Studies of Nuclear Reactions and Structure

这一奖项资助了佛罗里达州立大学(FSU)教职员工和学生在核物理方面的广泛测量计划。这些实验包括对核反应和衰变的研究，这些反应和衰变在恒星过程的所有阶段都起着关键作用。该计划的这一方面支持在世界范围内进行和正在进行的天文观测方面的大量投资。其他实验主要关注核壳结构随中子数增加而变化的情况，特别是在20和28的幻数附近。FSU和国家超导回旋实验室(NSCL)将通过使用伽马探测器阵列的离散伽马光谱来探索超高自旋原子核的行为。该小组还将利用相对论重离子对撞机(RHIC)上的重离子碰撞来研究夸克-胶子等离子体的特征。该项目更广泛的社会影响在于在实践环境中对本科生和研究生进行教育和培训。佛罗里达州立大学在核物理领域一直是领先的教育者之一(博士产量在美国排名第四)这笔赠款将使该小组能够继续吸引和培训实验核物理领域最优秀和最聪明的研究生。由于学生在前沿核物理实验室接受培训并使用高科技设备进行实践工作，FSU毕业生需求旺盛，目前在国土安全、国防、高科技产业、前沿研究和STEM教育中担任关键角色。最后，这些测量对于理解恒星过程和我们宇宙中元素的丰度将是重要的。这项拟议研究的很大一部分使用了来自佛罗里达州立大学福克斯实验室的短命稀有核同位素来研究不稳定核中的核反应和结构。这对于具有天体物理意义的反应非常重要，其中许多反应都是通过不稳定的原子核进行的。这些光束的强度很低，因此将受益于最近由FSU与路易斯安那州立大学合作开发的ANASE有源目标和探测器阵列。一种新开发的中子探测器阵列(RESONEUT)将用于研究放射性束流逆运动学中的(d，n)反应。计划进行一系列实验，以测量在TRIUMF的预期r过程路径上和接近预期的r过程路径上，重的、富含中子的核的贝塔衰变后的临界寿命参数。多重跨壳层激发的最新壳层模型计算与建议的核结构测量的对峙将增强它们外推到天体物理重要区域的可靠性。FSU 14C束将用于探索更多中子丰度较高的核的核结构，以及最近数字化的锗探测器阵列。使用伽马探测器阵列(Gretina和GAMMASPHERE)的测量将探索新提出的奇异形状和原子质量~150区域的超高自旋结构。其他工作包括使用PHENIX探测器系统研究带有重味道探测器的夸克-胶子等离子体，FSU建造了该探测器系统的一部分。在这种情况下，FSU的重点是冷核物质对重夸克尼亚产生的影响。

This award funds a broad program of measurements in nuclear physics by faculty and students at Florida State University (FSU). The experiments include studies of nuclear reactions and decays that play key roles in all stages of stellar processes. This aspect of the program supports the large investment made and being made in astronomical observations worldwide. Other experiments focus on the evolution of nuclear shell structure with increasing neutron number, especially near the magic numbers of 20 and 28. The behavior of nuclei at ultra-high spin will be explored through discrete gamma spectroscopy using arrays of gamma detectors at FSU and at the National Superconducting Cyclotron Laboratory (NSCL). The group will also exploit heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) to investigate the characteristics of the quark-gluon plasma. The broader societal impacts of this project lie in the education and training of undergraduate and graduate students in a hands-on environment. Florida State University has served as one of the leading educators in the field of nuclear physics (4th highest Ph.D. production in the U.S.) and this grant will enable the group to continue to attract and train the best and brightest graduate students in experimental nuclear physics. Because of the students' training and hands-on work with high tech equipment in a forefront nuclear physics laboratory, FSU graduates are in high demand and now serve in key roles in homeland security, national defense, high-tech industry, leading edge research, and STEM education. Finally, these measurements will be important for understanding stellar processes and the abundance of elements in our universe. A significant part of the proposed research uses short-lived rare nuclear isotopes from the FSU Fox Laboratory to study nuclear reactions and structure in unstable nuclei. This is very important for reactions of astrophysical importance, many of which proceed through unstable nuclei. These beams have low intensity and so will benefit from the ANASEN active target and detector array recently developed by FSU in collaboration with Louisiana State University. A newly developed neutron detector array (RESONEUT) will be used to study (d,n) reactions in inverse kinematics with radioactive beams. A series of experiments is planned to measure the critical parameter of lifetime following beta decay of heavy, neutron-rich nuclei on and close to the expected r-process path at TRIUMF. The confrontation of state-of-the-art shell model calculations for multiple cross-shell excitations with proposed nuclear structure measurements will strengthen their reliability for extrapolation to the astrophysically important region. The FSU 14C beam will be used to explore nuclear structure in more neutron-rich nuclei with a recently digitized Germanium detector array. Measurements using gamma detector arrays (GRETINA and GAMMASPHERE) will explore newly proposed exotic shapes and ultra-high-spin structures in the atomic mass ~ 150 region. Other work involves studying the quark-gluon plasma with heavy flavor probes using the PHENIX detector system, parts of which were constructed at FSU. In this instance the FSU focus is on the effects of cold nuclear matter on heavy quarkonia production.