0000000000162815

AUTHOR

H. Hakala

showing 3 related works from this author

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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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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Polychlorinated phenols and their metabolites in soil and earthworms of sawmill environment

1990

Abstract Topsoil and earthworm samples collected from three Finnish sawmill environments were analysed for polychlorinated phenols, 2,3,4,6-tetrachloro- and pentachlorophenol, and their metabolites. Analyses were carried out by gas chromatography/mass spectrometry using a selected ion monitoring technique and by dual-channel gas chromatography using quartz capillary columns and two electron capture detectors. The total chlorophenol concentrations ranged from ca. 260 to 480 μg/g (dry weight) in soil and from ca. 140 to 3500 μg/g fat in earthworms. The most important metabolites in soil were chlorinated dihydroxy-benzenes (also at ppm level); only traces of chlorinated anisoles were detected …

ChlorophenolTopsoilEnvironmental EngineeringChromatographybiologyHealth Toxicology and MutagenesisEarthwormPublic Health Environmental and Occupational HealthGeneral MedicineGeneral Chemistrybiology.organism_classificationPollutionSoil contaminationPentachlorophenolchemistry.chemical_compoundchemistryDry weightEnvironmental chemistryEnvironmental ChemistrySelected ion monitoringGas chromatographyChemosphere
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