Abstract
Silver chloride emulsions are prepared by three different compositions A, B and C and their gamma-ray sensitivity as well as the light sensitivity are studied.
Emulsion A is prepared by simultaneous addition of sodium chloride solution and silver nitrate solution into gelatin solution in 5 minutes at 48°C, and it has low sensitivity and high contrast. Emulsions of series B and C are mixed by dropping silver nitrate solution into sodium chloride-gelatin solution. The gamma-ray sensitivity of emulsions of the composition A without ripening is lower than that of emulsions B or C, but the sensitivity of emulsions of the series A can be increased by ripening of 30-180 minutes. Influence of the ripening on the gamma-ray sensitivity appears smaller for emulsions of the series B or C, even though the ripening increases the threshold light sensitivity of the emulsions. It is suggested that the gamma-ray sensitivity of the emulsions depends to some extent upon the sensitivity in the higher light exposure region.
It is also demonstrated that latent image fading of silver chloride emulsions depends on the nature of gelatin in emulsions, and fading phenomena are likely not affected by the temperature of mixing of emulsions.
We concluded that the silver chloride emulsions, including gaslight paper, become developable when they are irradiated by gamma-rays of Co60 of the order of 10 to 103 R and the emulsions are available for gamma-ray dosimetry in this range.
