Abstract
In order to design a rice irradiator with mass flow rate of 50 to 100 ton/h and with irradiation of 100 to 300 Gy (10 to 30 krad), the optimum dimensions of the irradiator were de-rived from the relation between the dimension and processing efficiency (mass flow rate/total activity of gamma-ray source) . The main results are: (1) processing efficiency depended on the incidence efficiency of gamma-ray energy into grain, the absorption efficiency of the energy in grain and the required dose of grain, (2) there was no difference in the optimum values of dose uniformity of grain irradiated in each irradiation region, (3) the optimum length of the source was 0.644 times of length of the region, (4) the optimum values of processing efficiency and dose uniformity of grain were 5.925×10-9 g/h/Bq and 1.57, respectively.