M. Venhart
A5008947862- Nuclear physics research studies
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- X-ray Spectroscopy and Fluorescence Analysis
- Radioactive Decay and Measurement Techniques
- Nuclear reactor physics and engineering
- Radiopharmaceutical Chemistry and Applications
- Rare-earth and actinide compounds
- Advanced NMR Techniques and Applications
- Particle physics theoretical and experimental studies
- Laser-induced spectroscopy and plasma
- Quantum, superfluid, helium dynamics
- Astro and Planetary Science
- Neutrino Physics Research
- Molecular Spectroscopy and Structure
- Cold Fusion and Nuclear Reactions
- Atomic and Subatomic Physics Research
- Dark Matter and Cosmic Phenomena
- Radioactive contamination and transfer
- Boron Compounds in Chemistry
- Solid-state spectroscopy and crystallography
- Particle Accelerators and Free-Electron Lasers
Institute of Physics of the Slovak Academy of Sciences
2016-2025
Slovak Academy of Sciences
2016-2025
Czech Technical University in Prague
2024
University of Jyväskylä
2006-2023
Czech Academy of Sciences, Institute of Physics
2019
KU Leuven
2009-2018
Institute of Chemistry of the Slovak Academy of Sciences
2016-2018
University of Manchester
2018
Comenius University Bratislava
2006-2014
Joint Institute for Nuclear Research
2008-2009
A very exotic process of $\ensuremath{\beta}$-delayed fission $^{180}\mathrm{Tl}$ is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment distribution post-$\ensuremath{\beta}$-decay daughter nucleus $^{180}\mathrm{Hg}$ ($N/Z=1.25$) asymmetric. This asymmetry more surprising since a mass-symmetric split this extremely neutron-deficient would lead two $^{90}\mathrm{Zr}$ fragments, magic...
The radioactive element astatine exists only in trace amounts nature. Its properties can therefore be explored by study of the minute quantities artificially produced isotopes or performing theoretical calculations. One most important influencing chemical behaviour is energy required to remove one electron from valence shell, referred as ionization potential. Here we use laser spectroscopy probe optical spectrum near threshold. observed series Rydberg states enabled first determination...
In-source resonant ionization laser spectroscopy of the even-$A$ polonium isotopes $^{192--210,216,218}\mathrm{Po}$ has been performed using $6{p}^{3}7s$ $^{5}S_{2}$ to $6{p}^{3}7p$ $^{5}P_{2}$ ($\ensuremath{\lambda}=843.38\text{ }\text{ }\mathrm{nm}$) transition in atom (Po-I) at CERN ISOLDE facility. The comparison measured isotope shifts $^{200--210}\mathrm{Po}$ with a previous data set allows us test for first time recent large-scale atomic calculations that are essential extract changes...
Isotope shifts have been measured for the odd-A polonium isotopes 191–211Po and changes in nuclear mean square charge radii δ〈r2〉 deduced. The measurements were performed at CERN-ISOLDE using in-source resonance-ionization spectroscopy technique. combined analysis of these data our recent results even-A indicates an onset deformation already 197,198Po, when going away from stability. This is significantly earlier than was suggested by previous theoretical experimental studies isotopes....
The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents first such measurement in superheavy whose stability is entirely derived from shell-correction energy. properties are compared those neighboring nuclei and it shown that kinematic dynamic moments inertia sensitive underlying single-particle shell specific location high-j orbitals. therefore provide test pairing which...
Mass distributions of fission fragments from the compound nuclei 180Hg and 190Hg formed in fusion reactions 36Ar + 144Sm 154Sm, respectively, were measured at initial excitation energies E⁎(Hg180)=33–66 MeV E⁎(Hg190)=48–71 MeV. In 180Hg, mass spectra well reproduced by assuming only an asymmetric-mass division, with most probable light heavy fragment masses A¯L/A¯H=79/101. The asymmetry for agrees that obtained low-energy β+/EC-delayed 180Tl, our earlier ISOLDE(CERN) experiment. Fission is...
Hyperfine splitting parameters have been measured for the neutron-deficient odd-mass polonium isotopes and isomers $^{193--203}\mathrm{Po}$${}^{g,m}$, $^{209,211}\mathrm{Po}$. The measurement was performed at ISOLDE (CERN) online mass separator using in-source resonance ionization spectroscopy technique. magnetic dipole moments $\ensuremath{\mu}$ spectroscopic electric quadrupole ${Q}_{S}$ deduced. Their implication understanding of nuclear structure in vicinity closed proton shell $Z=82$...
The structure of high-spin and nonyrast states the transfermium nucleus $^{250}\mathrm{Fm}$ has been studied in detail. isomeric nature a two-quasiparticle excitation exploited order to obtain spectroscopic data exceptional quality. allow configuration an isomer first discovered over 30 years ago be deduced, provide unambiguous determination location neutron single-particle very heavy nucleus. A comparison known $^{254,252}\mathrm{No}$ confirms existence deformed shell gaps at $N=152$ $Z=100$.
The low-energy structure of the neutron-rich nucleus $^{68}\mathrm{Ni}$ has been investigated by measuring $\ensuremath{\beta}$ decay low-spin isomer in $^{68}\mathrm{Co}$ selectively produced chain $^{68}\mathrm{Mn}$. A revised level scheme built based on clear identification $\ensuremath{\beta}\ensuremath{-}\ensuremath{\gamma}\ensuremath{-}E0$ delayed coincidences. Transitions between three lowest-lying ${0}^{+}$ and ${2}^{+}$ states are discussed basis measured intensities or their upper...
Abstract The $$\upalpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> -decay fine structure of $$^{179}$$ <mml:mmultiscripts> <mml:mrow/> <mml:mn>179</mml:mn> </mml:mmultiscripts> Hg and $$^{177}$$ <mml:mn>177</mml:mn> Au was studied by means decay spectroscopy. Two experiments were performed at the Accelerator Laboratory University Jyväskylä (JYFL), Finland, utilizing recoil separator RITU a digital data acquisition system. heavy-ion induced...
The β+/EC decay of 180Tl and excited states in the daughter nucleus 180Hg have been investigated at CERN On-Line Isotope Mass Separator (ISOLDE) facility. Many new low-lying energy levels were observed 180Hg, which most significant are 0+2 419.6 keV 2+2 601.3 keV. former is bandhead an band assumed originally to be prolate nature. From β feeding different ground-state spin was deduced (4−,5−).3 MoreReceived 23 June 2011DOI:https://doi.org/10.1103/PhysRevC.84.034307©2011 American Physical Society
The detailed analysis of the β-delayed fission data 180Tl is presented. experiment was performed by producing a pure beam means highly selective resonance laser ionization followed mass separation with ISOLDE (CERN, Geneva) isotope separator. A surprising asymmetric distribution fragments from 180Hg, daughter β decays, observed. Here, energy calibration silicon detectors, which crucial for proper determination fragments' and split, presented total kinetic its dependence on split ratio...
In-gas-cell laser ionization spectroscopy studies on the neutron deficient 97–101Ag isotopes have been performed with LISOL setup. Magnetic dipole moments and mean-square charge radii determined for first time exception of 101Ag, which was found in good agreement previous experimental values. The reported results allow tentatively assigning spin 97,99Ag to 92 confirming presence an isomeric state these two isotopes, whose collapsed hyperfine structure suggests a 12. effect N=50 shell closure...
The observation of the new nuclide 15975Re84 provides important insights into evolution single-particle structure and mass surface in heavy nuclei beyond proton drip line. This nuclide, 26 neutrons away from nearest stable rhenium isotope, was synthesised reaction 106Cd(58Ni, p4n) identified via its radioactivity using ritu gas-filled separator great focal-plane spectrometer. Comparisons measured energy (Ep=1805±20keV) decay half-life (t1/2=21±4μs) with values calculated WKB method indicate...
Very neutron deficient francium isotopes have been produced in fusion evaporation reactions using ${}^{60}$Ni ions on ${}^{141}$Pr targets. The gas-filled recoil separator RITU was employed to collect the products and separate them from scattered beam. activities were implanted into a position sensitive silicon detector after passing through gas-counter system. identified spatial time correlations between implants decays. Two $\ensuremath{\alpha}$-particle activities, with...
The \ensuremath{\alpha} decay of $^{159}\mathrm{Re}$ has been observed for the first time in reactions 300 MeV $^{58}\mathrm{Ni}$ ions with an isotopically enriched $^{106}\mathrm{Cd}$ target. were separated in-flight using RITU separator and implanted into GREAT spectrometer. emanates from proton-emitting $\ensuremath{\pi}{h}_{11/2}$ state energy ${E}_{\ensuremath{\alpha}}=6776\ifmmode\pm\else\textpm\fi{}26$ keV a branching ratio 7.5 \ifmmode\pm\else\textpm\fi{} 3.5%. This populates closed...
The rotational band structure of $^{255}\mathrm{Lr}$ has been investigated using advanced in-beam $\ensuremath{\gamma}$-ray spectroscopic techniques. To date, is the heaviest nucleus to be studied in this manner. One unambiguously observed and strong evidence for a second was found. structures are tentatively assigned based on $1/{2}^{\ensuremath{-}}[521]$ $7/{2}^{\ensuremath{-}}[514]$ Nilsson states, consistent with assignments from recently obtained $\ensuremath{\alpha}$ decay data....