Sc-47 production from titanium targets using electron linacs.

Abstract In this work we have studied the feasibility of photonuclear production of 47 Sc from 48 Ti via 48 Ti(γ,p) 47 Sc reaction. Photon flux distribution for electron beams of different energies incident on tungsten converter was calculated using MCNPX radiation transport code. 47 Sc production rate dependence on electron beam energy was found and 47 Sc yields were estimated. It was shown that irradiating a natural Ti target results in numerous scandium isotopes which can reduce the specific activity of 47 Sc. Irradiating enriched 48 Ti targets with a 22 MeV 1 mA beam will result in hundreds of MBq/g activity of 47 Sc and no other isotopes of scandium. Decreasing the size of the target will result in much higher average photon flux through the target and tens of GBq/g levels of specific activity of 47 Sc. Increasing the beam energy will also result in higher yields, but as soon as the electron energy exceeds the 48 Ti(γ,np) 46 Sc reaction threshold, 46 Sc starts being produced and its fraction in total scandium atoms grows as beam energy increases. The results of the simulations were benchmarked by irradiating natural titanium foil with 22 MeV electron beam incident on the tungsten converter. Measured 47 Sc activities were found to be in very good agreement with the predictions.