Abstract
Sensitization methods including chemical sensitization and halogen acceptors (HA) for ultra-fine-grain (UFG) emulsions with dif- ferent grain sizes and crystal habits were investigated and the desensitizing factors peculiar to UFG emulsions were analyzed. Sul- fur-gold sensitization or HA alone gave a small sensitivity increase but the combination of both gave the maximum effect; reduction sensitization alone had a large effect but the combination with HA decreased the sensitivity from this level. Rehalogenation was suggested to be an important factor in the desensitization of UFG emulsions. Sensitization effects with exposure intensities and crystal habits were qualitatively similar between low and high intensities, and {111} and {100} faces, but the former cases showed larger effects than the latter cases. The sensitivity after sensitizing treatments was proportional to the higher power than the third one of grain size. The sensitivity of the unsensitized UFG emulsion was also in this proportional relationship, but was much lower than that of the sensitized emulsions.
https://ror.org/01hjzeq58 
