In:
Physical Review Letters, American Physical Society (APS), Vol. 132, No. 26 ( 2024-6-25)
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 × 10 6 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 , He 3 , and He 4 fluxes. Above 4.5 GV, the D / He 4 flux ratio is time independent and its rigidity dependence is well described by a single power law ∝ R Δ with Δ D / He 4 = − 0.108 ± 0.005 . This is in contrast with the He 3 / He 4 flux ratio for which we find Δ He 3 / He 4 = − 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 He 4 flux and the secondary component of the D flux equal to 58 ± 5 % of the He 3 flux. Published by the American Physical Society 2024
Type of Medium:
Online Resource
ISSN:
0031-9007
,
1079-7114
DOI:
10.1103/PhysRevLett.132.261001
Language:
English
Publisher:
American Physical Society (APS)
Publication Date:
2024
detail.hit.zdb_id:
1472655-5
detail.hit.zdb_id:
208853-8
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