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The 14N(p,γ)15O reaction is the slowest process of the CN cycle, and thus it is of high astrophysical interest since it regulates the total rate of energy and neutrinos production through the cycle. The 14N+p ground state capture is strongly influenced by a sub-threshold resonance corresponding to the 6.79 MeV state in 15O. The width of this resonance is a major source of uncertainty in the extrapolation of the reaction cross section in the Gamow energy window. Preliminary results of a new Doppler Shift Attenuation measurement of the lifetime of the 6.79 MeV state in 15O are discussed. The level of interest was populated via the 2H(14N,n)15O reaction in inverse kinematics at 32 MeV beam energy. The gamma-rays emitted in the decay of the 6.79 MeV level to the ground state were detected with the AGATA Demonstrator array of high-purity germanium detectors. The sensitivity of the shape of the peak in the gamma-ray energy spectrum to the level lifetime is investigated comparing the experimental peaks with detailed Monte Carlo simulations of the reaction mechanisms and the gamma-ray emission and detection. Nuclear levels in 15N (also populated in the 14N+2H reaction) for which the lifetimes are known in the literature provided a test of the analysis technique. [ABSTRACT FROM AUTHOR]

The preliminary results of a new direct measurement of the lifetime of the first excited 3/2+ state in 15O are discussed. An accurate evaluation of this lifetime is of paramount importance for the determination of the cross section of the 14N(p,γ)15O reaction, the slowest one in the CNO cycle, at the energies of the solar Gamow peak. The 2H(14N,15O)n reaction in inverse kinematics at 32MeV beam energy (XTU Tandem, LNL) was used to populate the level of interest, which decays via a 6.79 MeV E1 gamma-ray transition to the ground state. Gamma rays were detected with 4 triple clusters of HPGe detectors of the AGATA Demonstrator array. The energy resolution and position sensitivity of this state-of-the-art gamma-ray spectrometer have been exploited to investigate the Doppler Shift Attenuation effect on the lineshape of the gamma-ray peak in the energy spectrum. The deconvolution of the lifetime effects from those due to the kinematics of the emitting nuclei has been performed using detailed Monte Carlo simulations of the gamma emission and detection. CDCC-CRC calculations for the nucleon transfer process have been used for this purpose and preliminary results are shown. [ABSTRACT FROM AUTHOR]

The AGATA Demonstrator Array has recently concluded a two-years campaign of measurements at the Laboratori Nazionali di Legnaro, Italy. In this contribution, the principles of operation of the device and the status of the AGATA project will be reviewed. The performance of the array will be discussed and highlights from a few selected measurements will be presented. [ABSTRACT FROM AUTHOR]

Multinucleon transfer reaction 40Ar+208Pb has been investigated with the PRISMA-CLARA experimental setup in LNL, INFN, Italy. The experimental differential cross sections have been obtained for different transfer channels by measuring more than Δθlab = 20° covered by three angular settings of PRISMA. Results have been compared with the semiclassical calculation GRAZING. Since the understanding of the reaction mechanism depends strongly on the determination of absolute cross section, effect of transport of ions through PRISMA has been studied via a Monte Carlo simulation code. [ABSTRACT FROM AUTHOR]

The transfer reaction for the 116Sn+60Ni system has been studied using the PRISMA magnetic spectrometer at different bombarding energies from above to well below the Coulomb barrier. The experiment has been done in inverse kinematics and light target-like ions have been detected with PRISMA placed at very forward angles. Good mass, nuclear charge and kinetic energy resolutions have been achieved. Sufficient statistics has been accumulated to extract angular distributions for different bombarding energies have been extracted and the response function of the spectrometer has been studied to correct for the aberration due to the transport of the ions in PRISMA. The comparison between the present case and the previously measured 96Zr+40Ca system, superfluid and near closed shells nuclei, respectively, should significantly improve our understanding of nucleon-nucleon correlation properties in multinucleon transfer processes. [ABSTRACT FROM AUTHOR]

Binary reactions at energies close to the Coulomb barrier received recently a significant boost thanks to the advent of the large solid angle magnetic spectrometer PRISMA coupled to the γ array CLARA. In the present paper different aspects of the recent results of nuclear structure and reaction dynamics will be presented, focusing more closely on the reaction mechanism. [ABSTRACT FROM AUTHOR]

The AGATA Demonstrator Array is presently under installation at Laboratori Nazionali di Legnaro, Italy, where it will replace the CLARA array at the target position of the PRISMA magnetic spectrometer. In the present contribution, the details of the installation will be reviewed. Preliminary results from the first in-beam commissioning test will be given. [ABSTRACT FROM AUTHOR]

This work focus on the electromagnetic decay properties of the heaviest known mirror pair 67As and 67Se, produced in the fusion evaporation reaction 32S+40Ca, with a E = 90 MeV beam provided by the ATLAS accelerator at Argonne National Laboratory. The high selectivity required to investigate these proton-rich nuclei was achieved with the concurrent employment of Gammasphere, Neutron-Shell, and Microball. The full array allowed to obtain the level scheme of the 67Se nucleus up to 5.56 MeV, and 5 new transitions were assigned to the known 67As level-scheme. The level spin and parities were assigned using the ADO analysis and symmetry arguments. [ABSTRACT FROM AUTHOR]

The CLARA-PRISMA setup, composed of an array of 25 Clover detectors placed at the target position of the magnetic spectrometer PRISMA, has recently concluded its campaign to study the structure of moderately neutron-rich nuclei. Results obtained in the vicinity of the doubly-magic nucleus 48Ca are presented here. The perspectives offered by the forthcoming operation of the AGATA Demonstrator Array coupled to PRISMA are also discussed. [ABSTRACT FROM AUTHOR]

The large solid angle magnetic spectrometer for heavy ions PRISMA was operated at LNL in conjunction with the highly efficient CLARA set-up up to the end of March 2008. The AGATA Demonstrator is being mounted around the target area of PRISMA replacing the CLARA set-up. It will allow to carry out nuclear structure and reaction mechanism studies with better resolution and higher statistics. New detectors for light ions and slow moving heavy ions have been designed for the focal plane of the spectrometer. [ABSTRACT FROM AUTHOR]

The lifetimes of excited states of the 122Ba ground—state band, populated via the 108Cd(16O,2n)122Ba and the 112Sn(13C,2n)122Ba reactions, have been measured using the Recoil Distance Doppler—Shift method. The level scheme of 122Ba has also been revised. [ABSTRACT FROM AUTHOR]

The performance of the AGATA Demonstrator Array coupled to the PRISMA magnetic spectrometer have been evaluated in a consistent way using detailed Monte Carlo simulations of the two devices. Results for the 90Zr+208Pb at 560 MeV reaction are presented and discussed here, proving that the Doppler correction capabilities of the AGATA+PRISMA setup will be very close to the intrinsic energy resolution of the germanium detectors. [ABSTRACT FROM AUTHOR]

The lifetimes of the first excited states of nuclei around the doubly-magic nucleus 48Ca have been determined using a novel method that combines the Recoil Distance Doppler Shift (RDDS) method with the CLARA-PRISMA spectrometers. This is the first time such a method is applied to measure lifetimes of neutron-rich nuclei populated via a multinucleon transfer reaction. This novel method and some preliminary results on lifetimes are presented. [ABSTRACT FROM AUTHOR]

The nucleus 37Ar has been studied with γ-ray spectroscopy in the 24Mg(16O,2pn) reaction at a beam energy of 70 MeV. Twenty two new excited states up to an excitation energy of 13 MeV have been observed. We compare the first negative and positive parity yrast states with large-scale-shell-model calculations using the Antoine code and the SDPF interaction, considering the excitation of the 1d5/2,2s1/2 and 1d3/2 nucleons to 1f7/2 and 2p3/2 in the sdpf valence space. [ABSTRACT FROM AUTHOR]

The PRISMA-CLARA setup, consisting of the large solid angle magnetic spectrometer for heavy-ions PRISMA coupled to the highly efficient CLARA array of 25 Clovers detectors, was operating at LNL since the end of 2003. The first experimental campaign has been completed at the end of 2004. Selected results on the structure of moderately neutron-rich nuclei, populated in multi-nucleon transfer and deep-inelastic reactions, are presented here. Some technical developments related to the setup are also discussed. © 2007 American Institute of Physics [ABSTRACT FROM AUTHOR]

The present work takes advantage of the multinucleon transfer mechanism between heavy reaction partners to study the population pattern of excited nuclear states in near spherical Zirconium isotopes following the 90Zr + 208Pb reaction at an energy closed to the Coulomb barrier. Both the projectile and the target are well known closed shell nuclei offering an optimum situation for clean experimental and theoretical conditions. Total kinetic energy loss (TKEL) distributions were compared with calculations performed with the GRAZING code. The ability to use the TKEL as a selection tool for the states at different excitation energies was shown. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Since the discovery of the breakdown of shell effects in very neutron-rich N=20 and 28 nuclei, studies of the properties of nuclei far from stability have been of intense interest since they provide a unique opportunity to increase our understanding of nuclear interactions in extreme conditions and often challenge our theoretical models. Deep-inelastic processes can be used to populated high spin states of neutron-rich nuclei. In the deep-inelastic processes, an equilibration in N/Z between the target and projectile nuclei is achieved. For most heavy neutron-rich target nuclei, the N/Z ratio is 1.5 – 1.6, while for the possible neutron-rich sdf-shell projectile it is about 1.2. Thus by using deep-inelastic processes one can populate neutron-rich nuclei around N=20 and N=28. New results for the spectroscopy of neutron-rich N=22 36Si and 37P are presented here. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

It has been proposed to associate the narrow (Γ=170 keV) and high spin (Jπ=36+) resonance in the 24Mg + 24Mg reaction at Ec.m= 45.7 MeV with a hyperdeformed molecular state in 48Cr. Such a description has important consequences for the resonance decay into the favoured inelastic channels. Through fragment-γ coincidence measurements performed ON and OFF resonance using the PRISMA-CLARA array, we have established that the 24Mg states selectively populated are the 2+ and 4+ members of the ground state band. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The CLARA-PRISMA setup is a powerful tool for spectroscopic studies of neutron-rich nuclei produced in multi-nucleon transfer and deep-inelastic reactions. It combines the large acceptance spectrometer PRISMA with the γ-ray array CLARA. At present, the ancillary heavy-ion detector DANTE, based on Micro-Channel Plates to be installed at the CLARA-PRISMA setup, is being constructed at LNL. DANTE will open the possibility of measuring γ-γ Doppler-corrected coincidences for the events outside the acceptance of PRISMA. In this presentation, it is described the heavy-ion detector DANTE, as well as the performances of the first prototype. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

This contribution reports on the results of an experiment to study the near-yrast states in selenium- and osmium-like nuclei, following their population in thick-target, multinucleon transfer reactions between an 82Se beam and a 192Os target. The experimental results for the level scheme for 84Se are presented together with investigations into the use of multi-dimensional gamma-ray energy gating to investigate angular momentum population in such heavy-ion binary reactions. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

A Monte Carlo code based on the C++ classes of Geant4 has been developed to meet the requirements of the AGATA project, which has the goal to develop an array of highly segmented high-purity germanium detectors based on the novel concepts of pulse shape analysis and γ-ray tracking. The code has been used to optimize the final geometry of the array and to evaluate realistically its performance under a wide range of experimental conditions. Some results of the extensive simulation work are presented here. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Deep-inelastic and multi-nucleon transfer reactions can be used to populate nuclei with relatively large neutron excess. Recently, at the Laboratori Nazionali di Legnaro, a setup consisting on an efficient γ-ray detection system CLARA coupled to the large acceptance magnetic spectrometer PRISMA, capable of tracking the trajectories of the reaction products, has been assembled. During the first year of activity, the experiments performed with the CLARA-PRISMA setup, have been focused mainly on the nuclear structure of neutron-rich nuclei. In particular, nuclei around N=20, N=50 and lying in the A∼60 transitional region with N<40, have been investigated. In this contribution, results of these experiments will be reported. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

Multinucleon transfer reactions with 40Ca beams on closed shell nuclei 96Zr and 208Pb at energies close to the Coulomb barrier were studied using magnetic spectrometers. The comparison between data and calculations, based on semiclassical models, allowed to identify the different degrees of freedom that influence the evolution of the reaction, like deformation, single, and pair transfer modes. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The energy spectra and relative transition rates of 176,178,180Os were found to be very similar to the values calculated in the framework of the critical point symmetry X(5). In order to enable more stringent tests, including also absolute transition probabilities, two coincidence RDDS lifetime measurements were performed at the Laboratori Nazionali di Legnaro with the GASP spectrometer using the 152,154Sm(29Si,5n)176,178Os reactions. The deduced transition quadrupole moments in 178Os agree well with the X(5) predictions. For 176Os only preliminary results were obtained so far. These preliminary data support an X(5) like structure also in the case of 176Os. The experimental data of both nuclei are compared to calculations in the framework of the interacting boson model (IBM) and of the general collective model (GCM). © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

High-spin states in 3674Kr38 were studied using the 40Ca(40Ca,α2p)74Kr fusion evaporation reaction at a beam energy of 165 MeV with GAMMASPHERE and MICROBALL and at a beam energy of 185 MeV with EUROBALL and ISIS multi-detector arrays. Lifetimes of the high-spin states for the ground-state band and the favoured negative-parity band have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments show a marginal decrease as a function of spin, suggesting that the rotational bands do not terminate at the maximum spin Imax. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

This contribution reports on the results of an experiment to study the near-yrast states in selenium isotopes around N=50, following their population in thick-target, multinucleon transfer reactions between an 82Se beam and a 192Os target. Discrete decays from states with spins of 20h and higher are clearly identified in the Os-like fragments. Information on the size of the energy gap between the f5/2 and p3/2 proton orbitals can be inferred from the spectroscopy of the N=48 isotone, 82Se. The experiment results for the level schemes for 80,82Se derived in the current work are compared with restricted-basis shell model calculations, which give a good description of the yrast sequences of these nuclei using a basis space limited to excitations in the (p3/2 , p1/2 , g9/2 ) neutron and (f5/2 , p3/2 , p1/2 ) proton orbitals. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The narrow (Γ=170 keV) and high spin (Jπ=36+) resonance in the 24Mg + 24Mg reaction at ECM= 45.7 MeV has been associated with a hyperdeformed molecular state in 48Cr. Such a description has important consequences for the resonance decay into the favored inelastic channels. Through fragment-γ coincidence measurements performed ON and OFF resonance using the PRISMA-CLARA array, we have identified the 24Mg states selectively populated: the 2+ and 4+ members of the ground state band. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Lifetime measurements in 134Pr were performed by means of the Recoil distance Doppler-shift and Doppler-shift attenuation methods using the multidetector array EUROBALL, in conjunction with the inner BGO ball. The derived B(E2) transition strengths within the two bands candidates for chiral partners behave differently with increasing spin while the corresponding B(M1) values have a similar behaviour within the experimental uncertainties. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Excited states have been studied in sd-shell nuclei following the 16O (70 MeV) + 24Mg (400 μg/cm2) fusion-evaporation reaction. The GASP spectrometer in conjunction with the charged-particle detector ISIS and the Neutron ring allowed the detection of the γ-rays in coincidence with evaporated light particles. New data on the mirror pairs A=31 and A=35 have been obtained. In particular, the comparison between the level schemes of 35Ar and 35Cl has confirmed the importance of the electromagnetic spin-orbit term, which explains the large Mirror Energy Difference values. Evidence of isospin mixing can be deduced from the E1 transitions. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Valuable information on the validity of the isospin symmetry was obtained by studying nuclei close to the N = Z line with the GASP and EUROBALL γ-ray spectrometres coupled to ancillary devices. Here a few selected results on the study of mirror nuclei are presented, together with an estimate of the isospin mixing probability through the measurement of a forbidden E1 transition in 64Ge. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

We have studied the high spin states in 160–162Ho in order to investigate the properties of the rotational bands and their dependence on the single particle orbits involved. The reaction 158,160Gd(7Li,xn) at 56 MeV were used to produce the Ho isotopes of interest. In all three Ho isotopes the known rotational bands have been significantly extended. New band-crossings have been observed for the first time in this work. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

High spin studies of A ≈ 60 nuclei have been carried out with EUROBALL. The nuclei of interest were populated in the fusion-evaporation reaction with a 125 MeV 16O beam bombarding a thin 56Fe target. The use of the Recoil Filter Detector and the charged particle detector EUCLIDES resulted in a significant reduction of γ-line widths and facilitated a reaction channel selection. In this article, several new linking transitions of the previously known terminating band in 64Zn are reported. Such bands are also observed in 61Cu and 63Cu. New SD bands identified in 61,63Cu are discussed. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

We have studied the γ-decay properties of 21Ne up to the limits of the particle emission thresholds in order to establish the band structure. The GASP γ-ray detector array together with the multi-detector array, ISIS, were used for the selection of the reaction channels. The reaction 16O(7Li,pn)21Ne has been studied at E=29 MeV. The observed decays in 21Ne, support the identification of parity doublets with states of opposite parity connected by strong dipole transitions. The behaviour of the octupole deformed bands in 21Ne is interpreted as consisting of an intrinsic reflection asymmetric (4He+16O)-structure with an additional valence neutron in σ- and π-orbitals. Using the same experimental set-up the emission of the light unbound cluster 8Be has been studied in the reaction 18O+13C→31Si→23Ne+8Be. The emission has been studied relative to the sequential emission of 2α-particles. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

The feasibility of the entire process of γ-ray tracking is demonstrated experimentally for the first time. The accurracy of the results is verified by the capability to carry out Doppler correction of γ-rays emitted in flight. The resolution of the 847.8 keV transition detected with the MARS detector after Coulomb excitation of a [sup 56]Fe beam could be improved from 15 keV to below 5 keV (FWHM). [ABSTRACT FROM AUTHOR]