A Computer Simulation of Latent Image Formation in Photographic Emulsion by a Monte Carlo Method

Abstract

A digital computer analysis has been made of photon absorption, chemical sensitization and latent image distribution in a silver halide photographic emulsion, using the Bayer Hamilton model but with a different approach in treating the positive holes.In discussing the effect of sulphur sensitization it has been assumed that silver sulphide molecules can play a dual role in latent image formation, undergoing partial thermal dissociation to increase both the number of electron traps by providing more interstitial silver ions and that of positive hole traps by forming AgS-. The increased interstitial silver ion concentration has also been supposed to lead to an increase in the stability of single silver atoms. As to gold sensitization, it has been assumed that the main effect of gold is to enhance the developahility of latent image centres.Parameter values for simulation under various conditions of chemical sensitization have been calculated, based upon the above assumptions. The results have, as expected, reproduced in many respects those shown by experiments. Finally, a relation between the concentration of interstitial silver ions and the sulphur content in the emulsion grain has been derived.