Monte Carlo simulations of complex geometries and an optimal 60cobalt source design using the integrated TIGER series (ITS 3.0)

In this work, the ITS 3.0/ACCEPT Monte Carlo code was used to determine the absorbed dose rates in a complex target consisting of various materials and densities. Dose rates in 512 sample vials packaged in dry ice and polyethylene were irradiated simultaneously using a 60Co semi-cylindrical source array. The vials were distributed in two carriers set 1 m apart each holding 256 vials. For this specific target and source geometry, dose rate variations of ±6% were achieved among 226 vials in the first carrier, and among 203 vials exposed to a lower dose rate in the second carrier. Dose rate variations were found to depend only slightly on the backscatter contribution from the radiation vault walls.