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: 1429189
• 负责人: Catherine Deibel
• 金额: $ 20.3万
• 依托单位: Louisiana 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 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1429189&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.

该主要研究仪器奖将在佛罗里达州立大学（FSU）的约翰·d·福克斯加速器实验室安装一个大容量、高分辨率的磁摄谱仪，并在其周围开发一套最先进的辅助探测器。这台仪器将允许对某些核性质进行精确测量，这些性质决定了恒星爆炸的能量释放和时间尺度，以及对一般未束缚原子核的物理学进行研究。该仪器恢复了在美国进行这种精密测量的能力。该合作核磁共振奖将资助在FSU的加速器实验室安装一个大接受度、高分辨率的恩格分极光谱仪（SPS），目的是研究影响核天体物理和核结构的共振核状态的物理。SPS在耶鲁大学赖特核结构实验室停止运行后开始使用。该项目将在FSU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，与路易斯安那州立大学（LSU）并行，用于有效的非束缚共振光谱。非束缚核状态的性质，或共振，已经成为当今核科学的焦点，因为它们是恒星和恒星爆炸建立元素和释放能量的门户。LSU/FSU合作之前开发了带有奇异光束的核天体物理和结构阵列（ANASEN），用于使用放射性原子核束对此类反应进行高效研究。SPS进行的高精度光谱学与ANASEN目前正在进行的放射性光束的高灵敏度研究计划的独特结合，为提高我们对具有天体物理学重要性的核反应的理解提供了一个新的机会。提出的SPS系统还通过系统地研究超出束缚极限的粒子轨道，为奇异核态的物理学创造了重要的发现潜力。核轨道在壳包层间的相互作用对束缚极限下奇异核的物理学具有重要意义。扩展波函数对核性质的影响将通过非束缚共振的详细光谱来研究，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的研究不仅是互补的，而且对FSU和未来的稀有同位素光束设施（FRIB）的放射性光束的当前和未来的研究也很重要。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实验机会的问题。SPS由两个充满活力的研究小组合作运营，有潜力成为下一代科学家教育的国家资源。