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The isotope Sg and its decay product Rf were produced in the nuclear reaction Pb(Cr, n)Sg . The radioactive decay of these isotopes was investigated by means of $ \alpha$ , $ \alpha$ - $ \gamma$ and/or $ \alpha$ -X-ray spectroscopy. Improved spectroscopic data concerning $ \alpha$ energies, $ \gamma$ transitions, tentative spin and parity assignments of low-lying Nilsson single-neutron orbitals are presented for these nuclei. [ABSTRACT FROM AUTHOR]

In a series of experiments performed at the velocity filter SHIP, new or improved decay data of neutron-deficient isotopes of elements from mendelevium ( Z = 101) to hassium ( Z = 108) were obtained. In particular, evidence for $ \alpha$ -decay or electron capture from isomeric states in 265Hs and 258Db was found. [ABSTRACT FROM AUTHOR]

The radioactive decay of the isotopes 254-256Lr and their daughter products was investigated by means of α , prompt α -γ and delayed conversion electron-γ coincidence spectroscopy. The isotopes were produced using the reaction 48Ca + 209Bi . [ABSTRACT FROM AUTHOR]

The decay of the isotopes 255Rf, 251No and 247Fm produced in the reactions $\mathrm{{}^{207}Pb\ensuremath({}^{50}Ti,2n){}^{255}Rf\ {}^{\alpha}_{\rightarrow}\ {}^{251}No\ \ensuremath{}^{\alpha}_{\rightarrow}\ {}^{247}Fm}$ , and $\mathrm{{}^{206}Pb\ensuremath({}^{48}Ca,3n){}^{251}No\ \ensuremath{}^{\alpha}_{\rightarrow}\ {}^{247}Fm}$ was investigated by means of α-γ spectroscopy. Previously observed γ transitions in coincidence with α decays of 255Rf were confirmed, their energies and line intensities were measured more precisely, and their multipolarities were determined as E1. In 251No a new isomeric state at E * > 1700keV with a half-life of ≈ 2μs was identified. The decay of 247Fm was measured more precisely. A partial level scheme of the daughter nucleus 243Cf could be established. [ABSTRACT FROM AUTHOR]

The decay of odd-mass mendelevium isotopes ( A = 247-255) has been studied by means of α-γ spectroscopy. Strong evidence for a small α branch in the decay of 253Md was found. γ lines in coincidence with α-decays of 247, 249, 251, 253Md have been observed for the first time. Levels in the einsteinium daughter nuclei were assigned on the basis of α-γ coincidence measurements. An energy systematics of the 7/2-[514] Nilsson level could be established, showing a correlation with the deformation parameter β2 of the corresponding nuclei. The results are compared with theoretical predictions [ABSTRACT FROM AUTHOR]

In recent experiments at the velocity filter Separator for Heavy Ion reaction Products (SHIP) (GSI, Darmstadt), an extended and improved set of α-decay data for more than 20 of the most neutron-deficient isotopes in the region from lead to thorium was obtained. The combined analysis of this newly available α-decay data, of which the 186Po decay is reported here, allowed us for the first time to clearly show that crossing the Z = 82 shell to higher proton numbers strongly accelerates the α decay. From the experimental data, the α-particle formation probabilities are deduced following the Universal Decay Law approach. The formation probabilities are discussed in the framework of the pairing force acting among the protons and the neutrons forming the α particle. A striking resemblance between the phenomenological pairing gap deduced from experimental binding energies and the formation probabilities is noted. These findings support the conjecture that both the N = 126 and Z = 82 shell closures strongly influence the α-formation probability. [ABSTRACT FROM AUTHOR]