The stellar weak interaction rates of proton-rich N≃Z nuclei in the A ∼70 mass region play a critical role during the rapid proton capture process (rp process) in type-I x-ray bursts taking place on the surface of neutron stars accreting hydrogen/helium-rich material from a low-mass close companion star. Nucleosynthesis in explosive hydrogen burning at high temperatures and densities is...
The photodisintegration cross sections for the 94Mo(γ,n) and 90Zr(γ,n) reactions have been experimentally investigated with quasi-monochromatic photon beams at the High Intensity γ-ray Source (HIγS) facility of the Triangle Universities Nuclear Laboratory (TUNL). The energy dependence of the photoneutron reaction cross sections was measured with high precision from the respective neutron...
An important upgrade of the Flerov Laboratory of Nuclear Reactions Radioactive Ion Beam facility at JINR is start of the operation of a new high acceptance device called ACCULINNA-2. An overview of the design, construction and commissioning studies of the ACCULINNA-2 separator are presented. The separator will be equipped with a modern cryogenic tritium target cell, with zero degree...
A small number of naturally occurring neutron deficient nuclides with proton number Z>33, referred to as p-nuclei, cannot be produced by neutron-capture processes [1]. Instead, these stable nuclides are thought to be produced by the photodisintegration (p-process) of slow-neutron capture (s-process) and rapid-neutron capture (r-process) seed nuclei [1]. However, for $^{180}$Ta, the p-process...
The development of the Radioactive Ion Beam (RIB) facilities, allowing the study
away from the stability line, has unveiled the concept of a standard Mean Field Approach (MFA) to particle systems. Closely tied to the MFA idea the independent shell model was developed, which assumes that the interaction between the many-body nucleon system can be suitably represented by a MF potential for...
In this presentation we discuss the emergence of clustering degrees of freedom in the nuclear many-body dynamics. We concentrate on alpha clustering broadly defined here as four-nucleon correlations that are of interest both as in-medium correlations and as real alphas seen in reactions.
Using configuration interaction approach and center-of-mass boosting technique we explore realistic and...
Understanding the behavior of flow within dynamic systems is important to optimize the required outputs from such active systems. Non-destructive methods offer a significant advantage since the system may be preserved over multiple studies. We present the first dual measurements of the steady-state flow of material within a laboratory scale tumbling mill system which combine observables...
Low-energy Coulomb excitation is one of the simplest and well known tools to study the nuclear shape, for this reason is widely used at radioactive beam facilities. In particular in the case of ISOL facilities the energy and the intensity of the available beams are suitable for low-energy Coulomb excitation. The SPES facility for the acceleration of radioactive beams will soon provide the...
The neutrinoless double beta (0???) decay of atomic nuclei is a possible way to access the nature and mass of the neutrino. These unknown features of the neutrino can be tackled by the 0???- decay experiments. In a simplistic picture the rate of 0??? decay depends on the second power of the double Gamow-Teller nuclear matrix element, M(0?) GTGT, containing virtual transitions through various...
High energy-resolution proton inelastic scattering experiments with Ep = 200 MeV were performed on 142, 144, 146, 148, 150Nd and 152Sm in the excitation-energy region of the Isovector Giant Dipole Resonance (IVGDR) using the zero-degree mode of the K600 magnetic spectrometer of iThemba LABS. The effect of deformation on both the broad and the fine...
Inelastic proton scattering at very forward angles and energies of a few hundred MeV has been established as a new tool to study the complete E1 response in nuclei in the excitation energy region between about 5 and 25 MeV [1,2]. Such data are crucial to determine the dipole polarizability of nuclei, which in turn provides important constraints on the neutron skin thickness and on the Equation...
The sextic oscillator V(r) = Ar^2 + Br^4 +Cr^6 + D/r^2 offers a flexible shape that can be used in the Bohr Hamiltonian to model transition between spherical and deformed shape phases in the r=beta variable. The general form of the sextic oscillator is not solvable, however, the A, B and C coefficients can be parametrized in terms of two independent parameters such that the problem reduces to...
Extreme Light Infrastructure – Nuclear Physics (ELI-NP) is a 310 Meuro project under implementation (2013-2020) in Măgurele, Romania. The aim of the project is to build a Pan-European Centre for scientific research in nuclear photonics based on two major instruments, a high-power laser system with 2x10 PW laser beams and a high intensity gamma beam system. ELI-NP will provide new opportunities...
Light nuclei are excellent test samples for structure models because of small number of included degrees of freedom. Recent progress in ab initio calculations of light nuclei in various frameworks demands more precise experimental spectroscopic data for identified key nuclear systems. The most advanced models are able to reproduce single particle and clustering features of light nuclei with up...
Promotion of nuclear applications for peaceful purposes and related capacity building is among the missions of the IAEA. In this context, accelerator applications and nuclear instrumentation is one of the thematic areas, where the IAEA supports its Member States in strengthening their capabilities to adopt and benefit from the usage of accelerators. A number of activities are being implemented...
Since 1990’s, the advent of in-flight radioactive isotope beams has created great opportunities for studies of the nuclear structure in short-lived exotic nuclei and of reactions with exotic nuclei, and many interesting natures of exotic nuclei have been discovered and our modern picture of the structure has been seriously questioned. In addition, the studies are essentially important for...
Neutron capture reactions are responsible for the synthesis of almost all of the elements heavier than iron: the slow (s) process proceeds on isotopes near stability; the rapid (r) process produces isotopes with short half-lives that subsequently decay towards stability. In hot r-process scenarios, final abundance patterns are relatively insensitive to neutron capture rates on waiting point...
Following the first observation of a neutron star merger [1] it became clear that this was one of the sites of the r-process [2]. With an astronomical site for the r-process known it has become more important than ever to have accurate nuclear input [3], and in particular accurate neutron capture rates for unstable neutron rich nuclei. Unfortunately, the neutron capture rates of short-lived...
The past decade has seen an increase in studies dedicated to understanding the low-lying electric dipole (E1) response, commonly referred to as the Pygmy Dipole Resonance (PDR). These studies revealed that the PDR has a mixed isospin nature, and that the use of complimentary probes is needed to fully understand this response. Since majority of studies on the PDR focussed on spherical nuclei,...
The Pygmy Dipole Resonance (PDR) is an electric dipole excitation below and around the particle separation threshold [1]. It may be understood, in a macroscopic picture, as a neutron skin oscillation against an isospin-saturated core. Such additional dipole strength on top of the low-energy tail of the Giant Dipole Resonance (GDR) can have a great impact on reaction rates within nuclear...
The description of shell structure has evolved in recent years extending toward the driplines. The role of shell closures has been challenged and modifications of shell structure have been observed in short-lived nuclei with extreme proton-to-neutron ratio.
The harmonic oscillator shell gap at N=40 is reduced as protons are removed from Ni to Fe and Cr isotopes. Both $^{66}$Fe and $^{64}$Cr...
The activity concentrations of $^{238}$U and $^{232}$Th series radionuclides in beach sand were measured using a gamma-ray spectrometer comprising four LaBr$_3$:Ce (2" x 2") detectors without background shielding. The sample was placed 10 cm equidistant from the detectors and counted for 48 hours. This spectrometer allowed for measurement in singles and coincidence (gamma-gamma) modes....
Neutron capture reactions are of utmost importance for the quantitative understanding of stellar nucleosynthesis and in a number of other significant topics of nuclear astrophysics. The n_TOF facility provides unique possibilities for establishing reliable and accurate data for this class of applications. To address the still open issues in stellar and primordial nucleosynthesis, the n_TOF...
Institute Laue-Langevin (ILL) is a reactor based European neutron source, which delivers a very intense neutrons for ~40 different instruments. There are two nuclear physics instruments in ILL, which use actinide targets. Lohengrin [1,2] is a fission recoil separator with very high mass and energy resolving power (A/ΔA =1500, E/ΔE = 100 – 1000). In 2018 series of successful experimental...
A vibrant program of nuclear structure studies through $\gamma$-ray and electron spectroscopy, together with magnetic-moment measurements, continues at the Australian National University. We have strong two-way international collaborations whereby we perform experiments at international facilities and also welcome international collaborators to perform experiments in our laboratory.
One of...
Boron Neutron Capture Therapy (BNCT) is the only form of radiotherapy based on the induction of nuclear reactions selectively in the tumor cells. For these features BNCT has been used as an experimental therapy for disseminated tumors or for cancers for which there is no other effective treatment. Modern BNCT is facing a new era due to the most recent clinical results for the Glioblastoma and...
The total deformation energy at the moment of neck rupture, for the heaviest nuclei for which spontaneous fission has been detected ($^{264-278}{\rm Hs}$, $^{268-280}{\rm Ds}$, $^{276-286}{\rm Cn}$, $^{285-287}{\rm Fl}$, $^{290-293}{\rm Lv}$ and $^{294}{\rm Og}$ ) [1,2], is calculated using the Strutinsky's prescription. The nuclear shapes just before scission are described in terms of...
Heavy quarks (charm and beauty) are regarded as ideal probes of the hot and dense deconfined QCD medium, the Quark-Gluon Plasma (QGP), formed in ultra-relativistic heavy-ion collisions at the LHC. They are produced in hard scattering processes in the early stages of a heavy-ion collision.
In addition, their characteristic flavour is conserved throughout the evolution of the medium formed in...
One of the major issues in modern astrophysics concerns the analysis and
understanding of the present composition of the Universe and its various constituting objects. Nucleosynthesis models aim to explain the origin of the different nuclei observed in nature by identifying the possible processes able to synthesize them. Though the origin of most of the nuclides lighter than iron through the...
After the start of space conquest studies of radiation induced effects on satellite electronics have been necessary to verify the operation of the components in the harsh radiation environment of space. The radiation errors can roughly be classified in two categories; Total Ionizing Doses (TID) and Single Event Effects (SEE). TID tests are carried out in numerous world existing Co-60...
Radioactive ion beam research plays an essential role in answering key questions in the fields of, amongst others, nuclear physics and nuclear astrophysics. Progress depends to a large extend on continuous innovative developments in the production and manipulation of the radioactive ion beams and in instrumentation. Moreover, the field of radioactive ion beam research has reached a level of...
The shape coexistence phenomenon is prevalent in the Z~34 region, with multiple neutron-deficient even Ge [1] , Se [2] and Kr [3] isotopes each exhibiting the characteristic low-lying coexisting $0^+$ bands which display quadrupole deformation different to that of the ground states.
In the selenium isotopes, coexisting shapes $^{72-78}\text{Se}$ seem to show a prolate ground structure with...
Classical novae are thermonuclear explosions that take place in the envelopes of accreting white dwarfs in stellar binary systems. The material piles up under degenerate conditions, driving a thermonuclear runaway. The energy released by the suite of nuclear processes operating at the envelope heats the material up to peak temperatures of (100 - 400) MK. During these events, about 10$^{-3}$ -...
The study of nuclei far from stability is one of the most active and challenging areas of nuclear structure physics. One of the most exotic neutron-rich nuclei currently accessible to experiment is 40Mg [1, 2], which lies at the intersection of the nucleon magic number N=28 and the dripline, and is expected to have a large prolate deformation similar to that observed in the neighboring lighter...
It is well established that the study of the low lying dipole states, the so called Pygmy Dipole Resonance (PDR), can be fruitful done by using an isoscalar probe in addition to the conventional isovector one due to the fact that their transition densities show a strong mixing of their isoscalar and isovector components[1]. Indeed, the combined use of real and virtual phonons and experiments...
An important fundamental question is how nature combines the building blocks, protons and neutrons, to form the large variety of complex manybody nuclei. Addressing this requires understanding the residual strong interaction, the nuclear force, between nucleons that characterizes the properties of the nuclei. This entails synthesizing observed properties of
nuclei and predictions from...
The 2015 Long Range Plan for Nuclear Science in the US recommends a high-energy, high-luminosity polarized Electron-Ion Collider (EIC) as the highest priority for new facility construction after the completion of FRIB. A U.S.-based EIC has also recently been endorsed by the U.S.
National Academies of Sciences finding the scientific case for the EIC compelling, unique, and timely.
The EIC...
Over the last decades nuclear spectroscopy has shown its capabilities to investigate the effective nucleon-nucleon interaction in nuclear matter. Technically, this has been possible thanks to the continuous improvement in germanium γ-arrays performances and in their associated instrumentation, that has allowed an enormous increase of the experimental sensitivity.
In this presentation, I would...
The Bay Area Neutron Group (BANG) has developed and characterized a high-intensity neutron source facility at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. A variety of white neutron sources have been produced via deuteron breakup on thick beryllium and tantalum targets with incident deuteron energies from 16-33 MeV. Neutron energy spectra are measured with activation...
The structure of $^{33}$Si and $^{35}$S was studied by one-neutron knockout reactions from $^{36}$S and $^{34}$Si beams at 88 MeV/u incident on a $^{9}$Be target. The prompt $\gamma$-rays following the de-excitation of $^{33}$Si and $^{35}$S were detected using the GRETINA $\gamma$-ray tracking array while the reaction residues were identified on an event-by-event basis in the focal plane of...
Several nuclear reactions are best investigated when the momentum transfer to the nucleus is small. Among these are the IsoScalar Giant Monopole Resonance (ISGMR) which helps determine one of the parameters of the equation of state, namely the incompressibility of nuclear matter, and proton elastic scattering from nuclei which is sensitive to parameters of nuclear density such as the matter...
Nuclear interactions of charged particles with matter play fundamental roles in many fields of applied research. Many challenges in radiotherapy with ions and in space radioprotection are related to the investigation of the same nuclear processes and require similar approaches to be addressed.
The growing popularity of radiotherapy with protons and carbon ions as well as the interest in...
