, PSR 1509-58, stands out as archetypal for the Pdot-dependence of its luminosity at different wavelengths.

P. Goldoni; C. Musso; P. A. Caraveo; G. F. Bignami

1995-02-07T23:59:59.000Z

189

Neutron-Neutron Scattering at Low Energies  

Science Journals Connector (OSTI)

This paper investigates the information contained in a neutron-neutron scattering experiment at low energies which could be performed by colliding beams coming from an underground nuclear explosion. The significance of such an experiment is discussed from the point of view of a check on charge symmetry and charge independence, and it is found that because of the electromagnetic complications in proton-proton scattering, and because of the proton-neutron mass difference, the knowledge of neutron-neutron scattering would be of considerable value. The functional form of the experimental data which is most convenient for analysis and the approximate relative magnitude of the terms is investigated, and it is concluded that for the kind of experiment which is envisaged (measuring cross sections to 10% from 20 keV to 2 MeV) only two parameters should be kept in the effective-range expansion. The connection between the number and distribution of energies at which the cross section is measured and the error on the individual measurements, on the one hand, and the accuracy of the effective-range parameters deduced from the experiments, on the other, is given explicitly and is found also to depend on the absolute magnitude of the scattering length. The results show that ten 10% measurements, suitably distributed between 20 keV and 2 MeV, can determine the sign of the scattering length to four standard deviations, the magnitude of the effective range to 50-70%, and the magnitude of the scattering length to about 3%. Finally, the relationship between the variation of the effective-range parameters and the corresponding variation in the parameters of the scattering potential is studied, and it is found that, while this relationship is strongly shape-dependent, a small change in the potential parameters, in any case, results in a large change in the scattering length, but a small one in the effective range. Numerical relationships show that, even in the worst case, the variation in the scattering length is about eight times the variation in the potential parameter. It is concluded that a 10% experiment at 20 energies between 20 keV and 2 MeV would be able to get information on the potential parameters sufficiently accurately so that charge-dependent or charge-symmetry violating effects could be detected.

Michael J. Moravcsik

1964-11-09T23:59:59.000Z

190

Neutron degeneracy and plasma physics effects on radiative neutron captures in neutron star crust  

Science Journals Connector (OSTI)

We consider the astrophysical reaction rates for radiative neutron capture reactions (n,?) in the crust of a neutron star. The presence of degenerate neutrons at high densities (mainly in the inner crust) can drastically affect the reaction rates. Standard rates assuming a Maxwell-Boltzmann distribution for neutrons can underestimate the rates by several orders of magnitude. We derive simple analytical expressions for reaction rates at a variety of conditions with account for neutron degeneracy. We also discuss the plasma effects on the outgoing radiative transition channel in neutron radiative capture reactions and show that these effects can also increase the reaction rates by a few orders of magnitude. In addition, using detailed balance, we analyze the effects of neutron degeneracy and plasma physics on reverse (?,n) photodisintegration. We discuss the dependence of the reaction rates on temperature and neutron chemical potential and outline the efficiency of these reactions in the neutron star crust.

P. S. Shternin; M. Beard; M. Wiescher; D. G. Yakovlev

2012-07-24T23:59:59.000Z

191

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

SciTech Connect

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

192

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

193

Neutron skin of nuclei near the neutron drip line  

Science Journals Connector (OSTI)

Performing Skyrme-type deformed Hartree-Fock calculations, the possible presence of neutron skin in nuclei towards neutron drip line is studied. The thickness of the neutron skin is found to be nearly constant in all directions if it is measured perpendicular to the surface, and in a given nucleus the number of neutrons being inside of the neutron skin is almost independent of the deformation (namely, spherical shape or normal deformation or superdeformation). In the region of medium-heavy nuclei our calculation shows the presence of a series of neutron-rich nuclei, in which a neutron skin is present and yet the neutron one-particle spectra are far from those in a harmonic oscillator (plus spin-orbit) potential.

I. Hamamoto and X. Z. Zhang

1995-11-01T23:59:59.000Z

194

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

SciTech Connect

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

195

Neutron Scattering Instrumentation for Biology at Spallation Neutron Sources  

Science Journals Connector (OSTI)

Conventional wisdom holds that since biological entities are large, they must be studied with cold neutrons, a domain in which reactor sources of neutrons are often supposed to be pre-eminent. ... fact, the curre...

Roger Pynn

1996-01-01T23:59:59.000Z

196

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

197

The neutron identified: Sir James Chadwick  

Science Journals Connector (OSTI)

The neutron identified: Sir James Chadwick ... Uses source material to describe the discovery of the neutron by James Chadwick. ...

Alfred B. Garrett

1962-01-01T23:59:59.000Z

198

Portable Neutron Sensors for Emergency Response Operations  

SciTech Connect

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

199

High-Efficiency Resonant RF Spin Rotator with Broad Phase Space Acceptance for Pulsed Polarized Cold Neutron Beams  

E-Print Network (OSTI)

We have developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to RF neutron spin flippers based on adiabatic fast passage. The spin rotator does not change the kinetic energy of the neutrons and leaves the neutron beam phase space unchanged to high precision. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically-polarized 3He neutron spin filters. The efficiency of the spin rotator was measured to be 98.0+/-0.8% on resonance for neutron energies from 3.3 to 18.4 meV over the full phase space of the beam. As an example of the application of this device to an experiment we describe the integration of the RF spin rotator into an apparatus to search for the small parity-violating asymmetry A_gamma in polarized cold neutron capture on para-hydrogen by the NPDGamma collaboration at LANSCE.

P. -N. Seo; L. Barron-Palos; J. D. Bowman; T. E. Chupp; C. Crawford; M. Dabaghyan; M. Dawkins; S. J. Freedman; T. Gentile; M. T. Gericke; R. C. Gillis; G. L. Greene; F. W. Hersman; G. L. Jones; M. Kandes; S. Lamoreaux; B. Lauss; M. B. Leuschner; R. Mahurin; M. Mason; J. Mei; G. S. Mitchell; H. Nann; S. A. Page; S. I. Penttila; W. D. Ramsay; A. Salas Bacci; S. Santra; M. Sharma; T. B. Smith; W. M. Snow; W. S. Wilburn; H. Zhu

2007-10-15T23:59:59.000Z

200

Neutron scattering above 25 MeV with monoenergetic neutrons  

Science Journals Connector (OSTI)

Technical problems encountered in measuring elastic and inelastic neutron scattering at kinetic energies well above 25 MeV are considered by extrapolating from experience with lower energy neutrons. It is concluded that all of the techniques required for a high?quality systematic study of neutron scatteringwith the notable exception of a suitable accelerator facilityare at hand.

Roger W. Finlay

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" from the National Library of EnergyBeta (NLEBeta).
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201

Sandia Neutron Detector Is Based on Polyacetylene  

Science Journals Connector (OSTI)

Sandia Neutron Detector Is Based on Polyacetylene ... It also might form the basis of an electrically readable dosimeter that records neutron flux (measured as neutrons per square centimeter) as well as a detector that could provide a cross-sectional image of neutron flux with high spatial resolution. ... Hence, most neutron detectors use a converter material that converts the neutrons to charged particles. ...

RUDY BAUM

1987-02-09T23:59:59.000Z

202

Neutron Science | More Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

ORNL's long history of neutron science began in the 1940s with the pioneering neutron scattering studies of Ernest Wollan and Clifford Shull. Shull was co-recipient of...

203

High flux compact neutron generators  

E-Print Network (OSTI)

High Flux Compact Neutron Generators J. Reijonen ,1 , T-Compact high flux neutron generators are developed at thevoltage feed through of the generator is shown in Fig. 4.

Reijonen, J.; Lou, T.-P.; Tolmachoff, B.; Leung, K.-N.; Verbeke, J.; Vujic, J.

2001-01-01T23:59:59.000Z

204

Neutron Scattering Conference Archive  

NLE Websites -- All DOE Office Websites (Extended Search)

Conference Archive Conference Archive A new portal for neutron scattering has just been established at neutronsources.org. The information contained here in the Neutron Scattering Web has been transferred to the new site. We will leave the current content here for archival purposes but no new content will be added. We encourage everyone interested in neutron scattering to take full advantage of this exciting new resource for our community. Neutronsources.org 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 2000 June 12-14, 2000 Workshop on "New Opportunities for Better User Group Software (NOBUGS III)" Location Daresbury Laboratory, Cheshire, UK Contact Mark Enderby, Daresbury Laboratory Email M.J.Enderby@dl.ac.uk URL http://nobugs.dl.ac.uk/

205

Industry - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Former User Group Chair Enthusiastic About Relevance of Neutron Scattering Former User Group Chair Enthusiastic About Relevance of Neutron Scattering to Industrial Research Former User Group Chair Mike Crawford Mike Crawford, DuPont Research and Development. The drive is intensifying to encourage research partnerships between Neutron Sciences and private industry. Such partnerships, a long-term strategic goal set by the DOE's Basic Energy Sciences Advisory Committee, will deliver industry and its technological problems to SNS and HFIR, where joint laboratory-industry teams can use the unparalleled resources available here to resolve them. "SNS is a tremendous facility. It has the potential to have a couple of thousand user visits a year and, if they build another target station in the future, you're probably talking about 4000 user visits a year,"

206

Contacts | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Science Points of Contact Science Points of Contact Name Research Area Doug Abernathy Wide Angular-Range Chopper Spectrometer (ARCS). Atomic-scale dynamics at thermal and epithermal energies Ke An Engineering Materials Diffractometer (VULCAN). Residual stress, deformation mechanism of materials, phase transitions/transformation, and in situ/operando neutron diffraction in material systems (e.g., working batteries). John Ankner Liquids Reflectometer (LR). Density profiles normal to the surface at liquid surfaces and liquid interfaces Bryan Chakoumakos Nuclear and magnetic crystal structure systematics and structure-property relationships among inorganic materials, powder and single-crystal neutron and x-ray diffraction methods Leighton Coates Macromolecular Neutron Diffractometer (MaNDi). Protein crystallography, biological structure and function

207

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

208

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

209

Cooling of neutron stars  

Science Journals Connector (OSTI)

On the basis of current physical understanding, it is impossible to predict with confidence the interior constitution of neutron stars. Cooling of neutron stars provides a possible way of discriminating among possible states of matter within them. In the standard picture of cooling by neutrino emission developed over the past quarter of a century, neutron stars are expected to cool relatively slowly if their cores are made up of nucleons, and to cool faster if matter is in an exotic state, such as a pion condensate, a kaon condensate, or quark matter. This view has recently been called into question by the discovery of a number of other processes that could lead to copious neutrino emission and rapid cooling.

C. J. Pethick

1992-10-01T23:59:59.000Z

210

Ultrafast neutron detector  

DOE Patents (OSTI)

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

Wang, Ching L. (Livermore, CA)

1987-01-01T23:59:59.000Z

211

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

212

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

213

Passive Neutron Detection at Borders  

SciTech Connect

Radiation portal monitor systems have been deployed to screen for illicit trafficking of radioactive materials at international border crossings. This report reviews some of the neutron detection requirements and capabilities of passive detection systems used for such applications. Simulations show the effects of cargo materials on neutron spectra, different detector geometries, using a large-array of neutron detectors, and the effects of backgrounds including ship effect neutrons.

Kouzes, Richard T.; Siciliano, Edward R.; Ely, James H.; Keller, Paul E.; McConn, Ronald J.

2008-03-01T23:59:59.000Z

214

Inelastic Neutron Scattering Instrumentation  

Science Journals Connector (OSTI)

Abstract Inelastic neutron scattering spectroscopy spans an enormous energy range, which is equivalent to a wide range of timescales. It is convenient to divide the whole energy range into three sectors, while recognising that there is significant overlap between them. In the lowest energy range, 10meV the applications are principally quasielastic scattering and tunneling spectroscopy. The second range, 01000meV covers the regions of vibrational spectroscopy and magnetic excitations. The highest range above 1000meV is the province of neutron Compton scattering. The instrumentation used in each of these energy regimes is described.

S.F. Parker

2014-01-01T23:59:59.000Z

215

Neutron Bombardment of Counting Diamonds  

Science Journals Connector (OSTI)

21 February 1956 research-article Neutron Bombardment of Counting Diamonds A. H...Examination was also made of the effect of neutron bombardment on pulse-height distribution...additional charge traps produced by the neutrons. The layered crystal texture disclosed...

1956-01-01T23:59:59.000Z

216

NOTES ON NEUTRON DEPTH PROFILING  

E-Print Network (OSTI)

NOTES ON NEUTRON DEPTH PROFILING by J.K. Shultis Department of Mechanical and Nuclear Engineering College of Engineering Kansas State University Manhattan, Kansas 66506 Dec. 2003 #12;Notes on Neutron Depth Profiling J. Kenneth Shultis December 2003 1 Introduction The purpose of neutron depth profiling

Shultis, J. Kenneth

217

Neutron - Mirror Neutron Oscillations: How Fast Might They Be?  

E-Print Network (OSTI)

We discuss the phenomenological implications of the neutron (n) oscillation into the mirror neutron (n'), a hypothetical particle exactly degenerate in mass with the neutron but sterile to normal matter. We show that the present experimental data allow a maximal n-n' oscillation in vacuum with a characteristic time $\\tau$ much shorter than the neutron lifetime, in fact as small as 1 sec. This phenomenon may manifest in neutron disappearance and regeneration experiments perfectly accessible to present experimental capabilities and may also have interesting astrophysical consequences, in particular for the propagation of ultra high energy cosmic rays.

Zurab Berezhiani; Luis Bento

2005-07-03T23:59:59.000Z

218

Scission neutron emission and prompt fission neutron spectrum  

E-Print Network (OSTI)

The mass, energy and angular integrated spectra of prompt fission neutrons for sup 2 sup 3 sup 5 U induced fission in the energy range from thermal to 5 MeV were analyzed. It allows assume that about 0.362+-0.025 neutrons per fission are emitted due to another mechanism then neutron emission from excited fragments after full acceleration. The spectrum of scission neutrons consists of two components with average energy 0.98 MeV and 2.74 MeV. The share of scission neutrons and their spectrum shape estimated in this work does not contradict to results of differential experiments analyzed in previous papers.

Kornilov, N V

2001-01-01T23:59:59.000Z

219

OPTICS 5  

NLE Websites -- All DOE Office Websites (Extended Search)

OPTICS (Version 5.1.02) OPTICS (Version 5.1.02) Release notes NOTE: See the Optics Knowledge Base for how to run this version of Optics on the Microsoft Vista and Microsoft Windows 7 operating systems March 5, 2003: Release Maintenance Pack 2 New ! January 7, 2003: Release Maintenance Pack 1 October 23, 2002: Release Optics 5.1.01 September 27, 2002: Release Optics 5.1.00 (only released on CDs at NFRC Annual Fall Meeting) Release notes Maintenance Pack 2 Bug fixes: New features: bullet Applied films that were created could not be saved or exported. This has been fixed. bullet Exporting glazing systems generated a message that the operation failed because the glazing system type is unknown. Glazing systems can now be exported to file (e.g. to view the spectral data), but the structure information will be lost.

220

Apparent Neutron Emissions from Polyethylene Capsules during Neutron Activation and Delayed Neutron Counting  

Science Journals Connector (OSTI)

At Imperial College uranium is determined at very low levels in environmental samples by delayed neutron counting. High density polyethylene capsules are used ... transfer system, from the reactor, to the neutron

R. Benzing; N. M. Baghini; B. A. Bennett

2000-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Optical Magnetism  

Science Journals Connector (OSTI)

Magnetic dipole radiation one fourth as intense as electric dipole radiation, as well as a novel nonlinear magneto-optical effect are reported in dielectric media.

Oliveira, Samuel L; Rand, Stephen C

222

Optics and Diagnostics  

NLE Websites -- All DOE Office Websites (Extended Search)

8 14 | Next | Last Back to Index Neutron Activation Target area operator removes the reentrant well Neutron Activation Diagnostic (NAD) from the target chamber. Photo Number:...

223

SciTech Connect: 2010 Neutron Review: ORNL Neutron Sciences Progress...  

Office of Scientific and Technical Information (OSTI)

117; GREENHOUSE GASES; HEAVY ION ACCELERATORS; HELIUM 3; HFIR REACTOR; IRON; JINR; MAGNETIC FIELDS; NEUTRON DETECTORS; NEUTRON SOURCES; NEUTRONS; ORNL; RELIABILITY;...

224

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

225

Proton-Neutron Scattering  

Science Journals Connector (OSTI)

Using Glauber multiple-scattering theory, the missing-mass spectrum for protons scattered off a deuterium target is computed. The relatively clean separation of the single- and double-scattering peaks offers the possibility of determining the high-energy proton-neutron differential cross section.

N. Straumann and C. Wilkin

1970-03-02T23:59:59.000Z

226

Optimization of neutron source  

SciTech Connect

I consider here the optimization of the two component neutron source, allowing beam species and energy to vary. A simple model is developed, based on the earlier publications, that permits the optimum to be obtained simply. The two component plasma, with one species of hot ion (D{sup +} or T{sup +}) and the complementary species of cold ion, is easy to analyze in the case of a spatially uniform cold plasma, as to good approximation the total number of hot ions is important but not their spatial distribution. Consequently, the optimization can ignore spatial effects. The problem of a plasma with both types of hot ions and cold ions is rather more difficult, as the neutron production by hot-hot interactions is sensitive to their spatial distributions. Consequently, consideration of this problem will be delayed to a future memorandum. The basic model is that used in the published articles on the two-component, beam-plasma mirror source. I integrate the Fokker-Planck equation analytically, obtaining good agreement with previous numerical results. This simplifies the optimization, by providing a functional form for the neutron production. The primary result is expressed in terms of the power efficiency: watts of neutrons/watts of primary power. The latter includes the positive ion neutralization efficiency. At 150 keV, the present model obtains an efficiency of 0.66%, compared with 0.53% of the earlier calculation.

Hooper, E.B.

1993-11-09T23:59:59.000Z

227

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

228

Ramsey Experiments Using Neutron Beams  

Science Journals Connector (OSTI)

Abstract Ramsey's technique of separated oscillatory fields adapted to cold neutron beams is a very sensitive method to probe for spin- dependent interactions of neutrons with magnetic and pseudomagnetic fields. In the last couple of years several distinctive experiments using this technique have been performed, e.g. to determine the incoherent neutron scattering length of the deuteron, to perform polarized neutron imaging of magnetic fields and samples, and lately, to search for new light spin-1 bosons. Here, some of these results are reviewed and possible future measurements with respect to a pulsed neutron source are presented.

Florian M. Piegsa

2014-01-01T23:59:59.000Z

229

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

230

Optical Expanders with Applications in Optical Computing  

E-Print Network (OSTI)

Optical Expanders with Applications in Optical Computing John H. Reif Akitoshi Yoshida July 20, 1999 Abstract We describe and investigate an optical system which we call an optical expander. An optical expander elec- trooptically expands an optical boolean pattern encoded in d bits into an optical

Reif, John H.

231

Kaon Condensation in a Neutron Star under Strong Magnetic Fields by Using the Modified Quark-meson Coupling Model  

E-Print Network (OSTI)

We have considered the antikaon condensation in a neutron star in the presence of strong magnetic fields by using the modified quark-meson coupling (MQMC) model. The structure of the neutron star is investigated with various magnetic fields and different kaon optical potentials, and the effects of the magnetic fields for kaon condensation is discussed. When employing strong magnetic fields inside a neutron star with hyperons and kaon condensation, the magnetic fields can cause the equation of state to be stiff; thus, a large maximum mass of the neutron star can be obtained.

C. Y. Ryu; S. W. Hong

2011-08-27T23:59:59.000Z

232

SNS | Spallation Neutron Source | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

SNS SNS Instruments Working with SNS Contact Us User Program Manager Laura Morris Edwards 865.574.2966 Spallation Neutron Source Home | User Facilities | SNS SNS | Spallation Neutron Source SHARE SNS is an accelerator-based neutron source in Oak Ridge, Tennessee, USA. This one-of-a-kind facility provides the most intense pulsed neutron beams in the world for scientific research and industrial development. The 80-acre SNS site is located on Chestnut Ridge and is part of Oak Ridge National Laboratory. Although most people don't know it, neutron scattering research has a lot to do with our everyday lives. For example, things like medicine, food, electronics, and cars and airplanes have all been improved by neutron scattering research. Neutron research also helps scientists improve materials used in a

233

Microscopic Optical Potentials for Helium-6 Scattering off Protons  

E-Print Network (OSTI)

The differential cross section and the analyzing power are calculated for elastic scattering of $^6$He from a proton target using a microscopic folding optical potential, in which the $^6$He nucleus is described in terms of a $^4$He-core with two additional neutrons in the valence p-shell. In contrast to previous work of that nature, all contributions from the interaction of the valence neutrons with the target protons are taken into account.

Ch. Elster; A. Orazbayev; S. P. Weppner

2012-09-28T23:59:59.000Z

234

Optical Glass  

Science Journals Connector (OSTI)

... space of time. In the forefront of such vital industries is the manufacture of optical glass. However great the other resources in men and material may be, it would be ... be, it would be quite impossible to wage successful warfare without adequate supplies of optical glass ior binocular field- ...

1919-03-27T23:59:59.000Z

235

Micro-array collimators for X-rays and neutrons  

SciTech Connect

The authors describe the fabrication techniques of novel, compact optical elements for collimating and/or focusing beams of X-rays or thermal neutrons. These optical elements are solid composite arrays consisting of regular stacks of alternating micro-foils, analogous in action to Soller slit collimators, but up to three orders of magnitude smaller. The arrays are made of alternating metals with suitable refractive indices for reflection and/or absorption of the specific radiation. In one implementation, the arrays are made of stacked micro-foils of transmissive elements (Al, Cu) coated and/or electroplated with absorbing elements (Gd, Cd), which are repeatedly rolled or drawn and restacked to achieve the required collimation parameters. The authors present results of these collimators using both X-rays and neutrons. The performance of the collimating element is limited only by the choice of micro-foil materials and the uniformity of their interfaces.

Cimmino, A.; Allman, B.E.; Klein, A.G. [Univ. of Melbourne, Parkville (Australia). School of Physics; Hamilton, W.A. [Oak Ridge National Lab., TN (United States). Solid State Div.; Anderson, I.S.; Hamelin, B.; Joeghoej, P. [Inst. Laue-Langevin, Grenoble (France); Bastie, P. [Univ. Joseph Fourier-Grenoble, Saint-Martin-d`Heres (France). Lab. de Spectrometrie Physique

1998-08-01T23:59:59.000Z

236

Neutron drops and neutron pairing energy  

Science Journals Connector (OSTI)

The ground state energy of a six-neutron drop is computed with variational and Greens function Monte Carlo methods using the Argonne v18 two-nucleon and the Urbana three-nucleon potentials. Combined with earlier results from investigations of the drops 8n and 7n, this energy gives a 1p-shell pairing energy of (1.80.4) MeV. The generalized Skyrme effective interaction discussed in the earlier work is applied to these nuclei by calculating, for the open-shell drops 7n and 6n, the matrix elements of the Skyrme t matrix directly for the states involved. The pairing energy obtained is 1.50 MeV, in reasonable agreement with the accurate calculations.

A. Smerzi; D. G. Ravenhall; V. R. Pandharipande

1997-11-01T23:59:59.000Z

237

Observation of Neutron Skyshine from an Accelerator Based Neutron Source  

SciTech Connect

A key feature of neutron based interrogation systems is the need for adequate provision of shielding around the facility. Accelerator facilities adapted for fast neutron generation are not necessarily suitably equipped to ensure complete containment of the vast quantity of neutrons generated, typically >10{sup 11} n{center_dot}s{sup -1}. Simulating the neutron leakage from a facility is not a simple exercise since the energy and directional distribution can only be approximated. Although adequate horizontal, planar shielding provision is made for a neutron generator facility, it is sometimes the case that vertical shielding is minimized, due to structural and economic constraints. It is further justified by assuming the atmosphere above a facility functions as an adequate radiation shield. It has become apparent that multiple neutron scattering within the atmosphere can result in a measurable dose of neutrons reaching ground level some distance from a facility, an effect commonly known as skyshine. This paper describes a neutron detection system developed to monitor neutrons detected several hundred metres from a neutron source due to the effect of skyshine.

Franklyn, C. B. [Radiation Science Department, Necsa, PO Box 582, Pretoria 0001 (South Africa)

2011-12-13T23:59:59.000Z

238

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

239

Neutron density distributions from antiprotonic 208Pb and 209Bi atoms  

E-Print Network (OSTI)

The X-ray cascade from antiprotonic atoms was studied for 208Pb and 209Bi. Widths and shifts of the levels due to the strong interaction were determined. Using modern antiproton-nucleus optical potentials the neutron densities in the nuclear periphery were deduced. Assuming two parameter Fermi distributions (2pF) describing the proton and neutron densities the neutron rms radii were deduced for both nuclei. The difference of neutron and proton rms radii /\\r_np equal to 0.16 +-(0.02)_{stat} +- (0.04)_{syst} fm for 208Pb and 0.14 +- (0.04)_{stat} +- (0.04)_{syst} fm for 209Bi were determined and the assigned systematic errors are discussed. The /\\r_np values and the deduced shapes of the neutron distributions are compared with mean field model calculations.

B. Klos; A. Trzcinska; J. Jastrzebski; T. Czosnyka; M. Kisielinski; P. Lubinski; P. Napiorkowski; L. Pienkowski; F. J. Hartmann; B. Ketzer; P. Ring; R. Schmidt; T. von Egidy; R. Smolanczuk; S. Wycech; K. Gulda; W. Kurcewicz; E. Widmann; B. A. Brown

2007-02-08T23:59:59.000Z

240

Nucleon semimagic numbers and low-energy neutron scattering  

E-Print Network (OSTI)

It is shown that experimental values of the cross sections of inelastic low-energy neutron scattering on even-even nuclei together with the description of these cross sections in the framework of the coupled channel optical model may be considered as a reliable method for finding nuclei with a semimagic number (or numbers) of nucleons. Some examples of the application of this method are considered.

D. A. Zaikin; I. V. Surkova

2010-04-09T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Cubic boron nitride: a new prospective material for ultracold neutron application  

E-Print Network (OSTI)

For the first time, the neutron optical wall-potential of natural cubic boron nitride (cBN) was measured at the ultracold neutron (UCN) source of the research reactor TRIGA Mainz using the time-of-flight method (TOF). The samples investigated had a wall-potential of (305 +/- 15) neV. This value is in good agreement with the result extracted from neutron reflectometry data and theoretical expectations. Because of its high critical velocity for UCN and its good dielectric characteristics, cubic boron nitride coatings (isotopically enriched) will be useful for a number of applications in UCN experiments.

Sobolev, Yu; Borisov, Yu; Daum, M; Fresne, N du; Goeltl, L; Hampel, G; Heil, W; Knecht, A; Keunecke, M; Kratz, J V; Lang, T; Meister, M; Plonka-Spehr, Ch; Pokotilovski, Yu; Reichert, P; Schmidt, U; Krist, Th; Wiehl, N; Zenner, J

2009-01-01T23:59:59.000Z

242

Temperature-controlled neutron reflectometry sample cell suitable for study of photoactive thin films  

SciTech Connect

We describe a novel cell design intended for the study of photoactive materials using neutron reflectometry. The cell can maintain sample temperature and control of ambient atmospheric environment. Critically, the cell is built with an optical port, enabling light irradiation or light probing of the sample, simultaneous with neutron reflectivity measurements. The ability to measure neutron reflectivity with simultaneous temperature ramping and/or light illumination presents unique opportunities for measuring photoactive materials. To validate the cell design, we present preliminary results measuring the photoexpansion of thin films of azobenzene polymer.

Yager, Kevin G.; Tanchak, Oleh M.; Barrett, Christopher J.; Watson, Mike J.; Fritzsche, Helmut [Department of Chemistry, McGill University, Lab 406, 801 Sherbrooke Street W., Montreal, Quebec H3A 2K6 (Canada); Chalk River Laboratories, Building 459, Station 18, Chalk River, Ontario K0J 1J0 (Canada)

2006-04-15T23:59:59.000Z

243

Fiber optic coupled optical sensor  

DOE Patents (OSTI)

A displacement sensor includes a first optical fiber for radiating light to a target, and a second optical fiber for receiving light from the target. The end of the first fiber is adjacent and not axially aligned with the second fiber end. A lens focuses light from the first fiber onto the target and light from the target onto the second fiber.

Fleming, Kevin J. (Albuquerque, NM)

2001-01-01T23:59:59.000Z

244

The unusual gamma-ray burst GRB 101225A explained as a minor body falling onto a neutron star  

Science Journals Connector (OSTI)

... onto neutron stars in our Galaxy. Here we report that the peculiarities of the Christmas gamma-ray burst (GRB 101225A) can be explained by a tidal disruption event ... long-lasting counterpart to the GRB. Strong variability is observed in the early X-ray light curve. The optical counterpart, which was detected in all of the UltravioletOptical Telescope ...

S. Campana; G. Lodato; P. DAvanzo; N. Panagia; E. M. Rossi; M. Della Valle; G. Tagliaferri; L. A. Antonelli; S. Covino; G. Ghirlanda; G. Ghisellini; A. Melandri; E. Pian; R. Salvaterra; G. Cusumano; V. DElia; D. Fugazza; E. Palazzi; B. Sbarufatti; S. D.Vergani

2011-11-30T23:59:59.000Z

245

First neutron generation in the BINP accelerator based neutron source  

Science Journals Connector (OSTI)

Pilot innovative facility for neutron capture therapy was built at Budker Institute of Nuclear Physics, Novosibirsk. This facility is based on a compact vacuum insulation tandem accelerator designed to produce proton current up to 10mA. Epithermal neutrons are proposed to be generated by 1.915MeV protons bombarding a lithium target using 7Li(p,n)7Be threshold reaction. The results of the first experiments on neutron generation are reported and discussed.

B. Bayanov; A. Burdakov; V. Chudaev; A. Ivanov; S. Konstantinov; A. Kuznetsov; A. Makarov; G. Malyshkin; K. Mekler; I. Sorokin; Yu. Sulyaev; S. Taskaev

2009-01-01T23:59:59.000Z

246

Protein crystallography with spallation neutrons: the user facility at Los Alamos Neutron Science Center  

Science Journals Connector (OSTI)

The protein crystallography user facility at the neutron spallation source run by Los Alamos Neutron Science Center is described.

Langan, P.

2004-01-17T23:59:59.000Z

247

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

248

Artificial Production of Neutrons  

Science Journals Connector (OSTI)

A porcelain vacuum tube capable of producing currents of positive ions up to 30 microamperes and with energies up to 106 electron-volts has been constructed and used for artificial disintegration experiments. Neutrons have been produced by bombarding beryllium with helium ions, and by bombarding lithium and beryllium with the ions of the heavy isotope of hydrogen. The curve obtained for the efficiency of production of neutrons by helium ions as a function of voltage is in agreement with the curve obtained by a downward extrapolation of curves known from work with polonium ?-particles. The present paper is mainly a discussion of the apparatus and methods of measurement, since brief reports of the results have already been presented.

H. R. Crane; C. C. Lauritsen; A. Soltan

1934-04-15T23:59:59.000Z

249

Coherence of neutron fields  

Science Journals Connector (OSTI)

Glauber's definition of quantum coherence is used for neutron fields under the assumption that the complete occupation number space is a direct product of Fermi subspaces. As a result, completely coherent microfields are obtained which define a density operator in full analogy to Glauber's P representation of boson fields. For better physical significance, a transformation from the P representation to a momentum representation is performed. It is proved that the second-order coherence function in this representation is equivalent to Wolf's second-order coherence function of a classical Dirac field. Finally, the results of the theory are used to calculate explicitly the second-order coherence function and the coherence time of an ideally collimated neutron beam.

E. Ledinegg and E. Schachinger

1983-05-01T23:59:59.000Z

250

Nonlinear optics  

E-Print Network (OSTI)

Nicolaas Bloembergen, recipient of the Nobel Prize for Physics (1981), wrote Nonlinear Optics in 1964, when the field of nonlinear optics was only three years old. The available literature has since grown by at least three orders of magnitude.The vitality of Nonlinear Optics is evident from the still-growing number of scientists and engineers engaged in the study of new nonlinear phenomena and in the development of new nonlinear devices in the field of opto-electronics. This monograph should be helpful in providing a historical introduction and a general background of basic ideas both for expe

Bloembergen, Nicolaas

1996-01-01T23:59:59.000Z

251

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

252

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

253

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

254

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

255

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

SciTech Connect

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

256

Review of Non?Neutron and Neutron Nuclear Data, 2004  

Science Journals Connector (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.

Norman E. Holden

2005-01-01T23:59:59.000Z

257

Optical Expanders with Applications in Optical Computing  

E-Print Network (OSTI)

Optical Expanders with Applications in Optical Computing John H. Reif \\Lambda Akitoshi Yoshida \\Lambda July 20, 1999 Abstract We describe and investigate an optical system which we call an optical expander. An optical expander elec­ trooptically expands an optical boolean pattern encoded in d bits

Reif, John H.

258

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 ~5?1011 K, but neutrino emission cools it to `only

Barnes, Joshua Edward

259

Neutron diffraction study of decaborane  

Science Journals Connector (OSTI)

Neutron diffraction study of decaborane ... The Molecular Structure of (PSH+)(nido-7,8-C2B9H12-) Determined by Neutron Diffraction (PS = Proton Sponge, 1,8-Bis(dimethylamino)naphthalene) ... The Molecular Structure of (PSH+)(nido-7,8-C2B9H12-) Determined by Neutron Diffraction (PS = Proton Sponge, 1,8-Bis(dimethylamino)naphthalene) ...

Armin Tippe; Walter C. Hamilton

1969-03-01T23:59:59.000Z

260

Neutron Imaging by Boric Acid  

E-Print Network (OSTI)

In this paper a new type of passive neutron detector based on the already existing one, CR39, is described. Its operation was verified by three different neutron sources: an Americium-Beryllium (Am241-Be) source; a TRIGA type nuclear reactor; and a fast neutron reactor called TAPIRO. The obtained results, reported here, positively confirm its operation and the accountability of the new developed detecting technique.

Fabio Cardone; Giovanni Cherubini; Walter Perconti; Andrea Petrucci; Alberto Rosada

2013-02-22T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Los Alamos Neutron Science Center  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Science Center gets capacity boost December 2, 2010 Los Alamos National Security funds upgrade to key facility LOS ALAMOS, New Mexico, December 2, 2010-The National Nuclear...

262

CHRPR Neutron Board Replacement Manual  

SciTech Connect

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

263

Supporting Organizations | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

support the researchers and maintain the instruments used across all of our neutron science research: Biology and Soft Matter Division The Biology and Soft Matter...

264

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

265

LANSCE | Lujan Neutron Scattering Center  

NLE Websites -- All DOE Office Websites (Extended Search)

Lujan Center Data Management Lujan Neutron Scattering Center Logo The Lujan Center within LANSCE utilizes a pulsed source and has a complement of 15 instruments. It maintains a...

266

Scattering of Neutrons by Lead  

Science Journals Connector (OSTI)

... THE University of Cambridge cyclotron and neutron velocity selector have been used for studying the ... velocity selector have been used for studying the scattering of ...

R. LATHAM; J. M. CASSELS

1948-02-21T23:59:59.000Z

267

Combined neutron reflectometry and rheology  

Science Journals Connector (OSTI)

Neutron reflectometry is combined with rheology in order to reveal the near surface structure of liquids and polymers under well defined deformation.

Wolff, M.

2013-10-26T23:59:59.000Z

268

Inelastic neutron scattering study on bioprotectant systems  

Science Journals Connector (OSTI)

...22 December 2005 Inelastic neutron scattering study on bioprotectant systems...UK We collected inelastic neutron scattering (INS) spectra of homologous...vibrational properties|neutron scattering| 1. Introduction In recent...

2005-01-01T23:59:59.000Z

269

Neutron scattering from adsorbed polymer layers  

Science Journals Connector (OSTI)

Neutron scattering from adsorbed polymer layers ... Small-Angle Neutron Scattering Study of Cyclic Poly(ethylene glycol) Adsorption on Colloidal Particles ... Small-Angle Neutron Scattering Study of Cyclic Poly(ethylene glycol) Adsorption on Colloidal Particles ...

Terence Cosgrove; Timothy G. Heath; Keith Ryan; Trevor L. Crowley

1987-11-01T23:59:59.000Z

270

Protein structures by spallation neutron crystallography  

Science Journals Connector (OSTI)

The capabilities of the Protein Crystallography Station at Los Alamos Neutron Science Center for determining protein structures by spallation neutron crystallography are illustrated, and the methodological and technological advances that are emerging from the Macromolecular Neutron Crystallography consortium are described.

Langan, P.

2008-04-18T23:59:59.000Z

271

Inelastic Neutron Scattering from Glass Formers  

Science Journals Connector (OSTI)

......research-article Articles Inelastic Neutron Scattering from Glass Formers U. Buchenau...transition. Coherent inelastic neutron scattering data indicate a mixture of...Supplement No. 126, 1997 Inelastic Neutron Scattering from Glass Formers U. BUCHENAU......

U. Buchenau

1997-01-01T23:59:59.000Z

272

Quasiclassical Approximation for Slow Neutron Scattering  

Science Journals Connector (OSTI)

......Approximation for Slow Neutron Scattering Takeo Nishigori Department...formula for the differential scattering cross section of a slow neutron is derived along the line...of Spherical Rotors and Neutron Scattering Juichiro Hama and Tuto......

Takeo Nishigori

1970-06-01T23:59:59.000Z

273

Neutron scattering in concrete and wood  

Science Journals Connector (OSTI)

......Article Computational techniques Neutron scattering in concrete and wood A. Facure...library were used to simulate the neutron scattering in barriers of conventional...of the barrier thickness on neutron scattering factors is also being studied......

A. Facure; A. X. Silva; R. C. Falco; V. R. Crispim

2006-09-01T23:59:59.000Z

274

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

275

Neutron Scattering in ORNL'S Calibration Facility  

Science Journals Connector (OSTI)

......Dosimetry Article Neutron Scattering in ORNL'S Calibration...C. Francis Room scattering corrections for several common neutron detectors in a new...and enclosed room scattering situations are compared...good. A personnel neutron spectrometer was......

J.C. Liu; C.S. Sims; W.H. Casson; H. Murakami; C. Francis

1991-01-01T23:59:59.000Z

276

Neutron Generators for Spent Fuel Assay  

E-Print Network (OSTI)

13, 2010. [11] D-D Neutron Generator Development at LBNL, J.12] High-yield DT Neutron Generator, B.A. Ludewigt et al. ,a Compact High-Yield Neutron Generator, O. Waldmann and B.

Ludewigt, Bernhard A

2011-01-01T23:59:59.000Z

277

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

278

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

279

NEUTRON PRODUCTION BY NEUTRAL BEAM SOURCES  

E-Print Network (OSTI)

HORSE CodeA 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

280

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

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Neutron Activation Analysis of Archaeological Artefacts  

Science Journals Connector (OSTI)

17 December 1970 research-article Neutron Activation Analysis of Archaeological...have been determined by non-destructive neutron activation analysis. Examples are given...1971065519 applications archaeology neutron activation analysis radioactivity 1969...

1970-01-01T23:59:59.000Z

282

Extracting buried twists with polarized neutron reflectometry  

Science Journals Connector (OSTI)

Polarized neutron reflectometry can extract the depth-dependent magnetization of ... the surface. Measuring the reflectivity first with neutrons glancing off the front surface and again with neutrons glancing off...

K.V. ODonovan; J.A. Borchers; C.F. Majkrzak; O. Hellwig

2002-12-01T23:59:59.000Z

283

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

284

Low-Energy Neutron-Neutron Scattering Parameters  

Science Journals Connector (OSTI)

A precise evaluation of the spectrum in the reaction ?-+D?2n+?, including final-state interactions is presented with a view of determining the neutron-neutron scattering length. Approximations of previous calculations are examined and avoided where their effect is found to be significant. Sufficiently accurate experiments should be capable of distinguishing this parameter to an error of 1 F.

Myron Bander

1964-06-08T23:59:59.000Z

285

Neutron scattering from ?-Ce at epithermal neutron energies  

Science Journals Connector (OSTI)

Neutron scattering data, using neutrons of incident energies as high as 2...?-Ce and ?-Ce-like systems such as CeRh2, CeNi2, CeFe2, CeRu2, and many others that point clearly to the substantially localized 4f elec...

A. P. Murani

2008-10-01T23:59:59.000Z

286

Slow neutron leakage spectra from spallation neutron sources  

SciTech Connect

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

287

The Optical Spectrum of the Vela Pulsar  

E-Print Network (OSTI)

Our knowledge of the optical spectra of Isolated Neutron Stars (INSs) is limited by their intrinsic faintness. Among the fourteen optically identified INSs, medium resolution spectra have been obtained only for a handful of objects. No spectrum has been published yet for the Vela pulsar (PSR B0833-45), the third brightest (V=23.6) INS with an optical counterpart. Optical multi-band photometry underlines a flat continuum.In this work we present the first optical spectroscopy observations of the Vela pulsar, performed in the 4000-11000 A spectral range.Our observations have been performed at the ESO VLT using the FORS2 instrument. The spectrum of the Vela pulsar is characterized by a flat power-law (alpha = -0.04 +/- 0.04), which compares well with the values obtained from broad-band photometry. This confirms, once more, that the optical emission of Vela is entirely of magnetospheric origin. The comparison between the optical spectral indeces of rotation-powered INSs does not show evidence for a spectral evolution suggesting that, as in the X-rays, the INS aging does not affect the spectral properties of the magnetospheric emission. At the same time, the optical spectral indeces are found to be nearly always flatter then the X-rays ones, clearly suggesting a general spectral turnover at lower energies.

R. P. Mignani; S. Zharikov; P. A. Caraveo

2007-07-13T23:59:59.000Z

288

Spallation Neutron Source The Spallation Neutron Source (SNS)  

NLE Websites -- All DOE Office Websites (Extended Search)

F/gim F/gim Spallation Neutron Source The Spallation Neutron Source (SNS) gives researchers more detailed informa- tion on the structure and dynamics of physical and biological materials than ever before possible. This accelerator- based facility provides the most intense pulsed neutron beams in the world. Scien- tists are able to count scattered neutrons, measure their energies and the angles at which they scatter, and map their final positions. SNS enables measurements of greater sensitivity, higher speed, higher resolution, and in more complex sample environments than have been possible at existing neutron facilities. Future Growth SNS was designed from the outset to accommodate a second target station, effectively doubling the capacity of the

289

Neutron halo effect on direct neutron capture and photodisintegration  

Science Journals Connector (OSTI)

A novel effect of the neutron halo formation is presented for the direct radiative neutron capture where a p-wave neutron is captured into an s orbit with neutron halo by emitting an E1 ? ray. As an example, an enormous enhancement is demonstrated for the cross section of C12(n,?)13C(1/2+) at low energy in excellent agreement with a recent experiment. The S factor of the final state is evaluated. The inverse process, i.e., photo disintegration is discussed for an example of Be11. A sharp but nonresonant peak near the threshold is obtained as a result of the neutron halo in its anomalous ground state.

T. Otsuka; M. Ishihara; N. Fukunishi; T. Nakamura; M. Yokoyama

1994-05-01T23:59:59.000Z

290

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

291

Neutron structure effects in the deuteron and one neutron halos  

Science Journals Connector (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, F1(n)(q2) and F2(n)(q2), lead to an electromagnetic potential of the neutron. Using this fact, we calculate the electromagnetic corrections to the binding energy, Bd, of the deuteron and a one-neutron halo nucleus (Be11) by evaluating the neutron-proton and the neutron-charged core (Be10) potential, respectively. The correction to Bd (?9 keV) is comparable to that arising due to the inclusion of the ?-isobar component in the deuteron wave function. In the case of the more loosely bound halo nucleus, Be11, the correction is close to about 2 keV.

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

2006-08-28T23:59:59.000Z

292

Neutron beam imaging at neutron spectrometers at Dhruva  

SciTech Connect

A low efficiency, 2-Dimensional Position Sensitive Neutron Detector based on delay line position encoding is developed. It is designed to handle beam flux of 10{sup 6}-10{sup 7} n/cm{sup 2}/s and for monitoring intensity profiles of neutron beams. The present detector can be mounted in transmission mode, as the hardware allows maximum neutron transmission in sensitive region. Position resolution of 1.2 mm in X and Y directions, is obtained. Online monitoring of beam images and intensity profile of various neutron scattering spectrometers at Dhruva are presented. It shows better dynamic range of intensity over commercial neutron camera and is also time effective over the traditionally used photographic method.

Desai, Shraddha S.; Rao, Mala N. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2012-06-05T23:59:59.000Z

293

Electroweak bremsstrahlung from neutron-neutron scattering  

Science Journals Connector (OSTI)

Background: Nucleon-nucleon (NN) bremsstrahlung processes NN? (nn?, np?, and pp?) have been extensively investigated. Neutrino-pair bremsstrahlung processes from nucleon-nucleon scattering NN?? (nn??, np??, and pp??) have recently attracted attention in studies of neutrino emission in neutron stars. The calculated NN?? cross sections (or emissivities) are found to be sensitive to the two-nucleon dynamical model used in the calculations. Purpose and Method: A realistic one-boson-exchange (ROBE) model for NN interactions is used to construct the electroweak bremsstrahlung amplitudes using the well-known nucleon electromagnetic and weak interaction vertices. The constructed nn? and nn?? amplitudes are investigated by applying them to calculate nn? and nn?? cross sections, respectively. Results: (i) The 190-MeV ROBE nn? cross sections agree well with those calculated using the TuTts amplitude, but they are in disagreement with those calculated using the Low amplitude. (ii) The calculated nn?? cross sections using the ROBE amplitude at the neutrino-pair energy ? = 1 MeV are in quantitative agreement with those calculated by Timmermans et al. [Phys. Rev. C 65, 064007 (2002)], who used the leading-order term of the soft neutrino-pair bremsstrahlung amplitude. Conclusions: The nn? amplitude in the ROBE approach, which obeys the soft-photon theorem, has a predictive power similar to that of the TuTts amplitude. The nn?? amplitude in the ROBE approach, which is consistent with the soft neutrino-pair bremsstrahlung theorem, has a predictive power similar to that of the soft neutrino-pair bremsstrahlung amplitude of Timmermans et al. in the low neutrino-pair energy region.

Yi Li; M. K. Liou; W. M. Schreiber

2009-09-22T23:59:59.000Z

294

Christmas burst reveals neutron star collision  

NLE Websites -- All DOE Office Websites (Extended Search)

Christmas burst reveals neutron star collision Christmas burst reveals neutron star collision Called the Christmas Burst, GRB 101225A was freakishly lengthy and it produced...

295

High energy neutron Computed Tomography developed  

NLE Websites -- All DOE Office Websites (Extended Search)

objects. May 9, 2014 Neutron tomography horizontal "slice" of a tungsten and polyethylene test object containing tungsten carbide BBs. Neutron tomography horizontal "slice"...

296

Search for: "neutron scattering" | DOE PAGES  

Office of Scientific and Technical Information (OSTI)

neutron scattering" Find + Advanced Search Advanced Search All Fields: "neutron scattering" Title: Full Text: Bibliographic Data: Creator Author: Name Name ORCID Type: All...

297

Scattering of Fast Neutrons by Boron  

Science Journals Connector (OSTI)

The cross section of boron for the scattering of fast neutrons through angles greater than 30 was measured at neutron energies between 0.2 and 3 Mev.

H. H. Barschall; M. E. Battat; W. C. Bright

1946-10-01T23:59:59.000Z

298

Neutron Imaging of Advanced Engine Technologies  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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...

299

NEUTRON: a program for computing phonon extinction rules of inelastic neutron scattering and thermal diffuse scattering experiments  

Science Journals Connector (OSTI)

NEUTRON is a program for the determination of phonon extinction rules in inelastic neutron scattering experiments.

Kirov, A.K.

2003-07-19T23:59:59.000Z

300

Superconductivity | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Highlights Research Highlights Superconductivity Neutron diffraction reveals semiconducting phase and contributes to new understanding of iron-based superconductors Contact: Huibo Cao New VULCAN tests of Japanese cable for US ITER's central magnet system (2012) Contact: Ke An ARCS maps collaborative magnetic spin behavior in iron telluride (2011) Published Work: "Unconventional Temperature Enhanced Magnetism in Fe1:1Te" Contact: Igor Zaliznyak Doug Scalapino discusses "common thread" linking unconventional superconducting materials (2011) Contact: Douglas Scalapino Materials Engineering Research at SNS Helps International Collaboration on Fusion Energy Scientists and engineers at ORNL are working with the ITER Organization and the Japanese Atomic Energy Agency to resolve issues with a critical

Note: This page contains sample records for the topic "optical televiewer neutron" 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

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

302

On Magnetized Neutron Stars  

E-Print Network (OSTI)

In this work we review the formalism normally used in the literature about the effects of density-dependent magnetic fields on the properties of neutron stars, expose some ambiguities that arise and propose a way to solve the related problem. Our approach uses a different prescription for the calculation of the pressure based on the chaotic field formalism for the stress tensor and also a different way of introducing a variable magnetic field, which depends on the energy density rather than on the baryonic density.

Lopes, Luiz L

2014-01-01T23:59:59.000Z

303

Neutron-Proton Exchange Demonstrated  

Science Journals Connector (OSTI)

Neutron-Proton Exchange Demonstrated ... EVIDENCE of the exchange of charge between protons and neutrons has recently been obtained from studies in the high power cyclotron, according to Ernest O. Lawrence, professor of physics at the University of California a* Berkeley. ...

1947-11-03T23:59:59.000Z

304

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

305

Incoherent Neutron Scattering by Polycrystals  

Science Journals Connector (OSTI)

General expressions are given for the first terms in the expansion in powers of the neutron to nuclear mass ratio of the total cross section for incoherent scattering of neutrons by polycrystals. Special limiting cases of these expressions had been published earlier.

G. Placzek

1957-02-15T23:59:59.000Z

306

Neutron Technologies for Bioenergy Research  

SciTech Connect

Neutron scattering is a powerful technique that can be used to probe the structures and dynamics of complex systems. It can provide a fundamental understanding of the processes involved in the production of biofuels from lignocellulosic biomass. A variety of neutron scattering technologies are available to elucidate both the organization and deconstruction of this complex composite material and the associations and morphology of the component polymers and the enzymes acting on them, across multiple length scales ranging from Angstroms to micrometers and time scales from microseconds to picoseconds. Unlike most other experimental techniques, neutron scattering is uniquely sensitive to hydrogen (and its isotope deuterium), an atom abundantly present throughout biomass and a key effector in many biological, chemical, and industrial processes for producing biofuels. Sensitivity to hydrogen, the ability to replace hydrogen with deuterium to alter scattering levels, the fact that neutrons cause little or no direct radiation damage, and the ability of neutrons to exchange thermal energies with materials, provide neutron scattering technologies with unique capabilities for bioenergy research. Further, neutrons are highly penetrating, making it possible to employ sample environments that are not suitable for other techniques. The true power of neutron scattering is realized when it is combined with computer simulation and modeling and contrast variation techniques enabled through selective deuterium labeling.

Langan, Paul [ORNL

2012-01-01T23:59:59.000Z

307

Optical memory  

DOE Patents (OSTI)

Optical memory comprising: a semiconductor wire, a first electrode, a second electrode, a light source, a means for producing a first voltage at the first electrode, a means for producing a second voltage at the second electrode, and a means for determining the presence of an electrical voltage across the first electrode and the second electrode exceeding a predefined voltage. The first voltage, preferably less than 0 volts, different from said second voltage. The semiconductor wire is optically transparent and has a bandgap less than the energy produced by the light source. The light source is optically connected to the semiconductor wire. The first electrode and the second electrode are electrically insulated from each other and said semiconductor wire.

Mao, Samuel S; Zhang, Yanfeng

2013-07-02T23:59:59.000Z

308

Neutron Log | Open Energy Information  

Open Energy Info (EERE)

Neutron Log Neutron Log Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Neutron Log Details Activities (4) Areas (4) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Downhole Techniques Exploration Sub Group: Well Log Techniques Parent Exploration Technique: Well Log Techniques Information Provided by Technique Lithology: if used in conjunction with other logs, this technique can provide information on the rock type and the porosity Stratigraphic/Structural: Corelation of rock units Hydrological: Estimate of formation porosity Thermal: Dictionary.png Neutron Log: The neutron log responds primarily to the amount of hydrogen in the formation which is contained in oil, natural gas, and water. The amount of hydrogen can be used to identify zones of higher porosity.

309

Scattering of Neutrons by Deuterons  

Science Journals Connector (OSTI)

The elastic scattering of neutrons by deuterons is considered for energies small enough so that only the l=0 part of the incident wave is different from the corresponding part of a plane wave. The Breit-Feenberg Hamiltonian is used, assuming the same potential between all pairs of particles. Any possible polarization of the deuteron by the neutron is neglected, although the individual particles in the deuteron are taken into account by an approximate method. This method is capable of including exchange between the two neutrons. When the exchange term is included, the theory gives a cross section for thermal neutrons two to three times greater than observed; the cross section for 2.5 Mev neutrons is slightly greater than observed.

L. I. Schiff

1937-08-01T23:59:59.000Z

310

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

311

Boron neutron capture enhancement of fast neutron radiotherapy  

Science Journals Connector (OSTI)

Clinical trials have revealed a therapeutic advantage for fast neutron radiation over conventional photon radiation for salivary gland cancer prostate cancer sarcoma and a subgroup of lung cancer. Conversely fast neutron treatment of high grade astrocytic brain tumors [glioblastoma multiforme (GBM)] resulted in tumor sterilization but also caused significant brain injury such that no therapeutic gain was attained. This effect was important however in that photon radiation and other conventional treatments have not demonstrated sterilization of GBM at any dose. Recent laboratory studies demonstrated that the hospital-based fast neutron beam from the University of Washington cyclotron has a thermal neutron component that may be used in a boron-10 neutron capture (BNC) reaction to enhance cell kill. The degree of enhancement was approximately 10 fold and was dependent upon the boron-10 concentration the boron-10 carrier agent and the fast neutron dose per fraction. The results of these experiments will be discussed in the context of creating a therapeutic window for treatment of glioblastoma using BNC-enhanced fast neutron radiation in a clinically tolerable regimen.

K. J. Stelzer; G. E. Laramore; R. Risler; L. Wiens; T. W. Griffin

1997-01-01T23:59:59.000Z

312

Effect of neutron orbitals on the nuclear shape in neutron-deficient and neutron-rich zirconium nuclei  

Science Journals Connector (OSTI)

The neutron-deficient and neutron-rich zirconium nuclei are studied using statistical theory. The deformation dependence of occupation numbers of the neutron orbitals in these nuclei near the Fermi level is investigated. The preference of the neutrons to occupy or vacate a particular orbital is found to contribute a particular shape to the nucleus.

N. Arunachalam; S. Veeraraghavan; A. Mohamed Akbar

1997-08-01T23:59:59.000Z

313

Neutron detector for fusion reaction-rate measurements  

SciTech Connect

We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response < 25-ps FWHM. A thin piece of scintillator material acts as a neutron-to- light converter. A zoom lens images light from the scintillator surface to a high-speed (15 ps) optical streak camera for recording. The zoom lens allows the scintillator to be positioned between 1 and 50 cm from a target. The camera simulaneously records an optical fiducial pulse which allows the camera time base to be calibrated relative to the incident laser power. Bursts of x rays formed by focusing 20-ps, 2.5-TW laser pulses onto gold disk targets demonstrate the detector resolution to be < 25 ps. We have recorded burn histories for deuterium/tritium-filled targets producing as few as 3 {times} 10{sup 7} neutrons.

Lerche, R.A.; Phillion, D.W.; Tietbohl, G.L.

1993-09-03T23:59:59.000Z

314

Remark on:- The Neutron Spherical Optical-Model Absorption  

NLE Websites -- All DOE Office Websites (Extended Search)

Argonne National Laboratory Argonne National Laboratory Argonne is a U.S. Department of Energy laboratory managed by UChicago Argonne, LLC under contract DE-AC02-06CH11357. The Laboratory's main facility is outside Chicago, at 9700 South Cass Avenue, Argonne, Illinois 60439. For information about Argonne, see www.anl.gov. Availability of This Report This report is available, at no cost, at http://www.osti.gov/bridge. It is also available on paper to the U.S. Department of Energy and its contractors, for a processing fee, from: U.S. Department of Energy Office of Scientific and Technical Information P.O. Box 62 Oak Ridge, TN 37831-0062 phone (865) 576-8401 fax (865) 576-5728 reports@adonis.osti.gov Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States

315

The Neutron-Hydrogen Mass Difference and the Neutron Mass  

Science Journals Connector (OSTI)

Data in the literature leading to the neutron-hydrogen mass difference and the neutron mass are summarized. The disintegration energy of the deuteron together with the HH-D mass spectroscopic doublet separation apparently yields the best value of n-H=0.7550.016 Mev and a neutron mass of 1.008,9410.000,02 mass units. Other transmutation-radioactivity cycles check this value. Several inconsistencies in these data and their possible explanation are pointed out. Experiments of interest for improvement in accuracy and reliability of these values are noted.

W. E. Stephens

1947-01-01T23:59:59.000Z

316

Protons and Neutrons for Testing at LBNL | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Protons and Neutrons for Testing at Protons and Neutrons for Testing at LBNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Spinoff Applications Spinoff Archives SBIR/STTR Applications of Nuclear Science and Technology Funding Opportunities Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3613 F: (301) 903-3833 E: sc.np@science.doe.gov More Information » Spinoff Archives Protons and Neutrons for Testing at LBNL Print Text Size: A A A RSS Feeds FeedbackShare Page Application/instrumentation: Use of protons and neutrons for testing of microelectronics, optical components and nanostructures for advanced accelerators, ground and space

317

EQ-SANS: the Extended Q-Range Small-Angle Neutron Scattering Diffractometer  

NLE Websites -- All DOE Office Websites (Extended Search)

The Extended Q-Range Small-Angle Neutron Scattering Diffractometer at SNS The Extended Q-Range Small-Angle Neutron Scattering Diffractometer at SNS Extended Q-Range Small Angle Diffractometer EQ-SANS detector array The EQ-SANS Diffractometer is designed to study non-crystalline, nano-sized materials in solid, liquid, or gas forms such as polymers, micelles, proteins, and other large biological molecular complexes in solution. It offers high neutron flux, high wavelength resolution (precision), and wide Q-coverage. EQSANS is located on beam line 6, viewing the top-downstream, coupled supercritical hydrogen moderator. It has a curved multichannel beam bender to avoid the direct line of sight of the moderator, which cleans out the background from the prompt neutron pulse quite effectively. The cutoff wavelength of the optics is ~1.5 Å. Above this minimum wavelength, the

318

Improvement of the polarized neutron interferometer setup demonstrating violation of a Bell-like inequality  

E-Print Network (OSTI)

For precise measurements with polarized neutrons high efficient spin-manipulation is required. We developed several neutron optical elements suitable for a new sophisticated setup, i.e., DC spin-turners and Larmor-accelerators which diminish thermal disturbances and depolarisation considerably. The gain in performance is exploited demonstrating violation of a Bell-like inequality for a spin-path entangled single-neutron state. The obtained value of S=2.365(13), which is much higher than previous measurements by neutron interferometry, is 28 $\\sigma$ above the limit of S=2 predicted by contextual hidden variable theories. The new setup is more flexible referring to state preparation and analysis, therefore new, more precise measurements can be carried out.

Hermann Geppert; Tobias Denkmayr; Stephan Sponar; Hartmut Lemmel; Yuji Hasegawa

2014-04-14T23:59:59.000Z

319

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

320

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

Note: This page contains sample records for the topic "optical televiewer neutron" 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

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, bs� is the maxwellian-averaged neutron capture cross-section, and t0 is the average neutron exposure (21). The branching decay of 186Re

West, Stuart

322

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

323

The World Neutron Monitor Network as a tool for the study of solar neutrons  

E-Print Network (OSTI)

The World Neutron Monitor Network as a tool for the study of solar neutrons I. G. Usoskin1 , G. A Neutron Monitor Network to detect high-energy solar neutrons is dis- cussed in detail. It is shown that the existing network can be used for the routine detection of intense sporadic solar-neutron events whenever

Paris-Sud XI, Université de

324

GPUs Neutron Sensitivity Dependence on Data Type  

Science Journals Connector (OSTI)

Graphics Processing Units are very prone to be corrupted by neutrons. Experimental results obtained irradiating the GPU with high energy neutrons show that the input data type has a strong influence on the neutron-induced error-rate of the executed algorithms. ... Keywords: Data types, GPU, Neutron radiation testing, Precision, Reliability

P. Rech, C. Frost, L. Carro

2014-06-01T23:59:59.000Z

325

Magnetic neutron scattering (invited)  

Science Journals Connector (OSTI)

The application of neutron scattering techniques to magnetic problems is reviewed. We will first discuss diffraction techniques used to solve magnetic structures as well as to measure magnetic form factors order parameters critical phenomena and the scattering from low?dimensional systems. We will also discuss inelastic scattering techniques including polarized beam methods utilized to determine the spin dynamics of various materials. Information will be provided about the types of spectrometers available at the user?oriented national facilities located at Argonne National Laboratory Brookhaven National Laboratory Los Alamos National Laboratory The National Institute of Standards and Technology and Oak Ridge National Laboratory as well as the spectrometers at the Missouri University Research Reactor.

J. W. Lynn

1994-01-01T23:59:59.000Z

326

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

SciTech Connect

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

Cremer, J. T.; Williams, D. L.; Fuller, M. J.; Gary, C. K.; Piestrup, M. A. [Adelphi Technology, Inc., 2003 East Bayshore Rd., Redwood City, California 94063 (United States); Pantell, R. H.; Feinstein, J. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Flocchini, R. G.; Boussoufi, M.; Egbert, H. P.; Kloh, M. D.; Walker, R. B. [Davis McClellan Nuclear Radiation Center, University of California, McClellan, California 95652 (United States)

2010-01-15T23:59:59.000Z

327

Amorphous Silicon Based Neutron Detector  

SciTech Connect

Various large-scale neutron sources already build or to be constructed, are important for materials research and life science research. For all these neutron sources, neutron detectors are very important aspect. However, there is a lack of a high-performance and low-cost neutron beam monitor that provides time and temporal resolution. The objective of this SBIR Phase I research, collaboratively performed by Midwest Optoelectronics, LLC (MWOE), the University of Toledo (UT) and Oak Ridge National Laboratory (ORNL), is to demonstrate the feasibility for amorphous silicon based neutron beam monitors that are pixilated, reliable, durable, fully packaged, and fabricated with high yield using low-cost method. During the Phase I effort, work as been focused in the following areas: 1) Deposition of high quality, low-defect-density, low-stress a-Si films using very high frequency plasma enhanced chemical vapor deposition (VHF PECVD) at high deposition rate and with low device shunting; 2) Fabrication of Si/SiO2/metal/p/i/n/metal/n/i/p/metal/SiO2/ device for the detection of alpha particles which are daughter particles of neutrons through appropriate nuclear reactions; and 3) Testing of various devices fabricated for alpha and neutron detection; As the main results: High quality, low-defect-density, low-stress a-Si films have been successfully deposited using VHF PECVD on various low-cost substrates; Various single-junction and double junction detector devices have been fabricated; The detector devices fabricated have been systematically tested and analyzed. Some of the fabricated devices are found to successfully detect alpha particles. Further research is required to bring this Phase I work beyond the feasibility demonstration toward the final prototype devices. The success of this project will lead to a high-performance, low-cost, X-Y pixilated neutron beam monitor that could be used in all of the neutron facilities worldwide. In addition, the technologies developed here could be used to develop X-ray and neutron monitors that could be used in the future for security checks at the airports and other critical facilities. The project would lead to devices that could significantly enhance the performance of multi-billion dollar neutron source facilities in the US and bring our nation to the forefront of neutron beam sciences and technologies which have enormous impact to materials, life science and military research and applications.

Xu, Liwei

2004-12-12T23:59:59.000Z

328

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

329

Combined neutron reflectometry and rheology  

E-Print Network (OSTI)

We have combined neutron reflectometry with rheology in order to investigate the solid boundary of liquids and polymers under shear deformation. Our approach allows one to apply a controlled stress to a material while resolving the structural arrangements on the sub nanometer length scale with neutron reflectivity, off-specular and small angle scattering at the same time. The specularly reflected neutron intensity of a 20 % by weight solution of the Pluronic F127 in deuterated water is evaluated. We find pronounced changes in the near interface structure under applied deformation for surfaces with different surface energies, which are correlated with changes in the storage and loss modulus.

Max Wolff; Peter Kuhns; Georg Liesche; John F. Ankner; Jim F. Browning; Philipp Gutfreund

2013-04-18T23:59:59.000Z

330

Research Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Highlights Research Highlights Biology & Medicine Biotechnology & Energy Fundamental Physics Imaging Magnetism Materials Nanotechnology Superconductivity Facilities and Capabilities Instruments User Program Publications and Resources Science and Education News and Awards NScD Careers Supporting Organizations Neutron Science Home | Science & Discovery | Neutron Science | Research Highlights SHARE Research Highlights No current Research Highlights found. 1-10 of 43 Results Comprehensive phonon "map" offers direction for engineering new thermoelectric devices January 08, 2014 - To understand how to design better thermoelectric materials, researchers are using neutron scattering at SNS and HFIR to study how a compound known as AgSbTe2, or silver antimony telluride, is

331

POWDER: The Neutron Powder Diffractometer at HFIR | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Powder Diffractometer Neutron Powder Diffractometer Neutron Powder Diffractometer. Neutron Powder Diffractometer. The HB-2A diffractometer is a workhorse instrument used to conduct crystal structural and magnetic structural studies of powdered and ceramic samples, particularly as a function of intensive conditions (T, P, H, etc.). Powder diffraction data collected on this instrument are ideally suited for the Rietveld method. A full range of ancillary sample environments can be used, including cryofurnaces (4-800 K), furnaces (to 1800 K), cryostats (to 0.3 K), and cryomagnets (to 7 T). The Powder Diffractometer has a Debye-Scherrer geometry. The detector bank has 44 3He tubes, each with 6' Soller collimators. A germanium wafer-stack monochromator is vertically focusing and provides one of three principal

332

How the Spallation Neutron Source Works | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (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...

333

Neutron Radiography Facilities Using Neutron Beams from Nuclear Reactors  

Science Journals Connector (OSTI)

The paper represents diagrams, descriptions and main technical characteristics of a number of Soviet neutron radiography facilities. The said facilieties for the ... inspection of the objects to be studied utiliz...

E. R. Kartashev

1983-01-01T23:59:59.000Z

334

Cold neutron facility for prompt gamma-neutron activation analysis  

Science Journals Connector (OSTI)

The restart of the recently upgraded research reactor in Budapest is foreseen at the end of this year. A number of fast, thermal and cold neutron beams will serve for research, industrial and educational activiti...

G. Molnr; ZS. Rvay; . Veres; A. Simonits

1993-01-01T23:59:59.000Z

335

Neutron-Anti-Neutron Oscillation: Theory and Phenomenology  

E-Print Network (OSTI)

The discovery of neutrino masses has provided strong hints in favor of the possibility that B-L symmetry is an intimate feature of physics beyond the standard model. I discuss how important information about this symmetry as well as other scenarios for TeV scale new physics can be obtained from the baryon number violating process, neutron-anti-neutron oscillation. This article presents an overview of different aspects of neutron-anti-neutron oscillation and is divided into the following parts : (i) the phenomenon; (ii) the physics, (iii) plausible models and (iv) applications to cosmology. In particular, it is argued how the discovery of $n-\\bar{n}$ oscillation can significantly affect our thinking about simple grand unified theory paradigms for physics beyond the standard model, elucidate the nature of forces behind neutrino mass and provide a new microphysical view of the origin of matter in the universe.

R. N. Mohapatra

2009-02-05T23:59:59.000Z

336

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

337

Small-angle neutron scattering and neutron reflectometry  

Science Journals Connector (OSTI)

Diffraction methods, interpreted loosely, could be applied to the techniques of wide-angle X-ray scattering, small-angle X-ray scattering, electron diffraction, small-angle neutron scattering, small-angle light s...

R. W. Richards

1993-01-01T23:59:59.000Z

338

Optics and Diagnostics  

NLE Websites -- All DOE Office Websites (Extended Search)

2 14 | Next | Last Back to Index Optics Line up of optics after cleaning. Photo Number: 2013-048779...

339

Delayed neutrons from the neutron irradiation of ?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 samples pneumatic flight time and the Nuclear Science Centers (NSCs) 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

340

The nuclear physics of neutron stars  

SciTech Connect

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

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Portable Neutron Sensors for Emergency Response Operations  

SciTech Connect

This article presents the experimental work performed in the area of neutron detector development at the Remote Sensing LaboratoryAndrews Operations (RSL-AO) sponsored by the U.S. Department of Energy, National Nuclear Security Administration (NNSA) in the last four years. During the 1950s neutron detectors were developed mostly to characterize nuclear reactors where the neutron flux is high. Due to the indirect nature of neutron detection via interaction with other particles, neutron counting and neutron energy measurements have never been as precise as gamma-ray counting measurements and gamma-ray spectroscopy. This indirect nature is intrinsic to all neutron measurement endeavors (except perhaps for neutron spin-related experiments, viz. neutron spin-echo measurements where one obtains ?eV energy resolution). In emergency response situations generally the count rates are low, and neutrons may be scattered around in inhomogeneous intervening materials. It is also true that neutron sensors are most efficient for the lowest energy neutrons, so it is not as easy to detect and count energetic neutrons. Most of the emergency response neutron detectors are offshoots of nuclear device diagnostics tools and special nuclear materials characterization equipment, because that is what is available commercially. These instruments mostly are laboratory equipment, and not field-deployable gear suited for mobile teams. Our goal is to design and prototype field-deployable, ruggedized, lightweight, efficient neutron detectors.

,

2012-06-24T23:59:59.000Z

342

Parallel optical sampler  

SciTech Connect

An optical sampler includes a first and second 1.times.n optical beam splitters splitting an input optical sampling signal and an optical analog input signal into n parallel channels, respectively, a plurality of optical delay elements providing n parallel delayed input optical sampling signals, n photodiodes converting the n parallel optical analog input signals into n respective electrical output signals, and n optical modulators modulating the input optical sampling signal or the optical analog input signal by the respective electrical output signals, and providing n successive optical samples of the optical analog input signal. A plurality of output photodiodes and eADCs convert the n successive optical samples to n successive digital samples. The optical modulator may be a photodiode interconnected Mach-Zehnder Modulator. A method of sampling the optical analog input signal is disclosed.

Tauke-Pedretti, Anna; Skogen, Erik J; Vawter, Gregory A

2014-05-20T23:59:59.000Z

343

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

344

Neutron Reflection Method for the Fast Estimation of Neutron Removal Cross Section in Hydrogenous Materials  

Science Journals Connector (OSTI)

Neutron reflection method was used for the fast estimation of the neutron removal cross section in hydrogenous materials of ... to hydrogenous materials with a low concentration of neutron absorbing elements.

L. Desdin; C. Ceballos

2000-03-01T23:59:59.000Z

345

Neutron Capture Reactions in a d(14)+Be Fast Neutron Beam  

Science Journals Connector (OSTI)

Since 1978 at the Essen University Hospital a compact cyclotron has been used for fast neutron therapy with neutrons produced by 14 MeV deuterons incident on ... seated tumors (Fig 1). During fast neutron therapy...

W. Sauerwein; I. Heselmann; F. Pller

1992-01-01T23:59:59.000Z

346

Awards 2007 | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

7 7 Staff Awards: 2007 Chakoumakos elected MSA Fellow Bryan Chakoumakos Neutron scientist Bryan Chakoumakos was recently elected a fellow of the Mineralogical Society of America. A member of the Neutron Scattering Science Division, Bryan leads the Single-Crystal Diffraction Group. The group has five neutron scattering instruments in various stages of design and construction, located at HFIR and SNS. The MSA was founded in 1919 and, among other goals, encourages fundamental research on natural materials and supports education through its publications, educational grants, and courses. Pharos Neutron Detector System Researchers at the Department of Energy's Oak Ridge National Laboratory have won six R&D 100 Awards, given annually by R&D Magazine to the year's

347

Aqueous Solutions and Neutron Scattering  

Science Journals Connector (OSTI)

The application of neutron diffraction techniques to aqueous solutions is described, and a framework involving the use of isotopic substitution is set up to illustrate the scope of the method. Specific applications described include a study of glassy ...

G. W. Neilson; J. E. Enderby

1996-01-25T23:59:59.000Z

348

Neutron Scattering Methods in Chemistry  

Science Journals Connector (OSTI)

Before going into details of the scattering of neutrons in condensed phases, some of this elementary particle should be recalled, as these characteristics play a central role in the scattering process.

2003-01-01T23:59:59.000Z

349

Low-Angle Neutron Scattering  

Science Journals Connector (OSTI)

A set of techniques that can be used to find the size of a particle in solution or to find the size or spacing of internal regions that can be distinguished by different neutron scattering power, such as the prot...

Jan W. Gooch

2011-01-01T23:59:59.000Z

350

Interaction of Neutrons with Matter  

Science Journals Connector (OSTI)

Boron neutron capture therapy (BNCT) is a binary radiotherapy modality used in treatment of brain lesions. First, the patient is injected with a tumor seeking drug containing a stable boron-10 nuclide that has a ...

Ervin B. Podgorak

2014-01-01T23:59:59.000Z

351

Neutron scattering in Mineral Sciences:  

Science Journals Connector (OSTI)

...de WWW page: http://www.kfa-juelich.de FRG-1 Geesthacht (D) Type: Swimming Pool Cold Neutron Source. Flux: 8...Div. Wfn-Neutronscattering, GKSS Research Centre, 21502 Geesthacht, Germany Telephone: 49 (0) 4152 87 1316 / 2503 Fax: 49...

Romano RINALDI

352

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

353

Scattering of Neutrons by Protons  

Science Journals Connector (OSTI)

... IT is known that hydrogen shows a large scattering cross-section for slow ... cross-section for slow neutrons. On the usual assumption that the forces between proton and ...

M. GOLDHABER

1936-05-16T23:59:59.000Z

354

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

355

Neutron reflectometry by refractive encoding  

Science Journals Connector (OSTI)

There is a great deal of interest in expanding the technique of neutron reflectivity beyond static structural measurements of layered structures to kinetic studies. The time resolution for kinetic studies is l...

R. Cubitt; J. Stahn

2011-11-01T23:59:59.000Z

356

Neutron Imaging of Diesel Particulate Filters | Department of...  

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

Neutron Imaging of Diesel Particulate Filters Neutron Imaging of Diesel Particulate Filters Neutron computed tomography shows soot and ash loading in a cordierite diesel...

357

Joint Institute for Neutron Sciences | ornl.gov  

NLE Websites -- All DOE Office Websites (Extended Search)

Facilities and Capabilities High Flux Isotope Reactor Spallation Neutron Source Joint Institute for Neutron Sciences Scientific Labs Neutron Science Home | Science & Discovery |...

358

About the Neutron and Nuclear Science Research (WNR) facility...  

NLE Websites -- All DOE Office Websites (Extended Search)

About the Neutron and Nuclear Science (WNR) Facility The Neutron and Nuclear Science (WNR) Facility provides neutron and proton beams and detector arrays for basic, applied,...

359

HFIR In-Vessel Irradiation Facilities | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

the permanent beryllium reflector. Please refer to the accompanying graph showing the neutron flux values for these regions. Radio neutron flux graph Neutron flux distributions at...

360

SciTech Connect: Nuclear Physics: The Ultracold Neutron Source  

Office of Scientific and Technical Information (OSTI)

Nuclear Physics: The Ultracold Neutron Source Citation Details In-Document Search Title: Nuclear Physics: The Ultracold Neutron Source Nuclear Physics: The Ultracold Neutron Source...

Note: This page contains sample records for the topic "optical televiewer neutron" 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.


361

11th LANSCE School on Neutron Scattering | About the School  

NLE Websites -- All DOE Office Websites (Extended Search)

students calculate results About the LANSCE School on Neutron Scattering The annual Los Alamos Neutron Science Center (LANSCE) School on Neutron Scattering is 9- to 10-day school...

362

Call issued for Lujan Neutron Scattering Center proposals  

NLE Websites -- All DOE Office Websites (Extended Search)

Call issued for Lujan Neutron Scattering Center proposals Call issued for Lujan Neutron Scattering Center proposals The Lujan Neutron Scattering Center invites proposals addressing...

363

Polarized neutron reflectometry at the IBR-2 pulsed reactor  

Science Journals Connector (OSTI)

Polarized neutron reflectometry as a method for investigating layered nanostructures ... and the development of the method of polarized neutron reflectometry on the polarized neutron spectrometer are presented. T...

V. L. Aksenov; Yu. V. Nikitenko

2007-05-01T23:59:59.000Z

364

Neutron detectors comprising boron powder  

SciTech Connect

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

365

Precise Neutron Magnetic Form Factors  

E-Print Network (OSTI)

Precise data on the neutron magnetic form factor G_{mn} have been obtained with measurements of the ratio of cross sections of D(e,e'n) and D(e,e'p) up to momentum transfers of Q^2 = 0.9 (GeV/c)^2. Data with typical uncertainties of 1.5% are presented. These data allow for the first time to extract a precise value of the magnetic radius of the neutron.

G. Kubon; H. Anklin; P. Bartsch; D. Baumann; W. U. Boeglin; K. Bohinc; R. Boehm; C. Carasco; M. O. Distler; I. Ewald; J. Friedrich; J. M Friedrich; M. Hauger; A. Honegger; P. Jennewein; J. Jourdan; M. Kahrau; K. W. Krygier; A. Liesenfeld; H. Merkel; U. Mueller; R. Neuhausen; Ch. Normand; Th. Petitjean; Th. Pospischil; M. Potokar; D. Rohe; G. Rosner; H. Schmieden; I. Sick; S. Sirca; Ph. Trueb; A. Wagner; Th. Walcher; G. Warren; M. Weis; H. Woehrle; M. ZeierJ. Zhao; B. Zihlmann

2001-07-26T23:59:59.000Z

366

Alternative Neutron Detection Testing Summary  

SciTech Connect

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

367

Neutron radii and the neutron equation of state in relativistic models  

Science Journals Connector (OSTI)

The root-mean-square radii for neutrons in nuclei and their relationship to the neutron equation of state are investigated in the relativistic Hartree model. A correlation between the neutron skin in heavy nuclei and the derivative of the neutron equation of state is found which provides a linear continuation of results obtained from nonrelativistic Hartree-Fock models. The relativistic models tend to give larger neutron radii and an associated stiffer neutron equation of state compared with the nonrelativistic models.

S. Typel and B. Alex Brown

2001-06-29T23:59:59.000Z

368

Optical Packet Switching -1 Optical Networks  

E-Print Network (OSTI)

Optical Packet Switching - 1 Optical Networks: from fiber transmission to photonic switching Optical Packet Switching Fabio Neri and Marco Mellia TLC Networks Group ­ Electronics Department e.mellia@polito.it ­ tel. 011 564 4173 #12;Optical Packet Switching - 2 · This work is licensed under the Creative Commons

Mellia, Marco

369

NXS 2010 - Neutron Scattering School  

NLE Websites -- All DOE Office Websites (Extended Search)

2-26, 2010 2-26, 2010 Argonne National Laboratory, Argonne, IL Oak Ridge National Laboratory, Oak Ridge, TN NXS2010 Travel Airport Shuttles Departure Flights Schedule Participants Lectures Lecturers Lecture Notes/Videos Experiments Schedule, Desc, Groups Student Presentations ANL Facilities APS Facility ANL Map ANL Visitor's Guide ORNL Facilities HFIR Facility SNS Facility HFIR/SNS Map Access Requirements ANL ORNL Rad Worker Training Study Guide Wireless Networks ANL ORNL Safety & Security Rules ANL ORNL NSSA New Initiatives NSSA Weblink Contacts ANL ORNL 12th National School on Neutron & X-ray Scattering 2009 Neutron Scattering School participants 2010 National School Participants Students share their thoughts about NXS 2010. Purpose: The main purpose of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major neutron and x-ray facilities. Lectures, presented by researchers from academia, industry, and national laboratories, will include basic tutorials on the principles of scattering theory and the characteristics of the sources, as well as seminars on the application of scattering methods to a variety of scientific subjects. Students will conduct four short experiments at Argonne's Advanced Photon Source and Oak Ridge's Spallation Neutron Source and High Flux Isotope Reactor facilities to provide hands-on experience for using neutron and synchrotron sources.

370

Spin-echo small-angle neutron scattering in neutron reflectometry  

Science Journals Connector (OSTI)

A new method to perform neutron reflectometry measurements is discussed, based on Larmor precession of polarized neutrons in the spin-echo mode.

Rekveldt, M.T.

2003-11-15T23:59:59.000Z

371

Optics and Optical Engineering Program Assessment Plan Program Learning Objectives  

E-Print Network (OSTI)

Optics and Optical Engineering Program Assessment Plan Program Learning, and processes that underlie optics and optical engineering. 2. Strong understanding of the fundamental science, mathematics, and processes that underlie optics and optical

Cantlon, Jessica F.

372

Diagnostic System for Time-of-Flight Neutron Measurements  

SciTech Connect

This paper presents the diagnostic system for time-of-flight neutron measurement consists of a number of mobile stands enabling to acquire transient electrical signals from spatially separated scintillation probes. The battery power supply of all the employed devices and only optical coupling with outside appliances as well as efficient shielding against electromagnetic interference allow carrying out data acquisition by means of the mobile stands in a harsh electromagnetic environment. The usefulness of presented system was proven in experiments carried out on the plasma-focus PF1000 device, installed at the Institute of Plasma Physics and Laser Microfusion, Warsaw, Poland.

Tomaszewski, Krzysztof J. [ACS Ltd., Advanced Diagnostics Laboratory, Hery 23 St., 01-497 Warsaw (Poland)

2006-12-04T23:59:59.000Z

373

Fast-neutron total and scattering cross sections of sup 58 Ni and nuclear models  

SciTech Connect

An extensive experimental and theoretical study of the fast-neutron interaction with {sup 58}Ni was undertaken. The neutron total cross sections of {sup 58}Ni were measured from {approx} 1 to > 10 MeV using white source techniques. Differential neutron elastic-scattering cross sections were measured from {approx} 4.5 to 10 MeV at {approx} 0.5 Mev intervals with {ge} 75 differential values per distribution. Differential neutron inelastic-scattering cross sections were measured, corresponding to fourteen levels with excitations up to {approx} 4.8 Mev. The measured results, combined with lower-energy values previously obtained at this laboratory and with relevant values available in the literature, were interpreted in terms of optical-statistical, dispersive-optical and coupled-channels models using both vibrational and rotational coupling schemes. The physical implications of the experimental results and their interpretation are discussed. The considerations are being extended to collective vibrational nuclei generally, exploring the potential for utilizing electro-magnetic matrix elements, deduced from experiment or predicted by the shell model, to determine the strengths of the neutron interaction. Detailed aspects of this work are given in the Laboratory Report, ANL/NDM-120 (in press). 9 refs., 10 figs.

Smith, A.B.; Guenther, P.T.; Whalen, J.F.; Lawson, R.D.; Chiba, S.

1991-01-01T23:59:59.000Z

374

UA/ORNL Collaboration: Neutron Scattering Studies of Antiferromagnetic Films, Final Report  

SciTech Connect

The work reported here was a collaborative project between the research groups of Dr. J.L. Robertson at Oak Ridge National Laboratory and Dr. G.J. Mankey at the University of Alabama. The main thrust is developing neutron optical devices and materials for the study of magnetic thin films and interfaces. The project is particularly timely, since facility upgrades are currently underway at the High Flux Isotope Reactor. A new neutron optical device, a multicrystal analyzer, was designed and built to take maximum advantage of the increased flux that the upgraded beamlines at HFIR will provide. This will make possible detailed studies of the magnetic structure of thin films, multilayers, and interfaces that are not feasible at present. We performed studies of the antiferromagnetic order in thin films and crystals using neutron scattering, determined magnetic structures at interfaces with neutron reflectometry and measured order in magnetic dispersions using small angle neutron scattering. The collaboration has proved fruitful: generating eleven publications, contributing to the training of a postdoc who is now on staff at the High Flux Isotope Reactor and providing the primary support for two recent Ph.D. recipients. The collaboration is still vibrant, with anticipated implementation of the multicrystal analyzer on one of the new cold source beamlines at the High Flux Isotope Reactor.

Mankey, Gary J.

2006-07-26T23:59:59.000Z

375

Optical microphone  

DOE Patents (OSTI)

An optical microphone includes a laser and beam splitter cooperating therewith for splitting a laser beam into a reference beam and a signal beam. A reflecting sensor receives the signal beam and reflects it in a plurality of reflections through sound pressure waves. A photodetector receives both the reference beam and reflected signal beam for heterodyning thereof to produce an acoustic signal for the sound waves. The sound waves vary the local refractive index in the path of the signal beam which experiences a Doppler frequency shift directly analogous with the sound waves.

Veligdan, James T. (Manorville, NY)

2000-01-11T23:59:59.000Z

376

Physics of Neutron Interactions with 238U: New Developments and Challenges  

Science Journals Connector (OSTI)

Abstract The latest release of the EMPIRE-3.1 system (codename Rivoli) is being used in the advanced modeling of neutron induced reactions on the 238U nucleus with the aim of improving our knowledge of neutron scattering. The reaction model includes: (i) a new rotational-vibrational dispersive optical model potential coupling the low-lying collective bands of vibrational character observed in even-even actinides, (ii) the Engelbrecht-Weidenmller transformation allowing for inclusion of compound-direct interference effects enhanced by a dispersive treatment of the optical model potential, (iii) a multi-humped fission barrier with absorption in the secondary well as described within the optical model for fission, and (iv) a modified Lorentzian model (MLO) of the radiative strength function. Impact of the advanced modeling on elastic and inelastic scattering cross section is being assessed by both comparison with selected microscopic experimental data and integral criticality benchmarks (e.g. FLATTOP, JEMIMA and BIGTEN assemblies). Benchmark calculations provide feedback to improve the reaction modeling and reduce both model and model-parameters uncertainties. Additionally, neutron scattering yields on 238U measured accurately at RPI by the time-of-flight technique at 29, 60, 112 and 153 degrees have been used as a further constraint on the incident energy dependence of elastic and inelastically scattered neutrons. Improvement of scattering cross sections in existing libraries is discussed.

R. Capote; A. Trkov; M. Sin; M. Herman; A. Daskalakis; Y. Danon

2014-01-01T23:59:59.000Z

377

Neutron-induced Mammary Neoplasms in the Rat  

Science Journals Connector (OSTI)

...Fission neutrons were appropriately...y-rays or thermal neutrons (12). The neutron fission spectrum (mean energy, about 1...changing the neutron energy from the fission spectrum to 540 keV...the types of induced mammary neoplasms...

Howard H. Vogel, Jr. and Robert Zaldvar

1972-05-01T23:59:59.000Z

378

Bound Neutrons Pave Way to Free Ones | Jefferson Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

neutron is that most neutrons are bound up inside the nucleus of atoms to protons. In nature, a free neutron lasts for only a few minutes, while in the nucleus, neutrons are...

379

Neutron Sciences - Neutron Scattering Dynamics in Polymer Family  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron scattering characterizes dynamics in polymer family Neutron scattering characterizes dynamics in polymer family Research Contact: Christine Gerstl December 2012, Written by Agatha Bardoel Understanding the interplay between structure and dynamics is the key to obtaining tailor-made materials. In the last few years, a large effort has been devoted to characterizing and relating the structure and dynamic properties in families of polymers with alkyl side groups. Now researchers have used quasielastic neutron scattering to investigate the hydrogen dynamics in poly(alkylene oxide)s with different side-chain lengths at temperatures below, as well as above, the glass transition. The combination of techniques and instruments used is bringing a more complete understanding of multiple contributions to system dynamics. The results

380

An imaging-plate detector for small-angle neutron scattering  

Science Journals Connector (OSTI)

Small-angle neutron scattering (SANS) measurements have been performed on long-flight-path pinhole-collimation SANS instruments using, as a two-dimensional position-sensitive detector, both a neutron imaging plate, incorporating gadolinium, and a two-step transfer method, with dysprosium foil as the image transfer medium. The reduced pixel size of the imaging plates provides definite advantages over a conventional position-sensitive gas proportional counter in certain specific situations, namely when limited space necessitates a short sample-to-detector distance, when only small samples (comparable in size to the detector pixels) are available, or when used in conjunction with focusing beam optics.

Cheng, Y.T.

2000-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

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) led to an accurate modeling of nuclear binding energies for heavier nuclei. These results lead to the rather obvious 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 an excellent description 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

382

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

383

The discovery of the electron, proton, and neutron  

Science Journals Connector (OSTI)

The discovery of the electron, proton, and neutron ... Brief history of the discovery of the electron, proton, and neutron. ...

Barrie M. Peake

1989-01-01T23:59:59.000Z

384

DOSE RATES FROM NEUTRON ACTIVATION OF FUSION REACTOR COMPONENTS  

E-Print Network (OSTI)

NEUTRON ACTIVATION OF FUSION REACTOR C01WONENTS LawrenceNeutron Activation of Fusion Reactor Components Lawrence

Ruby, Lawrence

2014-01-01T23:59:59.000Z

385

Neutron Activation Cross Sections with SbBe Neutrons  

Science Journals Connector (OSTI)

The neutron activation cross sections near 25 kev have been measured for about 50 nuclei. Gamma-ray scintillation spectrometers with known efficiency were used to compare the radioactivities produced by the several nuclei with I128. This gave a significant increase in sensitivity and precision over direct beta-counting methods in many cases. Absolute standardization was obtained through scintillation-beta-counting the I128 in NaI(Tl) crystals irradiated with a neutron source calibrated by the manganese bath technique.

R. L. Macklin; N. H. Lazar; W. S. Lyon

1957-07-15T23:59:59.000Z

386

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

387

Delayed neutron measurements of 232Th neutron-induced fission  

Science Journals Connector (OSTI)

Abstract Delayed neutrons (DN) play an important role in nuclear reactor physics. Innovative critical reactor studies bring to light the need of new DN yields data. For the thorium fuel cycle DN data for 232Th is needed. In the literature, significant discrepancies were observed for energies below 4MeV and data are dispersed around 14MeV. Therefore DN absolute yields from 232Th fission have been determined at the PTB Ion Accelerator Facility in Braunschweig. A consistent set of data has been measured for incident neutrons with energies of 2, 3, 4, 6, 7, 10 and 16MeV.

X. Ledoux; D. Dor; M. Mosconi; R. Nolte; S. Roettger; S. Varet

2015-01-01T23:59:59.000Z

388

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

389

Neutron Diffraction of Ice in Hydrogels  

Science Journals Connector (OSTI)

Neutron Diffraction of Ice in Hydrogels ... (14, 15) Neutrons are also especially suited for studying D2O water in hydrogels because hydrogen atoms (H) on the polymer chains are not detectable. ...

Yurina Sekine; Tomoko Ikeda-Fukazawa; Mamoru Aizawa; Riki Kobayashi; Songxue Chi; Jaime A. Fernandez-Baca; Hiroki Yamauchi; Hiroshi Fukazawa

2014-08-26T23:59:59.000Z

390

Spin in the Neutron | Jefferson Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Spin in the Neutron NEWPORT NEWS, Va. - Puzzling out the source of proton and neutron spin is part of the ongoing experimental effort at Jefferson Lab to understand their structure...

391

Neutron Scattering Methods of Investigating Clay Systems  

Science Journals Connector (OSTI)

Of the techniques surveyed in the present proceedings, neutron scattering is probably the least familiar to clay ... a rather simple account of the theory of neutron scattering, while the third section describes ...

D. Keith Ross; Peter L. Hall

1980-01-01T23:59:59.000Z

392

10th LANSCE School on Neutron Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

10th LANSCE School on Neutron Scattering LANSCE 10th LANSCE School on Neutron Scattering Home Abstract Lecturers Hands-On Experiments Free Day About the School Sponsors FAQ's...

393

11th LANSCE School on Neutron Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

11th LANSCE School on Neutron Scattering LANSCE 11th LANSCE School on Neutron Scattering Home Abstract Lecturers Hands-On Experiments Free Day About the School Sponsors FAQ's...

394

Neutron Imaging of Diesel Particulate Filters  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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...

395

Quantum correlations in a noisy neutron interferometer  

E-Print Network (OSTI)

We investigate quantum coherences in the presence of noise by entangling the spin and path degrees of freedom of the output neutron beam from a noisy three-blade perfect crystal neutron interferometer. We find that in the ...

Wood, Christopher J.

396

Thermal neutron flux contours from criticality event  

SciTech Connect

The generation of thermal neutron flux contours from a criticality event is demonstrated for an idealized building with a criticality event in one of the rooms. The MCNP Monte Carlo computer code is used to calculate the thermal neutron flux.

Carter, L.L., Westinghouse Hanford

1996-08-01T23:59:59.000Z

397

A High-Efficiency Neutron Detector  

Science Journals Connector (OSTI)

... for neutrons with energies lying between 100 and 100,000 eV. A practicable thickness of boron-10 (2-2J cm.) is effectively 'black' to neutrons of up to 10, ...

J. C. DUCKWORTH; A. W. MERRISON; A. WHITTAKER

1950-01-14T23:59:59.000Z

398

Prompt Fission Neutron Spectrum of Pu241  

Science Journals Connector (OSTI)

The energy distribution of prompt neutrons resulting from the thermal-neutron-induced fission of Pu241 is measured. Fast time-of-flight techniques are employed in the neutron energy range 0.3 to 6.0 Mev. Proton recoils in emulsions are utilized for the measurement of neutron energies from 1.6 to 7.0 Mev. The experimentally determined Pu241 fission neutron spectrum is well represented by the Maxwellian distribution, N(E)?E12e-ET, where E is the neutron energy in Mev, N(E) the number of neutrons per unit energy interval, and T=1.3350.034 Mev. The measured average Pu241 fission neutron energy is 2.0020.051 Mev.

A. B. Smith; R. K. Sjoblom; J. H. Roberts

1961-09-15T23:59:59.000Z

399

Polarized neutron reflectometry at Dhruva reactor  

Science Journals Connector (OSTI)

Polarized neutron reflectometry (PNR) is an ideal non-destructive ... have installed a position sensitive detector-based polarized neutron reflectometer at Dhruva reactor, Trombay. In ... the chemical structure o...

Surendra Singh; Saibal Basu

2004-08-01T23:59:59.000Z

400

SHARP Neutronics Expanded | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SHARP Neutronics Expanded SHARP Neutronics Expanded SHARP Neutronics Expanded January 29, 2013 - 1:28pm Addthis Fully heterogeneous predictions of thermal neutron flux in a hypothetical metal-oxide-fueled PWR Fully heterogeneous predictions of thermal neutron flux in a hypothetical metal-oxide-fueled PWR SHARP neutronics Module Development 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. The existing high-fidelity solver package was extended to be independent of reactor technology and demonstrated with 2-D MOC and Sn method simulations of LWR core configurations. Efforts to support verification and validation of the DeCART code, used as one reference solution method by the SHARP code

Note: This page contains sample records for the topic "optical televiewer neutron" 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

SCIENCE HIGHLIGHTS 2008 ANNUAL REPORT ORNL NEUTRON SCIENCES neutrons.ornl.gov  

E-Print Network (OSTI)

diseased areas of the body. Targeted Drug Delivery Systems A young researcher in the Neutron Scattering SciSCIENCE HIGHLIGHTS 2008 ANNUAL REPORT ORNL NEUTRON SCIENCES neutrons.ornl.gov 14 Studies when it is introduced into the body. So we developed a synergistic approach, combining various neutron

402

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

403

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron/Proton Capture Neutron/Proton Capture Beam Line 13 Fuels Discovery Fever for Fundamental Physicists Research Contact: Geoff Greene June 2011, Written by Agatha Bardoel Serpil Kucuker Dogan (left) and Matthew Musgrave prepare a helium-3 cooling cell that is used to measure the angle at which the neutron beam strikes the liquid hydrogen sample. The simplest, most sensible " Big Bang" universe, theoretical physicists believe, would be one in which equal numbers of particles and antiparticles are formed in pairs. As the universe cools, most of these particles would encounter their antiparticles, and they would annihilate. "In many ways, the most reasonable universe would be one in which there is no matter," says the University of Tennessee's Dr. Geoff Greene.

404

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

phase behavior in carbon pores phase behavior in carbon pores Neutrons measure phase behavior in pores at angstrom size Compelling new methods for assessing carbon pores for hydrogen storage in fuel cells Research Contact: Yuri Melnichenko Jan. 2012, Written by Agatha Bardoel Yuri Melnichenko and Lilin He GP-SANS instrument scientist Yuri Melnichenko (left) and postdoctoral associate Lilin He. Researchers have measured the phase behavior of green house gases in pores at the angstrom level, using small-angle neutron scattering (SANS) at the Oak Ridge National Laboratory's High Flux Isotope Reactor. Yuri Melnichenko, an instrument scientist on the General-Purpose Small-Angle Neutron Scattering (GP-SANS) Diffractometer at ORNL's High Flux Isotope Reactor, his postdoctoral associate Lilin He and collaborators

405

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Atomic-Scale Behavior of "Cobalt Blue" Atomic-Scale Behavior of "Cobalt Blue" Neutron Analysis Reveals Unique Atomic-Scale Behavior of "Cobalt Blue" Research Contact: Gregory MacDougall ORNL News Release, September 2011, Media Contact: Bill Cabage Cobalt aluminate Just as cobalt blue's lustrous hue attracts artists and decorators, the antiferromagnetic properties of the responsible compound-cobalt aluminate-are attracting neutron scientists at DOE's Oak Ridge National Laboratory. Studies of magnetic interactions deep within the material's atomic structure may provide clues toward the development of energy-efficient technologies. (Light sconce image courtesy of B. Jefferson Bolender. Click image for high res version.) Neutron scattering studies of "cobalt blue," a compound prized by artists

406

Superconductivity Highlights | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Superconductivity SHARE Superconductivity Highlights 1-6 of 6 Results Doug Scalapino discusses "common thread" linking unconventional superconducting materials December 01, 2012 - Douglas Scalapino was the inaugural speaker for a new joint lecture series sponsored by the Spallation Neutron Source and the Center for Nanophase Materials Sciences at Oak Ridge National Laboratory. New VULCAN tests of Japanese cable for US ITER's central magnet system February 01, 2012 - Neutron testing of the Japanese-made superconducting cable for the central solenoid (CS) magnetic system for US ITER begins next Tuesday, says Ke An, lead instrument scientist for the VULCAN Engineering Materials Diffractometer at the Spallation Neutron Source. ARCS maps collaborative magnetic spin behavior in iron telluride

407

LANSCE | Lujan Neutron Scattering Center  

NLE Websites -- All DOE Office Websites (Extended Search)

Department of Energy, National Office of Science Department of Energy, National Office of Science science.energy.gov Department of Energy, National Nuclear Security Administration nnsa.energy.gov Lujan Neutron Scattering Center Logo Lujan Center Mission The Lujan Center delivers science by exploiting the unique characteristics of intense beams of pulsed neutrons for academia, national security, and industry. Lujan Center Vision The Lujan Center will operate a world class user program in the service of the nation. Lujan Center scientists will be recognized for their leadership and innovation in neutron scattering. Lujan Center at LANSCE The Lujan Center is one of five user facilities supported by the LANSCE accelerator which is stewarded. Funding to operate 10 instruments in a national user program is provided by the Department of Energy's Office of

408

NXS 2013 - Neutron Scattering School  

NLE Websites -- All DOE Office Websites (Extended Search)

5th National School on Neutron and X-Ray Scattering 5th National School on Neutron and X-Ray Scattering August 10-24, 2013 Argonne National Laboratory, Argonne, IL Oak Ridge National Laboratory, Oak Ridge, TN NXS2013 Schedule Participants Image Gallery Travel Info Thank you Lectures Lecture Notes/Videos Experiments ANL Facilities ANL Map (jpg) ANL Map (pdf) ANL Visitor's Guide ORNL Facilities HFIR Facility SNS Facility HFIR/SNS Map Wireless Networks ORNL Safety & Security Rules ORNL NSSA Weblink Contacts ANL ORNL 2013 NXS School Participants 2013 NXS Participants. NXS interveiws 2013 Click the image to download the video. Video Interviews: Participants answer questions about their experiences at NXS 2011. Your feedback about lectures and experiments is important for evaluating this year's Neutron and X-ray Scattering School and for making improvements for future participants. We sincerely hope that each of you will complete the survey by the end of the school.

409

Scattering of Neutrons in Polycrystals  

Science Journals Connector (OSTI)

Although elastic and first-order inelastic cross sections for a neutron against a Debye crystal have already been determined, expressions for higher order inelastic collisions have not been calculated, and would be very complex for the Debye model. The calculation of the total inelastic cross section involving the emission of an arbitrarily large number of phonons is here presented for a neutron against an Einstein polycrystal. The result, as one would expect, is essentially the same as that given by Fermi for amorphous scatterers, except at high neutron energies where we have calculated the cross section for the ejection of the struck nucleus from its lattice. The coherent elastic cross section is also determined; it is important for energies as high as 1 volt, and does not differ appreciably from that previously calculated for a Debye crystal. The total cross section, the sum of the coherent and incoherent parts, is compared with the experimental data on beryllium.

R. J. Finkelstein

1947-11-15T23:59:59.000Z

410

Fundamentals of specular neutron reflectometry  

SciTech Connect

An introduction to the methodology of neutron reflectometry is given in which the fundamental aspects regarding the actual performance of specular reflection measurements and subsequent analysis of the data are described. The application of this technique to the determination of interfacial structure or composition in thin film and multilayer materials of interest in the fields of magnetism, superconductivity, polymer science, electrochemistry, and biology is illustrated by specific examples. The microscopic information provided by neutron reflectivity which complements that obtained by other probes is emphasized, in particular information which is obtainable because of the inherent isotopic (most notably in the case of hydrogenous materials) or magnetic moment (both magnitude and orientation) sensitivity of the neutron.

Majkrzak, C.F. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Materials Science and Engineering Lab.

1995-12-31T23:59:59.000Z

411

HFIR History - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Home › Facilities › HFIR › History Home › Facilities › HFIR › History History of HFIR HFIR was constructed in the mid-1960s to fulfill a need for the production of transuranic isotopes (i.e., "heavy" elements such as plutonium and curium). Since then its mission has grown to include materials irradiation, neutron activation, and, most recently, neutron scattering. In 2007, HFIR completed the most dramatic transformation in its 40-year history. During a shutdown of more than a year, the facility was refurbished and a number of new instruments were installed, as well as a cold neutron source. The reactor was restarted in mid-May; it attained its full power of 85 MW within a couple of days, and experiments resumed within a week. Improvements and upgrades to HFIR include an overhaul of the

412

Optical data latch  

DOE Patents (OSTI)

An optical data latch is formed on a substrate from a pair of optical logic gates in a cross-coupled arrangement in which optical waveguides are used to couple an output of each gate to an photodetector input of the other gate. This provides an optical bi-stability which can be used to store a bit of optical information in the latch. Each optical logic gate, which can be an optical NOT gate (i.e. an optical inverter) or an optical NOR gate, includes a waveguide photodetector electrically connected in series with a waveguide electroabsorption modulator. The optical data latch can be formed on a III-V compound semiconductor substrate (e.g. an InP or GaAs substrate) from III-V compound semiconductor layers. A number of optical data latches can be cascaded to form a clocked optical data shift register.

Vawter, G. Allen (Corrales, NM)

2010-08-31T23:59:59.000Z

413

Neutron sources and transmutation of nuclear waste  

Science Journals Connector (OSTI)

Intense neutron sources with different energy spectra are of interest for a variety of applications. In my presentation, after briefly touching on the situation of radioactive waste in Italy, I will try to give a broad picture of Italian existing or proposed neutron sources based on accelerators, ranging from thermal to fast neutrons. I will also describe a specific project for a low-power ADS, aimed at studying neutron spectra as well as at demonstrating incineration and transmutation of nuclear waste.

M. Ripani

2013-01-01T23:59:59.000Z

414

Neutron scattering reaps Nobel for physics  

Science Journals Connector (OSTI)

... through its joint award to Bertrand Brockhouse and Clifford Shull for their work in developing neutron inelastic ... inelastic scattering and ...

Philip Ball

1994-10-20T23:59:59.000Z

415

Magnetism Highlights| Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Magnetism Magnetism SHARE Magnetism Highlights 1-5 of 5 Results ARCS maps collaborative magnetic spin behavior in iron telluride December 01, 2011 - Researchers have long thought that magnetism and superconductivity are mutually exclusive. The former typically involves localized atomic electrons. The latter requires freely propagating, itinerant electrons. Unexpected Magnetic Excitations in Doped Insulator Surprise Researchers October 01, 2011 - When doping a disordered magnetic insulator material with atoms of a nonmagnetic material, the conventional wisdom is that the magnetic interactions between the magnetic ions in the material will be weakened. Neutron Analysis Reveals Unique Atomic-Scale Behavior of "Cobalt Blue" September 01, 2011 - Neutron scattering studies of "cobalt blue," a

416

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Superconductivity Superconductivity Research Highlights Superconductivity Archive New Neutron Studies Support Magnetism's Role in Superconductors Recent neutron scattering experiments give strong evidence that if superconductivity is related to a material's magnetic properties, the same mechanisms are behind both copper-based, high-temperature superconductors and the newly discovered iron-based superconductors. The research was performed at SNS and HFIR and the ISIS Facility at Rutherford Appleton Laboratory in England. (2010) Published Work: "Evolution of spin excitations into the superconducting state in FeTe1-xSex" Contact: Mark Lumsden Advances in Unconventional Iron-Based Superconductors The discovery of more diverse superconducting materials will lead to more

417

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Biology & Medicine Archive Biology & Medicine Archive Research Highlights Biology & Medicine Archive Small-Angle Neutron Scattering Team Finds Structural Differences in Sindbis Virus Particles from Different Host Species (2010) Published Work: "The Structure of Sindbis Virus Produced from Vertebrate and Invertebrate Hosts as Determined by Small-Angle Neutron Scattering" Contact: Flora Meilleur Targeted Drug Delivery Systems Studies of the unique structure of synthetic molecules will help in the development of drugs that can target diseased areas of the body. This researched on dendrimers revealed how molecules function within solutions at different pH levels. (2008) Research in progress. Contact: Wei-Ren Chen "Intelligent" Polymers for Biomedical Technologies

418

Protein crystallography with spallation neutrons  

SciTech Connect

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

419

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

420

Vus and neutron beta decay  

E-Print Network (OSTI)

We discuss the effect of the recent change of $V_{\\rm us}$ by three standard deviations on the standard model predictions for neutron beta decay observables. We also discuss the effect the experimental error bars of $V_{\\rm us}$ have on such predictions. Refined precision tests of the standard model will be made by a combined effort to improve measurements in neutron beta decay and in strangeness-changing decays. By itself the former will yield very precise measurements of $V_{\\rm ud}$ and make also very precise predictions for $V_{\\rm us}$.

A. Garcia; G. Sanchez-Colon

2010-06-28T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Coherence length of neutron superfluids  

Science Journals Connector (OSTI)

The coherence length of superfluid neutron matter is calculated from the microscopic BCS wave function of a Cooper pair in momentum space making use of recent nucleon-nucleon potential models and including polarization (RPA) effects. We find as our main result that the coherence length is proportional to the Fermi momentum to pairing gap ratio, in good agreement with simple estimates used in the literature, with a nearly interaction independent constant of proportionality. Our calculations can be applied to the problem of inhomogeneous superfluidity of hadronic matter in the crust of a neutron star.

F. V. De Blasio; M. Hjorth-Jensen; . Elgary; L. Engvik; G. Lazzari; M. Baldo; H.-J. Schulze

1997-10-01T23:59:59.000Z

422

Final Report - Nucelar Astrophysics & Neutron Cross Section Measurements  

SciTech Connect

This enduring research program of 28 years has taken advantage of the excellent research facility of ORELA at Oak Ridge National Laboratory. The fruitful collaborations include a number of scientists from ORNL and some from LASL. This program which has ranged from nuclear structure determinations to astrophysical applications has resulted in the identification and/or the refinement of the nuclear properties of more than 5,000 nuclear energy levels or compound energy states. The nuclei range from 30Si to 250Cf, the probes range from thermal to 50 MeV neutrons, and the studies range from capture gamma ray spectra to total and differential scattering and absorption cross sections. Specific target nuclei studied include the following: 120Sn 124Sn 125Sn 113Sn 115Sn 117Sn 119Sn 249Cf 33S 34S 249Bk 186Os 187Os 188Os 30Si 32S 40Ca 48Ca 60Ni 54Fe 86Kr 88Sr 40Ar 122Sn 90Zr 122Sn(n,?) 208Pb 204Pb 52Cr 54Cr 50Cr 53Cr As can be seen, we have studied, on average, more than one isotope per year of grant funding and have focused on exploiting those elements having multiple isotopes in order to investigate systematic trends in nuclear properties, for the purpose of providing more stringent tests of the nuclear spherical optical model with a surface imaginary potential. We have investigated an l-dependence of the real-well depth of the spherical optical model; we have used these measurements to deduce the existence of doorway states in the compound nucleus; and in the total cross section measurements we have, in addition to resonance energies and widths, obtained values for the level density and neutron strength function. Due to the high neutron energy resolution of the ORELA and in some cases the addition of differential scattering cross section data, we have been able to disaggregate the spin states and provide level spacing and strength function for each partial wave in the neutron-nucleus interaction, in some cases up to d5/2. In the following we will summarize the most recent analyses of neutron total cross section measurements, some of which have not been previously reported.

Carlton, Robert F

2009-12-01T23:59:59.000Z

423

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

424

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

425

Neutron-Proton Scattering at Small Angles  

Science Journals Connector (OSTI)

24 May 1955 research-article Neutron-Proton Scattering at Small Angles...Thresher R. G. P. Voss R. Wilson Neutron-proton scattering has been measured from 6 to 61 5 degrees c.m. for neutrons of effective energy 105 3 and 137 5...

1955-01-01T23:59:59.000Z

426

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

427

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.

428

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

429

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

430

Residual Stresses in Weldments by Neutron Diffraction  

E-Print Network (OSTI)

Residual Stresses in Weldments by Neutron Diffraction Shanmukha Rao M, Jon James, Shirley Northover :- The neutron diffraction is determined from Bragg's law. When neutron propagate through crystal sample, Coherent, Incoherent and Absorption Scattering phenomena take place Weld MaterialsPlate materials Stress

Bandara, Arosha

431

Optics and Diagnostics  

NLE Websites -- All DOE Office Websites (Extended Search)

1 14 | Next | Last Back to Index Optics Optics processing of Target Wedged Focus Lens into cleaningcoating frame. Photo Number: 2013-048765...

432

Optics and Diagnostics  

NLE Websites -- All DOE Office Websites (Extended Search)

3 14 | Next | Last Back to Index Optics Alignment Conducting an optics alignment after replacement of a Pockels Cell in the clean room. Photo Number: 2013-050691...

433

Optics and Diagnostics  

NLE Websites -- All DOE Office Websites (Extended Search)

9 14 | Next | Last Back to Index Optics Processing Optics for the National Ignition Facility must be manufactured to exacting standards. To ensure quality, precise measurements...

434

Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem  

SciTech Connect

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

435

2002 REVIEW OF NEUTRON AND NON NEUTRON NUCLEAR DATA.  

SciTech Connect

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

436

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

437

Resonant Cyclotron Scattering and Comptonization in Neutron Star Magnetospheres  

E-Print Network (OSTI)

Resonant cyclotron scattering of the surface radiation in the magnetospheres of neutron stars may considerably modify the emergent spectra and impede efforts to constraint neutron star properties. Resonant cyclotron scattering by a non-relativistic warm plasma in an inhomogeneous magnetic field has a number of unusual characteristics: (i) in the limit of high resonant optical depth, the cyclotron resonant layer is half opaque, in sharp contrast to the case of non-resonant scattering. (ii) The transmitted flux is on average Compton up-scattered by ~ $1+ 2 beta_T$, where $\\beta_T$ is the typical thermal velocity in units of the velocity of light; the reflected flux has on average the initial frequency. (iii) For both the transmitted and reflected fluxes the dispersion of intensity decreases with increasing optical depth. (iv) The emergent spectrum is appreciably non-Plankian while narrow spectral features produced at the surface may be erased. We derive semi-analytically modification of the surface Plankian emission due to multiple scattering between the resonant layers and apply the model to anomalous X-ray pulsar 1E 1048.1--5937. Our simple model fits just as well as the ``canonical'' magnetar spectra model of a blackbody plus power-law.

Maxim Lyutikov; Fotis P. Gavriil

2005-07-22T23:59:59.000Z

438

Optical NAND gate  

SciTech Connect

An optical NAND gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator and a photodetector. One pair of the optical waveguide devices is electrically connected in parallel to operate as an optical AND gate; and the other pair of the optical waveguide devices is connected in series to operate as an optical NOT gate (i.e. an optical inverter). The optical NAND gate utilizes two digital optical inputs and a continuous light input to provide a NAND function output. The optical NAND gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Skogen, Erik J. (Albuquerque, NM); Raring, James (Goleta, CA); Tauke-Pedretti, Anna (Albuquerque, NM)

2011-08-09T23:59:59.000Z

439

The Neutron-Proton and Neutron-Carbon Scattering Cross Sections for Fast Neutrons  

Science Journals Connector (OSTI)

An experimental investigation of the total scattering cross section of hydrogen and carbon for neutrons of energies 0.35 to 6.0 Mev is reported. Neutrons of discrete energies were produced by particle bombardment of lithium, carbon, and heavy water targets. Transmissions of cyclohexane (C6H12) and graphite scatterers under conditions of good geometry were measured. Results for ?s(H) are compared with the theoretical interpretations of Bohm and Richman in a later paper and to the experimental results of D. Frisch at lower energies in a companion paper. It is estimated that ?s(H) and ?s(C) are determined to approximately five percent.

Carl L. Bailey; William E. Bennett; Thor Bergstralth; Richard G. Nuckolls; Hugh T. Richards; John H. Williams

1946-11-01T23:59:59.000Z

440

Neutron scattering of transuranium materials  

SciTech Connect

A number of neutron experiments on transuranium materials are reviewed. Purpose of these experiments, which range from studies of crystal fields in the oxides to excitations in PuSb, is to increase our understanding of the 5f electron behavior across the first half of the actinide series. Comparisons are made with the more familiar uranium analogues.

Lander, G.H.

1986-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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

Scattering of Neutrons by Protons  

Science Journals Connector (OSTI)

... THEORETICAL investigations of the interaction of protons and neutrons have been given by Wigner, Heisenberg and Major ana. A very valuable check on ... ana. A very valuable check on their conclusions is provided by the study of the scattering cross-section of the hydrogen nucleus for ...

E. T. BOOTH; C. HURST

1936-12-12T23:59:59.000Z

442

HFIR Experiment Facilities | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Experiment Facilities Experiment Facilities HFIR Experiment Facilities Neutron Scattering Facilities Target Positions Experiment Facilities in the Beryllium Reflector Large Removable Beryllium Facilities Small Removable Beryllium Facilities Control-Rod Access Plug Facilities Small Vertical Experiment Facilities Large Vertical Experiment Facilities Hydraulic Tube Facility Peripheral Target Positions Neutron Activation Analysis (NAA) Laboratory and Pneumatic Tube Facilities Slant Engineering Facilities Gamma Irradiation Facility Quality Assurance Requirements Contact Information Neutron Scattering Facilities The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be designed exclusively for cold neutron experiments, located in a guide hall south of the reactor

443

Dr. Andrey Podlesnyak | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Andrey Podlesnyak Andrey Podlesnyak Dr. Andrey Podlesnyak Instrument Scientist: Cold Neutron Chopper Spectrometer (CNCS), SNS Education PhD in Physics, Institute for Metal Physics, Ekaterinburg, Russia Description of Research 2008 - present Instrument Scientist, Cold Neutron Chopper Spectrometer, Neutron Scattering Sciences Division, Oak Ridge National Laboratory 2006 - 2008 Instrument Scientist, single crystal diffractometer E-4, Hahn-Meitner-Institut, Berlin, Germany 2002 - 2006 Instrument Scientist, TOF spectrometer FOCUS, Laboratory for Neutron Scattering, ETH Zurich & Paul Scherrer Institute, Switzerland 2000 - 2002 Instrument Scientist, triple-axis spectrometer TASP, Laboratory for Neutron Scattering, ETH Zurich & Paul Scherrer Institute, Switzerland 1994 - 2000 Physicist, Institute for Metal Physics, Ekaterinburg, Russia

444

Neutrons from D + T and D + H  

Science Journals Connector (OSTI)

Continuous neutron spectra produced by bombarding T and H with deuterons have been measured using time-of-flight spectrometry for a wide range of deuteron bombarding energies and neutron emission angles. The observed spectra for the D + T interaction exhibit two maxima, one occurring at a neutron energy slightly below the maximum possible energy of neutrons from deuteron breakup and the other occurring several MeV lower. The high energy peak is interpreted as arising from monoenergetic neutrons which leave He4 in an excited state at 20 MeV. For the D + H interaction the observed spectra exhibit no structure.

C. H. Poppe; C. H. Holbrow; R. R. Borchers

1963-01-15T23:59:59.000Z

445

Experiment Design and Analysis Guide - Neutronics & Physics  

SciTech Connect

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

446

Effect of Si interlayers on the magnetic and mechanical properties of Fe/Ge neutron polarizing multilayer mirrors  

SciTech Connect

The neutron polarizing supermirror is one of the most important optical devices for polarizing neutron beams. To meet a variety of research demands, neutron polarizing supermirrors need to display high polarization efficiencies at low external magnetic fields. Fe/Si and Fe/Ge multilayers are typically used in neutron polarizing supermirrors because the contrast in scattering length densities almost vanishes for spin-down neutrons. The Fe/Si/Ge/Si multilayer, obtained by adding thin interlayers of Si to an Fe/Ge multilayer, is effective in reducing the external field strength necessary to achieve efficient neutron polarization. To gain insight into the mechanism that controls the required external field strength for a neutron polarizing supermirror, we investigated the magnetic and mechanical properties of Fe/Si, Fe/Ge, and Fe/Si/Ge/Si multilayers. The external field strength required to achieve efficient neutron polarization was found to be proportional to the compressive film stress. The compressive stress of the Fe/Si/Ge/Si multilayer was smaller by a factor of 4.4 and 2.7 than that of Fe/Si and Fe/Ge multilayers, respectively. These measurements and analyses showed that a reduction in the compressive film stress in the Fe/Si/Ge/Si multilayer permits the use of lower external field strength to achieve efficient neutron polarization. X-ray photoelectron spectroscopic studies showed that the formation of a Ge-Si solid solution in the Ge layer may explain the marked reduction in compressive stress in the case of the Fe/Si/Ge/Si multilayer. This study confirmed that a reduction in compressive film stress is very important for a high-performance neutron polarizing supermirror.

Maruyama, R.; Yamazaki, D.; Hayashida, H.; Soyama, K. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Okayasu, S. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Takeda, M. [J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Quantum Beam Science Directorate, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Zettsu, N.; Nagano, M.; Yamamura, K. [Research Center for Ultra-precision Science and Technology, Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan)

2012-03-15T23:59:59.000Z

447

Solid oxygen as converter for the production of ultra-cold neutrons  

E-Print Network (OSTI)

We have investigated solid oxygen as a converter material for the production of ultra-cold neutrons. In a first series of experiments the crystal preparation was examined. An optically semi-transparent solid $\\alpha$-oxygen crystal has been prepared. In a second series of experiments such a crystal prepared indentically as in the first series of experiments has been exposed to the cold neutron flux of the MEPHISTO beam line of the FRM II. Ultra-cold neutrons produced inside the oxygen crystal have been extracted and the count rates have been measured at different converter temperatures. The results of these measurements give a clear signal of the superthermal UCN production mechanism in $\\alpha$-oxygen. The mean free loss length of UCN inside the crystal at a temperature of 5\\,K was determined to be in the order of $20\\,\\mathrm{cm}$.

A. Frei; F. Bhle; R. Bozhanova; E. Gutsmiedl; T. Huber; J. Klenke; S. Paul; S. Wlokka

2010-06-15T23:59:59.000Z

448

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

NLE Websites -- All DOE Office Websites (Extended Search)

monochromatization Automation and control of micro... development for Data acquisition Neutron scattering data analysis Neutron detection Instrument control 12;... Neutronic...

449

Accelerator-based neutron brachytherapy  

Science Journals Connector (OSTI)

The development and evaluation of a new approach to neutronbrachytherapy is described. This approach accelerator-based fast neutronbrachytherapy involves the interstitial or intracavity insertion of a narrow evacuated accelerator beam tube such that its tip containing the neutron-producing target is placed in or near the tumor.Tumorirradiation via brachytherapy should result in a reduction in the healthy tissue complication rate observed when poorly collimated and/or low energy external neutron beam are used for treatment. Use of a variable energy accelerator provides an advantage over isotopesources for neutronbrachytherapy in that the neutron beam can be turned on and off and the neutronenergy spectrum varied for different treatment applications. A prototype accelerator-based fast neutronbrachytherapy device 10 cm long and 6 mm outer diameter has been constructed and evaluated in terms of its dosimetric output treatment time and practical feasibility. The prototype device is a tube-in-tube design with cooling water running between the inner and outer tubes to cool a beryllium target located at the tip of the inner tube. Cooling experiments were performed and coupled with Monte Carlo simulations to determine treatment times as a function of heat load for various neutron-producing reactions. Using the 9 Be (d n) 10 B reaction at E d =1.5 MeV 66 RBE-Gy (12 Gy physical dose) can be delivered to the boundary of a 4.5-cm-diam treatment volume in 8 min at a heat load of 130 W. Other reactions offer similar treatment times at somewhat higher bombarding energies and also show higher potential for dose enhancement with the boron-10 neutron capture reaction due to their softer neutron spectra. Dose distributions in a water phantom were measured with the prototype brachytherapy tube using the dual-ion chamber technique for the 9 Be (d n) 10 B reaction at E d =1.5 MeV. The measurements and simulations agree within uncertainties and demonstrate that fast neutrons contribute more than 90% of the dose to the target volume.

Haijun Song; Jacquelyn C. Yanch; Robert E. Klinkowstein

2002-01-01T23:59:59.000Z

450

Choppers - Instrument Support | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Choppers Neutron Choppers The primary mission of the Neutron Chopper Team is to provide functional, reliable, safe, and operationally proven neutron chopper systems as required by the SNS instrument beam lines. Type of Choppers Activities Facilities Equipment TOP2 T0 chopper installed and operating in a CTF lower level chopper test bay. (Click for a larger picture) Chopper technician Bill Jordan recording chopper balance data. Types of Choppers Neutron choppers are rotating mechanical devices designed to block the neutron beam for some fraction of each revolution of the chopper. Our goal is to have at least three different functional classes of neutron choppers available for user experiments. Most, if not all, of these will be designed in standard forms that are interchangeable among the instruments. Most

451

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

SciTech Connect

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

452

Fiber optic connector  

DOE Patents (OSTI)

A fiber optic connector and method for connecting composite materials within which optical fibers are imbedded. The fiber optic connector includes a capillary tube for receiving optical fibers at opposing ends. The method involves inserting a first optical fiber into the capillary tube and imbedding the unit in the end of a softened composite material. The capillary tube is injected with a coupling medium which subsequently solidifies. The composite material is machined to a desired configuration. An external optical fiber is then inserted into the capillary tube after fluidizing the coupling medium, whereby the optical fibers are coupled.

Rajic, Slobodan (Knoxville, TN); Muhs, Jeffrey D. (Lenior City, TN)

1996-01-01T23:59:59.000Z

453

Optical NOR gate  

DOE Patents (OSTI)

An optical NOR gate is formed from two pair of optical waveguide devices on a substrate, with each pair of the optical waveguide devices consisting of an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical NOR gate utilizes two digital optical inputs and a continuous light input to provide a NOR function digital optical output. The optical NOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

Skogen, Erik J. (Albuquerque, NM); Tauke-Pedretti, Anna (Albuquerque, NM)

2011-09-06T23:59:59.000Z

454

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

455

Neutron Science In the News - 2014 | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Neutron Science In the News - 2014 Neutron Science In the News - 2014 Because some media sources archive past articles and require a subscription for access, some of the links below might not be active. If a citation listed here is no longer available, please contact the newspaper or your library directly. January Multiphysics Simulations Transmuting Designs for Safer Nuclear Power Engineering.com 1/7 Like the rest of the US's nuclear research reactors, Oak Ridge National Lab's (ORNL) high flux isotope reactor (HFIR) is moving from high-enriched uranium (HEU) fuel to low-enriched uranium (LEU). As such, the safety of the system must be assessed to incorporate the changes in fuel properties and the subsequently modified fuel plate. Due to the recent growth in multiphysics, fluid-structure dynamics

456

Neutron-Proton Interaction: The Scattering of Neutrons by Protons  

Science Journals Connector (OSTI)

The inadequacy of present theories of proton-neutron interaction is shown in work in which 730 proton tracks produced by collisions of fast neutrons with hydrogen nuclei have been studied and measured to determine the distribution-in-angle. The recoils have been observed in three gaseous media; hydrogen, ethylene and hydrogen sulphide, by the use of a sylphon-type Wilson chamber and two cameras mounted in such a way as to give two views of each recoil, thus enabling a stereoscopic projection and a direct measurement of the angle of scattering to be made for each track. In this way it is found that the intensity distribution of recoil protons shows a maximum in the neighborhood of 25. The distribution referred to unit solid angle in each angle interval exhibits a sharp maximum at 0 in close agreement with the work of Kurie, but in contradiction to those who have believed the scattering to be of the classical type. Various factors, both geometrical and statistical, which may lead to distortion of the angular distribution are cited, and it is shown that their effect is taken into account in these experiments, but not necessarily in those of the other workers. The contradictions in the results reported at present in the literature are assumed to arise from these factors. The bearing of the distribution found in these experiments on the neutron-proton inter-action is considered in the light of the modern nuclear theories and evidence is deduced for an exchange or some other type of interaction at energies lower than predicted on the basis of these theories. The mechanism favored by both the classical and quantum theories, namely elastic collision of like spheres, is inadequate to explain the distribution. The present distribution is found to be consistent with Fermi's explanation for the efficiency of hydrogen nuclei in slowing fast neutrons, but indicates an even higher efficiency.

William D. Harkins; Martin D. Kamen; Henry W. Newson; David M. Gans

1936-12-01T23:59:59.000Z

457

Neutron charge radius and the neutron electric form factor  

Science Journals Connector (OSTI)

For nearly forty years, the Galster parametrization has been employed to fit existing data for the neutron electric form factor, GEn, vs the square of the four-momentum transfer, Q2. 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 GEn 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 GEn (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.

T. R. Gentile and C. B. Crawford

2011-05-12T23:59:59.000Z

458

2010 Review of neutron and non-neutron nuclear data  

SciTech Connect

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

459

Cyclotron-based neutron source for BNCT  

SciTech Connect

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

460

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

Note: This page contains sample records for the topic "optical televiewer neutron" 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.


461

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Fast Proton Hopping in Ice Fast Proton Hopping in Ice Fast Proton Hopping in Ice (Ih) Confirmed by Quasi-Elastic Neutron Scattering "With these results, we have an experimental proof of fast proton hopping in ice," researcher says Research Contact: Alexander Kolesnikov June 2011, Written by Agatha Bardoel Protons (positive hydrogen ions) in an ice lattice have been "seen" to fast hop from one water molecule to another, using quasi-elastic neutron scattering at the SNS Backscattering Spectrometer, BASIS. This fundamental phenomenon that occurs at very low temperatures has important consequences for future investigations of proton conductivity in solids. The research could open the door to a new understanding of how electrolytes work in a system. Proton hopping in ice occurs when "extra" protons diffuse through

462

Research Highlights | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Battery Studies Battery Studies A Wealth of New Battery Research at SNS and HFIR Technical Contacts: Xun-Li Wang, Ashfia Huq, Jung-Hyun Kim October 2010, Written by Carolyn Krause Neutron scattering, capable of looking deep inside the structures of materials used in technologies such as batteries and fuel cells, is a natural tool for research in energy storage and production. Several users of neutron scattering instruments at the SNS and HFIR presented details of their energy-related research to prospective scientific facility users attending the opening session of ORNL's User Week at SNS. Most of the energy-related research reported in the session dealt with batteries for electric and hybrid electric cars. Better batteries are also needed for storing excess electricity generated by wind and solar power so

463

Workshop on neutron capture therapy  

SciTech Connect

Potentially optimal conditions for Neutron Capture Therapy (NCT) may soon be in hand due to the anticipated development of band-pass filtered beams relatively free of fast neutron contaminations, and of broadly applicable biomolecules for boron transport such as porphyrins and monoclonal antibodies. Consequently, a number of groups in the US are now devoting their efforts to exploring NCT for clinical application. The purpose of this Workshop was to bring these groups together to exchange views on significant problems of mutual interest, and to assure a unified and effective approach to the solutions. Several areas of preclinical investigation were deemed to be necessary before it would be possible to initiate clinical studies. As neither the monomer nor the dimer of sulfhydryl boron hydride is unequivocally preferable at this time, studies on both compounds should be continued until one is proven superior.

Fairchild, R.G.; Bond, V.P. (eds.)

1986-01-01T23:59:59.000Z

464

Neutron in Strong Magnetic Fields  

E-Print Network (OSTI)

Relativistic world-line Hamiltonian for strongly interacting 3q systems in magnetic field is derived from the path integral for the corresponding Green's function. The neutral baryon Hamiltonian in magnetic field obeys the pseudomomentum conservation and allows a factorization of the c.m. and internal motion. The resulting expression for the baryon mass in magnetic field is written explicitly with the account of hyperfine, OPE and OGE (color Coulomb) interaction. The neutron mass is fast decreasing with magnetic field, losing 1/2 of its value at eB~0.25 GeV^2 and is nearly zero at eB~0.5 GeV^2. Possible physical consequences of the calculated mass trajectory of the neutron, M_n(B), are presented and discussed.

M. A. Andreichikov; B. O. Kerbikov; V. D. Orlovsky; Yu. A. Simonov

2013-12-08T23:59:59.000Z

465

Spin Waves and Neutron Scattering  

Science Journals Connector (OSTI)

A review is given of the problems in this field and of the possibilities opened up by the fact that neutron scattering gives access to the time?dependent spin?correlation function in magnets over virtually the whole range of q t and T. New experimental results are given in connection with magnon energy linewidth and renormalization and some data are presented for the spin?wave stiffness of bcc 3d transition?metal alloys as a function of electron concentration showing effects explained by the electronic density?of?states curve. It is pointed out that the ground?state fluctuations of magnets give rise to effects in the formulas for neutron scattering.

R. D. Lowde

1965-01-01T23:59:59.000Z

466

A toolkit for epithermal neutron beam characterisation in BNCT  

Science Journals Connector (OSTI)

......beams used in boron neutron capture...of different isotopes irradiated both...in-phantom for determination of the neutron...INTRODUCTION In boron neutron capture...of different isotopes irradiated both...in-phantom for determination of the neutron...Body Burden Boron Neutron Capture......

Iiro Auterinen; Tom Sern; Jouni Uusi-Simola; Antti Kosunen; Sauli Savolainen

2004-08-01T23:59:59.000Z

467

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

468

EPR dosimetry in a mixed neutron and gamma radiation field  

Science Journals Connector (OSTI)

......radicals induced by ionizing...of radio-induced free radicals...Mura, the neutron dose component...neutrons of energy comparable to fission spectrum(15...component of thermal neutron in the SILENE...34 for fission neutrons...shape line spectrum modification...SILENE neutron energies. Nevertheless......

F. Trompier; P. Fattibene; D. Tikunov; A. Bartolotta; A. Carosi; M. C. Doca

2004-08-01T23:59:59.000Z

469

Parallel Monte Carlo reactor neutronics  

SciTech Connect

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

470

Neutron scattering at high pressure  

Science Journals Connector (OSTI)

Neutron scattering spectra at pressures up to 30 kilobar in the temperature range 3004 K have been obtained with a compact clamped type apparatus. The pressure cell geometry by allowing the detection of neutronsscattered in a plane makes it compatible with operation on crystal spectrometers both for elastic and inelastic scattering. The instrument is light (4.5 kg) and easy to move. An external diameter of 68 mm makes the pressure cell adaptable to standard cryostats or furnaces.

D. Bloch; J. Paureau; J. Voiron; G. Parisot

1976-01-01T23:59:59.000Z

471

Neutron diagnostics for mirror hybrids  

SciTech Connect

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

472

Neutron Detection with Mercuric Iodide  

SciTech Connect

Mercuric iodide is a high-density, high-Z semiconducting material useful for gamma ray detection. This makes it convertible to a thermal neutron detector by covering it with a boron rich material and detecting the 478 keV gamma rays resulting from the {sup 10}B(n, {alpha}){sup 7}Li* reaction. However, the 374 barn thermal capture cross section of {sup nat}Hg, makes the detector itself an attractive absorber, and this has been exploited previously. Since previous work indicates that there are no low-energy gamma rays emitted in coincidence with the 368 keV capture gamma from the dominant {sup 199}Hg(n, {gamma}){sup 200}Hg reaction, only the 368 keV capture gamma is seen with any efficiency a relatively thin (few mm) detector. In this paper we report preliminary measurements of neutrons via capture reactions in a bare mercuric iodide crystal and a crystal covered in {sup 10}B-loaded epoxy. The covered detector is an improvement over the bare detector because the presence of both the 478 and 368 keV gamma rays removes the ambiguity associated with the observation of only one of them. Pulse height spectra, obtained with and without lead and cadmium absorbers, showed the expected gamma rays and demonstrated that they were caused by neutrons.

Bell, Z.A.

2003-06-17T23:59:59.000Z

473

Neutron-proton pairing reexamined  

Science Journals Connector (OSTI)

We reexamine neutron-proton pairing as a phenomenon that should be explainable in a microscopic theory of nuclear binding energies. Empirically, there is an increased separation energy when both neutron and proton numbers are even or if they are both odd. The enhancement is present at some level in nearly all nuclei: the separation energy difference has the opposite sign in less than 1% of the cases in which sufficient data exist. We discuss the possible origin of the effect in the context of density functional theory (DFT) and its extensions. Neutron-proton pairing from mean-field theory does not seem promising to explain the effect. Gao and Chen have argued that a significant part of the increased binding in odd-odd deformed nuclei might arise as a recoupling energy, and we find a similar result for spherical nuclei. This suggests that the DFT should be extended by angular momentum projection to reach an accuracy capable of treating this effect.

W. A. Friedman and G. F. Bertsch

2007-11-07T23:59:59.000Z

474

The neutron-proton mass difference from a composite neutron model  

Science Journals Connector (OSTI)

The authors previous results in general relativity about the neutron as a composite (p+-? ?(p+-p?)-e?...), having yielded the correct order of magnitude of the binding energy of this composite neutron

M. Sachs

1996-12-01T23:59:59.000Z

475

Neutron Reflection Method for the Fast Estimation of the Neutron Removal Cross Section in Complex Materials  

Science Journals Connector (OSTI)

The present paper is devoted to expand the use of neutron reflection method for the fast estimation of ... dependence of the removal cross section from the neutron reflection coefficient was found. The sensitivit...

L. Desdin; L. M. Garca

2000-11-01T23:59:59.000Z

476

The neutron binding energy in the neutron-rich nucleus93Sr  

Science Journals Connector (OSTI)

The neutron binding energy in93Sr has been determined to (52306) keV from energy correspondences between levels defined by ?-ray transitions and ?-delayed neutron emission.

K. -L. Kratz; H. Ohm

1980-01-01T23:59:59.000Z

477

HFIR Experiment Facilities | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering 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 designed exclusively for cold neutron experiments, located in a guide hall south of the reactor building. The currently available instruments and the status of new instruments can be found on the HFIR Instrument Systems pages. Particularly prominent in the cold neutron guide hall are the two small-angle neutron scattering (SANS) instruments, each terminating in a 70-ft-long evacuated cylinder containing a large moveable neutron detector. In addition to the instruments, laboratories are equipped for users to prepare samples. Perhaps the most exciting development at HFIR is the successfully

478

Dr. Georg Ehlers - ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Georg Ehlers Georg Ehlers Lead Instrument Scientist: Cold Neutron Chopper Spectrometer (CNCS), SNS Education PhD in Experimental Condensed Matter Physics, the Hahn Meitner Institut, in Berlin, Germany Description of Research Dr. Ehlers joined the Spallation Neutron Source (SNS) in 2003 as the lead instrument scientist for beam line 5, the Cold Neutron Chopper Spectrometer (CNCS). CNCS is a high-resolution, direct geometry, cold neutron, inelastic multi-chopper spectrometer, designed to make use of neutrons with an energy of <50 meV. Before joining the SNS, Dr. Ehlers worked at the Institute Laue-Langevin (ILL), a leading European neutron research facility situated in Grenoble, France for six years. At the ILL, he was instrument-responsible for the spin-echo spectrometers IN11 and IN15, and established a strong research

479

Neutron-chamber detectors and applications  

SciTech Connect

Detector applications in Nuclear Safeguards and Waste Management have included measuring neutrons from fission and (alpha,n) reactions with well-moderated neutron proportional counters, often embedded in a slab of polyethylene. Other less-moderated geometries are useful for detecting both bare and moderated fission-source neutrons with good efficiency. The neutron chamber is an undermoderated detector design comprising a large, hollow, polyethylene-walled chamber containing one or more proportional counters. Neutron-chamber detectors are relatively inexpensive; can have large apertures, usually through a thin chamber wall; and offer very good detection efficiency per dollar. Neutron-chamber detectors have also been used for monitoring vehicles and for assaying large crates of transuranic waste. Our Monte Carlo calculations for a new application (monitoring low-density waste for concealed plutonium) illustrate the advantages of the hollow-chamber design for detecting moderated fission sources. 9 refs., 6 figs., 2 tabs.

Fehlau, P.E.; Atwater, H.F.; Coop, K.L.

1990-01-01T23:59:59.000Z

480

Atmospheres and radiating surfaces of neutron stars  

E-Print Network (OSTI)

The beginning of the 21st century was marked by a breakthrough in the studies of thermal radiation of neutron stars. Observations with modern space telescopes have provided a wealth of valuable information. Being correctly interpreted, this information can elucidate physics of superdense matter in the interiors of these stars. The theory of formation of thermal spectra of neutron stars is based on the physics of plasmas and radiative processes in stellar photospheres. It provides the framework for interpretation of observational data and for extracting neutron-star parameters from these data. This paper presents a review of the current state of the theory of surface layers of neutron stars and radiative processes in these layers, with the main focus on the neutron stars that possess strong magnetic fields. In addition to the conventional deep (semi-infinite) atmospheres, radiative condensed surfaces of neutron stars and "thin" (finite) atmospheres are also considered.

Potekhin, A Y

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "optical televiewer neutron" 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.


481

Prospects for neutron-antineutron transition search  

SciTech Connect

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

482

DIRECTIONAL DETECTION OF A NEUTRON SOURCE.  

SciTech Connect

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

483

Latching micro optical switch  

DOE Patents (OSTI)

An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

Garcia, Ernest J; Polosky, Marc A

2013-05-21T23:59:59.000Z

484

New precision measurements of free neutron beta decay with cold neutrons  

E-Print Network (OSTI)

Precision measurements in free neutron beta decay serve to determine the coupling constants of beta decay, and offer several stringent tests of the Standard Model. This paper describes the free neutron beta decay program planned for the Fundamental Physics Beamline at the Spallation Neutron Source at Oak Ridge National Laboratory, and puts it into the context of other recent and planned measurements of neutron beta decay observables.

S. Baeler; J. D. Bowman; S. Penttil; D. Po?ani?

2014-08-20T23:59:59.000Z

485

Aerial Neutron Detection: Neutron Signatures for Nonproliferation and Emergency Response Applications  

SciTech Connect

From 2007 to the present, the Remote Sensing Laboratory has been conducting a series of studies designed to expand our fundamental understanding of aerial neutron detection with the goal of designing an enhanced sensitivity detection system for long range neutron detection. Over 35 hours of aerial measurements in a helicopter were conducted for a variety of neutron emitters such as neutron point sources, a commercial nuclear power reactor, nuclear reactor spent fuel in dry cask storage, depleted uranium hexafluoride and depleted uranium metal. The goals of the project were to increase the detection sensitivity of our instruments such that a 5.4 104 neutron/second source could be detected at 100 feet above ground level at a speed of 70 knots and to enhance the long-range detection sensitivity for larger neutron sources, i.e., detection ranges above 1000 feet. In order to increase the sensitivity of aerial neutron detection instruments, it is important to understand the dynamics of the neutron background as a function of altitude. For aerial neutron detection, studies have shown that the neutron background primarily originates from above the aircraft, being produced in the upper atmosphere by galactic cosmic-ray interactions with air molecules. These interactions produce energetic neutrons and charged particles that cascade to the earths surface, producing additional neutrons in secondary collisions. Hence, the neutron background increases as a function of altitude which is an impediment to long-range neutron detection. In order to increase the sensitivity for long range detection, it is necessary to maintain a low neutron background as a function of altitude. Initial investigations show the variation in the neutron background can be decreased with the application of a cosmic-ray shield. The results of the studies along with a representative data set are presented.

Maurer, Richard J.; Stampahar, Thomas G.; Smith, Ethan X.; Mukhopadhyay, Sanjoy; Wolff, Ronald S.; Rourke, Timothy J.; LeDonne, Jeffrey P.; Avaro, Emanuele; Butler, D. Andre; Borders, Kevin L.; Stampahar, Jezabel; Schuck, William H.; Selfridge, Thomas L.; McKissack, Thomas M.; Duncan, William W.; Hendricks, Thane J.

2012-10-17T23:59:59.000Z

486

Elastic neutron-scattering experiments at the Geesthacht Neutron Facility (GeNF)  

Science Journals Connector (OSTI)

The Geesthacht Neutron Facility (GeNF) comprises experimental facilities for elastic neutron scattering for materials research and engineering problems as well as for environmental research purposes at the research reactor FRG-1. The experimental facilities for elastic neutron-scattering experiments at GeNF, most of which can be optimally used with polarized neutrons, will be presented. They are open to national and international users from universities and other research institutes at no cost.

R Kampmann; R Wagner

1997-01-01T23:59:59.000Z

487

Polarization Analysis of Thermal-Neutron Scattering  

Science Journals Connector (OSTI)

A triple-axis neutron spectrometer with polarization-sensitive crystals on both the first and third axes is described. The calculation of polarized-neutron scattering cross sections is presented in a form particularly suited to apply to this instrument. Experimental results on nuclear incoherent scattering, paramagnetic scattering, Bragg scattering, and spin-wave scattering are presented to illustrate the possible applications of neutron-polarization analysis.

R. M. Moon; T. Riste; W. C. Koehler

1969-05-10T23:59:59.000Z

488

A beam swinger for neutron scattering  

Science Journals Connector (OSTI)

A conceptual design is presented for a system that provides for varying the angle of incidence of neutron flux on a scattering target. This makes possible the use of long flight paths for time?of?flight spectroscopy of scattered neutrons. The system is also applicable to measurements of neutron induced charged particle reactions. Special emphasis is placed on the energy range of 50200 MeV.

C. D. Goodman

1985-01-01T23:59:59.000Z

489

"Doublet", Neutron and Neutron stars --- An essay on Landau and Neutron stars  

E-Print Network (OSTI)

The concept of extremely dense matter at supra-nuclear density was first speculated by L. Landau in the beginning of 1930s when neutron was just discovered. A historical review on these issues not only explains the interaction between micro and cosmic physics, but also has profound implications for scientific innovation. It is surely meaningful in realistic physics education to look back to this history. (The review was published in Chinese.)

Renxin Xu

2011-03-02T23:59:59.000Z

490

Neutron stars and the equation of state  

Science Journals Connector (OSTI)

The static properties of neutron stars are probed using phenomenological equations of state. These properties include the maximum mass, radii, central densities, and binding energies. It is found that quite different equations of state can produce similar neutron stars. Likewise, it is also found that equations of state which are quite similar near saturation density can produce very different neutron stars, since it is the high density behavior which is most important. Symmetric matter results cannot be used to uniquely constrain neutron matter because of model dependence on the symmetry energy.

J. Cooperstein

1988-02-01T23:59:59.000Z

491

Spallation Neutron Source reaches megawatt power  

ScienceCinema (OSTI)

The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

Dr. William F. Brinkman

2010-01-08T23:59:59.000Z

492

Neutron Data Analysis & Visualization | More Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

Data Analysis and Visualization As the data sets generated by the increasingly powerful neutron scattering instruments at HFIR and SNS grow ever more massive, the facilities'...

493

Facilities and Capabilities | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

SHARE Facilities and Capabilities ORNL operates two of the world's most powerful neutron scattering user facilities: the High Flux Isotope Reactor and the Spallation...

494

LANSCE | Lujan Center | Highlights | Neutron Reflectometry (NR...  

NLE Websites -- All DOE Office Websites (Extended Search)

of the crystallinity of the sample (single crystal, polycrystalline, or amorphous). Neutron scattering is a unique tool to study such nanolayered composites because the...

495

Compound Refractive Lenses for Thermal Neutron Applications  

SciTech Connect

This project designed and built compound refractive lenses (CRLs) that are able to focus, collimate and image using thermal neutrons. Neutrons are difficult to manipulate compared to visible light or even x rays; however, CRLs can provide a powerful tool for focusing, collimating and imaging neutrons. Previous neutron CRLs were limited to long focal lengths, small fields of view and poor resolution due to the materials available and manufacturing techniques. By demonstrating a fabrication method that can produce accurate, small features, we have already dramatically improved the focal length of thermal neutron CRLs, and the manufacture of Fresnel lens CRLs that greatly increases the collection area, and thus efficiency, of neutron CRLs. Unlike a single lens, a compound lens is a row of N lenslets that combine to produce an N-fold increase in the refraction of neutrons. While CRLs can be made from a variety of materials, we have chosen to mold Teflon lenses. Teflon has excellent neutron refraction, yet can be molded into nearly arbitrary shapes. We designed, fabricated and tested Teflon CRLs for neutrons. We demonstrated imaging at wavelengths as short as 1.26 ? with large fields of view and achieved resolution finer than 250 ?m which is better than has been previously shown. We have also determined designs for Fresnel CRLs that will greatly improve performance.

Gary, Charles K.

2013-11-12T23:59:59.000Z

496

Neutron Imaging of Advanced Engine Technologies  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Science Division Hassina Z. Bilheux & Sophie Voisin Oak Ridge National Laboratory Neutron Scattering Science Division Jens Gregor University of Tennessee - Knoxville Dept....

497

26 Tesla DC Magnet for Neutron Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Previously, DC Magnets located at Neutron-Scattering Beamlines were commercially-manufactured superconducting magnets and limited to 17 T. A few pulsed magnet systems have been...

498

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 (more)

Ohlson, Alice Elisabeth

2009-01-01T23:59:59.000Z

499

Chemical and Engineering Materials | Neutron Science | ORNL  

NLE Websites -- All DOE Office Websites (Extended Search)

and novel engineering materials. The user community takes advantage of capabilities of neutron scattering for measurements over wide ranges of experimental and operating...

500

Neutron Imaging of Advanced Engine Technologies  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

during a series of partial regenerations (9302012). - Achieved * Determine temporal and spatial resolution of neutron imaging with respect to fluid density and flow in fuel...