On the design and use of a double camera for photographing artificial disintegrations

Abstract

In a recent paper a small automatic Wilson Chamber has been described in detail. This was used to photograph the artificial disintegration of nitrogen. It was shown from a study of the conditions in the chamber itself, that it is not possible to increase the number of expansions above about four a minute without detriment to the tracks. An increase in the speed of photographing tracks is therefore to be sought in the increase in the number of tracks in a photograph. It is shown in the following investigation that this number is limited by considerations concerning the size of the chamber, the width of the tracks, the design of the camera and the demand that each track shall have a reasonable chance of not being obscured by its neighbours. The importance of obtaining the best possible conditions needs no emphasis when it is remembered that it is generally necessary to photograph at least half-a-million tracks to obtain a few disintegration collisions with any one element.