Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (D) flux are presented. The measurements are based on 21×106 D nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the D flux exhibits nearly identical time variations with the p, He3, and He4 fluxes. Above 4.5 GV, the D/He4 flux ratio is time independent and its rigidity dependence is well described by a single power law ∝RΔ with ΔD/He4=-0.108±0.005. This is in contrast with the He3/He4 flux ratio for which we find ΔHe3/He4=-0.289±0.003. Above ∼13 GV we find a nearly identical rigidity dependence of the D and p fluxes with a D/p flux ratio of 0.027±0.001. These unexpected observations indicate that cosmic deuterons have a sizable primarylike component. With a method independent of cosmic ray propagation, we obtain the primary component of the D flux equal to 9.4±0.5% of the He4 flux and the secondary component of the D flux equal to 58±5% of the He3 flux.

Aguilar, M., Alpat, B., Ambrosi, G., Anderson, H., Arruda, L., Attig, N., et al. (2024). Properties of Cosmic Deuterons Measured by the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS, 132(26) [10.1103/physrevlett.132.261001].

Properties of Cosmic Deuterons Measured by the Alpha Magnetic Spectrometer

Consolandi, C.;Gervasi, M.;Grandi, D.;La Vacca, G.;Pensotti, S.;Rozza, D.;Tacconi, M.;
2024

Abstract

Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (D) flux are presented. The measurements are based on 21×106 D nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the D flux exhibits nearly identical time variations with the p, He3, and He4 fluxes. Above 4.5 GV, the D/He4 flux ratio is time independent and its rigidity dependence is well described by a single power law ∝RΔ with ΔD/He4=-0.108±0.005. This is in contrast with the He3/He4 flux ratio for which we find ΔHe3/He4=-0.289±0.003. Above ∼13 GV we find a nearly identical rigidity dependence of the D and p fluxes with a D/p flux ratio of 0.027±0.001. These unexpected observations indicate that cosmic deuterons have a sizable primarylike component. With a method independent of cosmic ray propagation, we obtain the primary component of the D flux equal to 9.4±0.5% of the He4 flux and the secondary component of the D flux equal to 58±5% of the He3 flux.
Articolo in rivista - Articolo scientifico
Cosmic Ray Deuterons
English
2024
132
26
261001
open
Aguilar, M., Alpat, B., Ambrosi, G., Anderson, H., Arruda, L., Attig, N., et al. (2024). Properties of Cosmic Deuterons Measured by the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS, 132(26) [10.1103/physrevlett.132.261001].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/488539
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