Compact accelerator based neutron source for Technetium-99m production

The radioisotope Technetium-99m (99m Tc) is used in 85% of all nuclear medicine procedures. 99mTc is produced from its precursor Molybdenum-99 (99 Mo), whose production is nearly all from one of only five ageing research reactors. Recently a number of accelerator-based methods have been proposed to fill this gap and to diversify this supply chain. In this paper we present a compact (4 m) 10 mA, 3.5 MeV accelerator design, to generate 99Mo via low-energy neutron bombardment of 98Mo. We consider a Li(p,n) target for neutron production, and propose the use of a novel moderator to optimally shift the target output neutron spectrum into the epithermal region of the 98Mo. This paper specifically focuses on numerical studies for an optimised target design capable of handling the thermal load.