Ponente
Descripción
The current cosmic-ray(CR) measurements show anomalies in secondary CRs, for example a hardening of the ratio of boron to carbon at high energies, which deviates from the standard galactic CR propagation model: $B/C \propto E^{-\delta}$. It may suggest the generation of secondary CRs near or inside the accelerators, e.g, SNRs. The accumulated grammage in the sources may be non-negligible and contribute to the measured grammage. We calculate the boron production in different SNRs(Type-Ia & core-collapse), and simulate in two diffusion regimes: 1. Bohm diffusion. 2. Turbulence self-generated by the CRs, which realistically models the enhanced confinement of CRs close to the accelerators. Our preliminary results show a hard B/C ratio in the energy range up to $10^{3}$ GeV/n developing within the SNRs. The level, approximately $10^{-3}-10^{-2}$, depends on the diffusion model, the density of the source region, and the acceleration time. It suggests that a significant fraction of the observed high-energy boron at TeV energies may originate from near-source production in SNRs, potentially explaining the flattening of the B/C ratio reported by DAMPE and AMS-02.
