Thermal neutron flux produced by EAS at various altitudes
  The results of Monte-Carlo simulations of Extensive Air Shower are presented to show the difference of hadronic component content at various altitudes with the aim to choose an optimal altitude for the PRISMA-like experiment. CORSIKA program for EAS simulations with QGSJET and GHEISHA models was used to calculate the number of hadrons reaching the observational level inside a ring of 50 m radius around the EAS axis. Then the number of neutrons produced by the hadronic component was calculated using an empirical relationship between the two components. We have tested the results with the ProtoPRISMA array at sea level, and recorded neutrons are close to the simulation results. 
Yu.V. Stenkin, V.V. Alekseenko, D.M. Gromushkin, Y. Liu, X.H. Ma, and   J. Zhao
astro-ph.HE