Table of Contents
Overview
Definition and Scope
Nuclear astrophysics is defined as the study of the origin of chemical elements and the processes governing the evolution of stars, focusing on the interactions between atomic nuclei. This field encompasses the examination of how stars shine, evolve, and ultimately die, with a particular emphasis on nuclear reactions that occur within them.[6.1] The core concept of nuclear astrophysics involves understanding nuclear reactions in stars, which include processes such as nuclear fusion, fission, and radioactive decay, leading to the transformation of one element or isotope into another.[1.1] Key topics within this discipline include the nuclear reactions that power stars, the formation of elements in the universe, and the behavior of matter under extreme conditions, such as those found in supernova explosions.[2.1] The energy produced in stars is primarily generated through nuclear reactions, where lighter elements fuse into heavier ones, releasing significant amounts of energy in the process.[3.1] By studying these nuclear processes, researchers can gain insights into the fundamental mechanisms that govern stellar evolution and element synthesis.[5.1] Nuclear astrophysics also investigates the role of nuclear energy generation in cosmic phenomena, including stars, supernovae, novae, and violent binary-star interactions, highlighting its interdisciplinary nature that bridges nuclear physics and astrophysics.[4.1] This collaboration among researchers from various subfields is essential for advancing our understanding of the universe's elemental composition and the life cycles of stars.[4.1]Importance in Astrophysics
Nuclear astrophysics plays a crucial role in understanding the formation and evolution of elements in the universe. Central to this field is the process of nucleosynthesis, which refers to the creation of elements within stars through nuclear reactions. This process is essential for comprehending stellar evolution and the elemental diversity observed in the universe. Stellar nucleosynthesis occurs during the lifetimes of stars, where lighter elements are fused into heavier ones, significantly contributing to the cosmic inventory of elements, including those essential for life, such as carbon and oxygen.[12.1] The life cycle of a star significantly influences the types of nuclear reactions that occur, which are crucial for the synthesis of elements in the universe. In solar-type stars, once the hydrogen in the core is depleted, the star transitions into the red giant phase. During this phase, nuclear reactions in a shell of gas surrounding the core provide a new source of energy, causing the star to expand outward.[8.1] High-mass stars, on the other hand, undergo nucleosynthesis at a much faster rate, allowing them to fuse heavier nuclei and produce elements beyond iron. These heavier elements are primarily formed during supernova explosions through rapid neutron capture processes, known as the r-process, which enrich the cosmos with essential building blocks for planets and life.[16.1] Supernova nucleosynthesis, which occurs during the explosive deaths of massive stars, is particularly significant as it enriches the cosmos with heavy elements through rapid neutron capture processes (r-process).[16.1] This process is vital for the creation of elements heavier than iron, which cannot be formed through standard fusion reactions.[15.1] The conditions present during supernovae facilitate the synthesis of a wide range of isotopes, contributing to the chemical diversity we observe in the universe today.[17.1]In this section:
History
Development of Nuclear Astrophysics as a Field
Nuclear astrophysics is a multidisciplinary field that merges nuclear physics and astrophysics to investigate the origins of chemical elements and isotopes, as well as the nuclear processes powering astronomical objects like stars, supernovae, and binary star interactions.[44.1] The field's principles are supported by significant observational evidence, such as the detection of technetium in stars, which confirms the presence of elements with no stable isotopes. Additionally, the identification of galactic gamma-ray line emitters like 26Al, 60Fe, and 44Ti reinforces foundational theories.[44.1] Observations of gamma-ray lines from the decay of 56Ni in supernovae SN1987A and SN2014J, coinciding with their optical light, provide further critical evidence.[44.1] The study of neutrinos from the Sun and supernova 1987A also contributes to validating the theories and models within this field.[44.1] Historically, the development of nuclear astrophysics is rooted in recognizing nuclear processes as fundamental to stellar life cycles, including reactions induced by hydrogen, helium, and heavy ions, crucial for understanding stellar helium burning.[42.1] The field has matured significantly, with advancements in experimental techniques allowing the study of nuclear reactions in stars, particularly those involving short-lived nuclei.[48.1] Recent progress at institutions like the China Institute of Atomic Energy, where direct measurements of astrophysical reactions have been conducted, has led to critical insights into the synthesis of heavy elements in stars, revealing previously unrecognized complexities in stellar nucleosynthesis.[43.1][47.1] A significant advancement in nuclear astrophysics has been the role of spectroscopy, enabling scientists to measure the abundances of light elements such as helium-4, deuterium, helium-3, and lithium-7.[54.1] These measurements are crucial for comparison with theoretical predictions from Big Bang nucleosynthesis models, enhancing our understanding of the early universe.[51.1] The detection of technetium in distant stars' spectra, facilitated by advancements in spectroscopy, underscores the processes governing nucleosynthesis and the chemical evolution of the universe.[52.1]In this section:
Nuclear Processes In Stars
Nuclear Fusion Mechanisms
Nuclear fusion mechanisms in stars are fundamental processes that govern both the synthesis of elements and the energy output of stars. Fusion primarily occurs in the core, where extreme temperatures and pressures enable the merging of light atomic nuclei into heavier ones. Initially, hydrogen nuclei fuse to form helium, releasing energy as heat and radiation, which powers the star throughout most of its life.[85.1] In stars similar to the Sun or smaller, the dominant fusion mechanism is the proton-proton chain reaction, converting hydrogen into helium.[94.1] More massive stars, exceeding 1.3 times the mass of the Sun, primarily utilize the Carbon-Nitrogen-Oxygen (CNO) cycle for fusion.[94.1] The choice between these hydrogen fusion processes is determined by their temperature dependency differences.[94.1] As stars evolve, they may engage in fusion processes that create heavier elements, particularly near the end of their luminous lifetimes, where fusion of elements up to iron can occur.[94.1] This progression significantly influences the chemical composition of the universe.[94.1] The synthesis of elements heavier than iron occurs during supernova explosions, marking the end of a massive star's life. These events release vast amounts of energy and neutrons, facilitating the formation of heavy elements.[97.1] Recent research has highlighted the complexity of stellar nucleosynthesis, revealing that the synthesis of elements like barium involves intricate neutron capture processes requiring detailed experimental analysis to fully understand.[86.1] The mass of a star significantly influences nuclear fusion, determining the core pressure and temperature necessary for these processes. Higher mass stars have elevated core temperatures, leading to more rapid fusion rates, greater luminosity, and shorter lifespans compared to less massive stars.[112.1] The energy produced can arise from various fusion processes, including proton-proton fusion, helium fusion, and the carbon cycle, depending on the star's age and mass.[97.1] During later stages, particularly near the end of its luminous lifetime, fusion can briefly produce heavier elements up to iron.[97.1] However, elements heavier than iron are primarily formed during supernova explosions, releasing substantial energy and neutrons.[97.1] Thus, a star's mass and lifecycle stages critically influence the types of nuclear fusion processes that occur, ultimately affecting the chemical composition of the universe.[112.1]Nucleosynthesis and Element Formation
Nucleosynthesis is the process through which elements are created within stars, fundamentally shaping the chemical composition of the universe. This cosmic phenomenon occurs as stars undergo nuclear fusion, where lighter elements combine to form heavier ones. Initially, all atoms in the universe began as hydrogen, which is transformed into helium through fusion processes within stars, releasing heat and radiation in the process.[102.1] As stars evolve, they activate further nuclear processes, leading to the formation of heavier elements, including carbon, oxygen, and iron, through mechanisms such as the triple-alpha process.[102.1] The stages of a star's lifecycle significantly influence the types of nuclear fusion processes that occur. For instance, during the main sequence phase, stars primarily fuse hydrogen into helium. As they age, they progress to fusing helium and subsequently heavier elements, which contributes to the diversity of elements observed in the universe.[103.1] This evolutionary trajectory is crucial for understanding the formation of elements essential for life, as nucleosynthesis in massive stars produces elements beyond helium, enriching the cosmic landscape.[101.1] Experimental techniques are vital for understanding nucleosynthesis, particularly in replicating the extreme conditions found in stellar interiors. Recent advancements have demonstrated that the high densities and temperatures relevant to these environments can indeed be produced in laboratory settings, allowing for nuclear physics experiments to be conducted under conditions similar to those in stars.[89.1] However, significant challenges persist in measuring nuclear reaction cross sections for stellar burning processes. These challenges include the need to transform experimental data into reaction rates that can be utilized for simulating both quiescent and explosive nuclear burning processes.[88.1] The methodologies for determining stellar (n, γ) rates have been outlined through recent cross-section measurements, highlighting ongoing quests related to existing laboratory neutron sources and new developments.[104.1] Furthermore, the measurement of these processes is crucial for interpreting the wealth of observational data on elemental and isotopic abundances obtained from satellite-based observatories and the analysis of meteoritic inclusions, which rely on complex computer simulations of stellar evolution and explosions.[87.1] Collaborative efforts across disciplines, such as plasma physics and nuclear astrophysics, are essential in addressing these challenges, as they facilitate experimental tests of phenomena that can only be found in the extreme plasma conditions of stellar interiors.[90.1]In this section:
Recent Advancements
Experimental Techniques and Findings
Recent advancements in nuclear astrophysics have been significantly influenced by innovative experimental techniques, particularly those employed at the China Jinping Underground Laboratory (CJPL) through the Jinping Underground Nuclear Astrophysics (JUNA) experimental platform. JUNA utilizes an ultra-low-background environment to conduct high-precision measurements of key nuclear reactions that are critical for understanding hydrostatic stellar evolution at relevant stellar energies.[135.1] This facility is designed to directly measure nuclear reactions such as (^{25} ext{Mg}(p,\gamma)^{26} ext{Al}) and (^{12} ext{C}(\alpha,\gamma)^{16} ext{O}) within the Gamow window, which is essential for elucidating the processes that govern stellar nucleosynthesis.[134.1] The experimental techniques at JUNA differ from traditional methods by focusing on extremely low background conditions, allowing for more reliable data collection on nuclear reaction cross sections of astrophysical interest.[133.1] This approach enhances the understanding of nucleosynthetic processes in celestial objects and addresses longstanding mysteries regarding the origins of elements in the universe.[133.1] For instance, the direct measurement of astrophysical reactions at JUNA has provided insights into the production of isotopes such as technetium, which is observed in stars, thereby supporting theories about element formation in cosmic environments.[122.1] Recent advancements in observational techniques, particularly high-resolution spectroscopy, have greatly improved our understanding of stellar nucleosynthesis and the formation of heavy elements in the universe. Abundances in stellar atmospheres provide the vast majority of clues to the nucleosynthesis that occurs within stellar interiors, with significant attention devoted to the study of the spectra of very low-metallicity stars, which are presumed to be among the oldest stars in the Galaxy.[130.1] Astronomers recognize two distinct episodes of nucleosynthesis: primordial (Big Bang) and stellar.[128.1] High-resolution spectroscopy enhances the analysis of stellar atmospheres by allowing for the optimization of diffraction gratings, which results in greater dispersion in wavelength.[128.1] This technique is crucial for developing models of nucleosynthesis processes, including the s- and r-processes that occur in red giants and supernovae, thereby contributing to our understanding of the abundance of elements from iron to uranium.[129.1]Theoretical Models and Simulations
Theoretical models and simulations play a crucial role in advancing our understanding of nuclear astrophysics, particularly in the context of stellar evolution and nucleosynthesis. These models trace the life cycle of stars from hydrogen burning to the eventual collapse of iron cores, simulating the explosive phenomena associated with supernovae using various approaches, including a 'piston' method to represent the dynamics of the explosion.[149.1] Key nuclear reactions are central to these simulations, as they significantly influence stellar evolution and the synthesis of elements. For instance, the rates of reactions such as (^{12} ext{C}(\alpha, \gamma)^{16} ext{O}) and (^{22} ext{Ne}(\alpha, n)^{25} ext{Mg}) are critical in determining the sizes of stellar cores and the pathways of nucleosynthesis.[149.1] Additionally, carbon fusion, which initiates at temperatures around 500 million K, produces essential elements like neon, oxygen, sodium, and magnesium, further illustrating the importance of these nuclear processes in stellar life cycles.[150.1] Stellar nucleosynthesis itself is defined as the creation of chemical elements through nuclear fusion reactions within stars, a process that has been ongoing since the Big Bang. This phenomenon explains the changing abundances of elements over time and the varying prevalence of certain isotopes.[151.1] As stars evolve, they transition through different stages of nuclear burning, starting with hydrogen and progressing to heavier elements, which are synthesized in their cores under extreme conditions of temperature and pressure.[153.1] Theoretical models also allow for the exploration of the energy production mechanisms in stars, represented in T-ρ diagrams that illustrate the nuclear energy output across various stellar conditions.[152.1] These comprehensive simulations and models are essential for understanding the complex processes that govern element formation in the universe and the lifecycle of stars.In this section:
Interdisciplinary Connections
Relationship with Nuclear Physics
Nuclear astrophysics is fundamentally an interdisciplinary field that necessitates close collaborations between researchers in nuclear physics and astrophysics. This collaboration is essential for determining various types of nuclear reaction and weak interaction rates that occur in extreme cosmic environments, as well as for constructing astrophysical models that describe observed phenomena and objects in the universe.[158.1] The study of nuclear processes is pivotal in understanding cosmic phenomena, including the formation of elements in stars and the mechanisms behind explosive events such as supernovae and neutron star mergers. For instance, nuclear fusion, which powers stars, involves light nuclei like hydrogen and helium combining under extreme conditions to form heavier nuclei, releasing vast amounts of energy in the process.[175.1] This interplay between nuclear reactions and stellar evolution provides critical insights into how stars change over time and contribute to the cosmic chemical landscape. Real-world examples illustrate the profound connections between nuclear physics and astrophysics. Observations of elements such as technetium in stars, along with the detection of gamma-ray line emitters and neutrinos from supernovae, underscore the role of nuclear processes in the universe.[173.1] Furthermore, the multi-messenger astrophysics framework has been successfully applied to constrain the equation of state of neutron star matter and to investigate the nature of compact binary mergers, demonstrating the practical applications of nuclear astrophysics in addressing fundamental questions about the universe.[163.1] The advancements in nuclear astrophysics also extend to practical applications in technology and medicine. For example, the principles derived from nuclear astrophysics are influencing developments in nuclear medicine, particularly in cancer diagnosis and therapy, where tumor-targeted radiopharmaceuticals are designed to preferentially eradicate tumors while minimizing damage to healthy tissues.[176.1] Additionally, the tools and methodologies developed in nuclear astrophysics research, such as sophisticated detector arrays and global nuclear models, enhance our understanding of both cosmic phenomena and practical applications in various fields.[174.1]Impact on Cosmology and Geology
Nuclear astrophysics significantly impacts both cosmology and geology through its exploration of element formation and the processes that govern the evolution of stars. The field examines nuclear processes such as fusion and nucleosynthesis, which are crucial for understanding the origins of chemical elements in the universe. For instance, stellar nucleosynthesis is responsible for creating elements beyond hydrogen and helium, which were formed during the Big Bang, thereby playing a fundamental role in the chemical evolution of the universe.[168.1] In cosmology, the study of supernovae is particularly important as these explosive events are major sources of chemical elements. Supernova nucleosynthesis occurs during the death of massive stars, where intense temperatures and pressures facilitate the fusion of lighter elements into heavier ones, contributing to the elemental diversity observed in the universe.[161.1] The products of these nucleosynthetic processes are ejected into the interstellar medium, enriching it with heavy elements and influencing the chemical evolution of galaxies.[160.1] Moreover, nuclear astrometry, a subfield of nuclear astrophysics, focuses on understanding element formation in stars, which is essential for tracing the chemical history of the universe.[155.1] The observation of specific isotopes, such as technetium in stars and gamma-ray emissions from supernovae, provides empirical evidence supporting the theoretical models of nucleosynthesis.[157.1] Nuclear astrophysics plays a significant role in various scientific fields, with practical applications evident in areas such as nuclear energy, radiomedicine, and archaeological dating. These applications highlight the real-world relevance of this scientific domain, demonstrating how advancements in nuclear astrophysics contribute to our understanding of the universe and its processes. Ongoing technological advancements and constant refinements in theoretical models further establish nuclear astrophysics as a central science in comprehending both cosmic phenomena and their implications for Earth.[154.1]Challenges And Future Directions
Unresolved Questions in Nuclear Astrophysics
Nuclear astrophysics faces several unresolved questions that highlight the complexities of the field and the need for further research. One significant challenge is the precision required in nuclear reaction studies, which is critical for accurately simulating stellar processes. Current experimental techniques often struggle to achieve the necessary precision, particularly in measuring nuclear physics quantities such as radioactive decay half-lives, branching ratios, and reaction cross sections. For instance, the cross-section uncertainty of the 77Be(p,γ)88B nuclear reaction, which influences the solar neutrino production rate, is currently at 7.5%.[206.1] Addressing these uncertainties is essential for advancing our understanding of stellar nucleosynthesis and the processes that govern element formation in stars. The integration of nuclear astrophysics with fields such as gamma-ray astronomy and cosmology presents significant opportunities for advancing our understanding of the universe. Gamma-ray astronomy, in particular, seeks to constrain the astrophysical origin sites of radioactive isotopes in the Galaxy, including supernovae, novae, and cosmic rays, although the dominant sources of Galactic radioactivity are not always immediately clear.[212.1] Recent advancements in gamma-ray spectroscopy have provided isotopic information from nucleosynthesis sites, revealing new results for isotopes such as (^{44})Ti from the Cas A core-collapse supernova and long-lived isotopes like (^{26})Al and (^{60})Fe.[213.1] Furthermore, the interplay between nuclear astrophysics and cosmology is crucial for understanding nucleosynthesis, which is the process through which elements are formed in stars. This process is essential for the creation of elements beyond helium, including iron and heavier elements, thereby contributing to the elemental diversity of the universe.[221.1] Additionally, nuclear physics plays a central role in Big Bang nucleosynthesis (BBN), which marks the first occurrence of nuclear reactions in the universe, necessitating precise measurements of nuclear cross sections and neutron lifetimes to further our understanding of these processes.[223.1] The integration of nuclear astrophysics into educational curricula presents significant challenges that require thoughtful planning and execution. Teachers must design curricula that effectively incorporate nuclear physics and mathematics, ensuring that essential concepts and mathematical tools are included to enhance student understanding.[199.1] Programs such as the Physics of Atomic Nuclei (PAN) at Michigan State University offer valuable opportunities for science educators, featuring a week-long experience that includes lectures, demonstrations, and hands-on experiments related to nuclear astrophysics.[200.1] This program not only allows educators to experience research in a world-class laboratory but also facilitates the sharing of curriculum ideas among peers.[200.1] Addressing these educational challenges is vital for inspiring the next generation of scientists and advancing the field of nuclear astrophysics.[199.1]Technological Innovations and Methodological Improvements
Technological innovations and methodological improvements are crucial for advancing nuclear science research, particularly in addressing the challenges of accurately simulating stellar processes. In October 2023, the Nuclear Science Advisory Committee (NSAC) released its latest roadmap for advancing the nation's nuclear science research over the next decade, known as the 2023 Long Range Plan (LRP) for Nuclear Science. This plan highlights the scientific opportunities necessary for maintaining world leadership in this vital area of research.[198.1] Additionally, the Facility for Rare Isotope Beams (FRIB) employs next-generation technology to conduct experiments that reveal properties of nuclei, which are then used as input for simulations. These simulations illuminate the thermodynamic conditions within the experiments, thereby assisting FRIB scientists in selecting their subsequent measurements.[203.1] Moreover, the integration of machine learning techniques into nuclear astrophysics is gaining traction. While researchers in astrophysics and nuclear physics have begun to utilize machine learning independently, its application within nuclear astrophysics remains limited.[226.1] However, the potential for machine learning to analyze large datasets, identify hidden correlations, and assist in experimental design is significant, as it aligns well with the complex systems and data prevalent in the field.[227.1] Additionally, advancements in detector technology, originally developed for particle physics, are being adapted for nuclear astrophysics. These innovations not only enhance the precision of measurements but also reduce exposure times in medical imaging applications, showcasing the versatility of these technologies.[205.1] The ongoing development of experimental facilities, such as the Jinping Underground Nuclear Astrophysics (JUNA), further exemplifies the commitment to improving methodologies for direct measurement of astrophysical reactions.[204.1]References
[1] Nuclear Astrophysics | Basics & Real-World Uses — The core concept of nuclear astrophysics lies in understanding nuclear reactions in stars. These reactions involve the transformation of one element or isotope into another through nuclear fusion, fission, or radioactive decay.
[2] A Beginner's Guide to Understanding Nuclear Physics — Some key topics in nuclear astrophysics include the nuclear reactions that power stars, the formation of elements in the universe, and the behavior of matter under extreme conditions such as in supernovae explosions.
[3] Nuclear Astrophysics - Definition & Detailed Explanation - Astrophysics ... — One of the key principles of nuclear astrophysics is that the energy produced in stars is primarily generated through nuclear reactions. These reactions involve the fusion of lighter elements into heavier ones, releasing energy in the process. By studying these reactions, scientists can gain insights into the fundamental processes that govern the evolution of stars and the formation of
[4] Nuclear astrophysics - Wikipedia — Nuclear astrophysics studies the origin of the chemical elements and isotopes, and the role of nuclear energy generation, in cosmic sources such as stars, supernovae, novae, and violent binary-star interactions. It is an interdisciplinary part of both nuclear physics and astrophysics, involving close collaboration among researchers in various subfields of each of these fields. This includes
[5] Nuclear Astrophysics - an overview | ScienceDirect Topics — Nuclear astrophysics is a field that studies the production of elements in the Universe and the evolution of stars by examining nuclear processes such as reactions induced by hydrogen, helium, neutron, and heavy ions. It focuses on understanding how stars generate energy and synthesize elements, particularly through reactions involving helium
[6] Astrophysical Nuclear Reactions - TRIUMF — overview. Nuclear astrophysics is the study of the origin of the chemical elements, and the study of how stars shine, evolve and ultimately die, both from the perspective of interactions between atomic nuclei. These interactions govern every phenomenon that we glimpse within stars using today's pantheon of astronomical instruments, from
[8] Stellar Evolution :: Phases - Harvard University — Nuclear reactions in a shell of gas outside the core will provide a new source of energy, and cause the aging star to expand outward in the "red giant" phase. A solar-type star becomes a red giant after nuclear fusion reactions that convert hydrogen to helium have consumed all the hydrogen in the core of the star.
[12] Nucleosynthesis: The Creation Of Elements In Stars — Nucleosynthesis: The Creation Of Elements In Stars Nucleosynthesis is the process through which elements are created within stars. Nucleosynthesis represents the cosmic process by which elements are formed in stars. Understanding this process is crucial for comprehending Stellar Evolution and the formation of the universe’s elemental diversity. In contrast, stellar nucleosynthesis refers to the formation of elements within stars during their lifetimes. Stellar nucleosynthesis plays a fundamental role in the formation of elements throughout the universe. In these massive stars, nucleosynthesis contributes to the formation of elements beyond helium, including iron and beyond. Nucleosynthesis in stars plays a critical role in the formation of elements essential for life.
[15] Neutron capture - Wikipedia — Neutron capture plays a significant role in the cosmic nucleosynthesis of heavy elements. In stars it can proceed in two ways: as a rapid process or a slow process . Nuclei of masses greater than 56 cannot be formed by exothermic thermonuclear reactions (i.e., by nuclear fusion) but can be formed by neutron capture.
[16] Exploring Nuclear Fusion in Stellar Physics: Mechanisms, Reactions, and ... — Scientific and Practical Significance of Nuclear Fusion 1. Element Formation in the Universe. Nuclear fusion in stars is responsible for creating elements up to iron. Elements heavier than iron are formed during supernovae through rapid neutron capture processes (r-process), enriching the cosmos with the building blocks for planets and life. 2.
[17] Supernova nucleosynthesis - Wikipedia — Jump to content Main menu Search Donate Create account Log in Personal tools Toggle the table of contents Supernova nucleosynthesis 18 languages Article Talk Read Edit View history Tools From Wikipedia, the free encyclopedia Supernova nucleosynthesis is the nucleosynthesis of chemical elements in supernova explosions. In sufficiently massive stars, the nucleosynthesis by fusion of lighter elements into heavier ones occurs during sequential hydrostatic burning processes called helium burning, carbon burning, oxygen burning, and silicon burning, in which the byproducts of one nuclear fuel become, after compressional heating, the fuel for the subsequent burning stage. A rapid final explosive burning is caused by the sudden temperature spike owing to passage of the radially moving shock wave that was launched by the gravitational collapse of the core. Together, shock-wave nucleosynthesis and hydrostatic-burning processes create most of the isotopes of the elements carbon (Z = 6), oxygen (Z = 8), and elements with Z = 10 to 28 (from neon to nickel).
[42] Nuclear Astrophysics - an overview | ScienceDirect Topics — Nuclear astrophysics is a field that studies the production of elements in the Universe and the evolution of stars by examining nuclear processes such as reactions induced by hydrogen, helium, neutron, and heavy ions. Because 4He is the second most abundant element in the observable Universe after hydrogen, α-capture reactions such as (α,γ), (α,n) and (α,p) play a crucial role in nuclear astrophysics, especially for understanding stellar helium burning which is a key phase during the evolution of stars. A major challenge in experimental nuclear astrophysics is the study of reactions and decay processes far from stability (e.g., the r- and rp-process) for the understanding of nucleosynthesis during stellar explosions such as Type II supernova.
[43] Recent progress in nuclear astrophysics research and its astrophysical ... — In this review, we summarize the recent progress in the investigation of astrophysical reactions and their astrophysical implications at the China Institute of Atomic Energy (CIAE), including direct measurement of astrophysical reactions using the Jinping Underground Nuclear Astrophysics (JUNA) experimental facility (see Sect. 2 Direct measurement of astrophysical reactions using the Jinping Underground Nuclear Astrophysics (JUNA) experimental facility B.P. Schmidt, N.B. Suntzeff, M.M. Phillips et al., The high \(Z\) supernova search: Measuring cosmic deceleration and global curvature of the universe using type Ia supernovae. Wei-Ping Liu, Bing Guo, Bao-Qun Cui, Yu-Chen Jiang, Chong Lv, Ge-Xing Li, Yun-Ju Li, Zhi-Hong Li, Gang Lian, Yi-Hui Liu, Wei Nan, Wei-Ke Nan, Yang-Ping Shen, Na Song, You-Bao Wang, Di Wu, Xiao-Feng Xi & Sheng-Quan Yan
[44] Nuclear astrophysics - Wikipedia — Nuclear astrophysics studies the origin of the chemical elements and isotopes, and the role of nuclear energy generation, in cosmic sources such as stars, supernovae, novae, and violent binary-star interactions. The concepts of nuclear astrophysics are supported by observation of the element technetium (the lightest chemical element without stable isotopes) in stars, by galactic gamma-ray line emitters (such as 26Al, 60Fe, and 44Ti), by radioactive-decay gamma-ray lines from the 56Ni decay chain observed from two supernovae (SN1987A and SN2014J) coincident with optical supernova light, and by observation of neutrinos from the Sun and from supernova 1987a.
[47] The Lifecycle of Stars: A Journey Through Nucleosynthesis — By leveraging advanced experimental techniques, the researchers provided critical insights into how barium and other heavy elements are synthesized in stars. “It is now clear that the synthesis of elements in stars is more complex than previously thought,” Spyrou stated, emphasizing that the nuances of stellar nucleosynthesis demand detailed experimental analysis in order to unravel the contributions from various astrophysical processes. With a deeper understanding of neutron capture processes, including their correlations with neutron-rich isotopes and the genesis of elements in stars, researchers can further refine their models of nucleosynthesis. This study not only enhances our understanding of the intricate processes within stars but also invites further questions regarding the interactions of heavy elements with the environment surrounding us.
[48] Nuclear Reactions in Stars Theoretical and Experimental Aspects — Experimental techniques have been strongly developed in the last decades, with two main objectives: going to energies as low as possible, and investigating reactions involv-ing radioactive nuclei. Many important reactions involve short-lived nuclei (such as 7Be, 8Li, 13N, 18F, etc.) and can be studied with radioactive beams only. Direct
[51] How does spectroscopy provide evidence for the big bang theory — Spectroscopy plays a crucial role in this context by allowing scientists to measure the abundances of light elements such as helium-4 (He4), deuterium (D), helium-3 (He3), and lithium-7 (Li7) in the universe. These measurements are then compared to theoretical predictions from Big Bang nucleosynthesis models.
[52] An Introduction to the Evidence for Stellar Nucleosynthesis — One of the strongest pieces of evidence for the theory of stellar nucleosynthesis is the observation of absorption lines of the element Technetium from distant stars. As Technetium's absorption lines were clearly present in several star's spectrum, it followed that the stars contained the radioactive element that - based on its half life - could not have been present in the stars composition when the star was born. With the direct observation of Technetium's spectral lines in stars, an understanding of spectroscopy, and the half life of the longest living isotopes of the element, this process that powers stars and creates the elements falls into place.
[54] Horizons: nuclear astrophysics in the 2020s and beyond... — Nuclear astrophysics is a field at the intersection of nuclear physics and astrophysics, which seeks to understand the nuclear engines of astronomical objects and the origin of the chemical elements. This white paper summarizes progress and status of the field, the new open questions that have emerged, and the tremendous scientific opportunities that have opened up with major advances in
[85] Stellar Nucleosynthesis: How Stars Make All of the Elements - ThoughtCo — Learn about our Editorial Process Updated on September 01, 2024 Stellar nucleosynthesis is the process through which elements are created within stars, by combining the protons and neutrons together from the nuclei of lighter elements. All of the atoms in the universe began as hydrogen. Fusion inside stars transforms hydrogen into helium, heat, and radiation. Once these clouds became large enough, they were drawn together by gravity with enough force to actually cause the atomic nuclei to fuse, in a process called nuclear fusion. Stellar nucleosynthesis continues to create heavier and heavier elements until you end up with iron.
[86] The Lifecycle of Stars: A Journey Through Nucleosynthesis — By leveraging advanced experimental techniques, the researchers provided critical insights into how barium and other heavy elements are synthesized in stars. “It is now clear that the synthesis of elements in stars is more complex than previously thought,” Spyrou stated, emphasizing that the nuances of stellar nucleosynthesis demand detailed experimental analysis in order to unravel the contributions from various astrophysical processes. With a deeper understanding of neutron capture processes, including their correlations with neutron-rich isotopes and the genesis of elements in stars, researchers can further refine their models of nucleosynthesis. This study not only enhances our understanding of the intricate processes within stars but also invites further questions regarding the interactions of heavy elements with the environment surrounding us.
[87] Experimental Challenges in Nuclear Astrophysics - ScienceDirect — The measure- ment of these processes by simulating stellar conditions in the laboratory are the crucial link for interpreting the wealth of observational elemental and isotopic abundance data from satellite based observatories and analysis of meteoritic inclusions through complex computer simulation of stellar evolution and stellar explosion.
[88] Experimental Nuclear Astrophysics - SpringerLink — This contribution describes the experimental challenges to investigate nuclear reaction cross sections for stellar burning processes in the laboratory and the theoretical needs to transform the experimental data into reaction rates to be used for simulating quiescent and explosive nuclear burning processes.
[89] Thermonuclear reactions probed at stellar-core conditions with laser ... — We have shown that the densities and temperatures relevant to stellar interiors can be produced in the laboratory and that nuclear physics experiments can be performed in these extreme environments.
[90] Scientists probe the conditions of stellar interiors to measure nuclear ... — In a unique cross-disciplinary collaboration between the fields of plasma physics, nuclear astrophysics and laser fusion, a team of researchers, including scientists from Lawrence Livermore National Laboratory (LLNL), ... for potential experimental tests of phenomena that can only be found in the extreme plasma conditions of stellar interiors
[94] Fusion Reactions in Stars: Proton-Proton Chain and CNO Cycle Reaction — ) Nuclear fusion reaction powers a star for most of its life. The primary nuclear fusion happens in the star core is the conversion of proton to helium. The proton-proton chain reaction dominates in stars the size of the Sun or smaller, while the Carbon-Nitrogen-Oxigen (CNO) cycle reaction dominates in stars that are more than 1.3 times as massive as the Sun. Summary The type of hydrogen fusion process that dominates in a star is determined by the temperature dependency differences between the two reactions.
[97] Nuclear Fusion in Stars - AQA GCSE Physics Revision Notes - Save My Exams — A beryllium nucleus fusing with a helium nucleus to form a carbon nucleus. Elements lighter than iron are formed in fusion reactions like the ones above. Formation of Elements Heavier than Iron. Elements heavier than iron are produced in supernova explosions. A supernova occurs at the end of a massive stars life. When the star explodes it releases very large amounts of energy and neutrons
[101] Nuclear Reactions in Stellar Interiors and Nucleosynthesis — In this detailed article, I’m going to investigate the intricacies of nuclear reactions transpiring within stellar cores, emphasising the significance of nucleosynthesis in the evolutionary trajectory of stars and the genesis of cosmic elements. In this elegantly orchestrated ballet of nuclear transformations, helium and carbon nuclei interact with prodigious energy, crafting a celestial tapestry of elemental diversity that enriches the stellar core. The relentless interplay of nuclear reactions within the neutron star’s core engenders the genesis of a diverse array of heavy elements, enriched by the cosmic legacies of nucleosynthesis. From the primordial fusion of hydrogen to the awe-inspiring nucleosynthesis beyond supernovae, each phase leaves an indelible mark on the evolution of stars and the genesis of cosmic elements.
[102] Stellar Nucleosynthesis: How Stars Make All of the Elements - ThoughtCo — Learn about our Editorial Process Updated on September 01, 2024 Stellar nucleosynthesis is the process through which elements are created within stars, by combining the protons and neutrons together from the nuclei of lighter elements. All of the atoms in the universe began as hydrogen. Fusion inside stars transforms hydrogen into helium, heat, and radiation. Once these clouds became large enough, they were drawn together by gravity with enough force to actually cause the atomic nuclei to fuse, in a process called nuclear fusion. Stellar nucleosynthesis continues to create heavier and heavier elements until you end up with iron.
[103] Stellar nucleosynthesis - Wikipedia — Jump to content Main menu Search Donate Create account Log in Personal tools Toggle the table of contents Stellar nucleosynthesis 38 languages Article Talk Read Edit View history Tools From Wikipedia, the free encyclopedia Logarithmic scale plot of the relative energy output (ε) of the following fusion processes at different temperatures (T): Proton–proton chain (PP) CNO cycle Triple-α process Combined energy generation of PP and CNO within a star The Sun's core temperature, at which PP is more efficient In astrophysics, stellar nucleosynthesis is the creation of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. It explains why the observed abundances of elements change over time and why some elements and their isotopes are much more abundant than others. Stars evolve because of changes in their composition (the abundance of their constituent elements) over their lifespans, first by burning hydrogen (main sequence star), then helium (horizontal branch star), and progressively burning higher elements. Later in its life, a low-mass star will slowly eject its atmosphere via stellar wind, forming a planetary nebula, while a higher–mass star will eject mass via a sudden catastrophic event called a supernova.
[104] Stellar neutron capture rates - key data for the s process — The experimental methods for the determination of stellar (n, γ) rates are outlined at the example of recent cross section measurements and remaining quests will be discussed with respect to existing laboratory neutron sources and new developments.
[112] PDF — How does a star's mass affect nuclear fusion? Stellar Mass and Fusion •The mass of a main-sequence star determines its core pressure and temperature. •Stars of higher mass have higher core temperature and more rapid fusion, making those stars both more luminous and shorter-lived.
[122] Nuclear astrophysics - Wikipedia — Nuclear astrophysics studies the origin of the chemical elements and isotopes, and the role of nuclear energy generation, in cosmic sources such as stars, supernovae, novae, and violent binary-star interactions. The concepts of nuclear astrophysics are supported by observation of the element technetium (the lightest chemical element without stable isotopes) in stars, by galactic gamma-ray line emitters (such as 26Al, 60Fe, and 44Ti), by radioactive-decay gamma-ray lines from the 56Ni decay chain observed from two supernovae (SN1987A and SN2014J) coincident with optical supernova light, and by observation of neutrinos from the Sun and from supernova 1987a.
[128] A Discussion of Stellar Nucleosynthesis | Answers Research Journal — I discuss stellar spectroscopy and nucleosynthesis. Astronomers recognize two distinct episodes of nucleosynthesis, primordial (big bang), and stellar. ... The primary advantage is that diffraction gratings can be optimized for particularly high resolution, that is, with greater dispersion in wavelength. The dispersing element spreads the light
[129] PDF — high resolution spectroscopy of stellar atmospheres ... stellar spectroscopy and nucleosynthesis models. from Fe to U: s- and r-process p - R e g i on Red Giants (s-process) s u p e r n o v a e ( r -p r o c e s s ) mass number abundance s-abundance x cross section = N σ= constant. decomposition of solar abundances.
[130] Atomic data for stellar spectroscopy: recent successes and remaining ... — Abundances in stellar atmospheres provide the vast majority of clues to the nucleosynthesis that takes place in stellar interiors. Much attention in the past couple of decades has been devoted to the study of the spectra of very low-metallicity stars, which are presumed from multiple lines of evidence to be among the oldest stars in the Galaxy
[133] [2306.00572] Underground laboratory JUNA shedding light on stellar ... — Extremely low background experiments to measure key nuclear reaction cross sections of astrophysical interest are conducted at the world's deepest underground laboratory, the Jingping Underground laboratory for Nuclear Astrophysics (JUNA). High precision measurements provide reliable information to understand nucleosynthetic processes in celestial objects and resolve mysteries on the origin of
[134] Underground nuclear astrophysics experiment JUNA in China — JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25 Mg(p,γ) 26 Al, 19 F(p,α) 16 O, 13 C(α, n) 16 O and 12 C(α,γ) 16 O near the Gamow window. The current progress of JUNA will be given.
[135] Progress of the Jinping Underground Nuclear Astrophysics experiment — Directly measuring key nuclear reactions within the Gamow window of stars is a critical frontier in modern nuclear astrophysics. The China Jinping Underground Laboratory (CJPL) offers an ultra-low-background environment, serving as the foundation for the China Jinping deep Underground Nuclear Astrophysics experimental platform (JUNA). By utilizing JUNA's high-intensity
[149] Massive star evolution: nucleosynthesis and nuclear reaction rate ... — We follow the stellar evolution from hydrogen burning till iron core collapse and simulate the explosion using a 'piston' approach. We discuss the influence of two key nuclear reaction rates, 12 C(α, γ) 16 O and 22 Ne(α, n) 25 Mg, on stellar evolution and nucleosynthesis. The former significantly influences the resulting core sizes (iron
[150] Nuclear Reactions In Stars - The Secrets Of The Universe — Let us glance over some key nuclear reactions in stars beyond helium. Carbon Fusion. Nuclear reactions in stars - Carbon burning. Carbon fusion begins at a whooping 500 million K. The common products of this reaction are neon, oxygen, sodium and magnesium. ... Juggling with these concepts, we are now ready to study stellar evolution in the
[151] Stellar nucleosynthesis - Wikipedia — Jump to content Main menu Search Donate Create account Log in Personal tools Toggle the table of contents Stellar nucleosynthesis 38 languages Article Talk Read Edit View history Tools From Wikipedia, the free encyclopedia Logarithmic scale plot of the relative energy output (ε) of the following fusion processes at different temperatures (T): Proton–proton chain (PP) CNO cycle Triple-α process Combined energy generation of PP and CNO within a star The Sun's core temperature, at which PP is more efficient In astrophysics, stellar nucleosynthesis is the creation of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. It explains why the observed abundances of elements change over time and why some elements and their isotopes are much more abundant than others. Stars evolve because of changes in their composition (the abundance of their constituent elements) over their lifespans, first by burning hydrogen (main sequence star), then helium (horizontal branch star), and progressively burning higher elements. Later in its life, a low-mass star will slowly eject its atmosphere via stellar wind, forming a planetary nebula, while a higher–mass star will eject mass via a sudden catastrophic event called a supernova.
[152] PDF — 21. Stellar Evolution: The Core 21.5 Nuclear Reactions We've now seen how Fig. 39 can be populated with tracks representing the central conditions for a range of stars. We can now also populate the T-ρ diagram with a set of orthogonal curves describing nuclear energy production in the cores of our stars.
[153] Stellar Nucleosynthesis | Core Process, Elements & Stars — Stellar Nucleosynthesis | Core Process, Elements & Stars Mechanics Wave Mechanics First Law of Thermodynamics Third Law of Thermodynamics Explore the fascinating process of stellar nucleosynthesis, where stars forge chemical elements, shaping the cosmic landscape and contributing to the universe’s diversity. Stellar nucleosynthesis is the process by which the natural abundances of the chemical elements within stars change due to nuclear fusion reactions in their interiors. The core mechanism of stellar nucleosynthesis begins in the hearts of stars, where extreme temperatures and pressures facilitate nuclear reactions. As stars age and evolve, they activate further nuclear processes, forging heavier elements through mechanisms such as the triple-alpha process, which creates carbon:
[154] Nuclear Astrophysics | Basics & Real-World Uses — The practical applications in fields such as nuclear energy, radiomedicine, and archaeological dating highlight the real-world relevance of this scientific domain. With ongoing advancements in technology and constant refinements in theoretical models, nuclear astrophysics continues to be a central science in understanding our universe and
[155] Nuclear Astrometry | Overview & Significance - Modern Physics Insights ... — Nuclear astrometry is a field that studies nuclear processes in stars, focusing on nuclear fusion and nucleosynthesis to understand element formation in the universe. Nuclear Astrometry: An Overview. Nuclear astrometry may sound like a term out of science fiction, but it is a very real and important field of study within physics.
[157] Nuclear astrophysics - Wikipedia — Nuclear astrophysics studies the origin of the chemical elements and isotopes, and the role of nuclear energy generation, in cosmic sources such as stars, supernovae, novae, and violent binary-star interactions. The concepts of nuclear astrophysics are supported by observation of the element technetium (the lightest chemical element without stable isotopes) in stars, by galactic gamma-ray line emitters (such as 26Al, 60Fe, and 44Ti), by radioactive-decay gamma-ray lines from the 56Ni decay chain observed from two supernovae (SN1987A and SN2014J) coincident with optical supernova light, and by observation of neutrinos from the Sun and from supernova 1987a.
[158] Nuclear Astrophysics — An interdisciplinary field. involving close collaborations among researchers in nuclear physics and astrophysics. The research field includes the determinations of various types of nuclear reaction and weak interaction rates for the extreme cosmic environments, the constructions of astrophysical models for describing the observed astrophysical phenomena and objects of where these nuclear
[160] Supernovae and the Chemical Evolution of Galaxies - ResearchGate — Supernovae are a major source of the chemical elements in galaxies and the universe. They are not only the site of nucleosynthetic processes, but they also deliver their products to the
[161] Supernova nucleosynthesis - Wikipedia — Jump to content Main menu Search Donate Create account Log in Personal tools Toggle the table of contents Supernova nucleosynthesis 18 languages Article Talk Read Edit View history Tools From Wikipedia, the free encyclopedia Supernova nucleosynthesis is the nucleosynthesis of chemical elements in supernova explosions. In sufficiently massive stars, the nucleosynthesis by fusion of lighter elements into heavier ones occurs during sequential hydrostatic burning processes called helium burning, carbon burning, oxygen burning, and silicon burning, in which the byproducts of one nuclear fuel become, after compressional heating, the fuel for the subsequent burning stage. A rapid final explosive burning is caused by the sudden temperature spike owing to passage of the radially moving shock wave that was launched by the gravitational collapse of the core. Together, shock-wave nucleosynthesis and hydrostatic-burning processes create most of the isotopes of the elements carbon (Z = 6), oxygen (Z = 8), and elements with Z = 10 to 28 (from neon to nickel).
[163] An updated nuclear-physics and multi-messenger astrophysics ... - Nature — The study of the gravitational-wave (GW) and electromagnetic (EM) signals GW1708171, AT2017gfo2,3,4,5,6,7,8,9,10,11,12, and GRB170817A13,14,15 has already enabled numerous scientific breakthroughs, for example, constraints on the properties of neutron stars (NSs) and the dense matter equation of state (EOS) at supranuclear densities16,17,18,19,20,21,22,23, an independent measurement of the Hubble constant22,24,25,26,27,28, the verified connection between binary NS (BNS) mergers and at least some of the observed short gamma-ray bursts (GRBs)29, and precise limits on the propagation speed of GWs29. Similarly, to these works, our previous Nuclear physics - Multi-Messenger Astrophysics (NMMA) framework has been successfully applied to provide constraints on the EOS of NS matter and on the Hubble constant22,33, to investigate the nature of the compact binary merger GW19081434, to provide techniques to search for kilonova transients35, to classify observed EM transients such as GRB200826A36, and to combine information from multi-messenger observations with data from nuclear-physics experiments such as heavy-ion collisions23.
[168] Exploring Nucleosynthesis: How Stars Create Elements and Shape the Universe — Nucleosynthesis: The Creation Of Elements In Stars Nucleosynthesis is the process through which elements are created within stars. Nucleosynthesis represents the cosmic process by which elements are formed in stars. Understanding this process is crucial for comprehending Stellar Evolution and the formation of the universe’s elemental diversity. In contrast, stellar nucleosynthesis refers to the formation of elements within stars during their lifetimes. Stellar nucleosynthesis plays a fundamental role in the formation of elements throughout the universe. In these massive stars, nucleosynthesis contributes to the formation of elements beyond helium, including iron and beyond. Nucleosynthesis in stars plays a critical role in the formation of elements essential for life.
[173] Nuclear astrophysics - Wikipedia — Nuclear astrophysics studies the origin of the chemical elements and isotopes, and the role of nuclear energy generation, in cosmic sources such as stars, supernovae, novae, and violent binary-star interactions. The concepts of nuclear astrophysics are supported by observation of the element technetium (the lightest chemical element without stable isotopes) in stars, by galactic gamma-ray line emitters (such as 26Al, 60Fe, and 44Ti), by radioactive-decay gamma-ray lines from the 56Ni decay chain observed from two supernovae (SN1987A and SN2014J) coincident with optical supernova light, and by observation of neutrinos from the Sun and from supernova 1987a.
[174] Nuclear Astrophysics - ORNL — Thanks to the growing popularity of nuclear astrophysics studies, as well as advances such as sophisticated detector arrays (including the GODDESS system) and target systems (including the JENSA gas jet target), intense beams of radioactive nuclei, traps for high precision mass measurements, and global nuclear models running on supercomputers
[175] Nuclear Astrophysics | Basics & Real-World Uses — Nuclear astrophysics examines how nuclear processes influence cosmic phenomena, from element formation in stars to applications in technology and medicine. Nuclear fusion, which powers stars, involves light nuclei such as hydrogen and helium combining under extreme conditions to form heavier nuclei, releasing enormous amounts of energy in the process. Stellar evolution is a pivotal concept in nuclear astrophysics, shedding light on how stars change over time due to nuclear reactions occurring in their cores. Gamma-Ray Observatories: Detect high-energy photons, which are key to understanding explosive nuclear processes like those seen in supernovae and neutron star mergers. Nuclear astrophysics is a profound and expansive field that bridges nuclear physics and celestial phenomena, providing insights into the life cycles of stars and the origin of elements.
[176] Transforming Nuclear Medicine with Nanoradiopharmaceuticals — Nuclear medicine is expected to make major advances in cancer diagnosis and therapy; tumor-targeted radiopharmaceuticals preferentially eradicate tumors while causing minimal damage to healthy tissues. ... 5 Nuclear Physics and Astrophysics Department, LPI of RAS, 119991 Moscow, Russia. 6 Department of Chemistry and Institute for Lasers
[198] PDF — In October 2023, the Nuclear Science Advisory Committee (NSAC) released its latest roadmap for advancing the nation's nuclear science research over the next decade. The 2023 Long Range Plan (LRP) for Nuclear Science highlights the scientific opportunities for maintaining world leadership in this vital area of research. It also describes the impact of nuclear science on the training of a
[199] PDF — Frontiers in Educational Research ISSN 2522-6398 Vol. 6, Issue 24: 142-147, DOI: 10.25236/FER.2023.062423 ... Teachers need to design a curriculum that integrates nuclear physics and mathematics, and then incorporates the concepts and mathematical tools of nuclear physics, ... integration of nuclear physics and mathematics, improve students
[200] JINA-CEE's Educational Outreach Programs - archive.jinaweb.org — Physics of Atomic Nuclei (PAN) @ MSU : Science educators participate in a week long program offering lectures, demonstrations, hands-on experiments related to nuclear astrophysics. Experience research in a world class laboratory and share curriculum ideas with other educators. WaMPS Outreach
[203] From atomic nuclei to astrophysics, collaborative program builds basis ... — FRIB applies its next-generation technology to conducting experiments that reveal properties of nuclei that it conveys as input to ENAF's simulations. In turn, the simulations illuminate the thermodynamic conditions within the experiments, helping FRIB scientists choose their next measurements. ... "The advances the nuclear astrophysics
[204] Recent progress in nuclear astrophysics research and its astrophysical ... — In this review, we summarize the recent progress in the investigation of astrophysical reactions and their astrophysical implications at the China Institute of Atomic Energy (CIAE), including direct measurement of astrophysical reactions using the Jinping Underground Nuclear Astrophysics (JUNA) experimental facility (see Sect. 2 Direct measurement of astrophysical reactions using the Jinping Underground Nuclear Astrophysics (JUNA) experimental facility B.P. Schmidt, N.B. Suntzeff, M.M. Phillips et al., The high \(Z\) supernova search: Measuring cosmic deceleration and global curvature of the universe using type Ia supernovae. Wei-Ping Liu, Bing Guo, Bao-Qun Cui, Yu-Chen Jiang, Chong Lv, Ge-Xing Li, Yun-Ju Li, Zhi-Hong Li, Gang Lian, Yi-Hui Liu, Wei Nan, Wei-Ke Nan, Yang-Ping Shen, Na Song, You-Bao Wang, Di Wu, Xiao-Feng Xi & Sheng-Quan Yan
[205] Section 6: Investing in the Future of Science and Technology — Detectors developed for vertexing, tracking, and photon detection in particle physics can also be used to minimize exposure times for patients. Over time, technology advancements in particle detectors have lowered detection thresholds and have thus allowed reduction of the dose needed for medical imaging applications.
[206] Challenges and Requirements in High-Precision Nuclear Astrophysics ... — Next Article in Journal Journals Journals Find a Journal Journal Journals For example, the 77Be solar neutrino flux has been measured to a precision of better than 5% , while the cross section uncertainty of the 77Be(p,𝛾γ)88B nuclear reaction, influencing the 77Be solar neutrino production rate, is 7.5% . It is therefore necessary to reduce the uncertainty of measured nuclear physics quantities, such as radioactive decay half-lives and branching ratios, nuclear structure data, energies and strengths of resonances, and most importantly the reaction cross sections. Therefore, only those topics are discussed where the author has enough experience, i.e., cross-section measurement of charged particle induced reactions with direct methods and mostly with rather conventional experimental techniques which are still widely used in nuclear astrophysics.
[212] Gamma‐Ray Line Emission from Radioactive Isotopes in Stars and Galaxies ... — Gamma‐ray astronomy seeks to constrain the astrophysical origin site(s) of radioactive isotopes in the Galaxy, and on smaller spatial scales, regions of coherent star formation. Sometimes the dominant origin site (supernovae, novae, Wolf‐Rayet stars, AGB stars, cosmic rays) of a Galactic radioactivity are not immediately clear from the
[213] Studies of Isotopic Abundances through Gamma‐Ray Lines — Cosmic gamma‐ray lines convey isotopic information from sites of nucleosynthesis and from their surrounding interstellar medium. With recent space‐borne gamma‐ray spectrometers of high resolution (INTEGRAL, RHESSI), new results have been obtained for 44 Ti from the Cas A core‐collapse supernova, from long‐lived radioactive 26 Al and 60 Fe, and from positron annihilation in our Galaxy
[221] Nucleosynthesis: The Creation Of Elements In Stars — Nucleosynthesis: The Creation Of Elements In Stars Nucleosynthesis is the process through which elements are created within stars. Nucleosynthesis represents the cosmic process by which elements are formed in stars. Understanding this process is crucial for comprehending Stellar Evolution and the formation of the universe’s elemental diversity. In contrast, stellar nucleosynthesis refers to the formation of elements within stars during their lifetimes. Stellar nucleosynthesis plays a fundamental role in the formation of elements throughout the universe. In these massive stars, nucleosynthesis contributes to the formation of elements beyond helium, including iron and beyond. Nucleosynthesis in stars plays a critical role in the formation of elements essential for life.
[223] Big Bang Nucleosynthesis: Nuclear Physics in the Early Universe — Nuclear physics plays a central role in BBN, which represents the first appearance of nuclear reactions in the universe. As we will see, BBN calculations require measurements of nuclear cross sections and the neutron lifetime at precisions unprecedented in nuclear astrophysics, and continued progress will demand a new generation of measurements.
[226] Machine learning opportunities for nucleosynthesis studies — 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.
[227] Colloquium : Machine learning in nuclear physics - Physical Review Link ... — Nuclear physics deals with complex systems, large datasets, and complicated correlations between parameters, which makes the field suitable for the application of machine learning techniques. Machine learning can help classify and analyze data, find hidden correlations, and assist in the design of new experiments and detectors. This Colloquium explains how this will lead to advances in nuclear