MRI Collaborative: Development of the LSU/FSU Split-Pole Spectrograph System at the FSU Accelerator Laboratory

MRI 协作：FSU 加速器实验室开发 LSU/FSU 分极摄谱仪系统

• 批准号: 1429019
• 负责人: Ingo Wiedenhoever
• 金额: $ 20.1万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-15 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1429019&HistoricalAwards=false
• 关键词: MRI; Collaborative; Development; LSU; FSU

This Major Research Instrumentation award will enable the installation of a large acceptance, high-resolution magnetic spectrograph at the John D. Fox Accelerator Laboratory of Florida State University (FSU) and the development of a suite of state-of-the-art auxiliary detectors around it. This instrument will allow precision measurements of certain nuclear properties, which determine the energy release and time scale of stellar explosions and studies of the physics of unbound atomic nuclei in general. This instrument reclaims the capability to perform such precision measurements in the USA. This collaborative MRI award will fund the installation of a large-acceptance, high-resolution Enge split-pole spectrograph (SPS) at the accelerator laboratory at FSU with the purpose of studying the physics of resonant nuclear states that impact nuclear astrophysics and nuclear structure. The SPS became available upon the cessation of operations at the Wright Nuclear Structure Laboratory at Yale University. This project will install the 32-tonne instrument at FSU and augment its research capabilities by upgrading its focal plane detectors and developing a new Silicon detector array, in parallel at Louisiana State University (LSU), for efficient spectroscopy of unbound resonances.The properties of un-bound nuclear states, or resonances, have become a focal point of present day nuclear science as they present the doorway through which stars and stellar explosions build up the elements and release energy. The LSU/FSU collaboration previously developed the Array for Nuclear Astrophysics and Structure with Exotic Beams (ANASEN) for high-efficiency studies of such reactions using beams of radioactive nuclei. A new opportunity for advancing our understanding of nuclear reactions with astrophysical importance stems from the unique combination of high-precision spectroscopy performed with the SPS with the existing program of high-sensitivity studies with radioactive beams currently being performed with ANASEN. The proposed SPS system also creates an important discovery potential for the physics of exotic nuclear states, studied through a systematic investigation of particle orbitals beyond the binding limit. The interaction of nuclear orbits across shell closures is of importance to the physics of exotic nuclei at the limits of binding. The modification of nuclear properties through the presence of extended wavefunctions will be studied through a detailed spectroscopy of un-bound resonances, studying the presence of the Super-radiance mechanism in the presence of competing particle-decay channels. Again, the research at the SPS is not only complementary, but important to current and future studies with radioactive beams at FSU and the future Facility for Rare isotope Beams (FRIB). The proposed program around the SPS is a complementary effort and aims to address a lack of experimental opportunities with stable nuclear beams within the U.S. scientific program. Operated by a collaboration of two vibrant research groups, the SPS has the potential to become a national resource in the education of the next generation of scientists.

这一重大研究仪器奖将使一个大的接受，高分辨率磁摄谱仪在约翰D。佛罗里达州立大学的福克斯加速器实验室，并在其周围开发了一套最先进的辅助探测器，该仪器将能够精确测量某些核特性，这些特性决定恒星爆炸的能量释放和时间尺度，并研究一般的非束缚原子核的物理学。该仪器在美国重新获得了执行此类精密测量的能力。该合作MRI奖将资助在FSU加速器实验室安装大接受度，高分辨率的Enge分裂极光谱仪（SPS），目的是研究影响核天体物理学和核结构的共振核状态的物理学。 SPS在耶鲁大学赖特核结构实验室停止运作后开始可用。 该项目将在佛罗里达州立大学安装32吨重的仪器，并通过升级其焦平面探测器和开发新的硅探测器阵列来增强其研究能力，同时在路易斯安那州立大学（LSU）进行非束缚共振的有效光谱分析。已成为当今核科学的焦点，因为它们提供了恒星和恒星爆炸建立元素并释放能量的途径。 路易斯安那州立大学/前苏联合作先前开发了具有奇异光束的核天体物理学和结构阵列（ANASEN），用于使用放射性核束对此类反应进行高效研究。 推进我们对具有天体物理重要性的核反应的理解的一个新机会源于SPS进行的高精度光谱学与目前正在与ANASEN进行的放射性束高灵敏度研究的现有方案的独特组合。拟议的SPS系统也创造了一个重要的发现潜力的物理学奇异的核状态，研究通过系统的调查粒子轨道超出约束力的限制。 壳层闭合时核轨道的相互作用对束缚极限下奇异核物理具有重要意义。 通过扩展波函数的存在对核性质的修改将通过详细的非束缚共振光谱学进行研究，研究在竞争粒子衰变通道存在下超辐射机制的存在。 同样，SPS的研究不仅是补充，而且对FSU和未来的稀有同位素束设施（FRIB）的放射性束的当前和未来研究很重要。围绕SPS的拟议计划是一项补充努力，旨在解决美国科学计划中缺乏稳定核束的实验机会。 由两个充满活力的研究小组合作运作，SPS有可能成为下一代科学家教育的国家资源。