Dr. Jack Silano from Lawrence Livermore National Laboratory (LLNL)

Title: Measurements of Fission Product Yields Using Monoenergetic Neutron and Gamma-ray Beams

Fission is the most complex and violent process in nuclear physics, splitting an atomic nucleus into two or more fragments and releasing enormous amounts of energy. Fission product yields (FPYs), the nuclei produced by the division of a fissioning nucleus, contain a wealth of information about the nuclear fission process. FPY distributions are sensitive to the species of nucleus undergoing fission, its excitation energy, spin, and the underlying microscopic physics that drive fission. In addition, FPYs are relevant to fundamental and applied science such as heavy element nucleosynthesis, the reactor antineutrino anomaly, nuclear forensics, reactor decay heat calculations, and stockpile stewardship. In this colloquium, I will give an overview of a joint LLNL-LANL-TUNL research program aimed at performing high-precision FPY measurements using quasimonoenergetic neutron and gamma-ray beams at Triangle Universities Nuclear Laboratory. Over the past decade, our efforts to modernize our experimental process and analysis – as well as the development of a state-of-the-art rapid target transfer system (RABITTS) – have enabled us to measure FPYs with half lives ranging from several months to less than one second. I will present a selection of our FPY data and demonstrate how they can be used to study fundamental science in the fission mechanism. Finally, I will discuss ongoing work to prepare for FPY measurements using radioactive isotope beams at facilities such as the Facility for Rare Isotope Beams (FRIB).

This talk is dedicated to Hugon Karwowski’s retirement.