Image intensification in silver halide photographic materials for detection of high-energy radiation by reprecipitation of elemental silver

A process for the intensification of silver images on AgHal photographic materials designed for detection of high-energy (X- and gamma-ray) radiation was proposed, which is based on the reprecipitation of elemental silver and a decrease in its dispersion and comprises the treatment of silver with an aqueous solution containing potassium hexacyanoferrate(III) and potassium chloride or bromide at the first step and with a solution containing tin(II) chloride, potassium thiocyanate, sodium N,N'-ethylenediamine tetraacetate, and potassium hydroxide at the second step. By this process, the optical densities of image over a wide (0.5-2.0) range was increased by a factor of 3-5; as a result, the photographic sensitivity S-0.85 and S-2.00 was enhanced by almost an order of magnitude with the retained or slightly increased gradient g, fog density D-0, and resolving power of the material.