HIGH-ENERGY COSMIC-RAY MASS-SPECTROSCOPY .2. MASSES IN THE RANGE 10(14)-10(17) EV

In earlier papers we made the case for there being two peaks in the ex tensive air shower (EAS) size spectra in the size range 5.10(5)-10(7) particles which we identified, somewhat tentatively, with, respectivel y, the CNO group of nuclei and Fe nuclei. Here, the problem of the mas s composition is looked at in more detail. From an analysis of the sha rpness of the first peak and its separation from the second we conclud e that the 'CNO' group in the 'single source' spectrum comprises mainl y oxygen nuclei, a conclusion that is consistent with a single local, recent supernova having provided the acceleration via shocks in the ho t interstellar medium. (C) 1997 Elsevier Science B.V.