Abstract
Sr-90 deposition will generally depends on rainfall, season and geographical location. The relations between them are investigated by coaxial method using the data of six stations in Japan during 1958, and it is found that though Sr-90 deposition increases with rainfall the rate of increasing varies widely with season, and also that local variation is not so large.
The relation of concentration of Sr-90 in rain with the amount of rainfall is then obtained from measured values and estimated ones from coaxial graph. The results show that the Sr-90 content in rain varies with rainfall, and where the rainfall is small there is a tendency of the concentration to increase with rainfall. It is difficult to explain this but it seems to be necessary to take this into account when we discuss the problems such as seasonal variation of Sr-90 concentration in rain.
It is interesting that almost similar results are obtained with the data of the same period in the U. K.
