What are the heaviest elements that can exist or be created in Nature? Does an ‘Island of Stability’ exist beyond uranium? Questions like these are often asked in connection with Long Range Plans of nuclear physics communities or large-scale accelerator facilities. Information on the chemical and physical properties of superheavy elements (Z>103) or nuclei is notoriously difficult to...
In 2019 US Department of Energy initiated the process of realizing the Electron Ion Collider (EIC) - by giving the project a Critical Decision 0 - status. This resulted after an almost twenty year effort by scientists around the world to make the scientistic and technical feasibility case for the same. Now the EIC project - being realized jointly by BNL and Jefferson Lab - is well underway....
Rare isotopes far from the valley of beta stability can be efficiently produced in-flight via projectile fragmentation or fission. This presentation will provide an overview of the facilities and their associated instrumentation that makes them unique.
Nuclear physics is built on a solid understanding of individual nucleons, which can ultimately be described in terms of light quarks and gluons. The surprising recent discoveries of several tetraquark and pentaquark candidates, each containing both light and heavy quarks, offer new insight into the physics of quarks and gluons. Lattice QCD is a rigorous first-principles computational...
General relativity imposes a one-to-one correspondence between the Equation of State (EoS) of nuclear matter and the static properties of neutron stars (NS). Because of that, since the LIGO/Virgo exceptional detection GW170817, nuclear theory and experiments were used to directly constrain the NS properties, together with the information coming from the observations. Gravitational waves and...
The experimental search for an isolated four-neutron system has been a long standing quest in nuclear physics. With only a few indications for its existence the tetraneutron remains an elusive nuclear system. In the recent experiment performed at RIKEN Nishina Center a resonance-like structure near 4n threshold was observed for the first time using quasi-free knockout of alpha particles from...
The solenoidal-spectrometer technique for direct-reaction studies has advanced significantly since it was first demonstrated with the HELIOS spectrometer at Argonne's ATLAS facility and has become an essential tool for nuclear structure, reaction mechanism, and nuclear astrophysics studies. There are now three dedicated solenoidal spectrometers: the ISOLDE Solenoidal Spectrometer at...
Constraining the dense nuclear matter equation of state (EOS) has been the goal of numerous theoretical and experimental efforts worldwide. Recent advancements include inferences from observations of neutron stars and neutron star mergers, measurements of neutron skins, and various theoretical developments.
This makes complementary efforts relying on models of relativistic heavy-ion...
In this talk, I will review the recent progress in the nucleon structure functions at large-x region. The ratio of F2 structure functions between the proton and neutron is of particular interest as it’s closely related to the d/u ratio, and its behavior at x->1 limit provides insights into the dynamics of quarks in non-perturbative region. The PDFs are poorly constrained in large-x low Q^2...
In order to provide an excellent particle identification (PID) of charged hadrons at the future high-rate Compressed Baryonic Matter (CBM) experiment the CBM-TOF group has developed a concept of a 120 m$^2$ large Time-of-Flight (ToF) wall (with 93000 channels) with a system time resolution below 80 ps based on Multi-gap Resistive Plate Chambers (MRPC). The MRPC detectors were extensively...
In ultra-relativistic heavy-ion collisions, strong electromagnetic fields arising from the Lorentz-contracted, highly charged nuclei can be approximated as a large flux of high-energy quasi-real photons that can interact via the Breit-Wheeler process to produce $e^{+}e^{-}$ pairs. The collision energy dependence of the cross section and the transverse momentum distribution of dielectrons from...
The Facility for Rare Isotope Beams (FRIB) [1] is currently providing primary beams of up to 300 MeV/u (most mid-mass beams are available at about 250 MeV/u) at 10 kW beam power. With this new facility and as the beam power is increased, FRIB is poised to provide access to a wide range of rare isotope beams. In this contribution, the initial results of the observation of new isotopes at FRIB...
Measurements of cross section and their extrapolation to stellar conditions are now routinely performed with accuracy of 5% or better. But the formation of 16O in the fusion of helium with 12C, in the 12C(a,g)16O reaction, is still not known with sufficient accuracy, in spite of the central role that this reaction plays in stellar evolution theory.
We developed [1] a new method to measure...
Even though beta-delayed proton emission is a phenomenon that typically occurs for neutron-deficient nuclei, the energy window for this process is open also in a few light, neutron-rich isotopes. Particularly interesting in this respect is 11Be, which is also a one-neutron halo nucleus. Several channels for beta-delayed particle emission from this isotope are open, including the proton branch,...
Ground state nuclei usually have compact geometries. However, there have been theoretical predictions that excited nuclei can take on more extended shapes such as toroids or bubbles. There have been many attempts to identify signatures of such shapes in experimental data. One signature both predicted by theory and reported in experimental data is narrow resonances at high excitation energy...
The advancement of production techniques to access unstable nuclei far from the stability line has resulted in the discovery of many exotic nuclei characterized by short half-lives and an unusual neutron-to-proton ratio. Such nuclei are of particular interest in fundamental and applied physics. For instance, measurement of interaction ($\sigma_{I}$) and charge-changing cross sections are...
Astrophysical $S$ factors of $E1$ and $E2$ transitions of radiative $\alpha$ capture on $^{12}$C, $^{12}$C($\alpha$,$\gamma$)$^{16}$O, at Gamow peak energy, $E_G=0.3$ MeV, in the helium-burning process are estimated in cluster effective field theory (EFT). We construct an EFT for the reaction by choosing a separation scale as the breakup energy of $p$-$^{15}$N open channel and introduce...
We present recent results on the gamma decay of a peculiar near-threshold state in 11B, expected to be located in the continuum just above the proton-decay threshold. The relevance of such a state is due to the observation of the rare beta-delayed proton emission process in the neutron-rich 11Be nucleus, with an unexpectedly high rate, at odds with the narrow energy window available for this...
The facility EXOTIC [1] at the Laboratori Nazionali di Legnaro (LNL, Italy) has been operational for the in-flight production of light Radioactive Ion Beams (RIBs) since 2003. RIBs are produced via two-body inverse kinematics reactions induced by a heavy-ion beam, delivered from the LNL-XTU tandem accelerator and impinging on a gas target. So far, secondary beams of $^8$Li, $^7$Be, $^8$B,...
Light nuclear clusters are expected to be ubiquitously present in astrophysical environments and play an important role in different astrophysical phenomena involving ultra-dense baryonic matter, but the estimation of their abundancy demands to correctly estimate the in-medium modification of their binding energy.
In the original measurements, Equilibrium Constants were extracted detecting...
Understanding the origin of elements in our universe is inevitable for modern nuclear physics. It is known that neutron-deficient stable isotopes, referred to as $p-$nuclei, are synthesized through the $p$-process triggered by photo-disintegration in supernovae. One of the major issues that remain unresolved is the anomalously large abundances for certain lighter $p-$nuclei in current...
Nuclear moments are fundamental probes to study the intrinsic structure of the nucleus. Various methods and applications are used in the past depending on the specific decay or de-exitation mode of the nucleus. Such experimental investigations for isomeric states were performed for example in various facilities as RIBF/RIKEN, ALTO, GSI/FAIR employing some of the well-known methods in...
The artEmis project is addressing one of the most damaging natural hazards on earth: earthquakes. The ultimate goal is to improve radon based earthquake forecasting methods. The artEmis project develops a smart and cheap sensor system with about 100 units monitoring radon, temperature, acidity and other observables in ground water in real time. The data from the sensor system will be combined...
The dynamical intranuclear cascade model INCL[1] has been improved by including short-range nucleon-nucleon correlations (SRCs), which are mainly dominated by the formation of np pairs. This new development allows us to obtain a better description of peripheral collisions involving the knockout of a few nucleons in spallation and fragmentation reactions. The new version of our dynamical model...
Dipole strengths of direct and cascade transitions to GDR energies in medium and heavy atomic mass nuclei are investigated in a theoretical approach based on EDF theory and extended by multiphonon degrees QRPA [1]. Recent developments of the method, including a reaction theory [2,3], have been applied in spectroscopic studies of two-phonon states [4], pygmy and giant resonances [1-5], thus...
Various information on the nuclear structure is imprinted on the density profiles, especially, near the nuclear surface. The total reaction cross section of medium- to high-energy nuclear collision has been a standard observable to extract the nuclear radius of unstable nuclei. As higher order information of the nuclear density profile, evaluating a surface diffuseness of the nuclear density...
Studies of hypernuclei have been contributing for understanding the fundamental baryonic interactions as well as the nature of dense nuclear matters. They have already been studied for almost seven decades in reactions involving cosmic rays and with meson- and electron-beams. In recent years, experimental hypernuclear physics enters a new era. Hypernuclei can also be studied by using energetic...
Since the 1938 $\it{Annus}$ $\it{mirabilis}$ which included the discovery of fission by Meitner and Frisch [1] and the recognition by Ruhlig that the D-T reaction was “highly probable” [2], nuclear science has offered society the promise of abundant energy. In the last decade the onset of global climate change has accelerated the development of advanced nuclear energy systems that utilize new...
The Active Target Time Projection Chamber (AT-TPC) has been used in experiments aimed at the exploration of structural effects in radioactive nuclei using one step reactions such as transfer or elastic and inelastic scattering. When used as a solenoidal spectrometer by placing it inside a magnetic field, the AT-TPC allows to perform this type of measurement in inverse kinematics with much...
Isotopes of SuperHeavy Elements (SHE) boast extraordinary numbers of protons and neutrons and push the boundaries of the nuclear chart and our understanding of nuclear structure. Typically, SHE isotopes follow one of two primary decay paths: emission of an $\alpha$ particle or Spontaneous Fission (SF). A more robust understanding of the mechanism for SF in the SHE region is of great...
The Jinping Underground experiment for Nuclear Astrophysics (JUNA) takes advantage of the ultra-low background of the CJPL to conduct experiments for directly studying crucial reactions at stellar energies in the evolution of stars. In 2020, JUNA commissioned an mA level high current accelerator based on an ECR source, as well as high efficiency BGO and $^3$He detectors. These combination...
In nuclei near the $N=20$ island of inversion, the non-central tensor components of the nuclear interaction drive the preferential population of $pf$-shell orbitals over the $sd$-shell orbitals predicted by the spherical shell model. High precision excited state lifetime measurements in nuclei across the Mg isotopic chain provide a means by which this evolution of neutron shells can be studied...
Recent investigations into the inelastic scattering cross sections of neutrons and protons off $^{56}$Fe were conducted at the GELINA neutron source of the EC-JRC in Geel (Belgium) and at the 9 MV Tandem accelerator of IFIN-HH (Romania). For each reaction, distinct HPGe-based spectrometers were employed to determine the production cross section of the first transition in $^{56}$Fe...
In this invited contribution, I will present highlights from recent nuclear structure and reaction studies conducted at the John D. Fox Superconducting Linear Accelerator Laboratory at Florida State University. I will focus on light-ion induced reactions measured with the Super-Enge Split-Pole Spectrograph (SE-SPS) and its ancillary detector systems, including the CeBrA demonstrator for...
Simultaneous analyses are performed for cross section data of elastic scattering, Coulomb breakup, transfer and other direct yields for the $d$+$^{197}$Au system at all available energies. The data are reproduced well by the optical model using bare and dynamical polarization potentials. This method of calculation can be successfully applied to the reactions of deuteron with with heavy targets.
Exploring neutron-rich nuclei near the drip-line with significant N/Z asymmetry exposes exotic phenomena like the existence of neutron halo or skin and (dis)appearance of existing magic numbers. Nuclear halos result from spatial distribution of outermost neutrons, causing a low-density extended neutron surface and a notable increase in matter radius. A systematic study of the point proton...
The Compressed Baryonic Matter (CBM) experiment aims to explore the phase structure of strong- interaction (QCD) matter at large net-baryon densities and moderate temperatures by means of heavy-ion collisions in the energy range √sNN = 2.9 - 4.9 GeV. The CBM is under construction at the Facility for Antiproton and Ion Research (FAIR) and will be equipped with fast and radiation hard detector...
Studying exotic nuclei exhibiting an extreme ratio of neutrons to protons is the primary means for better understanding of fundamental nuclear properties, which is crucial to comprehend the formation and existence of heavy elements in our universe. Nevertheless, it is well understood that nuclei from certain regions on the chart of nuclei, i.e., heavier and more neutron-rich than the heaviest...
The conventional magic number N=20 has been shown to break down in the region of neutron-rich nuclei centered around $^{32}$Mg (Z=12, N=20) known as the N=20 Island of Inversion. At the same time, a new magic number at N=16 has been suggested to emerge around $^{24}$O (Z=8, N=16). The neutron-rich nucleus $^{25}$Ne (Z=10, N=15) lies in this zone of rapid change in nuclear structure....
At the 88-inch cyclotron facility of Lawrence Berkeley National Laboratory (LBNL) the decay properties of heavy and superheavy elements are studied using the Berkeley Gas-filled Separator (BGS). So far, the heaviest known elements found on the periodic table are best produced through fusion-evaporation reactions involving actinide targets and intense beams of $^{48}$Ca. To search for potential...
TACTIC (TRIUMF Annular Chamber for Tracking and Identification of Charged particles), a cylindrical active target detector with an extended gas target, is being jointly developed by the University of York, UK and TRIUMF, Canada. The design of TACTIC is suitable for the direct measurement of alpha-induced charged particle reactions at multiple centre of mass energies utilising a single beam...
The origin of the elements in the universe is one of the long-standing problems in nuclear physics. In particular, the r-process attracts much attention since the hint of the heavy elements were detected after the gravitational wave was detected. To reveal the astrophysical conditions such as the neutron densities and the temperature, the nuclear physics parameters are highly demanded. Among...
The K500 Superconducting Cyclotron had been developed at Variable Energy Cyclotron Centre, Kolkata, for the basic nuclear physics experiment. Recently, the machine had delivered beam, for the first time, to the user for nuclear physics experiment. Detail characterization of the beams was performed with elastic scattering experiment with a 197Au target. Two independent approaches (one method by...
The Borromean structure of the dripline nucleus ${}^{19}$B has garnered the attention of theories and experiments. The enigma is whether the structure of ${}^{19}$B is '${}^{15}$B core + 4$n$' or '${}^{17}$B core + 2$n$'. The point proton radius ($R_p$) is an ideal measure for probing the structure of the nucleus. Further, a combined knowledge of $R_p$ and the point matter radius enables us to...
The semi-magic $^{120}_{50}$Sn$_{70}$ lies in the neutron mid-shell among the other stable Sn isotopes, where $2p-2h$ intruder configurations built on excited 0$^+$ states have been recently observed. However, the transition rates from the $0^+_3$ state in $^{120}$Sn are not well-known because its lifetime only has a lower limit of 6 ps, which prevents a firm assignment or exclusion of the...
Quasi-fission reactions present a substantial hindrance to the formation of super heavy elements. The collision of two heavy nuclei leading to a quasi-fission reaction produces fragments with strikingly similar characteristics to those of fusion-fission reactions. However, unlike fusion-fission, there is no intermediate formation of a fully equilibrated compound nucleus.
This departure from...
The abundance of $^{26}$Al carries a special role in astrophysics, since it probes active nucleosynthesis in the Milky Way and constrains the Galactic core-collapse supernovae rate.
It is estimated through the detection of the 1809 keV $\gamma$-line and from the superabundance of $^{26}$Mg in comparison with $^{24}$Mg in meteorites. For this reason, high precision is necessary also in the...
The world's first electron scattering off online-produced Radioisotope (RI) was successfully conducted at the SCRIT electron scattering facility. Electron scattering stands out as one of the most potent and reliable tools for investigating the structure of atomic nuclei, owing to the well-understood mechanism of electromagnetic interaction.
Despite a long-standing desire to explore exotic...
Several campaigns have been undertaken in order to synthesize new superheavy elements (SHEs). In order to determine the optimal experimental parameters for success, there has been much attention given to factors that are important to the survival of the compound nucleus. Among these factors is the effect of nuclear deformation: it is known that a larger quadrupole deformation results in an...
Heavy-ion collisions have been a fascinating venue to study Quantum Chromo-Dynamics (QCD), the theory of strong nuclear force, under extreme conditions. When the nuclei collide, an exotic phase of matter, the quark-gluon plasma (QGP), is created. The QGP is believed to have existed in the early universe microseconds after the Big Bang. Jets, sprays of particles originating from high-energy...
In the past two decades, significant progress has been made with the discovery of elements Z=114-118 through reactions between 48Ca beams and actinide targets, achieving production rates of atoms-per-day or more. Unfortunately, the pursuit of elements beyond Oganesson (Z=118) faces substantial challenges. The synthesis of elements with Z=119 or 120 using 48Ca would necessitate targets of Es...
Multinucleon transfer (MNT) reactions have recently gained renewed interest as they provide access to heavy neutron-rich (n-rich) nuclei, particularly around N = 126 and actinides, which are relevant to r-process nucleosynthesis [1]. They produce a wide variety of nuclides around both the projectile and the target, with a wide distribution of angles and energies, requiring the development of...
A comprehensive picture of nuclear structure results from the complementary information obtained at the different facilities by means of a variety of nuclear reactions and complex experimental setups. Gamma-ray spectroscopy is the ideal tool to obtain detailed information on different nuclear properties. The coupling of gamma-arrays to particle detectors has increase enormously the selective...
The partonic structure of the proton has been established in deep inelastic scattering and a detailed picture of the nucleon has emerged from a wide range of experiments and global analyses. Hadronic collisions allow direct access to the gluon content in the nucleon and polarized beams introduce an additional degree of freedom, spin, which is naturally connected to parton kinematics. Polarized...
In this talk, I will describe first-principles-based equations of state (EoSs) for QCD that serve as crucial input for simulations of hot, dense strongly-interacting matter. The first is solely informed by the fundamental theory by utilizing all available diagonal and off-diagonal terms that contribute to the Taylor expansion of the pressure up to $\mathcal{O}(\mu_B^4)$. This allows for the...
A search for new isotopes near the neutron dripline was conducted for fluorine, neon and sodium at RIKEN RIBF [1], in which isotopes were produced by projectile fragmentation of an intense 48Ca beam at 345 MeV/nucleon, and separated and identified in flight using the large-acceptance two-stage separator BigRIPS [2,3]. The 48Ca beam intensity was as high as ~540 pnA. In the experiment we...
The nuclear incompressibility parameter, K$_{\infty}$, is an important component characterizing the nuclear equation of state, with crucial bearing on diverse nuclear and astrophysical phenomena. The only direct experimental measurement of this quantity comes from the compression-mode giant resonances--the isoscalar giant monopole resonance (ISGMR) and the isoscalar giant dipole...
Since its inception, nuclear physics has used nuclear reactions to deepen our understanding of a quantum system as complex as the atomic nucleus. The arrival of the FAIR beams, in particular the improvement in the intensity delivered, and the development of state-of-the-art instrumentation, open up a wide range of possibilities for carrying out frontier experiments. R3B is a scientific...
Half of the elements heavier than iron are produced by a sequence of neutron captures, beta-decays and fission known as r-process. It requires an astrophysical site that ejects material with extreme neutron rich conditions. Once the r-process ends, the radioactive decay of the freshly synthesized material is able to power an electromagnetic transient with a typical intrinsic luminosity. Such...
Obtaining reliable data for nuclear reactions on unstable isotopes remains an important task and a formidable challenge. Cross sections for neutron-induced reactions are particularly elusive, as both projectile and target are unstable. Various indirect methods have been proposed to address this problem. The 'surrogate reaction method' [1] uses inelastic scattering or transfer ('surrogate')...
In the area known as the “island of inversion,” neutron-rich nuclei around N=20 exhibit substantial admixtures of intruder configurations in their ground states, thus leading to the breakdown of the N=20 major shell gap. Central to this island of inversion is the nucleus 32Mg, which has been the subject of study for several decades and serves as a critical benchmark for nuclear models and our...
The ratio [1,2] is a new reaction observable suggested to extract accurately structural information on halo nuclei. It is based on the Recoil Excitation Breakup (REB) model [3], which predicts that taking the ratio of angular distributions for breakup and scattering, the uncertainty related to the reaction dynamics is strongly reduced [1,2]. It exhibits a much better accuracy than traditional...
The rapid neutron capture process ($r$-process) is responsible for creating more than half of the nuclei heavier than iron. Through a series of neutron captures, $r$-process facilitates the creation of neutron-rich nuclei up to the neutron drip line. A theoretical input for the description of this process requires knowledge of nuclear masses, neutron capture mechanisms, $\alpha$-decays,...
I will review research activities ongoing in Japan related to low-energy electron scattering conducted for nuclear physics will be presented. These include electron scattering for proton charge radius measurement (ULQ2) and for structure studies of short-lived exotic nuclei (SCRIT).
ULQ2 (Ultra-Low Q2) for proton charge radius
Electron scattering off proton covering an extremely low...
PREX 2 and CREX, recently completed at Jefferson Lab in Newport News, Va, measured the weak form factors of lead and calcium. The PREX 2 result has confirmed that the neutron skin of lead is relatively large and has provided a precise determination of the interior baryon density of a heavy nucleus. The CREX measurement was performed at a non-optimal momentum transfer and has produced a...
In the region of the neutron deficient pre-actinides, around 198Pb and 180Hg, there is an unexpected island of asymmetric fission. That these asymmetric fission decay modes evaded detection until recently, but now are feasible, is a testament to the capabilities of rare isotope facilities. To develop a method to determine fission barriers for rare isotopes and to study the transition between...
In recent years, fusion-evaporation reactions have increasingly been used to study neutron-rich nuclides near the $N=20$ 'island of inversion' [1 - 3]. In this region, the evolution of the $N=20$ shell gap is indicated by the energies of negative parity states which primarily arise due to single neutron excitation to the higher lying $fp$ orbitals. These negative parity states often have...
Determining the equation of state (EoS) for nuclear matter is essential in order to understand the macroscopic properties of nuclear matter in equilibrium states in both finite systems (nuclei) and infinite systems (neutron stars). The purpose of this study is to derive the density-dependent parameter L of the symmetry-energy term of the EoS from the isotope dependence of neutron skin...
Astrophysical objects such as neutron star formation and structure and supernovae explosion, as well as nuclei properties and structure are described using the equation of state of nuclear matter. However, the coefficients of the equation state describing the nuclear matter with a huge charge asymmetry, notably the symmetry energy, is lacking constraints [1,2].
When a medium-to-heavy...
Intruder states that originate from the promotion of neutrons across the N=50 shell gap are observed along the N=49 isotones ($^{79}$Zn, $^{81}$Ge, $^{83}$Se, $^{85}$Kr), with the lowest energy in $^{83}$Se. The reduction of the N=50 shell gap towards $^{78}$Ni favors the lowering in the energy of these states. Moreover, since the $^{83}$Se nucleus (Z=34) is in the middle of the proton...
The projectile fragmentation reaction is crucial in experimental studies that use radioactive nuclear beams. The isotropic momentum ($P$) distribution of produced fragments, which is observed at relativistic energies, is reasonably explained by a simple model based on the Fermi motion of nucleons in a projectile [1]. At lower energies around 100 MeV/nucleon, the contribution of reaction...
The r-process nucleosynthesis (in explosive astrophysical events) is responsible for about half of the heavy elements observed in the universe. However, r-process outputs in the literature are difficult to replicate and vary across studies due to differences in nuclear mass models or initial conditions (e.g., seed nuclei). I will discuss why a thorough sensitivity analysis is required to...
The focus of this work is neutron-rich Fe and Mn isotopes with N~40, which lie within an Island of Inversion approximately centered at 64Cr. Here, a quenching of the N=40 sub-shell gap allows multi-particle multi-hole excitations and deformation to develop in the ground-state configurations of nuclei in the region. Limited spectroscopic information has been collected so far in the...
Our knowledge of the properties of dense nuclear matter is usually obtained indirectly via nuclear experiments, astrophysical observations, and nuclear theory calculations. Advancing our understanding of the nuclear equation of state (EOS, which is one of the most important properties and of central interest in nuclear physics) has relied on various data produced from experiments and...
The shell structure of nuclei is the backbone of the nuclear theory. A large energy gap with the completely filled spherical orbitals defines shell closure and magic number. One of the intriguing experimental findings is the disappearance of shell closure at certain N and Z, which is not predicted from the classical shell model. This Island of Inversion (IOI) has been successfully explained...
Mirror energy differences act as a magnifying glass into the evolution of the nuclear structure phenomena as a function of angular momenta. In recent years, detailed studies aimed to probe the influence of isospin non-conserving interaction and the effects of halo orbits and their occupation on the displacement of analogue excited states of mirror partners were performed, showing excellent...
The isospin character of the p-n pair at large relative momentum has been observed for the first time in the 16O ground state. We have measured the 16O(p,dp) and 16O(p,dn) cross sections for the neutron pick-up domain with 392 MeV incident proton at RCNP. The outgoing deuteron was momentum analyzed by the high-resolution spectrometer GrandRAIDEN. Recoiled nucleons N [p or n] were measured by...
We are all star dust. Everyone we know and everything we see here on Earth are the leftovers of massive nuclear explosions that occurred naturally in our universe, a long time ago. Understanding the origins of the chemical elements, and how we came to be, requires detailed knowledge of the complex subatomic interactions between neutrons and protons that led to the existence of bound nuclei and...
The Hoyle state, second excited state of 12C at an excitation energy of 7.65 MeV, plays an important role in nucleosynthesis. Particularly the radiative decay of the Hoyle state is the doorway to the production of heavier elements in stellar environment. An exclusive experiment has been performed to measure the radiative decay width of the Hoyle state of 12C through the 12C(p, pγγ)12C reaction...
Nuclear theories often operate under the assumption that the strong nuclear force is independent of electric charge. Therefore, it is expected that exchanging the number of protons with the number of neutrons in a nucleus will produce a ${\it mirror~nucleus}$ with identical structure after electromagnetic considerations. However, charge dependence in nuclear theories is required due to isospin...
The DEcay Spectroscopy (DESPEC) collaboration aims at measuring exotic nuclei produced via fragmentation and fission reactions at GSI/FAIR. In the DESPEC experiments, ions will be stopped in an active implanter and their subsequent decays measured. The active implanter’s role is to provide implantation times and positions and then detect the times and positions of subsequent decaying particles...
Heavy-ion fusion reaction is powerful in expanding the chart of nuclides and exploring the nuclear structure beyond Pb, especailly for high excited states.
The formation of Evaporation Residues (ERs) is governed by three terms: transmission coefficient to overcome the potential barrier, formation probability of Compound Nucleus (CN) and the survival probability of CN against fission. The...
Large-scale computations of fission properties play a crucial role in nuclear reaction network calculations simulating rapid neutron-capture process (r-process) nucleosynthesis. Due to the large number of fissioning nuclei contributing to the r-process, a description of particle-induced fission reactions is computationally challenging. In this contribution, we will use the experimental data on...
In recent times, it is quite complex to determine various nuclear characteristics, e.g., shape, mass, quadrupole ($\beta_{2}$) and hexadecapole ($\beta_{4}$) deformations, which is the fundamental interest of contemporary research. In this context, sd-shell nuclei ($^{20}$Ne, $^{28}$Si, $^{24}$Mg, and $^{32}$S) are of special interest as their deformation parameters vary in sign and magnitude...
Tin (Sn),with its magic proton number Z=50, stands out in the periodic table for having the most stable isotopes. This rich array of isotopes makes Tin an ideal candidate for testing theoretical models aimed at describing the effective nuclear force. The singly-magic nucleus Sn-114, with N=64, is situated in the neutron mid-shell between the N=50 and N=82 magic numbers. Tin isotopes that are...
Several works focused on light isotopes [1,2,3] have shown a reduction of the cross sections with respect to the theoretical predictions for single-nucleon knockout reactions. These studies have reached different conclusions regarding the dependence of the reduction factor observed of the spectroscopic factor with respect to the N/Z of the projectile. The study of (p,pX) knockout reactions...
The study of neutron unbound systems via the invariant mass technique is the primary focus of the MoNA Collaboration, which built and operates the Modular Neutron Array (MoNA) and the Large multi-Institutional Scintillator Array (LISA) at FRIB. Advancements in nuclear structure from theory and experiment along the neutron dripline have presented opportunities to understand the nature of...
Accurately characterizing the behaviour of collective states within the context of the shell model and capturing how this feature evolves throughout the chart of nuclides are ubiquitous objectives in the field of nuclear structure. This initiative continues to present as extraordinarily non-trivial when considering regions of heavy nuclei, as such nuclei are highly unique many-body systems...
Nowadays, the study of exotic nuclei is an active area of research, from both experimental and theoretical perspective. Due to low binding energies, exotic nuclei are weakly bound and as a result can break up very easily. This makes it interesting to study their nuclear structure. Our goal in this work is to contribute towards better understanding of the breakup process and its effect on other...
Exotic nuclei are transforming our understanding of the nuclear force, one manifestation of which is seen in nuclear shells. The conventional nuclear shell model fails to explain the exotic structures seen in nuclei far from stability. In this experiment we examine the exotic borromean nucleus $^{20}$Mg. $^{20}$Mg is located at the proton drip-line with an expected conventional N=8 shell...
In this presentation, I will discuss recent advancements in understanding the electric response of stable nuclei through the inelastic scattering of protons, utilizing the high-resolution Grand Raiden spectrometer. Our study focuses on several key phenomena, including the excitation of giant and pygmy dipole resonances, the electric dipole polarizability of nuclei, and the gamma-decay of giant...
Fusion ignition by inertial confinement requires compression and heating of the Deuterium-Tritium (DT) fuel to temperatures in excess of 5 keV and densities exceeding hundreds of g/cc resulting in self heating of the DT by $\alpha$-particles, and the release of more energy than use to implode the fuel capsule.
In August 2021 this scientific milestone was surpassed at the NIF when the...
The nuclear equation of state plays a central role for the physics of nuclei and dense matter in neutron stars. We discuss constraints on the equation of state from nuclear theory, experiments, and observations, focusing on neutron-rich conditions. On the theory side, we present chiral effective field theory calculations for arbitrary proton fraction and temperature using a Gaussian process...
Quasifission occurs in fully damped heavy-ion collisions following a significant mass transfer between the fragments, without formation of a compound nucleus. It is the primary reaction mechanism hindering the formation of a superheavy compound nucleus after the collision partners have reached contact. As in fission, quasi-fission is expected to be affected by quantum effects leading to...
Proton and alpha captures on unstable nuclei play a key role in determining the pathway of nucleosynthesis in explosive astrophysical environments, as well as energy generation throughout the cosmos. With remarkable advancements in radioactive ion beam technology, we are now able to study such reactions in terrestrial laboratories, and hence, have dramatically increased our understanding of...
The existence of a superconducting phase associated with the breaking of particle number conservation, has been first identified in metals in the context of the BCS theory. It was realized very soon that the underlying mechanism, connected with pairing correlations at work in the formation of Cooper pairs, bore great generality and was expected to be relevant for a large variety of fermionic...
The nuclear structure of doubly magic nuclei, such as 100Sn and its neighboring isotopes, has attracted significant attention from both experimental and theoretical perspectives. This interest stems from the unique insights it offers for testing the nuclear shell model and its relevance to the astrophysical rapid-proton capture process [1].
The Cd isotopic chain plays a crucial role in...
The exploration of heavier elements has resulted in several unexpected discoveries and has enhanced our understanding of nuclear synthesis and related phenomena. Although new elements and their isotopes have been synthesized, the amount of information with the Z ≥ 102, remains somewhat scarce. Also, the nuclear shell effects are of significant relevance for ensuring nuclear stability. Our...
We present a new revision of nuclear fusion reaction cycles whereby a solid room temperature lithium-6 deuteride ($^6$LiD) is burnt with neutrons beams. New calculations of the time evolution of a network of differential equations for the abundances of various nuclear species are presented. Data on nuclear cross-sections and non-thermal reaction rates are used to forecast the full time...
Laser-driven (LD) proton sources are of interest for various applications due to their ability to produce short proton bunches with high charge and low emittance. These sources can be used in biological studies investigating improvements to radiation cancer therapy. Recently, the differential sparing effect on normal tissues versus tumors using the delivery of high radiation doses >10 Gy at...
Determination of equation of state (EoS) for nuclear matter at high baryon density region is a topic of current interest in high-energy heavy-ion collisions and astrophysics. The pion/kaon HBT correlation (also called HBT interferometry) and intermittency are sensitive probes of the nuclear EoS. Within the UrQMD framework, it is found that the correlations of protons, correlated proton pairs...
Background: Over the past two decades high energy-resolution inelastic proton scattering studies were used to gain an understanding of the origin of fine structure observed in the isoscalar giant quadrupole resonance (ISGQR) and the isovector giant dipole resonance (IVGDR). Recently, the isoscalar giant monopole resonance (ISGMR) in $^{58}$Ni, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb was studied...
Heavy ion collisions are a powerful tool to explore nuclear matter at sub-saturation densities. Central collisions for 58,62Ni+40,48Ca systems at 25 and 35 AMeV were studied benefiting of the peculiarities of the CHIMERA 4π multidetector [1], an experimental apparatus installed at INFN-LNS in Italy, characterised by low identification thresholds, measurement of velocity by time-of-flight...
Heavy-ion fusion reactions are essential to investigate the fundamental problem of quantum tunnelling of many-body systems with intrinsic degrees of freedom. Fusion of light systems is a base for understanding the astrophysical reactions responsible for energy production and elemental synthesis in stellar environments$^1$. Large fusion enhancements are found near the barrier, however, a...
The anomalies in the electron-positron angular correlations from high-energy decays of 8Be were interpreted by the ATOMKI collaboration as evidence of a new beyond-the-Standard Model boson. A theoretical understanding of the nuclear physics involved is an important step towards verification of this claim. Hence, we investigate proton capture with the ab initio no-core shell model with...
The aim of this contribution is to introduce the recently developed experimental setup for laser-driven isomer production at the 1-PW laser arm of ELI-NP (E7 experimental area). The study of nuclear isomers production and their photoreactions has been a subject of lasting interest in the nuclear physics community. Nuclear isomers play a crucial role in the creation of the elements in the...
The ‘island’ of fission isomers identified in the actinide region ($Z$ = 92 - 97, $N$ = 141- 151) originates from multi-humped fission barriers, which can be described as the result of superimposing microscopic shell corrections to the macroscopic liquid drop barrier. For the first time, populating fission isomers by using the in-flight fragmentation and the electromagnetic dissociation...
New results on the strongly deformed proton-rich $A\approx 115 \div 130$ nuclei obtained from recent experiments performed using high-efficiency gamma-ray arrays and ancillary detectors will be presented. Shape coexistence in Cs nuclei and the extent of octupole correlations in Xe and Ba nuclei will be discussed. The experimental results will be compared with different theoretical models...
In nuclear matter at low density clusterization of α-particles is favored over nucleonic matter due to the density dependence of the nuclear symmetry energy. Time-dependent density functional theory calculations reveal that by driving regions of the system to low density during a collision formation of α-particles is enhanced. The dependence of this clusterization on neutron-excess is an open...
The $R^{3}B$ (Reactions with Relativistic Radioactive Beams) experiment as a major instrument of the NUSTAR collaboration for the research facility FAIR in Darmstadt is designed for kinematically complete studies of reactions with high-energy radioactive beams. Part of the broad physics program of $R^{3}B$ is to constrain the asymmetry term in the nuclear equation-of-state and hence improve...
To detect and track structural changes in atomic nuclei, the systematic study of nuclear levels with firm spin-parity assignments is important. While linear polarization measurements have been applied to determine the electromagnetic character of gamma-ray transitions, the applicable range is strongly limited due to the low efficiency of the detection system.The multi-layer Cadmium-Telluride...
Neutron stars represent the only known place in the universe where neutrons are held in close proximity. This unique scenario results from the extreme gravitational forces that compress them together in nearly pure neutron matter. However, the existence of an isolated multi-neutron system is still an open question.
Theoretical predictions have long suggested the existence of an exotic...
The experimental B(E2) values in light even-even Sn isotopes are found to be enhanced compared to theory, a discrepancy which has eluded a satisfactory solution for over a decade. For further examination, supplementary information such as spectroscopic quadrupole moments ($Q_s$) are needed.
A safe-energy Coulomb excitation of $^{110}$Sn was conducted at HIE-ISOLDE, CERN. The $^{110}$Sn beam...
Using the relativistic mean-field model with the isoscalar- and isovector-meson mixing, $\sigma^{2}{\mathbf{\delta}}^{2}$ and $\omega_{\mu}\omega^{\mu}{\mathbf{\rho}}_{\nu}{\mathbf{\rho}}^{\nu}$, we present a new nuclear equation of state (EoS), which satisfies the large neutron skin thickness, $R_{\rm skin}$, of $^{208}$Pb and the small neutron-star radius, respectively reported by the PREX-2...
We present new data for the $^{19}$F(p,$\alpha_0$)$^{16}$O and $^{19}$F(p,$\alpha_\pi$)$^{16}$O$^*$ reaction channels in the energy region close to the Coulomb barrier, thanks to a new experiment performed at the Singletron accelerator, in Catania (Italy). This measure allowed us to to extract new integrated cross section data and to reach two important goals: i) to solve an important...
The Coupled Channels (CC) model successfully explained the observed structures in the barrier distributions (BD) for many systems. However, there are several mechanisms whose influence on fusion is still not clear, as the role of weak (non-collective excitations) reaction channels. The experimental BD of some systems turned out to be without any structure, in contradiction to theoretical...
The MoNA-LISA neutron array is the primary detector to study neutron-rich nuclei along the neutron dripline by the MoNA Collaboration at the Facility for Rare Isotope Beams of Michigan State University. Recently, a Major Research Instrumentation funding request was awarded by the National Science Foundation to build a Next Generation neutron detector that will complement MoNA-LISA but also...
Accurate predictions of nuclear reaction rates are essential to refine our comprehension of the nucleosynthesis and to support the experimental study of unstable nuclei. Reactions involving light nuclei at low energies can be accurately described using first-principle methods, treating all nucleons as active. For reactions with heavier nuclei and at energies above ~10 MeV/nucleon, such...
New experimental data on various hypenuclei have been produced at J-PARC hadron experimental facility, in Japan. New information on hyperon-proton interactions are accumulated with high intensity hyperon proton scattering measurements one of which was J-PARC E40 measuring $\Sigma^+$p and $\Sigma^-$p scattering at rather high momentum. It was suggested that the effects of the repulsive core...
INFN-LNL is constructing an ISOL (Isotope Separation On Line) facility to deliver neutron rich ion beams up to 10 A MeV, making use of the linear accelerator ALPI as the post-accelerator. In parallel, an applied physics facility based on the usage of the high intensity proton beam from the cyclotron driver of the ISOL facility, is included. The status and future plans for completion of the...
The soft or low transverse momentum physics of relativistic heavy ion collisions can be well described by relativistic fluid dynamics. This is a universal theoretical description which employs from QCD as the underlying quantum field theory the thermodynamic equation of state and transport properties like viscosities and conductivities, as well as relaxation times. I will review the overall...
This presentation will provide an overview of ultrahigh dose-rate (FLASH) radiotherapy, one of the most exciting recent advancements in radiotherapy of cancer. FLASH radiotherapy, delivered in a fraction of a second, is an experimental treatment modality that reduces normal tissue toxicity while maintaining tumor control compared to conventional radiotherapy. FLASH radiotherapy is typically...
In 2017, a multimessenger era started with the first gravitational wave detection from the merger of two neutron stars (GW170817) and the rich electromagnetic follow-up. The most exciting electromagnetic counterpart was the kilonova. The neutron-rich material ejected during the neutron star merger undergoes an r-process (rapid neutron capture process) that produces heavy elements and a...
Superheavy nuclei (SHN) with extremely large amount of nucleons (e.g., protons up to Z = 126) are still one of the main subject in nuclear physics 1. The main purpose of this research is to examine the fission-stability of SHN at around Z = 114 − 126 and N = 184, where occurrences of next closed shells are theoretically expected [1].
To date, SHN with Z up to 118 (Og, Oganneson) are known...
Radiopharmaceutical therapy (RPT) is emerging as a promising method to treat advanced and hard-to-treat cancers. This approach relies on a radionuclide attached to a targeting vector that has strong affinity for unique cell biomarkers overexpressed on cancer cells, enabling the direct and selective delivery of a radioactive payload to diseased cells to facilitate diagnosis/staging or therapy,...
Heavy and super-heavy nuclei, which form the upper end of the chart of nuclei, owe their stability, and for the heaviest systems their sheer existence, to the delicate interplay between the repulsive Coulomb interaction between the many protons of the nucleus and the strong nuclear interaction, which binds the nucleons together. The study of the heaviest nuclei is not only an experimental...
It is well known that nucleons are arranged in specific shells resulting in greater stability, analogous to the electron shells in the atom and that this shell structure was expected to be very robust in the whole nuclear chart. However, with new experimental techniques and progress in the production of radioactive ion beams during the last two decays, we are now aware that the shell structure...
The penetrating nature of electromagnetic radiation makes it an ideal candidate to investigate the properties of the Quark-Gluon Plasma (QGP). A selection of recent developments in the theory and phenomenology of electromagnetic probes is discussed, with an emphasis towards how they can be employed to constrain transport phenomena in the QGP. The complementary between electromagnetic radiation...
The search for new element 119 is currently underway at RIKEN with the $^{248}$Cm($^{51}$V,$xn$)$^{299-x}$119 reaction [1]. The superconducting RIKEN heavy-ion Linear ACcelerator (SRILAC), the $^{248}$Cm target material supplied from Oak Ridge National Laboratory and GAs-filled Recoil Ion Separator III (GARIS-III) are being used. For the effective synthesis of superheavy nuclei, it is...
The gamma-ray decay of nuclear states in the quasi-continuum provides important nuclear data for various applications, insights into nuclear structure effects and constraints on nucleosynthesis processes. In particular, measurements of Nuclear Level Densities (NLDs) and Photon Strength Functions (PSFs) have and will continue to play a central role as we have entered an era of incredible...
Alpha clustering is a crucial concept to understand nuclear structures. Alpha particles, which are tightly bound with no excited states up to $E_x\sim 20$ MeV, often behave as well established subunits in nuclei, forming what are known as alpha cluster states.
Of particular interest are alpha condensed states where all alpha clusters are condensed into the lowest s orbit. Due to this unique...
Type I X-ray bursts are the most common stellar explosions in our Galaxy, resulting from explosive hydrogen-helium burning. These bursts are triggered by thermonuclear ignition in the envelopes of accreting neutron stars within low-mass binary systems. Understanding the mechanisms behind these bursts requires knowledge of key nuclear reactions occurring in this stellar environment. However,...
Understanding the Quark Gluon Plasma (QGP), whose existence was known from the combination of three observations, is the central goal of high energy nuclear physics. All the three observations came from studying elliptic flow, and the purpose of this research was to investigate the effect of electromagnetic field evolution created in relativistic heavy ion collision on the flow of identified...
We report new data on the 3He+13C->4He+12C* reaction investigated at very low bombarding energy with the solid-state OSCAR hodoscope at the AN-2000 accelerator of INFN-LNL.
Thanks to the excellent identification capabilities of the HELICA setup, several nuclear reactions, including 13C(3He,p)15N, 13C(3He,d)14N, 13C(3He,alpha)12C, leading the residual nucleus to several excited states, were...
One of the main questions in nuclear astrophysics is understanding how the elements heavier than iron are forged in the stars. Heavy element nucleosynthesis is largely governed by the slow and rapid neutron capture processes. However, a relatively small group of naturally occurring, neutron-deficient isotopes, the so called p nuclei, cannot be formed by either of those processes. These ~30...
The discovery in 2010 by Andreyev et al. of mass-asymmetric fission induced by the β-delayed fission of $^{180}$Tl demonstrated for the first time the existence of mass-asymmetric fission outside the actinides. The analysis of this data showed a novel mass-asymmetric fission mode not seen in the actinides, with peaks near Z = 35, 45. Being a single measurement it was not clear with which of...
The isospin dependence of the thermometric characteristics is investigated in the reactions 78Kr+40Ca and 86Kr+48Ca at 10 AMeV [1,2,3]. These reactions were realized in the context of the ISODEC experiment, performed at Laboratori Nazionali del Sud in Catania, by using the 4π multi-detector CHIMERA [4,5]. The results of the data analysis suggest that the temperature depends on the N/Z ratio....
A new facility was designed around the thermal column beam port of the 1 MW Research Reactor at the University of Massachusetts Lowell. Thermal neutrons are collimated to a narrow 1-inch diameter beam and incident on samples to induce the radiative neutron capture. The new measurements of capture gamma rays are planned for Mn, Cu, Ni, Cr, and Gd samples in the next three years. The experiments...
Jet quenching is considered a key signature for the creation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions, and can also provide valuable insights into the QGP properties. One particular observable utilized to study the jet quenching effect is the nuclear modification factor ($I_{AA}$) for semi-inclusive hadron-triggered recoil jets, which provides access to jets of low...
Large α production cross sections are observed in the reactions involving stable weakly bound (6,7Li, 9Be) projectiles due to α+x cluster structure. In the case of 9Be, as the neutron separation energy is low, the neutron transfer cross sections are dominant. There are few energy correlation studies performed using charged particle coincidences with 9Be projectile. However, angular...
Many important nucleosynthesis processes responsible for producing elements beyond iron are thought to be driven by ($\alpha$,n) reactions, for example the s-process and weak r-process. However, measurements of ($\alpha$,n) cross-sections present significant technical challenges, especially for reactions on radioactive nuclei or noble gases where targets are difficult or impossible to produce....
Microcalorimeters determine the energy of an incoming ion by measuring the temperature rise in an appropriate absorber. It has been frequently demonstrated that they can measure the kinetic energy of heavy ions up to uranium with a relative energy resolution of the order of $\Delta E/E \leq 5 \times 10^{-3}$. Such detectors have already been applied for the investigation of the stopping power...
The nuclear clustering is a cutting-edge topic with a rich historical background. It has been established for light nuclei, such as the Hoyle state in $^{12}$C, and in alpha-decay nuclei. However, quite little is known in the case of medium and medium heavy nuclei. Furthermore, an important question is remain unanswered: How can the mean-field picture be compatible with that with...
The generation of the fission fragments spins is one of the least understood mechanism and its theoretical description has been subject to renewed interest following Wilson et al. [1]. We report on a study of the radiative decay of fission fragments populated via neutronless fission of 252Cf(sf). In such rare events the fragments are populated below their neutron separation energy, meaning...
The natural time scales of nuclear physics are such that, in the course of a collision at energies near the barrier, both structure and dynamic effects are vitally important to the resulting reaction outcomes. While this complicates theoretical descriptions of heavy-ion reactions, it opens an avenue to study difficult-to-probe phenomena like neutron skins and nucleonic equilibration across a...
DAPPER has been designed, developed, and commissioned at Texas A&M University to measure (d,p) reactions in inverse kinematics, allowing for measurements using radioactive nuclei. The array consists of a third of a ton of highly segmented BaF2 scintillator (TAMU/ORNL) to measure individual gamma ray energies as well as the total gamma ray energy with high efficiency. An annular silicon...
The formation of p-nuclei and their abundances are an important and ongoing study in nuclear astrophysical measurements. To understand and constrain theoretical models on the abundances of p-nuclei, further measurements of reactions on relevant nuclei and important branching points of the $\gamma$-process are needed. For this purpose the cross sections of (p,$\gamma$) and ($\alpha$,$\gamma$)...
Fission reactions induced by relativistic heavy nuclei have recently allowed the first complete identification of both fission fragments in atomic and mass number [1]. By using different target materials (lead or protons), one could also favour fission reactions at low and high excitation energies. In addition, these kinematic conditions allow the study of a wide variety of unstable fissile...
The interaction of jets with the Quark-Gluon Plasma (“jet quenching”) provides incisive probes of QGP structure and dynamics, and extensive jet quenching measurements have been reported at RHIC and the LHC. However, the interpretation of such measurements in terms of properties of the QGP requires their comparison to realistic model calculations, which is computationally intensive. JETSCAPE is...
Octupole correlations in nuclei near 𝑁 = 𝑍 occur between nucleons when both protons and neutrons occupy the same orbitals. This phenomenon is prominent in light Te (𝑍 = 52), I (𝑍 = 53), and Xe (𝑍=54) nuclei, especially around 𝑁 ∼ 56 and 𝑍 ∼ 56. The Fermi surface for neutrons and protons lies close to orbitals from the $d_{5∕2}$ and $h_{11∕2}$ subshells, leading to enhanced octupole...
Nuclear reactions induced by neutrons play a key role in several astrophysical scenario like primordial nucleosynthesis, s and r process and so on. From an experimental point of view, their reaction cross sections and reaction rates at astrophysically relevant temperatures are usually a hard task to be measured directly. Nevertheless big efforts in the last decades have led to a better...
One of the most well-known challenges facing the field of nuclear physics is the creation of new superheavy elements via heavy ion collisions. As we increase the charge product in the entrance channel of these collisions ($Z_pZ_t$) in the pursuit of new elements, there is a corresponding increase in the suppression of the fused heavy product (evaporation residue). In order to investigate the...
Heavy quarks (c and b) are produced predominantly in initial hard-scatterings in heavy-ion collisions at RHIC and LHC, making them ideal probes of the matter created in heavy-ion collisions. Measurements at RHIC and LHC have shown heavy quarks acquire significant collective flow from the expanding Quark Gluon Plasma (QGP), and their yields show significant suppression compared to...
The National Physical Laboratory (NPL) is the UK national metrology institute, providing cutting measurement science for the UK. As part of this NPL understands the importance of nuclear physics and the accurate measurement of nuclear decay data to underpinning research in healthcare, energy, and the environment. The Nuclear Metrology group at NPL has been undertaking a variety of programmes...
Nuclear reactions are an essential probe into isotope structure and nuclear astrophysics. They are important to learn about where nuclei come from and how they are produced.They provide critical knowledge on how neutrons and protons organize themselves to form matter as we know it and at the limits of stability.
However until recently, models for nuclear reactions included no uncertainty...
Barrier passing models of fusion implement absorption (irreversible energy dissipation) through an incoming-wave boundary condition or imaginary potential located inside the barrier, ensuring separation between channel coupling effects and absorption. Couplings to few-nucleon transfer channels are found to be important in selected cases, otherwise nuclei fuse essentially unchanged....
Investigating the boundaries of the nuclear chart and understanding the structure of the heaviest elements are at the forefront of nuclear physics. The existence of the superheavy nuclei is intimately linked to nuclear shell effects which counterpart Coulomb repulsion and therefore hinder spontaneous fission. In the region of heavy deformed nuclei weak shell gaps arise around $Z$=100 and...
Fusion reactions play an essential role in the energy production, the nucleosynthesis of chemical elements and the evolution of massive stars. Among these reactions, carbon burning is a crucial ingredient to understand the late stages of massive stars essentially driven by the 12C+12C reaction [1]. It presents prominent resonances at energies ranging from a few MeV/nucleon down to sub-Coulomb...
The low-lying structure of 13Be has remained an enigma for decades. Despite numerous experimental and theoretical studies, inconsistencies remain. Being both unbound and one neutron away from 14Be, the heaviest bound beryllium nucleus, 13Be is difficult to study through simple reactions with weak radioactive-ion beams or more complex reactions with stable-ion beams. Data from a study of 13Be...
A precise determination of proton capture rates on oxygen is mandatory to predict the abundance ratios of the oxygen isotopes in a stellar environment where hydrogen burning is active. The $^{17}$O(p,$\gamma$)$^{18}$F reaction, in particular, plays a crucial role in AGB nucleosynthesis as well as in explosive hydrogen burning occurring in type Ia novae. At temperature of interest for the...
A quantitative description of the single-particle configurations of the low-lying states in $^{12}$Be still eludes us despite numerous attempts via direct and indirect reactions. For the three previous (d,p) reactions, their reaction energies and angular coverage were not optimized so the data could not be easily interpreted in terms of well-tested reaction mechanisms. For another, these...
Fusion forming superheavy elements is strongly inhibited by the faster non-equilibrium Deep Inelastic (DIC) and quasifission processes. Long considered distinct, recent extensive measurements at ANU$^{1,2,3}$ indicate that they form a continuum.$^{1}$
For reactions with non-fissile heavy nuclei, a novel experimental approach$^{2}$ gave direct information on the time dependence of mass...
To mitigate climate change; the world energy use must achieve carbon neutrality by 2050. To achieve this goal, it is now realized that nuclear power must be a major component of the world energy system by 2030.
Current nuclear reactors GIII (Generation III) are thermal reactors that use solid Uranium Fuel and cooled by water. They consume 235 U which is less that 1% of natural Uranium. In...
sPHENIX is a new detector at the Relativistic Heavy Ion Collider (RHIC), with state-of-the-art calorimeter, tracking, and forward detectors used to explore the properties and behavior of the strongly-coupled Quark Gluon Plasma (QGP) created in heavy-ion collisions. sPHENIX features qualitatively new capabilities never before available at RHIC, and a rare probes program intended to complement...
Exploring the new elements toward the high end of the nuclear chart is one of the most interesting topics in nuclear physics. The key ingredient to stabilize nucleus in this region is a nuclear shell structure and Z=114, 120, N=184 are predicted to be new magic numbers. However, the access to such nuclei and study of their shell structure is limited by the very low cross sections. To...
The evolution of the shell structure observed in exotic nuclei has led to a change of paradigm in our understanding of the nuclear force. Extensive knowledge of the modification of shell gaps in the oxygen chain has been gathered over the past decades. With two-protons below, the carbon isotopes show exotic properties and are a good testing ground for understanding new aspects of nuclear...
The NeNa-MgAl cycles are involved in the synthesis of Ne, Na, Mg, and Al isotopes. The 20Ne(p,γ)21Na (Q = 2431.68 keV) reaction is the first and slowest reaction of the NeNa cycle and it controls the speed at which the entire cycle proceeds. At the state of the art, the uncertainty on the 20Ne(p,γ)21Na reaction rate affects the production of the elements in the NeNa cycle. In particular, in...
The neutron-rich isotopes of hydrogen, such as $\rm ^{6}H$ and $\rm ^{7}H$, are good platforms for the study of NN interactions in neutron-rich environments because they have the largest neutron-to-proton ratios known so far. However, the experimental and theoretical studies of them are still limited. For $\rm ^{6}H$, the energy of its ground state is still controversial. It is about 2.7 MeV...
Several experiments aimed at chemical properties of superheavy elements (SHE) have studied the interactions of single atoms on the surface of Si-based solid-state α-detectors. Recent advancements include coating the detectors with thin layers, such as Au, to test the effects of different surfaces. Without advancements in α-spectroscopy, the results can be inconclusive.
To overcome this, a...
Over the past decade our group has studied the continuum structure of p-rich light nuclei using the invariant-mass technique. This effort has led to the discovery of 7 new isotopes beyond the proton-drip line. Just as important are the findings of new resonances in previously known nuclei and parameter refinement of previously known resonances. Some of the more interesting results (e.g....
An accurate understanding of the slowest reaction of the CNO cycle, the $^{14}$N(p,$\gamma$)$^{15}$O, is essential for estimating the lifetimes of massive stars and globular clusters. Additionally, it plays a crucial role in determining the CNO neutrino flux emitted by the Sun. Despite the significant efforts over the last twenty years, including pioneering underground measurements made by the...
General Fusion's Director of Strategic Partnerships, Myles Hildebrand, will give an overview of
MagneƟzed Target Fusion (MTF) research at General Fusion and where it exists in the landscape of
various fusion energy research concepts. General Fusion's proposed soluƟons to four long-standing
barriers to commercial fusion will be highlighted. This overview will include past experimental work...
The commissioning of transfer reaction measurements in inverse kinematics in the SOLARIS solenoid with the Active Target Time Projection Chamber (AT-TPC) was successfully completed in the summer of 2021 at the NSCL. The goal of this experiment was to demonstrate the possibility of performing transfer reaction measurements at low beam intensities (between 100 Hz - 1 kHz) using the high...
At the Cyclotron Institute at Texas A&M University, the Heavy Elements Group has been working to study compound nucleus survivability, develop new techniques for heavy element chemistry experiments, and increase the sensitivity of the AGGIE gas-filled separator. As an analog of superheavy element production, we have investigated the effects excitation energy, deformation, and neutron binding...
The $^3$He$(\alpha,\gamma)^7$Be reaction is an important part of ongoing processes occurring in stars like our very own sun. In the fusion reaction network of the sun, the $^3$He$(\alpha,\gamma)^7$Be reaction is key to determining the $^7$Be and $^8$B neutrino fluxes resulting from the pp-II chain . In standard solar model (SSM) predictions of these neutrino fluxes, the low-energy...
Nuclei in the vicinity of the proton-drip line are experimentally accessible via fusion-evaporation reactions. The arrays of HPGe detectors used for these studies have to be complemented with ancillary devices, which make possible accurate identification of the reaction channel. The channels with neutron and/or alpha emission lead to the most exotic nuclear structures, which are produced with...
By exploiting the near-perfect symplectic symmetry that emerges from the strong interaction, the symmetry-adapted no-core shell model provides a robust ab initio description of the nucleus capable of accurately capturing challenging collective correlations and clustering features [1,2,3]. Utilizing realistic nucleon-nucleon interactions within this framework allows for a completely *ab...
Nuclear reactors are the brightest artificial neutrino sources and have been the workhorse of neutrino physics since the discovery of the neutrino. In the 1970s Lev Mikaelyan realized that neutrinos also can be used to learn about the internal state of a nuclear reactor. The past decade has seen a significant increase in the interest in reactor neutrinos and their applications to nuclear...
Superfluidity and superconductivity are remarkable manifestations of quantum coherence at a macroscopic scale. The existence of superfluidity has been experimentally confirmed in many condensed matter systems, in He-3 and He-4 liquids, in nuclear systems including nuclei and neutron stars, in both fermionic and bosonic cold atoms in traps, and it is also predicted to show up in dense quark...
Nucleons are the building blocks of atomic nuclei, and are responsible for more than 99 % of the visible matter in the universe. Around 50 years after the establishment of Quantum Chromo Dynamics as the quantum field theory describing the strong
interaction within the Standard Model of particle physics, the precise way in which the quarks and gluons compose the nucleon and build up its global...
Nuclear fusion reactions are at the heart of nuclear astrophysics as they control the energy production in stars and determine the synthesis of the elements in our Universe. Most cross sections are too small to be directly measured in a laboratory at the stellar energies. They are extrapolated by means of phenomenological nuclear models anchored to available high energy data. Cosmic rays,...
The atomic masses of superheavy elements is a valuable for calibrating and improving models of nuclear structure in the upper bound of nuclear existence. In many cases, as the difference in binding energy between $^A_Z$X and $^A_{Z-1}$X far exceeds the variance among reasonable models, a sufficiently precise mass determination could provide an orthogonal method for element identification. To...
One of the biggest questions in nuclear astrophysics regards the origin of heavy elements in the universe. The picture of traditional neutron-capture nucleosynthesis showed that two main processes contribute to elemental abundances heavier than iron, namely the slow (s) and rapid (r) processes. In recent years, observations and stellar evolution models of carbon-enhanced metal poor stars...
The character of nuclear superfluidity and the isospin modes of nucleonic pair correlations is a longstanding problem of large interest in nuclear structure physics.
In recent years, intermediate-angular momentum states in heavy N~Z nuclei such as 88Ru are becoming accessible with advances in instrumentation, most notably the new generation of -ray tracking arrays.
The low-lying energy...
I will review our recent activities on breakup and knockout reactions. The following topics will be covered:
1) New reaction model for describing knockout reactions for fragile/unbound particles,
2) Effective polarization of the reaction residue of alpha knockout reactions.
3) Description of high-energy transfer reactions with the impulse approximation.
4) Semiclassical distorted wave...
Unlike any other physical system, the atomic nucleus represents a unique dual quantum many-body system. Its constituents, protons and neutrons, are assumed to be identical, except for their electric charge. They can be seen as two representations of the nucleon, with isospin components t_z = ±1/2 for neutrons and protons, respectively. Under the assumption of charge independence of the strong...
Indirect measurements are necessary to constrain cross sections and reaction rates of nuclear reactions that are inaccessible for direct measurement. One such indirect technique is the surrogate method. This method uses an alternate reaction channel to populate a nucleus of interest, and combines resulting experimental data with theory to constrain the (n,γ) cross section. Individual γ-decay...
The atomic nucleus is a complex many-body system, with behaviour dictated predominantly by the strong nuclear force. These features give rise to the emergent property of nuclear collectivity, in which the nucleus deviates from sphericity, becoming deformed. Understanding the onset of this deformation, predominantly in its quadrupole and octupole forms, therefore requires modelling both the...
Studying the nuclei along and near the N=Z line is the best way to find answers to some fundamental questions in nuclear structure, such as charge-dependence of the nuclear interaction or the role of the proton-neutron pairing. Despite our deep understanding of the electromagnetic interaction, the differences in the binding energies in mirror nuclei cannot be reproduced theoretically, thus...
Departures from the conventional liquid-drop-like saturated density of the nucleus represent a key interest in the study of nuclear structure. Phenomena of such as bubble structures offer a unique insight into the macroscopic effects of the nuclear interaction.
We present experimental indication of the occurrence of this phenomenon in $^{46}$Ar, where the depletion is generated by the level...
The space environment poses various threats to the survivability and durability of satellites and other spacecraft. One of the most prominent is the impact of radiation on electronics systems, which can be degraded, disrupted or even destroyed by background galactic cosmic rays and space weather events. Trapped protons and electrons in the Van Allen belts that surround the Earth also pose a...
Nuclear pairing, i.e., the tendency of nucleons to form pairs, has important consequences to the physics of heavy nuclei and compact stars. While the pairing found in nuclei typically happens between identical nucleons and in spin-singlet states, the exotic spin-triplet and mixed-spin pairing phases have also been hypothesized. In this talk, I will present new investigations confirming the...
Nucleon-nucleus optical-model potentials are an effective model to characterize the nuclear interaction. They are an essential input for nuclear reaction calculations required in nuclear physics, astrophysics, cosmology, and engineering applications. Proper uncertainty quantification of the optical model is necessary to obtain reliable uncertainties on extrapolations and on any result using...
Hyperpure Germanium (HPGe) gamma-ray detectors are fundamental tools for nuclear physics thanks to their exceptional energy resolution but have some well-known drawbacks. We present here recent advancements in HPGe-contacts technology based on the innovative pulsed laser melting (PLM) method. PLM promotes an efficient diffusion of high dopant concentrations into the melted HPGe subsurface...
Recently, high-energy nuclear collisions have been proposed as a powerful tool to image the global structure of heavy atomic nuclei, such as their shapes and radial profiles. We present the first quantitative demonstration of this method by extracting the quadruple deformation $\beta_2$ and triaxiality $\gamma$ for $^{238}$U nuclei, known for its large prolate shape. We achieve this by...
Heavy Ion Accelerators (HIA) is a network of ion accelerators in Australia funded by the Australian Government’s National Collaborative Research Infrastructure program. HIA supports frontier research into nuclear physics, quantum technologies, climate and environment, dark matter, astrophysics, material and space science. HIA and the unique capabilities built around them attract international...
Quasi-free knockout reactions have been established in the past years as a versatile spectroscopic tool to study exotic nuclei accelerated to high energy of few hundred MeV/nucleon. The advantage of inverse kinematics is the possibility of kinematical complete measurements of the reaction including the detection of the remaining residue after the knockout. The applications of quasi-free...
