Detection of nuclear tracks comprising gold grains in nuclear emulsion by using gold deposition development method

The gold deposition development method instead of the normal development method was applied to a nuclear track detector by using silver halide photography. Fine tracks formed by spherical gold grains were observed without any filaments. The grain size does not depend on the initial size of the silver halide crystals but only on the deposition period. This implies that the grain size can be adjusted to a size similar to the resolving power of an optical microscope in spite of the use of an ultra-fine crystal emulsion. In addition, the developer used in the gold deposition method does not contain harmful organic reagents, and it contains a lower amount of inorganic salts than normal developers. The solution can be safely handled and the disposing treatment of the solution is easy.