We present the first measurement of cosmic-ray fluxes of and isotopes in the rigidity range from 1.9 to 25 GV. The measurements are based on and 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 and fluxes exhibit nearly identical time variations and, above , the time variations of , , He, Be, B, C, N, and O fluxes are identical. Above , we find an identical rigidity dependence of the and 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 flux.
Aguilar, M., et al. "Properties of Cosmic Lithium Isotopes Measured by the Alpha Magnetic Spectrometer." Physical Review Letters, vol. 134, no. 20, May. 2025. 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., Battiston, R., Bayyari, A., Belyaev, N., Bertucci, B., Bindi, V., Bollweg, K., Bolster, J., Borchiellini, M., ... Zuccon, P. (2025). Properties of Cosmic Lithium Isotopes Measured by the Alpha Magnetic Spectrometer. Physical Review Letters, 134(20). https://doi.org/10.1103/PhysRevLett.134.201001
Aguilar, M., Ambrosi, G., Anderson, H., et al., "Properties of Cosmic Lithium Isotopes Measured by the Alpha Magnetic Spectrometer," Physical Review Letters 134, no. 20 (2025), https://doi.org/10.1103/PhysRevLett.134.201001
@article{osti_2567760,
author = {Aguilar, M. and Ambrosi, G. and Anderson, H. and Arruda, L. and Attig, N. and Bagwell, C. and Barao, F. and Barbanera, M. and Barrin, L. and Bartoloni, A. and others},
title = {Properties of Cosmic Lithium Isotopes Measured by the Alpha Magnetic Spectrometer},
annote = { We present the first measurement of cosmic-ray fluxes of Li 6 and Li 7 isotopes in the rigidity range from 1.9 to 25 GV. The measurements are based on 9.7 × 10 5 Li 6 and 1.04 × 10 6 Li 7 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 Li 6 and Li 7 fluxes exhibit nearly identical time variations and, above ∼ 4 GV , the time variations of Li 6 , Li 7 , He, Be, B, C, N, and O fluxes are identical. Above ∼ 7 GV , we find an identical rigidity dependence of the Li 6 and Li 7 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 Li 7 flux. Published by the American Physical Society 2025 },
doi = {10.1103/PhysRevLett.134.201001},
url = {https://www.osti.gov/biblio/2567760},
journal = {Physical Review Letters},
issn = {ISSN PRLTAO},
number = {20},
volume = {134},
place = {United States},
publisher = {American Physical Society},
year = {2025},
month = {05}}
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