The NUCLEON space experiment was carried out for three years. During the experiment, the charge composition and energy spectra of cosmic rays in the region of 2–500 TeV were measured. At the same time, a number of features that were not predicted by previously developed models of acceleration and propagation of cosmic rays were found to be of sufficiently high statistical significance. It turned out that the spectrum of rare odd nuclei (Z=9-19) is more rigid than the spectrum of abundant even nuclei (Z=10-20) in the field of magnetic rigidity of 300–10000 GV. Also, an analysis of the results of the NUCLEON experiment showed that in the source there is a systematic dependence of the spectral index on the nuclei charge. A possible explanation is the incomplete ionization of cosmic rays during their acceleration at the front of the supernova shock wave. An anisotropic diffusion model is also considered. Further astrophysical analysis of the NUCLEON experiment data is necessary in comparison with the data of other experiments.
Turundaevskiy et al. (Sun,) studied this question.