Measurements of Mass Ratios in Nuclear Emulsions

Abstract

IN an earlier communication in Nature¹, we have described a method of measuring photoelectrically the density of tracks in nuclear emulsions. It is analogous to the method of grain counts and can be used with electron-sensitive emulsions where the overlapping of individual grains prevents the use of the latter method. We have compared the residual ranges of particles from regions of their tracks which show the same projected area per unit length, that is, the same average track width. From these comparisons we have calculated the mass ratios. This corresponds to the method used by Lattes, Occhialini and Powell² in grain counting.