# First sub-MeV nuclear reaction measurements in a heavy-ion storage ring

## TL;DR

This paper reports the first nuclear reactions measured in a heavy-ion storage ring at sub-MeV energies, opening new possibilities for astrophysics research.

## Contribution

The first sub-MeV nuclear reaction measurements in a heavy-ion storage ring, enabling future studies in nuclear astrophysics.

## Key findings

- The (p,p) scattering results agree well with theoretical R matrix predictions.
- A (p,α) reaction was measured at E = 426 keV/u, the lowest energy for such a measurement in a heavy-ion storage ring.
- The study lays the groundwork for future investigations in stellar environments using this novel method.

## Abstract

Heavy-ion storage rings present a novel approach to studying nuclear reactions for astrophysics that have so far resisted traditional methods. In this paper, we report the first nuclear reactions studied in a ring at sub-MeV centre-of-mass energies. This is a major advance in nuclear reaction measurements at rings that lays the foundations for future investigations to address key problems in nuclear astrophysics affecting a wide range of stellar environments. We investigated the \documentclass[12pt]{minimal}
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\begin{document}$$^{12}$$\end{document}12C reactions in inverse kinematics from E = 1.125 MeV/u down to E = 426 keV/u, using the CARME array in the low-energy CRYRING@ESR heavy-ion storage ring, located at the GSI Helmholtz Center for Heavy Ion Research. Our (p,p) scattering results are in excellent agreement with theoretical R matrix predictions. We also report on a (p,\documentclass[12pt]{minimal}
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\begin{document}$$\alpha $$\end{document}α) measurement at E = 426 keV/u, corresponding to E\documentclass[12pt]{minimal}
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\begin{document}$$_\textrm{cm}$$\end{document}cm = 403 keV, by far the lowest energy at which a nuclear reaction has ever been measured in a heavy-ion storage ring.