bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear symmetry energy at work in heavy ion reactions: new results from the INDRA-FAZIA apparatus
Authors: Ciampi C , Piantelli S , Casini G , Pasquali G , Baldesi L , Barlini S , Borderie B , Bougault R , Camaiani A , Chbihi A , Dell’Aquila D , Cicerchia M , Dueñas J A , Fable Q , Fabris D , Frankland J D , Frosin C , Génard T , Gramegna F , Gruyer D , Henri M , Hong B , Kim S , Kordyasz A , Kozik T , Kweon M J , Lemarié J , Le Neindre N , Lombardo I , Lopez O , Marchi T , Nam S H , Ordine A , Ottanelli P , Park J , Park J H , Pârlog M , Poggi G , Quicray J , Rebillard-Soulié A , Stefanini A A , Upadhyaya S , Valdré S , Verde G , Vient E , Vigilante M ,   INDRA-FAZIA collaboration
Published: September 2023

The recently coupled INDRA-FAZIA apparatus offers unique opportunities to investigate heavy ion collisions at Fermi energies by combining the optimal identification capabilities of FAZIA and the large angular coverage of INDRA. We present a selection of the results of the analysis of the first experimental campaign performed with INDRA-FAZIA, in which the four reactions 58,64Ni+58,64Ni have been studied at two different beam energies (32 and 52 MeV/nucleon) in the intermediate energy regime. The present work is focused on the isospin diffusion effects in semiperipheral and peripheral collisions. A stronger isospin equilibration is found at 32 MeV/nucleon than at 52 MeV/nucleon, as expected due to a shorter projectile-target interaction time in the latter case.
The quantification of pairing interaction in a two-neutron transfer through the intermediary continuum
Authors: Singh G. , Fortunato L. , Vitturi A.
Published: September 2023

An unbound intermediate system (A+1) with the presence of a resonance, can aid in the pairing enhancement in a two-neutron transfer reaction from a bound system A to another bound system (A+2). This enhancement is a consequence of the constructive interference via the several reaction channels available in the (A+1) system. We test this feature through our study in 6He, modeled as two neutrons in the orbitals of an intermediate 5He nucleus. Weighing up the natural case of an unbound 5He with a hypothetically bound 5He, we find that the inclusion of a properly modeled continuum favours the pairing correlations leading to enhanced two-neutron transfer cross-sections.
Deblurring decay-energy distribution from an invariant-mass measurement
Authors: Nzabahimana Pierre , Redpath Thomas , Baumann Thomas , Danielewicz Pawel , Giuliani Pablo , Guèye Paul
Published: September 2023

Measured decay-energy spectra from invariant mass spectroscopy can give insights into the shell structure of particle-unbound systems. However, it is challenging to extract the underlying physics from a measured spectrum due to detector resolution and acceptance effects. In this work, we introduce a deblurring method used to restore the decay energy spectrum measured for the three-body decay of 26O. The method utilizes the Richardson-Lucy algorithm, which has proven to be successful in optics, and does not require any prior knowledge about the resonance states in the observed spectrum. It also circumvents the singularity issue by iteratively adjusting a positive definite distribution. The only inputs are the observed energy spectrum and the detector’s response matrix also referred to as the Transfer Matrix (TM). We test the method’s performance on a simulated spectrum using the MoNA-LISA-Sweeper setup and the associated TM. Finally, the approach is applied to the decay energy spectrum of the 26O system measured in an experiment conducted at the National Superconducting Cyclotron Laboratory (NSCL) by the Modular Neutron Array (MoNA) Collaboration. The deblurring approach suggests three peaks in the decay energy spectrum of 26O at 0.15, 1.5 MeV, and a broad peak between 4 and 6 MeV.
The model for describing the width of double-gamma decay of the quadrupole state of spherical nuclei
Authors: Severyukhin A. P. , Arsenyev N. N.
Published: September 2023

We study the competitive γγ-decay of the

2
1
+

state of an even-even spherical nucleus. An influence of the phonon-phonon coupling on the double γ-decay width is analysed within the microscopic model based on the Skyrme energy density functional. It is shown that the γγ-decay width is sensitive to the interaction of the one- and two-phonon configurations of the giant dipole resonance.
Production of nuclei and hypernuclei in relativistic ion reactions
Authors: Botvina A S , Bleicher M , Buyukcizmeci N
Published: September 2023

We study the production of small nuclei, nuclei of intermediate mass, and hypernuclei in relativistic nuclear reactions by using dynamical and statistical models. We propose a novel mechanism responsible for the formation of complex nuclei from nucleons and hyperons produced in collisions: In this reaction the excited clusters consisting of baryons can stochastically be formed at a low sub-nuclear density after the dynamical expansion of the nuclear matter. One can describe the nucleation process within such clusters with the statistical models. We suggest the hybrid approach allowing for the consistent description of the experimental data measured in central collisions, which was not possible with other theoretical methods. The important consequence of this novel mechanism is the correlations of the produced nuclear species. The energy limits for describing the fragmentation and nucleation processes in excited finite nuclear systems with statistical models are also obtained.
Isoscalar giant monopole resonance in 40,48Ca
Authors: Arsenyev N. N. , Severyukhin A. P.
Published: September 2023

Starting from the Skyrme energy-density functional, the microscopic model is developed for the monopole excitations. We take into account the coupling between one-, two-, and three-phonon terms in the wave functions of excited 0+ states. As an example, the properties of the isoscalar giant monopole resonance (ISGMR) for the doubly magic nuclei 40,48Ca are discussed. The inclusion of complex configurations leads to a fragmentation of the ISGMR strength to lower energy 0+ states and also higher energy tail.
Towards microscopic optical potentials in deformed nuclei
Authors: Idini A , Rotureau J , Boström J , Ljungberg J , Carlsson B G
Published: September 2023

A microscopic and consistent description of both nuclear structure and reactions is instrumental to extend the predictivity of models calculating scattering observables. In particular, this is crucial in the case of exotic nuclei not yet discovered.

In this manuscript, we will present the plan of the Lund effort for a symmetry breaking description of bound and scattering observables using a generator coordinate method model based on an effective Hamiltonian constrained with a (Skyrme) functional. Following this, we will illustrate the steps to construct an optical potential for deformed nuclei from microscopic wavefunctions obtained with projected generator coordinate method from Hartree-Fock-Bogoliubov basis.
Fusion barrier distribution from measurement of quasielastic scattering at θ
c.m. = 180°
Authors: Biswas Rohan , Nath S , Gehlot J , Gonika  , Kumar Chandra , Parihari A , Madhavan N , Vinayak A , Mahato Amritraj , Noor Shoaib , Sherpa Phurba
Published: September 2023

Distribution of fusion barriers reveals the effect of structure of the collision partners on the dynamics of fusion between two heavy ions. Experimental barrier distribution can be extracted from precisely measured fusion excitation function. Quasielastic excitation function is related to fusion excitation function by conservation of incident flux. Hence, barrier distribution can also be extracted from quasielastic excitation function, which is usually measured at large angles, by detecting the back-scattered projectile-like ions. However, the reflectance coefficient is exactly complementary to the transmittance coefficient at θ
c.m. = 180°, which corresponds to orbital angular momentum, ℓ = 0. We report here extraction of fusion barrier distribution for 16O+142 Ce from measurement of quasielastic scattering at θ
c.m. = 180°, by detecting the target-like ions in the forward angles using a recoil mass spectrometer. Quasielastic excitation functions were also measured by detecting the projectile-like ions at two large angles. Barrier distributions extracted from both fusion and quasielastic measurements were found to be nearly identical. This work, thus, provided the first experimental verification of validity of the scaling property and the iso-centrifugal approximation in extracting barrier distribution from quasielastic excitation functions measured at large angles.
Two proton emission and other exotic decays in the 48Ni region with ACTAR TPC
Authors: Ortega Moral A. ,   E791 Experiment Collaboration
Published: September 2023

Since the first indirect measurements of the two proton radioactivity in 2002 [1], some theoretical descriptions have been able to reproduce experimental results until the 2-proton radioactivity was established for 67Kr at RIKEN [2], with a lifetime about 20 times lower than expected. New theory inputs have recently been developed [3][4], predicting angular distributions of the emitted protons for some of the two proton emitters, that need to be confirmed experimentally. An experiment at GANIL/LISE3 facility was performed in May 2021 aiming to produce one of the 2 proton emitters (48Ni) and measure the angular distribution of the emitted protons. We used the ACTAR TPC detector to implant the ions and perform the tracking of their proton decays. In addition, other exotic nuclei in the 48Ni region were produced. For several of them we have found a first evidence of exotic decays such as β delayed 3- and 2-proton emission or low energy proton branches for β delayed single proton emission. The analysis of this decays will provide helpful experimental information about the structure and the partial decay schemes of these unstable nuclei.
Precise mass measurement of the 32S member of the (A=32, T=2) quintet of analogue states
Authors: Blank B , Thomas J.-C , Gerbaux M , Ascher P , Atanasov D , Cresto F , Délignac Q , de Roubin A , Flayol M , Gendre Q , Giovinazzo J , Grévy S , Husson A , Jurado B , Kurtukian Nieto T , Marini P , Mathieu L , Michaud J , Ortega Moral A , Sguazzin M , Swartz J A , Versteegen M
Published: September 2023

This contribution presents a precise measurement of the excitation energy of the lowest (0+, T=2) state in 32S. Combined with the mass excesses of the 32S ground state and of the four other members of the (A=32,T=2) quintet of analogue states, it allows to test the validity of the Isobaric Multiplet Mass Equation to the third order in Tz, which renders it highly sensitive to the mechanisms inducing isospin mixing in the involved sd-shell nuclei. The (0+, T=2) isobaric analogue state in 32S was resonantly populated in the 31P(p, γ) reaction at ~3.3 MeV incident energy. The measurement procedure, involving high-purity germanium detectors, is described and the preliminary result obtained with a digital data acquisition system is presented.
Shell effects in fission and quasi-fission reactions
Authors: Simenel C. , Godbey K. , Lee H. , McGlynn P. , Umar A.S.
Published: September 2023

Quantum shell effects are responsible for asymmetric fission. They are also expected to affect the formation of fission fragments in quasi-fission reactions occurring in heavy-ion collisions. Systematic time-dependent Hartree-Fock simulations of 40–56Ca+176Yb collisions show that quasi-fission fragment properties share strong similarities with fragments formed in fission of the compound nuclei. This is an indication that similar shell effects are responsible for the final asymmtery in both mechanisms.
Investigating the pygmy dipole resonance in 96Mo using the (p,d) reaction
Authors: Khumalo T C , Pellegri L , Wiedeking M , Cappuzzello F , Cavallaro M , Carbone D , Spatafora A , Adsley P , Agodi C , Brischetto G , Calabrese S , Ciraldo I , Isaak J , Jivan H , Jongile S , La Fauci L , Lanza E G , Malatji K L , Netshiya A A , Neveling R , Sgouros O , Sideras-Haddad E , Soukeras V , Torresi D
Published: September 2023

The pygmy dipole resonance (PDR) thus far has been described microscopically as a cluster of 1− states around the neutron separation energy (S
n
). This study is an attempt to probe the nature of the PDR, specifically the single-particle or collective character of these states. One-step transfer reactions represents a good probe for this study due to their selectivity in exciting single-particle states. The 97Mo(p,d) 96Mo and 95Mo(d,p)96Mo reactions, were used to populate the nucleus of interest. The experiment was conducted at the INFN-LNS facility in Catania, Italy. The ejectiles were momentum-analysed by the MAGNEX spectrometer and detected by its focal-plane detector. In this paper, preliminary results for the 97Mo(p, d) 96Mo reaction will be presented.
β-decay studies in the 220 <A< 230 Po-Fr region
Authors: Polettini M , Benzoni G , Pellumaj J , Valiente-Dobón J J , Zhang G , Mengoni D , Perez Vidal R M , Huang Z. , Bracco A ,   HISPEC-DESPEC collaboration for S460 experiment
Published: September 2023

The experimental study presented in this work aims at providing new inputs to the knowledge of β decay in the 220<A<230 n-rich region.

A systematic description of β decay in this region would be useful to probe the predictions of global nuclear models in exotic nuclei beyond N= 126, as an input to models describing r-process nucleosynthesis. The region mentioned is also one of the regions in the nuclear chart where the strongest octupole deformations are supposed to be found, and were measured experimentally in recent years in few selected cases.

This work focuses on preliminary results on an experiment performed by the HISPEC-DESPEC collaboration as a part of the FAIR-0 campaing in April 2021. β-decay half lives and γ-ray spectra studies are presented.
Evolution of fragment production at the onset of Multifragmentation
Authors: Geraci E , Cardella G , Colonna M , De Filippo E , Gnoffo B , Maiolino C , Martorana NS , Pagano A , Pagano EV , Pirrone S , Politi G , Russotto P , Rizzo F , Trifiró A , Trimarchi M , Barlini S , Bougault R , Casini G , D’Agostino M , Gramegna F , Le Neindre N , Piantelli S
Published: September 2023

The onset of Multifragmentation phenomenon is investigated at low excitation energies. A detailed study on the origin of Intermediate Mass Fragment (IMF, Z>=3) produced in central collisions in the 58Ni+40Ca reaction at 25 AMeV is presented. The experimental campaign was performed with CHIMERA multi-detector at INFN Laboratori Nazionali del Sud in Catania (Italy). The multiple identification techniques of the 4p apparatus, together with low detection thresholds, enable the performance of a careful selection of Fusion-evaporation residues, Multifragmentation sources and their decay products. Comparisons with dynamical approach based on Boltzmann-Langevin-One-Body (BLOB) model predictions coupled with sequential emission code, were used as useful tools to depict and understand the characteristics of fragments emitted from an equilibrated compound nucleus or formed simultaneously in the multifragmenting source. A comparison with the preliminary results obtained for fragment production in central collisions of the same system, 58Ni+40Ca, at higher incident energies Ebeam=35AMeV, allows to study and characterize the evolution of multifragmentation phenomenon at the lower end of Fermi energies.
The 46Ar(3He, d)47K direct reaction as a probe of the 46Ar proton wavefunction
Authors: Brugnara D , Gottardo A , Assié M , Mengoni D , Lemasson A , Clement E , Flavigny F , Ramos D , Galtarossa F , Matta A , Girard-Alcindor V , Babo M , Bazzacco D , Beaumel D , Blumenfeld Y , Bottoni S , Datta U , de Angelis G , de France G , Dudouet J , Duenas J , Goasduff A , Gregor E T , Hammache F , Illana A , Lalanne L , Leblond S , Lombardo I , Marchini N , Million B , Recchia F , Rezynkina K , Rocchini M , Rojo J S , Siciliano M , Valiente-Dobón J J , Zanon I , Zielinska M
Published: September 2023

The discrepancy between shell-model calculations and intermediate-energy Coulomb excitation measurements in 46Ar still stands as an unsolved puzzle in understanding the N = 28 shell evolution. This phenomenon has significant relevance considering the remarkable achievements of the shell model and the SDPF-U interaction in the region which is able to predict the fading of the N = 28 shell gap in neutron-rich 44S. Recent measurements narrowed down this discrepancy to an overestimation of the proton amplitude to the quadrupole transition matrix element. The current work aims to propose a different perspective on the puzzle, by studying a direct proton-transfer reaction on 46Ar as a means to directly probe the proton wavefunction of the ground state this isotope. By measuring the amount of l = 0 transfer to the ground state (1/2+) of 47K with respect to the l = 2 to the first excited state (3/2+), we aim to gain insight into the ground state proton wavefunction of 46Ar. We will present a brief description of the experiment performed at the SPIRAL1 facility in GANIL (France). The experimental apparatus allowed a full reconstruction of the two-body reaction thanks to the combination of AGATA, VAMOS, MUGAST, CATS2, and HECTOR.
Differential Cross Section for Proton Induced Deuteron Breakup at 108 MeV
Authors: Łobejko A. , Kalantar–Nayestanaki N. , Kistryn S. , Kłos B. , Kozela A. , Kulessa P. , Parol W. , Skwira-Chalot I. , Stephan E. , Szadziński A. , Wilczek A. , Włoch B. , Zejma J.
Published: September 2023

The differential cross sections for the proton-deuteron breakup reaction have been measured for more than 200 angular configurations of outgoing protons in the range of polar angles from 13 to 27 degrees with a proton beam at 108 MeV. The paper presents the experimental results of the selected configurations, which are compared to state-of-the-art theoretical calculations. In some regions of the phase space, a strong influence of the Coulomb interaction is observed.
Proton halo effects in the 8B+64Zn collision around the Coulomb barrier
Authors: Di Pietro A , Spartá R , Figuera P , Tengblad O , Moro A , Lei J , Fernandez Garcia JP , Acosta L , Jonson B , Borge MJ , Cederkäll J , Davinson T , Ovejas JD , Fraile L , Galaviz D , Halkjaer Jensen J , La Cognata M , Martel I , Perea A , Sanchez Benitez A , Soić N , Vignales S
Published: September 2023

The 8B+64Zn reaction at 38.5 MeV has been studied at HIE-ISOLDE CERN to investigate proton halo effect on the reaction dynamics. For the first time it was used the only existing post-accelerated 8B beam. The measured elastic scattering angular distribution showed a small suppression of the Coulomb-nuclear interference peak, opposite to what observed for the one-neutron halo nucleus 11Be on the same target where a large suppression was observed instead. Inclusive angular and energy distributions of breakup fragments were also measured showing that, both, elastic and non-elastic breakup contribute. The presence of the additional Coulomb interactions halo-core and halo-target in 8B makes the reaction dynamics in this proton-halo nucleus different than the neutron-halo case.
Spectroscopic factors with generator coordinate method and application to 25Mg states
Authors: Boström J , Rotureau J , Ljungberg J , Carlsson B G , Idini A
Published: September 2023

Nuclei can be studied through the analysis of their shell structure, that provides important information on the wavefunctions useful for interpreting many phenomena, from excitations to transfer reactions. Spectroscopic factors provide the degree of single particle behaviour of a nuclear state and are used to represent the shell structure of a nucleus.

In this manuscript, we expand our recently developed model, which uses the generator coordinate method with an effective Hamiltonian, to calculate spectroscopic factors of states of odd deformed nuclei. Here we provide the results for 25Mg.
New results on the decay spectroscopy of 254No with GABRIELA@SHELS
Authors: Forge M. , Dorvaux O. , Lopez-Martens A. , Kessaci K. , Gall B.J.P. , Hauschild K. , Asfari Z. , Chakma R. , Yeremin A.V. , Chelnokov M.L. , Chepigin V.I. , Isaev A.V. , Izosimov I.N. , Katrasev D. , Kuznetsova A.A. , Malyshev O.N. , Mukhin R. , Popeko A.G. , Popov Yu.A. , Svirikhin A.I. , Sokol E.A. , Tezekbayeva M.S. , Piot J.
Published: September 2023

The structure of the

102

254

No

152

nucleus has been studied for more than 20 years: the last publications on its decay spectroscopy are from LBNL [1], GSI [2], JYFL [3] and ANL [4]. Four decay schemes featuring two isomers have been published and are interpreted differently in terms of excitation energy and decay scheme of the 2
nd
isomer and configuration assignments of both K-isomers. These discrepancies have triggered new experiments including this one, performed with the GABRIELA [5, 6] array, at the focal plane of the SHELS [7] separator at the FLNR, Dubna. The first part of this proceeding will present the experimental setup and the analysis techniques used to reveal the electromagnetic decay of the known isomers in 254No. The second part will focus on the new results obtained with more than 1 million 254No nuclei implanted in the focal plane detector. In particular, the internal conversion electron spectrum observed in the decay of the 8− K-isomer has revealed the presence of a strong transition, most likely E0, suggesting low-lying shape coexistence in this nucleus as predicted in [8, 9]. The γ-ray spectrum obtained from the decay of the short-lived 170 μs isomer has revealed new γ-ray lines putting in doubt the previous interpretations about this isomer decay.
Pygmy Dipole Response in Samarium isotopes
Authors: Jivan H , Pellegri L , Adsley P. , Bahini A. , Brummer J.W. , Donaldson L.M. , Färber M. , Görgen A. , Jones P. , Jongile S. , Khumalo T. , Li K.C.W. , Marin-Lambarri D.J. , Lanza E.G. , Negret A. , von Neumann-Cosel P. , Neveling R , Olacel A. , Papka P. , Pesudo V , Savran D. , Sideras-Haddad E. , Siem S. , Smit F.D. , Steyn G.F. , Usman I. , Van Zyl J.J , Wiedeking M. , Weinert M.
Published: September 2023

The influence of nuclear shape deformation on the Pygmy Dipole Response (PDR) was investigated using (α,α′γ) scattering on 144Sm and 154Sm. Experiments were conducted at iThemba LABS, coupling for the first time the K600 magnetic spectrometer with the BaGeL (Ball of Germanium and LaBr detectors) array. Preliminary results showcasing the efficacy of the facility and set-up for performing these 0° scattering experiments to investigate the PDR region are presented.
Exploring shape coexistence in A < 190 nuclei through EM transition rate measurements
Authors: Chamoli S.K. , Bhushan Ravi , Pandey Anand
Published: September 2023

The nuclei having mass A ~ 190 exhibit some interesting structural phenomenon like shape coexistence and shape transition. The present work reports on some of the experimental evidence of shape coexistence in this mass region for some of the nuclei. To establish experimentally the shape of a nucleus and hence the presence of shape coexistence demands use of experimental tools such as coulomb excitation or lifetime measurements. Various possible measurable quantities and associated phenomena are discussed, together with details on experiments performed. Experiments performed to populate different isotopes in Tl, Pt and Hg nuclei. Several theoretical and experimental calculations suggest the presence of shape coexistence in different isotopes of Tl, Pt and Hg nuclei.
Shell evolution and emerging paradigm changes
Authors: Otsuka Takaharu
Published: September 2023

The shell structure conceived by Mayer and Jensen in 1949 has been shown to be quite appropriate for stable and near-stable nuclei, but substantial deviations from it have also been observed more recently for exotic nuclei with notable neutron excess. Such changes of the basic picture of the nuclear shell structure, called the shell evolution, seem to be the subject studied most extensively and most elaborately by RI beam experiments worldwide. An overview of the shell evolution is presented in this talk, from both theoretical and experimental perspectives. The shell structure is shown to be varied, for instance, from the one presented by Mayer and Jensen, by particular types of the monopole components of the effective nucleon-nucleon interaction in nuclei. Among various contributions, the importance of the tensor force is illuminated here, with an outstanding example: the emergence of new neutron magic number 34 in neutron-rich Ca isotopes. The mechanism of the shell evolution produces significant impacts also on the nuclear shapes. Type II shell evolution shifts the excitation energies of intruder deformed bands, for instance, in some Ni isotopes. In other more general cases, the monopole interaction is shown to produce unexpected crucial effects on the patters of rotational bands of heavy deformed nuclei. In fact, the shape of the ellipsoidal deformation is investigated by large-scale shell model calculations, which is nothing but the Monte Carlo Shell Model. The unique role of the monopole component of the tensor force is clarified: the interplay between this monopole interaction and the quadrupole interaction provides us with various patterns of triaxial shapes for many nuclei, such as 166Er, one of the traditional prolate deformed heavy nuclei. Thus, the prolate preponderance hypothesis by Aage Bohr is investigated for its microscopic validity. Some of the nuclear paradigms are changing now in this way, due to emerging aspects of nuclear-force effects.
The mass of odd-odd nuclei in microscopic mass models
Authors: Ryssens W. , Scamps G. , Grams G. , Kullmann I. , Bender M. , Goriely S.
Published: September 2023

Accurate estimates of the binding energy of nuclei far from stability that cannot be produced in the laboratory are crucial to our understanding of nuclear processes in astrophysical scenarios. Models based on energy density functionals have shown that they are capable of reproducing all known masses with root-mean-square error better than 800 keV, while retaining a firm microscopic foundation. However, it was recently pointed out in [M. Hukkanen et al., arXiv:2210.10674] that the recent BSkG1 model fails to account for a contribution to the binding energy that is specific to odd-odd nuclei, and which can be studied by using appropriate mass difference formulas. We analyse here the (lacking) performance of three recent microscopic mass models with respect to such formulas and examine possibilities to remedy this deficiency in the future.
New γ-ray production cross sections for the 4.439 and 6.129 MeV lines of 12C and 16O. Astrophysical implications
Authors: Ouichaoui S. , Rahma Y. , Kiener J. , Lawrie E. A. , Lawrie J.J. , Tatischeff V. , Belhout A. , Moussa D. , Yahia-Cherif W. , Benhabiles-Mezhoud H. , Bucher T. D. , Dinoko T. R. S. , Chafa A. , Conradie J. L. , Damache S. , Debabi M. , Deloncle I. , Easton J. L. , Fouka M. , Hamadache C. , Hammache F. , Jones P. , Kheswa B. V. , Khumalo N. A. , Lamula T. , Majola S. N. T. , Ndayishimye J. , Negi D. , Noncolela S. P. , Ouziane S. , Papka P. , Peterson S. , Kumar Raju M. , Ramanathan V. , Rebeiro B. M. , de Séréville N. , Sharpey-Schafer J. F. , Shirinda O. , Wiedeking M. , Wyngaardt S.
Published: September 2023

Gamma-ray line production cross sections from nuclear reactions induced by 30 - 200 MeV protons on natC and Mylar targets have been measured at the SSC facility of iThemba LABS. Results for the 4.439 and 6.129 MeV prominent lines of 12C and 16O of astrophysical concern are reported and discussed.
Electron screening in the 2H(19F,p)20F reaction
Authors: Cvetinović A. , Đeorđić D. , Guardo G. L. , Kelemen M. , La Cognata M. , Lamia L. , Markelj S. , Pizzone R. G. , Schwarz-Selinger T. , Tišma I. , Vencelj M. , Vesić J. , Lipoglavšek M.
Published: September 2023

The dependence of electron screening potential on the position of the target nucleus in host-material lattice was investigated by measuring the rate of the 2H(19F,p)20F reaction in zirconium, titanium and palladium targets containing deuterium. Very different values of the screening potential were measured, thus showing the link with the valence electron densities around deuterium nuclei.
Using (α, xn) reaction rates and abundance ratios to constrain the weak r-process
Authors: Psaltis Athanasios , Arcones Almudena , Avila Melina L. , Hansen Camilla Juul , Jacobi Maximilian , Lombardo Linda , Meisel Zach , Mohr Peter , Montes Fernando , Ong Wei Jia , Schatz Hendrik
Published: September 2023

The lighter heavy elements of the first r-process peak, between strontium and silver, can be synthesized in the moderately neutron-rich neutrino–driven ejecta of either core–collapse supernovae or neutron star mergers via the weak r–process. This nucleosynthesis scenario exhibits uncertainties from the absence of experimental data from (α, xn) reactions on neutron–rich nuclei, which are currently based on statistical model estimates. We have performed a new impact study to identify the most important (α, xn) reactions that can affect the production of the lighter heavy elements under different astrophysical conditions and using new, constrained (α, xn) reaction rates based on the Atomki-V2 αOMP. We have identified a list of relevant reactions that affect elemental abundance ratios that can be compared to abundances from metal-poor stars. Our results show how when reducing the nuclear physics uncertainties, we can use abundance ratios to constrain the astrophysical conditions/environment. This will be possible with the planned experiments to measure key (α, xn) reaction rates using the SECAR recoil separator at FRIB that will also be briefly discussed.
The r-process and νp-process in CCSNe, collapsars, hypernovae and mergers, and their effect on galactic chemical evolution
Authors: Mathews G. J. , Yamazaki Y. , Sasaki H. , Kajino T.
Published: September 2023

In spite of many years of effort, some aspects of the origin and evolution of heavy elements in nature are yet to be understood. Here, we overview the current status of models for the formation of both r-process and νp-process elements. We summarize recent state-of the art developments of supernova and binary neutron star evolution in both r-process and νp-process nucleosynthesis. In particular, we highlight two recent recent works detailing the emerging evidence for the important role of hypernovae (energetic supernovae) and collapsars (jets from the collapse of massive stars to a black hole). These studies illuminate how such events may play a key role in the origin and early explosive nucleosynthesis and evolution of some heavy-elements.
58Ni(3He,t)58Cu*(γ) measurements with GODDESS to constrain the astrophysical rate of 57Ni(p,γ)58Cu
Authors: Carmichael S R , Pain S D , Siciliano M , Allen J , Bardayan D W , Boomershine C , Campbell C M , Carpenter M P , Chipps K A , Cizewski J A , Copp P A , Forson J , Garland H , Ghirmire R , Kovoor J , Lauritsen T , Müller-Gatermann C , O’Malley P D , Ratkiewicz A , Reviol W , Seweryniak D , Sims H , Ummel C C , Wilson G
Published: September 2023

The observation of γ rays from the decay of 44Ti in the remnants of core-collapse supernovae (CCSNe) provides crucial information regarding the nucleosynthesis occurring in these events, as 44Ti production is sensitive to CCSNe conditions. The final abundance of 44Ti is also sensitive to specific nuclear input parameters, one of which is the 57Ni(p,γ)58Cu reaction rate. A precise rate for 57Ni(p,γ)58Cu is thus critical if 44Ti production is to be an effective probe into CCSNe. To experimentally constrain the 57Ni(p,γ)58Cu rate, the structure properties of 58Cu were measured via the 58Ni(3He,t)58Cu*(γ) reaction using GODDESS (GRETINA ORRUBA Dual Detectors for Experimental Structure Studies) at Argonne National Laboratory’s ATLAS facility. Details of the experiment, ongoing analysis, and plans are presented.
Photon strength functions from (p,γ) reactions
Authors: Netshiya A. A. , Wiedeking M. , Pellegri L. , Malatji K. L. , Jongile S. , Papka P. , Kheswa N. , Adsley P. , Jones P. , Donaldson L. , Chisapi M. V. , Sithole M. A. , Qhobosheane S.
Published: September 2023

The 50Cr(p,γ)51Mn proton capture reaction has been used to study the photon strength functions by utilizing primary gamma ray transitions from the entry states to discrete states of known spins and parities. The reaction was conducted with the 3 MV Tandetron accelerator at iThemba LABS which delivered proton beams of 2.5 to 2.740, 2.760 to 3.0 MeV and 3.675 to 4.498 MeV in intervals of 20-25 keV with beam currents of up to 5 μA. In this work the proton capture reaction was employed together with the Average Resonance Capture method to extract the shape of the PSF of 51Mn.
Nuclear physics inputs for dense-matter modelling in neutron stars. The nuclear equation of state
Authors: Fantina Anthea Francesca , Gulminelli Francesca
Published: September 2023

In this contribution, we briefly present the equation-of-state modelling for application to neutron stars and discuss current constraints coming from nuclear physics theory and experiments. To assess the impact of model uncertainties, we employ a nucleonic meta-modelling approach and perform a Bayesian analysis to generate posterior distributions for the equation of state with filters accounting for both our present low-density nuclear physics knowledge and high-density neutron-star physics constraints. The global structure of neutron stars thus predicted is discussed in connection with recent astrophysical observations.
The D(p,γ)3H reaction at LUNA: implications in cosmology, particle physics and theoretical nuclear physics
Authors: Gustavino Carlo
Published: September 2023

The D(p,γ)3He cross section at low energies affects the primordial deuterium abundance, that in turn depends on fundamental cosmological parameters such as the baryon density and the amount of relativistic particles permeating the early universe. This paper discusses a new measurement of the D(p,γ)3He cross-section in the 30-280 keV energy range, performed at the Gran Sasso Laboratory (LNGS) with the LUNA facility. This measurement provides a new determination of the universal baryon density at the BBN epoch Ωb(BBN) with improved accuracy, in excellent agreement with the baryon density value derived from the Cosmic Microwave Background data Ωb(CMB). Furthermore, the LUNA result allows to better constrain the existence of dark radiation, i.e. the amount of light particles not considered in the standard model of particle physics, such as sterile neutrinos or hot axions. This paper also discusses the results of a new analysis showing that the D(p,γ)3He differential cross section is in excellent agreement with recent ab-initio theoretical calculations.
Measuring response functions for a new compact neutron spectrometer
Authors: Jarvie E , Buffler A , Hutton T , Ndabeni Z , Nndanganeni R , Vandevoorde C
Published: September 2023

A compact neutron spectrometer consisting of a (0.6 x 0.6 x 12.0 cm3) EJ-276 plastic scintillator coupled to a silicon photomultiplier has been designed. An essential aspect of the characterisation of the spectrometer is the measurement of detector response functions for neutron energies above 20 MeV. The process of producing response functions for neutron energies between 10 MeV and 60 MeV for the compact detector using neutron time-of-flight measurements at iThemba LABS is presented.
Evaluation of neutron radiation damage on gold microstructure using MCNP
Authors: Temaugee S T , Bedhesi L , Mavunda R D , Connell S H , Daniels G C , Usman I T
Published: September 2023

The effects of radiation interaction with materials have been studied over the years on metals, semiconductors, and other alloys. The result of these interactions constitutes microstructural effects, like point defects, dislocation loops, and void swellings. The accumulation of these defects results to damage on the macroscopic scale. This study is aimed to predict the magnitude of radiation damage in gold sample due to neutron irradiation. Neutron flux, displacement-per-atom rate, as well as heat deposition, were calculated in MCNP6.2, using the SAFARI-1 reactor model. The total neutron flux and dpa rate in the gold sample were determined to be 2.262 × 1011 n.cm−2.s−1 and 5.209 × 10−7 s−1 respectively. Also, the total heat deposition due to neutrons and photons was 2.515 × 10−6 W.g−1 and 0.513 W.g−1, respectively. Hence, the predicted neutron dpa and flux for the gold sample in this study suggest a heavy damage regime.
Comparing film measurements and Monte Carlo simulations of dose delivered in a pelvic phantom with titanium hip prosthesis
Authors: Dumela K E , Oderinde O M , Usman I T
Published: September 2023

An increasing number of elderly prostate cancer patients with high-density material hip prostheses are referred for external beam Radiotherapy (EBRT). Radiation treatment of pelvis cancer patients with high-density hip prostheses needs special attention due to the artifacts created in the computed tomography (CT) field of view and the radiotherapy dosimetry challenges. This study investigated the pelvic prostate point dose with and without titanium hip prosthesis using a 0.6 cc PTW Farmer ionization chamber, EBT3 Gafchromic films, compared with the EGSnrc Monte Carlo (MC) simulation dose distribution. The doses were measured and simulated in a locally made pelvic phantom. MC and measured doses were compared with the Treatment Planning System (TPS) calculated prostate point dose. The ionization chamber, EBT3 Gafchromic films, and MC doses have a maximum deviation of 6.3 %, 5.7 %, and 7.4 % for 6 MV and 4.2 %, 4.7 %, and 5.5 % for 15 MV photon beam, respectively, when compared with TPS calculated dose. There is a significant difference between the prostate point dose measured with ionization chamber, EBT3 Gafchromic film in comparison MC simulated doses. The MC simulation dose shows the highest deviation especially on the lateral field passing through the prosthesis.
Networked Sensing for Radiation Detection, Localization, and Tracking
Authors: Cooper R.J. , Abgrall N. , Aversano G. , Bandstra M.S. , Hellfeld D. , Joshi T.H. , Negut V. , Quiter B.J. , Rofors E. , Salathe M. , Vetter K. , Beckman P. , Catlett C. , Ferrier N. , Kim Y. , Sankaran R. , Shahkarami S. , Amitkumar S. , Ayton E. , Kim J. , Volkova S.
Published: September 2023

The detection, identification, and localization of illicit radiological and nuclear material continue to be key components of nuclear non-proliferation and nuclear security efforts around the world. Networks of radiation detectors deployed at strategic locations in urban environments have the potential to provide continuous radiological/nuclear (R/N) surveillance and provide high probabilities of intercepting threat sources. The integration of contextual information from sensors such as video, Lidar, and meteorological sensors can provide significantly enhanced situational awareness, and improved detection and localization performance through the fusion of the radiological and contextual data. In this work, we present details of our work to establish a city-scale multi-sensor network testbed for intelligent, adaptive R/N detection in urban environments, and develop new techniques that enable city-scale source detection, localization, and tracking.
A multimodal neutron-based technique for the elemental analysis of materials in bulk
Authors: Mhlongo S , Buffler A , Hutton T , Ndabeni Z
Published: September 2023

Neutrons and gamma rays are effective probes for the elemental characterisation of bulk samples. Neutrons interactions with matter are characteristic of the nature of the target nucleus, and the incident neutron energy. Most nuclides exhibit distinctive structure in their total and differential cross sections, thus elements can be differentiated via their total, elastic and inelastic scattering cross sections, and the energies of prompt gamma rays produced in inelastic collisions. In this work we report on the use of the fast neutron transmission analysis technique for the analysis of 12C in graphite. We also present results of prompt gamma ray neutron activation analysis of graphite using 14 MeV neutrons, which was explored for the purpose of developing a multimodal neutron-based technique for elemental analysis of materials in bulk.
47Sc production with proton beams on isotopically enriched 48Ti and 49Ti targets
Authors: Dominicis L De , Mou L , Cisternino S , Campostrini M , Rigato V , Nigron E , Haddad F , Pupillo G
Published: September 2023

The theranostic emerging radionuclide 47Sc is under the spotlight of the scientific community due to its medically favorable decay characteristics (t1/2 =3.3492 d, Eγ=159.381 keV, E
β−, mean
=162.0 keV) for both the diagnostic and treatment procedures. In the framework of the LaRAMED (LAboratory of RAdionuclides for MEDicine) program at INFN-LNL (National Institute of Nuclear Physics-Legnaro National Laboratories), the investigation of the possible 47Sc production routes using a 70 MeV proton beam is one of the goals of the REMIX (Research on Emerging Medical radIonuclides from the X-sections) project, funded by INFN for the years 2021-2023. Since the LARAMED bunkers are currently under completion, experiments are performed in collaboration with the GIP ARRONAX facility (Nantes, France), where a 70 MeV multi-particle cyclotron is operational. In this work, the cross-section measurements using enriched 48,49Ti targets are reported and the results presented in comparison to the previous literature data, when available. The 47Sc excitation functions are analyzed in relation to the contaminants’ ones since the co-produced radionuclides can affect the dose delivered to a patient. 46Sc cross-section curves are mainly taken into account since 46Sc cannot be chemically separated from 47Sc and its half-life (t1/2=83.79 d) is longer than the 47Sc one (t1/2=3.3492 d).
Density-modified tracers for positron emission particle tracking
Authors: van Heerden M , Buffler A , Cole K , Leadbeater T
Published: September 2023

Positron emission particle tracking (PEPT) is a powerful non-invasive technique used to study the underlying dynamics of granular and multiphase flowing systems. The essence of PEPT is to attach (chemically or otherwise) sufficient positron-emitting radioisotope to a particle chosen as representative of the bulk material under study, and hence used as a flow-following tracer. We report on standardised methods for creating density-modified tracer particles to expand the range of applications feasible to research with the PEPT technique.
The NUMEN project: probing nuclear response to weak interaction by nuclear reactions
Authors: Carbone D , Agodi C , Bellone J I , Burrello S , Calabrese S , Cappuzzello F , Cavallaro M , Colonna M , De Gregorio G , Ferreira J L , Gargano A , Lenske H , Sgouros O , Spatafora A , Acosta L , Amador-Valenzuela P , Brischetto G A , Calvo D , Capirossi V , Chàvez Lomelì E R , Ciraldo I , Delaunay F , Djapo H , Eke C , Finocchiaro P , Firat S , Fisichella M , Guazzelli M A , Hacisalihoglu A , Iazzi F , Lay J A , Linares R , Lubian J , Medina N H , Moralles M , Oliveira J R B , Pakou A , Pandola L , Petrascu H , Pinna F , Russo G , Solakci S O , Soukeras V , Souliotis G , Torresi D , Tudisco S , Yildirim A , Zagatto V A B ,   on behalf of the
Published: September 2023

Different reactions channels induced by the 18O + 40Ca collisions at 275 MeV incident energy are simultaneously measured and analysed consistently within the same reaction and structure frameworks within the NUMEN project. The project aims to provide data-driven information for the determination of the nuclear matrix elements involved in the neutrinoless double beta decay. In particular, the elastic and inelastic scattering, one- and two-proton transfer, one-neutron transfer, and single charge exchange reactions are explored. The full quantum-mechanical calculations, performed by including microscopic nuclear structure inputs, describe well all the experimental data, giving support to a multi-channel strategy for the analysis of heavy-ion induced direct reactions.
Laser isotope separation to study for the neutrino-less double beta decay of 48Ca
Authors: Ogawa I , Hiraiwa T , Nakajima J , Yuhaku R , Tozawa M , Niki H , Tokita S , Miyanaga N , Uemukai M , Rittirong A , Umehara S , Matsuoka K , Yoshida S
Published: September 2023

The laser isotope separation (LIS) system is being developed for the study of neutrino-less double beta decay of 48Ca. A proof-of-principle experiment has been successfully conducted, and development of a mass production (∼1 mol/year) system is currently underway. For stable and efficient production, we are preparing an atomic beam system capable of producing a well-collimated beam with sufficient flux and a high-power semiconductor laser system with stable frequency over a long period of time.
Monitored neutrino beams and the next generation of high precision cross section experiments
Authors: Branca A , Acerbi F , Angelis I , Bomben L , Bonesini M , Bramati F , Brizzolari C , Brunetti G , Calviani M , Capelli S , Carturan S , Catanesi M G , Cecchini S , Charitonidis N , Cindolo F , Cogo G , Collazuol G , Dal Corso F , Delogu C , De Rosa G , Falcone A , Goddard B , Gola A , Halić L , Iacob F , Jollet C , Kain V , Klicek B , Kudenko Y , Lampoudis Ch , Laveder M , Longhin A , Ludovici L , Lutsenko E , Magaletti L , Mandrioli G , Margotti A , Mascagna V , Mauri N , Meazza L , Meregaglia A , Mezzetto M , Nessi M , Paoloni A , Pari M , Parozzi E G , Pasqualini L , Paternoster G , Patrizii L , Pozzato M , Prest M , Pupilli F , Radicioni E , Ruggeri A C , Sampsonidis D , Scian C , Sirri G , Stipcevic M , Tenti M , Terranova F , Torti M , Tzamarias S E , Vallazza E , Velotti F , Votano L
Published: September 2023

The main source of systematic uncertainty on neutrino cross section measurements at the GeV scale originates from the poor knowledge of the initial flux. The reduction of this uncertainty to 1% can be achieved through the monitoring of charged leptons produced in association with neutrinos. The goal of the ENUBET ERC project is to prove the feasibility of such a monitored neutrino beam. In this contribution, the final results of the ERC project, together with the complete assessment of the feasibility of its concept, are presented. An overview of the detector technology for a next generation of high precision neutrino-nucleus cross section measurements, to be performed with the ENUBET neutrino beam, is also given.
Overview of Solar Neutrino Experiments
Authors: Bagdasarian Zara
Published: September 2023

Solar neutrinos have played a major historic role in the development of neutrino physics and understanding of the fusion processes in the Sun. Neutrino experiments worldwide continue to measure neutrinos originating in the core of the Sun in the search for new insights. Recent years have marked the discovery of the carbon-nitrogen-oxygen fusion cycle, tackling the Sun metallicity problem, and the search for physics beyond the Standard Model.