A5057102307- Nuclear physics research studies
- Nuclear Physics and Applications
- Radioactive element chemistry and processing
- Astronomical and nuclear sciences
- Nuclear reactor physics and engineering
- Atomic and Molecular Physics
- Nuclear Materials and Properties
- Radiopharmaceutical Chemistry and Applications
- Chemical Synthesis and Characterization
- Rare-earth and actinide compounds
- Advanced Chemical Physics Studies
- Inorganic Fluorides and Related Compounds
- Quantum Chromodynamics and Particle Interactions
- Radioactive contamination and transfer
- Fusion materials and technologies
- Analytical chemistry methods development
- X-ray Spectroscopy and Fluorescence Analysis
- Mass Spectrometry Techniques and Applications
- Particle accelerators and beam dynamics
- Atomic and Subatomic Physics Research
- Cold Fusion and Nuclear Reactions
- Radioactive Decay and Measurement Techniques
- Analytical Chemistry and Chromatography
- Muon and positron interactions and applications
- Quantum, superfluid, helium dynamics
Japan Atomic Energy Agency
2016-2025
Advanced Science Research Center
2014-2024
Ibaraki University
2013-2021
Paul Scherrer Institute
2021
Niigata University
2004-2021
University of Tsukuba
2004-2021
Tokushima University
2021
Osaka University
2004-2021
RIKEN Nishina Center
2013
European Organization for Nuclear Research
2013
Theoretical calculations predict 270Hs (Z=108, N=162) to be a doubly magic deformed nucleus, decaying mainly by alpha-particle emission. In this work, based on rapid chemical isolation of Hs isotopes produced in the 26Mg+248Cm reaction, we observed 15 genetically linked nuclear decay chains. Four chains were attributed new nuclide 270Hs, which decays emission with Qalpha=9.02+/-0.03 MeV 266Sg undergoes spontaneous fission half-life 444(-148)(+444) ms. A production cross section about 3 pb...
The analysis of a large body heavy ion fusion reaction data with medium-heavy projectiles ($6\ensuremath{\le}Z\ensuremath{\le}18$) and actinide targets suggests disappearance the $3n$ exit channel increasing atomic number projectile. Here, we report measurement excitation function $^{248}\mathrm{Cm}(^{26}\mathrm{Mg},xn)^{274\mathrm{\text{\ensuremath{-}}}x}\mathrm{Hs}$ observation new nuclide $^{271}\mathrm{Hs}$ produced in evaporation at beam energy well below Bass barrier cross section...
Fragment mass distributions for fission after full momentum transfer were measured the reaction $^{36}\mathrm{S}+^{238}\mathrm{U}$ at bombarding energies around Coulomb barrier. The data revealed a transition from symmetry to asymmetry when beam decreased above-barrier sub-barrier values. main components of asymmetric distribution are ${A}_{\mathrm{H}}\ensuremath{\approx}200$ and ${A}_{\mathrm{L}}\ensuremath{\approx}74$. is attributed quasifission reacting system polar collisions, whereas...
Experimental investigations of transactinoide elements provide benchmark results for chemical theory and probe the predictive power trends in periodic table. So far, gas-phase reactions, simple inorganic compounds with its highest oxidation state have been synthesized. Single-atom production rates, short half-lives, harsh experimental conditions limited number experimentally accessible compounds. We applied a carbonylation technique previously tested on short-lived molybdenum (Mo) tungsten...
Spontaneous emission of some C, O, F, Ne, Mg, and Si isotopes, from heavy parent nuclei, have been experimentally observed since 1984, confirming earlier predictions. Experimental difficulties are mainly related to the low yield in presence a strong background $\ensuremath{\alpha}$ particles. Until now, only most favorable cases were investigated, leading magic or almost proton neutron numbers daughter nuclei. We present systematics experimental results compared calculations, clearly showing...
The synthesis of isotopes the element hassium was studied using reaction S34+U238→Hs272*. At a kinetic energy 163.0 MeV in center-of-mass system we observed one α-decay chain starting at isotope Hs267. cross section 1.8−1.5+4.2 pb. 152.0 decay new Hs268 observed. It decays with half-life 0.38−0.17+1.8 s by 9479±16 keV α-particle emission. Spontaneous fission daughter nucleus Sg264 confirmed. measured 0.54−0.45+1.3 In-beam measurements fission-fragment mass distributions were performed to...
Evaporation residue cross sections in the 16O+238U reaction were measured for energy range from above- to extreme sub-barrier. The are reproduced by a statistical model calculation, which partial calculated coupled-channel taking into account prolate deformation of 238U. Complete fusion was observed collision projectile with tips 238U target, same way as side collision.
Low-energy $\ensuremath{\beta}$-delayed fission of $^{194,196}\mathrm{At}$ and $^{200,202}\mathrm{Fr}$ was studied in detail at the mass separator ISOLDE CERN. The fission-fragment distributions daughter nuclei $^{194,196}\mathrm{Po}$ $^{202}\mathrm{Rn}$ indicate a triple-humped structure, marking transition between asymmetric $^{178,180}\mathrm{Hg}$ symmetric light Ra-Rn nuclei. Comparison with macroscopic-microscopic finite-range liquid-drop model self-consistent approach employing Gogny...
We report the first ionization potentials (IP1) of heavy actinides, fermium (Fm, atomic number Z = 100), mendelevium (Md, 101), nobelium (No, 102), and lawrencium (Lr, 103), determined using a method based on surface process coupled to an online mass separation technique in atom-at-a-time regime. The measured IP1 values agree well with those predicted by state-of-the-art relativistic calculations performed alongside present measurements. Similar well-established behavior for lanthanides,...
Hyperfine-structure parameters and isotope shifts of $^{195--211}\mathrm{At}$ have been measured for the first time at CERN-ISOLDE, using in-source resonance-ionization spectroscopy method. The hyperfine structures isotopes were recorded a triad experimental techniques monitoring photo-ion current. Multi-Reflection Time-of-Flight Mass Spectrometer, in connection with high-resolution electron multiplier, was used as an ion-counting setup that either affected by strong isobaric contamination...
Flerovium (Fl, element 114) is the heaviest chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported different types of interaction, however, each based on level a few registered atoms only. Whereas noble-gas-like properties were suggested from first experiment, second one pointed at volatile-metal-like character. Here, we present further experimental data adsorption studies Fl silicon oxide and surfaces,...
The transactinide nuclei, 261Rf and 262Db, have been produced in the 248Cm (18O, 5n) reaction at beam energies of 91, 94, 99 MeV, (19F, 106 respectively. production cross sections are evaluated from mother-daughter correlations α between 257No, 262Db 258Lr. maximum section is measured to be 13±3 nb around 94 while 1.3±0.4 MeV.
$\ensuremath{\alpha}\mathrm{\text{\ensuremath{-}}}\ensuremath{\gamma}$ and $\ensuremath{\alpha}$-electron coincidence spectroscopy for a short-lived heavy actinide nucleus $^{257}\mathrm{No}$ (${T}_{1/2}=24.5\text{ }\text{ }\mathrm{s}$) has been performed using gas-jet transport system an on-line isotope separator. Spin-parities of excited states in $^{253}\mathrm{Fm}$ fed by the $\ensuremath{\alpha}$ decay have identified on basis measured internal conversion coefficients. The...
An isothermal vacuum chromatography setup for superheavy element chemistry studies was developed and tested online at the one-atom-at-a-time level. As a model system, adsorption behavior of thallium on quartz chosen with respect to future chemical characterization its homologue, 113 (E113, Z = 113), using described setup. Short-lived 184Tl (t1/2 10.1(5) s) produced in reaction 152Gd(35Cl, 3n)184Tl delivered as mass-separated ion beam experiment: A subsurface implantation subsequent fast...
Nihonium (Nh, element 113) and flerovium (Fl, 114) are the first superheavy elements in which 7p shell is occupied. High volatility inertness were predicted for Fl due to strong relativistic stabilization of closed 1/2 sub-shell, originates from a large spin-orbit splitting between 3/2 orbitals. One unpaired electron outermost sub-shell Nh expected give rise higher chemical reactivity. Theoretical predictions reactivity discussed, along with results experimental attempts study chemistry gas...
Fluoride complexation of element 104, rutherfordium (Rf), produced in the 248Cm(18O,5n)261Rf reaction has been studied by anion-exchange chromatography on an atom-at-a-time scale. The chromatographic behavior Rf was investigated 1.9-13.9 M hydrofluoric acid together with those group-4 elements Zr and Hf 18O-induced reactions Ge Gd targets, respectively. It found that adsorption resin is quite different from Hf, suggesting influence relativistic effects fluoride Rf.
A short review is given on our current anion-exchange studies of element 104, rutherfordium (Rf), in HCl and HNO3 solutions. The distribution coefficients the Rf homologues Zr, Hf, Th (IV), Pu (IV) an resin were measured 1.0-11.5 M 1.1-13.1 with a batch method using radiotracers 88Zr, 175Hf, 234Th, 237Pu. In experiments for short-lived 261Rf, isotopes 85Zr, 169Hf, 169Rf produced 18O-induced reactions natGe, 248Gd, 248Cm targets, respectively, their behavior 4.0-11.5 8.0 was investigated...
Excited states in $^{251}\mathrm{Fm}$ populated via the $\ensuremath{\alpha}$ decay of $^{255}\mathrm{No}$ are studied detail through $\ensuremath{\alpha}$-$\ensuremath{\gamma}$ coincidence and fine-structure measurements. Five excited reported previously firmly established measurement, rotational bands built on one-quasiparticle newly measurement. Spin-parities neutron configurations as well ground state definitely identified basis deduced internal conversion coefficients, lifetimes...