The Structure of the Large Cosmic-Ray Air Showers

Abstract

A series of experiments on cosmic-ray air showers is described. Four "fast" ionization chambers, with electronic coincidence and photographic recording of pulse height, were used to investigate the structure of these showers in detail, at mountain altitudes. The experiments show that the showers have the structure characteristic of electron cascades. There is no evidence for unusually narrow showers. If the showers originate from the decay of neutral mesons, these mesons must be produced either singly, or in groups whose total angular divergence is not greater than ∼${10}^{-4\mathrm{}}$ radian.