2004 年 3 巻 2 号 p. 93-100
Penetration factors and related numerical data in “Manual of Practical Shield Calculation of Radiation Facilities (2000)”, which correspond to the irradiation geometries of point isotropic source in infinite thick material (PI), point isotropic source in finite thick material (PF) and vertical incident to finite thick material (VF), have been carefully examined. The shield calculation based on the PI geometry is usually performed with effective dose penetration factors of radioisotopes given in the “manual”. The present work clearly shows that such a calculation may lead to an overestimate more than twice larger, especially for thick shield of concrete and water.
Employing the numerical data in the “manual”, we have fabricated a simple computer program for the estimation of penetration factors and effective doses of radioisotopes in the different irradiation geometries, i.e., PI, PF and VF. The program is also available to calculate the effective dose from a set of radioisotopes in the different positions, which is necessary for the γ-ray shielding of radioisotope facilities.