Extensive Cosmic-Ray Showers and the Energy Distribution of Primary Cosmic Rays

Abstract

An experiment is described which determines the variation in the number of extensive cosmic-ray showers per unit time with altitude from sea level up to 4300 m. The number of showers which should have been observed with the apparatus used is calculated on the basis of the cascade theory in which various power law energy distributions for the primary cosmic rays are assumed. Good agreement is obtained between the observations and the calculation at high altitudes for suitable choice of parameters; at low altitudes the observed excess is what would be expected from a mesotron component in the extensive showers. It is found that the same choice of parameters which will give good agreement with the extensive shower data will also describe cosmic-ray observations at much lower energies. It is pointed out that this offers strong support for the hypothesis that there is but one type of primary cosmic-ray particle. The effects of choosing the proton as this primary particle are discussed.