New readout system for submicron tracks with nuclear emulsion

In this paper, we summarize a newly developed automatic readout system, composed of a microscope with an optics stage, to analyze charged particle tracks of less than 1 μm recorded in a fine-grained nuclear emulsion. This system's optics have the high spatial resolution, epi-illumination, and xenon-mercury lamp necessary to achieve sufficient contrast and brightness for small silver grains up to about 40 nm in diameter. Methods of shape recognition and focus point acquisition were developed that enabled the system to identify submicron tracks corresponding to nuclei on the order of 10–100 keV.