Modified development to improve the performance of AR10 stripping emulsions for use with the more energetic isotopes.

Gold latensification of the image to increase the efficiency of the more energetic isotopes, such as 14 carbon, has been used before for liquid emulsions, with mild developers, but never successfully with AR10 stripping emulsion. This paper describes the performance of different developers and assesses their ability to suppress background fog on Kodak AR10 emulsion. A 14 carbon source was used and the effect of gold latensification was examined. Kodak D19, an efficient Metol/hydroquinone developer, could be usefully modified by altering the sodium carbonate and sulphite contents (D19 A/S). This developer discriminated well against the background with AR10 emulsion, producing a far better signal:background ratio than Kodak D19. A pretreatment in aurous thiocyanate for 4 min before development in D19 A/S for 4 min at 291 K increased the signal:background ratio by 200% compared with ordinary development in Kodak D19. When gold latensification was used with D19 developer, the signal was increased, but not more than with D19 A/S, and the gain was offset by the intense background that resulted.