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

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

2

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

3

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

4

Neutron Activation Analysis of Manganese and Sodium in Bacterial Cells  

Science Journals Connector (OSTI)

...research-article Metabolism and Products Neutron Activation Analysis of Manganese and Sodium...Columbus, Ohio 43210. The application of neutron activation analysis for mineral determinations...two elements. The results indicate that neutron activation analysis is readily applicable...

Woodrow B. Krueger; Walter E. Carey; Bruno J. Kolodzeij

1970-12-01T23:59:59.000Z

5

Delayed neutron activation analysis for safeguards  

Science Journals Connector (OSTI)

Delayed neutron activation analysis (DNAA) presents a fast, accurate, and reliable method for quantification of fissile material. The method has relatively few sources of error and may be accomplished nondestruct...

D. C. Glasgow

2008-04-01T23:59:59.000Z

6

Neutron Activation Analysis for the Demonstration of Amphibolite Rock-Weathering Activity of a Yeast  

Science Journals Connector (OSTI)

...research-article General Microbial Ecology Neutron Activation Analysis for the Demonstration...University of Kiel, Kiel, Germany Neutron activation analysis was employed in a...demonstrated by comparing a spectrum of neutron-activated amphibolite powder (particle...

E. Rades-Rohkohl; P. Hirsch; O. Fränzle

1979-12-01T23:59:59.000Z

7

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. Molnár; ZS. Révay; Á. Veres; A. Simonits…

1993-01-01T23:59:59.000Z

8

Neutron activation analysis applied to perspiration electrolytes  

E-Print Network [OSTI]

) Member) (Eieisber) (Hie isbn r ) (Nc, . ib": ) J iniar ! Vl R P 3STR-'. CT Neutron ';ctivatior. Imalysis iipplied to Perspiration Electrolytes. (January 1969) Robert C. N Andrew:, B. S. , Norcester Poly' echnic Institut Directed by: Dr. James B... dlX II1 last Neutron Act ivsticn Cross-Eec!iona - - - 73 J Igf 0F TABL? S TABLE 1 TABLE 2 TABLE 3 TABLE 6! Nuclear Properties of Pertinent Elec!eats - - 6 Sodium Reactions Interfering Reactions - - - - - - ~ - - - - 13 Sodium Concentrations...

McAndrew, Robert Gavin

2012-06-07T23:59:59.000Z

9

On the determination of trace elements in cocoa and coffee by instrumental neutron activation analysis  

E-Print Network [OSTI]

. Charlene Helton for her helpful and productive suggestions, and, of course, for undertaking the laborious task or. typing the final manuscript. DEDICATION To mv parents. TABLE OF CONTENTS Chapter ~Pa e INTRODUCTION THEORY Neutron Activation..., commercial cocoa. CHAPTER II THEORY Neutron Activation Analysis Neutron Activation Analysis was proposed by Von Hevesy and Levi in 1936 (32). hey irradiated a yttrium sample with neutrons from a radium-beryllium source and determined the im urity...

Adanuvor, Prosper Kwasi

2012-06-07T23:59:59.000Z

10

The determination of phosphorus by fast neutron activation analysis  

E-Print Network [OSTI]

THE DETERMXNATIQN OF PHOSPHORUS BY FAST NEUTRON ACTIVATION ANAXYSIS Thesis MAEN TO ON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the reguirekents for the degree of MASTER OF SC XENCE May 1964 Major... subject, : chemistr'y THE DETERMXNATXON OF PHOSPHORUS BY FAST NEUTRON ACTXVATXON ANAXYSXS Thesis By MAEN TO ON Approved as to style and content by: (Chairman of Committee) (Memb of Committee) (Head of Department) (Member of Committee) May 1964 AC...

To-On, Maen

2012-06-07T23:59:59.000Z

11

Development of a new deuterium–deuterium (D–D) neutron generator for prompt gamma-ray neutron activation analysis  

Science Journals Connector (OSTI)

Abstract A new deuterium–deuterium (D–D) neutron generator has been developed by Adelphi Technology for prompt gamma neutron activation analysis (PGNAA), neutron activation analysis (NAA), and fast neutron radiography. The generator makes an excellent fast, intermediate, and thermal neutron source for laboratories and industrial applications that require the safe production of neutrons, a small footprint, low cost, and small regulatory burden. The generator has three major components: a Radio Frequency Induction Ion Source, a Secondary Electron Shroud, and a Diode Accelerator Structure and Target. Monoenergetic neutrons (2.5 MeV) are produced with a yield of 1010 n/s using 25–50 mA of deuterium ion beam current and 125 kV of acceleration voltage. The present study characterizes the performance of the neutron generator with respect to neutron yield, neutron production efficiency, and the ionic current as a function of the acceleration voltage at various RF powers. In addition the Monte Carlo N-Particle Transport (MCNP) simulation code was used to optimize the setup with respect to thermal flux and radiation protection.

K. Bergaoui; N. Reguigui; C.K. Gary; C. Brown; J.T. Cremer; J.H. Vainionpaa; M.A. Piestrup

2014-01-01T23:59:59.000Z

12

The investigation of spices by use of instrumental neutron activation analysis  

E-Print Network [OSTI]

contaminants. For this research, instrumental neutron-activation analysis (INAA) was used to determine the activities of U-235 fission products in common spices. Using this information, the concentrations of natural uranium in these spices and the doses...

Wise, Jatara Rob

2008-10-10T23:59:59.000Z

13

Improved mesh based photon sampling techniques for neutron activation analysis  

SciTech Connect (OSTI)

The design of fusion power systems requires analysis of neutron activation of large, complex volumes, and the resulting particles emitted from these volumes. Structured mesh-based discretization of these problems allows for improved modeling in these activation analysis problems. Finer discretization of these problems results in large computational costs, which drives the investigation of more efficient methods. Within an ad hoc subroutine of the Monte Carlo transport code MCNP, we implement sampling of voxels and photon energies for volumetric sources using the alias method. The alias method enables efficient sampling of a discrete probability distribution, and operates in 0(1) time, whereas the simpler direct discrete method requires 0(log(n)) time. By using the alias method, voxel sampling becomes a viable alternative to sampling space with the 0(1) approach of uniformly sampling the problem volume. Additionally, with voxel sampling it is straightforward to introduce biasing of volumetric sources, and we implement this biasing of voxels as an additional variance reduction technique that can be applied. We verify our implementation and compare the alias method, with and without biasing, to direct discrete sampling of voxels, and to uniform sampling. We study the behavior of source biasing in a second set of tests and find trends between improvements and source shape, material, and material density. Overall, however, the magnitude of improvements from source biasing appears to be limited. Future work will benefit from the implementation of efficient voxel sampling - particularly with conformal unstructured meshes where the uniform sampling approach cannot be applied. (authors)

Relson, E.; Wilson, P. P. H.; Biondo, E. D. [University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

2013-07-01T23:59:59.000Z

14

Utilization of neutron activation analysis in groundwater analyses  

SciTech Connect (OSTI)

Although work at the Massachusetts Institute of Technology's Nuclear Reactor Laboratory is basically research oriented, over the past number of years, numerous neutron activation analyses (NAAs) have been performed for commercial purposes. This has been true particularly in cases where other analytical techniques have been found to be insufficient or in cases where special sample considerations are involved. The requests for these analyses came from a wide range of institutions, including government laboratories, medical centers, utilities, and commercial companies. In most cases, instrumental NAA (INAA) was the method of choice because of the method's extremely low detection limits, multielement characteristics, nondestructive nature, and ability to work with different sample sizes.

Beal, J.W. (Fairfield Univ., CT (United States)); Olmez, I. (Massachusetts Institute of Technology, Cambridge, MA (United States))

1993-01-01T23:59:59.000Z

15

Bayesian statistics applied to neutron activation data for reactor flux spectrum analysis  

Science Journals Connector (OSTI)

Abstract In this paper, we present a statistical method, based on Bayesian statistics, to analyze the neutron flux spectrum from the activation data of different isotopes. The experimental data were acquired during a neutron activation experiment performed at the TRIGA Mark II reactor of Pavia University (Italy) in four irradiation positions characterized by different neutron spectra. In order to evaluate the neutron flux spectrum, subdivided in energy groups, a system of linear equations, containing the group effective cross sections and the activation rate data, has to be solved. However, since the system’s coefficients are experimental data affected by uncertainties, a rigorous statistical approach is fundamental for an accurate evaluation of the neutron flux groups. For this purpose, we applied the Bayesian statistical analysis, that allows to include the uncertainties of the coefficients and the a priori information about the neutron flux. A program for the analysis of Bayesian hierarchical models, based on Markov Chain Monte Carlo (MCMC) simulations, was used to define the problem statistical model and solve it. The first analysis involved the determination of the thermal, resonance-intermediate and fast flux components and the dependence of the results on the Prior distribution choice was investigated to confirm the reliability of the Bayesian analysis. After that, the main resonances of the activation cross sections were analyzed to implement multi-group models with finer energy subdivisions that would allow to determine the neutron flux groups, their uncertainties and correlations with good accuracy. The results were then compared with the ones obtained from the Monte Carlo simulations of the reactor fluxes performed with the MCNP code, finding in general a good agreement.

Davide Chiesa; Ezio Previtali; Monica Sisti

2014-01-01T23:59:59.000Z

16

Determination of thorium in seawater by neutron activation analysis and mass spectrometry  

SciTech Connect (OSTI)

The recent development of neutron activation analysis and mass spectrometric methods for the determination of /sup 232/Th in seawater has made possible rapid sampling and analysis of this long-lived, non-radiogenic thorium isotope on small-volume samples. The marine geochemical utility of /sup 232/Th, whose concentration in seawater is extremely low, warrants the development of these sensitive techniques. The analytical methods and some results are presented and discussed in this article. 24 refs., 3 figs.

Huh, Chih-An

1987-01-01T23:59:59.000Z

17

Multi-Group Transport Methods for High-Resolution Neutron Activation Analysis  

SciTech Connect (OSTI)

The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples. In these applications, high-resolution gamma-ray spectrometers are used to measure the spectrum of the emitted photon flux, which consists of both continuum and characteristic gamma rays with discrete energies. Monte Carlo transport is the most commonly used simulation tool for this type of problem, but computational times for many problems can be prohibitively long. This work explores the use of multi-group deterministic methods for the simulation of coupled neutron-photon problems.

Burns, Kimberly A.; Smith, Leon E.; Gesh, Christopher J.; Shaver, Mark W.

2009-09-24T23:59:59.000Z

18

Prompt gamma-ray neutron activation analysis methodology for determination of boron from trace to major contents  

Science Journals Connector (OSTI)

Prompt gamma ray neutron activation analysis (PGNAA) is an isotope specific online nuclear analytical technique for non-destructive determination of elements in diverse matrices [1–5...]. Though in principle all ...

R. Acharya

2009-08-01T23:59:59.000Z

19

Cold neutron prompt gamma activation analysis, a non-destructive technique for hydrogen level assessment in zirconium alloys  

E-Print Network [OSTI]

embrittlement by decreasing overall corrosion and/or by decreasing the amount of hydrogen ingress for a givenCold neutron prompt gamma activation analysis, a non-destructive technique for hydrogen level to quantitatively assess hydrogen concentration in zirconium alloys. The technique, called Cold Neutron Prompt Gamma

Motta, Arthur T.

20

Energy-dispersive X-ray microanalysis of the bone mineral content in human trabecular bone: A comparison with ICPES and neutron activation analysis  

Science Journals Connector (OSTI)

To evaluate the accuracy of bone mineral composition determination by electron microprobe analysis (EDX) the measurements have been compared to instrumental neutron activation analysis (INAA) and chemical anal...

K. Åkesson; M. D. Grynpas; R. G. V. Hancock; R. Odselius…

1994-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

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

22

Fusion-neutron-yield, activation measurements at the Z accelerator: Design, analysis, and sensitivity  

SciTech Connect (OSTI)

We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r{sup 2} decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm{sup 2} and is ? 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects.

Hahn, K. D., E-mail: kdhahn@sandia.gov; Ruiz, C. L.; Fehl, D. L.; Chandler, G. A.; Knapp, P. F.; Smelser, R. M.; Torres, J. A. [Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Diagnostics and Target Physics, Albuquerque, New Mexico 87123 (United States); Cooper, G. W.; Nelson, A. J. [Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States)] [Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Leeper, R. J. [Los Alamos National Laboratories, Plasma Physics Group, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratories, Plasma Physics Group, Los Alamos, New Mexico 87545 (United States)

2014-04-15T23:59:59.000Z

23

E-Print Network 3.0 - advanced neutronic analysis Sample Search...  

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

by Chadwick, neutron spectroscopy Summary: activation analysis (PGNAA) and delayed gamma-ray neutron activation analysis (DGNAA), i.e. with respect... improvement in neutron...

24

Prompt gamma activation analysis (PGAA) and short-lived neutron activation analysis (NAA) applied to the characterization of legacy materials  

E-Print Network [OSTI]

relative to the linear axis of the neutron generator and toto the linear axis of the neutron generator. To protectto the linear axis of the neutron generator) to reduce the

English, G.A.

2008-01-01T23:59:59.000Z

25

Advances in 14 MeV neutron activation analysis by means of a new intense neutron source  

Science Journals Connector (OSTI)

A new intense 14 MeV neutron generator with cylindrical acceleration structure has been put in operation at the GKSS Research Center Geesthacht. The sealed neutron tube is combined with...10 n/cm2s. Theoretical s...

R. Pepelnik; H. -U. Fanger; W. Michaelis; B. Anders

1982-01-01T23:59:59.000Z

26

Research trends in neutron activation analysis in nuclear science and technology: a global perspective  

Science Journals Connector (OSTI)

This paper quantitatively analyses the growth and development of research in Neutron Activation Analysis (NAA) in terms of publications. As per the International Nuclear Information System (INIS) database during 1993-2007, a total of 6491 publications were published. The highest number of papers in a year (615) was published in 2004. The average number of publications published per year was 432.73. Japan topped the list with 605 publications followed by the USA with 468, Brazil with 449, China with 442, the Russian Federation with 324 and India with 316. The authorship and collaboration trend is towards multi-authored papers. Researchers in Japan, Brazil and China are more inclined to work in larger groups. The highly productive institutions were Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, Brazil with 281 publications; Bhabha Atomic Research Centre, Mumbai, India with 257; Institute of High Energy Physics, Academia Sinica, Beijing, China with 162; and Japan Atomic Energy Agency, Tokai, Ibaraki, Japan with 140. The journals most preferred by the scientists for the publication of papers are the Journal of Radioanalytical and Nuclear Chemistry with 1204 papers, followed by Applied Radiation and Isotopes with 116 papers, and Nuclear Instruments and Methods in Physics Research-A with 84 papers.

Anil Sagar; B.S. Kademani; Vijai Kumar

2009-01-01T23:59:59.000Z

27

An investigation of the neutron flux in bone-fluorine phantoms comparing accelerator based in vivo neutron activation analysis and FLUKA simulation data  

Science Journals Connector (OSTI)

Abstract We have tested the Monte Carlo code FLUKA for its ability to assist in the development of a better system for the in vivo measurement of fluorine. We used it to create a neutron flux map of the inside of the in vivo neutron activation analysis irradiation cavity at the McMaster Accelerator Laboratory. The cavity is used in a system that has been developed for assessment of fluorine levels in the human hand. This study was undertaken to (i) assess the FLUKA code, (ii) find the optimal hand position inside the cavity and assess the effects on precision of a hand being in a non-optimal position and (iii) to determine the best location for our ?-ray detection system within the accelerator beam hall. Simulation estimates were performed using FLUKA. Experimental measurements of the neutron flux were performed using Mn wires. The activation of the wires was measured inside (1) an empty bottle, (2) a bottle containing water, (3) a bottle covered with cadmium and (4) a dry powder-based fluorine phantom. FLUKA was used to simulate the irradiation cavity, and used to estimate the neutron flux in different positions both inside, and external to, the cavity. The experimental results were found to be consistent with the Monte Carlo simulated neutron flux. Both experiment and simulation showed that there is an optimal position in the cavity, but that the effect on the thermal flux of a hand being in a non-optimal position is less than 20%, which will result in a less than 10% effect on the measurement precision. FLUKA appears to be a code that can be useful for modeling of this type of experimental system.

F. Mostafaei; F.E. McNeill; D.R. Chettle; W. Matysiak; C. Bhatia; W.V. Prestwich

2015-01-01T23:59:59.000Z

28

Data Analysis & Visualization | Neutron Science | ORNL  

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

29

Neutron Activation Analysis of Milligram Quantifies of Lunar Rocks and Soils  

Science Journals Connector (OSTI)

...Tl) detector, depending on efficiency and purity requirements. Approximately...performed at the Union Car-bide "swimming pool" reactor at Ster-ling Forest...RNAA; radiochemical, high-energy gamma, activation analysis, RGAA...

Karl K. Turekian; D. P. Kharkar

1970-01-30T23:59:59.000Z

30

E-Print Network 3.0 - analysis neutron activation Sample Search...  

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

2106533431 Large Scale Experimental Facilities at RRL Nuclear Research Reactor 5 MW power Neutron... Scattering Facilities ... Source: National Center for Scientific Research...

31

Neutron flux and energy characterization of a plutonium-beryllium isotopic neutron source by Monte Carlo simulation with verification by neutron activation analysis.  

E-Print Network [OSTI]

??The purpose of this research was to characterize the neutron energy distribution and flux emitted from the UNLV plutonium-beryllium source, serial number MRC-N-W PuBe 453.… (more)

Harvey, Zachary R

2010-01-01T23:59:59.000Z

32

Measurement of chromium VI and chromium III in stainless steel welding fumes with electron spectroscopy for chemical analysis and neutron activation analysis  

E-Print Network [OSTI]

Measurement of Chromium YI and Chromium III in Stainless Steel Welding Fumes with Electron Spectroscopy for Chemical Analysis and Neutron Activation Analysis (December 1977) Gerald Myron Lautner; B. S. , Louisiana State University; Co-Chairmen of Advisory... steel plates sized 15. 2 by 26. 7 by 0. 64 centimeters (6. 0 by 10. 5 by 0. 25 inches). The manufacturer lists the following typical analysis for Type 304 stainless plate; C ? 0. 08 percent; Mn - 2. 00 percent; Si - 1 00 percent; Cr = 18. 00 - 20. 00...

Lautner, Gerald Myron

1977-01-01T23:59:59.000Z

33

Prompt gamma ray neutron activation analysis of cadmium in municipal solid waste  

E-Print Network [OSTI]

EXPERIMENTAL. . 26 PGNAA Assembly. Detection System Background Determination of Detector Shielding. Self-Shielding. Optimal Bag Size and Orientation. . . . . . . . . . . . . . . Detection Limit and Sensitivity. . . . . . . . . . . . . . . . Neutron Flux... solid waste. This study modified a previous setup that was in a shadow- shield arrangement using Pu-Be neutron sources by: more elaborate detector shielding to reduce background levels; and, irradiating the target bilaterally. The system background...

Dendahl, Katherine Hoge

2012-06-07T23:59:59.000Z

34

Calcium sensitivity determinations by neutron activation analysis as applied to bone  

E-Print Network [OSTI]

. ated, eliminating a total body dose. But primarily, the ettuipment used is greatly reduced in size and cost froa~ praY. . ou" roric?u. in' a poa tai~lc neutron aource (againat t', u uacs of a cyclo' ton) aad on1 y onu acinti llatf on cry tnl...PII(IILiL'1 of r il 'lto. l Iir, 'L 'v;il'(i(i', N ~ ? - (1-e ) &5 Nc& i a e(5uation 1 N ? null&'~er of radioactive atoms present at end of irradiation (atoms) - neutron flux (neutrons/cm 'sec) 2. N . - total nuAer of orig" nal atoms (atoms) 1 ? decay...

Blasdel, Michael John

2012-06-07T23:59:59.000Z

35

Boron-10 Prompt Gamma Analysis Using a Diffracted Neutron Beam  

Science Journals Connector (OSTI)

A prompt gamma neutron activation analysis (PGNAA) facility has been built at the 5 MW MITR-II Research Reactor to support our ongoing boron neutron capture therapy (NCT) program. This facility is used to dete...

R. Rogus; O. K. Harling; I. Olmez…

1992-01-01T23:59:59.000Z

36

Nondestructive examination using neutron activated positron annihilation  

DOE Patents [OSTI]

A method is provided for performing nondestructive examination of a metal specimen using neutron activated positron annihilation wherein the positron emitter source is formed within the metal specimen. The method permits in situ nondestructive examination and has the advantage of being capable of performing bulk analysis to determine embrittlement, fatigue and dislocation within a metal specimen.

Akers, Douglas W. (Idaho Falls, ID); Denison, Arthur B. (Idaho Falls, ID)

2001-01-01T23:59:59.000Z

37

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

38

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

39

Determination of selected trace elements in human head hair by neutron activation analysis  

E-Print Network [OSTI]

the scope of this discussion. The final category of data contains barium and strontium. There was no data in the literature to use as a comparison, therefore the values of 49 ppm for barium and 87 ppm for strontium must stand on their own merit...) in Japan and of course, the current work in Texas. The results of the correlation analysis were that there were no significant correlations between any of the elements except in the case of strontium and barium which yielded a Pearson correlation coef...

Courson, Leonard Austin

2012-06-07T23:59:59.000Z

40

Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems  

SciTech Connect (OSTI)

Prompt Gamma Neutron Activation (PGNAA) systems require the use of a gamma-ray spectrometer to record the gamma-ray spectrum of an object under test and allow the determination of the object’s composition. Field-portable systems, such as Idaho National Laboratory’s PINS system, have used standard liquid-nitrogen-cooled high-purity germanium (HPGe) detectors to perform this function. These detectors have performed very well in the past, but the requirement of liquid-nitrogen cooling limits their use to areas where liquid nitrogen is readily available or produced on-site. Also, having a relatively large volume of liquid nitrogen close to the detector can impact some assessments, possibly leading to a false detection of explosives or other nitrogen-containing chemical. Use of a mechanically-cooled HPGe detector is therefore very attractive for PGNAA applications where nitrogen detection is critical or where liquid-nitrogen logistics are problematic. Mechanically-cooled HPGe detectors constructed from p-type germanium, such as Ortec’s trans-SPEC, have been commercially available for several years. In order to assess whether these detectors would be suitable for use in a fielded PGNAA system, Idaho National Laboratory (INL) has been performing a number of tests of the resistance of mechanically-cooled HPGe detectors to neutron damage. These detectors have been standard commercially-available p-type HPGe detectors as well as prototype n-type HPGe detectors. These tests compare the performance of these different detector types as a function of crystal temperature and incident neutron fluence on the crystal.

E.H. Seabury; C.J. Wharton; A.J. Caffrey; J.B. McCabe; C. DeW. Van Siclen

2013-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

Experiment Design and Analysis Guide - Neutronics & Physics  

SciTech Connect (OSTI)

The purpose of this guide is to provide a consistent, standardized approach to performing neutronics/physics analysis for experiments inserted into the Advanced Test Reactor (ATR). This document provides neutronics/physics analysis guidance to support experiment design and analysis needs for experiments irradiated in the ATR. This guide addresses neutronics/physics analysis in support of experiment design, experiment safety, and experiment program objectives and goals. The intent of this guide is to provide a standardized approach for performing typical neutronics/physics analyses. Deviation from this guide is allowed provided that neutronics/physics analysis details are properly documented in an analysis report.

Misti A Lillo

2014-06-01T23:59:59.000Z

42

Thermal Neutron Imaging in an Active Interrogation Environment  

SciTech Connect (OSTI)

We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutron-emitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

Vanier, Peter E. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Forman, Leon [Ion Focus Technology, Inc., Miller Place, NY 11764 (United States); Norman, Daren R. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

2009-03-10T23:59:59.000Z

43

Neutron Activation Cross Sections with Sb—Be 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

44

Neutron Data Analysis & Visualization | More Science | ORNL  

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

45

Data Analysis & Visualization | Neutron Science | ORNL  

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

46

Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples  

Science Journals Connector (OSTI)

Boron determination is of special interest for the analysis of biological samples in the context of boron neutron capture therapy (BNCT). BNCT is ... . This is achieved by enrichment of the isotope 10B in tumour ...

C. L. Schütz; C. Brochhausen; G. Hampel…

2012-10-01T23:59:59.000Z

47

Thermal neutron imaging in an active interrogation environment  

SciTech Connect (OSTI)

We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of xcitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

Vanier,P.E.; Forman, L., and Norman, D.R.

2009-03-10T23:59:59.000Z

48

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

49

Towards an optimum design of a P-MOS radiation detector for use in high-energy medical photon beams and neutron facilities: analysis of activation materials  

Science Journals Connector (OSTI)

......phantom surrounded by water-filled containers extending...depth of maximum dose in water for a 10 cm 10 cm square...all irradiations. The atmospheric pressure and internal...acetone and distilled water. They were then transferred...neutrons from a D-T generator. Table 1. Activation......

Robert A. Price

2005-12-20T23:59:59.000Z

50

Polarized neutron reflectometry with phase analysis  

Science Journals Connector (OSTI)

A novel technique, polarized neutron reflectometry with phase analysis (PNRPA), is suggested, in which not only the moduli of reflection matrix elements but also up to three phase differences are measured. It is realized in the scheme with two flippers and an analyzer, by reflection of neutrons with the spin, in succession, parallel and antiparallel to two inclined axes fixed to the sample. More detailed information about magnetic layered structures can be thus obtained. An adequate mathematical formalism is given.

N.K. Pleshanov

1999-01-01T23:59:59.000Z

51

Review of Neutron Radiography Development Activities at Argonne National Laboratory  

Science Journals Connector (OSTI)

Argonne National Laboratory developments and applications in neutron ... this Conference reporting direct work or support by Argonne reflect the more recent development activities.

A. DeVolpi

1983-01-01T23:59:59.000Z

52

Enhancement of absolute neutron dosimetry by activation technique  

Science Journals Connector (OSTI)

In this work, an activation technique was used for absolute neutron dosimetry. Induced gamma within two activation foils (115In and 197Au) was detected by (5 × 5) sodium iodide (NaI) crystal. Thermal neutron irradiation was performed using the thermal neutron irradiation facility at the National Institute for Standards (NIS). Two gamma lines of 416.9 keV and 411.8 keV from 115In and 198Au, respectively, were chosen for the estimation of the neutron fluence. Gamma lines of 416.8 keV and 1293.56 keV from 115In were used to assure the obtained values of neutron fluence. Absolute neutron dose was calculated utilising the measured neutron fluence. Estimated neutron dose was found to be 1.50 mSv/h. The calculated dose by activation technique was verified by neutron rem meter NM2. Enhancement of neutron fluence was performed by adding Perspex sheets behind the activation foils to produce multiple scattering on the foils, and hence resulting in increasing the capability of accurate estimation of low neutron fluence.

A.R. El-Sersy; N.E. Khaled; S.A. Eman

2012-01-01T23:59:59.000Z

53

Neutronic analysis of a fusion hybrid reactor  

SciTech Connect (OSTI)

In a PHYSOR 2010 paper(1) we introduced a fusion hybrid reactor whose fusion component is the gasdynamic mirror (GDM), and whose blanket was made of thorium - 232. The thrust of that study was to demonstrate the performance of such a reactor by establishing the breeding of uranium - 233 in the blanket, and the burning thereof to produce power. In that analysis, we utilized the diffusion equation for one-energy neutron group, namely, those produced by the fusion reactions, to establish the power distribution and density in the system. Those results should be viewed as a first approximation since the high energy neutrons are not effective in inducing fission, but contribute primarily to the production of actinides. In the presence of a coolant, however, such as water, these neutrons tend to thermalize rather quickly, hence a better assessment of the reactor performance would require at least a two group analysis, namely the fast and thermal groups. We follow that approach and write an approximate set of equations for the fluxes of these groups. From these relations we deduce the all-important quantity, k{sub eff}, which we utilize to compute the multiplication factor, and subsequently, the power density in the reactor. We show that k{sub eff} can be made to have a value of 0.99, thus indicating that 100 thermal neutrons are generated per fusion neutron, while allowing the system to function as 'subcritical.' Moreover, we show that such a hybrid reactor can generate hundreds of megawatts of thermal power per cm of length depending on the flux of the fusion neutrons impinging on the blanket. (authors)

Kammash, T. [Univ. of Michigan, NERS, 2355 Bonisteel Blvd., Ann Arbor, MI 48109 (United States)

2012-07-01T23:59:59.000Z

54

Gamma/neutron analysis for SNM signatures at high-data rates(greater than 107 cps) for single-pulse active interrogation  

SciTech Connect (OSTI)

We are developing a high data gamma/neutron spectrometer suitable for active interrogation of special nuclear materials (SNM) activated by a single burst from an intense source. We have tested the system at Naval Research Laboratory's (NRL) Mercury pulsed-power facility at distances approaching 10 meters from a depleted uranium (DU) target. We have found that the gamma-ray field in the target room 'disappears' 10 milliseconds after the x-ray flash, and that gamma ray spectroscopy will then be dominated by isomeric states/beta decay of fission products. When a polyethylene moderator is added to the DU target, a time-dependent signature of the DU is produced by thermalized neutrons. We observe this signature in gamma-spectra measured consecutively in the 0.1-1.0 ms time range. These spectra contain the Compton edge line (2.2 MeV) from capture in hydrogen, and a continuous high energy gamma-spectrum from capture or fission in minority constituents of the DU.

Forman L.; Dioszegi, I.; Salwen, C.

2011-04-26T23:59:59.000Z

55

Application of neutron activation analysis and high resolution x-ray spectrometry for the determination of trace quantities of elements with short-lived activation products  

E-Print Network [OSTI]

Conversion Interferences and Errors 3, PROCEDURES AND EXPERIMENTAL SETUP Sample Preparation Pneumatic Sample Transfer System Sample Irradiation X-ray Spectrometry Data Reduction 4. DISCUSSION AND RESULTS System Analysis Analysis Problems.... C. Roentgen made the classic observation that a highly penatrative radiation, unknown at that time, was produced when fast electrons impinged on matter. This radiation, which h called x-rays, was being studied in all parts of the world less than...

Marshall, John Richard

1974-01-01T23:59:59.000Z

56

Improved Fission Neutron Data Base for Active Interrogation of Actinides  

SciTech Connect (OSTI)

This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 – 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

2013-11-06T23:59:59.000Z

57

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

58

Standardizing Activation Analysis: New Software for Photon Activation Analysis  

SciTech Connect (OSTI)

Photon Activation Analysis (PAA) of environmental, archaeological and industrial samples requires extensive data analysis that is susceptible to error. For the purpose of saving time, manpower and minimizing error, a computer program was designed, built and implemented using SQL, Access 2007 and asp.net technology to automate this process. Based on the peak information of the spectrum and assisted by its PAA library, the program automatically identifies elements in the samples and calculates their concentrations and respective uncertainties. The software also could be operated in browser/server mode, which gives the possibility to use it anywhere the internet is accessible. By switching the nuclide library and the related formula behind, the new software can be easily expanded to neutron activation analysis (NAA), charged particle activation analysis (CPAA) or proton-induced X-ray emission (PIXE). Implementation of this would standardize the analysis of nuclear activation data. Results from this software were compared to standard PAA analysis with excellent agreement. With minimum input from the user, the software has proven to be fast, user-friendly and reliable.

Sun, Z. J.; Wells, D.; Green, J. [Idaho Accelerator Center, Idaho State University, 921 S. 8th Ave. Pocatello, ID 83209-8263 (United States); Department of Physics, Idaho State University, 921 S. 8th Ave. Pocatello, ID 83209-8106 (United States); Segebade, C. [Federal Institute for Materials Research and Testing, Unter den Eichen 87, Berlin 12205 (Germany)

2011-06-01T23:59:59.000Z

59

A new technique for beta attenuation studies in neutron activation foils using 4?- coincidence system  

Science Journals Connector (OSTI)

......low flux neutron measurements...low flux neutron measurements...Characteristics of the neutron activation...Resonance energy (eV) Resonance...46 barn (fission spectrum averaged...dose, the induced activity...irradiated in the thermal column of......

Deepa Sathian; M. P. Chougaonkar; Y. S. Mayya

2010-12-01T23:59:59.000Z

60

E-Print Network 3.0 - active neutron correlation Sample Search...  

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

Sample search results for: active neutron correlation Page: << < 1 2 3 4 5 > >> 1 The Neutron Scattering Society www.neutronscattering.org Summary: of antiferromagnetic spin...

Note: This page contains sample records for the topic "neutron activation analysis" 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 - active neutron scanner Sample Search Results  

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

Search Sample search results for: active neutron scanner Page: << < 1 2 3 4 5 > >> 1 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

62

E-Print Network 3.0 - activation 14-mev neutrons Sample Search...  

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

Sample search results for: activation 14-mev neutrons Page: << < 1 2 3 4 5 > >> 1 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

63

Enhanced reaction rates in NDP analysis with neutron scattering  

SciTech Connect (OSTI)

Neutron depth profiling (NDP) makes accessible quantitative information on a few isotopic concentration profiles ranging from the surface into the sample a few micrometers. Because the candidate analytes for NDP are few, there is little interference encountered. Furthermore, neutrons have no charge so mixed chemical states in the sample are of no direct concern. There are a few nuclides that exhibit large probabilities for neutron scattering. The effect of neutron scattering on NDP measurements has not previously been evaluated as a basis for either enhancing the reaction rates or as a source of measurement error. Hydrogen is a common element exhibiting large neutron scattering probability found in or around sample volumes being analyzed by NDP. A systematic study was conducted to determine the degree of signal change when neutron scattering occurs during analysis. The relative signal perturbation was evaluated for materials of varied neutron scattering probability, concentration, total mass, and geometry. Signal enhancements up to 50% are observed when the hydrogen density is high and in close proximity to the region of analysis with neutron beams of sub thermal energies. Greater signal enhancements for the same neutron number density are reported for thermal neutron beams. Even adhesive tape used to position the sample produces a measureable signal enhancement. Because of the shallow volume, negligible distortion of the NDP measured profile shape is encountered from neutron scattering.

Downing, R. Gregory, E-mail: gregory.downing@nist.gov [National Institute of Standards and Technology, Chemical Sciences Division, Gaithersburg, Maryland 20899 (United States)

2014-04-15T23:59:59.000Z

64

Neutronics analysis for HYLIFE-II  

SciTech Connect (OSTI)

A preliminary neutronics analysis of the HYLIFE-2 reactor concept gives a tritium breeding ratio of 1.17 and a system energy multiplication factor of 1.14. Modified SS-316 (in which Mn is substituted for Ni) is superior to Hastelloy X and Hastelloy N as a firstwall material considering He generation, dpa-limited lifetime, and shallow-burial index. Since Flibe is corrosive to Mn metals, however, a favorable first-wall material is yet to be decided on. Flibe impurities considered (e.g., inherent impurities and those arising from wall erosion or secondary-coolant leakage) do not increase the hazard to the public over that of pure Flibe. The main issues for HYLIFE-2 are the high shallow-burial index (106) and the requirement to contain some 99.7% of the {sup 18}F inventory to prevent its release to the public 18 refs., 3 figs., 9 tabs.

Tobin, M.T.

1990-12-20T23:59:59.000Z

65

Measurements of DT and DD neutron yields by neutron activation on TFTR  

SciTech Connect (OSTI)

A variety of elemental foils have been activated by neutron fluence from TFTR under conditions with the DT neutron yield per shot ranging from 10{sup 12} to over 10{sup 18}, and with the DT/(DD+DT) neutron ratio varying from 0.5% (from triton burnup) to unity. Linear response over this large dynamic range is obtained by reducing the mass of the foils and increasing the cooling time, all while accepting greatly improved counting statistics. Effects on background gamma-ray lines from foil-capsule-material contaminants. and the resulting lower limits on activation foil mass, have been determined. DT neutron yields from dosimetry standard reactions on aluminum, chromium, iron, nickel, zirconium, and indium are in agreement within the {plus_minus}9% (one-sigma,) accuracy of the measurements: also agreeing are yields from silicon foils using the ACTL library cross-section. While the ENDF/B-V library has too low a cross-section. Preliminary results from a variety of other threshold reactions are presented. Use of the {sup 115}In(n,n) {sup 115m}In reaction (0.42 times as sensitive to DT neutrons as DD neutrons) in conjunction with pure-DT reactions allows a determination of the DT/(DD+DT) ratio in trace tritium or low-power tritium beam experiments.

Barnes, C.W.; Larson, A.R. [Los Alamos National Lab., NM (United States); LeMunyan, G. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Loughlin, M.J. [JET Joint Undertaking, Abingdon (United Kingdom)

1994-05-05T23:59:59.000Z

66

Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS  

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

Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS This set of web pages provides reference information from the Magnetic Structure Analysis from Neutron Powder Diffraction Data Using GSAS workshop presented at the 2006 American Conference on Neutron Scattering held in St. Charles, IL, June 18-22, 2006. Workshop Schedule: 9:00-9:05 am: Introduction (B.H. Toby) 9:05-9:50 am: History, Color symmetry & Shubnikov space groups (B. Chakoumous) Lecture notes: History and Color symmetry & Shubnikov space groups 9:50-10:20 am: Magnetic extinctions classes & common magnetic structure types (R.B. Von Dreele) Lecture Notes Break 10:50-11:45 am: Overview of representational analysis & FullProf implementation (L.C. Chapon) Lecture Notes and Accompanying files

67

Neutron reflectometry with vector polarization analysis: First steps  

Science Journals Connector (OSTI)

The most detailed and reliable information about the magnetic state (magnetization depth profiles) of layers can be obtained by neutron reflectometry with vector polarization analysis. Two schemes of ... I. This ...

N. K. Pleshanov; L. A. Axel’rod…

2008-12-01T23:59:59.000Z

68

Digital Computer Methods for Processing Neutron Radioactivation Analysis Data  

E-Print Network [OSTI]

DIGITAL COMPUTER METHODS FOR PROCESSING NEUTRON RADIOACTIVATION ANALYSIS DATA A Thesis By William Elton Kuykendall, Jr. Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of tbe... retiuirements for the degree of MASTER OF SCIENCE May 1960 Major Subject: Electrical Engineering DIGITAL COMPUTER METHODS FOR PROCESSING NEUTRON RADIOACTIVATION ANALYSIS DATA A Thesis By William Elton Kuykendall, Jr. p oved as to sty e content by: Co...

Kuykendall, William E

1960-01-01T23:59:59.000Z

69

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

70

Experimental evaluation of neutron performance in boron-doped low activation concrete  

Science Journals Connector (OSTI)

......exposed to neutrons escaping...prediction of induced activity...Long-lived induced activity...capture of thermal and resonance neutrons by traces...neutrons in the spectrum. Consequently...monitored using a fission chamber was...resonance energy (E eff 6......

T. Ogawa; M. N. Morev; T. Abe; T. Iimoto; T. Kosako; K. Kimura; M. Kinno

2010-06-01T23:59:59.000Z

71

Lipid Bilayer Structure Determined by the Simultaneous Analysis of Neutron and X-Ray Scattering Data  

E-Print Network [OSTI]

Lipid Bilayer Structure Determined by the Simultaneous Analysis of Neutron and X-Ray Scattering) and dipalmitoylphosphatidylcholine (DPPC) bilayers by simultaneously analyzing x-ray and neutron scattering data. The neutron data electron and neutron scattering density profiles. A key result of the analysis is the molecular surface

Nagle, John F.

72

Neutron shielding and activation of the MASTU device and surrounds  

E-Print Network [OSTI]

A significant functional upgrade is planned for the Mega Ampere Spherical Tokamak (MAST) device, located at Culham in the UK, including the implementation of a notably greater neutral beam injection power. This upgrade will cause the emission of a substantially increased intensity of neutron radiation for a substantially increased amount of time upon operation of the device. Existing shielding and activation precautions are shown to prove insufficient in some regards, and recommendations for improvements are made, including the following areas: shielding doors to MAST shielded facility enclosure (known as "the blockhouse"); north access tunnel; blockhouse roof; west cabling duct. In addition, some specific neutronic dose rate questions are addressed and answered; those discussed here relate to shielding penetrations and dose rate reflected from the air above the device ("skyshine").

Taylor, David; Turner, Andrew; Davis, Andrew

2014-01-01T23:59:59.000Z

73

Radiography apparatus using gamma rays emitted by water activated by fusion neutrons  

SciTech Connect (OSTI)

Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the {sup 16}O(n,p) {sup 16}N reaction using 14-MeV neutrons produced at the neutron source via the {sup 3}H(d,n) {sup 4}He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second {sup 16}N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.13 seconds of the activated oxygen is sufficient to permit gamma ray generation at a remote location where the activated water is transported, while not presenting a chemical or radioactivity hazard because the radioactivity falls to negligible levels after 1--2 minutes.

Smith, D.L.; Ikeda, Yujiro; Uno, Yoshitomo

1995-12-31T23:59:59.000Z

74

Radiography apparatus using gamma rays emitted by water activated by fusion neutrons  

DOE Patents [OSTI]

Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the .sup.16 O(n,p).sup.16 N reaction using .sup.14 -MeV neutrons produced at the neutron source via the .sup.3 H(d,n).sup.4 He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second .sup.16 N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.13 seconds of the activated oxygen is sufficient to permit gamma ray generation at a remote location where the activated water is transported, while not presenting a chemical or radioactivity hazard because the radioactivity falls to negligible levels after 1-2 minutes.

Smith, Donald L. (Plainfield, IL); Ikeda, Yujiro (Ibaraki, JP); Uno, Yoshitomo (Ibaraki, JP)

1996-01-01T23:59:59.000Z

75

Radiography apparatus using gamma rays emitted by water activated by fusion neutrons  

DOE Patents [OSTI]

Radiography apparatus includes an arrangement for circulating pure water continuously between a location adjacent a source of energetic neutrons, such as a tritium target irradiated by a deuteron beam, and a remote location where radiographic analysis is conducted. Oxygen in the pure water is activated via the {sup 16}O(n,p){sup 16}N reaction using {sup 14}N-MeV neutrons produced at the neutron source via the {sup 3}H(d,n){sup 4}He reaction. Essentially monoenergetic gamma rays at 6.129 (predominantly) and 7.115 MeV are produced by the 7.13-second {sup 16}N decay for use in radiographic analysis. The gamma rays have substantial penetrating power and are useful in determining the thickness of materials and elemental compositions, particularly for metals and high-atomic number materials. The characteristic decay half life of 7.13 seconds of the activated oxygen is sufficient to permit gamma ray generation at a remote location where the activated water is transported, while not presenting a chemical or radioactivity hazard because the radioactivity falls to negligible levels after 1--2 minutes. 15 figs.

Smith, D.L.; Ikeda, Yujiro; Uno, Yoshitomo

1996-11-05T23:59:59.000Z

76

Analysis of experimental data on the neutron yield from muons  

SciTech Connect (OSTI)

Experimental data accumulated over 60 years of studying the yield of cosmogenic neutrons in a liquid scintillator (Y{sub LS}), iron (Y{sub Fe}), and lead (Y{sub Pb}) were analyzed. This analysis revealed that the main part of the results on the yield Y{sub LS} were overestimated by about 30%. With allowance for this circumstance, all experimental data can be described by the dependence Y(E{sub Micro-Sign }, A) = b{sub n}A{sup {beta}}E{sub Micro-Sign }{sup {alpha}}, where the product b{sub n}E{sub Micro-Sign }{sup {alpha}} stands for the energy spent by a muon on neutron production. The exponents of {alpha} = 0.78 and {beta} = 0.95 are determined by the properties of the medium and by neutron production in showers.

Agafonova, N. Yu.; Malgin, A. S., E-mail: Malgin@lngs.infn.it [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

2013-05-15T23:59:59.000Z

77

Protein Activity that Protects Our DNA - Research Highlights | ORNL Neutron  

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

Neutrons help shed light on critical protein activity that protects our DNA Neutrons help shed light on critical protein activity that protects our DNA "New study provides a framework for understanding how protein works and how it stimulates the DNA processing machines" Research Contact: Walter Chazin Illustration of the change in architecture of the essential eukaryotic ssDNA binding protein RPA as it engages progressively longer segments of ssDNA. Small-angle x-ray scattering data are displayed in the background for the DNA binding core of RPA in its DNA-free state (green) and when engaged on 10 (yellow), 20 (red, and 30 (blue) nucleotide ssDNA substrates. Overlaid molecular surfaces and ribbon representations of the three distinct architectural states of RPA are shown, one for the DNA-free protein and the two others for the initial and fully ssDNA-engaged modes, revealing the progressive compaction of the protein as it binds to the substrate. The RPA70 subunit is colored in blue, RPA32 in green, and RPA14 in red, with ssDNA displayed as a yellow ribbon.

78

NEUTRON DIFFRACTION ANALYSIS OF CYTOCHROME b5 RECONSTITUTED IN DEUTERATED LIPID MULTILAYERS  

E-Print Network [OSTI]

NEUTRON DIFFRACTION ANALYSIS OF CYTOCHROME b5 RECONSTITUTED IN DEUTERATED LIPID MULTILAYERS E. P centrosymmetric pairs of asymmetric lipid-protein bilayers. Lamellar neutron diffraction data were collected. A neutron diffraction analysis ofcytochrome b5, incorporated into ordered lipid multilayers, promised

79

Method of analysis of multiphonon and multiple-scattering effects in inelastic neutron scattering experiments  

Science Journals Connector (OSTI)

We present experimental results of inelastic neutron scattering experiments on a Ti–Zr alloy, together ... measurements. A method of analysis of inelastic neutron scattering experiments is proposed, aimed at obta...

J. Dawidowski; G.J. Cuello; M. Koza; J.J. Blostein; G. Aurelio…

2002-12-01T23:59:59.000Z

80

Advanced Neutron Source Reactor thermal analysis of fuel plate defects  

SciTech Connect (OSTI)

The Advanced Neutron Source Reactor (ANSR) is a research reactor designed to provide the highest continuous neutron beam intensity of any reactor in the world. The present technology for determining safe operations were developed for the High Flux Isotope Reactor (HFIR). These techniques are conservative and provide confidence in the safe operation of HFIR. However, the more intense requirements of ANSR necessitate the development of more accurate, but still conservative, techniques. This report details the development of a Local Analysis Technique (LAT) that provides an appropriate approach. Application of the LAT to two ANSR core designs are presented. New theories of the thermal and nuclear behavior of the U{sub 3}Si{sub 2} fuel are utilized. The implications of lower fuel enrichment and of modifying the inspection procedures are also discussed. Development of the computer codes that enable the automate execution of the LAT is included.

Giles, G.E.

1995-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

Neutron Capture Measurements and Resonance Analysis of Dysprosium Y.R. Kang,1  

E-Print Network [OSTI]

Neutron Capture Measurements and Resonance Analysis of Dysprosium Y.R. Kang,1 M.W. Lee,1 T.I. Ro,2 The electron linear accelerator facility at the Rensselaer Polytechnic Institute was used to measure neutron capture yields of dysprosium with the time-of-flight method in the neutron energy region from 10 eV to 1

Danon, Yaron

82

A Neutron Resonance Capture Analysis Experimental Station at the ISIS Spallation Source  

Science Journals Connector (OSTI)

Neutron resonance capture analysis (NRCA) is a nuclear technique that is used to determine the elemental composition of materials and artifacts (e.g., bronze objects) of...

Pietropaolo, Antonino; Gorini, Giuseppe; Festa, Giulia; Reali, Enzo; Grazzi, Francesco; Schooneveld, Erik M

2010-01-01T23:59:59.000Z

83

3D neutronic/thermal-hydraulic coupled analysis of MYRRHA  

SciTech Connect (OSTI)

The current tendency in multiphysics calculations applied to reactor physics is the use of already validated computer codes, coupled by means of an iterative approach. In this paper such an approach is explained concerning neutronics and thermal-hydraulics coupled analysis with MCNPX and COBRA-IV codes using a driver program and file exchange between codes. MCNPX provides the neutronic analysis of heterogeneous nuclear systems, both in critical and subcritical states, while COBRA-IV is a subchannel code that can be used for rod bundles or core thermal-hydraulics analysis. In our model, the MCNP temperature dependence of nuclear data is handled via pseudo-material approach, mixing pre-generated cross section data set to obtain the material with the desired cross section temperature. On the other hand, COBRA-IV has been updated to allow for the simulation of liquid metal cooled reactors. The coupled computational tool can be applied to any geometry and coolant, as it is the case of single fuel assembly, at pin-by-pin level, or full core simulation with the average pin of each fuel-assembly. The coupling tool has been applied to the critical core layout of the SCK-CEN MYRRHA concept, an experimental LBE cooled fast reactor presently in engineering design stage. (authors)

Vazquez, M.; Martin-Fuertes, F. [CIEMAT, Avda. Complutense 40, 28040 Madrid (Spain)

2012-07-01T23:59:59.000Z

84

Fast-Neutron Activation of Long-Lived Nuclides in Natural Pb  

E-Print Network [OSTI]

We measured the production of the long-lived nuclides Bi-207, Pb-202, and Hg-194 in a sample of natural Pb due to high-energy neutron interactions using a neutron beam at the Los Alamos Neutron Science Center. The activated sample was counted by a HPGe detector to measure the amount of radioactive nuclides present. These nuclides are critical in understanding potential backgrounds in low background experiments utilizing large amounts of Pb shielding due to cosmogenic neutron interactions in the Pb while residing on the Earth's surface. By scaling the LANSCE neutron flux to a cosmic neutron flux, we measure the sea level cosmic ray production rates of 8.0 +/- 1.3 atoms/kg/day of Hg-194, 120 +/- 25 atoms/kg/day Pb-202, and 0.17 +/- 0.04 atoms/kg/day Bi-207.

V. E. Guiseppe; S. R. Elliott; N. E. Fields; D. Hixon

2012-09-20T23:59:59.000Z

85

Validation of a method for neutron dosimetry and spectrometry using neutron activation of metal discs  

Science Journals Connector (OSTI)

......Belgium. MOX fuel is a mixture of depleted uranium oxide and plutonium oxide. The...multisphere neutron spectrometer data. Health Phys (1999) 77(5):579-583...the BD-PND bubble detector. Health Phys. Soc (1999) 77(2......

J. S. Elisabeth Wieslander; Göran Lövestam; Mikael Hult; Andreas Fessler; Joël Gasparro; Pierre Kockerols

2010-03-01T23:59:59.000Z

86

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

87

Calculations of neutron spectra after neutron–neutron scattering  

Science Journals Connector (OSTI)

A direct neutron–neutron 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 proton–proton 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 spectrum—Maxwellian plus epithermal tail. The shape of the neutron spectrum after scattering is appreciably different from the initial spectrum, due to collisions between thermal–thermal and thermal–epithermal 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

88

Improved Technique of Hydrogen Content Analysis by Slow Neutron Scattering  

DOE R&D Accomplishments [OSTI]

A slow-neutron-transmission method fro determining the H content of fluorcarbons is described (G.Y.)

Rainwater, L. J.; Havens, W. W. Jr.

1945-02-28T23:59:59.000Z

89

Investigation of elemental analysis using neutron-capture gamma ray spectra  

E-Print Network [OSTI]

This thesis evaluated the potential of neutron-capture gamma rays in elemental analysis. A large portion of the work was devoted to the development of a method for the analysis of weak peaks in gamma ray spectra. This was ...

Hamawi, John Nicholas

1969-01-01T23:59:59.000Z

90

Neutronics analysis for an accelerator-based nuclear waste transmuter  

SciTech Connect (OSTI)

The neutronic analysis for a target/blanket design that is capable of supporting the high level waste stream from 2.5 LWR`s is described. The target consists of a set of solid tungsten and lead plates, cooled by heavy water and surrounded by a lead annulus. The annular blanket, which surrounds the target, consists of a set of AcO{sub 2} slurry bearing tubes, each 3 meters long, surrounded by heavy water moderator. Heat removal from the slurry tubes is by passing the rapidly moving slurry through an external heat exchanger. There are separate regions for long-lived fission product burning. Using the Monte Carlo codes LAHET and MCNP we have optimized the design for a minimum beam current of 62.5 mA of 1.6 GeV protons.

Sailor, W.C.; Beard, C.A.

1993-07-01T23:59:59.000Z

91

Passive and Active Fast-Neutron Imaging in Support of Advanced Fuel Cycle Initiative Safeguards Campaign  

SciTech Connect (OSTI)

Results from safeguards-related passive and active coded-aperture fast-neutron imaging measurements of plutonium and highly enriched uranium (HEU) material configurations performed at Idaho National Laboratory s Zero Power Physics Reactor facility are presented. The imaging measurements indicate that it is feasible to use fast neutron imaging in a variety of safeguards-related tasks, such as monitoring storage, evaluating holdup deposits in situ, or identifying individual leached hulls still containing fuel. The present work also presents the first demonstration of imaging of differential die away fast neutrons.

Blackston, Matthew A [ORNL; Hausladen, Paul [ORNL

2010-04-01T23:59:59.000Z

92

Polarization analysis of neutron reflectometry on non-collinear magnetic media: polarized neutron reflectometry experiments on a thin cobalt film  

Science Journals Connector (OSTI)

In this work we present a full data analysis of polarized neutron reflectometry experiments on a thin magnetic film. A magnetic field was applied perpendicular to the layer magnetization, resulting in non spin-flip and spin-flip reflectivities. For moderate external fields, the gain or loss of Zeeman energy for spin-flipped neutrons results in off-specular reflected spin-flipped beams. The theoretical model used to explain all data simultaneously consists of a bulk cobalt layer, together with interfacial layers with low magnetization values.

R.W.E van de Kruijs; H Fredrikze; M.Th Rekveldt; A.A van Well; Yu.V Nikitenko; V.G Syromyatnikov

2000-01-01T23:59:59.000Z

93

Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials  

SciTech Connect (OSTI)

Using a beam of tagged 14.1 MeV neutrons to probe for the presence of fissionable materials, we have measured n-?-? coincidences from depleted uranium (DU). The multiple coincidence rate is substantially above that measured from lead, tungsten, and iron. The presence of coincidences involving delayed gammas in the DU time spectra provides a signature for fissionable materials that is distinct from non-fissionable ones. In addition, the information from the tagged neutron involved in the coincidence gives the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is more compact and that produces much less radiation than other solutions.

J.P. Hurley, R.P. Keegan, J.R. Tinsley, R. Trainham, and S.C. Wilde

2008-08-06T23:59:59.000Z

94

Mantid - Data Analysis and Visualization Package for Neutron Scattering and $\\mu SR$ Experiments  

E-Print Network [OSTI]

The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objectives, functionality and novel design aspects of Mantid are described.

Arnold, O; Borreguero, J M; Buts, A; Campbell, S I; Chapon, L; Doucet, M; Draper, N; Leal, R Ferraz; Gigg, M A; Lynch, V E; Markvardsen, A; Mikkelson, D J; Mikkelson, R L; Miller, R; Palmen, K; Parker, P; Passos, G; Perring, T G; Peterson, P F; Ren, S; Reuter, M A; Savici, A T; Taylor, J W; Taylor, R J; Tolchenov, R; Zhou, W; Zikovsky, J

2014-01-01T23:59:59.000Z

95

The fast neutron fluence and the activation detector activity calculations using the effective source method and the adjoint function  

SciTech Connect (OSTI)

This paper describes the application of effective source in forward calculations and the adjoint method to the solution of fast neutron fluence and activation detector activities in the reactor pressure vessel (RPV) and RPV cavity of a VVER-440 reactor. Its objective is the demonstration of both methods on a practical task. The effective source method applies the Boltzmann transport operator to time integrated source data in order to obtain neutron fluence and detector activities. By weighting the source data by time dependent decay of the detector activity, the result of the calculation is the detector activity. Alternatively, if the weighting is uniform with respect to time, the result is the fluence. The approach works because of the inherent linearity of radiation transport in non-multiplying time-invariant media. Integrated in this way, the source data are referred to as the effective source. The effective source in the forward calculations method thereby enables the analyst to replace numerous intensive transport calculations with a single transport calculation in which the time dependence and magnitude of the source are correctly represented. In this work, the effective source method has been expanded slightly in the following way: neutron source data were performed with few group method calculation using the active core calculation code MOBY-DICK. The follow-up neutron transport calculation was performed using the neutron transport code TORT to perform multigroup calculations. For comparison, an alternative method of calculation has been used based upon adjoint functions of the Boltzmann transport equation. Calculation of the three-dimensional (3-D) adjoint function for each required computational outcome has been obtained using the deterministic code TORT and the cross section library BGL440. Adjoint functions appropriate to the required fast neutron flux density and neutron reaction rates have been calculated for several significant points within the RPV and RPV cavity of the VVER-440 reacto rand located axially at the position of maximum power and at the position of the weld. Both of these methods (the effective source and the adjoint function) are briefly described in the present paper. The paper also describes their application to the solution of fast neutron fluence and detectors activities for the VVER-440 reactor. (authors)

Hep, J.; Konecna, A.; Krysl, V.; Smutny, V. [Calculation Dept., Skoda JS plc, Orlik 266, 31606 Plzen (Czech Republic)

2011-07-01T23:59:59.000Z

96

Measurements of Neutron Yield from Deuterium Plasmas at JET by Activation Techniques  

SciTech Connect (OSTI)

The paper reports on experiments carried out at JET to test the possibility of using some activating materials (e.g. {sup 89}Y, {sup 167}Er, {sup 204}Pb, {sup 180}Hf, {sup 111}Cd, etc.) to perform multi-foil neutron activation measurements. It is shown that apart from indium other materials can be successfully used in these measurements delivering more exact information about fluxes and also energy spectra of the analysed neutrons. These and other materials have threshold energy in the interesting energy range (0.5-15 MeV) and relatively large cross sections for the nuclear reactions, but have not been used in the activation measurements supposedly because produce daughter nuclides with a relatively short half-life time. We propose then some modification of the JET activation system mainly in order to convey the activation samples faster to the detector.

Prokopowicz, R. [Institute of Plasma Physics and Laser Microfusion, P.O. Box 49, 00-908 Warsaw (Poland); Institute of Atomic Energy, 05-400 Otwock-Swierk (Poland); Scholz, M. [Institute of Plasma Physics and Laser Microfusion, P.O. Box 49, 00-908 Warsaw (Poland); Szydlowski, A. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Popovichev, S. [EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon 0X14 3DB (United Kingdom)

2008-03-19T23:59:59.000Z

97

Analysis Activities at Pacific Northwest National Laboratory  

Broader source: Energy.gov [DOE]

Presentation on PNNL’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

98

Analysis Activities at Oak Ridge National Laboratory  

Broader source: Energy.gov [DOE]

Presentation on ORNL’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

99

Analysis Activities at National Renewable Energy Laboratory  

Broader source: Energy.gov [DOE]

Presentation on NREL’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

100

Analysis Activities at Sandia National Laboratory  

Broader source: Energy.gov [DOE]

Presentation on SNL’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

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101

Analysis Activities at Lawrence Livermore National Laboratory  

Broader source: Energy.gov [DOE]

Presentation on Lawrence Livermore’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

102

Digital discrimination of neutrons and gamma-rays in organic scintillation detectors using moment analysis  

SciTech Connect (OSTI)

Digital discrimination of neutron and gamma-ray events in an organic scintillator has been investigated by moment analysis. Signals induced by an americium-beryllium (Am/Be) isotropic neutron source in a stilbene crystal detector have been sampled with a flash analogue-to-digital converter (ADC) of 1 GSamples/s sampling rate and 10-bit vertical resolution. Neutrons and gamma-rays have been successfully discriminated with a threshold corresponding to gamma-ray energy about 217 keV. Moment analysis has also been verified against the results assessed by a time-of-flight (TOF) measurement. It is shown that the classification of neutrons and gamma-rays afforded by moment analysis is consistent with that achieved by digital TOF measurement. This method has been applied to analyze the data acquired from the stilbene crystal detector in mixed radiation field of the HL-2A tokamak deuterium plasma discharges and the results are described.

Xie Xufei; Zhang Xing; Yuan Xi; Chen Jinxiang; Li Xiangqing; Zhang Guohui; Fan Tieshuan [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing (China); Yuan Guoliang; Yang Jinwei; Yang Qingwei [Southwestern Institute of Physics, Chengdu (China)

2012-09-15T23:59:59.000Z

103

Modern Techniques for Inelastic Thermal Neutron Scattering Analysis  

Science Journals Connector (OSTI)

Abstract A predictive approach based on ab initio quantum mechanics and/or classical molecular dynamics simulations has been formulated to calculate the scattering law, S ( ? ? , ? ) , and the thermal neutron scattering cross sections of materials. In principle, these atomistic methods make it possible to generate the inelastic thermal neutron scattering cross sections of any material and to accurately reflect the physical conditions of the medium (i.e, temperature, pressure, etc.). In addition, the generated cross sections are free from assumptions such as the incoherent approximation of scattering theory and, in the case of solids, crystalline perfection. As a result, new and improved thermal neutron scattering data libraries have been generated for a variety of materials. Among these are materials used for reactor moderators and reflectors such as reactor-grade graphite and beryllium (including the coherent inelastic scattering component), silicon carbide, cold neutron media such as solid methane, and neutron beam filters such as sapphire and bismuth. Consequently, it is anticipated that the above approach will play a major role in providing the nuclear science and engineering community with its needs of thermal neutron scattering data especially when considering new materials where experimental information may be scarce or nonexistent.

A.I. Hawari

2014-01-01T23:59:59.000Z

104

Use of Activation Technique and MCNP Calculations for Measurement of Fast Neutron Spatial Distribution at the MJ Plasma Focus Device.  

Science Journals Connector (OSTI)

In this paper Plasma-Focus (PF) neutron emission properties have been studied using Monte Carlo calculations for neutron and photon transport. A Thermal Neutron Scaling Factor as a function of angular position of silver activation detectors placed around MJ Plasma Focus (PF-1000) device has been calculated. Detector responses calculated for 2.5 MeV neutrons and neutrons produced by Am-Be calibration source have been obtained .The results have shown the detector response dependence on the kind of calibration neutron source and on local geometrical/structural characteristics of the PF-1000 devices. Thus the proper calibration procedure ought to be performed for correct measurement of neutron yield within Plasma-Focus devices.

B. Bienkowska; M. Scholz; K. Wincel; B. Zar?ba

2008-01-01T23:59:59.000Z

105

Innovative high pressure gas MEM's based neutron detector for ICF and active SNM detection.  

SciTech Connect (OSTI)

An innovative helium3 high pressure gas detection system, made possible by utilizing Sandia's expertise in Micro-electrical Mechanical fluidic systems, is proposed which appears to have many beneficial performance characteristics with regards to making these neutron measurements in the high bremsstrahlung and electrical noise environments found in High Energy Density Physics experiments and especially on the very high noise environment generated on the fast pulsed power experiments performed here at Sandia. This same system may dramatically improve active WMD and contraband detection as well when employed with ultrafast (10-50 ns) pulsed neutron sources.

Martin, Shawn Bryan; Derzon, Mark Steven; Renzi, Ronald F.; Chandler, Gordon Andrew

2007-12-01T23:59:59.000Z

106

Neutron Capture Measurements and Resonance Analysis of Dysprosium  

Science Journals Connector (OSTI)

Abstract The electron linear accelerator facility at the Rensselaer Polytechnic Institute was used to measure neutron capture yields of dysprosium with the time-of-flight method in the neutron energy region from 10 eV to 1 keV. The neutron capture experiments were made at a flight path length of 25.5 m with a 16-section NaI multiplicity detector. High purity isotopic samples of 161Dy, 162Dy, 163Dy, 164Dy as well as one natural dysprosium sample with thickness of 0.508 mm were used in this measurement. Resonance parameters were extracted from the data using simultaneous fit with the multilevel R-matrix Bayesian code SAMMY 8.0. New resonances are proposed, and other resonances previously identified in the literature have been revised. The present results are compared with other evaluated values of ENDF/B-VII.1 and JENDL 4.0.

Y.R. Kang; M.W. Lee; T.I. Ro; G.N. Kim; Y. Danon; D. Williams

2014-01-01T23:59:59.000Z

107

Recent activities for ?-decay half-lives and ?-delayed neutron emission of very neutron-rich isotopes  

SciTech Connect (OSTI)

Beta-delayed neutron (?n) emitters play an important, two-fold role in the stellar nucleosynthesis of heavy elements in the 'rapid neutron-capture process' (r process). On one hand they lead to a detour of the material ?-decaying back to stability. On the other hand, the released neutrons increase the neutron-to-seed ratio, and are re-captured during the freeze-out phase and thus influence the final solar r-abundance curve. A large fraction of the isotopes inside the r-process reaction path are not yet experimentally accessible and are located in the (experimental) 'Terra Incognita'. With the next generation of fragmentation and ISOL facilities presently being built or already in operation, one of the main motivation of all projects is the investigation of these very neutron-rich isotopes. A short overview of one of the planned programs to measure ?n-emitters at the limits of the presently know isotopes, the BRIKEN campaign (Beta delayed neutron emission measurements at RIKEN) will be given. Presently, about 600 ?-delayed one-neutron emitters are accessible, but only for a third of them experimental data are available. Reaching more neutron-rich isotopes means also that multiple neutron-emission becomes the dominant decay mechanism. About 460 ?-delayed two-, three-or four-neutron emitters are identified up to now but for only 30 of them experimental data about the neutron branching ratios are available, most of them in the light mass region below A=30. The International Atomic and Energy Agency (IAEA) has identified the urgency and picked up this topic recently in a 'Coordinated Research Project' on a 'Reference Database for Beta-Delayed Neutron Emission Data'. This project will review, compile, and evaluate the existing data for neutron-branching ratios and half-lives of ?-delayed neutron emitters and help to ensure a reliable database for the future discoveries of new isotopes and help to constrain astrophysical and theoretical models.

Dillmann, Iris [TRIUMF, Vancouver BC, V6T 2A3, Canada and GSI Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt (Germany); Abriola, Daniel [Laboratorio Tandar, Comisión Nacional de Energía Atómica, B1650KINA, San Martín, Buenos Aires (Argentina); Singh, Balraj [Department of Physics and Astronomy, McMaster University, Hamilton ON, L8S 4M1 (Canada)

2014-05-02T23:59:59.000Z

108

Neutron radiation can activate K-ras via a point mutation in codon 146 and induces a different spectrum of ras mutations than does gamma radiation.  

Science Journals Connector (OSTI)

research-article Research Article Neutron radiation can activate K-ras via a point...School of Medicine, New York 10016. Neutron radiation is known to produce tumors in...RF/J mice by a single acute dose of neutron irradiation. Activated ras genes were...

S R Sloan; E W Newcomb; A Pellicer

1990-01-01T23:59:59.000Z

109

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

SciTech Connect (OSTI)

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

HOLDEN, N.E.

2004-09-26T23:59:59.000Z

110

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

111

Assessing the Feasibility of Using Neutron Resonance Transmission Analysis (NRTA) for Assaying Plutonium in Spent Fuel Assemblies  

SciTech Connect (OSTI)

Neutron resonance transmission analysis (NRTA) is an active-interrogation nondestructive assay (NDA) technique capable of assaying spent nuclear fuel to determine plutonium content. Prior experimental work has definitively shown the technique capable of assaying plutonium isotope composition in spent-fuel pins to a precision of approximately 3%, with a spatial resolution of a few millimeters. As a Grand Challenge to investigate NDA options for assaying spent fuel assemblies (SFAs) in the commercial fuel cycle, Idaho National Laboratory has explored the feasibility of using NRTA to assay plutonium in a whole SFA. The goal is to achieve a Pu assay precision of 1%. The NRTA technique uses low-energy neutrons from 0.1-40 eV, at the bottom end of the actinide-resonance range, in a time-of-flight arrangement. Isotopic composition is determined by relating absorption of the incident neutrons to the macroscopic cross-section of the actinides of interest in the material, and then using this information to determine the areal density of the isotopes in the SFA. The neutrons used for NRTA are produced using a pulsed, accelerator-based neutron source. Distinguishable resonances exist for both the plutonium (239,240,241,242Pu) and uranium (235,236,238U) isotopes of interest in spent fuel. Additionally, in this energy range resonances exists for six important fission products (99Tc, 103Rh, 131Xe, 133Cs, 145Nd, and 152Sm) which provide additional information to support spent fuel plutonium assay determinations. Based on extensive modeling of the problem using Monte Carlo-based simulation codes, our preliminary results suggest that by rotating an SFA to acquire four symmetric views, sufficient neutron transmission can be achieved to assay a SFA. In this approach multiple scan information for the same pins may also be unfolded to potentially allow the determination of plutonium for sub-regions of the assembly. For a 17 ? 17 pressurized water reactor SFA, a simplistic preliminary analysis indicates the mass of 239Pu may be determined with a precision on the order of 5%, without the need for operator-supplied fuel information or operational histories. This paper will present our work to date on this topic, indicate our preliminary findings for a conceptual assay approach, discuss resilience against spoofing, and outline our future plans for evaluating the NRTA technique for SFA plutonium determination.

D. L. Chichester; J. W. Sterbentz

2012-07-01T23:59:59.000Z

112

Advances in thermal hydraulic and neutronic simulation for reactor analysis and safety  

SciTech Connect (OSTI)

This paper describes several large-scale computational models developed at Argonne National Laboratory for the simulation and analysis of thermal-hydraulic and neutronic events in nuclear reactors and nuclear power plants. The impact of advanced parallel computing technologies on these computational models is emphasized.

Tentner, A.M.; Blomquist, R.N.; Canfield, T.R.; Ewing, T.F.; Garner, P.L.; Gelbard, E.M.; Gross, K.C.; Minkoff, M.; Valentin, R.A.

1993-03-01T23:59:59.000Z

113

The Analysis and Interpretation of Neutron and X-ray Specular Reflection  

Science Journals Connector (OSTI)

The analysis of neutron and X-ray reflectivity in terms of partial structure factors is described in detail. The method is shown to be an effective means of overcoming problems associated with phase and composition ambiguity. It also offers a means of enhancing the resolution of the experiment.

Lu, J.R.

1996-01-01T23:59:59.000Z

114

Mantid - Data Analysis and Visualization Package for Neutron Scattering and $\\mu SR$ Experiments  

SciTech Connect (OSTI)

The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by a large team of software engineers and scientists at the ISIS Neutron and Muon Facility and the Oak Ridge National Laboratory. The objective of the development is to improve software quality, both in terms of performance and ease of use, for the the user community of large scale facilities. The functionality and novel design aspects of the framework are described.

Arnold, Owen [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Bilheux, Jean-Christophe [ORNL; Borreguero Calvo, Jose M [ORNL; Buts, Alex [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Campbell, Stuart I [ORNL; Doucet, Mathieu [ORNL; Draper, Nicholas J [ORNL; Ferraz Leal, Ricardo F [ORNL; Gigg, Martyn [ISIS Facility, Rutherford Appleton Laboratory (ISIS); Lynch, Vickie E [ORNL; Mikkelson, Dennis J [ORNL; Mikkelson, Ruth L [ORNL; Miller, Ross G [ORNL; Perring, Toby G [ORNL; Peterson, Peter F [ORNL; Ren, Shelly [ORNL; Reuter, Michael A [ORNL; Savici, Andrei T [ORNL; Taylor, Jonathan W [ORNL; Taylor, Russell J [ORNL; Zhou, Wenduo [ORNL; Zikovsky, Janik L [ORNL

2014-01-01T23:59:59.000Z

115

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

SciTech Connect (OSTI)

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

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

2014-02-15T23:59:59.000Z

116

E-Print Network 3.0 - activ-87 fast neutron Sample Search Results  

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

2106533431 Large Scale Experimental Facilities at RRL Nuclear Research Reactor 5 MW power Neutron... Scattering Facilities Neutron diffractometer, ... Source: National Center for...

117

Transportation activity analysis using smartphones  

E-Print Network [OSTI]

Transportation activity surveys investigate when, where and how people travel in urban areas to provide information necessary for urban transportation planning. In Singapore, the Land Transport Authority (LTA) carries out ...

Xiao, Yu

118

HFIR Experiment Facilities | ORNL Neutron Sciences  

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

119

Compound and Elemental Analysis At Valley Of Ten Thousand Smokes...  

Open Energy Info (EERE)

analytical techniques employed included instrumental neutron activation analysis (INAA), atomic absorption spectroscopy (AAS), direct-current plasma atomic emission spectroscopy...

120

The 12B Counter: an active dosemeter for high-energy neutrons  

Science Journals Connector (OSTI)

......measures its own induced radioactivity...reaction Product Energy threshold...taken at a neutron energy of...the time spectra of the 12B...for neutron energy spectra, for instance...with other neutron dosemeters...cylinder 15 Th fission radiator...single-shot time spectrum of the 12B...right): Thermal neutrons (T12 0......

A. Leuschner

2005-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

Characterization of Organic and Conventional Coffee Using Neutron Activation Analysis  

SciTech Connect (OSTI)

Countries importing organic coffee are facing the difficulty of assessing the quality of the product to distinguish original organic coffee from other coffees, thereby eliminating possible fraud. Many analytical methods are matrix sensitive and require matrix-matching reference materials for validation, which are currently nonexistent. This work aims to establish the trace element characterization of organic and conventional Brazilian coffees and to establish correlations with the related soil and the type of fertilizer and agrochemicals applied. It was observed that the variability in element concentrations between the various types of coffee is not so large, which emphasizes the need for analytical methods of high accuracy, reproducibility, and a well-known uncertainty. Moreover, the analyses indicate that sometimes the coffee packages may contain some soil remnants.

E. A. De Nadai Fernandes; P. Bode; F. S. Tagliaferro

2000-11-12T23:59:59.000Z

122

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

123

Accelerating Data Acquisition, Reduction, and Analysis at the Spallation Neutron Source  

SciTech Connect (OSTI)

ORNL operates the world's brightest neutron source, the Spallation Neutron Source (SNS). Funded by the US DOE Office of Basic Energy Science, this national user facility hosts hundreds of scientists from around the world, providing a platform to enable break-through research in materials science, sustainable energy, and basic science. While the SNS provides scientists with advanced experimental instruments, the deluge of data generated from these instruments represents both a big data challenge and a big data opportunity. For example, instruments at the SNS can now generate multiple millions of neutron events per second providing unprecedented experiment fidelity but leaving the user with a dataset that cannot be processed and analyzed in a timely fashion using legacy techniques. To address this big data challenge, ORNL has developed a near real-time streaming data reduction and analysis infrastructure. The Accelerating Data Acquisition, Reduction, and Analysis (ADARA) system provides a live streaming data infrastructure based on a high-performance publish subscribe system, in situ data reduction, visualization, and analysis tools, and integration with a high-performance computing and data storage infrastructure. ADARA allows users of the SNS instruments to analyze their experiment as it is run and make changes to the experiment in real-time and visualize the results of these changes. In this paper we describe ADARA, provide a high-level architectural overview of the system, and present a set of use-cases and real-world demonstrations of the technology.

Campbell, Stuart I [ORNL; Kohl, James Arthur [ORNL; Granroth, Garrett E [ORNL; Miller, Ross G [ORNL; Doucet, Mathieu [ORNL; Stansberry, Dale V [ORNL; Proffen, Thomas E [ORNL; Taylor, Russell J [ORNL; Dillow, David [None

2014-01-01T23:59:59.000Z

124

Neutronic analysis of pebble-bed cores with transuranics  

E-Print Network [OSTI]

(ORNL). This Department of Energy sponsored center is authorized to collect, maintain, analyze, and distribute computer software and data sets in the area of radiation transport and safety. The full-core VHTR pebble-bed model was developed... II.A SCALE 5.0 The 3D full-core pebble-bed VHTR model was initially built using SCALE version 5.0. The modular code system is developed and maintained by ORNL and is readily validated and accepted for use in thermal reactor analysis around...

Pritchard, Megan Leigh

2009-05-15T23:59:59.000Z

125

Neutron Scattering Facilities 1982  

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

126

Use of delayed gamma rays for active non-destructive assay of 235U irradiated by pulsed neutron source (plasma focus)  

Science Journals Connector (OSTI)

Abstract A pulsed neutron source based on plasma focus device has been used for active interrogation and assay of 235U by monitoring its delayed high energy ?-rays. The method involves irradiation of fissile material by thermal neutrons obtained after moderation of a burst of neutrons emitted upon fusion of deuterium in plasma focus (PF) device. The delayed gamma rays emitted from the fissile material as a consequence of induced fission were detected by a large volume sodium iodide (NaI(Tl)) detector. The detector is coupled to a data acquisition system of 2k input size with 2k ADC conversion gain. Counting was carried out in pulse height analysis mode for time integrated counts up to 100 s while the temporal profile of delayed gamma has been obtained by counting in multichannel scaling mode with dwell time of 50 ms. To avoid the effect of passive (natural) and active (from surrounding materials) backgrounds, counts have been acquired for gamma energy between 3 and 10 MeV. The lower limit of detection of 235U in the oxide samples with this set-up is estimated to be 14 mg.

Sanjay Andola; Ram Niranjan; T.C. Kaushik; R.K. Rout; Ashwani Kumar; D.B. Paranjape; Pradeep Kumar; B.S. Tomar; K.L. Ramakumar; S.C. Gupta

2014-01-01T23:59:59.000Z

127

Scaling analysis of bio-molecular dynamics derived from elastic incoherent neutron scattering experiments  

SciTech Connect (OSTI)

Numerous neutron scattering studies of bio-molecular dynamics employ a qualitative analysis of elastic scattering data and atomic mean square displacements. We provide a new quantitative approach showing that the intensity at zero energy exchange can be a rich source of information of bio-structural fluctuations on a pico- to nano-second time scale. Elastic intensity scans performed either as a function of the temperature (back-scattering) and/or by varying the instrumental resolution (time of flight spectroscopy) yield the activation parameters of molecular motions and the approximate structural correlation function in the time domain. The two methods are unified by a scaling function, which depends on the ratio of correlation time and instrumental resolution time. The elastic scattering concept is illustrated with a dynamic characterization of alanine-dipeptide, protein hydration water, and water-coupled protein motions of lysozyme, per-deuterated c-phycocyanin (CPC) and hydrated myoglobin. The complete elastic scattering function versus temperature, momentum exchange, and instrumental resolution is analyzed instead of focusing on a single cross-over temperature of mean square displacements at the apparent onset temperature of an-harmonic motions. Our method predicts the protein dynamical transition (PDT) at T{sub d} from the collective (?) structural relaxation rates of the solvation shell as input. By contrast, the secondary (?) relaxation enhances the amplitude of fast local motions in the vicinity of the glass temperature T{sub g}. The PDT is specified by step function in the elastic intensity leading from elastic to viscoelastic dynamic behavior at a transition temperature T{sub d}.

Doster, W. [Physik-Department, Technische Universität München, D-85748 Garching (Germany)] [Physik-Department, Technische Universität München, D-85748 Garching (Germany); Nakagawa, H. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany) [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany); Japan Atomic Energy Agency, Quantum Beam Science Directorate, Tokai, Ibaraki 319-1195 (Japan); Appavou, M. S. [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)] [Jülich Centre for Neutron Science, Forschungszentrum Jülich GmbH, Outstation at MLZ, Lichtenbergstraße 1, 85747 Garching (Germany)

2013-07-28T23:59:59.000Z

128

Integrating advanced materials simulation techniques into an automated data analysis workflow at the Spallation Neutron Source  

SciTech Connect (OSTI)

This presentation will review developments on the integration of advanced modeling and simulation techniques into the analysis step of experimental data obtained at the Spallation Neutron Source. A workflow framework for the purpose of refining molecular mechanics force-fields against quasi-elastic neutron scattering data is presented. The workflow combines software components to submit model simulations to remote high performance computers, a message broker interface for communications between the optimizer engine and the simulation production step, and tools to convolve the simulated data with the experimental resolution. A test application shows the correction to a popular fixed-charge water model in order to account polarization effects due to the presence of solvated ions. Future enhancements to the refinement workflow are discussed. This work is funded through the DOE Center for Accelerating Materials Modeling.

Borreguero Calvo, Jose M [ORNL] [ORNL; Campbell, Stuart I [ORNL] [ORNL; Delaire, Olivier A [ORNL] [ORNL; Doucet, Mathieu [ORNL] [ORNL; Goswami, Monojoy [ORNL] [ORNL; Hagen, Mark E [ORNL] [ORNL; Lynch, Vickie E [ORNL] [ORNL; Proffen, Thomas E [ORNL] [ORNL; Ren, Shelly [ORNL] [ORNL; Savici, Andrei T [ORNL] [ORNL; Sumpter, Bobby G [ORNL] [ORNL

2014-01-01T23:59:59.000Z

129

Estimation of Performance of an Active Well Coincidence Counter Equipped with Boron-Coated Straw Neutron Detectors - 13401  

SciTech Connect (OSTI)

He-3, a very rare isotope of natural helium gas, has ideal properties for the detection of thermal neutrons. As such it has become the standard material for neutron detectors and sees ubiquitous use within many radiometric applications that require neutron sensitivity. Until recently, there has been a fairly abundant supply of He-3. However, with the reduction in nuclear weapons, production of tritium ceased decades ago and the stockpile has largely decayed away, reducing the available He-3 supply to a small fraction of that needed for neutron detection. A suitable and rapidly-deployable replacement technology for neutron detectors must be found. Many potential replacement technologies are under active investigation and development. One broad class of technologies utilizes B-10 as a neutron capture medium in coatings on the internal surfaces of proportional detectors. A particular implementation of this sort of technology is the boron-coated 'straw' (BCS) detectors under development by Proportional Technologies, Inc. (PTi). This technology employs a coating of B-10 enriched boron carbide (B{sub 4}C) on the inside of narrow tubes, roughly 4 mm in diameter. A neutron counter (e.g. a slab, a well counter, or a large assay counter designed to accommodate 200 liter drums) could be constructed by distributing these narrow tubes throughout the polyethylene body of the counter. One type of neutron counter that is of particular importance to safeguards applications is the Active Well Coincidence Counter (AWCC), which is a Los Alamos design that traditionally employs 42 He-3 detectors. This is a very flexible design which can accurately assay small samples of uranium- and plutonium-bearing materials. Utilizing the MCNPX code and benchmarking against measurements where possible, the standard AWCC has been redesigned to utilize the BCS technology. Particular aspects of the counter performance include the single-neutron ('singles') detection efficiency and the time constant for the decrease in neutron population in the counter following a fission event (a.k.a. the die-away time). Results of the modeling and optimization are presented. (authors)

Young, B.M. [Canberra Industries, Inc., 800 Research Parkway, Meriden, CT 06450 (United States)] [Canberra Industries, Inc., 800 Research Parkway, Meriden, CT 06450 (United States); Lacy, J.L.; Athanasiades, A. [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States)] [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States)

2013-07-01T23:59:59.000Z

130

Analysis Activities at Argonne National Laboratory  

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

Laboratory Laboratory Operated by The University of Chicago Center for Transportation Research Argonne National Laboratory Argonne National Laboratory Marianne M. Mintz Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. 2 ANL's Charter ANL's Charter ANL's Charter Systems analysis in Energy Systems (CTR), Decision and Information Sciences History of working in partnership with industry Analytical work has spanned the range of: Energy Supply - globally and by region Demand for transportation fuels - globally and region Assessment of vehicle technologies and fuels Economic analysis and interaction between energy prices and macro activity Life-cycle analyses of energy use and environmental impacts associated with

131

The Status of USITER Diagnostic Port Plug Neutronics Analysis Using Attila  

SciTech Connect (OSTI)

USITER is one of seven partner domestic agencies (DA) contributing components to the ITER project. Four diagnostic port plug packages (two equatorial ports and two upper ports) will be engineered and fabricated by Princeton Plasma Physics Lab (PPPL). Diagnostic port plugs as illustrated in Fig. 1 are large primarily stainless steel structures that serve several roles on ITER. The port plugs are the primary vacuum seal and tritium confinement barriers for the vessel. The port plugs also house several plasma diagnostic systems and other machine service equipment. Finally, each port plug must shield high energy neutrons and gamma photons from escaping and creating radiological problems in maintenance areas behind the port plugs. The optimization of the balance between adequate shielding and the need for high performance, high throughput diagnostics systems is the focus of this paper. Neutronics calculations are also needed for assessing nuclear heating and nuclear damage in the port plug and diagnostic components. Attila, the commercially available discrete-ordinates software package, is used for all diagnostic port plug neutronics analysis studies at PPPL.

Feder, Russell [1; Youssef, Mahamoud [2; Klabacha, Jonathan [1

2013-11-01T23:59:59.000Z

132

Neutron Scattering Methodology for Absolute Measurement of Room-Temperature Hydrogen Storage Capacity and Evidence for Spillover Effect in a Pt-Doped Activated Carbon  

Science Journals Connector (OSTI)

Neutron Scattering Methodology for Absolute Measurement of Room-Temperature Hydrogen Storage Capacity and Evidence for Spillover Effect in a Pt-Doped Activated Carbon ... A neutron scattering methodology is proposed to simultaneously determine the total hydrogen adsorption, the excess hydrogen adsorption, and hydrogen gas confined in the porous sample. ... It can be combined with an in situ small-angle neutron scattering to study the hydrogen spillover effect in the kinetic adsorption process. ...

Cheng-Si Tsao; Yun Liu; Mingda Li; Yang Zhang; Juscelino B. Leao; Hua-Wen Chang; Ming-Sheng Yu; Sow-Hsin Chen

2010-04-29T23:59:59.000Z

133

E-Print Network 3.0 - active neutron ipan Sample Search Results  

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

Academy of Sciences Collection: Computer Technologies and Information Sciences 2 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

134

E-Print Network 3.0 - absolute neutron activation Sample Search...  

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

... Source: Ecole Polytechnique, Centre de mathmatiques Collection: Mathematics 2 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

135

E-Print Network 3.0 - active neutron counter Sample Search Results  

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

... Source: Ecole Polytechnique, Centre de mathmatiques Collection: Mathematics 11 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

136

E-Print Network 3.0 - accelerator-based neutron activation Sample...  

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

Controlled Fusion Atomic Data Center (CFADC) Collection: Plasma Physics and Fusion 12 The Neutron Scattering Society www.neutronscattering.org Summary: techniques; and service and...

137

Photon Activation Analysis--An Analytical Application Of High-Energy Electron Accelerators  

SciTech Connect (OSTI)

Photon activation analysis (PAA) was introduced about contemporarily with the other activation analysis methods (neutron, NAA, and charged particle activation, CPAA). Nonetheless, for different reasons, PAA has been applied less frequently than the other techniques mentioned. The incident photon energy should exceed about 12 MeV (except in some special rare applications) so as to obtain appreciably high activity yields of the product nuclides. Thus, cyclic electron accelerators (LINACs or microtrons) are used for activation preferably. The predominant photonuclear reaction is of the ({gamma},n)-type. Thus, normally neutron-deficient nuclides are produced. These usually emit gamma rays, annihilation quanta and characteristic X-ray fluorescence, all of whom can be used for analytical evaluation. The spectrometry equipment is the same as used for the other activation techniques (semiconductor detectors, sodium iodide crystals in coincidence geometry). Being uncharged high energy photons have a large penetration power, thus do not suffer from strong matrix absorption. Although not having a detection power as large as in NAA (in the most cases), PAA offers several further convincing advantages, e.g. several elements not or hardly detectable by NAA can be analysed: Titanium, nickel, thallium, lead, bismuth and, in particular, the light elements carbon, nitrogen, oxygen, fluorine, phosphorus. Several typical applications will be described.

Segebade, Christian R.; Goerner, Wolf [Federal Institute of Materials Research and Testing Unter den Eichen 87, 12205 Berlin (Germany)

2009-03-10T23:59:59.000Z

138

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

139

Subcriticality measurements for coupled uranium metal cylinders using the /sup 252/Cf-source-driven neutron noise analysis method  

SciTech Connect (OSTI)

Experiments performed with two coupled uranium metal cylinders are the first application to coupled systems of the /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcritical neutron multiplication factor. These coaxial cylinders were separated axially by various thicknesses of either air or borated plaster between the flat surfaces. In all measurements, the /sup 252/Cf neutron source was located at the center of the outer flat surface of one cylinder, and the two detectors were located in three configurations. By comparing the subcriticality from the measurements performed with borated plaster separating the uranium cylinders to those separated by air, it was found that the neutron multiplication factor was always increased by the insertion of borated plaster between the cylinders, regardless of their separation.

Mihalezo, J.T.; King, W.T.; Blakeman, E.D.

1987-01-01T23:59:59.000Z

140

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

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

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

Analysis Activities at Idaho National Engineering & Environmental Laboratory  

Broader source: Energy.gov [DOE]

Presentation on INEENL’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

142

Analysis Activities at Fossil Energy/ National Energy Technology Laboratory  

Broader source: Energy.gov [DOE]

Presentation on NETL’s analysis activities to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004.

143

Further Evaluation of the Neutron Resonance Transmission Analysis (NRTA) Technique for Assaying Plutonium in Spent Fuel  

SciTech Connect (OSTI)

This is an end-of-year report (Fiscal Year (FY) 2011) for the second year of effort on a project funded by the National Nuclear Security Administration's Office of Nuclear Safeguards (NA-241). The goal of this project is to investigate the feasibility of using Neutron Resonance Transmission Analysis (NRTA) to assay plutonium in commercial light-water-reactor spent fuel. This project is part of a larger research effort within the Next-Generation Safeguards Initiative (NGSI) to evaluate methods for assaying plutonium in spent fuel, the Plutonium Assay Challenge. The second-year goals for this project included: (1) assessing the neutron source strength needed for the NRTA technique, (2) estimating count times, (3) assessing the effect of temperature on the transmitted signal, (4) estimating plutonium content in a spent fuel assembly, (5) providing a preliminary assessment of the neutron detectors, and (6) documenting this work in an end of the year report (this report). Research teams at Los Alamos National Laboratory (LANL), Lawrence Berkeley National Laboratory (LBNL), Pacific Northwest National Laboratory (PNNL), and at several universities are also working to investigate plutonium assay methods for spent-fuel safeguards. While the NRTA technique is well proven in the scientific literature for assaying individual spent fuel pins, it is a newcomer to the current NGSI efforts studying Pu assay method techniques having just started in March 2010; several analytical techniques have been under investigation within this program for two to three years or more. This report summarizes work performed over a nine month period from January-September 2011 and is to be considered a follow-on or add-on report to our previous published summary report from December 2010 (INL/EXT-10-20620).

J. W. Sterbentz; D. L. Chichester

2011-09-01T23:59:59.000Z

144

E-Print Network 3.0 - active fast-neutron imaging Sample Search...  

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

imaging Page: << < 1 2 3 4 5 > >> 1 GLASPPE200832 24 th November 2008 Summary: the polyethylene converter is used for the tracking fast neutrons. The results showed that such a...

145

Spacecraft Habitation Systems, Water Recovery and Waste Active Charged Particle and Neutron Radiation Measurement  

E-Print Network [OSTI]

-PMWC) Orbital Technologies Corporation Technical Abstract Model calculations and risk assessment estimates Particle and Neutron Radiation Measurement Technologies Technical Abstract The innovative High Efficiency the resultant plastic tiles. This system requires access to power, data, and cooling interfaces. The system

146

Application of dosimetry measurements to analyze the neutron activation of a stainless steel sample in a training nuclear reactor  

Science Journals Connector (OSTI)

Abstract All materials present in the core of a nuclear reactor are activated by neutron irradiation. The activity so generated produces a dose around the material. This dose is a potential risk for workers in the surrounding area when materials are withdrawn from the reactor. Therefore, it is necessary to assess the activity generated and the dose produced. In previous works, neutron activation of control rods and doses around the storage pool where they are placed have been calculated for a Boiling Water Reactor using the MCNP5 code based on the Monte Carlo method. Most of the activation is produced indeed in stainless steel components of the nuclear reactor core not only control rods. In this work, a stainless steel sample is irradiated in the Training Reactor AKR-2 of the Technical University Dresden. Dose measurements around the sample have been performed for different times after the irradiation. Experimental dosimetric values are compared with results of Monte Carlo simulation of the irradiation. Comparison shows a good agreement. Hence, the activation Monte Carlo model can be considered as validated.

J. Ródenas; S. Gallardo; F. Weirich; W. Hansen

2014-01-01T23:59:59.000Z

147

SUPPLEMENTARY MATERIAL Lipid bilayer structure determined by the simultaneous analysis of neutron  

E-Print Network [OSTI]

scattering intensities I(q) for both neutrons and x-rays using )()()()( qPqPqIqF TSLC= , (1.) where PLC in structure between oriented and spherical bilayers experimentally using both neutron and x-ray scattering in (2). Our study concluded no difference between the two for x-ray and neutron scattering data

Nagle, John F.

148

Active Automobile Engine Vibration Analysis Technical Report Number 1  

E-Print Network [OSTI]

Active Automobile Engine Vibration Analysis Technical Report Number 1 Page 1 of 26 DISTRIBUTION STATEMENT: Distribution authorized to all. Active Automobile Engine Vibration Analysis Technical Report at the University of Southern California #12;Active Automobile Engine Vibration Analysis Technical Report Number 1

Levi, Anthony F. J.

149

Phase Coherence Analysis of Solar Magnetic Activity  

E-Print Network [OSTI]

Over 24 years of synoptic data from the NSO Kitt Peak Vacuum Telescope is used to investigate the coherency and source of the 27-day (synodic) periodicity that is observed over multiple solar cycles in various solar-related time series. A strong 27.03-day period signal, recently reported by Neugebauer et al. (2000), is clearly detected in power spectra of time series from integrated full-disk measurements of the magnetic flux in the 868.8 nm Fe I line and the line equivalent width in the 1083.0 nm He I line. Using spectral analysis of synoptic maps of photospheric magnetic fields, in addition to constructing maps of the surface distribution of activity, we find that the origin of the 27.03-day signal is long-lived complexes of active regions in the northern hemisphere at a latitude of approximately 18 degrees. In addition, using a new time series analysis technique which utilizes the phase variance of a signal, the coherency of the 27.03-day period signal is found to be significant for the past two decades. However, using the past 120 years of the sunspot number time series, the 27.03-day period signal is found to be a short-lived, no longer than two 11-year solar cycles, quasi-stationary signal.

Carl J. Henney; John W. Harvey

2006-12-20T23:59:59.000Z

150

Dosimetry and spectrometry at accelerator based neutron source for boron neutron capture therapy  

Science Journals Connector (OSTI)

An innovative accelerator-based neutron source for boron neutron capture therapy has started operation at the Budker Institute of Nuclear Physics, Novosibirsk. This facility is based on a compact vacuum insulation tandem accelerator designed to produce proton current up to 10 mA. Epithermal neutrons are proposed to be generated by 1.915 MeV protons bombarding a lithium target using 7Li(p,n)7Be threshold reaction. In the article, techniques to detect neutron and gamma-rays at the facility are described. Gamma radiation is measured with NaI and BGO gamma-spectrometers. The total yield of neutrons is determined by measuring the 477 keV ?-quanta from beryllium decay. For the rough analysis of the generated neutron spectrum we used bubble detectors. As the epithermal neutrons are of interest for neutron capture therapy the NaI detector is used as activation detector. We plan to use a time-of-flight technique for neutron spectra measurement. To realize this technique a new solution of short time neutron generation is proposed.

B. Bayanov; A. Burdakov; A. Kuznetsov; A. Makarov; S. Sinitskii; Yu. Sulyaev; S. Taskaev

2010-01-01T23:59:59.000Z

151

NEUTRON MULTIPLICITY AND ACTIVE WELL NEUTRON COINCIDENCE VERIFICATION MEASUREMENTS PERFORMED FOR MARCH 2009 SEMI-ANNUAL DOE INVENTORY  

SciTech Connect (OSTI)

The Analytical Development (AD) Section field nuclear measurement group performed six 'best available technique' verification measurements to satisfy a DOE requirement instituted for the March 2009 semi-annual inventory. The requirement of (1) yielded the need for SRNL Research Operations Department Material Control & Accountability (MC&A) group to measure the Pu content of five items and the highly enrich uranium (HEU) content of two. No 14Q-qualified measurement equipment was available to satisfy the requirement. The AD field nuclear group has routinely performed the required Confirmatory Measurements for the semi-annual inventories for fifteen years using sodium iodide and high purity germanium (HpGe) {gamma}-ray pulse height analysis nondestructive assay (NDA) instruments. With appropriate {gamma}-ray acquisition modeling, the HpGe spectrometers can be used to perform verification-type quantitative assay for Pu-isotopics and HEU content. The AD nuclear NDA group is widely experienced with this type of measurement and reports content for these species in requested process control, MC&A booking, and holdup measurements assays Site-wide. However none of the AD HpGe {gamma}-ray spectrometers have been 14Q-qualified, and the requirement of reference 1 specifically excluded a {gamma}-ray PHA measurement from those it would accept for the required verification measurements. The requirement of reference 1 was a new requirement for which the Savannah River National Laboratory (SRNL) Research Operations Department (ROD) MC&A group was unprepared. The criteria for exemption from verification were: (1) isotope content below 50 grams; (2) intrinsically tamper indicating or TID sealed items which contain a Category IV quantity of material; (3) assembled components; and (4) laboratory samples. Therefore all (SRNL) Material Balance Area (MBA) items with greater than 50 grams total Pu or greater than 50 grams HEU were subject to a verification measurement. The pass/fail criteria of reference 7 stated 'The facility will report measured values, book values, and statistical control limits for the selected items to DOE SR...', and 'The site/facility operator must develop, document, and maintain measurement methods for all nuclear material on inventory'. These new requirements exceeded SRNL's experience with prior semi-annual inventory expectations, but allowed the AD nuclear field measurement group to demonstrate its excellent adaptability and superior flexibility to respond to unpredicted expectations from the DOE customer. The requirements yielded five SRNL items subject to Pu verification and two SRNL items subject to HEU verification. These items are listed and described in Table 1.

Dewberry, R.; Ayers, J.; Tietze, F.; Klapper, K.

2010-02-05T23:59:59.000Z

152

Neutronic analysis of the conversion of HEU to LEU fuel for a 5-MW MTR core  

SciTech Connect (OSTI)

In recent years, due to cessation of highly enriched uranium (HEU) fuel supply, practical steps have been taken to substitute HEU fuel in almost all research reactors by medium-enriched uranium or low-enriched uranium (LEU) fuels. In this study, a neutronic calculation of a 5-MW research reactor core fueled with HEU (93% /sup 235/U) is presented. In order to assess the performance of the core with the LEU (< 20%) fuel replacement, while keeping fuel element geometry nearly unchanged, several different /sup 235/U loadings were examined. The core consists of 22 standard fuel elements (SFEs) and 6 control fuel elements (CFEs). Each fuel elements has 18 curved plates of which two end plates are dummies. Initial /sup 235/U content is 195 g /sup 235/U/SFE and 9.7 g /sup 235/U/CFE or /PFE. In all calculations the permitted changes to the fuel elements are (a) 18 active plates per SFE, (b) fuel plates assumed to be flat, and (c) 8 or 9 active plates per CFE.

Pazirandeh, A.; Bartsch, G.

1987-01-01T23:59:59.000Z

153

Experimental evaluation of neutron performance in boron-doped low activation concrete  

Science Journals Connector (OSTI)

......concrete (LAC) without boron-doping exposed to reactor...and special limestone. Boron (0.8 wt.%) was introduced in the form of boron carbide. NaCl powder...counted twice to detect two isotopes, 97Zr and 95Zr. The...uncertainty in neutron spectra determination is independent from uncertainties......

T. Ogawa; M. N. Morev; T. Abe; T. Iimoto; T. Kosako; K. Kimura; M. Kinno

2010-06-01T23:59:59.000Z

154

Delayed-gamma signature calculation for neutron-induced fission and activation using MCNPX, Part I: Theory  

Science Journals Connector (OSTI)

The capability to conduct automated radiation-transport simulations of delayed-gamma emission spectra at discrete (line) energies created by the products of neutron fission and activation has been developed for MCNPX. To do so, the CINDER'90 isotopic transmutation code has been merged into MCNPX to seamlessly supply time-dependent, decay-chain atom densities for 3400 nuclides. A new dataset containing ENDF/B-VI emission-probability line data for 979 nuclides has been created for MCNPX, with the balance of the 3400 nuclides treated using existing 25-group emission spectra. Cumulative distribution sampling functions have been developed to accommodate line and multigroup emission data. Fission-product sampling for fissions induced by sub-20-MeV neutrons uses fission-yield data for thermal (E fission-spectrum (1 eV ? E energy (E ? 14 MeV) neutrons for isotopes of uranium, plutonium, thorium, americium, californium, curium, einsteinium, fermium, and neptunium. For higher-energy neutrons, LAHET, a physics package that is also a part of MCNPX, generates a list of residual nuclides. In Part II, we present simulation results for models based on experiments conducted by Fisher and Engle (1964) and Beddingfield and Cecil (1998) to validate the new capability. As will be seen therein, the MCNPX results are in good agreement with the measured data. Finally, in Part III we augment the Monte Carlo presentation with a transport-theory formulation to provide a succinct encapsulation of the relevant physics. The new MCNPX delayed-gamma development offers a powerful new tool for fission-related signature recognition.

Joe W. Durkee Jr.; Michael R. James; Gregg W. McKinney; Holly R. Trellue; Laurie S. Waters; William B. Wilson

2009-01-01T23:59:59.000Z

155

A neutron crystallographic analysis of a rubredoxin mutant at 1.6 ? resolution  

Science Journals Connector (OSTI)

A single-crystal neutron diffraction study has been carried out at 1.6 ? resolution on a mutant rubredoxin from the hyperthermophilic archeon P. furiosus.

Chatake, T.

2004-07-21T23:59:59.000Z

156

E-Print Network 3.0 - assesment neutronics analysis Sample Search...  

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

2106533431 Large Scale Experimental Facilities at RRL Nuclear Research Reactor 5 MW power Neutron... Scattering Facilities ... Source: National Center for Scientific Research...

157

Neutron Generators Developed at LBNL for Homeland Security andImaging Applications  

SciTech Connect (OSTI)

The Plasma and Ion Source Technology Group at Lawrence Berkeley National Laboratory has developed various types of advanced D-D (neutron energy 2.5 MeV), D-T (14 MeV) and T-T (0-9 MeV) neutron generators for wide range of applications. These applications include medical (Boron Neutron Capture Therapy), homeland security (Prompt Gamma Activation Analysis, Fast Neutron Activation Analysis and Pulsed Fast Neutron Transmission Spectroscopy) and planetary exploration with a sub-surface material characterization on Mars. These neutron generators utilize RF induction discharge to ionize the deuterium/tritium gas. This discharge method provides high plasma density for high output current, high atomic species from molecular gases, long life operation and versatility for various discharge chamber geometries. Four main neutron generator developments are discussed here: high neutron output co-axial neutron generator for BNCT applications, point neutron generator for security applications, compact and sub-compact axial neutron generator for elemental analysis applications. Current status of the neutron generator development with experimental data will be presented.

Reijonen, Jani

2006-08-13T23:59:59.000Z

158

Comparative analysis of neutron sources produced by low-energy electrons and deuterons for driving subcritical assemblies.  

SciTech Connect (OSTI)

A conceptual design of an accelerator driven subcritical assembly has been developed using the existing accelerators at Kharkov Institute of Physics and Technology (KIPT) in Ukraine. Two different external neutron source options were examined for driving the subcritical assembly. Electrons with energies below 200 MeV and deuterons with energies below 100 MeV were considered. Comparative analysis of these two options is presented and discussed. The Comparative analysis of neutron sources produced by low-energy electrons and deuterons show that: (1) An electron accelerator with electron energy in the range of 150 to 200 MeV is preferred for producing neutron source; (2) The uranium target material produces the highest neutron yield per electron; (3) The uranium target with 100 KW electron beam produces 3.3 x 10{sup 14} n/s; (4) The thermal hydraulics analyses of the uranium target operating with the 100 KW electron beam power satisfy the engineering design requirements; and (5) The peak thermal stresses (secondary stress) is less than the yield strength of the uranium target material.

Naberezhnev, D.; Gohar, Y.; Belch, H.; Duo, J.; Bolshinsky, I. (Nuclear Engineering Division); (INL)

2008-04-10T23:59:59.000Z

159

Automated Audio-visual Activity Analysis  

E-Print Network [OSTI]

Current computer vision techniques can effectively monitor gross activities in sparse environments. Unfortunately, visual stimulus is often not sufficient for reliably discriminating between many types of activity. In ...

Stauffer, Chris

2005-09-20T23:59:59.000Z

160

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

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

SciTech Connect (OSTI)

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

162

Inspecting the minefield and residual explosives by fast neutron activation method  

SciTech Connect (OSTI)

As an upgrade of a robotic mobile system for antipersonnel land-mine clearance, a fast neutron probe has been considered for the detection of mines and explosive residues. Laboratory tests were made by using the 14 MeV 6 x 10{sup 7} neutrons/sec beam with the associated alpha particle detection and with a LaBr{sub 3} gamma ray detector. Simulant of the anti-personal mine was used as a target. Several measurements were made with the target buried into the soil at different depths. For each depth minimal time measurement was estimated for false negative 0.4 % and false positive equal to 10 %. Tests showed that is possible to detect buried land-mine as well as residual explosives; however, in order to reach the optimal speed of 10 cm/s for de-mining vehicle it is necessarily to use several sealed tube neutron generators and few tens of LaBr{sub 3} gamma ray detectors. (authors)

Sudac, D. [Rudjer Boskovic Inst., Bijenicka c. 54, 10000 Zagreb (Croatia); Majetic, S. [DOK-ING Ltd., Kanalski put 1, 10000 Zagreb (Croatia); Kollar, R. [A.C.T. D.o.o., Prilesje 4, 10000 Zagreb (Croatia); Nad, K.; Obhodas, J. [Rudjer Boskovic Inst., Bijenicka c. 54, 10000 Zagreb (Croatia); Valkovic, V. [A.C.T. D.o.o., Prilesje 4, 10000 Zagreb (Croatia)

2011-07-01T23:59:59.000Z

163

Neutron Activation Analysis for the Demonstration of Amphibolite Rock-Weathering Activity of a Yeast  

Science Journals Connector (OSTI)

...cm' for 48 h in the nuclear reactor FIRG 1 of the GKSS at Geesthacht, Germany. To decrease the dangerously high radiation ofshort...fur Kernenergieverwertung in Schiffbau und Schiffahrt mbH, Geesthacht. 6. Haldar, B. C., and B. M. Tejam. 1976. Simultaneous...

E. Rades-Rohkohl; P. Hirsch; O. Fränzle

1979-12-01T23:59:59.000Z

164

Analysis of neutron scattering components inside a room with concrete walls  

Science Journals Connector (OSTI)

Abstract This paper describes the scattering corrections needed when neutron detectors are calibrated with a neutron point source at the center of a calibration room. The independence of scattering value from the geometric shape of the room was studied, which for more confidence in this case, two sets of rooms with same inner surface area were evaluated. The parameters that relate the air scattering part (A) and room-return part (R) with the additional contribution from scattered neutrons have been calculated for neutrons whose energy goes from 10?8 to 20 MeV. These parameters were calculated using Monte Carlo method for 150, 200, 300, 407, 500, 800 and 1000 cm-radius spherical cavity containing air. In the calculations, monoenergetic neutron sources were placed at the center of cavity, and then neutron fluences were determined at several distances of source to detector along the spherical cavity radius. The parameter R has been fitted as a function of surface area (or radius) of spherical room, and the related coefficient has been calculated for 16 monoenergetic neutron sources. It may produce a reasonable estimate (with difference scattering in any geometry of a calibration room.

Rahim Khabaz

2015-01-01T23:59:59.000Z

165

Neutronic Analysis of an Advanced Fuel Design Concept for the High Flux Isotope Reactor  

SciTech Connect (OSTI)

This study presents the neutronic analysis of an advanced fuel design concept for the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) that could significantly extend the current fuel cycle length under the existing design and safety criteria. A key advantage of the fuel design herein proposed is that it would not require structural changes to the present HFIR core, in other words, maintaining the same rated power and fuel geometry (i.e., fuel plate thickness and coolant channel dimensions). Of particular practical importance, as well, is the fact that the proposed change could be justified within the bounds of the existing nuclear safety basis. The simulations herein reported employed transport theory-based and exposure-dependent eigenvalue characterization to help improve the prediction of key fuel cycle parameters. These parameters were estimated by coupling a benchmarked three-dimensional MCNP5 model of the HFIR core to the depletion code ORIGEN via the MONTEBURNS interface. The design of an advanced HFIR core with an improved fuel loading is an idea that evolved from early studies by R. D. Cheverton, formerly of ORNL. This study contrasts a modified and increased core loading of 12 kg of 235U against the current core loading of 9.4 kg. The simulations performed predict a cycle length of 39 days for the proposed fuel design, which represents a 50% increase in the cycle length in response to a 25% increase in fissile loading, with an average fuel burnup increase of {approx}23%. The results suggest that the excess reactivity can be controlled with the present design and arrangement of control elements throughout the core's life. Also, the new power distribution is comparable or even improved relative to the current power distribution, displaying lower peak to average fission rate densities across the inner fuel element's centerline and bottom cells. In fact, the fission rate density in the outer fuel element also decreased at these key locations for the proposed design. Overall, it is estimated that the advanced core design could increase the availability of the HFIR facility by {approx}50% and generate {approx}33% more neutrons annually, which is expected to yield sizeable savings during the remaining life of HFIR, currently expected to operate through 2014. This study emphasizes the neutronics evaluation of a new fuel design. Although a number of other performance parameters of the proposed design check favorably against the current design, and most of the core design features remain identical to the reference, it is acknowledged that additional evaluations would be required to fully justify the thermal-hydraulic and thermal-mechanical performance of a new fuel design, including checks for cladding corrosion performance as well as for industrial and economic feasibility.

Xoubi, Ned [ORNL; Primm, Trent [ORNL; Maldonado, G. Ivan [University of Tennessee, Knoxville (UTK)

2009-01-01T23:59:59.000Z

166

Analysis Activities at National Renewable Energy Laboratory  

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

Laboratory Laboratory DOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. Margaret K. Mann Hydrogen Analysis Task Leader Charter * NREL's mission: NREL develops renewable energy and energy efficiency technologies and practices, advances related science and engineering, and transfers knowledge and innovations to address the nation's energy and environmental goals. * The NREL Hydrogen Analysis Group provides leadership in hydrogen production, delivery, transition, and market analysis, to increase the efficiency of hydrogen research and implementation. * The NREL Hydrogen Analysis Group has received the majority of its funding from the DOE Hydrogen Program (now HFCIT), with some funding coming from PBA and OFCVT

167

The Cornell University cold neutron beam facility  

SciTech Connect (OSTI)

The final version of a cold neutron beam facility under development at the Cornell 500-kW TRIGA reactor is nearing completion. The facility will provide an ultra-low background subthermal neutron beam, primarily for nuclear reaction experiments such as (n,gamma) and (n,ce) studies and applications such as prompt gamma neutron activation analysis. Its uses will also include exploration of new cold neutron methods and training of graduate students in cold neutron techniques. The facility employs a 13-m long Curved (500-m radius) Ni-on-glass neutron guide (2 cm x 5 cm) to filter out fast neutrons and gamma rays, location of the guide exit in a room isolated from other beams, cold neutrons to increase transmission through the guide, a mesitylene moderator at ca. 30K that avoids hazards of liquid hydrogen or solid methane, and cooling by Cu cold fingers attached to a cryorefrigerator outside the reactor bulk shield. The mesitylene chamber and the first 3 meters of guide are installed in a standard beamplug shell so that no modifications of the reactor structure were required. Design features of the cold source proper have been published in an article that also describes earlier stages of the project, and more recent design details and extensive subsystem tests are reported elsewhere. Final assembly and testing of the beamplug assembly is Currently underway (June 1994); completion is expected in Fall 1994. The project has involved more than seven graduate and undergraduate students.

Clark, D.D. [Cornell Univ., Ithaca, NY (United States)

1994-12-31T23:59:59.000Z

168

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

169

ANALYSIS OF GENE EXPRESSION PROFILES AND DRUG ACTIVITY PATTERNS BY  

E-Print Network [OSTI]

are more related to the kind of cancer than to drug activity patterns. Dependency analysis using Bayesian1 11 ANALYSIS OF GENE EXPRESSION PROFILES AND DRUG ACTIVITY PATTERNS BY CLUSTERING AND BAYESIAN of data produced from up- to-date biological experimental processes needs appropriate data mining

170

Analysis of randomly oriented structures by grazing-incidence small-angle neutron scattering  

Science Journals Connector (OSTI)

A formalism is presented which allows the quantitative evaluation of grazing-incidence small-angle neutron scattering patterns from randomly oriented one-dimensional paracrystal domains with lamellar structure.

Korolkov, D.

2012-03-15T23:59:59.000Z

171

Standard Practice for Application and Analysis of Nuclear Research Emulsions for Fast Neutron Dosimetry  

E-Print Network [OSTI]

1.1 Nuclear Research Emulsions (NRE) have a long and illustrious history of applications in the physical sciences, earth sciences and biological sciences (1,2) . In the physical sciences, NRE experiments have led to many fundamental discoveries in such diverse disciplines as nuclear physics, cosmic ray physics and high energy physics. In the applied physical sciences, NRE have been used in neutron physics experiments in both fission and fusion reactor environments (3-6). Numerous NRE neutron experiments can be found in other applied disciplines, such as nuclear engineering, environmental monitoring and health physics. Given the breadth of NRE applications, there exist many textbooks and handbooks that provide considerable detail on the techniques used in the NRE method. As a consequence, this practice will be restricted to the application of the NRE method for neutron measurements in reactor physics and nuclear engineering with particular emphasis on neutron dosimetry in benchmark fields (see Matrix E706). 1...

American Society for Testing and Materials. Philadelphia

2006-01-01T23:59:59.000Z

172

Characterization and Modeling of Off-Specular Neutron Scattering for Analysis of Two Dimentionally Ordered Structures .  

E-Print Network [OSTI]

??Off-specular neutron reflectometry is an instrumental technique which can be utilized for the characterization of thin-film systems in the depth and in-plane directions simultaneously. Currently,… (more)

Metting, Christopher Jason

2011-01-01T23:59:59.000Z

173

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 ŠLAUS

1967-07-01T23:59:59.000Z

174

Beam characterization at the Neutron Radiography Reactor  

SciTech Connect (OSTI)

The quality of a neutron-imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, potential image quality, and beam divergence, is vital for producing quality radiographic images. This paper provides a characterization of the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and potential image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. The NRAD has an effective collimation ratio greater than 125, a beam divergence of 0.3 +_ 0.1 degrees, and a gold foil cadmium ratio of 2.7. The flux profile has been quantified and the facility is an ASTM Category 1 radiographic facility. Based on bare and cadmium covered foil activation results, the neutron energy spectrum used in the current MCNP model of the radiography beamline over-samples the thermal region of the neutron energy spectrum.

Sarah W. Morgan; Jeffrey C. King; Chad L. Pope

2013-12-01T23:59:59.000Z

175

Effect of interaction with neutrons in matter on flavor conversion of super-light sterile neutrino with active neutrino  

E-Print Network [OSTI]

A super-light sterile neutrino was proposed to explain the absence of the expected upturn of the survival probability of low energy solar boron neutrinos. This is because this super-light sterile neutrino can oscillate efficiently with electron neutrino through a MSW resonance happened in Sun. One may naturally expect that a similar resonance should happen for neutrinos propagating in Earth matter. We study the flavor conversion of this super-light sterile neutrino with active neutrinos in Earth matter. We find that the scenario of the super-light sterile neutrino can easily pass through possible constraints from experiments which can test the Earth matter effect in oscillation of neutrinos. Interestinlgy, we find that this is because the naively expected resonant conversion disappears or is significantly suppressed due to the presence of a potential $V_n$ which arises from neutral current interaction of neutrino with neutrons in matter. In contrast, the neutron number density in the Sun is negligible and the effect of $V_n$ is effectively switched off. This enables the MSW resonance in Sun needed in oscillation of the super-light sterile neutrino with solar electron neutrinos. It's interesting to note that it is the different situation in the Sun and in the Earth that makes $V_n$ effectively turned off and turned on respectively. This observation makes the scenario of the super-light sterile neutrino quite interesting.

Wei Liao; Yuchen Luo; Xiao-Hong Wu

2014-03-11T23:59:59.000Z

176

CAFNA{sup (c)}, coded aperture imaging for fast neutron analysis: Application to contraband and explosive detection  

SciTech Connect (OSTI)

Fast neutron analysis is a technique for determination of the elemental composition of materials in bulk by detecting the energies of characteristic gamma rays, which are emitted by elements after a neutron interaction. These gamma rays are typically in the 2 to 6 MeV range and it is desired to image them with a high efficiency system. Coded aperture imaging is a technique, which can improve system sensitivity by as much as a factor of fifty as compared to conventional collimators. Such systems have been used in x-ray astronomy, but unlike x-ray astronomy, our system is designed for near field imaging. The choice of pattern is critical to the performance of the system but we have devised patterns such that the reconstruction of point like objects is clean and rapid with no spurious response. We have also used the technique for imaging of high energy radioisotopes used in nuclear medicine.

Lanza, R. C.; Zhang, L. [Department of Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02138 (United States)

1999-06-10T23:59:59.000Z

177

Analysis Activities at Pacific Northwest National Laboratory  

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

Pacific Northwest National Laboratory Pacific Northwest National Laboratory Pacific Northwest National Laboratory's Hydrogen Analysis Capabilities Marylynn Placet Manager, Energy Policy and Planning Group m.placet@pnl.gov (202) 646-5249 DOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. U.S. Department of Energy Pacific Northwest National Laboratory 2 Charter PNNL Energy Science and Technology Directorate's Energy Mission: Secure, clean, and affordable energy systems in a carbon constrained world. PNNL Analysis Objectives/Principles: * Development of state-of-the-art analysis tools for critical policy issues (e.g., climate change, electricity grid issues) * Use of tools appropriate to the need * Objectivity; analysis based on best available,

178

Activation of Soil and Chemical Reagents Exposed to the Neutrons Released by the JCO Criticality Accident in Tokai-mura  

Science Journals Connector (OSTI)

......hours) of fission neutrons to the environment...release of fission products. To evaluate the neutron doses to residents...of neutron-induced radionuclides...the apparent thermal S56 Y. MURATA...fluence and its energy spectrum. By using......

Yoshimasa Murata; Toshiharu Muroyama; Yoshiko Kawabata; Masayoshi Yamamoto; Kazuhisa Komura

2001-09-01T23:59:59.000Z

179

Special Analysis for the Disposal of the Neutron Products Incorporated Sealed Source Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada  

SciTech Connect (OSTI)

The purpose of this special analysis (SA) is to determine if the Neutron Products Incorporated (NPI) Sealed Sources waste stream (DRTK000000056, Revision 0) is suitable for disposal by shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS). The NPI Sealed Sources waste stream consists of 850 60Co sealed sources (Duratek [DRTK] 2013). The NPI Sealed Sources waste stream requires a special analysis (SA) because the waste stream 60Co activity concentration exceeds the Nevada National Security Site (NNSS) Waste Acceptance Criteria (WAC) Action Levels.

Shott, Gregory

2014-08-31T23:59:59.000Z

180

CALIBRATION OF THE HB LINE ACTIVE WELL NEUTRON COINCIDENCE COUNTER FOR MEASUREMENT OF LANL 3013 HIGHLY ENRICHED URANIUM PRODUCT SPLITS  

SciTech Connect (OSTI)

In this paper we describe set-up, calibration, and testing of the F-Area Analytical Labs active well neutron coincidence counter(HV-221000-NDA-X-1-DK-AWCC-1)in SRNL for use in HB-Line to enable assay of 3013EU/Pu metal product. The instrument was required within a three-month window for availability upon receipt of LANL Category IV uranium oxide samples into the SRS HB-Line facility. We describe calibration of the instrument in the SRNL nuclear nondestructive assay facility in the range 10-400 g HEU for qualification and installation in HB-Line for assay of the initial suite of product samples.

Dewberry, R; Donald02 Williams, D; Rstephen Lee, R; David-W Roberts, D; Leah Arrigo, L

2008-01-22T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

Active beam position stabilization of pulsed lasers for long-distance ion profile diagnostics at the Spallation Neutron Source (SNS)  

SciTech Connect (OSTI)

A high peak-power Q-switched laser has been used to monitor the ion beam profiles in the superconducting linac at the Spallation Neutron Source (SNS). The laser beam suffers from position drift due to movement, vibration, or thermal effects on the optical components in the 250-meter long laser beam transport line. We have designed, bench-tested, and implemented a beam position stabilization system by using an Ethernet CMOS camera, computer image processing and analysis, and a piezo-driven mirror platform. The system can respond at frequencies up to 30 Hz with a high position detection accuracy. With the beam stabilization system, we have achieved a laser beam pointing stability within a range of 2 rad (horizontal) to 4 rad (vertical), corresponding to beam drifts of only 0.5 mm 1 mm at the furthest measurement station located 250 meters away from the light source.

Hardin, Robert A [ORNL; Liu, Yun [ORNL; Long, Cary D [ORNL; Aleksandrov, Alexander V [ORNL; Blokland, Willem [ORNL

2011-01-01T23:59:59.000Z

182

Comparison of neutron probe and time domain reflectometry techniques of soil moisture analysis  

SciTech Connect (OSTI)

The Environmental Science Group of Los Alamos National Laboratory collected soil water content data using Time Domain Reflectometry (TDR) and neutron probe in order to correlate the results from the two techniques in a study performed at Los Alamos, NM. Two well-characterized field plots (3m {times} 10m) were instrumented with TDR waveguides and neutron probe access tubes at four locations. At each location, TDR rod pairs were placed horizontally at 5-,15-,30-,45- and 60-cm depths and vertical sets of rod pairs with lengths of 15-,30-,45- and 60-cm were installed. Neutron probe measurements were taken at 15-,30-,45- and 60-cm depths. Because the neutron probe measures a spherical volume, soil water content values were compared with horizontal TDR readings averaged over the same zone. Additionally, vertical TDR readings were compared to neutron probe readings averaged over the depths corresponding to each TDR length. Measurements for each technique were taken weekly since Fall of 1992. A time series comparison of the results is presented.

Schofield, T.G.; Langhorst, G.J.; Trujillo, G.; Bostick, K.V.; Hansen, W.R.

1994-04-01T23:59:59.000Z

183

Neutron activation diagnostics at the National Ignition Facility (invited) D. L. Bleuel, C. B. Yeamans, L. A. Bernstein, R. M. Bionta, J. A. Caggiano et al.  

E-Print Network [OSTI]

. H. G. Schneider1 1 Lawrence Livermore National Laboratory, Livermore, California 94550, USA 2 yields are measured at the National Ignition Facility (NIF) by an extensive suite of neutron activation manipulators in the NIF target chamber, 25­50 cm from the source, to measure 2.45 MeV deuterium

184

Neutron Irradiation of Hydrided Cladding Material in HFIR Summary...  

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

Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities Neutron Irradiation of Hydrided Cladding Material in HFIR Summary of Initial Activities...

185

Analysis Activities at Lawrence Livermore National Laboratory  

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

Laboratory / Energy Security and Technology Program Jeffrey Stewart Group Leader: Applied Statistics and Economics DOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. 2 Charter * LLNL's mission is to provide research in the areas of national and homeland security and other important areas to DOE such as Energy,Climate and Water * To conduct systems and economic modeling and analysis to determine the technical and economic characteristics of individual technologies within systems to achieve policy objectives * DOE NETL, NE,Policy,HEU; Japanese Govt, CEC, Internal 3 History * LLNL has had a systems analysis group for over 25 years supporting national security, defense, energy and environment programs

186

Analysis of the proposed relocation of the neutron criticality clusters in the process buildings for the Portsmouth Gaseous Diffusion Plant  

SciTech Connect (OSTI)

Radiation levels in Buildings X-326, X-330 and X-333 have been determined for the ANSI minimum accident of concern at both the current and the proposed locations of the criticality alum system neutron detectors. This was performed in order to evaluate whether or not the detectors could be lowered from their current positions and still respond to the minimum accident of concern. Relocating the detectors could reduce the potential for worker in injury when the approximately 90-pound alarms need to be removed for periodic maintenance. It could also decrease the incidence of battery failure from elevated temperatures which can exceed 160 degrees F. At the proposed 1-meter elevation the detectors would be surrounded by the cells containing the cascade equipment; therefore, the detectors would be less responsive to a criticality event. The results of this analysis indicate that the detectors could be lowered from their current height of 5 meters to a height of 1 meter and still respond to the minimum accident of concern. This analysis was performed using the MCNP monte carlo code with a source corresponding to a critical system of uranyl fluoride solutions of 1.2, 3.0, and 4.95 weight percent U-235 enrichment. The neutron dose rates were evaluated at positions of 69 meters and 100 meters radially outward from the source at 5 meter and 1 meter heights. All neutron detectors located in the three process buildings are located within 100 meters from any potential criticality. This report details the methodology used for this study, background on the data employed, and a comparison to a similar analysis performed in 1983.

Negron, S.B.; Tayloe, R.W. Jr. [Battelle, Columbus, OH (United States)

1994-01-01T23:59:59.000Z

187

Immune activation suppresses plasma testosterone level: a meta-analysis  

Science Journals Connector (OSTI)

...sizes of immune challenge on plasma T levels. (Immune challenges...M Sexual selection. In Princeton University Press 1994Princeton, NJ:Princeton University Press Barthelemy...Immune activation suppresses plasma testosterone level: a meta-analysis...

2008-01-01T23:59:59.000Z

188

CSER-98-009: antech neutron multiplicity counter for nondestructive analysis  

SciTech Connect (OSTI)

The ANTECH neutron multiplicity counter is a portable nondestructive assay (NDA) instrument which measures plutonium content by counting fission neutrons in the presence of (a,n) neutrons. Neutrons from the (a,n) process are discriminated against through the use of coincidence counting. The instrument will be used for the purpose of determining inventory of plutonium in the Plutonium Finishing Plant (PFP). The portability of the instrument will facilitate this task by minimizing the necessity of transporting fissile material. The use of the Antech counter is approved based on the inherent safety of the containers to be assayed in that an acceptable margin of subcriticality has been demonstrated for all normal and credible abnormal conditions in accordance with HNF-PRO-537 (F, 1997). A summary of the results of the abnormal conditions are tabulated in Table 2. For foreseeable contingencies, the calculated k{sub eff}s are less than 0.95 after taking into account the calculational bias and statistical uncertainty equal to or larger than the 95% confidence level. This approval is based on the requirement that only one container is to be put in the counter at a time and in accordance with the other limits listed in section 1.4. The design of the current instrument conforms with the acceptability criteria which allow the other NDA detectors currently employed at the facility to be safely used.

GOLDBERG, H.J.

1999-05-12T23:59:59.000Z

189

Neutron Scattering Software  

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

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

190

Analysis Activities at Oak Ridge National Laboratory  

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

Oak Ridge National Laboratory Oak Ridge National Laboratory David L. Greene Engineering Science and Technology Division Paul N. Leiby Environmental Sciences Division Juan Ferrada Nuclear Science and Technology Division DOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. 2 OAK RIDGE NATIONAL LABORATORY U. S. DEPARTMENT OF ENERGY Charter * The Engineering Science and Technology Division, National Transportation Research Center conducts engineering and analytical R&D for DOE, other federal sponsors and the private sector. * The Environmental Sciences Division conducts interdisciplinary research, develops technology, and performs analyses to understand and assess responses to global and regional change, environmental stress, and resource use.

191

SWEPP PAN assay system uncertainty analysis: Active mode measurements of solidified aqueous sludge waste  

SciTech Connect (OSTI)

The Idaho National Engineering and Environmental Laboratory is being used as a temporary storage facility for transuranic waste generated by the US Nuclear Weapons program at the Rocky Flats Plant (RFP) in Golden, Colorado. Currently, there is a large effort in progress to prepare to ship this waste to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. In order to meet the TRU Waste Characterization Quality Assurance Program Plan nondestructive assay compliance requirements and quality assurance objectives, it is necessary to determine the total uncertainty of the radioassay results produced by the Stored Waste Examination Pilot Plant (SWEPP) Passive Active Neutron (PAN) radioassay system. This paper is one of a series of reports quantifying the results of the uncertainty analysis of the PAN system measurements for specific waste types and measurement modes. In particular this report covers active mode measurements of weapons grade plutonium-contaminated aqueous sludge waste contained in 208 liter drums (item description codes 1, 2, 7, 800, 803, and 807). Results of the uncertainty analysis for PAN active mode measurements of aqueous sludge indicate that a bias correction multiplier of 1.55 should be applied to the PAN aqueous sludge measurements. With the bias correction, the uncertainty bounds on the expected bias are 0 {+-} 27%. These bounds meet the Quality Assurance Program Plan requirements for radioassay systems.

Blackwood, L.G.; Harker, Y.D.; Meachum, T.R.

1997-12-01T23:59:59.000Z

192

Using Photon Activation Analysis To Determine Concentrations Of Unknown Components In Reference Materials  

SciTech Connect (OSTI)

Using certified multi-element reference materials for instrumental analyses one frequently is confronted with the embarrassing fact that the concentration of some desired elements are not given in the respective certificate, nonetheless are detectable, e.g. by photon activation analysis (PAA). However, these elements might be determinable with sufficient quality of the results using scaling parameters and the well-known quantities of a reference element within the reference material itself. Scaling parameters include: activation threshold energy, Giant Dipole Resonance (GDR) peak and endpoint energy of the bremsstrahlung continuum; integrated photo-nuclear cross sections for the isotopes of the reference element; bremsstrahlung continuum integral; target thickness; photon flux density. Photo-nuclear cross sections from the unreferenced elements must be known, too. With these quantities, the integral was obtained for both the known and unknown elements resulting in an inference of the concentration of the unreported element based upon the reported value, thus also the concentration of the unreferenced element in the reference material. A similar method to determine elements using the basic nuclear and experimental data has been developed for thermal neutron activation analysis some time ago (k{sub 0} Method).

Green, Jaromy; Sun, Zaijing [Idaho State University, Physics Department, 921 S. 8th Avenue, Stop 8106, Pocatello, ID 83209 (United States); Wells, Doug [Idaho State University, Physics Department, 921 S. 8th Avenue, Stop 8106, Pocatello, ID 83209 (United States); Idaho Accelerator Center, 1500 Ricken Drive, Pocatello, ID 83201 (United States); Maschner, Herb [Idaho State University, Anthropology Department, 921 S. 8th Avenue, Stop 8005, Pocatello, ID 83209 (United States)

2011-06-01T23:59:59.000Z

193

Shielding analysis and design of the KIPT experimental neutron source facility of Ukraine.  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of an experimental neutron source facility based on the use of an electron accelerator driven subcritical (ADS) facility [1]. The facility uses the existing electron accelerators of KIPT in Ukraine. The neutron source of the sub-critical assembly is generated from the interaction of 100 KW electron beam with a natural uranium target. The electron beam has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Reactor physics experiments and material performance characterization will also be carried out. The subcritical assembly is driven by neutrons generated by the electron beam interactions with the target material. A fraction of these neutrons has an energy above 50 MeV generated through the photo nuclear interactions. This neutron fraction is very small and it has an insignificant contribution to the subcritical assembly performance. However, these high energy neutrons are difficult to shield and they can be slowed down only through the inelastic scattering with heavy isotopes. Therefore the shielding design of this facility is more challenging relative to fission reactors. To attenuate these high energy neutrons, heavy metals (tungsten, iron, etc.) should be used. To reduce the construction cost, heavy concrete with 4.8 g/cm{sup 3} density is selected as a shielding material. The iron weight fraction in this concrete is about 0.6. The shape and thickness of the heavy concrete shield are defined to reduce the biological dose equivalent outside the shield to an acceptable level during operation. At the same time, special attention was give to reduce the total shield mass to reduce the construction cost. The shield design is configured to maintain the biological dose equivalent during operation {le} 0.5 mrem/h inside the subcritical hall, which is five times less than the allowable dose for working forty hours per week for 50 weeks per year. This study analyzed and designed the thickness and the shape of the radial and top shields of the neutron source based on the biological dose equivalent requirements inside the subcritical hall during operation. The Monte Carlo code MCNPX is selected because of its capabilities for transporting electrons, photons, and neutrons. Mesh based weight windows variance reduction technique is utilized to estimate the biological dose outside the shield with good statistics. A significant effort dedicated to the accurate prediction of the biological dose equivalent outside the shield boundary as a function of the shield thickness without geometrical approximations or material homogenization. The building wall was designed with ordinary concrete to reduce the biological dose equivalent to the public with a safety factor in the range of 5 to 20.

Zhong, Z.; Gohar, M. Y. A.; Naberezhnev, D.; Duo, J.; Nuclear Engineering Division

2008-10-31T23:59:59.000Z

194

Cosmic ray modulation studies with Lead-free Gulmarg neutron monitor  

E-Print Network [OSTI]

A lead-free neutron monitor operating at High Altitude Research Laboratory (HARL), Gulmarg optimized for detecting 2.45 MeV neutron bursts produced during the atmospheric lightning discharges is also concurrently used for studying background neutron component present in the atmosphere. These background neutrons are produced due to the interaction of primary cosmic rays with the atmospheric constituents. In order to study and extract the information about the yield of the neutron production during transient atmospheric lightning discharges, the system is continuously operated to monitor and record the cosmic ray produced background secondary neutrons in the atmosphere. The data analysis of the background neutrons recorded by Lead-Free Gulmarg Neutron Monitor (LFGNM) has convincingly established that the modulation effects due to solar activity phenomena compare very well with those monitored by the worldwide IGY or NM64 type neutron monitors which have optimum energy response relatively towards the higher energy regime of the cosmic rays. The data has revealed various types of modulation phenomena like diurnal variation, Forbush decrease etc. during its entire operational period. However, a new kind of a periodic/seasonal variation pattern is also revealed in the data from September 2007 to September 2012, which is seen to be significantly consistent with the data recorded by Emilio Segre observatory, Israel (ESOI) Neutron Monitor. Interestingly, both these neutron monitors have comparable latitude and altitude. However, the same type of consistency is not observed in the data recorded by the other conventional neutron monitors operating across the globe.

M. A. Darzi; P. M. Ishtiaq; T. A. Mir; S. Mufti; G. N. Shah

2013-12-21T23:59:59.000Z

195

A Thermal Discrete Element Analysis of EU Solid Breeder Blanket subjected to Neutron Irradiation  

E-Print Network [OSTI]

Due to neutron irradiation, solid breeder blankets are subjected to complex thermo-mechanical conditions. Within one breeder unit, the ceramic breeder bed is composed of spherical-shaped lithium orthosilicate pebbles, and as a type of granular material, it exhibits strong coupling between temperature and stress fields. In this paper, we study these thermo-mechanical problems by developing a thermal discrete element method (Thermal-DEM). This proposed simulation tool models each individual ceramic pebble as one element and considers grain-scale thermo-mechanical interactions between elements. A small section of solid breeder pebble bed in HCPB is modelled using thousands of individual pebbles and subjected to volumetric heating profiles calculated from neutronics under ITER-relevant conditions. We consider heat transfer at the grain-scale between pebbles through both solid-to-solid contacts and the interstitial gas phase, and we calculate stresses arising from thermal expansion of pebbles. The overall effective conductivity of the bed depends on the resulting compressive stress state during the neutronic heating. The thermal-DEM method proposed in this study provides the access to the grain-scale information, which is beneficial for HCPB design and breeder material optimization, and a better understanding of overall thermo-mechanical responses of the breeder units under fusion-relevant conditions.

Yixiang Gan; Francisco Hernandez; Dorian Hanaor; Ratna Annabattula; Marc Kamlah; Pavel Pereslavtsev

2014-06-17T23:59:59.000Z

196

COMBINED ANALYSIS OF THORIUM AND FAST NEUTRON DATA AT THE LUNAR SURFACE  

SciTech Connect (OSTI)

The global distribution of the radioactive elements (U, K, Th) at the lunar surface is an important parameter for an understanding of lunar evolution, because they have provided continuous heat over the lifetime of the Moon. Today, only the thorium distribution is available for the whole lunar surface [1]. Another key parameter that characterize the surface of the Moon is the presence of mare basalts. These basalts are concentrated on the nearside and are represented by materials with high-Fe content, sometimes associated with high-Ti. We demonstrated elsewhere that the fast neutron measurement made by Lunar Prospector is representative of the average soil atomic mass [2]. is primarily dominated by Fe and Ti in basaltic terranes, and therefore the map of the fast neutrons provides a good delineation of mare basalts. We focus here on the correlated variations of thorium abundances and fast neutron fluxes averaged over areas of 360 km in diameter, in an attempt to provide a better understanding of the thorium emplacement on the surface of the Moon.

O. GASNAULT; W. FELDMAN; ET AL

2001-01-01T23:59:59.000Z

197

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

198

Neutronic analysis of candidate accident-tolerant cladding concepts in pressurized water reactors  

Science Journals Connector (OSTI)

Abstract A study analyzed the neutronics of alternate cladding materials in a pressurized water reactor (PWR) environment. Austenitic type 310 (310SS) and 304 stainless steels, ferritic Fe-20Cr-5Al (FeCrAl) and APMT™ alloys, and silicon carbide (SiC)-based materials were considered and compared with Zircaloy-4. SCALE 6.1 was used to analyze the associated neutronics penalty/advantage, changes in reactivity coefficients, and spectral variations once a transition in the cladding was made. In the cases examined, materials containing higher absorbing isotopes invoked a reduction in reactivity due to an increase in neutron absorption in the cladding. Higher absorbing materials produced a harder neutron spectrum in the fuel pellet, leading to a slight increase in plutonium production. A parametric study determined the geometric conditions required to match cycle length requirements for each alternate cladding material in a PWR. A method for estimating the end of cycle reactivity was implemented to compare each model to that of standard Zircaloy-4 cladding. By using a thinner cladding of 350 ?m and keeping a constant outer diameter, austenitic stainless steels require an increase of no more than 0.5 wt% enriched 235U to match fuel cycle requirements, while the required increase for FeCrAl was about 0.1%. When modeling SiC (with slightly lower thermal absorption properties than that of Zircaloy), a standard cladding thickness could be implemented with marginally less enriched uranium (?0.1%). Moderator temperature and void coefficients were calculated throughout the depletion cycle. Nearly identical reactivity responses were found when coolant temperature and void properties were perturbed for each cladding material. By splitting the pellet into 10 equal areal sections, relative fission power as a function of radius was found to be similar for each cladding material. FeCrAl and 310SS cladding have a slightly higher fission power near the pellet’s periphery due to the harder neutron spectrum in the system, causing more 239Pu breeding. An economic assessment calculated the change in fuel pellet production costs for use of each cladding. Implementing FeCrAl alloys would increase fuel pellet production costs about 15% because of increased 235U enrichment and the additional UO2 pellet volume enabled by using thinner cladding.

Nathan Michael George; Kurt Terrani; Jeff Powers; Andrew Worrall; Ivan Maldonado

2015-01-01T23:59:59.000Z

199

Neutron sources and applications  

SciTech Connect (OSTI)

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

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

1994-01-01T23:59:59.000Z

200

E-Print Network 3.0 - activation analysis pgaa Sample Search...  

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

for: activation analysis pgaa Page: << < 1 2 3 4 5 > >> 1 Combinatorial approaches for hydrogen storage materials Summary: Gamma Activation Analysis (PGAA) Quantitative H...

Note: This page contains sample records for the topic "neutron activation analysis" 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.


201

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

SciTech Connect (OSTI)

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

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

2013-11-15T23:59:59.000Z

202

INDUSTRIAL/MILITARY ACTIVITY-INITIATED ACCIDENT SCREENING ANALYSIS  

SciTech Connect (OSTI)

Impacts due to nearby installations and operations were determined in the Preliminary MGDS Hazards Analysis (CRWMS M&O 1996) to be potentially applicable to the proposed repository at Yucca Mountain. This determination was conservatively based on limited knowledge of the potential activities ongoing on or off the Nevada Test Site (NTS). It is intended that the Industrial/Military Activity-Initiated Accident Screening Analysis provided herein will meet the requirements of the ''Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants'' (NRC 1987) in establishing whether this external event can be screened from further consideration or must be included as a design basis event (DBE) in the development of accident scenarios for the Monitored Geologic Repository (MGR). This analysis only considers issues related to preclosure radiological safety. Issues important to waste isolation as related to impact from nearby installations will be covered in the MGR performance assessment.

D.A. Kalinich

1999-09-27T23:59:59.000Z

203

On the determination of phosphorous via charged particle activation analysis  

E-Print Network [OSTI]

of Cyclotron Terminal . "or Activation Analysis Ql ? WATER INLET Q2 ? BNC CONNECTOR Q3 ? LUCITE Q4 ? CA RBON Figure 3. Four-leaved Carl. on Pea, -. Monitor 1. Ta COLLIMATOR 2. Cu HEAT SINK K MONITOR 4. SAMPLE 5. Cu BASE PLATE 6. WATER COOLING I 2... of Cyclotron Terminal . "or Activation Analysis Ql ? WATER INLET Q2 ? BNC CONNECTOR Q3 ? LUCITE Q4 ? CA RBON Figure 3. Four-leaved Carl. on Pea, -. Monitor 1. Ta COLLIMATOR 2. Cu HEAT SINK K MONITOR 4. SAMPLE 5. Cu BASE PLATE 6. WATER COOLING I 2...

Poland, John Edward

2012-06-07T23:59:59.000Z

204

A revised structure and hydrogen bonding system in cellulose II from a neutron fiber diffraction analysis  

SciTech Connect (OSTI)

The crystal and molecular structure and hydrogen bonding system in cellulose II have been revised using new neutron diffraction data extending to 1.2 {angstrom} resolution collected from two highly crystalline fiber samples of mercerized flax. Mercerization was achieved in NaOH/H{sub 2}O for one sample and in NaOD/D{sub 2}O for the other, corresponding to the labile hydroxymethyl moieties being hydrogenated and deuterated, respectively. Fourier difference maps were calculated in which neutron difference amplitudes were combined with phases calculated from two revised X-ray models of cellulose II. The revised phasing models were determined by refinement against the X-ray data set of Kolpak and Blackwell, using the LALS methodology. Both models have two antiparallel chains organized in a P2{sub 1} space group and unit cell parameters: a = 8.01 {angstrom}, b = 9.04 {angstrom}, c = 10.36 {angstrom}, and {gamma} = 117.1{degree}. One has equivalent backbone conformations for both chains but different conformations for the hydroxymethyl moieties: gt for the origin chain and tg for the center chain. The second model based on the recent crystal structures of cellotetraose, has different conformations for the two chains but nearly equivalent conformations for the hydroxymethyl moieties. On the basis of the X-ray data alone, the models could not be differentiated. From the neutron Fourier difference maps, possible labile hydrogen atom positions were identified for each model and refined using LALS. The second model is significantly different from previous proposals based on the crystal structures of cellotetraose, MD simulations of cellulose II, and any potential hydrogen-bonding network in the structure of cellulose II determined in earlier X-ray fiber diffraction studies. The exact localization of the labile hydrogen atoms involved in this bonding, together with their donor and acceptor characteristics, is presented and discussed. This study provides, for the first time, the coordinates of all of the atoms in cellulose II.

Langan, P.; Nishiyama, Y.; Chanzy, H.

1999-11-03T23:59:59.000Z

205

Lifetime Analysis of First wall Materials Exposed to High Temperature and High Energy Neutrons in a Fusion Reactor  

Science Journals Connector (OSTI)

At first wall of a fusion power reactor will be subjected to neutrons, charged particles and radiation, leading to neutron irradiation damage, decrease of thickness by physical sputtering, and high heat flux, ...

K. Miya; H. Hashizume; H. Oomura; M. Akiyama

1987-01-01T23:59:59.000Z

206

NAPTH: Neutronics analysis code system for the fusion–fission hybrid reactor with pressure tube type blanket  

Science Journals Connector (OSTI)

The fusion–fission hybrid reactor is considered as a potential path to the early application of fusion energy. A new concept with pressure tube type blanket has recently been proposed for a feasible hybrid reactor. In this paper, a code system for the neutronics analysis of the pressure tube type hybrid reactor is developed based on the two-step calculation scheme: the few-group homogeneous constant calculation and the full blanket calculation. The few-group homogeneous constants are calculated using the lattice code DRAGON4. The blanket transport calculation is performed by the multigroup Monte Carlo code. A link procedure for fitting the cross sections is developed between these two steps. An additional procedure is developed to calculate the burnup, power distribution, energy multiplication factor, tritium breeding ratio and neutron multiplication factor. From some numerical results, it is found that the code system NAPTH is reliable and exhibits good calculation efficiency. It can be used for the conceptual design of the pressure tube type hybrid reactor with precise geometry.

Tiejun Zu; Hongchun Wu; Youqi Zheng; Liangzhi Cao; Chao Yang

2013-01-01T23:59:59.000Z

207

Nuclear Rocket Test Facility Decommissioning Including Controlled Explosive Demolition of a Neutron-Activated Shield Wall  

SciTech Connect (OSTI)

Located in Area 25 of the Nevada Test Site, the Test Cell A Facility was used in the 1960s for the testing of nuclear rocket engines, as part of the Nuclear Rocket Development Program. The facility was decontaminated and decommissioned (D&D) in 2005 using the Streamlined Approach For Environmental Restoration (SAFER) process, under the Federal Facilities Agreement and Consent Order (FFACO). Utilities and process piping were verified void of contents, hazardous materials were removed, concrete with removable contamination decontaminated, large sections mechanically demolished, and the remaining five-foot, five-inch thick radiologically-activated reinforced concrete shield wall demolished using open-air controlled explosive demolition (CED). CED of the shield wall was closely monitored and resulted in no radiological exposure or atmospheric release.

Michael Kruzic

2007-09-01T23:59:59.000Z

208

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

209

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

210

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

211

COUPLED MULTI-GROUP NEUTRON PHOTON TRANSPORT FOR THE SIMULATION OF HIGH-RESOLUTION GAMMA-RAY SPECTROSCOPY APPLICATIONS  

SciTech Connect (OSTI)

The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples.

Burns, Kimberly A.

2009-08-01T23:59:59.000Z

212

Neutron Diffraction @ TOPAZ  

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

213

Small-angle neutron scattering analysis of a water-based magnetic fluid with charge stabilization: contrast variation and scattering of polarized neutrons  

Science Journals Connector (OSTI)

The nuclear and magnetic scattering contributions in small-angle scattering experiments on a diluted water-based magnetic fluid are separated by the contrast variation technique and scattering of polarized neutrons. The significant difference found in the nuclear and magnetic apparent particle sizes is related to different nuclear and magnetic correlation lengths in the system.

Avdeev, M.V.

2009-10-30T23:59:59.000Z

214

About Neutrons  

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

215

High-Resolution Fast-Neutron Spectrometry for Arms Control and Treaty Verification  

SciTech Connect (OSTI)

Many nondestructive nuclear analysis techniques have been developed to support the measurement needs of arms control and treaty verification, including gross photon and neutron counting, low- and high-resolution gamma spectrometry, time-correlated neutron measurements, and photon and neutron imaging. One notable measurement technique that has not been extensively studied to date for these applications is high-resolution fast-neutron spectrometry (HRFNS). Applied for arms control and treaty verification, HRFNS has the potential to serve as a complimentary measurement approach to these other techniques by providing a means to either qualitatively or quantitatively determine the composition and thickness of non-nuclear materials surrounding neutron-emitting materials. The technique uses the normally-occurring neutrons present in arms control and treaty verification objects of interest as an internal source of neutrons for performing active-interrogation transmission measurements. Most low-Z nuclei of interest for arms control and treaty verification, including 9Be, 12C, 14N, and 16O, possess fast-neutron resonance features in their absorption cross sections in the 0.5- to 5-MeV energy range. Measuring the selective removal of source neutrons over this energy range, assuming for example a fission-spectrum starting distribution, may be used to estimate the stoichiometric composition of intervening materials between the neutron source and detector. At a simpler level, determination of the emitted fast-neutron spectrum may be used for fingerprinting 'known' assemblies for later use in template-matching tests. As with photon spectrometry, automated analysis of fast-neutron spectra may be performed to support decision making and reporting systems protected behind information barriers. This paper will report recent work at Idaho National Laboratory to explore the feasibility of using HRFNS for arms control and treaty verification applications, including simulations and experiments, using fission-spectrum neutron sources to assess neutron transmission through composite low-Z attenuators.

David L. Chichester; James T. Johnson; Edward H. Seabury

2012-07-01T23:59:59.000Z

216

Small angle neutron scattering analysis of novel carbons for lithium secondary batteries.  

SciTech Connect (OSTI)

Small angle neutron scattering analyses of carbonaceous materials used as anodes in lithium ion cells have been performed. The carbons have been synthesized using pillared clays (PILCs) as inorganic templates. Pillared clays are layered silicates whose sheets have been permanently propped open by sets of thermally stable molecular props. The calcined PILC was loaded with five different organic precursors and heated at 700 C under nitrogen. When the inorganic pillars were removed by acid treatment, carbon sheets are produced with holes. The fitting of the data in the high q region suggested that the carbon sheets have voids with radii ranging from 4 to 8 {angstrom}. Similar radii were obtained for the PILC and PILC/organic precursor, which suggests that the carbon was well distributed in the clay prior to pyrolysis.

Sandi, G.; Thiyagarajan, P.; Winans, R.; Carrado, K.

1998-01-14T23:59:59.000Z

217

Neutron Scattering Data Vickie Lynch, Jose Borreguero-Calvo,  

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

Discovery in Neutron Scattering Data Vickie Lynch, Jose Borreguero-Calvo, Mark Hagen & Thomas Proffen Neutron Data Analysis & Visualization Division Galen Shipman & Bobby Sumpter...

218

Post irradiation experiment analysis using the APOLLO2 deterministic tool. Validation of JEFF-3.1.1 thermal and epithermal actinides neutron induced cross sections through MELUSINE experiments  

SciTech Connect (OSTI)

Two different experiments performed in the 8 MWth MELUSINE experimental power pool reactor aimed at analyzing 1 GWd/t spent fuel pellets doped with several actinides. The goal was to measure the averaged neutron induced capture cross section in two very different neutron spectra (a PWR-like and an under-moderated one). This paper summarizes the combined deterministic APOLLO2-stochastic TRIPOLI4 analysis using the JEFF-3.1.1 European nuclear data library. A very good agreement is observed for most of neutron induced capture cross section of actinides and a clear underestimation for the {sup 241}Am(n,{gamma}) as an accurate validation of its associated isomeric ratio are emphasized. Finally, a possible huge resonant fluctuation (factor of 2.7 regarding to the 1=0 resonance total orbital momenta) is suggested for isomeric ratio. (authors)

Bernard, D.; Fabbris, O. [CEA, DEN, SPRC, Laboratoire d'Etudes de Physique, F-13108 Saint Paul Lez Durance (France)

2012-07-01T23:59:59.000Z

219

Neutron Thermal Cross Sections, Westcott Factors, Resonance Integrals, Maxwellian Averaged Cross Sections and Astrophysical Reaction Rates Calculated from Major Evaluated Data Libraries  

E-Print Network [OSTI]

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellianaveraged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented.

Pritychenko, B

2012-01-01T23:59:59.000Z

220

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

Analysis of alternatives for immobilized low activity waste disposal  

SciTech Connect (OSTI)

This report presents a study of alternative disposal system architectures and implementation strategies to provide onsite near-surface disposal capacity to receive the immobilized low-activity waste produced by the private vendors. The analysis shows that a flexible unit strategy that provides a suite of design solutions tailored to the characteristics of the immobilized low-activity waste will provide a disposal system that best meets the program goals of reducing the environmental, health, and safety impacts; meeting the schedule milestones; and minimizing the life-cycle cost of the program.

Burbank, D.A.

1997-10-28T23:59:59.000Z

222

Analyses of Oxyanion Materials by Prompt Gamma Activation Analysis  

SciTech Connect (OSTI)

Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed.

Firestone, Richard B; Perry, D.L.; English, G.A.; Firestone, R.B.; Leung, K.-N.; Garabedian, G.; Molnar, G.L.; Revay, Zs.

2008-03-24T23:59:59.000Z

223

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

224

Neutron Transport and Nuclear Burnup Analysis for the Laser Inertial Confinement Fusion-Fission Energy (LIFE) Engine  

SciTech Connect (OSTI)

Lawrence Livermore National Laboratory is currently developing a hybrid fusion-fission nuclear energy system, called LIFE, to generate power and burn nuclear waste. We utilize inertial confinement fusion to drive a subcritical fission blanket surrounding the fusion chamber. It is composed of TRISO-based fuel cooled by the molten salt flibe. Low-yield (37.5 MJ) targets and a repetition rate of 13.3 Hz produce a 500 MW fusion source that is coupled to the subcritical blanket, which provides an additional gain of 4-8, depending on the fuel. In the present work, we describe the neutron transport and nuclear burnup analysis. We utilize standard analysis tools including, the Monte Carlo N-Particle (MCNP) transport code, ORIGEN2 and Monteburns to perform the nuclear design. These analyses focus primarily on a fuel composed of depleted uranium not requiring chemical reprocessing or enrichment. However, other fuels such as weapons grade plutonium and highly-enriched uranium are also under consideration. In addition, we have developed a methodology using {sup 6}Li as a burnable poison to replace the tritium burned in the fusion targets and to maintain constant power over the lifetime of the engine. The results from depleted uranium analyses suggest up to 99% burnup of actinides is attainable while maintaining full power at 2GW for more than five decades.

Kramer, K J; Latkowski, J F; Abbott, R P; Boyd, J K; Powers, J J; Seifried, J E

2008-10-24T23:59:59.000Z

225

Neutron skins and neutron stars  

SciTech Connect (OSTI)

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

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

2013-11-07T23:59:59.000Z

226

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

227

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

228

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

229

SINGLE CRYSTAL NEUTRON DIFFRACTION.  

SciTech Connect (OSTI)

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

230

Beam Characterization at the Neutron Radiography Facility  

SciTech Connect (OSTI)

The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

Sarah Morgan; Jeffrey King

2013-01-01T23:59:59.000Z

231

Sulfur determination in blood from inhabitants of Brazil using neutron activation analysis  

SciTech Connect (OSTI)

In this study the NAA technique was applied to analyze sulfur in blood from inhabitants of Brazil for the proposition of an indicative interval. The measurements were performed considering lifestyle factors (non-smokers, non-drinkers and no history of toxicological exposure) of Brazilian inhabitants. The influence of gender was also investigated considering several age ranges (18-29, 30-39, 40-49, >50 years). These data are useful in clinical investigations, to identify or prevent diseases caused by inadequate sulfur ingestion and for nutritional evaluation of Brazilian population.

Oliveira, Laura C.; Zamboni, Cibele B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP) Av. Professor Lineu Prestes 2242 05508-000 Sao Paulo, SP (Brazil)

2013-05-06T23:59:59.000Z

232

Instrumental Neutron Activation Analysis of River Sediments from Rio Tigre (Venezuela) Employing a Planar Germanium Detector  

Science Journals Connector (OSTI)

Thirteen elements and eleven rare-earth elements (La, Ce, Nd, Sm, Eu, Gd, Tb, Ho, Tm, Yb, and Lu), as well as thorium and uranium, were determined in river sediment samples from the...

Labrecque, J J; Rosales, P A; Mejias, G

1986-01-01T23:59:59.000Z

233

Consilience: Radiocarbon, Instrumental Neutron Activation Analysis, and Litigation in the Ancestral Caddo Region  

E-Print Network [OSTI]

.................................................................................. 37 41CE19 (George C. Davis Site) ..................................................... 38 41DT6 (Tick Site)............................................................................. 39 41DT16 (Spike Site...) ......................................................................... 39 41HP106 (Hurricane Hill Site) ....................................................... 40 41LR297 (Stallings Ranch Site) ...................................................... 41 vii 41NA236 (Naconiche Creek Site...

Selden, Robert Zachary

2013-08-13T23:59:59.000Z

234

Neutron Capture Gamma-Ray Libraries for Nuclear Applications  

SciTech Connect (OSTI)

The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of discrete line spectra and cross sections for over 260 isotopes that was developed as part of an IAEA Coordinated Research project. EGAF is being used to improve the capture gamma production in ENDF libraries. For medium to heavy nuclei the quasi continuum contribution to the gamma cascades is not experimentally resolved. The continuum contains up to 90% of all the decay energy and is modeled here with the statistical nuclear structure code DICEBOX. This code also provides a consistency check of the level scheme nuclear structure evaluation. The calculated continuum is of sufficient accuracy to include in the ENDF libraries. This analysis also determines new total thermal capture cross sections and provides an improved RIPL database. For higher energy neutron capture there is less experimental data available making benchmarking of the modeling codes more difficult. They are investigating the capture spectra from higher energy neutrons experimentally using surrogate reactions and modeling this with Hauser-Feshbach codes. This can then be used to benchmark CASINO, a version of DICEBOX modified for neutron capture at higher energy. This can be used to simulate spectra from neutron capture at incident neutron energies up to 20 MeV to improve the gamma-ray spectrum in neutron data libraries used for transport modeling of unknown assemblies.

Sleaford, B W; Firestone, R B; Summers, N; Escher, J; Hurst, A; Krticka, M; Basunia, S; Molnar, G; Belgya, T; Revay, Z; Choi, H D

2010-11-04T23:59:59.000Z

235

Texture analysis of silicon with an heterogeneous morphology used for the photovoltaic conversion by neutron diffraction  

E-Print Network [OSTI]

603 Texture analysis of silicon with an heterogeneous morphology used for the photovoltaic.10F - 61.14F 1. Introduction. In order to lower the production cost of solar cells, the Research perpendicularly to growth axis, which led to photovoltaic efficiency q ~ 11 % under AM1 conditions, starting

Paris-Sud XI, Université de

236

Feasibility of boron neutron capture therapy (BNCT) for malignant pleural mesothelioma from a viewpoint of dose distribution analysis  

SciTech Connect (OSTI)

Purpose: To investigate the feasibility of boron neutron capture therapy (BNCT) for malignant pleural mesothelioma (MPM) from a viewpoint of dose distribution analysis using Simulation Environment for Radiotherapy Applications (SERA), a currently available BNCT treatment planning system. Methods and Materials: The BNCT treatment plans were constructed for 3 patients with MPM using the SERA system, with 2 opposed anterior-posterior beams. The {sup 1}B concentrations in the tumor and normal lung in this study were assumed to be 84 and 24 ppm, respectively, and were derived from data observed in clinical trials. The maximum, mean, and minimum doses to the tumors and the normal lung were assessed for each plan. The doses delivered to 5% and 95% of the tumor volume, D{sub 05} and D{sub 95}, were adopted as the representative dose for the maximum and minimum dose, respectively. Results: When the D{sub 05} to the normal ipsilateral lung was 5 Gy-Eq, the D{sub 95} and mean doses delivered to the normal lung were 2.2-3.6 and 3.5-4.2 Gy-Eq, respectively. The mean doses delivered to the tumors were 22.4-27.2 Gy-Eq. The D{sub 05} and D{sub 95} doses to the tumors were 9.6-15.0 and 31.5-39.5 Gy-Eq, respectively. Conclusions: From a viewpoint of the dose-distribution analysis, BNCT has the possibility to be a promising treatment for MPM patients who are inoperable because of age and other medical illnesses.

Suzuki, Minoru [Particle Oncology Research Center, Osaka (Japan)]. E-mail: msuzuki@rri.kyoto-u.ac.jp; Sakurai, Yoshinori [Division of Medical Physics, Department of Radiation Life Science, Research Reactor Institute, Kyoto University, Osaka (Japan); Masunaga, Shinichiro [Particle Oncology Research Center, Osaka (Japan); Kinashi, Yuko [Particle Oncology Research Center, Osaka (Japan); Nagata, Kenji [Particle Oncology Research Center, Osaka (Japan); Maruhashi, Akira [Division of Medical Physics, Department of Radiation Life Science, Research Reactor Institute, Kyoto University, Osaka (Japan); Ono, Koji [Particle Oncology Research Center, Osaka (Japan)

2006-12-01T23:59:59.000Z

237

Education | ORNL Neutron Sciences  

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

238

Post-initiating phase neutronics analysis of an unprotected LOF event in CRBRP  

SciTech Connect (OSTI)

The reactor system is expected to achieve permanent subcriticality in a loss-of-flow (LOF) event by virtue of fuel removal from the core even under the hypothetical assumption that both shutdown systems fail to function. Based on the analysis performed by S.K. Rhow, et al., adequate fuel removal would occur in the CRBRP heterogeneous core during a meltout period after the initiating phase of the unprotected LOF event. This paper discusses reactivity levels relative to fuel removal in the accident progression beyond the initiating phase for the CRBRP core at the beginning of cycle 1 (BOC-1).

Turski, R.B.; Rhow, S.K.

1983-01-01T23:59:59.000Z

239

ORNL Neutron Sciences Instruments  

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

240

Neutron Scattering Tutorials | Neutron Science | ORNL  

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

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

Photon Activation Analysis at the Idaho Accelerator Center  

SciTech Connect (OSTI)

Activation methods require minimal sample preparation and provide sufficiently high sensitivity for detecting the vast majority of the elements throughout the periodic table. In this paper we shall discuss photon activation analysis (PAA) at the Idaho Accelerator Center. The process of PAA begins with exposing a sample with photons in the energy range of 10 to 30 MeV. Many nuclides in the sample will become activated and, in turn, these radionuclides will decay by emitting characteristic radiation. These characteristic radiation decays are the telltale signatures for identifying elements which can then be measured with spectrometers such as a high-purity Germanium detector. PAA is not an 'absolute' method, as the samples under investigation must be irradiated along with a reference or calibrating material having a well-known elemental composition. The quantitative evaluation is performed through comparing the two resulting element spectra from the unknown sample and reference material. Besides the obvious advantage of being non-destructive, PAA has minimal contamination issues. Moreover, materials that are difficult to treat chemically, such as certain refractory metals, dusts, ashes, etc., offer no hindrance to the technique of PAA. A further advantage is that PAA is very well suited for investigated minute samples (sub-milligram dust particles) to very large ones (in the multi-kg range). PAA is a robust technique as there are no real limitations concerning the nature of material to be studied.

Wells, Douglas P.; Cole, Philip L. [Idaho Accelerator Center, 1500 Alvin Ricken Drive, Pocatello, ID 83201 (United States); Department of Physics, Idaho State University, Pocatello, Idaho 83209 (United States); Segebade, Christian R. [Idaho Accelerator Center, 1500 Alvin Ricken Drive, Pocatello, ID 83201 (United States)

2010-08-04T23:59:59.000Z

242

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

243

Followup of Waste Treatment and Immobilization Plant Low Activity Waste Melter Process Systems Hazards Analysis Activity Review, March 2013  

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

HSS Independent Activity Report - HSS Independent Activity Report - Rev. 0 Report Number: HIAR-WTP-2013-03-18 Site: Hanford Site Subject: Office of Enforcement and Oversight's Office of Safety and Emergency Management Evaluations Activity Report for Follow-up of Waste Treatment and Immobilization Plant Low Activity Waste Melter Process System Hazards Analysis Activity Review Dates of Activity : 03/18/13 - 03/21/13 Report Preparer: James O. Low Activity Description/Purpose: The Office of Health, Safety and Security (HSS) staff observed a limited portion of the restart of the Hazard Analysis (HA) for the Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) Melter Process (LMP) System. The primary purpose of this HSS field activity, on March 18-21, 2013, was to observe and understand the revised approach

244

Followup of Waste Treatment and Immobilization Plant Low Activity Waste Melter Process Systems Hazards Analysis Activity Review, March 2013  

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

HSS Independent Activity Report - HSS Independent Activity Report - Rev. 0 Report Number: HIAR-WTP-2013-03-18 Site: Hanford Site Subject: Office of Enforcement and Oversight's Office of Safety and Emergency Management Evaluations Activity Report for Follow-up of Waste Treatment and Immobilization Plant Low Activity Waste Melter Process System Hazards Analysis Activity Review Dates of Activity : 03/18/13 - 03/21/13 Report Preparer: James O. Low Activity Description/Purpose: The Office of Health, Safety and Security (HSS) staff observed a limited portion of the restart of the Hazard Analysis (HA) for the Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) Melter Process (LMP) System. The primary purpose of this HSS field activity, on March 18-21, 2013, was to observe and understand the revised approach

245

A Detailed Analysis and Monte Carlo Simulation of the Neutron Lifetime Experiment S. Arzumanov et al., Phys. Lett. B 483 (2000) 15  

E-Print Network [OSTI]

We performed a detailed analysis and the Monte Carlo simulation of the neutron lifetime experiment [S. Arzumanov et al., Phys. Lett. B 483 (2000) 15] because of the strong disagreement by 5.6 standard deviations between the results of this experiment and our experiment [A. Serebrov et al., Phys. Lett. B 605 (2005) 72]. We found a few effects which were not taken into account in the experiment [S. Arzumanov et al., Phys. Lett. B 483 (2000) 15]. The possible correction is -5.5 s with uncertainty of 2.4 s which comes from initial data knowledge. We assume that after taking into account this correction the result of work [S. Arzumanov et al., Phys. Lett. B 483 (2000) 15] for neutron lifetime 885.4 +/- 0.9stat +/- 0.4syst s could be corrected to 879.9 +/- 0.9stat +/- 2.4syst s.

A. K. Fomin; A. P. Serebrov

2010-05-17T23:59:59.000Z

246

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

247

Transmutation Performance Analysis for Inert Matrix Fuels in Light Water Reactors and Computational Neutronics Methods Capabilities at INL  

SciTech Connect (OSTI)

The urgency for addressing repository impacts has grown in the past few years as a result of Spent Nuclear Fuel (SNF) accumulation from commercial nuclear power plants. One path that has been explored by many is to eliminate the transuranic (TRU) inventory from the SNF, thus reducing the need for additional long term repository storage sites. One strategy for achieving this is to burn the separated TRU elements in the currently operating U.S. Light Water Reactor (LWR) fleet. Many studies have explored the viability of this strategy by loading a percentage of LWR cores with TRU in the form of either Mixed Oxide (MOX) fuels or Inert Matrix Fuels (IMF). A task was undertaken at INL to establish specific technical capabilities to perform neutronics analyses in order to further assess several key issues related to the viability of thermal recycling. The initial computational study reported here is focused on direct thermal recycling of IMF fuels in a heterogeneous Pressurized Water Reactor (PWR) bundle design containing Plutonium, Neptunium, Americium, and Curium (IMF-PuNpAmCm) in a multi-pass strategy using legacy 5 year cooled LWR SNF. In addition to this initial high-priority analysis, three other alternate analyses with different TRU vectors in IMF pins were performed. These analyses provide comparison of direct thermal recycling of PuNpAmCmCf, PuNpAm, PuNp, and Pu. The results of this infinite lattice assembly-wise study using SCALE 5.1 indicate that it may be feasible to recycle TRU in this manner using an otherwise typical PWR assembly without violating peaking factor limits.

Michael A. Pope; Samuel E. Bays; S. Piet; R. Ferrer; Mehdi Asgari; Benoit Forget

2009-05-01T23:59:59.000Z

248

Coupling High-Energy Radiography And Photon Activation Analysis (PAA) To Optimize The Characterization Of Nuclear Waste Packages  

SciTech Connect (OSTI)

Radiological characterization of nuclear waste packages is an industrial issue in order to select the best mode of storage. The alpha-activity, mainly due to the presence of actinides ({sup 235}U, {sup 238}U, {sup 239}Pu,...) inside the package, is one of the most important parameter to assess during the characterization. Photon Activation Analysis (PAA) is a non-destructive active method (NDA method) based on the photofission process and on the detection of delayed particles (neutrons and gammas). This technique is well-adapted to the characterization of large concrete waste packages. However, PAA methods often require a simulation step which is necessary to analyze experimental results and to quantify the global mass of actinides. The weak point of this approach is that characteristics of the package are often not well-known, these latter having a huge impact on the final simulation result. High-energy radiography, based on the use of a linear electron accelerator (LINAC), allows to visualize the content of the package and is also a performing way to tune simulation models and to optimize the characterization process by PAA. In this article, we present high-energy radiography results obtained for two different large concrete waste packages in the SAPHIR facility (Active Photon and Irradiation System). This facility is dedicated to PAA study and development and setup for a decade in CEA Saclay. We also discuss possibilities offered by the coupling between high-energy radiography and PAA techniques.

Carrel, F.; Agelou, M.; Gmar, M.; Laine, F.; Lamotte, T.; Lazaro, D.; Poumarede, B.; Rattoni, B. [CEA, LIST, F-91191, Gif-sur-Yvette (France)

2009-12-02T23:59:59.000Z

249

Isotopic Analysis- Rock | Open Energy Information  

Open Energy Info (EERE)

Isotopic Analysis- Rock Isotopic Analysis- Rock Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Isotopic Analysis- Rock Details Activities (13) Areas (11) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Water rock interaction Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Isotopic Analysis- Rock: Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in a given system, while the conditions which increase/decrease the number of neutrons are well understood and measurable.

250

Active charge/passive discharge solar heating systems: thermal analysis  

SciTech Connect (OSTI)

The performance of active charge/passive discharge solar space-heating systems is analyzed. This type of system combines liquid-cooled solar collector panels with a massive integral storage component that passively heats the building interior by radiation and free convection. The TRNSYS simulation program is used to evaluate system performance and to provide input for the development of a simplified analysis method. This method, which provides monthly calculations of delivered solar energy, is based on Klein's Phi-bar procedure and data from hourly TRNSYS simulations. The method can be applied to systems using a floor slab, a structural wall, or a water tank as the storage component. Important design parameters include collector area and orientation, building heat loss, collector and heat-exchanger efficiencies, storage capacity, and storage to room coupling.

Swisher, J.

1981-01-01T23:59:59.000Z

251

Testing the quasi-absolute method in photon activation analysis  

SciTech Connect (OSTI)

In photon activation analysis (PAA), relative methods are widely used because of their accuracy and precision. Absolute methods, which are conducted without any assistance from calibration materials, are seldom applied for the difficulty in obtaining photon flux in measurements. This research is an attempt to perform a new absolute approach in PAA - quasi-absolute method - by retrieving photon flux in the sample through Monte Carlo simulation. With simulated photon flux and database of experimental cross sections, it is possible to calculate the concentration of target elements in the sample directly. The QA/QC procedures to solidify the research are discussed in detail. Our results show that the accuracy of the method for certain elements is close to a useful level in practice. Furthermore, the future results from the quasi-absolute method can also serve as a validation technique for experimental data on cross sections. The quasi-absolute method looks promising.

Sun, Z. J. [Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States); Wells, D. [Physics Department, South Dakota School of Mines and Technology, 501 E. Saint Joseph St. Rapid City, SD 57701 (United States); Starovoitova, V.; Segebade, C. [Idaho Accelerator Center, Idaho State University, 921 S. 8th Ave. Pocatello, ID 83209 (United States)

2013-04-19T23:59:59.000Z

252

Carbon Dioxide Information Analysis Center: FY 1992 activities  

SciTech Connect (OSTI)

During the course of a fiscal year, Oak Ridge National Laboratory`s Carbon Dioxide Information Analysis Center (CDIAC) distributes thousands of specialty publications-numeric data packages (NDPs), computer model packages (CMPs), technical reports, public communication publications, newsletters, article reprints, and reference books-in response to requests for information related to global environmental issues, primarily those pertaining to climate change. CDIACs staff also provides technical responses to specific inquiries related to carbon dioxide (CO{sub 2}), other trace gases, and climate. Hundreds of referrals to other researchers, policy analysts, information specialists, or organizations are also facilitated by CDIAC`s staff. This report provides an account of the activities accomplished by CDIAC during the period October 1, 1991 to September 30, 1992. An organizational overview of CDIAC and its staff is supplemented by a detailed description of inquiries received and CDIAC`s response to those inquiries. As analysis and description of the preparation and distribution of numeric data packages, computer model packages, technical reports, newsletters, fact sheets, specialty publications, and reprints is provided. Comments and descriptions of CDIAC`s information management systems, professional networking, and special bilateral agreements are also described.

Cushman, R.M. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center; Stoss, F.W. [Tennessee Univ., Knoxville, TN (United States). Energy, Environment and Resources Center

1993-03-01T23:59:59.000Z

253

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. Gähler; A. Steyerl; W. Mampe

1985-05-06T23:59:59.000Z

254

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

255

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

256

Spectroscopical Analysis of Mechano-chemically Activated Surfaces  

E-Print Network [OSTI]

Mechano-chemical activation is fundamentally different than chemical activation in that energy is added to alter the state of bond energy instead of exciting electrons to produce a chemical reaction. Mechano-chemical activation has demonstrated...

Cooper, Rodrigo

2012-10-19T23:59:59.000Z

257

INAA multielemental analysis of Nigerian bituminous coal and coal ash  

Science Journals Connector (OSTI)

Instrumental neutron activation analysis (INAA) was used to analyzed Nigerian bituminous coal and ash. Good statistical agreement (p...?0.05) between the literature and reported elemental values of USGS AGV-1 sam...

V. O. Ogugbuaja; W. D. James

1995-03-01T23:59:59.000Z

258

KORONA; An intense sealed-tube 14-MeV neutron generator  

SciTech Connect (OSTI)

This paper describes a sealed-tube, high-current, low-energy accelerator (190 kV, 150 mA) in operation at the GKSS Research Center since 1981. The deuterium-tritium reaction yields a total source strength of 3 {times} 10 {sup 12} n/s. The neutron flux in the center of the hollow cylinder target is {approx} 3 {times} 10 n/cm{sup 2} {center dot} s in a 4-cm{sup 3} volume. Numerous 14-MeV neutron reaction cross sections have been determined with satisfactory accuracy; however, the system has been mainly used for neutron activation analysis. To predict the gamma-ray activity of any element after short-term irradiation with 14-MeV neutrons, a sensitivity study was performed, which proved to be a useful tool for analyzing complex spectra.

Pepelnik, R.; Fanger, H.U.; Michaelis, W. (GKSS-Forschungszentrum Geesthacht GmbH, Inst. fur Physik, Postfach 1160, D-2054 Geesthacht (DE))

1990-11-01T23:59:59.000Z

259

PINO - a tool for simulating neutron spectra resulting from the 7Li(p,n) reaction  

E-Print Network [OSTI]

The 7Li(p,n) reaction in combination with a 3.7 MV Van de Graaff accelerator was routinely used at FZK to perform activation as well as time-of-flight measurements with neutrons in the keV-region. Planned new setups with much higher proton currents like SARAF and FRANZ and the availability of liquid-lithium target technology will trigger a renaissance of this method. A detailed understanding of the neutron spectrum is not only important during the planning phase of an experiment, but also during for the analysis of activation experiments. Therefore, the Monte-Carlo based program PINO (Protons In Neutrons Out) was developed, which allows the simulation of neutron spectra considering the geometry of the setup and the proton-energy distribution.

R. Reifarth; M. Heil; F. Käppeler; R. Plag

2013-10-06T23:59:59.000Z

260

Binding site asymmetry in human transthyretin: insights from a joint neutron and X-ray crystallographic analysis using perdeuterated protein  

Science Journals Connector (OSTI)

A neutron crystallographic study of perdeuterated transthyretin reveals important aspects of the structure relating to its stability and its propensity to form fibrils, as well as evidence of a single water molecule that affects the symmetry of the two binding pockets.

Haupt, M.

2014-10-21T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

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

262

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

263

NEUTRON MONITOR DATA ON THE 15 JUNE 1991 FLARE: NEUTRONS AS A TEST FOR PROTON ACCELERATION SCENARIO  

E-Print Network [OSTI]

NEUTRON MONITOR DATA ON THE 15 JUNE 1991 FLARE: NEUTRONS AS A TEST FOR PROTON ACCELERATION SCENARIO.J.TANSKANEN University of Oulu, SF-90570, Oulu, Finland ABSTRACT. Response of A1ma-Ata neuuon monitor for solar neutrons of proton acceleration during the flare. The analysis of neutron monitor is an evidence in favour

Usoskin, Ilya G.

264

Analysis of Fuel Ethanol Transportation Activity and Potential Distribution Constraints  

SciTech Connect (OSTI)

This paper provides an analysis of fuel ethanol transportation activity and potential distribution constraints if the total 36 billion gallons of renewable fuel use by 2022 is mandated by EPA under the Energy Independence and Security Act (EISA) of 2007. Ethanol transport by domestic truck, marine, and rail distribution systems from ethanol refineries to blending terminals is estimated using Oak Ridge National Laboratory s (ORNL s) North American Infrastructure Network Model. Most supply and demand data provided by EPA were geo-coded and using available commercial sources the transportation infrastructure network was updated. The percentage increases in ton-mile movements by rail, waterways, and highways in 2022 are estimated to be 2.8%, 0.6%, and 0.13%, respectively, compared to the corresponding 2005 total domestic flows by various modes. Overall, a significantly higher level of future ethanol demand would have minimal impacts on transportation infrastructure. However, there will be spatial impacts and a significant level of investment required because of a considerable increase in rail traffic from refineries to ethanol distribution terminals.

Das, Sujit [ORNL; Peterson, Bruce E [ORNL; Chin, Shih-Miao [ORNL

2010-01-01T23:59:59.000Z

265

SHARP Neutronics Expanded | Department of Energy  

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

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

266

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; Frédéric Ott; Alain Menelle

1999-01-01T23:59:59.000Z

267

E-Print Network 3.0 - activity based analysis Sample Search Results  

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

Sciences 4 Reasoning about Repairability of Workflows at Design Time Summary: activities can be provided by the workflow designer based on the analysis of different aspects...

268

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

269

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

270

E-Print Network 3.0 - absorber neutronics performance Sample...  

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

of Summary: of this thesis is to perform neutron spectrum analysis in a model of the Subcritical Accelerator Driven System... neutrons) while another isotope is created....

271

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.

272

Digenetic Changes in Macro- to Nano-Scale Porosity in the St. Peter Sandstone:L An (Ultra) Small Angle Neutron Scattering and Backscattered Electron Imagining Analysis  

SciTech Connect (OSTI)

Small- and Ultra-Small Angle Neutron Scattering (SANS and USANS) provide powerful tools for quantitative analysis of porous rocks, yielding bulk statistical information over a wide range of length scales. This study utilized (U)SANS to characterize shallowly buried quartz arenites from the St. Peter Sandstone. Backscattered electron imaging was also used to extend the data to larger scales. These samples contain significant volumes of large-scale porosity, modified by quartz overgrowths, and neutron scattering results show significant sub-micron porosity. While previous scattering data from sandstones suggest scattering is dominated by surface fractal behavior over many orders of magnitude, careful analysis of our data shows both fractal and pseudo-fractal behavior. The scattering curves are composed of subtle steps, modeled as polydispersed assemblages of pores with log-normal distributions. However, in some samples an additional surface-fractal overprint is present, while in others there is no such structure, and scattering can be explained by summation of non-fractal structures. Combined with our work on other rock-types, these data suggest that microporosity is more prevalent, and may play a much more important role than previously thought in fluid/rock interactions.

Anovitz, Lawrence {Larry} M [ORNL; Cole, David [Ohio State University; Rother, Gernot [ORNL; Allard Jr, Lawrence Frederick [ORNL; Jackson, Andrew [NIST Center for Neutron Research (NCRN), Gaithersburg, MD; Littrell, Ken [ORNL

2013-01-01T23:59:59.000Z

273

Dosimetry of fission neutrons in a 1-W reactor, UTR-Kinki  

Science Journals Connector (OSTI)

......2, the neutron energy spectrum calculated by MCNP4B...technique and the thermal neutron fluence rates from...determining the energy spectrum of the reactor's fission neutrons. It also...value, the activity induced in the In foils......

Satoru Endo; Eiji Yoshida; Yusuke Yoshitake; Tetsuo Horiguchi; Wenyi Zhang; Kazuo Fujikawa; Masaharu Hoshi; Tetsuo Itoh; Masayori Ishikawa; Kiyoshi Shizuma

2002-12-01T23:59:59.000Z

274

Neutron scattering studies and modeling of high mobility group 14 core nucleosome complex  

Science Journals Connector (OSTI)

Neutron scattering studies and modeling of high mobility...were studied by use of small-angle neutron scattering techniques. By varying the H2O...occurring in active nucleosomes. Neutron scattering studies and modeling of high mobility...

E C Uberbacher; J K Mardian; R M Rossi; D E Olins; G J Bunick

1982-01-01T23:59:59.000Z

275

Composition and On Demand Deployment of Distributed Brain Activity Analysis Application on Global Grids  

E-Print Network [OSTI]

1 Composition and On Demand Deployment of Distributed Brain Activity Analysis Application on Global are brain science and high-energy physics. The analysis of brain activity data gathered from the MEG and analyze brain functions and requires access to large-scale computational resources. The potential platform

Abramson, David

276

Activation analysis of concrete and graphite in the experimental reactor RUS  

Science Journals Connector (OSTI)

......in the whole reactor, as a function...consistency and the reliability of the nuclear...for activation analysis. We believe...industrial nuclear reactors. INTRODUCTION...consistency and the reliability of the nuclear...for activation analysis. We believe...industrial nuclear reactors. | CEA Saclay......

M. Cometto; D. Ridikas; M. C. Aubert; F. Damoy; D. Ancius

2005-12-20T23:59:59.000Z

277

Specification and Analysis of the AER/NCA Active Network Protocol Suite in  

E-Print Network [OSTI]

Specification and Analysis of the AER/NCA Active Network Protocol Suite to the specification and analy- sis of the AER/NCA suite of active network multicast protocol compo- nents, AER/NCA poses challenging new problems for its formal specification and analysis. Real-Time Maude

Ã?lveczky, Peter Csaba

278

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

279

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

280

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

Audio visual information fusion for human activity analysis  

E-Print Network [OSTI]

xviii Chapter 1 Audio visual human activity4.2 Person tracking using audio-visual cues . . . . .Probabilistic framework for audio-visual information fusion

Thagadur Shivappa, Shankar

2010-01-01T23:59:59.000Z

282

FY 2006 Annual Progress Report for Advanced Vehicle Technology Analysis and Evaluation Activities  

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

AdvAnced vehicle Technology AdvAnced vehicle Technology AnAlysis And evAluATion AcTiviTies U.S. Department of Energy FreedomCAR and Vehicle Technologies Program 1000 Independence Avenue, S.W. Washington, DC 20585-0121 FY 2006 Annual Progress Report for Advanced Vehicle Technology Analysis and Evaluation Activities Submitted to: U.S. Department of Energy Energy Efficiency and Renewable Energy FreedomCAR and Vehicle Technologies Program Advanced Vehicle Technology Analysis and Evaluation Lee Slezak, Technology Manager Advanced Vehicle Technology Analysis and Evaluation Activities FY 2006 Annual Report CONTENTS I. INTRODUCTION............................................................................................................................ 1 II. MODELING AND SIMULATION ................................................................................................ 9

283

Neutron Scattering User Program | Neutron Science | ORNL  

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

284

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 (2.35±0.1)×10-24 cm2 in agreement with previous investigations. It is shown that the larger value of 3.15×10-24 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

285

Choppers - Instrument Support | ORNL Neutron Sciences  

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

286

Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body  

Science Journals Connector (OSTI)

......determining the energy of charged...emitted from neutron-induced nuclear reactions...of neutron spectra on D T and...spontaneous fission of 252Cf...Watt B. E. Energy spectrum of neutrons from thermal fission of 235U...irradiated by high energy hadrons......

Akira Endo; Tatsuhiko Sato

2013-04-01T23:59:59.000Z

287

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

SciTech Connect (OSTI)

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

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

2011-06-01T23:59:59.000Z

288

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

289

Atmospheric aerosols and possibilities of their analysis for elemental content at the IBR-2 reactor  

Science Journals Connector (OSTI)

Possibilities of neutron activation analysis for studying the elemental content of atmospheric aerosols at the IBR-2 reactor are discussed on the bases of the ... contents on the sensitivity of NAA, the reliability

V. F. Peresedov

1997-10-01T23:59:59.000Z

290

Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the Advanced Neutron Source reactor at Oak Ridge National Laboratory  

SciTech Connect (OSTI)

This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at ORNL. Damage propagation is postulated to occur from thermal conduction between dmaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur beause of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A parametric study was done for several uncertain variables. The study included investigating effects of plate contact area, convective heat transfer coefficient, thermal conductivity on fuel swelling, and initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects of damage propagation. Results provide useful insights into how variouss uncertain parameters affect damage propagation.

Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

1995-12-31T23:59:59.000Z

291

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

292

The Advanced Neutron Source research and development plan  

SciTech Connect (OSTI)

The Advanced Neutron Source (ANS) is being designed as a user-oriented neutron research laboratory centered around the most intense continuous beams of thermal and subthermal neutrons in the world. The ANS will be built around a new research reactor of {approximately} 330 MW fission power, producing an unprecedented peak thermal flux of > 7 {times} 10{sup 19} M{sup {minus}2} {center_dot} S{sup {minus}1}. Primarily a research facility, the ANS will accommodate more than 1000 academic, industrial, and government researchers each year. They will conduct basic research in all branches of science-as well as applied research-leading to better understanding of new materials, including high temperature super conductors, plastics, and thin films. Some 48 neutron beam stations will be set up in the ANS beam rooms and the neutron guide hall for neutron scattering and for fundamental and nuclear physics research. There also will be extensive facilities for materials irradiation, isotope production, and analytical chemistry. The R&D program will focus on the four objectives: Address feasibility issues; provide analysis support; evaluate options for improvement in performance beyond minimum requirements; and provide prototype demonstrations for unique facilities. The remainder of this report presents (1) the process by which the R&D activities are controlled and (2) a discussion of the individual tasks that have been identified for the R&D program, including their justification, schedule and costs. The activities discussed in this report will be performed by Martin Marietta Energy Systems, Inc. (MMES) through the Oak Ridge National Laboratory (ORNL) and through subcontracts with industry, universities, and other national laboratories. It should be noted that in general a success path has been assumed for all tasks.

Selby, D.L.

1992-11-30T23:59:59.000Z

293

The Advanced Neutron Source research and development plan  

SciTech Connect (OSTI)

The Advanced Neutron Source (ANS) is being designed as a user-oriented neutron research laboratory centered around the most intense continuous beams of thermal and subthermal neutrons in the world. The ANS will be built around a new research reactor of [approximately] 330 MW fission power, producing an unprecedented peak thermal flux of > 7 [times] 10[sup 19] M[sup [minus]2] [center dot] S[sup [minus]1]. Primarily a research facility, the ANS will accommodate more than 1000 academic, industrial, and government researchers each year. They will conduct basic research in all branches of science-as well as applied research-leading to better understanding of new materials, including high temperature super conductors, plastics, and thin films. Some 48 neutron beam stations will be set up in the ANS beam rooms and the neutron guide hall for neutron scattering and for fundamental and nuclear physics research. There also will be extensive facilities for materials irradiation, isotope production, and analytical chemistry. The R D program will focus on the four objectives: Address feasibility issues; provide analysis support; evaluate options for improvement in performance beyond minimum requirements; and provide prototype demonstrations for unique facilities. The remainder of this report presents (1) the process by which the R D activities are controlled and (2) a discussion of the individual tasks that have been identified for the R D program, including their justification, schedule and costs. The activities discussed in this report will be performed by Martin Marietta Energy Systems, Inc. (MMES) through the Oak Ridge National Laboratory (ORNL) and through subcontracts with industry, universities, and other national laboratories. It should be noted that in general a success path has been assumed for all tasks.

Selby, D.L.

1992-11-30T23:59:59.000Z

294

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

295

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

296

The impact of pulsed irradiation upon neutron activation calculations for inertial and magnetic fusion energy power plants  

SciTech Connect (OSTI)

Inertial fusion energy (IFE) and magnetic fusion energy (MFE) power plants will probably operate in a pulsed mode. The two different schemes, however, will have quite different time periods. Typical repetition rates for IFE power plants will be 1-5 Hz. MFE power plants will ramp up in current for about 1 hour, shut down for several minutes, and repeat the process. Traditionally, activation calculations for IFE and MFE power plants have assumed continuous operation and used either the ``steady state`` (SS) or ``equivalent steady state`` (ESS) approximations. It has been suggested recently that the SS and ESS methods may not yield accurate results for all radionuclides of interest. The present work expands that of Sisolak, et al. by applying their formulae to conditions which might be experienced in typical IFE and MFE power plants. In addition, complicated, multi-step reaction/decay chains are analyzed using an upgraded version of the ACAB radionuclide generation/depletion code. Our results indicate that the SS method is suitable for application to MFE power plant conditions. We also find that the ESS method generates acceptable results for radionuclides with half-lives more than a factor of three greater than the time between pulses. For components that are subject to 0.05 Hz (or more frequent) irradiation (such as coolant), use of the ESS method is recommended. For components or materials that are subject to less frequent irradiation (such as high-Z target materials), pulsed irradiation calculations should be used.

Latkowski, J.F. [Lawrence Livermore National Lab., CA (United States); Sanz, J. [Universidad Politecnica de Madrid (Spain); Vujic, J.L. [California Univ., Berkeley, CA (United States)

1996-06-26T23:59:59.000Z

297

Analysis Activities at Idaho National Engineering & Environmental Laboratory  

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

Engineering and Environmental Laboratory Engineering and Environmental Laboratory Systems Analysis Finis Southworth, PhD Department Manager Systems & Decision Science DOE Hydrogen, Fuel Cells, and Infrastructure Technologies Program Systems Analysis Workshop July 28-29, 2004 Washington, D.C. Idaho National Engineering and Environmental Laboratory Charter Systems & Decision Science Mission: Develop and apply science-based systems, systems engineering, and decision science capabilities that result in successful projects and effective, defensible decisions Systems & Decision Science Funding: 0 2 4 6 8 10 12 $M National & Homeland Security Systems Integration and Analysis Other (YMP, Cleanup, etc.) Energy Current S&DS Funding = $18M FY04 FY03 Idaho National Engineering and Environmental Laboratory

298

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

299

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

300

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

Comparison of MCNP calculation and measurement of neutron fluence in a channel for short-time irradiation in the LVR-15 reactor  

SciTech Connect (OSTI)

The main purpose of this work was to evaluate the neutron energy distribution in a channel of the LVR-15 reactor used mostly for short-time neutron activation analysis. Twenty types of activation monitors were irradiated in this channel equipped with a pneumatic facility with a transport time of 3.5 s. The activities measured and the corresponding reaction rates were used to determinate the neutron spectrum. The reaction rates were compared with MCNP calculations to confirm the results. The second purpose of this work was to verify our nuclear data library used for the reaction rate calculations. The experiment results were also incorporated into our database system of neutron energy distribution at the reactor core. (authors)

Lahodova, Z.; Flibor, S.; Klupak, V. [Nuclear Research Inst. Rez Plc, Reactor Services Div., 250 68 Rez (Czech Republic); Kucera, J. [Nuclear Physics Inst., Academy of Science of the Czech Republic, 250 68 Rez (Czech Republic); Marek, M.; Viererbl, L. [Nuclear Research Inst. Rez Plc, Reactor Services Div., 250 68 Rez (Czech Republic)

2006-07-01T23:59:59.000Z

302

Neutron emission studies in dense plasma focus  

Science Journals Connector (OSTI)

Neutron emission studies in dense plasma focus under low pressure and high pressure operation has been carried out. Parametric studies of dynamic behavior of plasma focus also has been made by means of laser holographic interferometry nuclear activation methods and neutron T. O. F detection including pinhole camera. Experimental result was compared with the z?pinch.

M. Yokoyama; Y. Kitagawa; Y. Yamada

1989-01-01T23:59:59.000Z

303

Total Neutron Scattering in Vitreous Silica  

Science Journals Connector (OSTI)

The structure of Corning superpure vitreous silica glass has been investigated with neutrons. A new method of analysis using variable neutron wavelengths and the measurement of total scattering cross sections from transmission experiments is developed and the results are compared with those from differential x-ray scattering. The total neutron scattering method permits a simple and direct structure analysis with resolution apparently superior to x-rays. The preliminary results compare well in a first approximation analysis with the basic structure model of Warren and others and in addition the neutron-determined atomic radial distribution curve exhibits some finer details than the x-ray results. Thermal inelastic scattering of neutrons was corrected for in an approximate way.

R. J. Breen; R. M. Delaney; P. J. Persiani; A. H. Weber

1957-01-15T23:59:59.000Z

304

Comparison of thermal neutron distributions within shield materials obtained by experiments, SN and monte carlo code calculations  

Science Journals Connector (OSTI)

......The TLDs for thermal neutrons, which consist...measurements of induced activity of gold...measurement of thermal neutron fluence was...region of the energy range 5.04...Watt neutron fission spectrum of 252Cf and......

Yoshihiro Asano; Takeshi Sugita; Takenori Suzaki; Hideyuki Hirose

2005-12-20T23:59:59.000Z

305

Chemical and biological methods for the analysis and remediation of environmental contaminants frequently identified at Superfund sites  

E-Print Network [OSTI]

of Sprague-Dawley rats throughout pregnancy. Based on evaluations of toxicity and neutron activation analysis of tissues, no significant differences were observed between animals receiving clay supplements and control animals, with the exception of slightly...

Wiles, Melinda Christine

2004-11-15T23:59:59.000Z

306

Analysis of chemical competition for binding sites on activated charcoal  

E-Print Network [OSTI]

. This interaction of adsorbates (6) is known as co-adsorption. The function of a co-adsorbate is not entirely clear, holm, it may be seen as a modification or The citations follow the style of the American Industrial ene Association Journal. deactivation... of the adsorbent. Since activated charcoal is a non-polar sorbent, the adsorbed oznpaund with the highest toiling point or largest nal~ volunN will be most strongly held, and wi11 displace other adsorbed carpounds in decreasing order down the length...

Gallerani, Susan Jane

2012-06-07T23:59:59.000Z

307

CONTROL SYSTEM FOR ACTIVE ANKLE-FOOT ORTHOSIS AND GAIT ANALYSIS  

E-Print Network [OSTI]

CONTROL SYSTEM FOR ACTIVE ANKLE-FOOT ORTHOSIS AND GAIT ANALYSIS CONTROL SYSTEM FOR ACTIVE ANKLE system has mounted into two basic components: insole for the healthy leg and ankle-foot orthoses. Proposed ankle-foot orthosis is with one degree of freedom which foot segment is connected to the shank

Mustakerov, Ivan

308

Analysis of Seismic Activity near Theodore Roosevelt Dam, Arizona, during the Occupation  

E-Print Network [OSTI]

E Analysis of Seismic Activity near Theodore Roosevelt Dam, Arizona, during the Occupation, and Lepolt Linkimer Online Material: Plot of viable focal mechanisms and table of regional seismic velocity model. INTRODUCTION Rate and distribution of seismic activity are important indica- tors of the overall

Fouch, Matthew J.

309

Water Research 36 (2002) 11811192 Accuracy analysis of a respirometer for activated sludge  

E-Print Network [OSTI]

Water Research 36 (2002) 1181­1192 Accuracy analysis of a respirometer for activated sludge dynamic transfer, pH, and the influence of sludge condition on ``start-up'' behaviour. It is shown to what extent Elsevier Science Ltd. All rights reserved. Keywords: Respirometry; Oxygen uptake rate; Activated sludge

310

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic Controlled Variable Selection  

E-Print Network [OSTI]

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic operation conducted on an activated sludge process model based on the test-bed benchmark simulation model no structure that leads to optimal economic operation, while promptly rejecting disturbances at lower layers

Skogestad, Sigurd

311

Specification and Analysis of the AER/NCA Active Network Protocol Suite in  

E-Print Network [OSTI]

Specification and Analysis of the AER/NCA Active Network Protocol Suite in Real­Time Maude Peter and the Maude formal methodology to the specification and analy­ sis of the AER/NCA suite of active network and the composability of its components, AER/NCA poses challenging new problems for its formal specification

Ã?lveczky, Peter Csaba

312

A method for activation analysis of ruthenium in sea water  

E-Print Network [OSTI]

of these isotopes in the marine environment, it is essential that a method for the analysis of trace amounts of stable ruthenium be developed, and applied to the study of the chemical and physical dis- tribution of ruthenium in sea water, marine biota... 100 27. 2 82 34. 8 100 30. 2 91 30. 6 92 26. 9 81 8 (Tracer Only) 34. 5 100 Standard 33. 3 Average Counting time ? Eorty minutes 103 Tracer ? Ru 93 Stable ruthenium added ? 0. Z6 ug 14 TABLE 4 Nuclear Data for Ruthenium Isotope Per Cent...

Dixon, Bryan William

2012-06-07T23:59:59.000Z

313

Magnetism and magnetic materials probed with neutron scattering  

Science Journals Connector (OSTI)

Abstract Neutron scattering techniques are becoming increasingly accessible to a broader range of scientific communities, in part due to the onset of next-generation, high-power spallation sources, high-performance, sophisticated instruments and data analysis tools. These technical advances also advantageously impact research into magnetism and magnetic materials, where neutrons play a major role. In this Current Perspective series, the achievements and future prospects of elastic and inelastic neutron scattering, polarized neutron reflectometry, small angle neutron scattering, and neutron imaging, are highlighted as they apply to research into magnetic frustration, superconductivity and magnetism at the nanoscale.

S.G.E. te Velthuis; C. Pappas

2014-01-01T23:59:59.000Z

314

Computational characterization and experimental validation of the thermal neutron source for neutron capture therapy research at the University of Missouri  

SciTech Connect (OSTI)

Parameter studies, design calculations and neutronic performance measurements have been completed for a new thermal neutron beamline constructed for neutron capture therapy cell and small-animal radiobiology studies at the University of Missouri Research Reactor. The beamline features the use of single-crystal silicon and bismuth sections for neutron filtering and for reduction of incident gamma radiation. The computational models used for the final beam design and performance evaluation are based on coupled discrete-ordinates and Monte Carlo techniques that permit detailed modeling of the neutron transmission properties of the filtering crystals with very few approximations. Validation protocols based on neutron activation spectrometry measurements and rigorous least-square adjustment techniques show that the beam produces a neutron spectrum that has the anticipated level of thermal neutron flux and a somewhat higher than expected, but radio-biologically insignificant, epithermal neutron flux component. (authors)

Broekman, J. D. [University of Missouri, Research Reactor Center, 1513 Research Park Drive, Columbia, MO 65211-3400 (United States); Nigg, D. W. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415 (United States); Hawthorne, M. F. [University of Missouri, International Institute of Nano and Molecular Medicine, 1514 Research Park Dr., Columbia, MO 65211-3450 (United States)

2013-07-01T23:59:59.000Z

315

WWER Expert System for Fuel Failure Analysis Using Data on Primary Coolant Activity  

SciTech Connect (OSTI)

The computer expert system for fuel failure analysis of WWER during operation is presented. The diagnostics is based on the measurement of specific activity of reference nuclides in reactor primary coolant and application of a computer code for the data interpretation. The data analysis includes an evaluation of tramp uranium mass in reactor core, detection of failures by iodine and caesium spikes, evaluation of burnup of defective fuel. Evaluation of defective fuel burnup was carried out by applying the relation of caesium nuclides activity in spikes and relations of activities of gaseous fission products for steady state operational conditions. The method of burnup evaluation of defective fuel by use of fission gas activity is presented in detail. The neural-network analysis is performed for determination of failed fuel rod number and defect size. Results of the expert system application are illustrated for several fuel campaigns on operating WWER NPPs. (authors)

Likhanskii, V.V.; Evdokimov, I.A.; Sorokin, A.A.; Khromov, A.G.; Kanukova, V.D.; Apollonova, O.V. [SRC RF TRINITI, 142190, Troitsk, Moscow Reg. (Russian Federation); Ugryumov, A.V. [JSC TVEL, 119017, 24/26 Bolshaya Ordynka st., Moscow (Russian Federation)

2007-07-01T23:59:59.000Z

316

Publications | Neutron Science | ORNL  

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

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

317

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

318

FY2003 Annual Progress Report for Advanced Vehicle Technology Analysis and Evaluation Activities  

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

Advanced Advanced Vehicle Technology Analysis and Evaluation Activities Bringing you a prosperous future where energy is clean, abundant, reliable and affordable 2003 Annual Progress Report freedomCAR & vehicle technologies program Less dependence on foreign oil, and eventual transition to an emissions-free, petroleum-free vehicle U.S. Department of Energy FreedomCAR & Vehicle Technologies Program 1000 Independence Avenue, S.W. Washington, DC 20585-0121 FY 2003 Annual Progress Report for Advanced Vehicle Technology Analysis and Evaluation Activities Submitted to: U.S. Department of Energy Energy Efficiency and Renewable Energy FreedomCAR and Vehicle Technologies Program Advanced Vehicle Technology Analysis and Evaluation Lee Slezak, Technology Manager Advanced Vehicle Technology Analysis and Evaluation Activities

319

Spallation Neutron Source | ORNL Neutron Sciences  

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

320

Design and implementation of a dynamic neutron radiographic imaging system: by John Winston Wright.  

E-Print Network [OSTI]

activity, V = the foil volume, (mass)/(density), Z = the macroscopic cross section, cm-i, di = neutron flux to be found, 2, = ln 2/(half-life of tssAu), te = irradiation time, and t = time between removal and measurement. Results of the analysis..., The neutron flux was calculated with the following equation: iyyyjzzzzzzzzzzzzzll7/Jizzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzqzy //////&/yy ///////////// ////~Z///&li iPZ~i WZZ///ll~ $4~:~) 4VRA S H 1) A(t) = V&5(1-e-~")e +, where A(t) = the measured...

Wright, John Winston

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

Elemental composition of nickel silicide layers using thermal and fast neutrons  

SciTech Connect (OSTI)

Metal silicides are important contact materials used in the manufacture of semiconductor devices. The presence of impurities has been observed to alter or control the formation of the silicide during fabrication and to influence critically the thermal and electrical performance characteristics of the metal-semiconductor interface. The purpose of this investigation has been to use neutron activation analysis (NAAA), relying on both thermal and fast neutrons, to determine relative concentrations of nickel and impurity elements in nickel silicide/silicon systems. 5 refs., 2 figs., 1 tab.

McGuire, S.C.; Wong, K.; Silcox, J. (Cornell Univ., Ithaca, NY (United States))

1992-01-01T23:59:59.000Z

322

Science | ORNL Neutron Sciences  

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

323

DOE Science Showcase - Neutron Sources for Studying Matter |...  

Office of Scientific and Technical Information (OSTI)

(DOE) Office of Basic Energy Sciences. This activity supports the operation of three neutron scattering facilities, one of the most powerful tools for characterizing matter....

324

UAL-BASED SIMULATION ENVIRONMENT FOR SPALLATION NEUTRON SOURCE RING.  

SciTech Connect (OSTI)

This paper outlines the major activities and applications of the Unified Accelerator Library environment for the Spallation Neutron Source (SNS) Ring.

MALITSKY,N.; SMITH,J.; WEI,J.

1999-03-29T23:59:59.000Z

325

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 ??=887.6±3 s.

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

1989-08-07T23:59:59.000Z

326

The National Nuclear Security Administration's Neutron Generator...  

Energy Savers [EERE]

National Nuclear Security Administration's Neutron Generator Activities OAS-L-14-11 August 2014 U.S. Department of Energy Office of Inspector General Office of Audits and...

327

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

328

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

329

Thermal neutron imaging support with other laboratories BL06-IM-TNI  

SciTech Connect (OSTI)

The goals of this project are: (1) detect and locate a source of thermal neutrons; (2) distinguish a localized source from uniform background; (3) show shape and size of thermalizing material; (4) test thermal neutron imager in active interrogation environment; and (5) distinguish delayed neutrons from prompt neutrons.

Vanier,P.E.

2008-06-17T23:59:59.000Z

330

Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the Advanced Neutron Source Reactor at Oak Ridge National Laboratory  

SciTech Connect (OSTI)

This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at the Oak Ridge National Laboratory (ORNL). Damage propagation is postulated to occur from thermal conduction between damaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur because of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A scoping study was conducted to learn what parameters are important for core damage propagation, and to obtain initial estimates of core melt mass for addressing recriticality and steam explosion events. The study included investigating the effects of the plate contact area, the convective heat transfer coefficient, thermal conductivity upon fuel swelling, and the initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects on damage propagation. The results provide useful insights into how various uncertain parameters affect damage propagation.

Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V.

1995-09-01T23:59:59.000Z

331

The Role of Neutron Activation Analysis in the Pathological Evaluation of Silver-Eluting Biomedical Devices in Biological Matrices  

E-Print Network [OSTI]

to their presence was not observed. INAA results correlated with these findings; silver was not detected adjacent to the test article, but a concentration of 74 ppm ± 29% of silver was observed in tissue adjacent to the control article. A complex system of ordinary...

Lancon, Trevor

2014-08-14T23:59:59.000Z

332

The Gas Chromatographic Resolution of Gamma-Ray Scintillation Spectra for the Neutron Activation Analysis of Short-Lived Isotopes  

Science Journals Connector (OSTI)

......separation of radiolysis degradation products containing...Hydrolysis products of fuel element mixtures...the microphoto- cell was a high intensity...MICRO THERMISTOR CELL REF. steel tubing...counting and the degradation products of the irradiated...radio-frequency discharge cells 1. Bartz, A. M......

S. P. Cram; J. L. Brownlee; Jr.

1968-06-01T23:59:59.000Z

333

Instrumental neutron activation analysis (INAA) characterization of pre-contact basalt quarries on the American Samoan Island of Tutuila  

E-Print Network [OSTI]

This thesis presents a material-centered characterization of 120 geologic samples from four fine-grained basalt quarries on the Samoan Island of Tutuila. Previous unsuccessful attempts at definitive Tutuilan quarry differentiation have utilized x...

Johnson, Phillip Ray, II

2007-04-25T23:59:59.000Z

334

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

335

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

336

Workplace characterisation in mixed neutron-gamma fields, specific requirements and available methods at high-energy accelerators  

Science Journals Connector (OSTI)

......activation is only induced with quite large fast neutron fluence rates...materials for neutron activation...respectively. The thermal and epithermal...components of the neutron spectrum are discriminated...the high-energy hadron component...registration of fission fragments...neutron-induced lighter secondary......

Marco Silari

2007-04-01T23:59:59.000Z

337

Magnetism Highlights| Neutron Science | ORNL  

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

338

Emission of Prompt Neutrons from Fission  

Science Journals Connector (OSTI)

An analysis of the total energies of the fragment pairs from fission is used with the mass equation of fission to estimate the distributions in the excitation energy of the fragments from spontaneous and neutron-induced fission of several nuclides. These excitations are used with simple neutron boil-off considerations to calculate the probabilities of emission of 0, 1, 2, 3... prompt neutrons. The calculated results are in good agreement with recent measurements.The same excitation energy distributions and neutron boil-off considerations are used with an assumption of an isotropic angular relation between the fragments and the emitted neutrons to calculate the energy spectrum of neutrons from thermal and 3-Mev neutron-induced fission of U235. For thermal-neutron fission, the calculated spectrum is in fair agreement with recent measurements. The calculations indicate little change in the spectrum for 3-Mev fission. The average energy of the prompt gamma rays is 3.8 Mev from this analysis.

R. B. Leachman

1956-02-01T23:59:59.000Z

339

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

340

Neutron–mirror-neutron oscillations in a trap  

Science Journals Connector (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 and O. Lychkovskiy

2008-06-27T23:59:59.000Z

Note: This page contains sample records for the topic "neutron activation analysis" 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

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

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

342

Neutron Scattering Application of Polarized Solid Target in Materials Research  

SciTech Connect (OSTI)

Neutron scattering is one of the most important tools for materials research. However, neutrons are very expensive to produce. Even with the best sources, such as the newly completed Spallation Neutron Source at the Oak Ridge National Laboratory, most neutron scattering experiments are still flux limited. One way to improve the experimental data is polarized neutron scattering from polarized solid target: the strong spin-dependent neutron scattering cross-section can increase the coherent scattering and decrease the incoherent scattering at the same time, thereby significantly enhancing the signal to noise ratio. Hydrogen, abundant in most soft condensed matters, has a strong spin-dependent scattering cross-section. Early applications of polarized neutron scattering in biological soft condensed matters have already demonstrated the huge potential of this technique. Here we describe the polarized target program at the SNS. The program is under active construction and is aimed at serving neutron scattering at the SNS.

Zhao, Jinkui [ORNL

2008-09-01T23:59:59.000Z

343

HFIR History - ORNL Neutron Sciences  

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

344

Cryogenic Neutron Protein Crystallography: routine methods and potential benefits  

SciTech Connect (OSTI)

The use of cryocooling in neutron diffraction has been hampered by several technical challenges such as the need for specialized equipment and techniques. Recently we have developed and deployed equipment and strategies that allow for routine neutron data collection on cryocooled crystals using off the shelf components. This system has several advantages, compared to a closed displex cooling system such as fast cooling coupled with easier crystal mounting and centering. The ability to routinely collect cryogenic neutron data for analysis will significantly broaden the range of scientific questions that can be examined by neutron protein crystallography. Cryogenic neutron data collection for macromolecules has recently become available at the new Biological Diffractometer BIODIFF at FRM II and the Macromolecular Diffractometer (MaNDi) at the Spallation Neutron Source, Oak Ridge National Laboratory. To evaluate the benefits of a cryocooled neutron structure we collected a full neutron data set on the BIODIFF instrument on a Toho-1 lactamase structure at 100K.

Weiss, Kevin L [ORNL; Tomanicek, Stephen J [ORNL; NG, Joseph D [ORNL

2014-01-01T23:59:59.000Z

345

Research Highlights | ORNL Neutron Sciences  

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

346

Fundamentals of specular neutron reflectometry  

SciTech Connect (OSTI)

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

347

Neutron crystallography aids drug design  

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

348

Los Alamos Neutron Science Center  

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

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

349

Measurement of the Neutron Lifetime by Counting Trapped Protons in a Cold Neutron Beam  

E-Print Network [OSTI]

A measurement of the neutron lifetime $\\tau_{n}$ performed by the absolute counting of in-beam neutrons and their decay protons has been completed. Protons confined in a quasi-Penning trap were accelerated onto a silicon detector held at a high potential and counted with nearly unit efficiency. The neutrons were counted by a device with an efficiency inversely proportional to neutron velocity, which cancels the dwell time of the neutron beam in the trap. The result is $\\tau_{n} = (886.6\\pm1.2{\\rm [stat]}\\pm3.2{\\rm [sys]})$ s, which is the most precise measurement of the lifetime using an in-beam method. The systematic uncertainty is dominated by neutron counting, in particular the mass of the deposit and the $^{6}$Li({\\it{n,t}}) cross section. The measurement technique and apparatus, data analysis, and investigation of systematic uncertainties are discussed in detail.

J. S. Nico; M. S. Dewey; D. M. Gilliam; F. E. Wietfeldt; X. Fei; W. M. Snow; G. L. Greene; J. Pauwels; R. Eykens; A. Lamberty; J. Van Gestel; R. D. Scott

2004-11-19T23:59:59.000Z

350

News & Events | ORNL Neutron Sciences  

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

News › 2005 News News › 2005 News Neutron Science In the News - 2005 December November October September August July June May April March February January John Sullivan, Associate Under Secretary, took a tour of the Spallation Neutron Source (SNS), October 4, 2005 John Sullivan, Associate Under Secretary, took a tour of the Spallation Neutron Source (SNS), October 4, 2005. 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. December Spallation Neutron Source Amazing Science Facts Newswise 12/22 The New Year is bringing the science community a grand present: The Spallation Neutron Source at Oak Ridge National Laboratory. On schedule for

351

Isotopic Analysis- Fluid | Open Energy Information  

Open Energy Info (EERE)

Isotopic Analysis- Fluid Isotopic Analysis- Fluid Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Isotopic Analysis- Fluid Details Activities (61) Areas (32) Regions (6) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Fluid Lab Analysis Parent Exploration Technique: Fluid Lab Analysis Information Provided by Technique Lithology: Water rock interaction Stratigraphic/Structural: Hydrological: Origin of hydrothermal fluids; Mixing of hydrothermal fluids Thermal: Isotopic ratios can be used to characterize and locate subsurface thermal anomalies. Dictionary.png Isotopic Analysis- Fluid: Isotopes are atoms of the same element that have different numbers of neutrons. An isotopic analysis looks at a particular isotopic element(s) in

352

Photon activation analysis as a new technique for body composition studies  

SciTech Connect (OSTI)

A study was undertaken to demonstrate the usefulness of the recently developed photon activation analysis (PAA) technique for in vivo body composition studies. PAA can be used for direct measurement of total-body oxygen, nitrogen, and carbon. Sequential measurements were made on rats fed diets of 0%, 4.2%, or 20% protein for 6 1/2 wk, and significant changes in body composition were noted. In addition, rats of different ages, strains, nutritional states, and degrees of obesity were included in a comparison of PAA results in vivo with results from chemical analysis after sacrifice of the animals. High positive correlations were found between PAA measurements of carbon and chemical analysis measurements of fat and between PAA measurements of oxygen and chemical analysis measurements of total-body water. A low positive correlation was found between PAA measurements of nitrogen and chemical analysis measurements of protein.

Ulin, K.; Meydani, M.; Zamenhof, R.G.; Blumberg, J.B.

1986-12-01T23:59:59.000Z

353

Ten channel background alpha radiometer for nondestructive analysis of low activity samples  

SciTech Connect (OSTI)

The description of a ten-channel alpha-radiometer based on large-area semiconductor detectors is presented in this paper. The radiometer is intended for determination of soil pollution by alpha-active radionuclides using thick samples. The analysis of isotopes is also provided. The concentrations of Pu and Am isotopes in soil samples are determined.

Pugatch, V.M.; Pavlenko, Y.N.; Vasiliev, Y.O.; Nenakhov, A.N.; Tkatch, N.M.; Barabash, L.I.; Berdnichenko, S.V.; Litovchenko, P.G.; Rosenfeld, A.B.; Zinets, O.S. (Inst. for Nuclear Research, Kiev (USSR))

1992-10-01T23:59:59.000Z

354

European Wind Energy Conference 2007 Milan Measurement based analysis of active and reactive power  

E-Print Network [OSTI]

European Wind Energy Conference 2007 ­ Milan 1 Measurement based analysis of active and reactive to the network through distribution systems. Because the production units, the distribution systems units will cover consumption in the vicinity. This can contribute to the reduction of the system losses

355

Performance Analysis of a Hybrid Asymmetric Multilevel Inverter for High Voltage Active Power Filter Applications  

E-Print Network [OSTI]

Performance Analysis of a Hybrid Asymmetric Multilevel Inverter for High Voltage Active Power voltage-source inverters connected in series (known as cascaded hybrid asymmetric multilevel inverter voltage application due to semiconductor constraint. In order to achieve higher power level, hybrid

Catholic University of Chile (Universidad Católica de Chile)

356

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

357

Cognitive tasks in information analysis: Use of event dwell time to characterize component activities  

SciTech Connect (OSTI)

Technology-based enhancement of information analysis requires a detailed understanding of the cognitive tasks involved in the process. The information search and report production tasks of the information analysis process were investigated through evaluation of time-stamped workstation data gathered with custom software. Model tasks simulated the search and production activities, and a sample of actual analyst data were also evaluated. Task event durations were calculated on the basis of millisecond-level time stamps, and distributions were plotted for analysis. The data indicate that task event time shows a cyclic pattern of variation, with shorter event durations (< 2 sec) reflecting information search and filtering, and longer event durations (> 10 sec) reflecting information evaluation. Application of cognitive principles to the interpretation of task event time data provides a basis for developing “cognitive signatures” of complex activities, and can facilitate the development of technology aids for information intensive tasks.

Sanquist, Thomas F.; Greitzer, Frank L.; Slavich, Antoinette L.; Littlefield, Rik J.; Littlefield, Janis S.; Cowley, Paula J.

2004-09-28T23:59:59.000Z

358

Small plasma focus as neutron pulsed source for nuclides identification  

SciTech Connect (OSTI)

In this paper, we present preliminary results on the feasibility of employing a low energy (2 kJ, 31 kV) plasma focus device as a portable source of pulsed neutron beams (2.45 MeV) generated by nuclear fusion reactions D-D, for the “in situ” analysis of substances by nuclear activation. This source has the relevant advantage of being pulsed at requirement, transportable, not permanently radioactive, without radioactive waste, cheap, among others. We prove the feasibility of using this source showing several spectra of the characteristic emission line for manganese, gold, lead, and silver.

Milanese, M.; Moroso, R.; Barbaglia, M. [Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires (CONICET-UNCPBA), Pinto 399, Tandil 7000, Buenos Aires (Argentina) [Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires (CONICET-UNCPBA), Pinto 399, Tandil 7000, Buenos Aires (Argentina); Universidad del Centro de la Provincia de Buenos Aires (CONICET-UNCPBA), Pinto 399, Tandil 7000, Buenos Aires (Argentina); Niedbalski, J. [CONICET(Consejo Nacional de Investigaciones Científicas y Técnicas), Rivadavia 1917, Buenos Aires (Argentina)] [CONICET(Consejo Nacional de Investigaciones Científicas y Técnicas), Rivadavia 1917, Buenos Aires (Argentina); Mayer, R. [CNEA (Comisión Nacional de Energía Atómica), Av. Bustillo 9500, San Carlos de Bariloche, Rio Negro (Argentina)] [CNEA (Comisión Nacional de Energía Atómica), Av. Bustillo 9500, San Carlos de Bariloche, Rio Negro (Argentina); Castillo, F. [UNAM (Universidad Nacional Autónoma de México)–Circuito Exterior s/n, Ciudad Universitaria, Delg. Coyoacán, P.O. Box 70-543, México DF (Mexico)] [UNAM (Universidad Nacional Autónoma de México)–Circuito Exterior s/n, Ciudad Universitaria, Delg. Coyoacán, P.O. Box 70-543, México DF (Mexico); Guichón, S. [Universidad del Centro de la Provincia de Buenos Aires (CONICET-UNCPBA), Pinto 399, Tandil 7000, Buenos Aires (Argentina)] [Universidad del Centro de la Provincia de Buenos Aires (CONICET-UNCPBA), Pinto 399, Tandil 7000, Buenos Aires (Argentina)

2013-10-15T23:59:59.000Z

359

Small plasma focus as neutron pulsed source for nuclides identification  

Science Journals Connector (OSTI)

In this paper we present preliminary results on the feasibility of employing a low energy (2 kJ 31 kV) plasma focus device as a portable source of pulsed neutron beams (2.45 MeV) generated by nuclear fusion reactions D-D for the “in situ” analysis of substances by nuclear activation. This source has the relevant advantage of being pulsed at requirement transportable not permanently radioactive without radioactive waste cheap among others. We prove the feasibility of using this source showing several spectra of the characteristic emission line for manganese gold lead and silver.

M. Milanese; J. Niedbalski; R. Moroso; M. Barbaglia; R. Mayer; F. Castillo; S. Guichón

2013-01-01T23:59:59.000Z

360

RESULTS OF FIRST EXPERIMENTS ON NEUTRON GENERATION IN THE VITA NEUTRON SOURCE  

E-Print Network [OSTI]

as activation detector due to capture of epithermal neutrons by iodine also. Bubble detectors were used shell and reliably protected from magnetic fields and electromagnetic noises. Stability of the power

Taskaev, Sergey Yur'evich

Note: This page contains sample records for the topic "neutron activation analysis" 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

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

362

Ultracold neutron depolarization in magnetic bottles  

Science Journals Connector (OSTI)

We analyze the depolarization of ultracold neutrons confined in a magnetic field configuration similar to those used in existing or proposed magnetogravitational storage experiments aiming at a precise measurement of the neutron lifetime. We use an extension of the semiclassical Majorana approach as well as an approximate quantum mechanical analysis, both pioneered by Walstrom et al. [Nucl. Instrum. Methods Phys. Res. A 599, 82 (2009)]. In contrast with this previous work we do not restrict the analysis to purely vertical modes of neutron motion. The lateral motion is shown to cause the predominant depolarization loss in a magnetic storage trap. The system studied also allowed us to estimate the depolarization loss suffered by ultracold neutrons totally reflected on a nonmagnetic mirror immersed in a magnetic field. This problem is of preeminent importance in polarized neutron decay studies such as the measurement of the asymmetry parameter A using ultracold neutrons, and it may limit the efficiency of ultracold neutron polarizers based on passage through a high magnetic field.

A. Steyerl; C. Kaufman; G. Müller; S. S. Malik; A. M. Desai

2012-12-07T23:59:59.000Z

363

Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE  

SciTech Connect (OSTI)

Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) from (n,f) events. The first evidence of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

Jandel, Marian [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

364

Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE  

SciTech Connect (OSTI)

Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) events from (n,f) events. The first direct observation of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Couture, A.; Haight, R. C.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M. [Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States); Stoyer, M. A.; Wu, C. Y.; Becker, J. A.; Haslett, R. J.; Henderson, R. A. [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

2009-01-28T23:59:59.000Z

365

Instruments | Neutron Science | ORNL  

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

366

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

367

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

368

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

369

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

370

Neutrons - 88-Inch Cyclotron  

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

371

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

372

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

373

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

374

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

375

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

376

Neuroscience Instrumentation and Distributed Analysis of Brain Activity Data: A Case for eScience on Global Grids  

E-Print Network [OSTI]

1 Neuroscience Instrumentation and Distributed Analysis of Brain Activity Data: A Case for e commonly observed in scientific disciplines. Two popular scientific disciplines of this nature are brain science and high-energy physics. The analysis of brain activity data gathered from the MEG

Buyya, Rajkumar

377

Neutron Absorption Cross Sections of Pa231 and Pa232  

Science Journals Connector (OSTI)

Activation studies of Pa231 in the graphite region of the Materials Testing Reactor have resulted in a value of 200±15 barns for the thermal neutron absorption cross section of Pa231. Resonance neutron effects were eliminated by the method of cadmium differences and by conducting the irradiations in a region where the ratio of resonance to thermal neutrons is small.Measurements of the Pa232 and Pa233 activities produced in a highly intense neutron irradiation of Pa231 have resulted in a value of 760±100 barns for the absorption cross section of Pa232.

R. R. Smith; N. P. Alley; R. H. Lewis; A. VanderDoes

1956-02-01T23:59:59.000Z

378

Dense Plasma Focus Fusion Neutron Sources Progress at NSTec, September 2011  

SciTech Connect (OSTI)

A number of dense plasma focus (DPF) sources are introduced, including their operating characteristics and current activities. Neutron resonance spectroscopy is discussed and the feasibility of using DPF for neutron sources is considered.

Hagen, E. C.

2011-07-02T23:59:59.000Z

379

Advanced Neutron Source (ANS) Project progress report  

SciTech Connect (OSTI)

This report discusses the following topics on the advanced neutron source: quality assurance (QA) program; reactor core development; fuel element specification; corrosion loop tests and analyses; thermal-hydraulic loop tests; reactor control concepts; critical and subcritical experiments; material data, structural tests, and analysis; cold source development; beam tube, guide, and instrument development; hot source development; neutron transport and shielding; I C research and development; facility concepts; design; and safety.

McBee, M.R.; Chance, C.M. (eds.) (Oak Ridge National Lab., TN (USA)); Selby, D.L.; Harrington, R.M.; Peretz, F.J. (Oak Ridge National Lab., TN (USA))

1990-04-01T23:59:59.000Z

380

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

The computerized identification of reactor-produced isotopes in an activation analysis environment  

E-Print Network [OSTI]

- ability of a complete, positive identification appears small. How- ever, with the addition of a least squares method of resolving interferences and the application of a figure indicating the value (figure-of-merit) placed on each elimination test...THE COMPUTERIZED IDENTIFICATION OF REACTOR-PRODUCED ISOTOP ' S IN AN ACTIVATION ANALYSIS ENVIRON&vIENT A Thesi. s by DANIEI. aOIIN SCHLUETER Submitted to the Grec'u&ate College of Texas ARM University in pa. tial fulfillment o...

Schlueter, Daniel John

1971-01-01T23:59:59.000Z

382

Optimization of Boron Neutron Capture Therapy for the Treatment of Undifferentiated Thyroid Cancer  

SciTech Connect (OSTI)

Purpose: To analyze the possible increase in efficacy of boron neutron capture therapy (BNCT) for undifferentiated thyroid carcinoma (UTC) by using p-boronophenylalanine (BPA) plus 2,4-bis ({alpha},{beta}-dihydroxyethyl)-deutero-porphyrin IX (BOPP) and BPA plus nicotinamide (NA) as a radiosensitizer of the BNCT reaction. Methods and Materials: Nude mice were transplanted with a human UTC cell line (ARO), and after 15 days they were treated as follows: (1) control, (2) NCT (neutrons alone), (3) NCT plus NA (100 mg/kg body weight [bw]/day for 3 days), (4) BPA (350 mg/kg bw) + neutrons, (5) BPA + NA + neutrons, and (6) BPA + BOPP (60 mg/kg bw) + neutrons. The flux of the mixed (thermal + epithermal) neutron beam was 2.8 x 10{sup 8} n/cm{sup 2}/sec for 83.4 min. Results: Neutrons alone or with NA caused some tumor growth delay, whereas in the BPA, BPA + NA, and BPA + BOPP groups a 100% halt of tumor growth was observed in all mice at 26 days after irradiation. When the initial tumor volume was 50 mm{sup 3} or less, complete remission was found with BPA + NA (2 of 2 mice), BPA (1 of 4), and BPA + BOPP (7 of 7). After 90 days of complete regression, recurrence of the tumor was observed in BPA + NA (2 of 2) and BPA + BOPP (1 of 7). The determination of apoptosis in tumor samples by measurements of caspase-3 activity showed an increase in the BNCT (BPA + NA) group at 24 h (p < 0.05 vs. controls) and after the first week after irradiation in the three BNCT groups. Terminal transferase dUTP nick end labeling analysis confirmed these results. Conclusions: Although NA combined with BPA showed an increase of apoptosis at early times, only the group irradiated after the combined administration of BPA and BOPP showed a significantly improved therapeutic response.

Dagrosa, Maria Alejandra; Thomasz, Lisa M.Sc. [Department of Radiobiology (Constituyentes Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Longhino, Juan [Nuclear Reactor RA-6 (Bariloche Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Perona, Marina [Department of Radiobiology (Constituyentes Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Calzetta, Osvaldo; Blaumann, Herman [Nuclear Reactor RA-6 (Bariloche Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Rebagliati, Raul Jimenez [Department of Chemistry (Constituyentes Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Cabrini, Romulo [Department of Radiobiology (Constituyentes Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Kahl, Steven [Department of Pharmaceutical Chemistry, University of California, San Francisco, CA (United States); Juvenal, Guillermo Juan [Department of Radiobiology (Constituyentes Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Pisarev, Mario Alberto [Department of Radiobiology (Constituyentes Atomic Center), National Atomic Energy Commission of Argentina, Buenos Aires (Argentina); Department of Human Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires (Argentina)], E-mail: pisarev@cnea.gov.ar

2007-11-15T23:59:59.000Z

383

Dynamic Albedo of Neutrons (DAN) Experiment Onboard NASA’s Mars Science Laboratory  

Science Journals Connector (OSTI)

The proper emission of neutrons produced by GCRs in the Moon, Mars and Mercury subsurface has been successfully measured with very high science output. The analysis of neutron data from Mars and Moon has provi...

I. G. Mitrofanov; M. L. Litvak; A. B. Varenikov; Y. N. Barmakov…

2012-09-01T23:59:59.000Z

384

ANALYSIS OF CDTE ACTIVATION TREATMENT WITH A NOVEL APPROACH Andrei Salavei^, Ivan Rimmaudo^, Fabio Piccinelli*, Daniele Menossi+  

E-Print Network [OSTI]

ANALYSIS OF CDTE ACTIVATION TREATMENT WITH A NOVEL APPROACH Andrei Salavei^, Ivan Rimmaudo^, Fabio approach for CdTe activation treatment. Starting from a baseline of CdTe devices made with CdCl2 activation­voltage characteristics) of finished devices. Keywords: CdTe, CdCl2, High-Efficiency. 1 INTRODUCTION CdTe thin film solar

Romeo, Alessandro

385

Analysis of influence of fuel price on individual activity-travel time expenditure  

Science Journals Connector (OSTI)

Abstract Fluctuation in fuel prices may lead to adaptations in people?s activity-travel behavior. Compared to other triggers of behavioral change, the impact of fuel prices has received only scant attention in the literature, especially with respect to short-run change in activity-travel behavior. To gain insight into this issue, travel diaries of a representative sample of individuals in the Netherlands who use the car for daily travel were analyzed. Seemingly unrelated regression analysis was used to examine the effects of fuel price on people?s travel time expenditures for different kinds of activities, differentiating between weekdays and weekends. The results indicate that fuel price is negatively correlated with travel time expenditures by car, and that this relationship differs between weekdays and weekends. When faced with increasing fuel prices, people seem to prefer reducing travel time expenditure by car for compulsory trips more than for leisure trips.

Dujuan Yang; Harry Timmermans

2013-01-01T23:59:59.000Z

386

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

387

Principles of neutron reflection  

SciTech Connect (OSTI)

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

388

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. Heyrovská

1992-01-01T23:59:59.000Z

389

Spallation Neutron Source, SNS  

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

390

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

391

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

392

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

SciTech Connect (OSTI)

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

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

2013-03-15T23:59:59.000Z

393

Imaging and Neutrons - IAN 2006 - Neutron Sciences  

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

394

PERFORMING DIAGNOSTICS ON THE SPALLATION NEUTRON SOURCE VISION BEAM LINE TO ELIMINATE HIGH VIBRATION LEVELS AND PROVIDE A SUSTAINABLE OPERATION  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL) provides variable energy neutrons for a variety of experiments. The neutrons proceed down beam lines to the experiment hall, which houses a variety of experiments and test articles. Each beam line has one or more neutron choppers which filter the neutron beam based on the neutron energy by using a rotating neutron absorbing material passing through the neutron beam. Excessive vibration of the Vision beam line, believed to be caused by the T0 chopper, prevented the Vision beam line from operating at full capacity. This problem had been addressed several times by rebalancing/reworking the T0 beam chopper but the problem stubbornly persisted. To determine the cause of the high vibration, dynamic testing was performed. Twenty-seven accelerometer and motor current channels of data were collected during drive up, drive down, coast down, and steady-state conditions; resonance testing and motor current signature analysis were also performed. The data was analyzed for traditional mechanical/machinery issues such as misalignment and imbalance using time series analysis, frequency domain analysis, and operating deflection shape analysis. The analysis showed that the chopper base plate was experiencing an amplified response to the excitation provided by the T0 beam chopper. The amplified response was diagnosed to be caused by higher than expected base plate flexibility, possibly due to improper grouting or loose floor anchors. Based on this diagnosis, a decision was made to dismantle the beam line chopper and remount the base plate. Neutron activation of the beam line components make modifications to the beam line especially expensive and time consuming due to the radiation handling requirements, so this decision had significant financial and schedule implications. It was found that the base plate was indeed loose because of improper grouting during its initial installation. The base plate was modified by splitting it into multiple sections, isolating the T0 chopper from the rest of the beam line, and each section was then reinstalled and re-grouted. After these modifications, the vibration levels were reduced by a factor of 30. The reduction in vibration level was sufficient to allow the Vision beam line to operate at full capacity for the first time since its completed construction date.

Van Hoy, Blake W [ORNL

2014-01-01T23:59:59.000Z

395

Neutron beta-decay, Standard Model and cosmology  

E-Print Network [OSTI]

The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. The neutron lifetime recently obtained, 878.5 +/- 0.7stat +/- 0.3sys s, is the most accurate one to date. The new result for the neutron lifetime differs from the world average value by 6.5 standard deviations. The impact of the new result on testing of Standard Model and on data analysis for the primordial nucleosynthesis model is scrutinized.

A. P. Serebrov

2006-11-22T23:59:59.000Z

396

International workshop on cold neutron sources  

SciTech Connect (OSTI)

The first meeting devoted to cold neutron sources was held at the Los Alamos National Laboratory on March 5--8, 1990. Cosponsored by Los Alamos and Oak Ridge National Laboratories, the meeting was organized as an International Workshop on Cold Neutron Sources and brought together experts in the field of cold-neutron-source design for reactors and spallation sources. Eighty-four people from seven countries attended. Because the meeting was the first of its kind in over forty years, much time was spent acquainting participants with past and planned activities at reactor and spallation facilities worldwide. As a result, the meeting had more of a conference flavor than one of a workshop. The general topics covered at the workshop included: Criteria for cold source design; neutronic predictions and performance; energy deposition and removal; engineering design, fabrication, and operation; material properties; radiation damage; instrumentation; safety; existing cold sources; and future cold sources.

Russell, G.J.; West, C.D. (comps.) (Los Alamos National Lab., NM (United States)) [comps.; Los Alamos National Lab., NM (United States)

1991-08-01T23:59:59.000Z

397

Cryogenic hydrogen circulation system of neutron source  

SciTech Connect (OSTI)

Cold neutron sources of reactors and spallation neutron sources are classic high flux neutron sources in operation all over the world. Cryogenic fluids such as supercritical or supercooled hydrogen are commonly selected as a moderator to absorb the nuclear heating from proton beams. By comparing supercritical hydrogen circulation systems and supercooled hydrogen circulation systems, the merits and drawbacks in both systems are summarized. When supercritical hydrogen circulates as the moderator, severe pressure fluctuations caused by temperature changes will occur. The pressure control system used to balance the system pressure, which consists of a heater as an active controller for thermal compensation and an accumulator as a passive volume controller, is preliminarily studied. The results may provide guidelines for design and operation of other cryogenic hydrogen system for neutron sources under construction.

Qiu, Y. N. [Institute of Physics and Chemistry, Chinese Academy of Sciences, BJ100190 China and University of Chinese Academy of Sciences, Chinese Academy of Sciences, BJ100049 (China); Hu, Z. J.; Wu, J. H.; Li, Q.; Zhang, Y. [Institute of Physics and Chemistry, Chinese Academy of Sciences, BJ100190 (China); Zhang, P. [School of Energy and Power Engineering, HuaZhong University of Science and Technology, WH430074 (China); Wang, G. P. [Institute of High Energy Physics, Chinese Academy of Sciences, BJ100049 (China)

2014-01-29T23:59:59.000Z

398

Neutron Science In the News - 2014 | ORNL Neutron Sciences  

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

399

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

400

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

Note: This page contains sample records for the topic "neutron activation analysis" 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

X-RAY FLUORESCENCE ANALYSIS OF HANFORD LOW ACTIVITY WASTE SIMULANTS  

SciTech Connect (OSTI)

Savannah River National Laboratory (SRNL) was requested to develop an x-ray fluorescence (XRF) spectrometry method for elemental characterization of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) pretreated low activity waste (LAW) stream to the LAW Vitrification Plant. The WTP is evaluating the potential for using XRF as a rapid turnaround technique to support LAW product compliance and glass former batching. The overall objective of this task was to develop XRF analytical methods that provide the rapid turnaround time (<8 hours) requested by the WTP, while providing sufficient accuracy and precision to determine waste composition variations. For Phase 1a, SRNL (1) evaluated, selected, and procured an XRF instrument for WTP installation, (2) investigated three XRF sample methods for preparing the LAW sub-sample for XRF analysis, and (3) initiated scoping studies on AN-105 (Envelope A) simulant to determine the instrument's capability, limitations, and optimum operating parameters. After preliminary method development on simulants and the completion of Phase 1a activities, SRNL received approval from WTP to begin Phase 1b activities with the objective of optimizing the XRF methodology. Three XRF sample methods used for preparing the LAW sub-sample for XRF analysis were studied: direct liquid analysis, dried spot, and fused glass. The direct liquid method was selected because its major advantage is that the LAW can be analyzed directly without any sample alteration that could bias the method accuracy. It also is the fastest preparation technique--a typical XRF measurement could be completed in < 1hr after sample delivery. Except for sodium, the method detection limits (MDLs) for the most important analytes in solution, the hold point elements, were achieved by this method. The XRF detection limits are generally adequate for glass former batching and product composition reporting, but may be inadequate for some species (Hg, Cd, and Ba) important to land disposal restrictions. The long term precision (24-hr) also was good with percent relative standard deviations (%RSDs) < 10 % for most elements in filtered solution. There were some issues with a few elements precipitating out of solution over time affecting the long term precision of the method. Additional research will need to be performed to resolve this sample stability problem. Activities related to methodology optimization in the Phase 1b portion of the study were eliminated as a result of WTP request to discontinue remaining activities due to funding reduction. These preliminary studies demonstrate that developing an XRF method to support the LAW vitrification plant is feasible. When funding is restored for the WTP, it is recommended that optimization of this technology should be pursued.

Jurgensen, A; David Missimer, D; Ronny Rutherford, R

2006-05-08T23:59:59.000Z

402

Spallation Neutron Source  

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

403

Activities  

Broader source: Energy.gov [DOE]

Activities and events provide Residential Network members the opportunity to discuss similar needs and challenges, and to collectively identify effective strategies and useful resources.

404

Vehicle Technologies Office Merit Review 2014: Overview and Progress of the Battery Testing, Design and Analysis Activity  

Broader source: Energy.gov [DOE]

Presentation given by the Department of Energy's Energy Storage area at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about the battery testing, design, and analysis activity.

405

Industry - ORNL Neutron Sciences  

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

406

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

407

Neutron Science Forum | ORNL  

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

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

408

Neutron Science | ORNL  

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

409

The national spallation neutron source target station: A general overview  

SciTech Connect (OSTI)

The technologies that are being utilized to design and build a state-of-the-art neutron spallation source, the National Spallation Neutron Source (NSNS), are discussed. Emphasis is given to the technology issues that present the greatest scientific challenges. The present facility configuration, ongoing analysis and the planned hardware research and development program are also described.

Gabriel, T.A.; Barnes, J.N.; Charlton, L.A. [and others

1997-06-01T23:59:59.000Z

410

Neutron scattering-modern techniques and their scientific impact  

E-Print Network [OSTI]

The sustained interest in the neutron and its use as a probe of the structure and dynamics of condensed matter is examined against the background of neutron availabil-ity. An analysis is made of developments in neutron source brightness, instrument physics and experimental methodology which have been or are likely to be of outstand-ing value in physics, chemistry, biology and materials technology studies. The role of pulsed sources as the next step ahead in neutron source brightness, their need for extensive instrument development to realise this potential and their complementarity with steady-state reactors is analysed using newly available experimental results. This review was received in December 1983.

J W White; C G Windsor; J W White; C G Windsor

411

Review of the Hanford Site Waste Treatment and Immobilization Plant Low Activity Waste Melter Process System Hazards Analysis Activity, December 2012  

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

the Hanford Site the Hanford Site Waste Treatment and Immobilization Plant Low Activity Waste Melter Process System Hazards Analysis Activity December 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose ................................................................................................................................................. 1 2.0 Background.......................................................................................................................................... 1 3.0 Scope and Methodology... ................................................................................................................... 1

412

Review of the Hanford Site Waste Treatment and Immobilization Plant Low Activity Waste Melter Process System Hazards Analysis Activity, December 2012  

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

the Hanford Site the Hanford Site Waste Treatment and Immobilization Plant Low Activity Waste Melter Process System Hazards Analysis Activity December 2012 Office of Safety and Emergency Management Evaluations Office of Enforcement and Oversight Office of Health, Safety and Security U.S. Department of Energy Table of Contents 1.0 Purpose ................................................................................................................................................. 1 2.0 Background.......................................................................................................................................... 1 3.0 Scope and Methodology... ................................................................................................................... 1

413

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

414

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

415

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

416

Neutron and Nuclear Science News  

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

417

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

418

Studies of Neutron Backgrounds for PoGOLite a Balloon-borne Gamma-ray Polarimeter  

E-Print Network [OSTI]

Studies of Neutron Backgrounds for PoGOLite ­ a Balloon-borne Gamma-ray Polarimeter Jaroslav, neutrons stars and jets from active galaxies. To this day, polarisation has only been measured for the Crab, performed using Monte Carlo simulations in Geant4, of the atmospheric neutron background and its effect

Haviland, David

419

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

420

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

E-Print Network [OSTI]

Neutron Experiment descriptions: N1: Triple-Axis Spectrometers, HFIR HB1A & HB3 Spin wave2A Magnetic structure of NiO Neutron diffraction measurements will be performed to investigate 600K to 288K, using the Neutron Powder Diffractometer at the HFIR. Rietveld analysis of the crystal

Pennycook, Steve

Note: This page contains sample records for the topic "neutron activation analysis" 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

Total cross section of neutron-proton scattering at low energies in quark-gluon model  

E-Print Network [OSTI]

We show that analysis of nonrelativistic neutron-proton scattering in a framework of relativistic QCD based quark model can give important information about QCD vacuum structure. In this model we describe total cross section of neutron-proton scattering at kinetic energies of projectile neutron from 1 eV up to 1 MeV.

V. A. Abramovsky; N. V. Radchenko

2011-07-30T23:59:59.000Z

422

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

423

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

424

Neutron and Nuclear Science Publications  

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

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

425

Neutron and Nuclear Science News  

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

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...

426

Neutron Science Research Areas | ORNL  

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

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

427

LANSCE School on Neutron Scattering:  

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

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...

428

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

429

Specification and Analysis of the AER/NCA Active Network Protocol Suite in Real-Time Maude  

E-Print Network [OSTI]

Specification and Analysis of the AER/NCA Active Network Protocol Suite in Real-Time Maude Peter-Time Maude tool and the Maude formal methodology to the specification and analysis of the AER/NCA suite-sensitive behavior, the presence of probabilistic algorithms, and the composability of its components, AER/NCA poses

Ã?lveczky, Peter Csaba

430

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...

431

Analysis of control strategies for thermally activated building systems under demand side management mechanisms  

Science Journals Connector (OSTI)

Abstract Thermally activated buildings systems (TABS) are systems that integrate heating/cooling devices in the building structure, so that the building elements act as thermal storage and have an active role in the energy supply and demand management. Although TABS are well known systems, there are still open questions in their realization, mainly concerning appropriate control strategies which are influenced by the large thermal inertia. The purpose of this paper is to analyze the influence of demand side management control strategies on the performance of a thermally activated building system applied in a commercial building. The goal is to estimate the potential of TABS for load shifting requested by the electricity grid. The analysis is performed by means of a sample case: first the existing TABS control strategy and then the possible implementation of DSM mechanisms are analyzed. In particular three different demand side management mechanisms are evaluated: (i) a peak shaving strategy, (ii) a random request of switching on/off the system and (iii) a night load shifting strategy. The simulation results show high potential of TABS within the DSM framework, since TABS allow load control while scarcely affect thermal comfort.

A. Arteconi; D. Costola; P. Hoes; J.L.M. Hensen

2014-01-01T23:59:59.000Z

432

Energy Density Functional for Nuclei and Neutron Stars  

SciTech Connect (OSTI)

Background: Recent observational data on neutron star masses and radii provide stringent constraints on the equation of state of neutron rich matter [ Annu. Rev. Nucl. Part. Sci. 62 485 (2012)]. Purpose: We aim to develop a nuclear energy density functional that can be simultaneously applied to finite nuclei and neutron stars. Methods: We use the self-consistent nuclear density functional theory (DFT) with Skyrme energy density functionals and covariance analysis to assess correlations between observables for finite nuclei and neutron stars. In a first step two energy functionals a high density energy functional giving reasonable neutron properties, and a low density functional fitted to nuclear properties are matched. In a second step, we optimize a new functional using exactly the same protocol as in earlier studies pertaining to nuclei but now including neutron star data. This allows direct comparisons of performance of the new functional relative to the standard one. Results: The new functional TOV-min yields results for nuclear bulk properties (energy, rms radius, diffraction radius, and surface thickness) that are of the same quality as those obtained with the established Skyrme functionals, including SV-min. When comparing SV-min and TOV-min, isoscalar nuclear matter indicators vary slightly while isovector properties are changed considerably. We discuss neutron skins, dipole polarizability, separation energies of the heaviest elements, and proton and neutron drip lines. We confirm a correlation between the neutron skin of 208Pb and the neutron star radius. Conclusions: We demonstrate that standard energy density functionals optimized to nuclear data do not carry information on the expected maximum neutron star mass, and that predictions can only be made within an extremely broad uncertainty band. For atomic nuclei, the new functional TOV-min performs at least as well as the standard nuclear functionals, but it also reproduces expected neutron star data within assumed error bands. This functional is expected to yield more reliable predictions in the region of very neutron rich heavy nuclei.

Erler, J. [UTK/ORNL/German Cancer Research Center-Heidelberg; Horowitz, C. J. [UTK/ORNL/Indiana University; Nazarewicz, Witold [UTK/ORNL/University of Warsaw; Rafalski, M. [UTK/ORNL; Reinhard, P.-G. [Universitat Erlangen, Germany

2013-01-01T23:59:59.000Z

433

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

434

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

435

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

436

Neutron Scattering | U.S. DOE Office of Science (SC)  

Office of Science (SC) Website

Neutron Scattering Neutron Scattering Materials Sciences and Engineering (MSE) Division MSE Home About Research Areas Energy Frontier Research Centers (EFRCs) DOE Energy Innovation Hubs BES Funding Opportunities The Computational Materials and Chemical Sciences Network (CMCSN) Theoretical Condensed Matter Physics Scientific Highlights Reports and Activities Principal Investigators' Meetings BES Home Research Areas Neutron Scattering Print Text Size: A A A RSS Feeds FeedbackShare Page This activity supports basic research on the fundamental interactions of neutrons with matter to achieve an understanding of the atomic, electronic, and magnetic structures and excitations of materials and their relationship to materials properties. Major emphasis is on the application of neutron scattering, spectroscopy, and imaging for materials research, primarily at

437

What's wrong with the field of bio-neutron scattering? 1) Not enough professional science and not enough professional scientists  

E-Print Network [OSTI]

What's wrong with the field of bio-neutron scattering? 1) Not enough professional science a paper in this field. Anybody can do it! The most detailed analysis of bio-neutron scattering data up independent moment analysis of the neutron scattering spectrum. Up to today nobody, not even MD people, picked

Doster, Wolfgang

438

Industry - ORNL Neutron Sciences  

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

439

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

440

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 (0.23×10-13cm)2 for the charge distribution and (0.41×10-13cm)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 "neutron activation analysis" 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

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect (OSTI)

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

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

2004-10-16T23:59:59.000Z

442

E-Print Network 3.0 - active network analysis Sample Search Results  

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

activity of coupled networks. The neurons... and activity propagation in coupled neural networks from rat cortical cells grown on a micro-electrode array... for parallel activity...

443

Neutron Log At Alum Area (Moos & Ronne, 2010) | Open Energy Information  

Open Energy Info (EERE)

Neutron Log At Alum Area (Moos & Ronne, 2010) Neutron Log At Alum Area (Moos & Ronne, 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Neutron Log At Alum Geothermal Area (Moos & Ronne, 2010) Exploration Activity Details Location Alum Geothermal Area Exploration Technique Neutron Log Activity Date Usefulness useful DOE-funding Unknown Notes Density, photo-electric factor (PEF), neutron, and gamma ray (GR) logs provided sufficient information to clearly delineate basement lithologic variations, suggesting that pulsed neutron logs may not in many cases be needed, References Daniel Moos, Joel Ronne (2010) Selecting The Optimal Logging Suite For Geothermal Reservoir Evaluation- Results From The Alum 25-29 Well, Nevada Retrieved from "http://en.openei.org/w/index.php?title=Neutron_Log_At_Alum_Area_(Moos_%26_Ronne,_2010)&oldid=511025"

444

Neutron Log At Silver Peak Area (DOE GTP) | Open Energy Information  

Open Energy Info (EERE)

Neutron Log Activity Date Usefulness not indicated DOE-funding Unknown References (1 January 2011) GTP ARRA Spreadsheet Additional References Retrieved from "http:en.openei.org...

445

Calibration of the neutron detectors for the cluster fusion experiment on the Texas Petawatt Laser  

SciTech Connect (OSTI)

Three types of neutron detectors (plastic scintillation detectors, indium activation detectors, and CR-39 track detectors) were calibrated for the measurement of 2.45 MeV DD fusion neutron yields from the deuterium cluster fusion experiment on the Texas Petawatt Laser. A Cf-252 neutron source and 2.45 MeV fusion neutrons generated from laser-cluster interaction were used as neutron sources. The scintillation detectors were calibrated such that they can detect up to 10{sup 8} DD fusion neutrons per shot in current mode under high electromagnetic pulse environments. Indium activation detectors successfully measured neutron yields as low as 10{sup 4} per shot and up to 10{sup 11} neutrons. The use of a Cf-252 neutron source allowed cross calibration of CR-39 and indium activation detectors at high neutron yields ({approx}10{sup 11}). The CR-39 detectors provided consistent measurements of the total neutron yield of Cf-252 when a modified detection efficiency of 4.6 Multiplication-Sign 10{sup -4} was used. The combined use of all three detectors allowed for a detection range of 10{sup 4} to 10{sup 11} neutrons per shot.

Bang, W.; Quevedo, H. J.; Dyer, G.; Rougk, J.; Kim, I.; McCormick, M.; Bernstein, A. C.; Ditmire, T. [Center for High Energy Density Science, Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

2012-06-15T23:59:59.000Z

446

Photon Activation Analysis Of Light Elements Using 'Non-Gamma' Radiation Spectroscopy - The Instrumental Determination Of Phosphorus  

SciTech Connect (OSTI)

Unlike metal determinations the analysis of light elements (e.g., carbon, oxygen, phosphorus) is frequently problematic, in particular if analysed instrumentally. In photon activation analysis (PAA) the respective activation products do not emit gamma radiation in the most cases. Usually, annihilation quanta counting and subsequent decay curve analysis have been used for determinations of C, N, O, and F. However, radiochemical separation of the respective radioisotopes mostly is indispensable. For several reasons, some of the light elements cannot be analysed following this procedure, e.g. phosphorus. In this contribution the instrumental PAA of phosphorus in organic matrix by activation with bremsstrahlung of an electron linear accelerator and subsequent beta spectroscopy is described. The accuracy of the results was excellent as obtained by analysis of a BCR Reference Material.

Segebade, Christian [Idaho Accelerator Centre (IAC), Idaho State University, 1500 Alvin Ricken Drive, Pocatello, ID 83201 (United States); Goerner, Wolf [Bundesanstalt fuer Materialforschung und -pruefung, unter den Eichen 86, 12205 Berlin (Germany)

2011-06-01T23:59:59.000Z

447

Characterization of fissile material using low energy neutron interrogation  

E-Print Network [OSTI]

The glaring need to develop methods for detecting and interdicting illicit nuclear trafficking has resulted in the exploration of various methods for active neutron interrogation, specifically for the presence of special ...

Padilla, Eduardo A

2007-01-01T23:59:59.000Z

448

Gamma/neutron time-correlation for special nuclear material characterization %3CU%2B2013%3E active stimulation of highly enriched uranium.  

SciTech Connect (OSTI)

A series of simulations and experiments were undertaken to explore and evaluate the potential for a novel new technique for fissile material detection and characterization, the timecorrelated pulse-height (TCPH) method, to be used concurrent with active stimulation of potential nuclear materials. In previous work TCPH has been established as a highly sensitive method for the detection and characterization of configurations of fissile material containing Plutonium in passive measurements. By actively stimulating fission with the introduction of an external radiation source, we have shown that TCPH is also an effective method of detecting and characterizing configurations of fissile material containing Highly Enriched Uranium (HEU). The TCPH method is shown to be robust in the presence of the proper choice of external radiation source. An evaluation of potential interrogation sources is presented.

Marleau, Peter; Nowack, Aaron B.; Clarke, Shaun D. [University of Michigan; Monterial, Mateusz [University of Michigan; Paff, Marc [University of Michigan; Pozzi, Sara A. [University of Michigan

2013-09-01T23:59:59.000Z

449

Measurement of the Neutron Spectrum of a DD Electronic Neutron Generator  

SciTech Connect (OSTI)

A Cuttler-Shalev (C-S) 3He proportional counter has been used to measure the energy spectrum of neutrons from a portable deuterium-deuterium electronic neutron generator. To improve the analysis of results from the C-S detector digital pulse shape analysis techniques have been used to eliminate neutron recoil artifacts in the recorded data. Data was collected using a 8-GHz, 10-bit waveform digitizer with its full scale corresponding to approximately 6-MeV neutrons. The measurements were made with the detector axis perpendicular to the direction of ions in the ENG in a plane 0.5-m to the side of the ENG, measuring neutrons emitted at an angle from 87.3? to 92.7? with respect to the path of ions in the ENG. The system demonstrated an energy resolution of approximately 0.040 MeV for the thermal peak and approximately 0.13 MeV at the DD neutron energy. In order to achieve the ultimate resolution capable with this type of detector it is clear that a higher-precision digitizer will be needed.

D. L. Chichester; J. T. Johnson; E. H. Seabury

2010-08-01T23:59:59.000Z

450

Neutron-neutron correlation in the halo dissociation of light exotic nuclei  

Science Journals Connector (OSTI)

We present model results for the two-halo-neutron correlation functions, Cnn, for the dissociation process of light exotic nuclei modelled as two neutrons and a core. A minimum is predicted for Cnn as a function of the relative momentum of the two neutrons, pnn, due to the coherence of the neutrons in the halo and final state interaction. Studying the systems Be14, Li11, and He6 within this model, we show that the numerical asymptotic limit, Cnn?1, occurs only for pnn?400MeV/c, while such limit is reached for much lower values of pnn in an independent particle model as the one used in the analysis of recent experimental data. Our model is consistent with data once the experimental correlation function is appropriately normalized.

M. T. Yamashita; T. Frederico; Lauro Tomio

2005-07-18T23:59:59.000Z

451

Helicity amplitudes for photoexcitation of nucleon resonances off neutrons  

SciTech Connect (OSTI)

The helicity amplitudes $A^{1/2}_n$ and $A^{3/2}_n$ for the photoexcitation of nucleon resonances off neutrons are determined in a multi-channel partial-wave analysis.

Anisovich, A. V. [Bonn; Burkert, Volker D. [JLAB; Klempt, Eberhard [Bonn; Nikonov, A. V. [Bonn, PNPI Gatchina; Sarantsev, A. V. [Bonn, PNPI Gatchina; Thoma, Ulrike [Bonn

2013-06-01T23:59:59.000Z

452

Neutron radiation area monitoring system for proton therapy facilities  

Science Journals Connector (OSTI)

......Germany A neutron radiation area monitoring system...hardware and a suite of software applications that were...facility. Additional software applications provide...analysis, plotting, radiation protection reporting...ultra-conservative shielding and safety systems, which would......

W. D. Newhauser; X. Ding; D. Giragosian; S. Nill; U. Titt

2005-12-20T23:59:59.000Z

453

DOE-HDBK-1163-2003; Integration of Multiple Hazard Analysis Requirements and Activities  

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

DOE-HDBK-1163-2003 October 2003 DOE HANDBOOK INTEGRATION OF MULTIPLE HAZARD ANALYSIS REQUIREMENTS AND ACTIVITIES U.S. Department of Energy AREA SAFT Washington, D.C. 20585 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. TS DOE-HDBK-1163-2003 ii This document has been reproduced directly from the best available copy. It is available to DOE and DOE contractors from ES&H Technical Information Services, U.S. Department of Energy, (800) 473-4375, fax: (301) 903-9823. Available to the public from the U.S. Department of Commerce, Technology Administration, National Technical Information Service, Springfield, VA 22161; (703) 605-6000. DOE-HDBK-1163-2003 iii FOREWORD 1. This Department of Energy (DOE) standard is approved for use by all DOE Components and

454

Development and testing of neutron pulse time stamping data acquisition system for neutron noise experiment  

Science Journals Connector (OSTI)

Abstract Statistical correlation techniques find applications in the analysis of zero power reactor noise and in passive neutron assay (PNA). A large number of apparently different techniques have been in use in these application areas and traditionally the electronics modules used for data acquisition and analysis is specific to the method used. In this paper we describe a data acquisition scheme developed by us, which is independent of the specific analysis method and can therefore be used for all of them. This is a neutron time stamping data acquisition system based on a timer card and an interface software to acquire and store the data in the required format. The system has been successfully tested with two statistically different types of neutron sources, namely a random Poisson source (Pu–Be) and a correlated source (a nuclear reactor).

Rajeev Kumar; M Yakub Ali; S.B. Degweker; S.C. Vishwasrao; R.T. Jadhav

2015-01-01T23:59:59.000Z

455

Solar Neutron Events of October-November 2003  

E-Print Network [OSTI]

During the period when the Sun was intensely active on October-November 2003, two remarkable solar neutron events were observed by the ground-based neutron monitors. On October 28, 2003, in association with an X17.2 large flare, solar neutrons were detected with high statistical significance (6.4 sigma) by the neutron monitor at Tsumeb, Namibia. On November 4, 2003, in association with an X28 class flare, relativistic solar neutrons were observed by the neutron monitors at Haleakala in Hawaii and Mexico City, and by the solar neutron telescope at Mauna Kea in Hawaii simultaneously. Clear excesses were observed at the same time by these detectors, with the significance calculated as 7.5 sigma for Haleakala, and 5.2 sigma for Mexico City. The detector onboard the INTEGRAL satellite observed a high flux of hard X-rays and gamma-rays at the same time in these events. By using the time profiles of the gamma-ray lines, we can explain the time profile of the neutron monitor. It appears that neutrons were produced at the same time as the gamma-ray emission.

K. Watanabe; M. Gros; P. H. Stoker; K. Kudela; C. Lopate; J. F. Valdes-Galicia; A. Hurtado; O. Musalem; R. Ogasawara; Y. Mizumoto; M. Nakagiri; A. Miyashita; Y. Matsubara; T. Sako; Y. Muraki; T. Sakai; S. Shibata

2005-09-19T23:59:59.000Z

456

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

457

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

SciTech Connect (OSTI)

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

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

2008-03-17T23:59:59.000Z

458

Determination of boron in aluminum and aluminum-magnesium alloy by charged particle activation analysis  

SciTech Connect (OSTI)

Charge particle activation analysis is applied to the determination of boron in aluminum and aluminum-magnesium alloy. The /sup 10/B(p,..cap alpha..)/sup 7/Be, the /sup 10/B(d,..cap alpha..n)/sup 7/Be, and the /sup 10/B(d,n)/sup 11/C reactions are used. Proton activation allows an instrumental determination. When the /sup 10/B(d,..cap alpha..n)/sup 7/Be reaction is used, beryllium-7 is separated from the matrix by liquid-liquid extraction; beryllium acetylacetonate is extracted with carbon tetrachloride after complexation of other metal ions with ethylenediaminetetraacetic acid. After back extraction beryllium is precipitated as beryllium hydroxide and heated to beryllium oxide. When the /sup 10/B(d,n)/sup 11/C reaction is used, carbon-11 is separated as carbon dioxide by dissolution of the sample in a mixture of sulfuric acid, phosphoric acid, water, and potassium dichromate. The chemical yield of both separation methods was determined. The results obtained have a relative standard deviation of 5-9% at the 1-33 ..mu..g/g concentration. The different nuclear reactions yield results that are in good mutual agreement and also agree satisfactorily with those of nonnuclear analytical methods.

Mortier, R.; Vandecasteele, C.; Strijckmans, K.; Hoste, J.

1984-10-01T23:59:59.000Z

459

Active charge/passive discharge solar heating systems: thermal analysis and performance comparisons  

SciTech Connect (OSTI)

This study analyzes the performance of active charge/passive discharge solar space heating systems. This type of system combines liquid-cooled solar collector panels with a massive integral storage component that passively heats the building interior by radiation and free convection. The TRNSYS simulation program is used to evaluate system performance and to provide input for the development of a simplified analysis method. This method, which provides monthly calculations of delivered solar energy, is based on Klein's Phi-bar procedure and data from hourly TRNSYS simulations. The method can be applied to systems using a floor slab, a structural wall, or a water tank as the storage component. Important design parameters include collector area and orientation, building heat loss, collector and heat-exchanger efficiencies, storage capacity, and storage-to-room coupling. Performance simulation results are used for comparisons with active and passive solar designs. Economic comparisons are based on these data and additional system features, such as cooling augmentation and integration of heating components with structural members.

Swisher, J.

1981-06-01T23:59:59.000Z

460

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

E-Print Network [OSTI]

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

Note: This page contains sample records for the topic "neutron activation analysis" from the National Library of EnergyBeta (NLEBeta).
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461

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

462

A Visual Analytics Approach to Structured Data Analysis to Enhance Nonproliferation and Arms Control Verification Activities  

SciTech Connect (OSTI)

Analysis activities for Nonproliferation and Arms Control verification require the use of many types of data. Tabular structured data, such as Excel spreadsheets and relational databases, have traditionally been used for data mining activities, where specific queries are issued against data to look for matching results. The application of visual analytics tools to structured data enables further exploration of datasets to promote discovery of previously unknown results. This paper discusses the application of a specific visual analytics tool to datasets related to the field of Arms Control and Nonproliferation to promote the use of visual analytics more broadly in this domain. Visual analytics focuses on analytical reasoning facilitated by interactive visual interfaces (Wong and Thomas 2004). It promotes exploratory analysis of data, and complements data mining technologies where known patterns can be mined for. Also with a human in the loop, they can bring in domain knowledge and subject matter expertise. Visual analytics has not widely been applied to this domain. In this paper, we will focus on one type of data: structured data, and show the results of applying a specific visual analytics tool to answer questions in the Arms Control and Nonproliferation domain. We chose to use the T.Rex tool, a visual analytics tool developed at PNNL, which uses a variety of visual exploration patterns to discover relationships in structured datasets, including a facet view, graph view, matrix view, and timeline view. The facet view enables discovery of relationships between categorical information, such as countries and locations. The graph tool visualizes node-link relationship patterns, such as the flow of materials being shipped between parties. The matrix visualization shows highly correlated categories of information. The timeline view shows temporal patterns in data. In this paper, we will use T.Rex with two different datasets to demonstrate how interactive exploration of the data can aid an analyst with arms control and nonproliferation verification activities. Using a dataset from PIERS (PIERS 2014), we will show how container shipment imports and exports can aid an analyst in understanding the shipping patterns between two countries. We will also use T.Rex to examine a collection of research publications from the IAEA International Nuclear Information System (IAEA 2014) to discover collaborations of concern. We hope this paper will encourage the use of visual analytics structured data analytics in the field of nonproliferation and arms control verification. Our paper outlines some of the challenges that exist before broad adoption of these kinds of tools can occur and offers next steps to overcome these challenges.

Gillen, David S.

2014-08-07T23:59:59.000Z

463

Magnetic Structure Determination from Neutron Diffraction Data  

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

logo logo Magnetic Structure Determination from Neutron Diffraction Data September 17 - 20, 2012 logo Oak Ridge National Laboratory - Oak Ridge, Tennessee, USA About the Workshop Program Lecture Notes Useful Links Organizers Travel & Lodging Wireless Networking Photos filler About the Workshop molecule The Magnetic Structure Determination Workshop 2012 concluded on September 20. The aim of this workshop was to enhance the community studying magnetism in materials by learning from experts the essential theoretical foundations to magnetic representation analysis and work through real examples to gain experience in solving and refining magnetic structures from neutron powder and single crystal diffraction data. Invited speakers: Juan Rodríguez-Carvajal (ILL, Grenoble)

464

Neutron single target spin asymmetries in SIDIS  

SciTech Connect (OSTI)

The experiment E06-010 in Hall A at Jefferson Lab took data between November 2008 and February 2009 to directly measure, for the first time, the pion (and kaon) single "neutron" target-spin asymmetry (SSA) in semi-inclusive DIS from a polarized 3He target. Collins, Sivers (and Pretzelosity) neutron asymmetries are going to be extracted from the measured SSA. Details of the experiment are described together with the preliminary results of the ongoing analysis. Near future Hall A experiments on transverse nucleon spin structure are shorty reviewed.

Evaristo Cisbani

2010-04-01T23:59:59.000Z

465

Physics design of a cold neutron source for KIPT neutron source facility.  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of a neutron source facility. It is based on the use of an electron accelerator driven subcritical (ADS) facility with low enriched uranium fuel, using the existing electron accelerators at KIPT of Ukraine [1]. The neutron source of the subcritical assembly is generated from the interaction of 100-KW electron beam, which has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, with a natural uranium target [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Neutron beam experiments and material studies are also included. Over the past two-three decades, structures with characteristic lengths of 100 {angstrom} and correspondingly smaller vibrational energies have become increasingly important for both science and technology [3]. The characteristic dimensions of the microstructures can be well matched by neutrons with longer vibrational wavelength and lower energy. In the accelerator-driven subcritical facility, most of the neutrons are generated from fission reactions with energy in the MeV range. They are slowed down to the meV energy range through scattering reactions in the moderator and reflector materials. However, the fraction of neutrons with energies less than 5 meV in a normal moderator spectrum is very low because of up-scattering caused by the thermal motion of moderator or reflector molecules. In order to obtain neutrons with energy less than 5 meV, cryogenically cooled moderators 'cold neutron sources' should be used to slow down the neutrons. These cold moderators shift the neutron energy spectrum down because the thermal motion of moderator molecules as well as the up-scattering is very small, which provides large gains in intensity of low energy neutrons, E < 5 meV. The accelerator driven subcritical facility is designed with a provision to add a cryogenically cooled moderator system. This cold neutron source could provide the neutrons beams with lower energy, which could be utilized in scattering experiment and material structures analysis. This study describes the performed physics analyses to define and characterize the cold neutron source of the KIPT neutron source facility. The cold neutron source is designed to optimize the cold neutron brightness to the experimental instruments outside the radial heavy concrete shield of the facility. Liquid hydrogen or solid methane with 20 K temperature is used as a cold moderator. Monte Carlo computer code MCNPX [4], with ENDF/B-VI nuclear data libraries, is utilized to calculate the cold neutron source performance and estimate the nuclear heat load to the cold moderator. The surface source generation capability of MCNPX code has been used to provide the possibility of analyzing different design configurations and perform design optimization analyses with reasonable computer resources. Several design configurations were analyzed and their performance were characterized and optimized.

Zhong, Z.; Gohar, Y.; Kellogg, R.; Nuclear Engineering Division

2009-02-17T23:59:59.000Z

466

Small-angle neutron scattering analysis of Mn–C clusters in high-manganese 18Mn–0.6C steel  

Science Journals Connector (OSTI)

Abstract Nanometer-scale particles (Mn–C clusters) were analyzed quantitatively using small-angle neutron scattering in 18Mn–0.6C (wt.%) austenite high-manganese steel. The size, number, and volume fraction of the particles were determined as a function of strain (0, 5, 15, 30, 45, 50%) at different temperatures (25 and 100 °C). The diameter of the cluster ranges from 2 to 14 nm in the matrix. The total volume fraction of the cluster significantly increases from 2.7 × 10? 6 to 8.7 × 10? 6 as the strain increases. Such clustering phenomenon is correlated to the serration behavior under loading in high-manganese steels.

Mihyun Kang; Eunjoo Shin; Wanchuck Woo; Young-Kook Lee

2014-01-01T23:59:59.000Z

467

Fission signal detection using helium-4 gas fast neutron scintillation detectors  

SciTech Connect (OSTI)

We demonstrate the unambiguous detection of the fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium fusion neutron generator and a high pressure {sup 4}He gas fast neutron scintillation detector. The energy deposition by individual neutrons is quantified, and energy discrimination is used to differentiate the induced fission neutrons from the mono-energetic interrogation neutrons. The detector can discriminate between different incident neutron energies using pulse height discrimination of the slow scintillation component of the elastic scattering interaction between a neutron and the {sup 4}He atom. Energy histograms resulting from this data show the buildup of a detected fission neutron signal at higher energies. The detector is shown here to detect a unique fission neutron signal from a natural uranium sample during active interrogation with a (d, d) neutron generator. This signal path has a direct application to the detection of shielded nuclear material in cargo and air containers. It allows for continuous interrogation and detection while greatly minimizing the potential for false alarms.

Lewis, J. M., E-mail: lewisj@ufl.edu; Kelley, R. P.; Jordan, K. A. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611 (United States); Murer, D. [Arktis Radiation Detectors Ltd., 8045 Zurich (Switzerland)

2014-07-07T23:59:59.000Z

468

News & Events | ORNL Neutron Sciences  

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

8 News 8 News Neutron Science In the News - 2008 November October September August July June May March February January 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. October Research Visits Just Budding at Spallation Neutron Source Knoxville News Sentinel 10/29 When the Spallation Neutron Source was in the proposal stage and under construction, its supporters said the $1.4 billion research complex would eventually attract about 2,000 scientists a year to Oak Ridge to perform experiments and otherwise do their thing. That number, as I recall, was lumped together with researchers at the recently upgraded High Flux Isotope

469

Detectors - Instrument Support | ORNL Neutron Sciences  

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

Detectors › R & D 100 Award Detectors › R & D 100 Award ORNL team wins R&D 100 award for wavelength-shifting scintillator detector Neutron facilities, national security monitoring will benefit from high-accuracy detector June 2012, Written by Agatha Bardoel A team of eight scientists and technicians in the Neutron Sciences Directorate has won a prestigious R&D 100 Award from R&D Magazine for developing a highly efficient new detector system that helps take pressure off dwindling worldwide supplies of 3He as an active neutron converter. Members of the team receiving an R&D 100 Award for the wavelength-shifting scintillator detector Members of the team receiving an R&D 100 Award for the wavelength-shifting scintillator detector are shown with their invention. They are (from left)

470

Optimizing Laser-accelerated Ion Beams for a Collimated Neutron Source  

SciTech Connect (OSTI)

High-flux neutrons for imaging and materials analysis applications have typically been provided by accelerator- and reactor-based neutron sources. A novel approach is to use ultraintense (>1018W/cm2) lasers to generate picosecond, collimated neutrons from a dual target configuration. In this article, the production capabilities of present and upcoming laser facilities are estimated while independently maximizing neutron yields and minimizing beam divergence. A Monte-Carlo code calculates angular and energy distributions of neutrons generated by D-D fusion events occurring within a deuterated target for a given incident beam of D+ ions. Tailoring of the incident distribution via laser parameters and microlens focusing modifies the emerging neutrons. Projected neutron yields and distributions are compared to conventional sources, yielding comparable on-target fluxes per discharge, shorter time resolution, larger neutron energies and greater collimation.

C.L. Ellison and J. Fuchs

2010-09-23T23:59:59.000Z

471

Industry - ORNL Neutron Sciences  

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

472

Neutron Science Center  

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

473

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

474

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

475

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

476

Neutron Star Superfluidity, Dynamics and Precession  

E-Print Network [OSTI]

Basic rotational and magnetic properties of neutron superfluids and proton superconductors in neutron stars are reviewed. The modes of precession of the neutron superfluid are discussed in detail. We emphasize that at finite temperature, pinning of superfluid vortices does not offer any constraint on the precession. Any pinning energies can be surmounted by thermal activation and there exists a dynamical steady state in which the superfluid follows the precession of the crust at a small lag angle between the crust and superfluid rotation velocity vectors. At this small lag the system is far from the critical conditions for unpinning, even if the observed precession of the crust may entail a large angle between the figure axis and the crust's rotation velocity vector. We conclude that if long period modulations of pulse arrival times and pulse shapes observed in a pulsar like the PSR B1828-11 are due to the precession of the neutron star, this does not have any binding implications about the existence of pinning by flux lines or the existence of Type II superconductivity in the neutron star.

M. Ali Alpar

2005-05-04T23:59:59.000Z

477

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.

478

Science Education Programs | Neutron Science | ORNL  

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

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

479

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