STUDIES ON THE NUCLEAR EMULSIONS WITH POLYVINYL ALCOHOL (II). THE GAMMA- RAY SENSITIVITY OF THE PVA NUCLEAR EMULSIONS (in Japanese)
Silver bromide emulsion was prepared by using polyvinyl alcohol (PVA) as the protective colloid, and its photographic properties and deg ray sensitivity were studied. The double injector method was used for mixing, and the freezing method used for gel formation of the emulsion which contained 70% silver bromide by weight. The thickhess of the emulsion layer was 45 mu and its moisture content was 2.8% at a relative humidity of 60%. The plates were exposed to light by use of a sensitometer for obtaining the characteristic curves and also to Co/ sup 60/ gamma rays, which were best developed at 20 deg C in 10 minutes with D- 11 developer diluted with 3 parts of water. The degree of light sensitivity of the emulsion was the same as that of the low sensitivity type of gelatin emulsion with silver chloride, and its contrast depended upon the temperature at which the precipitation of silver bromide was made. The emulsion can be used for photographic dosimetry of gamma rays in the range of lO/sup 3/ to 7 x 10/sup 3/ roentgen. In the higher region, blackening of the emulsion increased with the rise of the temperature at which the precipitation of silver bromide was made. The gamma ray sensitivity can be increased by hypersensitizing the emulsion with an aqueous solution of triethanolamine, the concentration of which must not exceed 6%, and the time of treatment must not exceed 10 minutes; otherwise, fog increases. When the plate was kept at a relative humidity of 37% at 20 approximately 22 deg C after irradiation, the degree of the fading of latent gamma -ray image was below 10% after 40 days and at a relative humidity of 81%, the degree of fading was about 50% after 4 weeks. The fading was also affected by the radiation dose and was greater in the case of low radiation dose than in the case of high. (P.C.H.)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-15-027828
- OSTI ID:
- 4843572
- Journal Information:
- Tokyo Kogyo Shikensho Hokoku (Japan) Changed to J. Natl. Chem. Lab. Ind., Journal Name: Tokyo Kogyo Shikensho Hokoku (Japan) Changed to J. Natl. Chem. Lab. Ind. Vol. Vol: 56; ISSN TKSHA
- Country of Publication:
- Country unknown/Code not available
- Language:
- Japanese
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