Opportunities for production and property research of neutron-rich nuclei around N = 126 at HIAF

Abstract

The study of nuclide production and its properties in the \({N}=126\) neutron-rich region is prevalent in nuclear physics and astrophysics research. The upcoming High-energy FRagment Separator (HFRS) at the High-Intensity heavy-ion Accelerator Facility (HIAF), an in-flight separator at relativistic energies, is characterized by high beam intensity, large ion-optical acceptance, high magnetic rigidity, and high momentum resolution power. This provides an opportunity to study the production and properties of neutron-rich nuclei around \({N}=126\). In this paper, an experimental scheme is proposed to produce neutron-rich nuclei around \({N}=126\) and simultaneously measure their mass and lifetime based on the HFRS separator; the feasibility of this scheme is evaluated through simulations. The results show that under the high-resolution optical mode, many new neutron-rich nuclei approaching the r-process abundance peak around \({A}=195\) can be produced for the first time, and many nuclei with unknown masses and lifetimes can be produced with high statistics. Using the time-of-flight corrected by the measured dispersive position and energy loss information, the cocktails produced from \({}^{208}\)Pb fragmentation can be unambiguously identified. Moreover, the masses of some neutron-rich nuclei near \({N}=126\) can be measured with high precision using the time-of-flight magnetic rigidity technique. This indicates that the HIAF-HFRS facility has the potential for the production and property research of neutron-rich nuclei around \({N}=126\), which is of great significance for expanding the chart of nuclides, developing nuclear theories, and understanding the origin of heavy elements in the universe.