Intensity of protons at the "knee" of the cosmic ray spectrum

A detailed study on the simultaneous observation of air showers and high energy families has been done through a Monte Carlo simulation. The simulation results are compared with the experimental data obtained at Mt. Norikura to obtain for the first time the absolute flux values of primary protons at energies around 10¹⁵-10¹⁶ eV. A large-scale hybrid experiment of air shower array and emulsion chamber at high altitude can provide unique information about the primary composition at energies around 10¹⁵-10¹⁷ eV. In particular the proton spectrum at the "knee" energy region can be obtained with accuracy better than 30%.