Measurements of projectile fragments from 70 Zn (15 MeV/nucleon) + 64 Ni collisions with the MAGNEX spectrometer at INFN-LNS

The present work is focused on our efforts to produce and identify neutron-richrare isotopes from peripheral reactions below the Fermi energy. High-quality experimental data were obtained from a recent experiment with the MAGNEX spectrometer at INFN-LNS in Catania, Italy. The main goal of this effort is to describe the adopted identification techniques used to analyze the data from the reaction 70 Zn (15 MeV/nucleon) + 64 Ni. The particle identification procedure is based on a novel approach that involves the reconstruction of both the atomic number Z and the ionic charge q of the ions, followed by the identification of themass. Our method was successfully applied to identify neutron-rich ejectiles from multinucleon transfer in the above reaction 70 Zn + 64 Ni at 15 MeV/nucleon. The analysis of the data is ongoing. We expect to obtain the angular and momentum distributions of the fragments, along with their production cross sections. These data, along with comparisons with theoretical models are expected to contribute to a better understanding of the complex reaction mechanisms of multinucleon transfer that dominate this energy regime

Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

Abstract. The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay halflife. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported and the experimental challenges characterizing such activity are describe

Study of the 6Li+p system in inverse kinematics with the MAGNEX spectrometer

This work refers to the study of the 6Li+p system in inverse kinematics with the MAGNEX spectrometer. Into this context, elastic scattering measurements have been performed for the 6Li+p system at the energies of 16, 20, 25 and 29 MeV while exclusive breakup measurements have been performed for the same system at the two highest energies. In both cases, the heavy ejectile was detected by the large acceptance MAGNEX spectrometer at the Laboratori Nazionali del Sud (INFN-LNS) in Catania, Italy. The goal of the present work for 6Li+p is based on a global study of all involved channels in order to probe coupling channels effects on elastic scattering in a Continuum Discretized Coupled Channel (CDCC) approach. Into this context, both elastic scattering and breakup channels were measured and combined with the results of the reaction 6Li+p→3He+4He measured in the same experiment, were found to be described very well in the CDCC framework. Coupling to the full continuum found to be strong and adequate in order to describe the experimental data in the most effective way. The direct and sequential (via the first 3+ resonance) breakup cross sections were found to be equally large at the higher incident energies, but the dominant effect on elastic scattering was due to coupling to the sequential breakup. This was also true for the lowest energy at 16 MeV, despite the negligible cross section for excitation of the resonance at this energy.The elastic scattering data were also considered in the microscopic approach of the JLM potential without any coupling. This failed to reproduce the data. It should be noted that it was the first time that the JLM potential was tested for a very light stable weakly bound projectile as 6Li and at very low energies.Η παρούσα διδακτορική διατριβή αφορά τη μελέτη του συστήματος 6Li+p σε αντίστροφη κινηματική με το φασματόμετρο MAGNEX. Σε αυτά τα πλαίσια πραγματοποιήθηκαν μετρήσεις ελαστικής σκέδασης για το εν λόγω σύστημα στις ενέργειες 16, 20, 25 και 29 MeV ενώ, μετρήσεις σύμπτωσης για την αντίδραση διάσπασης πραγματοποιηθήκαν στις δύο υψηλότερες ενέργειες. Και στις δύο περιπτώσεις, το βαρύτερο προϊόν της αντίδρασης ανιχνεύτηκε από το φασματόμετρο MAGNEX του Εθνικού Εργαστηρίου Νότου (INFN -LNS) που βρίσκεται στην Κατάνια της Ιταλίας.Ο στόχος της μελέτης αυτής για το σύστημα 6Li+p είναι η σφαιρική μελέτη όλων των εμπλεκόμενων καναλιών αντιδράσεων προκειμένου να διερευνηθούν φαινόμενα σύζευξης με την ελαστική σκέδαση μέσα σε ένα πλαίσιο υπολογισμών που λαμβάνουν υπόψη την σύζευξη των καταστάσεων των συνεχούς (CDCC). Στα πλαίσια αυτά, τα κανάλια της ελαστικής σκέδασης και της αντίδρασης διάσπασης καθώς και τα δεδομένα που προέρχονται από την αντίδραση 6Li+p→3He+4He, περιγράφονται πολύ καλά από τους CDCC υπολογισμούς. Βρέθηκε επίσης ότι η σύζευξη του ελαστικού καναλιού με τις καταστάσεις του συνεχούς είναι ισχυρή και καθοριστικής σημασίας στον υπολογισμό, προκειμένου να αναπαραχθούν τα αποτελέσματα της ελαστικής σκέδασης. Η ενεργός διατομή της αντίδρασης διάσπασης που πραγματοποιείται μέσω του 3+ συντονισμού και η ενεργός διατομή της αντίδρασης διάσπασης μέσω των άλλων καταστάσεων του συνεχούς, βρέθηκαν να έχουν το ίδιο μέτρο στις μεγαλύτερες ενέργειες. Η επίδραση όμως της σύζευξης του ελαστικού καναλιού με την κατάσταση που αντιστοιχεί στον 3+ συντονισμό βρέθηκε να είναι πολύ πιο ισχυρή. Το ίδιο συμπέρασμα προέκυψε και από την ανάλυση των δεδομένων στη χαμηλότερη ενέργεια των 16 MeV, παρόλο που στην περίπτωση αυτή η ενεργός διατομή της αντίδρασης διάσπασης που πραγματοποιείται μέσω σχηματισμού του 3+ συντονισμού ήταν πάρα πολύ μικρή. Η ανάλυση των δεδομένων της ελαστικής σκέδασης πραγματοποιήθηκε και υπό το πρίσμα της μικροσκοπικής περιγραφής του δυναμικού JLM, χωρίς να ληφθεί υπόψη οποιαδήποτε σύζευξη με μη-ελαστικές διεργασίες. Οι θεωρητικοί αυτοί υπολογισμοί απέτυχαν να περιγράψουν τα δεδομένα των γωνιακών κατανομών της ελαστικής σκέδασης. Θα πρέπει να σημειωθεί ότι για πρώτη φορά το δυναμικό JLM δοκιμάστηκε για ένα τόσο ελαφρύ ασθενικά δέσμιο πυρήνα όπως το 6Li και μάλιστα σε πολύ χαμηλές ενέργειες

The NUMEN Project: An Update of the Facility Toward the Future Experimental Campaigns

International audienceThe goal of NUMEN project is to access experimentally driven information on Nuclear Matrix Elements (NME) involved in the neutrinoless double beta decay (0νββ) by accurate measurements of the cross sections of heavy-ion induced double charge-exchange reactions. In particular, the (18O, 18Ne) and (20Ne, 20O) reactions are adopted as tools for β+β+ and β-β- decays, respectively. The experiments are performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania using the Superconducting Cyclotron to accelerate the beams and the MAGNEX magnetic spectrometer to detect the reaction products. The measured cross sections are very low, limiting the present exploration to few selected isotopes of interest in the context of typically low-yield experimental runs. In order to make feasible a systematic study of all the candidate nuclei, a major upgrade of the LNS facility is foreseen to increase the experimental yield by more than two orders of magnitude. To this purpose, frontier technologies are being developed for both the accelerator and the detection systems. An update description of the NUMEN project is presented here, focusing on recent achievements from the R&D activity

Recent experimental activity on heavy-ion induced reactions within the NUMEN project

The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The strategies adopted in the experimental campaigns performed at INFN - Laboratori Nazionali del Sud are briefly described, emphasizing the advantages of the multi-channel approach to nuclear reaction data analysis

Recent results on heavy-ion induced reactions of interest for neutrinoless double beta decay at INFN-LNS

The possibility to use a special class of heavy-ion induced direct reactions, such as double charge exchange reactions, is discussed in view of their application to extract information that may be helpful to determinate the nuclear matrix elements entering in the expression of neutrinoless double beta decay half-life. The methodology of the experimental campaign presently running at INFN - Laboratori Nazionali del Sud is reported andthe experimental challenges characterizing such activity are described