抄録
For evaluating weak leakage gamma-ray exposure a new method without background measurement has been developed. In a previous report the principle of this method was described in detail with a few examples under usual environment. In this report the method was examined under different environments, that is, environment consisting of high atomic number medium, geometric distribution of natural radioactivities, and the leakage gamma-ray of high energy. It was necessary to make small corrections for the results measured in the room whose wall was covered with such a material as lead sheet. It was found that there are no practical problems of this method under the environment with larger geometric factor of natural radioactivity distribution than π in a solid angle. With the present technique the dominant energy of leakage gamma-ray was necessary to be lower than 1.46MeV, that of primary gamma-ray of K-40.
