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.
