N. Belcari

Production of very neutron-deficient isotopes near 100Sn via reactions involving light-particle and cluster emission

Abstract The production of very neutron-deficient isotopes near 100Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete-fusion reactions. We measured the cross sections for 99Cd, 100In, 101Sn and 102In via 58Ni+58Ni fusion reactions followed by cluster emission, and via 58Ni+50Cr fusion reactions accompanied by evaporation of protons, neutrons or α particles. Both types of reactions yield similar cross sections for the production of exotic nuclei near 100Sn. The data are discussed in comparison with results obtained from statistical-model calculations.

Rotation induced octupole correlations in the neutron-deficient 109Te nucleus

High spin states in the neutron deficient nucleus 109Te have been populated with the 58Ni+54Fe reaction at 220 MeV and investigated through γ-spectroscopy methods at the GASP spectrometer making use of reaction channel selection with the ISIS Si-ball. The level scheme has been extended up to an excitation energy of ≈12.1 MeV. The spins and parities of the observed levels are assigned tentatively supporting the identification of two bands of opposite parity connected by strong dipole transitions inferred to be of E1 character. Octupole correlations in 109Te induced by rotation are suggested as the cause of this effect.

Search for hyperdeformed structures populated in the 37Cl+120Sn reaction by using EUROBALL III

Abstract: The ridge structure with ΔEγ=±30 keV, observed in the past in coincidence with protons emitted in the reaction 187 MeV 37Cl +120Sn and attributed to an hyperdeformed nuclear shape in 152Dy, has been studied in a new experiment performed with the EUROBALL III array. The ridge is now observed in coincidence with transitions in the yrast superdeformed band of 152Dy but no discrete rotational bands have been identified.

Production of N≅Z nuclei with A≈100 via complete heavy-ion fusion reactions followed by cluster emission

The production of isotopes near 100Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete fusion reactions. We measured β-delayed protons and γ-rays, deduced the mass-separated beam intensities for 99Cd, 100In, 101Sn and 102In, and determined the corresponding production cross-sections σ for 58Ni+58Ni reactions followed by emission of nuclear clusters, and for 58Ni+50Cr reactions accompanied by emission of protons, neutrons and α particles. The results indicate that the σ values for reactions followed by emission of clusters are comparable with those for reactions proceeding through light particle emission. Due to recoil-loss effects in on-line mass separation, the former mechanism is less suitable than the latter one for producing such neutron-deficient nuclei in this kind of experiments.

High spin studies of 64Ge with EUROBALL

The high-spin states of the N=Z nucleus 64Ge have been investigated using the EUROBALL array coupled to the ISIS Si-ball and to a highly efficient n-Wall. Spins and parities were assigned on the basis of a DCO and of a polarization analysis.

Absence of blocking effect in the N=Z odd-odd nucleus 62Ga: A new signature of the n-p pairing?

The high-spin structure of the N≃Z nuclei 62,64,65Ga have been investigated using the EUROBALL array coupled to the ISIS Si-ball. The collective bands of such nuclei are then compared showing an unexpected behavior.

High spin studies of 64Gewith EUROBALL

The high-spin states of the N=Z nucleus 64Ge have been investigated using the EUROBALL array coupled to the ISIS Si-ball and to a highly efficient n-Wall. Spins and parities were assigned on the basis of a DCO and of a polarization analysis.

High spin studies of {sup 64}Ge with EUROBALL

The high-spin states of the N=Z nucleus 64Ge have been investigated using the EUROBALL array coupled to the ISIS Si-ball and to a highly efficient n-Wall. Spins and parities were assigned on the basis of a DCO and of a polarization analysis.