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The low-spin structure of one-proton, one-neutron 210Bi nucleus was investigated in cold-neutron capture reaction on 209Bi. Theγ -coincidence measurements were performed with use of EXILL array consisted of 16 HPGe detectors. The experimental results were compared to shell-model calculations involving valence particles excitations. The 210Bi nucleus offers the potential to test the effective proton-neutron interactions because most of the states should arise from the proton-neutron excitations. Additionally, it was discovered that a few states should come from the couplings of valence particles to the 3- octupole vibration in 208Pb which provides also the possibility of testing the calculations involving the core excitations. [ABSTRACT FROM AUTHOR]

A new level scheme was constructed for 80Ga which is significantly different from the one previously reported [1]. The excitation energy of a new low-lying state recently reported in [2] was identified at 22.4 keV. Properties of the level scheme suggest that the ground state has spin J = 6 and the first excited state has spin J = 3. The spin assignments are in agreement with laser spectroscopy values previously measured [2]. Our work provides the first evidence for the J = 6 being the ground state. [ABSTRACT FROM AUTHOR]

The MgF2 monocrystals were irradiated at room temperature with 390 keV B+ ions up to the fluence of 1016 cm-2. The irradiated samples were (isochronally and isothermally) annealed in high vacuum at the temperatures 200° C, 300° C, 400° C, 500° C, 600° C and 700° C for the times ranging from 2–100 hours. After each annealing step, the boron depth distribution was determined using the neutron depth profiling technique. As implanted, the depth distributions of boron exhibited standard Gaussian-like forms, but the evaluated profile parameters, RP = 960 nm and Δ RP = 140 nm, were higher than those calculated using the SRIM code (RP = 870 nm and ΔRP = 115 nm). Annealing at temperatures up to 400° C did not change the depth profiles. Annealing at 600° C, however, led to a one-way gradual transfer of the boron atoms from the site of implantation towards the sample surface, and in this way a bimodal profile was created. The amount of boron atoms, transferred to the sample surface, was an increasing function of the annealing time. After annealing at 700° C for 64 hours the bimodal profile collapsed into a single broad distribution, extending from the sample surface up to the implantation depth. The observed phenomena clearly points out the stability of the as-implanted boron depth profiles at lower annealing temperatures. Thermal annealing above 600° C, however, liberates boron atoms, which then predominantly migrate from the implantation site towards the sample surface, where they are captured on some unspecified surface defects. [ABSTRACT FROM AUTHOR]

The reduced transition probabilities between the first excited 2+ state and the 0+ ground state, B(E2;0+→2+), have been measured in 106,108,110Sn using sub-barrier Coulomb excitation in inverse kinematics at REX-ISOLDE. The results are, B(E2;0+→2+) = 0.220(22), 0.226(17), and 0.228(32)e2b2, for 110Sn, 108Sn, and 106Sn, respectively. The results for 106,108Sn are preliminary. De-excitation γ-rays were detected by the MINIBALL Ge-array. The B(E2) reveals detailed information about the nuclear wave function. A shell model prediction based on an effective CD-Bonn interaction in the ν(0g7/2,2s,1d,0h11/2) model space using eeffν = 1.0 e follows the experimental values for the neutron rich Sn isotopes, but fails to reproduce the results presented here. [ABSTRACT FROM AUTHOR]

The neutron-rich nuclei 72Ni and 72Cu have been produced in the proton-induced fission of 238U at the LISOL and ISOLDE facilities of Louvain-La-Neuve and CERN. Partial β-decay schemes are presented, giving some information about the nuclear structure of their daughter nuclei 72Cu and 72Zn. The lifetime of 72Cu was determined to be T1/2 = 6.63(3) s, in line with previous measurements. No β-decaying isomeric states were identified in 72Cu, in contrast to 70Cu. The spin and the parity of several states in 72Cu are tentatively assigned and a comparison is made with different shell-model predictions. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Production rates of volatile elements following the spallation reaction of 1.4-GeV protons on a liquid Pb/Bi target have been measured. The experiment was performed at the ISOLDE facility at CERN. These data are of interest for the development of targets for accelerator-driven systems such as MEGAPIE. Additional data have been taken on a liquid Pb target. Calculations were performed using the FLUKA and MCNPX Monte Carlo codes coupled with the evolution codes ORIHET3 and FISPACT using different options for the intra-nuclear cascades and evaporation models. Preliminary results from the data analysis show good comparison with calculations for Hg and for noble gases. For other elements such as I, it is apparent that only a fraction of the produced isotopes is released. The agreement with the experimental data varies depending on the model combination used. The best results are obtained using MCNPX with the INCL4/ABLA models and with FLUKA. Discrepancies are found for some isotopes produced by fission using the MCNPX with the Bertini intranuclear cascade model coupled with the Dresner evaporation model. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The structure and decay of neutron-rich r-process nuclides has been studied by a variety of means that take advantage of enhanced selectivity to permit identification of exotic nuclides. New level structures are presented for 134,135Sb along with data for Ag isomers and Cd yrast structures. Some of the properties measured play an important role in calculations of the yields of elements and isotopes produced in r-process nucleosynthesis that takes place at high temperature in the presence of large densities of neutrons. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

We report on the results of the β-decay of 81Zn. The experiment was performed at the CERN ISOLDE facility in the framework of a systematic ultra-fast timing investigation of neutron-rich nuclei populated in the decay of Zn. The present analysis included β-gated γ-ray singles and γ-γ coincidences from the decay of 81Zn to 81Ga and leads to a new and much more extensive level scheme of 81Ga. A new half-life of 81Zn is provided. [ABSTRACT FROM AUTHOR]

We have investigated the levels in 65Fe populated in the β decay of 65Mn, with several new transitions and levels identified. Using the Advanced Time-Delayed Method we have measured the lifetime of the first two excited states with preliminary results of T1/2(363.7keV) = 95(2) ps and T1/2(455.6keV) = 340(30) ps. Also reported here are preliminary values for the β-delayed neutron branch of Pn = 5(1)% and an upper limit for the β-feeding to the ground state of < 8%. [ABSTRACT FROM AUTHOR]

The MgF2 monocrystals were irradiated at room temperature with 390 keV B+ ions up to the fluence of 1016 cm-2. The irradiated samples were (isochronally and isothermally) annealed in high vacuum at the temperatures 200° C, 300° C, 400° C, 500° C, 600° C and 700° C for the times ranging from 2–100 hours. After each annealing step, the boron depth distribution was determined using the neutron depth profiling technique. As implanted, the depth distributions of boron exhibited standard Gaussian-like forms, but the evaluated profile parameters, RP = 960 nm and Δ RP = 140 nm, were higher than those calculated using the SRIM code (RP = 870 nm and ΔRP = 115 nm). Annealing at temperatures up to 400° C did not change the depth profiles. Annealing at 600° C, however, led to a one-way gradual transfer of the boron atoms from the site of implantation towards the sample surface, and in this way a bimodal profile was created. The amount of boron atoms, transferred to the sample surface, was an increasing function of the annealing time. After annealing at 700° C for 64 hours the bimodal profile collapsed into a single broad distribution, extending from the sample surface up to the implantation depth. The observed phenomena clearly points out the stability of the as-implanted boron depth profiles at lower annealing temperatures. Thermal annealing above 600° C, however, liberates boron atoms, which then predominantly migrate from the implantation site towards the sample surface, where they are captured on some unspecified surface defects. [ABSTRACT FROM AUTHOR]