A New Method for Evaluating Weak Leakage Gamma-Ray Dose Using a 3″φ×3″ NaI(Tl) Scintillation Spectrometer (III)

Expanding of Applicable Energy Range

Abstract

Applying the leakage gamma-ray which energy exceeding primary gamma-ray of K-40, namely 1.46MeV, a method previously reported, this is, three component method is still not satisfactory. Therefore, a better approach for expanding applicable energy range was examined. The result of measurements showed that there was sufficiently a correlation between background exposure rate and concentration of Th. The present method by background exposure rate was estimated from only concentration of Th contained in environment was practically usable technique. Though the measured error will increase, applicable energy range of three component method could expanded to about 2.5MeV by this technique.