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The equation of state (EOS) of extremely dense matter is crucial for understanding the properties of rotating neutron stars. Starting from the widely used realistic Bonn potentials rooted in a relativistic framework, we derive EOSs by performing state-of-the-art relativistic Brueckner–Hartree–Fock calculations in the full Dirac space. The self-consistent and simultaneous consideration of both positive- and negative-energy states (NESs) of the Dirac equation allows us to avoid the uncertainties present in calculations where NESs are treated using approximations. To manifest the impact of rotational dynamics, several structural properties of neutron stars across a wide range of rotation frequencies and up to the Keplerian limit are obtained, including the gravitational and baryonic masses, the polar and equatorial radii, and the moments of inertia. Our theoretical predictions align well with the latest astrophysical constraints from observations of massive neutron stars and joint mass–radius measurements. The maximum mass for rotating configurations can reach up to 2.93 M ⊙ for Bonn A potential, while the radius of a 1.4 M ⊙ neutron star in the nonrotating case can be extended to around 17 km through constant baryonic mass sequences. Relations with good universalities between the Keplerian frequency and static mass as well as radius are obtained, from which the radius of the black widow PSR J0952-0607 is predicted to be less than 19.58 km. Furthermore, to understand how rotation deforms the equilibrium shape of a neutron star, the eccentricity is also calculated. The approximate universality between the eccentricity at the Keplerian frequency and the gravitational mass is found. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To fulfill the needs of neutron capture reaction cross-section measurement in the keV energy region in the field of nuclear astrophysics and advanced nuclear energy system development, the 4π BaF_2 Gamma-Ray Total Absorption Facility (GTAF) developed by the Key Laboratory of Nuclear Data of the China Institute of Atomic Energy (CIAE) was transplanted and installed at the Back-streaming White Neutron Source (Back-n) of the China Spallation Neutron Source (CSNS) in 2019. A series of results has been achieved and published based on the GTAF since then, and it has been identified that the need of reducing backgrounds is becoming increasingly urgent. In order to understand the origins of backgrounds and to optimize the facilities, a detailed simulation program using GEANT4 toolkits was established and is presented in this paper. The symmetry in the geometric arrangement of the 4π BaF2 detector array plays a critical role in ensuring uniform detection efficiency and accurate reconstruction of gamma-ray spectra, which is essential for neutron capture studies. To demonstrate the availability of the proven codes, several practical examples of assisting the process of experimental data and helping verify the optimization proposition are also shown in this paper. [ABSTRACT FROM AUTHOR]

The low-energy 19F(p, α )16O reaction has significant implications for nuclear astrophysics. The 19F(p, α )16O reaction occurs via three channels: (p, α 0 ), (p, α π ), and (p, α γ ). At lower temperatures, below 0.15 GK, the (p, α 0 ) channel is the dominant contributor of the reaction. The 19F(p, α 0 )16O reaction cross section in the energy range of 400–900 keV was studied in this work. Recent data in the literature reveals a roughly 1.4 increase compared to prior findings reported in the NACRE (Nuclear Astrophysics Compilation of REactions) compilation. Therefore, we present new additional result of the study published in EPJA [22] employing a silicon strip detector array (LHASA - Large High-resolution Array of Silicon for Astrophysics). The anguar distributions, the reaction cross sections and the astrophysical S-factors of the (p, α 0 ) channel were obtained through this experiment. Our findings resolve the discrepancies that exist between the two previously available data sets in the literature. [ABSTRACT FROM AUTHOR]

Isotopes at the limits of nuclear existence are of great interest for their critical role in nuclear astrophysical reactions and their exotic structure. Experimentally, exotic nuclides are challenging to address due to their low production cross-sections, overwhelming amounts of contamination, and lifetimes of typically less than a second. To this end, a Multiple-Reflection Time-of-Flight mass spectrometer at the TITAN-TRIUMF facility was built to determine atomic masses. This device is the preferred tool to work with exotic nuclides due to its ability to resolve the species of interest from contamination and short measurement cycle times, enabling mass measurements of isotopes with millisecond half-lives. With a relative precision of the order 10−7, we demonstrate why the TITAN MR-TOF MS is the tool of choice for precision mass surveys for nuclear structure and astrophysics. The capabilities of the device are showcased in this work, including new mass measurements of short-lived tin isotopes (104–107Sn) approaching the proton dripline as well as 89Zr, 90Y, and 91Y. The last three illustrate how the broadband surveys of MR-TOF MS reach beyond the species of immediate interest. [ABSTRACT FROM AUTHOR]

The neutrino dynamics in hot and dense magnetized matter corresponding to a supernova explosion is considered. It is shown that accounting for fluctuations during interaction of neutrinos with matter leads to the Fokker–Planck equation for the dynamics of the phase space distribution function. The addition to the energy transfer component of the kinetic equation is determined by straggling in neutrino collisions with a magnetized nucleon gas caused by the neutral current Gamow–Teller interaction. When accounting for the effect of fluctuations, the switching of acceleration and stopping regimes in neutrino evolution is evident for average energy. The effect of fluctuations leads to an additional increase in the hardness of the neutrino spectra. It is shown that the high-energy component of the electron antineutrino flux is enhanced in addition due to the effect of neutrino oscillations. Such a strengthening of the spectrum hardness is especially noticeable in the case of the inverted mass ordering and makes the signal more registrable by ground-based detectors. The possibilities of detecting supernova neutrinos by KM3NeT and Baikal-GVD observatories are discussed. The sensitivity of counting rate to the mass ordering is demonstrated to increase at growing difference in the hardness of energy spectra for various flavors. [ABSTRACT FROM AUTHOR]

This paper examines nucleosynthesis in a low-mass neutron star crust that loses mass due to accretion in a close binary system and reaching a hydrodynamically unstable configuration explodes. The r-process proceeds mainly in the inner crust. Nucleosynthesis in the outer crust is an explosive process with a sharp increase in temperature caused by an outward-propagating shockwave. The number of heavy elements produced in a low-mass neutron star crust during the explosion is approximately 0.041 M⊙, which exceeds the number of heavy elements ejected as jets in the neutron star merger scenario. [ABSTRACT FROM AUTHOR]

Nuclear astrophysics is an interdisciplinary field focused on exploring the impact of nuclear physics on the evolution and explosions of stars and the cosmic creation of the elements. While researchers in astrophysics and in nuclear physics are separately using machine learning approaches to advance studies in their fields, there is currently little use of machine learning in nuclear astrophysics. We briefly describe the most common types of machine learning algorithms, and then detail their numerous possible uses to advance nuclear astrophysics, with a focus on simulation-based nucleosynthesis studies. We show that machine learning offers novel, complementary, creative approaches to address many important nucleosynthesis puzzles, with the potential to initiate a new frontier in nuclear astrophysics research. [ABSTRACT FROM AUTHOR]

In recent years, several laboratory studies of CNO cycle-related nuclear reactions have been carried out. Nevertheless, extant models of stellar nucleosynthesis still adopt CNO reaction rates reported in old compilations, such as NACRE or CF88. In order to update these rates, we performed new calculations based on a Monte Carlo R-Matrix analysis. In more detail, a method was developed that is based on the collection of all the available data, including recent low-energy measurements obtained by the LUNA collaboration in the reduced background environment of the INFN-LNGS underground laboratory, on R-Matrix cross-section calculations with the AZURE2 code and on uncertainty evaluations with a Monte Carlo analysis. As a first scientific benchmark case, the reactions 17O (p , γ) 18F and 17O (p , α) 14N were investigated. Among the different stellar scenarios they can influence, the 16O/17O abundance ratio in RGB and AGB stars is the one that can be directly confirmed from spectroscopic measurements. The aim is to reduce the nuclear physics uncertainties, thus providing a useful tool to constrain deep mixing processes eventually taking place in these stars. In this work, we present the procedure we followed to calculate the 17O (p , γ) 18F and the 17O (p , α) 14N reaction stellar rates and preliminary comparisons with similar rates reported in widely used nuclear physics libraries are discussed. [ABSTRACT FROM AUTHOR]

The 22 Ne (α , n) 25 Mg reaction is of major importance in nuclear astrophysics. It is the main neutron source for the weak s-process and as such is responsible for the nucleosynthesis of 60 < A < 90 elements. In addition, it provides a strong neutron burst during the later, hottest phases of the main s-process, which modifies the final nucleosynthesis products, especially at so-called branch points, which can be used to provide insight into the stellar interior at that time. The reaction rate needs to be known below ca. 900 keV, and due to the low cross-section at these energies, a direct measurement has so far proven to be severely hampered by external neutron background at the surface of the Earth. To solve this problem, a measurement campaign (the ERC-funded SHADES project) was recently started at the deep underground Gran Sasso National Laboratory (LNGS) in Italy. We provide an overview of the experiment status and an outlook into the near future. [ABSTRACT FROM AUTHOR]

Cosmic-ray induced background sets a limit in the sensitivity of γ -ray and neutron measurements for low-energy nuclear reactions. To achieve the high precision required by stellar models, measurements must be performed in a low-background environment as possible at deep underground laboratories. At the National Laboratory of Gran Sasso the 1400 m of rock overburden suppresses the most penetrating component of the cosmic rays (i.e. muons) by a factor 10 6 with respect to the Earth's surface. In such an environment, during the last 30 years, the LUNA collaboration has performed several nuclear reaction cross-section measurements of interest for astrophysics, improving our understanding of scenarios like hydrogen burning, Big Bang nucleosynthesis and the s-process. In this work, some of the results achieved by the LUNA collaboration are discussed, with a focus on the reduction of intrinsic and beam-induced background. [ABSTRACT FROM AUTHOR]

The experimental methodologies of γ -ray detection and spectroscopy are widely used in nuclear astrophysics research that typically centers on the measurement of cross sections of reactions constituting the network of stellar nucleosynthesis. This article identifies the key factors of such endeavors and analyzes their impact on the aspired objectives. Such perspectives are known to be taken into cognizance while planning a facility for nuclear astrophysics research as well as in defining a research programme therein. [ABSTRACT FROM AUTHOR]

To address several outstanding problems in nuclear astrophysics, an accelerator centre has been developed in India. The Facility for Research in Experimental Nuclear Astrophysics (FRENA) will serve as a laboratory dedicated to nuclear astrophysics measurements. The 3 MV high current, low energy two-stage accelerator housed at FRENA is capable of delivering different types of beams—protons, alphas, carbon, silicon, among others. The accelerator can provide direct, as well as, pulsed beams of protons and alphas. A set of dedicated high efficiency detector arrays composed of solid state detectors, scintillation detectors and other particle detectors will be used at different end-stations to perform different experiments in the coming years. [ABSTRACT FROM AUTHOR]

Self-consistent strong plasma screening around light nuclei is implemented in the Big Bang nucleosynthesis (BBN) epoch to determine the short-range screening potential, e ϕ (r)/ T ≥ 1, relevant for thermonuclear reactions. We numerically solve the nonlinear Poisson–Boltzmann equation incorporating Fermi–Dirac statistics, adopting a generalized screening mass to find the electric potential in the cosmic BBN electron–positron plasma for finite-sized α particles (4He++) as an example. Although the plasma follows Boltzmann statistics at large distances, Fermi–Dirac statistics is necessary when work performed by ions on electrons is comparable to their rest-mass energy. While self-consistent strong screening effects are generally minor owing to the high BBN temperatures, they can enhance the fusion rates of high- Z (Z > 2) elements while leaving fusion rates of lower- Z (Z ≤ 2) elements relatively unaffected. Our results also reveal a pronounced spatial dependence of the self-consistent strong screening potential near the nuclear surface. These findings about the electron–positron plasma's role refine BBN theory predictions and offer broader applications for studying weakly coupled plasmas in diverse cosmic and laboratory settings. [ABSTRACT FROM AUTHOR]

Timing and/or position-sensitive MCP detectors, which detect secondary electrons (SEs) emitted from a conversion foil during ion passage, are widely utilized in nuclear physics and nuclear astrophysics experiments. This review covers high-performance timing and/or position-sensitive MCP detectors that use SE emission for mass measurements of exotic nuclei at nuclear physics facilities, along with their applications in new measurement schemes. The design, principles, performance, and applications of these detectors with different arrangements of electromagnetic fields are summarized. To achieve high precision and accuracy in mass measurements of exotic nuclei using time-of-flight (TOF) and/or position (imaging) measurement methods, such as high-resolution beam-line magnetic-rigidity time-of-flight (B ρ -TOF) and in-ring isochronous mass spectrometry (IMS), foil-MCP detectors with high position and timing resolution have been introduced and simulated. Beyond TOF mass measurements, these new detector systems are also described for use in heavy ion beam trajectory monitoring and momentum measurements for both beam-line and in-ring applications. Additionally, the use of position-sensitive timing foil-MCP detectors for Penning trap mass spectrometers and multi-reflection time-of-flight (MR-TOF) mass spectrometers is proposed and discussed to improve efficiency and enhance precision. [ABSTRACT FROM AUTHOR]

The r-process is one of the processes that produces heavy elements in the Universe. One of its possible astrophysical sites is the neutron star–black hole (NS-BH) merger. We first show that the neutrons can degenerate before and during the r-process in these mergers. Previous studies assumed neutrons were non-degenerate and the related rates were calculated under Maxwell–Boltzmann approximations. Hence, we corrected the related rates with neutron degeneracy put in the network code and calculated with the trajectories of NS-BH mergers. We show that there are differences in the nuclei distributions. The heating rates and the temperature at most can be two times larger. The change in heating rates and temperature can affect the light curves of the kilonovae. However, this has little effect on the final abundances. [ABSTRACT FROM AUTHOR]

This Resource Letter provides a guide to the literature on the field of nuclear astrophysics, and particularly the origin of the elements. Nuclear astrophysics is a multidisciplinary field that aims at understanding where everything we see around us comes from and how it came to be. Astronomical observations, astrophysics modeling, and nuclear physics experiment and theory come together to answer important questions like: Where and how are the elements created? How do stars evolve? What drives the different types of stellar explosions? What is left behind after the cataclysmic death of a star? This Resource Letter presents our current understanding of the origin of the various chemical elements, together with modern research and new developments in the field, with a particular focus on the measurement of nuclear properties for astrophysical applications. Editor's Note: For many years the source of the energy in stars was a mystery since conventional explanations (gravity and chemical reactions) yielded stellar lifetimes that were too short. With the development of nuclear physics and the interdisciplinary field of nuclear astrophysics, not only was this mystery solved, but others, like the production of elements heavier than helium, were as well. This Resource Letter describes resources that provide a guide to the field of nuclear astrophysics and the origin of the elements. [ABSTRACT FROM AUTHOR]

The University of Birmingham has a rich history in nuclear physics research dating back nearly 90 years, with key contributions to the field including the demonstration of the feasibility of an atomic bomb and the discovery of significant energy release from the fusion of light nuclei. The university operates a range of accelerators and research facilities, such as the MC40 Cyclotron and the Neutron Therapeutics BNCT accelerator, for various applications including isotope production, materials studies, and medical physics. These facilities support a wide array of research areas, from nuclear astrophysics to nuclear waste management, providing unique training opportunities for students at all levels. [Extracted from the article]

Research on radioactive ion beams produced with in-flight separation of relativistic beams has advanced significantly over the past decades, with contributions to nuclear physics, nuclear astrophysics, atomic physics, and other fields. Central to these advancements are improved production, separation, and identification methods.The FRS Ion Catcher at GSI/FAIRexemplifies these technological advancements. The system facilitates high-precision experiments by efficiently stopping and extracting exotic nuclei as ions and making these available at thermal energies. High-energy synchrotron beams enhance the system's capabilities, enabling unique experimental techniques such as multi-step reactions, mean range bunching, and optimized stopping, as well as novel measurement methods for observables such as beta-delayed neutron emission probabilities. The FRS Ion Catcher has already contributed to various scientific fields, and the future with the Super-FRS at FAIR promises to extend research to even more exotic nuclei and new applications. [ABSTRACT FROM AUTHOR]

A thorough understanding of nuclear reaction rates at low energies is essential for improving our understanding of energy generation in stars and primordial and stellar nucleosynthesis. At low energies, fusion reactions between charged particles are strongly suppressed by the presence of the Coulomb barrier, which classically inhibits the penetration of one nucleus into another. The barrier penetration causes the cross section to have a steep energy dependence at low energies, making cross section measurements very challenging. Furthermore, little is known about the impact of surrounding electrons in stellar plasmas that are currently beyond the reach of experiments. As a result, measuring the bare cross sections as accurately as possible is essential. Reaction rate measurements at very low energies have been made possible in recent years by the development of high-current low-energy accelerators as well as enhanced target and detection methods. Nevertheless, the presence of atomic electrons, which alter the Coulomb barrier by screening the nuclear charge and increase the cross section at low energies compared to the case of bare nuclei, complicates these observations. A review of the experimental and corresponding theoretical work on laboratory electron screening performed so far will be presented.

The JUNA (Jinping Underground Nuclear Astrophysics) platform has the facility with the world’s most intense beams, and provides a crucial opportunity for China to strive for a leading international position in nuclear astrophysics. The first phase of JUNA’s experiments has demonstrated a promising prospect for accurately measuring nuclear astrophysical reactions in underground laboratories. The windowless gas target is a critical component for directly measuring low-energy nuclear astrophysical reactions involving specific isotopes, thereby effectively expanding the scope of deep-underground experiments. Windowless gas targets have been employed in studies of low-energy nuclear reactions in several international laboratories. Represented by the work of Gran Sasso group from Italy, many achievements have been made in nuclear astrophysics research on windowless gas target equipment, including those on Big Bang nucleosynthesis and solar neutrino physics. However, these studies have focused on experiments with relatively low beam intensities. To meet the high-power, high-intensity beam requirements of the JUNA experiment, a dedicated gas target design is needed. In this work, a gas target device that can be used for high intensity beams was designed. Through modeling with ANSYS Fluent and COMSOL software, the feasibility of a multi-stage differential structure was validated. According to the simulation results, it is possible to achieve a total gradient decrease of about 6 orders of magnitude in gas pressure from the target chamber to the accelerator end. This indicates that the current gas target setup is sufficient for our future nuclear reaction measurement experiments. In addition, the heating effect proves to be important for gas target experiment. On one hand, when the beam passes through the gas target, some energy will be deposited, then the target density (i.e. target thickness) near the beam will correspondingly decrease. In nuclear physics experiments, precise measurement of target thickness is an important step in extracting key physical quantities (such as reaction cross-section). Therefore, systematic research is needed on the target thickness changes induced by beam to guide our future experimental set up. On the other hand, due to the possible changes in charge state when the beam passes through a gas target, which may not be detected by current measurement devices (such as Faraday cup), it is necessary to develop methods for normalizing the beam intensity that is insensitive to charge. The calorimeter is an optional solution. The response of calorimeter to thermal power input needs to be carefully studied to guide the future design of calorimeter. Both the beam induced heating effects on target thickness and thermal response of the calorimeter have been investigated by simulation. A design optimization for windowless gas target experiments has been proposed, which can effectively alleviate the beam heating effect and improve the accuracy of calorimeter measurement of beam intensity, providing a reliable foundation for the development of JUNA’s deep-underground experimental research in the future.

The field of nuclear science has considerably advanced since its beginning just over a century ago. Today, the science of rare isotopes is on the cusp of a new era with theoretical and computing advances complementing experimental capabilities at new facilities internationally. In this article we present a vision for the science of rare isotope beams (RIBs). We do not attempt to cover the full breadth of the field; rather, we provide a perspective and address a selection of topics that reflect our own interests and expertise. We focus in particular on systems near the drip lines, where one often finds nuclei that are referred to as exotic and where the role of the nuclear continuum is only just starting to be explored. An important aspect of this article is its attempt to highlight the crucial connections between nuclear structure and the nuclear reactions required to fully interpret and leverage the rich data to be collected in the next years at RIB facilities. Further, we connect the efforts in structure and reactions to key questions of nuclear astrophysics. [ABSTRACT FROM AUTHOR]

We describe the advancing knowledge of fusion cross sections from 1934 through the development of the first thermonuclear tests fielded by Los Alamos (the singular entity denoted Los Alamos Laboratory/Los Alamos Scientific Laboratory/Los Alamos National Laboratory at different times is designated "Los Alamos" in this paper) in the Pacific in 1951–1952; this technical history has not been previously documented. We compare these nuclear reaction cross sections to the current state of their knowledge as codified in the Evaluated Nuclear Data File (ENDF) databases, focusing on the Big Five reactions: 3H ${(d,n)^4}$ (d , n) 4 He, 3He ${(d,p)^4}$ (d , p) 4 He, 2H ${(d,n)^3}$ (d , n) 3 He, 2H ${(d,p)^3}$ (d , p) 3 H, and 3H ${(t,2n)^4}$ (t , 2 n) 4 He. At Oppenheimer's July 1942 University of California, Berkeley, "galaxy of luminaries" conference, Konopinski suggested that the cross section for 3H ${(d,n)^4}$ (d , n) 4 He "DT" could be large, and although Teller described this as an "inspired guess," we provide evidence instead suggesting that Konopinski knew of a 1938 measurement by Ruhlig that secondary DT reactions were "exceedingly probable." Bethe's direction that the DT cross section should be measured at Purdue University (Purdue) in 1943 led to the remarkable and unexpected finding that the DT cross section exceeds deuteron-deuteron (DD) by a factor of 100. This was a game-changing result, making Teller's dream, i.e., the terrestrial production of fusion energy, feasible. Eyewitness accounts are transcribed from the earliest discoveries of the large magnitude of the resonant DT cross section. A description is given of the Manhattan Project's early 1942–1944 DD measurements at the University of Chicago, the 1943 DT measurements at Purdue, and the subsequent 1945–1946 DD and DT measurements at Los Alamos. The Los Alamos experiments, led by Bretscher, were the first to extend to very low incident ion center-of-mass energies in the 6- to 50-keV range needed in applications and the first to identify, characterize, and document the 3/2+ "Bretscher state" responsible for the resonance-enhanced DT cross section. The early measurements were based on thick-target experiments that required a knowledge of hydrogen-isotope stopping powers, much of which was informed by 1930s German studies. We end with the high-accuracy APSST (named for Arnold, Phillips, Sawyer, Stovall, and Tuck) measurements at Los Alamos, 1951–1952. The very first 1942–1946 measurements were accurate to about 50% or somewhat better, but by the early 1950s, the cross sections were determined much more accurately, to within a few percent of our best values today, which come from R-matrix Energy Dependent Analysis (EDA) code analyses of the data, most notably the very accurate 1980s–1990 Los Alamos DT and DD fusion data from Jarmie and Brown. We show that Fermi, in his 1945 Los Alamos lectures, anticipated the S-factor (for the DT cross section), which is a concept widely used later in nuclear astrophysics. To this long abstract, we add a final tidbit: Marshall Holloway, a coauthor on the first-ever 1943 DT cross-section measurement at Purdue, went on to lead the engineering and fabrication of the first H-bomb test, Ivy Mike. [ABSTRACT FROM AUTHOR]

A thorough understanding of nuclear reaction rates at low energies is essential for improving our understanding of energy generation in stars and primordial and stellar nucleosynthesis. At low energies, fusion reactions between charged particles are strongly suppressed by the presence of the Coulomb barrier, which classically inhibits the penetration of one nucleus into another. The barrier penetration causes the cross section to have a steep energy dependence at low energies, making cross section measurements very challenging. Furthermore, little is known about the impact of surrounding electrons in stellar plasmas that are currently beyond the reach of experiments. As a result, measuring the bare cross sections as accurately as possible is essential. Reaction rate measurements at very low energies have been made possible in recent years by the development of high-current low-energy accelerators as well as enhanced target and detection methods. Nevertheless, the presence of atomic electrons, which alter the Coulomb barrier by screening the nuclear charge and increase the cross section at low energies compared to the case of bare nuclei, complicates these observations. A review of the experimental and corresponding theoretical work on laboratory electron screening performed so far will be presented. [ABSTRACT FROM AUTHOR]

With current and planned gravitational-wave (GW) observing runs, coincident multimessenger timing of resonant shattering flares (RSFs) and GWs may soon allow for neutron star (NS) asteroseismology to be used to constrain the nuclear symmetry energy, an important property of fundamental nuclear physics that influences the composition and equation of state of NSs. In this work, we examine the effects of combining multiple RSF detections on these symmetry energy constraints, and consider how realistic uncertainties in the masses of the progenitor NSs may weaken them. We show that the detection of subsequent multimessenger events has the potential to substantially improve constraints beyond those obtained from the first, and that this improvement is insensitive to the mass of the NSs that produce the RSFs and its uncertainty. This sets these asteroseismic constraints apart from bulk NS properties such as radius, for which the NS mass is highly important, meaning that any multimessenger RSF and GW events can equally improve our knowledge of fundamental physics. [ABSTRACT FROM AUTHOR]

This article discusses the field of nuclear physics and its various applications and frontiers. It highlights the importance of collaboration between theory and experiment in making breakthroughs in the field. The article includes contributions from researchers in different subfields of nuclear physics, such as nuclear structure, reactions, dynamics, hadron physics, nuclear astrophysics, and neutrino physics. It also discusses the use of different methodologies, including Monte Carlo approaches and ab initio methods. The article concludes by mentioning upcoming facilities and future opportunities for nuclear physics research. [Extracted from the article]

Fluorine is one of the most interesting elements in nuclear astrophysics. Its abundance can provide important hints to constrain the stellar models since fluorine production and destruction are strictly connected to the physical conditions inside the stars. The F 19 (p,α)16O reaction is one of the fluorine burning processes and the correction evaluation of its reaction rate is of pivotal importance to evaluate the fluorine abundance. Moreover, the F 19 (p,α)16O reaction rate can have an impact for the production of calcium in the first-generation of Population III stars. Here, we present the AsFiN collaboration efforts to the study of the F 19 (p, α)16O reaction by means of direct and indirect measurements. On the direct measurements side, an experimental campaign aimed to the measurement of the F 19 (p, α 0 , π )16O reaction is ongoing, taking advantage of the new versatile arrays of silicon strip detectors, LHASA and ELISSA. Moreover, the Trojan Horse Method (THM) was used to determine the F 19 (p, α 0 )16O reaction S(E)-factor in the energy range of astrophysical interest ( E c m ≈ 0–1 MeV), showing, for the first time, the presence of resonant structures within the astrophysical energy range. THM has been also applied for the study of the F 19 (p, α π )16O reaction; data analysis is ongoing. [ABSTRACT FROM AUTHOR]

The article discusses the n_TOF facility at CERN, which is a research facility designed for studying neutron-induced nuclear reactions. The facility uses a pulsed white neutron source and has three experimental areas where reactions are studied. The article highlights the importance of the neutron source intensity and energy distribution, the repetition rate of neutron-generating pulses, the time resolution of the neutron beam, and the background conditions for conducting accurate experiments. The facility's core program focuses on measuring neutron-induced reaction cross-sections for various applications, including nuclear astrophysics and advanced nuclear technologies. The article also mentions the facility's continuous upgrades and improvements, as well as the collaborative nature of the experiments conducted at n_TOF. [Extracted from the article]

The Facility for Rare Isotope Beams (FRIB) at Michigan State University is a user facility that supports a global community of scientists in studying rare isotopes. It offers opportunities in nuclear structure and reactions, astrophysics, and physics beyond the standard model. FRIB also provides research quantities of rare isotopes for medical diagnostics and material science. The facility has a range of scientific instruments and is expanding its capabilities with the addition of the High Rigidity Spectrometer (HRS) and an energy upgrade to the linac. The article highlights various instruments and technologies used at FRIB, as well as the development of new technologies that have potential applications in other industries. [Extracted from the article]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

1. This study focuses on the theoretical and computational determination of the activity of N-15 produced through the 12C(α, p)15N nuclear reaction. The investigation involves the use of alpha particles (α) bombarding carbon- 12 nuclei, resulting in the formation of nitrogen-15 (15N) through proton (p) emission. 2. The calculation methodology encompasses quantum mechanical models and nuclear reaction theory to predict the cross-sections governing the 12C(α, p)N15 reaction at various incident alpha particle energies. Utilizing these cross-sections, the reaction rates are computed, and subsequently, the activity of the produced N-15 is estimated. 3. The impact of reaction parameters such as energy, angular momentum, and nuclear structure on the reaction dynamics is explored. In this research, SRIM and MATLAB programs were used to calculate the Cross section for alpha and carbon-12 interaction, simulate the account yield of 15N, and predict the distribution of N-15 activity. The results of this study provide valuable insights into the fundamental processes governing the 12C(α, p)15N reaction, aiding in the understanding of nucleosynthesis pathways in astrophysical environments and contributing to the development of nuclear models. The calculated N-15 activity serves as a crucial parameter for applications in fields such as nuclear astrophysics, nuclear medicine, and isotope production for various scientific and industrial purposes. [ABSTRACT FROM AUTHOR]