X. Chi et al., COSMIC-RAYS ABOVE 10(17) EV .1. THE MASS-SPECTRUM AND THE OVERALL ANISOTROPIES, Journal of physics. G, Nuclear and particle physics, 19(5), 1993, pp. 769-785
The Sydney data on extensive air showers in the energy range 10(17) to
10(19) eV have been re-examined from the standpoint of endeavouring t
o determine the energy spectrum of the various masses of particles pre
sent in the cosmic ray beam, idealized as a simple mixture of protons
and iron nuclei. The analysis suggests that the ratio of iron nuclei t
o protons increases with energy in the range under consideration, bein
g congruent-to 1.0 at 10(18) eV and congruent-to 2.0 at 10(19) eV.