Mapping the AMS-02 and CALET data onto the source spectra and residence times of Galactic cosmic rays

The recent measurements of the spectral intensities of cosmic-ray nuclei have suggested that the ratio of boron to carbon nuclei, R ( E ) , comprises two components, R 1 ( E ) which carries all of the energy dependence and the other R A , a constant independent of energy per nucleon. This finding supports the earlier theoretical expectations and results of gamma-ray astronomy that one of these components is attributable to spallation in a cocoon like region surrounding the sources and the other in the general interstellar medium before cosmic rays leak away from the Galaxy. A new model-independent way of analyzing cosmic-ray spectra is presented here to shed light on the recent findings: Imposing the single constraint that the source function of B nuclei is minimal we use a cascade of rate equations to map point by point the observed cosmic-ray spectra of p, B, C, O, and Fe onto their source spectra and the two lifetimes of cosmic rays rG G in the Galaxy and rS S in the cocoons surrounding the sources. The model-independent results show that the appropriate choice rS(E) S ( E ) is responsible for R 1 ( E ) and the source spectra are power laws with indices of similar to - 2.7.