A possible explanation of the knee of cosmic light component spectrum from 100 TeV to 3 PeV**Supported by the National Natural Science Foundation of China (11433004, 11363006, 11103016, 11173020), Top Talents Program of Yunnan Province (2015HA030) and the Natural Science Foundation of Yunnan Province(2015FB103)

Abstract

A mixed hydrogen and helium (H + He) spectrum with a clear steepening at ∼ 700 TeV has been detected by the ARGO-YBJ experiments. In this paper, we demonstrate that the observed H + He spectrum can be reproduced well with a model of cosmic rays escaping from the supernova remnants (SNRs) in our Galaxy. In this model, particles are accelerated in a SNR through a non-linear diffusive shock acceleration mechanism. Three components of high energy light nuclei escaped from the SNR are considered. It should be noted that the proton spectrum observed by KASCADE can be also explained by this model given a higher acceleration efficiency.