optimization Experiments on Radioiodine Dry Distillation from TeO2 Target

Dry distillation method was used for production of high purity 123I radioisotope from irradiated 123TeO2 target. Several targets containing TeO2 glassy layer on Pt substrate were prepared by melting using high temperature tube oven. To determine the optimum parameters of dry distillation, unirradiated natTeO2 target was subjected to variable conditions of temperature, argon flow rate and distillation time. The percentage loss in the target mass was measured and plotted as, a function of these parameters. From the obtained curves, optimum conditions were deduced and applied in dry distillation experiments on irradiated target of 123TeO2 to measure the resulting separation efficiency of 123I radioisotope. The target was irradiated by 14.5 MeV protons for one hour using MGC-20 cyclotron, AEA, Cairo. To improve the separation efficiency several modifications were applied on the distillation system and the loss in the target mass was determined for every case. The maximum separation efficiency obtained was 83 % with target loss of about 3.5%.