Investigating the chemical fingerprints of massive stars through nuclear reactions
Prof. Matt Williams
University of Surrey, UK
Stars much more massive than are own Sun serve as cosmic cauldrons where almost all the elements we observe today were created by nuclear reactions. The extreme conditions found in their cores play host to a variety of unique nucleosynthetic processes, active both in stellar burning leading up to their demise and during the subsequent supernovae explosion. Hidden from view, the complex physical processes that constitute the final act of a massive star’s life must be pieced together from the chemical fingerprints left behind, interpreted through stellar modelling and nuclear data. In this talk, I will present three reaction studies that each investigate nuclear processes activated in massive stars. Firstly, I will discuss recent success in unlocking the so-called weak r-process for experimental reaction studies for the first time [1]. This involved the deployment of novel nanomaterial targets to measure key (α,n) reactions with radioactive beams produced at the TRIUMF laboratory. I will then present preliminary data from a measurement of 19F(p,γ)20Ne, aimed at constraining nucleosynthesis in the first generation of massive stars. Finally, looking towards the future, I will outline planned measurements with the newly commissioned SECAR facility [2] at FRIB to investigate the origin of the p-nuclei, a unique set of neutron-deficient isotopes thought to only be produced in supernovae.
[1] M. Williams, et al., Phys. Rev. Lett. 134, 112701 (2025)
[2] https://frib.msu.edu/user-
Hosted by Dr. deBoer