Study of Cosmic-Ray Air Showers With the Method of Coincident Bursts in Two Unshielded Ionization Chambers

Publisher Website
Google Scholar
Abstract
Cosmic-ray bursts of ionization occurring in each of two unshielded, thin-walled ionization chambers were recorded simultaneously on a single piece of photographic film. This recording made it possible to study events in each chamber separately, and also to determine when a burst, occurring in one chamber, was coincident in time with a burst in the other. The graphic relation between the size of bursts and their frequency is given for a single chamber and for the coincident bursts. The relation, between burst coincidence frequency and separation of the chamber for several burst sizes, is given in a separate graph. A study of these sets of curves reveals the presence of many high density cosmic-ray air showers of heretofore unsuspectedly small lateral spread. These showers cannot originate at the top of the atmosphere but must be a secondary phenomenon.