Search results for " clusters"

showing 10 items of 1091 documents

RILIS-ionized mercury and tellurium beams at ISOLDE CERN

2017

This paper presents the results of ionization scheme development for application at the ISOLDE Resonance Ionization Laser Ion Source (RILIS). Two new ionization schemes for mercury are presented: a three-step three-resonance ionization scheme, ionizing via an excitation to a Rydberg level and a three-step two-resonance ionization scheme, with a non-resonant final step to the ionization continuum that corresponded to a factor of four higher ionization efficiency. The efficiency of the optimal mercury ionization scheme was measured, together with the efficiency of a new three-step three resonance ionization scheme for tellurium. The efficiencies of the mercury and tellurium ionization schemes…

Nuclear and High Energy PhysicsHelium ionization detectorchemistry.chemical_elementCondensed Matter Physics7. Clean energy01 natural sciencesAtomic and Molecular Physics and OpticsIon source010305 fluids & plasmasMercury (element)Atmospheric-pressure laser ionizationIonsymbols.namesakechemistryIonization0103 physical sciencesRydberg formulasymbolsPhysics::Atomic and Molecular ClustersPhysics::Atomic PhysicsPhysical and Theoretical ChemistryAtomic physics010306 general physicsTellurium
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The SMILETRAP (Stockholm-Mainz-Ion-LEvitation-TRAP) facility

1996

Described in this paper is an experimental facility which measures atomic masses by using multiply charged ions from an electron beam ion source. The ions are injected into a Penning trap and the cyclotron frequencies measured. A precision of 2×10−9 has been reached using highly charged carbon, nitrogen, oxygen and neon.

Nuclear and High Energy PhysicsIon beamChemistryCyclotronchemistry.chemical_elementCondensed Matter PhysicsPenning trapAtomic and Molecular Physics and OpticsIon sourcelaw.inventionIonNeonPhysics::Plasma PhysicslawPhysics::Atomic and Molecular ClustersLevitationPhysics::Atomic PhysicsIon trapPhysical and Theoretical ChemistryAtomic physicsHyperfine Interactions
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Laser ion source tests at the HRIBF on stable Sn, Ge and Ni isotopes

2006

Abstract As one step in the ion source development for the Rare Isotope Accelerator, a hot-cavity laser ion source using an all-solid-state titanium–sapphire laser system has been tested at the Holifield Radioactive Ion Beam Facility. Resonance ionization of stable isotopes of Sn, Ge and Ni has been studied in a Ta hot cavity. Efficient three step resonant ionization schemes applying frequency tripling for the first excitation step and using auto-ionizing or atomic Rydberg states in the ionizing step have been identified for all three elements, resulting in laser ion beams of typically around 100 nA. By saturating most of the optical excitation steps involved, ionization efficiencies of 22%…

Nuclear and High Energy PhysicsIon beamChemistryStable isotope ratioAnalytical chemistryLaserIon sourceIonlaw.inventionIon beam depositionlawIonizationPhysics::Atomic and Molecular ClustersPhysics::Accelerator PhysicsPhysics::Atomic PhysicsAtomic physicsInstrumentationExcitationNuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Nuclear shape transition in neutron-deficient gold isotopes

1987

4 pages, 1 table, 4 figures.

Nuclear and High Energy PhysicsIsotopeChemistryPhotoionizationCondensed Matter PhysicsMass spectrometryAtomic and Molecular Physics and OpticsEffective nuclear chargeIonizationPhysics::Atomic and Molecular ClustersNuclear Physics - ExperimentNeutronPhysics::Atomic PhysicsIsotopes of goldPhysical and Theoretical ChemistryAtomic physicsNuclear ExperimentHyperfine structure
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Atom beam emersion from hot cavity laser ion sources

2020

Abstract Ion sources exploiting laser resonance ionization offer efficient and element-selective radioactive ion beam production at the leading isotope separation on-line facilities worldwide. Most commonly, laser resonance ionization takes place inside a resistively heated atomizer tube directly coupled to the production target, where the element of interest is evaporated and provided as atomic vapor. While naturally the majority of atoms is ionized inside this hot cavity, a fraction of the neutrals effuses towards the high voltage beam extraction system of the subsequent mass separator. We report on several systematic investigations on this phenomenon regarding its significance and implic…

Nuclear and High Energy PhysicsMaterials scienceIon beam010308 nuclear & particles physicsSeparator (oil production)Laser01 natural scienceslaw.inventionIonIsotope separationlawIonization0103 physical sciencesAtomPhysics::Atomic and Molecular ClustersPhysics::Accelerator PhysicsPhysics::Atomic PhysicsAtomic physics010306 general physicsInstrumentationBeam (structure)Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
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Investigation of corrosion defects in titanium by positron annihilation

2015

Abstract The positron annihilation method was used to study the formation of defects in titanium samples during their corrosion in the vapor of a 3% HCl solution. In particular, the distribution of defects depending on the distance from the corroding surface and the impact of an external magnetic field on the concentration of vacancies forming during the corrosion of titanium layers close to the surface were determined.

Nuclear and High Energy PhysicsMaterials scienceMetallurgychemistry.chemical_elementpositron annihilation spectroscopyCondensed Matter Physicscorrosion defectsCorrosionPositron annihilation spectroscopyCondensed Matter::Materials ScienceNuclear Energy and EngineeringchemistryPhysics::Atomic and Molecular Clusterslcsh:QPhysics::Chemical PhysicsSafety Risk Reliability and Qualitylcsh:ScienceWaste Management and DisposalInstrumentationTitaniumPositron annihilationNukleonika
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Luminescence Properties of ZnO Nanocrystals and Ceramics

2008

The luminescence excitation spectra, luminescence spectra and the nanosecond-scale decay kinetics were studied. The ZnO and ZnO:Al nanopowders were prepared by vaporization-condensation in a solar furnace using different raw powders: commercial, hydrothermal and those obtained by plasma synthesis. Exciton-phonon as well as exciton-exciton interaction processes in nanopowders, a bulk crystal and ZnO ceramics were studied and compared. The fast decay and low afterglow intensity of ZnO nanopowders and ceramics support these materials for scintillators.

Nuclear and High Energy PhysicsMaterials scienceSolar furnaceCondensed Matter::OtherDopingWide-bandgap semiconductorCathodoluminescenceCondensed Matter::Mesoscopic Systems and Quantum Hall EffectHydrothermal circulationCondensed Matter::Materials ScienceNuclear Energy and EngineeringNanocrystalChemical engineeringCondensed Matter::Superconductivityvisual_artPhysics::Atomic and Molecular Clustersvisual_art.visual_art_mediumCeramicElectrical and Electronic EngineeringLuminescenceIEEE Transactions on Nuclear Science
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Measurement of the top quark mass in the dilepton channel

2007

We present a measurement of the top quark mass in the dilepton channel based on approximately 370/pb of data collected by the D0 experiment during Run II of the Fermilab Tevatron collider. We employ two different methods to extract the top quark mass. We show that both methods yield consistent results using ensemble tests of events generated with the D0 Monte Carlo simulation. We combine the results from the two methods to obtain a top quark mass m_t = 178.1 +/- 8.2 GeV. The statistical uncertainty is 6.7 GeV and the systematic uncertainty is 4.8 GeV.

Nuclear and High Energy PhysicsParticle physicsTop quarkMonte Carlo methodTevatronFOS: Physical sciences01 natural sciencesBottom quarkHigh Energy Physics - Experimentlaw.inventionNuclear physicsHigh Energy Physics - Experiment (hep-ex)law0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Physics::Atomic and Molecular ClustersFermilab010306 general physicsColliderNuclear ExperimentPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyD0 experimentNonlinear Sciences::Exactly Solvable and Integrable SystemsExperimental High Energy PhysicsHigh Energy Physics::ExperimentCommunication channel
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Three beta-decaying states in 128In and 130In resolved for the first time using Penning-trap techniques

2020

Isomeric states in 128In and 130In have been studied with the JYFLTRAP Penning trap at the IGISOL facility. By employing state-of-the-art ion manipulation techniques, three different beta-decaying states in 128In and 130In have been separated and their masses measured. JYFLTRAP was also used to select the ions of interest for identification at a post-trap decay spectroscopy station. A new beta-decaying high-spin isomer feeding the isomer in 128Sn has been discovered in 128In at 1797.6(20) keV. Shell-model calculations employing a CD-Bonn potential re-normalized with the perturbative G-matrix approach suggest this new isomer to be a 16⁺ spin-trap isomer. In 130In, the lowest-lying (10⁻) isom…

Nuclear and High Energy PhysicsPenning trapAstronomy & Astrophysics01 natural sciencesIonPhysics Particles & Fieldsbeta-decay spectroscopyIsomersShell model0103 physical sciencesPhysics::Atomic and Molecular ClustersNuclear Experiment010306 general physicsSpectroscopyCouplingPhysicsScience & TechnologyNUCLEI010308 nuclear & particles physicsPhysicsPRECISION MASS-SPECTROMETRYNuclear shell modelR-PROCESSshell modelpenning trapRAMSEY METHODPenning traplcsh:QC1-999Physics NuclearExcited stateBeta (plasma physics)Physical SciencesSHELL-MODELTRANSITION-PROBABILITIESisomersAtomic physicsBeta-decay spectroscopylcsh:PhysicsIon cyclotron resonancePhysics Letters B
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Luminescence Properties and Energy Transfer Processes in Nanosized Cerium Doped YAG

2008

Luminescence properties of cerium doped Y3Al5O12 (YAG) nanocrystals in form of nanopowders and nanoceramics have been studied. The comparative analysis of luminescence characteristics for nano- and single-crystals has been done. It was detected that an excitonic mechanism of the energy transfer from the host lattice to cerium ions does not work in nanopowders and nanoceramics. It was also shown that antisite-related and self-trapped exciton-related luminescence bands are suppressed strongly in nanopowders, and it can be excited only under certain circumstances. These bands practically disappeared in the nanoceramic samples. It was suggested that nanoparticle's surface, which is an efficient…

Nuclear and High Energy PhysicsPhotoluminescenceMaterials scienceCondensed Matter::OtherDopingPhysics::Opticschemistry.chemical_elementNanoparticlePhotochemistryNanoceramicCondensed Matter::Materials ScienceCeriumNuclear Energy and EngineeringNanocrystalchemistryPhysics::Atomic and Molecular ClustersCharge carrierElectrical and Electronic EngineeringLuminescenceIEEE Transactions on Nuclear Science
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