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to obtain the most current and comprehensive results.


1

Polyneutron Chain Reactions  

SciTech Connect (OSTI)

Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of {approx}60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N{>=}12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between {sup 16}O and {sup A}Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound {sup 16}O {sup A}Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the {sup 16}O and {sup A}Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of {sup A}Nt is prevented by the buildup of Coulomb energy associated with transforming {sup A}Nt into {sup A}H in close proximity to {sup 16}O. Thus, it is possible that {sup 16}O {sup A}Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the {sup A}Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is {sup 18}O, a chain reaction can begin. The circumstances under which it can develop to produce macroscopic consequences depend on the mix of reactants and upon the appropriate removal of poisons and addition of fresh reactants to the reaction volume. With the proper conditions, there can be generation of sensible excess energy, helium, and other reaction products associated with the various cold fusion reactions.

John C. Fisher

2000-11-12T23:59:59.000Z

2

Nukes (notes on PFFP) Chain reactions  

E-Print Network [OSTI]

axis #12;Moore's Law data for memory and CPU #12;Back to Nuclear Physics The first selfNukes (notes on PFFP) Chain reactions: Must understand power laws and exponential growth "One grain = 8, 2 x 2 x 2 x 2 =16.....210=1024, ......264~1019 Will discuss and compare some aspects of nuclear

Browder, Tom

3

Low Energy Nuclear Reactions?  

E-Print Network [OSTI]

After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

CERN. Geneva; Faccini, R.

2014-01-01T23:59:59.000Z

4

DCHAIN V1.3. Radioactive Decay and Reaction Chain Calculations  

SciTech Connect (OSTI)

DCHAIN calculates the time-dependent daughter populations in radioactive decay and nuclear reaction chains. Chain members can have non-zero initial populations and be produced from the preceding chain member as the result of radioactive decay, a nuclear reaction, or both. Parent-daughter equilibrium times and relative activities at equilibrium can also be calculated. Program input can be supplied interactively or read from ASCII files.

East, L.V. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1994-04-01T23:59:59.000Z

5

Electrochemical Branched-DNA Assay for Polymerase Chain Reaction...  

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

Branched-DNA Assay for Polymerase Chain Reaction-Free Detection and Quantification of Oncogenes in Messenger RNA Electrochemical Branched-DNA Assay for Polymerase Chain...

6

Nuclear Reactions & Scaling Arguments 11 October 2011  

E-Print Network [OSTI]

Nuclear Reactions & Scaling Arguments 11 October 2011 Goals · Review nuclear reaction rates · Practice using scaling arguments Nuclear Reactions 1. Consider the simple reaction A k1 ---- B k2 ---- C = 3. #12;nuclear reactions & scaling arguments 2 3. Frequently, we approximate nuclear reaction rates

Militzer, Burkhard

7

Dual phase multiplex polymerase chain reaction  

DOE Patents [OSTI]

Highly specific and sensitive methods were developed for multiplex amplification of nucleic acids on supports such as microarrays. Based on a specific primer design, methods include five types of amplification that proceed in a reaction chamber simultaneously. These relate to four types of multiplex amplification of a target DNA on a solid support, directed by forward and reverse complex primers immobilized to the support and a fifth type--pseudo-monoplex polymerase chain reaction (PCR) of multiple targets in solution, directed by a single pair of unbound universal primers. The addition of the universal primers in the reaction mixture increases the yield over the traditional "bridge" amplification on a solid support by approximately ten times. Methods that provide multitarget amplification and detection of as little as 0.45-4.5.times.10.sup.-12 g (equivalent to 10.sup.2-10.sup.3 genomes) of a bacterial genomic DNA are disclosed.

Pemov, Alexander (Charlottesville, VA); Bavykin, Sergei (Darien, IL)

2008-10-07T23:59:59.000Z

8

Nuclear Reactions & Scaling Arguments 11 October 2011  

E-Print Network [OSTI]

Nuclear Reactions & Scaling Arguments 11 October 2011 Goals · Review nuclear reaction rates · Practice using scaling arguments Nuclear Reactions 1. Consider the simple reaction A k1 ---- B k2 ---- C rate for something like p + p D scales like n2 p. Think in microscopic terms. #12;nuclear reactions

Militzer, Burkhard

9

Integrated polymerase chain reaction/electrophoresis instrument  

DOE Patents [OSTI]

A new approach and instrument for field identification of micro-organisms and DNA fragments using a small and disposable device containing integrated polymerase chain reaction (PCR) enzymatic reaction wells, attached capillary electrophoresis (CE) channels, detectors, and read-out all on/in a small hand-held package. The analysis instrument may be made inexpensively, for example, of plastic, and thus is disposable, which minimizes cross contamination and the potential for false positive identification between samples. In addition, it is designed for multiple users with individual applications. The integrated PCR/CE is manufactured by the PCR well and CE channels are "stamped" into plastic depressions where conductive coatings are made in the wells and ends of the CE microchannels to carry voltage and current to heat the PCR reaction mixtures and simultaneously draw DNA bands up the CE channels. Light is transmitted through the instrument at appropriate points and detects PCR bands and identifies DNA fragments by size (retention time) and quantifies each by the amount of light generated as each phototransistor positioned below each CE channel detects a passing band. The instrument is so compact that at least 100 PCR/CE reactions/analyses can be performed easily on one detection device.

Andresen, Brian D. (Livermore, CA)

2000-01-01T23:59:59.000Z

10

Nuclear Reactions from Lattice QCD  

E-Print Network [OSTI]

One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculations of some of the low- energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.

Ral A. Briceo; Zohreh Davoudi; Thomas C. Luu

2014-11-25T23:59:59.000Z

11

Nuclear reactions from lattice QCD  

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

One of the overarching goals of nuclear physics is to rigorously compute properties of hadronic systems directly from the fundamental theory of strong interactions, Quantum Chromodynamics (QCD). In particular, the hope is to perform reliable calculations of nuclear reactions which will impact our understanding of environments that occur during big bang nucleosynthesis, the evolution of stars and supernovae, and within nuclear reactors and high energy/density facilities. Such calculations, being truly ab initio, would include all two-nucleon and three- nucleon (and higher) interactions in a consistent manner. Currently, lattice QCD provides the only reliable option for performing calculations of some of the low- energy hadronic observables. With the aim of bridging the gap between lattice QCD and nuclear many-body physics, the Institute for Nuclear Theory held a workshop on Nuclear Reactions from Lattice QCD on March 2013. In this review article, we report on the topics discussed in this workshop and the path planned to move forward in the upcoming years.

Briceno, Raul A. [JLAB; Davoudi, Zohreh; Luu, Thomas C.

2015-02-01T23:59:59.000Z

12

Astronomy with Radioactivities: Chapter 9, Nuclear Reactions  

E-Print Network [OSTI]

Nuclear reaction rates determine the abundances of isotopes in stellar burning processes. A multitude of reactions determine the reaction flow pattern which is described in terms of reaction network simulations. The reaction rates are determined by laboratory experiments supplemented by nuclear reaction and structure theory. We will discuss the experimental approach as well as the theoretical tools for obtaining the stellar reaction rates. A detailed analysis of a reaction is only possible for a few selected cases which will be highlighted in this section. The bulk of nuclear reaction processes is however described in terms of a statistical model approach, which relies on global nuclear structure and reaction parameters such as level density and mass and barrier penetration, respectively. We will discuss a variety of experimental facilities and techniques used in the field, this includes low energy stable beam experiments, measurements at radioactive beam accelerators, and neutron beam facilities.

M. Wiescher; T. Rauscher

2010-11-01T23:59:59.000Z

13

Securing the Sustainability of Global Medical Nuclear Supply Chains  

E-Print Network [OSTI]

, according to Kramer (2011), the South African Nuclear Energy Corp (Necsa) believes that the LEU productionSecuring the Sustainability of Global Medical Nuclear Supply Chains Through Economic Cost Recovery-17, 2012 University of Massachusetts Amherst Securing the Sustainability of Medical Nuclear Supply Chains

Nagurney, Anna

14

Securing the Sustainability of Global Medical Nuclear Supply Chains  

E-Print Network [OSTI]

with associated increased volumes of waste. Indeed, according to Kramer (2011), the South African Nuclear EnergySecuring the Sustainability of Global Medical Nuclear Supply Chains Through Economic Cost Recovery University of Massachusetts Amherst Securing the Sustainability of Medical Nuclear Supply Chains #12

Nagurney, Anna

15

Nuclear reaction rates and the primordial nucleosynthesis  

E-Print Network [OSTI]

The theoretical predictions of the primordial abundances of elements in the big-bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. We investigate the effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight. We have studied these yields as functions of evolution time or temperature. We find that using these new reaction rates results in only a little increase in helium mass fraction over that obtained previously in BBN calculations. This allows insights into the role of the nuclear reaction rates in the setting of the neutron-to-proton ratio during the BBN epoch. We observe that even with considerable nuclear physics uncertainties, most of these nuclear reactions have minimal effect on the standard BBN abundance yields of $^6$Li and $^7$Li.

Abhishek Mishra; D. N. Basu

2011-11-15T23:59:59.000Z

16

The Polymerase Chain Reaction and Branching Processes Fengzhu Sun  

E-Print Network [OSTI]

The Polymerase Chain Reaction and Branching Processes Fengzhu Sun Department of Mathematics, DRB is studied. We also study the distribution of the Hamming distance between two randomly chosen sequences long. The double-stranded DNA molecules are heated to near boiling temperature so that the double

Sun, Fengzhu - Sun, Fengzhu

17

Towards Quantum Transport for Nuclear Reactions  

E-Print Network [OSTI]

Nonequilibrium Green's functions represent a promising tool for describing central nuclear reactions. Even at the single-particle level, though, the Green's functions contain more information that computers may handle in the foreseeable future. In this study, we investigate whether all the information contained in the Green's functions is necessarily relevant when describing the time evolution of nuclear reactions. For this, we carry out mean-field calculations of slab collisions in one dimension.

Danielewicz, Pawel; Barker, Brent

2009-01-01T23:59:59.000Z

18

Towards Quantum Transport for Nuclear Reactions  

E-Print Network [OSTI]

Nonequilibrium Green's functions represent a promising tool for describing central nuclear reactions. Even at the single-particle level, though, the Green's functions contain more information that computers may handle in the foreseeable future. In this study, we investigate whether all the information contained in the Green's functions is necessarily relevant when describing the time evolution of nuclear reactions. For this, we carry out mean-field calculations of slab collisions in one dimension.

Pawel Danielewicz; Arnau Rios; Brent Barker

2009-06-26T23:59:59.000Z

19

Polymerase chain reaction system using magnetic beads for analyzing a sample that includes nucleic acid  

DOE Patents [OSTI]

A polymerase chain reaction system for analyzing a sample containing nucleic acid includes providing magnetic beads; providing a flow channel having a polymerase chain reaction chamber, a pre polymerase chain reaction magnet position adjacent the polymerase chain reaction chamber, and a post pre polymerase magnet position adjacent the polymerase chain reaction chamber. The nucleic acid is bound to the magnetic beads. The magnetic beads with the nucleic acid flow to the pre polymerase chain reaction magnet position in the flow channel. The magnetic beads and the nucleic acid are washed with ethanol. The nucleic acid in the polymerase chain reaction chamber is amplified. The magnetic beads and the nucleic acid are separated into a waste stream containing the magnetic beads and a post polymerase chain reaction mix containing the nucleic acid. The reaction mix containing the nucleic acid flows to an analysis unit in the channel for analysis.

Nasarabadi, Shanavaz (Livermore, CA)

2011-01-11T23:59:59.000Z

20

Polyneutrons as agents for cold nuclear reactions  

SciTech Connect (OSTI)

In this paper new nuclear reactions are described where polyneutrons exchange neutron pairs with charged nuclides, liberating substantial energy with only minor production of neutrons and tritium. It is postulated that polyneutrons are bound in a totally paired collective phase analogous to the Bardeen-Cooper-Schrieffer superconducting phase, that massive precursor hydrogen nuclides are bound in the same collective phase, and the polyneutrons are generated from precursor hydrogen by reaction with neutrons. The concentration and disposition of precursor hydrogen, of lithium, and of neutron-moderating and neutron-absorbing materials in the reactor environment emerge as key variables in cold nuclear reaction processes.

Fisher, J.C. (Thomas Paine Associates, Carpinteria, CA (United States))

1992-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Nuclear structure and reactions with stored nuclei  

SciTech Connect (OSTI)

The use of ion-storage rings is discussed for studies of nuclear reactions and structure, with emphasis on energetic beams of short- lived, radioactive nuclei. Aspects of internal versus external luminosity are considered as well as other issues connected with the inverse kinematics of reactions induced by a circulating beam of complex nuclei. Some of the physics motivation that is driving studies with radioactive beams is described.

Henning, W.

1996-12-31T23:59:59.000Z

22

Nuclear Reactions Used For Superheavy Element Research  

SciTech Connect (OSTI)

Some of the most fascinating questions about the limits of nuclear stability are confronted in the heaviest nuclei. How many more new elements can be synthesized? What are the nuclear and chemical properties of these exotic nuclei? Does the 'Island of Stability' exist and can we ever explore the isotopes inhabiting that nuclear region? This paper will focus on the current experimental research on the synthesis and characterization of superheavy nuclei with Z>112 from the Dubna/Livermore collaboration. Reactions using {sup 48}Ca projectiles from the U400 cyclotron and actinide targets ({sup 233,238}U, {sup 237}Np, {sup 242,244}Pu, {sup 243}Am, {sup 245,248}Cm, {sup 249}Cf) have been investigated using the Dubna Gas Filled Recoil Separator in Dubna over the last 8 years. In addition, several experiments have been performed to investigate the chemical properties of some of the observed longer-lived isotopes produced in these reactions. Some comments will be made on nuclear reactions used for the production of the heaviest elements. A summary of the current status of the upper end of the chart of nuclides will be presented.

Stoyer, Mark A. [N Division, Physical Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA 94550 (United States)

2008-04-17T23:59:59.000Z

23

Nuclear reactions used for superheavy element research  

SciTech Connect (OSTI)

Some of the most fascinating questions about the limits of nuclear stability are confronted in the heaviest nuclei. How many more new elements can be synthesized? What are the nuclear and chemical properties of these exotic nuclei? Does the 'Island of Stability' exist and can we ever explore the isotopes inhabiting that nuclear region? This paper will focus on the current experimental research on the synthesis and characterization of superheavy nuclei with Z > 112 from the Dubna/Livermore collaboration. Reactions using 48Ca projectiles from the U400 cyclotron and actinide targets ({sup 233,238}U, {sup 237}Np, {sup 242,244}Pu, {sup 243}Am, {sup 245,248}Cm, {sup 249}Cf) have been investigated using the Dubna Gas Filled Recoil Separator in Dubna over the last 8 years. In addition, several experiments have been performed to investigate the chemical properties of some of the observed longer-lived isotopes produced in these reactions. Some comments will be made on nuclear reactions used for the production of the heaviest elements. A summary of the current status of the upper end of the chart of nuclides will be presented.

Stoyer, M A

2008-02-26T23:59:59.000Z

24

Nested methylation-specific polymerase chain reaction cancer detection method  

DOE Patents [OSTI]

A molecular marker-based method for monitoring and detecting cancer in humans. Aberrant methylation of gene promoters is a marker for cancer risk in humans. A two-stage, or "nested" polymerase chain reaction method is disclosed for detecting methylated DNA sequences at sufficiently high levels of sensitivity to permit cancer screening in biological fluid samples, such as sputum, obtained non-invasively. The method is for detecting the aberrant methylation of the p16 gene, O 6-methylguanine-DNA methyltransferase gene, Death-associated protein kinase gene, RAS-associated family 1 gene, or other gene promoters. The method offers a potentially powerful approach to population-based screening for the detection of lung and other cancers.

Belinsky, Steven A. (Albuquerque, NM); Palmisano, William A. (Edgewood, NM)

2007-05-08T23:59:59.000Z

25

Enhancement Mechanisms of Low Energy Nuclear Reactions  

E-Print Network [OSTI]

The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle [1] and based on its different enhancement mechanisms of reaction rates are responsible for these processes [2]. The excitation and ionization of atoms may play role as a trigger for LENR. Superlow energy of external fields may stimulate LENR [3]. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics,... The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical ...

Gareev, F A

2005-01-01T23:59:59.000Z

26

First-Hand Recollections of the First Self-Sustaining Chain Reaction  

Broader source: Energy.gov [DOE]

Seventy years later, two of the men present at the first nuclear reaction recall the events of the memorable day.

27

Performance Improvements for Nuclear Reaction Network Integration  

E-Print Network [OSTI]

Aims: The aim of this work is to compare the performance of three reaction network integration methods used in stellar nucleosynthesis calculations. These are the Gear's backward differentiation method, Wagoner's method (a 2nd-order Runge-Kutta method), and the Bader-Deuflehard semi-implicit multi-step method. Methods: To investigate the efficiency of each of the integration methods considered here, a test suite of temperature and density versus time profiles is used. This suite provides a range of situations ranging from constant temperature and density to the dramatically varying conditions present in white dwarf mergers, novae, and x-ray bursts. Some of these profiles are obtained separately from full hydrodynamic calculations. The integration efficiencies are investigated with respect to input parameters that constrain the desired accuracy and precision. Results: Gear's backward differentiation method is found to improve accuracy, performance, and stability in integrating nuclear reaction networks. For te...

Longland, Richard; Jos, Jordi

2014-01-01T23:59:59.000Z

28

Investigations of nuclear structure and nuclear reactions induced by complex projectiles  

SciTech Connect (OSTI)

This report discusses research in the following areas: nuclear structure; fusion reactions near and below the barrier; incomplete fusion and fragmentation reactions; and instrumentation and analysis. (LSP).

Sarantites, D.G.

1990-01-01T23:59:59.000Z

29

Enhancement Mechanisms of Low Energy Nuclear Reactions  

E-Print Network [OSTI]

The review of possible stimulation mechanisms of LENR (low energy nuclear reaction) is represented. We have concluded that transmutation of nuclei at low energies and excess heat are possible in the framework of the modern physical theory - the universal resonance synchronization principle [1] and based on its different enhancement mechanisms of reaction rates are responsible for these processes [2]. The excitation and ionization of atoms may play role as a trigger for LENR. Superlow energy of external fields may stimulate LENR [3]. Investigation of this phenomenon requires knowledge of different branches of science: nuclear and atomic physics, chemistry and electrochemistry, condensed matter and solid state physics,... The results of this research field can provide a new source of energy, substances and technologies. The puzzle of poor reproducibility of experimental data is due to the fact that LENR occurs in open systems and it is extremely sensitive to parameters of external fields and systems. Classical reproducibility principle should be reconsidered for LENR experiments. Poor reproducibility and unexplained results do not means that the experiment is wrong. Our main conclusions:

F. A. Gareev; I. E. Zhidkova

2005-05-08T23:59:59.000Z

30

analysis nuclear reaction: Topics by E-print Network  

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

analysis nuclear reaction First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Nuclear Reactions Nuclear...

31

Theoretical descriptions of compound-nuclear reactions: open problems & challenges  

E-Print Network [OSTI]

Compound-nuclear processes play an important role for nuclear physics applications and are crucial for our understanding of the nuclear many-body problem. Despite intensive interest in this area, some of the available theoretical developments have not yet been fully tested and implemented. We revisit the general theory of compound-nuclear reactions, discuss descriptions of pre-equilibrium reactions, and consider extensions that are needed in order to get cross section information from indirect measurements.

Brett V. Carlson; Jutta E. Escher; Mahir S. Hussein

2014-03-04T23:59:59.000Z

32

Model microfluidic platform prototyping : design and fabrication of a Polymerase Chain Reaction (PCR) chip  

E-Print Network [OSTI]

Polymerase Chain Reaction (PCR) is a molecular biology method for the in vitro amplification of nucleic acid molecules, which has wide applications in the areas of genetics, medicine and biochemistry. MEMS technology offers ...

Kumar, Sumeet, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

33

Detection of Rhodococcus equi by polymerase chain reaction using species-specific, non-proprietary primers  

E-Print Network [OSTI]

Species-specific primers for the polymerase chain reaction (PCR) for the detection of Rhodococcus equi were developed. These primers were based on unique DNA fragments produced from R. equi reference strains and field isolates. Following random...

Arriaga, Jose Miguel

2002-01-01T23:59:59.000Z

34

Giovanni Raciti, in memoriam. NUCLEAR REACTIONS  

E-Print Network [OSTI]

) forma- tion of a quark-gluon plasma; (f) thermonuclear reactions; (g) and reactions with radioactive Electronic address: carlosbertulani@tamu-commmerce.edu C. Thermonuclear cross sections 22 IX. Reactions

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

35

Microscopic theory of protein folding rates. II. Local reaction coordinates and chain dynamics  

E-Print Network [OSTI]

Microscopic theory of protein folding rates. II. Local reaction coordinates and chain dynamics John involved in barrier crossing for protein folding are investigated in terms of the chain dynamics of the polymer backbone, completing the microscopic description of protein folding presented in the preceding

Takada, Shoji

36

Medical Nuclear Supply Chain Design: A Tractable Network Model and Computational Approach  

E-Print Network [OSTI]

Medical Nuclear Supply Chain Design: A Tractable Network Model and Computational Approach Anna, Economics and Law University of Gothenburg, Gothenburg, Sweden Ladimer S. Nagurney Department of Electrical of medical nuclear supply chains. Our focus is on the molybdenum supply chain, which is the most commonly

Nagurney, Anna

37

NUCLEAR WASTE VITRIFICATION EFFICIENCY COLD CAP REACTIONS  

SciTech Connect (OSTI)

The cost and schedule of nuclear waste treatment and immobilization are greatly affected by the rate of glass production. Various factors influence the performance of a waste-glass melter. One of the most significant, and also one of the least understood, is the process of batch melting. Studies are being conducted to gain fundamental understanding of the batch reactions, particularly those that influence the rate of melting, and models are being developed to link batch makeup and melter operation to the melting rate. Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass. The conversion of batch to glass consists of various chemical reactions, phase transitions, and diffusion-controlled processes. These include water evaporation (slurry feed contains as high as 60% water), gas evolution, the melting of salts, the formation of borate melt, reactions of borate melt with molten salts and with amorphous oxides (Fe{sub 2}O{sub 3} and Al{sub 2}O{sub 3}), the formation of intermediate crystalline phases, the formation of a continuous glass-forming melt, the growth and collapse of primary foam, and the dissolution of residual solids. To this list we also need to add the formation of secondary foam that originates from molten glass but accumulates on the bottom of the cold cap. This study presents relevant data obtained for a high-level-waste melter feed and introduces a one-dimensional (1D) mathematical model of the cold cap as a step toward an advanced three-dimensional (3D) version for a complete model of the waste glass melter. The 1D model describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, the model provides sensitivity analysis of the response of the cold cap to the batch makeup and melter conditions. The model demonstrates that batch foaming has a decisive influence on the rate of melting. Understanding the dynamics of the foam layer at the bottom of the cold cap and the heat transfer through it appears crucial for a reliable prediction of the rate of melting as a function of the melter-feed makeup and melter operation parameters. Although the study is focused on a batch for waste vitrification, the authors expect that the outcome will also be relevant for commercial glass melting.

KRUGER AA; HRMA PR; POKORNY R

2011-07-29T23:59:59.000Z

38

VII. Nuclear Chemistry (Chapter 17) A. Modes of radioactive decay, nuclear reactions, fission, fusion  

E-Print Network [OSTI]

40 VII. Nuclear Chemistry (Chapter 17) A. Modes of radioactive decay, nuclear reactions, fission #12;41 These masses are not exactly integer multiples due to nuclear interactions between the protons differences via the famous formula E = mc2 . Nuclear Fusion! For example, if you combine 2 protons and two

39

Charged-Particle Thermonuclear Reaction Rates: III. Nuclear Physics Input  

E-Print Network [OSTI]

The nuclear physics input used to compute the Monte Carlo reaction rates and probability density functions that are tabulated in the second paper of this series (Paper II) is presented. Specifically, we publish the input files to the Monte Carlo reaction rate code RatesMC, which is based on the formalism presented in the first paper of this series (Paper I). This data base contains overwhelmingly experimental nuclear physics information. The survey of literature for this review was concluded in November 2009.

Christian Iliadis; Richard Longland; Art Champagne; Alain Coc

2010-04-23T23:59:59.000Z

40

ChainReaction: uma Variante de Replicac~ao em Cadeia com Coer^encia Causal+  

E-Print Network [OSTI]

, o ChainReaction serve de base a um futuro sistema para Geo-replica¸c~ao (v´arios centros de dados desafios no desenho de sistemas de armazenamento de dados para suporte a aplica¸c~oes na nuvem. Por este propostas nos ´ultimos anos. Este artigo prop~oe um novo sis- tema de armazenamento de dados, chamado Chain

Rodrigues, Luís E.T.

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Physical Mechanism of Nuclear Reactions at Low Energies  

E-Print Network [OSTI]

The physical mechanism of nuclear reactions at low energies caused by spatial extension of electron is considered. Nuclear reactions of this type represent intra-electronic processes, more precisely, the processes occurring inside the area of basic localization of electron. Distinctive characteristics of these processes are defined by interaction of the own field produced by electrically charged matter of electron with free nuclei. Heavy nucleus, appearing inside the area of basic localization of electron, is inevitably deformed because of interaction of protons with the adjoining layers of electronic cloud, which may cause nuclear fission. If there occur "inside" electron two or greater number of light nuclei, an attractive force appears between the nuclei which may result in the fusion of nuclei. The intra-electronic mechanism of nuclear reactions is of a universal character. For its realization it is necessary to have merely a sufficiently intensive stream of free electrons, i.e. heavy electric current, and as long as sufficiently great number of free nuclei. This mechanism may operate only at small energies of translational motion of the centers of mass of nuclei and electron. Because of the existence of simple mechanism of nuclear reactions at low energies, nuclear reactor turns out to be an atomic delayed-action bomb which may blow up by virtue of casual reasons, as it has taken place, apparently, in Chernobyl. The use of cold nuclear reactions for production of energy will provide mankind with cheap, practically inexhaustible, and non-polluting energy sources.

V. P. Oleinik; Yu. D Arepjev

2003-06-09T23:59:59.000Z

42

Nuclear Many-Body Physics Where Structure And Reactions Meet  

E-Print Network [OSTI]

The path from understanding a simple reaction problem of scattering or tunneling to contemplating the quantum nuclear many-body system, where structure and continuum of reaction-states meet, overlap and coexist, is a complex and nontrivial one. In this presentation we discuss some of the intriguing aspects of this route.

Naureen Ahsan; Alexander Volya

2009-06-24T23:59:59.000Z

43

Theoretical studies in nuclear reactions and nuclear structure. Progress report  

SciTech Connect (OSTI)

Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon`s mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon`s mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon`s mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e{sup +}e{sup {minus}} problem and heavy ion dynamics.

Not Available

1992-05-01T23:59:59.000Z

44

Theoretical studies in nuclear reactions and nuclear structure  

SciTech Connect (OSTI)

Research in the Maryland Nuclear Theory Group focusses on problems in four basic areas of current relevance. Hadrons in nuclear matter; the structure of hadrons; relativistic nuclear physics and heavy ion dynamics and related processes. The section on hadrons in nuclear matter groups together research items which are aimed at exploring ways in which the properties of nucleons and the mesons which play a role in the nuclear force are modified in the nuclear medium. A very interesting result has been the finding that QCD sum rules supply a new insight into the decrease of the nucleon's mass in the nuclear medium. The quark condensate, which characterizes spontaneous chiral symmetry breaking of the late QCD vacuum, decreases in nuclear matter and this is responsible for the decrease of the nucleon's mass. The section on the structure of hadrons contains progress reports on our research aimed at understanding the structure of the nucleon. Widely different approaches are being studied, e.g., lattice gauge calculations, QCD sum rules, quark-meson models with confinement and other hedgehog models. A major goal of this type of research is to develop appropriate links between nuclear physics and QCD. The section on relativistic nuclear physics represents our continuing interest in developing an appropriate relativistic framework for nuclear dynamics. A Lorentz-invariant description of the nuclear force suggests a similar decrease of the nucleon's mass in the nuclear medium as has been found from QCD sum rules. Work in progress extends previous successes in elastic scattering to inelastic scattering of protons by nuclei. The section on heavy ion dynamics and related processes reports on research into the e{sup +}e{sup {minus}} problem and heavy ion dynamics.

Not Available

1992-05-01T23:59:59.000Z

45

Direct reactions for nuclear structure and nuclear astrophysics  

SciTech Connect (OSTI)

Direct reactions are powerful probes for studying the atomic nucleus. Modern direct reaction studies are illuminating both the fundamental nature of the nucleus and its role in nucleosynthetic processes occurring in the cosmos. This report covers experiments using knockout reactions on neutron-deficient fragmentation beams, transfer reactions on fission fragment beams, and theoretical sensitivity studies relating to the astrophysical r-process. Results from experiments on 108,106Sn at the NSCL, and on 131Sn at HRIBF are presented as well as the results from the nucleosynthesis study.

Jones, Katherine Louise [University of Tennessee

2014-12-18T23:59:59.000Z

46

Method of carbon chain extension using novel aldol reaction  

DOE Patents [OSTI]

Method of producing C.sub.8-C.sub.15 hydrocarbons comprising providing a ketone starting material; providing an aldol starting material comprising hydroxymethylfurfural; mixing the ketone starting material and the aldol starting material in a reaction in the presence of a proline-containing catalyst selected from the group consisting of Zn(Pro).sub.2, Yb(Pro).sub.2, and combinations thereof, or a catalyst having one of the structures (I), (II) or (III), and in the presence of a solvent, wherein the solvent comprises water and is substantially free of organic solvents, where (I), (II) and (III) respectively are: ##STR00001## where R.sub.1 is a C.sub.1-C.sub.6 alkyl moiety, X=(OH) and n=2. ##STR00002## In (III), X may be CH.sub.2, sulfur or selenium, M may be Zn, Mg, or a lanthanide, and R.sub.1 and R.sub.2 each independently may be a methyl, ethyl, phenyl moiety.

Silks, Louis A; Gordon, John C; Wu, Ruilan; Hangson, Susan Kloek

2013-08-13T23:59:59.000Z

47

Method of carbon chain extension using novel aldol reaction  

DOE Patents [OSTI]

Method of producing C.sub.8-C.sub.15 hydrocarbons. comprising providing a ketone starting material; providing an aldol starting material comprising chloromethylfurfural; mixing the ketone starting material and the aldol starting material in a reaction in the presence of a proline-containing catalyst selected from the group consisting of Zn(Pro).sub.2, Yb(Pro).sub.3, and combinations thereof, or a catalyst having one of the structures (I), (II) or (III), and in the presence of a solvent, wherein the solvent comprises water and is substantially free of organic solvents, where (I), (II) and (III) respectively are: ##STR00001## where R.sub.1 is a C.sub.1-C.sub.6 alkyl moiety, X=(OH) and n=2. ##STR00002## In (III), X may be CH.sub.2, sulfur or selenium, M may be Zn, Mg, or a lanthanide, and R.sub.1 and R.sub.2 each independently may be a methyl, ethyl, phenyl moiety.

Silks, Louis A; Gordon, John C; Wu, Ruilan; Hanson, Susan Kloek

2013-07-30T23:59:59.000Z

48

Enrico Fermi Achieves First Self Sustain Nuclear Chain Reaction | National  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia NanoparticlesSmartAffects the Future EnergyEnolSpectrometry Results

49

From Stopping to Viscosity in Nuclear Reactions  

SciTech Connect (OSTI)

Data on stopping in intermediate-energy central heavy-ion collisions are analyzed following transport theory based on the Boltzmann equation. In consequence, values of nuclear shear viscosity are inferred. The inferred values are significantly larger than obtained for free nucleon dispersion relations and free nucleon-nucleon cross sections.

Danielewicz, Pawel; Barker, Brent; Shi Lijun [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy Michigan State University, East Lansing, Michigan 48824 (United States)

2009-05-07T23:59:59.000Z

50

From Stopping to Viscosity in Nuclear Reactions  

E-Print Network [OSTI]

Data on stopping in intermediate-energy central heavy-ion collisions are analyzed following transport theory based on the Boltzmann equation. In consequence, values of nuclear shear viscosity are inferred. The inferred values are significantly larger than obtained for free nucleon dispersion relations and free nucleon-nucleon cross sections.

Danielewicz, P; Shi, L

2009-01-01T23:59:59.000Z

51

From Stopping to Viscosity in Nuclear Reactions  

E-Print Network [OSTI]

Data on stopping in intermediate-energy central heavy-ion collisions are analyzed following transport theory based on the Boltzmann equation. In consequence, values of nuclear shear viscosity are inferred. The inferred values are significantly larger than obtained for free nucleon dispersion relations and free nucleon-nucleon cross sections.

P. Danielewicz; B. Barker; L. Shi

2009-03-14T23:59:59.000Z

52

On the nuclear interaction. Potential, binding energy and fusion reaction  

E-Print Network [OSTI]

The nuclear interaction is responsible for keeping neutrons and protons joined in an atomic nucleus. Phenomenological nuclear potentials, fitted to experimental data, allow one to know about the nuclear behaviour with more or less success where quantum mechanics is hard to be used. A nuclear potential is suggested and an expression for the potential energy of two nuclear entities, either nuclei or nucleons, is developed. In order to estimate parameters in this expression, some nucleon additions to nuclei are considered and a model is suggested as a guide of the addition process. Coulomb barrier and energy for the addition of a proton to each one of several nuclei are estimated by taking into account both the nuclear and electrostatic components of energy. Studies on the binding energies of several nuclei and on the fusion reaction of two nuclei are carried out.

I. Casinos

2008-05-22T23:59:59.000Z

53

Pairing Effects in Nuclear Fusion Reaction  

E-Print Network [OSTI]

We simulate a heavy-ion collision using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) treating pairing correlation in the three-dimensional coordinate space. We apply the Cb-TDHFB to 22O+22O collision with a contact-type pairing energy functional, and compare results of Cb-TDHFB and TDHF to investigate the effects of pairing correlations in nuclear fusion. Our results seem to indicate that pairing effects do not increase the fusion cross section in this system.

Shuichiro Ebata; Takashi Nakatsukasa

2013-09-29T23:59:59.000Z

54

Nuclear waste vitrification efficiency: Cold cap reactions  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory | NationalJohnSecurityControls |NavyNuclearLife

55

Nuclear fusion in dense matter: Reaction rate and carbon burning  

E-Print Network [OSTI]

In this paper we analyze the nuclear fusion rate between equal nuclei for all five different nuclear burning regimes in dense matter (two thermonuclear regimes, two pycnonuclear ones, and the intermediate regime). The rate is determined by Coulomb barrier penetration in dense environments and by the astrophysical S-factor at low energies. We evaluate previous studies of the Coulomb barrier problem and propose a simple phenomenological formula for the reaction rate which covers all cases. The parameters of this formula can be varied, taking into account current theoretical uncertainties in the reaction rate. The results are illustrated for the example of the ^{12}C+^{12}C fusion reaction. This reaction is very important for the understanding of nuclear burning in evolved stars, in exploding white dwarfs producing type Ia supernovae, and in accreting neutron stars. The S-factor at stellar energies depends on a reliable fit and extrapolation of the experimental data. We calculate the energy dependence of the S-factor using a recently developed parameter-free model for the nuclear interaction, taking into account the effects of the Pauli nonlocality. For illustration, we analyze the efficiency of carbon burning in a wide range of densities and temperatures of stellar matter with the emphasis on carbon ignition at densities rho > 10^9 g/cc.

L. R. Gasques; A. V. Afanasjev; E. F. Aguilera; M. Beard; L. C. Chamon; P. Ring; M. Wiescher; D. G. Yakovlev

2005-06-16T23:59:59.000Z

56

Nuclear Physics A 587 (1995) 787-801 (3He,t) reactions on unstable nuclei  

E-Print Network [OSTI]

ELSEVIER NUCLEAR PHYSICS A Nuclear Physics A 587 (1995) 787-801 (3He,t) reactions on unstable,t) reactions on unstable nuclei theoretically. Since this charge-exchange reaction takes place on the nuclear in nuclear physics since we got a new tool, "beams of unstable nuclei" [1,2]. Many experimentalists have

Fernández de Córdoba, Pedro

57

E-Print Network 3.0 - alpha-induced nuclear reactions Sample...  

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

Davis Summary: Stephen Bolt Ben Lail Adam Davis 12;Nuclear History 1942 - First self sustaining nuclear... reaction occurs at University of Chicago 1945 - First atomic bomb...

58

E-Print Network 3.0 - astrophysical nuclear reactions Sample...  

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

Physics 2 Nuclear data for astrophysics Michael S. Smitha Summary: to determine thermonuclear reaction rates and Q-values to determine releases of nuclear energy. Astrophysical...

59

A string reaction coordinate for the folding of a polymer chain  

E-Print Network [OSTI]

We investigate the crystallization mechanism of a single, flexible homopolymer chain with short range attractions. For a sufficiently narrow attractive well, the system undergoes a first-order like freezing transition from an expanded disordered coil to a compact crystalline state. Based on a maximum likelihood analysis of committor values computed for configurations obtained by Wang-Landau sampling, we construct a non-linear string reaction coordinate for the coil-to-crystal transition. In contrast to a linear reaction coordinate, the string reaction coordinate captures the effect of different degrees of freedom controlling different stages of the transition. Our analysis indicates that a combination of the energy and the global crystallinity parameter Q6 provide the most accurate measure for the progress of the transition. While the crystallinity parameter Q6 is most relevant in the initial stages of the crystallization, the later stages are dominated by a decrease in the potential energy.

Leitold, Christian; Dellago, Christoph

2015-01-01T23:59:59.000Z

60

Sigma: Web Retrieval Interface for Nuclear Reaction Data  

SciTech Connect (OSTI)

The authors present Sigma, a Web-rich application which provides user-friendly access in processing and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The main interface includes browsing using a periodic table and a directory tree, basic and advanced search capabilities, interactive plots of cross sections, angular distributions and spectra, comparisons between evaluated and experimental data, computations between different cross section sets. Interactive energy-angle, neutron cross section uncertainties plots and visualization of covariance matrices are under development. Sigma is publicly available at the National Nuclear Data Center website at www.nndc.bnl.gov/sigma.

Pritychenko,B.; Sonzogni, A.A.

2008-06-24T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Sigma: Web Retrieval Interface for Nuclear Reaction Data  

SciTech Connect (OSTI)

We present Sigma, a Web-rich application which provides user-friendly access in processing and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The main interface includes browsing using a periodic table and a directory tree, basic and advanced search capabilities, interactive plots of cross sections, angular distributions and spectra, comparisons between evaluated and experimental data, computations between different cross section sets. Interactive energy-angle, neutron cross section uncertainties plots and visualization of covariance matrices are under development. Sigma is publicly available at the National Nuclear Data Center website at (http://www.nndc.bnl.gov/sigma)

Pritychenko, B. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)], E-mail: pritychenko@bnl.gov; Sonzogni, A.A. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

2008-12-15T23:59:59.000Z

62

DETERMINATION OF LOW-Z ELEMENTS IN ATMOSPHERIC AEROSOLS BY CHARGED-PARTICLE-INDUCED NUCLEAR REACTIONS  

E-Print Network [OSTI]

the nuclear reaction N14 (p,a)c 11 with low-energy protonsLOW-Z ELEMENTS IN ATMOSPHERIC AEROSOLS BY CHARGED-PARTICLE-INDUCED NUCLEAR REACTIONS Mark Steven Clemenson Energy

Clemenson, Mark Steven

2013-01-01T23:59:59.000Z

63

Delays associated with elementary processes in nuclear reaction simulations  

SciTech Connect (OSTI)

Scatterings, particularly those involving resonances, and other elementary processes do not happen instantaneously. In the context of semiclassical nuclear reaction simulations, we consider delays associated with an interaction for incident quantum wave packets. As a consequence, we express delays associated with elementary processes in terms of elements of the scattering matrix and phase shifts for elastic scattering. We show that, within the second order in density, the simulation must account for delays in scattering consistently with the mean field in order to properly model thermodynamic properties such as pressure and free-energy density. Delays associated with nucleon-nucleon and pion-nucleon scattering in free space are analyzed with their nontrivial energy dependence. Finally, an example of {ital s}-channel scattering of massless partons is studied, and scattering schemes in nuclear reaction simulations are investigated in the context of scattering delays. {copyright} {ital 1996 The American Physical Society.}

Danielewicz, P.; Pratt, S. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States)] [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); [Grand Accelerateur National dIons Lourds (GANIL), BP 5027, F-14021 Caen Cedex (France)

1996-01-01T23:59:59.000Z

64

Thermal distributions in stellar plasmas, nuclear reactions and solar neutrinos  

E-Print Network [OSTI]

The physics of nuclear reactions in stellar plasma is reviewed with special emphasis on the importance of the velocity distribution of ions. Then the properties (density and temperature) of the weak-coupled solar plasma are analysed, showing that the ion velocities should deviate from the Maxwellian distribution and could be better described by a weakly-nonexstensive (|q-1|solar neutrino fluxes, and on the pp neutrino energy spectrum, and analyse the consequences for the solar neutrino problem.

M. Coraddu; G. Kaniadakis; A. Lavagno; M. Lissia; G. Mezzorani; P. Quarati

1998-11-24T23:59:59.000Z

65

Time-dependent Green's functions approach to nuclear reactions  

SciTech Connect (OSTI)

Nonequilibrium Green's functions represent underutilized means of studying evolution of quantum many-body systems. In view of a rising computer power, an effort is underway to apply the Green's functions to the dynamics of central nuclear reactions. As the first step, mean-field evolution for the density matrix for colliding slabs is studied in one dimension. Strategy to extend the dynamics to correlations is described.

Rios, Arnau [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States); Danielewicz, Pawel [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 (United States)

2008-04-04T23:59:59.000Z

66

Time-dependent Green's functions approach to nuclear reactions  

E-Print Network [OSTI]

Nonequilibrium Green's functions represent underutilized means of studying the time evolution of quantum many-body systems. In view of a rising computer power, an effort is underway to apply the Green's functions formalism to the dynamics of central nuclear reactions. As the first step, mean-field evolution for the density matrix for colliding slabs is studied in one dimension. The strategy to extend the dynamics to correlations is described.

Arnau Rios; Pawel Danielewicz

2008-01-28T23:59:59.000Z

67

Neutrinoless $??$ decay nuclear matrix elements in an isotopic chain  

E-Print Network [OSTI]

We analyze nuclear matrix elements (NME) of neutrinoless double beta decay calculated for the Cadmium isotopes. Energy density functional methods including beyond mean field effects such as symmetry restoration and shape mixing are used. Strong shell effects are found associated to the underlying nuclear structure of the initial and final nuclei. Furthermore, we show that NME for two-neutrino double beta decay evaluated in the closure approximation, $M^{2\

Toms R. Rodrguez; Gabriel Martnez-Pinedo

2012-10-11T23:59:59.000Z

68

Microscopic Theory of Protein Folding Rates.II: Local Reaction Coordinates and Chain Dynamics  

E-Print Network [OSTI]

The motion involved in barrier crossing for protein folding are investigated in terms of the chain dynamics of the polymer backbone, completing the microscopic description of protein folding presented in the previous paper. Local reaction coordinates are identified as collective growth modes of the unstable fluctuations about the saddle-points in the free energy surface. The description of the chain dynamics incorporates internal friction (independent of the solvent viscosity) arising from the elementary isomerizations of the backbone dihedral angles. We find that the folding rate depends linearly on the solvent friction for high viscosity, but saturates at low viscosity because of internal friction. For $\\lambda$-repressor, the calculated folding rate prefactor, along with the free energy barrier from the variational theory, gives a folding rate that agrees well with the experimentally determined rate under highly stabilizing conditions, but the theory predicts too large a folding rate at the transition midpoint. This discrepancy obtained using a fairly complete quantitative theory inspires a new set of questions about chain dynamics, specifically detailed motions in individual contact formation.

John J. Portman; Shoji Takada; Peter G. Wolynes

2000-08-30T23:59:59.000Z

69

Mo Supply Chain for Nuclear Medicine Ladimer S. Nagurney  

E-Print Network [OSTI]

November 13, 2012 #12;Nuclear Medicine: Meeting Patient Needs with 99 Mo Ladimer S. Nagurney The 99 Mo of Physics Chemistry Biology Operations Research with some Biomedical Engineering thrown in at each step;Challenges Reactors are old nearing their end of life. Planned and unplanned shutdowns have created spot

Nagurney, Anna

70

EXFOR systems manual: Nuclear reaction data exchange format  

SciTech Connect (OSTI)

This document describes EXFOR, the exchange format designed to allow transmission of nuclear reaction data between the members of the Nuclear Data Centers Network. In addition to storing the data and its bibliographic information, experimental information, including source of uncertainties, is also compiled. The status and history of the data set is also included, e.g., the source of the data, any updates which have been made, and correlations to other data sets. The exchange format, as outlined, is designed to allow a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in an easily machine-readable format (for checking and indicating possible errors) and a format that can be read by personnel (for passing judgment on and correcting any errors indicated by the machine).

McLane, V. [ed.

1996-07-01T23:59:59.000Z

71

Experimental Observation of Nuclear Reactions in Palladium and Uranium  

SciTech Connect (OSTI)

By submitting various metals (Pd, U) containing hydrogen (from 2000 to 700 000 atoms of hydrogen for 1 000 000 atoms of the host metal) to the combined action of electrical currents and magnetic fields, we have observed a sizeable exothermal effect (from 0.1 to 8 W for 500 mg of metal used). This effect is beyond experimental errors, the energy output being typically 130 to 250{percent} of the energy input and not of chemical origin (exothermal effect in the range of 7000 MJ/mol of metal in the case of palladium and of 60 MJ/mol in the case of uranium). New chemical species also appear in the processes metals. It has been shown by a QED calculation that resonances of long lifetime (s), nuclear dimensions (fm), and low energy of formation (eV) could exist. This concept seems to look like the 'shrunken hydrogen atoms' proposed by various authors. It is indeed very different in two ways (a) being a metastable state, it needs energy to be formed (a few eV) and reverts to normal hydrogen after a few seconds, liberating back its energy of formation (it is thus not the source of the energy observed); (b) its formation can be described as the electron spin/proton nuclear spin interaction becoming first order in the lattice environment (whereas it is third order in a normal hydrogen atom). Moreover, we consider that the hydrex cannot yield a neutron because this reaction is strongly endothermic. To explain our results, we put forward the following working hypothesis: In a metal lattice and under proper conditions, the formation of such resonances (metastable state) could be favored. We propose to call them HYDREX, and we assume that they are actually formed in cold fusion (CF) and low-energy nuclear reaction (LENR) experiments. Once formed, a number of HYDREX could gather around a nucleus of the lattice to form a cluster of nuclear size and of very long life time compared to nuclear time (10{sup -22} s). In this cluster, nuclear rearrangements could take place, yielding mainly {sup 4}He, nuclei of atomic masses smaller than that of the host metal and small amounts of {sup 3}He and tritium. Because this nuclear rearrangement is a many-body reaction, the products formed should be stable products in their ground states, most of the reaction energy being carried away as kinetic energy by the alpha particles formed. The HYDREX hypothesis describes CF and LENR as fundamentally the same phenomenon, which we propose to call NUCLEAR CATALYSIS. Depending on the conditions of a CF or LENR experiment, the products formed may look very different, but the initial step is always the synthesis of HYDREX. When this synthesis is mastered, CF and LENR experiments should become fully reproducible.

J. Dufour; D. Murat; X. Dufour; J. Foos

2001-11-12T23:59:59.000Z

72

Global nuclear power supply chains and the rise of China's nuclear industry  

E-Print Network [OSTI]

China has embarked on a massive expansion of nuclear power that may fundamentally change the global nuclear industry, for better or for worse. Some industry observers argue that the incumbent nuclear power companies are ...

Metzler, Florian

2012-01-01T23:59:59.000Z

73

Ab Initio Nuclear Structure and Reaction Calculations for Rare Isotopes  

SciTech Connect (OSTI)

We have developed a novel ab initio symmetry-adapted no-core shell model (SA-NCSM), which has opened the intermediate-mass region for ab initio investigations, thereby providing an opportunity for first-principle symmetry-guided applications to nuclear structure and reactions for nuclear isotopes from the lightest p-shell systems to intermediate-mass nuclei. This includes short-lived proton-rich nuclei on the path of X-ray burst nucleosynthesis and rare neutron-rich isotopes to be produced by the Facility for Rare Isotope Beams (FRIB). We have provided ab initio descriptions of high accuracy for low-lying (including collectivity-driven) states of isotopes of Li, He, Be, C, O, Ne, Mg, Al, and Si, and studied related strong- and weak-interaction driven reactions that are important, in astrophysics, for further understanding stellar evolution, X-ray bursts and triggering of s, p, and rp processes, and in applied physics, for electron and neutrino-nucleus scattering experiments as well as for fusion ignition at the National Ignition Facility (NIF).

Draayer, Jerry P [Louisiana State University

2014-09-28T23:59:59.000Z

74

Securing the Sustainability of Global Medical Nuclear Supply Chains Through Economic Cost Recovery, Risk Management, and Optimization  

E-Print Network [OSTI]

Securing the Sustainability of Global Medical Nuclear Supply Chains Through Economic Cost Recovery of Business, Economics and Law University of Gothenburg, Gothenburg, Sweden Ladimer S. Nagurney Department of the complex operations of medical nuclear supply chains in the case of the radioisotope molybdenum

Nagurney, Anna

75

Probing anharmonic properties of nuclear surface vibration by heavy-ion fusion reactions  

E-Print Network [OSTI]

Describing fusion reactions between ^{16}O and ^{154}Dy and, between ^{16}O and ^{144}Sm by the $sd-$ and $sdf-$ interacting boson model, we show that heavy-ion fusion reactions are strongly affected by anharmonic properties of nuclear surface vibrations and nuclear shape, and thus provide a powerful method to study details of nuclear structure and dynamics.

N. Takigawa; K. Hagino; S. Kuyucak

1997-06-28T23:59:59.000Z

76

5. Energy Production and Transport 5.1 Energy Release from Nuclear Reactions  

E-Print Network [OSTI]

5. Energy Production and Transport 5.1 Energy Release from Nuclear Reactions As mentioned when we looked at energy generation, it is now known that most of the energy radiated by stars must be released by nuclear reactions. In this section we will consider why it is that energy can be released by nuclear

Peletier, Reynier

77

Low Energy Nuclear Reaction Research at the Naval Research Laboratory D.A. Kidwell1  

E-Print Network [OSTI]

Low Energy Nuclear Reaction Research at the Naval Research Laboratory D.A. Kidwell1 , D have explored the field of Low Energy Nuclear Reactions (LENR) for about eight years focusing energy (as heat) is produced ­ neither nuclear products nor transmutations have been firmly established

Noble, James S.

78

Redox reaction and foaming in nuclear waste glass melting  

SciTech Connect (OSTI)

This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process. Numerous redox reactions of waste glass components and potential feed additives, and the effects of other feed variables on these reactions are reviewed with regard to their potential effect on glass foaming. A major emphasis of this report is to examine the potential positive or negative aspects of adjusting feed with formic acid as opposed to other feed modification techniques including but not limited to use of other reducing agents. Feed modification techniques other than the use of reductants that should influence foaming behavior include control of glass melter feed pH through use of nitric acid. They also include partial replacement of sodium salts by lithium salts. This latter action (b) apparently lowers glass viscosity and raises surface tension. This replacement should decrease foaming by decreasing foam stability.

Ryan, J.L.

1995-08-01T23:59:59.000Z

79

The harmony between nuclear reactions and nuclear reactor structures and systems  

SciTech Connect (OSTI)

Advanced nuclear energy is one extremely viable approach for achieving the required goals. With its extraordinarily high energy density (both, per unit mass and per unit volume), it produces over seven orders of magnitude less waste than fossil fuels per unit of energy generated. Applying nano-technologies to nuclear reactors could potentially produce the extraordinary performance required. The actual nuclear reactors lack of performances, the complexity and hazard of the fuel cycle are in part due to the lack of understanding of the nature's laws related to energy distribution applied to fission products, and in part to the current technologic capabilities that make the economical optimum. In order to produce the desired increase of performances a novel multi-scale multi-physics and engineering approach have been developed, starting from the nuclear reactions involved, analyzing in detail the key features and requirements of the 'key players' in the process (neutrons, compound nucleus, fission products, transmutation products, decay radiation), the consequences of their interaction with matter. That complex interaction generates new reactions and new key-players (knock-on electrons, photons, phonons) that further interact with the matter represented by the nuclear fuel, cladding, cooling agents, structural materials and control systems. The understanding of this complexity of problems from fm-ps scale up to macro-system and mitigating all the requirements drives to that desired harmony that provides a safe energy delivery. (authors)

Popa-Simil, L. [LAVM LLC, Los Alamos, NM (United States)

2012-07-01T23:59:59.000Z

80

A comparative analysis of accident risks in fossil, hydro, and nuclear energy chains  

SciTech Connect (OSTI)

This study presents a comparative assessment of severe accident risks in the energy sector, based on the historical experience of fossil (coal, oil, natural gas, and LPG (Liquefied Petroleum Gas)) and hydro chains contained in the comprehensive Energy-related Severe Accident Database (ENSAD), as well as Probabilistic Safety Assessment (PSA) for the nuclear chain. Full energy chains were considered because accidents can take place at every stage of the chain. Comparative analyses for the years 1969-2000 included a total of 1870 severe ({>=} 5 fatalities) accidents, amounting to 81,258 fatalities. Although 79.1% of all accidents and 88.9% of associated fatalities occurred in less developed, non-OECD countries, industrialized OECD countries dominated insured losses (78.0%), reflecting their substantially higher insurance density and stricter safety regulations. Aggregated indicators and frequency-consequence (F-N) curves showed that energy-related accident risks in non-OECD countries are distinctly higher than in OECD countries. Hydropower in non-OECD countries and upstream stages within fossil energy chains are most accident-prone. Expected fatality rates are lowest for Western hydropower and nuclear power plants; however, the maximum credible consequences can be very large. Total economic damages due to severe accidents are substantial, but small when compared with natural disasters. Similarly, external costs associated with severe accidents are generally much smaller than monetized damages caused by air pollution.

Burgherr, P.; Hirschberg, S. [Paul Scherrer Institute, Villigen (Switzerland)

2008-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Repulsive aspects of pairing correlation in nuclear fusion reaction  

E-Print Network [OSTI]

Numerical simulation on nuclear collisions are performed using the canonical-basis time-dependent Hartree-Fock-Bogoliubov theory (Cb-TDHFB) in the three-dimensional coordinate space. Comparing results of the Cb-TDHFB and the conventional time-dependent Hartree-Fock (TDHF) calculations, we study effects of the pairing correlation on fusion reaction of $^{22}$O+$^{22}$O, $^{52}$Ca+$^{52}$Ca, and $^{22}$O+$^{52}$Ca, using the Skyrme SkM$^*$ functional and a contact-type pairing energy functional. Although current results are yet preliminary, they may suggest that the pairing correlation could hinder the fusion probability at energies in the vicinity of the Coulomb barrier height. We also perform a calculation for heavier nuclei, $^{96}$Zn+$^{124}$Sn, which seems to suggest a similar hindrance effect.

Ebata, Shuichiro

2014-01-01T23:59:59.000Z

82

Nuclear transparency in 90c.m. quasielastic A,,p,2p... reactions  

E-Print Network [OSTI]

Nuclear transparency in 90c.m. ° quasielastic A,,p,2p... reactions J. Aclander,7 J. Alster,7 G Synchrotron of BNL to measure the nuclear transparency of nuclei measured in the A p,2p quasielastic of the energy dependence of the nuclear transparency. In E850 the angular dependence of the nuclear transparency

Christensen, Nelson

83

The US nuclear reaction data network. Summary of the first meeting, March 13 & 14 1996  

SciTech Connect (OSTI)

The first meeting of the US Nuclear Reaction Data Network (USNRDN) was held at the Colorado School of Mines, March 13-14, 1996 chaired by F. Edward Cecil. The Agenda of the meeting is attached. The Network, its mission, products and services; related nuclear data and data networks, members, and organization are described in Attachment 1. The following progress reports from the members of the USNRDN were distributed prior to the meeting and are given as Attachment 2. (1) Measurements and Development of Analytic Techniques for Basic Nuclear Physics and Nuclear Applications; (2) Nuclear Reaction Data Activities at the National Nuclear Data Center; (3) Studies of nuclear reactions at very low energies; (4) Nuclear Reaction Data Activities, Nuclear Data Group; (5) Progress in Neutron Physics at Los Alamos - Experiments; (6) Nuclear Reaction Data Activities in Group T2; (7) Progress Report for the US Nuclear Reaction Data Network Meeting; (8) Nuclear Astrophysics Research Group (ORNL); (9) Progress Report from Ohio University; (10) Exciton Model Phenomenology; and (11) Progress Report for Coordination Meeting USNRDN.

NONE

1996-03-01T23:59:59.000Z

84

Charged particle assisted nuclear reactions in solid state environment: renaissance of low energy nuclear physics  

E-Print Network [OSTI]

The features of electron assisted neutron exchange processes in crystalline solids are survayed. It is stated that, contrary to expectations, the cross section of these processes may reach an observable magnitude even in the very low energy case because of the extremely huge increment caused by the Coulomb factor of the electron assisted processes and by the effect of the crystal-lattice. The features of electron assisted heavy charged particle exchange processes, electron assisted nuclear capure processes and heavy charged particle assisted nuclear processes are also overviewed. Experimental observations, which may be related to our theoretical findings, are dealt with. The anomalous screening phenomenon is related to electron assisted neutron and proton exchange processes in crystalline solids. A possible explanation of observations by Fleischmann and Pons is presented. The possibility of the phenomenon of nuclear transmutation is qualitatively explained with the aid of usual and charged particle assisted reactions. The electron assisted neutron exchange processes in pure $Ni$ and $Li-Ni$ composite systems (in the Rossi-type E-Cat) are analyzed and it is concluded that these reactions may be responsible for recent experimental observations.

Pter Klmn; Tams Keszthelyi

2015-02-05T23:59:59.000Z

85

REVISTA MEXICANA DE FISICA S 54 (3) 1118 DICIEMBRE 2008 Nuclear astrophysics from direct reactions  

E-Print Network [OSTI]

, and energy production in stars. 1.1. Nuclear reaction rates Low energy nuclear astrophysics requires plays a major role for the production of high energy neutrinos from the -decay of 8 B. These neutrinos reactions C. Bertulani Department of Physics, Texas A&M University, Commerce, TX 75429, USA, e

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

86

The role of nuclear reactions and -particle transport in the dynamics of inertial confinement fusion capsules  

E-Print Network [OSTI]

The role of nuclear reactions and -particle transport in the dynamics of inertial confinement fusion capsules Josselin Garnier1,a and Catherine Cherfils-Clérouin2 1 Laboratoire de Probabilités et the energy released by nuclear reactions, a nonlocal model for the -particle energy deposition process

Garnier, Josselin

87

DEVELOPMENT OF LASSA: A LARGE AREA SILICON STRIP ARRAY FOR NUCLEAR REACTION STUDIES AND  

E-Print Network [OSTI]

DEVELOPMENT OF LASSA: A LARGE AREA SILICON STRIP ARRAY FOR NUCLEAR REACTION STUDIES family for their support during my journey. My parents, sister and parents-in-law who never failed ARRAY FOR NUCLEAR REACTION STUDIES AND INVESTIGATION OF MID-VELOCITY FRAGMENT EMISSION IN 114 Cd + 92

de Souza, Romualdo T.

88

Nuclear spin selection rules in chemical reactions by angular momentum algebra  

E-Print Network [OSTI]

Nuclear spin selection rules in chemical reactions by angular momentum algebra Takeshi Oka of the representations of the permutation­inversion group for both nuclear spin and rovibronic coordinate wavefunctions, those of the rotation group for nuclear spin wavefunction only are used. The method allows more

Oka, Takeshi

89

PHYSICAL REVIEW C 72, 025806 (2005) Nuclear fusion in dense matter: Reaction rate and carbon burning  

E-Print Network [OSTI]

PHYSICAL REVIEW C 72, 025806 (2005) Nuclear fusion in dense matter: Reaction rate and carbon August 2005) In this paper we analyze the nuclear fusion rates among equal nuclei for all five different nuclear burning regimes in dense matter (two thermonuclear regimes, two pycnonuclear ones

90

Stimulated Emission of Radiation in a Nuclear Fusion Reaction  

E-Print Network [OSTI]

This letter claims that process of stimulated emission of radiation can be used to induce a fusion reaction in a HD molecule to produce Helium-3. An experimental set-up for this reaction is presented. It is proposed to study the technical potential of this reaction as an energy amplifier.

Michael Duren

1999-04-06T23:59:59.000Z

91

I. Nuclear Production Reaction and Chemical Isolation Procedure for 240Am II. New Superheavy Element Isotopes: 242Pu(48Ca,5n)285-114  

E-Print Network [OSTI]

the low excitation energy of the nuclear reaction results inof nuclear fusion reactions at low excitation energies withlow (1 eV 100 keV) neutron energies. It goes on to discuss the nuclear reactions

Ellison, Paul Andrew

2011-01-01T23:59:59.000Z

92

The nuclear fusion reaction rate based on relativistic equilibrium velocity distribution  

E-Print Network [OSTI]

The Coulomb barrier is in general much higher than thermal energy. Nuclear fusion reactions occur only among few protons and nuclei with higher relative energies than Coulomb barrier. It is the equilibrium velocity distribution of these high-energy protons and nuclei that participates in determining the rate of nuclear fusion reactions. In the circumstance it is inappropriate to use the Maxwellian velocity distribution for calculating the nuclear fusion reaction rate. We use the relativistic equilibrium velocity distribution for this purpose. The rate based on the relativistic equilibrium velocity distribution has a reduction factor with respect to that based on the Maxwellian distribution, which factor depends on the temperature, reduced mass and atomic numbers of the studied nuclear fusion reactions. This signifies much to the solar neutrino problem.

Jian-Miin Liu

2002-10-20T23:59:59.000Z

93

Nuclear Structure and Reactions (Quantum Monte Carlo, Lanczos Methods, Density Functional Methods), June 6 10  

E-Print Network [OSTI]

Nuclear Structure and Reactions (Quantum Monte Carlo, Lanczos Methods, Density Functional Methods systems: nuclei and the unitary Fermi gas" Thursday, June 9 10:00 am Stefano Gandolfi "Ab

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

94

A comparison of three serological assays, protein gel electrophoresis and the polymerase chain reaction for the detection of Chlomydia psittici infections in pet birds  

E-Print Network [OSTI]

: complement fixation (CF), elementary body agglutination (EBA), immunofluorescent antibodies (IFA), polymerase chain reaction (PCR), protein gel electrophoresis. Comparison of the results obtained showed a strong statistical association between EBA to CF, PCR...

Hofle, Michael David

2012-06-07T23:59:59.000Z

95

PoS(Bormio2013)041 Direct Reactions for Nuclear Astrophysics  

E-Print Network [OSTI]

PoS(Bormio2013)041 Direct Reactions for Nuclear Astrophysics C.A. Bertulani Department of Physics at the small astrophysical energies. In recent years indirect reaction methods have been developed and applied to extract low-energy astrophysical S-factors. These methods require a combination of new experimental

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

96

Compilation and R-matrix analysis of Big Bang nuclear reaction rates  

E-Print Network [OSTI]

We use the R-matrix theory to fit low-energy data on nuclear reactions involved in Big Bang nucleosynthesis. A special attention is paid to the rate uncertainties which are evaluated on statistical grounds. We provide S factors and reaction rates in tabular and graphical formats.

Pierre Descouvemont; Abderrahim Adahchour; Carmen Angulo; Alain Coc; Elisabeth Vangioni-Flam

2004-07-06T23:59:59.000Z

97

Screened Coulomb potentials for astrophysical nuclear fusion reactions  

E-Print Network [OSTI]

The electron-screening acceleration of laboratory fusion reactions at astrophysical energies is an unsolved problem of great importance to astrophysics. That effect is modeled here by considering the fusion of hydrogen-like atoms whose electron probability density is used in Poisson's equation in order to derive the corresponding screened Coulomb potential energy. That way atomic excitations and deformations of the fusing atoms can be taken into account. Those potentials are then treated semiclassically in order to obtain the screening (accelerating) factor of the reaction. By means of the proposed model the effect of a superstrong magnetic field on laboratory Hydrogen fusion reactions is investigated here for the first time showing that, despite the considerable increase in the cross section of the $% dd$ reaction, the $pp$ reaction is still too slow to justify experimentation. The proposed model is finally applied on the $H^{2}(d,p) H^{3}$ fusion reaction describing satisfactorily the experimental data although some ambiguity remains regarding the molecular nature of the deuteron target. Notably, the present method gives a sufficiently high screening energy for Hydrogen fusion reactions so that the take-away energy of the spectator nucleus can also be taken into account.

Theodore E. Liolios

2000-09-04T23:59:59.000Z

98

[Reaction mechanism studies of heavy ion induced nuclear reactions]. Annual progress report, [January 1992--February 1993  

SciTech Connect (OSTI)

Completed work is summarized on the topics of excitation energy division in deep-inelastic reactions and the onset of multifragmentation in La-induced reactions at E/A = 45 MeV. Magnetic fields are being calculated for the PHOBOS detector system, a two-arm multiparticle spectrometer for studying low-transverse-momentum particles produced at the Relativistic Heavy Ion Collider. The Maryland Forward Array is being developed for detection of the reaction products from very peripheral collisions; it consists of two individual units of detectors: the annular silicon detector in front and the plastic phoswich detector at back.

Mignerey, A.C.

1993-02-01T23:59:59.000Z

99

The Effective Energy in Nuclear Reactions from Exact Probability by Using the WKB Approximation  

SciTech Connect (OSTI)

The transmission coefficient through a Coulomb barrier in nuclear reaction is obtained by using the WKB approximation. Hence, we can determine the exact tunneling probability from this method. This probability can be applied in calculating the astrophysical thermonuclear reaction rates. One of the most important aspects in calculating the reaction rates is the value of the most effective energy, E{sub 0} for the reaction to occur. The Gamow peak produces a nonlinear equation that is solved iteratively to produce E{sub 0}.

Aziz, Azni Abdul; Yusof, Norhasliza; Kassim, Hasan Abu [Physics Department, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2008-05-20T23:59:59.000Z

100

Absorption-Fluctuation Theorem for Nuclear Reactions: Brink-Axel, Incomplete Fusion and All That  

E-Print Network [OSTI]

We discuss the connection between absorption, averages and fluctuations in nuclear reactions. The fluctuations in the entrance channel result in the compound nucleus, Hauser-Feshbach, cross section, the fluctuations in the intermediate channels, result in modifications of multistep reaction cross sections, while the fluctuations in the final channel result in hybrid cross sections that can be used to describe incomplete fusion reactions. We discuss the latter in details and comment on the validity of the assumptions used in the develpoment of the Surrogate method. We also discuss the theory of multistep reactions with regards to intermediate state fluctuations and the energy dependence and non-locality of the intermediate channels optical potentials.

M. S. Hussein

2008-01-13T23:59:59.000Z

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


101

arXiv:0802.3463v1[nucl-th]23Feb2008 Nuclear astrophysics from direct reactions  

E-Print Network [OSTI]

, and energy production in stars. A. Nuclear reaction rates Low energy nuclear astrophysics requires the knowl Be(p, ) 8 B plays a major role for the production of high energy neutrinos from the -decay of 8 B Department of Physics, Texas A&M University, Commerce, TX 75429, USA Accurate nuclear reaction rates

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

102

NUCLEAR REACTION AND STRUCTURE DATABASES OF THE NATIONAL NUCLEAR DATA CENTER.  

SciTech Connect (OSTI)

We discuss nuclear data resources of the National Nuclear Data Center (NNDC) of relevance to nuclear astrophysics applications. These resources include databases, tools and powerful web service at www.nndc.bnl.gov. Our objective is to provide an overview of nuclear databases, related products and demonstrate nuclear astrophysics potential of the ENDF/B-VII beta2 library. A detailed discussion on the Maxwellian neutron capture cross sections obtained from the ENDF/B-VII beta2 library is presented.

PRITYCHENKO, B.; HERMAN, M.W.; MUGHABGHAB, S.F.; OBLOZINSKY, P.; SONZOGNI, A.A.

2006-06-23T23:59:59.000Z

103

Low-Energy Nuclear Reactions of Protons in Host Metals at Picometre Distance  

SciTech Connect (OSTI)

A review is given for the explanation of the measurements of Miley et al. of a fully reproducible generation of nuclei of the whole periodic table by protons in host metals during a several-weeks reaction. Similar low-energy nuclear reactions (LENR) were observed by other groups. The fact that the heavy nuclides are not due to pollution can be seen from the fact that such very rare elements as thulium and terbium were detected by unique K-shell X-ray spectra. The nuclear reaction energy goes into the heavy nuclei as measured from much bigger traces in CR39 than from alphas. The fact that any reaction of the protons results in stable daughter nuclei is confirmed by the fact that the highest energy gain is resulting with stable reaction products. This has been explained in Ref. 2, and the energy gain for the heavy element generation by a compound reaction was discussed. The explanation is based on the model of the authors from 1989 to assume free motion of the protons contrary to localized crystalline states. A relation of the reaction time U on distance d of the reacting nuclei by a power law with an exponent 34.8 was derived. Based on few reproducible D-D reactions, a reaction time near the range of megaseconds and a reaction distance of nanometers was concluded. A splendid confirmation of the picometre-megasecond reactions was achieved by Li et al. from his direct quantum mechanical calculations of the hot fusion D-T reactions based on a one-step selective resonance tunneling model. Li et al. were able for the first time to derive the cross sections of the hot fusion. Li's application to picometre distance showed megasecond reaction times with no neutron or gamma emission. Because of the imaginary part in the Schroedinger potential, the problem of the level width is reduced by damping.

Heinrich Hora; George H. Miley; Jak C. Kelly

2000-11-12T23:59:59.000Z

104

Experimental study of nuclear fusion reactions in muonic molecular systems  

SciTech Connect (OSTI)

Since the pioneering discovery of the muon catalysis by Alvarez [L. W. Alvarez, K. Brander, F. S. Crawford, et al., Phys. Rev. 105, 1127 (1957)], considerable efforts were aimed at observation of various fusion processes. Results of these studies facilitated understanding the properties of lightest nuclei and dynamics of low-energy fusion reactions. There still remain unsolved theoretical and experimental problems, especially in case of pt fusion.

Bogdanova, L. N., E-mail: ludmila@itep.ru [Institute for Theoretical and Experimental Physics (Russian Federation)

2013-03-15T23:59:59.000Z

105

Isovector spin observables in nuclear charge reactions at LAMPF  

SciTech Connect (OSTI)

LAMPF has undertaken a major development program to upgrade facilities for nuclear charge-exchange studies at intermediate energies. The major components of this upgrade are a medium-resolution spectrometer and neutron time-of-flight system for good resolution (delta E < 1 MeV) charge-exchange perograms in (n,p) and (p,n) respectively. Major emphasis is placed on polarization phenomena using polarized beams and analyzing the polarization of the outgoing particle.

McClelland, J.B.

1988-01-01T23:59:59.000Z

106

Ranking the importance of nuclear reactions for activation and transmutation events  

E-Print Network [OSTI]

Pathways-reduced analysis is one of the techniques used by the Fispact-II nuclear activation and transmutation software to study the sensitivity of the computed inventories to uncertainties in reaction cross-sections. Although deciding which pathways are most important is very helpful in for example determining which nuclear data would benefit from further refinement, pathways-reduced analysis need not necessarily define the most critical reaction, since one reaction may contribute to several different pathways. This work examines three different techniques for ranking reactions in their order of importance in determining the final inventory, viz. a pathways based metric (PBM), the direct method and one based on the Pearson correlation coefficient. Reasons why the PBM is to be preferred are presented.

Arter, Wayne; Relton, Samuel D; Higham, Nicholas J

2015-01-01T23:59:59.000Z

107

Activation cross sections of $?$-particle induced nuclear reactions on hafnium and deuteron induced nuclear reaction on tantalum: production of $^{178}$W/$^{178m}$Ta generator  

E-Print Network [OSTI]

In the frame of a systematic study of charged particle production routes of medically relevant radionuclei, the excitation function for indirect production of $^{178m}$Ta through $^{nat}$Hf($\\alpha$,xn)$^{178}$W-$^{178m}$Ta nuclear reaction was measured for the first time up to 40 MeV. In parallel, the side reactions $^{nat}$Hf($\\alpha$,x)$^{179,177,176,175}$W, $^{183,182,178g,177,176,175}$Ta, $^{179m,177m,175}$Hf were also assessed. Stacked foil irradiation technique and $\\gamma$-ray spectrometry were used. New experimental cross section data for the $^{nat}$Ta(d,xn)$^{178}$W reaction are also reported up to 40 MeV. The measured excitation functions are compared with the results of the ALICE-IPPE, and EMPIRE nuclear reaction model codes and with the TALYS 1.4 based data in the TENDL-2013 library. The thick target yields were deduced and compared with yields of other charged particle ((p,4n), (d,5n) and ($^3$He,x)) production routes for $^{178}$W.

F. Trk'anyi; S. Tak'acs; F. Ditri; A. Hermanne; A. V. Ignatyuk; M. S. Uddin

2014-12-01T23:59:59.000Z

108

PoS(NIC-IX)040 Direct reactions in/for astrophysics  

E-Print Network [OSTI]

on the opposite ends of the energy scale of nuclear reactions: (a) the very high and (b) the very low relative scale are the low energy reactions of importance for stellar evolution. Chains of nuclear reactions lead reactions methods have been developed and applied to extract low-energy astrophysical S

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

109

Determining the density dependence of the nuclear symmetry energy using heavy-ion reactions  

E-Print Network [OSTI]

We review recent progress in the determination of the subsaturation density behavior of the nuclear symmetry energy from heavy-ion collisions as well as the theoretical progress in probing the high density behavior of the symmetry energy in heavy-ion reactions induced by high energy radioactive beams. We further discuss the implications of these results for the nuclear effective interactions and the neutron skin thickness of heavy nuclei.

Lie-Wen Chen; Che Ming Ko; Bao-An Li; Gao-Chan Yong

2007-11-12T23:59:59.000Z

110

Application of Dissolution Dynamic Nuclear Polarization to the Characterization of Reactions Involving Large Molecules  

E-Print Network [OSTI]

Determination of the pseudo first order reaction rate constant k?, using integrals from each peak of styrene monomer in the three reactions. ........ 88 IV-3 Apparent relaxation rates of the anionic living ends of polystyrene (rP), of polystyrene..., and of styrene monomer (rM). a Both carbons #5 are equivalent in styrene monomer.b These values are overall relaxation rates for the standard polystyrene, not the rates for the specific living chain ends. Since signals of atoms #3 & #4 in polystyrene were...

Lee, Youngbok

2013-03-13T23:59:59.000Z

111

Nuclear Matter Incompressibility Effect on the Cross Section of Fusion Reactions with a weakly bound projectile  

E-Print Network [OSTI]

Fusion reactions with a weakly bound projectile are studied using the double-folding model along with a repulsive interaction modifying term. Using this modified potential, including nuclear matter incompressibility effects, the fusion reaction cross sections and suppression parameters are calculated for 9Be +209Bi,208Pb,29Si and 27Al reactions. The results show that applying these effects at energies near the Coulomb barrier improves the agreement between the calculated and experimental cross sections, and modifies the mean values of the suppression parameter.

S. A. Seyyedi; H. Golnarkar

2015-01-19T23:59:59.000Z

112

Refined scenario of standard Big Bang nucleosynthesis allowing for nonthermal nuclear reactions in the primordial plasma  

SciTech Connect (OSTI)

The standard scenario of big bang nucleosynthesis (BBN) is generalized to take into account nonthermal nuclear reactions in the primordial plasma. These reactions are naturally triggered in the BBN epoch by fast particles generated in various exoergic processes. It is found that, although such particles can appreciably enhance the rates of some individual reactions, their influence on the whole process of element production is not significant. The nonthermal corrections to element abundances are obtained to be 0.1% ({sup 3}H), -0.03% ({sup 7}Li), and 0.34 %-0.63% (CNO group).

Voronchev, Victor T.; Nakao, Yasuyuki; Nakamura, Makoto; Tsukida, Kazuki [Institute of Nuclear Physics, Moscow State University, Moscow 119991 (Russian Federation); Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Motooka, Fukuoka 819-0395 (Japan); Division of Advanced Plasma Research, Japan Atomic Energy Agency, 2-166 Oaza-Obuchi-Aza-Omotedate, Rokkasho, Kamikita, Aomori 039-3212 (Japan); Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, Motooka, Fukuoka 819-0395 (Japan)

2012-11-12T23:59:59.000Z

113

Nuclear Matter Incompressibility Effect on the Cross Section of Fusion Reactions with a weakly bound projectile  

E-Print Network [OSTI]

Fusion reactions with a weakly bound projectile are studied using the double-folding model along with a repulsive interaction modifying term. Using this modified potential, including nuclear matter incompressibility effects, the fusion reaction cross sections and suppression parameters are calculated for 9Be +209Bi,208Pb,29Si and 27Al reactions. The results show that applying these effects at energies near the Coulomb barrier improves the agreement between the calculated and experimental cross sections, and modifies the mean values of the suppression parameter.

Seyyedi, S A

2015-01-01T23:59:59.000Z

114

PHYSICS OF NUCLEAR REACTORS Nuclear reactions and cross sections 1-10  

E-Print Network [OSTI]

neutron wavelength, D is given by: cE mM Mm 2 + = h D , (1.22) 1 Bell and Glasstone, Nuclear Reactor

Danon, Yaron

115

Relativistic equilibrium velocity distribution, nuclear fusion reaction rate and the solar neutrino problem  

E-Print Network [OSTI]

In solar interior, it is the equilibrium velocity distribution of few high-energy protons and nuclei that participates in determining nuclear fusion reaction rates. So, it is inappropriate to use the Maxwellian velocity distribution to calculate the rates of solar nuclear fusion reactions. We have to use the relativistic equilibrium velocity distribution for the purpose. The nuclear fusion reaction rate based on the relativistic equilibrium velocity distribution has a reduction factor with respect to that based on the Maxwellian distribution. The reduction factor depends on the temperature, reduced mass and atomic numbers of the studied nuclear fusion reactions, in other words, it varies with the sort of neutrinos. Substituting the relativistic equilibrium velocity distribution for the Maxwellian distribution is not important for the calculation of solar sound speeds. The relativistic equilibrium velocity distribution, if adopted in standard solar models, will lower solar neutrino fluxes and change solar neutrino energy spectra but maintain solar sound speeds. This velocity distribution is possibly a solution to the solar neutrino problem.

Jian-Miin Liu

2003-07-07T23:59:59.000Z

116

Temperature dependence of modified CNO nuclear reaction rates in dense stellar plasmas  

E-Print Network [OSTI]

We study the dependence of the CNO nuclear reaction rates on temperature, in the range of $10^7\\div 10^8$ K, the typical range of temperature evolution from a Sun-like star towards a white dwarf. We show that the temperature dependence of the CNO nuclear reaction rates is strongly affected by the presence of non-extensive statistical effects in the dense stellar core. A very small deviation from the Maxwell-Boltzmann particle distribution implies a relevant enhancement of the CNO reaction rate and could explain the presence of heavier elements (e.g. Fe, Mg) in the final composition of a white dwarf core. Such a behavior is consistent with the recent experimental upper limit to the fraction of energy that the Sun produces via the CNO fusion cycle.

F. Ferro; A. Lavagno; P. Quarati

2003-12-24T23:59:59.000Z

117

A Primer for Electro-Weak Induced Low Energy Nuclear Reactions  

E-Print Network [OSTI]

In a series of papers, cited in the main body of the paper below, detailed calculations have been presented which show that electromagnetic and weak interactions can induce low energy nuclear reactions to occur with observable rates for a variety of processes. A common element in all these applications is that the electromagnetic energy stored in many relatively slow moving electrons can -under appropriate circumstances- be collectively transferred into fewer, much faster electrons with energies sufficient for the latter to combine with protons (or deuterons, if present) to produce neutrons via weak interactions. The produced neutrons can then initiate low energy nuclear reactions through further nuclear transmutations. The aim of this paper is to extend and enlarge upon various examples analyzed previously, present simplified order of magnitude estimates for each and to illuminate a common unifying theme amongst all of them.

Y. N. Srivastava; A. Widom; L. Larsen

2008-10-01T23:59:59.000Z

118

Towards a nonequilibrium Green's function description of nuclear reactions: One-dimensional mean-field dynamics  

SciTech Connect (OSTI)

Research Highlights: > Dynamics of central nuclear reactions. > Nonequilibrium Green's functions and Kadanoff-Baym formalism. > Adiabatic switching on of interactions. > Mean-field time evolution of nuclear slabs. > Off-diagonal spatial structure of a collision density matrix. - Abstract: Nonequilibrium Green's function methods allow for an intrinsically consistent description of the evolution of quantal many-body body systems, with inclusion of different types of correlations. In this paper, we focus on the practical developments needed to build a Green's function methodology for nuclear reactions. We start out by considering symmetric collisions of slabs in one dimension within the mean-field approximation. We concentrate on two issues of importance for actual reaction simulations. First, the preparation of the initial state within the same methodology as for the reaction dynamics is demonstrated by an adiabatic switching on of the mean-field interaction, which leads to the mean-field ground state. Second, the importance of the Green's function matrix-elements far away from the spatial diagonal is analyzed by a suitable suppression process that does not significantly affect the evolution of the elements close to the diagonal. The relative lack of importance of the far-away elements is tied to system expansion. We also examine the evolution of the Wigner function and verify quantitatively that erasing of the off-diagonal elements corresponds to averaging out of the momentum-space details in the Wigner function.

Rios, Arnau, E-mail: A.Rios@surrey.ac.uk [National Superconducting Cyclotron Laboratory, Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States); Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Barker, Brent; Buchler, Mark; Danielewicz, Pawel [National Superconducting Cyclotron Laboratory, Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824-1321 (United States)

2011-05-15T23:59:59.000Z

119

Experimental Observation of Nuclear Reactions in Palladium and Uranium - Possible Explanation by Hydrex Mode  

SciTech Connect (OSTI)

Experiments with uranium are presented that show a highly exothermal reaction, which can only be of nuclear origin. One striking point of these results is that they clearly show that what is being observed is not some kind of fusion reaction of the deuterium present (only exceedingly small amounts of it are present). This is a strong indication that hydrogen can trigger nuclear reactions that seem to involve the nuclei of the lattice (which would yield a fission-like pattern of products). Confronted with a situation where some experiments in the field yield a fusion-like pattern of products (CF experiments) and others a fissionlike one (LENR experiments), one can reasonably wonder whether one is not observing two aspects of the same phenomenon. Thus, it is proposed to describe CF and LENR reactions as essentially the same phenomenon based on the possible existence of a still hypothetical proton/electron resonance, which would catalyze fissionlike reactions with a neutron sink. Finally, a series of experiments is proposed to assess this hypothesis.

Dufour, J.; Murat, D.; Dufour, X.; Foos, J

2001-07-15T23:59:59.000Z

120

Interplay between compound and fragments aspects of nuclear fission and heavy-ion reaction  

SciTech Connect (OSTI)

The scission point in nuclear fission plays a special role where one-body system changes to two-body system. Inverse of this situation is realized in heavy-ion fusion reaction where two-body system changes to one body system. Among several peculiar phenomena expected to occur during this change, we focus our attention to the behavior of compound and fragments shell effects. Some aspects of the interplay between compound and fragments shell effect are discussed related to the topics of the fission valleys in the potential energy surface of actinide nuclei and the fusion-like trajectory found in the cold fusion reaction leading to superheavy nuclei.

Moller, Peter [Los Alamos National Laboratory; Iwamoto, A [JAPAN; Ichikawa, I [JAPAN

2010-09-10T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Charged particle assisted nuclear reactions in solid state environment: renaissance of low energy nuclear physics  

E-Print Network [OSTI]

The features of electron assisted neutron exchange processes in crystalline solids are survayed. It is stated that, contrary to expectations, the cross section of these processes may reach an observable magnitude even in the very low energy case because of the extremely huge increment caused by the Coulomb factor of the electron assisted processes and by the effect of the crystal-lattice. The features of electron assisted heavy charged particle exchange processes, electron assisted nuclear capure processes and heavy charged particle assisted nuclear processes are also overviewed. Experimental observations, which may be related to our theoretical findings, are dealt with. The anomalous screening phenomenon is related to electron assisted neutron and proton exchange processes in crystalline solids. A possible explanation of observations by Fleischmann and Pons is presented. The possibility of the phenomenon of nuclear transmutation is qualitatively explained with the aid of usual and charged particle assisted r...

Klmn, Pter

2015-01-01T23:59:59.000Z

122

Enrico Fermi and the First Self-Sustaining Nuclear Chain Reaction  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing Zirconia NanoparticlesSmartAffects the Future EnergyEnolSpectrometryEnrico

123

Nuclear attenuation of three-hadron systems in neutrino-induced reactions  

E-Print Network [OSTI]

For the first time, the nuclear attenuation of three hadron systems is studied in neutrino-induced reactions using the data obtained with SKAT bubble chamber. The strongest attenuation (R_3 ~ 0.6) is observed for a system carrying an overwhelming fraction of the current quark energy, as well as for a system with the smallest effective mass. An indication is obtained that the correlation effects in the nuclear attenuation play only a minor role. The experimental data are compared with predictions of the quark string fragmentation model.

N. M. Agababyan; L. Grigorian; N. Grigoryan; H. Gulkanyan; A. A. Ivanilov; Zh. Karamyan; V. A. Korotkov

2011-08-08T23:59:59.000Z

124

A study of stopping power in nuclear reactions at intermediate energies  

E-Print Network [OSTI]

We show a systematic experimental study based on INDRA data of the stopping power in central symmetric nuclear reactions. Total mass of the systems goes from 80 to 400 nucleons while the incident energy range is from 12 AMeV to 100 AMeV. The role of isospin diffusion at 32 and 45 MeV/nucleon with 124,136Xe projectiles on 112,124Sn targets performed at GANIL is also discussed. Results suggest a strong memory of the entrance channel above 20 AMeV/A (nuclear transparency) and, as such, constitute valuable tests of the microscopic transport models.

G. Lehaut; D. Durand; O. Lopez

2010-01-25T23:59:59.000Z

125

Isospin aspects in nuclear reactions involving Ca beams at 25 MeV/nucleon  

SciTech Connect (OSTI)

Isospin dependence of dynamical and thermodynamical properties observed in reactions {sup 40}Ca+ {sup 40,48}Ca and {sup 40}Ca + {sup 46}Ti at 25 MeV/nucleon has been studied. We used the CHIMERA multi-detector array. Strong isospin effects are seen in the isotopic distributions of light nuclei and in the competition between different reaction mechanisms in semi-central collisions. We will show also preliminary results obtained in nuclear collision {sup 48}Ca + {sup 48}Ca at 25MeV/nucleon, having very high N/Z value in the entrance channel (N/Z = 1.4). The enhancement of evaporation residue production confirms the strong role played by the N/Z degree of freedom in nuclear dynamics.

Lombardo, I., E-mail: ilombardo@lns.infn.it; Agodi, C.; Alba, R.; Amorini, F.; Anzalone, A. [INFN Laboratori Nazionali del Sud (Italy); Auditore, L. [Universita di Messina, and INFN-Gr. Coll. Messina, Dipartimento di Fisica (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering (Romania); Cardella, G. [INFN, Sezione di Catania (Italy); Cavallaro, S. [INFN Laboratori Nazionali del Sud (Italy); Chatterjee, M. B. [Saha Institute of Nuclear Physics (India); Filippo, E. De [INFN, Sezione di Catania (Italy); Di Pietro, A.; Figuera, P. [INFN Laboratori Nazionali del Sud (Italy); Giuliani, G.; Geraci, E.; Grassi, L. [Dipartimento di Fisica e Astronomia Universita di Catania (Italy); Grzeszczuk, A. [University of Silesia, Institute of Physics (Poland); Han, J. [INFN Laboratori Nazionali del Sud (Italy); La Guidara, E. [INFN, Sezione di Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud (Italy); and others

2011-11-15T23:59:59.000Z

126

Experimental and phenomenological comparison between Piezonuclear reactions and Condensed Matter Nuclear Science phenomenology  

E-Print Network [OSTI]

The purpose of this paper is to place side by side the experimental results of Piezonu- clear reactions, which have been recently unveiled, and those collected during the last twenty years of experiments on low energy nuclear reactions (LENR). We will briefy re- port the results of our campaign of piezonuclear reactions experiments where ultrasounds and cavitation were applied to solutions of stable elements. These outcomes will be shown to be compatible with the results and evidences obtained from low energy nuclear reac- tion experiments. Some theoretical concepts and ideas, on which our experiments are grounded, will be sketched and it will be shown that, in order to trigger our measured effects, it exists an energy threshold, that has to be overcome, and a maximum inter- val of time for this energy to be released to the nuclear system. Eventually, a research hypothesis will be put forward about the chance to raise the level of analogy from the mere comparison of results up to the phenomenological level. H...

Cardone, F; Petrucci, A

2011-01-01T23:59:59.000Z

127

Experimental and phenomenological comparison between Piezonuclear reactions and Condensed Matter Nuclear Science phenomenology  

E-Print Network [OSTI]

The purpose of this paper is to place side by side the experimental results of Piezonu- clear reactions, which have been recently unveiled, and those collected during the last twenty years of experiments on low energy nuclear reactions (LENR). We will briefy re- port the results of our campaign of piezonuclear reactions experiments where ultrasounds and cavitation were applied to solutions of stable elements. These outcomes will be shown to be compatible with the results and evidences obtained from low energy nuclear reac- tion experiments. Some theoretical concepts and ideas, on which our experiments are grounded, will be sketched and it will be shown that, in order to trigger our measured effects, it exists an energy threshold, that has to be overcome, and a maximum inter- val of time for this energy to be released to the nuclear system. Eventually, a research hypothesis will be put forward about the chance to raise the level of analogy from the mere comparison of results up to the phenomenological level. Here, among the various evidences collected in LENR experiments, we will search for hints about the overcome of the energy threshold and about the mechanism that releases the loaded energy in a suitable interval of time.

F. Cardone; R. Mignani; A. Petrucci

2011-03-06T23:59:59.000Z

128

The Impact of Nuclear Reaction Rate Uncertainties on Evolutionary Studies of the Nova Outburst  

E-Print Network [OSTI]

The observable consequences of a nova outburst depend sensitively on the details of the thermonuclear runaway which initiates the outburst. One of the more important sources of uncertainty is the nuclear reaction data used as input for the evolutionary calculations. A recent paper by Starrfield, Truran, Wiescher, & Sparks (1998) has demonstrated that changes in the reaction rate library used within a nova simulation have significant effects, not just on the production of individual isotopes (which can change by an order of magnitude), but on global observables such as the peak luminosity and the amount of mass ejected. We present preliminary results of systematic analyses of the impact of reaction rate uncertainties on nova nucleosynthesis.

W. Raphael Hix; Michael S. Smith; Anthony Mezzacappa; Sumner Starrfield; Donald L. Smith

2000-01-27T23:59:59.000Z

129

Lost alpha-particle diagnostics from a D-T plasma by using nuclear reactions  

SciTech Connect (OSTI)

Among various methods proposed for alpha-particles loss measurement, we studied on those by measuring gamma rays of three cases, from (1) nuclear reactions induced by alpha particles, (2) those from short-life-time activities and (3) those from long-life-time activities induced by alpha particles. The time evolution of local alpha flux may possibly be measured by using the {sup 9}Be (a, n) {sup 12}C reaction (1). Using the same system, but with a target set up close to the first wall, activation measurement on site right after turning-off the discharge is possible (2). Nuclear reaction, {sup 25}Mg (a, p) {sup 28}Al, that produce radioisotopes of short lifetime of 2.2 minutes in one of the best candidates. As to the activation to a long lifetime (3), it is predicted that the gamma ray yield from {sup 19}F (a, n) {sup 22}Na reaction is enough for the measurement at the reactor site.

Sasao, Mamiko [Organization for Research Initiative and Development, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Wada, Motoi [Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Isobe, Mitsutaka [National Institute for Fusion Science, Toki Gifu 509-5292 (Japan)

2014-08-21T23:59:59.000Z

130

Mass Chain Evaluation for A=95  

SciTech Connect (OSTI)

A full evaluation of the mass chain A = 95 has been done in the ENSDF format taking into account all the available data until June 2009. Excited states populated by in-beam nuclear reactions and by radioactive decay have been considered. The 'evp' editor, developed at the NNDC, has been used for the evaluation. This mass chain was last evaluated in 1993. Many new and improved data were reported since then. A total of 13 nuclei have been evaluated.

Basu, S.K.; Sonzogni, A.; Basu, Swapan Kr.; Mukherjee, Gopal; Sonzogni, A. A.

2011-08-01T23:59:59.000Z

131

Proc. 19th Winter Workshop on Nuclear Dynamics (2003) 000000  

E-Print Network [OSTI]

Abstract. I discuss a few of the recent developments in nuclear reactions at very low energies ends of the energy scale for nuclear reactions: (a) the very high and (b) the very low relative. At the other end of the energy scale are the low energy reactions of importance for stellar evolution. A chain

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

132

Low-energy RI beam technology and nuclear clusters in the explosive pp-chain breakout process  

SciTech Connect (OSTI)

The lecture includes two parts: One is a discussion on the technology for developing RIB beam facility based on the in-flight method and relevant experimental technology. The second part is a discussion on experimental efforts for studying the breakout process from the pp-chain region based on recent works with low energy RI beams. The discussion of the second part specifically covers the problem of the vp-process in type II supernovae in terms of alpha cluster nature for the reactions.

Kubono, S. [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road 509, Lanzhou 73000 (China); RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0 (Japan); Yamaguchi, H.; Kahl, D. M.; Ohshiro, Y.; Watanabe, S.; Yamazaki, N. [Center for Nuclear Study, University of Tokyo, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Teranishi, T. [Department of Physics, Kyushu University, 6-10-1 Hakozaki, Fukuoka 812-858 (Japan); Yanagisawa, Y.; Wakabayashi, Y.; Kase, M. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Hayakawa, S. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Via S. Sofia 62, 95125 Catania (Italy); Kwon, Y. K. [Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon 305-81 (Korea, Republic of); Hashimoto, T.; Fukuda, Y. [Research Center for Nuclear Physics, Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); He, J. J. [Institute of Modern Physics, Chinese Academy of Sciences, Nanchang Road 509, Lanzhou 73000 (China); Goto, A. [Faculty of Medcine, Yamagata University, Yamagata 990-2331 (Japan); Muto, H. [Center of General Education, Tokyo University of Science at Suwa, Chino, Nagano 391-0292 (Japan)

2014-05-09T23:59:59.000Z

133

The Trojan Horse method for nuclear astrophysics: Recent results on resonance reactions  

SciTech Connect (OSTI)

Nuclear astrophysics aims to measure nuclear-reaction cross sections of astrophysical interest to be included into models to study stellar evolution and nucleosynthesis. Low energies, < 1 MeV or even < 10 keV, are requested for this is the window where these processes are more effective. Two effects have prevented to achieve a satisfactory knowledge of the relevant nuclear processes, namely, the Coulomb barrier exponentially suppressing the cross section and the presence of atomic electrons. These difficulties have triggered theoretical and experimental investigations to extend our knowledge down to astrophysical energies. For instance, indirect techniques such as the Trojan Horse Method have been devised yielding new cutting-edge results. In particular, I will focus on the application of this indirect method to resonance reactions. Resonances might dramatically enhance the astrophysical S(E)-factor so, when they occur right at astrophysical energies, their measurement is crucial to pin down the astrophysical scenario. Unknown or unpredicted resonances might introduce large systematic errors in nucleosynthesis models. These considerations apply to low-energy resonances and to sub-threshold resonances as well, as they may produce sizable modifications of the S-factor due to, for instance, destructive interference with another resonance.

Cognata, M. La; Pizzone, R. G. [Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Spitaleri, C.; Cherubini, S.; Romano, S. [Dipartimento di Fisica e Astronomia, Universit di Catania, Catania, Italy and Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Gulino, M.; Tumino, A. [Kore University, Enna, Italy and Laboratori Nazionali del Sud, Istituto Nazionale di Fisica Nucleare, Catania (Italy); Lamia, L. [Dipartimento di Fisica e Astronomia, Universit di Catania, Catania (Italy)

2014-05-09T23:59:59.000Z

134

EXFOR systems manual: Nuclear reaction data exchange format. Revision 97/1  

SciTech Connect (OSTI)

This document describes EXFOR, the exchange format designed to allow transmission of nuclear reaction data between the members of the Nuclear Data Center Network. In addition to storing the data and its` bibliographic information, experimental information, including source of uncertainties, is also compiled. The status and history of the data set is also included, e.g., the source of the data, any updates which have been made, and correlations to other data sets. EXFOR is designed for flexibility rather than optimization of data processing in order to meet the diverse needs of the nuclear reaction data centers. The exchange format should not be confused with a center-to-user format. Although users may obtain data from the centers in the EXFOR format, other center-to-user formats have been developed to meet the needs of the users within each center`s own sphere of responsibility. The exchange format, as outlined, is designed to allow a large variety of numerical data tables with explanatory and bibliographic information to be transmitted in an easily machine-readable format (for checking and indicating possible errors) and a format that can be read by personnel (for passing judgment on and correcting any errors indicated by the machine).

McLane, V. [ed.] [comp.

1997-07-01T23:59:59.000Z

135

Reaction mechanisms in transport theories: a test of the nuclear effective interaction  

E-Print Network [OSTI]

We review recent results concerning collective excitations in neutron-rich systems and reactions between charge asymmetric systems at Fermi energies. Solving numerically self-consistent transport equations for neutrons and protons with specific initial conditions, we explore the structure of the different dipole vibrations in the $^{132}Sn$ system and investigate their dependence on the symmetry energy. We evidence the existence of a distinctive collective mode, that can be associated with the Pygmy Dipole Resonance, with an energy well below the standard Giant Dipole Resonance and isoscalar-like character, i.e. very weakly dependent on the isovector part of the nuclear effective interaction. At variance, the corresponding strength is rather sensitive to the behavior of the symmetry energy below saturation, which rules the number of excess neutrons in the nuclear surface. In reactions between charge asymmetric systems at Fermi energies, we investigate the interplay between dissipation mechanisms and isospin effects. Observables sensitive to the isospin dependent part of nuclear interaction are discussed, providing information on the symmetry energy density dependence below saturation.

M. Colonna; V. Baran; M. Di Toro; B. Frecus; Y. X. Zhang

2012-09-07T23:59:59.000Z

136

COMMENTS ON "A NEW LOOK AT LOW-ENERGY NUCLEAR REACTION RESEARCH"  

SciTech Connect (OSTI)

Cold fusion researchers have accumulated a large body of anomalous results over the last 20 years that they claim proves a new, mysterious nuclear reaction is active in systems they study. Krivit and Marwan give a brief and wholly positive view of this body of research. Unfortunately, cold fusion researchers routinely ignore conventional explanations of their observations, and claim much greater than real accuracy and precision for their techniques. This paper attempts to equally briefly address those aspects of the field with the intent of providing a balanced view of the field, and to establish some criteria for subsequent publications in this arena.

Shanahan, K.

2009-12-30T23:59:59.000Z

137

Initiation of nuclear reactions under laser irradiation of Au nanoparticles in the presence of Thorium aqua-ions  

E-Print Network [OSTI]

Initiation of nuclear reactions in Thorium nuclei is experimentally studied under laser exposure of Au nanoparticles suspended in the aqueous solution of Th(NO3)4 (232Th). It is found that the reaction pathway depends in which water, either H2O or D2O, the laser exposure is carried out. Saturation of the liquids (H2O or D2O) with gaseous H2 or D2, respectively, enhances the nuclear reactions under laser exposure allowing their excitation at peak intensity as low as 1010 W/cm2. Enhanced gamma-activity of the probe is observed after the end of laser exposure for several hours.

A. V. Simakin; G. A. Shafeev

2009-06-23T23:59:59.000Z

138

Spectroscopy of element 115 decay chains  

SciTech Connect (OSTI)

A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.

Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2013-01-01T23:59:59.000Z

139

Nuclear Reaction Cross-Section Measurements via Characterization of Soft Radiation Emitting Products  

SciTech Connect (OSTI)

Nuclear reaction cross-section measurements via the activation technique are generally made using high-resolution {gamma}-ray spectrometry. However, in cases where the radioactive product decays exclusively by EC (without emitting a {gamma}-ray) resort has to be made to the rather subtle technique of x-ray spectrometry. Similarly for characterisation of pure {beta}- emitters, gas-flow proportional or liquid-scintillation counting is applied. In both cases the use of radiochemical methods is most essential. We studied the natTi(p,xn)49V and 85Rb(p,4n)82Sr reactions via x-ray spectrometry. In each case a clean radiochemical separation was performed and a thin source was prepared. The radioactivity of 49V was determined using the soft 4.5-keV k{alpha} x-rays and that of 82Sr via the 13.4-keV k{alpha} x-rays. In another study, the reactions natTi(p,x)45Ca, 89Y(n,p)89Sr, and natPb(p,x)204Tl were investigated. All the products are pure {beta}- emitters and therefore clean radiochemical separations were mandatory. The radioactivity of each of the three products was determined via low-level anticoincidence {beta}- counting. Furthermore, in the case of 45Ca, liquid-scintillation counting was also used. The results obtained using different techniques are compared.

Kettern, K.; Spahn, I.; Spellerberg, S.; Qaim, S.M.; Coenen, H.H. [Institut fuer Nuklearchemie, Forschungszentrum Juelich GmbH, D-52425 Juelich (Germany)

2005-05-24T23:59:59.000Z

140

Towards a nonequilibrium Green's function description of nuclear reactions: one-dimensional mean-field dynamics  

E-Print Network [OSTI]

Nonequilibrium Green's function methods allow for an intrinsically consistent description of the evolution of quantal many-body body systems, with inclusion of different types of correlations. In this paper, we focus on the practical developments needed to build a Green's function methodology for nuclear reactions. We start out by considering symmetric collisions of slabs in one dimension within the mean-field approximation. We concentrate on two issues of importance for actual reaction simulations. First, the preparation of the initial state within the same methodology as for the reaction dynamics is demonstrated by an adiabatic switching on of the mean-field interaction, which leads to the mean-field ground state. Second, the importance of the Green's function matrix-elements far away from the spatial diagonal is analyzed by a suitable suppression process that does not significantly affect the evolution of the elements close to the diagonal. The relative lack of importance of the far-away elements is tied t...

Rios, Arnau; Buchler, Mark; Danielewicz, Pawel

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Towards a nonequilibrium Green's function description of nuclear reactions: one-dimensional mean-field dynamics  

E-Print Network [OSTI]

Nonequilibrium Green's function methods allow for an intrinsically consistent description of the evolution of quantal many-body body systems, with inclusion of different types of correlations. In this paper, we focus on the practical developments needed to build a Green's function methodology for nuclear reactions. We start out by considering symmetric collisions of slabs in one dimension within the mean-field approximation. We concentrate on two issues of importance for actual reaction simulations. First, the preparation of the initial state within the same methodology as for the reaction dynamics is demonstrated by an adiabatic switching on of the mean-field interaction, which leads to the mean-field ground state. Second, the importance of the Green's function matrix-elements far away from the spatial diagonal is analyzed by a suitable suppression process that does not significantly affect the evolution of the elements close to the diagonal. The relative lack of importance of the far-away elements is tied to system expansion. We also examine the evolution of the Wigner function and verify quantitatively that erasing of the off-diagonal elements corresponds to averaging out of the momentum-space details in the Wigner function.

Arnau Rios; Brent Barker; Mark Buchler; Pawel Danielewicz

2010-09-01T23:59:59.000Z

142

New Nuclear Reaction Flow during r-Process Nucleosynthesis in Supernovae: Critical Role of Light Neutron-Rich Nuclei  

E-Print Network [OSTI]

We study the role of light neutron-rich nuclei during r-process nucleosynthesis in supernovae. Most previous studies of the r-process have concentrated on the reaction flow of heavy unstable nuclei. Although the nuclear reaction network includes a few thousand heavy nuclei, only limited reaction flow through light-mass nuclei near the stability line has been used in those studies. However, in a viable scenario of the r-process in neutrino-driven winds, the initial condition is a high-entropy hot plasma consisting of neutrons, protons, and electron-positron pairs experiencing an intense flux of neutrinos. In such environments light-mass nuclei as well as heavy nuclei are expected to play important roles in the production of seed nuclei and r-process elements. Thus, we have extended our fully implicit nuclear reaction network so that it includes all nuclei up to the neutron drip line for Z $ \\leq 10$, in addition to a larger network for Z $ \\geq 10$. In the present nucleosynthesis study, we utilize a wind model of massive SNeII explosions to study the effects of this extended network. We find that a new nuclear-reaction flow path opens in the very light neutron-rich region. This new nuclear reaction flow can change the final heavy-element abundances by as much as an order of magnitude.

M. Terasawa; K. Sumiyoshi; T. Kajino; G. J. Mathews; I. Tanihata

2001-07-19T23:59:59.000Z

143

Study of Nuclear Reactions with 11C and 15O Radioactive Ion Beams  

SciTech Connect (OSTI)

Nuclear reaction study with radioactive ion beams is one of the most exciting research topics in modern nuclear physics. The development of radioactive ion beams has allowed nuclear scientists and engineers to explore many unknown exotic nuclei far from the valley of nuclear stability, and to further our understanding of the evolution of the universe. The recently developed radioactive ion beam facility at the Lawrence Berkeley National Laboratory's 88-inch cyclotron is denoted as BEARS and provides {sup 11}C, {sup 14}O and {sup 15}O radioactive ion beams of high quality. These moderate to high intensity, proton-rich radioactive ion beams have been used to explore the properties of unstable nuclei such as {sup 12}N and {sup 15}F. In this work, the proton capture reaction on {sup 11}C has been evaluated via the indirect d({sup 11}C, {sup 12}N)n transfer reaction using the inverse kinematics method coupled with the Asymptotic Normalization Coefficient (ANC) theoretical approach. The total effective {sup 12}N {yields} {sup 11}C+p ANC is found to be (C{sub eff}{sup 12{sub N}}){sup 2} = 1.83 {+-} 0.27 fm{sup -1}. With the high {sup 11}C beam intensity available, our experiment showed excellent agreement with theoretical predictions and previous experimental studies. This study also indirectly confirmed that the {sup 11}C(p,{gamma}) reaction is a key step in producing CNO nuclei in supermassive low-metallicity stars, bypassing the slow triple alpha process. The newly developed {sup 15}O radioactive ion beam at BEARS was used to study the poorly known level widths of {sup 16}F via the p({sup 15}O,{sup 15}O)p reaction. Among the nuclei in the A=16, T=1 isobaric triad, many states in {sup 16}N and {sup 16}O have been well established, but less has been reported on {sup 16}F. Four states of {sup 16}F below 1 MeV have been identified experimentally: 0{sup -}, 1{sup -}, 2{sup -}, and 3{sup -} (E{sub x} = 0.0, 0.19, 0.42, and 0.72 MeV, respectively). Our study utilized R-matrix analysis and found that the 0- state has a level width of 23.1 {+-} 2.2 keV, and that the broader 1- state has a width of 91.1 {+-} 9.9 keV. The level width of the 2{sup -} state is found to be 3.3 {+-} 0.6 keV which is much narrower than the compiled value of 40 {+-} 30 keV, while a width of 14.1 {+-} 1.7 keV for the 3{sup -} state is in good agreement with the reported value (< 15 keV). These experimental level widths of all four levels are also in accordance with theoretical predictions using single particle shell model calculation.

Lee, Dongwon

2007-05-14T23:59:59.000Z

144

STARLIB: A NEXT-GENERATION REACTION-RATE LIBRARY FOR NUCLEAR ASTROPHYSICS  

SciTech Connect (OSTI)

STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (1) theoretical TALYS rates for reactions for which no experimental input is available, and (2) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p, {gamma}), (p, {alpha}), ({alpha}, n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.

Sallaska, A. L. [National Institute of Standards and Technology, Gaithersburg, MD 20899-8462 (United States); Iliadis, C.; Champange, A. E. [University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Goriely, S. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium); Starrfield, S.; Timmes, F. X., E-mail: anne.sallaska@nist.gov [Arizona State University, Tempe, AZ 85287-1504 (United States)

2013-07-15T23:59:59.000Z

145

Medical Nuclear Supply Chain Design: A Tractable Network Model and Computational  

E-Print Network [OSTI]

;Nuclear Medicine To create an image for medical diagnostic purposes, a radioactive isotope is bound emitted by the radioactive decay of the isotope are then used to create an image of that site or organ It is estimated that the global market for medical isotopes is 3.7 billion US$ per year (Kahn (2008)). Anna

Nagurney, Anna

146

The Dependence of the Proton-Triton Nuclear Reaction Rate on the Temperature and Energy Content of the High-Energy Proton Distribution Function  

E-Print Network [OSTI]

The Dependence of the Proton-Triton Nuclear Reaction Rate on the Temperature and Energy Content of the High-Energy Proton Distribution Function

147

Spectroscopy of particle-phonon coupled states in 133Sb by the cluster transfer reaction of 132Sn on 7Li: an advanced test of nuclear interactions  

E-Print Network [OSTI]

Spectroscopy of particle-phonon coupled states in 133Sb by the cluster transfer reaction of 132Sn on 7Li: an advanced test of nuclear interactions

Leoni S, University of Milano and INFN Milano (Italy); Bocchi G, University of Milano and INFN Milano (Italy); Bottoni S, University of Milano and INFN Milano (Italy); Bracco A, University of Milano and INFN Milano (Italy); Camera F, University of Milano and INFN Milano (Italy; Crespi F, University of Milano and INFN Milano (Italy); Morales A, University of Milano and INFN Milano (Italy); Fornal B, IFJ-PAN Krakow (Poland); Szpak B, IFJ-PAN Krakow (Poland); Bednarczyk P, IFJ-PAN Krakow (Poland); Cieplicka N, IFJ-PAN Krakow (Poland); Krolas W, IFJ-PAN Krakow ( Poland); Maj A, IFJ-PAN Krakow (Poland); Rusek K, Heavy Ion Laboratory University of Warsaw (Poland); Bazzacco D, INFN Padova (Italy); Lunardi S, University of Padova and INFN Padova (Italy); Mengoni D, University of Padova and INFN Padova (Italy); Recchia F, University of Padova and INFN Padova (Italy); Ur C, INFN Padova (Italy); Valiente-Dobon J, LNL-INFN (Italy); Gramegna F, LNL-INFN (Italy); Marchi T, LNL-INFN (Italy); Huyse M, KU Leuven (Belgium); Raabe R, KU Leuven (Belgium); VanDuppen P, KU Leuven (Belgium); Sferrazza M, Universit libre de Bruxelles (Belgium); Georgiev G, CSNSM Orsay (France); Blazhev A, Institut fur Kernphysik der Universitat zu Kln (Germany); Rosiak D, Institut fur Kernphysik der Universitat zu Kln (Germany); Siebeck B, Institut fur Kernphysik der Universitat zu Kln (Germany); Seidlitz M, Institut fur Kernphysik der Universitat zu Kln (Germany); Reiter P, Institut fur Kernphysik der Universitat zu Kln (Germany); Warr N, Institut fur Kernphysik der Universitat zu Koln (Germany); Hartig AL, TU Darmstadt (Germany); Henrich C, TU Darmstadt (Germany); Ilieva S, TU Darmstadt (Germany); Kroell T, TU Darmstadt (Germany); Thurauf M, TU Darmstadt (Germany); Gernhaeuser R, TU Munchen (Germany); Mucher D, TU Munchen (Germany); Janssens R, Argonne National Laboratory (USA); Carpenter MP, Argonne National Laboratory (USA); Zhu S, Argonne National Laboratory (USA); Kowalska M, ISOLDE-CERN (Switzerland); CERN. Geneva. ISOLDE and neutron Time-of-Flight Experiments Committee; INTC

2014-01-01T23:59:59.000Z

148

[Reaction mechanism studies of heavy ion induced nuclear reactions]. [Dept. of Chemistry and Biochemistry, Univ. of Maryland, College Park, Maryland  

SciTech Connect (OSTI)

Completed work is summarized on the topics of excitation energy division in deep-inelastic reactions and the onset of multifragmentation in La-induced reactions at E/A = 45 MeV. Magnetic fields are being calculated for the PHOBOS detector system, a two-arm multiparticle spectrometer for studying low-transverse-momentum particles produced at the Relativistic Heavy Ion Collider. The Maryland Forward Array is being developed for detection of the reaction products from very peripheral collisions; it consists of two individual units of detectors: the annular silicon detector in front and the plastic phoswich detector at back.

Mignerey, A.C.

1993-02-01T23:59:59.000Z

149

arXiv:nucl-th/0607015v213Jul2006 Direct reactions in/for astrophysics  

E-Print Network [OSTI]

. In recent years direct reactions methods have been developed and applied to extract low-energy astrophysical are focused on the opposite ends of the energy scale of nuclear reactions: (a) the very high and (b) the very end of the energy scale are the low energy reactions of importance for stellar evolution. Chains

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

150

Application of evolved gas analysis to cold-cap reactions of melter feeds for nuclear waste vitrification  

SciTech Connect (OSTI)

In the vitrification of nuclear wastes, the melter feed (a mixture of nuclear waste and glass forming and modifying additives) experiences multiple gas-evolving reactions in an electrical glass-melting furnace. Foams from the residual gases can significantly alter the melting rate through mass and heat transfers. We employed the thermogravimetry-gas chromatography-mass spectrometry (TGA-GC-MS) combination to perform quantitative evolved gas analysis (EGA) and developed a simple calibration model which correlates the overall mass loss rate with the evolution rates for individual gases. The model parameters are obtained from the least squares analysis, assuming that the gas-evolving reactions are independent. Thus, the EGA adds the chemical identity to the reactions indicated by the phenomenological kinetic model.

Rodriguez, Carmen P.; Chun, Jaehun; Schweiger, Michael J.; Kruger, Albert A.; Hrma, Pavel R.

2014-09-01T23:59:59.000Z

151

Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4$?$ detector  

E-Print Network [OSTI]

Heavy ion collisions have been widely used in the last decade to constraint the parameterizations of the symmetry energy term of nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density $\\rho_0$=0.16 fm$^{-3}$ down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi-detector array.

E. De Filippo; A. Pagano

2013-10-22T23:59:59.000Z

152

Nuclear Reaction Cross Sections Database at BNL | U.S. DOE Office...  

Office of Science (SC) Website

Nuclear Science Advisory Committee (NSAC) News & Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26Germantown Building 1000 Independence...

153

Nuclear reaction analysis profiling as direct evidence for lithium ion mass transport in thin film rocking-chair'' structures  

SciTech Connect (OSTI)

A nuclear reaction analysis technique using the [ital p],[gamma] reaction, [sup 7]Li([ital p],[gamma])[sup 8]Be, occurring at approximately 440 keV, (half-width[approx]12 keV), has been utilized to determine the lithium concentration profiles in multilayer electrochromic window ( smart window'')/rechargeable battery cells when in their colored''/charged and bleached''/discharged states. The lithium profiles have been observed to shift according to the cells' states, thereby providing direct experimental evidence for the so-called rocking-chair model for such structures.

Goldner, R.B.; Haas, T.E.; Arntz, F.O.; Slaven, S.; Wong, K.K. (Electro-Optics Technology Center, Tufts University, Medford, Massachusetts 02155 (United States)); Wilkens, B. (Bellcore, Red Bank, New Jersey 07001-7040 (United States)); Shepard, C.; Lanford, W. (Accelerator Laboratory, Physics Department, State University of New York at Albany, Albany, New York 12222 (United States))

1993-04-05T23:59:59.000Z

154

Proton-induced cross-sections of nuclear reactions on lead up to 37 MeV  

E-Print Network [OSTI]

Excitation function of proton induced nuclear reactions on lead for production of $^{206,205,204,203,202,201g}$Bi, $^{203cum,202m,201cum}$Pb and $^{202cum,201cum,200cum,199cum}$Tl radionuclides were measured up to 36 MeV by using activation method, stacked foil irradiation technique and $\\gamma$-ray spectrometry. The new experimental data were compared with the few earlier experimental results and with the predictions of the EMPIRE3.1, ALICE-IPPE (MENDL2p) and TALYS (TENDL-2012) theoretical reaction codes.

F. Ditri; F. Trknyi; S. Takcs; A. Hermanne

2014-11-07T23:59:59.000Z

155

The effect of nuclear reaction rates and convective mixing on the evolution of a 6M{sub ?} star  

SciTech Connect (OSTI)

We present the evolution of a 6M{sub ?} star, of solar-like initial metallicity, and investigate the effects of key nuclear reaction rates, as well as the treatment of the convective mixing on its evolution along the Cepheid instability strip. In particular, we study the effect of recent estimates of the {sup 14}N(p,?){sup 15}O reaction on the formation and extension of the blue loop during core helium burning. We also investigate the effects induced on this blue loop by the adoption of non-standard convective mixing prescriptions, as well as the implications of modifying the Mixing Length Theory.

Halabi, Ghina M., E-mail: gfm01@aub.edu.lb [American University of Beirut, Department of Physics, P.O. Box 11-0236, Riad El-Solh, Beirut (Lebanon)

2014-05-09T23:59:59.000Z

156

Application of evolved gas analysis to cold-cap reactions of melter feeds for nuclear waste vitrification  

SciTech Connect (OSTI)

In the vitrification of nuclear wastes, the melter feed (a mixture of nuclear waste and glass-forming and modifying additives) experiences multiple gas-evolving reactions in an electrical glass-melting furnace. We employed the thermogravimetry-gas chromatography-mass spectrometry (TGA-GC-MS) combination to perform evolved gas analysis (EGA). Apart from identifying the gases evolved, we performed quantitative analysis relating the weighed sum of intensities of individual gases linearly proportional with the differential themogravimetry. The proportionality coefficients were obtained by three methods based on the stoichiometry, least squares, and calibration. The linearity was shown to be a good first-order approximation, in spite of the complicated overlapping reactions.

Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.; Rodriguez, Carmen P.; Schweiger, Michael J.

2014-04-30T23:59:59.000Z

157

Nuclear parton distribution functions and energy loss effect in the Drell-Yan reaction off nuclei  

E-Print Network [OSTI]

The energy loss effect in nuclear matter is another nuclear effect apart from the nuclear effects on the parton distribution as in deep inelastic scattering process. The quark energy loss can be measured best by the nuclear dependence of the high energy nuclear Drell-Yan process. By means of two typical kinds of quark energy loss parametrization and the different sets of nuclear parton distribution functions, we present a analysis of the E866 experiments on the nuclear dependence of Drell-Yan lepton pair production resulting from the bombardment of Be, Fe and W targets by 800GeV protons at Fermilab. It is found that the quark energy loss in cold nuclei is strongly dependent on the used nuclear parton distribution functions. The further prospects of using relatively low energy proton incident on nuclear targets are presented by combining the quark energy loss rate determined from a fit to the E866 nuclear-dependent ratios versus $x_1$, with the nuclear parton distribution functions given from lA deep inelastic scattering (DIS) data. The experimental study of the relatively low energy nuclear Drell-Yan process can give valuable insight in the enengy loss of fast quark propagating a cold nuclei and help to pin down nuclear parton distributions functions.

ChunGui Duan; LiHua Song; ShuoHe Wang; GuangLie Li

2006-01-23T23:59:59.000Z

158

Fission-Fusion: A new reaction mechanism for nuclear astrophysics based on laser-ion acceleration  

SciTech Connect (OSTI)

We propose to produce neutron-rich nuclei in the range of the astrophysical r-process around the waiting point N = 126 by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a CH{sub 2} layer), where the light fission fragments of the beam fuse with the light fission fragments of the target. Via the 'hole-boring' mode of laser Radiation Pressure Acceleration using a high-intensity, short pulse laser, very efficiently bunches of {sup 232}Th with solid-state density can be generated from a Th target and a deuterated CD{sub 2} foil, both forming the production target assembly. Laser-accelerated Th ions with about 7 MeV/u will pass through a thin CH{sub 2} layer placed in front of a thicker second Th foil (both forming the reaction target) closely behind the production target and disintegrate into light and heavy fission fragments. In addition, light ions (d,C) from the CD{sub 2} layer of the production target will be accelerated as well, inducing the fission process of {sup 232}Th also in the second Th layer. The laser-accelerated ion bunches with solid-state density, which are about 10{sup 14} times more dense than classically accelerated ion bunches, allow for a high probability that generated fission products can fuse again. The high ion beam density may lead to a strong collective modification of the stopping power, leading to significant range and thus yield enhancement. Using a high-intensity laser as envisaged for the ELI-Nuclear Physics project in Bucharest (ELI-NP), order-of-magnitude estimates promise a fusion yield of about 10{sup 3} ions per laser pulse in the mass range of A = 180-190, thus enabling to approach the r-process waiting point at N = 126.

Thirolf, P. G.; Gross, M.; Allinger, K.; Bin, J.; Henig, A.; Kiefer, D. [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-85748 Garching (Germany); Habs, D. [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Ma, W.; Schreiber, J. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany)

2011-10-28T23:59:59.000Z

159

The role of electron-screening deformations in solar nuclear fusion reactions and the solar neutrino puzzle  

E-Print Network [OSTI]

Thermonuclear fusion reaction rates in the solar plasma are enhanced by the presence of the electron cloud that screens fusing nuclei. The present work studies the influence of electron screening deformations on solar reaction rates in the framework of the Debye-Huckel model. These electron-ion cloud deformations, assumed here to be static and axially symmetric, are shown to be able to considerably influence the solar neutrino fluxes of the pp and the CNO chains, with reasonable changes in the macroscopic parameters of the standard solar model (SSM) . Various known deformation sources are discussed but none of them is found strong enough to have a significant impact on the SSM neutrino fluxes.

Theodore E. Liolios

2000-08-13T23:59:59.000Z

160

Cold-cap reactions in vitrification of nuclear waste glass: experiments and modeling  

SciTech Connect (OSTI)

Cold-cap reactions are multiple overlapping reactions that occur in the waste-glass melter during the vitrification process when the melter feed is being converted to molten glass. In this study, we used differential scanning calorimetry (DSC) to investigate cold-cap reactions in a high-alumina high-level waste melter feed. To separate the reaction heat from both sensible heat and experimental instability, we employed the run/rerun method, which enabled us to define the degree of conversion based on the reaction heat and to estimate the heat capacity of the reacting feed. Assuming that the reactions are nearly independent and can be approximated by the nth order kinetics, we obtained the kinetic parameters using the Kissinger method combined with least squares analysis. The resulting mathematical simulation of the cold-cap reactions provides a key element for the development of an advanced cold-cap model.

Chun, Jaehun [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Pierce, David A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Pokorny, Richard [Inst. of Chemical Technology, Prague (Czech Republic); Hrma, Pavel R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Pohang Univ. of Science and Techology (Korea, Republic of)

2013-05-10T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" from the National Library of EnergyBeta (NLEBeta).
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161

Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np  

SciTech Connect (OSTI)

Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age must be considered more uncertain than if the calculated rates of beta-delayed fission were found to be acceptable. The nuclear level structure of 238Np has been investigated using the 237Np(n,..gamma..)238Np reaction and the alpha decay of 242mAm as experimental probes. Having established a level scheme for 238Np that includes 47 excited levels and 93 secondary transitions, we find a high degree of correspondence between the experimental band structure and that of a semi-empirical model developed to predict excitations in odd-odd deformed nuclei. 35 refs., 4 figs., 3 tabs.

Hoff, R.W.

1988-02-19T23:59:59.000Z

162

E-Print Network 3.0 - alpha-particle-induced nuclear reactions...  

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

production balances the various energy losses and the fusion reaction is self-sustaining. The product ions Source: Bishop, Christopher M. - Microsoft Research Cambridge &...

163

Initiation of nuclear reactions under laser irradiation of Au nanoparticles in the aqueous solution of Uranium salt  

E-Print Network [OSTI]

Laser exposure of suspension of either gold or palladium nanoparticles in aqueous solutions of UO2Cl2 of natural isotope abundance was experimentally studied. Picosecond Nd:YAG lasers at peak power from 1011 to 1013 W/cm2 at the wavelength of 1064 and 355 nm were used as well as a visible-range Cu vapor laser at peak power of 1010 W/cm2. The composition of colloidal solutions before and after laser exposure was analyzed using atomic absorption and gamma spectroscopy between 0.06 and 1 MeV range of photon energy. A real-time gamma-spectroscopy was used to characterize the kinetics of nuclear reactions during laser exposure. It was found that laser exposure initiated nuclear reactions involving both 238U and 235U nuclei via different channels in H2O and D2O. The influence of saturation of both the liquid and nanoparticles by gaseous H2 and D2 on the kinetics of nuclear transformations was found. Possible mechanisms of observed processes are discussed.

A. V. Simakin; G. A. Shafeev

2009-11-29T23:59:59.000Z

164

Measurement of nuclear transparency from A(e,e'[pi]?) reactions  

E-Print Network [OSTI]

The color transparency phenomenon refers to the suppression of final-state interactions of a hadron propagating through the nuclear medium at large momentum transfer when the hadron is produced with small transverse size. ...

Clasie, Benjamin Michael Patrick

2006-01-01T23:59:59.000Z

165

Experimental study to explore the $\\rm ^8Be$ induced nuclear reaction via the Trojan Horse Method  

E-Print Network [OSTI]

To explore a possible indirect method for $\\rm ^8Be$ induced astrophysical reactions, the $\\rm ^9Be=({}^8Be+\\it n)$ cluster structure was studied via the Trojan Horse Method. It is the first time to study a super short life nucleus $\\rm ^8Be$ via the Trojan Horse Method, and it is the first time to make a valid test for $l=1$ Trojan-horse nucleus. The $\\rm ^9Be$ nucleus is assumed to have a ($\\rm {}^8Be+\\it n$) cluster structure and used as the Trojan-horse nucleus. The $\\rm ^8Be$ nucleus acts as a participant, while the neutron is a spectator to the virtual $\\rm ^8Be +{\\it d}\\rightarrow \\alpha + {}^6Li$ reaction via a suitable 3-body reaction $\\rm ^9Be +{\\it d}\\rightarrow \\alpha + {}^6Li +\\it n$. The experimental neutron momentum distribution inside $\\rm ^9Be$ was reconstructed. The agreement between experimental and theoretical momentum distribution indicates that there should be a ($\\rm {}^8Be+\\it n$) cluster structure inside $\\rm ^9Be$. Therefor the experimental study of $\\rm ^8Be$ induced reactions, for example the experimental measurement of the $\\rm ^8Be +\\alpha \\rightarrow {}^{12}C$ reaction proceeding through the Hoyle state, is possible.

Wen Qun-Gang; Li Cheng-Bo; Zhou Shu-Hua; Bakhadir Irgaziev; Fu Yuan-Yong; Claudio Spitaleri; Marco La Cognata; Zhou Jing; Meng Qiu-Ying; Livio Lamia; Marcello Lattuada

2014-12-30T23:59:59.000Z

166

Excitation of nuclear anharmonic vibrations in heavy-ion fusion reactions  

E-Print Network [OSTI]

We discuss the effects of multi-phonon excitations on heavy-ion fusion reactions at energies near and below the Coulomb barrier, focusing especially on the role of anharmonicities. We carry out a systematic study of those effects on the excitation function of the fusion cross section and on the fusion barrier distribution, by using the vibrational limit of the interacting boson model. We also analyze the recently measured high-precision data of the $^{16}$O + $^{148}$Sm fusion reaction with this model and discuss the anharmonic properties of the quadrupole as well as the octupole vibrations in $^{148}$Sm. Negative and positive static quadrupole moments are deduced for the first 2$^+$ and 3$^-$ states in $^{148}$Sm, respectively. It is shown that the fusion barrier distribution strongly depends on the sign of the quadrupole moments, suggesting that subbarrier fusion reactions offer an alternative method to extract the static quadrupole moments of phonon states in spherical nuclei.

K. Hagino; S. Kuyucak; N. Takigawa

1997-11-05T23:59:59.000Z

167

A solid-state nuclear magnetic resonance study of the reactions of propene on HY zeolite  

E-Print Network [OSTI]

, and condensation. The main objective of this study was to determine the reaction mechanism (including the observation of intermediates) for propane adsorbed on HY zeolite. C enriched propene was adsorbed on HY zeolite at room temperature, and it was observed..., as denoted by arrows C CP/MAS spectrum of propene-2- C 13 adsorbed on HY zeolite at room temperature 10 The polymerization reaction proposed in reference 13 for the adsorption of propene on HY zeolite The Bloch decay pulse sequence in NMR experiments...

Oshiro, Irene Sueko

1988-01-01T23:59:59.000Z

168

Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon  

E-Print Network [OSTI]

Record of Cycling Operation of the Natural Nuclear Reactor in the Oklo/Okelobondo Area in Gabon A billion yr old Oklo natural nuclear reactor. In addition to elevated abundances of fission-produced Zr, Ce nuclear chain reaction was predicted by Kuroda [1] 20 years before the remnants of the natural reactor

169

Sensitivity of the blue loops of intermediate-mass stars to nuclear reactions  

SciTech Connect (OSTI)

We investigate the effects of a modification of the {sup 14}N(p,{gamma}){sup 15}O reaction rate, as suggested by recent evaluations, on the formation and extension of the blue loops encountered during the evolution of the stars in the mass range 5M{sub Circled-Dot-Operator} to 12M{sub Circled-Dot-Operator }. We show that the blue loops of stars in the mass range 5M{sub Circled-Dot-Operator} to 8M{sub Circled-Dot-Operator }, that is the range of super ABG stars, are severely affected by a modification of the important {sup 14}N(p,{gamma}){sup 15}O reaction rate. We also show that the blue loops can be restored if envelope overshooting is included, which is necessary to explain the observations of the Cepheid stars.

Halabi, Ghina M.; El Eid, Mounib [American University of Beirut, Department of Physics, P.O. Box 11-0236, Riad El-Solh, Beirut (Lebanon)

2012-11-20T23:59:59.000Z

170

Complex particle and light fragment emission in the cascade-excitation model of nuclear reactions  

SciTech Connect (OSTI)

A brief description of our improvements and refinements that led from the CEM95 version of the Cascade-Exciton Model (CEM) code to CEM97 and to CEM2k is given. The increased accuracy and predictive power of the code CEM2k are shown by several examples. To describe fission and light-fragment (heavier than {sup 4}He) production, the CEM2k code has been merged with the GEM2 code of Furihata. We present some results on proton-induced fragmentation and fission reactios predicted by this extended version of CEM2k. We show that merging CEM2k with GEM2 allows us to describe many fission and fragmentation reactions in addition to the spallation reactions which are already relatively well described.

Mashnik, S. G. (Stepan G.); Sierk, A. J. (Arnold J.); Gudima, K. K. (Konstantin K.)

2002-01-01T23:59:59.000Z

171

Nuclear reaction rates and energy in stellar plasmas : The effect of highly damped modes  

E-Print Network [OSTI]

The effects of the highly damped modes in the energy and reaction rates in a plasma are discussed. These modes, with wavenumbers $k \\gg k_{D}$, even being only weakly excited, with less than $k_{B}T$ per mode, make a significant contribution to the energy and screening in a plasma. When the de Broglie wavelength is much less than the distance of closest approach of thermal electrons, a classical analysis of the plasma can

Merav Opher; Luis O. Silva; Dean E. Dauger; Viktor K. Decyk; John M. Dawson

2001-05-09T23:59:59.000Z

172

The Dynamical Dipole Mode in Fusion Reactions with Exotic Nuclear Beams  

E-Print Network [OSTI]

We report the properties of the prompt dipole radiation, produced via a collective bremsstrahlung mechanism, in fusion reactions with exotic beams. We show that the gamma yield is sensitive to the density dependence of the symmetry energy below/around saturation. Moreover we find that the angular distribution of the emitted photons from such fast collective mode can represent a sensitive probe of its excitation mechanism and of fusion dynamics in the entrance channel.

V. Baran; C. Rizzo; M. Colonna; M. Di Toro; D. Pierroutsakou

2009-02-09T23:59:59.000Z

173

Effect of nuclear spin on chemical reactions and internal molecular rotation  

SciTech Connect (OSTI)

Part I of this dissertation is a study of the magnetic isotope effect, and results are presented for the separation of /sup 13/C and /sup 12/C isotopes. Two models are included in the theoretical treatment of the effect. In the first model the spin states evolve quantum mechanically, and geminate recombination is calculated by numerically integrating the collision probability times the probability the radical pair is in a singlet state. In the second model the intersystem crossing is treated via first-order rate constants which are average values of the hyperfine couplings. Using these rate constants and hydrodynamic diffusion equations, an analytical solution, which accounts for all collisions, is obtained for the geminate recombination. The two reactions studied are photolysis of benzophenone and toluene and the photolytic decomposition of dibenzylketone (1,3-diphenyl-2-propanone). No magnetic isotope effect was observed in the benzophenone reaction. /sup 13/C enrichment was observed for the dibenzylketone reaction, and this enrichment was substantially enhanced at intermediate viscosities and low temperatures. Part II of this dissertation is a presentation of theory and results for the use of Zeeman spin-lattice relaxation as a probe of methyl group rotation in the solid state. Experimental results are presented for the time and angular dependences of rotational polarization, the methyl group magnetic moment, and methyl-methyl steric interactions. The compounds studied are 2,6-dimethylphenol, methyl iodide, 1,4,5,8-tetramethylanthracene, 1,4,5,8-tetramethylnaphthalene, 1,2,4,5-tetramethylbenzene, and 2,3-dimethylmaleicanhydride.

Sterna, L.L.

1980-12-01T23:59:59.000Z

174

Entrance channel dependence in compound nuclear reactions with loosely bound nuclei  

E-Print Network [OSTI]

The measurement of light charged particles evaporated from the reaction 6,7Li+6Li has been carried out at extreme backward angle in the energy range 14 - 20 MeV. Calculations from the code ALICE91 show that the symmetry of the target-projectile combination and the choice of level density parameter play important roles in explaining the evaporation spectra for these light particle systems. In above barrier energy region the fusion cross-section is not suppressed for these loosely bound nuclei.

S. Adhikari; C. Samanta; C. Basu; S. Ray; A. Chattaerjee; S. Kailas

2005-05-13T23:59:59.000Z

175

GPU ACCELERATION OF THE ISO7 NUCLEAR REACTION NETWORK USING OPENCL  

E-Print Network [OSTI]

in the analysis. This equation is of the form: dvectory dt = vectorf (vectory) (1.7) This equation is therefore a first order, nonlinear, system of ODE. There are many ways to solve a system of this form. These will be discussed in the methods section. Open... METHODOLOGY Solution techniques The iso?7 reaction network takes the form of equation (1.7). This is a non-linear system of ODE. Every worthwhile method to solve these systems of ODE is going to have its advantages, as well as its shortcomings; no method...

Holladay, Daniel 1989-

2012-05-01T23:59:59.000Z

176

Using Nuclear Fusion Reactions to Peer Inside the Core of a Dense Hot  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism inS-4500II Field Emission SEMUsedUserUsing Less Energy

177

Russian Military and Security Forces: A Postulated Reaction to a Nuclear Detonation  

SciTech Connect (OSTI)

In this paper, we will examine how Russia's military and security forces might react to the detonation of a 10-kiloton nuclear weapon placed next to the walls surrounding the Kremlin. At the time of this 'big bang,' Putin is situated outside Moscow and survives the explosion. No one claims responsibility for the detonation. No other information is known. Numerous variables will determine how events ultimately unfold and how the military and security forces will respond. Prior to examining these variables in greater detail, it is imperative to elucidate first what we mean by Russia's military and security forces.

Ball, D

2005-04-29T23:59:59.000Z

178

Nuclear Reaction Cross Sections Database at BNL | U.S. DOE Office of  

Office of Science (SC) Website

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched5 IndustrialIsadoreConnecticut RegionsScienceHampshire RegionsNorthNovemberScience

179

Argonne nuclear pioneers: Chicago Pile 1  

ScienceCinema (OSTI)

On December 2, 1942, 49 scientists, led by Enrico Fermi, made history when Chicago Pile 1 (CP-1) went critical and produced the world's first self-sustaining, controlled nuclear chain reaction. Seventy years later, two of the last surviving CP-1 pioneers, Harold Agnew and Warren Nyer, recall that historic day.

Agnew, Harold; Nyer, Warren

2013-04-19T23:59:59.000Z

180

Development of Dodecaniobate Keggin Chain Materials as Alternative Sorbents for SR and Actinide Removal from High-Level Nuclear Waste Solutions  

SciTech Connect (OSTI)

The current baseline sorbent (monosodium titanate) for Sr and actinide removal from Savannah River Site's high level wastes has excellent adsorption capabilities for Sr but poor performance for the actinides. We are currently investigating the development of alternative materials that sorb radionuclides based on chemical affinity and/or size selectivity. The polyoxometalates, negatively-charged metal oxo clusters, have known metal binding properties and are of interest for radionuclide sequestration. We have developed a class of Keggin-ion based materials, where the Keggin ions are linked in 1- dimensional chains separated by hydrated, charge-balancing cations. These Nb-based materials are stable in the highly basic nuclear waste solutions and show good selectivity for Sr and Pu. Synthesis, characterization and structure of these materials in their native forms and Sr-exchanged forms will be presented.

Nyman, May; Bonhomme, Francois

2004-03-28T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Nuclear Fusion via Triple Collisions in Solar Plasma  

E-Print Network [OSTI]

We consider several nuclear fusion reactions that take place at the center of the sun, which are omitted in the standard pp-chain model. More specifically the reaction rates of the nonradiative production of ^3He, ^7Be, and ^8B nuclei in triple collisions involving electrons are estimated within the framework of the adiabatic approximation. These rates are compared with those of the corresponding binary fusion reactions.

V. B. Belyaev; D. E. Monakhov; N. Shevchenko; S. A. Sofianos; S. A. Rakityansky; M. Braun; L. L. Howell; W. Sandhas

1997-09-09T23:59:59.000Z

182

On Thermonuclear Reaction Rates  

E-Print Network [OSTI]

Nuclear reactions govern major aspects of the chemical evolution od galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the case of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are also discussed.

H. J. Haubold; A. M. Mathai

1996-12-02T23:59:59.000Z

183

Experimental effects on dynamics and thermodynamics in nuclear reactions on the symmetry energy as seen by the CHIMERA 4$\\pi$ detector  

E-Print Network [OSTI]

Heavy ion collisions have been widely used in the last decade to constraint the parameterizations of the symmetry energy term of nuclear equation of state (EOS) for asymmetric nuclear matter as a function of baryonic density. In the Fermi energy domain one is faced with variations of the density within a narrow range of values around the saturation density $\\rho_0$=0.16 fm$^{-3}$ down towards sub-saturation densities. The experimental observables which are sensitive to the symmetry energy are constructed starting from the detected light particles, clusters and heavy fragments that, in heavy ion collisions, are generally produced by different emission mechanisms at different stages and time scales of the reaction. In this review the effects of dynamics and thermodynamics on the symmetry energy in nuclear reactions are discussed and characterized using an overview of the data taken so far with the CHIMERA multi-detector array.

De Filippo, E

2013-01-01T23:59:59.000Z

184

Decay Properties of {sup 266}Bh and {sup 262}Db Produced in the {sup 248}Cm+{sup 23}Na Reaction - Further Confirmation of the {sup 278}113 Decay Chain  

SciTech Connect (OSTI)

Decay properties of an isotope {sup 266}Bh and its daughter nucleus {sup 262}Db produced by the {sup 248}Cm({sup 23}Na,5n) reaction were studied by using a gas-filled recoil separator coupled with a position-sensitive semiconductor detector. {sup 266}Bh was clearly identified from the correlation of the known nuclide, {sup 262}Db. The obtained decay properties of {sup 266}Bh and {sup 262}Db are consistent with those observed in the {sup 278}113 chain by RIKEN collaboration, which provided further confirmation of the discovery of {sup 278}113.

Morita, K.; Morimoto, K.; Kaji, D.; Haba, H.; Ozeki, K.; Kudou, Y.; Yoneda, A.; Ichikawa, T.; Katori, K.; Yoshida, A. [RIKEN Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); Sato, N. [RIKEN Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); Department of Physics, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan); Sumita, T. [RIKEN Nishina Center, RIKEN, Wako, Saitama 351-0198 (Japan); Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510 (Japan); Fujimori, Y.; Tokanai, F. [Department of Physics, Yamagata University, Yamagata 990-8560 (Japan); Goto, S. [Center for Instrumental Analysis, Niigata University, Ikarashi, Nishi-ku, Niigata 950-2181 (Japan); Ideguchi, E. [Center for Nuclear Study, University of Tokyo, Wako, Saitama 351-0198 (Japan); Kasamatsu, Y.; Koura, H.; Tsukada, K. [Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Komori, Y. [Department of Chemistry, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

2010-06-01T23:59:59.000Z

185

Coupled-channels density-matrix approach to low-energy nuclear collision dynamics: A technique for quantifying quantum decoherence effects on reaction observables  

E-Print Network [OSTI]

The coupled-channels density-matrix technique for nuclear reaction dynamics, which is based on the Liouville-von Neumann equation with Lindblad dissipative terms, is developed with the inclusion of full angular momentum couplings. It allows a quantitative study of the role and importance of quantum decoherence in nuclear scattering. Formulae of asymptotic observables that can reveal effects of quantum decoherence are given. A method for extracting energy-resolved scattering information from the time-dependent density matrix is introduced. As an example, model calculations are carried out for the low-energy collision of the $^{16}$O projectile on the $^{154}$Sm target.

Alexis Diaz-Torres

2010-10-18T23:59:59.000Z

186

Activation cross-sections of long lived products of deuteron induced nuclear reactions on dysprosium up to 50 MeV  

E-Print Network [OSTI]

Activation cross-sections for production of 162m,161,155Ho,165,159,157,155Dy and 161,160,156,155Tb radionuclides in deuteron induced nuclear reactions on elemental dysprosium were measured up to 50 MeV for practical application and the test of the predictive power of nuclear reaction model codes. A stacked-foil irradiation technique and off-line gamma-ray spectrometry were used to determine the activities. No earlier cross-section data were found in the literature. The experimental data are compared with the predictions of the ALICE-D, EMPIRE-D and TALYS codes. Integral production yields were calculated from the fitted experimental data.

F. Trknyi; F. Ditri; S. Takcs; J. Csikai; A. Hermanne; A. V. Ignatyuk

2014-02-05T23:59:59.000Z

187

Determination of the cross sections of (n,2n), (n,gamma) nuclear reactions on germanium isotopes at the energy of neutrons 13.96 MeV  

E-Print Network [OSTI]

The cross sections of 70Ge(n,2n)69Ge, 72Ge(n,2n)71Ge, 76Ge(n,gamma)77(g+0.21m)Ge, 76Ge(n,2n)75Ge nuclear reactions were measured at the energy of neutrons 13.96(6) MeV by activation method with gamma-ray and X-ray spectra studies.

S. V. Begun; O. G. Druzheruchenko; O. O. Pupirina; V. K. Tarakanov

2007-01-23T23:59:59.000Z

188

Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)  

SciTech Connect (OSTI)

For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.

Rodriguez, Carmen P. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); ; Pierce, David A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); ; Schweiger, Michael J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); ; Kruger, Albert A. [USDOE Office of River Protection, Richland, WA (United States); Chun, Jaehun [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); ; Hrma, Pavel R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States);

2013-12-03T23:59:59.000Z

189

PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON NUCLEAR PHYSICS  

E-Print Network [OSTI]

STRUCTURE OF NUCLEAR REACTION INDUCED BY LOW ENERGY DEUTERONin the nuclear reaction induced by low energy deuteron on

Saxon, D.S.

2010-01-01T23:59:59.000Z

190

Nuclear structure of {sup 10}B studied with (e,e{prime}), ({pi},{pi}{prime}) and ({gamma},{pi}) reactions  

SciTech Connect (OSTI)

The authors studied nuclear structure of {sup 10}B using (e,e{prime}),({pi},{pi}{prime}) and ({gamma},{pi}) reactions under the distorted wave impulse approximation (DWIA). For this purpose the off-shell dependence of the amplitude was taken into account in the momentum space DWIA. They used the off-shell elementary amplitude of ({pi},{pi}) and ({gamma},{pi}) by the model of Nozawa, Blankleider and Lee. The first order core polarization effects were incorporated with the p-shell wave functions of Cohen and Kurath and Hauge and Maripuu. It was shown that the core-polarization effects greatly improve the agreement with the experimental data and that the simultaneous study of these reactions is useful to probe the spin structure of p-shell nuclei.

Sato, T.; Odagawa, N.; Ohtsubo, H. [Osaka Univ., Toyonaka (Japan). Dept. of Physics; Lee, T.S.H. [Argonne National Lab., IL (United States)

1994-05-01T23:59:59.000Z

191

Nuclear transparency and effective kaon-nucleon cross section from the A(e,e?K+) reaction  

E-Print Network [OSTI]

We have determined the transparency of the nuclear medium to kaons from A(e,e[superscript ?]K+) measurements on [superscript 12]C, [superscript 63]Cu, and [superscript 197]Au targets. The measurements were performed at the ...

Clasie, Benjamin Michael Patrick

192

Nuclear Data Sheets for A=150  

SciTech Connect (OSTI)

The experimental results from the various reaction and decay studies leading to nuclides in the A=150 mass chain have been reviewed. These data are summarized and presented, together with the adopted level schemes and properties, for the nuclides from Cs(Z=55) through Lu(Z=71). This evaluation replaces the previous evaluation by E. der Mateosian and J. K. Tuli (1995De28), which appeared in Nuclear Data Sheets 75, 827 (1995)

Basu, S.K.; Sonzogni, A.A.

2013-04-15T23:59:59.000Z

193

Nuclear Data Sheets for A = 88  

SciTech Connect (OSTI)

The experimental results from the various reaction and radioactive decay studies leading to nuclides in the A=88 mass chain have been reviewed. Nuclides ranging from Ge (Z=32) to Ru (Z=44) are included. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given. This work supersedes the previous evaluation of the data on these nuclides (G. Mukherjee, A.A. Sonzogni Nucl.Data Sheets 105, 419 (2005))

McCutchan, E.A.; Sonzogni, A.A.

2014-01-15T23:59:59.000Z

194

Weak reactions with light nuclei - 6He beta-decay as a test case for the nuclear weak current  

E-Print Network [OSTI]

We present a microscopic calculation of the 6He beta-decay into the ground state of 6Li. To this end we use the impulse approximation to describe the nuclear weak current. The ground state wave functions are obtained from the solution of the nuclear 6-body problem. The nucleonnucleon interaction is described via the J-matrix inverse scattering potential (JISP), and the nuclear problem is solved using the hyperspherical-harmonics approach. This approach results in numerical accuracy of about 2 per mil in the transition matrix element. Bearing in mind that the contribution of meson-exchange currents to the transition matrix element is about 5%, these results pave the way for accurate estimation of their effect.

Doron Gazit; Sergey Vaintraub; Nir Barnea

2009-01-18T23:59:59.000Z

195

Method of controlling fusion reaction rates  

DOE Patents [OSTI]

This invention relates to a method of controlling the reaction rates in a nuclear fusion reactor; and more particularly, to the use of polarized nuclear fuel.

Kulsrud, R.M.; Furth, H.P.; Valeo, E.J.; Goldhaber, M.

1983-05-09T23:59:59.000Z

196

Neutron-proton effective mass splitting in neutron-rich matter and its impacts on nuclear reactions  

E-Print Network [OSTI]

The neutron-proton effective mass splitting in neutron-rich nucleonic matter reflects the space-time nonlocality of the isovector nuclear interaction. It affects the neutron/proton ratio during the earlier evolution of the Universe, cooling of protoneutron stars, structure of rare isotopes and dynamics of heavy-ion collisions. While there is still no consensus on whether the neutron-proton effective mass splitting is negative, zero or positive and how it depends on the density as well as the isospin-asymmetry of the medium, significant progress has been made in recent yeas in addressing these issues. We first recall the connections among the neutron-proton effective mass splitting, the momentum dependence of the isovector potential and the density dependence of the symmetry energy. We then make a few observations about the progress in calculating the neutron-proton effective mass splitting using various nuclear many-body theories and its effects on the isospin-dependence of in-medium nucleon-nucleon cross sec...

Li, Bao-An

2015-01-01T23:59:59.000Z

197

Nuclear transparency and effective kaon-nucleon cross section from the A(e, e'K+) reaction  

E-Print Network [OSTI]

We have determined the transparency of the nuclear medium to kaons from $A(e,e^{'} K^{+})$ measurements on $^{12}$C, $^{63}$Cu, and $^{197}$Au targets. The measurements were performed at the Jefferson Laboratory and span a range in four-momentum-transfer squared Q$^2$=1.1 -- 3.0 GeV$^2$. The nuclear transparency was defined as the ratio of measured kaon electroproduction cross sections with respect to deuterium, ($\\sigma^{A}/\\sigma^{D}$). We further extracted the atomic number ($A$) dependence of the transparency as parametrized by $T= (A/2)^{\\alpha-1}$ and, within a simple model assumption, the in-medium effective kaon-nucleon cross sections. The effective cross sections extracted from the electroproduction data are found to be smaller than the free cross sections determined from kaon-nucleon scattering experiments, and the parameter $\\alpha$ was found to be significantly larger than those obtained from kaon-nucleus scattering. We have included similar comparisons between pion- and proton-nucleon effective cross sections as determined from electron scattering experiments, and pion-nucleus and proton-nucleus scattering data.

Nuruzzaman; D. Dutta; J. Arrington; R. Asaturyan; F. Benmokhtar; W. Boeglin; P. Bosted; A. Bruell; B. Clasie; M. E. Christy; E. Chudakov; M. M. Dalton; A. Daniel; D. Day; L. El Fassi; R. Ent; H. C. Fenker; J. Ferrer; N. Fomin; H. Gao; K. Garrow; D. Gaskel; C. Gray; T. Horn; G. M. Huber; M. K. Jones; N. Kalantarians; C. E. Keppel; K. Kramer; Y. Li; Y. Liang; A. F. Lung; S. Malace; P. Markowitz; A. Matsumura; D. G. Meekins; T. Mertens; T. Miyoshi; H. Mkrtchyan; R. Monson; T. Navasardyan; G. Niculescu; I. Niculescu; Y. Okayasu; A. K. Opper; C. Perdrisat; V. Punjabi; X. Qian; A. W. Rauf; V. M. Rodriquez; D. Rohe; J. Seely; E. Segbefia; G. R. Smith; M. Sumihama; V. Tadevosyan; L. Tang; V. Tvaskis; W. F. Vulcan; F. R. Wesselmann; S. A. Wood; L. Yuan; X. C. Zheng

2011-08-02T23:59:59.000Z

198

Nuclear fission and nuclear safeguards: Common technologies and challenges  

SciTech Connect (OSTI)

Nuclear fission and nuclear safeguards have much in common, including the basic physical phenomena and technologies involved as well as the commitments and challenges posed by expanding nuclear programs in many countries around the world. The unique characteristics of the fission process -- such as prompt and delayed neutron and gamma ray emission -- not only provide the means of sustaining and controlling the fission chain reaction, but also provide unique ''signatures'' that are essential to quantitative measurement and effective safeguarding of key nuclear materials (notably /sup 239/Pu and /sup 235/U) against theft, loss, or diversion. In this paper, we trace briefly the historical emergence of safeguards as an essential component of the expansion of the nuclear enterprise worldwide. We then survey the major categories of passive and active nondestructive assay techniques that are currently in use or under development for rapid, accurate measurement and verification of safe-guarded nuclear materials in the many forms in which they occur throughout the nuclear fuel cycle. 23 refs., 14 figs.

Keepin, G.R.

1989-01-01T23:59:59.000Z

199

NNSA TRITIUM SUPPLY CHAIN  

SciTech Connect (OSTI)

Savannah River Site plays a critical role in the Tritium Production Supply Chain for the National Nuclear Security Administration (NNSA). The entire process includes: Production of Tritium Producing Burnable Absorber Rods (TPBARs) at the Westinghouse WesDyne Nuclear Fuels Plant in Columbia, South Carolina Production of unobligated Low Enriched Uranium (LEU) at the United States Enrichment Corporation (USEC) in Portsmouth, Ohio Irradiation of TPBARs with the LEU at the Tennessee Valley Authority (TVA) Watts Bar Reactor Extraction of tritium from the irradiated TPBARs at the Tritium Extraction Facility (TEF) at Savannah River Site Processing the tritium at the Savannah River Site, which includes removal of nonhydrogen species and separation of the hydrogen isotopes of protium, deuterium and tritium.

Wyrick, Steven [Savannah River National Laboratory, Aiken, SC, USA; Cordaro, Joseph [Savannah River National Laboratory, Aiken, SC, USA; Founds, Nanette [National Nuclear Security Administration, Albuquerque, NM, USA; Chambellan, Curtis [National Nuclear Security Administration, Albuquerque, NM, USA

2013-08-21T23:59:59.000Z

200

Why Supply Chain  

E-Print Network [OSTI]

Why supply chain explains the importance of supply chains. It includes an introduction to ERP as designed by SAP.

Datta, Shoumen

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Sleeve reaction chamber system  

DOE Patents [OSTI]

A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

Northrup, M. Allen (Berkeley, CA); Beeman, Barton V. (San Mateo, CA); Benett, William J. (Livermore, CA); Hadley, Dean R. (Manteca, CA); Landre, Phoebe (Livermore, CA); Lehew, Stacy L. (Livermore, CA); Krulevitch, Peter A. (Pleasanton, CA)

2009-08-25T23:59:59.000Z

202

The basic K nuclear cluster K- pp and its enhanced formation in the p + p -> K+ + X reaction  

E-Print Network [OSTI]

We have studied the structure of K- pp nuclear cluster comprehensively by solving this three-body system exactly in a variational method starting from the Ansatz that the Lambda(1405) resonance (Lambda*) is a K-p bound state. We have found that our original prediction for the presence of K-pp as a compact bound system with M = 2322$ MeV/c2, B = 48 MeV and Gamma = 60 MeV remains unchanged by varying the Kba-rN and NN interactions widely as far as they reproduce Lambda(1405). The structure of K- pp reveals a molecular feature, namely, the K- in Lambda* as an "atomic center" plays a key role in producing strong covalent bonding with the other proton. We have shown that the elementary process, p + p -> K+ + Lambda* + p, which occurs in a short impact parameter and with a large momentum transfer (Q ~ 1.6$ GeV/c), leads to unusually large self-trapping of Lambda* by the participating proton, since the Lambda*-p system exists as a compact doorway state propagating to K- pp (R{Lambda*-p} ~ 1.67 fm).

Toshimitsu Yamazaki; Yoshinori Akaishi

2007-09-06T23:59:59.000Z

203

I. Nuclear Production Reaction and Chemical Isolation Procedure for 240Am II. New Superheavy Element Isotopes: 242Pu(48Ca,5n)285-114  

E-Print Network [OSTI]

of superheavy nuclei in cold fusion reactions. Phys. Rev. C,transfermium elements in cold fusion reactions. Phys. Rev.have been deemed cold fusion reactions because of the low

Ellison, Paul Andrew

2011-01-01T23:59:59.000Z

204

Nuclear reactor engineering  

SciTech Connect (OSTI)

Chapters are presented concerning energy from nuclear fission; nuclear reactions and radiations; diffusion and slowing-down of neutrons; principles of reactor analysis; nuclear reactor kinetics and control; energy removal; non-fuel reactor materials; the reactor fuel system; radiation protection and environmental effects; nuclear reactor shielding; nuclear reactor safety; and power reactor systems.

Glasstone, S.; Sesonske, A.

1981-01-01T23:59:59.000Z

205

Absolute nuclear material assay  

DOE Patents [OSTI]

A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

2012-05-15T23:59:59.000Z

206

Nuclear Processes at Solar Energy  

E-Print Network [OSTI]

LUNA, Laboratory for Underground Nuclear Astrophysics at Gran Sasso, is measuring fusion cross sections down to the energy of the nucleosynthesis inside stars. Outstanding results obtained up to now are the cross-section measurements within the Gamow peak of the Sun of $^{3}He(^{3}He,2p)^{4}He$ and the $D(p,\\gamma)^{3}He$. The former plays a big role in the proton-proton chain, largely affecting the calculated solar neutrino luminosity, whereas the latter is the reaction that rules the proto-star life during the pre-main sequence phase. The implications of such measurements will be discussed. Preliminary results obtained last year on the study of $^{14}N(p,\\gamma)^{15}O$, the slowest reaction of the CNO cycle, will also be shown.

Carlo Broggini

2003-08-29T23:59:59.000Z

207

Charge separation in photoredox reactions. Final report  

SciTech Connect (OSTI)

The structural aspects controlling charge separation in molecular photoionization reactions in organized molecular assemblies involving micelles, reverse micelles and vesicles are being studied by optical and electron magnetic resonance techniques including the time domain technique of deuterium electron spin echo modulation (ESEM) and matrix proton electron nuclear double resonance (ENDOR) to measure weak electron-nuclear dipolar interactions. ESEM and matrix ENDOR are particularly well adapted to the study of disordered systems as exemplified by micelles and vesicles. The photoionization yields of alkylphenothiazines in micelles and vesicles have been shown to depend on the alkyl chain length and to correlate with relative distances from the surfactant assembly interface measured by deuterium ESEM and matrix proton ENDOR. The photoionization of alkylmethylviologens versus alkyl chain length has also been studied in vesicles, micelles and reverse micelles. Nitroxide spin probes have been used to study the degree of water penetration into mixed ionic/nonionic poly(ethylene oxide) and cationic/anionic micelles by using ESEM methods and selectively deuterated surfactants. The effect of urea interaction at micellar interfaces on the interface hydration has also been evaluated by studying nitroxide probes with ESEM.

Kevan, L.

1993-07-15T23:59:59.000Z

208

Nuclear Reactions and Reactor Safety  

E-Print Network [OSTI]

. Snoeijer 85 On the drag of turbulent vortex rings L. Gan, J. R. Dawson & T. B. Nickels 106 Subcritical Linear water waves: the horizontal motion of a structure in the time domain P. McIver 313 Transmission

Onuchic, José

209

Nuclear Science--A Guide to the Nuclear Science Wall Chart 2003 Contemporary Physics Education Project (CPEP)  

E-Print Network [OSTI]

Nuclear Science--A Guide to the Nuclear Science Wall Chart ©2003 Contemporary Physics Education Project (CPEP) 7-1 Chapter 7 Nuclear Reactions Nuclear reactions and nuclear scattering are used, protons, alphas, or "heavy ions"), creates these reactions when they strike a target nucleus. Nuclear

210

acrosome reaction rate: Topics by E-print Network  

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

fertilizing capacity29 . A Received 1 March; accepted 23 April Myhr, Karen 2 On thermonuclear reaction rates Astrophysics (arXiv) Summary: Nuclear reactions govern major...

211

A Classical Approach in Simple Nuclear Fusion Reaction 1H2 + 1H3 using Two-Dimension Granular Molecular Dynamics Model  

E-Print Network [OSTI]

Molecular dynamics in 2-D accompanied by granular model provides an opportunity to investigate binding between nuclei particles and its properties that arises during collision in a fusion reaction. A fully classical approach is used to observe the influence of initial angle of nucleus orientation to the product yielded by the reaction. As an example, a simplest fusion reaction between 1H2 and 1H3 is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary 2He4 nucleus.

Sparisoma Viridi; Rizal Kurniadi; Abdul Waris; Yudha Satya Perkasa

2011-09-30T23:59:59.000Z

212

Stellar reaction rate for (22)Mg + p -> (23)Al from the asymptotic normalization coefficient in the mirror nuclear system (22)Ne + n -> (23)Ne  

E-Print Network [OSTI]

The production of (22)Na in ONe novae can be influenced by the (22)Mg(p,gamma)(23)Al reaction. To investigate this reaction rate at stellar energies, we have determined the asymptotic normalization coefficient (ANC) for (22)Mg + p -> (23)Al through...

Al-Abdullah, T.; Carstoiu, F.; Chen, X.; Clark, H. L.; Fu, C.; Gagliardi, Carl A.; Lui, Y. -W; Mukhamedzhanov, A.; Tabacaru, G.; Tokimoto, Y.; Trache, L.; Tribble, Robert E.

2010-01-01T23:59:59.000Z

213

E-Print Network 3.0 - allele-specific polymerase chain Sample...  

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

is allele-specific Polymerase Chain Reaction (PCR). This requires genomic DNA Source: Los Alamos National Laboratory, Theoretical Division, Condensed Matter and Statistical Physics...

214

Nuclear evaporation process with simultaneous multiparticle emission  

E-Print Network [OSTI]

The nuclear evaporation process is reformulated by taking into account simultaneous multiparticle emission from a hot compound nucleus appearing as an intermediate state in many nuclear reaction mechanisms. The simultaneous emission of many particles is particularly relevant for high excitation energy of the compound nucleus.These channels are effectively open in competition with the single particle emissions and fission in this energy regime. Indeed, the inclusion of these channels along the decay evaporating chain shows that the yield of charged particles and occurrence of fission are affected by these multiparticle emission processes of the compounded nucleus, when compared to the single sequential emission results. The effect also shows a qualitative change in the neutron multiplicity of different heavy compound nucleus considered. This should be an important aspect for the study of spallation reaction in Acceleration Driven System (ADS) reactors. The majority of neutrons generated in these reactions come from the evaporation stage of the reaction, the source of neutron for the system. A Monte Carlo simulation is employed to determine the effect of these channels on the particle yield and fission process. The relevance of the simultaneous particle emission with the increasing of excitation energy of the compound nucleus is explicitly shown.

Leonardo P. G. De Assis; Sergio B. Duarte; Bianca M. Santos

2012-08-07T23:59:59.000Z

215

Nuclear Astrophysics  

E-Print Network [OSTI]

Nuclear physics has a long and productive history of application to astrophysics which continues today. Advances in the accuracy and breadth of astrophysical data and theory drive the need for better experimental and theoretical understanding of the underlying nuclear physics. This paper will review some of the scenarios where nuclear physics plays an important role, including Big Bang Nucleosynthesis, neutrino production by our sun, nucleosynthesis in novae, the creation of elements heavier than iron, and neutron stars. Big-bang nucleosynthesis is concerned with the formation of elements with A nuclear physics inputs required are few-nucleon reaction cross sections. The nucleosynthesis of heavier elements involves a variety of proton-, alpha-, neutron-, and photon-induced reactions, coupled with radioactive decay. The advent of radioactive ion beam facilities has opened an important new avenue for studying these processes, as many involve radioactive species. Nuclear physics also plays an important role in neutron stars: both the nuclear equation of state and cooling processes involving neutrino emission play a very important role. Recent developments and also the interplay between nuclear physics and astrophysics will be highlighted.

Carl R. Brune

2005-02-28T23:59:59.000Z

216

New measurements of the astrophysical S factor for {sup 12}C(p,{gamma}){sup 13}N reaction at low energies and the asymptotic normalization coefficient (nuclear vertex constant) for the p+{sup 12}C{yields}{sup 13}N reaction  

SciTech Connect (OSTI)

New measurements of differential and total cross sections for the {sup 12}C(p,{gamma}){sup 13}N reaction have been made at beam energies of E{sub p}=354,390,460,463,565,750, and 1061 keV. Analysis of the astrophysical S factor S(E) for the {sup 12}C(p,{gamma}){sup 13}N reaction at low energies and of the reaction rates has been carried out within the R-matrix approach by using the previously measured nuclear vertex constant (or the respective asymptotic normalization coefficient) for the virtual decay {sup 13}N{yields}p+{sup 12}C to fix the direct capture part of the amplitude in S(E). It is demonstrated that the R-matrix approach, using the measured asymptotic normalization coefficient, can be employed as an ideal tool, minimizing the uncertainties associated with a calculation of the direct capture cross section of the {sup 12}C(p,{gamma}){sup 13}N reaction at extremely low energies. New information on the proton and {gamma} width for the first excited state of {sup 13}N is obtained.

Burtebaev, N.; Zazulin, D. M. [Institute of Nuclear Physics, 050032 Almaty (Kazakhstan); Igamov, S. B.; Yarmukhamedov, R. [Institute of Nuclear Physics, 100214 Tashkent (Uzbekistan); Peterson, R. J. [Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States)

2008-09-15T23:59:59.000Z

217

Polypeptide chain collapse and protein folding Jayant B. Udgaonkar  

E-Print Network [OSTI]

Review Polypeptide chain collapse and protein folding Jayant B. Udgaonkar National Centre is an integral component of a protein folding reaction. In this review, exper- imental characterization solvent [2]. A distinctive physical feature of any protein folding reaction is the greater than 3-fold

218

Microfabricated sleeve devices for chemical reactions  

DOE Patents [OSTI]

A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and non-silicon based materials to provide the thermal properties desired. For example, the chamber may combine a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

Northrup, M. Allen (Berkeley, CA)

2003-01-01T23:59:59.000Z

219

NUCLEAR STRUCTURE AND HEAVY-ION FUSION  

E-Print Network [OSTI]

mechanisms leading to fusion, nuclear structure is affectingknoi,. A [he "nuclear structure" in fusion will consist ofCI i CO I0 + Be fusion I0 ' -cm Nuclear reaction S-factors

Stokstad, R.G.

2010-01-01T23:59:59.000Z

220

Ernst Boris Chain CHAIN-FLOREY  

E-Print Network [OSTI]

Professor Benjamin Chain Professor Sir Andrew McMichael Professor Dame Kay Davies 11 Mentors Professor Irene Jiexin Zhao Dr James Tomlinson Dr Thomas Oates Dr Philip Webster Dr Eleanor Sandhu Dr Andrew Innes Dr knowledge of norman heatley, resulted in the isolation and first medical application of an antibiotic

Rosso, Lula

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Nuclear Science References Coding Manual D.F. Winchell  

E-Print Network [OSTI]

Nuclear Science References Coding Manual D.F. Winchell National Nuclear Data Center Brookhaven and coding procedures for specific topics . . 18 3.2.1 NUCLEAR REACTIONS . . . . . . . . . . . . . . . . 19 3.2.2 RADIOACTIVITY . . . . . . . . . . . . . . . . . . . . 20 3.2.3 NUCLEAR STRUCTURE

Ohta, Shigemi

222

Chapter 25: Radioactivity, Nuclear Processes, and Applications  

E-Print Network [OSTI]

Chapter 25: Radioactivity, Nuclear Processes, and Applications 1 The discovery of nuclear chain only must do everything in our power to safeguard against its abuse. ~ Albert Einstein Did you read Contains positively charged protons. Held together by the Nuclear Strong ForceNuclear Strong Force. James

Hart, Gus

223

E-Print Network 3.0 - alpha reactions cross-sections Sample Search...  

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

+ Ag reaction for di27;erent cross sections, as a function of time. 12... ; 50 P. Danielewicz Another nuclear stopping observable has been the reaction cross section for...

224

European supply chain study  

E-Print Network [OSTI]

Introduction: Supply chain management has been defined as, "..a set of approaches utilized to efficiently integrate suppliers, manufacturers, warehouses and stores, so that merchandise is produced and distributed at the ...

Puri, Mohitkumar

2009-01-01T23:59:59.000Z

225

Improving supply chain resilience  

E-Print Network [OSTI]

Due to the global expansion of Company A's supply chain network, it is becoming more vulnerable to many disruptions. These disruptions often incur additional costs; and require time to respond to and recover from these ...

Leung, Elsa Hiu Man

2009-01-01T23:59:59.000Z

226

Chemistry of heavy ion reactions  

SciTech Connect (OSTI)

The use of heavy ions to induce nuclear reactions was reported as early as 1950. Since that time it has been one of the most active areas of nuclear research. Intense beams of ions as heavy as uranium with energies high enough to overcome the Coulomb barriers of even the heaviest elements are available. The wide variety of possible reactions gives rise to a multitude of products which have been studied by many ingenious chemical and physical techniques. Chemical techniques have been of special value for the separation and unequivocal identification of low yield species from the plethora of other nuclides present. Heavy ion reactions have been essential for the production of the trans-Md elements and a host of new isotopes. The systematics of compound nucleus reactions, transfer reactions, and deeply inelastic reactions have been elucidated using chemical techniques. A review of the variety of chemical procedures and techniques which have been developed for the study of heavy ion reactions and their products is given. Determination of the chemical properties of the trans-Md elements, which are very short-lived and can only be produced an ''atom-at-a-time'' via heavy ion reactions, is discussed. 53 refs., 19 figs.

Hoffman, D.C.

1988-10-01T23:59:59.000Z

227

Electromagnetic reactions on light nuclei  

E-Print Network [OSTI]

Electromagnetic reactions on light nuclei are fundamental to advance our understanding of nuclear structure and dynamics. The perturbative nature of the electromagnetic probes allows to clearly connect measured cross sections with the calculated structure properties of nuclear targets. We present an overview on recent theoretical ab-initio calculations of electron-scattering and photonuclear reactions involving light nuclei. We encompass both the conventional approach and the novel theoretical framework provided by chiral effective field theories. Because both strong and electromagnetic interactions are involved in the processes under study, comparison with available experimental data provides stringent constraints on both many-body nuclear Hamiltonians and electromagnetic currents. We discuss what we have learned from studies on electromagnetic observables of light nuclei, starting from the deuteron and reaching up to nuclear systems with mass number A=16.

Sonia Bacca; Saori Pastore

2014-07-13T23:59:59.000Z

228

Large Scale Computing and Storage Requirements for Nuclear Physics Research  

E-Print Network [OSTI]

Low-Energy Nuclear Physics National Joseph Carlson / HPC Initiative: Building a Universal Joseph Carlson Jonathan Engel Nuclear Energy Density Functional Structure and Reactions

Gerber, Richard A.

2012-01-01T23:59:59.000Z

229

The definition of reaction coordinates for reaction-path dynamics Gregory A. Natanson  

E-Print Network [OSTI]

The definition of reaction coordinates for reaction-path dynamics Gregory A. Natanson Computer only small-amplitude deviations from a minimum-energy path (MEP) through nuclear coordinate space. Thus. In choosing the coordinate system, the critical issue is the definition of the reaction coordinate. Along

Truong, Thanh N.

230

[Nuclear theory: Annual report  

SciTech Connect (OSTI)

This report discusses topics on : nuclear structure models; algebraic models of hadronic structure; nuclear reactions; hot rotating nuclei; chaos in nuclei; signatures of the quark-gluon plasma; hadronic spectroscopy; octupole collectivity in nuclei; finite-temperature methods for the many-body problem; and classical limit of algebraic hamiltonians. (LSP)

Iachello, F.; Alhassid, Y.; Kusnezov, D.

1991-12-31T23:59:59.000Z

231

(Nuclear theory: Annual report)  

SciTech Connect (OSTI)

This report discusses topics on : nuclear structure models; algebraic models of hadronic structure; nuclear reactions; hot rotating nuclei; chaos in nuclei; signatures of the quark-gluon plasma; hadronic spectroscopy; octupole collectivity in nuclei; finite-temperature methods for the many-body problem; and classical limit of algebraic hamiltonians. (LSP)

Iachello, F.; Alhassid, Y.; Kusnezov, D.

1991-01-01T23:59:59.000Z

232

Statistical Description of Cluster Emission Including Direct Reactions  

SciTech Connect (OSTI)

The coalescence idea of the Iwamoto-Harada-Bisplinghoff model within the pre-equilibrium (exciton model) approach to nuclear reactions has been generalized and the links to direct reactions have been outlined.

Betak, Emil [Institute of Physics, Slovak Academy of Sciences, 84511 Bratislava (Slovakia); Faculty of Philosophy and Sciences, Silesian University, 74601 Opava (Czech Republic)

2006-04-26T23:59:59.000Z

233

activation reaction rate: Topics by E-print Network  

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

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 On thermonuclear reaction rates Astrophysics (arXiv) Summary: Nuclear reactions govern major...

234

Chemical Reactions in DSMC  

SciTech Connect (OSTI)

DSMC simulations of chemically reacting gas flows have generally employed procedures that convert the macroscopic chemical rate equations to reaction cross-sections at the microscopic level. They therefore depend on the availability of experimental data that has been fitted to equations of the Arrhenius form. This paper presents a physical model for dissociation and recombination reactions and a phenomenological model for exchange and chain reactions. These are based on the vibrational states of the colliding molecules and do not require any experimentally-based data. The simplicity of the models allows the corresponding rate equations to be written down and, while these are not required for the implementation of the models, they facilitate their validation. The model is applied to a typical hypersonic atmospheric entry problem and the results are compared with the corresponding results from the traditional method. It is also used to investigate both spontaneous and forced ignition as well as the structure of a deflagration wave in an oxygen-hydrogen mixture.

Bird, G. A. [GAB Consulting Pty Ltd, 144/110 Sussex Street, Sydney NSW 2000 (Australia)

2011-05-20T23:59:59.000Z

235

Nuclear Data Sheets for A = 239  

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

Spectroscopic data and level schemes from radioactive decay and nuclear reaction studies are presented here for all nuclei with mass number A=239. In general, a relatively small amount of new data on this mass chain has been reported since the previous evaluation in 2003. However, special evaluations, such as ''Database of prompt gamma rays from slow neutroncapture from elemental analysis'' (2007ChZX), have provided additional precise data for levels in 29U. Also, new Coulomb excitation measurements in 239Pu have extended the knowledge of the 1/2[631] rotational band up to J?=(55/2+)J?=(55/2+), and that of the octupole vibrational band up to J?=(53/2-)J?=(53/2-). For historical knowledge it is worth mentioning the report on the Discovery of isotopes of the transuranium elements with 93 0) interpolated from those for eveneven adjacent nuclei given by 1998Ak04.

Browne, E. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Brookhaven National Laboratory (BNL), Upton, NY (United States), National Nuclear Data Center; Tuli, J. K. [Brookhaven National Laboratory (BNL), Upton, NY (United States), National Nuclear Data Center

2014-11-01T23:59:59.000Z

236

Theories of Low Energy Nuclear Transmutations  

E-Print Network [OSTI]

Employing concrete examples from nuclear physics it is shown that low energy nuclear reactions can and have been induced by all of the four fundamental interactions (i) (stellar) gravitational, (ii) strong, (iii) electromagnetic and (iv) weak. Differences are highlighted through the great diversity in the rates and similarity through the nature of the nuclear reactions initiated by each.

Y. N. Srivastava; A. Widom; J. Swain

2012-10-27T23:59:59.000Z

237

THE NUCLEAR SURFACE D. F. JACKSON  

E-Print Network [OSTI]

THE NUCLEAR SURFACE D. F. JACKSON Dept. of Physics, University of Surrey, Guildford, U.K. Abstract. -- Nuclear scattering and reactions which give information on the nuclear surface are described. These processes include elastic scattering of electrons and of high energy protons, pion reactions with nuclei

Boyer, Edmond

238

Safe Chain Saw Operation.  

E-Print Network [OSTI]

Electric-powered saws start instantly, are rela tively quiet, have no exhaust fumes or hot muffier, carry no fuel and are generally less expensive than gasoline saws. However, electric saws are limited in size (usually under 14-inch bars) and reach only... AND FELLING WEDGES I EXTI~bRJiSHER ~ ~ CHAIN FILING ~ ~ TOOLS FUEL CAN AND FUNNEL SHARP AX Figure 3. Use proper equipment to help you do the job safely. 2 /. SLEDGE HAMMER SHOVEL Special cautions: Electrically-powered chain saws re quire special...

Nelson, Gary S.

1982-01-01T23:59:59.000Z

239

acute-phase reaction: Topics by E-print Network  

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

After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an...

240

alpha-transfer reactions: Topics by E-print Network  

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

After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an...

Note: This page contains sample records for the topic "nuclear chain reaction" 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

aldol condensation reactions: Topics by E-print Network  

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

of the Bose-Einstein condensation mechanism for low-energy nuclear reaction (LENR) and transmutation processes in condensed matters. For the case of deutron-lithium...

242

NUFinancials Supply Chain  

E-Print Network [OSTI]

NUFinancials Supply Chain FMS801 & 803 Purchasing Glossary 03/31/2010 © 2010 Northwestern University FMS801 & 803 1 Purchasing Glossary Guide to terms used in iBuyNU and NUFinancials purchasing Term, faculty salary, office supplies. Similar to CUFS Object Code, Revenue Source, and Balance Sheet. Note

Shull, Kenneth R.

243

Nuclear Fabrication Consortium  

SciTech Connect (OSTI)

This report summarizes the activities undertaken by EWI while under contract from the Department of Energy (DOE) â?? Office of Nuclear Energy (NE) for the management and operation of the Nuclear Fabrication Consortium (NFC). The NFC was established by EWI to independently develop, evaluate, and deploy fabrication approaches and data that support the re-establishment of the U.S. nuclear industry: ensuring that the supply chain will be competitive on a global stage, enabling more cost-effective and reliable nuclear power in a carbon constrained environment. The NFC provided a forum for member original equipment manufactures (OEM), fabricators, manufacturers, and materials suppliers to effectively engage with each other and rebuild the capacity of this supply chain by : â?¢ Identifying and removing impediments to the implementation of new construction and fabrication techniques and approaches for nuclear equipment, including system components and nuclear plants. â?¢ Providing and facilitating detailed scientific-based studies on new approaches and technologies that will have positive impacts on the cost of building of nuclear plants. â?¢ Analyzing and disseminating information about future nuclear fabrication technologies and how they could impact the North American and the International Nuclear Marketplace. â?¢ Facilitating dialog and initiate alignment among fabricators, owners, trade associations, and government agencies. â?¢ Supporting industry in helping to create a larger qualified nuclear supplier network. â?¢ Acting as an unbiased technology resource to evaluate, develop, and demonstrate new manufacturing technologies. â?¢ Creating welder and inspector training programs to help enable the necessary workforce for the upcoming construction work. â?¢ Serving as a focal point for technology, policy, and politically interested parties to share ideas and concepts associated with fabrication across the nuclear industry. The report the objectives and summaries of the Nuclear Fabrication Consortium projects. Full technical reports for each of the projects have been submitted as well.

Levesque, Stephen

2013-04-05T23:59:59.000Z

244

Lesson 5 - Fission and Chain Reactions | Department of Energy  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in3.pdfEnergy Health andofIanJenniferLeslie Pezzullo: ... Biomass Program Webinar3 -5 -

245

NUCLEAR DATA RESOURCES FOR ADVANCED ANALYSIS AND SIMULATION.  

SciTech Connect (OSTI)

The mission of the National Nuclear Data Center (NNDC) includes collection, evaluation, and dissemination of nuclear physics data for basic nuclear research and applied nuclear technologies. In 2004, to answer the needs of nuclear data users, NNDC completed a project to modernize storage and management of its databases and began offering new nuclear data Web services. Examples of nuclear reaction, nuclear structure and decay database applications along with a number of nuclear science codes are also presented.

PRITYCHENKO, B.

2006-06-05T23:59:59.000Z

246

Nuclear Structure Aspects in Nuclear Astrophysics  

SciTech Connect (OSTI)

Nuclear Astrophysics as a broad and diverse field of study can be viewed as a magnifier of the impact of microscopic processes on the evolution of macroscopic events. One of the primary goals in Nuclear Astrophysics is the understanding of the nucleosynthesis processes that take place in the cosmos and the simulation of the correlated stellar and explosive burning scenarios. These simulations are strongly dependent on the input from Nuclear Physics which sets the time scale for all stellar dynamic processes--from giga-years of stellar evolution to milliseconds of stellar explosions--and provides the basis for most of the signatures that we have for the interpretation of these events--from stellar luminosities, elemental and isotopic abundances to neutrino flux from distant supernovae. The Nuclear Physics input comes through nuclear structure, low energy reaction rates, nuclear masses, and decay rates. There is a common perception that low energy reaction rates are the most important component of the required nuclear physics input; however, in this article we take a broader approach and present an overview of the close correlation between various nuclear structure aspects and their impact on nuclear astrophysics. We discuss the interplay between the weak and the strong forces on stellar time scales due to the limitations they provide for the evolution of slow and rapid burning processes. The effects of shell structure in nuclei on stellar burning processes as well as the impact of clustering in nuclei is outlined. Furthermore we illustrate the effects of the various nuclear structure aspects on the major nucleosynthesis processes that have been identified in the last few decades. We summarize and provide a coherent overview of the impact of all aspects of nuclear structure on nuclear astrophysics.

Smith, Michael Scott [ORNL

2006-12-01T23:59:59.000Z

247

The Role of the Sellafield Ltd Centres of Expertise in Engaging with the Science, Environment and Technology Supply Chain and University Sector to Support Site Operations and Decommissioning in the UK Nuclear Industry - 13018  

SciTech Connect (OSTI)

The development and maintenance of the broad range of the highly technical skills required for safe and successful management of nuclear sites is of vital importance during routine operations, decommissioning and waste treatment activities.. In order to maintain a core team of technical experts, across all of the disciplines required for these tasks, the approach which has been taken by the Sellafield Ltd has been the formation of twenty five Centres of Expertise (CoE), each covering key aspects of the technical skills required for nuclear site operations. Links with the Specialist University Departments: The CoE leads are also responsible for establishing formal links with university departments with specialist skills and facilities relevant to their CoE areas. The objective of these links is to allow these very specialist capabilities within the university sector to be more effectively utilized by the nuclear industry, which benefits both sectors. In addition to the utilization of specialist skills, the university links are providing an important introduction to the nuclear industry for students and researchers. This is designed to develop the pipeline of potential staff, who will be required in the future by both the academic and industrial sectors. (authors)

Butcher, Ed [Uranium and Reactive Metals Centre of Expertise Lead, Technical Directorate, Sellafield Ltd, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom)] [Uranium and Reactive Metals Centre of Expertise Lead, Technical Directorate, Sellafield Ltd, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Connor, Donna [Technical Capability Manager, Technical Directorate, Sellafield Ltd, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom)] [Technical Capability Manager, Technical Directorate, Sellafield Ltd, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Keighley, Debbie [Head of Profession, Technical Directorate, Sellafield Ltd, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom)] [Head of Profession, Technical Directorate, Sellafield Ltd, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom)

2013-07-01T23:59:59.000Z

248

Third Party Nuclear Liability: The Case of a Supplier in the United Kingdom  

E-Print Network [OSTI]

The law surrounding third party nuclear liability is important to all parties in the nuclear supply chain whether they are providing decommissioning services, project management expertise or a new reactor. This paper examines third party nuclear...

Thomas, Anthony; Heffron, Raphael J.

2012-02-27T23:59:59.000Z

249

Nuclear effects in Neutrino Nuclear Cross-sections  

E-Print Network [OSTI]

Nuclear effects in the quasielastic and inelastic scattering of neutrinos(antineutrinos) from nuclear targets have been studied. The calculations are done in the local density approximation which take into account the effect of nucleon motion as well as renormalisation of weak transition strengths in the nuclear medium. The inelastic reaction leading to production of pions is calculated in a $\\Delta$ dominance model taking into account the renormalization of $\\Delta$ properties in the nuclear medium.

S. K. Singh; M. Sajjad Athar

2007-10-24T23:59:59.000Z

250

Photoneutron reactions in astrophysics  

SciTech Connect (OSTI)

Among key problems in nuclear astrophysics, that of obtaining deeper insight into the mechanism of synthesis of chemical elements is of paramount importance. The majority of heavy elements existing in nature are produced in stars via radiative neutron capture in so-called s- and r processes, which are, respectively, slow and fast, in relation to competing ?{sup ?}-decay processes. At the same time, we know 35 neutron-deficient so-called bypassed p-nuclei that lie between {sup 74}Se and {sup 196}Hg and which cannot originate from the aforementioned s- and r-processes. Their production is possible in (?, n), (?, p), or (?, ?) photonuclear reactions. In view of this, data on photoneutron reactions play an important role in predicting and describing processes leading to the production of p-nuclei. Interest in determining cross sections for photoneutron reactions in the threshold energy region, which is of particular importance for astrophysics, has grown substantially in recent years. The use of modern sources of quasimonoenergetic photons obtained in processes of inverse Compton laser-radiation scattering on relativistic electronsmakes it possible to reveal rather interesting special features of respective cross sections, manifestations of pygmy E1 and M1 resonances, or the production of nuclei in isomeric states, on one hand, and to revisit the problem of systematic discrepancies between data on reaction cross sections from experiments of different types, on the other hand. Data obtained on the basis of our new experimental-theoretical approach to evaluating cross sections for partial photoneutron reactions are invoked in considering these problems.

Varlamov, V. V., E-mail: Varlamov@depni.sinp.msu.ru; Ishkhanov, B. S.; Orlin, V. N.; Peskov, N. N.; Stopani, K. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2014-12-15T23:59:59.000Z

251

Nuclear Science Division Annual Report 1984-85  

E-Print Network [OSTI]

M. Xcssi. and W. Wolf. Nuclear-Reaction-Time Studies of U +K Produced in Relativistic Nuclear Collisions Phys. Lett.Momentum Distributions of Nuclear Fragments in im Collisions

Mahoney Editor, Jeannette

2010-01-01T23:59:59.000Z

252

The Tourism Global Value Chain  

E-Print Network [OSTI]

The Tourism Global Value Chain ECONOMIC UPGRADING AND WORKFORCE DEVELOPMENT Michelle Christian 2011 CENTER on GLOBALIZATION, GOVERNANCE & COMPETITIVENESS #12;The Tourism Global Value Chain: Economic: November 17, 2011 #12;The Tourism Global Value Chain: Economic Upgrading and Workforce Development i Table

Richardson, David

253

Environmental decision making: supply-chain considerations  

E-Print Network [OSTI]

manufacturing environmental impact and enable the reductionthe supply chain (3) environmental impact and cost must bethe supply chains environmental impact and flexibility (

Reich-Weiser, Corinne; Dornfeld, David

2008-01-01T23:59:59.000Z

254

Supply Chain Analysis Center for Transportation Analysis  

E-Print Network [OSTI]

Supply Chain Analysis Center for Transportation Analysis 2360 Cherahala Boulevard Knoxville, TN experience in supply chain analysis and automated support for supply chain systems. ORNL's Capabilities Optimization modeling for supply chain systems, including: Facility number and location analysis

255

Nuclear Science References Database  

E-Print Network [OSTI]

The Nuclear Science References (NSR) database together with its associated Web interface, is the world's only comprehensive source of easily accessible low- and intermediate-energy nuclear physics bibliographic information for more than 210,000 articles since the beginning of nuclear science. The weekly-updated NSR database provides essential support for nuclear data evaluation, compilation and research activities. The principles of the database and Web application development and maintenance are described. Examples of nuclear structure, reaction and decay applications are specifically included. The complete NSR database is freely available at the websites of the National Nuclear Data Center http://www.nndc.bnl.gov/nsr and the International Atomic Energy Agency http://www-nds.iaea.org/nsr.

B. Pritychenko; E. B?tk; B. Singh; J. Totans

2014-07-08T23:59:59.000Z

256

Radioactive target needs for nuclear reactor physics and nuclear astrophysics , G. Barreau1  

E-Print Network [OSTI]

Radioactive target needs for nuclear reactor physics and nuclear astrophysics B.Jurado1* , G Gradignan, France 2 IPN, CNRS/IN2P3, Univ. Paris-Sud, 91405 Orsay, France Abstract: Nuclear reaction cross sections of short-lived nuclei are key inputs for new generation nuclear reactor simulations and for models

Boyer, Edmond

257

Industry Supply Chain Development (Ohio)  

Broader source: Energy.gov [DOE]

Supply Chain Development programs are focused on targeted industries that have significant growth opportunities for Ohio's existing manufacturing sector from emerging energy resources and...

258

Nuclear Theory and Applications progress report, January 1, 1989-- April 1, 1990  

SciTech Connect (OSTI)

This report contains brief papers on the following topics: data evaluation and libraries; data processing; nuclear applications; reactions; fission; and nuclear structure.

Strottman, D.D.; Mutschlecner, A.D. (comps.)

1990-12-01T23:59:59.000Z

259

E-Print Network 3.0 - above-ground nuclear tests Sample Search...  

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

Davis Summary: Stephen Bolt Ben Lail Adam Davis 12;Nuclear History 1942 - First self sustaining nuclear... reaction occurs at University of Chicago 1945 - First atomic bomb...

260

PHYSICAL REVIEW C 81, 064603 (2010) Pauli blocking and medium effects in nucleon knockout reactions  

E-Print Network [OSTI]

distributions up to 10% in the energy range Elab = 50­300 MeV/nucleon. The effect is more evident in reactions Nuclear structure calculations are now able to reproduce the measured masses, charge radii, and low-particle structure in short-lived nuclei typically uses direct nuclear reactions. Nucleon knockout reactions

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Selected topics in nuclear astrophysics  

SciTech Connect (OSTI)

In this lectures after a brief introduction to stellar reaction rates and its implementation in nuclear networks, I discuss the nuclear physics aspects of core collapse supernova and explosive nucleosynthesis and their significance for the production of heavy elements by the rapid neutron capture process and potentially also by the recently discovered {nu}p process.

Martinez-Pinedo, Gabriel [Institut fuer Kernphysik (Theoriezentrum), Technische Universitaet Darmstadt, Schlossgartenstrasse 2, 64289 Darmstadt, Germany and GSI Helmholtzzentrum fuer Schwerioneneforschung, Planckstrasse 1, 64291 Darmstadt (Germany)

2013-06-10T23:59:59.000Z

262

Panel report: nuclear physics  

SciTech Connect (OSTI)

Nuclear science is at the very heart of the NNSA program. The energy produced by nuclear processes is central to the NNSA mission, and nuclear reactions are critical in many applications, including National Ignition Facility (NIF) capsules, energy production, weapons, and in global threat reduction. Nuclear reactions are the source of energy in all these applications, and they can also be crucial in understanding and diagnosing the complex high-energy environments integral to the work of the NNSA. Nuclear processes are complex quantum many-body problems. Modeling and simulation of nuclear reactions and their role in applications, coupled tightly with experiments, have played a key role in NNSA's mission. The science input to NNSA program applications has been heavily reliant on experiment combined with extrapolations and physical models 'just good enough' to provide a starting point to extensive engineering that generated a body of empirical information. This body of information lacks the basic science underpinnings necessary to provide reliable extrapolations beyond the domain in which it was produced and for providing quantifiable error bars. Further, the ability to perform additional engineering tests is no longer possible, especially those tests that produce data in the extreme environments that uniquely characterize these applications. The end of testing has required improvements to the predictive capabilities of codes simulating the reactions and associated applications for both well known and well characterized cases as well as incompletely known cases. Developments in high performance computing, computational physics, applied mathematics and nuclear theory have combined to make spectacular advances in the theory of fission, fusion and nuclear reactions. Current research exploits these developments in a number of Office of Science and NNSA programs, and in joint programs such as the SciDAC (Science Discovery through Advanced Computing) that supports the project Building a Universal Nuclear Energy Density Fuctional whose goals are to provide the unified approach to calculating the properties of nuclei. The successful outcome of this, and similar projects is a first steps toward a predictive nuclear theory based on fundamental interactions between constituent nucleons. The application of this theory to the domain of nuclei important for national security missions will require computational resources at the extreme scale, beyond what will be available in the near term future.

Carlson, Joseph A [Los Alamos National Laboratory; Hartouni, Edward P [LLNL

2010-01-01T23:59:59.000Z

263

Absolute nuclear material assay using count distribution (LAMBDA) space  

DOE Patents [OSTI]

A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

2012-06-05T23:59:59.000Z

264

Theoretical Studies on the CH3CO + Cl Reaction: Hydrogen Abstraction versus CO Displacement  

E-Print Network [OSTI]

potential energy surface reveals this reaction to be a capture-limited association-elimination reaction the efficiency of a chain reaction. Recently Maricq et al.1 reported the real-time kinetic mea- surements for one earlier potential energy surface,3 is also consistent with an addition-elimination mechanism since

Nguyen, Minh Tho

265

Nuclear activation technique for analysis of laser induced energetic protons  

E-Print Network [OSTI]

. For that purpose, we have developed a method in which the particles induce nuclear reactions in a stack of copper for medical applications [6]). In addition, nuclear reaction yields and nuclear decay rates might be studied radioactive nuclei. In a stack of samples, each foil acts as a low energy proton filter for the following ones

Paris-Sud XI, Université de

266

Statistical Methods for Thermonuclear Reaction Rates and Nucleosynthesis Simulations  

E-Print Network [OSTI]

Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly complex quantities derived from a multitude of different measured nuclear parameters (e.g., astrophysical S-factors, resonance energies and strengths, particle and gamma-ray partial widths). We discuss the application of the Monte Carlo method to two distinct, but related, questions. First, given a set of measured nuclear parameters, how can one best estimate the resulting thermonuclear reaction rates and associated uncertainties? Second, given a set of appropriate reaction rates, how can one best estimate the abundances from nucleosynthesis (i.e., reaction network) calculations? The techniques described here provide probability density functions that can be used to derive statistically meaningful reaction rates and final abundances for any desired coverage probability. Examples ...

Iliadis, Christian; Coc, Alain; Timmes, F X; Champagne, Art E

2014-01-01T23:59:59.000Z

267

Methyl viologen radical reactions with several oxidizing agents. [Gamma Radiation  

SciTech Connect (OSTI)

The rates of oxidation of the methyl viologen radical by peroxodisulfate and hydrogen peroxide has been investigated. The methyl viologen free radical was produced by pulse radiolysis. The reaction of the peroxodisulfate radical with the methyl viologen radical was first order in both species, and the reaction rate constant is reported. A el-radiation study revealed a chain decomposition of the peroxodisulfate radical involving the methyl viologen radical when methanol, ethanol, or 2-propanol was present. Loss of the methyl viologen radical was then no longer observed to be a simple first-order reaction. The reaction of hydrogen peroxide with the methyl viologen radical was very slow in the presence of 1 M methanol. A much faster reaction in the absence of methanol was interpreted to be a reaction of the methyl viologen radical with the peroxy radicals. Hydrogen peroxide, in contrast to the chain decomposition of peroxodisulfate radicals, does not participate in a chain reaction involving the methyl viologen radical and methanol. Rate constants for the reaction of methyl viologen radical with dichromate radical, iodate radical, and ferricyanide radical are reported.

Levey, G.; Ebbesen, T.W.

1983-01-01T23:59:59.000Z

268

Cross sections of neutron-induced reactions  

SciTech Connect (OSTI)

We study the properties of the neutron-nucleus total and reaction cross sections for several nuclei. We have applied an analytical model, the nuclear Ramsauer model, justified it from the nuclear reaction theory approach, and extracted the values of 12 parameters used in the model. The given parametrization has an advantage as phenomenological optical model potentials are limited up to 150-200 MeV. The present model provides good estimates of the total cross sections for several nuclei particularly at high energies.

Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N. [Variable Energy Cyclotron Centre, 1/AF Bidhan Nagar, Kolkata 700064 (India)

2010-10-15T23:59:59.000Z

269

Improve supply chain resilience by multi-stage supply chain  

E-Print Network [OSTI]

Due to the global expansion of Company A's supply chain network, it is becoming more vulnerable to many disruptions. These disruptions often incur additional costs; and require time to respond to and recover from these ...

Xu, Jie, M. Eng. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

270

Improving supply chain resilience by multi-stage supply chain  

E-Print Network [OSTI]

Due to the global expansion of Company A's supply chain network, it is becoming more vulnerable to many disruptions. These disruptions often incur additional costs; and require time to respond to and recover from these ...

Yang, Jingxia, M. Eng, Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

271

Nuclear Physics B (Proc. Suppl.) 77 (1999) 64--72 Standard Solar Models  

E-Print Network [OSTI]

reactions. Thirty­nine experts in low energy nuclear ex­ periments and theory, representing many di#er­ ent In this section, I will first summarize the new and relevant results on nuclear fusion reactions and on the screening of nuclear reactions and then summarize the situation with respect to neu­ trino cross sections

Bahcall, John

272

Theoretical nuclear physics: Final report for period February 1, 1984 to January 31, 1987  

SciTech Connect (OSTI)

Nuclear theory at the University of Colorado emphasizes the study of nuclear structure through the use of nuclear reactions. Recent efforts have been focussed on the role of relativistic models in nucleon-nucleus scattering and reactions. Further work delves into the underlying bases of the reaction theory itself.

Rost, E.; Kunz, P.D.

1987-01-23T23:59:59.000Z

273

Low-energy proton capture reactions  

SciTech Connect (OSTI)

An overview of experimental problems in measuring the cross sections for (p,?) and (p,n) reactions at low energies is given with a specific emphasis on electron screening in metallic targets. Thick target ?-ray and neutron yields are compared for Ni and NiO targets, V and VO{sub 2} targets and Mn and MnO targets. The {sup 1}H({sup 7}Li,?){sup 4}He reaction was studied in inverse kinematics with hydrogen loaded into Pd and PdAg alloy foils from gas phase. Based on these results, a new approach to electron screening in nuclear reactions is suggested.

Lipoglavsek, M.; Cvetinovic, A.; Gajevic, J.; Likar, A.; Vavpetic, P. [Jozef Stefan Institute, Jamova ulica 39, Ljubljana (Slovenia); Petrovic, T. [Jozef Stefan Institute, Jamova ulica 39, Ljubljana, Slovenia and Cosylab d.d., Teslova ulica 30, Ljubljana (Slovenia)

2014-05-09T23:59:59.000Z

274

Effective contracts in supply chains  

E-Print Network [OSTI]

In the past decade, we have seen significant increase in the level of outsourcing in many industries. This increase in the level of outsourcing increases the importance of implementing effective contracts in supply chains. ...

Shum, Wanhang

2007-01-01T23:59:59.000Z

275

Total supply chain cost model  

E-Print Network [OSTI]

Sourcing and outsourcing decisions have taken on increased importance within Teradyne to improve efficiency and competitiveness. This project delivered a conceptual framework and a software tool to analyze supply chain ...

Wu, Claudia

2005-01-01T23:59:59.000Z

276

Extracorporeal membrane oxygenation promotes long chain fatty...  

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

membrane oxygenation promotes long chain fatty acid oxidation in the immature swine heart in vivo. Extracorporeal membrane oxygenation promotes long chain fatty acid oxidation...

277

Nuclear Resonance Fluorescence for Nuclear Materials Assay  

E-Print Network [OSTI]

Potential of Nuclear Resonance Fluorescence . . . . . . . .2.9.1 Nuclear ThomsonSections . . . . . . . . . . . . . . . Nuclear Resonance

Quiter, Brian Joseph

2010-01-01T23:59:59.000Z

278

Replenishment prioritization of highly perishable goods : a case study on nuclear medicine  

E-Print Network [OSTI]

Serving customers in a nuclear medicine supply chain requires frequent and responsive replenishments. Nuclear medicine is a special category of perishable goods that is subject to rapid, but predictable radioactive decay. ...

Yea, Young-bai Michael

2007-01-01T23:59:59.000Z

279

Neutron multiplicity distributions for 30 MeVu sup 14 N reactions with the indicated targets  

SciTech Connect (OSTI)

This report contains short papers on the following topics: Heavy ion reactions; nuclear structure and fundamental interactions; nuclear theory; atomic molecular and materials science; and superconducting cyclotron and instrumentation. (LSP)

Not Available

1992-06-01T23:59:59.000Z

280

acid-promoted cyclization reactions: Topics by E-print Network  

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

After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an...

Note: This page contains sample records for the topic "nuclear chain reaction" 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

E-Print Network 3.0 - atom reaction product Sample Search Results  

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

and product electronic states. As for hydrogen atom and hydride transfer reactions, the nuclear quantum... -4235020301 17.50+.500 33 Comparison of Hydride, Hydrogen Atom,...

282

Analysis of cross sections using various nuclear potential  

SciTech Connect (OSTI)

The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

Aziz, Azni Abdul [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Kulliyah of Science, International Islamic University Malaysia, 25200 Kuantan (Malaysia); Quantum Science Center, Faculty of Science, University of Malaya, 50603 Kuala Lump (Malaysia); Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Quantum Science Center, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Institute of Space Science, Universiti Kebangsaan Malaysia, 43600 Bangi, Se (Malaysia); Yusof, Norhasliza [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Quantum Science Center, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Muhammad Zamrun, F. [Quantum Science Center, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Jurusan Fisika FMIPA, Universitas Haluoleo Kendari, Sulawesi Tenggara, J3232 (Indonesia)

2014-05-02T23:59:59.000Z

283

Containment building : architecture between the city and advanced nuclear reactors  

E-Print Network [OSTI]

Since the inception of nuclear energy research, the element thorium (Th) has been considered the superior fuel for nuclear reactions because of its potency, safety, abundance and reduced waste. Cold War agendas broke from ...

Pauli, Lisa M

2011-01-01T23:59:59.000Z

284

A,B,C`s of nuclear science  

SciTech Connect (OSTI)

This introductory level presentation contains information on nuclear structure, radioactivity, alpha decay, beta decay, gamma decay, half-life, nuclear reactions, fusion, fission, cosmic rays, and radiation protection. Nine experiments with procedures and test questions are included.

Noto, V.A. [Mandeville High School, LA (United States); Norman, E.B.; Chan, Yuen-Dat; Dairiki, J.; Matis, H.S.; McMahan, M.A.; Otto, R. [Lawrence Berkeley Lab., CA (United States)

1995-08-07T23:59:59.000Z

285

A program in Medium-Energy Nuclear Physics  

SciTech Connect (OSTI)

This report discusses research on the following topics: single electron scattering; coincidence electron scattering; photonuclear reactions; pion scattering; and the GWU nuclear detector. (LSP).

Berman, B.L.

1991-12-31T23:59:59.000Z

286

A program in Medium-Energy Nuclear Physics  

SciTech Connect (OSTI)

This report discusses research on the following topics: single electron scattering; coincidence electron scattering; photonuclear reactions; pion scattering; and the GWU nuclear detector. (LSP).

Berman, B.L.

1991-01-01T23:59:59.000Z

287

Exploring medium effects on the nuclear force  

SciTech Connect (OSTI)

This STI product contains a description of results from theoretical studies in nuclear physics. The goal is a systematic investigation of the nuclear force in the nuclear medium. The problems addressed are: density-dependent effective interactions as seen through proton-nucleus reactions, nuclear matter with unequal densities of protons and neutrons, applications to asymmetric nuclei through predictions of neutron radii and neutron skins.

F. Sammarruca

2004-04-18T23:59:59.000Z

288

Experimental and theoretical studies of OH-initiated reactions of isoprene  

E-Print Network [OSTI]

and pathways. In each step of the chain reaction, organic radical intermediates are produced and they further propagate or terminate the oxidation process. Currently, there is very little understanding of the chemistry of these organic radicals. This study...

Zhang, Dan

2012-06-07T23:59:59.000Z

289

Chemical Functionalization of Nanostructured Materials Using Supercritical Reaction Media  

SciTech Connect (OSTI)

There exists a need for durable and thin functional coatings to utilize the afforded surface area of highly porous ceramic materials. Deposition of silane-based Self Assembled Monolayers (SAMs) has thus far been limited to maximum coverages of 4-5 molecules/nm2 and long processing times (up to 2 weeks), due to the restricted internal geometry of the substrates. Results are presented for SAMs deposited on high surface area silica from supercritical fluids (SCFs). The SAMs so produced display unprecedented coverages, high monolayer integrity, and extremely low surface defect density. Moreover, the depositions and subsequent removal of reaction byproducts are complete in a matter of minutes rather than days. Nuclear Magnetic Resonance (NMR) spectra of the surface modified silica are presented, demonstrating the SAM integrity and evolution over time. Sorption of aqueous metal ions is demonstrated, and results are given demonstrating the broad pH stability of the deposited SAMs. A chemical explanation for the enhanced deposition is posited, and the kinetics of mass transport into and out of the nanostructured spaces are discussed.Related experiments using zeolite substrates show deposition of thiol-terminated silanes to internal surfaces of 6? microporous material. After oxidation of the thiol functional group size selective chemistry was demonstrated using the produced catalyst, proving the efficacy of the supercritical reaction medium for installing functional coatings inside pores of similar diameters to the chain length of the deposited molecule[]. Comparisons are made between the response of the different substrates to the supercritical fluid-based processing, and remarks on the utility of SCF based processing of nanostructured materials are presented.

Zemanian, Thomas S.; Fryxell, Glen E.; Liu, Jun; Mattigod, Shas V.; Shin, Yongsoon; Franz, James A.; Ustyugov, Oleksiy A.; Nie, Zimin

2001-12-15T23:59:59.000Z

290

Nuclear Nonproliferation  

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

Nuclear Nonproliferation As more countries embrace nuclear power as a cost-effective and clean alternative to fossil fuels, the need exists to ensure that the nuclear fuel cycle is...

291

Nuclear Engineering Nuclear Criticality Safety  

E-Print Network [OSTI]

Nuclear Engineering Nuclear Criticality Safety The Nuclear Engineering Division (NE) of Argonne National Laboratory is experienced in performing criticality safety and shielding evaluations for nuclear, and neutron spectra. The NE nuclear criticality safety (NCS) capabilities are based on a staff with decades

Kemner, Ken

292

CALCULATING THE CARBON FOOTPRINT SUPPLY CHAIN FOR  

E-Print Network [OSTI]

CALCULATING THE CARBON FOOTPRINT SUPPLY CHAIN FOR THE SEMICONDUCTOR INDUSTRY By: Yasser Dessouky #12;Carbon Footprint Supply Chain Carbon Trust defines carbon footprint of a supply chain as follows: "The carbon footprint of a product is the carbon dioxide emitted across the supply chain for a single

Su, Xiao

293

Nuclear Physics  

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

Underground Research Facility in South Dakota, which will search for neutrinoless double-beta decay. Strong Los Alamos programs in nuclear data and nuclear theory supports...

294

Nuclear Energy  

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

Nuclear Energy Idaho National Laboratory is the Department of Energy's lead nuclear energy research and development facility. Building upon its legacy responsibilities,...

295

Evaluated Nuclear Data  

SciTech Connect (OSTI)

This chapter describes the current status of evaluated nuclear data for nuclear technology applications. We start with evaluation procedures for neutron-induced reactions focusing on incident energies from the thermal energy up to 20 MeV, though higher energies are also mentioned. This is followed by examining the status of evaluated neutron data for actinides that play dominant role in most of the applications, followed by coolants/moderators, structural materials and fission products. We then discuss neutron covariance data that characterize uncertainties and correlations. We explain how modern nuclear evaluated data libraries are validated against an extensive set of integral benchmark experiments. Afterwards, we briefly examine other data of importance for nuclear technology, including fission yields, thermal neutron scattering and decay data. A description of three major evaluated nuclear data libraries is provided, including the latest version of the US library ENDF/B-VII.0, European JEFF-3.1 and Japanese JENDL-3.3. A brief introduction is made to current web retrieval systems that allow easy access to a vast amount of up-to-date evaluated nuclear data for nuclear technology applications.

Oblozinsky, P.; Oblozinsky,P.; Herman,M.; Mughabghab,S.F.

2010-10-01T23:59:59.000Z

296

Nuclear Masses in Astrophysics  

E-Print Network [OSTI]

Among all nuclear ground-state properties, atomic masses are highly specific for each particular combination of N and Z and the data obtained apply to a variety of physics topics. One of the most crucial questions to be addressed in mass spectrometry of unstable radionuclides is the one of understanding the processes of element formation in the Universe. To this end, accurate atomic mass values of a large number of exotic nuclei participating in nucleosynthesis are among the key input data in large-scale reaction network calculations. In this paper, a review on the latest achievements in mass spectrometry for nuclear astrophysics is given.

Christine Weber; Klaus Blaum; Hendrik Schatz

2008-12-09T23:59:59.000Z

297

Nuclear Fusion: A Solution to the GlobalNuclear Fusion: A Solution to the Global Energy CrisisEnergy Crisis  

E-Print Network [OSTI]

Nuclear Fusion: A Solution to the GlobalNuclear Fusion: A Solution to the Global Energy Crisis.maclellan@strath.ac.uk Introduction and Motivation What is Nuclear Fusion? Laser Plasma Interactions The world, and particularly is harnessing the power of nuclear fusion. It is however, extremely difficult to sustain a fusion reaction

Strathclyde, University of

298

THE STRUCTURE AND REACTIONS OF NEUTRON-RICH NUCLEI  

E-Print Network [OSTI]

dissociation experiments 351 2.3. Low-energy behaviour of "Li dissociation cross 6.2. Direct measurements 355 of the understanding of the structure and reactions of neutron-rich nuclei. The properties of the low-lying soft giant and total nuclear reaction cross section isalso calculated using the microscopic tp, p 2-Glauber theory

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

299

Differential evolution Markov chain with snooker updater and fewer chains  

SciTech Connect (OSTI)

Differential Evolution Markov Chain (DE-MC) is an adaptive MCMC algorithm, in which multiple chains are run in parallel. Standard DE-MC requires at least N=2d chains to be run in parallel, where d is the dimensionality of the posterior. This paper extends DE-MC with a snooker updater and shows by simulation and real examples that DE-MC can work for d up to 50--100 with fewer parallel chains (e.g. N=3) by exploiting information from their past by generating jumps from differences of pairs of past states. This approach extends the practical applicability of DE-MC and is shown to be about 5--26 times more efficient than the optimal Normal random walk Metropolis sampler for the 97.5% point of a variable from a 25--50 dimensional Student T{sub 3} distribution. In a nonlinear mixed effects model example the approach outperformed a block-updater geared to the specific features of the model.

Vrugt, Jasper A [Los Alamos National Laboratory; Ter Braak, Cajo J F [NON LANL

2008-01-01T23:59:59.000Z

300

Nuclear Matter and Nuclear Dynamics  

E-Print Network [OSTI]

Highlights on the recent research activity, carried out by the Italian Community involved in the "Nuclear Matter and Nuclear Dynamics" field, will be presented.

M Colonna

2009-02-26T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Cold nuclear fusion  

SciTech Connect (OSTI)

Recent accelerator experiments on fusion of various elements have clearly demonstrated that the effective cross-sections of these reactions depend on what material the target particle is placed in. In these experiments, there was a significant increase in the probability of interaction when target nuclei are imbedded in a conducting crystal or are a part of it. These experiments open a new perspective on the problem of so-called cold nuclear fusion.

Tsyganov, E. N., E-mail: edward.tsyganov@utsouthwestern.edu [University of Texas Southwestern Medical Center at Dallas (United States)

2012-02-15T23:59:59.000Z

302

FLATNESS OF HEAV CHAIN SYSTEMS  

E-Print Network [OSTI]

a load, addressed in partial derivatives equations framework. parameterize system trajectories chain systems described by a onedimensional (1D) partial di#erential wave equation. Dealing#erential equations, constant varying delay equations, even partial di#erential equations. these cases open loop

303

SUPPLY CHAIN MANAGER CHICAGO, IL  

E-Print Network [OSTI]

at project leader to bring best practices into the organization. He or she will recommend solutions to break developing new technology to meet the ever-changing demands of modern industry. The US Headquarters with broad responsibilities that include assessing, managing and improving the supply chain function

Smilowitz, Karen

304

Nuclear Data Sheets for A = 148  

SciTech Connect (OSTI)

The experimental nuclear structure data available through October 2013 have been reviewed. A summary of information obtained in various reaction and decay experiments is presented, together with adopted level schemes.

Nica, N.

2014-03-01T23:59:59.000Z

305

Microfluidic chemical reaction circuits  

SciTech Connect (OSTI)

New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

Lee, Chung-cheng (Irvine, CA); Sui, Guodong (Los Angeles, CA); Elizarov, Arkadij (Valley Village, CA); Kolb, Hartmuth C. (Playa del Rey, CA); Huang, Jiang (San Jose, CA); Heath, James R. (South Pasadena, CA); Phelps, Michael E. (Los Angeles, CA); Quake, Stephen R. (Stanford, CA); Tseng, Hsian-rong (Los Angeles, CA); Wyatt, Paul (Tipperary, IE); Daridon, Antoine (Mont-Sur-Rolle, CH)

2012-06-26T23:59:59.000Z

306

Shutdown system for a nuclear reactor  

DOE Patents [OSTI]

An ultimate shutdown system is provided for termination of neutronic activity in a nuclear reactor. The shutdown system includes bead chains comprising spherical containers suspended on a flexible cable. The containers are comprised of mating hemispherical shells which provide a ruggedized enclosure for reactor poison material. The bead chains, normally suspended above the reactor core on storage spools, are released for downward travel upon command from an external reactor monitor. The chains are capable of horizontal movement, so as to flow around obstructions in the reactor during their downward motion. 8 figs.

Groh, E.F.; Olson, A.P.; Wade, D.C.; Robinson, B.W.

1984-06-05T23:59:59.000Z

307

Shutdown system for a nuclear reactor  

DOE Patents [OSTI]

An ultimate shutdown system is provided for termination of neutronic activity in a nuclear reactor. The shutdown system includes bead chains comprising spherical containers suspended on a flexible cable. The containers are comprised of mating hemispherical shells which provide a ruggedized enclosure for reactor poison material. The bead chains, normally suspended above the reactor core on storage spools, are released for downward travel upon command from an external reactor monitor. The chains are capable of horizontal movement, so as to flow around obstructions in the reactor during their downward motion.

Groh, Edward F. (Naperville, IL); Olson, Arne P. (Western Springs, IL); Wade, David C. (Naperville, IL); Robinson, Bryan W. (Oak Lawn, IL)

1984-01-01T23:59:59.000Z

308

Modelling proton-induced reactions at low energies in the MARS15 code  

E-Print Network [OSTI]

An implementation of both the ALICE code and TENDL evaluated nuclear data library in order to describe nuclear reactions by low-energy projectiles in the Monte Carlo code MARS15 is presented. Comparisons between results of modelling and experimental data on reaction cross sections and secondary particle distributions are shown as well.

Rakhno, Igor L; Gudima, Konstantin K

2015-01-01T23:59:59.000Z

309

Nuclear Data Sheets for A = 215  

SciTech Connect (OSTI)

The evaluated spectroscopic data are presented for 12 known nuclides of mass 215 (Hg, Tl, Pb, Bi, Po, At, Rn, Fr, Ra, Ac, Th, Pa). For {sup 215}Hg, {sup 215}Tl, {sup 215}Pb, and {sup 215}Pa nuclei, no excited states are known. The decay characteristics of {sup 215}Hg and {sup 215}Tl are unknown. The decay scheme of {sup 215}Pb is considered as incomplete. Ordering of ? cascades in the decay of 36.9s isomer of {sup 215}Bi and for highspin states above 2251 keV in {sup 215}Fr are not established. Highspin excitations, including several isomeric states, are well known in {sup 215}Bi, {sup 215}Po, {sup 215}Rn, {sup 215}Fr, {sup 215}Ra, and {sup 215}Ac. No particletransfer reaction data are available for any of the A=215 nuclei. The rms charge radii for {sup 215}Pb, {sup 215}Bi, {sup 215}Po, {sup 215}Rn, {sup 215}Fr and {sup 215}Ra have been evaluated by Daniel Abriola, from extrapolation or interpolation of available evaluated data in 2013An02 for radii of respective Z chains using formula 9 in 2004An14. This evaluation was carried out as part of ENSDDworkshop at VECC, Kolkata for Nuclear Structure and Decay Data, organized and hosted by VECC and Board of Research in Nuclear Sciences (BRNS) in Kolkata, India, November 2629, 2012. This work supersedes the previous A = 215 evaluation (2001Br31) published by E. Browne which covered literature prior to May 2001.

Singh, Balraj; Mukherjee, Gopal; Abriola, Daniel [International Atomic Energy Agency (IAEA), Vienna (Austria); Basu, Swapan Kumar [VECC, Kolkata (India); Demetriou, Paraskevi [IAEA, Vienna (Austria); Jain, Ashok [Indian Institute of Technology (IIT), Roorkee (India); Kumar, Suresh [Delhi University, Delhi (India); Singh, Sukhjeet [M.M. University, Mullana, Ambala (India); Tuli, Jagdish [Brookhaven National Laboratory (NNDC, BNL), Upton, NY (United States)

2013-12-15T23:59:59.000Z

310

Stau-catalyzed Nuclear Fusion  

E-Print Network [OSTI]

We point out that the stau may play a role of a catalyst for nuclear fusions if the stau is a long-lived particle as in the scenario of gravitino dark matter. In this letter, we consider d d fusion under the influence of stau where the fusion is enhanced because of a short distance between the two deuterons. We find that one chain of the d d fusion may release an energy of O(10) GeV per stau. We discuss problems of making the stau-catalyzed nuclear fusion of practical use with the present technology of producing stau.

K. Hamaguchi; T. Hatsuda; T. T. Yanagida

2006-10-06T23:59:59.000Z

311

Supply chain management in the cement industry  

E-Print Network [OSTI]

Traditionally supply chain management has played an operational role within cement and mineral extraction commodity companies. Recently, cost reduction projects have brought supply chain management into the limelight. In ...

Agudelo, Isabel

2009-01-01T23:59:59.000Z

312

Supply Chain Management Faculty Brian Fugate  

E-Print Network [OSTI]

relationships, strategy and sustainability in the supply chain, and she won the College of Business Excellence involvement in new product development, and sustainability practices in supply chain management. He has

313

An integrative framework for architecting supply chains  

E-Print Network [OSTI]

This thesis explores the limitations of classic models of supply chain management, and proposes a new view based on the concept of value-driven supply chains, and a method of analysis and design based on the concepts of ...

Cela Daz, Fernando

2006-01-01T23:59:59.000Z

314

Charlotte Green Supply Chain: Residential Retrofitting | Department...  

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

Charlotte Green Supply Chain: Residential Retrofitting Charlotte Green Supply Chain: Residential Retrofitting July 30, 2010 - 10:50am Addthis Joshua DeLung What does this mean for...

315

Loss of coordination in competitive supply chains  

E-Print Network [OSTI]

The loss of coordination in supply chains quantifies the inefficiency (i.e. the loss of total profit) due to the presence of competition in the supply chain. In this thesis, we discuss four models: one model with multiple ...

Teo, Koon Soon

2009-01-01T23:59:59.000Z

316

computational infrastructure for nuclear astrophysics Michael Smith, Physics Division, Oak Ridge Na:onal Lab coordinator@nucastrodata.org  

E-Print Network [OSTI]

computational infrastructure for nuclear astrophysics Michael Smith, Physics Division, Oak Ridge Na:onal Lab coordinator@nucastrodata.org #12;computational infrastructure for nuclear astrophysics system overview ·work with nuclear information, reaction rates, & simulations ·operates "in

317

Research in heavy-ion nuclear physics  

SciTech Connect (OSTI)

This report discusses the following topics: Fusion-fission in light nuclear systems; High-resolution Q-value measurement for the {sup 24}Mg+{sup 24}Mg reaction; Heavy-ion reactions and limits to fusion; and Hybrid MWPC-Bragg curve detector development.

Sanders, S.J.; Prosser, F.W.

1992-01-01T23:59:59.000Z

318

Nuclear physics and heavy element research at LLNL  

SciTech Connect (OSTI)

This paper highlights some of the current basic nuclear physics research at Lawrence Livermore National Laboratory (LLNL). The work at LLNL concentrates on investigating nuclei at the extremes. The Experimental Nuclear Physics Group performs research to improve our understanding of nuclei, nuclear reactions, nuclear decay processes and nuclear astrophysics; an expertise utilized for important laboratory national security programs and for world-class peer-reviewed basic research.

Stoyer, M A; Ahle, L E; Becker, J A; Bernstein, L A; Bleuel, D L; Burke, J T; Dashdorj, D; Henderson, R A; Hurst, A M; Kenneally, J M; Lesher, S R; Moody, K J; Nelson, S L; Norman, E B; Pedretti, M; Scielzo, N D; Shaughnessy, D A; Sheets, S A; Stoeffl, W; Stoyer, N J; Wiedeking, M; Wilk, P A; Wu, C Y

2009-05-11T23:59:59.000Z

319

Nuclear astrophysics and electron beams  

SciTech Connect (OSTI)

Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

Schwenk, A. [Institut fr Kernphysik, Technische Universitt Darmstadt, 64289 Darmstadt, Germany and ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum fr Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

2013-11-07T23:59:59.000Z

320

Data resources for nuclear medicine  

SciTech Connect (OSTI)

The objective of this article is to list data resources needed for nuclear medicine and provide information on how to access them. This list will include publications of data compilations or evaluations, databases, and data processing codes for both nuclear structure and decay, as well as reaction data. Sources of bibliographic and related information on nuclear data are also be listed. The authors of this article have used their judgement in choosing a representative list of data sources; a more complete listing may be found in the references.

Bhat, M.R. [Brookhaven National Lab., Upton, NY (United States); Lemmel, H.D. [International Atomic Energy Agency, Vienna (Austria). Nuclear Data Section

1995-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Harmonic Chain with Weak Dissipation  

E-Print Network [OSTI]

We consider finite harmonic chain (consisting of N classical particles) plus dissipative force acting on one particle (called dissipating particle) only. We want to prove that "in the generic case" the energy (per particle) for the whole system tends to zero in the large time limit and then in the large N limit. "In the generic case" means: for almost all initial conditions and for almost any choice of the dissipating particle, in the thermodynamic limit.

A. A. Lykov; V. A. Malyshev

2013-02-20T23:59:59.000Z

322

Agents on the Web Supply Chains  

E-Print Network [OSTI]

Agents on the Web Automating Supply Chains 90 JULY · AUGUST 2001 http://computer.org/internet/ 1089

Almor, Amit

323

TRIMOLECULAR REACTIONS OF URANIUM HEXAFLUORIDE WITH WATER  

SciTech Connect (OSTI)

The hydrolysis reaction of uranium hexafluoride (UF{sub 6}) is a key step in the synthesis of uranium dioxide (UO{sub 2}) powder for nuclear fuels. Mechanisms for the hydrolysis reactions are studied here with density functional theory and the Stuttgart small-core scalar relativistic pseudopotential and associated basis set for uranium. The reaction of a single UF{sub 6} molecule with a water molecule in the gas phase has been previously predicted to proceed over a relatively sizeable barrier of 78.2 kJ {center_dot} mol{sup -1}, indicating this reaction is only feasible at elevated temperatures. Given the observed formation of a second morphology for the UO{sub 2} product coupled with the observations of rapid, spontaneous hydrolysis at ambient conditions, an alternate reaction pathway must exist. In the present work, two trimolecular hydrolysis mechanisms are studied with density functional theory: (1) the reaction between two UF{sub 6} molecules and one water molecule, and (2) the reaction of two water molecules with a single UF{sub 6} molecule. The predicted reaction of two UF{sub 6} molecules with one water molecule displays an interesting 'fluorine-shuttle' mechanism, a significant energy barrier of 69.0 kJ {center_dot} mol{sup -1} to the formation of UF{sub 5}OH, and an enthalpy of reaction ({Delta}H{sub 298}) of +17.9 kJ {center_dot} mol{sup -1}. The reaction of a single UF{sub 6} molecule with two water molecules displays a 'proton-shuttle' mechanism, and is more favorable, having a slightly lower computed energy barrier of 58.9 kJ {center_dot} mol{sup -1} and an exothermic enthalpy of reaction ({Delta}H{sub 298}) of -13.9 kJ {center_dot} mol{sup -1}. The exothermic nature of the overall UF{sub 6} + 2 {center_dot} H{sub 2}O trimolecular reaction and the lowering of the barrier height with respect to the bimolecular reaction are encouraging; however, the sizable energy barrier indicates further study of the UF{sub 6} hydrolysis reaction mechanism is warranted to resolve the remaining discrepancies between the predicted mechanisms and experimental observations.

Westbrook, M.; Becnel, J.; Garrison, S.

2010-02-25T23:59:59.000Z

324

Argonne National Laboratory 9700 S. Cass Avenue  

E-Print Network [OSTI]

the world's first man-made controlled nuclear chain reaction. · Submarine Thermal Reactor physics critical of Nuclear Fission led to the First Controlled Nuclear Chain Reaction, which led to Commercial and Advanced Reactor Designs The Discovery of Nuclear Fission led to the First Controlled Nuclear Chain Reaction, which

Kemner, Ken

325

Swedish nuclear waste efforts  

SciTech Connect (OSTI)

After the introduction of a law prohibiting the start-up of any new nuclear power plant until the utility had shown that the waste produced by the plant could be taken care of in an absolutely safe way, the Swedish nuclear utilities in December 1976 embarked on the Nuclear Fuel Safety Project, which in November 1977 presented a first report, Handling of Spent Nuclear Fuel and Final Storage of Vitrified Waste (KBS-I), and in November 1978 a second report, Handling and Final Storage of Unreprocessed Spent Nuclear Fuel (KBS II). These summary reports were supported by 120 technical reports prepared by 450 experts. The project engaged 70 private and governmental institutions at a total cost of US $15 million. The KBS-I and KBS-II reports are summarized in this document, as are also continued waste research efforts carried out by KBS, SKBF, PRAV, ASEA and other Swedish organizations. The KBS reports describe all steps (except reprocessing) in handling chain from removal from a reactor of spent fuel elements until their radioactive waste products are finally disposed of, in canisters, in an underground granite depository. The KBS concept relies on engineered multibarrier systems in combination with final storage in thoroughly investigated stable geologic formations. This report also briefly describes other activities carried out by the nuclear industry, namely, the construction of a central storage facility for spent fuel elements (to be in operation by 1985), a repository for reactor waste (to be in operation by 1988), and an intermediate storage facility for vitrified high-level waste (to be in operation by 1990). The R and D activities are updated to September 1981.

Rydberg, J.

1981-09-01T23:59:59.000Z

326

The Offshore Services Global Value Chain  

E-Print Network [OSTI]

The Offshore Services Global Value Chain ECONOMIC UPGRADING AND WORKFORCE DEVELOPMENT Karina & COMPETITIVENESS #12;The Offshore Services Global Value Chain: Economic Upgrading and Workforce Development "Skills & Competitiveness, Duke University Posted: November 17, 2011 #12;The Offshore Services Global Value Chain: Economic

Richardson, David

327

Supply Chain and Information Sciences Technology 2010  

E-Print Network [OSTI]

Supply Chain and Information Sciences Technology 2010 Supply Chain and Information Systems Technology Minor SCIST Minor Application Department of Supply Chain & Information Systems College of Information Sciences and Technology Overview The minor in SCIST is structured to provide students not majoring

Guiltinan, Mark

328

Nuclear diagnostics for inertial confinement fusion implosions  

SciTech Connect (OSTI)

This abstract contains viewgraphs on nuclear diagnostic techniques for inertial confinement fusion implosions. The viewgraphs contain information on: reactions of interest in ICF; advantages and disadvantages of these methods; the properties nuclear techniques can measure; and some specifics on the detectors used.

Murphy, T.J.

1997-11-01T23:59:59.000Z

329

Nuclear structure studies with intermediate energy probes  

SciTech Connect (OSTI)

Nuclear structure studies with pions are reviewed. Results from a recent study of 1 p-shell nuclei using (e,e{prime}), ({pi}, {pi}{prime}), and ({gamma},{pi}) reactions are reported. Future nuclear structure studies with GeV electrons at CEBAF are also briefly discussed.

Lee, T.S.H.

1993-10-01T23:59:59.000Z

330

Nuclear spectroscopic studies  

SciTech Connect (OSTI)

The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

1993-02-08T23:59:59.000Z

331

Charged-Particle Thermonuclear Reaction Rates: IV. Comparison to Previous Work  

E-Print Network [OSTI]

We compare our Monte Carlo reaction rates (see Paper II of this series) to previous results that were obtained by using the classical method of computing thermonuclear reaction rates. For each reaction, the comparison is presented using two types of graphs: the first shows the change in reaction rate uncertainties, while the second displays our new results normalized to the previously recommended reaction rate. We find that the rates have changed significantly for almost all reactions considered here. The changes are caused by (i) our new Monte Carlo method of computing reaction rates (see Paper I of this series), and (ii) newly available nuclear physics information (see Paper III of this series).

Christian Iliadis; Richard Longland; Art Champagne; Alain Coc

2010-04-23T23:59:59.000Z

332

Sandia National Laboratories: Petrochemical Supply Chain and Incident  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErik Spoerke SSLSMolten-SaltReliabilityIntroductionAnalysis Supply Chain and

333

Nudat: Nuclear Structure and Decay Data from the National Nuclear Data Center (NNDC)  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

NuDat allows users to search and plot nuclear structure and decay data interactively. NuDat was developed by the National Nuclear Data Center (NNDC)but utilizes contributions from physicists around the world. It provides an interface between web users and several databases containing nuclear structure, nuclear decay and some neutron-induced nuclear reaction information. Users can search for nuclear level properties (energy, half-life, spinparity), gamma-ray information (energy, intensity, multipolarity, coincidences), radiation information following nuclear decay (energy, intensity, dose), and neutron-induced reaction data from the BNL-325 book (thermal cross section and resonance integral). The information provided by NuDat 2 can be viewed in tables, level schemes and an interactive chart of nuclides.

334

Proton induced reactions on natural U at 62.9 MeV  

E-Print Network [OSTI]

that are efficient shields against low-energy background neutrons - surrounded each detector resulting in a signal of the first silicon detector determines the low energy thresholds of our set-up, which are respectively 2.5 Me reaction on (C3H6)n target and nuclear reactions. The H(p,p) reaction allows by changing the angular posi

Boyer, Edmond

335

An Improved Reaction Rate Formulation for Charged-Particle Induced Thermonuclear Reaction of {sup 2}H(d,{gamma}){sup 4}He  

SciTech Connect (OSTI)

The reaction rate formula utilized in compilations such as the Nuclear Astrophysics Compilation of Reaction Rates (NACRE) uses low energy approximation due to temperatures in stars are in the region of a few keVs. Most nuclear reaction experiments were done in MeV range and the interior temperatures of massive stars are {approx}10{sup 9} K. Hence an improved formulation for calculating the nuclear reaction rate that is applicable to high temperatures is discussed in this work. The exact tunneling probability that is applicable for all energies is obtained by solving the Schroedinger equation. This yields an enhanced expression for the astrophysical S-factor for calculating the thermonuclear reaction rate at high temperature. The thermonuclear reaction rate from this work is applied to the {sup 2}H(d,{gamma}){sup 4}He reaction and is compared with the NACRE compilation. This improved reaction rate can be included in the nuclear reaction network in a Big Bang nucleosynthesis (BBN) code or a stellar nuclear network code.

Aziz, Azni Abdul; Yusof, Norhasliza; Idris, Mahirah; Kassim, Hasan Abu [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-03-30T23:59:59.000Z

336

O V E R L A P S I N L O W -E N E R G Y N U C L E A R P H Y S I C S STRUCTURE, REACTIONS,  

E-Print Network [OSTI]

, ASTROPHYSICS #12;OVERVIEW · Some basic nuclear physics · Transfer reactions · Example of structure- reactions and vibrations of the nucleus as a whole, come into play. Desig nuclei live in the low-energy world in which to the recent report.1 Jones and Nazarewicz, The Physics Teacher, 48 (2010). Nuclear structure Nuclear reactions

Dai, Pengcheng

337

Modeling nuclear fusion in dense plasmas using a cryogenic non-neutral plasmaa...  

E-Print Network [OSTI]

the nuclear reaction rate in a dense neutral plasma and the energy equipartition rate in a strongly magnetized and at low temperatures, cyclotron energy, like nuclear energy, is released only through rare close as for nuclear reactions. Rate enhancements of up to 1010 are measured in simulations of equipartition

California at San Diego, University of

338

Nuclear Engineer (Nuclear Safety Specialist)  

Broader source: Energy.gov [DOE]

A successful candidate of this position will serve as a Nuclear Engineer (Nuclear Safety Specialist) responsible for day-to-day technical monitoring, and evaluation of aspects of authorization...

339

Nuclear Astrophysics in Rare Isotope Facilities C.A. Bertulania  

E-Print Network [OSTI]

, beam energies should be in the range of a few 10-100 MeV per nucleon [5]. Low energy reactions projectile velocity va, the low energy reaction A + x = B + c is induced at very low (even vanishing and Astronomy, Texas A&M University, Commerce, TX 75429, USA Nuclear reactions in stars are difficult to measure

Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

340

The NACRE Thermonuclear Reaction Compilation and Big Bang Nucleosynthesis  

E-Print Network [OSTI]

The theoretical predictions of big bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction cross sections. In this paper, we examine the impact on BBN of the recent compilation of nuclear data and thermonuclear reactions rates by the NACRE collaboration. We confirm that the adopted rates do not make large overall changes in central values of predictions, but do affect the magnitude of the uncertainties in these predictions. Therefore, we then examine in detail the uncertainties in the individual reaction rates considered by NACRE. When the error estimates by NACRE are treated as 1\\sigma limits, the resulting BBN error budget is similar to those of previous tabulations. We propose two new procedures for deriving reaction rate uncertainties from the nuclear data: one which sets lower limits to the error, and one which we believe is a reasonable description of the present error budget. We propagate these uncertainty estimates through the BBN code, and find that when the nuclear data errors are described most accurately, the resulting light element uncertainties are notably smaller than in some previous tabulations, but larger than others. Using these results, we derive limits on the cosmic baryon-to-photon ratio $\\eta$, and compare this to independent limits on $\\eta$ from recent balloon-borne measurements of the cosmic microwave background radiation (CMB). We discuss means to improve the BBN results via key nuclear reaction measurements and light element observations.

Richard H. Cyburt; Brian D. Fields; Keith A. Olive

2001-05-17T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Method for polymer synthesis in a reaction well  

DOE Patents [OSTI]

A method of synthesis for building a polymer chain, oligonucleotides in particular, by sequentially adding monomer units to at least one solid support for growing and immobilizing a polymer chain thereon in a liquid reagent solution. The method includes the step of: A) depositing a liquid reagent in a reaction well (26) in contact with at least one solid support and at least one monomer unit of the polymer chain affixed to the solid support. The well (26) includes at least one orifice (74) extending into the well (26), and is of a size and dimension to form a capillary liquid seal to retain the reagent solution in the well (26) to enable polymer chain growth on the solid support. The method further includes the step of B) expelling the reagent solution from the well (26), while retaining the polymer chain therein. This is accomplished by applying a first gas pressure to the reaction well such that a pressure differential between the first gas pressure and a second gas pressure exerted on an exit (80) of the orifice (74) exceeds a predetermined amount sufficient to overcome the capillary liquid seal and expel the reagent solution from the well (26) through the orifice exit (80).

Brennan, Thomas M. (San Francisco, CA)

1998-01-01T23:59:59.000Z

342

Method for polymer synthesis in a reaction well  

DOE Patents [OSTI]

A method of synthesis is described for building a polymer chain, oligonucleotides in particular, by sequentially adding monomer units to at least one solid support for growing and immobilizing a polymer chain thereon in a liquid reagent solution. The method includes the step of: (A) depositing a liquid reagent in a reaction well in contact with at least one solid support and at least one monomer unit of the polymer chain affixed to the solid support. The well includes at least one orifice extending into the well, and is of a size and dimension to form a capillary liquid seal to retain the reagent solution in the well to enable polymer chain growth on the solid support. The method further includes the step of (B) expelling the reagent solution from the well, while retaining the polymer chain therein. This is accomplished by applying a first gas pressure to the reaction well such that a pressure differential between the first gas pressure and a second gas pressure exerted on an exit of the orifice exceeds a predetermined amount sufficient to overcome the capillary liquid seal and expel the reagent solution from the well through the orifice exit. 9 figs.

Brennan, T.M.

1998-09-29T23:59:59.000Z

343

Single chain elasticity and thermoelasticity of polyethylene  

E-Print Network [OSTI]

Single-chain elasticity of polyethylene at $\\theta$ point up to 90% of stretching with respect to its contour length is computed by Monte-Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature dependent parameter. Beyond this value of elongation simple ideal chain models are not able to describe the Monte Carlo data in a thermodynamic consistent way. This study reinforces the use of the wormlike chain model to interpret experimental data on the elasticity of synthetic polymers in the finite extensibility regime, provided the chain is not yet in its fully stretched regime. Specific solvent effects on the elasticity law and the partition between energetic and entropic contributions to single chain elasticity are investigated.

John T. Titantah; Carlo Pierleoni; Jean-Paul Ryckaert

2002-09-05T23:59:59.000Z

344

4 studies of the 1.84.8 GeV 3 Au reactions.  

E-Print Network [OSTI]

to very low energies, indicative of emission from an extended nuclear system with / 0 1/3. Predictions into the nuclear equation of state EOS at low densities, limiting temperatures in the nuclear medium, and liquid a higher level of understanding; e.g., reaction time scales, the excitation energy and degree

Maryland at College Park, University of

345

Intermediate-energy nuclear chemistry workshop  

SciTech Connect (OSTI)

This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities.

Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

1981-05-01T23:59:59.000Z

346

Photonuclear Reaction Cross Sections for Gallium Isotopes  

E-Print Network [OSTI]

The photon induced reactions which are named as photonuclear reactions have a great importance in many field of nuclear, radiation physics and related fields. Since we have planned to perform photonuclear reaction on gallium target with bremmstrahlung photons from clinical linear accelerator in the future, the cross-sections of neutron (photo-neutron ({\\gamma},xn)) and proton (photo-proton ({\\gamma},xn)) productions after photon activation have been calculated by using TALYS 1.2 computer code in this study. The target nucleus has been considered gallium which has two stable isotopes, 69Ga and 71Ga. According to the results, we have seen that the calculations are in harmony in the limited literature values. Furthermore, the pre-equilibrium and compound process contributions to the total cross-section have been investigated.

Serkan Akkoyun; Tuncay Bayram

2014-09-08T23:59:59.000Z

347

Critical phenomena of asymmetric nuclear matter in the extended  

E-Print Network [OSTI]

Critical phenomena of asymmetric nuclear matter in the extended Zimanyi-Moszkowski model K nuclear matter produced by heavy-ion reactions is isospin asymmetric. Although the critical exponents. Miyazaki Abstract We have studied the liquid-gas phase transition of warm asymmetric nuclear matter

348

NUCLEAR SCIENCE PUBLICATIONS OF ROBERT B. WEISENMILLER, PH.D.  

E-Print Network [OSTI]

1 NUCLEAR SCIENCE PUBLICATIONS OF ROBERT B. WEISENMILLER, PH.D. 1. Two-proton Pickup Studies, K. H. Wilcox, G. J. Wozniak, M. S. Zisman, and J. Cerny. Nuclear Physics A 280, 217. 1977. 3 Spectroscopic Measurement via Exotic Nuclear Rearrangement: The Reaction 26 Mg (7 Li, 8 B), 25 Ne. With K. H

349

Nuclear Science and Technology, November 2000. NEUTRON CROSS SECTION EVALUATIONS  

E-Print Network [OSTI]

Nuclear Science and Technology, November 2000. 1 NEUTRON CROSS SECTION EVALUATIONS FOR 238 U UP and Power Engineering, 249020 Obninsk, Russia A.Ventura ENEA, Nuclear Data Center and INFN, Bologna Section of the statistical description that includes direct, pre-equilibrium and equilibrium mechanisms of nuclear reactions

350

Nuclear reactor engineering: Reactor design basics. Fourth edition, Volume One  

SciTech Connect (OSTI)

This new edition of this classic reference combines broad yet in-depth coverage of nuclear engineering principles with practical descriptions of their application in design and operation of nuclear power plants. Extensively updated, the fourth edition includes new material on reactor safety and risk analysis, regulation, fuel management, waste management, and operational aspects of nuclear power. This volume contains the following: energy from nuclear fission; nuclear reactions and radiations; neutron transport; nuclear design basics; nuclear reactor kinetics and control; radiation protection and shielding; and reactor materials.

Glasstone, S.; Sesonske, A.

1994-12-31T23:59:59.000Z

351

The LHC Lead Injector Chain  

E-Print Network [OSTI]

A sizeable part of the LHC physics programme foresees lead-lead collisions with a design luminosity of 1027 cm-2 s-1. This will be achieved after an upgrade of the ion injector chain comprising Linac3, LEIR, PS and SPS machines [1,2]. Each LHC ring will be filled in 10 min by almost 600 bunches, each of 7107 lead ions. Central to the scheme is the Low Energy Ion Ring (LEIR) [3,4], which transforms long pulses from Linac3 into high-brilliance bunches by means of multi-turn injection, electron cooling and accumulation. Major limitations along the chain, including space charge, intrabeam scattering, vacuum issues and emittance preservation are highlighted. The conversion from LEAR (Low Energy Antiproton Ring) to LEIR involves new magnets and power converters, high-current electron cooling, broadband RF cavities, and a UHV vacuum system with getter (NEG) coatings to achieve a few 10-12 mbar. Major hardware changes in Linac3 and the PS are also covered. An early ion scheme with fewer bunches (but each at nominal...

Beuret, A; Blas, A; Burkhardt, H; Carli, Christian; Chanel, M; Fowler, A; Gourber-Pace, M; Hancock, S; Hourican, M; Hill, C E; Jowett, John M; Kahle, K; Kchler, D; Lombardi, A M; Mahner, E; Manglunki, Django; Martini, M; Maury, S; Pedersen, F; Raich, U; Rossi, C; Royer, J P; Schindl, Karlheinz; Scrivens, R; Sermeus, L; Shaposhnikova, Elena; Tranquille, G; Vretenar, Maurizio; Zickler, T

2004-01-01T23:59:59.000Z

352

Continuous chain bit with downhole cycling capability  

DOE Patents [OSTI]

A continuous chain bit for hard rock drilling is capable of downhole cycling. A drill head assembly moves axially relative to a support body while the chain on the head assembly is held in position so that the bodily movement of the chain cycles the chain to present new composite links for drilling. A pair of spring fingers on opposite sides of the chain hold the chain against movement. The chain is held in tension by a spring-biased tensioning bar. A head at the working end of the chain supports the working links. The chain is centered by a reversing pawl and piston actuated by the pressure of the drilling mud. Detent pins lock the head assembly with respect to the support body and are also operated by the drilling mud pressure. A restricted nozzle with a divergent outlet sprays drilling mud into the cavity to remove debris. Indication of the centered position of the chain is provided by noting a low pressure reading indicating proper alignment of drilling mud slots on the links with the corresponding feed branches.

Ritter, Don F. (Albuquerque, NM); St. Clair, Jack A. (Albuquerque, NM); Togami, Henry K. (Albuquerque, NM)

1983-01-01T23:59:59.000Z

353

Kaon production in heavy ion reactions at intermediate energies  

E-Print Network [OSTI]

The article reviews the physics related to kaon and antikaon production in heavy ion reactions at intermediate energies. Chiral dynamics predicts substantial modifications of the kaon properties in a dense nuclear environment. The status of the theoretical predictions as well as experimental evidences for medium effects such as repulsive/attractive mass shifts for $K^+/K^-$ are reviewed. In the vicinity of the thresholds, and even more pronounced below threshold, the production of strangeness is a highly collective process. Starting from elementary reaction channels the phenomenology of $K^+$ and $K^-$ production, i.e. freeze-out densities, time scales etc. as derived from experiment and theoretical transport calculations is presented. Below threshold kaon production shows a high sensitivity on the nuclear compression reached in heavy ion reactions. This allows to put constraints on the nuclear equation-of-state which are finally discussed.

Christian Fuchs

2005-09-01T23:59:59.000Z

354

Detailed Chemical Kinetic Reaction Mechanism for Biodiesel Components Methyl Stearate and Methyl Oleate  

SciTech Connect (OSTI)

New chemical kinetic reaction mechanisms are developed for two of the five major components of biodiesel fuel, methyl stearate and methyl oleate. The mechanisms are produced using existing reaction classes and rules for reaction rates, with additional reaction classes to describe other reactions unique to methyl ester species. Mechanism capabilities were examined by computing fuel/air autoignition delay times and comparing the results with more conventional hydrocarbon fuels for which experimental results are available. Additional comparisons were carried out with measured results taken from jet-stirred reactor experiments for rapeseed methyl ester fuels. In both sets of computational tests, methyl oleate was found to be slightly less reactive than methyl stearate, and an explanation of this observation is made showing that the double bond in methyl oleate inhibits certain low temperature chain branching reaction pathways important in methyl stearate. The resulting detailed chemical kinetic reaction mechanism includes more approximately 3500 chemical species and more than 17,000 chemical reactions.

Naik, C; Westbrook, C K; Herbinet, O; Pitz, W J; Mehl, M

2010-01-22T23:59:59.000Z

355

Nuclear Counterterrorism  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The Order defines requirements for the protection of sensitive improvised nuclear device information and provides a framework to support DOE activities related to nuclear counterterrorism. (A supplemental DOE Manual, Control of and Access to Improvised Nuclear Device Information, provides requirements and procedures for protecting Sigma 20 information.) Appendices A and B are Official Use Only. Point of contact is Adam Boyd (NA-82), 202-586-0010. Cancels DOE O 457.1 and DOE M 457.1-1.

2013-08-26T23:59:59.000Z

356

Terracentric Nuclear Fission Reactor: Background, Basis, Feasibility, Structure, Evidence, and Geophysical Implications  

E-Print Network [OSTI]

The background, basis, feasibility, structure, evidence, and geophysical implications of a naturally occurring Terracentric nuclear fission georeactor are reviewed. For a nuclear fission reactor to exist at the center of the Earth, all of the following conditions must be met: (1) There must originally have been a substantial quantity of uranium within Earth's core; (2) There must be a natural mechanism for concentrating the uranium; (3) The isotopic composition of the uranium at the onset of fission must be appropriate to sustain a nuclear fission chain reaction; (4) The reactor must be able to breed a sufficient quantity of fissile nuclides to permit operation over the lifetime of Earth to the present; (5) There must be a natural mechanism for the removal of fission products; (6) There must be a natural mechanism for removing heat from the reactor; (7) There must be a natural mechanism to regulate reactor power level, and; (8) The location of the reactor or must be such as to provide containment and prevent meltdown. Herndon's georeactor alone is shown to meet those conditions. Georeactor existence evidence based upon helium measurements and upon antineutrino measurements is described. Geophysical implications discussed include georeactor origin of the geomagnetic field, geomagnetic reversals from intense solar outbursts and severe Earth trauma, as well as georeactor heat contributions to global dynamics.

J. Marvin Herndon

2013-12-31T23:59:59.000Z

357

nuclear controls  

National Nuclear Security Administration (NNSA)

the Office of Nonproliferation and International Security (NIS) is to prevent the proliferation of nuclear weapons, materials, technology, and expertise. NIS applies technical...

358

Nuclear and gravitational energies in stars  

E-Print Network [OSTI]

The force that governs the evolution of stars is gravity. Indeed this force drives star formation, imposes thermal and density gradients into stars at hydrostatic equilibrium and finally plays the key role in the last phases of their evolution. Nuclear power in stars governs their lifetimes and of course the stellar nucleosynthesis. The nuclear reactions are at the heart of the changes of composition of the baryonic matter in the Universe. This change of composition, in its turn, has profound consequences on the evolution of stars and galaxies. The energy extracted from the gravitational, respectively nuclear reservoirs during the lifetimes of stars of different masses are estimated. It is shown that low and intermediate mass stars (M 8 Msol), which explode in a supernova explosion, extract more than 5 times more energy from the gravitational reservoir than from the nuclear one. We conclude by discussing a few important nuclear reactions and their link to topical astrophysical questions.

Meynet, Georges; Ekstrm, Sylvia

2013-01-01T23:59:59.000Z

359

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration  

E-Print Network [OSTI]

, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL ­ Supply chains and logistics ­ Systems of systems (e.g., the nuclear fuel cycle, fleet management) #12

Langerhans, Brian

360

Reports to the DOE Nuclear Data Committee  

SciTech Connect (OSTI)

The report in this document were submitted to the Department of Energy, Nuclear Data Committee (DOE-NDC) in April 1988. The reporting laboratories are those with a substantial program for the measurement of neutron and nuclear cross sections of relevance to the US applied nuclear energy program. Appropriate subjects are microscopic neutron cross sections relevant to the nuclear energy program, including shielding. Inverse reactions where pertinent are included; charged-particle cross sections where relevant to developing and testing nuclear models; gamma ray production, radioactive decay, and theoretical developments in nuclear structure which are applicable to nuclear energy programs; and proton and alpha-particle cross sections, at energies of up to 1 GeV, which are of interest to the space program.

Not Available

1988-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Optimizing a Retailer's Containerized Import Supply Chain  

E-Print Network [OSTI]

M.G. , 2005. Distribution network design: New problems andapproach for distribution chain design in agile virtualinto a strategic distribution network design model with

Davidson, Evan Taitz

2012-01-01T23:59:59.000Z

362

Chart of Nuclides from the National Nuclear Data Center (NNDC)  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The Chart of Nuclides is a software product that allows users to search and plot nuclear structure and nuclear decay data interactively. The Chart of Nuclides was developed by the National Nuclear Data Center (NNDC). It provides an interface between web users and several databases containing nuclear structure, nuclear decay and some neutron-induced nuclear reaction information. Using the Chart of Nuclides, it is possible to search for nuclear level properties (energy, half-life, spin-parity), gamma-ray information (energy, intensity, multipolarity, coincidences),radiation information following nuclear decay (energy, intensity, dose), and neutron-induced reaction data from the BNL-325 book (thermal cross section and resonance integral). The information provided by the Chart of Nuclides can be seen in tables, level schemes and an interactive chart of nuclides. (From the Chart of Nuclides Description at http://www.nndc.bnl.gov/chart/help/index.jsp?product=chart)

363

Reaction Rate Sensitivity of the gamma-Process Path  

E-Print Network [OSTI]

The location of the (gamma,p)/(gamma,n) and (gamma,alpha)/(gamma,n) line at gamma-process temperatures is discussed, using recently published reaction rates based on global Hauser-Feshbach calculations. The results can directly be compared to previously published, classic gamma-process discussions. The nuclei exhibiting the largest sensitivity to uncertainties in nuclear structure and reaction parameters are specified.

T. Rauscher

2004-07-16T23:59:59.000Z

364

Nuclear astrophysics studies with ultra-peripheral heavy-ion collisions  

E-Print Network [OSTI]

I describe in very simple terms the theoretical tools needed to investigate ultra-peripheral nuclear reactions for nuclear astrophysics purposes. For a more detailed account, see arXiv:0908.4307.

C. A. Bertulani

2009-12-17T23:59:59.000Z

365

Supply Chain The effective supply chain has become a new organizational and operational  

E-Print Network [OSTI]

MBA in Supply Chain Management #12;The effective supply chain has become a new organizational a virtual integration of business partners to achieve new levels of efficiency and productivity, as well

Lin, Xiaodong

366

PROBING DENSE NUCLEAR MATTER VIA NUCLEAR COLLISIONS  

E-Print Network [OSTI]

University of California. LBL-12095 Probing Dense NuclearMatter Nuclear Collisions* v~a H. Stocker, M.Gyulassy and J. Boguta Nuclear Science Division Lawrence

Stocker, H.

2012-01-01T23:59:59.000Z

367

Reactor for exothermic reactions  

DOE Patents [OSTI]

A liquid phase process for oligomerization of C.sub.4 and C.sub.5 isoolefins or the etherification thereof with C.sub.1 to C.sub.6 alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120.degree. to 300.degree. F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

Smith, Jr., Lawrence A. (Bellaire, TX); Hearn, Dennis (Houston, TX); Jones, Jr., Edward M. (Friendswood, TX)

1993-01-01T23:59:59.000Z

368

Reactor for exothermic reactions  

DOE Patents [OSTI]

A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

1993-03-02T23:59:59.000Z

369

Statistical Methods for Thermonuclear Reaction Rates and Nucleosynthesis Simulations  

E-Print Network [OSTI]

Rigorous statistical methods for estimating thermonuclear reaction rates and nucleosynthesis are becoming increasingly established in nuclear astrophysics. The main challenge being faced is that experimental reaction rates are highly complex quantities derived from a multitude of different measured nuclear parameters (e.g., astrophysical S-factors, resonance energies and strengths, particle and gamma-ray partial widths). We discuss the application of the Monte Carlo method to two distinct, but related, questions. First, given a set of measured nuclear parameters, how can one best estimate the resulting thermonuclear reaction rates and associated uncertainties? Second, given a set of appropriate reaction rates, how can one best estimate the abundances from nucleosynthesis (i.e., reaction network) calculations? The techniques described here provide probability density functions that can be used to derive statistically meaningful reaction rates and final abundances for any desired coverage probability. Examples are given for applications to s-process neutron sources, core-collapse supernovae, classical novae, and big bang nucleosynthesis.

Christian Iliadis; Richard Longland; Alain Coc; F. X. Timmes; Art E. Champagne

2014-09-19T23:59:59.000Z

370

In-medium effects for nuclear matter in the Fermi energy domain D. Durand,1  

E-Print Network [OSTI]

In-medium effects for nuclear matter in the Fermi energy domain O. Lopez,1 D. Durand,1 G. Lehaut,1 of nuclear reactions in the Fermi energy domain. I. INTRODUCTION Transport properties in nuclear matter energy domain, transport features should exhibit the in- terplay between mean-field (nuclear degrees

Boyer, Edmond

371

Introduction The Sustainable Supply Chain Taxes Permits Integration Future Research Sustainable Supply Chains  

E-Print Network [OSTI]

Introduction The Sustainable Supply Chain Taxes Permits Integration Future Research Sustainable;Introduction The Sustainable Supply Chain Taxes Permits Integration Future Research 1 Introduction 2 The Sustainable Supply Chain 3 Taxes 4 Permits 5 Integration 6 Future Research Dissertation Defense by Trisha D

Nagurney, Anna

372

Nuclear correlation and finite interaction-range effects in high-energy $(e,e'p)$ nuclear transparency  

E-Print Network [OSTI]

Nuclear transparency is calculated for high-energy, semi-inclusive $(e,e'p)$ reactions, by accounting for all orders of Glauber multiple-scattering and by using realistic finite-range $p N$ interaction and (dynamically and statistically) correlated nuclear wave functions. The nuclear correlation effect is reduced due to the $p N$ finite-range effect. The net effect is small, and depends sensitively on details of the nuclear correlations in finite nuclei, which are poorly known at present.

Ryoichi Seki; T. D. Shoppa; Akihisa Kohama; Koichi Yazaki

1995-12-06T23:59:59.000Z

373

Supply Chain Networks: Challenges and Opportunities  

E-Print Network [OSTI]

School of Management University of Massachusetts Amherst, Massachusetts 01003 Department of Management, and consumers at the demand markets. Today, supply chains may span thousands of miles across the globe, involve as the stability and resiliency of supply chains, as well as their adaptability and responsiveness to events

Nagurney, Anna

374

Supply Chain Networks: Challenges and Opportunities  

E-Print Network [OSTI]

School of Management University of Massachusetts Amherst, Massachusetts 01003 Boston INFORMS Chapter and suppliers, distributors, retailers, and consumers at the demand markets. Today, supply chains may span chains, as well as their adaptability and responsiveness to events in a global environment of increasing

Nagurney, Anna

375

Supply Chain Networks: Challenges and Opportunities  

E-Print Network [OSTI]

School of Management University of Massachusetts Amherst, Massachusetts 01003 International Conference of manufacturers and suppliers, distributors, retailers, and consumers at the demand markets. Today, supply chains chains, as well as their adaptability and responsiveness to events in a global environment of increasing

Nagurney, Anna

376

Supply Chains and Transportation Networks Anna Nagurney  

E-Print Network [OSTI]

Management Isenberg School of Management University of Massachusetts Amherst, Massachusetts 01003 December, and consumers at the demand markets. Supply chains are the backbones of our globalized Network Economy of cooperation. For example, in a vertically integrated supply chain the same firm may be responsible

Nagurney, Anna

377

Internal Markets for Supply Chain Capacity Allocation  

E-Print Network [OSTI]

Internal Markets for Supply Chain Capacity Allocation David McAdams and Thomas W. Malone Sloan David McAdams & Thomas Malone #12;Internal Markets for Supply Chain Capacity Allocation David Mc ("internal markets") to help allocate manufacturing capacity and determine the prices, delivery dates

378

The XY Spin Chain Random Block Operators  

E-Print Network [OSTI]

The XY Spin Chain Random Block Operators Proof of Main Result Open Questions Localization for Random Block Operators Related to the XY Spin Chain Jacob W. Chapman Division of Science Southern Wesleyan University Central, SC Joint work with G¨unter Stolz UAB NSF-CBMS Conference on Quantum Spin

Jung, Paul

379

Energy Balanced Chain in Distributed Sensor Networks  

E-Print Network [OSTI]

Energy Balanced Chain in Distributed Sensor Networks Ivan Howitt Electrical & Computer Engineering because of their higher traffic. This paper suggests an energy balanced chain (EBC) which can efficiently the energy balance optimization problem in terms of the segmentation space. By adjusting the transmission

Howitt, Ivan

380

TORUS: Theory of Reactions for Unstable iSotopes - Year 1 Continuation and Progress Report  

SciTech Connect (OSTI)

The TORUS collaboration derives its name from the research it focuses on, namely the Theory of Reactions for Unstable iSotopes. It is a Topical Collaboration in Nuclear Theory, and funded by the Nuclear Theory Division of the Office of Nuclear Physics in the Office of Science of the Department of Energy. The funding started on June 1, 2010, it will have been running for nine months by the date of submission of this Annual Continuation and Progress Report on March 1, 2011. The extent of funding was reduced from the original application, and now supports one postdoctoral researcher for the years 1 through 3. The collaboration brings together as Principal Investigators a large fraction of the nuclear reaction theorists currently active within the USA. The mission of the TORUS Topical Collaboration is to develop new methods that will advance nuclear reaction theory for unstable isotopes by using three-body techniques to improve direct-reaction calculations, and, by using a new partial-fusion theory, to integrate descriptions of direct and compound-nucleus reactions. This multi-institution collaborative effort is directly relevant to three areas of interest: the properties of nuclei far from stability; microscopic studies of nuclear input parameters for astrophysics, and microscopic nuclear reaction theory.

Arbanas, G; Elster, C; Escher, J; Mukhamedzhanov, A; Nunes, F; Thompson, I J

2011-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Comparison of reactions for the production of 258,257Db: 208Pb(51V,xn) and 209Bi(50Ti,xn)  

E-Print Network [OSTI]

as 10 - 15 MeV, hence cold fusion. These low excitationmodel for predicting cold fusion reaction cross sections [7,been produced in cold nuclear fusion reactions with Pb and

Gates, Jacklyn M.

2008-01-01T23:59:59.000Z

382

Nuclear Counterterrorism  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The Order defines requirements for the protection of sensitive improvised nuclear device information and provides a framework to support DOE activities related to nuclear counterterrorism. (A supplemental DOE Manual, Control of and Access to Improvised Nuclear Device Information, provides requirements and procedures for protecting Sigma 20 information. The Manual is Official Use Only, and is not available on the Directives Portal. The point of contact for the Manual is Randall Weidman, NA-121.2, 202-586-4582.) Canceled by DOE O 457.1A

2006-02-07T23:59:59.000Z

383

$?$-cluster ANCs for nuclear astrophysics  

E-Print Network [OSTI]

Background. Many important $\\alpha$-particle induced reactions for nuclear astrophysics may only be measured using indirect techniques due to small cross sections at the energy of interest. One of such indirect technique, is to determine the Asymptotic Normalization Coefficients (ANC) for near threshold resonances extracted from sub-Coulomb $\\alpha$-transfer reactions. This approach provides a very valuable tool for studies of astrophysically important reaction rates since the results are practically model independent. However, the validity of the method has not been directly verified. Purpose. The aim of this letter is to verify the technique using the $^{16}$O($^6$Li,$d$)$^{20}$Ne reaction as a benchmark. The $^{20}$Ne nucleus has a well known $1^-$ state at excitation energy of 5.79 MeV with a width of 28 eV. Reproducing the known value with this technique is an ideal opportunity to verify the method. Method. The 1$^-$ state at 5.79 MeV is studied using the $\\alpha$-transfer reaction $^{16}$O($^6$Li,$d$)$^{20}$Ne at sub-Coulomb energies. Results. The partial $\\alpha$ width for the $1^-$ state at excitation energy of 5.79 MeV is extracted and compared with the known value, allowing the accuracy of the method to be evaluated. Conclusions. This study demonstrates that extracting the Asymptotic Normalization Coefficients using sub-Coulomb $\\alpha$-transfer reactions is a powerful tool that can be used to determine the partial $\\alpha$ width of near threshold states that may dominate astrophysically important nuclear reaction rates. \\end{description}

M. L Avila; G. V. Roachev; E. Koshchiy; L. T. Baby; J. Belarge; K. W. Kemper; A. N. Kuchera; D. Santiago-Gonzalez

2014-06-23T23:59:59.000Z

384

PHYS 390 Lecture 18 -Reactions I -Tunneling 18 -1 2001 by David Boal, Simon Fraser University. All rights reserved; further resale or copying is strictly prohibited.  

E-Print Network [OSTI]

. 4.1 and 4.5 Coulomb barrier to nuclear reactions The elementary particle reactions that occurred K. Such low temperatures affect reactions in two ways: · the reactions may occur through the phenomenon of quantum mechanical tunneling · the low energy end of a thermal distribution of particles may

Boal, David

385

Countering Nuclear Terrorism and Trafficking | National Nuclear...  

National Nuclear Security Administration (NNSA)

Countering Nuclear Terrorism and Trafficking | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing...

386

Single-Chain Antibody Library  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Researchers at Pacific Northwest National Laboratory (PNNL) have constructed a nonimmune library consisting of 109 human antibody scFv fragments, which have been cloned and expressed on the surface of yeast. Nanomolar-affinity scFvs are routinely obtained by magnetic bead screening and flow cytometric sorting. The yeast library can be amplified 1010 fold without measurable loss of clonal diversity. This allows for indefinite expansion of the library. All scFv clones can be assessed directly on the yeast cell surface by immunofluorescent labeling and flow cytometry, obviating separate subcloning, expression, and purification steps. The ability to use multiplex library screening demonstrates the utility of this approach for high-throughput antibody isolation for proteomic applications. The yeast library may be used for research projects or teaching performed for U.S. Government purposes only. If you would like to request an aliquot of the single-chain antibody library for your research, please print and fill out the Materials Transfer Agreement (MTA) [PDF, 20K]. The website provides the contact information for mailing the MTA. [copied from http://www.sysbio.org/dataresources/singlechain.stm

Baird, Cheryl

387

Neutron multiplicity distributions for 30 MeVu {sup 14}N reactions with the indicated targets. Progress in research, April 1, 1991--March 31, 1992  

SciTech Connect (OSTI)

This report contains short papers on the following topics: Heavy ion reactions; nuclear structure and fundamental interactions; nuclear theory; atomic molecular and materials science; and superconducting cyclotron and instrumentation. (LSP)

Not Available

1992-06-01T23:59:59.000Z

388

NUCLEAR PLANT OPERATIONS AND  

E-Print Network [OSTI]

NUCLEAR PLANT OPERATIONS AND CONTROL KEYWORDS: neutron flux, cur- rent noise, vibration diagnostics: Swedish Nuclear Powe

Pzsit, Imre

389

Reaction network and kinetics for the catalytic oxidation of toluene over V sub 2 O sub 5  

SciTech Connect (OSTI)

The oxidation of three methyl-diphenylmethane isomers and of bibenzyl, benzyl alcohol, and benzaldehyde, which are intermediates in the catalytic oxidation of toluene over V{sub 2}O{sub 5}, has been studied to elucidate the reaction network and relative importance of various reactions. Selectivity dependences reveal that the network is composed mainly of three parallel reaction routes: (1) side-chain oxidation with consecutive reactions, (2) oxidative coupling with both parallel and consecutive reactions, and (3) carbon oxide formation. Coupling products are not negligible, with an initial selectivity of 29% (400{degree}C). Anthraquinone is produced mainly from o-methyl-diphenylmethane conditions and catalyst used. Selectivity dependences suggested product lumping and a simplified network. Kinetic analysis of this reaction network indicates that higher temperatures favor route 2 over route 1. The same initial intermediates for route 1 of side-chain oxidation and for route 2 of oxidative coupling are suggested.

Zhu, J.; Andersson, L.T. (Univ. of Lund (Sweden))

1990-11-01T23:59:59.000Z

390

Space Nuclear  

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

Space Nuclear Today the INL is preparing to assist with the Multi-Mission RTG (MMRTG). The INL is assigned the final assembly and testing of the RTG for the project which is...

391

Nuclear Golf  

E-Print Network [OSTI]

Broadcast Transcript: Pay no attention to that nuclear warhead behind the 18th hole; just shout "Fore!" and drive your Titleist down the fairway. In a development that is bizarre even by North Korean standards, the country ...

Hacker, Randi; Tsutsui, William

2006-12-06T23:59:59.000Z

392

Nuclear Hydrogen  

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

Hydrogen High temperature options for nuclear generation of hydrogen on a commercial basis are several years in the future. Thermo-chemical water splitting has been proven to be...

393

Nuclear forces  

SciTech Connect (OSTI)

These lectures present an introduction into the theory of nuclear forces. We focus mainly on the modern approach, in which the forces between nucleons emerge from low-energy QCD via chiral effective field theory.

Machleidt, R. [Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States)

2013-06-10T23:59:59.000Z

394

Synthesis, Decay Properties, and Identification of Superheavy Nuclei Produced in {sup 48}Ca-induced Reactions  

SciTech Connect (OSTI)

Thirty-four new nuclides with Z = 104-116, 118 and N = 161-177 have been synthesized in the complete-fusion reactions of {sup 238}U, {sup 237}Np, {sup 242,244}Pu, {sup 243}Am, {sup 245,248}Cm, and {sup 249}Cf targets with {sup 48}Ca beams. The masses of evaporation residues were identified through measurements of the excitation functions of the xn-evaporation channels and from cross bombardments. The decay properties of the new nuclei agree with those of previously known heavy nuclei and with predictions from different theoretical models. A discussion of self-consistent interpretations of all observed decay chains originating from the parent isotopes {sup 282,283}112, {sup 282}113, {sup 286-289}114, {sup 287,288}115, {sup 290-293}116, and {sup 294}118 is presented. Decay energies and lifetimes of the neutron-rich superheavy nuclei as well as their production cross sections indicate a considerable increase in the stability of nuclei with the approach to the theoretically predicted nuclear shells with N = 184 and Z = 114.

Oganessian, Yu. Ts.; Utyonkov, V. K.; Lobanov, Yu. V.; Abdullin, F. Sh.; Polyakov, A. N.; Sagaidak, R. N.; Shirokovsky, I. V.; Tsyganov, Yu. S.; Voinov, A. A.; Iliev, S.; Subbotin, V. G.; Sukhov, A. M.; Gulbekian, G. G.; Bogomolov, S. L.; Gikal, B. N.; Mezentsev, A. N.; Subotic, K.; Zagrebaev, V. I.; Itkis, M. G. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Moody, K. J. [University of California, Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)] (and others)

2007-10-26T23:59:59.000Z

395

THEOREMES DE BASSE ENERGIE ET REACTIONS PHOTO-PIONIQUES SUR LES NOYAUX J. DELORME, M. ERICSON et A. FIGUREAU  

E-Print Network [OSTI]

. The application of low energy theorems to nuclear photopion reactions in here displayed Various experimental testsTHEOREMES DE BASSE ENERGIE ET REACTIONS PHOTO-PIONIQUES SUR LES NOYAUX J. DELORME, M. ERICSON et A;THEOREMES DE BASSE ENERGIE E T REACTIONS PHOTO-PIONIQUES SUR LES NOYAUX constantes de ccuplage ou facteurs

Boyer, Edmond

396

Few-body models for nuclear astrophysics  

SciTech Connect (OSTI)

We present applications of microscopic models to nuclear reactions of astrophysical interest, and we essentially focus on few-body systems. The calculation of radiative-capture and transfer cross sections is outlined, and we discuss the corresponding reaction rates. Microscopic theories are briefly presented, and we emphasize on the matrix elements of four-body systems. The microscopic extension of the R-matrix theory to nuclear reactions is described. Applications to the {sup 2}H(d, ?){sup 4}He, {sup 2}H(d, p){sup 3}H and {sup 2}H(d, n){sup 3}He reactions are presented. We show the importance of the tensor force to reproduce the low-energy behaviour of the cross sections.

Descouvemont, P., E-mail: pdesc@ulb.ac.be [Physique Nuclaire Thorique et Physique Mathmatique, C.P. 229, Universit Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Baye, D., E-mail: dbaye@ulb.ac.be [Physique Nuclaire Thorique et Physique Mathmatique, C.P. 229, Universit Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Physique Quantique, C.P. 165/82, Universit Libre de Bruxelles (ULB), B 1050 Brussels (Belgium); Suzuki, Y., E-mail: suzuki@nt.sc.niigata-u.ac.jp [Department of Physics, Niigata University, Niigata 950-2181 (Japan); RIKEN Nishina Center, Wako 351-0198 (Japan); Aoyama, S., E-mail: aoyama@cc.niigata-u.ac.jp [Center for Academic Information Service, Niigata University, Niigata 950-2181 (Japan); Arai, K., E-mail: arai@nagaoka-ct.ac.jp [Division of General Education, Nagaoka National College of Technology, 888 Nishikatakai, Nagaoka, Niigata 940-8532 (Japan)

2014-04-15T23:59:59.000Z

397

E-Print Network 3.0 - activation reaction cross Sample Search...  

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

and Stochastics Collection: Mathematics 8 Vol. 31 (2000) ACTA PHYSICA POLONICA B No 2 NUCLEAR REACTIONS IN THE STARS Summary: with the low cross section or with activity of the...

398

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

399

Quantum spin chains and random matrix theory  

E-Print Network [OSTI]

The spectral statistics and entanglement within the eigenstates of generic spin chain Hamiltonians are analysed. A class of random matrix ensembles is defined which include the most general nearest-neighbour qubit chain Hamiltonians. For these ensembles, and their generalisations, it is seen that the long chain limiting spectral density is a Gaussian and that this convergence holds on the level of individual Hamiltonians. The rate of this convergence is numerically seen to be slow. Higher eigenvalue correlation statistics are also considered, the canonical nearest-neighbour level spacing statistics being numerically observed and linked with ensemble symmetries. A heuristic argument is given for a conjectured form of the full joint probability density function for the eigenvalues of a wide class of such ensembles. This is numerically verified in a particular case. For many translationally-invariant nearest-neighbour qubit Hamiltonians it is shown that there exists a complete orthonormal set of eigenstates for which the entanglement present in a generic member, between a fixed length block of qubits and the rest of the chain, approaches its maximal value as the chain length increases. Many such Hamiltonians are seen to exhibit a simple spectrum so that their eigenstates are unique up to phase. The entanglement within the eigenstates contrasts the spectral density for such Hamiltonians, which is that seen for a non-interacting chain of qubits. For such non-interacting chains, their always exists a basis of eigenstates for which there is no entanglement present.

Huw J Wells

2014-10-07T23:59:59.000Z

400

Velocity pump reaction turbine  

DOE Patents [OSTI]

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Velocity pump reaction turbine  

DOE Patents [OSTI]

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1984-01-01T23:59:59.000Z

402

Some Reactions of Formamidines  

E-Print Network [OSTI]

.1028 x .01401 11.36 % H. HCH*0CHCeH5 Theoretical for HC ' or C 3 4H 2 70 9H5 N HECeH*OCH*CeHs H = 70.05 v 10.99 $ nitrogen found - H.36 $ 19 Preparation of oyanaoetio derivatives of di-p~benzyl-oxy-di-phenyl- formamidin. Heat molecular... as hydrochloride b.- Piorates o.- Chloroplatinates. 2.- Reaction with compounds containing methylene hydrogen. a.- Reaction of oyanacetio ethyl ester with a substi tuted formamidine. OH OH I R I CHa * HO = 0 * HCHH R ^ R M a I * HER I COOCaHs COOCa...

Malleis, Otto Oscar

1913-05-15T23:59:59.000Z

403

Alternate Alpha Induced Reactions for NIF Radiochemistry  

SciTech Connect (OSTI)

Radiochemical analysis of NIF capsule residues has been identified as a potential diagnostic of NIF capsule performance. In particular, alpha-induced nuclear reactions that occur on tracer elements added to the NIF capsule have been shown through simulation to be a very sensitive diagnostic for mix. The short range of the alpha particles makes them representative of the hot spot where they are created through the fusion of deuterium and tritium. Reactions on elements doped into the innermost part of the capsule ablator would therefore be sensitive to material that had mixed into the hot spot. Radiochemical determinations of activated detector elements may perhaps be the only true measure of mix that occurs in a NIF capsule, particularly in cases when the capsule fails.

Shaughnessy, D A; Moody, K J; Bernstein, L A

2010-02-26T23:59:59.000Z

404

Symmetry energy in the structure and in reactions  

E-Print Network [OSTI]

Efforts to extract information on magnitude and density dependence of the nuclear symmetry energy are discussed. The utilized data include those on mass dependence of the excitation energies to the isobaric analog states of ground states, as well as data on the diffusion of isospin in heavy-ion reactions. Results following from different observables are compared.

P. Danielewicz

2010-03-21T23:59:59.000Z

405

Symmetry energy in the structure and in reactions  

E-Print Network [OSTI]

Efforts to extract information on magnitude and density dependence of the nuclear symmetry energy are discussed. The utilized data include those on mass dependence of the excitation energies to the isobaric analog states of ground states, as well as data on the diffusion of isospin in heavy-ion reactions. Results following from different observables are compared.

Danielewicz, P

2010-01-01T23:59:59.000Z

406

Nuclear-spectroscopy problems studied with neutrons  

SciTech Connect (OSTI)

Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions have been obtained that are not ony interesting per se but are also grist for old and new theory mills. The above technical advances have opened up new opportunities for further discoveries.

Raman, S.

1982-01-01T23:59:59.000Z

407

Nuclear Waste Disposal and Strategies for Predicting Long-Term Performance of Material  

SciTech Connect (OSTI)

Ceramics have been an important part of the nuclear community for many years. On December 2, 1942, an historic event occurred under the West Stands of Stagg Field, at the University of Chicago. Man initiated his first self-sustaining nuclear chain reaction and controlled it. The impact of this event on civilization is considered by many as monumental and compared by some to other significant events in history, such as the invention of the steam engine and the manufacturing of the first automobile. Making this event possible and the successful operation of this first man-made nuclear reactor, was the use of forty tons of UO2. The use of natural or enriched UO2 is still used today as a nuclear fuel in many nuclear power plants operating world-wide. Other ceramic materials, such as 238Pu, are used for other important purposes, such as ceramic fuels for space exploration to provide electrical power to operate instruments on board spacecrafts. Radioisotopic Thermoelectric Generators (RTGs) are used to supply electrical power and consist of a nuclear heat source and converter to transform heat energy from radioactive decay into electrical power, thus providing reliable and relatively uniform power over the very long lifetime of a mission. These sources have been used in the Galileo spacecraft orbiting Jupiter and for scientific investigations of Saturn with the Cassini spacecraft. Still another very important series of applications using the unique properties of ceramics in the nuclear field, are as immobilization matrices for management of some of the most hazardous wastes known to man. For example, in long-term management of radioactive and hazardous wastes, glass matrices are currently in production immobilizing high-level radioactive materials, and cementious forms have also been produced to incorporate low level wastes. Also, as part of nuclear disarmament activities, assemblages of crystalline phases are being developed for immobilizing weapons grade plutonium, to not only produce environmentally friendly products, but also forms that are proliferation resistant. All of these waste forms as well as others, are designed to take advantage of the unique properties of the ceramic systems.

Wicks, G.G.

2001-03-28T23:59:59.000Z

408

Nuclear Data Sheets for A = 230  

SciTech Connect (OSTI)

The evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reactions for all isobars with mass number A=230. This evaluation includes the first experimental evidence of {sup 230}Am, produced through the {sup 197}Au({sup 40}Ar,3n){sup 234}Bk ({alpha} decay to {sup 230}Am) reaction, E({sup 40}Ar)=188.4 MeV (2003MoZX).

Browne, E.; Tuli, J.K. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

2012-08-15T23:59:59.000Z

409

Nuclear Data Sheets for A = 251259 (odd)  

SciTech Connect (OSTI)

The evaluators present in this publication spectroscopic data and level schemes from radioactive decay and nuclear reaction studies for all known nuclei with mass numbers A = 251, 253, 255, 257, and 259.

Browne, E.; Tuli, J.K.

2013-08-15T23:59:59.000Z

410

Outstanding problems in nuclear astrophysics: recent progress at TRIUMF  

SciTech Connect (OSTI)

Recent experimental and theoretical efforts at TRIUMF on nuclear reactions relevant to big bang nucleosynthesis, quiescent stellar fusion, classical novae, and Type I X-ray bursts are described.

Davids, B., E-mail: davids@triumf.ca [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada)

2014-04-15T23:59:59.000Z

411

A program in medium-energy nuclear physics  

SciTech Connect (OSTI)

This report discusses the following topics: electron-scattering nuclear-structure studies; coincidence electrodisintegration studies of light nuclei; pion scattering and reactions on the three-body nuclei; and pion scattering from shell-model nuclei.

Berman, B.L.; Dhuga, K.S.

1990-01-01T23:59:59.000Z

412

Low energy ($p,?$) reactions in Ni and Cu nuclei using microscopic optical model  

E-Print Network [OSTI]

Radiative capture reactions for low energy protons have been theoretically studied for Ni and Cu isotopes using the microscopic optical model. The optical potential has been obtained in the folding model using different microscopic interactions with the nuclear densities from Relativistic Mean Field calculations. The calculated total cross sections as well as the cross sections for individually low lying levels have been compared with measurements involving stable nuclear targets. Rates for the rapid proton capture process have been evaluated for astrophysically important reactions.

G. Gangopadhyay

2010-08-05T23:59:59.000Z

413

Impact of demographics on supply chain risk management practices  

E-Print Network [OSTI]

Do demographic factors play a role in the choice of supply chain risk management practices by supply chain professionals? Are there stronger relationships between certain demographic factors and supply chain risk management ...

Kanyagui, Kenneth (Kenneth K.)

2010-01-01T23:59:59.000Z

414

Criticality without Frustration for Quantum Spin-1 Chains  

E-Print Network [OSTI]

Frustration-free (FF) spin chains have a property that their ground state minimizes all individual terms in the chain Hamiltonian. We ask how entangled the ground state of a FF quantum spin-s chain with nearest-neighbor ...

Movassagh, Ramis

415

Dynamic Electric Power Supply Chains and Transportation Networks  

E-Print Network [OSTI]

Dynamic Electric Power Supply Chains and Transportation Networks: an Evolutionary Variational energy Electric power supply chains, provide the foundations for theElectric power supply chains, provide and societies. Communication, transportation, heating, lighting, cooling,Communication, transportation, heating

Nagurney, Anna

416

An engineering approach to improving hospital supply chains  

E-Print Network [OSTI]

This thesis explores supply chain management practices that have been implemented, and have improved supply chains in industries outside of healthcare. The presented supply chain practices have been selected because they ...

Cheng, Scott Hsiang-Jen

2008-01-01T23:59:59.000Z

417

Nuclear Data Sheets for A=69  

SciTech Connect (OSTI)

Experimental data on ground and excitedstate properties for all known nuclei with mass number A=69 have been compiled and evaluated. States populated in radioactive decay, as well as in nuclear reactions, have been considered. For these nuclei, level and decay schemes, as well as tables of nuclear properties, are given in detail. This work supersedes the 2000 evaluation by M.R. Bhat and J.K. Tuli (2000Bh05)

Nesaraja, C.D.

2014-01-15T23:59:59.000Z

418

Reaction product imaging  

SciTech Connect (OSTI)

Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

419

Ion-induced nuclear radiotherapy  

DOE Patents [OSTI]

Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue.

Horn, Kevin M. (Albuquerque, NM); Doyle, Barney L. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

420

Ion-induced nuclear radiotherapy  

DOE Patents [OSTI]

Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue. 25 figs.

Horn, K.M.; Doyle, B.L.

1996-08-20T23:59:59.000Z

Note: This page contains sample records for the topic "nuclear chain reaction" 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

Strong plasma screening in thermonuclear reactions: Electron drop model  

E-Print Network [OSTI]

We analyze enhancement of thermonuclear fusion reactions due to strong plasma screening in dense matter using a simple electron drop model. The model assumes fusion in a potential that is screened by an effective electron cloud around colliding nuclei (extended Salpeter ion-sphere model). We calculate the mean field screened Coulomb potentials for atomic nuclei with equal and nonequal charges, appropriate astrophysical S factors, and enhancement factors of reaction rates. As a byproduct, we study analytic behavior of the screening potential at small separations between the reactants. In this model, astrophysical S factors depend not only on nuclear physics but on plasma screening as well. The enhancement factors are in good agreement with calculations by other methods. This allows us to formulate the combined, pure analytic model of strong plasma screening in thermonuclear reactions. The results can be useful for simulating nuclear burning in white dwarfs and neutron stars.

Kravchuk, P A

2014-01-01T23:59:59.000Z

422

Strong plasma screening in thermonuclear reactions: Electron drop model  

E-Print Network [OSTI]

We analyze enhancement of thermonuclear fusion reactions due to strong plasma screening in dense matter using a simple electron drop model. The model assumes fusion in a potential that is screened by an effective electron cloud around colliding nuclei (extended Salpeter ion-sphere model). We calculate the mean field screened Coulomb potentials for atomic nuclei with equal and nonequal charges, appropriate astrophysical S factors, and enhancement factors of reaction rates. As a byproduct, we study analytic behavior of the screening potential at small separations between the reactants. In this model, astrophysical S factors depend not only on nuclear physics but on plasma screening as well. The enhancement factors are in good agreement with calculations by other methods. This allows us to formulate the combined, pure analytic model of strong plasma screening in thermonuclear reactions. The results can be useful for simulating nuclear burning in white dwarfs and neutron stars.

P. A. Kravchuk; D. G. Yakovlev

2014-01-11T23:59:59.000Z

423

Solid state laser media driven by remote nuclear powered fluorescence  

DOE Patents [OSTI]

An apparatus is provided for driving a solid state laser by a nuclear powered fluorescence source which is located remote from the fluorescence source. A nuclear reaction produced in a reaction chamber generates fluorescence or photons. The photons are collected from the chamber into a waveguide, such as a fiber optic waveguide. The waveguide transports the photons to the remote laser for exciting the laser.

Prelas, Mark A. (Columbia, MO)

1992-01-01T23:59:59.000Z

424

Interlaboratory reaction rate program. 12th progress report, November 1976-October 1979  

SciTech Connect (OSTI)

The Interlaboratory Reaction Rate UILRR) program is establishing the capability to accurately measure neutron-induced reactions and reaction rates for reactor fuels and materials development programs. The goal for the principal fission reactions, /sup 235/U, /sup 238/U and /sup 239/Pu, is an accuracy to within +- 5% at the 95% confidence level. Accurate measurement of other fission and nonfission reactions is also required, but to a lesser accuracy, between +- 5% and 10% at the 95% confidence level. A secondary program objective is improvement in knowledge of the nuclear parameters involved in the standarization of fuels and materials dosimetry measurements of neutron flux, spectra, fluence and burnup.

Lippincott, E.P.; McElroy, W.N.; Preston, C.C. (comps.)

1980-09-01T23:59:59.000Z

425

The AMEDEE Nuclear Structure Database  

SciTech Connect (OSTI)

The increasing need for nuclear data far from the valley of stability requires information on nuclei which cannot be accessed experimentally or for which almost no experimental data is known. Consequently, the use of microscopic approaches to predict properties of such poorly known nuclei is necessary as a first step to improve our understanding of nuclear reaction on exotic nuclei. Within this context, large scale axial mean field calculations from proton to neutron drip-lines have been performed using the Hartree-Fock-Bogoliubov method based on the DIS Gogny nucleon-nucleon effective interaction. Nearly 7000 nuclei have been studied under the axial symmetry hypothesis and several properties are now available for the nuclear scientific community on an Internet web site for every individual nucleus.

Hilaire, S.; Girod, M. [CEA/DAM Ile-de-France, Service de Physique Nucleaire, BP 12, F-91680 Bruyeres-le-Chatel (France)

2008-05-12T23:59:59.000Z

426

The supply chain response to environmental pressures  

E-Print Network [OSTI]

Understanding and shaping the relationship between supply chain management and the natural environment is critical not only to human health and the environment, but to the future success of business. While the cumulative ...

Paquette, Julie Rebecca

2006-01-01T23:59:59.000Z

427

Internal Markets for Supply Chain Capacity Allocation  

E-Print Network [OSTI]

This paper explores the possibility of solving supply chain capacity allocation problems using internal markets among employees of the same company. Unlike earlier forms of transfer pricing, IT now makes it easier for such ...

McAdams, David

2005-07-08T23:59:59.000Z

428

Global supply chain design and optimization methodology  

E-Print Network [OSTI]

The work for this thesis was performed at Honeywell in the Automation and Control Solutions (ACS) division. The project focuses on ACS's manufacturing strategy regarding its global supply chain design, primarily discussing ...

Henkle, Aimee L. (Aimee Leigh), 1975-

2004-01-01T23:59:59.000Z

429

Economic analysis of the meat supply chain  

E-Print Network [OSTI]

and overseas animal disease outbreaks on the Korean meat supply chain. Market impacts are investigated using both forecasts and historical decomposition of price innovations based on an error correction model (ECM) of the Korean meat sector. Results indicate...

Park, Moon-Soo

2009-05-15T23:59:59.000Z

430

Supply chain and the executive agenda  

E-Print Network [OSTI]

In recent years, supply chain pundits and consultants emphasized the importance of strategies such as just-in-time, lean manufacturing, off- shoring or frequent deliveries to retail outlets. However, with significant ...

Peruvankal, James Paul

2011-01-01T23:59:59.000Z

431

Segmentation strategies for managing retail supply chains  

E-Print Network [OSTI]

High-technology manufacturing companies often face rapid price decline and capacity constraints. Especially in the retail side of the business where the supply chain is much longer and revenue is sometimes not recognized ...

Liang, Catherine G. (Catherine Gloria)

2011-01-01T23:59:59.000Z

432

Customer service driven supply chain segmentation  

E-Print Network [OSTI]

The objective of this thesis is to develop a supply chain segmentation model for Company X, which is in the chemical and construction materials industry. The company sells products in an expanding Southeast Asia market. ...

Worawattananon, Prakit

2008-01-01T23:59:59.000Z

433

Supply chain practices in the petroleum downstream  

E-Print Network [OSTI]

This thesis studies current supply chain practices in the petroleum downstream industry, using ExxonMobil as a case study. Based on the analysis of the literature and the interaction with industry experts, this work describes ...

Santos Manzano, Fidel

2005-01-01T23:59:59.000Z

434

Polynomial policies in supply chain networks  

E-Print Network [OSTI]

This thesis aims to solve the periodic-reviewed inventory control problem in supply chain networks with uncertain demand so as to minimize the overall cost of the system over a fixed planning time horizon. In such problems, ...

He, Liwei

2010-01-01T23:59:59.000Z

435

Risk in the Global Supply Chain  

E-Print Network [OSTI]

Carbon footprints are not on the priority list of risk analysts in operations management for at least half or more of global businesses. What are the other risks in the global supply chain?

Datta, Shoumen

2006-01-01T23:59:59.000Z

436

Energy Department Announces $2 Million to Develop Supply Chain...  

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

2 Million to Develop Supply Chain, Manufacturing Competitiveness Analysis for Hydrogen and Fuel Cell Technologies Energy Department Announces 2 Million to Develop Supply Chain,...

437

The role of chemical reactions in the Chernobyl accident  

SciTech Connect (OSTI)

It is shown that chemical reactions played an essential role in the Chernobyl accident at all of its stages. It is important that the reactor before the explosion was at maximal xenon poisoning, and its reactivity, apparently, was not destroyed by the explosion. The reactivity release due to decay of Xe-235 on the second day after the explosion led to a reactor power of 80-110 MW. Owing to this power, the chemical reactions of reduction of uranium, plutonium, and other metals at a temperature of about 2000 Degree-Sign C occurred in the core. The yield of fission products thus sharply increased. Uranium and other metals flew down in the bottom water communications and rooms. After reduction of the uranium and its separation from the graphite, the chain reaction stopped, the temperature of the core decreased, and the activity yield stopped.

Grishanin, E. I., E-mail: egrishanin@orexovo.net [Russian Research Center Kurchatov Institute (Russian Federation)

2010-12-15T23:59:59.000Z

438

Transitions of tethered chain molecules under tension  

E-Print Network [OSTI]

An applied tension force changes the equilibrium conformations of a polymer chain tethered to a planar substrate and thus affects the adsorption transition as well as the coil-globule and crystallization transitions. Conversely, solvent quality and surface attraction are reflected in equilibrium force-extension curves that can be measured in experiments. To investigate these effects theoretically, we study tethered chains under tension with Wang-Landau simulations of a bond-fluctuation lattice model. Applying our model to pulling experiments on biological molecules we obtain a good description of experimental data in the intermediate force range, where universal features dominate and finite size effects are small. For tethered chains in poor solvent, we observe the predicted two-phase coexistence at transitions from the globule to stretched conformations and also discover direct transitions from crystalline to stretched conformations. A phase portrait for finite chains constructed by evaluating the density of states for a broad range of solvent conditions and tensions shows how increasing tension leads to a disappearance of the globular phase. For chains in good solvents tethered to hard and attractive surfaces we find the predicted scaling with the chain length in the low-force regime and show that our results are well described by an analytical, independent-bond approximation for the bond-fluctuation model for the highest tensions. Finally, for a hard or slightly attractive surface the stretching of a tethered chain is a conformational change that does not correspond to a phase transition. However, when the surface attraction is sufficient to adsorb a chain it will undergo a desorption transition at a critical value of the applied force. Our results for force-induced desorption show the transition to be discontinuous with partially desorbed conformations in the coexistence region.

Jutta Luettmer-Strathmann; Kurt Binder

2014-09-09T23:59:59.000Z

439

Nuclear scales  

SciTech Connect (OSTI)

Nuclear scales are discussed from the nuclear physics viewpoint. The conventional nuclear potential is characterized as a black box that interpolates nucleon-nucleon (NN) data, while being constrained by the best possible theoretical input. The latter consists of the longer-range parts of the NN force (e.g., OPEP, TPEP, the {pi}-{gamma} force), which can be calculated using chiral perturbation theory and gauged using modern phase-shift analyses. The shorter-range parts of the force are effectively parameterized by moments of the interaction that are independent of the details of the force model, in analogy to chiral perturbation theory. Results of GFMC calculations in light nuclei are interpreted in terms of fundamental scales, which are in good agreement with expectations from chiral effective field theories. Problems with spin-orbit-type observables are noted.

Friar, J.L.

1998-12-01T23:59:59.000Z

440

Microscopic Description of the Exotic Nuclei Reactions by Using Folding model Potentials  

SciTech Connect (OSTI)

A microscopic folding approach based upon the effective M3Y nucleon-nucleon interaction and the nuclear matter densities of the interacting nuclei has been carried out to explain recently measured experimental data of the {sup 6}He+{sup 120}Sn elastic scattering reaction at four different laboratory energies near the Coulomb barrier. The corresponding reaction cross sections are also considered.

Ibraheem, Awad A. [Physics Department, Al-Azhar University, Assiut Branch, Assiut 71524 (Egypt); Physics Department, King Khalid University, Abha (Saudi Arabia); Hassanain, M. A. [Physics Department, King Khalid University, Abha (Saudi Arabia); Sciences Department, New-Valley Faculty of Education, Assiut University, El-Kharga, New-Valley (Egypt); Mokhtar, S. R.; El-Azab Farid, M. [Physics Department, Assiut University, Assiut 71516 (Egypt); Zaki, M. A. [Physics Department, South-Valley University, Aswan (Egypt); Mahmoud, Zakaria M. M. [Sciences Department, New-Valley Faculty of Education, Assiut University, El-Kharga, New-Valley (Egypt)

2011-10-27T23:59:59.000Z

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


441

Scattering and reaction cross-sections measured at SPES I Results compiled by  

E-Print Network [OSTI]

for low energy nuclear physics measurements i.e. : diffe- rential cross-section (a = deT/dQ) versus This article gives all the differential cross-sections for two body reactions at intermediate energy measured (Saclay) in 1971 in order to investigate intermediate energy two body reactions. This magne- tic

Boyer, Edmond

442

The New SuperORRUBA Detector for Transfer Reaction Studies of Exotic Nuclei  

E-Print Network [OSTI]

(inverse kinematics) [4, 5]. The ejected protons from such reactions carry the nuclear spectroscopic of the extreme inverse nature of the reaction, the proton energy rapidly changes as a function of laboratory is also required because of the relatively low intensity of exotic beams. Figure 1: Expected energies

443

Nuclear Physics  

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

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444

Nuclear Structure  

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

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445

Nuclear Forensics  

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

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446

Near and sub-barrier fusion as a probe of nuclear structure Sub-barrier fusion is particularly sensitive to the tail of the nuclear matter distribution,  

E-Print Network [OSTI]

Near and sub-barrier fusion as a probe of nuclear structure Sub-barrier fusion is particularly sensitive to the tail of the nuclear matter distribution, hence provides a good probe of the neutron and proton distributions. Measuring fusion for an isotopic chain of projectile nuclei one can sensitively

de Souza, Romualdo T.

447

TRANSPORT OF ANGULAR MOMENTUM IN DAMPED NUCLEAR REACTIONS  

E-Print Network [OSTI]

Academic Pres. 415-496. Bruland, K.W. , Bertine, K. , Koide,Sci. Technol. 8: 425-432. Bruland, K.W. , Knauer, G.A. and1975; Ahrland, 1975; Bruland However, have progressed

Randrup, Jorgen

2012-01-01T23:59:59.000Z

448

TRANSPORT OF ANGULAR MOMENTUM IN DAMPED NUCLEAR REACTIONS  

E-Print Network [OSTI]

SUMMARY The operation of an OTEC plant will result in the m~material passing through an OTEC plant. The characterizationand the lack of any OTEC program collected particulate

Randrup, Jorgen

2012-01-01T23:59:59.000Z

449

TRANSPORT OF ANGULAR MOMENTUM IN DAMPED NUCLEAR REACTIONS  

E-Print Network [OSTI]

Sediment DH Netal *Cu by XRF Total NAA TABLE 10 (Continued)FH Sediment HH He - - tal *Cu by XRF NAA NAA NAA Total NAAand x-ray fluorescence (XRF) analysis. The analyses were

Randrup, Jorgen

2012-01-01T23:59:59.000Z

450

Fusion reactions in nuclear astrophysics: The MUSIC approach  

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

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451

Nuclear Nonproliferation Programs | ORNL  

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

Nuclear Nonproliferation Programs SHARE Nuclear Nonproliferation Programs image Oak Ridge National Laboratory covers the entire spectrum of nuclear nonproliferation work, from...

452

NUCLEAR PROXIMITY FORCES  

E-Print Network [OSTI]

One might summarize of nuclear potential energy has beendegree of freedom) for the nuclear interaction between anyUniversity of California. Nuclear Proximity Forces 'I< at

Randrup, J.

2011-01-01T23:59:59.000Z

453

Global Nuclear Security  

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

Global Nuclear Security Both DOE and the National Nuclear Security Administration are working to reduce the risk of nuclear proliferation and provide technologies to improve...

454

Reaction chemistry of cerium  

SciTech Connect (OSTI)

It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.

NONE

1997-01-01T23:59:59.000Z

455

Nuclear Data Evaluations for Americium Isotopes  

SciTech Connect (OSTI)

Recent upgrades of 241Am, 242mAm, and 240Am nuclear data in the keV - 30-MeV range are described. The new evaluation takes advantage of recent measurements and advances in calculational modeling methods. The model calculations are especially important for the nuclear data of americium isotopes, because few measurements are available. The nuclear-model code GNASH is extensively used for our evaluations. The new evaluations are given for total, fission, capture (n, 2n), and (n, 3n) reaction cross sections, and vp for 241Am and 242mAm. A new evaluation for 240Am is also given by expanding our modeling feasibility.

Kawano, T.; Talou, P.; Chadwick, M.B.; MacFarlane, R.E.; Young, P.G. [T-16 Nuclear Physics, Los Alamos National Laboratory (United States)

2005-05-24T23:59:59.000Z

456

Photochemical reaction dynamics  

SciTech Connect (OSTI)

The purpose of the program is to develop a fundamental understanding of unimolecular and bimolecular reaction dynamics with application in combustion and energy systems. The energy dependence in ketene isomerization, ketene dissociation dynamics, and carbonyl substitution on organometallic rhodium complexes in liquid xenon have been studied. Future studies concerning unimolecular processes in ketene as well as energy transfer and kinetic studies of methylene radicals are discussed.

Moore, B.C. [Lawrence Berkeley Laboratory, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

457

Nuclear Science/Nuclear Chemistry  

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

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458

Initiative in Nuclear Theory at the Variable Energy Cyclotron Centre  

E-Print Network [OSTI]

We recall the path breaking contributions of the nuclear theory group of the Variable Energy Cyclotron Centre, Kolkata. From a beginning of just one person in 1970s, the group has steadily developed into a leading group in the country today, with seminal contributions to almost the entire range of nuclear physics, viz., low energy nuclear reactions, nuclear structure, deep inelastic collisions, fission, liquid to gas phase transitions, nuclear matter, equation of state, mass formulae, neutron stars, relativistic heavy ion collisions, medium modification of hadron properties, quark gluon plasma, and cosmology of early universe.

D. K. Srivastava; J. Alam; D. N. Basu; A. K. Chaudhuri; J. N. De; K. Krishan; S. Pal

2005-06-24T23:59:59.000Z

459

Theoretical nuclear physics  

SciTech Connect (OSTI)

This report discusses the following topics: Exact 1-loop vacuum polarization effects in 1 + 1 dimensional QHD; exact 1-fermion loop contributions in 1 + 1 dimensional solitons; exact scalar 1-loop contributions in 1 + 3 dimensions; exact vacuum calculations in a hyper-spherical basis; relativistic nuclear matter with self- consistent correlation energy; consistent RHA-RPA for finite nuclei; transverse response functions in the {triangle}-resonance region; hadronic matter in a nontopological soliton model; scalar and vector contributions to {bar p}p {yields} {bar {Lambda} {Lambda}} reaction; 0+ and 2+ strengths in pion double-charge exchange to double giant-dipole resonances; and nucleons in a hybrid sigma model including a quantized pion field.

Rost, E.; Shephard, J.R.

1992-08-01T23:59:59.000Z

460

Application of nuclear models to neutron nuclear cross section calculations  

SciTech Connect (OSTI)

Nuclear theory is used increasingly to supplement and extend the nuclear data base that is available for applied studies. Areas where theoretical calculations are most important include the determination of neutron cross sections for unstable fission products and transactinide nuclei in fission reactor or nuclear waste calculations and for meeting the extensive dosimetry, activation, and neutronic data needs associated with fusion reactor development, especially for neutron energies above 14 MeV. Considerable progress has been made in the use of nuclear models for data evaluation and, particularly, in the methods used to derive physically meaningful parameters for model calculations. Theoretical studies frequently involve use of spherical and deformed optical models, Hauser-Feshbach statistical theory, preequilibrium theory, direct-reaction theory, and often make use of gamma-ray strength function models and phenomenological (or microscopic) level density prescriptions. The development, application, and limitations of nuclear models for data evaluation are discussed, with emphasis on the 0.1 to 50 MeV energy range. (91 references).

Young, P.G.

1982-01-01T23:59:59.000Z

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


461

Nuclear spectroscopic studies. Progress report  

SciTech Connect (OSTI)

The Nuclear Physics group at the University of Tennessee, Knoxville is involved in several aspects of heavy-ion physics including both nuclear structure and reaction mechanisms. While our main emphasis is on experimental problems involving heavy-ion accelerators, we have maintained a strong collaboration with several theorists in order to best pursue the physics of our measurements. During the last year we have led several experiments at the Holifield Heavy Ion Research Facility and participated in others at Argonne National Laboratory. Also, we continue to be very active in the collaboration to study ultra-relativistic heavy ion physics utilizing the SPS accelerator at CERN in Geneva, Switzerland and in a RHIC detector R&D project. Our experimental work is in four broad areas: (1) the structure of nuclei at high angular momentum, (2) heavy-ion induced transfer reactions, (3) the structure of nuclei far from stability, and (4) ultra-relativistic heavy-ion physics. The results of studies in these particular areas will be described in this document in sections IIA, IIB, IIC, and IID, respectively. Areas (1), (3), and (4) concentrate on the structure of nuclear matter in extreme conditions of rotational motion, imbalance of neutrons and protons, or very high temperature and density. Area (2) pursues the transfer of nucleons to states with high angular momentum, both to learn about their structure and to understand the transfer of particles, energy, and angular momentum in collisions between heavy ions. An important component of our program is the strong emphasis on the theoretical aspects of nuclear structure and reactions.

Bingham, C.R.; Guidry, M.W.; Riedinger, L.L.; Sorensen, S.P.

1993-02-08T23:59:59.000Z

462

Advances in instrumentation for nuclear astrophysics  

SciTech Connect (OSTI)

The study of the nuclear physics properties which govern energy generation and nucleosynthesis in the astrophysical phenomena we observe in the universe is crucial to understanding how these objects behave and how the chemical history of the universe evolved to its present state. The low cross sections and short nuclear lifetimes involved in many of these reactions make their experimental determination challenging, requiring developments in beams and instrumentation. A selection of developments in nuclear astrophysics instrumentation is discussed, using as examples projects involving the nuclear astrophysics group at Oak Ridge National Laboratory. These developments will be key to the instrumentation necessary to fully exploit nuclear astrophysics opportunities at the Facility for Rare Isotope Beams which is currently under construction.

Pain, S. D. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)] [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2014-04-15T23:59:59.000Z

463

Theoretical and simulation tools for electron transfer and chain reactions in single walled carbon nanotubes  

E-Print Network [OSTI]

Single walled carbon nanotubes (SWNT) are cylindrical sheets of graphene whose electronic structures and diameters are determined by their chiralities. Current synthetic methods produce batches of nanotubes containing a ...

Nair, Nitish

2009-01-01T23:59:59.000Z

464

Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Analysis of Large Polymerases Chain Reaction Products  

SciTech Connect (OSTI)

We have attempted to expand the size range of PCR products that can be analyzed by electroscopy ionization (ESI) Fourier transformion cyclotron resonance (FTICR) mass spectrometry. The mass measurement accuracy obtained illustrates that a signel base substitution could be identified at the size of PCR product with a 7 tesla ESI-FTICR

Wunschel, David S.(BATTELLE (PACIFIC NW LAB)) [BATTELLE (PACIFIC NW LAB); Pasa Tolic, Ljiljana (BATTELLE (PACIFIC NW LAB)) [BATTELLE (PACIFIC NW LAB); Feng, Bingbing (ASSOC WESTERN UNIVERSITY) [ASSOC WESTERN UNIVERSITY; Smith, Richard D.(BATTELLE (PACIFIC NW LAB)) [BATTELLE (PACIFIC NW LAB)

2000-04-01T23:59:59.000Z

465

Three Dimensional Simulation of Rayleigh-Bnard Convection for Rapid Microscale Polymerase Chain Reaction  

E-Print Network [OSTI]

Rayleigh-Bnard convection has been extensively studied in literature owing to its ubiquitous nature. However, most of the studies have been confined to geometries where the aspect ratio of the cylinder was less than 1. Here we study the motion...

Muddu, Radha Malini Gowri

2012-02-14T23:59:59.000Z

466

On-chip real-time single-copy polymerase chain reaction in picoliter droplets  

SciTech Connect (OSTI)

The first lab-on-chip system for picoliter droplet generation and PCR amplification with real-time fluorescence detection has performed PCR in isolated droplets at volumes 10{sup 6} smaller than commercial real-time PCR systems. The system utilized a shearing T-junction in a silicon device to generate a stream of monodisperse picoliter droplets that were isolated from the microfluidic channel walls and each other by the oil phase carrier. An off-chip valving system stopped the droplets on-chip, allowing them to be thermal cycled through the PCR protocol without droplet motion. With this system a 10-pL droplet, encapsulating less than one copy of viral genomic DNA through Poisson statistics, showed real-time PCR amplification curves with a cycle threshold of {approx}18, twenty cycles earlier than commercial instruments. This combination of the established real-time PCR assay with digital microfluidics is ideal for isolating single-copy nucleic acids in a complex environment.

Beer, N R; Hindson, B; Wheeler, E; Hall, S B; Rose, K A; Kennedy, I; Colston, B

2007-04-20T23:59:59.000Z

467

Electrochemical Branched-DNA Assay for Polymerase Chain Reaction-Free  

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

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468

DSS-mediated Inhibition of Quantitative Real-time Polymerase Chain Reaction  

E-Print Network [OSTI]

........................................................................................................3 2 Real-Time PCR Graph ...........................................................................................4 3 Fecal Sample Collection Timeline .........................................................................6 4 Purification... 280 ratio between 1.8-1.9 indicates highly purified DNA; whereas, a ratio less than 1.8 indicates protein contamination (2). Unfortunately, co-purification of acidified polysaccharides, such as DSS cannot be detected using a spectrophotometrically...

Kaur, Jaspreet

2011-08-04T23:59:59.000Z

469

Building a Universal Nuclear Energy Density Functional  

SciTech Connect (OSTI)

During the period of Dec. 1 2006 Jun. 30, 2012, the UNEDF collaboration carried out a comprehensive study of all nuclei, based on the most accurate knowledge of the strong nuclear interaction, the most reliable theoretical approaches, the most advanced algorithms, and extensive computational resources, with a view towards scaling to the petaflop platforms and beyond. The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: ? First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties; ? Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data; ? Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.

Carlson, Joe A. [Michigan State University; Furnstahl, Dick; Horoi, Mihai; Lust, Rusty; Nazaewicc, Witek; Ng, Esmond; Thompson, Ian; Vary, James

2012-12-30T23:59:59.000Z

470

Imperfect World of $??$-decay Nuclear Data Sets  

E-Print Network [OSTI]

The precision of double-beta ($\\beta\\beta$) decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for $\\beta\\beta$-decay T$_{1/2}^{2\

B. Pritychenko

2015-01-09T23:59:59.000Z

471

Flatness of heavy chain systems Nicolas Petit 1  

E-Print Network [OSTI]

.e. trolleys carrying a fixed length heavy chain that may carry a load, is addressed in the partial derivatives the homogeneous chain carrying a load, see equation (13). In [11] the flatness [3, 4] of heavy chain systems, i dimensional case. Under small angle approximations, these heavy chain systems are described by a 1D partial

472

Nuclear Incident Team | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

Incident Team | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear...

473

Nuclear Medicine CT Angiography  

E-Print Network [OSTI]

Nuclear Medicine CT Angiography Stress Testing Rotation The Nuclear Medicine/CT angiography. Understand the indications for exercise treadmill testing and specific nuclear cardiology tests, safe use Level 2 proficiency in performing and interpreting cardiac nuclear imaging tests. Progression

Ford, James

474

The Nuclear Equation of State at high densities  

E-Print Network [OSTI]

Ab inito calculations for the nuclear many-body problem make predictions for the density and isospin dependence of the nuclear equation-of-state (EOS) far away from the saturation point of nuclear matter. I compare predictions from microscopic and phenomenological approaches. Constraints on the EOS derived from heavy ion reactions, in particular from subthreshold kaon production, as well as constraints from neutron stars are discussed.

Christian Fuchs

2006-10-10T23:59:59.000Z

475

National Nuclear Security Administration  

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

FROM: SUBJECT: USIUK Memorandum of Understanding between National Nuclear Security Administration's (NNSA) Associate Administrator for Defense Nuclear Security (AADNS)...

476

{alpha}-particle optical potentials for nuclear astrophysics (NA) and nuclear technology (NT)  

SciTech Connect (OSTI)

The high precision of recent measurements for low-energy {alpha}-particle elastic-scattering as well as induced-reaction data makes possible the understanding of actual limits and possible improvement of the global optical model potentials parameters. Involvement of recent optical potentials for reliable description of both the elastic scattering and emission of {alpha}-particles, of equal interest for nuclear astrophysics (NA) and nuclear technology (NT) for fusion devices, is discussed in the present work.

Avrigeanu, V.; Avrigeanu, M. [Horia Hulubei National Institute for Physics and Nuclear Engineering, POBox MG-6, 077125 Magurele, Ilfov (Romania)

2012-11-20T23:59:59.000Z

477

A laser application to nuclear astrophysics  

SciTech Connect (OSTI)

In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions {sup 3}He(d,p){sup 4}He and d(d,n){sup 3}He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with {sup 3}He atoms. The yield of 14.7 MeV protons from the {sup 3}He(d,p){sup 4}He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX (United States); Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX 78712 (United States); Bonasera, A. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX, U.S.A. and INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Kimura, S. [Department of Physics, Universit degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Mazzocco, M. [Dipartimento di Fisica e Astronomia Universit degli Studi di Padova and INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Consoli, F.; De Angelis, R.; Andreoli, P. [Associazione Euratom-ENEA Sulla Fusione, Via Enrico Fermi 45, CP 65-00044 Frascati, Rome (Italy); Ditmire, T. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX, 78712 (United States)

2014-05-09T23:59:59.000Z

478

NEUTRON AND NON-NEUTRON NUCLEAR DATA FOR RADIATION DOSIMETRY  

SciTech Connect (OSTI)

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

HOLDEN,N.E.

1999-09-10T23:59:59.000Z

479

Molecular dynamics simulation of chains mobility in polyethylene crystal  

E-Print Network [OSTI]

The mobility of polymer chains in perfect polyethylene (PE) crystal was calculated as a function of temperature and chain length through Molecular dynamics (MD) in united atom approximation. The results demonstrate that the chain mobility drastically increases in the vicinity of the phase transition from the orthorhombic to quasi-hexagonal phase. In the quasi-hexagonal phase, the chain mobility is almost independent on temperature and inversely proportional to the chain length.

V. I. Sultanov; V. V. Atrazhev; D. V. Dmitriev; S. F. Burlatsky

2014-01-17T23:59:59.000Z

480

Reaction Path Optimization with Holonomic Constraints and Kinetic Energy Potentials  

SciTech Connect (OSTI)

Two methods are developed to enhance the stability, efficiency, and robustness of reaction path optimization using a chain of replicas. First, distances between replicas are kept equal during path optimization via holonomic constraints. Finding a reaction path is, thus, transformed into a constrained optimization problem. This approach avoids force projections for finding minimum energy paths (MEPs), and fast-converging schemes such as quasi-Newton methods can be readily applied. Second, we define a new objective function - the total Hamiltonian - for reaction path optimization, by combining the kinetic energy potential of each replica with its potential energy function. Minimizing the total Hamiltonian of a chain determines a minimum Hamiltonian path (MHP). If the distances between replicas are kept equal and a consistent force constant is used, then the kinetic energy potentials of all replicas have the same value. The MHP in this case is the most probable isokinetic path. Our results indicate that low-temperature kinetic energy potentials (<5 K) can be used to prevent the development of kinks during path optimization and can significantly reduce the required steps of minimization by 2-3 times without causing noticeable differences between a MHP and MEP. These methods are applied to three test cases, the C?eq-to-Cax isomerization of an alanine dipeptide, the ?C?- to-C? transition of an ?-D-glucopyranose, and the helix-to-sheet transition of a GNNQQNY heptapeptide. By applying the methods developed in this work, convergence of reaction path optimization can be achieved for these complex transitions, involving full atomic details and a large number of replicas (>100). For the case of helix-to-sheet transition, we identify pathways whose energy barriers are consistent with experimental measurements. Further, we develop a method based on the work energy theorem to quantify the accuracy of reaction paths and to determine whether the atoms used to define a path are enough to provide quantitative estimation of energy barriers.

Brokaw, Jason B.; Haas, Kevin R.; Chu, Jhih-wei

2009-08-11T23:59:59.000Z

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481

Subbarrier fusion reactions and many-particle quantum tunneling  

E-Print Network [OSTI]

Low energy heavy-ion fusion reactions are governed by quantum tunneling through the Coulomb barrier formed by a strong cancellation of the repulsive Coulomb force with the attractive nuclear interaction between the colliding nuclei. Extensive experimental as well as theoretical studies have revealed that fusion reactions are strongly influenced by couplings of the relative motion of the colliding nuclei to several nuclear intrinsic motions. Heavy-ion subbarrier fusion reactions thus provide a good opportunity to address a general problem on quantum tunneling in the presence of couplings, which has been a popular subject in the past decades in many branches of physics and chemistry. Here we review theoretical aspects of heavy-ion subbarrier fusion reactions from the view point of quantum tunneling in systems with many degrees of freedom. Particular emphases are put on the coupled-channels approach to fusion reactions, and the barrier distribution representation for multi-channel penetrability. We also discuss an application of the barrier distribution method to elucidation of the mechanism of dissociative adsorption of H$_2$ melecules in surface science.

K. Hagino; N. Takigawa

2012-10-17T23:59:59.000Z

482

Transfer reactions at ATLAS  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2Topo II: AnTraining andfor a CleanTransfer Service

483

Peppytides: Interactive Models of Polypeptide Chains  

SciTech Connect (OSTI)

Peppytides are scaled, 3D-printed models of polypeptide chains that can be folded into accurate protein structures. Designed and created by Berkeley Lab Researcher, Promita Chakraborty, and Berkeley Lab Senior Scientist, Dr. Ron Zuckermann, Peppytides are accurate physical models of polypeptide chains that anyone can interact with and fold intro various protein structures - proving to be a great educational tool, resulting in a deeper understanding of these fascinating structures and how they function. Build your own Peppytide model and learn about how nature's machines fold into their intricate architectures!

Zuckermann, Ron; Chakraborty, Promita; Derisi, Joe

2014-01-21T23:59:59.000Z

484

Catalysts for synthesizing various short chain hydrocarbons  

DOE Patents [OSTI]

Method and apparatus (10), including novel photocatalysts, are disclosed for the synthesis of various short chain hydrocarbons. Light-transparent SiO.sub.2 aerogels doped with photochemically active uranyl ions (18) are fluidized in a fluidized-bed reactor (12) having a transparent window (16), by hydrogen and CO, C.sub.2 H.sub.4 or C.sub.2 H.sub.6 gas mixtures (20), and exposed to radiation (34) from a light source (32) external to the reactor (12), to produce the short chain hydrocarbons (36).

Colmenares, Carlos (Alamo, CA)

1991-01-01T23:59:59.000Z

485

Peppytides: Interactive Models of Polypeptide Chains  

ScienceCinema (OSTI)

Peppytides are scaled, 3D-printed models of polypeptide chains that can be folded into accurate protein structures. Designed and created by Berkeley Lab Researcher, Promita Chakraborty, and Berkeley Lab Senior Scientist, Dr. Ron Zuckermann, Peppytides are accurate physical models of polypeptide chains that anyone can interact with and fold intro various protein structures - proving to be a great educational tool, resulting in a deeper understanding of these fascinating structures and how they function. Build your own Peppytide model and learn about how nature's machines fold into their intricate architectures!

Zuckermann, Ron; Chakraborty, Promita; Derisi, Joe

2014-10-28T23:59:59.000Z

486

Nuclear photonics  

SciTech Connect (OSTI)

With the planned new {gamma}-beam facilities like MEGa-ray at LLNL (USA) or ELI-NP at Bucharest (Romania) with 10{sup 13}{gamma}/s and a band width of {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -3}, a new era of {gamma} beams with energies up to 20MeV comes into operation, compared to the present world-leading HI{gamma}S facility at Duke University (USA) with 10{sup 8}{gamma}/s and {Delta}E{gamma}/E{gamma} Almost-Equal-To 3 Dot-Operator 10{sup -2}. In the long run even a seeded quantum FEL for {gamma} beams may become possible, with much higher brilliance and spectral flux. At the same time new exciting possibilities open up for focused {gamma} beams. Here we describe a new experiment at the {gamma} beam of the ILL reactor (Grenoble, France), where we observed for the first time that the index of refraction for {gamma} beams is determined by virtual pair creation. Using a combination of refractive and reflective optics, efficient monochromators for {gamma} beams are being developed. Thus, we have to optimize the total system: the {gamma}-beam facility, the {gamma}-beam optics and {gamma} detectors. We can trade {gamma} intensity for band width, going down to {Delta}E{gamma}/E{gamma} Almost-Equal-To 10{sup -6} and address individual nuclear levels. The term 'nuclear photonics' stresses the importance of nuclear applications. We can address with {gamma}-beams individual nuclear isotopes and not just elements like with X-ray beams. Compared to X rays, {gamma} beams can penetrate much deeper into big samples like radioactive waste barrels, motors or batteries. We can perform tomography and microscopy studies by focusing down to {mu}m resolution using Nuclear Resonance Fluorescence (NRF) for detection with eV resolution and high spatial resolution at the same time. We discuss the dominating M1 and E1 excitations like the scissors mode, two-phonon quadrupole octupole excitations, pygmy dipole excitations or giant dipole excitations under the new facet of applications. We find many new applications in biomedicine, green energy, radioactive waste management or homeland security. Also more brilliant secondary beams of neutrons and positrons can be produced.

Habs, D.; Guenther, M. M.; Jentschel, M.; Thirolf, P. G. [Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany); Max Planck Institut fuer Quantenoptik, D-85748 Garching (Germany); Institut Laue-Langevin, F-38042 Grenoble (Germany); Ludwig-Maximilians-Universitaet Muenchen, D-85748 Garching (Germany)

2012-07-09T23:59:59.000Z

487

BUILDING A UNIVERSAL NUCLEAR ENERGY DENSITY FUNCTIONAL (UNEDF)  

SciTech Connect (OSTI)

The long-term vision initiated with UNEDF is to arrive at a comprehensive, quantitative, and unified description of nuclei and their reactions, grounded in the fundamental interactions between the constituent nucleons. We seek to replace current phenomenological models of nuclear structure and reactions with a well-founded microscopic theory that delivers maximum predictive power with well-quantified uncertainties. Specifically, the mission of this project has been three-fold: First, to find an optimal energy density functional (EDF) using all our knowledge of the nucleonic Hamiltonian and basic nuclear properties. Second, to apply the EDF theory and its extensions to validate the functional using all the available relevant nuclear structure and reaction data. Third, to apply the validated theory to properties of interest that cannot be measured, in particular the properties needed for reaction theory.

Nazarewicz, Witold

2012-07-01T23:59:59.000Z

488

Free-radical reactions in glow and explosion of carbon monoxide-oxygen mixtures  

SciTech Connect (OSTI)

Examination of published compilations of rate coefficients of free-radical reactions yields reactions that are associated with chain branching in mixtures of CO and O/sub 2/ and small quantities of hydrogen or water vapor. The complete mechanism included diffusion of HO/sub 2/ radicals to the vessel wall and their adsorption and reaction at the surface. This mechanism is applied to the data of E.J. Buckler and R.G.W. Norrish on the branched-chain explosion of CO-O/sub 2/ mixtures containing H/sub 2/ in the order of 1 mm Hg. Substantial agreement is found between theory and experiment. Further, the mechanism is applied to experiments of Bond, Gray, and Griffiths with an H/sub 2/ content of 0.01-0.05 mm Hg. By specifying details of the adsorption and surface reaction of HO/sub 2/ on the basis of Langmuir's adsorption the phenomenon of flow is explained and the regions of slow reaction, glow, and explosion are described in accord with the experimental data. It is confirmed that the reaction between CO and O/sub 2/ requires the presence of a hydrogenous compound such as H/sub 2/, H/sub 2/O, CH/sub 4/, etc., and that ''dry'' homogenous reaction is not possible except at very high temperatures.

Von Elbe, G.; Lewis, B.

1986-02-01T23:59:59.000Z

489

Critical phenomena of nuclear matter in the extended Zimanyi-Moszkowski model  

E-Print Network [OSTI]

Critical phenomena of nuclear matter in the extended Zimanyi-Moszkowski model K. Miyazaki Abstract in nuclear multifragmentation reactions and the critical temperature has been derived as TC = 20 3 MeV in Ref] to estimate the critical temperature for in...nite nuclear matter, that is, TC = 16:6 0:86 Me

490

IAEA advisory group meeting on basic and applied problems of nuclear level densities  

SciTech Connect (OSTI)

Separate entries were made in the data base for 17 of the 19 papers included. Two papers were previously included in the data base. Workshop reports are included on (1) nuclear level density theories and nuclear model reaction cross-section calculations and (2) extraction of nuclear level density information from experimental data. (WHK)

Bhat, M.R. (ed.)

1983-06-01T23:59:59.000Z

491

ccsd-00008225,version1-26Aug2005 Multifragmentation of very heavy nuclear  

E-Print Network [OSTI]

started in reference [9]. Two nuclear reactions, at similar available energy per nucleon were experccsd-00008225,version1-26Aug2005 Multifragmentation of very heavy nuclear systems (III): fragment´eaire, IN2P3-CNRS, F-91406 Orsay Cedex, France bNational Institute for Physics and Nuclear Engineering, RO

Boyer, Edmond

492

Multifragment emission and the experimental characterization of breakup reactions  

SciTech Connect (OSTI)

The production of three or more particles in nuclear reactions is discussed in terms of physically meaningful variables for the description of the asymptotic exit-channel configuration. The emphasis is placed in a direct comparison between these basic variables obtained in a purely experimental way and the corresponding results of generic model calculations. Applications of this approach to a few examples of recent inclusive and exclusive measurements of breakup reactions in the {sup 6,7}Li+{sup 144}Sm systems are presented.

Martinez Heimann, D.; Pacheco, A. J.; Arazi, A.; Fernandez Niello, J. O.; Figueira, J. M.; Negri, A. [Departamento de Fisica-Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina); CONICET, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Capurro, O. A.; Carnelli, P.; Cardona, M. A.; Barbara, E. de; Fimiani, L.; Hojman, D. L.; Marti, G. V. [Departamento de Fisica-Laboratorio TANDAR, Comision Nacional de Energia Atomica, Av. Gral. Paz 1499, BKNA1650 San Martin (Argentina)

2010-08-04T23:59:59.000Z

493

Radiative capture reactions in lattice effective field theory  

E-Print Network [OSTI]

We outline a general method for computing nuclear capture reactions on the lattice. The method consists of two major parts. In this study we detail the second part which consists of calculating an effective two-body capture reaction on the lattice at finite volume. We solve this problem by calculating the two-point Green's function using an infrared regulator and the capture amplitude to a two-body bound state. We demonstrate the details of this method by calculating on the lattice the leading M1 contribution to the radiative neutron capture on proton at low energies using pionless effective field theory. We find good agreement with exact continuum results.

Gautam Rupak; Dean Lee

2013-02-18T23:59:59.000Z

494

Evidence for delta-hole components from pion reactions  

SciTech Connect (OSTI)

Some anomalies observed in pion-induced reactions have been qualitatively explained with a model which includes ..delta../sub 3/ /sub 3/ admixtures in low lying nuclear states. Semi-quantitative analysis of these effects indicates the amplitudes for the ..delta../sub 3/ /sub 3/ admixtures necessary to explain these effects are on the order of a few percent. Although a more rigorous theoretical treatment of this problem is necessary, it appears that pion-induced reactions may provide a tool with which the spectroscopy of these ..delta../sub 3/ /sub 3/-admixtures can be studied.

Morris, C.L.

1982-01-01T23:59:59.000Z

495

Charged-Particle Thermonuclear Reaction Rates: II. Tables and Graphs of Reaction Rates and Probability Density Functions  

E-Print Network [OSTI]

Numerical values of charged-particle thermonuclear reaction rates for nuclei in the A=14 to 40 region are tabulated. The results are obtained using a method, based on Monte Carlo techniques, that has been described in the preceding paper of this series (Paper I). We present a low rate, median rate and high rate which correspond to the 0.16, 0.50 and 0.84 quantiles, respectively, of the cumulative reaction rate distribution. The meaning of these quantities is in general different from the commonly reported, but statistically meaningless expressions, "lower limit", "nominal value" and "upper limit" of the total reaction rate. In addition, we approximate the Monte Carlo probability density function of the total reaction rate by a lognormal distribution and tabulate the lognormal parameters {\\mu} and {\\sigma} at each temperature. We also provide a quantitative measure (Anderson-Darling test statistic) for the reliability of the lognormal approximation. The user can implement the approximate lognormal reaction rate probability density functions directly in a stellar model code for studies of stellar energy generation and nucleosynthesis. For each reaction, the Monte Carlo reaction rate probability density functions, together with their lognormal approximations, are displayed graphically for selected temperatures in order to provide a visual impression. Our new reaction rates are appropriate for bare nuclei in the laboratory. The nuclear physics input used to derive our reaction rates is presented in the subsequent paper of this series (Paper III). In the fourth paper of this series (Paper IV) we compare our new reaction rates to previous results.

Christian Iliadis; Richard Longland; Art Champagne; Alain Coc; Ryan Fitzgerald

2010-04-23T23:59:59.000Z

496

Neutron Reactions in Astrophysics  

E-Print Network [OSTI]

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

R. Reifarth; C. Lederer; F. Kppeler

2014-03-22T23:59:59.000Z

497

Kinetic and mechanistic studies of free-radical reactions in combustion  

SciTech Connect (OSTI)

Combustion is driven by energy-releasing chemical reactions. Free radicals that participate in chain reactions carry the combustion process from reactants to products. Research in chemical kinetics enables us to understand the microscopic mechanisms involved in individual chemical reactions as well as to determine the rates at which they proceed. Both types of information are required for an understanding of how flames burn, why engines knock, how to minimize the production of pollutants, and many other important questions in combustion. In this program the authors emphasize accurate measurements over wide temperature ranges of the rates at which ubiquitous free radicals react with stable molecules. The authors investigate a variety of OH, CN, and CH + stable molecule reactions important to fuel conversion, emphasizing application of the extraordinarily precise technique of laser photolysis/continuous-wave laser-induced fluorescence (LP/cwLIF). This precision enables kinetic measurements to serve as mechanistic probes. Since considerable effort is required to study each individual reaction, prudent selection is critical. Two factors encourage selection of a specific reaction: (1) the rates and mechanisms of the subject reaction are required input to a combustion model; and (2) the reaction is a chemical prototype which, upon characterization, will provide fundamental insight into chemical reactivity, facilitate estimation of kinetic parameters for similar reactions, and constrain and test the computational limits of reaction-rate theory. Most studies performed in this project satisfy both conditions.

Tully, F.P. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

498

Chernobyl nuclear accident: Effects on food. (Latest citations from the Food Science and Technology Abstracts database). Published Search  

SciTech Connect (OSTI)

The bibliography contains citations concerning studies and measurements of the radioactive contamination by the Chernobyl nuclear reactor accident of food and the food chain. The studies cover meat and dairy products, vegetables, fish, food chains, and radioactive contamination of agricultural farms and lands. (Contains 250 citations and includes a subject term index and title list.)

NONE

1993-09-01T23:59:59.000Z

499

Assessment of the current status of basic nuclear data compilations  

SciTech Connect (OSTI)

The Panel on Basic Nuclear Data Compilations believes that it is important to provide the user with an evaluated nuclear database of the highest quality, dependability, and currency. It is also important that the evaluated nuclear data are easily accessible to the user. In the past the panel concentrated its concern on the cycle time for the publication of A-chain evaluations. However, the panel now recognizes that publication cycle time is no longer the appropriate goal. Sometime in the future, publication of the evaluated A-chains will evolve from the present hard-copy Nuclear Data Sheets on library shelves to purely electronic publication, with the advent of universal access to terminals and the nuclear databases. Therefore, the literature cut-off date in the Evaluated Nuclear Structure Data File (ENSDF) is rapidly becoming the only important measure of the currency of an evaluated A-chain. Also, it has become exceedingly important to ensure that access to the databases is as user-friendly as possible and to enable electronic publication of the evaluated data files. Considerable progress has been made in these areas: use of the on-line systems has almost doubled in the past year, and there has been initial development of tools for electronic evaluation, publication, and dissemination. Currently, the nuclear data effort is in transition between the traditional and future methods of dissemination of the evaluated data. Also, many of the factors that adversely affect the publication cycle time simultaneously affect the currency of the evaluated nuclear database. Therefore, the panel continues to examine factors that can influence cycle time: the number of evaluators, the frequency with which an evaluation can be updated, the review of the evaluation, and the production of the evaluation, which currently exists as a hard-copy issue of Nuclear Data Sheets.

Riemer, R.L.

1992-12-31T23:59:59.000Z

500

Nuclear and gravitational energies in stars  

SciTech Connect (OSTI)

The force that governs the evolution of stars is gravity. Indeed this force drives star formation, imposes thermal and density gradients into stars at hydrostatic equilibrium and finally plays the key role in the last phases of their evolution. Nuclear power in stars governs their lifetimes and of course the stellar nucleosynthesis. The nuclear reactions are at the heart of the changes of composition of the baryonic matter in the Universe. This change of composition, in its turn, has profound consequences on the evolution of stars and galaxies. The energy extracted from the gravitational, respectively nuclear reservoirs during the lifetimes of stars of different masses are estimated. It is shown that low and intermediate mass stars (M < 8 M{sub ?}) extract roughly 90 times more energy from their nuclear reservoir than from their gravitational one, while massive stars (M > 8 M{sub ?}), which explode in a supernova explosion, extract more than 5 times more energy from the gravitational reservoir than from the nuclear one. We conclude by discussing a few important nuclear reactions and their link to topical astrophysical questions.

Meynet, Georges; Ekstrm, Sylvia [Astronomical Observatory of Geneva University (Switzerland); Courvoisier, Thierry [ISDC, Astronomical Observatory of Geneva University (Switzerland)

2014-05-09T23:59:59.000Z