On the Analysis of the Slow Particles Emitted from Cosmic-Ray Stars (I)

Abstract

An analysis of the nature of tracks of the stars ending in the G5 emulsion was made by measuring their width (diameter). Six groups of tracks having different width were observed. We identified two of these groups as that of α particles and Li nuclei by comparing their width with those of α particles emitted from radiothorium stars and with those of hammer tracks. As for the more thicker tracks, the charge determination on the tracks of each group was made by measuring their thin-down lengths. These measurements seem to indicate that the width of track was approximately proportional to \(\sqrt{Z}\) ( Z : atomic number). The energy and the angular distribution of each group were also examined. The curves of the energy distribution of protons and α particles approximately agreed with those deduced from the evaporation model, assuming the appropriate nuclear temperature and Coulomb barrier height. The angular distributions of these were nearly isotropic. It was noted That the number of slower a particles measured seems to be considerably larger than that deduced from theory.