A New Photographic Emulsion for the Detection of Fast Charged Particles

Abstract

A new photographic emulsion has been produced for the detection of fast charged particles, for experiments in nuclear physics, which has greatly improved properties over the ordinary `half-tone' emulsion. Characteristic photomicrographs are reproduced of the tracks of α-particles and protons and it is shown that the `energy resolution' given by the method is much greater than that previously attained. The improved visibility of the tracks and the absence of background allows a new approach to be made to the technical problems of (a) searching for rare events, (b) counting and measuring large numbers of tracks and (c) loading emulsions with other atoms for specific experiments. The objections of some experimenters to the method would appear to have been overcome and this should lead to its widespread adoption for work in nuclear physics.