Energy spectra of secondary pions from hadron-nuclear interactions in the field of energies E≥1013 eV

In the report there are results of studying the hadron interactions of cosmic rays with atomic nuclei of C and Fe. Experimental data is obtained at complex facilities consisting of ion calorimeter of are 9 and 44 m2 , roentgen-emulsion chambers of the same area nad dense targets located at fixed height above the calorimeters. Since we had data on complete interaction energy E0 , measured in calorimeter and on individual energy of high-energy gamma-quanta ( π0 - mesons) we had an opportunity to study energy spectra of leading secondary π0 - mesons in Feynman variables X =Eπ0 /E0 in energy field E0≥1013 eV. This report also compares spectra obtained in interactions with C and Fe nuclei and give their comparison with spectra of leading π0 - mesons from p - N interactions at accelerating energies E0 = 50 GeV. Basing the results we make conclusion on scaling conservation in the area of fragmentation in energy interval E 5·109 - 5·1013 eV and independence of energy spectra from target nucleus nature