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The experimental setup GAMIPE used for gyro magnetic factor measurements at Laboratori Nazionali di Legnaro and a recent experimental work regarding K-isomers in 174W are described. Aim of the experiment is to study the detailed structure of the isomeric states wave functions, by the measurement of the magnetic dipole moments. This piece of information can provide interesting hints for theoretical models. Preliminary results concerning the population of the isomers of interest and half-lives are presented.

In the last period, two classes of experiments have been carried out with the large acceptance magnetic spectrometer PRISMA. In particular, the one- and two-neutron transfer processes at energies ranging from the Coulomb barrier to deep below it and the population of exotic neutron rich nuclei in the A~130 and A~200 mass regions have been studied. Both kinds of experiments have been performed in inverse kinematics identifying in A, Z and velocity the light target-like recoils with PRISMA placed at very forward angles in order to have, at the same time, high efficiency and good energy and mass resolutions.

Isospin mixing induced by the Coulomb interaction has been studied in the compound nucleus 80Zr at T~2 MeV produced in the fusion-evaporation reaction 40Ca+40Ca at Ebeam = 136 MeV. The isospin impurity was measured using the first step of the Giant Dipole Resonance γ decay. The preliminary value of the Coulomb spreading width has been extracted via statistical model analysis of the measured γ spectrum.

Lifetimes of first 4+ and 6+ states have been measured in neutron-rich isotopes of Zr, Mo, Ru and Pd using the recoil distance Doppler shift method at GANIL. The nuclei were produced through a fusion-fission reaction in inverse kinematics. The fission fragments were fully identified in the large-acceptance VAMOS spectrometer and γ-rays were detected in coincidence with the EXOGAM germanium array. Lifetimes of excited states in the range of 1–100 ps were measured with the Cologne plunger. Preliminary lifetime results are presented as well as a discussion on the evolution of the collectivity in this region.

This short paper presents the investigation of reaction mechanism induced by 6Li through a particle­γ coincidence measurement. The data have been taken from a 6Li+89Y experimentwhich is performed inINFN-LNL, Italy. In this experiment, the light charged particles are detected by a Si­ball, named EUCLIDES, and the γ rays are collected by a HPGe detector array, called GALILEO. In this contribution, scientific motivations, experimental details and some results, such as α­γ analysis, are presented.

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.

This short paper presents the identification of a metastable, isomeric-state decay in the neutron-rich odd-odd, prolate-deformed nucleus 166Tb. The nucleus of interest was formed using the in-flight fission of a 345 MeV per nucleon 238U primary beam at the RIBF facility, RIKEN, Japan. Gamma-ray transitions decaying from the observed isomeric states in 166Tb were identified using the EURICA gamma-ray spectrometer, positioned at the final focus of the BigRIPS fragments separator. The current work identifies a single discrete gamma-ray transition of energy 119 keV which de-excites an isomeric state in 166Tb with a measured half-life of 3.5(4) μs. The multipolarity assignment for this transition is an electric dipole and is made on the basis internal conversion and decay lifetime arguments. Possible two quasi-particle Nilsson configurations for the initial and final states which are linked by this transition in 166Tb are made on the basis of comparison with Blocked BCS Nilsson calculations, with the predicted ground state configuration for this nucleus arising from the coupling of the v(1-/2)[521] and π(3+/2) Nilsson orbitals.

Multineutron and multiproton transfer channels, populated in the inverse kinematics reaction 197Au+130Te at Elab=1.07 GeV, were measured at Laboratori Nazionali di Legnaro using the presently heaviest ion beam delivered by the PIAVE-ALPI accelerator complex and detecting both projectile-like and targetlike ions. To this end the large solid angle magnetic spectrometer PRISMA was coupled to a second arm for the detection of the heavy fragments in kinematic coincidence with the light ones selected and identified with the spectrometer. The data analysis is still in progress and will allow to compare the yields of both light and heavy partner with theoretical predictions performed with the GRAZING code to get quantitative information on transfer channels and the effect of evaporation and fission on the production rate of primary fragments. The mass integrated Z distribution, extracted from the experimental data, evidenced the population of proton pickup channels that, in conjunction with the neutron stripping ones from the 130Te, open the path for the production of neutron-rich heavy nuclei. In the following, we will present some preliminary results as well as details on the experimental configuration and perspectives for future investigations in the neutron-rich heavy region.

The region of neutron-rich nuclei beyond 208Pb has been very difficult to explore due to its high mass and exoticity. However, recent experimental improvements allowed one to perform a quite extended isomer decay spectroscopy of these nuclei.

The neutron-rich isotopes of tungsten, osmium and platinum have different shapes in their ground states and present also shape transitions phenomena. Spectroscopic information for these nuclei is scarce and often limited to the gamma rays from the decay of isomeric states. For the neutron-rich even-even osmium isotopes 194Os and 198Os, a shape transition between a slightly prolate deformed to an oblate deformed ground state was deduced from the observed level schemes. For the even-even nucleus lying in between, 196Os, no gamma ray transition is known. In order to elucidate the shape transition and to test the nuclear models describing it, this region was investigated through gamma-ray spectroscopy using the AGATA demonstrator and the large acceptance heavy-ion spectrometer PRISMA at LNL, Italy. A two-nucleon transfer from a 198Pt target to a stable 82Se beam was utilized to populate medium-high spin states of 196Os. The analysis method and preliminary results, including the first life-time measurement of isomeric states with AGATA, are presented.

The study of the collective properties of nuclear excitations far from stability provides information about the shell structure at extreme conditions. Spectroscopic observables such as the energy or the transition probabilities of the lowest states, in nuclei with large neutron excess, allow to probe the density and isospin dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Emblematic is the case of the evolution of the Ni isotopic chain where several features showed up moving from the most neutron rich stable isotope (64Ni) towards the 78Ni nucleus where the large neutron excess coincides with a double shell closure. In this framework, we have recently performed an experiment with the goal to extract the B(E2; 0+ → 2+) value for the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment: preliminary results are discussed.

The study of the evolution of nuclear shells far from stability provides fundamental information about the shape and symmetry of the nuclear mean field. Nuclei with large neutron/proton ratio allow to probe the density dependence of the effective interaction. Indeed, it was recently shown that tensor and three-body forces play an important role in breaking and creating magic numbers. Of particular interest is the region of 78Ni where the large neutron excess coincides with a double shell closure. We have recently measured the B(E2; 0+ → 2+) of the 74Ni nucleus in an intermediate-energy Coulomb excitation experiment performed at the National Superconducting Cyclotron Laboratory of the Michigan State University. The 74Ni secondary beam has been produced by fragmentation of 86Kr at 140 AMeV on a thick Be target. Selected radioactive fragments impinged on a secondary 197Au target where the measurement of the emitted γ-rays allows to extract the Coulomb excitation cross section and related structure information. Preliminary B(E2) values do not point towards an enhancement of the transition matrix element and the comparison to what was already measured by Aoi and co-workers in [1] opens new scenarios in the interpretation of the shell evolution of the Z=28 isotopes.

Multinucleon transfer reactions have been investigated in 40Ar+208Pb with the Prisma+Clara set-up. The experimental differential cross sections of different neutron transfer channels have been obtained at three different angular settings taking into account the transmission through the spectrometer. The experimental yields of the excited states have been determined via particle-γ coincidences. In odd Ar isotopes, we reported a signif cant population of 11/2− states, reached via neutron transfer. Their structure matches a stretched conf guration of the valence neutron coupled to vibration quanta.

Multinucleon transfer cross sections in the system 40Ca+96Zr have been measured at bombarding energies ranging from the Coulomb barrier to ~ 25% below. Target-like (lighter) recoils in inverse kinematics have been completely identif ed in A,Z and Q-value with the large solid angle magnetic spectrometer PRISMA. The experimental slopes of the neutron transfer probabilities at large internuclear separation are consistent with the values derived from the binding energies. A phenomenological interpretation of the transfer probabilities indicates the presence of enhanced values for the even number of neutron transfers.