0000000000262586

AUTHOR

P. Egelhof

Evidence for a two-phonon octupole vibrational state in208Pb

Collective properties of206,208Pb have been investigated with gamma-ray spectroscopy using nuclear and electromagnetic excitation by208Pb projectiles. From the measurement of particle-particle-γ and particle-particle-γ γ coincidences a new energy level in208Pb at 5.683 MeV was observed and the data suggest an interpretation as a 2-phonon octupole vibrational state with spin 4+ or 6+. For this state one finds the same dynamical deformation parameterβ3 as for the first-excited collective 3− state. The results are compared to predictions of models which consider, in particular, the aspects of the quadrupole interaction and the interaction of the 2-particle pairing vibration with the 2-phonon o…

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Nuclear shape transition in neutron-deficient gold isotopes

4 pages, 1 table, 4 figures.

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Nuclear-matter density distribution in the neutron-rich nuclei 12,14Be from proton elastic scattering in inverse kinematics

Abstract In the present work, the differential cross sections for small-angle proton elastic scattering on the 12,14 Be nuclei were measured in inverse kinematics, using secondary radioactive beams with energies near 700 MeV/u produced with the fragment separator FRS at GSI. The main part of the experimental setup was the active target IKAR, which was used simultaneously as a target and a detector for the recoil protons. Auxiliary detectors for projectile tracking and isotope identification completed the setup. The measured differential cross sections were analyzed using the Glauber multiple-scattering theory. For the evaluation of the data several phenomenological nuclear-matter density pa…

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First absolute mass measurements of short-lived isotopes

Absolute mass measurements of short-lived isotopes have been performed at the on-line mass separator ISOLDE at CERN by determining the cyclotron frequencies of ions confined in a Penning trap. The cyclotron frequencies for77,78,85,86,88Rb and88Sr ions could be determined with a resolving power of 3×105 and an accuracy of better than 10−6, which corresponds to 100 keV for massA=100. The shortest-lived isotope under investigation was77Rb with a half-life of 3.7 min. The resonances obtained for the isobars88Rb and88Sr were clearly resolved.

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First feasibility study for EXL prototype detectors at the ESR and detector simulations

This contribution presents some results from the first feasibility measurement performed at GSI using a 350 MeV/nucleon 136 Xe beam and a Hydrogen gas-jet target. In this feasibility study, one element of every possible detection part of the future EXL detection system was investigated. In addition, simulation results for EXL setup will be presented.

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Proton Inelastic Scattering onNi56in Inverse Kinematics

Inelastic proton scattering to the first excited ${2}^{+}$ state of the doubly magic $^{56}\mathrm{Ni}$ nucleus was investigated in inverse kinematics, using a secondary beam of radioactive $^{56}\mathrm{Ni}$ nuclei. At an incident energy of 101 MeV/nucleon, a value $B(E2,{0}^{+}\ensuremath{\rightarrow}{2}^{+})=600\ifmmode\pm\else\textpm\fi{}120 {e}^{2}$ ${\mathrm{fm}}^{4}$ was measured. This result completes the set of experimental data for the first excited ${2}^{+}$ states in the $1f\ensuremath{-}2p$ shell with a closed shell of neutrons or protons. These data are compared to recent shell-model calculations.

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Sudden change in the nuclear charge distribution of very light gold isotopes

4 pages, 3 tables, 2 figures.-- PACS nrs.: 21.10.Ft, 21.10.Ky, 27.70.+q.

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Investigation of the (d, p)-reaction on136, 132Xe in inverse kinematics

The one-neutron transfer reactions d(132,136 Xe, p)133,137 Xe have been investigated in inverse kinematics with xenon beams incident on deuterium loaded titanium targets. The angular distributions of the protons, measured with a detector array of 100 PIN-photodiodes, have been analyzed using standard DWBA. Generally, good agreement is obtained with results previously obtained in reactions induced by light-ion beams.

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