Method of grain counting for identification of nuclear tracks in diluted photographic emulsion

In the present paper we consider the experiment on heavy nuclei identification by the method of grain counting in photographic emulsions exposed on board a spacecraft as early as 1974. Since we carried out the experiment, the theory of nuclear track detection has undergone a considerable evolution, and in the present paper based on this experiment we trace how the theory's evolution influences its interpretation. The proposed consideration of the experiment is the third one. It has been done based on a new theoretical approach [Ditlov V.A. (1980) Theory of special calculation of primary action of δ-electrons in track detectors with account of multiple scattering. In Solid State Nuclear Track Detectors, Vol. 2. Pergamon Press, Oxford]. The first one was made in 1975 [Bogomolov C.S. (1975) Scientific Reports Proceedings. Gosniichimfotoproeki 20, pp. 22-34], the second one in 1976 [Bogomolov C.S. and Ditlov V.A. (1977) The determination of nuclear charges by the method of grain counting heavy particles tracks. Rad. Effects 2, 105-115]. At the end of of the paper the results of counting are proposed and discussed for further experiments on heavy and superheavy nuclei identification. (author)