1987 Volume 36 Issue 3 Pages 129-132
The highest 60Co γ-ray field available in Radiation Center of Osaka Prefecture was determined employing a cylindrical cavity chamber which has been calibrated with the national standard up to 7.7 (C kg-1) /h (30 kR/h) . For higher exposure rate regionn four stage of calibrations were carried out up to 3.7 (kC kg-1) /h (14 MR/h), which is higher than ever reported, based on the additivity of gamma intensity in terms of the source activity. The errors accompanied with the resultant values were estimated as 6% at most. Axial dose rate distributions in the irradiation cans used in the irradiation pool were measured with PMMA dosimeters.