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The unbound proton-rich nuclei 16 F and 15 F are investigated experimentally and theoretically. Several experiments using the resonant elastic scattering method were performed at GANIL with radioactive beams to determine the properties of the low lying states of these nuclei. Strong asymmetry between 16 F– 16 N and 15 F– 15 C mirror nuclei is observed. The strength of the n u c l e o n - n u c l e o n effective interaction involving the loosely bound proton in the s 1 / 2 orbit is significantly modified with respect to their mirror nuclei 16 N and 15 C. The reduction of the effective interaction is estimated by calculating the interaction energies with a schematic zero-range force. It is found that, after correcting for the effects due to changes in the radial distribution of the single-particle wave functions, the mirror symmetry of the n - p interaction is preserved between 16 F and 16 N, while a difference of 63% is measured between the p - p versus n - n interactions in the second excited state of 15 F and 15 C nuclei. Several explanations are proposed. [ABSTRACT FROM AUTHOR]

In an experiment performed at the SPIRAL1 facility of GANIL, the β decay of 32 Ar has been studied by means of the “Silicon Cube” device associated with germanium clover detectors from the EXOGAM array. Beta-delayed protons and γ rays have been observed and allowed the determination of all relevant decay branches. The Gamow–Teller strength distribution is compared to shell-model calculations and excellent agreement is found. The Fermi strength is inline with expectations. A quasi-complete decay scheme of 32 Ar is established. [ABSTRACT FROM AUTHOR]

Proton-rich isotopes of zinc and germanium, 57Zn and 61Ge, have been produced by fragmentation of a 70Ge beam at the LISE3 facility of GANIL. Their main decay characteristics have been studied after implantation in a double-sided silicon strip detector. In addition, the production cross-sections of proton-rich isotopes in the copper-to-germanium region have been determined. These cross-sections are much lower than predicted by the EPAX formula. These findings question to some extent the production rates expected for present and future fragmentation facilities. [ABSTRACT FROM AUTHOR]

We report a measurement of the g-factor of the I π = 9/2+, t 1/2 = 22ns isomer in 65Ni. The state of interest was populated and spin-oriented using a single-neutron transfer on an enriched 64Ni target. The value, which was obtained, g(9/2+,65m Ni) = - 0.296(3) is well in agreement with the g-factors of the other 9/2+ states in the region and with large-basis shell model calculations. The known g-factor of the 9/2+ isomer in 63Ni was used in order to verify the strength of the hyperfine field of Ni( Ni) at room temperature. [ABSTRACT FROM AUTHOR]

In an experiment performed at the LISE3 facility of GANIL, we studied the decay of 22Al produced by the fragmentation of a 36Ar primary beam. A β-decay half-life of T 1/2 = 91.1±0.5ms was measured. The β-delayed one- and two-proton emission as well as β-α and β-delayed γ-decays were measured and allowed us to establish a partial decay scheme for this nucleus. New levels were determined in the daughter nucleus 22Mg. The comparison with model calculations strongly favours a spin-parity of I π = 4+ for the ground state of 22Al. [ABSTRACT FROM AUTHOR]

The excitation function for the elastic-scattering reaction p(18Ne, p)18Ne was measured with the first radioactive beam from the SPIRAL facility at the GANIL laboratory and with a solid cryogenic hydrogen target. Several broad resonances have been observed, corresponding to new excited states in the unbound nucleus19Na. In addition, two-proton emission events have been identified and are discussed. [ABSTRACT FROM AUTHOR]

The neutron-rich nuclei 2157, 58Sc, 2258-60Ti, 2360-63V, 2462-66Cr have been produced at Ganil via interactions of a 61.8A MeV76Ge beam with a58Ni target. Beta-decay studies have been performed using combined ß- and ?-ray spectroscopy. Half-lives have been determined and ß-decay schemes are proposed for58Ti,61V and62Cr. From these studies, new hints for the existence of ß-decaying isomers in60V and in62Mn are provided. These results are compared to shell model calculations. The role of the pf7/2- ?f5/2 proton-neutron interaction is examined through its influence on the lifetime values. [ABSTRACT FROM AUTHOR]

The structure of theA/Z = 3 nucleus15B has been investigated using the in-beam-spectroscopy technique with a fragmentation reaction of a36S beam on a9Be target at 77.5. The fragments were identified and selected by their energy loss and time of flight using the SPEG spectrograph.-ray energies and intensities have been measured in coincidence with the projectile-like fragments. From this information as well as from the-coincidence relationships a level scheme is proposed for15B up to the neutron separation energy. The experimental results have been interpreted using shell model calculations in thepsdvalence space. Effects of the weakly bound nature of the valence neutrons have been observed. [ABSTRACT FROM AUTHOR]

The β-decay properties of the neutron-deficient nuclei 25Si and 26P have been investigated at the GANIL/LISE3 facility by means of charged-particle and γ-ray spectroscopy. The decay schemes obtained and the Gamow­Teller strength distributions are compared to shell-model calculations based on the USD interaction. B(GT) values derived from the absolute measurement of the β-decay branching ratios give rise to a quenching factor of the Gamow­Teller strength of 0.6. A precise half-life of 43.7 (6) ms was determined for 26P, the β-(2)p decay mode of which is described. [ABSTRACT FROM AUTHOR]

The neutron-rich nuclei2360-63V have been produced at GANIL via interactions of a 61.8A·MeV76Ge beam with a58Ni target. Beta-decay to2460-63Cr has been investigated using combined β- and γ-ray spectroscopy. Half-lives of the60-63V nuclei have been determined, and the existence of a beta-decay isomer in the60V nucleus is strongly supported. The observation of low-energy 2+ states in60Cr (646keV) and62Cr (446keV) suggests that these isotopes are strongly deformed with β2 ∼ 0.3. This is confirmed by shell model calculations which show the dominant influence of the intruder g and d orbitals to obtain low 2+ energies in the neutron-rich Cr isotopes. [ABSTRACT FROM AUTHOR]

We report results from a pioneering experiment to measure the g factors of isomeric states of neutron-rich nuclei around [sup 68]Ni, far from the valley of β stability. For the first time, the timedependent perturbed angular distribution method was applied in combination with the heavy-ion-γ correlation technique to study g factors of spin-aligned isomers produced in a projectile fragmentation reaction and mass-separated. Some technical aspects are discussed and illustrated with preliminary results. [ABSTRACT FROM AUTHOR]

The β-decay of the Tz = - 2 nucleus 36Ca was studied at the LISE3 magnetic spectrometer at GANIL. Two new proton-emitting states have been detected and the other nine known βp and βγ transitions have been remeasured with improved resolution. A simulation with the GEANT code has been applied to this experimental setup. A comparison with shell model calculations is given. [ABSTRACT FROM AUTHOR]

Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have been performed during a projectile fragmentation experiment at the GANIL/LISE3 separator. For all nuclei studied in this work, 39, 40Ti, 42, 43Cr, 46Mn, 45, 46, 47Fe and 49Ni, half-lives and decay spectra have been measured. In a few cases, γ coincidence measurements helped to successfully identify the initial and final states of transitions. In these cases, partial decay scheme are proposed. For the most exotic isotopes, 39Ti, 42Cr, 45Fe and 49Ni, which are candidates for two-proton radioactivity from the ground state, no clear evidence of this process is seen in our spectra and we conclude rather on a delayed particle decay. [ABSTRACT FROM AUTHOR]

In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich zinc isotopes 55,56Zn have been observed for the first time. The experiment was performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a nickel target. The identification of 55,56Zn opens the way to 54Zn, a good candidate for two-proton radioactivity according to theoretical predictions. [ABSTRACT FROM AUTHOR]

The MORA (M atter's O rigin from the R adioA ctivity of trapped and oriented ions) project aims at measuring with unprecedented precision the D correlation in the nuclear beta decay of trapped and oriented ions. The D correlation offers the possibility to search for new CP-violating interactions, complementary to searches done at the LHC and with electric dipole moments. Technically, MORA uses an innovative in-trap orientation method which combines the high trapping efficiency of a transparent Paul trap with laser orientation techniques. The trapping, detection, and laser setups are under development. The project will first focus on the proof-of-principle of the in-trap laser orientation technique, before the actual measurement of the D correlation in the decay of 23Mg+ ions is undertaken firstly at JYFL and then later, at GANIL, with full sensitivity to new physics. [ABSTRACT FROM AUTHOR]

We report the results from the first experiment to measure gyromagnetic factors of μs isomers in neutron-rich nuclei produced by intermediate-energy projectile-fragmentation reactions. The Time Dependent Perturbed Angular Distribution (TDPAD) method was applied in combination with the heavy-ion-gamma correlation technique. The nuclides in the vicinity of 68Ni were produced and spin-oriented following the fragmentation of a 76Ge, 61.4 MeV/u beam at GANIL. The results obtained, |g|(69mCu) = 0.225(25) and |g|(67mNi) = 0.125(6) provide another indication of the importance of proton excitation across the Z = 28 shell gap for the description of these states. [ABSTRACT FROM AUTHOR]