NSF PAR Search | NSF Public Access Repository

Properties of Cosmic Lithium Isotopes Measured by the Alpha Magnetic Spectrometer

https://doi.org/10.1103/PhysRevLett.134.201001

Aguilar, M; Ambrosi, G; Anderson, H; Arruda, L; Attig, N; Bagwell, C; Barao, F; Barbanera, M; Barrin, L; Bartoloni, A; et al (May 2025, Physical Review Letters)

We present the first measurement of cosmic-ray fluxes of

{}^{6}{Li}

and

{}^{7}{Li}

isotopes in the rigidity range from 1.9 to 25 GV. The measurements are based on

9.7 \times 10^{5}

{}^{6}{Li}

and

1.04 \times 10^{6}

{}^{7}{Li}

nuclei collected by the Alpha Magnetic Spectrometer on the International Space Station from May 2011 to October 2023. We observe that over the entire rigidity range the

{}^{6}{Li}

and

{}^{7}{Li}

fluxes exhibit nearly identical time variations and, above

\sim 4 GV

, the time variations of

{}^{6}{Li}

{}^{7}{Li}

, He, Be, B, C, N, and O fluxes are identical. Above

\sim 7 GV

, we find an identical rigidity dependence of the

{}^{6}{Li}

and

{}^{7}{Li}

fluxes. This shows that they are both produced by collisions of heavier cosmic-ray nuclei with the interstellar medium and, in particular, excludes the existence of a sizable primary component in the

{}^{7}{Li}

flux. Published by the American Physical Society2025

Free, publicly-accessible full text available May 1, 2026

Search for: All records