Search results for "Delayed neutron"

showing 10 items of 59 documents

Beta Decay Studies of Neutron Rich Nuclei Using Total Absorption Gamma-ray Spectroscopy and Delayed Neutron Measurements

2010

International audience; A complete characterisation of the β-decay of neutron-rich nuclei can be obtained from the measurement of β-delayed gamma rays and, whenever the process is energetically possible, β-delayed neutrons. The accurate determination of the β-intensity distribution and the β-delayed neutron emission probability is of great relevance in the fields of reactor technology and nuclear astrophysics. A programme for combined measurements using the total absorption gamma-ray spectroscopy technique and both neutron counters and neutron time-of-flight spectrometers is presented.

Astrofísica nuclearNeutron emissionAstrophysics::High Energy Astrophysical PhenomenaNuclear TheoryGeneral Physics and AstronomyBeta decayNeutron scattering[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]7. Clean energy01 natural sciencesNuclear physicsPrompt neutronNuclear Technology0103 physical sciencesNuclear AstrophysicsNeutron cross sectionNeutronDelayed neutrons emission010306 general physicsNuclear ExperimentSpectroscopyPhysics:Energies::Energia nuclear [Àrees temàtiques de la UPC]Total Absorption Gamma-Rayta114010308 nuclear & particles physicsRadioactivitat betaNeutron stimulated emission computed tomographyBeta DecayDelayed Neutron Emission3. Good healthNeutron Detectors23.40.Bw 29.30.KvNuclear astrophysicsPrompt neutronsDelayed neutronNeutron activation
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The BRIKEN Project: Extensive Measurements of $\beta $-delayed Neutron Emitters for the Astrophysical r Process

2018

An ambitious program to measure decay properties, primarily β-delayed neutron emission probabilities and half-lives, for a significant number of nuclei near or on the path of the rapid neutron capture process, has been launched at the RIKEN Nishina Center. We give here an overview of the status of the project.

AstrofísicaDelayed neutronNeutron emissionAstrophysics::High Energy Astrophysical PhenomenaNuclear dataNuclear TheoryMeasure (physics)General Physics and AstronomyNeutronAstrophysics01 natural sciencesNuclear physics0103 physical sciencesNeutronNuclear Experiment010306 general physics:Energies::Energia nuclear [Àrees temàtiques de la UPC]NeutronsPhysics:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsNuclear dataNeutron capture:Física::Astronomia i astrofísica [Àrees temàtiques de la UPC]r-processDelayed neutronActa Physica Polonica B
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Commissioning of the BRIKEN beta-delayed neutron detector for the study of exotic neutron-rich nuclei

2017

Beta-delayed neutron emission (Beta-n) is a form of radioactive decay in which an electron, an anti-neutrino and one or more neutrons are emitted. This process arises if the energy window of the decay Q_Beta is greater than the neutron separation energy S n of the daughter. The probability in each decay of emitting neutrons is called the Pn value. This form of decay plays a key role in the synthesis of chemical elements in the Universe via the rapid neutron capture process, or r-process. The r-process proceeds far from the valley of nuclear stability, and leads to very neutron-rich nuclei that then decay to the line of stability. Most of these nuclei are ßn emitters. The initial abundance d…

AstrofísicaNeutron emissionQC1-999Astrophysics::High Energy Astrophysical PhenomenaNeutron detectorNuclear TheoryElectronNeutronAstrophysics01 natural sciencesNuclear physics0103 physical sciencesNeutron detectionNeutron010306 general physicsNuclear ExperimentDelayed neutronsPhysics:Energies::Energia nuclear [Àrees temàtiques de la UPC]Neutrons:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsPhysicsNuclear structureDetectorNeutron captureDelayed neutronRadioactive decay
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Beta-delayed neutron spectroscopy by the TOF technique at IGISOL: 95Rb as a test case

2003

Nuclides with a large neutron excess have high Q β values, making it possible to extract the β-strength function (SF) over a large energy range using β-decay spectroscopy. However, because of the low neutron binding energies, neutron emission from excited states will occur and β-delayed neutron spectroscopy is required to determine the SF over the full Q β window.

Materials scienceNeutron emissionAstrophysics::High Energy Astrophysical PhenomenaExcited stateNuclear TheoryBinding energyNeutronNuclideAtomic physicsNuclear ExperimentSpectroscopyDelayed neutronNeutron spectroscopy
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New accurate measurements of neutron emission probabilities for relevant fission products

2017

We have performed new accurate measurements of the beta-delayed neutron emission probability for ten isotopes of the elements Y, Sb, Te and I. These are fission products that either have a significant contribution to the fraction of delayed neutrons in reactors or are relatively close to the path of the astrophysical r process. The measurements were performed with isotopically pure radioactive beams using a constant and high efficiency neutron counter and a low noise beta detector. Preliminary results are presented for six of the isotopes and compared with previous measurements and theoretical calculations. peerReviewed

Neutron emissionQC1-999Nuclear physicsNeutronAstrophysics7. Clean energy01 natural sciencesNuclear physics0103 physical sciencesNeutron010306 general physicsNuclear Experimentastro nuclear physicsPhysicsNeutrons:Energies::Energia nuclear [Àrees temàtiques de la UPC]Fission productsPnta114Isotope:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsPhysicsDetectorBeta (plasma physics)r-processFísica nuclearDelayed neutronNeutron emission
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Development of a Reference Database for Beta-Delayed Neutron Emission

2021

Beta-delayed neutron emission is important for nuclear structure and astrophysics as well as for reactor applications. Significant advances in nuclear experimental techniques in the past two decades have led to a wealth of new measurements that remain to be incorporated in the databases. We report on a coordinated effort to compile and evaluate all the available beta-delayed neutron emission data. The different measurement techniques have been assessed and the data have been compared with semi-microscopic and microscopic-macroscopic models. The new microscopic database has been tested against aggregate total delayed neutron yields, time-dependent group parameters in 6-and 8-group re-present…

Nuclear and High Energy PhysicsFissile material010308 nuclear & particles physicsNeutron emissionAstrophysics::High Energy Astrophysical PhenomenaAggregate (data warehouse)Nuclear TheoryNuclear dataFOS: Physical sciences[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]01 natural sciencesNuclear physicsBeta (plasma physics)0103 physical sciencesReference databaseEnvironmental scienceNuclear Experiment (nucl-ex)010306 general physicsNuclear ExperimentDelayed neutronNuclear Experiment
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β-delayed neutron emission of r-process nuclei at the N = 82 shell closure

2021

This experiment was performed at RI Beam Factory operated by RIKEN Nishina Center and CNS, University of Tokyo. O.H, T.D, P.J.W, C.G.B, C.J.G and D.K would like to thank STFC, UK for support. This research was sponsored in part by the Office of Nuclear Physics, U.S. Department of Energy under Award No. DE-FG02-96ER40983 (UTK) and DEAC05-00OR22725 (ORNL), and by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Award No. DENA0002132. This work was supported by National Science Foundation under Grants No. PHY-1430152 (JINA Center for the Evolution of the Elements), No. PHY-1565546 (NSCL), and No. PHY-1714153 (Central Michigan Uni…

Nuclear and High Energy PhysicsNational securityQC1-999ß-delayedNuclear physicsLibrary scienceNeutrons--Capturaβ-delayed neutron emission7. Clean energy01 natural sciencesNeutrons--CaptureAstrophysical0103 physical sciencesEuropean commissionr-processimportant010306 general physicsChinaNuclear ExperimentNeutron emissionr-processPhysics:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsbusiness.industryr-processPhysicsChinese academy of sciencesbeta-delayed neutron emissionResearch councilChristian ministryFísica nuclearNational laboratorybusinessAdministration (government)Physics Letters B
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Characterization of a neutron-beta counting system with beta-delayed neutron emitters

2016

Abstract A new detection system for the measurement of beta-delayed neutron emission probabilities has been characterized using fission products with well known β-delayed neutron emission properties. The setup consists of BELEN-20, a 4π neutron counter with twenty 3He proportional tubes arranged inside a large polyethylene neutron moderator, a thin Si detector for β counting and a self-triggering digital data acquisition system. The use of delayed-neutron precursors with different neutron emission windows allowed the study of the effect of energy dependency on neutron, β and β–neutron rates. The observed effect is well reproduced by Monte Carlo simulations. The impact of this dependency on …

Nuclear and High Energy PhysicsNeutron emissionAstrophysics::High Energy Astrophysical PhenomenaNuclear TheoryMontecarlo Mètode de01 natural sciencesSelf-triggered digital data acquisition systemNuclear physicsNeutron and beta counters0103 physical sciencesGeant4 simulationsNeutron cross sectionNeutron detectionNeutronself-triggered digital data acquisition system010306 general physicsNuclear ExperimentInstrumentationBeta-delayed neutron emission probabilityPhysicsBonner spherebeta-delayed neutron emission probability:Energies::Energia nuclear [Àrees temàtiques de la UPC]Neutronsta114ta213010308 nuclear & particles physicsNeutron stimulated emission computed tomographyNeutron temperatureMonte Carlo method:Física::Física molecular [Àrees temàtiques de la UPC]Delayed neutronneutron and beta counters
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Characterization and performance of the DTAS detector

2018

11 pags., 16 figs., 3 tabs.

Nuclear and High Energy PhysicsPhysics - Instrumentation and DetectorsPhysics::Instrumentation and DetectorsAstrophysics::High Energy Astrophysical PhenomenaMonte Carlo methodspektrometritβ decayFOS: Physical sciencesNon-proportional scintillation light yield: Monte Carlo simulationsMonte Carlo simulations [Non-proportional scintillation light yield]y-ray spectrometerB decay[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]01 natural sciencesMonte Carlo simulationsOpticsDistortion0103 physical sciencesNeutron[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]Nuclear Experiment (nucl-ex)010306 general physicsAbsorption (electromagnetic radiation)Nuclear ExperimentInstrumentation[formula omitted] decayNuclear ExperimentPhysicsta114Spectrometer010308 nuclear & particles physicsbusiness.industryNaI(Tl) detectorPulse generatorTotal absorption [formula omitted]-ray spectrometerDetectornon-proportional scintillation light yieldInstrumentation and Detectors (physics.ins-det)Total absorption γ -ray spectrometerNon-proportional scintillation light yieldFísica nuclearTotal absorptionydinfysiikkabusinessDelayed neutronExotic nucleiNuclear instruments & methods inphysics research section A: Accelerators spectrometers detectors and associated equipment 910: 79-89 (2018)
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Delayed-neutrons from arsenic isotopes 84As, 85As and 86As

1973

Abstract Short-lived arsenic isotopes were produced by thermal-neutron fission of 235U and isolated within 2·5 sec by volatilization of arsenic hydride. The existence of a strong delayed-neutron precursor of 2·05±0·05 sec half-life among the arsenic isotopes is confirmed and its assignment to 85As ascertained by milking of the daughter product 33 sec 85Se and 3·1 min 84Se, which is the final nucleus in the neutron decay branch of 85As. A delayed-neutron yield of 7·8 ± 1·2 neutrons/104 fissions was obtained for 85As. A new isotope, 0·9 ± 0·2 sec 86As, was detected by delayed-neutron counting and by following the decay of its most prominent γ-ray. The mass assignment was verified by milking o…

Nuclear fission productCluster decayPolymers and PlasticsIsotopeIsotopes of uraniumChemistryNeutron emissionIsotopes of samariumRadiochemistryMaterials ChemistryFission product yieldDelayed neutronJournal of Inorganic and Nuclear Chemistry
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