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The neutron rich 123 Ag nucleus was populated via induced photofission of UC x at the ALTO ISOL facility. Its β -decay properties were studied by means of detecting β -delayed γ and neutron activities. The measured half-life T 1 / 2 = 0.350(20) s agreed with the earlier data; the β -delayed neutron emission branching P 1 n = 1.01(24)% was reestablished using γ and neutron counting. [ABSTRACT FROM AUTHOR]

During test runs dedicated to the commissioning of ALTO (Accélérateur Linéaire et Tandem à Orsay), β and β-n decay of the very neutron rich $_{31}^{84} {\rm{Ga}}_{53} $ could be observed at the tape station installed on-line with the PARRNe mass-separator. γ-lines observed in the resulting spectra and a careful analysis of the balance of their relative intensities point toward the existence of two β-decaying states in 84Ga. The decay of these long-lived states appear to feed the $2_1^ + $ and $4_1^ + $ excited states of $_{32}^{84} {\rm{Ge}}_{52} $ and the $1/2_1^ + $ state in $_{32}^{83} {\rm{Ge}}_{51} $ allowing a significant improvement of the knowledge on nuclear structure in the immediate vicinity of 78Ni. [ABSTRACT FROM AUTHOR]

The γ-ray de-excitations following the β-decay of 83Ga and the β-n decay of 84Ga have been studied. The radioactive species were produced using the PARRNe on-line mass-separator installed at the IPN Orsay Tandem accelerator. Two γ-lines were attributed to 83Ge with the aid of β-γ and γ-γ coincidences. The Z identification of the γ-lines was provided by time analysis of a buid-up/decay cycle. The excited levels of 83Ge can be explained by the coupling of the single neutron state ν2 d 5/2 to the first 2+ excitation of the 82Ge core. [ABSTRACT FROM AUTHOR]

The γ-ray de-excitations following the β-decay of 83Ga and the β-n decay of 84Ga have been studied. The radioactive species were produced using the PARRNe on-line mass-separator installed at the IPN Orsay Tandem accelerator. Two γ-lines were attributed to 83Ge with the aid of β-γ and γ-γ coincidences. The Z identification of the γ-lines was provided by time analysis of a buid-up/decay cycle. The excited levels of 83Ge can be explained by the coupling of the single neutron state ν2 d 5/2 to the first 2+ excitation of the 82Ge core. [ABSTRACT FROM AUTHOR]

The 83, 81As nuclei have been produced as fission fragments in the fusion reaction 18O + 208Pb at 85 MeV bombarding energy and studied with the Euroball array. Medium-spin states of 83, 81As have been established up to ~3.5 MeV excitation energy. From angular correlation analysis, spin values have been assigned to most of the 81As excited states. The behaviors of the yrast structures identified in this work are discussed in comparison with the general features known in the mass région. Then they are compared to the results of two theoretical approaches: the "rotor + quasiparticle" for 81As and the shell model using the effective interactions JUN45 for 83, 81Ks. [ABSTRACT FROM AUTHOR]

We study the development of collectivity in neutron rich nuclei in the close vicinity of 78Ni. We report on the large scale shell model calculations in the N=52-54 even-even nuclei with Z=30-36. We predict maximum of triaxiality in 86Ge and explain this phenomenon on the basis of a pseudo-SU(3) symmetry interpretation. For the cases where signs for nonaxial shapes appear, we perform the triaxial Gogny calculations with particle number and angular momentum projections. The comparison of results obtained in the laboratory and intrinsic frames provides a comprehensive and complete picture of nuclear deformation in this region. [ABSTRACT FROM AUTHOR]