Search results for "Heavy element"
showing 7 items of 67 documents
First Study on Nihonium (Nh, Element 113) Chemistry at TASCA
2021
Frontiers in Chemistry 9, 753738 (2021). doi:10.3389/fchem.2021.753738
Historical Reminiscences: The Pioneering Years of Superheavy Element Research
2013
This chapter deals with the pioneering years of superheavy element research, from the mid 1960s to the mid 1980s. The prediction that superheavy nuclides could form an island around element 114 with half-lives long enough to have survived in Nature since nucleosynthesis led to intensive searches—not unlike “gold fever”—for such relic nuclei in all sorts of natural environments. Positive claims were raised from time to time but could not stand up under further scrutiny. Numerous attempts to synthesize superheavy nuclei by large leaps from the mainland of elemental stability to the island of superheavy elements went without success as well. The discovery of three more transactinide elements, …
Structure of superheavy nuclei along decay chains of element 115
2014
[Introduction] A recent high-resolution α , X -ray, and γ -ray coincidence-spectroscopy experiment offered the first glimpse of excitation schemes of isotopes along α -decay chains of Z = 115. To understand these observations and to make predictions about shell structure of superheavy nuclei below 288 115, we employ two complementary mean-field models: the self-consistent Skyrme energy density functional approach and the macroscopic-microscopic Nilsson model. We discuss the spectroscopic information carried by the new data. In particular, candidates for the experimentally observed E 1 transitions in 276 Mt are proposed. We find that the presence and nature of low-energy E 1 transitions in w…
117番元素Ts合成のための48Ca+249Bk融合反応
2019
We have performed an experiment to synthesize the element 117 (Ts) with the $^{48}$Ca+$^{249}$Bk fusion reaction. Four $\alpha$-decay chains attributed to the element 117 were observed. Two of them were long decay chains which can be assigned to the one originating from the $\alpha$ decay of $^{294}$Ts. The other two were short decay chains which are consistent with the one originating from the $\alpha$ decay of $^{293}$Ts. We have compared the present results with the literature data, and found that our present results mostly confirmed the literature data, leading to the firm confirmation of the synthesis of the element 117.
Fission Barrier of Superheavy Nuclei and Persistence of Shell Effects at High Spin: Cases of 254No and 220Th
2014
We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5 MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9 MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)8 MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.
On the adsorption and reactivity of element 114, flerovium
2022
Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly v…
Rotational properties of nuclei around 254 No investigated using a spectroscopic-quality Skyrme energy density functional
2014
Abstract. Background: Nuclei in the Z≈100 mass region represent the heaviest systems where detailed spectroscopic information is experimentally available. Although microscopic-macroscopic and self-consistent models have achieved great success in describing the data in this mass region, a fully satisfying precise theoretical description is still missing. Purpose: By using fine-tuned parametrizations of the energy density functionals, the present work aims at an improved description of the single-particle properties and rotational bands in the nobelium region. Such locally optimized parametrizations may have better properties when extrapolating towards the superheavy region. Methods: Skyrme H…