Observation of new isotopes at FRIB, and reaction mechanisms for exotic nuclei production*

The Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) is a new facility based on a superconducting linear accelerator with a wide array of primary beams around 200 MeV/u, which allows some flexibility in rare isotope production. The experimental program at FRIB began in May 2022, and in this report, I present the first observations of new isotopes using a 198Pt beam. Additionally, I will focus on investigating the reaction mechanisms involved in the production of unstable isotopes located far from stability, which helps determine with primary beam to use and what the extent of isotopes can be produced.

Statistical models, such as the abrasion-ablation (AA) or intra-nuclear cascade (INC) models, have shown good agreement with experimental data [1]. A multi-step reaction scheme has been found to be an effective approach for exploring the neutron-rich region [2], supported by experimental results [3,4]. In this context, I will discuss the key requirements for qualitatively predicting production cross sections for unknown isotopes using the AA model, taking into account the multi-step reaction scheme. The discussion will encompass advancements in theoretical and experimental studies, as well as computing.

 

1. O. B. Tarasov et al., Phys. Rev. C 87, 054612 (2013)

2. L.Neufcourt et al., Phys. Rev. C 101, 044307 (2020).

3. H. Suzuki et al., Phys. Rev. C 102, 064615 (2020).

4. O. B. Tarasov et al., Phys. Rev. Lett. 122, 022501 (2018).