1969 年 4 巻 1 号 p. 24-31
In order to measure the particle size distribution of α-emitting dusts, the autoradiography method has been studied. Dusts involving 10% enriched Uranium oxide and Pu nitrate have been measured by the method after being sampled on the millpore filter AA. MMD of about 2.8μ in the UO2 case and that of about 1.7μ in the Pu case were obtained. The results are compared with those measured by conventional microscopic method.
Several points to be exposed to careful consideration are discussed, in which (1) transfer rate of dusts from filter to photo-film, (2) Distribution pattern of dusts on the film for measuring of the alpha track, (3) geometrical efficiency of α-emittion in the film emulsion, (4) exposing time for radiography, and (5) determination of real gravity of dusts, are supposed to be of importance.
The authers think the method is rather simple and economical and easy for the treatment, compared with those conventionally used for particle size measurement, and particularly worth while for applying to that of α-emitting dusts.