Machine-Learning-Enabled Measurements of Astrophysical (p,n) Reactions with the SECAR Recoil Separator
Abstract
The synthesis of heavy elements in supernovae is affected by low-energy (n,p) and (p,n) reactions on unstable nuclei, yet experimental data on such reaction rates are scarce. The SECAR (SEparator for CApture Reactions) recoil separator at FRIB (Facility for Rare Isotope Beams) was originally designed to measure astrophysical reactions that change the mass of a nucleus significantly. We used a novel approach that integrates machine learning with ion-optical simulations to find an ion-optical solution for the separator that enables the measurement of (p,n) reactions, despite the reaction leaving the mass of the nucleus nearly unchanged. A new measurement of the Fe(p,n)Co reaction in inverse kinematics with a 3.660.12 MeV/nucleon Fe beam (corresponding to 3.690.12 MeV proton energy in normal kinematics) yielded a cross-section of 20.36.3 mb and served as a benchmark for the new technique demonstrating its effectiveness in achieving the required performance criteria. This novel approach marks a significant advancement in experimental nuclear astrophysics, as it paves the way for studying astrophysically important (p,n) reactions on unstable nuclei produced at FRIB.
Keywords
Cite
@article{arxiv.2411.03338,
title = {Machine-Learning-Enabled Measurements of Astrophysical (p,n) Reactions with the SECAR Recoil Separator},
author = {P. Tsintari and N. Dimitrakopoulos and R. Garg and K. Hermansen and C. Marshall and F. Montes and G. Perdikakis and H. Schatz and K. Setoodehnia and H. Arora and G. P. A. Berg and R. Bhandari and J. C. Blackmon and C. R. Brune and K. A. Chipps and M. Couder and C. Deibel and A. Hood and M. Horana Gamage and R. Jain and C. Maher and S. Miskovitch and J. Pereira and T. Ruland and M. S. Smith and M. Smith and I. Sultana and C. Tinson and A. Tsantiri and A. Villari and L. Wagner and R. G. T. Zegers},
journal= {arXiv preprint arXiv:2411.03338},
year = {2025}
}