CORRECTION COEFFICIENT COMPUTATION FOR DETERMINATION OF VOLUMINOUS SOURCE ABSOLUTE RADIOACTIVITY

A new computing algorithm has been developed to calculate the correcti on coefficient for a voluminous radiation source. The algorithm is bas ed on the conception of a virtual efficiency center whose detector loc ation depending on the radiation energy can be computed relatively to a point arbitrarily fixed on the detector axis. A scheme for the inter action of the gamma-radiation with the detector is proposed to minimiz e the number of preliminary experiments for the determination of empir ical functions needed for realization of the method. Data are presente d for computation of the linear attenuation coefficient of any materia l with known chemical composition and density. The validity of the dev eloped approach has been proved by comparison of real and computed rad ioactivities for 5 different radiation energies in 12 cylindrical sour ce - detector geometries.