Progress of underground nuclear astrophysics JUNA

Abstract

The Jinping Underground experiment for Nuclear Astrophysics (JUNA) takes advantage of the ultra-low background of the CJPL to conduct experiments for directly studying crucial reactions at stellar energies in the evolution of stars. In 2020, JUNA commissioned a mA level high current accelerator based on an ECR source, as well as high efficiency BGO and ³He detectors. Direct measurements of key nuclear reactions, including ${}^{25}\mathrm{Mg}{(p,\gamma )}^{26}\mathrm{Al}$, ${}^{19}F{(p,\alpha \gamma )}^{16}O$, ${}^{19}F{(p,\gamma )}^{20}\mathrm{Ne}$, ${}^{12}C{(\alpha ,\gamma )}^{16}O$ and ${}^{18}O{(\alpha ,\gamma )}^{22}\mathrm{Ne}$, were performed in JUNA with improved precision and closer to the Gamow window relative to previous measurements. These precise reaction rates provide valuable insights into the high precision astrophysics simulation.