Yazar "Recchia, F." seçeneğine göre listele
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Öğe Electromagnetic transition strengths in S-33(IOP Publishing Ltd, 2014) Dimitrov, B. I.; Goutev, N.; Gavrilov, G. Tz.; Tonev, D.; Petkov, P.; de Angelis, G.; Recchia, F.; Aydın, S.An experiment using the Doppler Shift Attenuation Method was performed for S-33 at Laboratori Nazionali di Legnaro using the multi-detector array GASP. Excited states were populated in the fusion-evaporation reaction Mg-24(N-14, alpha p)(33) S. The data were analyzed using the Differential Decay Curve Method with gates set on the shifted component of a directly feeding transition thus eliminating the problem of the unobserved feeding. Reliable and precise lifetimes were determined and the data derived for the reduced transition probabilities are going to be compared to the predictions of shell model calculations.Öğe First measurement of the g factor in the chiral band: The case of the Cs-128 Isomeric state(American Physical Society, 2018) Grodner, E.; Srebrny, J.; Droste, Ch.; Prochniak, L.; Rohozinski, S. G.; Kowalczyk, M.; Ionescu-Bujor, M.; Ur, C. A.; Starosta, K.; Ahn, T.; Kisielinski, M.; Marchlewski, T.; Aydın, S.; Recchia, F.; Georgiev, G.; Lozeva, R.; Fiori, E.; Zielinska, M.; Chen, Q. B.; Zhang, S. Q.; Yu, L. F.; Zhao, P. W.; Meng, J.The g factor of the 56 ns half-life isomeric state in Cs-128 has been measured using the time-differential perturbed angular distribution method. This state is the bandhead of the positive-parity chiral rotational band, which emerges when an unpaired proton, an unpaired neutron hole, and an even-even core are coupled such that their angular momentum vectors are aplanar (chiral configuration). g-factor measurements can give important information on the relative orientation of the three angular momentum vectors. The measured g factor g = +0.59(1) shows that there is an important contribution of the core rotation in the total angular momentum of the isomeric state. Moreover, a quantitative theoretical analysis supports the conclusion that the three angular momentum vectors lie almost in one plane, which suggests that the chiral configuration in Cs-128 demonstrated in previous works by characteristic patterns of electromagnetic transitions appears only above some value of the total nuclear spin.Öğe High-Spin Structure in K-40(American Physical Society, 2012) Soderstrom, P. -A.; Recchia, F.; Nyberg, J.; Gadea, A.; Lenzi, S. M.; Poves, A.; Atac, A.; Aydın, Sezgin; Bazzacco, D.; Bednarczyk, P.; Bellato, M.; Birkenbach, B.; Bortolato, D.; Boston, A. J.; Boston, H. C.; Bruyneel, B.; Bucurescu, D.; Calore, E.; Cederwall, B.; Charles, L.; Chavas, J.; Colosimo, S.; Crespi, F. C. L.; Cullen, D. M.; de Angelis, G.; Desesquelles, P.; Dosme, N.; Duchene, G.; Eberth, J.; Farnea, E.; Filmer, F.; Gorgen, A.; Gottardo, A.; Grebosz, J.; Gulmini, M.; Hess, H.; Hughes, T. A.; Jaworski, G.; Jolie, J.; Joshi, P.; Judson, D. S.; Jungclaus, A.; Karkour, N.; Karolak, M.; Kempley, R. S.; Khaplanov, A.; Korten, W.; Ljungvall, J.; Lunardi, S.; Maj, A.; Maron, G.; Meczynski, W.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Molini, P.; Napoli, D. R.; Nolan, P. J.; Norman, M.; Obertelli, A.; Podolyak, Zs.; Pullia, A.; Quintana, B.; Redon, N.; Regan, P. H.; Reiter, P.; Robinson, A. P.; Sahin, E.; Simpson, J.; Salsac, M. D.; Smith, J. F.; Stezowski, O.; Theisen, Ch.; Tonev, D.; Unsworth, C.; Ur, C. A.; Valiente-Dobon, J. J.; Wiens, A.High-spin states of K-40 have been populated in the fusion-evaporation reaction C-12(Si-30,np)K-40 and studied by means of gamma-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10(-) have been discovered. These states are discussed in terms of J = 3 and T = 0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum.Öğe High-spin structure in K-40(APS Physics, 2012) Aydın, Sezgin; Soderstrom, P. A.; Recchia, F.; Nyberg, J.; Gadea, A.; Lenzi, S. M.; Poves, A.; Atac, A.; Bazzacco, D.High-spin states of K-40 have been populated in the fusion-evaporation reaction C-12(Si-30,np)K-40 and studied by means of gamma-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10(-) have been discovered. These states are discussed in terms of J = 3 and T = 0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum.Öğe Interaction position resolution simulations and in-beam measurements of the AGATA HPGe detectors(Elsevier, 2011) Soderstrom, P. -A.; Recchia, F.; Nyberg, J.; Al-Adili, A.; Ataç, A.; Aydın, S.; Bazzacco, D.; Bednarczyk, P.; Birkenbach, B.; Bortolato, D.; Boston, A. J.; Boston, H. C.; Bruyneel, B.; Bucurescu, D.; Calore, E.; Colosimo, S.; Crespi, F. C. L.; Dosme, N.; Eberth, J.; Farnea, E.; Filmer, F.; Gadea, A.; Gottardo, A.; Grave, X.; Grebosz, J.; Griffiths, R.; Gulmini, M.; Habermann, T.; Hess, H.; Jaworski, G.; Jones, P.; Joshi, P.; Judson, D. S.; Kempley, R.; Khaplanov, A.; Legay, E.; Lersch, D.; Ljungvall, J.; Lopez-Martens, A.; Meczynski, W.; Mengoni, D.; Michelagnoli, C.; Molini, P.; Napoli, D. R.; Orlandi, R.; Pascovici, G.; Pullia, A.; Reiter, P.; Sahin, E.; Smith, J. F.; Strachan, J.; Tonev, D.; Unsworth, C.; Ur, C. A.; Valiente-Dobon, J. J.; Veyssiere, C.; Wiens, A.The interaction position resolution of the segmented HPGe detectors of an AGATA triple cluster detector has been studied through Monte Carlo simulations and in an in-beam experiment. A new method based on measuring the energy resolution of Doppler-corrected gamma-ray spectra at two different target to detector distances is described. This gives the two-dimensional position resolution in the plane perpendicular to the direction of the emitted gamma-ray. The gamma-ray tracking was used to determine the full energy of the gamma-rays and the first interaction point, which is needed for the Doppler correction. Five different heavy-ion induced fusion-evaporation reactions and a reference reaction were selected for the simulations. The results of the simulations show that the method works very well and gives a systematic deviation of <1 mm in the FVVHM of the interaction position resolution for the gamma-ray energy range from 60 keV to 5 MeV. The method was tested with real data from an in-beam measurement using a (30)5i beam at 64 MeV on a thin (12)C target. Pulse-shape analysis of the digitized detector waveforms and gamma-ray tracking was performed to determine the position of the first interaction point, which was used for the Doppler corrections. Results of the dependency of the interaction position resolution on the gamma-ray energy and on the energy, axial location and type of the first interaction point, are presented. The FVVHM of the interaction position resolution varies roughly linearly as a function of gamma-ray energy from 8.5 mm at 250 key to 4 mm at 1.5 MeV, and has an approximately constant value of about 4 mm in the gamma-ray energy range from 1.5 to 4 MeV. (C) 2011 Elsevier B.V. All rights reserved.Öğe Isospin dependence of electromagnetic transition strengths among an isobaric triplet(Elsevier, 2019) Boso, A.; Milne, S. A.; Bentley, M. A.; Recchia, F.; Lenzi, S. M.; Rudolph, D.; Labiche, M.; Aydın, SezginElectric quadrupole matrix elements, Mp, for the J? = 2+ ? 0+, T = 0, T = 1 transitions across the A = 46 isobaric multiplet 46Cr-46V-46Ti have been measured at GSI with the FRS-LYCCA-AGATA setup. This allows direct insight into the isospin purity of the states of interest by testing the linearity of Mp with respect to Tz . Pairs of nuclei in the T = 1 triplet were studied using identical reaction mechanisms in order to control systematic errors. The Mp values were obtained with two different methodologies: (i) a relativistic Coulomb excitation experiment was performed for 46Cr and 46Ti; (ii) a “stretched target” technique was adopted here, for the first time, for lifetime measurements in 46V and 46Ti. A constant value of Mp across the triplet has been observed. Shell-model calculations performed within the f p shell fail to reproduce this unexpected trend, pointing towards the need of a wider valence space. This result is confirmed by the good agreement with experimental data achieved with an interaction which allows excitations from the underlying sd shell. A test of the linearity rule for all published data on complete T = 1 isospin triplets is presented.Öğe Isospin symmetry breaking in mirror nuclei 23mg-23Na(Jagiellonian University Press, 2017) Boso, A.; Lenzi, S. M.; Recchia, F.; Bonnard, J.; Aydin, S.; Bentley, M. A.; Cederwall, B.; Clement, E.; De France, G.; Di Nitto, A.; Dijon, A.; Doncel, M.; Ghazi-Moradi, F.; Gottardo, A.; Henry, T.; Huyuk, T.; Jaworski, G.; John, P. R.; Juhasz, K.; Kuti, I.; Melon, B.; Mengoni, D.; Michelagnoli, C.; Modamio, V.; Napoli, D. R.; Nyako, B. M.; Nyberg, J.; Palacz, M.; Valiente-Dobon, J. J.Mirror energy differences (MED) are a direct consequence of isospin symmetry breaking. Moreover, the study of MED has proved to give valuable information of several nuclear structure properties. We present the results of an experiment performed in GANIL to study the MED in mirror nuclei Mg-23-Na-23 up to high spin. The experimental values are compared with state-of-the-art shell model calculations. This permits to enlighten several nuclear structure properties, such as the way in which the nucleons alignment proceeds, the radius variation with J, the role of the spin-orbit interaction and the importance of isospin symmetry breaking terms of nuclear origin.Öğe Performance of an AGATA prototype detector estimated by Compton-imaging techniques(Elsevier, 2009) Recchia, F.; Bazzacco, D.; Farnea, E.; Venturelli, R.; Aydın, Sezgin; Suliman, G.; Ur, C. A.The imaging capabilities of an AGATA detector have been determined experimentally. Fundamental information on the detector performance can be obtained by a back-projection of the events consisting in a Compton scattering and a subsequent photoelectric absorption. The procedure presented will allow to obtain a feedback on the over-all position resolution of tracking detectors with a high energy resolution. Thanks to its simplicity the method will be used to guarantee the maximal operational performance of tracking arrays such as AGATA. (C) 2009 Elsevier B.V. All rights reserved.Öğe Spectroscopy of neutron-rich Fe isotopes populated in the 70Zn+238U reaction(Jagiellonian University, 2024) Bazzacco, D.; Lenzi, S.M.; Recchia, F.; Axiotis, M.; Aydın, S.; Benito, J.; Benzoni, G; Bizzeti, P.G.; Bizzeti-Sona, A.M.; Bracco, A.; Broda, R.; Bucurescu, D.The excited states of neutron-rich Fe isotopes have been studied through a multinucleon transfer reaction of a 70Zn beam on a 238U target. Unambiguous identification of prompt ? rays belonging to each nucleus was performed by coincidence detection of the ions in a high-acceptance magnetic spectrometer. The observed spectra are compared with large-scale shell-model calculations in the fpgd model space.
