Speaker
Description
Beryllium nuclei in cosmic rays are expected to be secondaries produced by the fragmentation of primary cosmic rays during their propagation in the Galaxy, and their fluxes contain essential information on cosmic-ray propagation and sources. Owing to the radioactive decay of $^{10}$Be to $^{10}$B with a half-life comparable to the cosmic-ray residence time in the Galaxy, $^{10}$Be/$^{9}$Be ratio provides unique sensitivity to the size of the Milky Way cosmic-ray propagation volume,a key parameter underlying the interpretation of secondary cosmic-ray fluxes. Prior to this study, measurements of the $^{10}$Be/$^{9}$Be ratio were restricted to kinetic energies below 2 GeV/n and were affected by large uncertainties, while the individual fluxes of $^{7}$Be, $^{9}$Be and $^{10}$Be were measured only below 0.4 GeV/n. We present measurements of the $^{7}$Be, $^{9}$Be and $^{10}$Be fluxes and their ratios over the energy range from 0.6 GeV/n to 18 GeV/n, where improved experimental precision contributes to a more accurate determination of the propagation volume.
| 请选择分会 | 中微子物理、粒子天体物理与宇宙学 |
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