Nature of Extensive Cosmic Ray Showers

Abstract

THE counter experiments of Auger, Maze and Grivet-Meyer¹, and those of Kolhörster, Matthes and Weber², indicate the existence of very large cosmic ray showers, extending over an area of many square metres, and consisting of several thousand particles. In order to obtain information about the constituents of these showers, a cloud chamber with a 2 cm. lead plate across its centre, situated in a room with a light roof, has been used in a magnetic field of 800 gauss. The chamber was controlled by the five-fold coincidences of counters, distributed so that the outer counters were separated by 5 metres. With this counter arrangement the chamber took, on the average, 0·2 photographs per hour.