Dose distribution studies of a gamma industrial irradiator using a PC code

This paper present a comparison between calculated and experimental absorbed dose values, for a typical product, irradiated in a 60 Co industrial irradiator, at ININ. Such industrial irradiator is two tiers and two layer systems, with overlapping product to source configuration; source activity was around 300 kCi. Calculated absorbed dose values were obtained by FUGI code, running in a PC microcomputer. This code is based in a point kernel over the source area, by means of Gauss quadrature technique, based in FUDGE-4A code. Build-up factors were estimated by Goldstein and Wilkins factors for punctual sources, using Taylor's approximation formula. Experimental dosimetry data of Petri dishes packages, with apparent density of 0.13 g/cm 3 data was performed using red acrylic dosimeters, during irradiation; required minimum dose for this material was 15 kGy. Absorbed dose data have shown good approximation, particulary a 15% desviation of results from FUGI code. However, this code can be used for rough calculation of irradiator parameters, before trying to use a more complex and time-consuming code, for detailed analysis.