An experiment to measure the spectra of primary proton, helium and iron nuclei at the 'knee' region at a high altitude

The possibility of measuring the energy spectra of some single elements (proton, helium and iron) in primary cosmic rays at the 'knee' energies, by setting up an air shower (AS) core detector in the ASγ array (4300 m a.s.l., Tibet, China) is investigated. Taking into account the sensitivity and the acceptance needed for this measurement, the feasibility of construction and operation of the apparatus at a high altitude, and the cost, it is shown that this aim can be achieved by a simple AS core detector that mainly measures the high-energy electromagnetic components in AS cores. In this paper, such a detector is described. With a three-year exposure, proton, helium and iron spectra at the 'knee' energy region can be obtained with three event samples selected by an artificial neural network (ANN).