Nuclear Reaction Studies for Nuclear Structure and Nucleosynthesis

核结构和核合成的核反应研究

• 批准号: 1812316
• 负责人: Jolie Cizewski
• 金额: $ 45万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1812316&HistoricalAwards=false
• 关键词: Nuclear; Reaction; Studies; Structure; Nucleosynthesis

Experimental nuclear physics helps us to understand the properties of the nuclei at the center of atoms and how the elements are synthesized in stars and their explosions. This project enhances our understanding of these fundamental questions by accelerating nuclei to high energies and measuring gamma and charged particle radiation that is emitted when they interact with other atomic nuclei. The focus is on accelerating beams of atomic nuclei that are unstable to beta decay, living for times as short as seconds. The interactions between atomic nuclei informs our understanding of the properties of atomic nuclei, especially those far from stability that are more weakly bound, as well as helping us to understand how the parents of the stable elements were synthesized. This project will serve to advance our understanding of the structure of and reactions on atomic nuclei away from the valley of stability and their synthesis in stars and their explosions. It will exploit state-of-the-art instruments and accelerator facilities in the U.S. Central to this effort is enhancing the education of students and preparing them for careers in education and fundamental and applied research. The anticipated nuclear physics results are also of importance in astronomy, to understand the abundance of elements observed in the cosmos, and for nuclear energy and national security, to understand properties of and reactions on fission fragments. The structure of the proposed activities is designed to have a positive impact on the education and training of graduate students. The project will also serve to enhance the diversity of the nuclear science workforce by seeking out early career scientists who are women or come from other under-represented backgrounds. The participation of these early career scholars in the forefront research and the development of arrays of instruments would prepare them for careers in higher education and fundamental and applied research, at national laboratories and in industry. One of the frontier areas of nuclear physics is the study of the structure of atomic nuclei far from the valley of stability. In atomic nuclei the single-particle orbitals are expected to change as a function of neutron and proton number and, in addition, are very sensitive to the presence of deformation. Single-particle characteristics can be probed in single-particle transfer reactions and are important in calculating the direct component in neutron capture reactions that are responsible for the synthesis of elements heavier than iron. Light-ion transfer reactions will be studied with radioactive ion beams with energies near the Coulomb barrier and about 40-MeV per nucleon. Studies will concentrate on neutron-rich nuclei near the N=50 neutron shell closure, accelerated fragments following spontaneous fission of 252Cf and light nuclei important for understanding the synthesis of nuclei in stars and their explosions. These studies will be carried out with radioactive ion beams at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University, the ATLAS accelerator facility at Argonne National Laboratory and the Nuclear Science Laboratory at the University of Notre Dame. The focus at NSCL is to constrain the shape of the potential that binds neutrons in a neutron-rich nucleus and, therefore, extract spectroscopic strengths with reduced dependence on theoretical model parameters. Both charged particles and coincident gamma radiation will be measured with flexible configurations of detectors. At ATLAS, Gammasphere-ORRUBA: Dual Detectors for Experimental Structure Studies will be exploited to probe the fragmentation of single-particle strength with coincidence measurements between charged particles (measured with ORRUBA, the Oak Ridge Rutgers University Barrel Array of position-sensitive silicon strip detectors) and gamma rays (measured with large, highly segmented germanium gamma-ray detector arrays). The Rutgers-led efforts will be complemented by efforts led by other members of the ORRUBA collaboration. The results will be compared with theoretical predictions of nuclear structure away from stability and disseminated as input into calculations of nucleosynthesis in stars and their explosions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

实验核物理帮助我们了解位于原子中心的原子核的性质，以及元素是如何在恒星及其爆炸中合成的。这个项目通过将原子核加速到高能并测量它们与其他原子核相互作用时发射的伽马和带电粒子辐射来增强我们对这些基本问题的理解。重点是加速原子核的光束，这些原子核对β衰变不稳定，寿命短至几秒钟。原子核之间的相互作用使我们了解原子核的性质，特别是那些远离稳定的弱结合原子核，也有助于我们理解稳定元素的母体是如何合成的。这个项目将有助于增进我们对远离稳定谷的原子核的结构和反应的理解，以及它们在恒星及其爆炸中的合成。它将利用美国最先进的仪器和加速器设施。这一努力的核心是加强对学生的教育，并为他们在教育以及基础和应用研究方面的职业生涯做好准备。预期的核物理结果对于天文学、了解在宇宙中观察到的元素的丰度以及对于核能和国家安全、了解裂变碎片的性质和反应也很重要。拟议活动的结构旨在对研究生的教育和培训产生积极影响。该项目还将通过寻找女性或来自其他代表性不足背景的早期职业科学家，来加强核科学工作人员的多样性。这些早期职业学者参与前沿研究和一系列仪器的开发，将为他们在高等教育、基础和应用研究、国家实验室和工业领域的职业生涯做好准备。核物理的前沿领域之一是研究远离稳定谷的原子核的结构。在原子核中，单粒子轨道预计会随着中子和质子数的变化而变化，此外，它对形变的存在非常敏感。单粒子特性可以在单粒子转移反应中探测到，并在计算中子俘获反应中的直接成分时很重要，中子俘获反应负责合成比铁更重的元素。将使用能量接近库仑势垒、每个核子约40 MeV的放射性离子束来研究光离子转移反应。研究将集中在N=50中子壳关闭附近的富中子核、252Cf自发裂变后的加速碎片和对理解恒星中核的合成及其爆炸非常重要的轻核。这些研究将在密歇根州立大学的国家超导回旋实验室(NSCL)、阿贡国家实验室的ATLAS加速器设施和圣母大学的核科学实验室使用放射性离子束进行。NSCL的重点是限制在富含中子的原子核中束缚中子的势的形状，从而在减少对理论模型参数的依赖的情况下提取光谱强度。带电粒子和符合伽马辐射都将使用灵活的探测器配置进行测量。在ATLAS，Gammasphere-ORRUBA：将利用用于实验结构研究的双探测器来探测单粒子强度的碎裂，并在带电粒子(用橡树岭罗格斯大学位置敏感硅条探测器的桶形阵列ORRUBA测量)和伽马射线(用大的、高度分段的锗伽马射线探测器阵列测量)之间进行符合测量。罗格斯大学领导的努力将得到ORRUBA合作的其他成员领导的努力的补充。结果将与核结构远离稳定性的理论预测进行比较，并作为计算恒星核合成及其爆炸的输入。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Neutron transfer reactions on the ground state and isomeric state of a Sn130 beam

Sn130 束基态和异构态的中子转移反应

• DOI: 10.1103/physrevc.105.024602
• 发表时间: 2022
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Jones, K. L.;Bey, A.;Burcher, S.;Allmond, J. M.;Galindo-Uribarri, A.;Radford, D. C.;Ahn, S.;Ayres, A.;Bardayan, D. W.;Cizewski, J. A.
• 通讯作者: Cizewski, J. A.

γ -ray spectroscopy of astrophysically important states in Ca39

Ca39 中天体物理重要状态的 γ 射线光谱

• DOI: 10.1103/physrevc.101.015804
• 发表时间: 2020
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Hall, M. R.;Bardayan, D. W.;Baugher, T.;Lepailleur, A.;Pain, S. D.;Ratkiewicz, A.;Ahn, S.;Allen, J. M.;Anderson, J. T.;Ayangeakaa, A. D.
• 通讯作者: Ayangeakaa, A. D.

Using 19F(3He,t)19Ne*(γ) to study astrophysically important levels near the 18F+p threshold

使用 19F(3He,t)19Ne*(γ) 研究 18F p 阈值附近的天体物理重要水平

• DOI: 10.1063/1.5127732
• 发表时间: 2019
• 期刊: AIP Conference Proceedings
• 作者: Hall, M. R.;Bardayan, D. W.;Ahn, S.;Allen, J. M.;Anderson, J. T.;Ayangeakaa, A. D.;Baugher, T.;Blackmon, J. C.;Blankstein, D.;Burcher, S.
• 通讯作者: Burcher, S.

Nuclear Reactions in Astrophysics: A Review of Useful Probes for Extracting Reaction Rates

天体物理学中的核反应：用于提取反应速率的有用探针的回顾

• DOI: 10.1146/annurev-nucl-020620-063734
• 发表时间: 2020
• 期刊: Annual Review of Nuclear and Particle Science
• 影响因子: 12.4
• 作者: Nunes, F.M.;Potel, G.;Poxon-Pearson, T.;Cizewski, J.A.
• 通讯作者: Cizewski, J.A.

Direct neutron capture cross section on Ge80 and probing shape coexistence in neutron-rich nuclei

Ge80 上的直接中子俘获截面和富中子核中的探测形状共存

• DOI: 10.1103/physrevc.100.044613
• 发表时间: 2019
• 期刊: Physical Review C
• 影响因子: 3.1
• 作者: Ahn, S.;Bardayan, D. W.;Jones, K. L.;Adekola, A. S.;Arbanas, G.;Blackmon, J. C.;Chae, K. Y.;Chipps, K. A.;Cizewski, J. A.;Hardy, S.
• 通讯作者: Hardy, S.