A Cloud-Chamber Study of Cosmic-Ray Air Showers at Sea Level

Abstract

A diffusion-type cloud chamber eight feet long, four feet wide, and five inches deep has been used to study the lateral structure of cosmic-ray air showers in a region near the core. Three showers were recorded in which the core lay within sixty to ninety centimeters from some point on the periphery of the chamber. The results show that the lateral distribution of the shower particles in all but one photograph follow exceedingly well the Molière distribution. The deviations from the Molière distribution are almost all within the expected Gaussian fluctuations. In those pictures exhibiting little or no gradient, the deviations from the average density were normal.