0000000000432562

AUTHOR

B. J. Varley

γ decay of excited states in 198Rn identified using correlated radioactive decay

The low-lying level structure of the neutron-deficient isotope 198Rn has been studied for the first time, using the 166Er(36Ar,4n) reaction at a beam energy of 175 MeV. Evaporation residues were selected using an in-flight gas-filled separator, RITU, and implanted at the focal plane into a 16-element position-sensitive, passivated ion-implanted planar silicon detector. Prompt γ rays in 198Rn were observed at the target position using the JUROSPHERE array of 24 Compton-suppressed germanium detectors, and were identified by the subsequent radioactive decay of associated recoiling ions in the silicon detector. Isotopic assignments of the nuclei produced were made on the basis of the energy and…

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Influence of fusion barrier distributions on spin populations

Abstract Heavy-ion fusion barrier distributions are now routinely obtained directly from experimental data. By measuring the total γ -ray multiplicity for the 58 Ni + 60 Ni system, which has a striking yet well understood barrier distribution, we show that some evidence of the barrier structures is present in the derived spin populations. In particular, very high spins can be populated at energies rather close to (and even below) the ‘nominal’ Coulomb barrier.

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Low-lying structure of light radon isotopes

The excited states in the neutron-deficient isotopes Rn have been populated using the Er(Ar,4n), Er(Ar,4n), and Er(Ar,4n) reactions at beam energies of 175, 182, and 177 MeV, respectively. Evaporation residues were selected using an in-flight gas-filled separator and implanted at the focal plane into a 16-element position-sensitive, passivated ion-implanted planar silicon detector. Prompt γ rays were observed at the target position using an array of Compton-suppressed germanium detectors. Correlation with the subsequent radioactive decay of associated recoiling ions in the silicon detector, recoil-γ and recoil-γ-γ coincidences were used to construct decay schemes of light radon isotopes. Me…

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γdecay of excited states in198Rnidentified using correlated radioactive decay

The low-lying level structure of the neutron-deficient isotope ${}^{198}\mathrm{Rn}$ has been studied for the first time, using the ${}^{166}\mathrm{Er}{(}^{36}\mathrm{Ar},4n)$ reaction at a beam energy of 175 MeV. Evaporation residues were selected using an in-flight gas-filled separator, RITU, and implanted at the focal plane into a 16-element position-sensitive, passivated ion-implanted planar silicon detector. Prompt $\ensuremath{\gamma}$ rays in ${}^{198}\mathrm{Rn}$ were observed at the target position using the JUROSPHERE array of 24 Compton-suppressed germanium detectors, and were identified by the subsequent radioactive decay of associated recoiling ions in the silicon detector. Is…

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A 15 ?s isomer in thez=70n=83 nucleus153Yb

Gamma-ray measurements following mass analysis of102Pd+245 MeV54Fe reaction products have characterized a 15 μs isomeric decay in153Yb and elucidated the systematics of proton-rich N=83 nuclei.

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High K bands in mid-supershell nuclei

The spectrum of prompt conversion electrons emitted by excited 254No nuclei has been measured, revealing discrete lines arising from transitions within the ground state band. A striking feature is a broad distribution that peaks near 100 keV and comprises high multiplicity electron cascades, probably originating from M1 transitions within rotational bands built on high K states. Evidence for the existence of isomeric states in 254No is presented. peerReviewed

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