Windows on the Universe: Nuclear Astrophysics at the NSCL

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The nuclear astrophysics group at the National Superconducting Cyclotron (NSCL) will use their experimental facilities to address long-standing questions about the origin of the elements in the Universe. The goal is to restage, in the laboratory, the same nuclear reactions that produce new elements in nova and supernova explosions, merging neutron stars, accreting neutron stars, the Big Bang, and other extreme astrophysical environments. The interacting atomic nuclei are unstable and need to be artificially produced at the NSCL rare isotope facility. Experiments can then be carried out, where the relevant isotopes are produced and detected within fractions of a second. The nuclear data will be used in computer simulations of stars that are then confronted with multi-messenger astronomical observations using light, gamma rays, gravitational waves and neutrinos from various astrophysical sites. In the era of multi-messenger astronomy the interpretation of astronomical observations using light, gamma-rays, gravitational waves, and neutrinos requires an understanding of the nuclear processes that create these messengers. The NSCL group proposes to continue their experimental nuclear astrophysics program and other facilities to provide this important nuclear physics data. They will carry out a synergistic and interconnected experimental program using stable and rare isotope beams that employs a wide variety of existing experimental equipment, and continued development of key experimental capabilities. The experiments either measure astrophysical reactions directly (as they occur in nova and supernova explosions, neutron star mergers, accreting neutron stars, and other astrophysical sites) or provide indirect constraints on the reactions. Interpreting multi-messenger observations with accurate nuclear physics measurements obtained in this program will open a new window on the universe providing insight into element synthesis and nuclear matter in extreme astrophysical environments. This provides the opportunity to address long standing questions in nuclear science identified in the NP2010 National Academy study and the nuclear science long rage plan, including the questions we aim to address here; Where do the chemical elements come from, and how did they evolve? How does structure arise in the universe and how is it related to the emergence of the elements in stars and explosive processes? What is the nature of matter at extreme temperatures and densities? and "What is dark matter". These questions will be addressed by advancing our knowledge of stellar nuclear processes through laboratory experiments in close collaboration with nuclear theorists and astrophysicists. This group will perform experiments providing new data on proton capture in Novae, X-ray bursts, and Supernovae. They will measure a range of nuclear properties needed to understand the synthesis of heavy elements by rapid and intermediate neutron capture, study weak interactions in supernovae and neutron stars, and search for new nuclear decay modes that may shed light on element synthesis in the Big Bang. Broader Impacts: The proposed program of studies at the intersection of nuclear physics and astrophysics will attract a diverse group of undergraduate students, graduate students and postdocs to nuclear science by taking advantage of the compelling science of the NSF Big Idea "Windows on the Universe". Students and postdocs will receive interdisciplinary training by taking advantage of the synergistic connections available at MSU with the Joint Institute for Nuclear Astrophysics (JINA-CEE), the MSU Astronomy group, and the new MSU Department of Computational Mathematics Science and Engineering. This will help prepare the students and postdocs for successful nuclear careers in academia, industry and the US national laboratories.To further increase interest in STEM careers in general, and nuclear-science careers specifically, especially among women and minorities, the PI team will expand the very successful annual Nuclear Science Summer School at NSCL. The School provides undergraduate students access to nuclear science education that is not available at their home institutions and takes advantage of the compelling science in this proposal to attract and educate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.