Speaker
antonio codino
(university of Perugia and INFN)
Description
According to recent measurements the tendency of the chemical composition above the ankle is characterized by increasing fractions of intermediate and heavy nuclei and a dominance of light nuclei around the ankle featured by a minimum of the log(A) profile. Calculations of the chemical composition in the range 3.5x10**18-5x10**19 eV according to new principles are reported and compared with the experimental data. The calculation outcomes explain both the rising tendency and the minimum of log(A). The estimate is prolonged to the adjacent interval 5x10**19-10**21 eV using the same theoretical background and some features of the cosmic-ray spectrum at the maximum observed energies. It results that above the energy of 6.7x10**20 eV the cosmic radiation consists only of nuclei heavier than Zinc with a rate of (1-5)x10**-34 particles/m2 s sr GeV. The support of the data on this last estimate is debated.
Primary author
antonio codino
(university of Perugia and INFN)
