Monte carlo simulations and experimental studies of yttrium-90 production using a 33 MeV linac

The purpose of this research is the investigation of the 90Zr(n,p)90Y reaction as an alternative method to the traditional fission product based on the 90Sr/90Y generator. The fast neutrons necessary to activate 90Zr are generated through (p,xn) reactions during 33 MeV proton irradiation of natural tungsten or other targets. Since 90Y is a pure beta emitter, the gamma-rays from the 90Zr(n,2n)59Zr reaction were used to quantify the neutron flux incident on the 90Zr sample. Using the simulation code MCNPX (Monte Carlo N-Particle System), the angular and energy distributions of neutrons incident on the Zr target were calculated. Based on the MCNPX neutron flux predictions, the 90Y activity was determined.