An Automated Microscope Scanning Stage for Fission-track Dating

A microcomputer controlled scanning stage has been developed which greatly facilitates track counting. It has been designed specifically for the external detector method of fission-track dating, although the basic hardware could be used for a variety of different scanning requirements. With this system, the microscope stage is automatically controlled to move between corresponding points on the mount and detector, deleting the requirement for manual search for corresponding points. This gives very significant time savings over manual methods for mapping of grain locations and their equivalent sites on the external detector, which are mirror images. As well, it is possible to identify and record very faint sites. Focussing is automatically adjusted to allow for the differing heights of sample and detector. The stage is driven under joystick control by the operator during identification of suitable grains and the locations of plotted sites can be stored for future recall.