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The MAGNEX large-acceptance spectrometer has been commissioned with beams from the Tandem accelerator at INFN-LNS Catania. The optics were tested with elastically-scattered 7Li, 16O and 48Ti beams with various apertures mounted after the target. The momentum dispersion was verified to be in agreement with the optics calculations. A demonstration of the particle identification capabilities of the PSD start detector and the focal plane detector was given by a measurement of the 27Al(7Li,6Li)28Al transfer reaction at a mean angle of 25°. The measured charge state distribution of 48Ti ions is in agreement with predictions for a gold stripping foil. Preliminary results of the software reconstruction of incident angle and excitation energy, obtained through matrices based on a 3D-interpolation of the measured field maps, are encouraging.

Low-lying levels of 103Pd have been investigated through the (d,t) reaction on 104Pd, at an incident deuteron energy of 15.0 MeV. Outgoing particles were momentum analyzed by an Enge magnetic spectrograph and detected in nuclear emulsion plates, with an energy resolution of 8 keV. Previous (d,t) work suffered from a much worse resolution than that here achieved. A partial analysis of the data obtained is reported, referring to six out of the fourteen scattering angles for which data were obtained. Angular distributions associated with eight of the thirteen levels seen up to 1.1 MeV of excitation have been compared to DWBA one-neutron pick-up predictions. Both, the attributed excitation energy values and the transferred angular momenta are in excellent agreement with the results of other kind of experiments, as tabulated by the Nuclear Data Sheets. Some peculiar structure characteristics, associated with the yrast 5/2+, 3/2+ and 7/2+ states found in the Ru chain could be recognized also in 103Pd, pointing to the possibility of a more global understanding of this transitional mass region.

The 9Be(6Li,d)13C and 12,13C(6Li,d)16,17O reactions were measured at the Sao Paulo Pelletron-Enge-Spectrograph facility at 25.5 MeV incident energy. The nuclear emulsion detection technique was applied. Several narrow resonances were populated up to approximately 17 MeV of excitation energy. An excellent energy resolution was obtained: 40 keV for 13C and 15-30 keV for 16O. The upper limit for the resonance widths were determined. Recently, d-a angular correlations were measured at θd = 0° with incident energy of 25 MeV using the LNS Tandem-MAGNEX Spectrometer facility.

Several narrow alpha resonant 16O states were detected through the 12C(6Li,d) reaction, in the range of 13.5 to 17.5 MeV of excitation energy. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion technique. Experimental angular distributions associated with natural parity quasi-bound states around the 4α threshold are presented and compared to DWBA predictions. The upper limit for the resonance widths obtained is near the energy resolution (15 keV).

The excitation energies of the primary hot isotopes in multifragmentation events are experimentally reconstructed in the reaction system 64Zn + 112Sn at 40 MeV/nucleon. A kinematical focusing method is employed to evaluate the multiplicities of the evaporated light particles associated with isotopically identified fragments with 3≤Z≤14. Angular distributions of the velocity spectra of light charged particles and neutrons associated with trigger isotopes are examined. A moving source fit is used to separate the kinematically correlated particles, evaporated from the parents of the detected isotopes, from the uncorrelated particles originating from other sources. The latter are evaluated experimentally relative to those in coincidence with the Li isotopes. A parameter, k, is used to adjust the yield of the uncorrelated particles for different trigger isotopes. For each experimentally detected isotope, the multiplicities, apparent temperatures, and k values for n, p, d, t, and α particles are extracted. Using the extracted values, the excitation energies of the primary hot isotopes are reconstructed employing a Monte Carlo method. The extracted excitation energies are in the range of 1 to 4 MeV/nucleon but show a significant decreasing trend as a function of A for a given Z of the isotopes. The results are compared with those of antisymmetrized molecular dynamics (AMD) and statistical multifragmentation model (SMM) simulations. While some of the experimental characteristics are predicted partially by each model, neither simulation reproduces the overall characteristics of the experimental results. © 2013 American Physical Society.

A systematic study of the response of different nuclei to the (18O,16O) two-neutron transfer reaction at 84 MeV incident energy was pursued at the INFN-LNS in Catania (Italy).The experiments were performed using several solid targets from light (9Be, 11B, 12,13C, 16O, 28Si) to heavier ones (58,64Ni, 120Sn, 208Pb). The 16O ejectiles were detected at forward angles by the MAGNEX magnetic spectrometer and identified without the need of time of flight measurements. Exploiting the large momentum (≈ 25%) and angular (50 msr) acceptance of the spectrometer, energy spectra were obtained with a relevant yield up to about 20 MeV excitation energy.A common feature of the light nuclei spectra is the strong population of states with well known configuration of two-particle over a core and the appearance of unknown resonant structures in the continuum. These latter can reveal the excitation of a collective mode connected with the transfer of a pair.For the heavier nuclei as 66Ni a completely different behaviour is observed indicating the presence of more dissipative processes in the reaction mechanisms that hide the spectroscopic information.

The 13C(18O, 16O)15C reaction has been studied at 84 MeV incident energy. The ejectiles have been detected at forward angles and 15C excitation energy spectra have been obtained up to about 20 MeV. Several known bound and resonant states of 15C have been identified together with two unknown structures at 10.5 MeV ( FWHM = 2.5 MeV ) and 13.6 MeV ( FWHM = 2.5 MeV ). Calculations based on the removal of two uncorrelated neutrons from the projectile describe a significant part of the continuum observed in the energy spectra. In particular the structure at 10.5 MeV is dominated by a resonance of 15C near the C 13 + n + n threshold. Similar structures are found in nearby nuclei such as 14C and 11Be.

The 9Be(6Li,d)13C reaction was used to investigate alpha resonant states in 13C up to 15 MeV of excitation. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron‐Enge‐Spectrograph facility and the nuclear emulsion detection technique. An energy resolution of 50 keV was obtained. Several narrow alpha resonant states not previously measured were detected, in particular the one at the (3α+n) threshold populated by an L = 2 transfer, revealing a 9Be+α component for the 1/2− cluster state candidate at this threshold. Experimental angular distributions are presented in comparison with DWBA predictions.

The MAGNEX large‐acceptance ray‐tracing magnetic spectrometer has recently been used with beams from the INFN‐LNS Tandem accelerator. After an accurate commissioning, the instrument has started an ambitious experimental program. In the first experiment the 19F(7Li,7Be)19O charge‐exchange reaction was studied at 52 MeV incident energy. The 19O excitation energy spectrum was reconstructed and the angular distributions measured. The second experiment was aimed at the study of the 15C via the 13C(18O,16O)15C reaction at 84 MeV incident energy. The ejectiles where detected at forward angles and mass identified by means of an innovative technique. The 15C excitation energy spectra up to about 20 MeV were obtained with a 250 keV FWHM energy resolution. In addition to several known states, the spectra show two unknown resonant‐like structures at 11.4 and 14.0 MeV. The strong population of these structures, together with the measured widths, could indicate the collective nature of these states associated to a corr...

The 9Be(6Li,d)13C reaction was used to investigate alpha resonant states in 13C up to 13 MeV of excitation. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron‐Enge‐Spectrograph facility and the nuclear emulsion detection technique. The resolution of 50 keV allowed for the separation of the resonant contributions to the known 7/2− at 10.753 MeV and (5/2−) at 10.818 MeV 13C states. The alpha resonance seen at the (3α+n) threshold was not previously reported. The experimental angular distributions are presented in comparison with DWBA predictions.

A study of the 15C states was pursued in 2008 at the Catania INFN‐LNS laboratory by the 13C(18O,16O)15C reaction at 84 MeV incident energy. The 16O ejectiles were detected at forward angles by the MAGNEX magnetic spectrometer. The spectra show several known low lying states up to about 7 MeV excitation energy as well as two unknown resonant structures at about 11.4 and 13.5 MeV. The strong excitation of these latter together with the measured width of about 2 MeV FWHM could indicate the presence of collective modes of excitation connected to the transfer of a correlated neutron pair.

Ratios of $B(E2)$ to $B(IS2)$, that is, of the reduced quadrupole transition probabilities related, respectively, to charge and mass were extracted through Coulomb-nuclear interference (CNI) for the excitation of the ${2}_{1}^{+}$ states in $^{70,72,74}\mathrm{Ge}$, with a relative accuracy of less than 4%. For this purpose, the CNI angular distributions associated with the inelastic scattering of 28-MeV incident $^{6}\mathrm{Li}$ ions accelerated by the S\~ao Paulo Pelletron, and momentum analyzed by the Enge magnetic spectrograph were interpreted within the DWBA-DOMP approach (distorted wave approximation for the scattering process and deformed optical model for the structure representation) with global $^{6}\mathrm{Li}$ optical parameters. The present CNI results demonstrate an abrupt change in the $B(E2)/B(IS2)$ ratio for $^{74}\mathrm{Ge}$: although for $^{70,72}\mathrm{Ge}$, values of the order of 1.0 or slightly higher were obtained, this ratio is 0.66 (7) for $^{74}\mathrm{Ge}$. The heavier Ge isotope is thus one of the few nuclei that, so far, have been shown to present clear mixed symmetry components in their ground-state band.

The study of the odd 99;101Ru nuclei complements the investigation of the collectivity of the first quadrupolar excitations in 100;102;104Ru. Angular distributions for the 99;101Ru(d, d') reactions at 13 MeV were obtained in the Pelletron Laboratory using nuclear emulsion plates on the focal plane of the Enge spectrograph. A Coulomb-Nuclar Interference analysis employing DWBA-DOMP predictions with global optical potential parameters was applied to the excitation of states which could belong to the multiplet built on the first quadrupolar excitation of the core. In the analysis, three states were identified for each of the isotopes and associated, respectively, with adopted levels in the Nuclear Data Sheets Compilation of Jpi= 5=2+, 7=2+ and 9=2+. Through the comparison of experimental and predicted cross section angular distributions, the values of ()² and of the ratio C = / were obtained.