0000000000850813
AUTHOR
K. Eberhardt
The thermal neutron capture cross section of the radioactive isotope $^{60}$Fe
50% of the heavy element abundances are produced via slow neutron capture reactions in different stellar scenarios. The underlying nucleosynthesis models need the input of neutron capture cross sections. One of the fundamental signatures for active nucleosynthesis in our galaxy is the observation of long-lived radioactive isotopes, such as $^{60}$Fe with a half-life of $2.60\times10^6$ yr. To reproduce this $\gamma$-activity in the universe, the nucleosynthesis of $^{60}$Fe has to be understood reliably. A $^{60}$Fe sample produced at the Paul-Scherrer-Institut was activated with thermal and epithermal neutrons at the research reactor at the Johannes Gutenberg-Universit\"at Mainz. The therm…
On the adsorption and reactivity of element 114, flerovium
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…
Direct detection of the elusive 229thorium isomer: Milestone towards a nuclear clock
Recently, the first direct detection of the long-searched low-lying isomeric first excited state of 229Th could be realized via its internal conversion decay branch, which confirms the isomer's existence and lays the foundation for precise studies of its decay parameters, in particular its half-life and excitation energy. Follow-up studies confirmed the theoretically expected lifetime reduction by about 109 of neutral 229mTh compared to charged isomers with τ∼10 μS thus emphasizing the need to efficiently suppress internal conversion when aiming for the detection of a potential photonic decay branch of 229mTh. Work towards precisely determining the excitation energy of the thorium isomer is…
Recoil-alpha-fission and Recoil-alpha-alpha-fission Chains Stemming from Element 115
GSI Scientific Report 2014 - GSI Report 2015-1
Study of non-fusion products in the 50Ti + 249Cf reaction
Physics letters / B B 784, 199 - 205 (2018). doi:10.1016/j.physletb.2018.07.058
Spectroscopic Tools Applied to Element Z = 115 Decay Chains
Nuclides that are considered to be isotopes of element Z = 115 were produced in the reaction 48Ca + 243Am at the GSI Helmholtzzentrum für Schwerionenforschung Darmstadt. The detector setup TASISpec was used. It was mounted behind the gas-filled separator TASCA. Thirty correlated α-decay chains were found, and the energies of the particles were determined with high precision. Two important spectroscopic aspects of the offline data analysis are discussed in detail: the handling of digitized preamplified signals from the silicon strip detectors, and the energy reconstruction of particles escaping to upstream detectors relying on pixel-by-pixel dead-layer thicknesses.
117番元素Ts合成のための48Ca+249Bk融合反応
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.