Abstract: In the emulsifying process of AgBr microcrystals in the double-jet apparatus controlled by a microcomputer,a certain amount of oxalate salt was injected at specific time and pAg into a reactor to prepare cubic AgBr grain emulsions in which oxalate ions were doped at subsurface of AgBr microcrystals.The observation results from the whole experiments and sensitometric results from these emulsions showed: 1) the sensitivities (S_d) of oxalate-doped emulsions,relative to those (S₀) of the corresponding undoped ones as the controlled,regardless of whether it is primitive,or sensitized chemically and spectrally,were remarkably increased (S_d/S₀≥1.5); 2) fog level of oxalate-doped emulsions,regardless of whether it is primitive,or sensitized chemically and spectrally,were kept low; 3) sensitization gains of oxalate-doped emulsions were nearly same as one of formate-doped emulsions; 4) the preparation of cubic AgBr emulsions doped with oxalate was more simple than those of cubic ones doped with formate,and the formers’ shape was more sharper than the latters’.

Key words: oxalate, doping, cubic, silver bromide, sensitization