Study of Cosmic Ray Spectral Features Using GALPROP

Recent space-based and balloon-borne experiments have reported significant spectral hardening of cosmic ray data at around 200 GV. Many different cosmic ray spectra reflect this feature, including primary and secondary elements. To investigate this spectral hardening, the numerical cosmic-ray propagation code GALPROP was used. As a base model, the Plain Diffusion model with reacceleration effects was used. Rigidity-dependent parameters were used to study three cases: (1) a diffusion coefficient break, (2) source spectrum breaks, and (3) a combination of both effects. To explain the positron excess above ~27 GeV, an additional positron source was also investigated. From our prior work in this study, special care was done to account for the low-energy behavior of the B/C ratio and the hydrogen-helium quartet ratios. Elemental spectra and ratios for the three cases will be compared and presented. Plans for improvements will also be discussed.