TY - JOUR
T1 - Properties of Cosmic Deuterons Measured by the Alpha Magnetic Spectrometer
AU - AMS Collaboration
AU - Aguilar, Magnolia Martinez
AU - Alpat, B.
AU - Ambrosi, G.
AU - Anderson, H
AU - Bagwell, C.
AU - Barao, F.
AU - Barbanera, M.
AU - Borchiellini, Marta
AU - Vecchi, Manuela
PY - 2024/6/25
Y1 - 2024/6/25
N2 - 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.
AB - 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.
U2 - 10.1103/PhysRevLett.132.261001
DO - 10.1103/PhysRevLett.132.261001
M3 - Article
SN - 0031-9007
VL - 132
JO - Physical Review Letters
JF - Physical Review Letters
M1 - 261001
ER -