Papers by Fabiana Gramegna
European Journal of Nuclear Medicine and Molecular Imaging, Jun 27, 2023
Recent Results at nlTOF and Future Perspectives
Acta Physica Polonica B Proceedings Supplement, 2013
Isospin transport phenomena in dissipative heavy ion collisions have been investigated at Fermi e... more Isospin transport phenomena in dissipative heavy ion collisions have been investigated at Fermi energies with a beam of 84 Kr at 35AMeV. A comparison of the N /Z of light and medium products forward-emitted in the centre of mass frame when the beam impinges on two different targets, the n-poor 112 Sn and the n-rich 124 Sn, is presented. Data were collected by means of a three-layer telescope with very good performances in terms of mass identification (full isotopic resolution up to Z ∼ 20 for ions punching through the first detector layer) built by the FAZIA Collaboration and located just beyond the grazing angle for both reactions. The N /Z of the products detected when the n-rich target is used is always higher than that associated to the n-poor one; since the detector was able to measure only fragments coming from the QuasiProjectile decay and/or neck emission, the observed behaviour can be ascribed to the isospin diffusion process, driven by the isospin gradient between QuasiProjectile and QuasiTarget. Moreover, for light fragments the N /Z as a function of the lab velocity of the fragment is observed to increase when we move from the QuasiProjectile velocity to the centre of mass (neck zone). This effect can be interpreted as an evidence of isospin drift driven by the density gradient between the QuasiProjectile zone (at normal density) and the more diluted neck zone.
Measurement of neutron capture cross-section of indium in the energy region from 0.003 eV to 30 keV
Annals of Nuclear Energy, 2002
The neutron capture cross-section of indium (In) has been measured in the energy region from 0.00... more The neutron capture cross-section of indium (In) has been measured in the energy region from 0.003 eV to 30 keV by the neutron time-of-flight (TOF) method with a 46-MeV electron linear accelerator (linac) of the Research Reactor Institute, Kyoto University. An assembly of Bi4Ge3O12 (BGO) scintillators, which was composed of 12 pieces of BGO and placed at a distance of
The European Physical Journal Special Topics, 2007
A possible solution for a target system aimed at the production of exotic nuclei as a result of h... more A possible solution for a target system aimed at the production of exotic nuclei as a result of high energy fissions in 238 U compounds has been analyzed. The proposed configuration is constituted by a primary proton beam (40 MeV, 0.2 mA) directly impinging on a UC x multiple disc target inserted within a cylindrical carbon box. In order to extract the fission fragments, the box has to be hold at 2000°C. This system has been conceived to obtain both a high number of neutron rich atoms (about 1•10 13 fissions/s) and a quite low power deposition in the target. The thermal and thermo-mechanical analysis of the proposed configuration shows the capability of the thermal radiation to cool the discs with a reasonable margin below the material melting point. Moreover, the possibility of increasing such margin with simple modifications of the target design is shown by means of parametric analyses.. Preliminary calculations of the target induced activity, and the atoms effusion inside the target container, have also been performed.
EPJ Web of Conferences, 2019
The 32S(3He,d)33Cl one-proton transfer reaction is a powerful tool to investigate the spectroscop... more The 32S(3He,d)33Cl one-proton transfer reaction is a powerful tool to investigate the spectroscopy of low-lying states in the proton-rich 33Cl nucleus. However, the extraction of firm differential cross-section data at various angles to benchmark and constrain theoretical models is made challenging by the presence of competitive reactions on target contaminants. In this paper we report on arecent measurement using a new generation hodoscope of silicon detectors, capable to detect and identify emitted deuterons down to energies of the order of 2 MeV. The high angular segmentation of our hodoscope combined with a suitable target to control possible contaminants, allowed to unambiguously disentangle the contribution of various states in 33Cl, in particular the 2.352 MeV state lying just few tens of keV above the proton separation energy.
The SPES Project at LNL
AIP Conference Proceedings, 2009
SPES (Selective Production of Exotic Species) is an INFN project to develop a Radioactive Ion Bea... more SPES (Selective Production of Exotic Species) is an INFN project to develop a Radioactive Ion Beam (RIB) facility as an intermediate step toward EURISOL. The key feature of SPES is to provide high intensity and high-quality beams of neutron rich nuclei to perform forefront research in nuclear structure, reaction dynamics and interdisciplinary fields like medical, biological and material sciences. The exotic isotopes will be reaccelerated by the ALPI Superconducting Linac at energies of 11 AMeV for masses in the region of A=130 amu with an expected rate on target of 109 pps. This represent a substantial improvement to the actual available ISOL facilities both from the point of view of intensity and energy of the exotic beam.
Improved accuracy (N,gamma) measurements at n_TOF
... Bustreo, N.; Calvino, F.; Cano-Ott, D.; Capote, R.; Carlson, P.; Cennini, P.; Chepel, V.; Chi... more ... Bustreo, N.; Calvino, F.; Cano-Ott, D.; Capote, R.; Carlson, P.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Cortina ... Affiliation: AA(Instituto Nazionale di Fisica Nuclear-Trieste, Italy), AB(CEA/Saclay - DSM, Gif-sur-Yvette, France), AC(Universidade de Santiago de ...
Hybrid detectors of neutrons based on 3D silicon sensors with PolySiloxane converter
We report on the first prototypes of hybrid detectors for neutrons from the INFN HYDE project. De... more We report on the first prototypes of hybrid detectors for neutrons from the INFN HYDE project. Devices consist of 3D silicon sensors coupled to PolySiloxane-based converters. The sensor design and fabrication technology are presented, along with initial results from the functional characterization of the devices in response to radioactive sources and neutron beams of different energies.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
A Micromegas detector was used in the neutron Time-Of-Flight ðn TOFÞ facility at CERN to evaluate... more A Micromegas detector was used in the neutron Time-Of-Flight ðn TOFÞ facility at CERN to evaluate the spatial distribution of the neutron beam as a function of its kinetic energy. This was achieved over a large range of neutron energies by using two complementary processes: at low energy by capture of a neutron via the 6 Liðn; aÞt reaction, and at high energy by elastic scattering of neutrons on gas nuclei (argon+isobutane or helium+isobutane). Data are compared to Monte Carlo simulations and an analytic function fitting the beam profile has been calculated with a sufficient precision to use in neutron capture experiments at the n TOF facility.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2004
The accurate determination of neutron cross-sections as a function of the neutron energy at a tim... more The accurate determination of neutron cross-sections as a function of the neutron energy at a time-of-flight facility requires a precise knowledge of the time-energy relation for the neutron beam. For the n TOF neutron beam at CERN, produced by spallation of high-energy protons on a Pb target, the time-energy relation is connected to the production mechanism and to the subsequent moderation process. A calibration of the neutron energy scale is proposed based on detailed Monte Carlo simulations of the facility. This time-energy relation has been experimentally validated by means of dedicated measurements of standard energy resonances, from 1 eV to approximately 1 MeV. On the basis of the present measurements, it is proposed to correct the energy of the 1.3 eV resonance of 193 Ir, which is commonly considered as an energy standard.
Multifragmentation in EA=35 MeV Collisions: Evidence for a Coulomb Driven Breakup?
Physical Review Letters, 1996
... D. 0. Handzy,6 WC Hsi,6 M. Huang ,6 MA Lisa6* WG Lynch,6 PF Mastinu,2 CP Montoya,6t A. Moroni... more ... D. 0. Handzy,6 WC Hsi,6 M. Huang ,6 MA Lisa6* WG Lynch,6 PF Mastinu,2 CP Montoya,6t A. Moroni,4 GF Peaslee,6 t L. Phair,6 * R. Rui, C. Schwarz,6&amp;#x27;§ MB Tsang,6 G ... PACS numbers: 25.70.Pq, 25.70.Gh Very highly charged nuclear systems are fundamen-tally unstable. ...
Physical Review C, 2007
The (n, γ) cross section of 206 Pb has been measured at the CERN n TOF facility with high resolut... more The (n, γ) cross section of 206 Pb has been measured at the CERN n TOF facility with high resolution in the energy range from 1 eV to 620 keV by using two optimized C6D6 detectors. In the investigated energy interval about 130 resonances could be observed, from which 61 had enough statistics to be reliably analyzed via the R-matrix analysis code SAMMY. Experimental uncertainties were minimized, in particular with respect to (i) angular distribution effects of the prompt capture γ-rays, and to (ii) the TOF-dependent background due to sample-scattered neutrons. Other background components were addressed by background measurements with an enriched 208 Pb sample. The effect of the lower energy cutoff in the pulse height spectra of the C6D6 detectors was carefully corrected via Monte Carlo simulations. Compared to previous 206 Pb values, the Maxwellian averaged capture cross sections derived from these data are about 20% and 9% lower at thermal energies of 5 keV and 30 keV, respectively. These new results have a direct impact on the s-process abundance of 206 Pb, which represents an important test for the interpretation of the cosmic clock based on the decay of 238 U.
Physical Review C, 2006
The neutron capture cross section of 209 Bi has been measured at the CERN n TOF facility by emplo... more The neutron capture cross section of 209 Bi has been measured at the CERN n TOF facility by employing the pulse-height-weighting technique. Improvements over previous measurements are mainly because of an optimized detection system, which led to a practically negligible neutron sensitivity. Additional experimental sources of systematic error, such as the electronic threshold in the detectors, summing of γ-rays, internal electron conversion, and the isomeric state in bismuth, have been taken into account. γ-Ray absorption effects inside the sample have been corrected by employing a nonpolynomial weighting function. Because 209 Bi is the last stable isotope in the reaction path of the stellar s-process, the Maxwellian averaged capture cross section is important for the recycling of the reaction flow by α decays. In the relevant stellar range of thermal energies between kT = 5 and 8 keV our new capture rate is about 16% higher than the presently accepted value used for nucleosynthesis calculations. At this low temperature an important part of the heavy Pb-Bi isotopes are supposed to be synthesized by the s-process in the He shells of low mass, thermally pulsing asymptotic giant branch stars. With the improved set of cross sections we obtain an s-process fraction of 19±3% of the solar bismuth abundance, resulting in an r-process residual of 81±3%. The present (n, γ) cross-section measurement is also of relevance for the design of accelerator driven systems based on a liquid metal Pb/Bi spallation target.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1993
To investigate complex fragment emission in intermediate energy nucleus-nucleus collisions, an ar... more To investigate complex fragment emission in intermediate energy nucleus-nucleus collisions, an array of three-element telescopes has been constructed. The array is designed to measure energy, charge and emission angles of fragments with Z values from 2 up to the projectile atomic number when studying reactions in reverse kinematics. In this case it has a good efficiency even for events with complex fragment high multiplicity. Each telescope is made of an ionization chamber (filled with CF4 at a pressure up to 300 mbar), a Si detector (500 wm thick, position sensitive in two dimensions) and a CsI(Tl) scintillator with photodiode readout.
Journal of Physics: Conference Series, 2006
A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative feature... more A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed.
Applied Radiation and Isotopes, 2010
Neutrino oscillations have implications for the Standard Model of particle physics. The CERN Beta... more Neutrino oscillations have implications for the Standard Model of particle physics. The CERN Beta Beam has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration EUROnu (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance,
Nuovo Cimento C Geophysics Space Physics C, Sep 1, 2019
Постановка проблеми. Кримінальний процесуальний закон містить різні положення, які формально регл... more Постановка проблеми. Кримінальний процесуальний закон містить різні положення, які формально регламентують і регулюють діяльність слідчого, прокурора, слідчого судді та суду на різних стадіях кримінального провадження. У такому разі зацікавленість викликає стадія досудового розслідування. Саме на цій стадії проводяться слідчі (розшукові) дії (далі -СРД) та негласні слідчі (розшукові) дії (далі -НСРД), які згідно з ч. 1 ст. 246 є різновидом слідчих (розшукових) дій. Особливістю зазначеного різновиду СРД, відповідно до ст. 246 Кримінально-процесуального кодексу (далі -КПК), є те, що: по-перше, відомості про факт і методи проведення НСРД не підлягають розголошенню; по-друге, НСРД проводять у випадках, якщо відомості про злочин та особу, яка його скоїла, неможливо отримати в інший
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Papers by Fabiana Gramegna