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

这一重大研究仪器奖将使佛罗里达州立大学(FSU)约翰·D·福克斯加速器实验室(FSU)安装一台获得认可的大型高分辨率磁谱仪，并围绕其开发一套最先进的辅助探测器。这台仪器将能够精确测量某些核性质，这些性质决定了恒星爆炸的能量释放和时间尺度，以及对非束缚原子核的一般物理研究。这台仪器在美国拥有进行这种精密测量的能力。这项合作的核磁共振奖将资助在俄亥俄州立大学加速器实验室安装一台大接受度、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和核结构的共振核态的物理。在耶鲁大学赖特核结构实验室停止运行后，SPS就可以使用了。该项目将在路易斯安那州立大学安装32吨重的仪器，并通过升级焦平面探测器和开发新的硅探测器阵列来增强研究能力，路易斯安那州立大学(LSU)同时开发了一种新的硅探测器阵列，用于高效地进行自由共振光谱。非束缚核态或共振的性质已经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和释放能量的门户。LSU/FSU的合作以前开发了核天体物理和具有奇异光束的结构阵列(ANASE N)，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来自于SPS执行的高精度光谱与现有的高灵敏度研究计划的独特组合，该计划目前正由ANASN执行。所提出的SPS系统还为奇异核态的物理学创造了一个重要的发现潜力，通过系统地研究超出束缚极限的粒子轨道来进行研究。跨壳层闭合的核轨道的相互作用对于处于束缚极限的奇异核的物理是重要的。通过研究非束缚共振的详细光谱，研究在存在竞争粒子衰变通道的情况下，超辐射机制的存在，将研究通过扩展波函数存在的核性质的改变。同样，SPS的研究不仅是补充，而且对FSU和未来稀有同位素束设施(FRIB)目前和未来的放射性束流研究也很重要。围绕SPS提出的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。SPS由两个充满活力的研究小组合作运营，有可能成为培养下一代科学家的国家资源。

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.