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A large volume NaI detector was used to lodge inside of a cylindrical opening, targets, subsequently bombarded by beams of the 9MV Tandem of IFIN-HH. The gamma response of the spectrometer allows in many cases to determine the total reaction cross section and even its parts due to inelastic scattering and fusion. Excitation functions have been measured for reactions induced by protons, alpha particles and 6Li ions on a several different targets up from near barrier energies. The device has potential for in beam measurements at (deep) below barrier energies. [ABSTRACT FROM AUTHOR]

High precision neutron inelastic scattering cross section data are very important for the development of the new generation of nuclear reactors (Gen IV). Our experiments, performed using the GELINA neutron source and the GAINS spectrometer of the European Commission Joint Research Center, Geel, produce highly reliable and precise cross section data. We will present the details of the setup and the data analysis technique allowing production of such unique results, and we will show examples of two experimental results. [ABSTRACT FROM AUTHOR]

The results of the IS530 experiment at ISOLDE revealed new information concerning several nuclei close to the N ≈ 20 'Island of Inversion' - 34Mg, 34Al, 34Si. The half-life of 34Mg was found to be three times larger than the adopted value (63(1) ms instead of 20(10) ms). The beta-gamma spectroscopy of 34Mg performed for the first time in this experiment, led to the first experimental level scheme for 34Al, also showing that the full beta strength goes through the predicted 1+ isomer in 34Al [1] and/or excited states that deexcite to it. The subsequent beta-decay of the 1+ isomer in 34Al allowed the observation of new gamma lines in 34Si, (tentatively) associated with low-spin high-energy excited states previously unobserved. [ABSTRACT FROM AUTHOR]

It is well known that the nuclear shell structure changes for the most exotic nuclei. One of theconsequences of this phenomenon is the modification of the "classical" magic numbers, as experimentally observed at N = 20 and N = 28. Nevertheless, the mechanisms responsible for such changesare still under discussion and more experimental information is needed to better constrain the theoretical models. In these proceedings, we report on the discovery and the experimental study by precise spectroscopy experiments of the 02+ state in 34Si and 44S. The 34Si is located between the magic spherical 36S the deformed 32Mg, member of the so-called island of inversion, whereas 44S is located between the magic spherical 48Ca and the deformed 42Si. Therefore, the structure of these nuclei, and in particular the phenomenon of shape coexistence, is of crucial importance to understand how the intruder configurations progressively dominate the ground state structure of the most exotic nuclei at both N = 20 and N = 28. [ABSTRACT FROM AUTHOR]

The two-proton radioactivity has been evidenced experimentally in 2002 in the ground-state decay of 45Fe, while this new decay mode was predicted since the 60's. The first observations have been done indirectly, from various global quantities measured in the decay process (half-file, Q-value, daughter decay,...). Since then, new devices have been developed in order to perform energy and angular measurements of the emitted particles. The comparison of full experimental observations with theoretical models opens a new access to nuclear structure a the drip-line. [ABSTRACT FROM AUTHOR]

The 'Neutrons for Science' (NFS) facility will be a component of SPIRAL-2, the future accelerator dedicated to the production of very intense radioactive ion beams, under construction at GANIL in Caen (France). NFS will be composed of a pulsed neutron beam for in-flight measurements and irradiation stations for cross-section measurements and material studies. Continuous and quasi-monokinetic energy spectra will be available at NFS respectively produced by the interaction of deuteron beam on thick a Be converter and by the 7Li(p,n) reaction on a thin converter. The flux at NFS will be up to 2 orders of magnitude higher than those of other existing time-of-flight facilities in the 1 MeV to 40 MeV range. NFS will be a very powerful tool for physics and fundamental research as well as applications like the transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. [ABSTRACT FROM AUTHOR]

Studies of β-delayed emission of protons for 43Cr and 51Ni were performed with a Time Projection Chamber. This detection setup allows to reconstruct in the three-dimensional space the tracks of the protons emitted. For the first time, β-delayed emission of two protons is directly observed for 43Cr and 51Ni. The question about correlations between protons can be accessed. Finally, we show that 43Cr can emit up to three delayed protons. [ABSTRACT FROM AUTHOR]

After the discovery of two-proton radioactivity in 2002, an important effort has been made in order to observe each emitted particle individually. Energy and angular correlations between the protons should reveal details about the mechanism of this exotic decay mode. In this framework, an experiment has been performed at LISE/GANIL, where the two protons emitted in the decay of 54Zn have been individually observed for the first time. Angular and energy correlations were determined and allowed a first comparison with theoretical predictions. [ABSTRACT FROM AUTHOR]

Two-proton radioactivity is an exotic decay mode for very proton-rich nuclei. It was observed experimentally for the first time in 2002 for the nucleus 45Fe but the two protons could not be directly detected. So a new detector has been developed, a Time Projection Chamber, to individually observe the two protons emitted. It was used successfully during two experiments for the study of 45Fe and 54Zn. Energy correlations have been studied and the relative angle between the two protons is calculated. [ABSTRACT FROM AUTHOR]

In the present paper, we present measurements that led to the discovery of two-proton radioactivity. After the first observation of this decay mode for 45Fe, new measurements evidenced this decay mode also for 54Zn and most likely 48Ni. A new detector based on the time-projection chamber principle allowed now to visualize the two protons directly. [ABSTRACT FROM AUTHOR]

After the recent discovery of two-proton radioactivity, an important effort has been made in order to observe each emitted particle individually. Such kind of studies may result in energy and angular correlation measurements of the protons, which are required to give a precise theoretical description of this exotic decay mode. In this frame, we performed an experiment at the GANIL/SISSI/LISE3 facility, where we used a Time Projection Chamber to observe tracks of protons in the decay of 45Fe, produced in projectile fragmentation reactions. [ABSTRACT FROM AUTHOR]

An experimental spectroscopic investigation of some neutron rich Mg and Al isotopes around the shell closure N=20 has been performed. The delayed neutron and γ spectra, following the β-decay of 33Mg and 35Al have been measured using the delayed neutron detector array TONNERRE coupled with high efficiency EXOGAM clover detectors, a LEPS detector and eight low-energy neutron detectors. A detailed analysis of such spectra allows one to construct the level schemes of their daughters, 32,33Al and 34,35Si. The resulting spectroscopic information will provide stringent tests of large scale shell model calculations including np - nh excitations aimed at the understanding of the structural effects occurring in this region. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The interest in 209Bi, the only stable isotope of this element, originates from its proposed use in the spallation module and as moderator/coolant of an accelerator driven system (ADS). Inelastic scattering that constitutes 30% of the total neutron cross section of 209Bi is a major contributor to uncertainties in predicted ADS parameters. New data were obtained for production cross sections of 19 transitions up to about 18 MeV, incident energy. One transition was observed per excited level for the first 8 levels. From the measured gamma-ray production cross sections, total and level inelastic cross sections were deduced. The experiment was performed at GELINA, with a white neutron spectrum, at 200 m flight path length using the time-of-flight method. The gamma rays from the 209Bi(n,n′γ)209Bi reaction were detected with two large volume HPGe detectors and the neutron flux was monitored with a multilayer 235U fission chamber. For the main transitions the inelastic cross section is given with an incident neutron energy resolution ranging from 1.1 keV at 1 MeV to 35.7 keV at 10 MeV within overall statistical error of less than 5%. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The nuclear reactions 207Pb(n,2n)206Pb and 232Th(n,5n)228Th were studied by measuring prompt gamma-ray emission spectra from the interaction of neutrons with an enriched 207Pb sample and a natTh sample. For 207Pb the measurements were performed at the white neutron beam of the GELINA neutron source at IRMM Geel in the neutron energy range up to 20 MeV. The Th measurements were done at the quasi-monoenergetic 7Li(p,n)7Be neutron source at the Université Catholique de Louvain for five peak neutron energies in the range 29 MeV to 42 MeV. The measurements were complemented by model calculations using the code system EMPIRE-II. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Shape coexistence in the light krypton isotopes was studied in a series of experiments at GANIL using various experimental techniques. A new low-lying 0+ state, a so-called shape isomer, was found in delayed conversion-electron spectroscopy after fragmentation reactions. The systematics of such low-lying 0+ states suggests that the ground states of the isotopes 78Kr and 76Kr have prolate deformation, while states with prolate and oblate shape are practically degenerate and strongly mixed in 74Kr, and that the oblate configuration becomes the ground state in 72Kr. This scenario was tested in experiments performing low-energy Coulomb excitation of radioactive 76Kr and 74Kr beams from the SPIRAL facility. Both transitional and diagonal electromagnetic matrix elements were extracted from the observed γ-ray yields. The results find the prolate shape for the ground-state bands in 76Kr and 74Kr and an oblate deformation for the excited 22+ state in 74Kr, confirming the proposed scenario of shape coexistence. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

In-beam gamma-spectroscopy using fragmentation reactions of both stable and radioactive beams have been performed in order to study the structure of excited states in the neutron-rich 18,20C, 21–24O and 23,25F isotopes. For the produced fragments, γ-ray energies, intensities and γγ coincidences have been measured. Based on this information new level schemes are proposed up to the neutron separation energy for some of these isotopes. The systematics of the 2+ energy has been extended up to 20C in the C isotopic chain. Level schemes are suggested for 21O and 22O. The non observation of any γ-ray from 23O and 24O suggests that their excited states lie above the neutron decay thresholds. The study of F isotopes provides hint of the possible change in nuclear structure between the F and O isotopic chains. These results, together with the size of the N=14 and N=16 shell gaps in C,O,F isotopes are discussed in the framework of shell model calculations. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

According to most mass models, several of the best candidates for two-proton radioactivity lie in the A = 50 mass region, at the proton drip-line. Recent experiments using the fragmentation of a 58Ni beam allowed us to reach this region and observe some of these candidates, like 45Fe and 48Ni. During an experiment at the GANIL / LISE3 facility helded in 2000, we could identify 22 events of implantation of 45Fe nuclei. The energy distribution of the corresponding decay events shows a clear peak at (1.14 ± 0.04) MeV that could be assigned to the direct 2-proton emission from the ground state. This energy is in very good agreement with several theoretical predictions, and no coincident β particle has been observed experimentally. A half-life of (4.7[sub -1.4][sup +3.4]) ms has been measured for the decay of 45Fe. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

In experiments at the FRS of GSI and at the SISSI-LISE3 facility of GANIL, the decay of the proton drip-line nucleus [sup 45]Fe has been studied after projectile fragmentation of a [sup 58]Ni primary beam. Fragment-implantation events have been correlated with radioactive decay events in silicon telescopes on an event-by-event basis. The decay-energy spectrum of [sup 45]Fe implants shows a distinct peak consistent with a two-proton ground-state decay of [sup 45]Fe. None of the events in the peak were found to be in coincidence with γ radiation or with β particles which were searched for in the telescope-surrounding detectors. The decay energy for [sup 45]Fe agrees nicely with several theoretical predictions for two-proton emission. These predictions strongly support the observed decay to be a simultaneous two-proton ground-state decay. [ABSTRACT FROM AUTHOR]

We report on the first application of the TDPAD method to measure the g factor of neutron-rich isomeric states, produced and aligned in a projectile fragmentation reaction. The feasibility of similar measurement opens up a new, unexplored region of the nuclear chart for studies of the magnetic moments of microsecond isomers. Nuclei around [sup 68]Ni were produced following the fragmentation of 61.6 MeV/u [sup 76]Ge on a 145 mg/cm² Be target. The isotopes of interest were selected using the LISE spectrometer at GANIL, Caen, France, and were implanted in a high purity Cu foil fixed between the poles of an electromagnet. Two Ge Clover detectors, positioned in a plane perpendicular to the holding magnetic field, were used to observe the rotation of the nuclear spin ensemble and to derive the experimental R(t) function. The experimental result for the isomer in [sup 67]Ni (Jπ = 9/2[sup +], T[sub ½] = 13.3 µs, E[sub x] = 1007 keV), g = 0.125(6), is presented herein and is also compared to the theoretical expectations. [ABSTRACT FROM AUTHOR]

Carbon and oxygen isotopes very close to the neutron drip-line have been studied using in beam gamma spectroscopy with fragmentation reactions of radioactive secondary beams. No γ-ray transitions have been observed in both [sup 23]O and [sup 24]O suggesting that probably only the ground state of these two oxygen isotopes is bound with respect to particle emission. In the case of [sup 19]C and [sup 20]C only a single line has been observed in each of the corresponding γ-ray spectra. The interpretation of the results is made by comparison to shell model calculations. [ABSTRACT FROM AUTHOR]

A new high-flux spallation neutron source, the neutron Time-Of-Flight facility (nTOF), recently became operational at CERN. The neutron energy ranges from the thermal to the GeV range. Performance results from the commissioning are reported. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The MISTRAL experiment (Mass measurements at ISOLDE/CERN with a Transmission and Radiofrequency spectrometer on-Line), is well suited for mass determination of very short-lived nuclides. Masses are determined by measuring the cyclotron frequency of an ion in a homogeneous magnetic field. This technique is rapid, and capable of very high resolving power (m/Δm∼10[sup 5]). Results have been obtained in conformity with all aspects of the projected spectrometer performance: masses of nuclides with half-lives as short as 30 ms have been measured and accuracies of ∼5×10[sup -7] have been achieved. Masses of several nuclides have been significantly improved. The [sup 30]Na and [sup 32]Mg results show an overbinding compared to previous measurements, indicating enhanced deformation, where N=20 magicity was expected. Recently the N=Z nuclide [sup 74]Rb has been measured. This mass will allow to study the Wigner energy. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The doubly magic nucleus [sup48]Ni has been observed for the first time at GANIL. The experiment was performed using a high intensity [sup58]Ni beam at 74.5 MeV/A on a nickel target. This T[subZ] = −4 nucleus is the most proton-rich nucleus ever observed, and is a good candidate for two-proton radioactivity. In this experiment, we also implanted around 280 [sup42]Cr, 50 [sup45]Fe and 100 [sup49]Ni isotopes, for which no experimental information about the decay is available [ABSTRACT FROM AUTHOR]

An island of isomers have recently been observed on both sides of the N=40 shell below the Ni isotopes. Isomeric states in the 65Fe and 67Fe allow the knowledge of the single particle structure around the νg9/2 shell. Moreover, the excitation energy of the first 2+ and 4+ states in the 68Fe have been established by β-γ correlation. The evolution of the structure of the Fe isotopes going far away from the valley of stability is, for the first time, given for N>40. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

207Pb(n,2nγ)206Pb cross section were measured for incident neutron energies between 6 and 20 MeV with the white neutron beam produced at GELINA. The γ-ray production cross section for the main transition (803 keV, 2+→ 0+) in 206Pb is compared to results obtained at Los Alamos and to the TALYS and EMPIRE-II code predictions. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]